Prevalence of AmpC and other beta-lactamases in enterobacteria at a large urban university hospital in Brazil

PubMed Central

Dias, Rubens Clayton da Silva; Borges-Neto, Armando Alves; Ferraiuoli, Giovanna Ianini D’Almeida; de-Oliveira, Márcia P.; Riley, Lee W.; Moreira, Beatriz Meurer

2010-01-01

Production of extended-spectrum β-lactamases (ESBL) has been reported in virtually all species of Enterobacteriaceae, which greatly complicates the therapy of infections caused by these organisms. However, the frequency of isolates producing AmpC β-lactamases, especially plasmid mediated AmpC (pAmpC), is largely unknown. These β-lactamases confer resistance to extended spectrum cephalosporins and aztreonam, a multidrug-resistant (MDR) profile. The aim of the present study was to determine the occurrence of ESBL and pAmpC β-lactamases in a hospital where MDR enterobacterial isolates recently emerged. A total of 123 consecutive enterobacterial isolates obtained from 112 patients at a university hospital in Rio de Janeiro, Brazil during March-June 2001 were included in the study. ESBL was detected by the addition of clavulanate to cephalosporin containing disks and by double diffusion. AmpC production was evaluated by a modified tridimensional test and a modified Hodge test. The presence of plasmid-mediated ampC β-lactamase genes was evaluated by multiplex-PCR. Sixty-five (53%) of 123 enterobacterial isolates were MDR, obtained from 56 patients. ESBL production was detected in 35 isolates; 5 clonal E. coli isolates exhibited high levels of chromosomal AmpC and ESBL production. However, no isolates contained pAmpC genes. Infection or colonization by MDR enterobacteria was not associated with any predominant resistant clones. A large proportion of hospital infections caused by ESBL-producing enterobacteria identified during the study period were due to sporadic infections rather than undetected outbreaks. This observation emphasizes the need to improve our detection methods for ESBL- and AmpC-producing organisms in hospitals where extended-spectrum cephalosporins are in wide use. PMID:17900845

Antibiotic sensitivity and sequence amplification patterns of genes in multidrug resistant enterobacteria isolates from processed foods in some West African countries.

PubMed

Owoseni, Abimbola Adetokunboh; Onilude, Abiodun Anthony

2011-01-01

Diarrhoea, dysentery and other diseases due to other enteric bacteria have reportedly been found to resist chemotherapeutic treatment in some West African communities with fatal consequences in some cases. This study was carried out to determine multidrug resistance patterns of Enterobacteria isolates from processed ready-to-eat foods. Indigenously processed food samples of different types were collected from two Francophone and two Anglophone countries in the West African sub-region during the wet and dry seasons of a sampling period of two years. Enterobacteria were isolated from the samples using standard techniques. Amplification of chromosomal DNA of the isolates using the Polymerase Chain Reaction was carried out. The results obtained were subjected to statistical analyses. All isolates showed resistance to cefuroxime (90.7%), nitrofurantoin (90.6%), augmentin (86.1%) and ampicillin (51.2%) while all were sensitive to gentamycin and ciprofloxacin. There was amplification indicating the presence of invA gene at a position of 240 bp. There was no amplification at all for the spvC gene in any of the isolates tested. Multidrug resistant enteric bacteria in these foods containing the invA gene could lead to infections with uncontrolled antibiotic use. The presence of enteric bacteria in the foods analyzed which provide undeniable evidence of the poor microbiological quality of these foods could form the basis of a useful databank in formulation of food-borne disease control and prevention strategies.

[R factors in strains of pathogenic enterobacteria isolated from domestic animals and particularly from dogs].

PubMed

Roy, R S

1972-01-01

Strains of enterobacteria (nine Escherichia coli and two Salmonella) isolated from primary or secondary infections in the dog, cat, pig, calf and kangaroo were studied for the presence of extrachromosomal drug resistance factors (R factors). Seven strains of E. coli and two strains of Salmonella transferred resistance involving the following antibiotics: streptomycin, ampicillin, chloramphenicol, neomycin and tetracycline. All strains harboring R factors transferred streptomycin resistance and the identified resistance patterns were as follows: Sm Am, Sm Te, Sm Neo, Sm Am Te, Sm CI Neo and Sm Am CI Te. The levels of resistance observed were comparable for all donor strains and their converted recipients. Strains of E. coli harboring R factors were isolated from three dogs that had died of either otitis (followed by a generalized infection), enteritis or bronchopneumonia - secondary to distemper. The bacteria isolated from cats were recovered at the necropsy of animals that had died of purulent pleuresy and feline panleukopenia. The other strains (two Salmonella and one E. coli were isolated from fatal enteric diseases in the pig, calf and kangaroo.

Evolution of the metabolic and regulatory networks associated with oxygen availability in two phytopathogenic enterobacteria

PubMed Central

2012-01-01

Background Dickeya dadantii and Pectobacterium atrosepticum are phytopathogenic enterobacteria capable of facultative anaerobic growth in a wide range of O2 concentrations found in plant and natural environments. The transcriptional response to O2 remains under-explored for these and other phytopathogenic enterobacteria although it has been well characterized for animal-associated genera including Escherichia coli and Salmonella enterica. Knowledge of the extent of conservation of the transcriptional response across orthologous genes in more distantly related species is useful to identify rates and patterns of regulon evolution. Evolutionary events such as loss and acquisition of genes by lateral transfer events along each evolutionary branch results in lineage-specific genes, some of which may have been subsequently incorporated into the O2-responsive stimulon. Here we present a comparison of transcriptional profiles measured using densely tiled oligonucleotide arrays for two phytopathogens, Dickeya dadantii 3937 and Pectobacterium atrosepticum SCRI1043, grown to mid-log phase in MOPS minimal medium (0.1% glucose) with and without O2. Results More than 7% of the genes of each phytopathogen are differentially expressed with greater than 3-fold changes under anaerobic conditions. In addition to anaerobic metabolism genes, the O2 responsive stimulon includes a variety of virulence and pathogenicity-genes. Few of these genes overlap with orthologous genes in the anaerobic stimulon of E. coli. We define these as the conserved core, in which the transcriptional pattern as well as genetic architecture are well preserved. This conserved core includes previously described anaerobic metabolic pathways such as fermentation. Other components of the anaerobic stimulon show variation in genetic content, genome architecture and regulation. Notably formate metabolism, nitrate/nitrite metabolism, and fermentative butanediol production, differ between E. coli and the phytopathogens

Microcins from Enterobacteria: On the Edge Between Gram-Positive Bacteriocins and Colicins

NASA Astrophysics Data System (ADS)

Rebuffat, Sylvie

Most bacteria and archaea produce gene-encoded antimicrobial peptides/proteins called bacteriocins, which are secreted by the producing bacteria to compete against other microorganisms in a given niche. They are considered important mediators of intra- and interspecies interactions and therefore a factor in ­maintaining the microbial diversity and stability. They are ribosomally synthesized, and most of them are produced as inactive precursor proteins, which in some cases are further enzymatically modified. Bacteriocins generally exert potent antibacterial activities directed against bacterial species closely related to the producing bacteria. Bacteriocins are abundant and diverse in Gram-negative and Gram-positive bacteria. This chapter focuses on colicins and microcins from enterobacteria (mainly Escherichia coli) and on bacteriocins from lactic acid bacteria (LAB). Microcins are the lower-molecular-mass bacteriocins produced by Gram-negative bacteria with a repertoire of only 14 representatives. They form a very restricted family of bacteriocins, compared to the huge family of LAB bacteriocins that is constituted of several hundreds of peptides, with which microcins share common characteristics. Nevertheless, microcins also show similarities, particularly in their uptake mechanisms, with the higher-molecular-mass colicins, also produced by E. coli strains. On the edge between LAB bacteriocins and colicins, microcins appear to combine highly efficient strategies developed by both Gram-positive and Gram-negative bacteria at different levels, including uptake, translocation, killing of target cells, and immunity of the producing bacteria, making them important actors of bacterial competitions and fascinating models for novel concepts toward antimicrobial strategies and against resistance mechanisms.

Epidemiology of third-generation cephalosporin-resistant community-acquired Enterobacteria isolated from elderly patients.

PubMed

Thibaut, S; Caillon, J; Marquet, A; Grandjean, G; Potel, G; Ballereau, F

2014-02-01

This survey was made to study the epidemiology of multiresistant bacteria (MRB) in the French community, among elderly patients 65 years of age or more, carrying third-generation cephalosporin-resistant (3GC-resistant) Enterobacteriaceae, and the co-resistance of prescribed antibiotics. The data was collected in 2009 in the West of France by MedQual, a network of 174 private laboratories. Two thousand one hundred and sixty strains of the 88,255 identified Enterobacteria strains were 3GC-resistant (2.4%) and 945 of these strains (41.8%) were isolated from elderly patients 65 years of age or more. Escherichia coli was the predominant 3GC-resistant strain (72.7%). 51.4% of the 945 patients in whom a 3GC-resistant strain was isolated produced an extended-spectrum β-lactamase (ESBL). The main risk factors for infection with the 3GC-resistant strain were hospitalization and antibiotic treatment in the previous year (58.2 and 86.9%, respectively). Hospitalization during the previous year was more frequent among elderly patients who lived at home compared with those who lived in nursing homes (P<0.05). The production of ESBL, among the 945 patients who carried the 3GC-resistant strains, was similar among patients who lived at home compared with those who lived in nursing homes (51.4% versus 49.7%). Microbiologists should warn family physicians about MRB isolates with a specific antimicrobial resistance pattern (3GC-resistant, fluoroquinolone-resistant, etc.) to prescribe more effective medications. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Evolution of a Heavy Metal Homeostasis/Resistance Island Reflects Increasing Copper Stress in Enterobacteria

PubMed Central

Staehlin, Benjamin M.; Gibbons, John G.; Rokas, Antonis; O’Halloran, Thomas V.; Slot, Jason C.

2016-01-01

Copper homeostasis in bacteria is challenged by periodic elevation of copper levels in the environment, arising from both natural sources and human inputs. Several mechanisms have evolved to efflux copper from bacterial cells, including the cus (copper sensing copper efflux system), and pco (plasmid-borne copper resistance system) systems. The genes belonging to these two systems can be physically clustered in a Copper Homeostasis and Silver Resistance Island (CHASRI) on both plasmids and chromosomes in Enterobacteria. Increasing use of copper in agricultural and industrial applications raises questions about the role of human activity in the evolution of novel copper resistance mechanisms. Here we present evidence that CHASRI emerged and diversified in response to copper deposition across aerobic and anaerobic environments. An analysis of diversification rates and a molecular clock model suggest that CHASRI experienced repeated episodes of elevated diversification that could correspond to peaks in human copper production. Phylogenetic analyses suggest that CHASRI originated in a relative of Enterobacter cloacae as the ultimate product of sequential assembly of several pre-existing two-gene modules. Once assembled, CHASRI dispersed via horizontal gene transfer within Enterobacteriaceae and also to certain members of Shewanellaceae, where the original pco module was replaced by a divergent pco homolog. Analyses of copper stress mitigation suggest that CHASRI confers increased resistance aerobically, anaerobically, and during shifts between aerobic and anaerobic environments, which could explain its persistence in facultative anaerobes and emergent enteric pathogens. PMID:26893455

More than One Way To Control Hair Growth: Regulatory Mechanisms in Enterobacteria That Affect Fimbriae Assembled by the Chaperone/Usher Pathway▿

PubMed Central

Clegg, Steven; Wilson, Janet; Johnson, Jeremiah

2011-01-01

Many Gram-negative enterobacteria produce surface-associated fimbriae that facilitate attachment and adherence to eucaryotic cells and tissues. These organelles are believed to play an important role during infection by enabling bacteria to colonize specific niches within their hosts. One class of these fimbriae is assembled using a periplasmic chaperone and membrane-associated scaffolding protein that has been referred to as an usher because of its function in fimbrial biogenesis. The presence of multiple types of fimbriae assembled by the chaperone/usher pathway can be found both within a single bacterial species and also among different genera. One way of controlling fimbrial assembly in these bacteria is at the genetic level by positively or negatively regulating fimbrial gene expression. This minireview considers the mechanisms that have been described to control fimbrial gene expression and uses specific examples to demonstrate both unique and shared properties of such regulatory mechanisms. PMID:21398554

High-throughput microarray technology in diagnostics of enterobacteria based on genome-wide probe selection and regression analysis.

PubMed

Friedrich, Torben; Rahmann, Sven; Weigel, Wilfried; Rabsch, Wolfgang; Fruth, Angelika; Ron, Eliora; Gunzer, Florian; Dandekar, Thomas; Hacker, Jörg; Müller, Tobias; Dobrindt, Ulrich

2010-10-21

The Enterobacteriaceae comprise a large number of clinically relevant species with several individual subspecies. Overlapping virulence-associated gene pools and the high overall genome plasticity often interferes with correct enterobacterial strain typing and risk assessment. Array technology offers a fast, reproducible and standardisable means for bacterial typing and thus provides many advantages for bacterial diagnostics, risk assessment and surveillance. The development of highly discriminative broad-range microbial diagnostic microarrays remains a challenge, because of marked genome plasticity of many bacterial pathogens. We developed a DNA microarray for strain typing and detection of major antimicrobial resistance genes of clinically relevant enterobacteria. For this purpose, we applied a global genome-wide probe selection strategy on 32 available complete enterobacterial genomes combined with a regression model for pathogen classification. The discriminative power of the probe set was further tested in silico on 15 additional complete enterobacterial genome sequences. DNA microarrays based on the selected probes were used to type 92 clinical enterobacterial isolates. Phenotypic tests confirmed the array-based typing results and corroborate that the selected probes allowed correct typing and prediction of major antibiotic resistances of clinically relevant Enterobacteriaceae, including the subspecies level, e.g. the reliable distinction of different E. coli pathotypes. Our results demonstrate that the global probe selection approach based on longest common factor statistics as well as the design of a DNA microarray with a restricted set of discriminative probes enables robust discrimination of different enterobacterial variants and represents a proof of concept that can be adopted for diagnostics of a wide range of microbial pathogens. Our approach circumvents misclassifications arising from the application of virulence markers, which are highly affected by

Portable exhausters POR-004 SKID B, POR-005 SKID C, POR-006 SKID D storage plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelson, O.D.

1997-09-04

This document provides a storage plan for portable exhausters POR-004 SKID B, POR-005 SKID C, AND POR-006 SKID D. The exhausters will be stored until they are needed by the TWRS (Tank Waste Remediation Systems) Saltwell Pumping Program. The storage plan provides criteria for portable exhauster storage, periodic inspections during storage, and retrieval from storage.

Characterization of Extended Spectrum Β-Lactamase Producing Enterobacteria and Methicillin-Resistant Staphylococcus aureus Isolated from Raw Pork and Cooked Pork Products in South China.

PubMed

Li, Lili; Ye, Lei; Yu, Li; Zhou, Chenqing; Meng, Hecheng

2016-07-01

In this study, we assessed the co-colonization with extended spectrum β-lactamase producing Enterobacteria (ESBL-E) and methicillin-resistant Staphylococcus aureus (MRSA) in raw pork and cooked pork products in south China. In total, 240 raw pork and 240 cooked pork samples collected from supermarkets (n = 20) and local butcher shops (n = 20) in the city of Guangzhou (China) were investigated. Raw pork and cooked pork was more frequent colonization with ESBL-E (7.5% in raw pork and 0.4% in cooked pork products) than with MRSA (4.2% in raw pork). Two of samples were contaminated with both tested types of multidrug-resistant bacteria. High antibiotic-resistance rate with wide spectrums of both ESBL-E and MRSA isolated were observed. In ESBL-E isolates, TEM (n = 15), CTX-M-1 (n = 3), CTX-M-9 (n = 1), and SHV (n = 1) genes were detected. TEM and SHV genes were associated with CTX-M-1 in 2 isolates, respectively. The CTX-M-9 gene of 1 isolate from cooked pork samples was found to be transferred to Escherichia coli J53 by conjugation. Detected MLST-types of MRSA were livestock-associated ST7 (n = 5) and ST9 (n = 4), as well as hospital-acquired ST239 (n = 1), suggesting contamination from human source(s) during meat processing. These findings confirmed a contamination of raw pork and cooked pork with ESBL-E and MRSA and emphasized the necessity of enforcing hygienic practices and specific detection of MRSA and ESBL-producing bacteria in meat processing and storage. © 2016 Institute of Food Technologists®

Portable exhauster POR-007/Skid E and POR-008/Skid F storage plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelson, O.D.

1998-07-25

This document provides storage requirements for 1,000 CFM portable exhausters POR-O07/Skid E and POR-008/Skid F. These requirements are presented in three parts: preparation for storage, storage maintenance and testing, and retrieval from storage. The exhauster component identification numbers listed in this document contain the prefix POR-007 or POR-008 depending on which exhauster is being used.

Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System.

PubMed

Gorasia, Dhana G; Veith, Paul D; Hanssen, Eric G; Glew, Michelle D; Sato, Keiko; Yukitake, Hideharu; Nakayama, Koji; Reynolds, Eric C

2016-08-01

The type IX secretion system (T9SS) has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32-36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component.

Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System

PubMed Central

Gorasia, Dhana G.; Veith, Paul D.; Hanssen, Eric G.; Glew, Michelle D.; Sato, Keiko; Yukitake, Hideharu; Nakayama, Koji; Reynolds, Eric C.

2016-01-01

The type IX secretion system (T9SS) has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32–36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component. PMID:27509186

The PorX Response Regulator of the Porphyromonas gingivalis PorXY Two-Component System Does Not Directly Regulate the Type IX Secretion Genes but Binds the PorL Subunit

PubMed Central

Vincent, Maxence S.; Durand, Eric; Cascales, Eric

2016-01-01

The Type IX secretion system (T9SS) is a versatile multi-protein complex restricted to bacteria of the Bacteriodetes phylum and responsible for the secretion or cell surface exposition of diverse proteins that participate to S-layer formation, gliding motility or pathogenesis. The T9SS is poorly characterized but a number of proteins involved in the assembly of the secretion apparatus in the oral pathogen Porphyromonas gingivalis have been identified based on genome substractive analyses. Among these proteins, PorY, and PorX encode typical two-component system (TCS) sensor and CheY-like response regulator respectively. Although the porX and porY genes do not localize at the same genetic locus, it has been proposed that PorXY form a bona fide TCS. Deletion of porX in P. gingivalis causes a slight decrease of the expression of a number of other T9SS genes, including sov, porT, porP, porK, porL, porM, porN, and porY. Here, we show that PorX and the soluble cytoplasmic domain of PorY interact. Using electrophoretic mobility shift, DNA-protein co-purification and heterologous host expression assays, we demonstrate that PorX does not bind T9SS gene promoters and does not directly regulate expression of the T9SS genes. Finally, we show that PorX interacts with the cytoplasmic domain of PorL, a component of the T9SS membrane core complex and propose that the CheY-like PorX protein might be involved in the dynamics of the T9SS. PMID:27630829

Iron, copper, zinc, and manganese transport and regulation in pathogenic Enterobacteria: correlations between strains, site of infection and the relative importance of the different metal transport systems for virulence

PubMed Central

Porcheron, Gaëlle; Garénaux, Amélie; Proulx, Julie; Sabri, Mourad; Dozois, Charles M.

2013-01-01

For all microorganisms, acquisition of metal ions is essential for survival in the environment or in their infected host. Metal ions are required in many biological processes as components of metalloproteins and serve as cofactors or structural elements for enzymes. However, it is critical for bacteria to ensure that metal uptake and availability is in accordance with physiological needs, as an imbalance in bacterial metal homeostasis is deleterious. Indeed, host defense strategies against infection either consist of metal starvation by sequestration or toxicity by the highly concentrated release of metals. To overcome these host strategies, bacteria employ a variety of metal uptake and export systems and finely regulate metal homeostasis by numerous transcriptional regulators, allowing them to adapt to changing environmental conditions. As a consequence, iron, zinc, manganese, and copper uptake systems significantly contribute to the virulence of many pathogenic bacteria. However, during the course of our experiments on the role of iron and manganese transporters in extraintestinal Escherichia coli (ExPEC) virulence, we observed that depending on the strain tested, the importance of tested systems in virulence may be different. This could be due to the different set of systems present in these strains, but literature also suggests that as each pathogen must adapt to the particular microenvironment of its site of infection, the role of each acquisition system in virulence can differ from a particular strain to another. In this review, we present the systems involved in metal transport by Enterobacteria and the main regulators responsible for their controlled expression. We also discuss the relative role of these systems depending on the pathogen and the tissues they infect. PMID:24367764

Prevalence of ESBL-positive bacteria in the community in the Czech Republic.

PubMed

Cekanová, Luboslava; Kolár, Milan; Chromá, Magdalena; Sauer, Pavel; Sedlácková, Michaela; Koukalová, Dagmar

2009-07-01

Problematic bacteria in the community include enterobacteria which produce extended-spectrum beta-lactamases. As yet there is no description of the prevalence of these bacteria in persons in the community in the Czech Republic. Therefore the main goal of this study was to determine the prevalence of ESBL-positive enterobacteria in the gastrointestinal tracts of subjects in the community in the Czech Republic. Rectal swabs from the investigated subjects were inoculated onto chromID ESBL selective medium and enterobacteria were identified by the Vitek2 automated system. ESBL were detected using a modified DDST test. The results were confirmed by PCR and direct sequencing of CTX-M-positive amplicons. A total of 579 rectal swabs from subjects in the community were analyzed and ESBL production was both phenotypically and genotypically confirmed in 7 isolates. Thus the prevalence of ESBL-positive bacteria in the gastrointestinal tracts of the persons in the community was 1.2%. All the cases were Escherichia coli strains producing the CTX-M-type ESBL. CTX-M-15 was the most prevalent type in this group of isolates. The presented results are in accord with other authors' studies and suggest that the epidemiologic profile of ESBL-positive enterobacteria in the Czech Republic is comparable to that in other European countries.

Enterobacterial colonization in captive red-eared sliders (Trachemys scripta elegans).

PubMed

Gioia-Di Chiacchio, Rosely; Penido Júnior, Gilberto Nogueira; De Souza, Claudia Almeida Igayara; Prioste, Fabiola Eloisa Setim; Prado, Miriam Siqueira; Knöbl, Terezinha; Menão, Marcia Cristina; Matushima, Eliana Reiko

2014-12-01

The handling of turtles and other reptiles can be associated with risk of pathogenic enterobacteria transmission, mainly Salmonella spp. The aim of this study was to identify the enterobacteria in cloacal swabs of 39 red-eared sliders (Trachemys scripta elegans). Cloacal swabs from 39 captive individuals were analyzed. After sample enrichment in brain-heart infusion broth and 1% peptone water, bacterial isolation was performed through cultivation in blood, MacConkey and xylose lysine desoxycholate agar. Bacterial identification was achieved through conventional tests and automated turbidity analysis. The results indicated the growth of Kluyvera ascorbata (38/39), Leclercia adecarboxylata (37/39), Raoultella planticola (30/39), Citrobacter freundii (20/39), Proteus spp. (15/39), and Escherichia coli (5/39). Salmonella spp. were not detected. The intestinal enterobacteria identified inthis study differed from that reported in the literature for other reptiles.

Influence of oregano essential oil on traditional Argentinean cheese elaboration: Effect on lactic starter cultures.

PubMed

Marcial, Guillermo E; Gerez, Carla L; de Kairuz, Martha Nuñez; Araoz, Victoria Coll; Schuff, Carola; de Valdez, Graciela Font

The aim of this work is to study the oregano essential oil (OEO) composition from Northwestern Argentinean regions and to evaluate its effect on the lactic starter cultures. The oregano used, Origanum vulgare var hirtum, was obtained from Andalgalá, Catamarca. The essential oil presented high amounts of α-terpinene (10%), γ-terpinene (15.1%), terpinen-4-ol (15.5%) and thymol (13.0%) as the main components. No negative effect on growth or metabolic activity of lactic acid bacteria Streptococcus thermophilus CRL 728 and CRL 813, Lactobacillus delbrueckii subsp. bulgaricus CRL 656 and CRL 468, and Lactococcus lactis subsp. lactis CRL 597 up to the maximum concentration (200μg/g) assayed was observed. No differences in the organoleptic characteristics of semi-hard cheeses flavored with oregano essential oil (200μg/g) and homemade cheeses flavored with oregano leaves were found. With respect to the microbiological quality of the products, neither enterobacteria nor mold and yeast were detected during ripening in essential-oil flavored cheese compared to control cheese (enterobacteria 2×10 3 UFC/g) and cheese flavored with oregano leaves (mold/yeast 4×10 4 CFU/g). Our results showed that the use of oregano essential oil and lactic starter culture considerably improved cheese quality. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Antibiotic resistance of vibrio cholerae: special considerations of R-plasmids.

PubMed

Kuwahara, S

1978-09-01

Studies on the transmission of R plasmid by conjugation between enterobacteria and vibrio or related bacteria were reviewed. The majority of the reports confirmed successful transmission from enterobacteria to Vibrio cholerae and related species, although the transmission frequencies were extremely low and the transmitted R plasmid was very unstable except for thermosensitive kanamycin plasmid and usual R plasmid coexisting with P plasmid. Strains of V. cholerae and Aeromonas liquefaciens as well as A. salmonicida bearing R plasmid were detected in nature. R plasmid was relatively unstable in V. cholerae strains with which transmission of R plasmid to enterobacteria was confirmed. At present, only 3 R plasmids have been obtained from naturally occurring strains of V. cholerae. Although the 2 European plasmids belong to the C incompatibility group with 98 megadalton closed covalent circular DNA molecule, one plasmid belongs to the J group with more than 25 megadalton molecular weight, and no CCC of satelite DNA was detected in bacteria harboring this plasmid.

Effect of six different starter cultures on the concentration of residual nitrite in fermented sausages during in vitro human digestion.

PubMed

Kim, Hyeong Sang; Hur, Sun Jin

2018-01-15

The objective of this study was to determine the effect of six different starter cultures of enterobacteria on the concentration of residual nitrite in fermented sausages during in vitro human digestion. Before digestion, the concentration of residual nitrite was dependent on starter culture in fermented sausage and ranged from 25.2 to 33.2mg/kg. Among the six starter cultures of enterobacteria, Pediococcus acidilactici, Pediococcus pentosaceus, and Staphylococcus carnosus showed higher nitrite depletion ability than the other three strains in fermented sausages. The concentration of residual nitrite in fermented sausages was significantly (p<0.05) decreased after stomach digestion and ranged from 17.4 to 21.6mg/kg. Enterobacteria Escherichia coli (E. coli) and/or Lactobacillus casei (L. casei) effectively increased the degree of depletion of residual nitrite in large intestine digestion. In conclusion, starter cultures could influence the concentration of residual nitrite during in vitro human digestion. They could deplete residual nitrite in fermented sausages. Copyright © 2017 Elsevier Ltd. All rights reserved.

Identification of Porphyromonas gingivalis proteins secreted by the Por secretion system.

PubMed

Sato, Keiko; Yukitake, Hideharu; Narita, Yuka; Shoji, Mikio; Naito, Mariko; Nakayama, Koji

2013-01-01

The Gram-negative bacterium Porphyromonas gingivalis possesses a number of potential virulence factors for periodontopathogenicity. In particular, cysteine proteinases named gingipains are of interest given their abilities to degrade host proteins and process other virulence factors such as fimbriae. Gingipains are translocated on the cell surface or into the extracellular milieu by the Por secretion system (PorSS), which consists of a number of membrane or periplasmic proteins including PorK, PorL, PorM, PorN, PorO, PorP, PorQ, PorT, PorU, PorV (PG27, LptO), PorW and Sov. To identify proteins other than gingipains secreted by the PorSS, we compared the proteomes of P. gingivalis strains kgp rgpA rgpB (PorSS-proficient strain) and kgp rgpA rgpB porK (PorSS-deficient strain) using two-dimensional gel electrophoresis and peptide-mass fingerprinting. Sixteen spots representing 10 different proteins were present in the particle-free culture supernatant of the PorSS-proficient strain but were absent or faint in that of the PorSS-deficient strain. These identified proteins possessed the C-terminal domains (CTDs), which had been suggested to form the CTD protein family. These results indicate that the PorSS is used for secretion of a number of proteins other than gingipains and that the CTDs of the proteins are associated with the PorSS-dependent secretion. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Suppression of Cytochrome P450 Reductase (POR) Expression in Hepatoma Cells Replicates the Hepatic Lipidosis Observed in Hepatic POR-Null Mice

PubMed Central

Banerjee, Subhashis; Stolarczyk, Elzbieta I.; Zou, Ling

2011-01-01

Cytochrome P450 reductase (POR) is a microsomal electron transport protein essential to cytochrome P450-mediated drug metabolism and sterol and bile acid synthesis. The conditional deletion of hepatic POR gene expression in mice results in a marked decrease in plasma cholesterol levels counterbalanced by the accumulation of triglycerides in lipid droplets in hepatocytes. To evaluate the role of cholesterol and bile acid synthesis in this hepatic lipidosis, as well as the possible role of lipid transport from peripheral tissues, we developed a stable, small interfering RNA (siRNA)-mediated cell culture model for the suppression of POR. POR mRNA and protein expression were decreased by greater than 50% in McArdle-RH7777 rat hepatoma cells 10 days after transfection with a POR-siRNA expression plasmid, and POR expression was nearly completely extinguished by day 20. Immunofluorescent analysis revealed a marked accumulation of lipid droplets in cells by day 15, accompanied by a nearly 2-fold increase in cellular triglyceride content, replicating the lipidosis seen in hepatic POR-null mouse liver. In contrast, suppression of CYP51A1 (lanosterol demethylase) did not result in lipid accumulation, indicating that loss of cholesterol synthesis is not the basis for this lipidosis. Indeed, addition of cholesterol to the medium appeared to augment the lipidosis in POR-suppressed cells, whereas removal of lipids from the medium reversed the lipidosis. Oxysterols did not accumulate in POR-suppressed cells, discounting a role for liver X receptor in stimulating triglyceride synthesis, but addition of chenodeoxycholate significantly repressed lipid accumulation, suggesting that the absence of bile acids and loss of farnesoid X receptor stimulation lead to excessive triglyceride synthesis. PMID:21368239

Suppression of cytochrome P450 reductase (POR) expression in hepatoma cells replicates the hepatic lipidosis observed in hepatic POR-null mice.

PubMed

Porter, Todd D; Banerjee, Subhashis; Stolarczyk, Elzbieta I; Zou, Ling

2011-06-01

Cytochrome P450 reductase (POR) is a microsomal electron transport protein essential to cytochrome P450-mediated drug metabolism and sterol and bile acid synthesis. The conditional deletion of hepatic POR gene expression in mice results in a marked decrease in plasma cholesterol levels counterbalanced by the accumulation of triglycerides in lipid droplets in hepatocytes. To evaluate the role of cholesterol and bile acid synthesis in this hepatic lipidosis, as well as the possible role of lipid transport from peripheral tissues, we developed a stable, small interfering RNA (siRNA)-mediated cell culture model for the suppression of POR. POR mRNA and protein expression were decreased by greater than 50% in McArdle-RH7777 rat hepatoma cells 10 days after transfection with a POR-siRNA expression plasmid, and POR expression was nearly completely extinguished by day 20. Immunofluorescent analysis revealed a marked accumulation of lipid droplets in cells by day 15, accompanied by a nearly 2-fold increase in cellular triglyceride content, replicating the lipidosis seen in hepatic POR-null mouse liver. In contrast, suppression of CYP51A1 (lanosterol demethylase) did not result in lipid accumulation, indicating that loss of cholesterol synthesis is not the basis for this lipidosis. Indeed, addition of cholesterol to the medium appeared to augment the lipidosis in POR-suppressed cells, whereas removal of lipids from the medium reversed the lipidosis. Oxysterols did not accumulate in POR-suppressed cells, discounting a role for liver X receptor in stimulating triglyceride synthesis, but addition of chenodeoxycholate significantly repressed lipid accumulation, suggesting that the absence of bile acids and loss of farnesoid X receptor stimulation lead to excessive triglyceride synthesis.

[Effect of tigecycline on selected multiresistant bacteria].

PubMed

Kolár, Milan; Hanulík, Vojtech; Chromá, Magdalena

2009-02-01

Currently, one of the most serious problems in medicine is the increasing resistance of pathogenic bacteria to antimicrobial drugs. Bacterial resistance may potentially be solved in particular by decreasing the consumption of antibiotics and increasing the quality of their use. Equally important, however, is the development of new antimicrobial drugs and their use in clinical practice. One of the new antibiotic agents is tigecycline of the glycylcycline group. The presented work aimed at assessing its in vitro effect on selected multiresistant bacteria. Clinical samples were collected from patients hospitalized in the University Hospital Olomouc to isolate ESBL- and AmpC beta-lactamase-producing enterobacteria, methicillin-resistant Staphylococcus aureus (MRSA) strains and vancomycin-resistant enterococci (VRE). In the isolates, susceptibility to tigecycline was determined by the standard microdilution method. A total of 350 isolates were tested (100 MRSA, 10 0 VRE, 100 ESBL-positive and 50 AmpC-positive enterobacteria). In the cases of VRE and MRSA, no resistance to tigecycline was detected and the minimum inhibitory concentrations (MIC) did not exceed 0.25 mg/l and 0.5 mg/l, respectively. In ESBL-positive enterobacteria, 97% susceptibility (MIC range = or <0.06 to 4 mg/l) was detected; in AmpC-positive enterobacteria, the MIC range was = or <0.03-2 mg/l and susceptibility reached 98 %. Tigecycline may be considered a suitable alternative in the treatment of infections caused by the above-mentioned multiresistant strains.

[Interaction of chaotropically modified immunoglobulins with protein and glicolipid antigens].

PubMed

Gordienko, A I; Khimich, N V

2006-01-01

The features of interaction of native and chaotropically modified immunoglobulins with proteins (ovalbumin) and glicolipids (lipopolysaccharides, LPS) enterobacteria Escherichia coli K235, Salmonella minnesota and Salmonella enteritidis have been investigated. It has been established, that after processing of native antibodies with 3.5 M KSCN their ability to contact to the specified antigenes repeatedly grows. Besides the intensity of interaction of modified immunoglobulins with the mentioned above antigenes was various, that is determined by the presence of structural distinctions between antigen determinants of proteins and glycolipid antigens, and also between O-polysaccharide chains of LPS in different species of enterobacteria.

[Enterobacteria of bats (Chiroptera) (author's transl)].

PubMed

Pinus, M; Müller, H E

1980-08-01

The aerobic gram-negative faecal flora of 38 bats consisting of 10 species and genera respectively, of Microchiroptera, and of 4 species and genera respectively, of Megachiroptera was studied (Table 1 and 3). There were no specific differences between Insectivora and Frugivora: E. coli 15-24%, Citrobacter 8-10%, Enterobacter-Klebsiella-group 40-43% and Proteus-group 28-30% (Table 2). The overwhelming majority of the isolated bacteria were lactose-positive (Table 3), corresponding to the membership of the bats to the mammals. The vampire bats (Desmodus rotundus), however, nourishing exclusively with mammalian blood, possess a fundamental other faecal flora. Here we always found Aeromonas hydrophila sometimes as a pure culture and sometimes in combination with E. coli, Enterobacter, Providencia, and Arizona. The normal habitat of Aeromonas hydrophila in vampire bats suggests that these bacteria are necessary for digest the drunken blood in a similar manner as in leechs. The observations were discussed regarding their ecological, epidemiological, and phylogenetic significances.

System design description for portable 1,000 CFM exhauster Skids POR-007/Skid E and POR-008/Skid F

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelson, O.D.

1998-07-25

The primary purpose of the two 1,000 CFM Exhauster Skids, POR-007-SKID E and POR-008-SKID F, is to provide backup to the waste tank primary ventilation systems for tanks 241-C-106 and 241-AY-102, and the AY-102 annulus in the event of a failure during the sluicing of tank 241-C-106 and subsequent transfer of sluiced waste to 241-AY-102. This redundancy is required since both of the tank ventilation systems have been declared as Safety Class systems.

Zeolite food supplementation reduces abundance of enterobacteria.

PubMed

Prasai, Tanka P; Walsh, Kerry B; Bhattarai, Surya P; Midmore, David J; Van, Thi T H; Moore, Robert J; Stanley, Dragana

2017-01-01

According to the World Health Organisation, antibiotics are rapidly losing potency in every country of the world. Poultry are currently perceived as a major source of pathogens and antimicrobial resistance. There is an urgent need for new and natural ways to control pathogens in poultry and humans alike. Porous, cation rich, aluminosilicate minerals, zeolites can be used as a feed additive in poultry rations, demonstrating multiple productivity benefits. Next generation sequencing of the 16S rRNA marker gene was used to phylogenetically characterize the fecal microbiota and thus investigate the ability and dose dependency of zeolite in terms of anti-pathogenic effects. A natural zeolite was used as a feed additive in laying hens at 1, 2, and 4% w/w for a 23 week period. At the end of this period cloacal swabs were collected to sample faecal microbial communities. A significant reduction in carriage of bacteria within the phylum Proteobacteria, especially in members of the pathogen-rich family Enterobacteriaceae, was noted across all three concentrations of zeolite. Zeolite supplementation of feed resulted in a reduction in the carriage of a number of poultry pathogens without disturbing beneficial bacteria. This effect was, in some phylotypes, correlated with the zeolite concentration. This result is relevant to zeolite feeding in other animal production systems, and for human pathogenesis. Copyright © 2016 Elsevier GmbH. All rights reserved.

Effect of In Vitro Human Digestion on Biogenic Amine (Tyramine) Formation in Various Fermented Sausages.

PubMed

Kim, Hyeong Sang; Hur, Sun Jin

2018-03-01

Biogenic amines are formed in various fermented foods by microbial amino acid decarboxylation activities, and ingestion of these amines may cause human illness. However, the effect of digestion on the biogenic amines in fermented sausages has not been studied. This study was conducted to determine the effect of in vitro human digestion with the enterobacteria Escherichia coli and Lactobacillus casei on concentrations of the biogenic amine tyramine in six types of fermented sausages. Tyramine concentration was not significantly changed until simulated digestion in the small intestine. However, tyramine concentration for all sausage samples was increased after simulated digestion in the large intestine. Addition of E. coli and L. casei dramatically increased the tyramine concentrations ( P < 0.05). This result indicates that enterobacteria increase biogenic amine concentrations during human digestion.

THE EFFECT OF X-RAY IRRADIATION ON THE RESISTANCE OF WHITE MICE TO B. TYPHI ABDOMINALIS (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alexeva, O.G.

1957-01-01

White mice were sensitized by intraperitoneal injection of 2.5 million B. typhi abdominalis Felix Ty/sub 2/ or 50 million B. dysenteria Flexner No. 26-w. Four days later they were subjected to total x-ray irradiation with a LD 10/13 dose (300 r). Experiments on 250 mice showed that in irradiated mice the biologic effect of a sensibilizing dose increases from DL 18/13 to DL 48/13 for typhus and from DL 3/13 to DL24/13 for dysentery. Mice sensitized with B. typhus abdominalis and irradiated died after periods typical for radiation sickness, but developed also bacteriemia pointing to a complicated pathologic process. Themore » degree of active antityphus immunization developed after sensibilization by the stated method was determined by intraperitoneal inoculation of 2 DCL (200 million) on the 1, 3, 5, 7, 10, 20, 30 day after irradiation with 300r. Experiments on 600 mice have shown that the earlier developed immunity does not change during the first days of radiation sickness. During the III period of radiation sickness (3-1Oth days) and in the reparation period (20--30th days) the survival of experimental mice is 40--45% less than of the unirradiated controls. The reduced tension of active immunity is also manifested by inhibition of phagocytosis in vivo, accumulation of enormous amounts of bacteria in the place of injection, and, protracted bacteriemia. (tr-auth)« less

Regulation by gut bacertia of immune response, Bacillus thuringiensis susceptibility and hemolin expression in Plodia interpunctella

USDA-ARS?s Scientific Manuscript database

Plodia interpunctella (Hübner) is an important stored grain insect pest worldwide, and the first lepidopteran with reported resistance to Bacillus thuringiensis (Bt) toxins. Since gut bacteria may affect Bt insecticidal activity, we determined whether P. interpunctella lacking gut enterobacteria had...

Outer membrane vesicles from Neisseria gonorrhoeae target PorB to mitochondria and induce apoptosis

PubMed Central

Elgass, Kirstin D.; Gabriel, Kipros; Dougan, Gordon; Lithgow, Trevor; Heinz, Eva

2018-01-01

Neisseria gonorrhoeae causes the sexually transmitted disease gonorrhoea by evading innate immunity. Colonizing the mucosa of the reproductive tract depends on the bacterial outer membrane porin, PorB, which is essential for ion and nutrient uptake. PorB is also targeted to host mitochondria and regulates apoptosis pathways to promote infections. How PorB traffics from the outer membrane of N. gonorrhoeae to mitochondria and whether it modulates innate immune cells, such as macrophages, remains unclear. Here, we show that N. gonorrhoeae secretes PorB via outer membrane vesicles (OMVs). Purified OMVs contained primarily outer membrane proteins including oligomeric PorB. The porin was targeted to mitochondria of macrophages after exposure to purified OMVs and wild type N. gonorrhoeae. This was associated with loss of mitochondrial membrane potential, release of cytochrome c, activation of apoptotic caspases and cell death in a time-dependent manner. Consistent with this, OMV-induced macrophage death was prevented with the pan-caspase inhibitor, Q-VD-PH. This shows that N. gonorrhoeae utilizes OMVs to target PorB to mitochondria and to induce apoptosis in macrophages, thus affecting innate immunity. PMID:29601598

Changes of sodium nitrate, nitrite, and N-nitrosodiethylamine during in vitro human digestion.

PubMed

Kim, Hyeong Sang; Hur, Sun Jin

2017-06-15

This study aimed to determine the changes in sodium nitrate, sodium nitrite, and N-nitrosodiethylamine (NDEA) during in vitro human digestion, and the effect of enterobacteria on the changes in these compounds. The concentrations of nitrate, nitrite, and NDEA were significantly reduced from 150, 150, and 1ppm to 42.8, 63.2, and 0.85ppm, respectively, during in vitro human digestion (p<0.05). The enterobacteria Escherichia coli and Lactobacillus casei reduced the amount of these compounds present during in vitro human digestion. This study is the first to report that E. coli can dramatically reduce the amount of nitrite during in vitro human digestion and this may be due to the effect of nitrite reductase present in E. coli. We therefore conclude that the amounts of potentially harmful substances and their toxicity can be decreased during human digestion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Computational determination of the effects of virulent Escherichia coli and salmonella bacteriophages on human gut.

PubMed

Mostafa, Marwa Mostafa; Nassef, Mohammad; Badr, Amr

2016-10-01

Salmonella and Escherichia coli are different types of bacteria that cause food poisoning in humans. In the elderly, infants and people with chronic conditions, it is very dangerous if Salmonella or E. coli gets into the bloodstream and then they must be treated by phage therapy. Treating Salmonella and E. coli by phage therapy affects the gut flora. This research paper presents a system for detecting the effects of virulent E. coli and Salmonella bacteriophages on human gut. A method based on Domain-Domain Interactions (DDIs) model is implemented in the proposed system to determine the interactions between the proteins of human gut bacteria and the proteins of bacteriophages that infect virulent E. coli and Salmonella. The system helps gastroenterologists to realize the effect of injecting bacteriophages that infect virulent E. coli and Salmonella on the human gut. By testing the system over Enterobacteria phage 933W, Enterobacteria phage VT2-Sa and Enterobacteria phage P22, it resulted in four interactions between the proteins of the bacteriophages that infect E. coli O157:H7, E. coli O104:H4 and Salmonella typhimurium and the proteins of human gut bacterium strains. Several effects were detected such as: antibacterial activity against a number of bacterial species in human gut, regulation of cellular differentiation and organogenesis during gut, lung, and heart development, ammonia assimilation in bacteria, yeasts, and plants, energizing defense system and its function in the detoxification of lipopolysaccharide, and in the prevention of bacterial translocation in human gut. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Gliding Motility and Por Secretion System Genes Are Widespread among Members of the Phylum Bacteroidetes

PubMed Central

Zhu, Yongtao

2013-01-01

The phylum Bacteroidetes is large and diverse, with rapid gliding motility and the ability to digest macromolecules associated with many genera and species. Recently, a novel protein secretion system, the Por secretion system (PorSS), was identified in two members of the phylum, the gliding bacterium Flavobacterium johnsoniae and the nonmotile oral pathogen Porphyromonas gingivalis. The components of the PorSS are not similar in sequence to those of other well-studied bacterial secretion systems. The F. johnsoniae PorSS genes are a subset of the gliding motility genes, suggesting a role for the secretion system in motility. The F. johnsoniae PorSS is needed for assembly of the gliding motility apparatus and for secretion of a chitinase, and the P. gingivalis PorSS is involved in secretion of gingipain protease virulence factors. Comparative analysis of 37 genomes of members of the phylum Bacteroidetes revealed the widespread occurrence of gliding motility genes and PorSS genes. Genes associated with other bacterial protein secretion systems were less common. The results suggest that gliding motility is more common than previously reported. Microscopic observations confirmed that organisms previously described as nonmotile, including Croceibacter atlanticus, “Gramella forsetii,” Paludibacter propionicigenes, Riemerella anatipestifer, and Robiginitalea biformata, exhibit gliding motility. Three genes (gldA, gldF, and gldG) that encode an apparent ATP-binding cassette transporter required for F. johnsoniae gliding were absent from two related gliding bacteria, suggesting that the transporter may not be central to gliding motility. PMID:23123910

Antigenic topology of chlamydial PorB protein and identification of targets for immune neutralization of infectivity.

PubMed

Kawa, Diane E; Stephens, Richard S

2002-05-15

The outer membrane protein PorB is a conserved chlamydial protein that functions as a porin and is capable of eliciting neutralizing Abs. A topological antigenic map was developed using overlapping synthetic peptides representing the Chlamydia trachomatis PorB sequence and polyclonal immune sera. To identify which antigenic determinants were surface accessible, monospecific antisera were raised to the PorB peptides and were used in dot-blot and ELISA-based absorption studies with viable chlamydial elementary bodies (EBs). The ability of the surface-accessible antigenic determinants to direct neutralizing Ab responses was investigated using standardized in vitro neutralization assays. Four major antigenic clusters corresponding to Phe(34)-Leu(59) (B1-2 and B1-3), Asp(112) -Glu(145) (B2-3 and B2-4), Gly(179)-Ala(225) (B3-2 to B3-4), and Val(261)-Asn(305) (B4-4 to B5-2) were identified. Collectively, the EB absorption and dot-blot assays established that the immunoreactive PorB Ags were exposed on the surface of chlamydial EBs. Peptide-specific antisera raised to the surface-accessible Ags neutralized chlamydial infectivity and demonstrated cross-reactivity to synthetic peptides representing analogous C. pneumoniae PorB sequences. Furthermore, neutralization of chlamydial infectivity by C. trachomatis PorB antisera was inhibited by synthetic peptides representing the surface-exposed PorB antigenic determinants. These findings demonstrate that PorB Ags may be useful for development of chlamydial vaccines.

External Bacterial Flora and Antimicrobial Susceptibility Patterns of Staphylococcus spp. and Pseudomonas spp. Isolated from Two Household Cockroaches, Blattella germanica and Blatta orientalis.

PubMed

Menasria, Taha; Tine, Samir; Mahcene, Djaouida; Benammar, Leyla; Megri, Rochdi; Boukoucha, Mourad; Debabza, Manel

2015-04-01

A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches (Blattella germanica and Blatta orientalis) collected from households in Tebessa (northeast Algeria). Three major bacterial groups were cultured (total aerobic, enterobacteria, and staphylococci) from 14 specimens of cockroaches, and antibiotic susceptibility was tested for both Staphylococcus and Pseudomonas isolates. Culturing showed that the total bacterial load of cockroaches from different households were comparable (P<0.001) and enterobacteria were the predominant colonizers of the insect surface, with a bacterial load of (2.1 × 10⁵ CFU/insect), whereas the staphylococci group was the minority. Twenty-eight bacterial species were isolated, and susceptibility patterns showed that most of the staphylococci isolates were highly susceptible to chloramphenicol, gentamycin, pristinamycin, ofloxacin, clindamycin, and vancomycin; however, Pseudomonas strains exhibited resistance to amoxicillin/clavulanic acid, imipenem, and the second-generation antibiotic cephalosporin cefuroxime. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Freezing of meat raw materials affects tyramine and diamine accumulation in spontaneously fermented sausages.

PubMed

Bover-Cid, Sara; Miguelez-Arrizado, M Jesús; Luz Latorre Moratalla, L; Vidal Carou, M Carmen

2006-01-01

Biogenic amine accumulation was studied in spontaneously fermented sausages (Fuet) manufactured from unfrozen-fresh meat (U-sausages) and frozen-thawed meat (F-sausages). The aim was to investigate whether the frozen storage of raw materials affects the microbial composition and its aminogenic activity during sausage fermentation. Tyramine was the major amine in all sausages. Although the final levels were similar, tyramine accumulated more rapidly in F-sausages, which contained putrescine as the second amine. By contrast, U-sausages accumulated much more cadaverine than putrescine. F-sausages showed a slightly lower pH and free amino acid content as well as higher counts of technological flora (lactic acid and gram positive catalase positive bacteria) and lower counts of enterobacteria. Therefore, to freeze the meat raw materials for few days before sausage manufacture could be a useful practice, especially for the artisan fermented sausages (without starter), because it helps to reduce enterobacteria development and cadaverine production.

Aminogenesis control in fermented sausages manufactured with pressurized meat batter and starter culture.

PubMed

Latorre-Moratalla, M L; Bover-Cid, S; Aymerich, T; Marcos, B; Vidal-Carou, M C; Garriga, M

2007-03-01

The application of high hydrostatic pressure (200MPa) to meat batter just before sausage fermentation and the inoculation of starter culture were studied to improve the safety and quality of traditional Spanish fermented sausages (fuet and chorizo). Higher amounts of biogenic amines were formed in chorizo than in fuet. Without interfering with the ripening performance in terms of acidification, drying and proteolysis, hydrostatic pressure prevented enterobacteria growth but did not affect Gram-positive bacteria significantly. Subsequently, a strong inhibition of diamine (putrescine and cadaverine) accumulation was observed, but that of tyramine was not affected. The inoculated decarboxylase-negative strains, selected from indigenous bacteria of traditional sausages, were resistant to the HHP treatment, being able to lead the fermentation process, prevent enterococci development and significantly reduce enterobacteria counts. In sausages manufactured with either non-pressurized or pressurized meat batter, starter culture was the most protective measure against the accumulation of tyramine and both diamines.

Low oxygen environment facilitates embryo availability for older ovarian responders (PORs).

PubMed

Li, Mingzhao; Li, Zhibin; Shi, Juanzi

2018-04-18

We aimed to investigate the different effects of low oxygen (5% O 2 ) and atmospheric oxygen (20% O 2 ) on in vitro fertilization for older poor ovarian responders (PORs). We selected 1080 older PORs who met two criteria: (i) advanced maternal age (≥40) and (ii) an abnormal ovarian reserve test. All the patients used the ultra-short term protocols with GnRH agonist and recombinant FSH for controlled ovarian hyperstimulation (COH). About 506 cycles were performed in the incubators with 5% O 2 and 574 cycles were performed in the incubators with 20% O 2 . No significant differences were observed in normal fertilization rates (59.68 versus 60.25%; p = .691) and cancelation rates (18.97 versus 19.34%; p = .879) between two groups. The number of available embryos (1.77 ± 0.57 versus 1.52 ± 0.50; p = .041) and mean number of cells on Day 3 (7.49 ± 1.82 versus 7.16 ± 1.70; p = .032) were significantly higher in 5% O 2 group compared to that in 20% O 2 group. It showed no significant differences in the implantation rates (27.43 versus 24.11%; p = .803) and clinical pregnancy rates (36.34 versus 30.05%; p = .307) between two groups. The employ of low oxygen culture did not improve clinical pregnancy rate for older PORs. However, it benefited early embryonic development for older PORs.

[Multi-resistant microorganisms: Acinetobacter. Nursing care].

PubMed

Milà Enrique, A; Barbeito Zaldúa, N; Paunellas Albert, J; Castillejo Badia, N

1997-09-01

There has recently been an increase in the incidence of bacteria that are resistant to a variety of medications. Acinetobactor, a gram-negative bacillus, is one that appears most often. This microbe, which has two subspecies, can be carried in the blood of one fourth of the healthy population. It manifests itself pathologically in hospital situations in which the patient becomes gravely ill. The principle infections it can provoke are: meningitis, endocarditis, pneumonia, urinary tract infections, bacteriemia, etc. Treatment is dependent upon antibacterial sensibility tests. As in the case of all microorganisms, prevention of infection is absolutely imperative to stop the spread of this very dangerous bacteria.

[Use of cefotaxime in severe infections in newborn infants].

PubMed

Peskine, F; Astruc, J; Rodiére, M; Echenne, B; Brunel, D

1984-12-01

Twenty-seven septicemia, 2 urinary tract infections and 2 meningitis were treated with Cefotaxime. The pathogenic organisms were most often entero-bacteria (16 E. coli, 2 Klebsiella, 2 Enterobacter cloacae, 1 Proteus, 1 Acinetobacter); sometimes they were Streptococcus (5 Streptococcus D, 3 Streptococcus B, 1 Streptococcus Salivarius). Cefotaxime was given alone to 16 patients, in association to an aminoglycoside in 15 cases. It was administered by infusion over 30 minutes every 8 hours in a daily dose of 150 mg/kg (during 10 days in case of septicemia and during 18 days if it was a meningitis). A clinical and bacteriological success was obtained in 86% of the 22 cases caused by Enterobacteria, in one of the 5 septicemia due to Streptococcus D and in the 3 infections caused by Streptococcus B. It may be concluded from these results that cefotaxime may be used in neonate infection due to a Gram-. But when a Listeria or a Streptococcus D is discovered the ampicillin classically prescribed must be maintained.

[Efflux systems in Serratia marcescens].

PubMed

Mardanova, A M; Bogomol'naia, L M; Romanova, Iu D; Sharipova, M R

2014-01-01

A widespread bacterium Serratia marcescens (family Enterobacteriaceae) is an opportunistic and exhibits multiple drug resistance. Active removal of antibiotics and other antimicrobials from pathogen and exhibits multiple drug resistance. Active removal of antibiotics and other antimicrobials from the cells by efflux systems is one of the mechanisms responsible for microbial resistance to these compounds. Among enterobacteria, efflux systems of Escherichia coli and Salmonella enterica var. Typhimurium have been studied most extensively. Few efflux systems that belong to different families have been reported for S. marcescens. In this review, we analyzed available literature about S. marcescens efflux systems and carried out the comparative analysis of the genes encoding the RND type systems in different Serratia species and in other enterobacteria. Bioinformatical analysis of the S. marcescens genome allowed us to identify the previously unknown efflux systems based on their homology with the relevant E. coli genes. Identification of additional efflux systems in S. marcescens genome will promote our understanding of physiology of these bacteria, will detect new molecular mechanisms of resistance and will reveal their resistance potential.

Inversor Resonante de Tres Elementos L-LC con Caracteristica Cortocircuitable para Aplicaciones de Calentamiento por Induccion

NASA Astrophysics Data System (ADS)

Espi Huerta, Jose Miguel

Los generadores de calentamiento por induccion son puentes inversores con carga resonante, cuya mision es basicamente crear una corriente sinusoidal de gran amplitud sobre la "bobina de caldeo", que forma parte del tanque resonante. En el interior de esta bobina se introduce la pieza que se desea calentar. EI campo magnetico creado induce corrientes superficiales (corrientes de Foucault) sobre la pieza, que producen su calentamiento. Los tanques resonantes (tambien llamados osciladores) utilizados en la actualidad son el resonante serie y el resonante paralelo. Aunque ya desde hace algun tiempo se vienen construyendo generadores de alta potencia basados en estos dos osciladores, el exito nunca ha. sido completo en ninguno de los dos casos. Tal y como se explica en la introduccion de esta memoria, los puentes inversores utilizados deben operar sobre una carga inductiva (corriente retrasada) para evitar el fenomeno de la recuperacion inversa de sus diodos y la consiguiente ruptura de los transistores. De la restriccion topologica anterior se deduce que el generador paralelo debe conmutar a frecuencias inferiores a la resonancia, y el serie a frecuencias superiores. A esta restriccion topologica hay que unir otra que es exclusiva del calentamiento por induccion: La corriente por la bobina de caldeo debe ser sinusoidal. De no ser asi, resultaria imposible disponer toda la potencia de calentamiento sobre la pieza en el espesor requerido por la aplicacion. Como consecuencia, los inversores no pueden operar por debajo de la frecuencia de resonancia del oscilador, pues en ese caso se amplifican los armonicos de orden superior de la tension/corriente de entrada situados sobre la resonancia, con la consiguiente distorsion de la corriente de salida. La conjuncion de las dos restricciones anteriores obligan al inversor paralelo a funcionar a la frecuencia de resonancia del oscilador. Esto imposibilita un control por variacion de frecuencia, regulandose la potencia desde la

Influence of refuse sites on the prevalence of Campylobacter spp. and Salmonella serovars in seagulls.

PubMed

Ramos, Raül; Cerdà-Cuéllar, Marta; Ramírez, Francisco; Jover, Lluís; Ruiz, Xavier

2010-05-01

Wild animals are well-known reservoirs of Campylobacter and Salmonella. We investigated the influence of insalubrious diets on the prevalence of both enterobacteria in seagulls. Campylobacter occurrence in gull chicks sampled along the northeastern Iberian coast was directly related to the degree of refuse consumption. High Salmonella values from the sampling sites did not reflect any dietary relationship.

Early diagnostic value of plasma PCT and BG assay for CRBSI after OLT.

PubMed

Chen, J; Wang, Y; Shen, Z; Zhu, Z; Song, Y; Han, R

2011-06-01

The aim was to evaluate the role of procalcitonin (PCT) and (1-3)-β-D-glucan (BG) tests for early detection or exclusion of central venous catheter-related bloodstream infections (CRBSI) in patients after orthotopic liver transplantation (OLT). Fifty-five patients with clinically suspected CRBSI were assessed after OLT in this prospective study. On the day of clinical suspicion of CRBSI, blood samples were obtained from central venous catheters and a peripheral vein for blood cultures and from a peripheral vein for PCT and BG tests. Plasma PCT and BG values were measured by using an immunoluminometric assay and Fungitell BG assay, respectively. No prisoners or organs from prisoners were used in this study. Twenty-five patients (45%) were diagnosed with CRBIS. Among them, 13 (52%) displayed gram-positive bacteriemia, 11 (44%) gram-negative bacteriemia, and 1 (4%) fungemia. The PCT values were higher in CRBSI than in non-CRBSI patients (P = .003). CRBSI patients did not show significant increases in plasma BG values compared with non-CRBSI subjects (P = .051). PCT and BG area under receiver operating characteristic curves were 0.840 and 0.486, respectively. Sensitivity, specificity, and positive and negative predictive values of a PCT of ≥ 3.1 ng/mL for the diagnosis of CRBSI were 0.72, 0.87, 0.82, and 0.79, respectively. The figures for a BG of ≥ 83 pg/mL were 0.32, 0.90, 0.73, and 0.61, respectively. Among the 24 patients with bacteria infections, PCT was higher in patients with gram-negative than those with gram-positive bacterial infections (P = .022). We concluded that the PCT assay may be a useful rapid diagnostic adjunct for the diagnosis of suspected CRBSI in OLT patients. Copyright © 2011 Elsevier Inc. All rights reserved.

Multiple active site residues are important for photochemical efficiency in the light-activated enzyme protochlorophyllide oxidoreductase (POR).

PubMed

Menon, Binuraj R K; Hardman, Samantha J O; Scrutton, Nigel S; Heyes, Derren J

2016-08-01

Protochlorophyllide oxidoreductase (POR) catalyzes the light-driven reduction of protochlorophyllide (Pchlide), an essential, regulatory step in chlorophyll biosynthesis. The unique requirement of the enzyme for light has provided the opportunity to investigate how light energy can be harnessed to power biological catalysis and enzyme dynamics. Excited state interactions between the Pchlide molecule and the protein are known to drive the subsequent reaction chemistry. However, the structural features of POR and active site residues that are important for photochemistry and catalysis are currently unknown, because there is no crystal structure for POR. Here, we have used static and time-resolved spectroscopic measurements of a number of active site variants to study the role of a number of residues, which are located in the proposed NADPH/Pchlide binding site based on previous homology models, in the reaction mechanism of POR. Our findings, which are interpreted in the context of a new improved structural model, have identified several residues that are predicted to interact with the coenzyme or substrate. Several of the POR variants have a profound effect on the photochemistry, suggesting that multiple residues are important in stabilizing the excited state required for catalysis. Our work offers insight into how the POR active site geometry is finely tuned by multiple active site residues to support enzyme-mediated photochemistry and reduction of Pchlide, both of which are crucial to the existence of life on Earth. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

VERA-CS User Support Activities for PoR 14

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kochunas, Brendan

2017-11-01

The purpose of this milestone is to document the user support activities that took place between 10/1/2016 and 3/31/2017 (PoR 14). In the normal PHI workflow, that also extends to several activities within RTM, a Kanban process is followed. This involves creating tickets for specific work items and track the progress to complete these specific work items.

Influence of Refuse Sites on the Prevalence of Campylobacter spp. and Salmonella Serovars in Seagulls▿

PubMed Central

Ramos, Raül; Cerdà-Cuéllar, Marta; Ramírez, Francisco; Jover, Lluís; Ruiz, Xavier

2010-01-01

Wild animals are well-known reservoirs of Campylobacter and Salmonella. We investigated the influence of insalubrious diets on the prevalence of both enterobacteria in seagulls. Campylobacter occurrence in gull chicks sampled along the northeastern Iberian coast was directly related to the degree of refuse consumption. High Salmonella values from the sampling sites did not reflect any dietary relationship. PMID:20208027

Characteristics and tolerances of the pocket mouse and incidence of disease. [CNS lesions during space flights

NASA Technical Reports Server (NTRS)

Lindberg, R. G.; Kraft, L. M.; Simmonds, R. C.; Bailey, O. T.; Dunlap, W. A.; Haymaker, W.

1975-01-01

Studies carried out on the pocket mouse colony on Apollo XVII are reported. They revealed no serological evidence of viral disease, no pathogenic enterobacteria or respiratory Mycoplasma on culture, a 25% incidence of sarcosporidiosis, and a 2% incidence of chronic meningitis or meningoencephalitis. It is concluded that the pocket mouse is a highly adaptive animal and very well-suited to space flight.

Effect of breast feeding time on physiological, immunological and microbial parameters of weaned piglets in an intensive breeding farm.

PubMed

García, G R; Dogi, C A; Ashworth, G E; Berardo, D; Godoy, G; Cavaglieri, L R; de Moreno de LeBlanc, A; Greco, C R

2016-08-01

The aim of this work was to study the long-lasting consequences of different weaning age on physiological, immunological and microbiological parameters of weaned piglets. Piglets were weaned at 14 days (14W) or 21 days (21W). Blood samples were taken for IgG and cortisol determination on preweaning day and at 4; 20 and 40 post-weaning days. Three animals of each group were sacrificed. Small intestines for morphometric studies and secretory-IgA determination in fluid were taken. The cecum was obtained for enterobacteria, lactobacilli and total anaerobes enumeration. A significant decrease in piglet's plasma IgG concentrations was observed immediately after weaning and no differences were found between 14W and 21W. An increase in intestinal S-IgA was observed according to piglet's age. This increase was significantly higher in piglets 14W compared to piglets 21W. Animals from 14W group showed a decrease in villus length and in the number of goblet cells and intraepithelial lymphocytes. Other parameters were not affected by the weaning age. A short-term increase in cortisol was observed after weaning in both experimental groups. Enterobacteria decreased significantly after weaning in both groups, reaching values of weaning after 40 days. Lactobacilli counts decreased in both groups after weaning; however their counts were always higher than those obtained for enterobacteria. No differences were observed between 14W and 21W with regards to counts of anaerobes. The shortening of breast feeding time would favor an early synthesis of intestinal S-IgA after weaning. The changes observed in the microbiota could decrease postweaning enteric infections. However, early weaning induced negative effects on the cells of gut innate immunity and villi atrophy. This work provides knowledge about advantages and disadvantages at different weaning and long-lasting consequences on pig health. It is critical that swine producers become aware of the biological impacts of weaning age, so

A role for POR1, a Rac1-interacting protein, in ARF6-mediated cytoskeletal rearrangements.

PubMed Central

D'Souza-Schorey, C; Boshans, R L; McDonough, M; Stahl, P D; Van Aelst, L

1997-01-01

The ARF6 GTPase, the least conserved member of the ADP ribosylation factor (ARF) family, associates with the plasma membrane and intracellular endosome vesicles. Mutants of ARF6 defective in GTP binding and hydrolysis have a marked effect on endocytic trafficking and the gross morphology of the peripheral membrane system. Here we report that expression of the GTPase-defective mutant of ARF6, ARF6(Q67L), remodels the actin cytoskeleton by inducing actin polymerization at the cell periphery. This cytoskeletal rearrangement was inhibited by co-expression of ARF6(Q67L) with deletion mutants of POR1, a Rac1-interacting protein involved in membrane ruffling, but not with the dominant-negative mutant of Rac1, Rac1(S17N). A synergistic effect between POR1 and ARF6 for the induction of actin polymerization was detected. Furthermore, we observed that ARF6 interacts directly with POR1 and that this interaction was GTP dependent. These findings indicate that ARF6 and Rac1 function on distinct signaling pathways to mediate cytoskeletal reorganization, and suggest a role for POR1 as an important regulatory element in orchestrating cytoskeletal rearrangements at the cell periphery induced by ARF6 and Rac1. PMID:9312003

Effect of SPM-based cleaning POR on EUV mask performance

NASA Astrophysics Data System (ADS)

Choi, Jaehyuck; Lee, Han-shin; Yoon, Jinsang; Shimomura, Takeya; Friz, Alex; Montgomery, Cecilia; Ma, Andy; Goodwin, Frank; Kang, Daehyuk; Chung, Paul; Shin, Inkyun; Cho, H.

2011-11-01

EUV masks include many different layers of various materials rarely used in optical masks, and each layer of material has a particular role in enhancing the performance of EUV lithography. Therefore, it is crucial to understand how the mask quality and patterning performance can change during mask fabrication, EUV exposure, maintenance cleaning, shipping, or storage. The fact that a pellicle is not used to protect the mask surface in EUV lithography suggests that EUV masks may have to undergo more cleaning cycles during their lifetime. More frequent cleaning, combined with the adoption of new materials for EUV masks, necessitates that mask manufacturers closely examine the performance change of EUV masks during cleaning process. We have investigated EUV mask quality and patterning performance during 30 cycles of Samsung's EUV mask SPM-based cleaning and 20 cycles of SEMATECH ADT exposure. We have observed that the quality and patterning performance of EUV masks does not significantly change during these processes except mask pattern CD change. To resolve this issue, we have developed an acid-free cleaning POR and substantially improved EUV mask film loss compared to the SPM-based cleaning POR.

Detección y estudio mediante Fluorescencia Inducida por Láser de radicales libres formados por Disociación Multifotónica Infrarroja

NASA Astrophysics Data System (ADS)

Santos, M.; Díaz, L.; Torresano, J. A.; Rubio, L.; Samoudi, B.

Una de las principales aplicaciones actuales de los procesos de disociación multifotónica inducidos por radiación láser infrarroja (DMI) es la producción de radiales libres, con el fin de estudiar sus propiedades cinéticas y espectroscópicas. La disociación de moléculas poliatómicas en el IR con láseres de CO2 tiene lugar desde la superficie de energía molecular mas baja y conduce generalmente a la formación de fragmentos en el estado electrónico fundamental, con diversos grados de excitación vibracional. En el Grupo de Procesos Multifotónicos del Instituto de Estructura de la Materia del C.S.I.C. hemos puesto a punto la técnica de Fluorescencia Inducida por Láser (LIF) para la detección y análisis en tiempo real de los fragmentos producidos en la DMI inducida mediante uno o dos campos láseres de diferentes longitudes de onda. Objetivos de nuestro trabajo han sido el estudio de los canales de disociación mayoritarios y de las especies transitoria producidas, así como de la distribución de energía interna con que éstas son generadas. En particular hemos detectado mediante LIF las especies: C2, CF, CH, SiH2, CF2, CH2, SiHCl, y CF3 a partir de la disociación de, entre otras, las siguientes moléculas: C2H3Br, C3F6, C4H8Si, C2H5ClSi y CH5ClSi. En este trabajo presentamos algunos de los resultados obtenidos mediante el estudio por LIF de estos radicales: estudio temporal de la señal LIF obtenida con determinación de tiempos de vida, espectros de excitación y fluorescencia, temperaturas vibracionales de formación, variación de la intensidad LIF con el tiempo de retraso entre los láseres de disociación y prueba, etc.

Determinacion del error sistematico del momentum de muones producidos por interacciones neutrino-nucleon en el detector MINER$$\

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diaz Bautista, Gonzalo A.

El Modelo Estandar describe todas las partculas observadas en el naturaleza hasta el momento as como las caractersticas que gobiernan a las interacciones fundamentales entre ellas. En especial es posible identicar a las interacciones electromagnetica y debil, las cuales bajo determinadas condiciones de temperatura y energa pueden ser descritas a traves de una sola teora que engloba a ambas. A esta teora se le denomina electrodebil y tiene como nalidad caracterizar las propiedades de la interaccion maniesta a partir de la mezcla de las interacciones electromagnetica y debil, la que tambien lleva como nombre interaccion electrodebil. Particularmente, los neutrinos sonmore » de especial interes ya que, por un lado, interactuan por medio de la interaccion debil muy raramente en comparacion con otras partculas y, por el otro, no son acertadamente descritos por el Modelo Estandar. Por medio de observaciones experimentales que demostraban que los neutrinos cambian de sabor al propagarse, fenomeno llamado oscilaciones de neutrinos, se pudo llegar a la conclusion de que la implicancia de este fenomeno da como consecuencia que los neutrinos efectivamente s tienen masa, algo que entra en contradiccion con la descripcion inicial del Modelo Estandar, el cual los describe como partculas sin masa. Es de esta manera que las oscilaciones de neutrinos han sido y siguen siendo en la actualidad objeto de interes en la Fsica de Altas Energas tanto teorica como experimental. A n de poder realizar mediciones precisas de oscilaciones de neutrinos, los experimentos encargados de estas mediciones deben tratar de reducir sus incertidumbres en lo posible. Una de estas proviene de la caracterizacion de las secciones de choque de los neutrinos cuando interactuan con la materia, particularmente los nucleones al interior de los nucleos atomicos. El experimento MINERA esta orientado, entre otras cosas, a hacer una correcta caracterizacion de secciones de choque neutrino-nucleon por medio del

Mapping the Laminin Receptor Binding Domains of Neisseria meningitidis PorA and Haemophilus influenzae OmpP2

PubMed Central

Mahdavi, Jafar; Oldfield, Neil J.; Wheldon, Lee M.; Wooldridge, Karl G.; Ala'Aldeen, Dlawer A. A.

2012-01-01

Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae are major bacterial agents of meningitis. They each bind the 37/67-kDa laminin receptor (LamR) via the surface protein adhesins: meningococcal PilQ and PorA, H. influenzae OmpP2 and pneumococcal CbpA. We have previously reported that a surface-exposed loop of the R2 domain of CbpA mediates LamR-binding. Here we have identified the LamR-binding regions of PorA and OmpP2. Using truncated recombinant proteins we show that binding is dependent on amino acids 171–240 and 91–99 of PorA and OmpP2, respectively, which are predicted to localize to the fourth and second surface-exposed loops, respectively, of these proteins. Synthetic peptides corresponding to the loops bound LamR and could block LamR-binding to bacterial ligands in a dose dependant manner. Meningococci expressing PorA lacking the apex of loop 4 and H. influenzae expressing OmpP2 lacking the apex of loop 2 showed significantly reduced LamR binding. Since both loops are hyper-variable, our data may suggest a molecular basis for the range of LamR-binding capabilities previously reported among different meningococcal and H. influenzae strains. PMID:23049988

Mapping the laminin receptor binding domains of Neisseria meningitidis PorA and Haemophilus influenzae OmpP2.

PubMed

Abouseada, Noha M; Assafi, Mahde Saleh A; Mahdavi, Jafar; Oldfield, Neil J; Wheldon, Lee M; Wooldridge, Karl G; Ala'Aldeen, Dlawer A A

2012-01-01

Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae are major bacterial agents of meningitis. They each bind the 37/67-kDa laminin receptor (LamR) via the surface protein adhesins: meningococcal PilQ and PorA, H. influenzae OmpP2 and pneumococcal CbpA. We have previously reported that a surface-exposed loop of the R2 domain of CbpA mediates LamR-binding. Here we have identified the LamR-binding regions of PorA and OmpP2. Using truncated recombinant proteins we show that binding is dependent on amino acids 171-240 and 91-99 of PorA and OmpP2, respectively, which are predicted to localize to the fourth and second surface-exposed loops, respectively, of these proteins. Synthetic peptides corresponding to the loops bound LamR and could block LamR-binding to bacterial ligands in a dose dependant manner. Meningococci expressing PorA lacking the apex of loop 4 and H. influenzae expressing OmpP2 lacking the apex of loop 2 showed significantly reduced LamR binding. Since both loops are hyper-variable, our data may suggest a molecular basis for the range of LamR-binding capabilities previously reported among different meningococcal and H. influenzae strains.

Efficacy of an Optimised Bacteriophage Cocktail to Clear Clostridium difficile in a Batch Fermentation Model

PubMed Central

Nale, Janet Y.; Redgwell, Tamsin A.; Millard, Andrew; Clokie, Martha R. J.

2018-01-01

Clostridium difficile infection (CDI) is a major cause of infectious diarrhea. Conventional antibiotics are not universally effective for all ribotypes, and can trigger dysbiosis, resistance and recurrent infection. Thus, novel therapeutics are needed to replace and/or supplement the current antibiotics. Here, we describe the activity of an optimised 4-phage cocktail to clear cultures of a clinical ribotype 014/020 strain in fermentation vessels spiked with combined fecal slurries from four healthy volunteers. After 5 h, we observed ~6-log reductions in C. difficile abundance in the prophylaxis regimen and complete C. difficile eradication after 24 h following prophylactic or remedial regimens. Viability assays revealed that commensal enterococci, bifidobacteria, lactobacilli, total anaerobes, and enterobacteria were not affected by either regimens, but a ~2-log increase in the enterobacteria, lactobacilli, and total anaerobe abundance was seen in the phage-only-treated vessel compared to other treatments. The impact of the phage treatments on components of the microbiota was further assayed using metagenomic analysis. Together, our data supports the therapeutic application of our optimised phage cocktail to treat CDI. Also, the increase in specific commensals observed in the phage-treated control could prevent further colonisation of C. difficile, and thus provide protection from infection being able to establish. PMID:29438355

Green kiwifruit modulates the colonic microbiota in growing pigs.

PubMed

Han, K S; Balan, P; Molist Gasa, F; Boland, M

2011-04-01

To investigate whether green kiwifruit modulates the composition of colonic microbiota in growing pigs. Thirty-two pigs were fed the control diet or one of the three test diets containing either cellulose, freeze-dried kiwifruit or kiwifruit fibre as the sole fibre source for 14-day study. A Ward's dendrogram of similarity cluster analysis on PCR-DGGE gels revealed that inclusion of freeze-dried kiwifruit and kiwifruit fibre into diets altered the bacterial community, indicating the presence of two distinct clusters. Quantification of different bacterial groups by qPCR demonstrated that pigs fed the freeze-dried kiwifruit or kiwifruit fibre diets had a significantly higher number (P < 0·05) of total bacteria and Bacteroides group and a lower number of Enterobacteria and Escherichia coli group, as well as a greater ratio of Lactobacillus to Enterobacteria when compared to pigs fed the control or cellulose diets. Green kiwifruit, mainly because of fibre, modulated the colonic microbiota, leading to an improved intestinal environment in growing pigs. This is the first report regarding the effect of green kiwifruit on gut microbiota using the in vivo pig model. These results provide the first evidence of interaction between green kiwifruit and colonic microbiota. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

Drug resistance, AmpC-β-lactamase and extended-spectrum β-lactamase-producing Enterobacteriaceae isolated from fish and shrimp

PubMed Central

de Almeida, Marília Viana Albuquerque; Cangussú, Ítalo Mendes; de Carvalho, Antonia Leonadia Siqueira; Brito, Izabelly Linhares Ponte; Costa, Renata Albuquerque

2017-01-01

ABSTRACT The present study aims to detect the production of extended-spectrum beta-lactamases (ESBL) by enterobacteria isolated from samples of fresh shrimp and fish obtained from the retail trade of the city of Sobral, Ceará State, Brazil. All bacterial isolates were submitted to identification and antimicrobial susceptibility testing using aminopenicillin, beta-lactamase inhibitors, carbapenem, 1st, 2nd, 3rd and 4th generation cephalosporins, and monobactam. Three types of beta-lactamases - ESBL, AmpC and KPC - were investigated. 103 strains were identified, and the most frequent species in shrimp and fish samples was Enterobacter cloacae (n = 54). All the strains were resistant to penicillin and more than 50% of the isolates were resistant to ampicillin and cephalothin. Resistance to three 3rd generation cephalosporins (cefotaxime, ceftriaxone and ceftazidime) and one fourth generation cephalosporin (cefepime) was detected in two isolates of E. cloacae from shrimp samples. Phenotypic detection of AmpC was confirmed in seven strains. The ESBL was detected in two strains of E. cloacae from shrimp samples. No strain showed KPC production. These data can be considered alarming, since food (shrimp and fish) may be carriers of enterobacteria resistant to drugs of clinical interest. PMID:29116290

A Novel High-Resolving Method for Genomic PCR-Fingerprinting of Enterobacteria

PubMed Central

Isaeva, A.S.; Kulikov, E.E.; Tarasyan, K.K.

2010-01-01

We developed a novel PCR–fingerprinting system for differentiation of enterobacterial strains using a single oligonucleotide primer IS1tr that matches the inverted terminal repeats of the IS1 insertion element. Compared to widely used BOX–PCR and ribotyping methods, our system features higher resolution allowing differentiation of closely related isolates that appear identical in BOX–PCR and ribotyping but differ in their phage sensitivity. The IS1–profiling system is less sensitive to the quality of the material and equipment used. At the same time, BOX–PCR is more universal and suitable for bacterial strain grouping and reconstruction of the low–distance phylogeny. Thus, our system represents an important supplement to the existing set of tools for bacterial strain differentiation; it is particularly valuable for a detailed investigation of highly divergent and rapidly evolving natural bacterial populations and for studies on coliphage ecology. However, some isolates could not be reliably differentiated by IS1–PCR, because of the low number of bands in their patterns. For improvement of IS1–fingerprinting characteristics, we offer to modify the system by introducing the second primer TR8834 hybridizing to the sequence of a transposase gene that is widely spread in enterobacterial genomes. PMID:22649631

Molecular genetic and physical analysis of gas vesicles in buoyant enterobacteria

PubMed Central

Tashiro, Yosuke; Monson, Rita E.; Ramsay, Joshua P.

2016-01-01

Summary Different modes of bacterial taxis play important roles in environmental adaptation, survival, colonization and dissemination of disease. One mode of taxis is flotation due to the production of gas vesicles. Gas vesicles are proteinaceous intracellular organelles, permeable only to gas, that enable flotation in aquatic niches. Gene clusters for gas vesicle biosynthesis are partially conserved in various archaea, cyanobacteria, and some proteobacteria, such as the enterobacterium, S erratia sp. ATCC 39006 (S39006). Here we present the first systematic analysis of the genes required to produce gas vesicles in S39006, identifying how this differs from the archaeon H alobacterium salinarum. We define 11 proteins essential for gas vesicle production. Mutation of gvpN or gvpV produced small bicone gas vesicles, suggesting that the cognate proteins are involved in the morphogenetic assembly pathway from bicones to mature cylindrical forms. Using volumetric compression, gas vesicles were shown to comprise 17% of S39006 cells, whereas in E scherichia coli heterologously expressing the gas vesicle cluster in a deregulated environment, gas vesicles can occupy around half of cellular volume. Gas vesicle production in S39006 and E . coli was exploited to calculate the instantaneous turgor pressure within cultured bacterial cells; the first time this has been performed in either strain. PMID:26743231

Trombocitopenia induzida por heparina em paciente com oclusão arterial aguda

PubMed Central

Pimenta, Rafael Elias Farres; Yoshida, Winston Bonetti; Rollo, Hamilton Almeida; Sobreira, Marcone Lima; Bertanha, Matheus; Mariúba, Jamil Victor de Oliveira; Jaldin, Rodrigo Gibin; de Camargo, Paula Angeleli Bueno

2016-01-01

Resumo A trombocitopenia induzida por heparina é uma complicação grave da terapêutica anticoagulante com heparina e está associada à formação de anticorpos antifator IV plaquetário. Costuma surgir a partir do quinto dia do tratamento, com queda de pelo menos 50% da contagem plaquetária. Em decorrência da ativação plaquetária concomitante, pode ocorrer quadro de trombose, venosa ou arterial, com repercussões clínicas graves. Apresentamos um caso de paciente portador de síndrome do anticorpo antifosfolípide, com quadro de oclusão arterial aguda, que foi tratado cirurgicamente e recebeu heparina não fracionada no intra e pós-operatório. No quinto dia de tratamento anticoagulante, apresentou queda maior de 50% da contagem de plaquetas em relação à contagem pré-heparina. A suspeita de trombocitopenia induzida por heparina e seus aspectos diagnósticos e terapêuticos serão abordados neste desafio terapêutico.

Prevalencia y tamizaje del Trastorno por Déficit de Atención con Hiperactividad en Costa Rica

PubMed Central

Weiss, Nicholas T.; Schuler, Jovita; Monge, Silvia; McGough, James J.; Chavira, Denise; Bagnarello, Monica; Herrera, Luis Diego; Mathews, Carol A.

2015-01-01

Resumen La investigación tuvo como propósito estimar la prevalencia del Trastorno por Déficit de Atención con Hiperactividad (TDAH) en Costa Rica y determinar si la versión en español del cuestionario Swanson Nolan and Pelham Scale IV (SNAP-IV) es un instrumento de tamizaje útil en una población de niños y niñas escolares costarricenses. El instrumento fue entregado a padres y maestros de 425 niños entre 5 y 13 años de edad (promedio = 8.8). Todos fueron evaluados con el instrumento Swanson, Kotkin, Agler, M-Flynn and Pelham Scale (SKAMP). Su diagnóstico fue confirmado con una entrevista clínica. La sensibilidad y la especificidad del SNAP-IV fueron evaluadas como predictores de criterios de diagnóstico según el DSM-IV. La prevalencia puntual en la muestra del TDAH fue del 5%. El tamizaje más preciso lo hizo el SNAP-IV completado por el maestro en un corte de 20%, con una sensibilidad de 96% y una especificidad de un 82%. La sensibilidad de los instrumentos completados por los padres fue más baja que aquella de los maestros. El SNAP-IV completado por las maestras con un corte aislando el 20% de los mayores puntajes categorizó correctamente a un 87% de los sujetos. PMID:22432094

Iron fortification adversely affects the gut microbiome, increases pathogen abundance and induces intestinal inflammation in Kenyan infants.

PubMed

Jaeggi, Tanja; Kortman, Guus A M; Moretti, Diego; Chassard, Christophe; Holding, Penny; Dostal, Alexandra; Boekhorst, Jos; Timmerman, Harro M; Swinkels, Dorine W; Tjalsma, Harold; Njenga, Jane; Mwangi, Alice; Kvalsvig, Jane; Lacroix, Christophe; Zimmermann, Michael B

2015-05-01

In-home iron fortification for infants in developing countries is recommended for control of anaemia, but low absorption typically results in >80% of the iron passing into the colon. Iron is essential for growth and virulence of many pathogenic enterobacteria. We determined the effect of high and low dose in-home iron fortification on the infant gut microbiome and intestinal inflammation. We performed two double-blind randomised controlled trials in 6-month-old Kenyan infants (n=115) consuming home-fortified maize porridge daily for 4 months. In the first, infants received a micronutrient powder (MNP) containing 2.5 mg iron as NaFeEDTA or the MNP without iron. In the second, they received a different MNP containing 12.5 mg iron as ferrous fumarate or the MNP without the iron. The primary outcome was gut microbiome composition analysed by 16S pyrosequencing and targeted real-time PCR (qPCR). Secondary outcomes included faecal calprotectin (marker of intestinal inflammation) and incidence of diarrhoea. We analysed the trials separately and combined. At baseline, 63% of the total microbial 16S rRNA could be assigned to Bifidobacteriaceae but there were high prevalences of pathogens, including Salmonella Clostridium difficile, Clostridium perfringens, and pathogenic Escherichia coli. Using pyrosequencing, +FeMNPs increased enterobacteria, particularly Escherichia/Shigella (p=0.048), the enterobacteria/bifidobacteria ratio (p=0.020), and Clostridium (p=0.030). Most of these effects were confirmed using qPCR; for example, +FeMNPs increased pathogenic E. coli strains (p=0.029). +FeMNPs also increased faecal calprotectin (p=0.002). During the trial, 27.3% of infants in +12.5 mgFeMNP required treatment for diarrhoea versus 8.3% in -12.5 mgFeMNP (p=0.092). There were no study-related serious adverse events in either group. In this setting, provision of iron-containing MNPs to weaning infants adversely affects the gut microbiome, increasing pathogen abundance and

Racism in digital era: Development and initial validation of the Perceived Online Racism Scale (PORS v1.0).

PubMed

Keum, Brian TaeHyuk; Miller, Matthew J

2017-04-01

The purpose of this study was to develop the Perceived Online Racism Scale (PORS) to assess perceived online racist interpersonal interactions and exposure to online racist content among people of color. Items were developed through a multistage process involving a comprehensive literature review, focus-groups, qualitative data collection, and survey of online racism experiences. Based on a sample of 1,023 racial minority participants, exploratory and confirmatory factor analyses provided support for a 30-item bifactor model accounted by the general factor and the following 3 specific factors: (a) personal experience of racial cyber-aggression, (b) vicarious exposure to racial cyber-aggression, and (c) online-mediated exposure to racist reality. The PORS demonstrated measurement invariance across racial/ethnic groups in our sample. Internal reliability estimates for the total and subscale scores of the PORS were above .88 and the 4-week test-retest reliability was adequate. Limitations and future directions for research are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

[Professor Frantisek Por MD and Professor Robert Klopstock MD, students at Budapest and Prague Faculties of Medicine].

PubMed

Mydlík, M; Derzsiová, K

2010-11-01

Professor Frantisek Por MD and Professor Robert Klopstock MD were contemporaries, both born in 1899, one in Zvolen, the other in Dombovar, at the time of Austro-Hungarian Monarchy. Prof. Por attended the Faculty of Medicine in Budapest from 1918 to 1920, and Prof. Klopstock studied at the same place between 1917 and 1919. From 1920 until graduation on 6th February 1926, Prof. Por continued his studies at the German Faculty of Medicine, Charles University in Prague. Prof. Klopstock had to interrupt his studies in Budapest due to pulmonary tuberculosis; he received treatment at Tatranske Matliare where he befriended Franz Kafka. Later, upon Kafka's encouragement, he changed institutions and continued his studies at the German Faculty of Medicine, Charles University in Prague, where he graduated the first great go. It is very likely that, during their studies in Budapest and Prague, both professors met repeatedly, even though their life paths later separated. Following his graduation, Prof. Por practiced as an internist in Prague, later in Slovakia, and from 1945 in Kosice. In 1961, he was awarded the title of university professor of internal medicine at the Faculty of Medicine, Pavol Jozef Safarik University in Kosice, where he practiced until his death in 1980. Prof. Klopstock continued his studies in Kiel and Berlin. After his graduation in 1933, he practiced in Berlin as a surgeon and in 1938 left for USA. In 1962, he was awarded the title of university professor of pulmonary surgery in NewYork, where he died in 1972.

Passiflora edulis peel intake and ulcerative colitis: approaches for prevention and treatment.

PubMed

Cazarin, Cinthia Bb; da Silva, Juliana K; Colomeu, Talita C; Batista, Angela G; Vilella, Conceição A; Ferreira, Anderson L; Junior, Stanislau Bogusz; Fukuda, Karina; Augusto, Fabio; de Meirelles, Luciana R; Zollner, Ricardo de L; Junior, Mário R Maróstica

2014-05-01

Inflammatory bowel disease is a chronic relapsing disease that affects millions of people worldwide; its pathogenesis is influenced by genetic, environmental, microbiological, and immunological factors. The aim of this study was to evaluate the effects of short- and long-term Passiflora edulis peel intake on the antioxidant status, microbiota, and short-chain fatty acids formation in rats with 2,4,6-trinitrobenzenesulphonic acid-induced colitis using two "in vivo" experiments: chronic (prevention) and acute (treatment). The colitis damage score was determined using macroscopic and microscopic analyses. In addition, the antioxidant activity in serum and other tissues (liver and colon) was evaluated. Bifidobacteria, lactobacilli, aerobic bacteria and enterobacteria, and the amount of short-chain fatty acids (acetic, butyric, and propionic acids) in cecum content were counted. Differences in the colon damage scores were observed; P. edulis peel intake improved serum antioxidant status. In the treatment protocol, decreased colon lipid peroxidation, a decreased number of aerobic bacteria and enterobacteria, and an improvement in acetic and butyric acid levels in the feces were observed. An improvement in the bifidobacteria and lactobacilli was observed in the prevention protocol. These results suggested that P. edulis peel can modulate microbiota and could be used as source of fiber and polyphenols in the prevention of oxidative stress through the improvement of serum and tissue antioxidant status.

Cellulose modulates biofilm formation by counteracting curli-mediated colonization of solid surfaces in Escherichia coli.

PubMed

Gualdi, Luciana; Tagliabue, Letizia; Bertagnoli, Stefano; Ieranò, Teresa; De Castro, Cristina; Landini, Paolo

2008-07-01

In enterobacteria, the CsgD protein activates production of two extracellular structures: thin aggregative fimbriae (curli) and cellulose. While curli fibres promote biofilm formation and cell aggregation, the evidence for a direct role of cellulose as an additional determinant for biofilm formation is not as straightforward. The MG1655 laboratory strain of Escherichia coli only produces limited amounts of curli and cellulose; however, ectopic csgD expression results in strong stimulation of curli and cellulose production. We show that, in a csgD-overexpressing derivative of MG1655, cellulose production negatively affects curli-mediated surface adhesion and cell aggregation, thus acting as a negative determinant for biofilm formation. Consistent with this observation, deletion of the bcsA gene, necessary for cellulose production, resulted in a significant increase in curli-dependent adhesion. We found that cellulose production increased tolerance to desiccation, suggesting that the function of cellulose might be related to resistance to environmental stresses rather than to biofilm formation. Production of the curli/cellulose network in enterobacteria typically takes place at low growth temperature (<32 degrees C), but not at 37 degrees C. We show that CsgD overexpression can overcome temperature-dependent control of the curli-encoding csgBA operon, but not of the cellulose-related adrA gene, suggesting very tight temperature control of cellulose production in E. coli MG1655.

Establishment of intestinal microbiota with focus on yeasts of unweaned and weaned piglets kept under different farm conditions.

PubMed

Urubschurov, Vladimir; Janczyk, Pawel; Souffrant, Wolfgang-Bernhard; Freyer, Gertraude; Zeyner, Annette

2011-09-01

This study aimed to characterize the intestinal yeasts in weaning piglets and to establish their possible relationships with main bacterial groups. German Landrace piglets were weaned (WP, n=32) at 28 days of age or kept with the dams until day 39 without creep feed (UP, n=32). The experiment was performed at an experimental and a commercial farm (CF). Faeces were collected from the piglets, sows and pen floors on days 28, 33 and 39 for isolation of DNA and cultivation for enumeration of yeasts, enterobacteria, enterococci and lactobacilli. Fragments of the D1 domain of 26S rRNA gene were amplified and separated by denaturing gradient gel electrophoresis (DGGE). No yeasts could be cultured from water and feed samples. No or only low numbers of yeasts were detected among all UP. In WP at CF, yeasts correlated with lactobacilli (r=0.456; P=0.009) and enterobacteria (r=-0.407; P=0.021). Kazachstania slooffiae dominated among the cultured yeasts. It was the only yeast species detected by PCR-DGGE. Yeasts, especially K. slooffiae, established in the porcine gastrointestinal tract after consumption of grain-based feed and may interrelate with the intestinal microbiota. The study provides data indicating importance of K. slooffiae for the development of balanced porcine gut microbiota. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

[Antibacterial antibodies in human immunoglobulins and sera: past and present].

PubMed

Romanov, V A; Kulibin, A Iu; Zaĭtseva, I P

2010-01-01

To measure levels of several types of antibacterial antibodies in preparations of normal human immunoglobulin as well as in samples of donor sera obtained in 1965 and 2009. Five batches of human normal immunoglobulin manufactured in 1965 and five batches manufactured in 2009 as well as 77 and 28 blood serum samples respectively were tested by agglutination assay for the presence of antibodies to enterobacteria, Brucella species, tularemia agent, Rickettsia burnetii, Rickettsia prowazekii, and several species of opportunistic bacteria. Higher antibody titers to Salmonella typhi, Salmonella paratyphi A and B, Salmonella enteritidis, Salmonella typhimurium, Shigella flexneri and Shigella sonnei were revealed in immunoglobulin preparations and donor sera obtained in 1965 compared to that obtained in 2009. There was no difference in antibody titers to Shigella boydii, Salmonella choleraesuis, Escherichia coli O-55, Pseudomonas aeruginosa, Proteus vulgaris, Serratia marcescens and E. coli. Antibodies to Brucella species, tularemia agent, R. burnetii, R. prowazekii were not detected in normal human immunoglobulin. Decrease of antibody levels to several pathogenic enterobacteria in human immunoglobulin preparations as well as in sera of donors for 40 years could be linked with decrease of number of immunized persons, changes in circulation of pathogenic bacteria, decrease of rate of asymptomatic infections. Stability of antibody titers to opportunistic bacteria is a rationale to use them for assessment of humoral immunity function.

Effects of Streptococcus bovis Isolated from Bovine Rumen on the Fermentation Characteristics and Nutritive Value of Tanzania Grass Silage

PubMed Central

Zanine, Anderson de Moura; Bonelli, Emerson Alencar; de Souza, Alexandre Lima; Ferreira, Daniele de Jesus; Santos, Edson Mauro; Ribeiro, Marinaldo Divino; Geron, Luiz Juliano Valério; Pinho, Ricardo Martins Araujo

2016-01-01

This study aimed to evaluate the effects of Streptococcus bovis on the fermentation characteristics and nutritive value of Tanzania grass silage. Tanzania grass was chopped and left untreated (U) or treated with Streptococcus bovis JB1 at 1 × 106 colony-forming units per gram (cfu/g) of fresh forage or Streptococcus bovis HC5 at 1 × 106 cfu/g of fresh forage and packed into sixtuplicate laboratory silos. The largest number of enterobacteria, molds and yeast (M&Y) occurred in untreated silages and the smallest populations of enterobacteria and M&Y and the largest numbers of lactic acid bacteria (LAB), at 9.81 and 9.87 log cfu/g, were observed in Streptococcus bovis JB1 and HC5, respectively (P < 0.05). Silages treated with JB1 and HC5 had lower (P < 0.05) silage pHs and concentrations of ammoniacal nitrogen (NH3-N) than untreated silages. The application of Streptococcus bovis JB1 and HC5 resulted in fewer losses through gases and effluents (P < 0.05), which resulted in greater dry matter recovery (DMR) and crude protein recovery (CPR) (P < 0.05). Streptococcus bovis JB1 and HC5 improved the fermentative profile and increased the concentration of crude protein and DMR and CPR in Tanzania grass silage. PMID:27073806

Encefalitis por anticuerpos contra el receptor de NMDA: experiencia con seis pacientes pediátricos. Potencial eficacia del metotrexato

PubMed Central

Bravo-Oro, Antonio; Abud-Mendoza, Carlos; Quezada-Corona, Arturo; Dalmau, Josep; Campos-Guevara, Verónica

2016-01-01

Introducción La encefalitis por anticuerpos contra el receptor de N-metil-D-aspartato (NMDA) es una entidad cada vez más diagnosticada en edad pediátrica. A diferencia de los adultos, en muchos casos no se asocia a tumores y las manifestaciones iniciales en niños más frecuentes son crisis convulsivas y trastornos del movimiento, mientras que en los adultos predominan las alteraciones psiquiátricas. Casos clínicos Presentamos seis casos pediátricos confirmados con anticuerpos contra la subunidad NR1 del receptor de NMDA en suero y líquido cefalorraquídeo. Cinco de los casos comenzaron con crisis convulsivas como manifestación clínica inicial antes de desarrollar el cuadro clásico de esta entidad. En todos los casos se utilizaron esteroides como primera línea de tratamiento, con los que sólo se observó control de las manifestaciones en uno, por lo que el resto de los pacientes requirió inmunomoduladores de segunda línea. Todos los pacientes recibieron metotrexato como tratamiento inmunomodulador para evitar recaídas y la evolución fue a la mejoría en todos ellos. Conclusiones En nuestra serie de pacientes con encefalitis por anticuerpos contra el receptor de NMDA, ninguno se asoció a tumores. Todos los casos recibieron metotrexato por lo menos durante un año, no observamos eventos adversos clínicos ni por laboratorio, ni hubo secuelas neurológicas ni recaídas durante el tratamiento. Aunque es una serie pequeña y es deseable incrementar el número y tiempo de evolución, consideramos el metotrexato una excelente alternativa como tratamiento inmunomodulador para esta patología. PMID:24150952

Structural and functional probing of PorZ, an essential bacterial surface component of the type-IX secretion system of human oral-microbiomic Porphyromonas gingivalis.

PubMed Central

Lasica, Anna M.; Goulas, Theodoros; Mizgalska, Danuta; Zhou, Xiaoyan; de Diego, Iñaki; Ksiazek, Mirosław; Madej, Mariusz; Guo, Yonghua; Guevara, Tibisay; Nowak, Magdalena; Potempa, Barbara; Goel, Apoorv; Sztukowska, Maryta; Prabhakar, Apurva T.; Bzowska, Monika; Widziolek, Magdalena; Thøgersen, Ida B.; Enghild, Jan J.; Simonian, Mary; Kulczyk, Arkadiusz W.; Nguyen, Ky-Anh; Potempa, Jan; Gomis-Rüth, F. Xavier

2016-01-01

Porphyromonas gingivalis is a member of the human oral microbiome abundant in dysbiosis and implicated in the pathogenesis of periodontal (gum) disease. It employs a newly described type-IX secretion system (T9SS) for secretion of virulence factors. Cargo proteins destined for secretion through T9SS carry a recognition signal in the conserved C-terminal domain (CTD), which is removed by sortase PorU during translocation. Here, we identified a novel component of T9SS, PorZ, which is essential for surface exposure of PorU and posttranslational modification of T9SS cargo proteins. These include maturation of enzyme precursors, CTD removal and attachment of anionic lipopolysaccharide for anchorage in the outer membrane. The crystal structure of PorZ revealed two β-propeller domains and a C-terminal β-sandwich domain, which conforms to the canonical CTD architecture. We further documented that PorZ is itself transported to the cell surface via T9SS as a full-length protein with its CTD intact, independently of the presence or activity of PorU. Taken together, our results shed light on the architecture and possible function of a novel component of the T9SS. Knowledge of how T9SS operates will contribute to our understanding of protein secretion as part of host-microbiome interactions by dysbiotic members of the human oral cavity. PMID:27883039

The enhanced immune responses induced by Salmonella enteritidis ghosts loaded with Neisseria gonorrhoeae porB against Salmonella in mice.

PubMed

Jiao, Hongmei; Yang, Hui; Zhao, Dan; He, Li; Chen, Jin; Li, Guocai

2016-11-01

Human health has been seriously endangered by highly prevalent salmonellosis and multidrug-resistant Salmonella strains. Current vaccines suffer from variable immune-protective effects, so more effective ones are needed to control Salmonella infection : Bacterial ghosts have been produced by the expression of lysis gene E from bacteriophage PhiX174 and can be filled with considerable exogenous substances such as DNA or drugs as a novel platform. In this study, Salmonella enteritidis (SE) ghosts were developed and loaded with Neisseria gonorrhoeae porin B (porB) to construct a novel inactive vaccine. Our new studies show that SE ghosts loaded with porB displayed increased production of pro-inflammatory cytokines (IL-1β, IL-6, IL-10 and IL-12p70) in bone marrow-derived dendritic cells (BMDCs), and elicited significantly higher specific systemic and mucosal immune responses to Salmonella than SE ghosts alone. In addition, the novel porB-loaded ghosts conferred higher protective effects on virulent Salmonella challenge. For the first time, we demonstrate that N. gonorrhoeae porB, as a novel adjuvant, can increase the immunogenicity of SE ghosts. Our studies suggested that Salmonella enteritidis ghosts loaded with Neisseria gonorrhoeae porin B might be a useful mucosal Salmonella vaccine candidate for practical use in the future. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Survival of two enterobacteria in feces buried in soil under field conditions.

PubMed Central

Temple, K L; Camper, A K; McFeters, G A

1980-01-01

Feces samples, inoculated with 10(6) Escherichia coli resistant to streptomycin and nalidixic acid and with 10(5) Salmonella typhimurium per g, were buried at five mountain field sites ranging from 2,005 to 2,730 m in elevation. Counts of each bacterium rose initially and then declined to 10(3) or 10(4) per g of feces in 8 weeks. The survival pattern was similar at all sites regardless of marked differences in elevation, soil, moisture, exposure, and vegetation. S. typhimurium numbers were consistently higher than E. coli numbers after week 3. The test encompassed most of the time that the area is snow-free and accessible for hiking. The results were judged to discredit the recommendation for shallow burial of feces and to indicate a potential health hazard under intensive use. PMID:6999999

Diagnóstico diferencial en la encefalitis por anticuerpos contra el receptor NMDA

PubMed Central

González-Valcárcel, J.; Rosenfeld, M.R.; Dalmau, J.

2011-01-01

Resumen Introducción La encefalitis por anticuerpos contra el receptor de NMDA (NMDAR) suele desarrollarse como un síndrome característico de evolución multifásica y diagnóstico diferencial amplio. Pacientes Presentamos a 2 pacientes diagnosticadas de encefalitis por anticuerpos NMDAR con un cuadro clínico típico, pero que inicialmente señaló otras etiologías. Discusión La afectación frecuente de pacientes jóvenes con manifestaciones psiquiátricas prominentes indica frecuentemente otras consideraciones diagnósticas; las más frecuentes son las encefalitis virales, los procesos psiquiátricos y el síndrome neuroléptico maligno. Varios síndromes previamente definidos de manera parcial o descriptiva en adultos y pacientes pediátricos probablemente eran casos de encefalitis anti-NMDAR. Conclusiones La encefalitis anti-NMDAR debe considerarse en pacientes jóvenes con manifestaciones psiquiátricas subagudas, movimientos anormales y alteraciones autonómicas. La caracterización clínica e inmunológica de esta enfermedad ha llevado a la identificación de nuevos anticuerpos que afectan a procesos de memoria, aprendizaje, conducta y psicosis. PMID:20964986

Reconstrução tridimensional de arcos magnéticos por tomografia

NASA Astrophysics Data System (ADS)

Simões, P. J. A.; Costa, J. E. R.

2003-08-01

Uma explosão solar é uma variação súbita do brilho que ocorre nas regiões ativas da atmosfera solar. Estas regiões são constituídas por um plasma magnetizado com intensa indução magnética e em cenários bem complexos como visto recentemente através de experimentos embarcados em satélites operando instrumentos em raios X moles e ultra-violeta distante. A energia magnética, que pode ser armazenada por um período de horas até dias em configurações magnéticas estressadas, é subitamente lançada na atmosfera solar e transferida para partículas como elétrons, prótons e núcleos pesados, que são acelerados e/ou aquecidos, produzindo radiação eletromagnética. A proposta final deste projeto é determinar as características espaciais de alta resolução da emissão e polarização girossincrotrônica de explosões solares em ambientes complexos de campos magnéticos. Os recentes resultados da emissão difusa em EUV apresentado pelos satélites TRACE e SOHO dos arcos magnéticos conectando as diferentes polaridades magnéticas sobre as regiões ativas possibilitam novas abordagens sobre o papel do campo magnético na emissão em rádio. Nesta etapa apresentamos os resultados da reconstrução da geometria tridimensional das linhas de força destes arcos utilizando técnicas tomográficas, a partir de imagens de alta resolução espacial obtidas pelo instrumento EIT (Extreme ultraviolet Imaging Telescope), além da modelagem das induções magnéticas por um campo dipolar e as densidades de partículas aceleradas. Utilizamos para a reconstrução geométrica, imagens tomadas em vários ângulos dos arcos devido à rotacão solar. Com estes resultados, daremos continuidade ao projeto, com os cálculos da transferência radiativa nos modos ordinário e extraordinário de propagação da radiação girossincrotrônica de explosões solares.

The Acquisition of Lexical Meaning in a Study Abroad Context: The Spanish Prepositions "por" and "para."

ERIC Educational Resources Information Center

Lafford, Barbara A.; Ryan, John M.

1995-01-01

Examination of the development of form/function relations of the prepositions "por" and "para" at different levels of proficiency in the interlanguage of study-abroad students in Granada, Spain, revealed "noncanonical" as well as "canonical" uses of these prepositions. The most common noncanonical uses were…

Characterization of the RcsC sensor kinase from Erwinia amylovora and other enterobacteria

USDA-ARS?s Scientific Manuscript database

RcsC is a hybrid sensor kinase which contains a sensor domain, a histidine kinase domain and a receiver domain. We have previously demonstrated that, while the Erwinia amylovora rcsC mutant produces more amylovoran than the wild type strain in vitro, the mutant remains avirulent on both immature pea...

Improved purification of native meningococcal porin PorB and studies on its structure/function.

PubMed

Massari, Paola; King, Carol A; MacLeod, Heather; Wetzler, Lee M

2005-12-01

The outer membrane protein PorB of Neisseria meningitidis is a pore-forming protein which has various effects on eukaryotic cells. It has been shown to (1) up-regulate the surface expression of the co-stimulatory molecule CD86 and of MHC class II (which are TLR2/MyD88 dependent and related to the porin's immune-potentiating ability), (2) be involved in prevention of apoptosis by modulating the mitochondrial membrane potential, and (3) form pores in eukaryotic cells. As an outer membrane protein, its native trimeric form isolation is complicated by its insoluble nature, requiring the presence of detergent throughout the whole procedure, and by its tight association with other outer membrane components, such as neisserial LOS or lipoproteins. In this study, an improved chromatographic purification method to obtain an homogeneous product free of endotoxin and lipoprotein is described, without loss of any of the above-mentioned properties of the porin. Furthermore, we have investigated the requirement of the native trimeric structure for the porin's activity. Inactivation of functional PorB trimers into non-functional monomers was achieved by incubation on ice. Thus, routine long- and medium-term storage at low temperature may be a cause of porin inactivation.

[A Listeria breast abscess in a man].

PubMed

Marsaudon, E; Berthy, J; Mamoune, S; Deniel, A; Ksiyer, S; Tiuca, D

2018-03-01

Listeriosis is a food-borne illness leading to bacteriemia or central nervous system infection especially in pregnant women or high-risk patients. It is rarely a localized infection. Breast contamination has rarely been reported in lactating women. We report a breast abscess in man. A 80 year old man, hypertensive and arrhythmic, was explored for weakness and dehydration. Type 2 diabetes and chronic lymphocytic leukemia were diagnosed. Clinical examination disclosed a breast abcess related to L monocytogenes infection. Histopathological study also revealed a breast subcutaneous infiltration by chronic lymphocytic leukemia. Listeriosis sometimes uncover an unknown immunosuppression, especially in the elderly. Breast is a non-sterile tissue containing a stable microbiome partly from digestive origin. It can thereby be contaminated by Listeria. The specific cutaneous infiltrate of chronic lymphocytic leukemia can create the conditions for a local infection. Copyright © 2017 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

[Bartonella henselae, an ubiquitous agent of proteiform zoonotic disease].

PubMed

Edouard, S; Raoult, D

2010-06-01

Bartonella henselae is the causative agent of cat scratch disease, a human infection usually characterized by persistent regional lymphadenopathy. It is transmitted to humans by cat scratches or bites. Cats are the major reservoir for this bacterium thus B. henselae has a worldwide distribution. The bacterial pathogenicity may bay emphasized by the immune status of the infected host. Angiomatosis or hepatic peliosis are the most frequent clinical manifestations in immunocompromised patients. B. henselae is also responsible for endocarditis in patients with valvular diseases, and may induce various clinical presentations such as: bacteriemia, retinitis, musculoskeletal disorders, hepatic or splenic diseases, encephalitis, or myocarditis. Several diagnostic tools are available; they may be combined and adapted to every clinical setting. B. henselae is a fastidious bacterium; its diagnosis is mainly made by PCR and blood tests. No treatment is required for the benign form of cat scratch disease. For more severe clinical presentations, the treatment must be adapted to every clinical presentation.

[18F-FDG PET/CT diagnosis of liver cyst infection in a patient with autosomal dominant polycystic kidney disease and fever of unknown origin].

PubMed

Banzo, J; Ubieto, M A; Gil, D; Prats, E; Razola, P; Tardín, L; Andrés, A; Rambalde, E F; Ayala, S M; Cáncer, L; Velilla, J

2013-01-01

The diagnosis, localization and treatment of infected cysts in the kidney or liver of patients with autosomal dominant polycystic kidney disease (ADPKD) remain a clinical challenge. We report the findings of (18)F-FDG PET-CT in an ADPKD diagnosed patient who required renal transplantation five years before and in his follow up presented repeated episodes of bacteriemia without known focus on radiological tests performed. The (18)F-FDG PET-CT scan showed numerous hypermetabolic images with focal or ring-shaped morphology related to the content and the wall of some hepatic cysts. The increased metabolic activity was localized on segments VI and VII. We proceeded to drainage of one cyst in segment VI, removing 110 cc of purulent fluid which grew E. Coli BLEE. The (18)F-FDG PET/CT scan should be included in the diagnostic algorithm for detecting infected liver cysts in patients with ADPKD and fever of unknown origin. Copyright © 2012 Elsevier España, S.L. and SEMNIM. All rights reserved.

[Isolation of anaerobes during a 30-month observation at a hospital microbiology laboratory].

PubMed

Pistono, P G; Rapetti, I; Stacchini, E; Vironda, N; D'Usi, M P; Guasco, C

1989-01-01

The authors evaluate retrospectively the results obtained from the research of anaerobial bacteria on 1313 samples received at the Microbiology Laboratory of the "Ospedale Civile di Ivrea" over a period of 31 months (6/1/86-12/31/88). From this evaluation, high percentages of detection of anaerobic bacteria are emerging in the following infections: appendiculare abscesses (60%), intestinal operations (71%), wounds (57%), tubovarian abscesses (100%), as well as thoracic empyema (50%). Also relevant are the isolations from skin and subcutaneous tissues: breast infections (50%) preputial infections (60%), perineal and perirectal abscesses (60%). The incident of anaerobic bacteria in bacteriemia is 17%. The most representative anaerobic bacteria group are: Bacteroides spp. (56%), Peptostreptococcus spp. (12%), Propionibacterium spp. (9%), Fusobacterium spp. (7%) Clostridium spp. (6%), Veillonella spp. and Eubacterium spp. (3%). In the intraabdominal infections prevails the Bacteroides group, particularly fragilis species, while in the skin and subcutaneous infections prevails the Peptostreptococcus group.

Adjuvant Effects Elicited by Novel Oligosaccharide Variants of Detoxified Meningococcal Lipopolysaccharides on Neisseria meningitidis Recombinant PorA Protein: A Comparison in Mice

PubMed Central

Mehta, Ojas H.; Norheim, Gunnstein; Hoe, J . Claire; Rollier, Christine S.; Nagaputra, Jerry C.; Makepeace, Katherine; Saleem, Muhammad; Chan, Hannah; Ferguson, David J. P.; Jones, Claire; Sadarangani, Manish; Hood, Derek W.; Feavers, Ian; Derrick, Jeremy P.; Pollard, Andrew J.; Moxon, E . Richard

2014-01-01

Neisseria meningitidis lipopolysaccharide (LPS) has adjuvant properties that can be exploited to assist vaccine immunogenicity. The modified penta-acylated LPS retains the adjuvant properties of hexa-acylated LPS but has a reduced toxicity profile. In this study we investigated whether two modified glycoform structures (LgtE and IcsB) of detoxified penta-acylated LPS exhibited differential adjuvant properties when formulated as native outer membrane vesicles (nOMVs) as compared to the previously described LgtB variant. Detoxified penta-acylated LPS was obtained by disruption of the lpxL1 gene (LpxL1 LPS), and three different glycoforms were obtained by disruption of the lgtB, lgtE or icsB genes respectively. Mice (mus musculus) were immunized with a recombinant PorA P1.7-2,4 (rPorA) protein co-administered with different nOMVs (containing a different PorA serosubtype P1.7,16), each of which expressed one of the three penta-acylated LPS glycoforms. All nOMVs induced IgG responses against the rPorA, but the nOMVs containing the penta-acylated LgtB-LpxL1 LPS glycoform induced significantly greater bactericidal activity compared to the other nOMVs or when the adjuvant was Alhydrogel. Compared to LgtE or IcsB LPS glycoforms, these data support the use of nOMVs containing detoxified, modified LgtB-LpxL1 LPS as a potential adjuvant for future meningococcal protein vaccines. PMID:25545241

CTX-M-producing Escherichia coli in a maternity ward: a likely community importation and evidence of mother-to-neonate transmission.

PubMed

Dubois, Véronique; De Barbeyrac, Bertille; Rogues, Anne-Marie; Arpin, Corinne; Coulange, Laure; Andre, Catherine; M'zali, Fatima; Megraud, Francis; Quentin, Claudine

2010-07-01

To investigate the high prevalence of extended-spectrum beta-lactamase (ESBL)-producing strains of Escherichia coli (4%, 10/250 consecutive isolates) recovered during a 5 month period in the maternity ward of the University Hospital of Bordeaux, France. beta-Lactam resistance transfer was analysed by conjugation and transformation. ESBLs were characterized by isoelectric focusing, PCR amplification and sequencing. The relatedness of the strains was examined by PFGE and phylogenetic group determination. Plasmids were characterized by incompatibility group and restriction analysis. Ten ESBL-producing E. coli were isolated from urinary or genital samples of eight mothers and from gastric fluids of two newborns of carrier mothers. The patients were hospitalized in five different units of the maternity ward. Transconjugants, obtained for 7 of the 10 strains, and wild-type strains exhibited various antibiotypes. Different CTX-M enzymes were characterized: CTX-M-1 (n = 4); CTX-M-14 (n = 3); CTX-M-32 (n = 2); and CTX-M-28 (n = 1). The strains recovered from two mothers and their respective babies were identical. All the other strains were epidemiologically unrelated. Furthermore, various plasmids were identified. Environmental samples from the common echographic and sampling rooms did not reveal the presence of ESBL-producing enterobacteria. The data argue against the occurrence of a nosocomial outbreak and support the hypothesis of an importation of community-acquired ESBL-producing strains into the hospital through colonized/infected patients. At present, not only patients transferred from other hospitals or long-term care facilities are at risk of carrying ESBL-producing enterobacteria on hospital admission, but also community patients.

[Emergence of CMY-2-type plasmid-mediated AmpC β-lactamase in Shigella sonnei and Salmonella spp. in Costa Rica, 2003-2015].

PubMed

Ayala, Anamariela Tijerino; Acuña, Hilda María Bolaños; Calvo, María Teresa Acuña; Morales, José Luis Vargas; Chacón, Elena Campos

2016-08-01

Plasmid-mediated AmpC are enzymes belonging to the group of β-lactamases and encoded by bla AmpC genes. Of these enzymes, those known as type CMY-2 are the most frequently reported worldwide. Detection of enterobacteria that produce CMY-2-type plasmid-mediated AmpC is clinically important since the use of β-lactam antibiotics can result in treatment failure. It is also important from a public health standpoint owing to the capacity for conjugative plasmid transfer to other enterobacteria, both within the community and in nosocomial environments. Thus, bacteria of this kind are considered to have clear epidemic potential. To investigate the circulation of this resistance mechanism among Salmonella and Shigella isolates in Costa Rica, from January 2003 to May 2015 we carried out a retrospective review of the data contained in the laboratory surveillance databases of the National Reference Bacteriology Center (CNRB) of the Costa Rican Nutrition and Health Research Institute (Inciensa). Over this period, 4363 Shigella isolates and 1785 Salmonella isolates were examined. Among them, 15 Shigella sonnei isolates and nine Salmonella isolates (four from human clinical specimens and five of avian origin) displayed a phenotype suspected of carrying plasmid-mediated AmpC. Polymerase chain reaction confirmed that all these isolates belong to type CMY-2. In light of these results, we recommend that the microbiology laboratories in the national network continue to conduct surveillance and confirm any suspicious isolates using phenotypic and molecular methods. This is particularly relevant when dealing with bacterial isolates from extraintestinal infections so as to prevent treatment failure.

Role and Regulation of the Flp/Tad Pilus in the Virulence of Pectobacterium atrosepticum SCRI1043 and Pectobacterium wasabiae SCC3193

PubMed Central

Nykyri, Johanna; Mattinen, Laura; Niemi, Outi; Adhikari, Satish; Kõiv, Viia; Somervuo, Panu; Fang, Xin; Auvinen, Petri; Mäe, Andres; Palva, E. Tapio; Pirhonen, Minna

2013-01-01

In this study, we characterized a putative Flp/Tad pilus-encoding gene cluster, and we examined its regulation at the transcriptional level and its role in the virulence of potato pathogenic enterobacteria of the genus Pectobacterium. The Flp/Tad pilus-encoding gene clusters in Pectobacterium atrosepticum, Pectobacterium wasabiae and Pectobacterium aroidearum were compared to previously characterized flp/tad gene clusters, including that of the well-studied Flp/Tad pilus model organism Aggregatibacter actinomycetemcomitans, in which this pilus is a major virulence determinant. Comparative analyses revealed substantial protein sequence similarity and open reading frame synteny between the previously characterized flp/tad gene clusters and the cluster in Pectobacterium, suggesting that the predicted flp/tad gene cluster in Pectobacterium encodes a Flp/Tad pilus-like structure. We detected genes for a novel two-component system adjacent to the flp/tad gene cluster in Pectobacterium, and mutant analysis demonstrated that this system has a positive effect on the transcription of selected Flp/Tad pilus biogenesis genes, suggesting that this response regulator regulate the flp/tad gene cluster. Mutagenesis of either the predicted regulator gene or selected Flp/Tad pilus biogenesis genes had a significant impact on the maceration ability of the bacterial strains in potato tubers, indicating that the Flp/Tad pilus-encoding gene cluster represents a novel virulence determinant in Pectobacterium. Soft-rot enterobacteria in the genera Pectobacterium and Dickeya are of great agricultural importance, and an investigation of the virulence of these pathogens could facilitate improvements in agricultural practices, thus benefiting farmers, the potato industry and consumers. PMID:24040039

Role and regulation of the Flp/Tad pilus in the virulence of Pectobacterium atrosepticum SCRI1043 and Pectobacterium wasabiae SCC3193.

PubMed

Nykyri, Johanna; Mattinen, Laura; Niemi, Outi; Adhikari, Satish; Kõiv, Viia; Somervuo, Panu; Fang, Xin; Auvinen, Petri; Mäe, Andres; Palva, E Tapio; Pirhonen, Minna

2013-01-01

In this study, we characterized a putative Flp/Tad pilus-encoding gene cluster, and we examined its regulation at the transcriptional level and its role in the virulence of potato pathogenic enterobacteria of the genus Pectobacterium. The Flp/Tad pilus-encoding gene clusters in Pectobacterium atrosepticum, Pectobacterium wasabiae and Pectobacterium aroidearum were compared to previously characterized flp/tad gene clusters, including that of the well-studied Flp/Tad pilus model organism Aggregatibacter actinomycetemcomitans, in which this pilus is a major virulence determinant. Comparative analyses revealed substantial protein sequence similarity and open reading frame synteny between the previously characterized flp/tad gene clusters and the cluster in Pectobacterium, suggesting that the predicted flp/tad gene cluster in Pectobacterium encodes a Flp/Tad pilus-like structure. We detected genes for a novel two-component system adjacent to the flp/tad gene cluster in Pectobacterium, and mutant analysis demonstrated that this system has a positive effect on the transcription of selected Flp/Tad pilus biogenesis genes, suggesting that this response regulator regulate the flp/tad gene cluster. Mutagenesis of either the predicted regulator gene or selected Flp/Tad pilus biogenesis genes had a significant impact on the maceration ability of the bacterial strains in potato tubers, indicating that the Flp/Tad pilus-encoding gene cluster represents a novel virulence determinant in Pectobacterium. Soft-rot enterobacteria in the genera Pectobacterium and Dickeya are of great agricultural importance, and an investigation of the virulence of these pathogens could facilitate improvements in agricultural practices, thus benefiting farmers, the potato industry and consumers.

Global Microlending in Education Reform: Enseñá Por Argentina and the Neoliberalization of the Grassroots

ERIC Educational Resources Information Center

Friedrich, Daniel S.

2010-01-01

This article examines the workings and underlying assumptions behind Enseñá por Argentina (Teach for Argentina), one specific program that takes part in the larger and expanding network of Teach for All, by thinking about the ways in which a global push for redefining teaching and teacher education encounters local characteristics and histories,…

Concepciones y concepciones alternativas de estudiantes universitarios/as de biologia y futuros maestros/as de Ciencia de escuela secundaria sobre la teoria de evolucion biologica por seleccion natural

NASA Astrophysics Data System (ADS)

Morales Ramos, Egda M.

La teoria de evolucion biologica (TEB) por seleccion natural es uno de los conceptos unificadores mas importantes del curriculo de Biologia. En Puerto Rico se han hecho pocas investigaciones que abunden sobre las concepciones y concepciones alternativas (CA) que tienen los estudiantes universitarios/as de Biologia y los maestros/as de Ciencia del nivel secundario sobre esta teoria. La politica publica educativa actual establece mediante documentos normativos como los Estandares de contenido y Expectativas de grado del Programa de Ciencias [Puerto Rico Core Standards] la ensenanza de esta teoria. Sin embargo, no se encontraron preguntas sobre la seleccion natural en los ejercicios de practica provistos por el Departamento de Educacion para las pruebas estandarizadas lo cual puede influir para que no se ensene adecuadamente. Las preguntas de investigacion fueron 1. ¿Cuales son las concepciones y concepciones alternativas de estudiantes universitarios/as y de los futuros maestros y maestras de Ciencia sobre la TEB? 2. ¿Cuales conceptos que seleccionan los estudiantes universitarios/as y los futuros maestros y maestras de Ciencia sobre la TEB coinciden con lo aceptado como valido por la comunidad cientifica? y 3. ¿Como comparan las respuestas de la prueba original. v. Entendiendo el cambio biologico que mide concepciones y CA sobre la TEB por seleccion natural, con las de la traducida al idioma espanol? Se utilizo el metodo cuantitativo con un diseno de investigacion transversal por encuesta. La tecnica principal para recopilar los datos fue una prueba con doce items, que formo parte de un instrumento para el cual se recopilaron diversas fuentes de evidencia acerca de su validez. Las muestras estuvieron formadas por 69 estudiantes de Ciencias Naturales y por 16 estudiantes futuros maestros y maestras del nivel secundario de la UPR-RP. Se utilizaron estadisticas descriptivas, analisis de Ji cuadrado y se calcularon los coeficientes alfa de Cronbach y de Spearman

Culture-independent quantification of physiologically-active microbial groups in fermented foods using rRNA-targeted oligonucleotide probes: application to pozol, a Mexican lactic acid fermented maize dough.

PubMed

Ampe, F; ben Omar, N; Guyot, J P

1999-07-01

Nine phylogenetic oligonucleotide probes were used to describe at the genus level the microbial community responsible for the spontaneous fermentation of maize, leading to the production of Mexican pozol. Ribosomal RNAs of specific groups and genera, in particular, lactic acid bacteria, were quantified using a culture-independent approach. In the early stage of the fermentation, Lactococcus and Leuconostoc appeared to be the dominant genera. A contrario, these represented minor genera at the end of the fermentation when Lactobacillus dominated the process. In addition, eukaryotes seemed to play a significant role throughout the fermentation and enterobacteria could be detected by this method.

[Scombroid syndrome with severe and prolonged cardiovascular involvement].

PubMed

Tursi, A; Modeo, M E; Cascella, A M; Cuccorese, G; Spinazzola, A M; Miglietta, A

2001-09-01

Scombroid poisoning is a form of ichthyosarcotoxism caused by eating spoiled fish, mainly of the scombroid family. Inappropriate storage of these fish can lead to the decarboxylation of histidine in the flesh to histamine by enterobacteria. The symptoms of histamine poisoning mimic those of an IgE-mediated food allergy, as well as flushing, headache, diarrhea and palpitations. However, in some cases, the scombroid poisoning can be characterized by very serious symptoms, as well as cardiovascular compromission. We describe two cases of scombroid poisoning with severe hypotension requiring continuous intravenous dopamine with resolution of symptoms only several hours later.

[Urinary tract infection caused by Enterobacteriaceae and its relationship with vesicoureteral reflux].

PubMed

Díaz Álvarez, Manuel; Acosta Batista, Bárbara; Pérez Córdova, Rodolfo; Hernández Robledo, Ernesto

The first urinary tract infection can be a marker of a urinary tract anomaly, mainly vesicoureteral reflux. The aim of this work was to determine the association between isolated enterobacteria with the presence and grade of vesicoureteral reflux in neonatal patients with their first urinary tract infection. A retrospective, observational and analytic study of newborns, who were admitted to the Neonatal Department, University Pediatric Hospital "Juan Manuel Márquez," in Havana, Cuba, from 1992 to 2013 was conducted. The causal microorganism of urinary tract infection was from the Enterobacteriaceae family. They were evaluated by radio imaging. The association between the presence and grade of vesicoureteral reflux with the causal microorganism of the urinary tract infection was analyzed. Newborn infants with urinary tract infection (450) were studied. Bacterial isolations in the urine cultures corresponded to E. coli in 316 cases (70.2%). The prevalence of vesicoureteral reflux was 18.2%. The presence of bacteria corresponding to the Enterobacteriaceae family (other than E. coli) had significant risk association with vesicoureteral reflux (OR: 2.02; p < 0.01) and vesicoureteral reflux classification (for higher grades, p < 0.01). E. coli is the most frequent causal microorganism in neonatal urinary tract infection. However, an association between the isolation of a microorganism of the Enterobacteriaceae family different to E. coli with the presence of vesicoureteral reflux and mainly with higher grades of vesicoureteral reflux exists. Copyright © 2017 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

Pincharse sin infectarse: estrategias para prevenir la infección por el VIH y el VHC entre usuarios de drogas inyectables

PubMed Central

MATEU-GELABERT, P.; FRIEDMAN, S.; SANDOVAL, M.

2011-01-01

Resumen Objetivo Desde principios de los noventa, en la ciudad de Nueva York se han implementado con éxito programas para reducir la incidencia del virus de la inmunodeficiencia humana (VIH) y, en menor medida, del virus de la hepatitis C (VHC). A pesar de ello, aproximadamente el 70% de los usuario de drogas inyectables (UDI) están infectados por el VHC. Queremos investigar cómo el 30% restante se las ha arreglado para no infectarse. El Staying safe (nombre original del estudio) explora los comportamientos y mecanismos que ayudan a evitar la infección por el VHC y el VIH a largo plazo. Material y métodos Hemos utilizado el concepto de «desviación positiva» aplicado en otros campos de salud pública. Estudiamos las estrategias, prácticas y tácticas de prevención de aquellos UDI que, viviendo en contextos de alta prevalencia, se mantienen sin infectar por VIH y el VHC, a pesar de haberse inyectado heroína durante años. Los resultados preliminares presentados en este artículo incluyen el análisis de las entrevistas realizadas a 25 UDI (17 doble negativos, 3 doble positivos y 5 con infección por el VHC y sin infección por el VIH). Se usaron entrevistas semiestructuradas que exploraban con detalle la historia de vida de los sujetos, incluyendo su consumo de drogas, redes sociales, contacto con instituciones, relaciones sexuales y estrategias de protección y vigilancia. Resultados La intencionalidad es importante para no infectarse, especialmente durante períodos de involución (períodos donde hay un deterioro económico y/o social que llevan al que se inyecta a situaciones de mayor riesgo). Presentamos tres dimensiones independientes de intencionalidad que conllevan comportamientos que pueden ayudar a prevenir la infección: a) evitar «el mono» (síntomas de abstención) asegurando el acceso a la droga; b) «llevarlo bien» para no convertirse en un junkie y así evitar la «muerte social» y la falta de acceso a los recursos, y c) seguir sin

[Microbiología, sensibilidad antibiótica y factores asociados a bacteriemia en la prostatitis aguda].

PubMed

Ferré, C; Llopis, F; Jacob, J

2016-08-01

The aim of the study was to analyze the characteristics of patients with acute prostatitis presenting to the Emergency Department, the microbiological findings, antibiotic susceptibility, and bacteraemia associated factors. Observational and cohort study with prospective follow-up including patients with acute prostatitis presenting to the Emergency Department from January-December 2012. Data were collected for demographic variables, comorbidities, microbiological findings, antibiotic treatment and outcome. Two hundred and forty one episodes of acute prostatitis were included. Mean age was 62.9 ± 16 years, a history of prostate adenoma was reported in 54 cases (22.5%) and prior manipulation of the lower urinary tract in 40 (17%). Mean symptoms duration was 3.38 ± 4.04 days, voiding symptoms were present in 176 cases (73%) and fever in 154 (64%). Seventy patients (29%) were admitted to the hospital and 3 died. From 216 urine cultures, 128 were positive (59%) and 24 (17.6%) out of 136 blood cultures. Escherichia coli was the main pathogen (58.6% of urine cultures and 64% of blood cultures) with resistant strains to fluoroquinolones, cotrimoxazole and amoxicillin/clavulanic in 27.7%, 22.9% and 27.7% of cases respectively. In the univariate analysis, only chills were associated to bacteraemia (p=0.013). At 30-day follow-up, patients with bacteraemia returned more frequently to the Emergency Department (p=0.037) and were more often admitted to the hospital (p=0.003). Patients with acute prostatitis discharged from the Emergency Department need clinical follow-up and monitoring of microbiological findings in order to assure an adequate antibiotic treatment. Return to Emergency Department and admission to the hospital were significantly more frequent among patients with bacteraemia.

Acceptance test report for portable exhauster POR-007/Skid E

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kriskovich, J.R.

1998-07-24

This document describes Acceptance Testing performed on Portable Exhauster POR-007/Skid E. It includes measurements of bearing vibration levels, pressure decay testing, programmable logic controller interlocks, high vacuum, flow and pressure control functional testing. The purpose of Acceptance testing documented by this report was to demonstrate compliance of the exhausters with the performance criteria established within HNF-0490, Rev. 1 following a repair and upgrade effort at Hanford. In addition, data obtained during this testing is required for the resolution of outstanding Non-conformance Reports (NCR), and finally, to demonstrate the functionality of the associated software for the pressure control and high vacuummore » exhauster operating modes provided for by W-320. Additional testing not required by the ATP was also performed to assist in the disposition and close out of receiving inspection report and for application design information (system curve). Results of this testing are also captured within this document.« less

Carriage by the housefly (Musca domestica) of multiple-antibiotic-resistant bacteria that are potentially pathogenic to humans, in hospital and other urban environments in Misurata, Libya.

PubMed

Rahuma, N; Ghenghesh, K S; Ben Aissa, R; Elamaari, A

2005-12-01

Using standard microbiological procedures, bacteria that are potentially pathogenic to humans were isolated from 150 houseflies collected in the Libyan city of Misurata (50 flies each from the Central Hospital, streets and abattoir). Salmonella spp., Yersinia enterocolitica and Edwardsiella tarda were isolated from flies collected on the streets and in the abattoir but not from those collected in the hospital. Shigella sonnei was detected in just one fly, which was collected in the abattoir. Of the flies collected in the hospital, streets and abattor, 42%, 42% and 32% were positive for Escherichia coli, 70%, 50% and 62% for Klebsiella spp., 2%, 20% and 10% for Aeromonas spp., 96%, 36% and 34% for Pseudomonas spp., 20%, 12% and 16% for Staphylococcus spp., and 24%, 22% and 18% for Streptococcus spp., respectively. When the antibiotic susceptibilities of the fly isolates were investigated, the Enterobacteria isolated from the houseflies collected in the hospital were found to be resistant to significantly more of the commonly used antibiotics that were tested than the Enterobacteria isolated from the flies caught in the streets or abattoir. Whatever the source of the flies from which they were collected, the Pseudomonas isolates frequently showed resistance to multiple antibiotics, with >50% each being resistant to at least 10 antimicrobial agents. Two isolates of Sta. aureus (both from flies collected in the hospital) were resistant to methicillin. The present study supports the belief that the housefly is a potential vector of multiple-antibiotic-resistant, pathogenic bacteria, including methicillin-resistant Sta. aureus, in the hospital environment. Given their mobility, it seems likely that houseflies carry such pathogens from hospitals to surrounding communities, and vice versa.

[Dynamics of enterobacterial multiplication in a mouse model of intraperitoneal infection in the presence of iron cations as dependent on the availability and type of K antigens].

PubMed

Petrovskaia, V G; Nastichkin, I A; Lycheva, T A

1983-09-01

In this work the results of research on the influence of iron cations on the characteristics of the infectious process caused by different enterobacteria (Shigella sonnei, Shigella flexneri, Escherichia coli) are analyzed. In the experimental intraperitoneal infection of mice in the presence of saccharose and iron cations S. sonnei in phase I showed the decrease of 1g LD50 by 3-4 orders, while S. flexneri in the S-form, by not more than 1 order. The absence of correlation between the virulence of the Shigella species used for comparison, as determined in the keratoconjunctival test, and their behavior in vitro in the presence of iron was revealed. E. coli reference strains synthetizing (according to the nomenclature of I. Orskov et al.) "true" K-antigens (K1, K10) or "not true" ones (K8, K9, K27, K57) also showed different virulence in the experimental infection used in this research: the behavior of the former group corresponded to that of S. sonnei in phase I, the latter group occupied the intermediate position between the former group and S. sonnei on one hand and S. flexneri on the other hand. The sharp drop of 1g LD50 after the injection of S. sonnei in phase I in combination with iron cations can be attributed to differences in the characteristics of bacterial surface structures with antiphagocytic function and indicates that the species-specific antigen of S. sonnei in phase I should be classified with K-antigens. The experimental intraperitoneal infection of mice in the presence of trivalent iron cations can be used for making a tentative judgement on the presence of K-antigens in enterobacteria.

Periodontal-disease-associated biofilm: A reservoir for pathogens of medical importance.

PubMed

Vieira Colombo, Ana Paula; Magalhães, Clarissa Bichara; Hartenbach, Fátima Aparecida Rocha Resende; Martins do Souto, Renata; Maciel da Silva-Boghossian, Carina

2016-05-01

The ecological diversity of the periodontal microenvironment may provide suitable conditions for the colonization of species not usually considered members of the oral microbiota. In this investigation, we aimed to determine the prevalence and levels of pathogenic species of medical relevance in the microbiota of individuals with distinct periodontal clinical status. Subgingival biofilm was obtained from patients with periodontal health (H, n = 81), gingivitis (G, n = 55), generalized aggressive (AgP, n = 36) or chronic periodontitis (CP, n = 98), and analyzed for 39 microbial taxa using a checkerboard DNA-DNA hybridization technique. Microbial differences among groups, as well as associations between clinical and microbiological parameters were sought by non-parametric and univariate correlation tests. Neisseria spp., Peptostreptococus anaerobius, Candida albicans, enterobacteria, Pseudomonas aeruginosa, Eubacterium saphenum, Clostridium difficile and Olsenella uli were detected in high mean prevalence and counts in the subgingival microbiota of the study population. Species that were more related to periodontal inflammation and tissue destruction at the patient and site levels included enterobacteria, C. albicans, Neisseria spp., P. aeruginosa, O. uli, Hafnia alvei, Serratia marcescens and Filifactor alocis (p < 0.05). In contrast, Fusobacterium necrophorum, Lactobacillus acidophilus, Staphylococcus aureus and Streptococcus pneumoniae were associated with periodontal health (p < 0.05). Pathogenic species of medical importance may be detected in high prevalence and levels in the periodontal microbiota. Regardless of their role in periodontal health or disease, the periodontal biofilm may be a source for dissemination and development of systemic infections by these pathogenic microorganisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

New insights about excisable pathogenicity islands in Salmonella and their contribution to virulence.

PubMed

Nieto, Pamela A; Pardo-Roa, Catalina; Salazar-Echegarai, Francisco J; Tobar, Hugo E; Coronado-Arrázola, Irenice; Riedel, Claudia A; Kalergis, Alexis M; Bueno, Susan M

2016-05-01

Pathogenicity islands (PAIs) are regions of the chromosome of pathogenic bacteria that harbor virulence genes, which were probably acquired by lateral gene transfer. Several PAIs can excise from the bacterial chromosome by site-specific recombination and in this review have been denominated "excisable PAIs". Here, the characteristic of some of the excisable PAIs from Salmonella enterica and the possible role and impact of the excision process on bacterial virulence is discussed. Understanding the role of PAI excision could provide important insights relative to the emergence, evolution and virulence of pathogenic enterobacteria. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Bacterial contamination of stored water and stored food: a potential source of diarrhoeal disease in West Africa.

PubMed Central

Mølbak, K.; Højlyng, N.; Jepsen, S.; Gaarslev, K.

1989-01-01

The food and water hygiene in two Liberian communities was studied in a house-to-house diarrhoea survey. The level of contamination with enterobacteria of drinking water stored in the households was significantly higher than at the water sources. Food hygiene standards were low, particularly in the urban slum where storage of cooked food for long periods led to bacterial multiplication at high levels. Infant foods were particularly heavily contaminated. It is concluded that when water supply programmes are planned, the presence of other risk factors for water-related diseases should be investigated. To ensure maximum health benefits, water projects should as a rule be accompanied by other interventions. PMID:2703024

Aspergillus spondylodiscitis after multivisceral transplantation.

PubMed

Gerlach, Undine A; Kohler, Sven; Sauer, Igor M; Joerres, Dinah; Kandziora, Frank; Neuhaus, Peter; Pratschke, Johann; Pascher, Andreas

2009-01-01

Although spondylodiscitis is rare, it is increasingly described in patients with compromised immunity due to malignancy, chemotherapy or immunosuppression. Typical pathogens are staphylococcus aureus and enterobacteria; fungal spondylodiscitis is uncommon. We present a case of aspergillus spondylodiscitis following pulmonary aspergillosis in a patient with multivisceral and kidney transplantation. Due to irreversible disc destruction, surgical restoration by autologous iliac crest graft was required in addition to intravenous antifungal therapy, which consisted of voriconazole, caspofungin and liposomal amphotericin B. Aspergillus spondylodiscitis is a diagnostic and therapeutic challenge, a combination of surgical debridement and antifungal therapy is inevitable to prevent rapid progression of invasive aspergillosis and neurological damage.

Study of the interaction mechanisms between absorbed NO{sub 2} and por-Si/SnO{sub x} nanocomposite layers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolotov, V. V.; Kan, V. E., E-mail: kan@obisp.oscsbras.ru; Makushenko, R. K.

2013-10-15

The interaction mechanisms between NO{sub 2} molecules and the surface of por-Si/SnO{sub x} nanocomposites obtained by magnetron deposition and chemical vapor deposition (CVD) are studied by infrared absorption spectroscopy and electron paramagnetic resonance methods. The observed increase in the free carrier concentration in the por-Si/SnO{sub x} nanocomposite layers is explained by a change in the charge state of P{sub b} centers due to the formation of neutral 'surface defect-adsorbed NO{sub 2} molecule' complexes with free carrier generation in the crystallite bulk. In the nanocomposite layers grown by the CVD method, the increase in the free hole concentration during NO{sub 2}more » adsorption is much less pronounced in comparison with the composite grown by magnetron deposition, which is caused by the competing interaction channel of NO{sub 2} molecules with electrically neutral P{sub b} centers.« less

Acceptance test report for portable exhauster POR-008/Skid F

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kriskovich, J.R.

1998-07-24

Portable Exhauster POR-008 was procured via HNF-0490, Specification for a Portable Exhausted System for Waste Tank Ventilation. Prior to taking ownership, acceptance testing was performed at the vendors. However at the conclusion of testing a number of issues remained that required resolution before the exhausters could be used by Project W-320. The purpose of acceptance testing documented by this report was to demonstrate compliance of the exhausters with the performance criteria established within HNF-O49O, Rev. 1 following a repair and upgrade effort at Hanford. In addition, data obtained during this testing is required for the resolution of outstanding Non-conformance Reportsmore » (NCR), and finally, to demonstrate the functionality of the associated software for the pressure control and high vacuum exhauster operating modes provided for by W-320. Additional testing not required by the ATP was also performed to assist in the disposition and close out of receiving inspection report and for application design information (system curve). Results of this testing are also captured within this document.« less

Análise dos Conceitos Astronômicos Apresentados por Professores de Algumas Escolas Estaduais Brasileiras

NASA Astrophysics Data System (ADS)

Voelzke, Marcos Rincon; Gonzaga, Edson Pereira

2011-12-01

A razão para o desenvolvimento deste trabalho baseia-se no fato de que muitos professores da Educação Básica (EB) não lidam com conceitos relacionados à astronomia, e quando o fazem eles simplesmente seguem livros didáticos que podem conter erros conceituais. Como é de conhecimento geral a astronomia é um dos conteúdos a serem ensinados na EB fazendo parte dos Parâmetros Curriculares Nacionais e das Propostas Curriculares do Estado de São Paulo, mas é um fato, que vários pesquisadores apontam, a existência de muitos problemas no ensino da astronomia. Com o propósito de minimizar algumas dessas deficiências foi realizado um trabalho de pesquisa com a utilização de questionários pré e pós pesquisa, para tanto foi desenvolvido um Curso de Extensão Universitária para professores da Diretoria de Ensino Regional (DE) que abrange Mauá, Ribeirão Pires e Rio Grande da Serra (no Estado de São Paulo) com os seguintes objetivos: levantar concepções alternativas; subsidiar os professores por meio de palestras, debates e workshops, e verificar o sucesso da aprendizagem após o curso, adotando-se como referência, para a análise dos resultados, os dicionários de Língua Portuguesa (FERREIRA, 2004) e Enciclopédico de Astronomia e Astronáutica (MOURĀO, 1995). Portanto, dezesseis questões foram aplicadas antes e após o curso, assim pode-se verificar após a pesquisa que 100,0% dos professores sabiam os nomes das fases da Lua, 97,0% entenderam que o Sistema Solar é composto por oito planetas, 78,1% foram capazes de explicar como ocorre um eclipse lunar, um eclipse solar e um solstício, 72,7% sabiam como explicar a ocorrência das estações do ano; 64,5% explicaram corretamente a ocorrência do equinócio, 89,7% foram capazes de definir adequadamente o termo cometa; 63,6% definiram asteróide, 54,5% meteoro, 58,1% galáxia, e 42,4% planeta. Os resultados obtidos indicam uma aprendizagem significativa por parte dos participantes.

[ON THE ORIGIN OF HYPERVIRULENCE OF THE CAUSATIVE AGENT OF PLAGUE].

PubMed

Anisimov, N V; Kislichkina, A A; Platonov, M E; Evseeva, V V; Kadnikova, L A; Lipatnikova, N A; Bogun, A G; Dentovskaya, S V; Anisimov, A P

2016-01-01

The attempt to combine Yersinia pseudotuberculosis and Yersinia pestis into one species has been unsupported by microbiologists due to the specific features of the epidemiology and clinical presentations of their induced diseases and to basic differences in their virulence. Pseudotuberculosis is predominantly a relatively mild human intestinal infection transmitted through contaminated food and plague is an acute generalized disease with high mortality, which is most frequently transmitted by the bites of infected fleas. Y. pestis hypervirulence, the ability of single bacteria to ensure the development of predagonal bacteriemia in rodents, which is sufficient to contaminate the fleas, is one of the main events during pathogen adaptation to a new ecological niche. By analyzing the data of molecular typing of the representative kits of naturally occurring Y. pestis isolates, the authois consider the issues of formation of intraspecies groups with universal hypervirulence, as well as biovars that are highly virulent only to their major host. A strategy for searching for selective virulence factors, the potential molecular targets for vaccination and etiotropic treatment of plague, is discussed.

Using the PORS Problems to Examine Evolutionary Optimization of Multiscale Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinhart, Zachary; Molian, Vaelan; Bryden, Kenneth

2013-01-01

Nearly all systems of practical interest are composed of parts assembled across multiple scales. For example, an agrodynamic system is composed of flora and fauna on one scale; soil types, slope, and water runoff on another scale; and management practice and yield on another scale. Or consider an advanced coal-fired power plant: combustion and pollutant formation occurs on one scale, the plant components on another scale, and the overall performance of the power system is measured on another. In spite of this, there are few practical tools for the optimization of multiscale systems. This paper examines multiscale optimization of systemsmore » composed of discrete elements using the plus-one-recall-store (PORS) problem as a test case or study problem for multiscale systems. From this study, it is found that by recognizing the constraints and patterns present in discrete multiscale systems, the solution time can be significantly reduced and much more complex problems can be optimized.« less

Characterization of AcrD, a resistance-nodulation-cell division-type multidrug efflux pump from the fire blight pathogen Erwinia amylovora.

PubMed

Pletzer, Daniel; Weingart, Helge

2014-01-21

Multidrug efflux pumps are membrane translocases that have the ability to extrude a variety of structurally unrelated compounds from the cell. AcrD, a resistance-nodulation-cell division (RND) transporter, was shown to be involved in efflux of highly hydrophilic aminoglycosides and a limited number of amphiphilic compounds in E. coli. Here, a homologue of AcrD in the plant pathogen and causal agent of fire blight disease Erwinia amylovora was identified. The substrate specificity of AcrD was studied by overexpression of the corresponding gene from a high-copy plasmid in E. amylovora Ea1189-3, which is hypersensitive to many drugs due to a deficiency of the major multidrug pump AcrB. AcrD mediated resistance to several amphiphilic compounds including clotrimazole and luteolin, two compounds hitherto not described as substrates of AcrD in enterobacteria. However, AcrD was not able to expel aminoglycosides. An acrD mutant exhibited full virulence on apple rootstock and immature pear fruits. RT-PCR analysis revealed an induction of acrD expression in infected apple tissue but not on pear fruits. Moreover, a direct binding of BaeR, the response regulator of the two-component regulatory system BaeSR, to the acrD promoter was observed as has already been shown in other enterobacteria. AcrD from E. amylovora is involved in resistance to a limited number of amphiphilic compounds, but in contrast to AcrD of E. coli, it is not involved in resistance to aminoglycosides. The expression of acrD was up-regulated by addition of the substrates deoxycholate, naringenin, tetracycline and zinc. AcrD appears to be regulated by the BaeSR two-component system, an envelope stress signal transduction pathway.

Characterization of AcrD, a Resistance-Nodulation-Cell Division-type multidrug efflux pump from the fire blight pathogen Erwinia amylovora

PubMed Central

2014-01-01

Background Multidrug efflux pumps are membrane translocases that have the ability to extrude a variety of structurally unrelated compounds from the cell. AcrD, a resistance-nodulation-cell division (RND) transporter, was shown to be involved in efflux of highly hydrophilic aminoglycosides and a limited number of amphiphilic compounds in E. coli. Here, a homologue of AcrD in the plant pathogen and causal agent of fire blight disease Erwinia amylovora was identified. Results The substrate specificity of AcrD was studied by overexpression of the corresponding gene from a high-copy plasmid in E. amylovora Ea1189-3, which is hypersensitive to many drugs due to a deficiency of the major multidrug pump AcrB. AcrD mediated resistance to several amphiphilic compounds including clotrimazole and luteolin, two compounds hitherto not described as substrates of AcrD in enterobacteria. However, AcrD was not able to expel aminoglycosides. An acrD mutant exhibited full virulence on apple rootstock and immature pear fruits. RT-PCR analysis revealed an induction of acrD expression in infected apple tissue but not on pear fruits. Moreover, a direct binding of BaeR, the response regulator of the two-component regulatory system BaeSR, to the acrD promoter was observed as has already been shown in other enterobacteria. Conclusions AcrD from E. amylovora is involved in resistance to a limited number of amphiphilic compounds, but in contrast to AcrD of E. coli, it is not involved in resistance to aminoglycosides. The expression of acrD was up-regulated by addition of the substrates deoxycholate, naringenin, tetracycline and zinc. AcrD appears to be regulated by the BaeSR two-component system, an envelope stress signal transduction pathway. PMID:24443882

Use of autochthonous starters to ferment red and yellow peppers (Capsicum annum L.) to be stored at room temperature.

PubMed

Di Cagno, Raffaella; Surico, Rosalinda F; Minervini, Giovanna; De Angelis, Maria; Rizzello, Carlo G; Gobbetti, Marco

2009-03-31

Strains of Lactobacillus curvatus, Leuconostoc mesenteroides, Lactobacillus plantarum and Weissella confusa were identified from raw red and yellow peppers (RYPs) by partial 16S rRNA gene sequence and subjected to typing by Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) analysis. L. plantarum PE21, L. curvatus PE4 and W. confusa PE36 were selected based on the kinetics of growth and acidification, and used as the autochthonous mixed starter for the fermentation of RYPs. A protocol which included blanching at 85 degrees C for 2 min, fermentation at 35 degrees C for 15 h in brine (1%, w/v), and heat treatment at 85 degrees C for 15 min, followed by storage at room temperature for 30 days with and without sunflower seeds oil was set up. Unstarted RYPs subjected to the same treatments were used as the control. Cell numbers of autochthonous starter in the RYPs were ca. 1000 times higher than presumptive lactic acid bacteria in unstarted RYPs. As shown by RAPD-PCR analysis, all three autochthonous strains persisted during processing and storage. Presumptive lactic acid bacteria found in started RYPs progressively decreased during storage, leading to a microbiota mainly consisting of autochthonous starters. Started RYPs showed rapid decrease of pH (<3.7), marked consumption of fermentable carbohydrates, and inhibition of total enterobacteria and yeasts. Unstarted RYPs were subjected to slight acidification (pH ca. 4.87) and considerable contamination by total enterobacteria and yeasts throughout storage. After 30 days of storage, started RYPs had significantly (P<0.05) higher firmness and colour indexes with respect to unstarted RYPs. The microbial and sensory features of started RYPs stored with sunflower seeds oil were almost similar to those of RYPs stored without suspending liquid.

Bacterial lineages putatively associated with the dissemination of antibiotic resistance genes in a full-scale urban wastewater treatment plant.

PubMed

Narciso-da-Rocha, Carlos; Rocha, Jaqueline; Vaz-Moreira, Ivone; Lira, Felipe; Tamames, Javier; Henriques, Isabel; Martinez, José Luis; Manaia, Célia M

2018-06-05

Urban wastewater treatment plants (UWTPs) are reservoirs of antibiotic resistance. Wastewater treatment changes the bacterial community and inevitably impacts the fate of antibiotic resistant bacteria and antibiotic resistance genes (ARGs). Some bacterial groups are major carriers of ARGs and hence, their elimination during wastewater treatment may contribute to increasing resistance removal efficiency. This study, conducted at a full-scale UWTP, evaluated variations in the bacterial community and ARGs loads and explored possible associations among them. With that aim, the bacterial community composition (16S rRNA gene Illumina sequencing) and ARGs abundance (real-time PCR) were characterized in samples of raw wastewater (RWW), secondary effluent (sTWW), after UV disinfection (tTWW), and after a period of 3 days storage to monitoring possible bacterial regrowth (tTWW-RE). Culturable enterobacteria were also enumerated. Secondary treatment was associated with the most dramatic bacterial community variations and coincided with reductions of ~2 log-units in the ARGs abundance. In contrast, no significant changes in the bacterial community composition and ARGs abundance were observed after UV disinfection of sTWW. Nevertheless, after UV treatment, viability losses were indicated ~2 log-units reductions of culturable enterobacteria. The analysed ARGs (qnrS, bla CTX-M , bla OXA-A , bla TEM , bla SHV , sul1, sul2, and intI1) were strongly correlated with taxa more abundant in RWW than in the other types of water, and which associated with humans and animals, such as members of the families Campylobacteraceae, Comamonadaceae, Aeromonadaceae, Moraxellaceae, and Bacteroidaceae. Further knowledge of the dynamics of the bacterial community during wastewater treatment and its relationship with ARGs variations may contribute with information useful for wastewater treatment optimization, aiming at a more effective resistance control. Copyright © 2018 Elsevier Ltd. All rights

In vitro antibacterial activity and acute toxicity studies of aqueous-methanol extract of Sida rhombifolia Linn. (Malvaceae)

PubMed Central

2010-01-01

Background Many bacteria among the Enterobacteria family are involved in infectious diseases and diarrhoea. Most of these bacteria become resistant to the most commonly used synthetic drugs in Cameroon. Natural substances seem to be an alternative to this problem. Thus the aim of this research was to investigate the in vitro antibacterial activity of the methanol and aqueous-methanol extracts of Sida rhombifolia Linn (Malvaceae) against seven pathogenic bacteria involved in diarrhoea. Acute toxicity of the most active extract was determined and major bioactive components were screened. Methods The agar disc diffusion and the agar dilution method were used for the determination of inhibition diameters and the Minimum Inhibitory Concentration (MICs) respectively. The acute toxicity study was performed according WHO protocol. Results The aqueous-methanol extract (1v:4v) was the most active with diameters of inhibition zones ranging from 8.7 - 23.6 mm, however at 200 μg/dic this activity was relatively weak compared to gentamycin. The MICs of the aqueous-methanol extract (1v:4v) varied from 49.40 to 78.30 μg/ml. Salmonella dysenteriae was the most sensitive (49.40 μg/ml). For the acute toxicity study, no deaths of rats were recorded. However, significant increase of some biochemical parameters such as aspartate amino-transferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and creatinine (CRT) were found. The phytochemical analysis of the aqueous methanol extract indicated the presence of tannins, polyphenols, alkaloids, glycosides, flavonoids and saponins Conclusion The results showed that the aqueous-methanol extract of S. rhombifolia exhibited moderate antibacterial activity. Some toxic effects were found when rats received more than 8 g/kg bw of extract. Antibacterial; Enterobacteria; Acute toxicity; Phytochemical analysis PMID:20663208

Effect of feeding pasture-finished cattle different conserved forages on Escherichia coli in the rumen and faeces.

PubMed

Jacobson, Laura H; Nagle, Tanya A; Gregory, Neville G; Graham Bell, R; Le Roux, Guillaume; Haines, Joanne M

2002-09-01

The effects of eight different pre-slaughter diets on gut microflora, pH and dry matter were evaluated in 112 slaughter-weight, pasture-finished heifers. Hide dirtiness at slaughter, plasma cortisol, meat pH and stickiness, and liveweight loss, were also examined. The pre-slaughter diets were: 48 h of 100% meadow hay, lucerne hay, red clover hay, perennial ryegrass hay, haylage, haylage supplemented with maize silage, pasture, or 24 h fasting before transport. Fasted animals had the highest counts of rumen Escherichia coli and Enterobacteria compared to other treatments (P<0.001), while red clover hay and haylage had the lowest (P<0.05). Faecal E. coli counts were also highest for fasted animals (P<0.05). Rumen E. coli and Enterobacteria counts were positively correlated with rumen pH (P<0.001), and negatively correlated with fibre intake (P<0.001). Diet significantly affected the pH of both the rumen and faeces (P<0.001), with fasted animals having the highest rumen pH and haylage and red-clover hay-fed animals the lowest. Dry matter (%) of the rumen contents was also significantly affected by diet (P<0.001). The mean carcass weight of fed heifers was 5 kg heavier than that of the fasted heifers (P<0.05). A pH/volatile fatty acid (VFA) dependent mechanism is suggested as the major mode for E. coli suppression by feeds used in the study. Coumarins may have contributed to lower ruminal and faecal E. coli counts with E. coli counts negatively correlated with expected coumarin ingestion (P<0.01). Feeding pasture-fed cattle conserved herbaceous forages, in preference to fasting, before transport for slaughter may prove beneficial in reducing the risk of carcass contamination with E. coli and other bacteria of digesta and/or faecal origin, and in protecting carcass weight.

Effect of Lactobacillus johnsonii CRL1647 on different parameters of honeybee colonies and bacterial populations of the bee gut.

PubMed

Audisio, M C; Sabaté, D C; Benítez-Ahrendts, M R

2015-01-01

Lactobacillus johnsonii CRL1647, isolated from the intestinal tract of a worker-bee in Salta, Argentina, was delivered to Apis mellifera L. honey bee colonies according to two different administration schedules: 1×10(5) cfu/ml every 15 days (2011) or monthly (2012). The effect of each treatment on the bee-colony performance was monitored by measuring honey production, and the prevalence of varroasis and nosemosis. Worker bees from each assay were randomly captured 3 days after administration and assayed for the following intestinal culturable and defined bacterial populations: total aerobic microorganisms, Bacillus spp. spores, Lactobacillus spp., Enterococcus spp. and enterobacteria. Interestingly, both treatments generated a similar increase in honey production in treated colonies compared to controls: 36.8% (every 15 days) and 36.3% (monthly). Nosema index always exhibited a reduction when lactobacilli were administered; in turn, Varroa incidence was lower when the lactobacilli were administered once a month. Moreover, the administration of L. johnsonii CRL1647 every 15 days produced an increase in the total number of aerobic microorganisms and in bacteria belonging to the genera Lactobacillus and Enterococcus; at the same time, a decrease was observed in the number of total spores at the end of the treatment. The number of enterobacteria was constant and remained below that of control hives at the end of the assay. On the other hand, the delivery of lactobacilli once a month only showed an increase in the number of bacteria belonging to the genus Lactobacillus; meanwhile, viable counts of the remaining microorganisms assayed were reduced. Even though it seems that both treatments were similar, those bee colonies that received L. johnsonii CRL1647 every 15 days became so strong that they swarmed.

Potential Role of Gut Microbiota in ALS Pathogenesis and Possible Novel Therapeutic Strategies.

PubMed

Mazzini, Letizia; Mogna, Luca; De Marchi, Fabiola; Amoruso, Angela; Pane, Marco; Aloisio, Irene; Cionci, Nicole Bozzi; Gaggìa, Francesca; Lucenti, Ausiliatrice; Bersano, Enrica; Cantello, Roberto; Di Gioia, Diana; Mogna, Giovanni

2018-05-18

Recent preclinical studies suggest that dysfunction of gastrointestinal tract may play a role in amyotrophic lateral sclerosis (ALS) pathogenesis through a modification of the gut microbiota brain axis. Our study is the first focused on microbiota analysis in ALS patients. Our aim was to study the main human gut microbial groups and the overall microbial diversity in ALS and healthy subjects. Moreover we have examined the influence of a treatment with a specific bacteriotherapy composed of Lactobacillus strains (Lactobacillus fermentum, Lactobacillus delbrueckii, Lactobacillus plantarum, Lactobacillus salivarius) acting on the gastrointestinal barrier. We enrolled 50 ALS patients and 50 healthy controls, matched for sex, age, and origin. Fecal samples were used for total genomic DNA extraction. Enterobacteria, Bifidobacterium spp., Lactobacillus spp., Clostridium sensu stricto, Escherichia coli and yeast were quantified using quantitative polymerase chain reaction approach. Denaturing gradient gel electrophoresis analyses were performed to investigate total eubacteria and yeasts populations. Patients were randomized to double-blind treatment either with microorganisms or placebo for 6 months and monitored for clinical progression and microbiota composition. The comparison between ALS subjects and healthy group revealed a variation in the intestinal microbial composition with a higher abundance of E. coli and enterobacteria and a low abundance of total yeast in patients. Polymerase chain reaction denaturing gradient gel electrophoresis analysis showed a cluster distinction between the bacterial profiles of ALS patients and the healthy subjects. The complexity of the profiles in both cases may indicate that a real dysbiosis status is not evident in the ALS patients although differences between healthy and patients exist. The effects of the progression of the disease and of the bacteriotherapy on the bacterial and yeast populations are currently in progress. Our

Adult Student Retention and Achievement with Language-Based Modular Materials. POR FIN: Program Organizing Related Family Instruction in the Neighborhood.

ERIC Educational Resources Information Center

Bexar County School Board, San Antonio, TX.

The goal of the POR FIN research design was to develop a language-based curriculum emphasizing the audiolingual approach and integrating academic and social-functioning subject matter. The modular curriculum is designed so that each lesson is independent and complete in itself, and provides a high degree of motivation, retention, and achievement…

RNA silencing in plant symbiotic bacteria: Insights from a protein-centric view.

PubMed

Jiménez-Zurdo, José I; Robledo, Marta

2017-12-02

Extensive work in model enterobacteria has evidenced that the RNA chaperone Hfq and several endoribonucleases, such as RNase E or RNase III, serve pivotal roles in small RNA-mediated post-transcriptional silencing of gene expression. Characterization of these protein hubs commonly provide global functional and mechanistic insights into complex sRNA regulatory networks. The legume endosymbiont Sinorhizobium meliloti is a non-classical model bacterium with a very complex lifestyle in which riboregulation is expected to play important adaptive functions. Here, we discuss current knowledge about RNA silencing in S. meliloti from the perspective of the activity of Hfq and a recently discovered endoribonuclease (YbeY) exhibiting unprecedented catalytic versatility for the cleavage of single- and double-stranded RNA molecules.

Characterisation by multilocus sequence and porA and flaA typing of Campylobacter jejuni isolated from samples of dog faeces collected in one city in New Zealand.

PubMed

Mohan, V; Stevenson, M A; Marshall, J C; French, N P

2017-07-01

To investigate the prevalence of Campylobacter spp. and C. jejuni in dog faecal material collected from dog walkways in the city of Palmerston North, New Zealand, and to characterise the C. jejuni isolates by multilocus sequence typing (MLST) and porA and flaA antigen gene typing. A total of 355 fresh samples of dogs faeces were collected from bins provided for the disposal of dog faeces in 10 walkways in Palmerston North, New Zealand, between August 2008-July 2009. Presumptive Campylobacter colonies, cultured on modified charcoal cefoperazone deoxycholate plates, were screened for genus Campylobacter and C. jejuni by PCR. The C. jejuni isolates were subsequently characterised by MLST and porA and flaA typing, and C. jejuni sequence types (ST) were assigned. Of the 355 samples collected, 72 (20 (95% CI=16-25)%) were positive for Campylobacter spp. and 22 (6 (95% CI=4-9)%) were positive for C. jejuni. Of the 22 C. jejuni isolates, 19 were fully typed by MLST. Ten isolates were assigned to the clonal complex ST-45 and three to ST-52. The allelic combinations of ST-45/flaA 21/porA 44 (n=3), ST-45/flaA 22/porA 53 (n=3) and ST-52/ flaA 57/porA 905 (n=3) were most frequent. The successful isolation of C. jejuni from canine faecal samples collected from faecal bins provides evidence that Campylobacter spp. may survive outside the host for at least several hours despite requiring fastidious growth conditions in culture. The results show that dogs carry C. jejuni genotypes (ST-45, ST-50, ST-52 and ST-696) that have been reported in human clinical cases. Although these results do not provide any evidence either for the direction of infection or for dogs being a potential risk factor for human campylobacteriosis, dog owners are advised to practice good hygiene with respect to their pets to reduce potential exposure to infection.

Enterobacteria associated with houseflies (Musca domestica) as an infection risk indicator in swine production farms.

PubMed

Cervelin, V; Fongaro, G; Pastore, J B; Engel, F; Reimers, M A; Viancelli, A

2018-04-23

Houseflies (Musca domestica) spend part of their life development on animal or human manure. Manure is high in pathogenic microbes; thus, houseflies have been known as a mechanical vector for various important zoonotic diseases. Therefore, the present study showcases captured houseflies from intensive swine production regions (which are areas of high manure concentration) in Southern Brazil, and analyses their bodies' to the presence of Escherichia coli and Salmonella sp. and the sensitivity of these bacteria to various antibiotics. Additionally, Quantitative Microbiology Risk Assessment was performed simulating the contamination of lettuce by flies' bacteria and subsequent lettuce consumption by an adult human being. Houseflies were captured in swine buildings and farm houses from five farms. E. coli quantification values ranged from 10 4 to 10 6 CFU/20 flies, and all sampling sites had positive results from bacteria presence in the collected houseflies. On the other hand, Salmonella sp. presence was observed in only three farms, where the quantification ranged from 10 2 to 10 5 CFU/20 flies. The bacteria showed to be resistant to at least two from the four tested antibiotics (ampicillin, Cefalotin, Ciprofloxacin and Norfloxacin) antibiotics used in human or veterinary medicine. Infection probability analyses showed risk of human infection by E.coli, indicating possible transmission of zoonotic pathogens through flies. In this context, it was possible to conclude that there is a need for flies control, especially in swine farms where zoonotic pathogens can be abundant, to minimize the health impact of the vectorization of enteric bacteria. Copyright © 2018 Elsevier B.V. All rights reserved.

Refrigerated poultry breast fillets packed in modified atmosphere and irradiated: bacteriological evaluation, shelf life and sensory acceptance

PubMed Central

Mantilla, Samira Pirola Santos; Santos, Érica Barbosa; de Freitas, Mônica Queiroz; de Carvalho Vital, Helio; Mano, Sérgio Borges; Franc, Robson Maia

2012-01-01

In the present study the effects on shelf life and sensory acceptance of gamma-irradiated refrigerated poultry breast fillets subjected to modified atmosphere packaging (80% CO2/20% N2 or vacuum) were investigated. After irradiation with 2 kGy, sensory acceptance tests and monitoring of bacterial growth were performed in order to determine the sanitary quality of the samples. It has been found that irradiation, used in combination with modified atmosphere packaging, can double the shelf life of refrigerated poultry breast fillets by reducing the populations of aerobic mesophilic and psychrotrophic bacteria, enterobacteria, coliforms, Listeria spp. and Aeromonas spp., without significantly modifying its color or its overall appearance, the lactic acid bacteria being the most resistant to exposure to radiation and carbon dioxide. PMID:24031967

Biofilm formation as a method of survival of Escherichia coli and Pantoea spp in the marine environment

NASA Astrophysics Data System (ADS)

Buzoleva, L. S.; Golozubova, Y. S.; Eskova, A. I.; Kim, A. V.; Bogatyrenko, E. A.

2018-01-01

The article shows the formation of biofilms of bacteria Escherichia and Pantoea, which were isolated from sea water, both in monoculture and in associations with marine heterotrophs. It studied the influence of the nutrient medium and temperature on the biofilm-forming properties of marine strains. The highest biofilm formation properties were found in monoculture in family enterobacteria compared to saprophytic marine bacteria, regardless of the medium and the culture temperature. In association with saprophytes, Pantoea spp. possess more pronounced biofilm-forming properties at 37 ° C compared to the control than at 22 ° C and 5 ° C irrespective of the culture medium. Escherichia coli, in association with saprophytes, have less pronounced biofilm formation properties than monoculture, regardless of the temperature and culture medium.

El proceso hacia la integracion de la equidad por genero al curriculo.(The Process of the Integration of Gender Equity in the Curriculum.)

ERIC Educational Resources Information Center

Rivera-Bermudez, Carmen D.

"El Proyecto Colaborativo de Equidad por Genero en la Educacion," or the Collaborative Project for Gender Equity in Education, was undertaken in Puerto Rico between 1990 and 1992 to study how to facilitate the integration of gender equity themes in the curriculum through the direct action of participating teachers. A study examined the…

A Proteomic Analysis Reveals Differential Regulation of the σS-Dependent yciGFE(katN) Locus by YncC and H-NS in Salmonella and Escherichia coli K-12

PubMed Central

Beraud, Mélanie; Kolb, Annie; Monteil, Véronique; D'Alayer, Jacques; Norel, Françoise

2010-01-01

The stationary phase sigma factor σS (RpoS) controls a regulon required for general stress resistance of the closely related enterobacteria Salmonella and Escherichia coli. The σS-dependent yncC gene encodes a putative DNA binding regulatory protein. Application of the surface-enhanced laser desorption/ionization-time of flight (SELDI-TOF) ProteinChip technology for proteome profiling of wild-type and mutant strains of Salmonella enterica serovar Typhimurium revealed potential protein targets for YncC regulation, which were identified by mass spectrometry, and subsequently validated. These proteins are encoded by the σS-dependent operon yciGFEkatN and regulation of their expression by YncC operates at the transcriptional level, as demonstrated by gene fusion analyses and by in vitro transcription and DNase I footprinting experiments with purified YncC. The yciGFE genes are present (without katN) in E. coli K-12 but are poorly expressed, compared with the situation in Salmonella. We report that the yciGFE(katN) locus is silenced by the histone-like protein H-NS in both species, but that σS efficiently relieves silencing in Salmonella but not in E. coli K-12. In Salmonella, YncC acts in concert with σS to activate transcription at the yciG promoter (pyciG). When overproduced, YncC also activated σS-dependent transcription at pyciG in E. coli K-12, but solely by countering the negative effect of H-NS. Our results indicate that differences between Salmonella and E. coli K-12, in the architecture of cis-acting regulatory sequences upstream of pyciG, contribute to the differential regulation of the yciGFE(katN) genes by H-NS and YncC in these two enterobacteria. In E. coli, this locus is subject to gene rearrangements and also likely to horizontal gene transfer, consistent with its repression by the xenogeneic silencer H-NS. PMID:20713450

Protective effects of indigenous Escherichia coli against a pathogenic E. coli challenge strain in pigs.

PubMed

Vahjen, W; Cuisiniere, T; Zentek, J

2017-10-13

To investigate the inhibitory effect of indigenous enterobacteria on pathogenic Escherichia coli, a challenge trial with postweaning pigs was conducted. A pathogenic E. coli strain was administered to all animals and their health was closely monitored thereafter. Faecal samples were taken from three healthy and three diarrhoeic animals. Samples were cultivated on MacConkey agar and isolates were subcultured. A soft agar overlay assay was used to determine the inhibitory activity of the isolates. A total of 1,173 enterobacterial isolates were screened for their ability to inhibit the E. coli challenge strain. Colony forming units of enterobacteria on MacConkey agar were not different between healthy and diarrhoeic animals in the original samples. Furthermore, numbers of isolates per animal were also not significantly different between healthy (482 isolates) and diarrhoeic animals (691 isolates). A total of 43 isolates (3.7%) with inhibitory activity against the pathogenic E. coli challenge strain were detected. All inhibitory isolates were identified as E. coli via MALDI-TOF. The isolates belonged to the phylotypes A, C and E. Many isolates (67.4%) were commensal E. coli without relevant porcine pathogenic factors, but toxin- and fimbrial genes (stx2e, fae, estIb, elt1a, fas, fan) were detected in 14 inhibitory isolates. Healthy animals showed significantly (P=0.003) more inhibitory isolates (36 of 482 isolates; 7.5%) than diseased animals (7 of 691 isolates; 1.0%). There were no significant correlations regarding phylotype or pathogenic factors between healthy and diseased animals. This study has shown that a small proportion of indigenous E. coli is able to inhibit in vitro growth of a pathogenic E. coli strain in pigs. Furthermore, healthy animals possess significantly more inhibitory E. coli strains than diarrhoeic animals. The inhibition of pathogenic E. coli by specific indigenous E. coli strains may be an underlying principle for the containment of pathogenic

Protection by meningococcal outer membrane protein PorA-specific antibodies and a serogroup B capsular polysaccharide-specific antibody in complement-sufficient and C6-deficient infant rats.

PubMed

Toropainen, Maija; Saarinen, Leena; Vidarsson, Gestur; Käyhty, Helena

2006-05-01

The relative contributions of antibody-induced complement-mediated bacterial lysis and antibody/complement-mediated phagocytosis to host immunity against meningococcal infections are currently unclear. Further, the in vivo effector functions of antibodies may vary depending on their specificity and Fc heavy-chain isotype. In this study, a mouse immunoglobulin G2a (mIgG2a) monoclonal antibody (MN12H2) to meningococcal outer membrane protein PorA (P1.16), its human IgG subclass derivatives (hIgG1 to hIgG4), and an mIgG2a monoclonal antibody (Nmb735) to serogroup B capsular polysaccharide (B-PS) were evaluated for passive protection against meningococcal serogroup B strain 44/76-SL (B:15:P1.7,16) in an infant rat infection model. Complement component C6-deficient (PVG/c-) rats were used to assess the importance of complement-mediated bacterial lysis for protection. The PorA-specific parental mIgG2a and the hIgG1 to hIgG3 derivatives all induced efficient bactericidal activity in vitro in the presence of human or infant rat complement and augmented bacterial clearance in complement-sufficient HsdBrlHan:WIST rats, while the hIgG4 was unable to do so. In C6-deficient PVG/c- rats, lacking complement-mediated bacterial lysis, the augmentation of bacterial clearance by PorA-specific mIgG2a and hIgG1 antibodies was impaired compared to that in the syngeneic complement-sufficient PVG/c+ rat strain. This was in contrast to the case for B-PS-specific mIgG2a, which conferred similar protective activity in both rat strains. These data suggest that while anti-B-PS antibody can provide protection in the infant rats without membrane attack complex formation, the protection afforded by anti-PorA antibody is more dependent on the activation of the whole complement pathway and subsequent bacterial lysis.

Seguridad del paciente en Radioterapia Intraoperatoria: Impacto de los elementos controlados por el Radiofisico

NASA Astrophysics Data System (ADS)

Tarjuelo, Juan Lopez

Introduccion: En la administracion de la radioterapia intervienen profesionales y equipos de tratamiento, por lo que existe el riesgo de error y se precisa que dicho equipamiento funcione conforme a lo esperado. A los radiofisicos les corresponde participar en las actividades de garantia o aseguramiento de la calidad, incluyendo el control de calidad de los equipos, y en la evaluacion de los riesgos asociados. La radioterapia intraoperatoria (RIO) es una tecnica radioterapica de intensificacion de dosis, altamente selectiva, dirigida a volumenes anatomicos restringidos durante el tratamiento quirurgico oncologico, basada en la administracion de una dosis absorbida alta por medio de un haz de electrones tras el examen visual directo del lecho tumoral. Como incorporar los ultimos avances en el refuerzo de la seguridad en radioterapia es una tarea ambiciosa y compleja, resulta mas concreta y de inmediata aplicacion su introduccion en la RIO. El objetivo es analizar los elementos que reducen los riesgos y aumentan la seguridad en la RIO y su dosimetria, y valorar la funcion del radiofisico en esta labor. Material y metodos: Se emplearon el planificador Radiance de GMV y el acelerador lineal de los tratamientos de RIO Elekta Precise, controlado con el verificador diario de haces Daily QA Check 1090 y medido con las camaras de ionizacion PPC 40, FC65-G y FC65-P de PTW-Freiburg, a su vez verificadas con fuentes radiactivas adecuadas de estroncio-90 modelos CDP y CDC de IBA Dosimetry. Se realizo un analisis de modos de fallo y efectos (failure mode and effect analysis, FMEA) con el fin de identificar los elementos que forman la RIO y aplicar las herramientas necesarias para la minimizacion de los riesgos y la mejora de la seguridad en la tecnica. Se estudiaron las verificaciones diarias de dicho acelerador Precise con el control estadistico de procesos (statistical process control, SPC) y se simularon intervenciones para devolverlo al estado llamado en control. El SPC

Fabrication of por-Si/SnO{sub x} nanocomposite layers for gas microsensors and nanosensors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolotov, V. V., E-mail: bolotov@obisp.oscsbras.ru; Korusenko, P. M.; Nesov, S. N.

2011-05-15

Two-phase nanocomposite layers based on porous silicon and nonstoichiometric tin oxide were fabricated by various methods. The structure, as well as elemental and phase composition, of the obtained nanocomposites were studied using transmission and scanning electron microscopy, Raman spectroscopy, Auger electron spectroscopy, and X-ray photoelectron spectroscopy. The results obtained confirm the formation of nanocomposite layers with a thickness as large as 2 {mu}m thick and SnO{sub x} stoichiometry coefficients x = 1.0-2.0. Significant tin diffusion into the porous silicon matrix with D{sub eff} Almost-Equal-To 10{sup -14} cm{sup 2} s{sup -1} was observed upon annealing at 770 K. Test sensor structuresmore » based on por-Si/SnO{sub x} nanocomposite layers grown by magnetron deposition showed fairly high stability of properties and sensitivity to NO{sub 2}.« less

Being a mother and a por día domestic worker. Companionship and deprivation.

PubMed

Bernal, P; Meleis, A I

1995-08-01

This article presents qualitative findings concerning women's maternal roles, based on interviews conducted in a study on role integration and health, in a Colombian sample of 60 women who are "por día" domestic workers. The results describe the women's worldview as they discuss the stresses and the satisfactions of their mothering roles. The results also include the coping strategies used to deal with the stresses inherent in the maternal role. Women describe how the companionship of their children, watching their children grow, and the nurturing they give their children provides them with pride and deep satisfaction. These satisfying aspects of their role are burdened by the stress related to worry about children's bad behavior, their illness, and a pervasive generalized sense of constant worry. Being single parents adds more stress to these women's lives. Participants coped emotionally through distraction and through talking with friends. Other coping strategies included calming self, problem solving, talking with children, and substance use. The authors conclude with a discussion of the relationship between poverty and work situation as contexts for understanding maternal roles.

[Clinico-laboratory parallels during celiac disease in children].

PubMed

Kamilova, A T; Aripov, A N

2000-11-01

Forty-five patients with celiac disease and 73 with the celiakia syndrome were observed. The clinical picture was identical and was characterized by disordered intestinal absorption. Depression of T and B lymphocytes was typical of both forms of the disease. High values of antigliadin IgA and IgG correlated with the severity of atrophic processes in the small intestinal mucosa. Intestinal microflora was characterized by a decrease in the main defense flora and growth of hemolytical and lactonegative enterobacteria and Proteus. Hypocholesterolemia was characteristic of congenital and acquired celiakia. Hemoglobin and albumin levels were in direct correlation while growth deficiency and increment of glycemia were in inverse correlation in patients with celiac disease. The celiakia syndrome was characterized by an inverse correlation between the number of defecations and content of full-value E. coli, body weight deficit, and glucose tolerance test.

[Not Available].

PubMed

Germán Díaz, Marta; Moreno Villares, José Manuel; Gomis Muñoz, Pilar

2016-07-19

Introducción: la nutrición parenteral domiciliaria se ha convertido en un punto clave en el tratamiento de pacientes con fracaso intestinal crónico. A pesar de los importantes avances que se han producido en las últimas décadas, tanto en los accesos vasculares, como en las soluciones empleadas, las infecciones asociadas a catéter venoso central siguen constituyendo una de las complicaciones más importantes. Dentro de las estrategias para la prevención o el tratamiento de estas infecciones se encuentra el empleo de sellados con antisépticos, como el etanol o la taurolidina, o de antibióticos.Objetivo: el objetivo de este artículo es revisar la evidencia disponible sobre el empleo de sellados con antisépticos o antibióticos en el manejo de pacientes pediátricos con nutrición parenteral domiciliaria.Material y métodos: el uso de sellados con etanol o taurolidina para prevenir el desarrollo de infecciones asociadas a catéter central estaría indicado en pacientes con nutrición parenteral domiciliaria que hayan tenido más de una infección en el año anterior o que se consideren pacientes de riesgo. Los sellados con antibióticos están indicados en el tratamiento de bacteriemias asociadas a catéter central producidas por S. coagulasa-negativo o gramnegativos, asociados a un tratamiento sistémico, siempre que sea posible, con el fin de salvar el catéter. Se debería llevar a cabo la retirada del mismo cuando existan signos de infección del punto de entrada o del trayecto subcutáneo, o cuando el germen responsable de la infección sea S. aureus o Cándida.Conclusión: a pesar de que la fuerza de la evidencia sobre la eficacia del sellado en la prevención o el tratamiento de infecciones asociadas al catéter es limitada, tanto en el niño como en el adulto, cada vez existen más datos a usar esta alternativa en pacientes con nutrición parenteral domiciliaria en los que la atención y salvaguarda de los catéteres es primordial.

Demodex phylloides infection in swine reared in a peri-urban family farm located on the outskirts of the Metropolitan Region of São Paulo, Brazil.

PubMed

Bersano, Josete Garcia; Mendes, Márcia Cristina; Duarte, Fernanda Calvo; Del Fava, Claudia; de Oliveira, Sueli Moda; Filha, Elizabeth Spósito; Pinheiro, Eliana Scarcelli; de Castro Nassar, Alessandra Figueiredo; de Vasconcellos Bilynskyj, Maria Cristina; Ogata, Renato Akio; Sampaio, Paulo Henrique Selbmann; Genovez, Margareth Élide

2016-10-30

This paper reports the occurrence of porcine demodicosis caused by the mite Demodex phylloides in hogs reared in a peri-urban family farm located in Francisco Morato, a municipality of the Metropolitan Region of São Paulo, capital city of the state of São Paulo, Brazil. In a parcel of forty Landrace - Large White cross hogs, approximately four months old, four animals presented severe skin lesions in the form of small nodules over their entire body, especially in the periocular region, snout, lower abdomen and flanks. Two hogs had to be euthanized for animal welfare reasons, which enabled post-mortem examination. Skin scrapings revealed eggs, larvae, nymphs and adults of D. phylloides. Purulent subcutaneous nodules with intense parasitic folliculitis and intense perifollicular inflammatory reaction were present. Enterobacteria and coagulase-positive Staphylococcus spp. were isolated from the skin pustules. Necropsy revealed milk spotted liver, enteritis and enlargement of mesenteric lymph nodes. Protozoa (Eimeria spp. and Balantidium sp.), helminth eggs (Ascaris suum, Trichuris suis and strongyles) and Brachyspira spp. were found in faeces. Staphylococcus spp. and enterobacteria were isolated from internal organs. All remaining hogs were treated with ivermectin at a daily oral dose of 0.45g/kg of feed, during seven days. Fifteen days after treatment, remission of symptoms was observed in the surviving animals with demodicosis; absence of mites was confirmed by skin scraping examinations. The hogs were reared under poor environmental, nutritional and sanitary conditions, resulting in multimorbidity and immunosuppression. Severe clinical porcine demodicosis was triggered when the animals were castrated. Family pig farmers had been suffering economic losses due to the stunted growth of the herd. In addition to that, the lesions found on the skin and in the internal organs would result in condemnation of meat and viscera for human consumption. As part of a Public

Modification of in-pack conditions to extend the storage life of vacuum packaged lamb.

PubMed

Gill, C O; Penney, N

1985-01-01

High pH (>5·9) lamb loins from a research abattoir were subjected to differing packaging treatments to determine whether package modification could reliably extend the storage life of chilled lamb cuts beyond that attained by cuts vacuum-packaged in film of low gas permeability, as in current commercial practice. Treatments applied were carbon dioxide flushing or addition of a citrate buffer (pH 4·8), a 5% lactic acid solution or a Lactobacillus inoculum (plastic packs only) and packaging in a plastic film of moderately low oxygen permeability (140 cc/m(2)/24 h at 25°C and 90% relative humidity) or in a foil laminate of immeasurably low oxygen permeability. After 12 weeks' storage at -0.5°C, the cuts packaged in the plastic film were spoiled by off-odours produced by enterobacteria, except for inoculated cuts, which, instead, had developed unacceptable dairy flavours. In contrast, cuts packaged in foil laminate developed floras of lactobacilli that had not caused spoilage after 12 weeks, and meat colour was much improved by the exclusion of oxygen. Loin cuts from a commercial packaging operation were packaged in a shrinkable plastic film of low oxygen permeability (30 to 40 cc/m(2)/24 h at 25°C and 90% relative humidity), in foil laminate, or in foil laminate after the addition of 5% lactic acid solution. For the first 6 weeks, cuts were stored in a commercial chiller nominally operating at 0°C; subsequently, they were held in a laboratory chiller at -0.5°C. Some cuts packaged in the shrinkable plastic were spoiled after 9 weeks' storage and all were spoiled at 12 weeks, because of off-flavours produced by enterobacteria. All cuts packaged in the foil laminate were very acceptable at 9 weeks but most were spoiled by off-flavours at 12 weeks. Most cuts treated with lactic acid and packaged in foil laminate were unspoiled after 12 weeks. The packaging requirements indicated to be necessary for reliable extension of the storage life of vacuum packaged lamb are

Phylogenomic, Pan-genomic, Pathogenomic and Evolutionary Genomic Insights into the Agronomically Relevant Enterobacteria Pantoea ananatis and Pantoea stewartii

PubMed Central

De Maayer, Pieter; Aliyu, Habibu; Vikram, Surendra; Blom, Jochen; Duffy, Brion; Cowan, Don A.; Smits, Theo H. M.; Venter, Stephanus N.; Coutinho, Teresa A.

2017-01-01

Pantoea ananatis is ubiquitously found in the environment and causes disease on a wide range of plant hosts. By contrast, its sister species, Pantoea stewartii subsp. stewartii is the host-specific causative agent of the devastating maize disease Stewart’s wilt. This pathogen has a restricted lifecycle, overwintering in an insect vector before being introduced into susceptible maize cultivars, causing disease and returning to overwinter in its vector. The other subspecies of P. stewartii subsp. indologenes, has been isolated from different plant hosts and is predicted to proliferate in different environmental niches. Here we have, by the use of comparative genomics and a comprehensive suite of bioinformatic tools, analyzed the genomes of ten P. stewartii and nineteen P. ananatis strains. Our phylogenomic analyses have revealed that there are two distinct clades within P. ananatis while far less phylogenetic diversity was observed among the P. stewartii subspecies. Pan-genome analyses revealed a large core genome comprising of 3,571 protein coding sequences is shared among the twenty-nine compared strains. Furthermore, we showed that an extensive accessory genome made up largely by a mobilome of plasmids, integrated prophages, integrative and conjugative elements and insertion elements has resulted in extensive diversification of P. stewartii and P. ananatis. While these organisms share many pathogenicity determinants, our comparative genomic analyses show that they differ in terms of the secretion systems they encode. The genomic differences identified in this study have allowed us to postulate on the divergent evolutionary histories of the analyzed P. ananatis and P. stewartii strains and on the molecular basis underlying their ecological success and host range. PMID:28959245

Effects of the probiotic Enterococcus faecium NCIMB 10415 on selected lactic acid bacteria and enterobacteria in co-culture.

PubMed

Starke, I C; Zentek, J; Vahjen, W

2015-01-01

Enterococcus faecium NCIMB 10415 is used as a probiotic for piglets and has been shown to modify the porcine intestinal microbiota. However, the mode of action of this probiotic modification is still unclear. One possible explanation is the direct growth inhibiting or stimulating effect of the probiotic on other indigenous bacteria. Therefore, the aim of the present study was to examine the growth interactions of the probiotic with different indigenous porcine bacteria in vitro. Reference strains were cultivated with the probiotic E. faecium strain NCIMB10415 (SF68) in a checkerboard assay with 102 to 105 cells/ml inoculum per strain. Growth kinetics were recorded for 8 h and used to determine specific growth of the co-cultures. Additionally, total DNA was extracted from the co-cultures at the end of the incubation to verify which strain in the co-culture was affected. Co-cultivation with eight Enterococcus spp. tester strains showed strain-specific growth differences. Three of four E. faecium strains were not influenced by the probiotic strain. PCR results showed reduced growth of the probiotic strain in co-culture with E. faecium DSM 6177. Three of four Enterococcus faecalis strains showed reduced specific growth in co-culture with the probiotic strain. However, E. faecalis DSM 20478 impaired growth of the probiotic E. faecium strain. The growth of Lactobacillus johnsonii DSM 10533 and Lactobacillus reuteri DSM 20016 was enhanced in co-culture with the probiotic strain, but co-cultivations with Lactobacillus mucosae DSM13345 or Lactobacillus amylovorus DSM10533 showed no differences. Co-cultures with the probiotic E. faecium showed no impact on the growth rate of four different enterobacterial reference strains (2 strains of Salmonella enterica and 2 strains of Escherichia coli), but PCR results showed reduced cell numbers for a pathogenic E. coli isolate at higher concentration of the probiotic strain. As the in vitro effect of the probiotic E. faecium on enterococci was strain specific and the growth of certain Lactobacillus spp. was enhanced by the probiotic, these results indicate a direct effect of the probiotic on certain members of the porcine gastro intestinal microbiota.

Phylogenomic, Pan-genomic, Pathogenomic and Evolutionary Genomic Insights into the Agronomically Relevant Enterobacteria Pantoea ananatis and Pantoea stewartii.

PubMed

De Maayer, Pieter; Aliyu, Habibu; Vikram, Surendra; Blom, Jochen; Duffy, Brion; Cowan, Don A; Smits, Theo H M; Venter, Stephanus N; Coutinho, Teresa A

2017-01-01

Pantoea ananatis is ubiquitously found in the environment and causes disease on a wide range of plant hosts. By contrast, its sister species, Pantoea stewartii subsp. stewartii is the host-specific causative agent of the devastating maize disease Stewart's wilt. This pathogen has a restricted lifecycle, overwintering in an insect vector before being introduced into susceptible maize cultivars, causing disease and returning to overwinter in its vector. The other subspecies of P. stewartii subsp. indologenes , has been isolated from different plant hosts and is predicted to proliferate in different environmental niches. Here we have, by the use of comparative genomics and a comprehensive suite of bioinformatic tools, analyzed the genomes of ten P. stewartii and nineteen P. ananatis strains. Our phylogenomic analyses have revealed that there are two distinct clades within P. ananatis while far less phylogenetic diversity was observed among the P. stewartii subspecies. Pan-genome analyses revealed a large core genome comprising of 3,571 protein coding sequences is shared among the twenty-nine compared strains. Furthermore, we showed that an extensive accessory genome made up largely by a mobilome of plasmids, integrated prophages, integrative and conjugative elements and insertion elements has resulted in extensive diversification of P. stewartii and P. ananatis . While these organisms share many pathogenicity determinants, our comparative genomic analyses show that they differ in terms of the secretion systems they encode. The genomic differences identified in this study have allowed us to postulate on the divergent evolutionary histories of the analyzed P. ananatis and P. stewartii strains and on the molecular basis underlying their ecological success and host range.

Aquisição fonológica do português brasileiro por crianças ouvintes bilíngues bimodais e surdas usuárias de implante coclear

PubMed Central

Cruz, Carina Rebello; Finger, Ingrid

2014-01-01

Resumo O presente estudo investiga a aquisição fonológica do Português Brasileiro (PB) por 24 crianças ouvintes bilíngues bimodais, com acesso irrestrito à Língua Brasileira de Sinais (Libras), e por 6 crianças surdas que utilizam implante coclear (IC), com acesso restrito ou irrestrito à Libras. Para a avaliação do sistema fonológico das crianças em PB, foi utilizada a Parte A, Prova de Nomeação, do ABFW – Teste de Linguagem Infantil (ANDRADE et al. 2004). Os resultados revelaram que as crianças ouvintes bilíngues bimodais e a criança surda usuária de IC com acesso irrestrito à Libras apresentaram processo de aquisição fonológica esperada (normal) para a sua faixa etária. Considera-se que a aquisição precoce e o acesso irrestrito à Libras podem ter sido determinantes para o desempenho dessas crianças no teste oral utilizado. PMID:25506105

Severe invasive listeriosis--case report.

PubMed

Teodor, Andra; Teodor, D; Miftode, Egidia; Prisăcaru, D; Leca, Daniela; Petrovici, Cristina; Dorneanu, Olivia; Dorobăt, Carmen-Mihaela

2012-01-01

Listeriosis is a rare food borne infection which, in the invasive form, presents as bloodstream infection, central nervous system infection, materno-fetal infection, or focal infection. Certain immunosuppressive conditions have been identified as risk factors for severe invasive disease. The invasive forms of listeriosis are associated with a high case fatality rate. We present the case of a 62-year-old male with an unremarkable medical history admitted to the Iasi Infectious Diseases Hospital for fever. headache, ataxia, and diplopia. Physical examination revealed high temperature, confusion, relative bradycardia, and signs of meningeal irritation. Laboratory test showed leukocyt osis with neutrophilia. pathological CSF findings (high WBC count with predominance of neutrophils, low glucose and high protein levels), increased liver enzymes (ALAT, ASAT, AP, gammaGT), and important renal impairment (normal levels at presentation). No abnormalities at chest x-ray, cranial CT and abdominal ultrasound. CSF and blood cultures were positive for Listeria monocytogenes. Under antibiotics (ampicillin and ciprofloxacin), the course was marked by respiratory failure requiring mechanical ventilation, coma, hypotension, tachycardia. and death 12 days after admission. The particularity of this case consists in the association of the two classical forms of invasive listeriosis, meningitis and bacteriemia, with a focal infection. acute hepatitis, and a course marked by multiple organ dysfunction syndromes and exitus in a previously apparently healthy individual.

Evaluation of PCR Approaches for Detection of Bartonella bacilliformis in Blood Samples.

PubMed

Gomes, Cláudia; Martinez-Puchol, Sandra; Pons, Maria J; Bazán, Jorge; Tinco, Carmen; del Valle, Juana; Ruiz, Joaquim

2016-03-01

The lack of an effective diagnostic tool for Carrion's disease leads to misdiagnosis, wrong treatments and perpetuation of asymptomatic carriers living in endemic areas. Conventional PCR approaches have been reported as a diagnostic technique. However, the detection limit of these techniques is not clear as well as if its usefulness in low bacteriemia cases. The aim of this study was to evaluate the detection limit of 3 PCR approaches. We determined the detection limit of 3 different PCR approaches: Bartonella-specific 16S rRNA, fla and its genes. We also evaluated the viability of dry blood spots to be used as a sample transport system. Our results show that 16S rRNA PCR is the approach with a lowest detection limit, 5 CFU/μL, and thus, the best diagnostic PCR tool studied. Dry blood spots diminish the sensitivity of the assay. From the tested PCRs, the 16S rRNA PCR-approach is the best to be used in the direct blood detection of acute cases of Carrion's disease. However its use in samples from dry blood spots results in easier management of transport samples in rural areas, a slight decrease in the sensitivity was observed. The usefulness to detect by PCR the presence of low-bacteriemic or asymptomatic carriers is doubtful, showing the need to search for new more sensible techniques.

Internal and external contamination of donor corneas before in situ excision: bacterial risk factors in 93 donors.

PubMed

Robert, Pierre-Yves; Camezind, Philippe; Drouet, Mireille; Ploy, Marie-Cécile; Adenis, Jean-Paul

2002-04-01

Most studies of corneal donor contamination concentrate on postenucleation contamination of the eyeball. The purpose of the present study was to evaluate the relative contamination of in situ excised corneal tissue and relevance to final success or rejection by recipients of the corneal grafts. Ninety-three donors underwent anterior chamber puncture (ACP) and corneal epithelium scarification (CS) before and after disinfection with 5% povidone-iodine. Following in situ excision, corneas were preserved in culture medium at +35 degrees C. Morphological and bacteriological assessment was carried out after culture, and recipients were followed up over a 2-year period. Samples taken by ACP, CS before disinfection, CS after disinfection and a culture medium sample were contaminated by bacteria in, respectively, 8 (8.6%), 23 (24.7%) 4 (4.3%) and 5 (5.4%) donors. Contamination of aqueous humor was significantly associated with age, death-to-sample time and premortem systemic infection. Contamination of epithelium significantly increased culture medium contamination. External bacteria on donor cornea are mainly skin bacteria (especially Staphylococcus) and can be partially eliminated by a povidone-iodine wash. Internal bacteria are mainly gut bacteria and may be due to perimortem bacteriemia. However, bacterial infection at the time of death appears to have no effect on the incidence of endophthalmitis in recipients and should no longer prevent use of such corneal tissue in grafts.

Prevalence and persistence of potentially pathogenic and antibiotic resistant bacteria during anaerobic digestion treatment of cattle manure.

PubMed

Resende, Juliana Alves; Silva, Vânia Lúcia; de Oliveira, Tamara Lopes Rocha; de Oliveira Fortunato, Samuel; da Costa Carneiro, Jailton; Otenio, Marcelo Henrique; Diniz, Cláudio Galuppo

2014-02-01

Anaerobic digestion figures as a sustainable alternative to avoid discharge of cattle manure in the environment, which results in biogas and biofertilizer. Persistence of potentially pathogenic and drug-resistant bacteria during anaerobic digestion of cattle manure was evaluated. Selective cultures were performed for enterobacteria (ENT), non-fermenting Gram-negative rods (NFR) and Gram-positive cocci (GPC). Antimicrobial susceptibility patterns were determined and a decay of all bacterial groups was observed after 60days. Multidrug-resistant bacteria were detected both the influent and effluent. GPC, the most prevalent group was highly resistant against penicillin and levofloxacin, whereas resistance to ampicillin, ampicillin-sulbactam and chloramphenicol was frequently observed in the ENT and NFR groups. The data point out the need of discussions to better address management of biodigesters and the implementation of sanitary and microbiological safe treatments of animal manures to avoid consequences to human, animal and environmental health. Copyright © 2013 Elsevier Ltd. All rights reserved.

Poultry blood from slaughterhouses: development of a biopreservation system to improve microbiological quality prior to transforming blood into by-products.

PubMed

Zbrun, M V; Frizzo, L S; Soto, L P; Rosmini, M R; Sequeira, G J; Astesana, D M; Blajman, J E; Rossler, E; Berisvil, A; Romero Scharpen, A; Signorini, M L

2016-10-01

The aim of this study was to investigate the use of indigenous lactic acid bacteria (LAB) with specific additives as a Biopreservation System (BS) for poultry blood during its storage in slaughterhouses. The BS consisted of two LAB (Enterococcus faecalis DSPV 008SA or Lactobacillus salivarius DSPV 032SA) with 4 additives (lactose 2 g/l, yeast extract 0.4 g/l, ammonium citrate 0.4 g/l and NaCl 1 g/l). After 24 h storage at 30ºC, lower counts of enterobacteria, coliforms, Pseudomonas spp. and Staphylococcus aureus were evident in blood treated with the BS than in untreated blood. The ability of LAB to prevent haemolysis was evident. A decrease in pH was associated with control of spoilage microorganisms but it needed to be regulated to prevent coagulation of proteins. On the basis of these results it is recommended to supplement blood with a BS to avoid undesirable changes during blood storage before processing.

Induction of peroxisomal beta-oxidation by a microbial catabolite of cholic acid in rat liver and cultured rat hepatocytes.

PubMed Central

Nishimaki-Mogami, T; Takahashi, A; Toyoda, K; Hayashi, Y

1993-01-01

The capability of (4R)-4-(2,3,4,6,6a beta,7,8,9,9a alpha,9b beta-decahydro-6a beta-methyl-3-oxo-1H-cyclopental[f]quinolin-7 beta-yl)valeric acid (DCQVA), a catabolite of cholic acid produced by enterobacteria, to induce peroxisome proliferation in vivo and in vitro was studied. Rats given 0.3% DCQVA in the diet for 2 weeks showed marked increases in peroxisomal beta-oxidation, mitochondrial 2,4-dienoyl-CoA reductase and microsomal laurate omega-oxidation activities in the liver compared with control rats given the diet without DCQVA. Cultured rat hepatocytes treated with DCQVA for 72 h also exhibited greatly enhanced beta-oxidation activity. The increased activity was concentration-dependent and the effective concentrations were comparable with those of clofibric acid that produced the same degree of induction in the assay. The results demonstrate that DCQVA is a potent peroxisome proliferator that occurs naturally in rat intestine. PMID:8216219

The effect of sub-inhibitory concentrations of rifaximin on urease production and on other virulence factors expressed by Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa and Staphylococcus aureus.

PubMed

Ricci, Annalisa; Coppo, Erika; Barbieri, Ramona; Debbia, Eugenio A; Marchese, Anna

2017-04-01

Rifaximin, a topical derivative of rifampin, inhibited urease production and other virulence factors at sub-MIC concentrations in strains involved in hepatic encephalopathy and the expression of methicillin resistance in Staphylococcus aureus. In particular, urease production was affected in all Proteus mirabilis and Klebsiella pneumoniae strains as well as in all tested Pseudomonas aeruginosa isolates. Other exotoxins, synthesized by P. aeruginosa, such as protease, gelatinase, lipase, lecithinase and DNAse were also not metabolized in the presence of rifaximin. This antibiotic inhibited pigment production in both P. aeruginosa and Chromobacterium violaceum, a biosensor control strain. Lastly, rifaximin affected haemolysin production in S. aureus and was able to restore cefoxitin susceptibility when the strain was cultured in the presence of sub-MICs of the drug. The present findings confirm and extend previous observations about the beneficial effects of rifaximin for the treatment of gastrointestinal diseases, since in this anatomic site, it reaches a large array of concentrations which prevents enterobacteria from thriving and/or producing their major virulence factors.

Long-range correlations and charge transport properties of DNA sequences

NASA Astrophysics Data System (ADS)

Liu, Xiao-liang; Ren, Yi; Xie, Qiong-tao; Deng, Chao-sheng; Xu, Hui

2010-04-01

By using Hurst's analysis and transfer approach, the rescaled range functions and Hurst exponents of human chromosome 22 and enterobacteria phage lambda DNA sequences are investigated and the transmission coefficients, Landauer resistances and Lyapunov coefficients of finite segments based on above genomic DNA sequences are calculated. In a comparison with quasiperiodic and random artificial DNA sequences, we find that λ-DNA exhibits anticorrelation behavior characterized by a Hurst exponent 0.5

Characterisation of source-separated household waste intended for composting

PubMed Central

Sundberg, Cecilia; Franke-Whittle, Ingrid H.; Kauppi, Sari; Yu, Dan; Romantschuk, Martin; Insam, Heribert; Jönsson, Håkan

2011-01-01

Large-scale composting of source-separated household waste has expanded in recent years in the Nordic countries. One problem can be low pH at the start of the process. Incoming biowaste at four composting plants was characterised chemically, physically and microbiologically. The pH of food waste ranged from 4.7 to 6.1 and organic acid concentration from 24 to 81 mmol kg−1. The bacterial diversity in the waste samples was high, with all samples dominated by Gammaproteobacteria, particularly Pseudomonas and Enterobacteria (Escherichia coli, Klebsiella, Enterobacter). Lactic acid bacteria were also numerically important and are known to negatively affect the composting process because the lactic acid they produce lowers the pH, inhibiting other bacteria. The bacterial groups needed for efficient composting, i.e. Bacillales and Actinobacteria, were present in appreciable amounts. The results indicated that start-up problems in the composting process can be prevented by recycling bulk material and compost. PMID:21075618

Characterisation of source-separated household waste intended for composting.

PubMed

Sundberg, Cecilia; Franke-Whittle, Ingrid H; Kauppi, Sari; Yu, Dan; Romantschuk, Martin; Insam, Heribert; Jönsson, Håkan

2011-02-01

Large-scale composting of source-separated household waste has expanded in recent years in the Nordic countries. One problem can be low pH at the start of the process. Incoming biowaste at four composting plants was characterised chemically, physically and microbiologically. The pH of food waste ranged from 4.7 to 6.1 and organic acid concentration from 24 to 81 mmol kg(-1). The bacterial diversity in the waste samples was high, with all samples dominated by Gammaproteobacteria, particularly Pseudomonas and Enterobacteria (Escherichia coli, Klebsiella, Enterobacter). Lactic acid bacteria were also numerically important and are known to negatively affect the composting process because the lactic acid they produce lowers the pH, inhibiting other bacteria. The bacterial groups needed for efficient composting, i.e. Bacillales and Actinobacteria, were present in appreciable amounts. The results indicated that start-up problems in the composting process can be prevented by recycling bulk material and compost. Copyright © 2010 Elsevier Ltd. All rights reserved.

The coffee-machine bacteriome: biodiversity and colonisation of the wasted coffee tray leach

PubMed Central

Vilanova, Cristina; Iglesias, Alba; Porcar, Manuel

2015-01-01

Microbial communities are ubiquitous in both natural and artificial environments. However, microbial diversity is usually reduced under strong selection pressures, such as those present in habitats rich in recalcitrant or toxic compounds displaying antimicrobial properties. Caffeine is a natural alkaloid present in coffee, tea and soft drinks with well-known antibacterial properties. Here we present the first systematic analysis of coffee machine-associated bacteria. We sampled the coffee waste reservoir of ten different Nespresso machines and conducted a dynamic monitoring of the colonization process in a new machine. Our results reveal the existence of a varied bacterial community in all the machines sampled, and a rapid colonisation process of the coffee leach. The community developed from a pioneering pool of enterobacteria and other opportunistic taxa to a mature but still highly variable microbiome rich in coffee-adapted bacteria. The bacterial communities described here, for the first time, are potential drivers of biotechnologically relevant processes including decaffeination and bioremediation. PMID:26592442

The coffee-machine bacteriome: biodiversity and colonisation of the wasted coffee tray leach.

PubMed

Vilanova, Cristina; Iglesias, Alba; Porcar, Manuel

2015-11-23

Microbial communities are ubiquitous in both natural and artificial environments. However, microbial diversity is usually reduced under strong selection pressures, such as those present in habitats rich in recalcitrant or toxic compounds displaying antimicrobial properties. Caffeine is a natural alkaloid present in coffee, tea and soft drinks with well-known antibacterial properties. Here we present the first systematic analysis of coffee machine-associated bacteria. We sampled the coffee waste reservoir of ten different Nespresso machines and conducted a dynamic monitoring of the colonization process in a new machine. Our results reveal the existence of a varied bacterial community in all the machines sampled, and a rapid colonisation process of the coffee leach. The community developed from a pioneering pool of enterobacteria and other opportunistic taxa to a mature but still highly variable microbiome rich in coffee-adapted bacteria. The bacterial communities described here, for the first time, are potential drivers of biotechnologically relevant processes including decaffeination and bioremediation.

Prevalencia y factores de riesgo para infecciones del tracto urinario de inicio en la comunidad causadas por Escherichia coli productor de betalactamasas de espectro extendido en Colombia

PubMed Central

Blanco, Victor M.; Maya, Juan J.; Correa, Adriana; Perenguez, Marcela; Muñoz, Juan S.; Motoa, Gabriel; Pallares, Christian J.; Rosso, Fernando; Matta, Lorena; Celis, Yamile; Garzon, Martha; Villegas, y María V.

2016-01-01

RESUMEN Introducción Las infecciones del tracto urinario (ITU) son frecuentes en la comunidad. Sin embargo, la información de aislamientos resistentes en este contexto es limitada en Latinoamérica. Este estudio tiene como objetivo determinar la prevalencia y los factores de riesgo asociados con ITU de inicio en la comunidad (ITU-IC) causadas por Escherichia coli productor de betalactamasas de espectro extendido (BLEE) en Colombia. Materiales y métodos Entre agosto y diciembre de 2011 se realizó un estudio de casos y controles en 3 instituciones de salud de tercer nivel en Colombia. Se invitó a participar a todos los pacientes admitidos a urgencias con diagnóstico probable de ITU-IC, y se les pidió una muestra de orina. En los aislamien-tos de E. coli se realizaron pruebas confirmatorias para BLEE, susceptibilidad antibiótica, caracterización molecular (PCR en tiempo real para genes bla, repetitive element palindromic PCR [rep-PCR], multilocus sequence typing [MLST] y factores de virulencia por PCR). Se obtuvo información clínica y epidemiológica, y posteriormente se realizó el análisis estadístico. Resultados De los 2.124 pacientes seleccionados, 629 tuvieron un urocultivo positivo, en 431 de estos se aisló E. coli, 54 fueron positivos para BLEE y 29 correspondieron a CTX-M-15. La mayoría de los aislamientos de E. coli productor de BLEE fueron sensibles a ertapenem, fosfomicina y amikacina. La ITU complicada se asoció fuertemente con infecciones por E. coli productor de BLEE (OR = 3,89; IC 95%: 1,10–13,89; p = 0,03). E. coli productor de CTX-M-15 mostró 10 electroferotipos diferentes; de estos, el 65% correspondieron al ST131. La mayoría de estos aislamientos tuvieron 8 de los 9 factores de virulencia analizados. Discusión E. coli portador del gen blaCTX-M-15 asociado al ST131 sigue siendo frecuente en Colombia. La presencia de ITU-IC complicada aumenta el riesgo de tener E. coli productor de BLEE, lo cual debe tenerse en cuenta para ofrecer

La inserción en el mercado laboral de los inmigrantes latinos en España y en los Estados Unidos: Diferencias por país de origen y estatus legal

PubMed Central

Connor, Phillip; Massey, Douglas

2013-01-01

Resumen Este artículo compara los resultados económicos entre los inmigrantes latinoamericanos en España y Estados Unidos. Detectamos un efecto de selección por el que la mayoría de los inmigrantes latinoamericanos en España proceden de Sudamérica de un entorno de clases medias, mientras la mayoría de los inmigrantes que van a los Estados Unidos son centroamericanos de clase baja. Este efecto de selección explica las diferencias transnacionales en la probabilidad de empleo, logro ocupacional y salarios obtenidos. A pesar de las diferencias en los orígenes y las características de los latinoamericanos en ambos países, los factores demográficos, humanos y de capital social parecen operar de forma similar en ambos países; y cuando los modelos se estiman separadamente por estatus legal, descubrimos que los efectos se acentúan más entre los inmigrantes irregulares cuando se los compara con los regulares, especialmente en Estados Unidos. PMID:24532857

"Estudio tribologico de aceros para moldes. Aplicacion al moldeo por inyeccion de polibutilentereftalato reforzado con fibra de vidrio"

NASA Astrophysics Data System (ADS)

Martinez Mateo, Isidoro Jose

Mould materials for injection moulding of polymers and polymer-matrix composites represent a relevant industrial economic sector due to the large quantity of pieces and components processed. The material selection for mould manufacturing, its composition and heat treatment, the hardening procedures and machining and finishing processes determine the service performance and life of the mould. In the first part of the present study, the relationship between the hardness and microstructure and the wear resistance of mould steels from large blocks has been studied by pin-on-disc tests, studying the main wear mechanisms. In order to determine the surface damage on mould steels under real injection conditions, different commercial steels have been studied by measuring the variation of surface roughness with the number of injected pieces with different reinforcement percentages and different mould geometries, by using optical profilometry and scanning electron microscopy techniques. It was important to determine the variation of surface roughness of the moulded pieces with the number of injection operations. The materials used were polybutyleneterephthalate pure and reinforced with either 20% or 50% glass fibre. For the different mould designs, the evolution of the glass fibre orientation with injection flow has been determined by image analysis and related to roughness changes and surface damage, both of the composite parts and of the mould steel surface. Finally, the abrasion resistance of the composite parts has been studied by scratch tests as a function of the number of injected parts and of the scratch direction with respect to injection flow and glass fibre orientation. Los materiales para moldes de inyeccion de polimeros y materiales compuestos representan un sector economicamente muy relevante debido al gran aumento del numero de componentes fabricados a partir de materiales polimericos obtenidos mediante moldeo por inyeccion. La seleccion del material para la

Mujeres felices por ser saludables: a breast cancer risk reduction program for Latino women.

PubMed

Fitzgibbon, Marian L; Gapstur, Susan M; Knight, Sara J

2003-05-01

Breast cancer is the most commonly diagnosed cancer and the most common cause of cancer mortality among Latino women. Several behavioral factors such as early detection and dietary practices could help decrease morbidity and mortality associated with breast cancer in this population. Unfortunately, there are few data regarding the efficacy of health-related interventions for young Latino women. Mujeres Felices por ser Saludables is a randomized intervention project designed to assess breast cancer risk reduction behavior among Latino women ages 20-40 years. The primary objectives of the project were to determine whether an 8-month integrated dietary/breast health intervention could lead to a greater reduction in dietary fat, increase in dietary fiber, increase in the frequency and proficiency of breast self examination (BSE), and reduction in anxiety related to BSE compared to controls. Herein we describe the overall design of the project and present baseline characteristics of the 256 randomized women. Our results suggest that the average daily intake of dietary fat (percentage of total energy) was slightly below 30% (percentage of total energy) among the women randomized. While over half of these women reported that they practice BSE, and few reported anxiety related to BSE, less than 27% of women were proficient in the recommended BSE technique. There are few data on the dietary and breast health behaviors of young low-acculturated Latino women. This study documents the feasibility of recruiting, randomizing, and obtaining both baseline dietary and breast health data on this unique and underserved population.

Relación masa-radio para estrellas enanas blancas y la interpretación de recientes mediciones hechas por Hipparcos

NASA Astrophysics Data System (ADS)

Panei, J. A.; Althaus, L. G.; Benvenuto, O. G.

Recientes mediciones de la masa y el radio hechas por Hipparcos de las estrellas enanas blancas 40 Eri B y Procyon B (Shipman, H. & Provencal, J. - ApJ. 1998, 494, 759), sugieren un núcleo compuesto de hierro para dichas estrellas, en lugar de carbono y oxígeno como predice la teoría standard de evolución estelar. Para interpretar estas observaciones, presentamos aquí, relaciones masa-radio para configuraciones degeneradas a temperatura finita para distintas composiciones químicas centrales. Para tal fin hemos calculado secuencias evolutivas de enanas blancas utilizando el código de evolución estelar, desarrollado en el Observatorio de La Plata. Dicho código resuelve las ecuaciones de estructura y evolución estelar mediante la técnica de relajación de Henyey, y esta basado en una descripción física muy detallada y actualizada.

Relationship of CYP2D6, CYP3A, POR, and ABCB1 genotypes with galantamine plasma concentrations.

PubMed

Noetzli, Muriel; Guidi, Monia; Ebbing, Karsten; Eyer, Stephan; Zumbach, Serge; Giannakopoulos, Panteleimon; von Gunten, Armin; Csajka, Chantal; Eap, Chin B

2013-04-01

The frequently prescribed antidementia drug galantamine is extensively metabolized by the enzymes cytochrome P450 (CYP) 2D6 and CYP3A and is a substrate of the P-glycoprotein. We aimed to study the relationship between genetic variants influencing the activity of these enzymes and transporters with galantamine steady state plasma concentrations. In this naturalistic cross-sectional study, 27 older patients treated with galantamine were included. The patients were genotyped for common polymorphisms in CYP2D6, CYP3A4/5, POR, and ABCB1, and galantamine steady state plasma concentrations were determined. The CYP2D6 genotype seemed to be an important determinant of galantamine pharmacokinetics, with CYP2D6 poor metabolizers presenting 45% and 61% higher dose-adjusted galantamine plasma concentrations than heterozygous and homozygous CYP2D6 extensive metabolizers (median 2.9 versus 2.0 ng/mL · mg, P = 0.025, and 1.8 ng/mL · mg, P = 0.004), respectively. The CYP2D6 genotype significantly influenced galantamine plasma concentrations. The influence of CYP2D6 polymorphisms on the treatment efficacy and tolerability should be further investigated.

Identification and Characterization of T5-Like Bacteriophages Representing Two Novel Subgroups from Food Products

PubMed Central

Sváb, Domonkos; Falgenhauer, Linda; Rohde, Manfred; Szabó, Judit; Chakraborty, Trinad; Tóth, István

2018-01-01

During recent years, interest in the use of bacteriophages as biocontrol agents against foodborne pathogens has increased, particularly for members of the family Enterobacteriaceae, with pathogenic Escherichia coli, Shigella, and Salmonella strains among them. Here, we report the isolation and characterisation of 12 novel T5-like bacteriophages from confiscated food samples. All bacterophages effectively lysed E. coli K-12 strains and were able to infect pathogenic E. coli strains representing enterohaemorrhagic (EHEC), enteropathogenic (EPEC), enterotoxigenic (ETEC), and enteroinvasive (EIEC) pathotypes, Shigella dysenteriae, S. sonnei strains, as well as multidrug-resistant (MDR) E. coli and multiple strains representing different Salmonella enterica serovars. All the bacteriophages exhibited Siphoviridae morphology. Whole genome sequencing of the novel T5-like bacteriophages showed that they represent two distinct groups, with the genome-based grouping correlating to the different host spectra. As these bacteriophages are of food origin, their stability and lack of any virulence genes, as well as their broad and mutually complementary host spectrum makes these new T5-like bacteriophages valuable candidates for use as biocontrol agents against foodborne pathogenic enterobacteria. PMID:29487585

[Interaction of a causative agent with associative bacteria during salmonellosis].

PubMed

Bukharin, O V; Valyshev, A V; Ivanova, E V; Chaĭnikova, I N; Perunova, N B

2008-01-01

To determine a composition of gut microflora during salmonellosis and to study the modification of persistent characteristics (antilysozyme activity, ALA) of symbiotic microorganisms in associations. Bacteriologic study of feces was performed in 90 patients aged 18-39 years, which were divided to three groups: patients with salmonellosis in acute phase, reconvalescent patients, and conditionally healthy persons. Condition of gut microflorawas determined; microorganisms associated with Salmonella infection were isolated, and their influence on ALA of Salmonella was studied. Gut microbiocenosis was more diverse in patients compared with healthy persons. Significant reduction of bifidobacteria quantity (to 10(7) CFU/g of feces and less), especially in reconvalescent period, was noted. Association between bifidoflora deficiency and excessive increase of quantity of yeast fungi was revealed. It was determined that exometabolites of indigenous anaerobic microflora (bifidobacteria) promoted decrease of ALA of Salmonella, whereas opportunistic facultatively anaerobic microorganisms (enterobacteria, staphylococci) rendered mainly stimulating effect on the ALA of Salmonella. Obtained data reveal characteristics of bacterial interactions in associative symbiosis and provide insights about mechanisms of formation of pathobiocenosis and state of bacterial carriage.

Antimicrobial activity evaluation and comparison of methods of susceptibility for Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacter spp. isolates.

PubMed

Rechenchoski, Daniele Zendrini; Dambrozio, Angélica Marim Lopes; Vivan, Ana Carolina Polano; Schuroff, Paulo Alfonso; Burgos, Tatiane das Neves; Pelisson, Marsileni; Perugini, Marcia Regina Eches; Vespero, Eliana Carolina

The production of KPC (Klebsiella pneumoniae carbapenemase) is the major mechanism of resistance to carbapenem agents in enterobacterias. In this context, forty KPC-producing Enterobacter spp. clinical isolates were studied. It was evaluated the activity of antimicrobial agents: polymyxin B, tigecycline, ertapenem, imipenem and meropenem, and was performed a comparison of the methodologies used to determine the susceptibility: broth microdilution, Etest ® (bioMérieux), Vitek 2 ® automated system (bioMérieux) and disc diffusion. It was calculated the minimum inhibitory concentration (MIC) for each antimicrobial and polymyxin B showed the lowest concentrations for broth microdilution. Errors also were calculated among the techniques, tigecycline and ertapenem were the antibiotics with the largest and the lower number of discrepancies, respectively. Moreover, Vitek 2 ® automated system was the method most similar compared to the broth microdilution. Therefore, is important to evaluate the performance of new methods in comparison to the reference method, broth microdilution. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Global Maps of ProQ Binding In Vivo Reveal Target Recognition via RNA Structure and Stability Control at mRNA 3' Ends.

PubMed

Holmqvist, Erik; Li, Lei; Bischler, Thorsten; Barquist, Lars; Vogel, Jörg

2018-05-15

The conserved RNA-binding protein ProQ has emerged as the centerpiece of a previously unknown third large network of post-transcriptional control in enterobacteria. Here, we have used in vivo UV crosslinking and RNA sequencing (CLIP-seq) to map hundreds of ProQ binding sites in Salmonella enterica and Escherichia coli. Our analysis of these binding sites, many of which are conserved, suggests that ProQ recognizes its cellular targets through RNA structural motifs found in small RNAs (sRNAs) and at the 3' end of mRNAs. Using the cspE mRNA as a model for 3' end targeting, we reveal a function for ProQ in protecting mRNA against exoribonucleolytic activity. Taken together, our results underpin the notion that ProQ governs a post-transcriptional network distinct from those of the well-characterized sRNA-binding proteins, CsrA and Hfq, and suggest a previously unrecognized, sRNA-independent role of ProQ in stabilizing mRNAs. Copyright © 2018 Elsevier Inc. All rights reserved.

Quality characteristics of pork burger added with albedo-fiber powder obtained from yellow passion fruit (Passiflora edulis var. flavicarpa) co-products.

PubMed

López-Vargas, Jairo H; Fernández-López, Juana; Pérez-Álvarez, José Ángel; Viuda-Martos, Manuel

2014-06-01

The aim of this work determined the technological, nutritional and sensory characteristics of pork burgers, added with different concentrations (2.5 and 5%) of passion fruit albedo (PFA) co-product, obtained from passion fruit juice processing. The addition of PFA on pork burgers improves their nutritional value (higher fiber content). In raw and cooked burger, all textural parameters, except springiness and cohesiveness, were affected by the incorporation of PFA. PFA addition was found to be effective improving the cooking yield, moisture retention and fat retention. The raw and cooked pork burgers added with PFA had lower TBA values and lower counts of aerobic mesophilic bacteria and enterobacteria than the control samples. No Escherichia coli and molds were found in the samples. The overall acceptability scores showed that the most appreciated sample was the one containing 2.5% PFA. According to the results obtained, 2.5 and 5% of PFA addition can be recommended in pork burger production as a new dietary fiber source. Copyright © 2014 Elsevier Ltd. All rights reserved.

Occurrence of carbapenemase-producing bacteria in coastal recreational waters.

PubMed

Montezzi, Lara Feital; Campana, Eloiza Helena; Corrêa, Laís Lisboa; Justo, Livia Helena; Paschoal, Raphael Paiva; da Silva, Isabel Lemos Vieira Dias; Souza, Maria do Carmo Maciel; Drolshagen, Marcia; Picão, Renata Cristina

2015-02-01

The spread of carbapenemase-producing Gram-negative rods is an emerging global problem. Although most infections due to carbapenemase producers are limited to healthcare institutions, reports of the occurrence of clinically relevant carbapenemase producers in sewage and polluted rivers are increasingly frequent. Polluted rivers flowing to oceans may contaminate coastal waters with multidrug-resistant bacteria, potentially threatening the safety of recreational activities in these locations. Here we assessed the occurrence of carbapenemase producers in water from touristic beaches located in Rio de Janeiro, Brazil, showing distinct pollution patterns. The presence of enterobacteria was noted, including the predominantly environmental genus Kluyvera spp., producing either Klebsiella pneumoniae carbapenemase (KPC) or Guyana extended-spectrum (GES)-type carbapenemases and often associated with quinolone resistance determinants. An Aeromonas sp. harbouring blaKPC and qnrS was also observed. These findings strengthen the role of aquatic matrices as reservoirs and vectors of clinically relevant antimicrobial-resistant bacteria, with potential to favour the spread of these resistance threats throughout the community. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Prospects for new antibacterials: can we do better?

PubMed

Georgopapadakou, Nafsika H

2014-02-01

Bacterial resistance to antibacterial drugs has been increasing relentlessly over the past two decades. This includes common residents of the human body: Staphylococcus aureus (methicillin resistant or MRSA) Enteroccus faecalis and E. faecium (vancomycin resistant or VRE): Enterobacteriaceae (multiresistant, carbapenems included or CRE). It also includes environmental, opportunistic, but intrinsically multiresistant species: Pseudomonas aeruginosa and Acinetobacter baumannii. Financial considerations have curtailed R&D activity in the antibacterial field in all, but a couple of large pharmaceutical companies and small biotech companies have largely been unable to fill the drug discovery gap. Antibacterials currently under development have targeted, almost exclusively, Gram-positive bacteria; hence, greater effort must be directed against Gram-negative bacteria, particularly enterobacteria. There also has to be more transparency and care in clinical development. To get ahead of the problem of resistance, we must look for first-in-class antibacterials and new targets. The need to innovate is best addressed through partnerships between drug-makers and public institutions. Such partnerships would provide a long-term view and stability to projects, but also balance the interests of corporate and public stakeholders.

[Detection of endotoxins of Gram-negative bacteria on the basis of electromagnetic radiation frequency spectrum].

PubMed

Likhoded, V G; Kuleshova, N V; Sergieva, N V; Konev, Iu V; Trubnikova, I A; Sudzhian, E V

2007-01-01

Method of Gram-negative bacteria endotoxins detection on the basis of their own spectrum of electromagnetic radiation frequency was developed. Frequency spectrum typical for chemotype Re glycolipid, which is a part of lypopolysaccharides in the majority of Gram-negative bacteria, was used. Two devices--"Mini- Expert-DT" (manufactured by IMEDIS, Moscow) and "Bicom" (manufactured by Regumed, Germany)--were used as generators of electromagnetic radiation. Detection of endotoxin using these devices was performed by electropuncture vegetative resonance test. Immunoenzyme reaction with antibodies to chemotype Re glycolipid was used during analysis of preparations for assessment of resonance-frequency method specificity. The study showed that resonance-frequency method can detect lypopolysaccharides of different enterobacteria in quantities up to 0.1 pg as well as bacteria which contain lypopolysaccharides. At the same time, this method does not detect such bacteria as Staphylococcus aureus, Bifidobacterium spp., Lactobacillus spp., and Candida albicans. The method does not require preliminary processing of blood samples and can be used for diagnostics of endotoxinemia, and detection of endotoxins in blood samples or injection solutions.

The Amino Acid Valine Is Secreted in Continuous-Flow Bacterial Biofilms▿ ‡

PubMed Central

Valle, Jaione; Da Re, Sandra; Schmid, Solveig; Skurnik, David; D'Ari, Richard; Ghigo, Jean-Marc

2008-01-01

Biofilms are structured communities characterized by distinctive gene expression patterns and profound physiological changes compared to those of planktonic cultures. Here, we show that many gram-negative bacterial biofilms secrete high levels of a small-molecular-weight compound, which inhibits the growth of only Escherichia coli K-12 and a rare few other natural isolates. We demonstrate both genetically and biochemically that this molecule is the amino acid valine, and we provide evidence that valine production within biofilms results from metabolic changes occurring within high-density biofilm communities when carbon sources are not limiting. This finding identifies a natural environment in which bacteria can encounter high amounts of valine, and we propose that in-biofilm valine secretion may be the long-sought reason for widespread but unexplained valine resistance found in most enterobacteria. Our results experimentally validate the postulated production of metabolites that is characteristic of the conditions associated with some biofilm environments. The identification of such molecules may lead to new approaches for biofilm monitoring and control. PMID:17981982

Drug Resistance in Salmonella Typhimurium and its Implications*

PubMed Central

Anderson, E. S.

1968-01-01

A rise in Salmonella typhimurium infection was observed in calves in Britain during 1964–6, follwing the adoption of the intensive farming method. A single phage type of S. typhimurium, type 29, was incriminated as the major pathogen. Attempts to treat and control the disease with a range of antibiotics were ineffective, but resulted in the acquisition of transferable multiple drug resistance by type 29. The transmission of drug-resistant type 29, directly or indirectly, from bovines to man resulted in many human infections. Transferable drug resistance reaching man from enterobacteria of animal origin may ultimately enter specifically human pathogens. Infections such as that caused by type 29 can be eliminated, not by the massive use of antibiotics but by improvement in conditions of animal husbandry and reduction in the opportunities for the initiation and spread of the disease. A reappraisal is needed of the methods of using antibiotics to determine how these methods can be improved, in order to conserve the long-term efficacy of the antibiotics. PMID:4874171

Trends in Human Fecal Carriage of Extended-Spectrum β-Lactamases in the Community: Toward the Globalization of CTX-M

PubMed Central

Burdet, Charles; Chachaty, Elisabeth; Andremont, Antoine

2013-01-01

SUMMARY In the last 10 years, extended-spectrum β-lactamase-producing enterobacteria (ESBL-E) have become one of the main challenges for antibiotic treatment of enterobacterial infections, largely because of the current CTX-M enzyme pandemic. However, most studies have focused on hospitalized patients, though today it appears that the community is strongly affected as well. We therefore decided to devote our investigation to trends in ESBL-E fecal carriage rates and comprehensively reviewed data from studies conducted on healthy populations in various parts of the world. We show that (i) community ESBL-E fecal carriage, which was unknown before the turn of the millennium, has since increased significantly everywhere, with developing countries being the most affected; (ii) intercontinental travel may have emphasized and globalized the issue; and (iii) CTX-M enzymes, especially CTX-M-15, are the dominant type of ESBL. Altogether, these results suggest that CTX-M carriage is evolving toward a global pandemic but is still insufficiently described. Only a better knowledge of its dynamics and biology will lead to further development of appropriate control measures. PMID:24092853

The Sangre Por Salud Biobank: Facilitating Genetic Research in an Underrepresented Latino Community.

PubMed

Shaibi, Gabriel; Singh, Davinder; De Filippis, Eleanna; Hernandez, Valentina; Rosenfeld, Bill; Otu, Essen; Montes de Oca, Gregorio; Levey, Sharon; Radecki Breitkopf, Carmen; Sharp, Richard; Olson, Janet; Cerhan, James; Thibodeau, Stephen; Winkler, Erin; Mandarino, Lawrence

2016-01-01

The Sangre Por Salud (Blood for Health; SPS) Biobank was created for the purpose of expanding precision medicine research to include underrepresented Latino patients. It is the result of a unique collaboration between Mayo Clinic and Mountain Park Health Center, a federally qualified community health center in Phoenix, Arizona. This report describes the rationale, development, implementation, and characteristics of the SPS Biobank. Latino adults (ages 18-85 years) who were active patients within Mountain Park Health Center's internal medicine practice in Phoenix, Ariz., and had no history of diabetes were eligible. Participants provided a personal and family history of chronic disease, completed a sociodemographic, psychosocial, and behavioral questionnaire, underwent a comprehensive cardiometabolic risk assessment (anthropometrics, blood pressure and labs), and provided blood samples for banking. Laboratory results of cardiometabolic testing were returned to the participants and their providers through the electronic health record. During the first 2 years of recruitment into the SPS Biobank, 2,335 patients were approached and 1,432 (61.3%) consented to participate; 1,354 (94.5%) ultimately completed all requisite questionnaires and medical evaluations. The cohort is primarily Spanish-speaking (72.9%), female (73.3%), with a mean age of 41.3 ± 12.5 years. Most participants were born outside of the US (77.9%) and do not have health insurance (77.5%). The prevalence of overweight (35.5%) and obesity (45.0%) was high, as was previously unidentified prediabetes (55.9%), type 2 diabetes (7.4%), prehypertension (46.8%), and hypertension (16.2%). The majority of participants rated their health as good to excellent (72.1%) and, as a whole, described their overall quality of life as high (7.9/10). Collaborative efforts such as the SPS Biobank are critical for ensuring that underrepresented minority populations are included in precision medicine initiatives and biomedical

The Sangre Por Salud Biobank: Facilitating Genetic Research in an Underrepresented Latino Community

PubMed Central

Shaibi, Gabriel; Singh, Davinder; De Filippis, Eleanna; Hernandez, Valentina; Rosenfeld, Bill; Otu, Essen; de Oca, Gregorio Montes; Levey, Sharon; Breitkopf, Carmen Radecki; Sharp, Richard; Olson, Janet; Cerhan, James; Thibodeau, Stephen; Winkler, Erin; Mandarino, Lawrence

2018-01-01

Background/Aims The Sangre Por Salud (Blood for Health; SPS) Biobank was created for the purpose of expanding precision medicine research to include underrepresented Latino patients. It is the result of a unique collaboration between Mayo Clinic and Mountain Park Health Center, a federally qualified community health center in Phoenix, Arizona. This report describes the rationale, development, implementation, and characteristics of the SPS Biobank. Methods Latino adults (ages 18–85 years) who were active patients within Mountain Park Health Center’s internal medicine practice in Phoenix, Ariz., and had no history of diabetes were eligible. Participants provided a personal and family history of chronic disease, completed a sociodemographic, psychosocial, and behavioral questionnaire, underwent a comprehensive cardiometabolic risk assessment (anthropometrics, blood pressure and labs), and provided blood samples for banking. Laboratory results of cardiometabolic testing were returned to the participants and their providers through the electronic health record. Results During the first 2 years of recruitment into the SPS Biobank, 2,335 patients were approached and 1,432 (61.3%) consented to participate; 1,354 (94.5%) ultimately completed all requisite questionnaires and medical evaluations. The cohort is primarily Spanish-speaking (72.9%), female (73.3%), with a mean age of 41.3 ± 12.5 years. Most participants were born outside of the US (77.9%) and do not have health insurance (77.5%). The prevalence of overweight (35.5%) and obesity (45.0%) was high, as was previously unidentified prediabetes (55.9%), type 2 diabetes (7.4%), prehypertension (46.8%), and hypertension (16.2%). The majority of participants rated their health as good to excellent (72.1%) and, as a whole, described their overall quality of life as high (7.9/10). Conclusion Collaborative efforts such as the SPS Biobank are critical for ensuring that underrepresented minority populations are included in

[Characterization of Escherichia coli isolates derived from phylogenetic groups A and B1 causing extraintestinal infection].

PubMed

Moreno, Eva; Prats, Guillem; Planells, Irene; Planes, Ana M; Pérez, Teresa; Andreu, Antonia

2006-10-01

Escherichia coli isolates from the non-pathogenic phylogenetic groups A and B1 rarely cause extraintestinal infections. The aim of this study was to analyze 37 E. coli isolates pertaining to phylogenetic groups A and B1 and compare them with 37 E. coli isolates from group B2 and 31 from group D, which caused the same infections. Among 105 E. coli isolated from the urine of patients with cystitis and pyelonephritis and from the blood of patients with urinary-source and other-source bacteriemia, the E. coli phylogenetic groups, 15 virulence-associated genes, 7 O-antigens and fluoroquinolone resistance were analyzed. E. coli from groups A and B1 showed fewer virulence determinants (median 3.5) than E. coli from group B2 (8.6, P < 0.01) or D (5.3, P < .001); however, a subgroup containing 3 isolates from group A and 5 from B1 harbored 5 or more factors. E. coli from groups A/B1 were associated with resistance to fluoroquinolones (74%, P < .001), whereas E. coli from group B2 were associated with susceptibility to this antibiotic (76%, P = .003). E. coli from groups A/B1 were isolated significantly more frequently in patients with pyelonephritis or sepsis and local or general factors favoring infection, association not observed in patients with cystitis. Even though most of the E. coli isolates from phylogenetic groups A and B1 presented a low virulence potential, they were able to cause extraintestinal infections, particularly in compromised patients.

Bacteria and Candida yeasts in inflammations of the oral mucosa in children with secondary immunodeficiency.

PubMed

Olczak-Kowalczyk, Dorota; Daszkiewicz, Marta; Krasuska-Sławińska; Dembowska-Bagińska, Bozena; Gozdowski, Dariusz; Daszkiewicz, Paweł; Fronc, Beata; Semczuk, Katarzyna

2012-08-01

Oral microbial flora and a damaged oral mucosa may increase the risk of bacteriemia, fungemia and complications in immunocompromised patients. Assessment of presence: bacteria and Candida spp. in different oral lesions, and the incidence of bacteremia in the case of a damaged mucosa in transplant recipients and patients receiving anti-tumour chemotherapy. Forty-five patients – 18 months to 18 years of life, were included (20 – organ recipients, 14– anti-tumour chemotherapy, 11 – control group). Clinical, oral mucosa examination focused on the type, severity and site of lesions, and microbiology assessed the presence of bacteria and fungi in the material from lesions. Blood cultures were performed in ten immunocompromised patients with manifestations of systemic infection. The control material consisted of blood cultures made prior to the onset of oral lesions and after 4–6 weeks following their remission in a diagnosed bacteremia. The statistical analysis was performed. In the subjects with secondary immunodeficiency, among other coagulase-negative Staphylococcus (CoNS), Candidia spp. were more frequent. In cancer patients, mucositis was associated with Candida spp., Streptococcus spp. Organ recipients with stomatitis exhibited the presence of CoNS, Streptococcus viridians and other. Oral lesions in the control group contained Haemophilus parainfluenzae, Neisseria spp. and Staphylococcus aureus. In 30% of immunocompromised patients, oral lesions were accompanied by bacteremia. A correlation has been found between oral lesions and the presence of S. aureus in patients without secondary immunodeficiency, and of CoNS, Enterococcus spp., Candida spp. in immunocompromised patients.

A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

PubMed Central

Van der Heiden, Edwige; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

2013-01-01

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus. PMID:23524682

A pathway closely related to the (D)-tagatose pathway of gram-negative enterobacteria identified in the gram-positive bacterium Bacillus licheniformis.

PubMed

Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M; Galleni, Moreno; Joris, Bernard

2013-06-01

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

Astronomy in the Classroom: Why? (Spanish Title: Astronomía en la Clase: ¿Por Qué?) Astronomia na Sala de Aula: Por Quê?

NASA Astrophysics Data System (ADS)

Daros Gama, Leandro; Bagdonas Henrique, Alexandre

2010-07-01

There are many discussions about the relevance of the topics covered in classes. One subject in particular is the focus of this essay: astronomy. In what sense and to what extent it would be worth to teach it in science or other kind of classes? In this paper we discuss some aspects of the advantages of dealing with this area of knowledge in schools, taking into account the epistemological and axiological dimensions of astronomy, in light of the vision of science as an intelligent dialogue with the world (Bachelard), in addition to the "problematization" knowledge of Paulo Freire. We propose that in fact the Astronomy does not need to be seen as just a new set of contents to be taught, but appears as a set of motivational contents for historical-philosophical discussions, and permit the discussion of concepts of other disciplines. Numerosas discusiones se están llevando a cabo acerca de la pertinencia de los temas tradicionalmente tratados en las clases. Uno de los temas, en particular, es el foco de este ensayo: la astronomía. ¿En qué sentido y en qué medida sería conveniente tratarla en clase, ya sea en clases de ciencias naturales, específicamente en las de astronomía o asignaturas afines? Elaboramos en este artículo algunos aspectos de las ventajas de tratar esta área del conocimiento en las escuelas, teniendo en cuenta las dimensiones epistemológica y axiológica de la astronomía, a la luz de la visión de la ciencia como un diálogo inteligente con el mundo (Bachelard), además de la propuesta del conocimiento "problematizador" de Paulo Freire. Proponemos que en realidad la astronomía no tiene por qué ser vista sólo como un nuevo conjunto de contenidos que se enseñan, sino que aparece como un conjunto de temas de motivación para el debate histórico-filosófico y para permitir la discusión de los conceptos típicos de otras disciplinas. Muitas discussões vêm acontecendo sobre a relevância dos temas abordados em sala de aula. Um tema, em

Trayectoria de los tornillos pediculares lumbares y sacros: Comparación entre el abordaje por linea media versus el abordaje posterolateral tipo wiltse

PubMed Central

Gagliardi, Martín; Guiroy, Alfredo; Molina, Federico Fernández; Fasano, Francisco; Ciancio, Alejandro Morales; Mezzadri, Juan José; Jalón, Pablo

2017-01-01

Resumen Objetivos: El objetivo de este estudio fue comparar, en fusiones lumbosacras cortas, el ángulo de convergencia de los tornillos pediculares entre el abordaje posterolateral tipo Wiltse y el abordaje mediano convencional. Método: Se revisaron en forma retrospectiva los controles en tomografía axial computada (TAC) de 76 tornillos pediculares lumbares y sacros colocados por vía posterior, mediante un abordaje mediano convencional (n: 38) o por vía posterolateral transmuscular tipo Wiltse (n: 38). Se incluyeron fusiones lumbosacras cortas desde L3 a S1, en pacientes adultos, con patología degenerativa. Se excluyeron los tornillos con una brecha ósea >4 mm en cualquier dirección, los casos con instrumentaciones pediculares previas y aquellos con curvas en el plano coronal mayores de 20°. Resultados: Considerando la totalidad de los implantes, el ángulo de convergencia fue de 23,3° (+/- 15,82). La angulación promedio, en el grupo AW, fue de 29,3° (+/- 9,72). En el grupo AC, el grado de convergencia de los implantes fue de 17,2° (+/- 10,58). Esta diferencia fue estadísticamente significativa (P < 0,0001). Para el grupo AW, el grado de convergencia según nivel fue el siguiente: L3: 31,2° (+/- 1,9); L4: 31,4° (+/- 2,76); L5: 31,1° (+/- 5,62); S1: 24,2° (+/- 12,16). El promedio del ángulo del tornillo según nivel para el grupo AC fue: L3: 16° (+/- 7,16); L4: 20,3° (+/- 6,9) L5: 15,9° (+/- 13,38); S1: 15,2° (+/- 14,32). Los implantes del grupo AW tuvieron ángulos significativamente más convergentes que el grupo AC en todos los segmentos explorados. Conclusión: En las fusiones lumbosacras cortas, la utilización del abordaje tipo Wiltse permitió la colocación de tornillos pediculares con más convergencia que en el abordaje mediano convencional. La relevancia clínica de este hecho es desconocida y se requerirían trabajos prospectivos randomizados para determinar la misma. PMID:29142777

Estimaciones de Prevalencia del VIH por Género y Grupo de Riesgo en Tijuana, México: 2006

PubMed Central

Iñiguez-Stevens, Esmeralda; Brouwer, Kimberly C.; Hogg, Robert S.; Patterson, Thomas L.; Lozada, Remedios; Magis-Rodriguez, Carlos; Elder, John P.; Viani, Rolando M.; Strathdee, Steffanie A.

2010-01-01

OBJETIVO Estimar la prevalencia del VIH en adultos de 15-49 años de edad en Tijuana, México - en la población general y en subgrupos de riesgo en el 2006. METODOS Se obtuvieron datos demográficos del censo Mexicano del 2005, y la prevalencia del VIH se obtuvo de la literatura. Se construyó un modelo de prevalencia del VIH para la población general y de acuerdo al género. El análisis de sensibilidad consistió en estimar errores estándar del promedio-ponderado de la prevalencia del VIH y tomar derivados parciales con respecto a cada parámetro. RESULTADOS La prevalencia del VIH es 0.54%(N = 4,347) (Rango: 0.22%–0.86%, (N = 1,750–6,944)). Esto sugiere que 0.85%(Rango: 0.39%–1.31%) de los hombres y 0.22%(Rango: 0.04%–0.40%) de las mujeres podrían ser VIH-positivos. Los hombres que tienen sexo con hombres (HSH), las trabajadoras sexuales usuarias de drogas inyectables (MTS-UDI), MTS-noUDI, mujeres UDI, y los hombres UDI contribuyeron las proporciones más elevadas de personas infectadas por el VIH. CONCLUSIONES El número de adultos VIH-positivos entre subgrupos de riesgo en la población de Tijuana es considerable, marcando la necesidad de enforcar las intervenciones de prevención en sus necesidades específicas. El presente modelo estima que hasta 1 en cada 116 adultos podrían ser VIH-positivos. PMID:19685824

Characterisation of the bacterial community structures in the intestine of Lampetra morii.

PubMed

Li, Yingying; Xie, Wenfang; Li, Qingwei

2016-07-01

The metagenomic analysis and 16S rDNA sequencing method were used to investigate the bacterial community in the intestines of Lampetra morii. The bacterial community structure in L. morii intestine was relatively simple. Eight different operational taxonomic units were observed. Chitinophagaceae_unclassified (26.5 %) and Aeromonas spp. (69.6 %) were detected as dominant members at the genus level. The non-dominant genera were as follows: Acinetobacter spp. (1.4 %), Candidatus Bacilloplasma (2.5 %), Enterobacteria spp. (1.5 %), Shewanella spp. (0.04 %), Vibrio spp. (0.09 %), and Yersinia spp. (1.8 %). The Shannon-Wiener (H) and Simpson (1-D) indexes were 0.782339 and 0.5546, respectively. The rarefaction curve representing the bacterial community richness and Shannon-Wiener curve representing the bacterial community diversity reached asymptote, which indicated that the sequence depth were sufficient to represent the majority of species richness and bacterial community diversity. The number of Aeromonas in lamprey intestine was two times higher after stimulation by lipopolysaccharide than PBS. This study provides data for understanding the bacterial community harboured in lamprey intestines and exploring potential key intestinal symbiotic bacteria essential for the L. morii immune response.

UTI diagnosis and antibiogram using Raman spectroscopy

NASA Astrophysics Data System (ADS)

Kastanos, Evdokia; Kyriakides, Alexandros; Hadjigeorgiou, Katerina; Pitris, Constantinos

2009-07-01

Urinary tract infection diagnosis and antibiogram require a 48 hour waiting period using conventional methods. This results in ineffective treatments, increased costs and most importantly in increased resistance to antibiotics. In this work, a novel method for classifying bacteria and determining their sensitivity to an antibiotic using Raman spectroscopy is described. Raman spectra of three species of gram negative Enterobacteria, most commonly responsible for urinary tract infections, were collected. The study included 25 samples each of E.coli, Klebsiella p. and Proteus spp. A novel algorithm based on spectral ratios followed by discriminant analysis resulted in classification with over 94% accuracy. Sensitivity and specificity for the three types of bacteria ranged from 88-100%. For the development of an antibiogram, bacterial samples were treated with the antibiotic ciprofloxacin to which they were all sensitive. Sensitivity to the antibiotic was evident after analysis of the Raman signatures of bacteria treated or not treated with this antibiotic as early as two hours after exposure. This technique can lead to the development of new technology for urinary tract infection diagnosis and antibiogram with same day results, bypassing urine cultures and avoiding all undesirable consequences of current practice.

SENCA: A Multilayered Codon Model to Study the Origins and Dynamics of Codon Usage

PubMed Central

Pouyet, Fanny; Bailly-Bechet, Marc; Mouchiroud, Dominique; Guéguen, Laurent

2016-01-01

Gene sequences are the target of evolution operating at different levels, including the nucleotide, codon, and amino acid levels. Disentangling the impact of those different levels on gene sequences requires developing a probabilistic model with three layers. Here we present SENCA (site evolution of nucleotides, codons, and amino acids), a codon substitution model that separately describes 1) nucleotide processes which apply on all sites of a sequence such as the mutational bias, 2) preferences between synonymous codons, and 3) preferences among amino acids. We argue that most synonymous substitutions are not neutral and that SENCA provides more accurate estimates of selection compared with more classical codon sequence models. We study the forces that drive the genomic content evolution, intraspecifically in the core genome of 21 prokaryotes and interspecifically for five Enterobacteria. We retrieve the existence of a universal mutational bias toward AT, and that taking into account selection on synonymous codon usage has consequences on the measurement of selection on nonsynonymous substitutions. We also confirm that codon usage bias is mostly driven by selection on preferred codons. We propose new summary statistics to measure the relative importance of the different evolutionary processes acting on sequences. PMID:27401173

Sodium alginate ameliorates indomethacin-induced gastrointestinal mucosal injury via inhibiting translocation in rats

PubMed Central

Yamamoto, Atsuki; Itoh, Tomokazu; Nasu, Reishi; Nishida, Ryuichi

2014-01-01

AIM: To investigate the effects of sodium alginate (AL-Na) on indomethacin-induced small intestinal lesions in rats. METHODS: Gastric injury was assessed by measuring ulcerated legions 4 h after indomethacin (25 mg/kg) administration. Small intestinal injury was assessed by measuring ulcerated legions 24 h after indomethacin (10 mg/kg) administration. AL-Na and rebamipide were orally administered. Myeloperoxidase activity in the stomach and intestine were measured. Microvascular permeability, superoxide dismutase content, glutathione peroxidase activity, catalase activity, red blood cell count, white blood cell count, mucin content and enterobacterial count in the small intestine were measured. RESULTS: AL-Na significantly reduced indomethacin-induced ulcer size and myeloperoxidase activity in the stomach and small intestine. AL-Na prevented increases in microvascular permeability, superoxide dismutase content, glutathione peroxidase activity and catalase activity in small intestinal injury induced by indomethacin. AL-Na also prevented decreases in red blood cells and white blood cells in small intestinal injury induced by indomethacin. Moreover, AL-Na suppressed mucin depletion by indomethacin and inhibited infiltration of enterobacteria into the small intestine. CONCLUSION: These results indicate that AL-Na ameliorates non-steroidal anti-inflammatory drug-induced small intestinal enteritis via bacterial translocation. PMID:24627600

Probiotic administration effect on fecal mutagenicity and microflora in the goat's gut.

PubMed

Apás, Ana Lidia; Dupraz, Javier; Ross, Romina; González, Silvia Nelina; Arena, Mario Eduardo

2010-11-01

The application of potentially beneficial microorganisms to increase host defense is a new trend to increase health benefits. In this paper the first specific host probiotics for goats from a mixture isolated from healthy animals (Lactobacillus reuteri DDL 19, Lactobacillus alimentarius DDL 48, Enterococcus faecium DDE 39 and Bifidobacterium bifidum DDBA) was assayed. The effect of probiotic oral administration on goats' weight, gut microbiota, as well as on the production of mutagen compounds and their indicator (putrescine), were evaluated. The probiotic supplement was able to modify microflora balance by reducing Enterobacteria like Salmonella/Shigella (1.09 and 1.21 log CFU/g feces, respectively) and increasing lactic acid bacteria and Bifidobacteria (1.67 and 2.34 log CFU/g feces, respectively). The probiotics administration was correlated with a ten time diminution of fecal putrescine (cancer and bacterial disease marker) and a decrease of 60% mutagen fecal concentration, indicating the protective effect of the treatment. Additionally, a significant increase in ruminant weight was observed after probiotic administration. These results are encouraging towards the use of probiotic mixtures as functional food for goats. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Regulation of glutamine synthetase activity in the unicellular cyanobacterium Synechocystis sp. strain PCC 6803 by the nitrogen source: effect of ammonium.

PubMed Central

Mérida, A; Candau, P; Florencio, F J

1991-01-01

Glutamine synthetase activity from Synechocystis sp. strain PCC 6803 is regulated as a function of the nitrogen source available in the medium. Addition of 0.25 mM NH4Cl to nitrate-grown cells promotes a clear short-term inactivation of glutamine synthetase, whose enzyme activity decreases to 5 to 10% of the initial value in 25 min. The intracellular levels of glutamine, determined under various conditions, taken together with the results obtained with azaserine (an inhibitor of transamidases), rule out the possibility that glutamine per se is responsible for glutamine synthetase inactivation. Nitrogen starvation attenuates the ammonium-mediated glutamine synthetase inactivation, indicating that glutamine synthetase regulation is modulated through the internal balance between carbon-nitrogen compounds and carbon compounds. The parallelism observed between the glutamine synthetase activity and the internal concentration of alpha-ketoglutarate suggests that this metabolite could play a role as a positive effector of glutamine synthetase activity in Synechocystis sp. Despite the similarities of this physiological system to that described for enterobacteria, the lack of in vivo 32P labeling of glutamine synthetase during the inactivation process excludes the existence of an adenylylation-deadenylylation system in this cyanobacterium. Images PMID:1676397

Effect of clindamycin prophylaxis on the colonic microflora in patients undergoing colorectal surgery.

PubMed Central

Kager, L; Liljeqvist, L; Malmborg, A S; Nord, C E

1981-01-01

Clindamycin was given intravenously to 15 patients undergoing colorectal surgery in an initial dose of 600 mg, given at induction of anesthesia followed by 6 doses of 600 mg at 8-h intervals. Series of serum samples and fecal specimens were taken for analysis of clindamycin concentrations. Tissue samples from the gut wall were taken at surgery. The highest serum concentrations observed occurred 30 min after administration of clindamycin and varied between 6.8 and 37.9 microgram/ml (mean, 14.8 +/- 2.0 [standard error] microgram/ml). The clindamycin concentrations in the tissue samples were between 1.8 and 13.0 microgram/g. Clindamycin concentration in the fecal samples varied between 2.1 and 460 microgram/g. Fecal samples were also collected during the investigation period for cultivation of aerobic and anaerobic bacteria. Among the aerobic bacteria, enterococci and streptococci decreased during the prophylaxis period. Anaerobic bacteria also decreased significantly during the same period. After the clindamycin administration period, enterococci, streptococci and anaerobic bacteria proliferated. No anaerobic strains resistant to clindamycin were isolated. Postoperative infections due to Streptococcus faecalis and different enterobacteria such as Escherichia coli, Enterobacter cloacae, Citrobacter freundii, and Klebsiella occurred in five patients. PMID:7325640

Effect of clindamycin prophylaxis on the colonic microflora in patients undergoing colorectal surgery.

PubMed

Kager, L; Liljeqvist, L; Malmborg, A S; Nord, C E

1981-12-01

Clindamycin was given intravenously to 15 patients undergoing colorectal surgery in an initial dose of 600 mg, given at induction of anesthesia followed by 6 doses of 600 mg at 8-h intervals. Series of serum samples and fecal specimens were taken for analysis of clindamycin concentrations. Tissue samples from the gut wall were taken at surgery. The highest serum concentrations observed occurred 30 min after administration of clindamycin and varied between 6.8 and 37.9 microgram/ml (mean, 14.8 +/- 2.0 [standard error] microgram/ml). The clindamycin concentrations in the tissue samples were between 1.8 and 13.0 microgram/g. Clindamycin concentration in the fecal samples varied between 2.1 and 460 microgram/g. Fecal samples were also collected during the investigation period for cultivation of aerobic and anaerobic bacteria. Among the aerobic bacteria, enterococci and streptococci decreased during the prophylaxis period. Anaerobic bacteria also decreased significantly during the same period. After the clindamycin administration period, enterococci, streptococci and anaerobic bacteria proliferated. No anaerobic strains resistant to clindamycin were isolated. Postoperative infections due to Streptococcus faecalis and different enterobacteria such as Escherichia coli, Enterobacter cloacae, Citrobacter freundii, and Klebsiella occurred in five patients.

Microbial deterioration of vacuum-packaged chilled beef cuts and techniques for microbiota detection and characterization: a review.

PubMed

Hernández-Macedo, Maria Lucila; Barancelli, Giovana Verginia; Contreras-Castillo, Carmen Josefina

2011-01-01

Gas production from microbial deterioration in vacuum-packs of chilled meat leads to pack distension, which is commonly referred as blown pack. This phenomenon is attributed to some psychrophilic and psychrotrophic Clostridium species, as well as Enterobacteria. The ability of these microorganisms to grow at refrigeration temperatures makes the control by the meat industry a challenge. This type of deterioration has been reported in many countries including some plants in the Midwestern and Southeastern regions of Brazil. In addition to causing economic losses, spoilage negatively impacts the commercial product brand, thereby impairing the meat industry. In the case of strict anaerobes species they are difficult to grow and isolate using culture methods in conventional microbiology laboratories. Furthermore, conventional culture methods are sometimes not capable of distinguishing species or genera. DNA-based molecular methods are alternative strategies for detecting viable and non-cultivable microorganisms and strict anaerobic microorganisms that are difficult to cultivate. Here, we review the microorganisms and mechanisms involved in the deterioration of vacuum-packaged chilled meat and address the use of molecular methods for detecting specific strict anaerobic microorganisms and microbial communities in meat samples.

Resistant starch modifies gut microflora and microbial metabolism in human flora-associated rats inoculated with faeces from Italian and UK donors.

PubMed

Silvi, S; Rumney, C J; Cresci, A; Rowland, I R

1999-03-01

The effect of sucrose and resistant starch ('CrystaLean'--a retrograded, amylose starch) on human gut microflora and associated parameters was studied in human flora-associated (HFA) rats, colonized with microfloras from UK or Italian subjects, to determine whether such floras were affected differently by dietary carbohydrates. Consumption of the resistant starch diet resulted in significant changes in four of the seven main groups of bacteria enumerated. In both the UK and Italian flora-associated rats, numbers of lactobacilli and bifidobacteria were increased 10-100-fold, and there was a concomitant decrease in enterobacteria when compared with sucrose-fed rats. The induced changes in caecal microflora of both HFA rat groups were reflected in changes in bacterial enzyme activities and caecal ammonia concentration. Although it had little effect on caecal short-chain fatty acid concentration, CrystaLean markedly increased the proportion of n-butyric acid in both rat groups and was associated with a significant increase in cell proliferation in the proximal colon of the Italian flora-associated rats. CrystaLean appeared to play a protective role in the colon environment, lowering caecal ammonia concentration, caecal pH and beta-glucuronidase activity.

Devitalization of bacterial and parasitic germs in sewage sludge during aerobic digestion under laboratory conditions.

PubMed

Juris, P; Plachý, P; Lauková, A

1995-05-01

The survival of 8 bacterial species (Pseudomonas sp., Salmonella sp., Enterobacteriae, Streptococcus sp., Escherichia coli) was detected in municipal sewage sludge up to 37 hours of mesophilic aerobic digestion under laboratory conditions. The model strain Enterococcus faecium CCM 4231 survived almost twice as long as the above-mentioned isolates. Similar findings, regarding the viability of the microorganisms studied, were also determined during thermophilic aerobic digestion of municipal sewage sludges. The final reduction in the total count of bacteria was not directly dependent on the temperature during aerobic digestion. It may be supposed that E. faecium CCM 4231 strain as a bacteriocin-producing strain with a broad antimicrobial spectrum, inoculated into the sludges, could inhibit the growth of microorganisms in the sludges by the way of its bacteriocin activity. Studying the effect of aerobic digestion on the viability of helminth eggs, the observed negative effect of higher temperatures was more expressive in comparison with bacterial strains. During thermophilic digestion process all helminth eggs (Ascaris suum, Toxocara canis) were devitalized. All eggs of T. canis were killed in experiments under mesophilic temperature. However, 32% of nonembryonated A. suum eggs remained viable.

Cross-feeding between bifidobacteria and butyrate-producing colon bacteria explains bifdobacterial competitiveness, butyrate production, and gas production.

PubMed

De Vuyst, Luc; Leroy, Frédéric

2011-09-01

Inulin-type fructans are not digested and reach the human colon intact, where they are selectively fermented by the colon microbiota, in particular bifidobacteria. As a result, they are converted, directly or indirectly, to short-chain fatty acids and other organic acids, as well as gases, and lead to both bifidogenic and butyrogenic health-promoting effects. Bifidobacteria display phenotypic variation on strain level as to their capacity to degrade inulin-type fructans. Also, different chain lengths of inulin-type fructans may stimulate different subgroups within the bifidobacterial population. The end-metabolites of inulin-type fructan degradation by bifidobacteria reflect their growth rates on these polymers. Other colon bacteria are also able to degrade inulin-type fructans, as is the case for lactobacilli, Bacteroides, certain enterobacteria, and butyrate producers. Bacterial cross-feeding mechanisms in the colon lay at the basis of overall butyrate production, a functional characteristic of several colon bacteria that is always accompanied by gas production. Finally, specificity of polysaccharide use by the colon microbiota may determine diet-induced alterations in the microbiota and consequent metabolic effects. Copyright © 2011 Elsevier B.V. All rights reserved.

Urinary tract infection diagnosis and response to antibiotics using Raman spectroscopy

NASA Astrophysics Data System (ADS)

Kastanos, Evdokia; Kyriakides, Alexandros; Hadjigeorgiou, Katerina; Pitris, Constantinos

2009-02-01

Urinary tract infection diagnosis and antibiogram require a 48 hour waiting period using conventional methods. This results in ineffective treatments, increased costs and most importantly in increased resistance to antibiotics. In this work, a novel method for classifying bacteria and determining their sensitivity to an antibiotic using Raman spectroscopy is described. Raman spectra of three species of gram negative Enterobacteria, most commonly responsible for urinary tract infections, were collected. The study included 25 samples each of E.coli, Klebsiella p. and Proteus spp. A novel algorithm based on spectral ratios followed by discriminant analysis resulted in classification with over 94% accuracy. Sensitivity and specificity for the three types of bacteria ranged from 88-100%. For the development of an antibiogram, bacterial samples were treated with the antibiotic ciprofloxacin to which they were all sensitive. Sensitivity to the antibiotic was evident after analysis of the Raman signatures of bacteria treated or not treated with this antibiotic as early as two hours after exposure. This technique can lead to the development of new technology for urinary tract infection diagnosis and antibiogram with same day results, bypassing urine cultures and avoiding all undesirable consequences of current practice.

Transcriptome Complexity and Riboregulation in the Human Pathogen Helicobacter pylori

PubMed Central

Pernitzsch, Sandy R.; Sharma, Cynthia M.

2012-01-01

The Gram-negative Epsilonproteobacterium Helicobacter pylori is considered as one of the major human pathogens and many studies have focused on its virulence mechanisms as well as genomic diversity. In contrast, only very little is known about post-transcriptional regulation and small regulatory RNAs (sRNAs) in this spiral-shaped microaerophilic bacterium. Considering the absence of the common RNA chaperone Hfq, which is a key-player in post-transcriptional regulation in enterobacteria, H. pylori was even regarded as an organism without riboregulation. However, analysis of the H. pylori primary transcriptome using RNA-seq revealed a very complex transcriptional output from its small genome. Furthermore, the identification of a wealth of sRNAs as well as massive antisense transcription indicates that H. pylori uses riboregulation for its gene expression control. The ongoing functional characterization of sRNAs along with the identification of associated RNA binding proteins will help to understand their potential roles in Helicobacter virulence and stress response. Moreover, research on riboregulation in H. pylori will provide new insights into its virulence mechanisms and will also help to shed light on post-transcriptional regulation in other Epsilonproteobacteria, including widespread and emerging pathogens such as Campylobacter. PMID:22919606

A Trojan-Horse Strategy Including a Bacterial Suicide Action for the Efficient Use of a Specific Gram-Positive Antibiotic on Gram-Negative Bacteria.

PubMed

Schalk, Isabelle J

2018-05-10

In the alarming context of rising bacterial antibiotic resistance, there is an urgent need to discover new antibiotics or increase and/or enlarge the activity of those currently in use. The need for new antibiotics is even more urgent in the case of Gram-negative bacteria, such as Acinetobacter, Pseudomonas, and Enterobacteria, which have become resistant to many antibiotics and have an outer membrane with very low permeability to drugs. Vectorization of antibiotics using siderophores may be a solution to bypass such a bacterial wall: the drugs use the iron transporters of the outer membrane as gates to enter bacteria in a Trojan-horse strategy. Designing siderophore-antibiotics that can cross outer membranes has become almost routine, but their transport across the inner membrane is still a limiting step, as well as a strategy that allows dissociation of the antibiotic from the siderophore once inside the bacteria. Liu et al. ( J. Med. Chem. 2018 , DOI: 10.1021/acs.jmedchem.8b00218 ) report the synthesis of a siderophore-cephalosporin compound and demonstrate that β-lactams, such as cephalosporins, can serve as β-lactamase-triggered releasable linkers to allow intracellular delivery of Gram-positive antibiotics to Gram-negative bacteria.

Characterization, Genome Sequence, and Analysis of Escherichia Phage CICC 80001, a Bacteriophage Infecting an Efficient L-Aspartic Acid Producing Escherichia coli.

PubMed

Xu, Youqiang; Ma, Yuyue; Yao, Su; Jiang, Zengyan; Pei, Jiangsen; Cheng, Chi

2016-03-01

Escherichia phage CICC 80001 was isolated from the bacteriophage contaminated medium of an Escherichia coli strain HY-05C (CICC 11022S) which could produce L-aspartic acid. The phage had a head diameter of 45-50 nm and a tail of about 10 nm. The one-step growth curve showed a latent period of 10 min and a rise period of about 20 min. The average burst size was about 198 phage particles per infected cell. Tests were conducted on the plaques, multiplicity of infection, and host range. The genome of CICC 80001 was sequenced with a length of 38,810 bp, and annotated. The key proteins leading to host-cell lysis were phylogenetically analyzed. One protein belonged to class II holin, and the other two belonged to the endopeptidase family and N-acetylmuramoyl-L-alanine amidase family, respectively. The genome showed the sequence identity of 82.7% with that of Enterobacteria phage T7, and carried ten unique open reading frames. The bacteriophage resistant E. coli strain designated CICC 11021S was breeding and its L-aspartase activity was 84.4% of that of CICC 11022S.

[Formation of microbial biofilms in causative agents of acute and chronic pyelonephritis].

PubMed

Lagun, L V; Atanasova, Iu V; Tapal'skiĭ, D V

2013-01-01

Study the intensity of formation of microbial biofilms by Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus strains isolated during various forms of pyelonephritis. 150 clinical isolates of microorganisms isolated from urine ofpatientswith acute and chronic pyelonephritiswere included into the study. Determination of intensity of film-formation was carried out by staining of the formed biofilms by crystal violet with consequent extraction of the dye and measurement of its concentration in washout solution. Among causative agents ofpyelonephritis P. aeruginosa isolates had the maximum film-forming ability. The intensity of biofilm formation of these isolates was 2-3 time higher than staphylococcus and enterobacteria strains. Strains isolated from patients with chronic pyelonephritis by ability to form biofilms significantly surpassed strains isolated from acute pyelonephritis patients. A higher ability to form microbial biofilms for microorganisms--causative agents of pyelonephritis progressing against the background ofurolithiasis was noted. The ability to form biofilms is determined by both causative agent species and character of the infectious process in which this microorganism participates. Intensive formation of biofilms by E. coli, P. aeruginosa, K. pneumoniae, S. aureus clinical isolates may be an important factor of chronization of urinary tract infections.

Oral Administration of P. gingivalis Induces Dysbiosis of Gut Microbiota and Impaired Barrier Function Leading to Dissemination of Enterobacteria to the Liver

PubMed Central

Nakajima, Mayuka; Arimatsu, Kei; Kato, Tamotsu; Matsuda, Yumi; Minagawa, Takayoshi; Takahashi, Naoki; Ohno, Hiroshi; Yamazaki, Kazuhisa

2015-01-01

Although periodontitis has been implicated as a risk factor for various systemic diseases, the precise mechanisms by which periodontitis induces systemic disease remain to be elucidated. We have previously revealed that repeated oral administration of Porphyromonas gingivalis elicits endotoxemia via changes in the gut microbiota of the ileum, and thereby induces systemic inflammation and insulin resistance. However, it is not clear to what extent a single administration of P. gingivalis could affect gut microbiota composition, gut barrier function, and subsequent influx of gut microbiota into the liver. Therefore, in the present study, C57BL/6 mice were orally administered P. gingivalis (strain W83) once and compared to sham-inoculated mice. The phylogenetic structure and diversity of microbial communities in the gut and liver were analyzed by pyrosequencing the 16S ribosomal RNA genes. Serum endotoxin activity was determined by a Limulus amebocyte lysate test. Gene expression in the intestine and expression of 16S rRNA genes in the blood and liver were examined by quantitative polymerase chain reaction. Administration of P. gingivalis significantly altered gut microbiota, with an increased proportion of phylum Bacteroidetes, a decreased proportion of phylum Firmicutes, and increased serum endotoxin levels. In the intestinal tissues, gene expression of tjp-1 and occludin, which are involved in intestinal permeability, were downregulated. Higher amounts of bacterial DNA were detected in the liver of infected mice. Importantly, changes in gut microbiota preceded systemic inflammatory changes. These results further support the idea that disturbance of the gut microbiota composition by orally derived periodontopathic bacteria may be a causal mechanism linking periodontitis and systemic disease. PMID:26218067

[Chromatographic mass spectrometric determination of low-molecular-weight aromatic compounds of microbial origin in the serum from patients with sepsis].

PubMed

Beloborodova, N V; Arkhipova, A S; Beloborodov, D M; Boĭko, N B; Mel'ko, A I; Olenin, A Iu

2006-02-01

The investigation quantitatively determined the content of low-molecular-weight aromatic compounds of microbial origin in the sera of 34 individuals by chromatographic mass spectrometry. An "Agilent Technogies 6890N" gas chromatograph with a 5973 mass selective detector was applied; chromatographic separation of components was effected on an Hp-5MS quartz capillary column. Aromatic small molecules originating from microbes (SMOM) were determined in the sera of 7 patients with sepsis. The diagnosis of sepsis was documented by the presence of the systemic inflammation syndrome and by that of bacteriemia and/or artificial ventilation-associated pneumonia along with the level of procalcitonin of higher than 10 ng/ml. The levels of aromatic SMOM were compared in 10 healthy donors, 8 preoperative cardiosurgical patients, and 9 patients with different abnormalities without sepsis treated in an intensive care unit (ICU). Serum phenylacetic and 3-phenylpropionic acids were found to be prevalent in the healthy donors and postoperative cardiosurgical patients. In ICU patients with different complications without sepsis, more than half the compounds under study were undetectable, the others were found in very low concentrations, which may be accounted for by antibiotic therapy. At the same time, almost the whole spectrum of the test compounds (other than 3-phenylpropionic acid) with the highest concentrations of 3-phenyllactic, p-hydroxyphenylacetic, 3-(p-hydroxyphenyl)lactic and 2-hydroxybutanic acids, was detectable in septic patients receiving a more intensive therapy. The differences were statistically significant (by the Mann-Whitney U-test; p < 0.05). By taking into account the potentially high biological activity of the test compounds, studies are to be continued in this area.

Procalcitonin: a marker of bacteraemia in SIRS.

PubMed

Bell, K; Wattie, M; Byth, K; Silvestrini, R; Clark, P; Stachowski, E; Benson, E M

2003-12-01

A number of European studies have documented the ability of procalcitonin (PCT), a novel inflammatory marker, to discriminate patients with sepsis from those with other causes of systemic inflammatory response syndrome (SIRS). The aim of this study was to assess procalcitonin's performance in an Australian intensive care unit (ICU) setting to examine whether it could discriminate between these two conditions. One hundred and twenty-three consecutive adult ICU patients fulfilling criteria for SIRS were enlisted in the study. Over a period of five days, daily serum PCT and C-reactive protein (CRP) levels were measured. At least two sets of cultures were taken of blood, sputum/broncho-alveolar lavage (BAL) and urine. Other cultures were taken as clinically indicated. Questionnaires to ascertain clinical suspicion of sepsis were prospectively answered by the ICU senior registrars. PCT values were ten times higher in patients with positive blood cultures; CRP values were also significantly higher in the bacteraemic patients. Both PCT and CRP had a good ability to discriminate bacteraemia from non-infectious SIRS, with the area under receiver operating characteristics (ROC) curves for PCT being 0.8 and for CRP being 0.82. However neither PCT or CRP was able to discriminate patients with localized sepsis from those without. Utilizing both tests resulted in a more sensitive screen than either one alone, while PCT was a more accurate diagnostic test for bacteraemia than CRP. The PCT value also differed between those who died in hospital and those who survived. Measurement of PCT alone or in combination with CRP can aid discrimination of septicaemia/bacteriemia with associated SIRS from non-infectious SIRS in an Australian ICU setting.

[Assessment of the impact of vitamin and dietary fiber content in the diet on the characteristics of protective colon microbiota populations of rats].

PubMed

Markova, Yu M; Sheveleva, S A

2015-01-01

The content of lactobacilli and enterobacteria in the experiment in rats with varying levels of vitamins and dietary fiber was studied. The study was performed on 48 male weanling Wistar rats randomized into 8 groups, with the creation of vitamin deficiency (30 d.) and its further compensation (5 d.). Vitamin content in the semisynthetic diet in rats of the control group N 1 corresponded to 100% of a daily adequate intake. In the similar composition of the diet of the control group N 2 wheat bran was added in amount of 5% of the weight of the diet. In groups N 3–8 rats received a diet with the reduced amount of vitamin mixture by 5 times (20% of the adequate intake) and the total exclusion of tocopherol, thiamine and riboflavin from the mixture. The wheat bran (5% of diet mass) was added to the diets in Groups N 4, 6, 8. At the stage of compensation of deficiency rats were fed with the diets with increased content of vitamin mixture: Group 5–6 to 80% 7–8 to 200% (100 and 220% of the adequate intake, respectively), and the groups N 3–4 continued to receive deficient diet with or without wheat bran until the end of the experiment. After 35 days rats were anesthetized with ether, decapitated, necropsied and the cecum segments were selected for quantitative microbiological analysis of its contents. It has been shown that the addition of wheat bran to vitamin deficient diet lead to the reduction of the manifestation of physical sign of hypovitaminosis. It also eliminated the differences in the integrated index of growth and development of rats in comparison with the group without vitamin deficiency. It was found that the vitamin deficiency in the diet, regardless of the presence or absence of wheat bran, led to a significant reduction of the number of lactobacilli in the intestinal contents, but almost did not affect the number of normal and opportunistic pathogenic enterobacteria. The compensation of deficiency during 5 days lead to the increased number of

Results of Mujeres Felices por ser Saludables: a dietary/breast health randomized clinical trial for Latino women.

PubMed

Fitzgibbon, Marian L; Gapstur, Susan M; Knight, Sara J

2004-10-01

Data are limited on the efficacy of health-focused interventions for young, low-acculturated Latino women. Because breast cancer is the most commonly diagnosed cancer and the most common cause of cancer mortality in this population, combined interventions that address both early detection and dietary patterns could help reduce both morbidity and mortality associated with breast cancer in this underserved population. Mujeres Felices por ser Saludables was randomized intervention study designed to assess the efficacy of an 8-month combined dietary and breast health intervention to reduce fat and increase fiber intake as well as to increase the frequency and proficiency of breast self-examination (BSE) and reduce anxiety related to BSE among Latinas. Blocked randomization in blocks of 6 was used to randomize 256 20- to 40-year-old Latinas to the intervention (n = 127) or control group (n = 129). The intervention group attended an 8-month multicomponent education program designed specifically for low-acculturated Latinas. The control group received mailed health education material on a schedule comparable to the intervention. A total of 195 women (76.2%) completed both the baseline and 8-month follow-up interviews. The intervention and control groups were similar on baseline sociodemographic characteristics. At the 8-month follow up, the intervention group reported lower dietary fat (P < .001) and higher fiber intake (p = .06); a higher proportion reported practicing BSE at the recommended interval (p < .001) and showed improved BSE proficiency (p < .001) compared to the control group. BSE-related anxiety was low for both groups at baseline, and no difference in reduction was observed. This project provides a successful model for achieving dietary change and improving breast health behavior in young, low-acculturated Latinas.

Detection and characterization of multidrug-resistant enterobacteria bearing aminoglycoside-modifying gene in a university hospital at Rio de Janeiro, Brazil, along three decades.

PubMed

Dias-Gonçalves, Verônica; Bohrer-Lengruber, Françoise; Oliveira-Fonseca, Bianca; Santos-Pereira, Renata Meirelles; Barbosa de Melo, Luis Dione; Gazos-Lopes, Ulisses; Ribeiro-Bello, Alexandre; Adler-Pereira, José Augusto

2015-01-01

Multidrug-resistant Enterobacteriaceae, particularly those resistant to gentamicin, have become one of the most important causes of nosocomial infections. We sought to investigate the presence of genes conferring resistance to aminoglycosides, specially to gentamicin, in Klebsiella pneumoniae and Escherichia coli multidrug-resistant strains isolated from different clinical materials among patients hospitalized in a university hospital in Rio de Janeiro, Brazil. Ten colonization strains and 20 infection strains were evaluated during three decades (1980 to 2010) using selective media containing 8 µg/ml of gentamicin. Thirty strains were tested for antimicrobial susceptibility. Twenty two strains were subjected to plasmid DNA extraction and 12 to hybridization assays using as probe a 1.9 kb plasmid DNA fragment from one of the K. pneumoniae strains isolated from faecal samples. This fragment was sequenced and assigned to the GQ422439 GenBank record. PCR was also performed using oligonucleotides designed for aminoglycoside-modifying enzymes. An accC2 acetylase, besides transposons and insertion sequences, were evidenced. Twenty-four (80%) of the isolates were positive for the aacC2 gene in agreement with antibiotic susceptibility testing profiles, indicating the persistent presence of this gene throughout the three decades. We detected high molecular weight plasmids in 54,5% of the strains. Of the tested strains, 91% showed positive signal in the hybridization assays. A gene codifying for one specific aminoglycoside-modifying enzyme was detected all throughout the three decades. Our data back the adoption of preventive measures, such as a more conscious use of antimicrobial agents in hospital environments, which can contribute to control the dissemination of microorganisms harboring resistance gene plasmids.

Development of diagnostic prediction tools for bacteraemia caused by third-generation cephalosporin-resistant enterobacteria in suspected bacterial infections: a nested case-control study.

PubMed

Rottier, W C; van Werkhoven, C H; Bamberg, Y R P; Dorigo-Zetsma, J W; van de Garde, E M; van Hees, B C; Kluytmans, J A J W; Kuck, E M; van der Linden, P D; Prins, J M; Thijsen, S F T; Verbon, A; Vlaminckx, B J M; Ammerlaan, H S M; Bonten, M J M

2018-03-23

Current guidelines for the empirical antibiotic treatment predict the presence of third-generation cephalosporin-resistant enterobacterial bacteraemia (3GCR-E-Bac) in case of infection only poorly, thereby increasing unnecessary carbapenem use. We aimed to develop diagnostic scoring systems which can better predict the presence of 3GCR-E-Bac. A retrospective nested case-control study was performed that included patients ≥18 years of age from eight Dutch hospitals in whom blood cultures were obtained and intravenous antibiotics were initiated. Each patient with 3GCR-E-Bac was matched to four control infection episodes within the same hospital, based on blood-culture date and onset location (community or hospital). Starting from 32 commonly described clinical risk factors at infection onset, selection strategies were used to derive scoring systems for the probability of community- and hospital-onset 3GCR-E-Bac. 3GCR-E-Bac occurred in 90 of 22 506 (0.4%) community-onset infections and in 82 of 8110 (1.0%) hospital-onset infections, and these cases were matched to 360 community-onset and 328 hospital-onset control episodes. The derived community-onset and hospital-onset scoring systems consisted of six and nine predictors, respectively. With selected score cut-offs, the models identified 3GCR-E-Bac with sensitivity equal to existing guidelines (community-onset: 54.3%; hospital-onset: 81.5%). However, they reduced the proportion of patients classified as at risk for 3GCR-E-Bac (i.e. eligible for empirical carbapenem therapy) with 40% (95%CI 21-56%) and 49% (95%CI 39-58%) in, respectively, community-onset and hospital-onset infections. These prediction scores for 3GCR-E-Bac, specifically geared towards the initiation of empirical antibiotic treatment, may improve the balance between inappropriate antibiotics and carbapenem overuse. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Bifurcación de las soluciones de vientos impulsados por radiación en estrellas Be: formación de líneas

NASA Astrophysics Data System (ADS)

Curé, M.; Rial, D.; Cidale, L.; Venero, R.

Se ha estudiado la topología de la ecuación hidrodinámica no-lineal que describe el perfil de velocidades de vientos impulsados por radiación en estrellas tempranas. Al aplicar este modelo a estrellas Be se encuentra que existen dos tipos De soluciones: la estándar, que describe el viento polar, y una nueva, que describe un viento más denso y lento y que explicaría el disco que se encuentra alrededor de estos objetos. Existe una región de transición en donde ambas soluciones coexisten (bifurcación}). Ambas soluciones satisfacen en esta región las mismas condiciones de borde. Para estas dos soluciones se han obtenido los perfiles de líneas de hidrógeno del visible y del IR, resolviendo el transporte de radiación en el ``comoving frame". Para la solución estándar, se obtienen perfiles con componentes en emisión, mientras que para la nueva solución se obtienen perfiles en absorción. Se comparan cualitativamente los resultados con las observaciones.

Multiresistant opportunistic pathogenic bacteria isolated from polluted rivers and first detection of nontuberculous mycobacteria in the Algerian aquatic environment.

PubMed

Djouadi, Lydia Neïla; Selama, Okba; Abderrahmani, Ahmed; Bouanane-Darenfed, Amel; Abdellaziz, Lamia; Amziane, Meriam; Fardeau, Marie-Laure; Nateche, Farida

2017-08-01

Opportunistic infections constitute a major challenge for modern medicine mainly because the involved bacteria are usually multiresistant to antibiotics. Most of these bacteria possess remarkable ability to adapt to various ecosystems, including those exposed to anthropogenic activities. This study isolated and identified 21 multiresistant opportunistic bacteria from two polluted rivers, located in Algiers. Cadmium, lead, and copper concentrations were determined for both water samples to evaluate heavy metal pollution. High prevalence of Enterobacteria and non-fermentative Gram-negative rods was found and a nontuberculous Mycobacterium (NTM) strain was isolated. To the best of our knowledge, this is the first detection of NTM in the Algerian environment. The strains were tested for their resistance against 34 antibiotics and 8 heavy metals. Multiple antibiotics and heavy metals resistance was observed in all isolates. The two most resistant strains, identified as Acinetobacter sp. and Citrobacter freundii, were submitted to plasmid curing to determine if resistance genes were plasmid or chromosome encoded. Citrobacter freundii strain P18 showed a high molecular weight plasmid which seems to code for resistance to zinc, lead, and tetracycline, at the same time. These findings strongly suggest that anthropized environments constitute a reservoir for multiresistant opportunistic bacteria and for circulating resistance genes.

[Vaginitis and vaginosis. Comparison of two periods].

PubMed

Ceruti, M; Canestrelli, M; Piantelli, G; Amone, F; Condemi, V; De Paolis, P; Ludovici, G; Somenzi, P

1993-10-01

Vaginitis is the most frequent gynecological disease. It is characterized by objective and subjective signs of inflammation and differs from bacterial vaginosis (BV) which is an abnormal condition of the vaginal ecosystem caused by the excessive growth of aerobic and anaerobic flora normally present in the vagina with an increased risk of pelvic inflammatory disease (PID). The authors report the results of a study carried out at the Centre for Gynecological Infections at the Clinic of Obstetrics and Gynecology of the University of Parma. 828 patients were enrolled in the study during the period 1985-86 and 1559 patients during the two-year period 1991-92. The aim of the study was to evaluate variations in epidemiological data for vaginitis and bacterial vaginosis in the two periods examined. No significant changes were observed (p > 0.05) with regard to the prevalence of Ca, Tv and BV forms. On the other hand, there was a significant reduction (p < 0.001) in the forms sustained by other microorganisms (above all, streptococcus and enterobacteria) between the first and second periods with a parallel increase in the number of negative cases. The analysis of the age distribution of vaginitis and BV showed a reduction of other microorganisms and an increase in negative vaginal swabs in adults (> 20 years old).

Sensitive Monitoring of Enterobacterial Contamination of Food Using Self-Propelled Janus Microsensors.

PubMed

Pacheco, M; Jurado-Sánchez, B; Escarpa, A

2018-02-20

Food poisoning caused by bacteria is a major cause of disease and death worldwide. Herein we describe the use of Janus micromotors as mobile sensors for the detection of toxins released by enterobacteria as indicators of food contamination. The micromotors are prepared by a Pickering emulsion approach and rely on the simultaneous encapsulation of platinum nanoparticles for enhanced bubble-propulsion and receptor-functionalized quantum dots (QDs) for selective binding with the 3-deoxy-d-manno-oct-2-ulosonic acid target in the endotoxin molecule. Lipopolysaccharides (LPS) from Salmonella enterica were used as target endotoxins, which upon interaction with the QDs induce a rapid quenching of the native fluorescence of the micromotors in a concentration-dependent manner. The micromotor assay can readily detect concentrations as low as 0.07 ng mL -1 of endotoxin, which is far below the level considered toxic to humans (275 μg mL -1 ). Micromotors have been successfully applied for the detection of Salmonella toxin in food samples in 15 min compared with several hours required by the existing Gold Standard method. Such ultrafast and reliable approach holds considerable promise for food contamination screening while awaiting the results of bacterial cultures in a myriad of food safety and security defense applications.

Sheep milk: physical-chemical characteristics and microbiological quality.

PubMed

Merlin Junior, Ivandré Antonio; Santos, Joice Sifuentes dos; Costa, Ligia Grecco; Costa, Renan Grecco; Ludovico, Agostinho; Rego, Fabiola Cristine de Almeida; Santana, Elsa Helena Walter de

2015-09-01

Sheep milk is the third most consumed milk in Brazil. It is much appreciated for its nutritional status and is important for children that have problems with cow milk. Little information is known about the chemical, physical and microbiological composition of sheep milk from South Brazil. Thus, the aim of this study was to describe chemical and microbiological characteristics of sheep milk produced on two rural properties located in southern Brazil (ParanA and Rio Grande do Sul). The chemical composition of sheep milk was 17.32 g/100 g total solids, 5.86 g/100 g total protein, 4.46 g/100 g casein, 1.08 g/100 g whey protein, 7.28 g/100 g fat, 0.93 g/100 g ash, and 3.41 g/100 g lactose. High somatic cell count (1.7x106 cells/mL), total mesophilic bacterias (16.0 x 106 CFU/mL) and psychrotrophics (5.8 x 106 CFU/mL) were observed. Growth of Staphylococcus aureus, enterobacteria and coliforms occurred in 100% of the samples, and 45% of the samples showed growth of Escherichia coli. The sheep milk physical-chemical and microbiology parameters are similar to those presented in the literature for other countries but somatic cell count presented high levels.

Diversity of bacteriome associated with Phlebotomus chinensis (Diptera: Psychodidae) sand flies in two wild populations from China

PubMed Central

Li, Kaili; Chen, Huiying; Jiang, Jinjin; Li, Xiangyu; Xu, Jiannong; Ma, Yajun

2016-01-01

Sand fly Phlebotomus chinensis is a primary vector of transmission of visceral leishmaniasis in China. The sand flies have adapted to various ecological niches in distinct ecosystems. Characterization of the microbial structure and function will greatly facilitate the understanding of the sand fly ecology, which would provide critical information for developing intervention strategy for sand fly control. In this study we compared the bacterial composition between two populations of Ph. chinensis from Henan and Sichuan, China. The phylotypes were taxonomically assigned to 29 genera of 19 families in 9 classes of 5 phyla. The core bacteria include Pseudomonas and enterobacteria, both are shared in the sand flies in the two regions. Interestingly, the endosymbionts Wolbachia and Rickettsia were detected only in Henan, while the Rickettsiella and Diplorickettsia only in Sichuan. The intracellular bacteria Rickettsia, Rickettsiella and Diplorickettsia were reported for the first time in sand flies. The influence of sex and feeding status on the microbial structure was also detected in the two populations. The findings suggest that the ecological diversity of sand fly in Sichuan and Henan may contribute to shaping the structure of associated microbiota. The structural classification paves the way to function characterization of the sand fly associated microbiome. PMID:27819272

Recovery and screening for antibiotic susceptibility of potential bacterial pathogens from the oral cavity of shark species involved in attacks on humans in Recife, Brazil.

PubMed

Interaminense, J A; Nascimento, D C O; Ventura, R F; Batista, J E C; Souza, M M C; Hazin, F H V; Pontes-Filho, N T; Lima-Filho, J V

2010-08-01

The number of incidents involving sharks and humans at beaches in Recife, on the north-eastern Brazilian coast, is among the highest worldwide. In addition, wound infections in survivors are common; but the nature and risk of the aetiological agents is unknown. In the present study, 81 potential bacterial pathogens were identified in the oral cavity of sharks involved in attacks in Recife, and were subjected to antibiotic susceptibility tests using the standardized disc-diffusion method. The majority were enterobacteria such as Enterobacter spp., Citrobacter spp., Proteus spp., Providencia alcalifaciens, Escherichia coli, Moellerella wisconcensis and Leclercia adecarboxylata. Other Gram-negative bacteria included Vibrio spp., Burkholderia cepacia, Acinetobacter spp. and Pseudomonas spp. In addition, coagulase-positive and coagulase-negative Staphylococcus spp., Enterococcus spp. and Micrococcus spp. were identified, besides Streptococcus spp. from the viridans group. Resistance was especially found in the Proteus mirabilis and Citrobacter freundii, and ranged from 4 to 6 antibiotics out of the 13 tested. Gentamicin and vancomycin were the most effective against Gram-positive cocci strains, whereas levofloxacin was fully inhibitory against Gram-positive and Gram-negative bacteria. These data are discussed in light of a retrospective evaluation of the medical records of three shark victims treated at Restauração Hospital in Recife.

Effect of Bifidobacterium breve on the Intestinal Microbiota of Coeliac Children on a Gluten Free Diet: A Pilot Study.

PubMed

Quagliariello, Andrea; Aloisio, Irene; Bozzi Cionci, Nicole; Luiselli, Donata; D'Auria, Giuseppe; Martinez-Priego, Llúcia; Pérez-Villarroya, David; Langerholc, Tomaž; Primec, Maša; Mičetić-Turk, Dušanka; Di Gioia, Diana

2016-10-22

Coeliac disease (CD) is associated with alterations of the intestinal microbiota. Although several Bifidobacterium strains showed anti-inflammatory activity and prevention of toxic gliadin peptides generation in vitro, few data are available on their efficacy when administered to CD subjects. This study evaluated the effect of administration for three months of a food supplement based on two Bifidobacterium breve strains (B632 and BR03) to restore the gut microbial balance in coeliac children on a gluten free diet (GFD). Microbial DNA was extracted from faeces of 40 coeliac children before and after probiotic or placebo administration and 16 healthy children (Control group). Sequencing of the amplified V3-V4 hypervariable region of 16S rRNA gene as well as qPCR of Bidobacterium spp., Lactobacillus spp., Bacteroides fragilis group Clostridium sensu stricto and enterobacteria were performed. The comparison between CD subjects and Control group revealed an alteration in the intestinal microbial composition of coeliacs mainly characterized by a reduction of the Firmicutes/Bacteroidetes ratio, of Actinobacteria and Euryarchaeota . Regarding the effects of the probiotic, an increase of Actinobacteria was found as well as a re-establishment of the physiological Firmicutes/Bacteroidetes ratio. Therefore, a three-month administration of B. breve strains helps in restoring the healthy percentage of main microbial components.

Purification and characterization of the bifunctional uridylyltransferase and the signal transducing proteins GlnB and GlnK from Herbaspirillum seropedicae.

PubMed

Bonatto, Ana C; Couto, Gustavo H; Souza, Emanuel M; Araújo, Luiza M; Pedrosa, Fabio O; Noindorf, Lilian; Benelli, Elaine M

2007-10-01

GlnD is a bifunctional uridylyltransferase/uridylyl-removing enzyme that has a central role in the general nitrogen regulatory system NTR. In enterobacteria, GlnD uridylylates the PII proteins GlnB and GlnK under low levels of fixed nitrogen or ammonium. Under high ammonium levels, GlnD removes UMP from these proteins (deuridylylation). The PII proteins are signal transduction elements that integrate the signals of nitrogen, carbon and energy, and transduce this information to proteins involved in nitrogen metabolism. In Herbaspirillum seropedicae, an endophytic diazotroph isolated from grasses, several genes coding for proteins involved in nitrogen metabolism have been identified and cloned, including glnB, glnK and glnD. In this work, the GlnB, GlnK and GlnD proteins of H. seropedicae were overexpressed in their native forms, purified and used to reconstitute the uridylylation system in vitro. The results show that H. seropedicae GlnD uridylylates GlnB and GlnK trimers producing the forms PII (UMP)(1), PII (UMP)(2) and PII (UMP)(3), in a reaction that requires 2-oxoglutarate and ATP, and is inhibited by glutamine. The quantification of these PII forms indicates that GlnB was more efficiently uridylylated than GlnK in the system used.

Indigenous bacteria and bacterial metabolic products in the gastrointestinal tract of broiler chickens.

PubMed

Rehman, Habib Ur; Vahjen, Wilfried; Awad, Wageha A; Zentek, Jürgen

2007-10-01

The gastrointestinal tract is a dynamic ecosystem containing a complex microbial community. In this paper, the indigenous intestinal bacteria and the microbial fermentation profile particularly short chain fatty acids (SCFA), lactate, and ammonia concentrations are reviewed. The intestinal bacterial composition changes with age. The bacterial density of the small intestine increases with age and comprises of lactobacilli, streptococci, enterobacteria, fusobacteria and eubacteria. Strict anaerobes (anaerobic gram-positive cocci, Eubacterium spp., Clostridium spp., Lactobacillus spp., Fusobacterium spp. and Bacteroides) are predominating caecal bacteria in young broilers. Data from culture-based studies showed that bifidobacteria could not be isolated from young birds, but were recovered from four-week-old broilers. Caecal lactobacilli accounted for 1.5-24% of the caecal bacteria. Gene sequencing of caecal DNA extracts showed that the majority of bacteria belonged to Clostridiaceae. Intestinal bacterial community is influenced by the dietary ingredients, nutrient levels and physical structure of feed. SCFA and other metabolic products are affected by diet formulation and age. Additional studies are required to know the bacterial metabolic activities together with the community analysis of the intestinal bacteria. Feed composition and processing have great potential to influence the activities of intestinal bacteria towards a desired direction in order to support animal health, well-being and microbial safety of broiler meat.

Physico-chemical parameters, bioactive compounds and microbial quality of thermo-sonicated carrot juice during storage.

PubMed

Martínez-Flores, Héctor E; Garnica-Romo, Ma Guadalupe; Bermúdez-Aguirre, Daniela; Pokhrel, Prashant Raj; Barbosa-Cánovas, Gustavo V

2015-04-01

Thermosonication has been successfully tested in food for microbial inactivation; however, changes in bioactive compounds and shelf-life of treated products have not been thoroughly investigated. Carrot juice was thermo-sonicated (24 kHz, 120 μm amplitude) at 50 °C, 54 °C and 58 °C for 10 min (acoustic power 2204.40, 2155.72, 2181.68 mW/mL, respectively). Quality parameters and microbial growth were evaluated after processing and during storage at 4 °C. Control and sonicated treatments at 50 °C and 54 °C had 10, 12 and 14 d of shelf-life, respectively. Samples sonicated at 58 °C had the best quality; microbial growth remained low at around 3-log for mesophiles, 4.5-log for yeasts and molds and 2-log for enterobacteria after 20 d of storage. Furthermore, thermo-sonicated juice at 58 °C retained >98% of carotenoids and 100% of ascorbic acid. Phenolic compounds increased in all stored, treated juices. Thermo-sonication is therefore a promising technology for preserving the quality of carrot juice by minimising the physicochemical changes during storage, retarding microbial growth and retaining the bioactive compounds. Copyright © 2014 Elsevier Ltd. All rights reserved.

Survival of Listeria monocytogenes and Staphylococcus aureus in Synthetic Brines. Studying the Effects of Salt, Temperature and Sugar through the Approach of the Design of Experiments

PubMed Central

Bevilacqua, Antonio; Campaniello, Daniela; Speranza, Barbara; Sinigaglia, Milena; Corbo, Maria R.

2018-01-01

The fermentation of table olives relies on a complex microbiota of lactic acid bacteria (LAB), yeasts, and enterobacteria. Producers often add sugar to increase the growth rate of LAB, “but this practice could also increase the survival rate of some pathogens. Therefore, the main topic of this paper was to study the effect of sugar, salt and temperature on the survival of Staphylococcus aureus and Listeria monocytogenes in a synthetic brine through the theory of the Design of Experiments (simplex centroid). The addition of sugar could prolong the survival time of L. monocytogenes by 40 days, whereas an increase of the temperature caused a decrease of survival from 18 to 3 days. The survival time of S. aureus was prolonged by 50 days by combining sugar (2–4 g/l) and low temperatures (5–15°C). The use of desirability approach and prediction profiles suggests that the prolongation of the survival time of L. monocytogenes could be related to a shift in the geometrical shape of the death kinetic. This paper offers a structured statistical approach on the variables acting on the survival of two pathogens in brines and represents the first step to set up and design a predictive approach for olive producers. PMID:29497414

Enterobacteriaceae ISOLATES FROM THE ORAL CAVITY OF WORKERS IN A BRAZILIAN ONCOLOGY HOSPITAL

PubMed Central

LEÃO-VASCONCELOS, Lara Stefânia Netto de Oliveira; LIMA, Ana Beatriz Mori; COSTA, Dayane de Melo; ROCHA-VILEFORT, Larissa Oliveira; de OLIVEIRA, Ana Claúdia Alves; GONÇALVES, Nádia Ferreira; VIEIRA, José Daniel Gonçalves; PRADO-PALOS, Marinésia Aparecida

2015-01-01

The evaluation of workers as potential reservoirs and disseminators of pathogenic bacteria has been described as a strategy for the prevention and control of healthcare-associated infections (HAIs). The aim of this study was to evaluate the presence of Enterobacteriaceae in the oral cavity of workers at an oncology hospital in the Midwest region of Brazil, as well as to characterize the phenotypic profile of the isolates. Saliva samples of 294 workers from the hospital’s healthcare and support teams were collected. Microbiological procedures were performed according to standard techniques. Among the participants, 55 (18.7%) were colonized by Enterobacteriaceae in the oral cavity. A total of 64 bacteria were isolated, including potentially pathogenic species. The most prevalent species was Enterobacter gergoviae (17.2%). The highest rates of resistance were observed for β-lactams, and 48.4% of the isolates were considered multiresistant. Regarding the enterobacteria isolated, the production of ESBL and KPC was negative. Nevertheless, among the 43 isolates of the CESP group, 51.2% were considered AmpC β-lactamase producers by induction, and 48.8% were hyper-producing mutants. The significant prevalence of carriers of Enterobacteriaceae and the phenotypic profile of the isolates represents a concern, especially due to the multiresistance and production of AmpC β-lactamases. PMID:25923890

Dietary supplementation with bovine lactoferrampin-lactoferricin produced by Pichia pastoris fed-batch fermentation affects intestinal microflora in weaned piglets.

PubMed

Tang, Xiang-Shan; Shao, Hua; Li, Tie-Jun; Tang, Zhi-Ru; Huang, Rui-Ling; Wang, Sheng-Ping; Kong, Xiang-Feng; Wu, Xin; Yin, Yu-Long

2012-10-01

This work is aimed at investigating the effects of recombinant bovine lactoferrampin-lactoferricin (LFA-LFC) instead of chlortetracycline on intestinal microflora in weaned piglets. The high cost of peptide production from either native digestion or chemical synthesis limits the clinical application of antimicrobial peptides. The expression of recombinant peptides in yeast may be an effective alternative. In the current study, recombinant LFA-LFC was produced via fed-batch fermentation in recombinant strain Pichia pastoris (KM71) XS10. Uniform design U6(6(4)) was used to optimize the fermentation conditions. The target peptide purified via cation-exchange and size-exclusion chromatography was added into the dietary of weaned piglets. After 21 days, the Lactobacilli, Bifidobacteria, and Enterobacteria in the chyme of the gut were quantified using real-time polymerase chain reaction. The results showed that approximately 82 mg of LFA-LFC was secreted into 1 L of medium under optimized conditions. Moreover, purified peptide showed strong antimicrobial activities against all the tested microorganisms. Compared with the control group, the LFA-LFC group increased the amount of Lactobacilli and Bifidobacteria (P<0.05) in the chyme of the stomach, duodenum, jejunum, ileum, colon, and caecum. These results show that dietary supplementation with LFA-LFC can affect intestinal microflora in weaned piglets.

Two groups of phenylalanine biosynthetic operon leader peptides genes: a high level of apparently incidental frameshifting in decoding Escherichia coli pheL

PubMed Central

Gurvich, Olga L.; Näsvall, S. Joakim; Baranov, Pavel V.; Björk, Glenn R.; Atkins, John F.

2011-01-01

The bacterial pheL gene encodes the leader peptide for the phenylalanine biosynthetic operon. Translation of pheL mRNA controls transcription attenuation and, consequently, expression of the downstream pheA gene. Fifty-three unique pheL genes have been identified in sequenced genomes of the gamma subdivision. There are two groups of pheL genes, both of which are short and contain a run(s) of phenylalanine codons at an internal position. One group is somewhat diverse and features different termination and 5′-flanking codons. The other group, mostly restricted to Enterobacteria and including Escherichia coli pheL, has a conserved nucleotide sequence that ends with UUC_CCC_UGA. When these three codons in E. coli pheL mRNA are in the ribosomal E-, P- and A-sites, there is an unusually high level, 15%, of +1 ribosomal frameshifting due to features of the nascent peptide sequence that include the penultimate phenylalanine. This level increases to 60% with a natural, heterologous, nascent peptide stimulator. Nevertheless, studies with different tRNAPro mutants in Salmonella enterica suggest that frameshifting at the end of pheL does not influence expression of the downstream pheA. This finding of incidental, rather than utilized, frameshifting is cautionary for other studies of programmed frameshifting. PMID:21177642

Survival of Listeria monocytogenes and Staphylococcus aureus in Synthetic Brines. Studying the Effects of Salt, Temperature and Sugar through the Approach of the Design of Experiments.

PubMed

Bevilacqua, Antonio; Campaniello, Daniela; Speranza, Barbara; Sinigaglia, Milena; Corbo, Maria R

2018-01-01

The fermentation of table olives relies on a complex microbiota of lactic acid bacteria (LAB), yeasts, and enterobacteria. Producers often add sugar to increase the growth rate of LAB, "but this practice could also increase the survival rate of some pathogens. Therefore, the main topic of this paper was to study the effect of sugar, salt and temperature on the survival of Staphylococcus aureus and Listeria monocytogenes in a synthetic brine through the theory of the Design of Experiments (simplex centroid). The addition of sugar could prolong the survival time of L. monocytogenes by 40 days, whereas an increase of the temperature caused a decrease of survival from 18 to 3 days. The survival time of S. aureus was prolonged by 50 days by combining sugar (2-4 g/l) and low temperatures (5-15°C). The use of desirability approach and prediction profiles suggests that the prolongation of the survival time of L. monocytogenes could be related to a shift in the geometrical shape of the death kinetic. This paper offers a structured statistical approach on the variables acting on the survival of two pathogens in brines and represents the first step to set up and design a predictive approach for olive producers.

Effect of irradiation of frozen meat/fat trimmings on microbiological and physicochemical quality attributes of dry fermented sausages.

PubMed

Chouliara, I; Samelis, J; Kakouri, A; Badeka, A; Savvaidis, I N; Riganakos, K; Kontominas, M G

2006-10-01

Changes in microbiological and physicochemical quality attributes resulting from the use of irradiation in the production of Greek dry fermented sausage were investigated as a function of fermentation/ripening time. Results showed that irradiating meat/fat trimmings at 2 or 4kGy prior to sausage production eliminated natural contamination with Listeria spp., and reduced pseudomonads, enterococci and pathogenic staphylococci, and enterobacteria, to less than 2 and 1logcfug(-1), respectively. Pseudomonads were very sensitive (>3.4 log reduction) to either radiation dose. Yeasts were the most resistant followed by inherent lactic acid bacteria; their reductions on the trimmings were radiation dose-dependent. Residual effects of irradiation were noted against enterococci, but not against gram-negatives which died off fast during fermentation even in non-irradiated samples. Growth of the starter bacteria, Lactobacillus pentosus and Staphylococcus carnosus, inoculated in the sausage batters post-irradiation was unaffected by the 2 or 4kGy pre-treatment of the trimmings. Irradiation had little or no effect at the end of ripening period (28 days) on pH, moisture content and color (parameters L(∗), a(∗), and b(∗)). Changes in TBA values were small but statistically significant with irradiated samples having higher TBA values than control samples.

[S. Pyogenes invasive disease in a paediatric hospital: 1996-2009].

PubMed

Caetano, Joana Serra; Neto, Paula; Alves, Manuela Costa; Rodrigues, Fernanda

2010-01-01

S. pyogenes is among the most common bacteria in Pediatrics, and is associated with a wide variety of infections and large range of severity. The aim was to evaluate trends of Group A Streptococcal invasive disease in a paediatric tertiary hospital. Retrospective analyses of the medical records of all children with group A streptococcal invasive disease (positive culture obtained from sterile sites), from January 1996 to December 2009 (14 years). There were 24 cases, with a maximum of four cases/year. Eighteen cases (75%) ocurred in the second half of the study. Sixty-seven percent were boys and the median age was three years. The most frequent clinical manifestations were fever (79%), rash (54%) and arthalgia/limbs' pain (46%). The diagnoses were bacteriemia (six), osteoarticular infection (five), celulitis (three), pyomyositis, mastoiditis, surgical wound infection, toxic shock syndrome (two each), necrotizing fasciitis and pneumonia (one each). Four cases occurred during the course of varicella. Other risk factors were present in six cases. Median neutrophyl count was 10.690 x 105/L (2.013-19.180 x 105/L) and median C reactive protein was 146 mg/L (3-425 mg/L). Bacteria were isolated mainly from blood (71%). The outcome was good for most cases but there were two deaths due to toxic shock syndrome. M typing and the presence of virulence factors genes were not assessed. Although the number is small, there was an increase of S. pyogenes invasive disease in the second half of the study. Several cases occurred in the course of varicela or in the presence of other risk factors. Fatal outcome was associated with two toxic shock syndrome cases. Microbiological investigation is essential to understand which M types or virulence factors genes are involved.

Contaminación por mercurio de leche materna de madres lactantes de municipios de Antioquia con explotación minera de oro.

PubMed

Molina, Carlos Federico; Arango, Catalina María; Sepúlveda, Hernán

2018-05-01

Introducción. La leche materna es esencial para el desarrollo del ser humano, pero puede contener sustancias tóxicas provenientes de la contaminación ambiental, especialmente en las áreas mineras.Objetivo. Determinar la prevalencia de la contaminación con mercurio de la leche materna de mujeres lactantes residentes en los municipios con explotación minera de oro.Materiales y métodos. Se hizo un estudio transversal de 150 madres lactantes de cuatro municipios mineros de Antioquia (El Bagre, Segovia, Remedios y Zaragoza), a quienes se les hizo una encuesta sobre factores sociodemográficos, ocupacionales y ambientales relacionados con el mercurio, y se les tomaron muestras de leche materna, de orina y de cabello. Se calculó el promedio de la concentración de mercurio y las prevalencias municipales de contaminación.Resultados. El promedio de la concentración de mercurio en la leche materna fue de 2,5 (± desviación estándar 9,2) μg/L. La prevalencia de muestras de leche materna con niveles altos de mercurio fue de 11,7 %.Conclusión. En este estudio se evidencia un grave problema en las regiones mineras auríferas de Antioquia por el efecto de la contaminación con mercurio en sectores de la población más vulnerable.

Fuentes de variabilidad en el diagnóstico de gastritis atrófica multifocal asociada con la infección por Helicobacter pylori1

PubMed Central

Bravo, Luis Eduardo; Bravo, Juan Carlos; Realpe, José Luis; Zarama, Guillermo; Piazuelo, MarÍa Blanca; Correa, Pelayo

2014-01-01

RESUMEN Introducción El mapeo de las diferentes regiones del estómago y el número de fragmentos de mucosa gástrica disponibles para evaluación histopatológica son fuentes importantes de variación en el momento de clasificar y hacer la gradación de la gastritis crónica. Objetivos Estimar la sensibilidad del número de fragmentos de mucosa gástrica necesarios para establecer los diagnósticos de gastritis atrófica con metaplasia intestinal (MI), displasia y estado de infección por Helicobacter pylori. Además evaluar la variabilidad intra-observador en la clasificación de estas lesiones precursoras del cáncer gástrico. Materiales y métodos En una cohorte de 6 años de seguimiento se evaluaron 1,958 procedimientos de endoscopia realizados por dos gastroenterólogos. En cada procedimiento y de cada participante se obtuvieron 5 biopsias de mucosa gástrica que representaban antro, incisura angularis y cuerpo. Un único patólogo hizo la interpretación histológica de las 5 biopsias y proporcionó un diagnóstico definitivo global que se utilizó como patrón de referencia. Cada fragmento de mucosa gástrica examinado condujo a un diagnóstico individual para cada biopsia que se comparó con el patrón de referencia. La variabilidad intra-observador se evaluó en 127 personas que corresponden a una muestra aleatoria de 20% del total de endoscopias hechas a los 72 meses de seguimiento. Resultados La sensibilidad del diagnóstico de MI y displasia gástrica aumentó de manera significativa con el número de fragmentos de mucosa gástrica evaluados El sitio anatómico de mayor sensibilidad para el diagnóstico de MI y displasia fue la incisura angularis. Para descubrir H. pylori se logró alta sensibilidad con el estudio de un solo fragmento de mucosa gástrica (95.9%) y fue independiente del sitio de obtención de la biopsia. El acuerdo intra-observador para el diagnóstico de gastritis crónica fue 86.1% con valor kappa de 0.79 IC 95% (0.76-0.85). Las

Oral treatment of Fischer 344 rats with weathered crude oil and a dispersant influences intestinal metabolism and microbiota.

PubMed

George, S E; Nelson, G M; Kohan, M J; Warren, S H; Eischen, B T; Brooks, L R

2001-06-22

that of dispersant alone. One-week nitroreductase activity in the small intestine and cecum was unaffected in the three treatment groups, but elevated activity was observed in the large intestines of animals treated with oil or dispersant. The effect of the combination dose was not significantly different from the control value. Due to experimental error, no 3- or 5-wk NR data were available. By 5 wk of treatment, enterobacteria and enterococci were eliminated from ceca of oil-treated rats. When oil was administered in combination with dispersant, an apparent protective effect was observed on the enterococci and lactose-fermenting and nonfermenting enterobacteria. A more detailed analysis at the species level revealed qualitative differences dependent on the treatment. This study suggests that prolonged exposure of mammals to oil, dispersant, or in combination impacts intestinal metabolism, which ultimately could lead to altered detoxification of oil constituents and coexposed toxicants.

[Guidelines for the diagnosis and treatment of patients with bacteriemia. Guidelines of the Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica].

PubMed

Cisneros-Herreros, José Miguel; Cobo-Reinoso, Javier; Pujol-Rojo, Miquel; Rodríguez-Baño, Jesús; Salavert-Lletí, Miguel

2007-02-01

Bacteremia is a complex clinical syndrome in constant transformation that is an important, growing cause of morbidity and mortality. Even though there is a great deal of specific information about bacteremia, few comprehensive reviews integrate this information with a practical AIM. The main objective of these Guidelines, which target hospital physicians, is to improve the clinical care provided to patients with bacteremia by integrating blood culture results with clinical data, and optimizing the use of diagnostic procedures and antimicrobial testing. The document is structured into sections that cover the epidemiology and etiology of bacteremia, stratified according to the various patient populations, and the diagnostic work-up, therapy, and follow-up of patients with bacteremia. Diagnostic and therapeutic decisions are presented as recommendations based on the grade of available scientific evidence.

Effects of Mutations and Ligands on the Thermostability of the l-Arginine/Agmatine Antiporter AdiC and Deduced Insights into Ligand-Binding of Human l-Type Amino Acid Transporters

PubMed Central

Ilgü, Hüseyin; Jeckelmann, Jean-Marc; Colas, Claire; Ucurum, Zöhre; Schlessinger, Avner; Fotiadis, Dimitrios

2018-01-01

The l-arginine/agmatine transporter AdiC is a prokaryotic member of the SLC7 family, which enables pathogenic enterobacteria to survive the extremely acidic gastric environment. Wild-type AdiC from Escherichia coli, as well as its previously reported point mutants N22A and S26A, were overexpressed homologously and purified to homogeneity. A size-exclusion chromatography-based thermostability assay was used to determine the melting temperatures (Tms) of the purified AdiC variants in the absence and presence of the selected ligands l-arginine (Arg), agmatine, l-arginine methyl ester, and l-arginine amide. The resulting Tms indicated stabilization of AdiC variants upon ligand binding, in which Tms and ligand binding affinities correlated positively. Considering results from this and previous studies, we revisited the role of AdiC residue S26 in Arg binding and proposed interactions of the α-carboxylate group of Arg exclusively with amide groups of the AdiC backbone. In the context of substrate binding in the human SLC7 family member l-type amino acid transporter-1 (LAT1; SLC7A5), an analogous role of S66 in LAT1 to S26 in AdiC is discussed based on homology modeling and amino acid sequence analysis. Finally, we propose a binding mechanism for l-amino acid substrates to LATs from the SLC7 family. PMID:29558430

The effects of iron fortification and supplementation on the gut microbiome and diarrhea in infants and children: a review.

PubMed

Paganini, Daniela; Zimmermann, Michael B

2017-12-01

In infants and young children in Sub-Saharan Africa, iron-deficiency anemia (IDA) is common, and many complementary foods are low in bioavailable iron. In-home fortification of complementary foods using iron-containing micronutrient powders (MNPs) and oral iron supplementation are both effective strategies to increase iron intakes and reduce IDA at this age. However, these interventions produce large increases in colonic iron because the absorption of their high iron dose (≥12.5 mg) is typically <20%. We reviewed studies in infants and young children on the effects of iron supplements and iron fortification with MNPs on the gut microbiome and diarrhea. Iron-containing MNPs and iron supplements can modestly increase diarrhea risk, and in vitro and in vivo studies have suggested that this occurs because increases in colonic iron adversely affect the gut microbiome in that they decrease abundances of beneficial barrier commensal gut bacteria (e.g., bifidobacteria and lactobacilli) and increase the abundance of enterobacteria including entropathogenic Escherichia coli These changes are associated with increased gut inflammation. Therefore, safer formulations of iron-containing supplements and MNPs are needed. To improve MNP safety, the iron dose of these formulations should be reduced while maximizing absorption to retain efficacy. Also, the addition of prebiotics to MNPs is a promising approach to mitigate the adverse effects of iron on the infant gut. © 2017 American Society for Nutrition.

Diversity, community structure, and bioremediation potential of mercury-resistant marine bacteria of estuarine and coastal environments of Odisha, India.

PubMed

Dash, Hirak R; Das, Surajit

2016-04-01

Both point and non-point sources increase the pollution status of mercury and increase the population of mercury-resistant marine bacteria (MRMB). They can be targeted as the indicator organism to access marine mercury pollution, besides utilization in bioremediation. Thus, sediment and water samples were collected for 2 years (2010-2012) along Odisha coast of Bay of Bengal, India. Mercury content of the study sites varied from 0.47 to 0.99 ppb irrespective of the seasons of sampling. A strong positive correlation was observed between mercury content and MRMB population (P < 0.05) suggesting the utilization of these bacteria to assess the level of mercury pollution in the marine environment. Seventy-eight percent of the MRMB isolates were under the phylum Firmicutes, and 36 and 31% of them could resist mercury by mer operon-mediated volatilization and mercury biosorption, respectively. In addition, most of the isolates could resist a number of antibiotics and toxic metals. All the MRMB isolates possess the potential of growth and survival at cardinal pH (4-8), temperature (25-37 °C), and salinity (5-35 psu). Enterobacteria repetitive intergenic consensus (ERIC) and repetitive element palindromic PCR (REP-PCR) produced fingerprints corroborating the results of 16S rRNA gene sequencing. Fourier transform infrared (FTIR) spectral analysis also revealed strain-level speciation and phylogenetic relationships.

Microbiological stabilization of tiger nuts' milk beverage using ultra-high pressure homogenization. A preliminary study on microbial shelf-life extension.

PubMed

Codina-Torrella, I; Guamis, B; Zamora, A; Quevedo, J M; Trujillo, A J

2018-02-01

Tiger nuts' milk beverages are highly perishable products. For this reason, the interest of food industry for their commercialization makes necessary the application of preservation treatments to prolong their shelf-life. In the current study, the effect of ultra-high pressure homogenization (UHPH) on the microbiological and sensory qualities of tiger nuts' milk beverage was evaluated. Characteristics of UHPH-treated products (at 200 and 300 MPa, with inlet temperature of 40 °C) were compared with those of raw (RP) and conventionally homogenized-pasteurized (H-P) beverages, after treatment and during cold storage at 4 °C. Microbiological quality of beverages was studied by enumerating total counts, psychrotrophic bacteria, lactobacilli, enterobacteria, molds and yeasts, and mesophilic spores. Evolution of color and sensory characteristics of beverages were also determined. Microbiological shelf-life of the tiger nuts' milk beverages was extended from 3 to 25, 30 and 57 days by applying H-P and UHPH treatments at 200 and 300 MPa, respectively. Color of beverages was the only attribute that differentiated UHPH samples from the others, with greater luminosity and whiteness. Hence, UHPH treatments showed to be an alternative to the conventional H-P for obtaining tiger nuts' milk beverages with an improved microbiological shelf-life and good sensorial characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intrastrand triplex DNA repeats in bacteria: a source of genomic instability

PubMed Central

Holder, Isabelle T.; Wagner, Stefanie; Xiong, Peiwen; Sinn, Malte; Frickey, Tancred; Meyer, Axel; Hartig, Jörg S.

2015-01-01

Repetitive nucleic acid sequences are often prone to form secondary structures distinct from B-DNA. Prominent examples of such structures are DNA triplexes. We observed that certain intrastrand triplex motifs are highly conserved and abundant in prokaryotic genomes. A systematic search of 5246 different prokaryotic plasmids and genomes for intrastrand triplex motifs was conducted and the results summarized in the ITxF database available online at http://bioinformatics.uni-konstanz.de/utils/ITxF/. Next we investigated biophysical and biochemical properties of a particular G/C-rich triplex motif (TM) that occurs in many copies in more than 260 bacterial genomes by CD and nuclear magnetic resonance spectroscopy as well as in vivo footprinting techniques. A characterization of putative properties and functions of these unusually frequent nucleic acid motifs demonstrated that the occurrence of the TM is associated with a high degree of genomic instability. TM-containing genomic loci are significantly more rearranged among closely related Escherichia coli strains compared to control sites. In addition, we found very high frequencies of TM motifs in certain Enterobacteria and Cyanobacteria that were previously described as genetically highly diverse. In conclusion we link intrastrand triplex motifs with the induction of genomic instability. We speculate that the observed instability might be an adaptive feature of these genomes that creates variation for natural selection to act upon. PMID:26450966

Multidrug-Resistance and Toxic Metal Tolerance of Medically Important Bacteria Isolated from an Aquaculture System

PubMed Central

Resende, Juliana Alves; Silva, Vânia L.; Fontes, Cláudia Oliveira; Souza-Filho, Job Alves; de Oliveira, Tamara Lopes Rocha; Coelho, Cíntia Marques; César, Dionéia Evangelista; Diniz, Cláudio Galuppo

2012-01-01

The use of antimicrobials and toxic metals should be considered carefully in aquaculture and surrounding environments. We aimed to evaluate medically relevant bacteria in an aquaculture system and their susceptibility to antimicrobials and toxic metals. Selective cultures for enterobacteria (ENT), non-fermenting Gram-negative rods (NFR) and Gram-positive cocci (GPC) were obtained from water samples collected in two different year seasons. The isolated bacteria were biochemically identified and antimicrobial and toxic metal susceptibility patterns were determined. Overall, 407 representative strains were recovered. In general, bacteria isolated from fish ponds showed higher multiple antibiotic resistance indices when compared to those isolated from a water-fed canal. Resistance to penicillin and azithromycin was observed more frequently in the GPC group, whereas resistance to ampicillin and ampicillin/sulbactam or gentamicin was observed more frequently in the ENT and NFR groups, respectively. All the isolated bacteria were tolerant to nickel, zinc, chromium and copper at high levels (≥1,024 μg mL−1), whereas tolerance to cadmium and mercury varied among the isolated bacteria (2–1,024 μg mL−1). Multidrug-resistant bacteria were more frequent and diverse in fish ponds than in the water-fed canal. A positive correlation was observed between antimicrobial resistance and metal tolerance. The data point out the need for water treatment associated with the aquaculture system. PMID:22972388

Survey of pathogens in threatened wild red-tailed Amazon parrot (Amazona brasiliensis) nestlings in Rasa Island, Brazil.

PubMed

Vaz, Frederico Fontanelli; Serafini, Patrícia Pereira; Locatelli-Dittrich, Rosangela; Meurer, Rafael; Durigon, Edison Luiz; de Araújo, Jansen; Thomazelli, Luciano Matsumiya; Ometto, Tatiana; Sipinski, Elenise Angelotti Bastos; Sezerban, Rafael Meirelles; Abbud, Maria Cecília; Raso, Tânia Freitas

The red-tailed Amazon parrot (Amazona brasiliensis) is a threatened species of psittacine bird that inhabit coastal regions of Brazil. In view of the threat of this species, the aim of this study was to perform a health evaluation in wild nestlings in Rasa Island, determining the prevalence of enterobacteria and infectious agents according to type of nest. Blood samples were collected from 64 birds and evaluated for antibodies of Chlamydia psittaci by commercial dot-blot ELISA. Cloacal and oropharyngeal swabs samples were collected from 23 birds from artificial wooden nests, 15 birds from PVC nests and 2 birds from natural nests for microbiological analysis. Swab samples were collected from 58 parrots for C. psittaci detection by PCR and from 50 nestlings for Avian Influenza, Newcastle Disease and West Nile viruses' detection analysis by real-time RT-PCR. Ten bacterial genera and 17 species were identified, and the most prevalent were Escherichia coli and Klebsiella oxytoca. There was no influence of the type of nest in the nestlings' microbiota. All samples tested by ELISA and PCR were negative. There is currently insufficient information available about the health of A. brasiliensis and data of this study provide a reference point for future evaluations and aid in conservation plans. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

[Microbiology of pressure and vascular ulcer infections].

PubMed

Ortiz Balbuena, Jorge; García Madero, Rodrigo; Segovia Gómez, Teresa; Cantero Caballero, Miriea; Sánchez Romero, Isabel; Ramos Martínez, Antonio

2015-01-01

Pressure ulcer (PU) infection is a significant clinical problem in many elderly patients. To determine the microbiology of PU and vascular ulcer (VU) infections by conducting a cross-sectional study of outpatients treated in a chronic wounds unit over an 18 month period. Sixty six patients with PU infection and 159 patients with an infected VU were identified. The PUs were located below the knee in 36 patients (52%). Patients with pressure ulcers had a higher proportion of institutionalization, cognitive impairment, inability to walk, and sphincter incontinence. There was a greater number of infections caused by Enterobacteriaceae (52%, P=.002) and fewer S. aureus infections (24%, P<.001) in patients with a PU compared to those with those with a VU. Forty-one percent of S. aureus strains isolated in all the patients were resistant to methicillin (MRSA). The proportion of Enterobacteriaceae infections was similar in patients with infection of pelvic girdle PU and in those located below the knee. PU patients suffer a higher rate of infection by enterobacteria. The most common pathogen in UV infections is S. aureus. The proportion of MRSA infection in patients with chronic wounds is high. The microbiology of the infection in the pelvic girdle PU is similar to those located below the knee. Copyright © 2014 SEGG. Published by Elsevier Espana. All rights reserved.

Hha has a defined regulatory role that is not dependent upon H-NS or StpA

PubMed Central

Solórzano, Carla; Srikumar, Shabarinath; Canals, Rocío; Juárez, Antonio; Paytubi, Sonia; Madrid, Cristina

2015-01-01

The Hha family of proteins is involved in the regulation of gene expression in enterobacteria by forming complexes with H-NS-like proteins. Whereas several amino acid residues of both proteins participate in the interaction, some of them play a key role. Residue D48 of Hha protein is essential for the interaction with H-NS, thus the D48N substitution in Hha protein abrogates H-NS/Hha interaction. Despite being a paralog of H-NS protein, StpA interacts with HhaD48N with higher affinity than with the wild type Hha protein. To analyze whether Hha is capable of acting independently of H-NS and StpA, we conducted transcriptomic analysis on the hha and stpA deletion strains and the hhaD48N substitution strain of Salmonella Typhimurium using a custom microarray. The results obtained allowed the identification of 120 genes regulated by Hha in an H-NS/StpA-independent manner, 38% of which are horizontally acquired genes. A significant number of the identified genes are involved in functions related to cell motility, iron uptake, and pathogenicity. Thus, motility assays, siderophore detection and intra-macrophage replication assays were performed to confirm the transcriptomic data. Our findings point out the importance of Hha protein as an independent regulator in S. Typhimurium, highlighting a regulatory role on virulence. PMID:26284052

Bacterial communities of fresh goat meat packaged in modified atmosphere.

PubMed

Carrizosa, Elia; Benito, María José; Ruiz-Moyano, Santiago; Hernández, Alejandro; Villalobos, Maria Del Carmen; Martín, Alberto; Córdoba, María de Guía

2017-08-01

The objective of this work was to study the growth and development of fortuitous flora and food pathogens in fresh goat meat packaged under modified atmospheres containing two different concentrations of CO 2 . Meat samples were stored at 10 °C under two different modified-atmosphere packing (MAP) conditions: treatment A had 45% CO 2  + 20% O 2  + 35% N 2 and treatment B had 20% CO 2  + 55% O 2  + 25% N 2 . During 14 days of storage, counts of each bacterial group and dominant species identification by 16S rRNA gene sequencing were performed to determine the microbial diversity present. The MAP condition used for treatment A was a more effective gas mixture for increasing the shelf life of fresh goat meat, significantly reducing the total number of viable bacteria and enterobacteria counts. Members of the Enterobacteriaceae family were the most common contaminants, although Hafnia alvei was dominant in treatment A and Serratia proteamaculans in treatment B. Identification studies at the species level showed that different microorganisms develop under different storage conditions, reflecting the importance of gas composition in the modified atmosphere on the bacterial community. This work provides new insights into the microbial changes of goat meat storage under different MAP conditions, which will be beneficial for the meat industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

Membrane Stored Curvature Elastic Stress Modulates Recruitment of Maintenance Proteins PspA and Vipp1

PubMed Central

McDonald, Christopher; Jovanovic, Goran; Ces, Oscar

2015-01-01

ABSTRACT Phage shock protein A (PspA), which is responsible for maintaining inner membrane integrity under stress in enterobacteria, and vesicle-inducting protein in plastids 1 (Vipp1), which functions for membrane maintenance and thylakoid biogenesis in cyanobacteria and plants, are similar peripheral membrane-binding proteins. Their homologous N-terminal amphipathic helices are required for membrane binding; however, the membrane features recognized and required for expressing their functionalities have remained largely uncharacterized. Rigorously controlled, in vitro methodologies with lipid vesicles and purified proteins were used in this study and provided the first biochemical and biophysical characterizations of membrane binding by PspA and Vipp1. Both proteins are found to sense stored curvature elastic (SCE) stress and anionic lipids within the membrane. PspA has an enhanced sensitivity for SCE stress and a higher affinity for the membrane than Vipp1. These variations in binding may be crucial for some of the proteins’ differing roles in vivo. Assays probing the transcriptional regulatory function of PspA in the presence of vesicles showed that a relief of transcription inhibition occurs in an SCE stress-specific manner. This in vitro recapitulation of membrane stress-dependent transcription control suggests that the Psp response may be mounted in vivo when a cell’s inner membrane experiences increased SCE stress. PMID:26330516

Insights into the molecular basis for substrate binding and specificity of the wild-type L-arginine/agmatine antiporter AdiC.

PubMed

Ilgü, Hüseyin; Jeckelmann, Jean-Marc; Gapsys, Vytautas; Ucurum, Zöhre; de Groot, Bert L; Fotiadis, Dimitrios

2016-09-13

Pathogenic enterobacteria need to survive the extreme acidity of the stomach to successfully colonize the human gut. Enteric bacteria circumvent the gastric acid barrier by activating extreme acid-resistance responses, such as the arginine-dependent acid resistance system. In this response, l-arginine is decarboxylated to agmatine, thereby consuming one proton from the cytoplasm. In Escherichia coli, the l-arginine/agmatine antiporter AdiC facilitates the export of agmatine in exchange of l-arginine, thus providing substrates for further removal of protons from the cytoplasm and balancing the intracellular pH. We have solved the crystal structures of wild-type AdiC in the presence and absence of the substrate agmatine at 2.6-Å and 2.2-Å resolution, respectively. The high-resolution structures made possible the identification of crucial water molecules in the substrate-binding sites, unveiling their functional roles for agmatine release and structure stabilization, which was further corroborated by molecular dynamics simulations. Structural analysis combined with site-directed mutagenesis and the scintillation proximity radioligand binding assay improved our understanding of substrate binding and specificity of the wild-type l-arginine/agmatine antiporter AdiC. Finally, we present a potential mechanism for conformational changes of the AdiC transport cycle involved in the release of agmatine into the periplasmic space of E. coli.

Biosynthesis of the antifungal haterumalide, oocydin A, in Serratia, and its regulation by quorum sensing, RpoS and Hfq

PubMed Central

Matilla, Miguel A; Leeper, Finian J; Salmond, George P C

2015-01-01

Polyketides represent an important class of bioactive natural products with a broad range of biological activities. We identified recently a large trans-acyltransferase (AT) polyketide synthase gene cluster responsible for the biosynthesis of the antifungal, anti-oomycete and antitumor haterumalide, oocydin A (ooc). Using genome sequencing and comparative genomics, we show that the ooc gene cluster is widespread within biocontrol and phytopathogenic strains of the enterobacteria, Serratia and Dickeya. The analysis of in frame deletion mutants confirmed the role of a hydroxymethylglutaryl-coenzyme A synthase cassette, three flavin-dependent tailoring enzymes, a free-standing acyl carrier protein and two hypothetical proteins in oocydin A biosynthesis. The requirement of the three trans-acting AT domains for the biosynthesis of the macrolide was also demonstrated. Expression of the ooc gene cluster was shown to be positively regulated by an N-acyl-L-homoserine lactone-based quorum sensing system, but operating in a strain-dependent manner. At a post-transcriptional level, the RNA chaperone, Hfq, plays a key role in oocydin A biosynthesis. The Hfq-dependent regulation is partially mediated by the stationary phase sigma factor, RpoS, which was also shown to positively regulate the synthesis of the macrolide. Our results reveal differential regulation of the divergently transcribed ooc transcriptional units, highlighting the complexity of oocydin A production. PMID:25753587

Silage review: Foodborne pathogens in silage and their mitigation by silage additives.

PubMed

Queiroz, O C M; Ogunade, I M; Weinberg, Z; Adesogan, A T

2018-05-01

Silage is one of the main ingredients in dairy cattle diets and it is an important source of nutrients, particularly energy and digestible fiber. Unlike properly made and managed silage, poorly made or contaminated silage can also be a source of pathogenic bacteria that may decrease dairy cow performance, reduce the safety and quality dairy products, and compromise animal and human health. Some of the pathogenic bacteria that are frequently or occasionally associated with silage are enterobacteria, Listeria, Bacillus spp., Clostridium spp., and Salmonella. The symptoms caused by these bacteria in dairy cows vary from mild diarrhea and reduced feed intake by Clostridium spp. to death and abortion by Listeria. Contamination of food products with pathogenic bacteria can cause losses of millions of dollars due to recalls of unsafe foods and decreases in the shelf life of dairy products. The presence of pathogenic bacteria in silage is usually due to contamination or poor management during the fermentation, aerobic exposure, or feed-out stages. Silage additives and inoculants can improve the safety of silage as well as the fermentation, nutrient recovery, quality, and shelf life. This review summarizes the literature on the main foodborne pathogens that occasionally infest silage and how additives can improve silage safety. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Longitudinal Analyses of Gut Mucosal Microbiotas in Ulcerative Colitis in Relation to Patient Age and Disease Severity and Duration

PubMed Central

Fite, Alemu; Furrie, Elizabeth; Bahrami, Bahram; Cummings, John H.; Steinke, Douglas T.; Macfarlane, George T.

2013-01-01

Bacteria belonging to the normal colonic microbiota are associated with the etiology of ulcerative colitis (UC). Although several mucosal species have been implicated in the disease process, the organisms and mechanisms involved are unknown. The aim of this investigation was to characterize mucosal biofilm communities over time and to determine the relationship of these bacteria to patient age and disease severity and duration. Multiple rectal biopsy specimens were taken from 33 patients with active UC over a period of 1 year. Real-time PCR was used to quantify mucosal bacteria in UC patients compared to 18 noninflammatory bowel disease controls, and the relationship between indicators of disease severity and bacterial colonization was evaluated by linear regression analysis. Significant differences were detected in bacterial populations on the UC mucosa and in the control group, which varied over the study period. High clinical activity indices (CAI) and sigmoidoscopy scores (SS) were associated with enterobacteria, desulfovibrios, type E Clostridium perfringens, and Enterococcus faecalis, whereas the reverse was true for Clostridium butyricum, Ruminococcus albus, and Eubacterium rectale. Lactobacillus and bifidobacterium numbers were linked with low CAI. Only E. rectale and Clostridium clostridioforme had a high age dependence. These findings demonstrated that longitudinal variations in mucosal bacterial populations occur in UC and that bacterial community structure is related to disease severity. PMID:23269735

Establishment of a universal and rational gene detection strategy through three-way junction-based remote transduction.

PubMed

Tang, Yidan; Lu, Baiyang; Zhu, Zhentong; Li, Bingling

2018-01-21

The polymerase chain reaction and many isothermal amplifications are able to achieve super gene amplification. Unfortunately, most commonly-used transduction methods, such as dye staining and Taqman-like probing, still suffer from shortcomings including false signals or difficult probe design, or are incompatible with multi-analysis. Here a universal and rational gene detection strategy has been established by translating isothermal amplicons to enzyme-free strand displacement circuits via three-way junction-based remote transduction. An assistant transduction probe was imported to form a partial hybrid with the target single-stranded nucleic acid. After systematic optimization the hybrid could serve as an associative trigger to activate a downstream circuit detector via a strand displacement reaction across the three-way junction. By doing so, the detection selectivity can be double-guaranteed through both amplicon-transducer recognition and the amplicon-circuit reaction. A well-optimized circuit can be immediately applied to a new target detection through simply displacing only 10-12 nt on only one component, according to the target. More importantly, this property for the first time enables multi-analysis and logic-analysis in a single reaction, sharing a single fluorescence reporter. In an applicable model, trace amounts of Cronobacter and Enterobacteria genes have been clearly distinguished from samples with no bacteria or one bacterium, with ultra-high sensitivity and selectivity.

IroN, a Novel Outer Membrane Siderophore Receptor Characteristic of Salmonella enterica

PubMed Central

Bäumler, Andreas J.; Norris, Tracy L.; Lasco, Todd; Voigt, Wolfgang; Reissbrodt, Rolf; Rabsch, Wolfgang; Heffron, Fred

1998-01-01

Speciation in enterobacteria involved horizontal gene transfer. Therefore, analysis of genes acquired by horizontal transfer that are present in one species but not its close relatives is expected to give insights into how new bacterial species were formed. In this study we characterize iroN, a gene located downstream of the iroBC operon in the iroA locus of Salmonella enterica serotype Typhi. Like iroBC, the iroN gene is present in all phylogenetic lineages of S. enterica but is absent from closely related species such as Salmonella bongori or Escherichia coli. Comparison of the deduced amino acid sequence of iroN with other proteins suggested that this gene encodes an outer membrane siderophore receptor protein. Mutational analysis in S. enterica and expression in E. coli identified a 78-kDa outer membrane protein as the iroN gene product. When introduced into an E. coli fepA cir fiu aroB mutant on a cosmid, iroN mediated utilization of structurally related catecholate siderophores, including N-(2,3-dihydroxybenzoyl)-l-serine, myxochelin A, benzaldehyde-2,3-dihydroxybenzhydrazone, 2-N,6-N-bis(2,3-dihydroxybenzoyl)-l-lysine, 2-N,6-N-bis(2,3-dihydroxybenzoyl)-l-lysine amide, and enterochelin. These results suggest that the iroA locus functions in iron acquisition in S. enterica. PMID:9515912

Reconstruction of extended Petri nets from time series data and its application to signal transduction and to gene regulatory networks

PubMed Central

2011-01-01

Background Network inference methods reconstruct mathematical models of molecular or genetic networks directly from experimental data sets. We have previously reported a mathematical method which is exclusively data-driven, does not involve any heuristic decisions within the reconstruction process, and deliveres all possible alternative minimal networks in terms of simple place/transition Petri nets that are consistent with a given discrete time series data set. Results We fundamentally extended the previously published algorithm to consider catalysis and inhibition of the reactions that occur in the underlying network. The results of the reconstruction algorithm are encoded in the form of an extended Petri net involving control arcs. This allows the consideration of processes involving mass flow and/or regulatory interactions. As a non-trivial test case, the phosphate regulatory network of enterobacteria was reconstructed using in silico-generated time-series data sets on wild-type and in silico mutants. Conclusions The new exact algorithm reconstructs extended Petri nets from time series data sets by finding all alternative minimal networks that are consistent with the data. It suggested alternative molecular mechanisms for certain reactions in the network. The algorithm is useful to combine data from wild-type and mutant cells and may potentially integrate physiological, biochemical, pharmacological, and genetic data in the form of a single model. PMID:21762503

Totally implantable central venous access port infections in patients with digestive cancer: incidence and risk factors.

PubMed

Touré, Abdoulaye; Vanhems, Philippe; Lombard-Bohas, Catherine; Cassier, Philippe; Péré-Vergé, Denis; Souquet, Jean-Christophe; Ecochard, René; Chambrier, Cécile

2012-12-01

Central venous access port-related bloodstream infection (CVAP-BSI) is associated with morbidity and mortality in patients with cancer. This study examined the incidence rates and risk factors for CVAP-BSI in adult patients with digestive cancer. This prospective observational cohort study was performed from 2007 to 2011 in 2 oncology units of a university hospital. Incidence rate was expressed as number of CVAP-BSI per 1,000 catheter-days. A Cox regression model was used to identify risk factors for CVAP-BSI. A total of 315 patients were included. CVAP-BSI occurred in 41 patients (13.0%). The overall incidence rate was 0.76/1,000 catheter-days. The rate was higher in patients with esophageal cancer (1.28. P = .05) and pancreatic cancer (1.24; P = .007). Risk factors independently associated with CVAP-BSI were World Health Organization performance status between 2 and 4, catheter utilization-days in the previous month, pancreatic cancer, and parenteral nutrition. Coagulase-negative Staphylococci and enterobacteria were the main microorganisms isolated. In adult patients with digestive cancer, pancreatic cancer, cumulative catheter utilization-days, World Health Organization performance status, and parenteral nutrition were identified as independent risk factors for CVAP-BSI. Patients with any of these risk factors could be candidates for preventive strategies. Copyright © 2012 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Structural insights into the Escherichia coli lysine decarboxylases and molecular determinants of interaction with the AAA+ ATPase RavA

PubMed Central

Kandiah, Eaazhisai; Carriel, Diego; Perard, Julien; Malet, Hélène; Bacia, Maria; Liu, Kaiyin; Chan, Sze W. S.; Houry, Walid A.; Ollagnier de Choudens, Sandrine; Elsen, Sylvie; Gutsche, Irina

2016-01-01

The inducible lysine decarboxylase LdcI is an important enterobacterial acid stress response enzyme whereas LdcC is its close paralogue thought to play mainly a metabolic role. A unique macromolecular cage formed by two decamers of the Escherichia coli LdcI and five hexamers of the AAA+ ATPase RavA was shown to counteract acid stress under starvation. Previously, we proposed a pseudoatomic model of the LdcI-RavA cage based on its cryo-electron microscopy map and crystal structures of an inactive LdcI decamer and a RavA monomer. We now present cryo-electron microscopy 3D reconstructions of the E. coli LdcI and LdcC, and an improved map of the LdcI bound to the LARA domain of RavA, at pH optimal for their enzymatic activity. Comparison with each other and with available structures uncovers differences between LdcI and LdcC explaining why only the acid stress response enzyme is capable of binding RavA. We identify interdomain movements associated with the pH-dependent enzyme activation and with the RavA binding. Multiple sequence alignment coupled to a phylogenetic analysis reveals that certain enterobacteria exert evolutionary pressure on the lysine decarboxylase towards the cage-like assembly with RavA, implying that this complex may have an important function under particular stress conditions. PMID:27080013

Unusual cellular fatty acids and distinctive ultrastructure in a new spiral bacterium (Campylobacter pyloridis) from the human gastric mucosa.

PubMed

Goodwin, C S; McCulloch, R K; Armstrong, J A; Wee, S H

1985-04-01

Spiral bacteria, named Campylobacter pyloridis, were obtained from endoscopic biopsies of the gastric antrum of 14 patients with active chronic gastritis. Methyl esters of their cellular fatty acids were prepared by acid-catalysed transmethylation of whole cells. Their major fatty acids were tetradecanoic acid (14:0) and cis-9,10-methyleneoctadecanoic acid (19:0 delta), with a very small amount of hexadecanoic acid (16:0). This is markedly different from the fatty acids of other Campylobacter sp. whose major fatty acids are hexadecanoic, octadecenoic (18:1) and hexadecenoic acids (16:1). This is also different from other enterobacteria. Thin-section electronmicroscopy of gastric mucosal biopsies, and negative staining of cultured C. pyloridis, revealed features that differ from those of other campylobacters so far studied. C. pyloridis has a smooth not a rugose surface and multiple unipolar flagella of the sheathed type, each with a terminal bulb. Flagellar sheaths were in continuity with the unit membrane of the outer cell wall. The proposed species C. pyloridis does not belong among the spirochaetes and its DNA composition is incompatible with membership of the genera Spirillum or Vibrio but is compatible with Campylobacter. Thus C. pyloridis is either an atypical member of the genus Campylobacter, the limits of which may have to be redefined to accommodate the new species, or a representative of a new genus.

Cpe1786/IscR of Clostridium perfringens represses expression of genes involved in Fe-S cluster biogenesis.

PubMed

André, Gaelle; Haudecoeur, Elise; Courtois, Emmanuelle; Monot, Marc; Dupuy, Bruno; Rodionov, Dmitry A; Martin-Verstraete, Isabelle

2017-05-01

Cpe1786 of Clostridium perfringens is an Rrf2-type regulator containing the three-cysteine residues coordinating a Fe-S in IscR, the repressor controlling Fe-S homeostasis in enterobacteria. The cpe1786 gene formed an operon with iscSU involved in Fe-S biogenesis and tmrU. This operon was transcribed from a σ A -dependent promoter. We showed that in the heterologous host Bacillus subtilis, Cpe1786, renamed IscR Cp , negatively controlled its own transcription. We constructed an iscR mutant in C. perfringens. We then compared the expression profile of strain 13 and of the iscR mutant. IscR Cp controlled expression of genes involved in Fe-S biogenesis, in amino acid or sugar metabolisms, in fermentation pathways and in host compound utilization. We then demonstrated, using a ChIP-PCR experiment, that IscR Cp interacted with its promoter region in vivo in C. perfringens and with the promoter of cpe2093 encoding an amino acid ABC transporter. We utilized a comparative genomic approach to infer a candidate IscR binding motif and reconstruct IscR regulons in clostridia. We showed that point mutations in the conserved motif of 29 bp identified upstream of iscR decreased the cysteine-dependent repression of iscR mediated by IscR Cp . Copyright © 2016 Institut Pasteur. All rights reserved.

Insight on specificity of uracil permeases of the NAT/NCS2 family from analysis of the transporter encoded in the pyrimidine utilization operon of Escherichia coli.

PubMed

Botou, Maria; Lazou, Panayiota; Papakostas, Konstantinos; Lambrinidis, George; Evangelidis, Thomas; Mikros, Emmanuel; Frillingos, Stathis

2018-04-01

The uracil permease UraA of Escherichia coli is a structurally known prototype for the ubiquitous Nucleobase-Ascorbate Transporter (NAT) or Nucleobase-Cation Symporter-2 (NCS2) family and represents a well-defined subgroup of bacterial homologs that remain functionally unstudied. Here, we analyze four of these homologs, including RutG of E. coli which shares 35% identity with UraA and is encoded in the catabolic rut (pyrimidine utilization) operon. Using amplified expression in E. coli K-12, we show that RutG is a high-affinity permease for uracil, thymine and, at low efficiency, xanthine and recognizes also 5-fluorouracil and oxypurinol. In contrast, UraA and the homologs from Acinetobacter calcoaceticus and Aeromonas veronii are permeases specific for uracil and 5-fluorouracil. Molecular docking indicates that thymine is hindered from binding to UraA by a highly conserved Phe residue which is absent in RutG. Site-directed replacement of this Phe with Ala in the three uracil-specific homologs allows high-affinity recognition and/or transport of thymine, emulating the RutG profile. Furthermore, all RutG orthologs from enterobacteria retain an Ala at this position, implying that they can use both uracil and thymine and, possibly, xanthine as substrates and provide the bacterial cell with a range of catabolizable nucleobases. © 2018 John Wiley & Sons Ltd.

Effect of Lactobacillus johnsonii La1 and antioxidants on intestinal flora and bacterial translocation in rats with experimental cirrhosis.

PubMed

Chiva, Maite; Soriano, Germán; Rochat, Isabelle; Peralta, Carmen; Rochat, Florence; Llovet, Teresa; Mirelis, Beatriz; Schiffrin, Eduardo J; Guarner, Carlos; Balanzó, Joaquim

2002-10-01

Probiotics and antioxidants could be alternatives to antibiotics in the prevention of bacterial infections in cirrhosis. The aim of the present study was to determine the effect of Lactobacillus johnsonii La1 and antioxidants on intestinal flora, endotoxemia, and bacterial translocation in cirrhotic rats. Twenty-nine Sprague-Dawley rats with cirrhosis induced by CCl(4) and ascites received Lactobacillus johnsonii La1 10(9)cfu/day in vehicle (antioxidants: vitamin C+glutamate) (n=10), vehicle alone (n=11), or water (n=8) by gavage. Another eight non-cirrhotic rats formed the control group. After 10 days of treatment, a laparotomy was performed to determine microbiological study of ileal and cecal feces, bacterial translocation, endotoxemia, and intestinal malondialdehyde (MDA) levels as index of intestinal oxidative damage. Intestinal enterobacteria and enterococci, bacterial translocation (0/11 and 0/10 vs. 5/8, P<0.01), and ileal MDA levels (P<0.01) were lower in cirrhotic rats treated with antioxidants alone or in combination with Lactobacillus johnsonii La1 compared to cirrhotic rats receiving water. Only rats treated with antioxidants and Lactobacillus johnsonii La1 showed a decrease in endotoxemia with respect to cirrhotic rats receiving water (P<0.05). Antioxidants alone or in combination with Lactobacillus johnsonii La1 can be useful in preventing bacterial translocation in cirrhosis.

Antibodies against recombinant heat shock proteins of 60 kDa from enterobacteria in the sera and synovial fluid of HLA-B27 positive ankylosing spondylitis patients.

PubMed

Domínguez-López, M L; Ortega-Ortega, Y; Manríquez-Raya, J C; Burgos-Vargas, R; Vega-López, A; García-Latorre, E

2009-01-01

To study the association of HLA-B27 with IgG antibodies to different enterobacterial HSP60s in patients with ankylosing spondylitis (AS). IgG antibodies to 60 kDa enterobacterial HSPs were determined by ELISA in paired samples of sera and synovial fluid from 21 HLA-B27+ ankylosing spondylitis (AS) patients; and in sera from 32 HLA-B27+ AS patients, 35 HLA-B27+ healthy relatives of AS patients, and 60 HLA-B27- healthy individuals with no family members with AS. HLA-B27+ patients and healthy individuals showed significantly higher IgG antibody levels to recombinant enterobacterial HSP60s than HLA-B27- healthy controls. The levels of anti-HSP60Sf and anti-HSP60Ec antibodies correlated with disease activity and anti-HSP60Ec antibodies with male gender. No association between enterobacterial HSP60 antibody levels and disease duration was observed. All groups had lower levels of IgG antibodies to rHSP60 from Streptococcus pyogenes (rHSP60 Spy). In paired samples of sera and synovial fluid from B27+ patients, IgG antibodies to enterobacterial HSP60s were detected, but in significantly higher levels in sera than in synovial fluid. The anti-rHSPSpy IgG response in these samples was lower and similar in the three groups. A correlation was found between HLA-B27 and the response to recombinat enterobacterial HSP60s. This response could be associated with disease activitir and gender in some proteins and the presence eof IgG antibodies to these proteins in synovial fluid could be associated with the inflammatory process and initiation of AS.

Novel aqueous oil-in-water emulsions containing extracts of natural coniferous resins are strongly antimicrobial against enterobacteria, staphylococci and yeasts, as well as on bacterial biofilms.

PubMed

Haapakorva, E; Holmbom, T; von Wright, A

2018-01-01

The aim of this study was to examine the antimicrobial properties of novel aqueous natural rapeseed oil/saline emulsions containing different soluble components of spruce resin. The composition of aqueous resin emulsions was analysed by GC-MS and their antimicrobial properties were studied with challenge tests and with turbidometric assays. The emulsions were strongly antimicrobial against common Gram-positive and Gram-negative bacteria (including MRSA) as well as common yeasts. Furthermore, they inhibited the biofilm formation and eradicated the microbial biofilms on tested microbes. Characteristic for the emulsions was the presence of oxidized resin acids. Other main components present in emulsions, such as lignans and coumaric acids, were not antimicrobial, when tested separately. The results indicated that the oxidized resin acids were the antimicrobial components in the emulsions. Also, there appears to be a stoichiometric relationship between the number of resin acid molecules and the number microbe cells in the antimicrobial action. The fact that these solutions do not contain abietic acid, which is the main allergenic compound in resins, suggests that these solutions would be suitable, well-tolerated antimicrobials for various medical applications. The aqueous formulation will also allow the expansion of the use of these emulsions in from medical applications to the food preservatives and disinfectants. © 2017 The Authors. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of the Society for Applied Microbiology.

Biodegradable gelatin-chitosan films incorporated with essential oils as antimicrobial agents for fish preservation.

PubMed

Gómez-Estaca, J; López de Lacey, A; López-Caballero, M E; Gómez-Guillén, M C; Montero, P

2010-10-01

Essential oils of clove (Syzygium aromaticum L.), fennel (Foeniculum vulgare Miller), cypress (Cupressus sempervirens L.), lavender (Lavandula angustifolia), thyme (Thymus vulgaris L.), herb-of-the-cross (Verbena officinalis L.), pine (Pinus sylvestris) and rosemary (Rosmarinus officinalis) were tested for their antimicrobial activity on 18 genera of bacteria, which included some important food pathogen and spoilage bacteria. Clove essential oil showed the highest inhibitory effect, followed by rosemary and lavender. In an attempt to evaluate the usefulness of these essential oils as food preservatives, they were also tested on an extract made of fish, where clove and thyme essential oils were the most effective. Then, gelatin-chitosan-based edible films incorporated with clove essential oil were elaborated and their antimicrobial activity tested against six selected microorganisms: Pseudomonas fluorescens, Shewanella putrefaciens, Photobacterium phosphoreum, Listeria innocua, Escherichia coli and Lactobacillus acidophilus. The clove-containing films inhibited all these microorganisms irrespectively of the film matrix or type of microorganism. In a further experiment, when the complex gelatin-chitosan film incorporating clove essential oil was applied to fish during chilled storage, the growth of microorganisms was drastically reduced in gram-negative bacteria, especially enterobacteria, while lactic acid bacteria remained practically constant for much of the storage period. The effect on the microorganisms during this period was in accordance with biochemical indexes of quality, indicating the viability of these films for fish preservation. 2010 Elsevier Ltd. All rights reserved.

Polyphasic Study of the Spatial Distribution of Microorganisms in Mexican Pozol, a Fermented Maize Dough, Demonstrates the Need for Cultivation-Independent Methods To Investigate Traditional Fermentations

PubMed Central

Ampe, Frédéric; ben Omar, Nabil; Moizan, Claire; Wacher, Carmen; Guyot, Jean-Pierre

1999-01-01

The distribution of microorganisms in pozol balls, a fermented maize dough, was investigated by a polyphasic approach in which we used both culture-dependent and culture-independent methods, including microbial enumeration, fermentation product analysis, quantification of microbial taxa with 16S rRNA-targeted oligonucleotide probes, determination of microbial fingerprints by denaturing gradient gel electrophoresis (DGGE), and 16S ribosomal DNA gene sequencing. Our results demonstrate that DGGE fingerprinting and rRNA quantification should allow workers to precisely and rapidly characterize the microbial assemblage in a spontaneous lactic acid fermented food. Lactic acid bacteria (LAB) accounted for 90 to 97% of the total active microflora; no streptococci were isolated, although members of the genus Streptococcus accounted for 25 to 50% of the microflora. Lactobacillus plantarum and Lactobacillus fermentum, together with members of the genera Leuconostoc and Weissella, were the other dominant organisms. The overall activity was more important at the periphery of a ball, where eucaryotes, enterobacteria, and bacterial exopolysacharide producers developed. Our results also showed that the metabolism of heterofermentative LAB was influenced in situ by the distribution of the LAB in the pozol ball, whereas homolactic fermentation was controlled primarily by sugar limitation. We propose that starch is first degraded by amylases from LAB and that the resulting sugars, together with the lactate produced, allow a secondary flora to develop in the presence of oxygen. Our results strongly suggest that cultivation-independent methods should be used to study traditional fermented foods. PMID:10584005

Development and Evaluation of a Multiplex Real-Time Polymerase Chain Reaction Procedure to Clinically Type Prevalent Salmonella enterica Serovars

PubMed Central

Muñoz, Nélida; Diaz-Osorio, Miguel; Moreno, Jaime; Sánchez-Jiménez, Miryan; Cardona-Castro, Nora

2010-01-01

A multiplex real-time polymerase chain reaction procedure was developed to identify the most prevalent clinical isolates of Salmonella enterica subsp. enterica. Genes from the rfb, fliC, fljB, and viaB groups that encode the O, H, and Vi antigens were used to design 15 primer pairs and TaqMan probes specific for the genes rfbJ, wzx, fliC, fljB, wcdB, the sdf-l sequence, and invA, which was used as an internal amplification control. The primers and probes were variously combined into six sets. The first round of reactions used two of these sets to detect Salmonella O:4, O:9, O:7, O:8, and O:3,10 serogroups. Once the serogroups were identified, the results of a second round of reactions that used primers and probes for the flagellar antigen l genes, 1,2; e,h; g,m; d; e,n,x; and z10, and the Vi gene were used to identify individual serovars. The procedure was standardized using 18 Salmonella reference strains and other enterobacteria. The procedure's reliability and sensitivity was evaluated using 267 randomly chosen serotyped Salmonella clinical isolates. The procedure had a sensitivity of 95.5% and was 100% specific. Thus, our technique is a quick, sensitive, reliable, and specific means of identifying S. enterica serovars and can be used in conjunction with traditional serotyping. Other primer and probe combinations could be used to increase the number of identifiable serovars. PMID:20110454

Scavenging iron: a novel mechanism of plant immunity activation by microbial siderophores.

PubMed

Aznar, Aude; Chen, Nicolas W G; Rigault, Martine; Riache, Nassima; Joseph, Delphine; Desmaële, Didier; Mouille, Grégory; Boutet, Stéphanie; Soubigou-Taconnat, Ludivine; Renou, Jean-Pierre; Thomine, Sébastien; Expert, Dominique; Dellagi, Alia

2014-04-01

Siderophores are specific ferric iron chelators synthesized by virtually all microorganisms in response to iron deficiency. We have previously shown that they promote infection by the phytopathogenic enterobacteria Dickeya dadantii and Erwinia amylovora. Siderophores also have the ability to activate plant immunity. We have used complete Arabidopsis transcriptome microarrays to investigate the global transcriptional modifications in roots and leaves of Arabidopsis (Arabidopsis thaliana) plants after leaf treatment with the siderophore deferrioxamine (DFO). Physiological relevance of these transcriptional modifications was validated experimentally. Immunity and heavy-metal homeostasis were the major processes affected by DFO. These two physiological responses could be activated by a synthetic iron chelator ethylenediamine-di(o-hydroxyphenylacetic) acid, indicating that siderophores eliciting activities rely on their strong iron-chelating capacity. DFO was able to protect Arabidopsis against the pathogenic bacterium Pseudomonas syringae pv tomato DC3000. Siderophore treatment caused local modifications of iron distribution in leaf cells visible by ferrocyanide and diaminobenzidine-H₂O₂ staining. Metal quantifications showed that DFO causes a transient iron and zinc uptake at the root level, which is presumably mediated by the metal transporter iron regulated transporter1 (IRT1). Defense gene expression and callose deposition in response to DFO were compromised in an irt1 mutant. Consistently, plant susceptibility to D. dadantii was increased in the irt1 mutant. Our work shows that iron scavenging is a unique mechanism of immunity activation in plants. It highlights the strong relationship between heavy-metal homeostasis and immunity.

Photodynamic therapy with water-soluble phtalocyanines against bacterial biofilms in teeth root canals

NASA Astrophysics Data System (ADS)

Gergova, Raina; Georgieva, Tzvetelina; Angelov, Ivan; Mantareva, Vanya; Valkanov, Serjoga; Mitov, Ivan; Dimitrov, Slavcho

2012-06-01

The study presents the PDT with metal phthalocyanines on biofilms grown in root canals of ten representatives of the Gram-positive and the Gram-negative bacterial species and a fungus Candida albicans which cause aqute teeth infections in root canals.. The extracted human single-root teeth infected for 48 h with microorganisms in conditions to form biofilms of the above pathogens were PDT treated. The stage of biofilm formation and PDT effect of the samples of the teeth were determined by the scaning electron microscopy and with standard microbial tests. The PDT treating procedure included 10 min incubation with the respected phthalocyanine and irradiated with 660 nm Diode laser for 10 min. The most strongly antibacterial activity was achieved with zinc(II) phthalocyanine (ZnPc) against Enterococcus faecalis, Staphylococcus aureus and Moraxella catarrhalis. The other Gram-negative bacteria and Candida albicans were 10-100 times more resistant than the Gram-positive species. The Gram-negative Moraxella catarrhalis and Acinetobacter baumannii were more sensitive than the enterobacteria, but eradication of Pseudomonas aeruginosa in biofilm was insignificant. The influence of the stage of biofilm formation and the initial conditions (bacterial density, photosensitizer concentration and energy fluence of radiation) to the obtained level of inactivation of biofilms was investigated. The PDT with ZnPc photosensitizers show a powerful antimicrobial activity against the most frequent pathogens in endodontic infections and this method for inactivation of pathogens may be used with sucsses for treatment of the bacterial biofilms in the root canals.

Cloned Erwinia chrysanthemi out genes enable Escherichia coli to selectively secrete a diverse family of heterologous proteins to its milieu.

PubMed Central

He, S Y; Lindeberg, M; Chatterjee, A K; Collmer, A

1991-01-01

The out genes of the enterobacterial plant pathogen Erwinia chrysanthemi are responsible for the efficient extracellular secretion of multiple plant cell wall-degrading enzymes, including four isozymes of pectate lyase, exo-poly-alpha-D-galacturonosidase, pectin methylesterase, and cellulase. Out- mutants of Er. chrysanthemi are unable to export any of these proteins beyond the periplasm and are severely reduced in virulence. We have cloned out genes from Er. chrysanthemi in the stable, low-copy-number cosmid pCPP19 by complementing several transposon-induced mutations. The cloned out genes were clustered in a 12-kilobase chromosomal DNA region, complemented all existing out mutations in Er. chrysanthemi EC16, and enabled Escherichia coli strains to efficiently secrete the extracellular pectic enzymes produced from cloned Er. chrysanthemi genes, while retaining the periplasmic marker protein beta-lactamase. DNA sequencing of a 2.4-kilobase EcoRI fragment within the out cluster revealed four genes arranged colinearly and sharing substantial similarity with the Klebsiella pneumoniae genes pulH, pulI, pulJ, and pulK, which are necessary for pullulanase secretion. However, K. pneumoniae cells harboring the cloned Er. chrysanthemi pelE gene were unable to secrete the Erwinia pectate lyase. Furthermore, the Er. chrysanthemi Out system was unable to secrete an extracellular pectate lyase encoded by a gene from a closely related plant pathogen. Erwinia carotovora ssp. carotovora. The results suggest that these enterobacteria secrete polysaccharidases by a conserved mechanism whose protein-recognition capacities have diverged. Images PMID:1992458

Cloned Erwinia chrysanthemi out genes enable Escherichia coli to selectively secrete a diverse family of heterologous proteins to its milieu.

PubMed

He, S Y; Lindeberg, M; Chatterjee, A K; Collmer, A

1991-02-01

The out genes of the enterobacterial plant pathogen Erwinia chrysanthemi are responsible for the efficient extracellular secretion of multiple plant cell wall-degrading enzymes, including four isozymes of pectate lyase, exo-poly-alpha-D-galacturonosidase, pectin methylesterase, and cellulase. Out- mutants of Er. chrysanthemi are unable to export any of these proteins beyond the periplasm and are severely reduced in virulence. We have cloned out genes from Er. chrysanthemi in the stable, low-copy-number cosmid pCPP19 by complementing several transposon-induced mutations. The cloned out genes were clustered in a 12-kilobase chromosomal DNA region, complemented all existing out mutations in Er. chrysanthemi EC16, and enabled Escherichia coli strains to efficiently secrete the extracellular pectic enzymes produced from cloned Er. chrysanthemi genes, while retaining the periplasmic marker protein beta-lactamase. DNA sequencing of a 2.4-kilobase EcoRI fragment within the out cluster revealed four genes arranged colinearly and sharing substantial similarity with the Klebsiella pneumoniae genes pulH, pulI, pulJ, and pulK, which are necessary for pullulanase secretion. However, K. pneumoniae cells harboring the cloned Er. chrysanthemi pelE gene were unable to secrete the Erwinia pectate lyase. Furthermore, the Er. chrysanthemi Out system was unable to secrete an extracellular pectate lyase encoded by a gene from a closely related plant pathogen. Erwinia carotovora ssp. carotovora. The results suggest that these enterobacteria secrete polysaccharidases by a conserved mechanism whose protein-recognition capacities have diverged.

Modelling of enterobacterial loads to the Baie des Veys (Normandy, France).

PubMed

Lafforgue, Michel; Gerard, Laure; Vieillard, Celine; Breton, Marguerite

2018-06-01

The Baie des Veys (Normandy, France) has abundant stocks of shellfish (oyster and cockle farms). Water quality in the bay is affected by pollutant inputs from a 3500 km 2 watershed and notably occasional episodes of contamination by faecal coliforms. In order to characterise enterobacterial loads and develop a plan of action to improve the quality of seawater and shellfish in the bay, a two-stage modelling procedure was adopted. This focused on Escherichia coli and included a catchment model describing the E. coli releases, and the transport and die-off of this bacteria up to the coast. The output from this model then served as input for a marine model used to determine the concentration of E. coli in seawater. A total 60 scenarios were tested, including different wind, tidal, rainfall and temperature conditions and accidental pollution events, for both current situations and future scenarios. The modelling results highlighted the impact of rainfall on E. coli loadings to the sea, as well as the effects of sluice gates and tidal cycles, which dictated the use of an hourly timescale for the modelling process. The coupled models also made it possible to identify the origin of these enterobacteria as found in shellfish harvesting areas, both in terms of the contributing watercourses and the sources of contamination of those watercourses. The tool can accordingly be used to optimise remedial action. Copyright © 2018 Elsevier GmbH. All rights reserved.

[Capability of national reference laboratories in Latin America to detect emerging resistance mechanisms].

PubMed

Corso, Alejandra; Guerriero, Leonor; Pasterán, Fernando; Ceriana, Paola; Callejo, Raquel; Prieto, Mónica; Tuduri, Ezequiel; Lopardo, Horacio; Vay, Carlos; Smayevsky, Jorgelina; Tokumoto, Marta; Alvarez, Jorge Matheu; Pardo, Pilar Ramón; Galas, Marcelo

2011-12-01

To evaluate the capability of 17 national reference laboratories participating in the Latin American Quality Control Program in Bacteriology and Antibiotic Resistance (LA-EQAS) to detect emerging resistance mechanisms- namely: resistance of enterobacteria to carbapenems due to the presence of Klebsiella pneumoniae carbapenemase (KPC) and metallo-beta-lactamase (MBL) type IMP, and intermediate resistance of Staphylococcus aureus isolates to vancomycin (vancomycin-intermediate resistant S. aureus-VISA). The following three isolates were sent to the 17 participating LA-EQAS laboratories: KPC -producing Klebsiella pneumoniae PAHO-161, IMP-producing Enterobacter cloacae PAHO-166, and S. aureus PAHO-165 with intermediate resistance to vancomycin. Performance of each of the following operations was evaluated: interpretation of sensitivity tests, detection of the resistance mechanism, and assessment of either inhibition halo size (disk diffusion method) or minimum inhibitory concentration (MIC). Concordance in the detection of resistance mechanisms was 76.4%, 73.3%, and 66.7% for the K. pneumoniae PAHO-161, E. cloacae PAHO-166, and S. aureus PAHO-165 strains, respectively. Concordance between the inhibition areas observed by the participating laboratories and the ranges established by the coordinating laboratory was acceptable for all three isolates, at 90.8%, 92.8%, and 88.9%, respectively. Overall concordance in on the detection of KPC, MBL, and VISA resistance mechanisms was 72.1%. We consider the national reference laboratories in Latin America capable of recognizing these emerging resistance mechanisms and expect that maximum levels of concordance will be reached in the future.

Scavenging Iron: A Novel Mechanism of Plant Immunity Activation by Microbial Siderophores1[C][W

PubMed Central

Aznar, Aude; Chen, Nicolas W.G.; Rigault, Martine; Riache, Nassima; Joseph, Delphine; Desmaële, Didier; Mouille, Grégory; Boutet, Stéphanie; Soubigou-Taconnat, Ludivine; Renou, Jean-Pierre; Thomine, Sébastien; Expert, Dominique; Dellagi, Alia

2014-01-01

Siderophores are specific ferric iron chelators synthesized by virtually all microorganisms in response to iron deficiency. We have previously shown that they promote infection by the phytopathogenic enterobacteria Dickeya dadantii and Erwinia amylovora. Siderophores also have the ability to activate plant immunity. We have used complete Arabidopsis transcriptome microarrays to investigate the global transcriptional modifications in roots and leaves of Arabidopsis (Arabidopsis thaliana) plants after leaf treatment with the siderophore deferrioxamine (DFO). Physiological relevance of these transcriptional modifications was validated experimentally. Immunity and heavy-metal homeostasis were the major processes affected by DFO. These two physiological responses could be activated by a synthetic iron chelator ethylenediamine-di(o-hydroxyphenylacetic) acid, indicating that siderophores eliciting activities rely on their strong iron-chelating capacity. DFO was able to protect Arabidopsis against the pathogenic bacterium Pseudomonas syringae pv tomato DC3000. Siderophore treatment caused local modifications of iron distribution in leaf cells visible by ferrocyanide and diaminobenzidine-H2O2 staining. Metal quantifications showed that DFO causes a transient iron and zinc uptake at the root level, which is presumably mediated by the metal transporter iron regulated transporter1 (IRT1). Defense gene expression and callose deposition in response to DFO were compromised in an irt1 mutant. Consistently, plant susceptibility to D. dadantii was increased in the irt1 mutant. Our work shows that iron scavenging is a unique mechanism of immunity activation in plants. It highlights the strong relationship between heavy-metal homeostasis and immunity. PMID:24501001

Agroforestry leads to shifts within the gammaproteobacterial microbiome of banana plants cultivated in Central America

PubMed Central

Köberl, Martina; Dita, Miguel; Martinuz, Alfonso; Staver, Charles; Berg, Gabriele

2015-01-01

Bananas (Musa spp.) belong to the most important global food commodities, and their cultivation represents the world's largest monoculture. Although the plant-associated microbiome has substantial influence on plant growth and health, there is a lack of knowledge of the banana microbiome and its influencing factors. We studied the impact of (i) biogeography, and (ii) agroforestry on the banana-associated gammaproteobacterial microbiome analyzing plants grown in smallholder farms in Nicaragua and Costa Rica. Profiles of 16S rRNA genes revealed high abundances of Pseudomonadales, Enterobacteriales, Xanthomonadales, and Legionellales. An extraordinary high diversity of the gammaproteobacterial microbiota was observed within the endophytic microenvironments (endorhiza and pseudostem), which was similar in both countries. Enterobacteria were identified as dominant group of above-ground plant parts (pseudostem and leaves). Neither biogeography nor agroforestry showed a statistically significant impact on the gammaproteobacterial banana microbiome in general. However, indicator species for each microenvironment and country, as well as for plants grown in Coffea intercropping systems with and without agri-silvicultural production of different Fabaceae trees (Inga spp. in Nicaragua and Erythrina poeppigiana in Costa Rica) could be identified. For example, banana plants grown in agroforestry systems were characterized by an increase of potential plant-beneficial bacteria, like Pseudomonas and Stenotrophomonas, and on the other side by a decrease of Erwinia. Hence, this study could show that as a result of legume-based agroforestry the indigenous banana-associated gammaproteobacterial community noticeably shifted. PMID:25717322

Agroforestry leads to shifts within the gammaproteobacterial microbiome of banana plants cultivated in Central America.

PubMed

Köberl, Martina; Dita, Miguel; Martinuz, Alfonso; Staver, Charles; Berg, Gabriele

2015-01-01

Bananas (Musa spp.) belong to the most important global food commodities, and their cultivation represents the world's largest monoculture. Although the plant-associated microbiome has substantial influence on plant growth and health, there is a lack of knowledge of the banana microbiome and its influencing factors. We studied the impact of (i) biogeography, and (ii) agroforestry on the banana-associated gammaproteobacterial microbiome analyzing plants grown in smallholder farms in Nicaragua and Costa Rica. Profiles of 16S rRNA genes revealed high abundances of Pseudomonadales, Enterobacteriales, Xanthomonadales, and Legionellales. An extraordinary high diversity of the gammaproteobacterial microbiota was observed within the endophytic microenvironments (endorhiza and pseudostem), which was similar in both countries. Enterobacteria were identified as dominant group of above-ground plant parts (pseudostem and leaves). Neither biogeography nor agroforestry showed a statistically significant impact on the gammaproteobacterial banana microbiome in general. However, indicator species for each microenvironment and country, as well as for plants grown in Coffea intercropping systems with and without agri-silvicultural production of different Fabaceae trees (Inga spp. in Nicaragua and Erythrina poeppigiana in Costa Rica) could be identified. For example, banana plants grown in agroforestry systems were characterized by an increase of potential plant-beneficial bacteria, like Pseudomonas and Stenotrophomonas, and on the other side by a decrease of Erwinia. Hence, this study could show that as a result of legume-based agroforestry the indigenous banana-associated gammaproteobacterial community noticeably shifted.

High Diversity of CTX-M Extended-Spectrum β-Lactamases in Municipal Wastewater and Urban Wetlands

PubMed Central

Borgogna, Timothy R.; Borgogna, Joanna-Lynn; Mielke, Jenna A.; Brown, Celeste J.; Top, Eva M.; Botts, Ryan T.

2016-01-01

The CTX-M-type extended-spectrum β-lactamases (ESBLs) present a serious public health threat as they have become nearly ubiquitous among clinical gram-negative pathogens, particularly the enterobacteria. To aid in the understanding and eventual control of the spread of such resistance genes, we sought to determine the diversity of CTX-M ESBLs not among clinical isolates, but in the environment, where weaker and more diverse selective pressures may allow greater enzyme diversification. This was done by examining the CTX-M diversity in municipal wastewater and urban coastal wetlands in southern California, United States, by Sanger sequencing of polymerase chain reaction amplicons. Of the five known CTX-M phylogroups (1, 2, 8, 9, and 25), only genes from groups 1 and 2 were detected in both wastewater treatment plants (WWTPs), and group 1 genes were also detected in one of the two wetlands after a winter rain. The highest relative abundance of blaCTX-M group 1 genes was in the sludge of one WWTP (2.1 × 10−4 blaCTX-M copies/16S rRNA gene copy). Gene libraries revealed surprisingly high nucleotide sequence diversity, with 157 new variants not found in GenBank, representing 99 novel amino acid sequences. Our results indicate that the resistomes of WWTPs and urban wetlands contain diverse blaCTX-M ESBLs, which may constitute a mobile reservoir of clinically relevant resistance genes. PMID:26670020

Anionic lipids and the cytoskeletal proteins MreB and RodZ define the spatio-temporal distribution and function of membrane stress controller PspA in Escherichia coli.

PubMed

Jovanovic, Goran; Mehta, Parul; Ying, Liming; Buck, Martin

2014-11-01

All cell types must maintain the integrity of their membranes. The conserved bacterial membrane-associated protein PspA is a major effector acting upon extracytoplasmic stress and is implicated in protection of the inner membrane of pathogens, formation of biofilms and multi-drug-resistant persister cells. PspA and its homologues in Gram-positive bacteria and archaea protect the cell envelope whilst also supporting thylakoid biogenesis in cyanobacteria and higher plants. In enterobacteria, PspA is a dual function protein negatively regulating the Psp system in the absence of stress and acting as an effector of membrane integrity upon stress. We show that in Escherichia coli the low-order oligomeric PspA regulatory complex associates with cardiolipin-rich, curved polar inner membrane regions. There, cardiolipin and the flotillin 1 homologue YqiK support the PspBC sensors in transducing a membrane stress signal to the PspA-PspF inhibitory complex. After stress perception, PspA high-order oligomeric effector complexes initially assemble in polar membrane regions. Subsequently, the discrete spatial distribution and dynamics of PspA effector(s) in lateral membrane regions depend on the actin homologue MreB and the peptidoglycan machinery protein RodZ. The consequences of loss of cytoplasmic membrane anionic lipids, MreB, RodZ and/or YqiK suggest that the mode of action of the PspA effector is closely associated with cell envelope organization. © 2014 The Authors.

[News of antibiotic resistance among Gram-negative bacilli in Algeria].

PubMed

Baba Ahmed-Kazi Tani, Z; Arlet, G

2014-06-01

Antibiotic resistance has become a major public health problem in Algeria. Indeed the past decade, we have seen a significant increase in resistance to antibiotics especially in Gram-negative bacilli. Resistance to β-lactams in enterobacteria is dominated by the production of ESBL CTX-M-3 and CTX-M-15. The strains producing these enzymes are often the cause of potentially serious infections in both hospital and community settings. Identified plasmid cephalosporinases are CMY-2, CMY-12 and DHA-1. The isolation of strains of Enterobacteriaceae and Pseudomonas aeruginosa producing carbapenemases is rare in Algeria. Some Enterobacteriaceae producing OXA-48 or VIM-19 have been reported; so far, only VIM-2 has been identified in P. aeruginosa. However, the situation regarding the strains of Acinetobacter baumannii resistant to carbapenemases seems to be more disturbing. The carbapenemase OXA-23 is the most common and seems to be endemic in the north. The carbapenemase NDM-1 has also been identified. Resistance to aminoglycosides is marked by the identification armA gene associated with blaCTX-M genes in strains of Salmonella sp. Several other resistance genes have been identified sporadically in strains of Enterobacteriaceae, P. aeruginosa and A. baumannii. Resistance genes to fluoroquinolones are more recent identification in Algeria. The most common are the Qnr determinants followed by the bifunctional enzyme AAC[6']-Ib-cr. Resistance to sulfonamides and trimethoprim was also reported in Enterobacteriaceae strains in the west of the country. Copyright © 2014. Published by Elsevier SAS.

Pyruvate formate-lyase interacts directly with the formate channel FocA to regulate formate translocation.

PubMed

Doberenz, Claudia; Zorn, Michael; Falke, Dörte; Nannemann, David; Hunger, Doreen; Beyer, Lydia; Ihling, Christian H; Meiler, Jens; Sinz, Andrea; Sawers, R Gary

2014-07-29

The FNT (formate-nitrite transporters) form a superfamily of pentameric membrane channels that translocate monovalent anions across biological membranes. FocA (formate channel A) translocates formate bidirectionally but the mechanism underlying how translocation of formate is controlled and what governs substrate specificity remains unclear. Here we demonstrate that the normally soluble dimeric enzyme pyruvate formate-lyase (PflB), which is responsible for intracellular formate generation in enterobacteria and other microbes, interacts specifically with FocA. Association of PflB with the cytoplasmic membrane was shown to be FocA dependent and purified, Strep-tagged FocA specifically retrieved PflB from Escherichia coli crude extracts. Using a bacterial two-hybrid system, it could be shown that the N-terminus of FocA and the central domain of PflB were involved in the interaction. This finding was confirmed by chemical cross-linking experiments. Using constraints imposed by the amino acid residues identified in the cross-linking study, we provide for the first time a model for the FocA-PflB complex. The model suggests that the N-terminus of FocA is important for interaction with PflB. An in vivo assay developed to monitor changes in formate levels in the cytoplasm revealed the importance of the interaction with PflB for optimal translocation of formate by FocA. This system represents a paradigm for the control of activity of FNT channel proteins. Copyright © 2014 Elsevier Ltd. All rights reserved.

Viral Communities Associated with Human Pericardial Fluids in Idiopathic Pericarditis

PubMed Central

Fancello, Laura; Monteil, Sonia; Popgeorgiev, Nikolay; Rivet, Romain; Gouriet, Frédérique; Fournier, Pierre-Edouard; Raoult, Didier; Desnues, Christelle

2014-01-01

Pericarditis is a common human disease defined by inflammation of the pericardium. Currently, 40% to 85% of pericarditis cases have no identified etiology. Most of these cases are thought to be caused by an infection of undetected, unsuspected or unknown viruses. In this work, we used a culture- and sequence-independent approach to investigate the viral DNA communities present in human pericardial fluids. Seven viral metagenomes were generated from the pericardial fluid of patients affected by pericarditis of unknown etiology and one metagenome was generated from the pericardial fluid of a sudden infant death case. As a positive control we generated one metagenome from the pericardial fluid of a patient affected by pericarditis caused by herpesvirus type 3. Furthermore, we used as negative controls a total of 6 pericardial fluids from 6 different individuals affected by pericarditis of non-infectious origin: 5 of them were sequenced as a unique pool and the remaining one was sequenced separately. The results showed a significant presence of torque teno viruses especially in one patient, while herpesviruses and papillomaviruses were present in the positive control. Co-infections by different genotypes of the same viral type (torque teno viruses) or different viruses (herpesviruses and papillomaviruses) were observed. Sequences related to bacteriophages infecting Staphylococcus, Enterobacteria, Streptococcus, Burkholderia and Pseudomonas were also detected in three patients. This study detected torque teno viruses and papillomaviruses, for the first time, in human pericardial fluids. PMID:24690743

Changes in Composition and Function of Human Intestinal Microbiota Exposed to Chlorpyrifos in Oil as Assessed by the SHIME® Model

PubMed Central

Reygner, Julie; Joly Condette, Claire; Bruneau, Aurélia; Delanaud, Stéphane; Rhazi, Larbi; Depeint, Flore; Abdennebi-Najar, Latifa; Bach, Veronique; Mayeur, Camille; Khorsi-Cauet, Hafida

2016-01-01

The presence of pesticide residues in food is a public health problem. Exposure to these substances in daily life could have serious effects on the intestine—the first organ to come into contact with food contaminants. The present study investigated the impact of a low dose (1 mg/day in oil) of the pesticide chlorpyrifos (CPF) on the community structure, diversity and metabolic response of the human gut microbiota using the SHIME® model (six reactors, representing the different parts of the gastrointestinal tract). The last three reactors (representing the colon) were inoculated with a mixture of feces from human adults. Three time points were studied: immediately before the first dose of CPF, and then after 15 and 30 days of CPF-oil administration. By using conventional bacterial culture and molecular biology methods, we showed that CPF in oil can affect the gut microbiota. It had the greatest effects on counts of culturable bacteria (with an increase in Enterobacteria, Bacteroides spp. and clostridia counts, and a decrease in bifidobacterial counts) and fermentative activity, which were colon-segment-dependent. Our results suggest that: (i) CPF in oil treatment affects the gut microbiota (although there was some discordance between the culture-dependent and culture-independent analyses); (ii) the changes are “SHIME®-compartment” specific; and (iii) the changes are associated with minor alterations in the production of short-chain fatty acids and lactate. PMID:27827942

Functional Analysis of the Twin-Arginine Translocation Pathway in Corynebacterium glutamicum ATCC 13869▿

PubMed Central

Kikuchi, Yoshimi; Date, Masayo; Itaya, Hiroshi; Matsui, Kazuhiko; Wu, Long-Fei

2006-01-01

Compared to those of other gram-positive bacteria, the genetic structure of the Corynebacterium glutamicum Tat system is unique in that it contains the tatE gene in addition to tatA, tatB, and tatC. The tatE homologue has been detected only in the genomes of gram-negative enterobacteria. To assess the function of the C. glutamicum Tat pathway, we cloned the tatA, tatB, tatC, and tatE genes from C. glutamicum ATCC 13869 and constructed mutants carrying deletions of each tat gene or of both the tatA and tatE genes. Using green fluorescent protein (GFP) fused with the twin-arginine signal peptide of the Escherichia coli TorA protein, we demonstrated that the minimal functional Tat system required TatA and TatC. TatA and TatE provide overlapping function. Unlike the TatB proteins from gram-negative bacteria, C. glutamicum TatB was dispensable for Tat function, although it was required for maximal efficiency of secretion. The signal peptide sequence of the isomaltodextranase (IMD) of Arthrobacter globiformis contains a twin-arginine motif. We showed that both IMD and GFP fused with the signal peptide of IMD were secreted via the C. glutamicum Tat pathway. These observations indicate that IMD is a bona fide Tat substrate and imply great potential of the C. glutamicum Tat system for industrial production of heterologous folded proteins. PMID:16997984

Physiological and molecular characteristics of carbapenem resistance in Klebsiella pneumoniae and Enterobacter aerogenes.

PubMed

Pereira, Rito Santo; Dias, Vanessa Cordeiro; Ferreira-Machado, Alessandra Barbosa; Resende, Juliana Alves; Bastos, André Netto; Andrade Bastos, Lucas Quinet; Andrade Bastos, Victor Quinet; Bastos, Ricardo Villela; Da Silva, Vânia Lúcia; Diniz, Cláudio Galuppo

2016-06-30

Bacterial resistance is a growing concern in the nosocomial environment in which Klebsiella pneumoniae and Enterobacter aerogenes play an important role due to their opportunism and carbapenemase-production. This work aimed to evaluate physiological and molecular characteristics of carbapenem-resistant K. pneumoniae and E. aerogenes isolated in a Brazilian tertiary hospital. In total, 42 carbapenem-resistant bacteria isolated from clinical specimens were included (21 K. pneumoniae and 21 E. aerogenes). Drug-sensitive K. pneumoniae (n = 27) were also included. Antimicrobial susceptibility and biocide tolerance patterns, hemolytic activity, tolerance to oxidative stress, and aggregative ability were assessed. Genetic markers related to carbapenem resistance, or ESBL-production were screened by PCR. Compared to drug-sensitive strains, carbapenem-resistant K. pneumoniae were more tolerant to biocides and to oxidative stress, and they displayed an increase in biofilm formation. The genetic markers blaKPC (95.2%) and blaTEM (90.5%) were the most frequent. Among the carbapenem-resistant E. aerogenes strains, blaKPC, and blaTEM were detected in all bacteria. Drug-sensitive E. aerogenes were not isolated in the same period. blaSHV, blaVIM, and blaCTX markers were also observed among carbapenem-resistant bacteria. Results suggest that carbapenemase-producing enterobacteria might show peculiar characteristics regarding their physiology associated with their environmental persistency, virulence, and multidrug resistance. The observed phenomenon may have implications not only for antimicrobial chemotherapy, but also for the prognosis of infectious diseases and infection control.

Porcine Epidemic Diarrhea in Europe: In-Detail Analyses of Disease Dynamics and Molecular Epidemiology.

PubMed

Hanke, Dennis; Pohlmann, Anne; Sauter-Louis, Carola; Höper, Dirk; Stadler, Julia; Ritzmann, Mathias; Steinrigl, Adi; Schwarz, Bernd-Andreas; Akimkin, Valerij; Fux, Robert; Blome, Sandra; Beer, Martin

2017-07-06

Porcine epidemic diarrhea (PED) is an acute and highly contagious enteric disease of swine caused by the eponymous virus (PEDV) which belongs to the genus Alphacoronavirus within the Coronaviridae virus family. Following the disastrous outbreaks in Asia and the United States, PEDV has been detected also in Europe. In order to better understand the overall situation, the molecular epidemiology, and factors that might influence the most variable disease impact; 40 samples from swine feces were collected from different PED outbreaks in Germany and other European countries and sequenced by shot-gun next-generation sequencing. A total of 38 new PEDV complete coding sequences were generated. When compared on a global scale, all investigated sequences from Central and South-Eastern Europe formed a rather homogeneous PEDV S INDEL cluster, suggesting a recent re-introduction. However, in-detail analyses revealed two new clusters and putative ancestor strains. Based on the available background data, correlations between clusters and location, farm type or clinical presentation could not be established. Additionally, the impact of secondary infections was explored using the metagenomic data sets. While several coinfections were observed, no correlation was found with disease courses. However, in addition to the PEDV genomes, ten complete viral coding sequences from nine different data sets were reconstructed each representing new virus strains. In detail, three pasivirus A strains, two astroviruses, a porcine sapelovirus, a kobuvirus, a porcine torovirus, a posavirus, and an enterobacteria phage were almost fully sequenced.

Efficacy of chlorhexidine digluconate-containing formulations and other mouthrinses against periodontopathogenic microorganisms.

PubMed

Eick, Sigrun; Goltz, Susann; Nietzsche, Sandor; Jentsch, Holger; Pfister, Wolfgang

2011-09-01

To determine in vitro the action of chlorhexidine digluconate and different commercially available mouthrinses on oral microorganisms. Minimal inhibitory concentrations and possible induction of resistance by chlorhexidine digluconate, an essential oil-containing mouthwash and an amine fluoride/stannous fluoride solution, were determined against microorganisms normally found in the oral cavity (10 streptococci, 2 enterobacteria, 1 Candida albicans, 8 Porphyromonas gingivalis, 6 Aggregatibacter actinomycetemcomitans, and 1 Fusobacterium nucleatum). Further, the effect of a 1-minute exposure on cell and bacterial viability was studied. The susceptibility of the oral microorganisms to chlorhexidine digluconate ranged from 0.01% to 0.50%. Passages on agar plates containing subinhibitory concentrations of chlorhexidine digluconate resulted in a transitory moderate increase in the tolerance to chlorhexidine digluconate in five of the 24 isolates. After 1 minute of exposure, chlorhexidine digluconate solutions as well as the essential oil and the amine/stannous fluoride-containing solutions showed a high activity against the tested microorganisms. Commercially available chlorhexidine digluconate formulations (ie, those with antidiscoloration systems) were partly less efficient than the corresponding manually prepared chlorhexidine digluconate preparation. The determination of MTT resulted in a strong cytotoxicity of all tested preparations to gingival fibroblasts. The results indicate that most of the chlorhexidine digluconate formulations as well as essential oil and the amine fluoride/stannous fluoride solutions are active against oral microbes. Long-term use of these agents would not result in emergent antimicrobial resistance.

Production of L-carnitine by secondary metabolism of bacteria

PubMed Central

Bernal, Vicente; Sevilla, Ángel; Cánovas, Manuel; Iborra, José L

2007-01-01

The increasing commercial demand for L-carnitine has led to a multiplication of efforts to improve its production with bacteria. The use of different cell environments, such as growing, resting, permeabilized, dried, osmotically stressed, freely suspended and immobilized cells, to maintain enzymes sufficiently active for L-carnitine production is discussed in the text. The different cell states of enterobacteria, such as Escherichia coli and Proteus sp., which can be used to produce L-carnitine from crotonobetaine or D-carnitine as substrate, are analyzed. Moreover, the combined application of both bioprocess and metabolic engineering has allowed a deeper understanding of the main factors controlling the production process, such as energy depletion and the alteration of the acetyl-CoA/CoA ratio which are coupled to the end of the biotransformation. Furthermore, the profiles of key central metabolic activities such as the TCA cycle, the glyoxylate shunt and the acetate metabolism are seen to be closely interrelated and affect the biotransformation efficiency. Although genetically modified strains have been obtained, new strain improvement strategies are still needed, especially in Escherichia coli as a model organism for molecular biology studies. This review aims to summarize and update the state of the art in L-carnitine production using E. coli and Proteus sp, emphasizing the importance of proper reactor design and operation strategies, together with metabolic engineering aspects and the need for feed-back between wet and in silico work to optimize this biotransformation. PMID:17910757

Common and divergent features in transcriptional control of the homologous small RNAs GlmY and GlmZ in Enterobacteriaceae

PubMed Central

Göpel, Yvonne; Lüttmann, Denise; Heroven, Ann Kathrin; Reichenbach, Birte; Dersch, Petra; Görke, Boris

2011-01-01

Small RNAs GlmY and GlmZ compose a cascade that feedback-regulates synthesis of enzyme GlmS in Enterobacteriaceae. Here, we analyzed the transcriptional regulation of glmY/glmZ from Yersinia pseudotuberculosis, Salmonella typhimurium and Escherichia coli, as representatives for other enterobacterial species, which exhibit similar promoter architectures. The GlmY and GlmZ sRNAs of Y. pseudotuberculosis are transcribed from σ54-promoters that require activation by the response regulator GlrR through binding to three conserved sites located upstream of the promoters. This also applies to glmY/glmZ of S. typhimurium and glmY of E. coli, but as a difference additional σ70-promoters overlap the σ54-promoters and initiate transcription at the same site. In contrast, E. coli glmZ is transcribed from a single σ70-promoter. Thus, transcription of glmY and glmZ is controlled by σ54 and the two-component system GlrR/GlrK (QseF/QseE) in Y. pseudotuberculosis and presumably in many other Enterobacteria. However, in a subset of species such as E. coli this relationship is partially lost in favor of σ70-dependent transcription. In addition, we show that activity of the σ54-promoter of E. coli glmY requires binding of the integration host factor to sites upstream of the promoter. Finally, evidence is provided that phosphorylation of GlrR increases its activity and thereby sRNA expression. PMID:20965974

Interactive effect of trivalent iron on activated sludge digestion and biofilm structure in attached growth reactor of waste tire rubber.

PubMed

Sharafat, Iqra; Saeed, Dania Khalid; Yasmin, Sumera; Imran, Asma; Zafar, Zargona; Hameed, Abdul; Ali, Naeem

2018-01-01

Waste tire rubber (WTR) has been introduced as an alternative, novel media for biofilm development in several experimental systems including attached growth bioreactors. In this context, four laboratory-scale static batch bioreactors containing WTR as a support material for biofilm development were run under anoxic condition for 90 days using waste activated sludge as an inoculum under the influence of different concentrations (2.5, 6.5, 8.5 mg/l) of trivalent ferric iron (Fe 3+ ). The data revealed that activated sludge with a Fe 3+ concentration of 8.5 mg/l supported the maximum bacterial biomass [4.73E + 10 CFU/ml cm 2 ]; besides, it removed 38% more Chemical oxygen demand compared to Fe 3+ free condition from the reactor. Biochemical testing and 16S rDNA phylogenetic analysis of WTR-derived biofilm communities further suggested the role of varying concentrations of Fe 3+ on the density and diversity of members of Enterobacteria(ceae), ammonium (AOB) and nitrite oxidizing bacteria. Furthermore, Fluorescent in situ hybridization with phylogenetic oligonucleotide probes and confocal laser scanning microscopy of WTR biofilms indicated a significant increase in density of eubacteria (3.00E + 01 to.05E + 02 cells/cm 2 ) and beta proteobacteria (8.10E + 01 to 1.42E + 02 cells/cm 2 ), respectively, with an increase in Fe 3+ concentration in the reactors, whereas, the cell density of gamma proteobacteria in biofilms decreased.

Effects of Mutations and Ligands on the Thermostability of the l-Arginine/Agmatine Antiporter AdiC and Deduced Insights into Ligand-Binding of Human l-Type Amino Acid Transporters.

PubMed

Ilgü, Hüseyin; Jeckelmann, Jean-Marc; Colas, Claire; Ucurum, Zöhre; Schlessinger, Avner; Fotiadis, Dimitrios

2018-03-20

The l-arginine/agmatine transporter AdiC is a prokaryotic member of the SLC7 family, which enables pathogenic enterobacteria to survive the extremely acidic gastric environment. Wild-type AdiC from Escherichia coli, as well as its previously reported point mutants N22A and S26A, were overexpressed homologously and purified to homogeneity. A size-exclusion chromatography-based thermostability assay was used to determine the melting temperatures ( T m s) of the purified AdiC variants in the absence and presence of the selected ligands l-arginine (Arg), agmatine, l-arginine methyl ester, and l-arginine amide. The resulting T m s indicated stabilization of AdiC variants upon ligand binding, in which T m s and ligand binding affinities correlated positively. Considering results from this and previous studies, we revisited the role of AdiC residue S26 in Arg binding and proposed interactions of the α-carboxylate group of Arg exclusively with amide groups of the AdiC backbone. In the context of substrate binding in the human SLC7 family member l-type amino acid transporter-1 (LAT1; SLC7A5), an analogous role of S66 in LAT1 to S26 in AdiC is discussed based on homology modeling and amino acid sequence analysis. Finally, we propose a binding mechanism for l-amino acid substrates to LATs from the SLC7 family.

StpA and Hha stimulate pausing by RNA polymerase by promoting DNA-DNA bridging of H-NS filaments.

PubMed

Boudreau, Beth A; Hron, Daniel R; Qin, Liang; van der Valk, Ramon A; Kotlajich, Matthew V; Dame, Remus T; Landick, Robert

2018-06-20

In enterobacteria, AT-rich horizontally acquired genes, including virulence genes, are silenced through the actions of at least three nucleoid-associated proteins (NAPs): H-NS, StpA and Hha. These proteins form gene-silencing nucleoprotein filaments through direct DNA binding by H-NS and StpA homodimers or heterodimers. Both linear and bridged filaments, in which NAPs bind one or two DNA segments, respectively, have been observed. Hha can interact with H-NS or StpA filaments, but itself lacks a DNA-binding domain. Filaments composed of H-NS alone can inhibit transcription initiation and, in the bridged conformation, slow elongating RNA polymerase (RNAP) by promoting backtracking at pause sites. How the other NAPs modulate these effects of H-NS is unknown, despite evidence that they help regulate subsets of silenced genes in vivo (e.g. in pathogenicity islands). Here we report that Hha and StpA greatly enhance H-NS-stimulated pausing by RNAP at 20°C. StpA:H-NS or StpA-only filaments also stimulate pausing at 37°C, a temperature at which Hha:H-NS or H-NS-only filaments have much less effect. In addition, we report that both Hha and StpA greatly stimulate DNA-DNA bridging by H-NS filaments. Together, these observations indicate that Hha and StpA can affect H-NS-mediated gene regulation by stimulating bridging of H-NS/DNA filaments.

An RpoS-dependent sRNA regulates the expression of a chaperone involved in protein folding

PubMed Central

Silva, Inês Jesus; Ortega, Álvaro Darío; Viegas, Sandra Cristina; García-del Portillo, Francisco; Arraiano, Cecília Maria

2013-01-01

Small noncoding RNAs (sRNAs) are usually expressed in the cell to face a variety of stresses. In this report we disclose the first target for SraL (also known as RyjA), a sRNA present in many bacteria, which is highly induced in stationary phase. We also demonstrate that this sRNA is directly transcribed by the major stress σ factor σS (RpoS) in Salmonella enterica serovar Typhimurium. We show that SraL sRNA down-regulates the expression of the chaperone Trigger Factor (TF), encoded by the tig gene. TF is one of the three major chaperones that cooperate in the folding of the newly synthesized cytosolic proteins and is the only ribosome-associated chaperone known in bacteria. By use of bioinformatic tools and mutagenesis experiments, SraL was shown to directly interact with the 5′ UTR of the tig mRNA a few nucleotides upstream of the Shine-Dalgarno region. Namely, point mutations in the sRNA (SraL*) abolished the repression of tig mRNA and could only down-regulate a tig transcript target with the respective compensatory mutations. We have also validated in vitro that SraL forms a stable duplex with the tig mRNA. This work constitutes the first report of a small RNA affecting protein folding. Taking into account that both SraL and TF are very well conserved in enterobacteria, this work will have important repercussions in the field. PMID:23893734

An RpoS-dependent sRNA regulates the expression of a chaperone involved in protein folding.

PubMed

Silva, Inês Jesus; Ortega, Alvaro Darío; Viegas, Sandra Cristina; García-Del Portillo, Francisco; Arraiano, Cecília Maria

2013-09-01

Small noncoding RNAs (sRNAs) are usually expressed in the cell to face a variety of stresses. In this report we disclose the first target for SraL (also known as RyjA), a sRNA present in many bacteria, which is highly induced in stationary phase. We also demonstrate that this sRNA is directly transcribed by the major stress σ factor σ(S) (RpoS) in Salmonella enterica serovar Typhimurium. We show that SraL sRNA down-regulates the expression of the chaperone Trigger Factor (TF), encoded by the tig gene. TF is one of the three major chaperones that cooperate in the folding of the newly synthesized cytosolic proteins and is the only ribosome-associated chaperone known in bacteria. By use of bioinformatic tools and mutagenesis experiments, SraL was shown to directly interact with the 5' UTR of the tig mRNA a few nucleotides upstream of the Shine-Dalgarno region. Namely, point mutations in the sRNA (SraL*) abolished the repression of tig mRNA and could only down-regulate a tig transcript target with the respective compensatory mutations. We have also validated in vitro that SraL forms a stable duplex with the tig mRNA. This work constitutes the first report of a small RNA affecting protein folding. Taking into account that both SraL and TF are very well conserved in enterobacteria, this work will have important repercussions in the field.

Characterization of a new phage, termed ϕA318, which is specific for Vibrio alginolyticus.

PubMed

Lin, Ying-Rong; Chiu, Chi-Wen; Chang, Feng-Yi; Lin, Chan-Shing

2012-05-01

Vibrio alginolyticus is an opportunistic pathogen of animals and humans; its related strains can also produce tetrodotoxin and hemolysins. A new phage, ϕA318, which lysed its host V. alginolyticus with high efficiency, was characterized. The burst size of ϕA318 in V. alginolyticus was 72 PFU/bacterium at an MOI of 1 at room temperature; the plaque size was as large as 5 mm in diameter. Electron microscopy (EM) of the phage particles revealed a 50- to 55-nm isomorphous icosahedral head with a 12-nm non-contractile tail, similar to the T7-like phages of the family Podoviridae. Phylogenetic analysis based on complete sequences of the DNA-directed RNA polymerase gene revealed that ϕA318 had 28-47% amino acid identity to enterobacteria phages T7 and SP6, and other Vibrio phages, and the phylogenetic distance suggested that ϕA318 could be classified as a new T7-like bacteriophage. Nevertheless, several motifs in the ϕA318 phage RNA polymerase were highly conserved, including DFRGR (T7-421 motif), DG (T7-537 motif), PSEKPQDIYGAVS (T7-563 motif), RSMTKKPVMTL PYGS (T7-627 motif), and HDS (T7-811 motif). Genetic analysis indicated that phage ϕA318 is not a thermostable direct hemolysin producer. The results suggest that the MOI should be higher than 0.1 to prevent the chance of hemolysin production by the bacteria before they are lysed by the phage.

Anaerobic bacteria commonly colonize the lower airways of intubated ICU patients.

PubMed

Agvald-Ohman, C; Wernerman, J; Nord, C E; Edlund, C

2003-05-01

To investigate respiratory tract colonization by aerobic and anaerobic bacteria in mechanically ventilated patients. Bacterial colonization of the stomach and the respiratory tract was qualitatively and quantitatively analyzed over time in 41 consecutive mechanically ventilated patients in a Swedish intensive care unit (ICU), with special emphasis on elucidation of the role of anaerobic bacteria in the lower respiratory tract. Samples were taken from the oropharynx, gastric juice, subglottic space and trachea within 24 h (median 14 h) of intubation, and then every third day until day 18 and every fifth day until day 33. The patients were often heavily colonized with microorganisms not considered to belong to a healthy normal oropharyngeal and gastric flora on admission to the ICU. A majority harbored enterococci, coagulase-negative staphylococci and Candida spp. in at least one site on day 1. Anaerobic bacteria, mainly peptostreptococci and Prevotella spp., were isolated from subglottic and/or tracheal secretions in 59% of the patients. Different routes of tracheal colonization for different groups of microorganisms were found. Primary or concomitant colonization of the oropharynx with staphylococci, enterococci, enterobacteria and Candida was often seen, while Pseudomonas spp., other non-fermenting Gram-negative rods and several anaerobic species often primarily colonized the trachea, indicating exogenous or direct gastrointestinal routes of colonization. Mechanically ventilated patients were heavily colonized in their lower airways by potential pathogenic microorganisms, including a high load of anaerobic bacteria. Different routes of colonization were shown for different species.

A protein secretion system linked to bacteroidete gliding motility and pathogenesis

PubMed Central

Sato, Keiko; Naito, Mariko; Yukitake, Hideharu; Hirakawa, Hideki; Shoji, Mikio; McBride, Mark J.; Rhodes, Ryan G.; Nakayama, Koji

2009-01-01

Porphyromonas gingivalis secretes strong proteases called gingipains that are implicated in periodontal pathogenesis. Protein secretion systems common to other Gram-negative bacteria are lacking in P. gingivalis, but several proteins, including PorT, have been linked to gingipain secretion. Comparative genome analysis and genetic experiments revealed 11 additional proteins involved in gingipain secretion. Six of these (PorK, PorL, PorM, PorN, PorW, and Sov) were similar in sequence to Flavobacterium johnsoniae gliding motility proteins, and two others (PorX and PorY) were putative two-component system regulatory proteins. Real-time RT-PCR analysis revealed that porK, porL, porM, porN, porP, porT, and sov were down-regulated in P. gingivalis porX and porY mutants. Disruption of the F. johnsoniae porT ortholog resulted in defects in motility, chitinase secretion, and translocation of a gliding motility protein, SprB adhesin, to the cell surface, providing a link between a unique protein translocation system and a motility apparatus in members of the Bacteroidetes phylum. PMID:19966289

Differential Regulation of Duplicate Light-Dependent Protochlorophyllide Oxidoreductases in the Diatom Phaeodactylum tricornutum

PubMed Central

Hunsperger, Heather M.; Cattolico, Rose Ann

2016-01-01

Background Diatoms (Bacilliariophyceae) encode two light-dependent protochlorophyllide oxidoreductases (POR1 and POR2) that catalyze the penultimate step of chlorophyll biosynthesis in the light. Algae live in dynamic environments whose changing light levels induce photoacclimative metabolic shifts, including altered cellular chlorophyll levels. We hypothesized that the two POR proteins may be differentially adaptive under varying light conditions. Using the diatom Phaeodactylum tricornutum as a test system, differences in POR protein abundance and por gene expression were examined when this organism was grown on an alternating light:dark cycles at different irradiances; exposed to continuous light; and challenged by a significant decrease in light availability. Results For cultures maintained on a 12h light: 12h dark photoperiod at 200μE m−2 s−1 (200L/D), both por genes were up-regulated during the light and down-regulated in the dark, though por1 transcript abundance rose and fell earlier than that of por2. Little concordance occurred between por1 mRNA and POR1 protein abundance. In contrast, por2 mRNA and POR2 protein abundances followed similar diurnal patterns. When 200L/D P. tricornutum cultures were transferred to continuous light (200L/L), the diurnal regulatory pattern of por1 mRNA abundance but not of por2 was disrupted, and POR1 but not POR2 protein abundance dropped steeply. Under 1200μE m−2 s−1 (1200L/D), both por1 mRNA and POR1 protein abundance displayed diurnal oscillations. A compromised diel por2 mRNA response under 1200L/D did not impact the oscillation in POR2 abundance. When cells grown at 1200L/D were then shifted to 50μE m−2 s−1 (50L/D), por1 and por2 mRNA levels decreased swiftly but briefly upon light reduction. Thereafter, POR1 but not POR2 protein levels rose significantly in response to this light stepdown. Conclusion Given the sensitivity of diatom por1/POR1 to real-time light cues and adherence of por2/POR2 regulation to

Population pharmacokinetic approach to evaluate the effect of CYP2D6, CYP3A, ABCB1, POR and NR1I2 genotypes on donepezil clearance

PubMed Central

Noetzli, Muriel; Guidi, Monia; Ebbing, Karsten; Eyer, Stephan; Wilhelm, Laurence; Michon, Agnès; Thomazic, Valérie; Stancu, Ioana; Alnawaqil, Abdel-Messieh; Bula, Christophe; Zumbach, Serge; Gaillard, Michel; Giannakopoulos, Panteleimon; von Gunten, Armin; Csajka, Chantal; Eap, Chin B

2014-01-01

Aims A large interindividual variability in plasma concentrations has been reported in patients treated with donepezil, the most frequently prescribed antidementia drug. We aimed to evaluate clinical and genetic factors influencing donepezil disposition in a patient population recruited from a naturalistic setting. Methods A population pharmacokinetic study was performed including data from 129 older patients treated with donepezil. The patients were genotyped for common polymorphisms in the metabolic enzymes CYP2D6 and CYP3A, in the electron transferring protein POR and the nuclear factor NR1I2 involved in CYP activity and expression, and in the drug transporter ABCB1. Results The average donepezil clearance was 7.3 l h−1 with a 30% interindividual variability. Gender markedly influenced donepezil clearance (P < 0.01). Functional alleles of CYP2D6 were identified as unique significant genetic covariate for donepezil clearance (P < 0.01), with poor metabolizers and ultrarapid metabolizers demonstrating, respectively, a 32% slower and a 67% faster donepezil elimination compared with extensive metabolizers. Conclusion The pharmacokinetic parameters of donepezil were well described by the developed population model. Functional alleles of CYP2D6 significantly contributed to the variability in donepezil disposition in the patient population and should be further investigated in the context of individual dose optimization to improve clinical outcome and tolerability of the treatment. PMID:24433464

Population pharmacokinetic approach to evaluate the effect of CYP2D6, CYP3A, ABCB1, POR and NR1I2 genotypes on donepezil clearance.

PubMed

Noetzli, Muriel; Guidi, Monia; Ebbing, Karsten; Eyer, Stephan; Wilhelm, Laurence; Michon, Agnès; Thomazic, Valérie; Stancu, Ioana; Alnawaqil, Abdel-Messieh; Bula, Christophe; Zumbach, Serge; Gaillard, Michel; Giannakopoulos, Panteleimon; von Gunten, Armin; Csajka, Chantal; Eap, Chin B

2014-07-01

A large interindividual variability in plasma concentrations has been reported in patients treated with donepezil, the most frequently prescribed antidementia drug. We aimed to evaluate clinical and genetic factors influencing donepezil disposition in a patient population recruited from a naturalistic setting. A population pharmacokinetic study was performed including data from 129 older patients treated with donepezil. The patients were genotyped for common polymorphisms in the metabolic enzymes CYP2D6 and CYP3A, in the electron transferring protein POR and the nuclear factor NR1I2 involved in CYP activity and expression, and in the drug transporter ABCB1. The average donepezil clearance was 7.3 l h(-1) with a 30% interindividual variability. Gender markedly influenced donepezil clearance (P < 0.01). Functional alleles of CYP2D6 were identified as unique significant genetic covariate for donepezil clearance (P < 0.01), with poor metabolizers and ultrarapid metabolizers demonstrating, respectively, a 32% slower and a 67% faster donepezil elimination compared with extensive metabolizers. The pharmacokinetic parameters of donepezil were well described by the developed population model. Functional alleles of CYP2D6 significantly contributed to the variability in donepezil disposition in the patient population and should be further investigated in the context of individual dose optimization to improve clinical outcome and tolerability of the treatment. © 2014 The British Pharmacological Society.

Differential regulation of duplicate light-dependent protochlorophyllide oxidoreductases in the diatom Phaeodactylum tricornutum

DOE PAGES

Hunsperger, Heather M.; Ford, Christopher J.; Miller, James S.; ...

2016-07-01

Diatoms (Bacilliariophyceae) encode two light-dependent protochlorophyllide oxidoreductases (POR1 and POR2) that catalyze the penultimate step of chlorophyll biosynthesis in the light. Algae live in dynamic environments whose changing light levels induce photoacclimative metabolic shifts, including altered cellular chlorophyll levels. We hypothesized that the two POR proteins may be differentially adaptive under varying light conditions. Using the diatom Phaeodactylum tricornutum as a test system, differences in POR protein abundance and por gene expression were examined when this organism was grown on an alternating light:dark cycles at different irradiances; exposed to continuous light; and challenged by a significant decrease in light availability.more » As a result, for cultures maintained on a 12h light: 12h dark photoperiod at 200μEm –2 s –1 ( 200L/D), both por genes were up-regulated during the light and down-regulated in the dark, though por1 transcript abundance rose and fell earlier than that of por2. Little concordance occurred between por1 mRNA and POR1 protein abundance. In contrast, por2 mRNA and POR2 protein abundances followed similar diurnal patterns. When 200L/D P. tricornutum cultures were transferred to continuous light ( 200L/L), the diurnal regulatory pattern of por1 mRNA abundance but not of por2 was disrupted, and POR1 but not POR2 protein abundance dropped steeply. Under 1200μEm –2 s –1 ( 1200L/D), both por1 mRNA and POR1 protein abundance displayed diurnal oscillations. A compromised diel por2 mRNA response under 1200L/D did not impact the oscillation in POR2 abundance. When cells grown at 1200L/D were then shifted to 50μEm –2 s –1 (50L/D), por1 and por2 mRNA levels decreased swiftly but briefly upon light reduction. Thereafter, POR1 but not POR2 protein levels rose significantly in response to this light stepdown.« less

Complications of central venous catheter in patients transplanted with hematopoietic stem cells in a specialized service.

PubMed

Barretta, Lidiane Miotto; Beccaria, Lúcia Marinilza; Cesarino, Cláudia Bernardi; Pinto, Maria Helena

2016-06-07

to identify the model, average length of stay on site and complications of central venous catheter in patients undergoing transplant of hematopoietic stem cells and verify the corresponding relationship between the variables: age, gender, medical diagnosis, type of transplant, implanted catheter and insertion site. a retrospective and quantitative study with a sample of 188 patients transplanted records between 2007 and 2011. the majority of patients used Hickman catheter with an average length of stay on site of 47.6 days. The complication fever/bacteremia was significant in young males with non-Hodgkin's lymphoma undergoing autologous transplant, which remained with the device for a long period in the subclavian vein. nurses should plan with their team the minimum waiting time, recommended between the catheter insertion and start of the conditioning regimen, as well as not to extend the length of time that catheter should be on site and undertake their continuing education, focusing on the prevention of complications. identificar o modelo, tempo médio de permanência e complicações de cateter venoso central em pacientes submetidos ao transplante de células-tronco hematopoiéticas e verificar a relação de correspondência entre as variáveis: idade, sexo, diagnóstico médico, tipo de transplante, cateter implantado e local de inserção. retrospectivo, quantitativo, com amostra de prontuários de 188 pacientes transplantados, entre 2007 e 2011. a maioria dos pacientes utilizou o cateter de Hickman com permanência média de 47,6 dias. A complicação febre/bacteremia foi significante em jovens do sexo masculino, com linfoma não Hodgkin, submetidos ao transplante autólogo, que permaneceram com o dispositivo por longo período, em veia subclávia. os enfermeiros devem planejar com a equipe o aguardo do tempo mínimo preconizado entre o implante do cateter e início do regime de condicionamento, assim como não estender o período de permanência e realizar

A study on the stability of O{sub 2} on oxometalloporphyrins by the first principles calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubota, Yoshiyuki; Escano, Mary Clare Sison; Dy, Eben Sy

2007-05-21

The authors investigated the interaction of oxometalloporphyrins (MO(por))--specifically, MoO(por), WO(por), TiO(por), VO(por), and CrO(por)--with O{sub 2} by using first principles calculations. MoO(por) and WO(por) undergo reactions with O{sub 2}; on the other hand, TiO(por), VO(por), and CrO(por) do not. Next, they compared the interaction of MoO(por) and WO(por) with O{sub 2}. Activation barriers for the reactions of MoO(por) and WO(por) with a side-on O{sub 2} are small. For MoO(por)(O{sub 2}), the activation barrier for the reverse reaction that liberates O{sub 2} is also small; however, that for WO(por)(O{sub 2}) is large. The experimental results that photoirradiation with visible light ormore » heating of Mo {sup VI}O(tmp)(O{sub 2}) regenerates Mo {sup VI}O(tmp) by liberating O{sub 2} while W {sup VI}O(tmp)(O{sub 2}) does not [J. Tachibana, T. Imamura, and Y. Sasaki, Bull. Chem. Soc. Jpn. 71, 363 (1998)] are explained by the difference in activation barriers of the reverse reactions. This means that bonds formed between the W atom and O{sub 2} are stronger than those between the Mo atom and O{sub 2}. The bond strengths can be explained by differences in the energy levels between the highest occupied molecular orbital of MoO(por) and WO(por), which are mainly formed from the a orbitals of the central metal atom and {pi}{sup *} orbitals of O{sub 2}.« less

Type IX secretion: the generation of bacterial cell surface coatings involved in virulence, gliding motility and the degradation of complex biopolymers.

PubMed

Veith, Paul D; Glew, Michelle D; Gorasia, Dhana G; Reynolds, Eric C

2017-10-01

The Type IX secretion system (T9SS) is present in over 1000 sequenced species/strains of the Fibrobacteres-Chlorobi-Bacteroidetes superphylum. Proteins secreted by the T9SS have an N-terminal signal peptide for translocation across the inner membrane via the SEC translocon and a C-terminal signal for secretion across the outer membrane via the T9SS. Nineteen protein components of the T9SS have been identified including three, SigP, PorX and PorY that are involved in regulation. The inner membrane proteins PorL and PorM and the outer membrane proteins PorK and PorN interact and a complex comprising PorK and PorN forms a large ring structure of 50 nm in diameter. PorU, PorV, PorQ and PorZ form an attachment complex on the cell surface of the oral pathogen, Porphyromonas gingivalis. P. gingivalis T9SS substrates bind to PorV suggesting that after translocation PorV functions as a shuttle protein to deliver T9SS substrates to the attachment complex. The PorU component of the attachment complex is a novel Gram negative sortase which catalyses the cleavage of the C-terminal signal and conjugation of the protein substrates to lipopolysaccharide, anchoring them to the cell surface. This review presents an overview of the T9SS focusing on the function of T9SS substrates and machinery components. © 2017 John Wiley & Sons Ltd.

Escherichia coli and Cronobacter sakazakii in 'Tommy Atkins' minimally processed mangos: Survival, growth and effect of UV-C and electrolyzed water.

PubMed

Santo, David; Graça, Ana; Nunes, Carla; Quintas, Célia

2018-04-01

These studies were aimed at assessing the growing capacity of Escherichia coli and Cronobacter sakazakii and the effectiveness of Ultraviolet-C (UV-C) radiation, acidic electrolyzed (AEW) and neutral electrolyzed (NEW) waters in the inhibition of these bacteria on minimally processed 'Tommy Atkins' mangoes (MPM). The fruits were contaminated by dip inoculation and kept 10 days at 4, 8, 12 and 20 °C while enumerating bacteria. Contaminated mangoes were disinfected using UV-C (2.5, 5, 7.5 and 10 kJ/m 2 ), AEW, NEW and sodium hypochlorite (SH) and the microorganisms were monitored. None of the enterobacteria grew at 4, 8 and 12 °C regardless of having persisted during the 10-day period. At 20 °C, E. coli and C. sakazakii grew, after adaption phases of 48 h and 24 h, to values of 8.7 and 8.5 log cfu/g at day eight, respectively. E. coli showed the highest reduction counts on the MPM washed with NEW and SH (2.2 log cfu/g). UV-C was more effective in reducing C. sakazakii (2.4-2.6 log cfu/g), when compared to AEW, NEW and SH (1.2-1.8 log cfu/g). The efficacy of decontamination technologies depends on microorganisms, highlighting the importance of preventing contamination at the primary production and of combining different methods to increase the safety of fresh-cut fruits. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chronic coffee consumption in the diet-induced obese rat: impact on gut microbiota and serum metabolomics.

PubMed

Cowan, Theresa E; Palmnäs, Marie S A; Yang, Jaeun; Bomhof, Marc R; Ardell, Kendra L; Reimer, Raylene A; Vogel, Hans J; Shearer, Jane

2014-04-01

Epidemiological data confirms a strong negative association between regular coffee consumption and the prevalence of type 2 diabetes. Coffee is initially absorbed in the stomach and small intestine but is further fermented in the colon by gut microbiota. The bioavailability, production and biological activity of coffee polyphenols is modulated, in part, by gut microbiota. The purpose of this study was to determine if chronic coffee consumption could mitigate negative gut microbiota and metabolomic profile changes induced by a high-fat diet. Male Sprague-Dawley rats were randomized to chow (12% kcal fat) or high-fat (60% kcal fat) diet. Each group was further divided into water or caffeinated coffee for 10 weeks. Coffee consumption in high-fat-fed rats was associated with decreased body weight, adiposity, liver triglycerides and energy intake. Despite a more favorable body composition, rats displayed profound systemic insulin resistance, likely due to caffeine. Coffee consumption attenuated the increase in Firmicutes (F)-to-Bacteroidetes (B) ratio and Clostridium Cluster XI normally associated with high-fat feeding but also resulted in augmented levels of Enterobacteria. In the serum metabolome, coffee had a distinct impact, increasing levels of aromatic and circulating short-chain fatty acids while lowering levels of branched-chain amino acids. In summary, coffee consumption is able to alter gut microbiota in high-fat-fed rats although the role of these changes in reducing diabetes risk is unclear given the increased insulin resistance observed with coffee in this study. Copyright © 2014 Elsevier Inc. All rights reserved.

[Risk factors associated with bacterial growth in derivative systems from cerebrospinal liquid in pediatric patients].

PubMed

de Jesús Vargas-Lares, José; Andrade-Aguilera, Angélica Rocío; Díaz-Peña, Rafael; Barrera de León, Juan Carlos

2015-01-01

To determine risk factors associated with bacterial growth in systems derived from cerebrospinal fluid in pediatric patients. Case and controls study from January to December 2012, in patients aged <16 years who were carriers of hydrocephalus and who required placement or replacement of derivative system. Cases were considered as children with cultures with bacterial growth and controls with negative bacterial growth. Inferential statistics with Chi-squared and Mann-Whitney U tests. Association of risk with odds ratio. We reviewed 746 registries, cases n=99 (13%) and controls n=647 (87%). Masculine gender 58 (57%) vs. feminine gender 297 (46%) (p=0.530). Age of cases: median, five months and controls, one year (p=0.02). Median weight, 7 vs. 10 kg (p=0.634). Surgical interventions: median n=2 (range, 1-8) vs. n=1 (range, 1-7). Infection rate, 13.2%. Main etiology ductal stenosis, n=29 (29%) vs. n=50 (23%) (p=0.530). Non-communicating, n=50 (51%) vs. 396 (61%) (p=0.456). Predominant microorganisms: enterobacteria, pseudomonas, and enterococcus. Non-use of iodized dressing OR=2.6 (range, 1.8-4.3), use of connector OR=6.8 (range, 1.9-24.0), System replacement OR=2.0 (range, 1.3-3.1), assistant without surgical facemask OR=9.7 (range, 2.3-42.0). Being a breastfeeding infant, of low weight, non-application of iodized dressing, use of connector, previous derivation, and lack of adherence to aseptic technique were all factors associated with ependymitis.

[Bacterial brain abscess--experiences with 67 patients].

PubMed

Berlit, P; Fedel, C; Tornow, K; Schmiedek, P

1996-08-01

Sixty-seven patients with brain abscess were managed over 19 years (1975-1993). Our series had a 2.5 to 1 male predominance; the age distribution was from 3 days to 81 years. The underlying conditions of hematogenic brain abscesses (n = 33; 49%) included lung infections (n = 16), heart disease (n = 4), sepsis (n = 10), and other foci (n = 3). Otolaryngologic infections led to the abscess in 10 cases; there were 9 traumatic abscesses. The causes remained unknown in 15 cases. There were 47 solitary abscesses (70%) and 20 multiple abscesses. The most frequent presenting signs and symptoms were neurologic deficits (n = 17), disturbances of consciousness (n = 14), seizures (n = 6), and headaches, meningism and vomiting (n = 13). Causative organisms were isolated in 39 cases (58%) and included staphylococci (n = 6), streptococci (n = 6), enterobacteriae (n = 2), and anaerobic pathogens (n = 9). The most reliable laboratory sign of inflammation was an elevated ESR (52/59 patients). With the advent of computed tomography, burr hole aspiration of the abscess with or without drainage was possible in 30 cases; the mortality in this subgroup was 9%. All 4 patients with surgical excision in the pre CT-era died. The mortality of patients treated with antibiotics only was 62% (18/29). Overall mortality was 37% (25/67), including 5 cases with post mortem-diagnosis of brain abscess. Good recovery was achieved in 29/42 survivors. Predictors of a poor outcome were the patient's age, the level of consciousness, multiple abscesses, polybacterial cultures, and a hematogenic etiology, but not the size of the abscess.

Potential impact of soil microbial heterogeneity on the persistence of hydrocarbons in contaminated subsurface soils.

PubMed

Aleer, Sam; Adetutu, Eric M; Weber, John; Ball, Andrew S; Juhasz, Albert L

2014-04-01

In situ bioremediation is potentially a cost effective treatment strategy for subsurface soils contaminated with petroleum hydrocarbons, however, limited information is available regarding the impact of soil spatial heterogeneity on bioremediation efficacy. In this study, we assessed issues associated with hydrocarbon biodegradation and soil spatial heterogeneity (samples designated as FTF 1, 5 and 8) from a site in which in situ bioremediation was proposed for hydrocarbon removal. Test pit activities showed similarities in FTF soil profiles with elevated hydrocarbon concentrations detected in all soils at 2 m below ground surface. However, PCR-DGGE-based cluster analysis showed that the bacterial community in FTF 5 (at 2 m) was substantially different (53% dissimilar) and 2-3 fold more diverse than communities in FTF 1 and 8 (with 80% similarity). When hydrocarbon degrading potential was assessed, differences were observed in the extent of (14)C-benzene mineralisation under aerobic conditions with FTF 5 exhibiting the highest hydrocarbon removal potential compared to FTF 1 and 8. Further analysis indicated that the FTF 5 microbial community was substantially different from other FTF samples and dominated by putative hydrocarbon degraders belonging to Pseudomonads, Xanthomonads and Enterobacteria. However, hydrocarbon removal in FTF 5 under anaerobic conditions with nitrate and sulphate electron acceptors was limited suggesting that aerobic conditions were crucial for hydrocarbon removal. This study highlights the importance of assessing available microbial capacity prior to bioremediation and shows that the site's spatial heterogeneity can adversely affect the success of in situ bioremediation unless area-specific optimizations are performed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Antibiotic resistance patterns of urinary tract pathogens in Turkish children.

PubMed

Gunduz, Suzan; Uludağ Altun, Hatice

2018-01-01

Knowledge of local antimicrobial resistance patterns is essential for evidence- based empirical antibiotic prescribing. We aimed to investigate the distribution and changes in causative agents of urinary tract infections in children and the resistance rates, and to recommend the most appropriate antibiotics. In this retrospective study, we evaluated causative agents and antimicrobial resistance in urine isolates from the positive community from September 2014 to April 2016 in a single hospital in Ankara, Turkey. A total of 850 positive urine cultures were identified, of which 588 (69.2%) were from girls and 262 (30.8%) were from boys. Their mean age was 36.5 ± 45.0 months. The most common causative agent was Escherichia coli (64.2% of cases) followed by Klebsiella pneumoniae (14.9%). The overall resistance to ampicillin (62.6%), cephalothin (44.2%), co-trimoxazole (29.8%) and cefuroxime (28.7%) was significant. No resistance to imipenem was detected in the isolates. The least resistance was for amikacin, ceftriaxone, ciprofloxacin and cefepime (0.1, 2.4, 7.5 and 8.3%, respectively). Imipenem was the most active agent against E. coli followed by amikacin (0.2%), ceftriaxone (2.7%) and nitrofurantoin (5.1%). High resistance rates to nitrofurantoin were detected in K. pneumoniae, Proteus and Enterobacteriae . E. coli was the most common causative agent of urinary tract infection in children. Ampicillin, trimethoprim-sulfometaxazole, cephalothin and cefuroxim had the highest resistance rates against urinary tract pathogens in our center. For oral empirical antibiotherapy, cefixime is the most appropriate choice so as to include Klebsiella strains.

Oral Administration of Probiotics Increases Paneth Cells and Intestinal Antimicrobial Activity.

PubMed

Cazorla, Silvia I; Maldonado-Galdeano, Carolina; Weill, Ricardo; De Paula, Juan; Perdigón, Gabriela D V

2018-01-01

The huge amount of intestinal bacteria represents a continuing threat to the intestinal barrier. To meet this challenge, gut epithelial cells produce antimicrobial peptides (AMP) that act at the forefront of innate immunity. We explore whether this antimicrobial activity and Paneth cells, the main intestinal cell responsible of AMP production, are influenced by probiotics administration, to avoid the imbalance of intestinal microbiota and preserve intestinal barrier. Administration of Lactobacillus casei CRL 431 (Lc 431) and L. paracasei CNCM I-1518 (Lp 1518) to 42 days old mice, increases the number of Paneth cells on small intestine, and the antimicrobial activity against the pathogens Staphylococcus aureus and Salmonella Typhimurium in the intestinal fluids. Specifically, strong damage of the bacterial cell with leakage of cytoplasmic content, and cellular fragmentation were observed in S. Typhimurium and S. aureus . Even more important, probiotics increase the antimicrobial activity of the intestinal fluids at the different ages, from weaning (21 days old) to old age (180 days old). Intestinal antimicrobial activity stimulated by oral probiotics, do not influence significantly the composition of total anaerobic bacteria, lactobacilli and enterobacteria in the large intestine, at any age analyzed. This result, together with the antimicrobial activity observed against the same probiotic bacteria; endorse the regular consumption of probiotics without adverse effect on the intestinal homeostasis in healthy individuals. We demonstrate that oral probiotics increase intestinal antimicrobial activity and Paneth cells in order to strengthen epithelial barrier against pathogens. This effect would be another important mechanism by which probiotics protect the host mainly against infectious diseases.

Increased gut microbiota diversity and abundance of Faecalibacterium prausnitzii and Akkermansia after fasting: a pilot study.

PubMed

Remely, Marlene; Hippe, Berit; Geretschlaeger, Isabella; Stegmayer, Sonja; Hoefinger, Ingrid; Haslberger, Alexander

2015-05-01

An impaired gut microbiota has been reported as an important factor in the pathogenesis of obesity. Weight reduction has already been mentioned to improve gut microbial subpopulations involved in inflammatory processes, though other subpopulations still need further investigation. Thus, weight reduction in the context of a fasting program together with a probiotic intervention may improve the abundance and diversity of gut microbiota. In this pilot study, overweight people underwent a fasting program with laxative treatment for 1 week followed by a 6 week intervention with a probiotic formula. Gut microbiota were analyzed on the basis of 16s rDNA with a quantitative real time polymerase chain reaction. Additionally, a food frequency questionnaire with questions about nutritional behavior, lifestyle, and physical activity was administered before and after the intervention. We observed an increase in microbial diversity over the study period. No significant changes in abundance of total bacteria, or of Bacteroidetes, Prevotella, Clostridium cluster XIVa, or Clostridium cluster IV were found, although Faecalibacterium prausnitzii showed an increase over the study period. In addition, Akkermanisa and Bifidobacteria increased in abundance due to intervention. The inflammation-associated gut microbes Enterobacteria and Lactobacilli increased during the first week and then declined by the end of the intervention. Two-thirds of the study participants harbored Archaea. No significant improvements of eating habits were reported, although physical activity improved due to the intervention. Our results show that caloric restriction affects gut microbiota by proliferating mucin-degrading microbial subpopulations. An additional intervention with a probiotic formula increased probiotic-administered gut microbial populations.

Evolutionary genomics suggests that CheV is an additional adaptor for accommodating specific chemoreceptors within the chemotaxis signaling complex

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ortega, Davi R.; Zhulin, Igor B.; Punta, Marco

Escherichia coli and Salmonella enterica are models for many experiments in molecular biology including chemotaxis, and most of the results obtained with one organism have been generalized to another. While most components of the chemotaxis pathway are strongly conserved between the two species, Salmonella genomes contain some chemoreceptors and an additional protein, CheV, that are not found in E. coli. The role of CheV was examined in distantly related species Bacillus subtilis and Helicobacter pylori, but its role in bacterial chemotaxis is still not well understood. We tested a hypothesis that in enterobacteria CheV functions as an additional adaptor linkingmore » the CheA kinase to certain types of chemoreceptors that cannot be effectively accommodated by the universal adaptor CheW. Phylogenetic profiling, genomic context and comparative protein sequence analyses suggested that CheV interacts with specific domains of CheA and chemoreceptors from an orthologous group exemplified by the Salmonella McpC protein. Structural consideration of the conservation patterns suggests that CheV and CheW share the same binding spot on the chemoreceptor structure, but have some affinity bias towards chemoreceptors from different orthologous groups. Finally, published experimental results and data newly obtained via comparative genomics support the idea that CheV functions as a "phosphate sink" possibly to off-set the over-stimulation of the kinase by certain types of chemoreceptors. Altogether, our results strongly suggest that CheV is an additional adaptor for accommodating specific chemoreceptors within the chemotaxis signaling complex.« less

IDENTIFICATION OF NICOTINAMIDE MONONUCLEOTIDE DEAMIDASE OF THE BACTERIAL PYRIDINE NUCLEOTIDE CYCLE REVEALS A NOVEL BROADLY CONSERVED AMIDOHYDROLASE FAMILY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galeazzi, Luca; Bocci, Paolo; Amici, Adolfo

2011-09-27

The pyridine nucleotide cycle (PNC) is a network of salvage and recycling routes maintaining homeostasis of NAD(P) cofactor pool in the cell. Nicotinamide mononucleotide (NMN) deamidase (EC 3.5.1.42), one of the key enzymes of the bacterial PNC was originally described in Enterobacteria, but the corresponding gene eluded identification for over 30 years. A genomics-based reconstruction of NAD metabolism across hundreds bacterial species suggested that NMN deamidase reaction is the only possible way of nicotinamide salvage in the marine bacterium Shewanella oneidensis. This prediction was verified via purification of native NMN deamidase from S. oneidensis followed by the identification of themore » respective gene, termed pncC. Enzymatic characterization of the PncC protein, as well as phenotype analysis of deletion mutants, confirmed its proposed biochemical and physiological function in S. oneidensis. Of the three PncC homologs present in E. coli, NMN deamidase activity was confirmed only for the recombinant purified product of the ygaD gene. A comparative analysis at the level of sequence and three dimensional structure, which is available for one of the PncC family member, shows no homology with any previously described amidohydrolases. Multiple alignment analysis of functional and non functional PncC homologs, together with NMN docking experiments, allowed us to tentatively identify the active site area and conserved residues therein. An observed broad phylogenomic distribution of predicted functional PncCs in bacterial kingdom is consistent with a possible role in detoxification of NMN, resulting from NAD utilization by DNA ligase.« less

Intestinal microbiota of 6-week-old infants across Europe: geographic influence beyond delivery mode, breast-feeding, and antibiotics.

PubMed

Fallani, Matteo; Young, David; Scott, Jane; Norin, Elisabeth; Amarri, Sergio; Adam, Rüdiger; Aguilera, Marga; Khanna, Sheila; Gil, Angel; Edwards, Christine A; Doré, Joël

2010-07-01

: There are many differences in diet and lifestyle across Europe that may influence the development of the infant gut microbiota. This work aimed to assess the impact of geographic area, mode of delivery, feeding method, and antibiotic treatment on the fecal microbiota of infants from 5 European countries with different lifestyle characteristics: Sweden, Scotland, Germany, Italy, and Spain. : Fecal samples from 606 infants (age 6 weeks) recruited within the European project INFABIO were analyzed by fluorescent in situ hybridization combined with flow cytometry using a panel of 10 rRNA targeted group- and species-specific oligonucleotide probes. Information on factors potentially affecting gut microbiota composition was collected with questionnaires and associations were evaluated with multivariate analyses. : The Bifidobacterium genus was predominant (40% average proportion of total detectable bacteria), followed by Bacteroides (11.4%) and enterobacteria (7.5%). Northern European countries were associated with higher proportions of bifidobacteria in infant feces, whereas a more diverse microbiota with more bacteroides characterized southern countries. Bifidobacteria dominated the microbiota of breast-fed infants, whereas formula-fed babies had significantly higher proportions of Bacteroides and members of the Clostridium coccoides and Lactobacillus groups. Newborns delivered by cesarean section or from mothers treated with antibiotics perinatally had lower proportions of Bacteroides and members of the Atopobium cluster. : Delivery mode and feeding method influenced the fecal microbiota of European infants at 6 weeks, as expected, but the effect of country of birth was more pronounced, with dominant bifidobacteria in northern countries and greater early diversification in southern European countries.

UV light tolerance and reactivation potential of tetracycline-resistant bacteria from secondary effluents of a wastewater treatment plant.

PubMed

Huang, Jing-Jing; Xi, Jinying; Hu, Hong-Ying; Li, Yi; Lu, Sun-Qin; Tang, Fang; Pang, Yu-Chen

2016-03-01

Tetracycline-resistant bacteria (TRB) are of concern as emerging microbial contaminants in reclaimed water. To understand the effects of UV disinfection on TRB, both inactivation and reactivation profiles of TRB, as well as 16 tetracycline-resistant isolates from secondary effluent, were characterized in this study. The inactivation ratio of TRB was significantly lower (3.0-log) than that of heterotrophic bacteria (>4.0-log) in the secondary effluent. Additionally, the proportion of TRB significantly increased from 1.65% to 15.51% under 20mJ/cm(2) ultraviolet (UV) exposure. The inactivation rates of tetracycline-resistant isolates ranged from 0.57/s to 1.04/s, of which tetracycline-resistant Enterobacter-1 was the most tolerant to UV light. The reactivation of TRB, tetracycline-resistant isolated strains, as well as heterotrophic bacteria commonly occurred in the secondary effluent even after 20mJ/cm(2) UV exposure. The colony forming ability of TRB and heterotrophic bacteria reached 3.2-log and 3.0-log under 20mJ/cm(2) UV exposure after 22hr incubation. The final inactivation ratio of tetracycline-resistant Enterobacter-1 was 1.18-log under 20mJ/cm(2) UV exposure after 22hr incubation, which is similar to those of TRB (1.18-log) and heterotrophic bacteria (1.19-log). The increased proportion of TRB and the reactivation of tetracycline-resistant enterobacteria in reclaimed water could induce a microbial health risk during wastewater reuse. Copyright © 2015. Published by Elsevier B.V.

Evolutionary genomics suggests that CheV is an additional adaptor for accommodating specific chemoreceptors within the chemotaxis signaling complex

DOE PAGES

Ortega, Davi R.; Zhulin, Igor B.; Punta, Marco

2016-02-04

Escherichia coli and Salmonella enterica are models for many experiments in molecular biology including chemotaxis, and most of the results obtained with one organism have been generalized to another. While most components of the chemotaxis pathway are strongly conserved between the two species, Salmonella genomes contain some chemoreceptors and an additional protein, CheV, that are not found in E. coli. The role of CheV was examined in distantly related species Bacillus subtilis and Helicobacter pylori, but its role in bacterial chemotaxis is still not well understood. We tested a hypothesis that in enterobacteria CheV functions as an additional adaptor linkingmore » the CheA kinase to certain types of chemoreceptors that cannot be effectively accommodated by the universal adaptor CheW. Phylogenetic profiling, genomic context and comparative protein sequence analyses suggested that CheV interacts with specific domains of CheA and chemoreceptors from an orthologous group exemplified by the Salmonella McpC protein. Structural consideration of the conservation patterns suggests that CheV and CheW share the same binding spot on the chemoreceptor structure, but have some affinity bias towards chemoreceptors from different orthologous groups. Finally, published experimental results and data newly obtained via comparative genomics support the idea that CheV functions as a "phosphate sink" possibly to off-set the over-stimulation of the kinase by certain types of chemoreceptors. Altogether, our results strongly suggest that CheV is an additional adaptor for accommodating specific chemoreceptors within the chemotaxis signaling complex.« less

Anti-inflammatory and antioxidant effects of polyphenols extracted from Antirhea borbonica medicinal plant on adipocytes exposed to Porphyromonas gingivalis and Escherichia coli lipopolysaccharides.

PubMed

Le Sage, Fanny; Meilhac, Olivier; Gonthier, Marie-Paule

2017-05-01

In obesity, gut microbiota LPS may translocate into the blood stream and then contribute to adipose tissue inflammation and oxidative stress, leading to insulin resistance. A causal link between periodontal infection, obesity and type 2 diabetes has also been suggested. We evaluated the ability of polyphenols from Antirhea borbonica medicinal plant to improve the inflammatory and redox status of 3T3-L1 adipocytes exposed to LPS of Porphyromonas gingivalis periodontopathogen or Escherichia coli enterobacteria. Our results show that LPS enhanced the production of Toll-like receptor-dependent MyD88 and NFκB signaling factors as well as IL-6, MCP-1, PAI-1 and resistin. Plant polyphenols reduced LPS pro-inflammatory action. Concomitantly, polyphenols increased the production of adiponectin and PPARγ, known as key anti-inflammatory and insulin-sensitizing mediators. Moreover, both LPS increased intracellular ROS levels and the expression of genes encoding ROS-producing enzymes including NOX2, NOX4 and iNOS. Plant polyphenols reversed these effects and up-regulated MnSOD and catalase antioxidant enzyme gene expression. Noticeably, preconditioning of cells with caffeic acid, chlorogenic acid or kaempferol identified among A. borbonica major polyphenols, led to similar protective properties. Altogether, these findings demonstrate the anti-inflammatory and antioxidant effects of A. borbonica polyphenols on adipocytes, in response to P. gingivalis or E. coli LPS. It will be of major interest to assess A. borbonica polyphenol benefits against obesity-related metabolic disorders such as insulin resistance in vivo. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evolution of gut Bifidobacterium population in healthy Japanese infants over the first three years of life: a quantitative assessment.

PubMed

Nagpal, Ravinder; Kurakawa, Takashi; Tsuji, Hirokazu; Takahashi, Takuya; Kawashima, Kazunari; Nagata, Satoru; Nomoto, Koji; Yamashiro, Yuichiro

2017-08-30

Bifidobacteria are important members of human gut microbiota; however, quantitative data on their early-life dynamics is limited. Here, using a sensitive reverse transcription-qPCR approach, we demonstrate the carriage of eight signature infant-associated Bifidobacterium species (B. longum, B. breve, B. bifidum, B. catenulatum group, B. infantis, B. adolescentis, B. angulatum and B. dentium) in 76 healthy full-term vaginally-born infants from first day to three years of life. About 21% babies carry bifidobacteria at first day of life (6.2 ± 1.9 log 10  cells/g feces); and this carriage increases to 64% (8.0 ± 2.2), 79% (8.5 ± 2.1), 97% (9.3 ± 1.8), 99% (9.6 ± 1.6), and 100% (9.7 ± 0.9) at age 7 days, 1, 3 and 6 months, and 3 years, respectively. B. longum, B. breve, B. catenulatum group and B. bifidum are among the earliest and abundant bifidobacterial clades. Interestingly, infants starting formula-feed as early as first week of life have higher bifidobacterial carriage compared to exclusively breast-fed counterparts. Bifidobacteria demonstrate an antagonistic correlation with enterobacteria and enterococci. Further analyses also reveal a relatively lower/ delayed bifidobacterial carriage in cesarean-born babies. The study presents a quantitative perspective of the early-life gut Bifidobacterium colonization and shows how factors such as birth and feeding modes could influence this acquisition even in healthy infants.

Altered Functionality of Anti-Bacterial Antibodies in Patients with Chronic Hepatitis C Virus Infection

PubMed Central

Lamontagne, Anne; Long, Ronald E.; Comunale, Mary Ann; Hafner, Julie; Rodemich-Betesh, Lucy; Wang, Mengjun; Marrero, Jorge; Di Bisceglie, Adrian M.; Block, Timothy; Mehta, Anand

2013-01-01

Background Using comparative glycoproteomics, we have previously identified a glycoprotein that is altered in both amount and glycosylation as a function of liver cirrhosis. The altered glycoprotein is an agalactosylated (G0) immunoglobulin G molecule (IgG) that recognizes the heterophilic alpha-gal epitope. Since the alpha gal epitope is found on gut enterobacteria, it has been hypothesized that anti-gal antibodies are generated as a result of increased bacterial exposure in patients with liver disease. Methods The N-linked glycosylation of anti-gal IgG molecules from patients with fibrosis and cirrhosis was determined and the effector function of anti-bacterial antibodies from over 100 patients examined. In addition, markers of microbial exposure were determined. Results Surprisingly, the subset of agalactosylated anti-gal antibodies described here, was impaired in their ability to mediate complement mediated lysis and inhibited the complement-mediated destruction of common gut bacteria. In an analysis of serum from more than 100 patients with liver disease, we have shown that those with increased levels of this modified anti-gal antibody had increased levels of markers of bacterial exposure. Conclusions Anti-gal antibodies in patients with liver cirrhosis were reduced in their ability to mediate complement mediated lysis of target cells. As bacterial infection is a major complication in patients with cirrhosis and bacterial products such as LPS are thought to play a major role in the development and progression of liver fibrosis, this finding has many clinical implications in the etiology, prognosis and treatment of liver disease. PMID:23750224

Characterization of Tifton 85 bermudagrass haylage with different layers of polyethylene film and storage time.

PubMed

Nath, Caroline Daiane; Neres, Marcela Abbado; Scheidt, Kácia Carine; Bersot, Luciano Dos Santos; Sunahara, Samantha Mariana Monteiro; Sarto, Jaqueline Rocha Wobeto; Stangarlin, José Renato; Gomes, Simone Damasceno; Sereno, Mallu Jagnow; Perin, Ana Paula

2018-03-02

The objective was to characterize the fermentative and microbiological profile of Tifton 85 bermudagrass haylage with different layers of polyethylene film and storage time. The experimental design consisted of a randomized block design with four and six wrapping layers (100 and 150 microns in total. respectively) allocated in the main plots, through repeated measures analysis (30, 60, and 90 days of storage) with four replicates. The storage time and number of wrapping layers did not show changes in the population of Clostridium and lactic acid bacteria. A decrease was observed in the enterobacteria population with an increase in the storage period in the two wrapping layers studied. Upon opening of the haylage at 30 days, the population of Bacillus was lower in haylages made with six layers of wrapping (3.63 log colony forming units (CFU) g-1). No growth of Listeria sp. or Salmonella sp. was observed during the experimental period. The fungal genera with greater occurrence were Penicillium sp. and Fusarium sp. The following mycotoxins were not detected: ochratoxin A, fumonisins, and zearalenone. Relative to the organic butyric, propionic, and acetic acids, the haylages presented a low concentration of lactic acid; this may have prevented a drop in the pH, which was high when the silos were opened (5.4). The levels of ammoniacal nitrogen and soluble carbohydrates presented no variation among the number of wrapping layers, with an overall average of 35.55 and 38.04 g kg-1. Tifton 85 bermudagrass haylage wrapped with four and six layers presented adequate fermentation and microbiological characteristics in the evaluated periods.

Effect of Moringa oleifera consumption on diabetic rats.

PubMed

Villarruel-López, A; López-de la Mora, D A; Vázquez-Paulino, O D; Puebla-Mora, A G; Torres-Vitela, Ma R; Guerrero-Quiroz, L A; Nuño, K

2018-04-10

Therapeutic use of leaves of M. oleifera has been evaluated in diabetes because of its possible capacity to decrease blood glucose and lipids concentration after ingestion, as result of the polyphenols content and others compounds. Nevertheless most results have been obtain from leaf extract, therefore this study would use leaf powder as the regular way of consumption of population to know effects over toxicity glucose, triglycerides, cholesterol, corporal weight, and predominant groups of microbiota. Powdered leaf was administrated in different doses to know toxicity and genotoxicity using LD50 and micronuclei assay. Hyperglycemia was induced by alloxan on Sprague Dawley rats. Glucose and body weight were measured once a week meanwhile cholesterol and triglycerides were analyzed at the end of the study by commercial kits. Different organs were examined by hematoxylin-eosin technique. Lactic acid bacteria and Enterobacteriaceae were enumerated from stool samples. The tested doses revealed no lethal dose and no significant differences in genotoxicity parameter. The consumption of the leaves showed a hypoglycemic effect (< 250 mg/dL in diabetic M. oleifera treated group), however in corporal weight showed an increased (> 30 g over no M. oleifera treated groups). There was no change in enumeration of lactic acid bacteria (8.4 CFU/g) but there were differences in the predominance of type of lactobacillus and enterobacteria enumeration. These results help to increase information over the most popular use of M. oleifera and its safety. However there are needed more studies over the hypoglycemic mechanisms and effects over intestinal microbiota.

The effect of β-saturated pyrrolic rings on the electronic structures and aromaticity of magnesium porphyrin derivatives: a density functional study.

PubMed

Wan, Liang; Qi, Dongdong; Zhang, Yuexing

2011-09-01

Density functional theory (DFT) calculation on the molecular structures, molecular orbitals, electronic absorption spectra, and magnetic properties of magnesium porphyrin (MgPor) and a series of five hydrogenated magnesium porphyrin complexes with different number of β-saturated pyrrolic rings, namely MgPor-β-1Hy, MgPor-β-opp-2Hy, MgPor-β-adj-2Hy, MgPor-β-3Hy, and MgPor-β-4Hy, clarifies the red-shift of the lowest energy absorption band from chlorophyll a to bacteriochlorophyll and reveals the strong chemical stability for both of them. The energy levels of highest occupied molecular orbitals (HOMO) and HOMO-1 for MgPor are reversed upon hydrogenation at β-positions (2 and 3, 7 and 8, 12 and 13, and 17 and 18) of porphyrin ring. Along with the increase of β-saturated pyrrolic rings from 1, 2, 3, to 4, the HOMO energy increases from -4.78 eV to -3.10 eV in a regular manner. In contrast, the lowest unoccupied molecular orbitals (LUMO) energy levels of MgPor, MgPor-β-1Hy, and MgPor-β-opp-2Hy are very similar with each other. As a result, the lowest energy absorption band involving main transition from HOMO to LUMO is red-shifted from MgPor-β-1Hy to MgPor-β-opp-2Hy which is representative of chlorophyll a and bacteriochlorophyll, respectively. Natural hydroporphyrins represented by MgPor, MgPor-β-1Hy, and MgPor-β-opp-2Hy have turned out to be aromatic and stable enough, in good accordance with the ubiquity of their derivatives in the nature. In contrast, MgPor-β-adj-2Hy, MgPor-β-3Hy, and MgPor-β-4Hy with relatively weak aromaticity seem to be unstable and therefore were not found in nature. Copyright © 2011 Elsevier Inc. All rights reserved.

Legal Knowledge as a Tool for Social Change: La Mesa por la Vida y la Salud de las Mujeres as an Expert on Colombian Abortion Law.

PubMed

González Vélez, Ana Cristina; Jaramillo, Isabel Cristina

2017-06-01

In May 2006, Colombia's Constitutional Court liberalized abortion, introducing three circumstances under which the procedure would not be considered a crime: (1) rape or incest; (2) a risk to the woman's health or life; and (3) fetal malformations incompatible with life. Immediately following the court's ruling, known as Sentence C-355, members of La Mesa por la Vida y Salud de las Mujeres (hereinafter La Mesa) began to mobilize to ensure the decision's implementation, bearing in mind the limited impact that the legal framework endorsed by the court has had in other countries in the region. We argue that La Mesa's strategy is an innovative one in the field of legal mobilization insofar as it presumes that law can be shaped not just by public officials and universities but also by social actors engaged in the creation and diffusion of legal knowledge. In this regard, La Mesa has become a legal expert on abortion by accumulating knowledge about the multiple legal rules affecting the practice of abortion and about the situations in which these rules are to be applied. In addition, by becoming a legal expert, La Mesa has been able to persuade health providers that they will not risk criminal prosecution or being fired if they perform abortions. We call this effect of legal mobilization a "pedagogical effect" insofar as it involves the production of expertise and appropriation of knowledge by health professionals. We conclude by discussing La Mesa's choice to become a legal expert on abortion as opposed to recruiting academics to do this work or encouraging women to produce and disseminate this knowledge.

Effect of P450 Oxidoreductase Polymorphisms on the Metabolic Activities of Ten Cytochrome P450s Varied by Polymorphic CYP Genotypes in Human Liver Microsomes.

PubMed

Fang, Yan; Gao, Na; Tian, Xin; Zhou, Jun; Zhang, Hai-Feng; Gao, Jie; He, Xiao-Pei; Wen, Qiang; Jia, Lin-Jing; Jin, Han; Qiao, Hai-Ling

2018-06-27

Background/ Aims: Little is known about the effect of P450 oxidoreductase (POR) gene polymorphisms on the activities of CYPs with multiple genotypes. We genotyped 102 human livers for 18 known POR single nucleotide polymorphisms (SNPs) with allelic frequencies greater than 1% as well as for 27 known SNPs in 10 CYPs. CYP enzyme activities in microsomes prepared from these livers were determined by measuring probe substrate metabolism by high performance liquid chromatograph. We found that the effects of the 18 POR SNPs on 10 CYP activities were CYP genotype-dependent. The POR mutations were significantly associated with decreased overall Km for CYP2B6 and 2E1, and specific genotypes within CYP1A2, 2A6, 2B6, 2C8, 2D6 and 2E1 were identified as being affected by these POR SNPs. Notably, the effect of a specific POR mutation on the activity of a CYP genotype could not be predicted from other CYP genotypes of even the same CYP. When combining one POR SNP with other POR SNPs, a hitherto unrecognized effect of multiple-site POR gene polymorphisms (MSGP) on CYP activity was uncovered, which was not necessarily consistent with the effect of either single POR SNP. The effects of POR SNPs on CYP activities were not only CYP-dependent, but more importantly, CYP genotype-dependent. Moreover, the effect of a POR SNP alone and in combination with other POR SNPs (MSGP) was not always consistent, nor predictable. Understanding the impact of POR gene polymorphisms on drug metabolism necessitates knowing the complete SNP complement of POR and the genotype of the relevant CYPs. © 2018 The Author(s). Published by S. Karger AG, Basel.

[Streptococcus suis infection--clinical manifestations].

PubMed

Dragojlović, Julijana; Milosević, Branko; Sasić, Neda; Pelemis, Mijomir; Sasić, Milan

2005-01-01

Streptococcus suis is a bacterium causing a disease in pigs and rarely in humans. This zoonosis is mostly found as a sporadic disease in individuals that were in contact with the affected or infected pigs: farmers, veterinarians and workers engaged in fresh pork processing. It is assumed that the bacterium enters the body through a cut abrasion in the skin. Initially, the condition resembles a flu, followed by signs of bacteriemia and sepsis. The most frequent clinical manifestation of Streptococcus suis infection is meningitis, leading to hearing loss in over 75% of patients, and subsequent arthritis, endophtalmitis, endocarditis and pneumonia. Toxic shock syndrome with hemorhagic manifestations rarely develops. This study included five male patients aged 22 to 63 years treated in the Intensive Care Unit of the Institute of Infectious and Tropical Diseases in Belgrade, due to Streptococcus suis infection. The aim of this study was to point to the existence of this bacteria in our environment, to describe clinical manifestations of the disease and to point out the importance of its prevention. All patients had epidemiological evidence of being in contact with pork meat. There were no data about diseased pigs. The estimated incubation period was 4 to 8 days. All patients had meningeal signs. Clinical symptoms included shivering, fever, vomiting, headache, malaise, vertigo and tinitus. Three patients presented with alerterd level of awarrness. Four patients developed very severe bilateral hearing impairment, whereas one endophtalmtis and one developed endocarditis. The cerebrospinal fluid (CSF) was opalescent in four patients, and only one patient presented with clear CSF. CSF examination showed typical changes characteristic for bacterial meningitis. Streptoccocus suis was isolated in CSF in all patients, and in one patient the bacteria was isolated in blood as well. All patients underwent treatement with II and III generation cephalosporins and one with one

Evaluating Por Nuestra Salud: A Feasibility Study.

PubMed

Marshall, Brenda; Gonzales, Gustavo; Kernan, William

2016-01-01

This feasibility study evaluated the impact of a culturally consistent diabetes educational program, led by a Latino pastor, on Latino community diabetes knowledge levels. Latino adults were recruited from two churches serving Latino populations, one identified as intervention, the other as nonintervention. Both churches received the American Diabetes Association's booklets on diabetes education, "Four Steps to Control Your Diabetes for Life." The intervention group also received weekly reviews of the booklet's information from the church pastor, who was educated about diabetes by a Latino family nurse practitioner. Pre- and postintervention levels of diabetes knowledge were measured using the Diabetes Knowledge Questionnaire. Mean changes in the Diabetes Knowledge Questionnaire (DKQ-24) survey from pretest to posttest indicated a significant increase in knowledge in both groups. Only the grades for the participants from the pastor-led group, however, moved from failure in knowledge to high levels of passing. One hundred percent of intervention group participants reported having read the literature. This pilot study supports the feasibility of a local Latino pastor, as a culturally consistent diabetes educator, to increase Latino parishioner's knowledge of diabetes. © 2015 Society for Public Health Education.

Heterologous expression of equine CYP3A94 and investigation of a tunable system to regulate co-expressed NADPH P450 oxidoreductase levels.

PubMed

Dettwiler, Ramona; Schmitz, Andrea L; Plattet, Philippe; Zielinski, Jana; Mevissen, Meike

2014-01-01

The activity of cytochrome P450 enzymes depends on the enzyme NADPH P450 oxidoreductase (POR). The aim of this study was to investigate the activity of the equine CYP3A94 using a system that allows to regulate the POR protein levels in mammalian cells. CYP3A94 and the equine POR were heterologously expressed in V79 cells. In the system used, the POR protein regulation is based on a destabilizing domain (DD) that transfers its instability to a fused protein. The resulting fusion protein is therefore degraded by the ubiquitin-proteasome system (UPS). Addition of "Shield-1" prevents the DD fusion protein from degradation. The change of POR levels at different Shield-1 concentrations was demonstrated by cytochrome c reduction, Western immunoblot analysis, and immunocytochemistry. The alteration of CYP3A94 activity was investigated using a substrate (BFC) known to detect CYP3A4 activity. Equine CYP3A94 was demonstrated to be metabolically active and its activity could be significantly elevated by co-expression of POR. Cytochrome c reduction was significantly increased in V79-CYP3A94/DD-POR cells compared to V79-CYP3A94 cells. Surprisingly, incubation with different Shield-1 concentrations resulted in a decrease in POR protein shown by Western immunoblot analysis. Cytochrome c reduction did not change significantly, but the CYP3A94 activity decreased more than 4-fold after incubation with 500 nM and 1 µM Shield-1 for 24 hours. No differences were obtained when V79-CYP3A94 POR cells with and without Shield-1 were compared. The basal activity levels of V79-CYP3A94/DD-POR cells were unexpectedly high, indicating that DD/POR is not degraded without Shield-1. Shield-1 decreased POR protein levels and CYP3A94 activity suggesting that Shield-1 might impair POR activity by an unknown mechanism. Although regulation of POR with the pPTuner system could not be obtained, the cell line V79-CYP3A94/DD-POR system can be used for further experiments to characterize the equine CYP3A94

Primary language and cultural background as factors in resident burnout in medical specialties: a study in a bilingual US city.

PubMed

Afzal, Khalid I; Khan, Farhan M; Mulla, Zuber; Akins, Ralista; Ledger, Elizabeth; Giordano, Frank L

2010-07-01

The aim of this study was to identify the degree of burnout among resident physicians enrolled in seven postgraduate training programs at Texas Tech University Health Sciences Center (TTUHSC), Paul L. Foster School of Medicine, El Paso, Texas, as it related to residents' age, gender, marital status, number of hours worked per week, primary language, race/ethnicity, and cultural background. : The Maslach Burnout Inventory Human Service Survey (MBI) was administered to measure the level of burnout according to the prevalence of emotional exhaustion (EE), depersonalization (DP), and reduced personal accomplishment (PA). : Eighty-one percent of the residents at TTUHSC participated in the study. Residents raised in the United States or Canada comprised 28% and 35% of the study, and all reported English as their primary language. The EE scale was significant for obstetrics/gynecology (OB/GYN) residents (prevalence odds ratio [POR] = 13.55, P = 0.02) and psychiatry (PSY) residents (POR = 6.50, P = 0.03). Emergency medicine (EM) residents (POR = 23.35, P = 0.002), OB/GYN (POR = 10.89, P = 0.02), and general surgery (GS) (POR = 6.24, P = 0.03) residents had high DP. Internal medicine (IM) residents (primarily Spanish-speaking) reported significantly low EE (POR = 0.22, P = 0.03) and PA (POR = 0.09, P = 0.001) scores. Residents from the United States or Canada who reported English as their primary language and noted their race as white, had high EE (POR = 3.06, P = 0.03; POR = 5.61, P = 0.0001; POR = 2.91, P = 0.004), DP (POR = 3.19, P = 0.02; POR = 8.34, P < or = 0.0001; POR = 4.70, P < or = 0.0001) and PA (POR = 2.61, P = 0.02; POR = 2.35, P = 0.05, POR 0.29, P = 0.3) scores. Using valid measures, this pilot study identified a statistically significant relationship between burnout and residents' race/ethnicity, primary language, and cultural background. Larger studies with similar focus would be necessary to generalize these findings. At-risk residents in bilingual

Reduction in hepatic drug metabolizing CYP3A4 activities caused by P450 oxidoreductase mutations identified in patients with disordered steroid metabolism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flueck, Christa E.; Mullis, Primus E.; Pandey, Amit V., E-mail: amit@pandeylab.org

2010-10-08

Research highlights: {yields} Cytochrome P450 3A4 (CYP3A4), metabolizes 50% of drugs in clinical use and requires NADPH-P450 reductase (POR). {yields} Mutations in human POR cause congenital adrenal hyperplasia from diminished activities of steroid metabolizing P450s. {yields} We are reporting that mutations in POR may reduce CYP3A4 activity. {yields} POR mutants Y181D, A457H, Y459H, V492E and R616X lost 99%, while A287P, C569Y and V608F lost 60-85% CYP3A4 activity. {yields} Reduction of CYP3A4 activity may cause increased risk of drug toxicities/adverse drug reactions in patients with POR mutations. -- Abstract: Cytochrome P450 3A4 (CYP3A4), the major P450 present in human liver metabolizesmore » approximately half the drugs in clinical use and requires electrons supplied from NADPH through NADPH-P450 reductase (POR, CPR). Mutations in human POR cause a rare form of congenital adrenal hyperplasia from diminished activities of steroid metabolizing P450s. In this study we examined the effect of mutations in POR on CYP3A4 activity. We used purified preparations of wild type and mutant human POR and in vitro reconstitution with purified CYP3A4 to perform kinetic studies. We are reporting that mutations in POR identified in patients with disordered steroidogenesis/Antley-Bixler syndrome (ABS) may reduce CYP3A4 activity, potentially affecting drug metabolism in individuals carrying mutant POR alleles. POR mutants Y181D, A457H, Y459H, V492E and R616X had more than 99% loss of CYP3A4 activity, while POR mutations A287P, C569Y and V608F lost 60-85% activity. Loss of CYP3A4 activity may result in increased risk of drug toxicities and adverse drug reactions in patients with POR mutations.« less

Altered heme catabolism by heme oxygenase-1 caused by mutations in human NADPH cytochrome P450 reductase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pandey, Amit V., E-mail: amit@pandeylab.org; Flueck, Christa E.; Mullis, Primus E.

2010-09-24

Research highlights: {yields} Mutations in POR identified from patients lead to reduced HO-1 activities. {yields} POR mutation Y181D affecting FMN binding results in total loss of HO-1 activity. {yields} POR mutations A287P, C569Y and V608F, lost 50-70% activity. {yields} Mutations in FAD binding domain, R457H, Y459H and V492E lost all HO-1 activity. {yields} POR polymorphisms P228L, R316W, G413S, A503V and G504R have normal activity. -- Abstract: Human heme oxygenase-1 (HO-1) carries out heme catabolism supported by electrons supplied from the NADPH through NADPH P450 reductase (POR, CPR). Previously we have shown that mutations in human POR cause a rare formmore » of congenital adrenal hyperplasia. In this study, we have evaluated the effects of mutations in POR on HO-1 activity. We used purified preparations of wild type and mutant human POR and in vitro reconstitution with purified HO-1 to measure heme degradation in a coupled assay using biliverdin reductase. Here we show that mutations in POR found in patients may reduce HO-1 activity, potentially influencing heme catabolism in individuals carrying mutant POR alleles. POR mutants Y181D, A457H, Y459H, V492E and R616X had total loss of HO-1 activity, while POR mutations A287P, C569Y and V608F lost 50-70% activity. The POR variants P228L, R316W and G413S, A503V and G504R identified as polymorphs had close to WT activity. Loss of HO-1 activity may result in increased oxidative neurotoxicity, anemia, growth retardation and iron deposition. Further examination of patients affected with POR deficiency will be required to assess the metabolic effects of reduced HO-1 activity in affected individuals.« less

In vitro antibacterial activity and acute toxicity studies of aqueous-methanol extract of Sida rhombifolia Linn. (Malvaceae).

PubMed

Assam, Assam J P; Dzoyem, J P; Pieme, C A; Penlap, V B

2010-07-27

Many bacteria among the Enterobacteria family are involved in infectious diseases and diarrhoea. Most of these bacteria become resistant to the most commonly used synthetic drugs in Cameroon. Natural substances seem to be an alternative to this problem. Thus the aim of this research was to investigate the in vitro antibacterial activity of the methanol and aqueous-methanol extracts of Sida rhombifolia Linn (Malvaceae) against seven pathogenic bacteria involved in diarrhoea. Acute toxicity of the most active extract was determined and major bioactive components were screened. The agar disc diffusion and the agar dilution method were used for the determination of inhibition diameters and the Minimum Inhibitory Concentration (MICs) respectively. The acute toxicity study was performed according WHO protocol. The aqueous-methanol extract (1v:4v) was the most active with diameters of inhibition zones ranging from 8.7 - 23.6 mm, however at 200 microg/dic this activity was relatively weak compared to gentamycin. The MICs of the aqueous-methanol extract (1v:4v) varied from 49.40 to 78.30 microg/ml. Salmonella dysenteriae was the most sensitive (49.40 microg/ml). For the acute toxicity study, no deaths of rats were recorded. However, significant increase of some biochemical parameters such as aspartate amino-transferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and creatinine (CRT) were found. The phytochemical analysis of the aqueous methanol extract indicated the presence of tannins, polyphenols, alkaloids, glycosides, flavonoids and saponins The results showed that the aqueous-methanol extract of S. rhombifolia exhibited moderate antibacterial activity. Some toxic effects were found when rats received more than 8 g/kg bw of extract.

Rebamipide inhibits indomethacin-induced small intestinal injury: possible involvement of intestinal microbiota modulation by upregulation of α-defensin 5.

PubMed

Tanigawa, Tetsuya; Watanabe, Toshio; Otani, Koji; Nadatani, Yuji; Ohkawa, Fumikazu; Sogawa, Mitsue; Yamagami, Hirokazu; Shiba, Masatsugu; Watanabe, Kenji; Tominaga, Kazunari; Fujiwara, Yasuhiro; Takeuchi, Koji; Arakawa, Tetsuo

2013-03-15

Enterobacteria play important roles in the pathophysiology of small intestinal injuries induced by nonsteroidal anti-inflammatory drugs (NSAIDs). We investigated the effects of rebamipide, a gastrointestinal mucoprotective drug, on indomethacin-induced small intestinal injuries, intestinal microbiota, and expression levels of α-defensin 5, which is a Paneth cell-specific antimicrobial peptide and is important for the regulation of intestinal microbiota. Indomethacin (10mg/kg) was orally administered to mice after oral administration of rebamipide (100 or 300 mg/kg) or vehicle for 1 week, and the small intestinal injuries were assessed. After oral administration of rebamipide, the small intestinal contents were subjected to terminal restriction fragment length polymorphism (T-RFLP) analysis to assess the intestinal microbiota composition. Further, the expression levels of mRNA and protein for α-defensin 5 in the ileal tissue were determined by real-time reverse transcription-polymerase chain reaction and western blotting analysis, respectively. Rebamipide inhibited indomethacin-induced small intestinal injuries and T-RFLP analysis showed that rebamipide increased the percentage of Lactobacillales and decreased the percentage of Bacteroides and Clostridium than that in vehicle-treated controls. The mice that were treated with rebamipide showed an increase in α-defensin 5 mRNA expression and protein levels in the ileal tissue compared to vehicle-treated control mice. Indomethacin reduced expression of α-defensin 5 mRNA in ileal tissue, while rebamipide reversed expression of α-defensin 5 mRNA. In conclusion, our study results suggest that rebamipide inhibits indomethacin-induced small intestinal injuries, possibly by modulating microbiota in the small intestine by upregulation of α-defensin 5. Copyright © 2013 Elsevier B.V. All rights reserved.

Antimicrobial activity of Calendula officinalis, Camellia sinensis and chlorhexidine against the adherence of microorganisms to sutures after extraction of unerupted third molars.

PubMed

Faria, Raquel Lourdes; Cardoso, Lincoln Marcelo Lourenço; Akisue, Gokithi; Pereira, Cristiane Aparecida; Junqueira, Juliana Campos; Jorge, Antonio Olavo Cardoso; Santos Júnior, Paulo Villela

2011-10-01

The objective of this study was to compare the antimicrobial effect of mouthwashes containing Calendula officinalis L., Camellia sinensis (L.) Kuntze and 0.12% chlorhexidine digluconate on the adherence of microorganisms to suture materials after extraction of unerupted third molars. Eighteen patients with unerupted maxillary third molars indicated for extraction were selected (n=6 per mouthwash). First, the patients were subjected to extraction of the left tooth and instructed not to use any type of antiseptic solution at the site of surgery (control group). After 15 days, the right tooth was extracted and the patients were instructed to use the Calendula officinalis, Camellia sinensis or chlorhexidine mouthwash during 1 week (experimental group). For each surgery, the sutures were removed on postoperative day 7 and placed in sterile phosphate-buffered saline. Next, serial dilutions were prepared and seeded onto different culture media for the growth of the following microorganisms: blood agar for total microorganism growth; Mitis Salivarius bacitracin sucrose agar for mutans group streptococci; mannitol agar for Staphylococcus spp.; MacConkey agar for enterobacteria and Pseudomonas spp., and Sabouraud dextrose agar containing chloramphenicol for Candida spp. The plates were incubated during 24-48 h at 37ºC for microorganism count (CFU/mL). The three mouthwashes tested reduced the number of microorganisms adhered to the sutures compared to the control group. However, significant differences between the control and experimental groups were only observed for the mouthwash containing 0.12% chlorhexidine digluconate. Calendula officinalis L. and Camellia sinensis (L.) Kuntze presented antimicrobial activity against the adherence of microorganisms to sutures but were not as efficient as chlorhexidine digluconate.

Antimicrobial activity of Calendula officinalis, Camellia sinensis and chlorhexidine against the adherence of microorganisms to sutures after extraction of unerupted third molars

PubMed Central

FARIA, Raquel Lourdes; CARDOSO, Lincoln Marcelo Lourenço; AKISUE, Gokithi; PEREIRA, Cristiane Aparecida; JUNQUEIRA, Juliana Campos; JORGE, Antonio Olavo Cardoso; SANTOS JÚNIOR, Paulo Villela

2011-01-01

Objective The objective of this study was to compare the antimicrobial effect of mouthwashes containing Calendula officinalis L., Camellia sinensis (L.) Kuntze and 0.12% chlorhexidine digluconate on the adherence of microorganisms to suture materials after extraction of unerupted third molars. Material and Methods Eighteen patients with unerupted maxillary third molars indicated for extraction were selected (n=6 per mouthwash). First, the patients were subjected to extraction of the left tooth and instructed not to use any type of antiseptic solution at the site of surgery (control group). After 15 days, the right tooth was extracted and the patients were instructed to use the Calendula officinalis, Camellia sinensis or chlorhexidine mouthwash during 1 week (experimental group). For each surgery, the sutures were removed on postoperative day 7 and placed in sterile phosphate-buffered saline. Next, serial dilutions were prepared and seeded onto different culture media for the growth of the following microorganisms: blood agar for total microorganism growth; Mitis Salivarius bacitracin sucrose agar for mutans group streptococci; mannitol agar for Staphylococcus spp.; MacConkey agar for enterobacteria and Pseudomonas spp., and Sabouraud dextrose agar containing chloramphenicol for Candida spp. The plates were incubated during 24-48 h at 37ºC for microorganism count (CFU/mL). Results The three mouthwashes tested reduced the number of microorganisms adhered to the sutures compared to the control group. However, significant differences between the control and experimental groups were only observed for the mouthwash containing 0.12% chlorhexidine digluconate. Conclusions Calendula officinalis L. and Camellia sinensis (L.) Kuntze presented antimicrobial activity against the adherence of microorganisms to sutures but were not as efficient as chlorhexidine digluconate. PMID:21986652

Hydrolysis of Clavulanate by Mycobacterium tuberculosis β-Lactamase BlaC Harboring a Canonical SDN Motif

PubMed Central

Soroka, Daria; Li de la Sierra-Gallay, Inès; Dubée, Vincent; Triboulet, Sébastien; van Tilbeurgh, Herman; Compain, Fabrice; Ballell, Lluis; Barros, David; Mainardi, Jean-Luc

2015-01-01

Combinations of β-lactams with clavulanate are currently being investigated for tuberculosis treatment. Since Mycobacterium tuberculosis produces a broad spectrum β-lactamase, BlaC, the success of this approach could be compromised by the emergence of clavulanate-resistant variants, as observed for inhibitor-resistant TEM variants in enterobacteria. Previous analyses based on site-directed mutagenesis of BlaC have led to the conclusion that this risk was limited. Here, we used a different approach based on determination of the crystal structure of β-lactamase BlaMAb of Mycobacterium abscessus, which efficiently hydrolyzes clavulanate. Comparison of BlaMAb and BlaC allowed for structure-assisted site-directed mutagenesis of BlaC and identification of the G132N substitution that was sufficient to switch the interaction of BlaC with clavulanate from irreversible inactivation to efficient hydrolysis. The substitution, which restored the canonical SDN motif (SDG→SDN), allowed for efficient hydrolysis of clavulanate, with a more than 104-fold increase in kcat (0.41 s−1), without affecting the hydrolysis of other β-lactams. Mass spectrometry revealed that acylation of BlaC and of its G132N variant by clavulanate follows similar paths, involving sequential formation of two acylenzymes. Decarboxylation of the first acylenzyme results in a stable secondary acylenzyme in BlaC, whereas hydrolysis occurs in the G132N variant. The SDN/SDG polymorphism defines two mycobacterial lineages comprising rapidly and slowly growing species, respectively. Together, these results suggest that the efficacy of β-lactam–clavulanate combinations may be limited by the emergence of resistance. β-Lactams active without clavulanate, such as faropenem, should be prioritized for the development of new therapies. PMID:26149997

Diversity and dynamics of antibiotic-resistant bacteria in cheese as determined by PCR denaturing gradient gel electrophoresis.

PubMed

Flórez, Ana Belén; Mayo, Baltasar

2015-12-02

This work reports the composition and succession of tetracycline- and erythromycin-resistant bacterial communities in a model cheese, monitored by polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). Bacterial 16S rRNA genes were examined using this technique to detect structural changes in the cheese microbiota over manufacturing and ripening. Total bacterial genomic DNA, used as a template, was extracted from cultivable bacteria grown without and with tetracycline or erythromycin (both at 25 μg ml(-1)) on a non-selective medium used for enumeration of total and viable cells (Plate Count agar with Milk; PCA-M), and from those grown on selective and/or differential agar media used for counting various bacterial groups; i.e., lactic acid bacteria (de Man, Rogosa and Sharpe agar; MRSA), micrococci and staphylococci (Baird-Parker agar; BPA), and enterobacteria (Violet Red Bile Glucose agar; VRBGA). Large numbers of tetracycline- and erythromycin-resistant bacteria were detected in cheese samples at all stages of ripening. Counts of antibiotic-resistant bacteria varied widely depending on the microbial group and the point of sampling. In general, resistant bacteria were 0.5-1.0 Log10 units fewer in number than the corresponding susceptible bacteria. The PCR-DGGE profiles obtained with DNA isolated from the plates for total bacteria and the different bacterial groups suggested Escherichia coli, Lactococcus lactis, Enterococcus faecalis and Staphylococcus spp. as the microbial types resistant to both antibiotics tested. This study shows the suitability of the PCR-DGGE technique for rapidly identifying and tracking antibiotic resistant populations in cheese and, by extension, in other foods. Copyright © 2015 Elsevier B.V. All rights reserved.

Distribution of microbial arsenic reduction, oxidation and extrusion genes along a wide range of environmental arsenic concentrations.

PubMed

Escudero, Lorena V; Casamayor, Emilio O; Chong, Guillermo; Pedrós-Alió, Carles; Demergasso, Cecilia

2013-01-01

The presence of the arsenic oxidation, reduction, and extrusion genes arsC, arrA, aioA, and acr3 was explored in a range of natural environments in northern Chile, with arsenic concentrations spanning six orders of magnitude. A combination of primers from the literature and newly designed primers were used to explore the presence of the arsC gene, coding for the reduction of As (V) to As (III) in one of the most common detoxification mechanisms. Enterobacterial related arsC genes appeared only in the environments with the lowest As concentration, while Firmicutes-like genes were present throughout the range of As concentrations. The arrA gene, involved in anaerobic respiration using As (V) as electron acceptor, was found in all the systems studied. The As (III) oxidation gene aioA and the As (III) transport gene acr3 were tracked with two primer sets each and they were also found to be spread through the As concentration gradient. Sediment samples had a higher number of arsenic related genes than water samples. Considering the results of the bacterial community composition available for these samples, the higher microbial phylogenetic diversity of microbes inhabiting the sediments may explain the increased number of genetic resources found to cope with arsenic. Overall, the environmental distribution of arsenic related genes suggests that the occurrence of different ArsC families provides different degrees of protection against arsenic as previously described in laboratory strains, and that the glutaredoxin (Grx)-linked arsenate reductases related to Enterobacteria do not confer enough arsenic resistance to live above certain levels of As concentrations.

Intestinal microbiota and innate immunity-related gene alteration in cirrhotic rats with liver transplantation.

PubMed

Xie, Y R; Liu, S L; Liu, X; Luo, Z B; Zhu, B; Li, Z F; Li, L J; He, Y; Jiang, L; Li, H; Ruan, B

2011-12-01

The present study investigated the alteration of intestinal microbiota, innate immunity-related genes, and bacterial translocation in rats with cirrhosis and liver transplantation. Specific pathogen-free Sprague-Dawley rats were randomized into 4 groups: (1) normal controls (N); (2) liver cirrhosis (LC); (3) normal control groups with liver transplantation (LTN); and (4) liver cirrhosis with liver transplantation (LTC). We examined plasma endotoxin, bacterial tacslocation, denaturing gradient gel electrophoresis (DGGE) profile of intestinal mucosa-associated bacteria, abundance of key bacterial populations, and expression of innate immunity-related gene. The LTC and LC group, showed higher endotoxin levels (1.08±0.73 EU/mL and 0.74±0.70 EU/mL, respectively) than the N group (0.27±0.13 EU/mL; P<.05). the incidence of bacterial translocation (BT) to liver and mesenteric lymph nodes (MLN), and the number of total bacteria were increased significantly in the LTC and LC groups compared with the N group (P<.05). The counts of Lactobacilli and Bacteroides were lower, whereas Enterobacteria were higher in the LC than the N group (P<.05). Mucins (MUC2, MUC3) and Toll-like receptors (TLR2, TLR4) messenger RNA (mRNA) expression were significantly higher in the LC and LTC groups than the N group (P<.05). The marked difference between the groups in the overall structure of the bacterial community was also generated by DGGE profiles. Liver cirrhosis disturbs intestinal microbiota and innate immunity-related genes, which contributes to endotoxemia and bacterial translocation. These had not completely recovered in cirrhotic rats until 1 month after orthotopic liver transplantation. Copyright © 2011 Elsevier Inc. All rights reserved.

Traffic at the tmRNA Gene

PubMed Central

Williams, Kelly P.

2003-01-01

A partial screen for genetic elements integrated into completely sequenced bacterial genomes shows more significant bias in specificity for the tmRNA gene (ssrA) than for any type of tRNA gene. Horizontal gene transfer, a major avenue of bacterial evolution, was assessed by focusing on elements using this single attachment locus. Diverse elements use ssrA; among enterobacteria alone, at least four different integrase subfamilies have independently evolved specificity for ssrA, and almost every strain analyzed presents a unique set of integrated elements. Even elements using essentially the same integrase can be very diverse, as is a group with an ssrA-specific integrase of the P4 subfamily. This same integrase appears to promote damage routinely at attachment sites, which may be adaptive. Elements in arrays can recombine; one such event mediated by invertible DNA segments within neighboring elements likely explains the monophasic nature of Salmonella enterica serovar Typhi. One of a limited set of conserved sequences occurs at the attachment site of each enterobacterial element, apparently serving as a transcriptional terminator for ssrA. Elements were usually found integrated into tRNA-like sequence at the 3′ end of ssrA, at subsites corresponding to those used in tRNA genes; an exception was found at the non-tRNA-like 3′ end produced by ssrA gene permutation in cyanobacteria, suggesting that, during the evolution of new site specificity by integrases, tropism toward a conserved 3′ end of an RNA gene may be as strong as toward a tRNA-like sequence. The proximity of ssrA and smpB, which act in concert, was also surveyed. PMID:12533482

Study of the Effectiveness of Multipurpose Solutions on the Bacterial Disinfection of Silicone Hydrogel Contact Lenses In Vitro.

PubMed

Correa, Priscila C; Lui, Aline C F; Silva, Cely B; Gracitelli, Carolina P B; Mimica, Lycia M; Sasagawa, Suzethe M; Netto, Adamo L

2017-10-12

To assess the antimicrobial effectiveness of multipurpose solutions in regard to the disinfection of silicone hydrogel contact lenses (CL) using a study of clinical bacterial isolates from ocular material. Three multipurpose solutions (solution A: polyhexamethylene biguanide 0.00025 g/100 mL; solution B: polyquaternary-1 0.001% and myristamidopropyl dimethylamine 0.0006%; and solution C: polyaminopropyl biguanide 0.00013% and polyquaternary 0.0001%) were used as a 3-phase disinfection on silicone hydrogel CL contaminated with bacteria from clinical isolates that were divided into five groups (group 1: Pseudomonas aeruginosa; group 2: Staphylococcus aureus; group 3: Staphylococcus epidermidis; group 4: Streptococcus spp; and group 5: enterobacteria). No differences were observed between the 24- and 48-hr measurements in any of the samples, and the positivity of microorganisms in T0 was 100% for all solutions; it was 0% in T3. Therefore, only steps T1 (rubbing followed by rinsing) and T2 (rubbing followed by rinsing and immersion of CL into solution) were considered for analysis at the 24-hr measurement time. Throughout the phases, a decrease in the number of bacteria was observed, culminating in the elimination (no recovery) of all microorganisms in the three solutions. At the end of the proposed process, the tested solutions were effective.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

Phenotypic Tests for the Detection of β-Lactamase-Producing Enterobacteriaceae Isolated from Different Environments.

PubMed

de Oliveira, Daniele V; Van Der Sand, Sueli T

2016-07-01

Some bacteria from the Enterobacteriaceae family are showing a significant capability to disseminate β-lactams resistance mechanisms among them, and these same mechanisms can be carried out from the hospital environment to superficial water. The aim of this study was to evaluate different phenotypic methods for the detection β-lactamases production by enterobacteria isolated from the anthropogenic environment: hospital wastewater and from a stream that cross the city of Porto Alegre. The applied tests were the modified Hodge test (MHT) and phenotypic tests with the following inhibitors: carbapenemase-phenylboronic acid (APB), metallo-β-lactamase-EDTA, AmpC β-lactamase-cloxacillin, and the confirmatory test for extended-spectrum β-lactamase (ESBL)-clavulanic acid. For this evaluation, 131 isolates were initially subjected to antibiogram using the following antimicrobials: cefotaxime (30 µg), cefpodoxime (10 μg), ceftazidime (30 µg), ertapenem (10 μg), meropenem (10 μg), and aztreonam (30 μg). After this first screening, 62 isolates showed a profile resistance for at least one antimicrobial. These isolates were subjected to all phenotypic tests. Of those, 40 isolates were positive for at least one phenotypic test. In MHT test, one isolate was positive and five were with inconclusive results. The results achieved with the inhibitors are as follows: APB 25/40 positive strains; EDTA 8/40 positive strains; and with CLOXA 2/40 positive strains. ESBL production was observed for 34/40 strains. This assessment shows a high level of bacteria which can produce enzymes that inactivate β-lactams present in the different environment like the stream waters and from the hospital settings.

Shelf life, physicochemical, microbiological and antioxidant properties of purple cactus pear (Opuntia ficus indica) juice after thermoultrasound treatment.

PubMed

Cruz-Cansino, Nelly Del Socorro; Ramírez-Moreno, Esther; León-Rivera, Jesús Ernesto; Delgado-Olivares, Luis; Alanís-García, Ernesto; Ariza-Ortega, José Alberto; Manríquez-Torres, José de Jesús; Jaramillo-Bustos, Diana Pamela

2015-11-01

The objective of this study was to evaluate changes in color, betalain content, browning index, viscosity, physical stability, microbiological growth, antioxidant content and antioxidant activity of purple cactus pear juice during storage after thermoultrasonication at 80% amplitude level for 15 and 25 min in comparison with pasteurized juice. Thermoultrasound treatment for 25 min increased color stability and viscosity compared to treatment for 15 min (6.83 and 6.72 MPa, respectively), but this last parameter was significantly lower (p<0.05) compared to the control and pasteurized juices (22.47 and 26.32 MPa, respectively). Experimental treatment reduced significantly (p<0.05) sediment solids in juices. Total plate counts decreased from the first day of storage exhibiting values of 1.38 and 1.43 logCFU/mL, for 15 and 25 min treatment, respectively. Compared to the control, both treatments reduced enterobacteria counts (1.54 logCFU/mL), and compared to pasteurized juice decreased pectinmethylesterase activity (3.76 and 3.82 UPE/mL), maintained high values of ascorbic acid (252.05 and 257.18 mg AA/L) and antioxidant activity (by ABTS: 124.8 and 115.6 mg VCEAC/100 mL; and DPPH: 3114.2 and 2757.1 μmol TE/L). During storage thermoultrasonicated juices had a minimum increase in pectinmethylesterase activity (from day 14), and exhibited similar total plate counts to pasteurized juice. An increase of phenolic content was observed after 14 days of storage, particularly for treatment at 80%, 25 min, and an increase in antioxidant activity (ABTS, DPPH) by the end of storage. Copyright © 2015 Elsevier B.V. All rights reserved.

Coordination of FocA and Pyruvate Formate-Lyase Synthesis in Escherichia coli Demonstrates Preferential Translocation of Formate over Other Mixed-Acid Fermentation Products

PubMed Central

Beyer, Lydia; Doberenz, Claudia; Falke, Dörte; Hunger, Doreen; Suppmann, Bernhard

2013-01-01

Enterobacteria such as Escherichia coli generate formate, lactate, acetate, and succinate as major acidic fermentation products. Accumulation of these products in the cytoplasm would lead to uncoupling of the membrane potential, and therefore they must be either metabolized rapidly or exported from the cell. E. coli has three membrane-localized formate dehydrogenases (FDHs) that oxidize formate. Two of these have their respective active sites facing the periplasm, and the other is in the cytoplasm. The bidirectional FocA channel translocates formate across the membrane delivering substrate to these FDHs. FocA synthesis is tightly coupled to synthesis of pyruvate formate-lyase (PflB), which generates formate. In this study, we analyze the consequences on the fermentation product spectrum of altering FocA levels, uncoupling FocA from PflB synthesis or blocking formate metabolism. Changing the focA translation initiation codon from GUG to AUG resulted in a 20-fold increase in FocA during fermentation and an ∼3-fold increase in PflB. Nevertheless, the fermentation product spectrum throughout the growth phase remained similar to that of the wild type. Formate, acetate, and succinate were exported, but only formate was reimported by these cells. Lactate accumulated in the growth medium only in mutants lacking FocA, despite retaining active PflB, or when formate could not be metabolized intracellularly. Together, these results indicate that FocA has a strong preference for formate as a substrate in vivo and not other acidic fermentation products. The tight coupling between FocA and PflB synthesis ensures adequate substrate delivery to the appropriate FDH. PMID:23335413

A Survey of Escherichia coli and Salmonella in the Hyporheic Zone of a Subtropical Stream: Their Bacteriological, Physicochemical and Environmental Relationships

PubMed Central

Mugnai, Riccardo; Sattamini, Ana; Albuquerque dos Santos, José Augusto; Regua-Mangia, Adriana Hamond

2015-01-01

The Hyporheic Zone is among the most important interstitial freshwater habitats, but the relationship between biotic and abiotic factors in this zone remains under-explored. Enterobacteria were expected to be present, but no specific studies had ever confirmed this prediction. The aim of this study was, therefore, to evaluate the total coliforms, Escherichia coli and Salmonella spp. in hyporheic water and to determine the relationship of the physical, chemical and environmental factors at different depths in a rainforest stream. To this end, thirty-six water samples were collected at three depths in sites located in the first, second and third orders in diverse substrates. The total coliforms, Escherichia coli and Salmonella sp. were evaluated in terms of their CFU/ml. In the interstitial samples, coliforms were detected in 100% of the samples. The total coliform counts had higher values at intermediate depths, while E. coli and Salmonella spp. instead had higher values at intermediate and large depths, often reaching or exceeding the values of the surface samples. Our results revealed that Salmonella spp. and the coliforms have different microhabitat preferences. Salmonella spp. and coliform species prefer deposition areas, such as lateral sides of pools, curves and bars, but they have a tendency to distribute into different depths, likely due to temperature differences. Salmonella spp. prefer compact substrata, with fewer fluids passing through and with upwelling areas with lower oxygen inflow. The coliform species showed the opposite preference. Our results suggest that bacterial variation is related to environmental factors and physical-chemical parameters within the HZ and may play a key role in the microbial diversity and distribution in these ecosystems. PMID:26067288

Identification and differentiation of food-related bacteria: A comparison of FTIR spectroscopy and MALDI-TOF mass spectrometry.

PubMed

Wenning, Mareike; Breitenwieser, Franziska; Konrad, Regina; Huber, Ingrid; Busch, Ulrich; Scherer, Siegfried

2014-08-01

The food industry requires easy, accurate, and cost-effective techniques for microbial identification to ensure safe products and identify microbial contaminations. In this work, FTIR spectroscopy and MALDI-TOF mass spectrometry were assessed for their suitability and applicability for routine microbial diagnostics of food-related microorganisms by analyzing their robustness according to changes in incubation time and medium, identification accuracy and their ability to differentiate isolates down to the strain level. Changes in the protocol lead to a significantly impaired performance of FTIR spectroscopy, whereas they had only little effects on MALDI-TOF MS. Identification accuracy was tested using 174 food-related bacteria (93 species) from an in-house strain collection and 40 fresh isolates from routine food analyses. For MALDI-TOF MS, weaknesses in the identification of bacilli and pseudomonads were observed; FTIR spectroscopy had most difficulties in identifying pseudomonads and enterobacteria. In general, MALDI-TOF MS obtained better results (52-85% correct at species level), since the analysis of mainly ribosomal proteins is more robust and seems to be more reliable. FTIR spectroscopy suffers from the fact that it generates a whole-cell fingerprint and intraspecies diversity may lead to overlapping species borders which complicates identification. In the present study values between 56% and 67% correct species identification were obtained. On the opposite, this high sensitivity offers the opportunity of typing below the species level which was not possible using MALDI-TOF MS. Using fresh isolates from routine diagnostics, both techniques performed well with 88% (MALDI-TOF) and 75% (FTIR) correct identifications at species level, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

Etiologic agents of cervicovaginitis in Turkish women.

PubMed

Ozturk, Cihadiye E; Ozdemir, Ismail; Yavuz, Tevfik; Kaya, Demet; Behcet, Mustafa

2006-10-01

To investigate the distribution of microbiologic agents causing cervicovaginitis. We conducted the study between October 2002 and December 2004 in Abant Izzet Baysal University, Duzce School of Medicine Hospital, Turkey. The samples were obtained from the posterior vaginal fornix and cervix by swabs in 828 patients. Direct microscopic examination, culture and enzyme immune assay (EIA) methods were performed in all patients for diagnosis of microbiologic agents. Gardnerella vaginalis (G. vaginalis) were diagnosed in 254 (30.7%) patients, Candida albicans (C. albicans) in 152 (18.4%), Candida glabrata (C. glabrata) in 36 (4.3%), Candida species in 52 (6.3%), Staphylococcus aureus (S. aureus) in 62 (7.5%), Streptococcus group B in 28 (3.4%), Escherichia coli (E. coli) in 42 (5.1%), Klebsiella species in 24 (2.9%), and Streptococcus group D in 8 (1%) patients in culture. Less frequent enterobacteria in 30 (3.6%) were: Pseudomonas species, Proteus species Enterobacter species, Hafnia alvei and Nonfermenter species. Neisseria gonorrheae (N. gonorrheae) was detected in one patient (0.1%) in culture. The Chlamydia trachomatis (C. trachomatis) antigen was detected by EIA methods in 130 (15.7%) patients and Trichomonas vaginalis (T. vaginalis) was observed in 8 (1%) patients by direct microscopic examination. Performing the etiologic diagnosis of cervicovaginitis is necessary in order to take appropriate therapeutic and preventive measures. Therefore, we recommend G. vaginalis, C. albicans and C. trachomatis should be investigated in patients having a diagnosis of cervicovaginitis in our population, since these were detected in a considerable number of cases. Additionally, C. glabrata and T. vaginalis should be kept in mind as possible pathogens.

Recurrent Reverse Evolution Maintains Polymorphism after Strong Bottlenecks in Commensal Gut Bacteria

PubMed Central

Ramiro, Ricardo S.; Barroso-Batista, João; Güleresi, Daniela; Lourenço, Marta; Gordo, Isabel

2017-01-01

Abstract The evolution of new strains within the gut ecosystem is poorly understood. We used a natural but controlled system to follow the emergence of intraspecies diversity of commensal Escherichia coli, during three rounds of adaptation to the mouse gut (∼1,300 generations). We previously showed that, in the first round, a strongly beneficial phenotype (loss-of-function for galactitol consumption; gat-negative) spread to >90% frequency in all colonized mice. Here, we show that this loss-of-function is repeatedly reversed when a gat-negative clone colonizes new mice. The regain of function occurs via compensatory mutation and reversion, the latter leaving no trace of past adaptation. We further show that loss-of-function adaptive mutants reevolve, after colonization with an evolved gat-positive clone. Thus, even under strong bottlenecks a regime of strong-mutation-strong-selection dominates adaptation. Coupling experiments and modeling, we establish that reverse evolution recurrently generates two coexisting phenotypes within the microbiota that can or not consume galactitol (gat-positive and gat-negative, respectively). Although the abundance of the dominant strain, the gat-negative, depends on the microbiota composition, gat-positive abundance is independent of the microbiota composition and can be precisely manipulated by supplementing the diet with galactitol. These results show that a specific diet is able to change the abundance of specific strains. Importantly, we find polymorphism for these phenotypes in indigenous Enterobacteria of mice and man. Our results demonstrate that natural selection can greatly overwhelm genetic drift at structuring the strain diversity of gut commensals and that competition for limiting resources may be a key mechanism for maintaining polymorphism in the gut. PMID:28961745

Microbial Quality of and Biochemical Changes in Fresh Soft, Acid-Curd Xinotyri Cheese Made from Raw or Pasteurized Goat’s Milk

PubMed Central

Tasioula-Margari, Maria

2017-01-01

Summary The microbiological quality of and changes in the main physicochemical parameters, together with the evolution of proteolysis, lipolysis and volatile profiles of soft Xinotyri, a traditional Greek acid-curd cheese (pH≈4.4, moisture 65%, salt 1%) made from raw (RMC) or pasteurized (PMC) goat’s milk without starters, were evaluated during aerobic storage at 4 oC for 60 days. No statistically significant differences between the total nitrogen (TN) and nitrogen fraction (% of TN) contents, the degradation of intact αs- or β-caseins, total free amino acid (FAA) contents, and the ratio of hydrophilic and hydrophobic peptides in the water-soluble fraction of RMC and PMC were found. Threonine, alanine and lysine were the principal FAAs. Oleic, palmitic, capric and caprylic acids, and ethyl hexonate, ethyl octanoate, ethyl decanoate, ethanol, 3-methyl butanol, phenyl ethyl alcohol and acetone were the most abundant free fatty acids and volatile compounds, respectively. Cheese lipolysis evolved slowly at 4 oC, and milk pasteurization had no significant effect on it. Mesophilic lactic acid bacteria (LAB) were predominant in fresh cheese samples. PMC samples had significantly lower levels of enterococci and enterobacteria than RMC samples, while yeasts grew at similar levels during storage at 4 oC. All cheese samples (25 g) were free of Salmonella and Listeria monocytogenes. Coagulase-
-positive staphylococci exceeded the 5-log safety threshold in fresh RMC samples, whereas they were suppressed (<100 CFU/g) in all PMC samples. Consequently, pasteurization of raw goat milk’s and utilization of commercially defined or natural mesophilic LAB starters are recommended for standardizing the biochemical, microbial and safety qualities of fresh soft Xinotyri cheese. PMID:29540984

Identification of cyanobacterial non-coding RNAs by comparative genome analysis.

PubMed

Axmann, Ilka M; Kensche, Philip; Vogel, Jörg; Kohl, Stefan; Herzel, Hanspeter; Hess, Wolfgang R

2005-01-01

Whole genome sequencing of marine cyanobacteria has revealed an unprecedented degree of genomic variation and streamlining. With a size of 1.66 megabase-pairs, Prochlorococcus sp. MED4 has the most compact of these genomes and it is enigmatic how the few identified regulatory proteins efficiently sustain the lifestyle of an ecologically successful marine microorganism. Small non-coding RNAs (ncRNAs) control a plethora of processes in eukaryotes as well as in bacteria; however, systematic searches for ncRNAs are still lacking for most eubacterial phyla outside the enterobacteria. Based on a computational prediction we show the presence of several ncRNAs (cyanobacterial functional RNA or Yfr) in several different cyanobacteria of the Prochlorococcus-Synechococcus lineage. Some ncRNA genes are present only in two or three of the four strains investigated, whereas the RNAs Yfr2 through Yfr5 are structurally highly related and are encoded by a rapidly evolving gene family as their genes exist in different copy numbers and at different sites in the four investigated genomes. One ncRNA, Yfr7, is present in at least seven other cyanobacteria. In addition, control elements for several ribosomal operons were predicted as well as riboswitches for thiamine pyrophosphate and cobalamin. This is the first genome-wide and systematic screen for ncRNAs in cyanobacteria. Several ncRNAs were both computationally predicted and their presence was biochemically verified. These RNAs may have regulatory functions and each shows a distinct phylogenetic distribution. Our approach can be applied to any group of microorganisms for which more than one total genome sequence is available for comparative analysis.

Massive increase, spread, and exchange of extended spectrum β-lactamase-encoding genes among intestinal Enterobacteriaceae in hospitalized children with severe acute malnutrition in Niger.

PubMed

Woerther, Paul-Louis; Angebault, Cécile; Jacquier, Hervé; Hugede, Henri-Charles; Janssens, Ann-Carole; Sayadi, Sani; El Mniai, Assiya; Armand-Lefèvre, Laurence; Ruppé, Etienne; Barbier, François; Raskine, Laurent; Page, Anne-Laure; de Rekeneire, Nathalie; Andremont, Antoine

2011-10-01

From the time of CTX-M emergence, extended-spectrum β-lactamase-producing enterobacteria (ESBL-E) have spread worldwide in community settings as well as in hospitals, particularly in developing countries. Although their dissemination appears linked to Escherichia coli intestinal carriage, precise paths of this dynamic are largely unknown. Children from a pediatric renutrition center were prospectively enrolled in a fecal carriage study. Antibiotic exposure was recorded. ESBL-E strains were isolated using selective media from fecal samples obtained at admission and, when negative, also at discharge. ESBL-encoding genes were identified, their environments and plasmids were characterized, and clonality was assessed with polymerase chain reaction-based methods and pulsed-field gel electrophoresis for E. coli and Klebsiella pneumoniae. E. coli strains were subjected to multilocus sequence typing. The ESBL-E carriage rate was 31% at admission in the 55 children enrolled. All children enrolled received antibiotics during hospitalization. Among the ESBL-E-negative children, 16 were resampled at discharge, and the acquisition rate was 94%. The bla(CTX-M-15) gene was found in >90% of the carriers. Genetic environments and plasmid characterization evidenced the roles of a worldwide, previously described, multidrug-resistant region and of IncF plasmids in CTX-M-15 E. coli dissemination. Diversity of CTX-M-15-carrying genetic structures and clonality of acquired ESBL E. coli suggested horizontal genetic transfer and underlined the potential of some ST types for nosocomial cross-transmission. Cross-transmission and high selective pressure lead to very high acquisition of ESBL-E carriage, contributing to dissemination in the community. Strict hygiene measures as well as careful balancing of benefit-risk ratio of current antibiotic policies need to be reevaluated.

Fast and Sensitive Detection of Enteropathogenic Yersinia by Immunoassays

PubMed Central

Laporte, Jérôme; Savin, Cyril; Lamourette, Patricia; Devilliers, Karine; Volland, Hervé; Carniel, Elisabeth; Créminon, Christophe

2014-01-01

Yersinia enterocolitica and Yersinia pseudotuberculosis, the two Yersinia species that are enteropathogenic for humans, are distributed worldwide and frequently cause diarrhea in inhabitants of temperate and cold countries. Y. enterocolitica is a major cause of foodborne disease resulting from consumption of contaminated pork meat and is further associated with substantial economic cost. However, investigation of enteropathogenic Yersinia species is infrequently performed routinely in clinical laboratories because of their specific growth characteristics, which make difficult their isolation from stool samples. Moreover, current isolation procedures are time-consuming and expensive, thus leading to underestimates of the incidence of enteric yersiniosis, inappropriate prescriptions of antibiotic treatments, and unnecessary appendectomies. The main objective of the study was to develop fast, sensitive, specific, and easy-to-use immunoassays, useful for both human and veterinary diagnosis. Monoclonal antibodies (MAbs) directed against Y. enterocolitica bioserotypes 2/O:9 and 4/O:3 and Y. pseudotuberculosis serotypes I and III were produced. Pairs of MAbs were selected by testing their specificity and affinity for enteropathogenic Yersinia and other commonly found enterobacteria. Pairs of MAbs were selected to develop highly sensitive enzyme immunoassays (EIAs) and lateral flow immunoassays (LFIs or dipsticks) convenient for the purpose of rapid diagnosis. The limit of detection of the EIAs ranged from 3.2 × 103 CFU/ml to 8.8 × 104 CFU/ml for pathogenic serotypes I and III of Y. pseudotuberculosis and pathogenic bioserotypes 2/O:9 and 4/O:3 of Y. enterocolitica and for the LFIs ranged from 105 CFU/ml to 106 CFU/ml. A similar limit of detection was observed for artificially contaminated human feces. PMID:25355759

Heterologous Expression of Equine CYP3A94 and Investigation of a Tunable System to Regulate Co-Expressed NADPH P450 Oxidoreductase Levels

PubMed Central

Dettwiler, Ramona; Schmitz, Andrea L.; Plattet, Philippe; Zielinski, Jana; Mevissen, Meike

2014-01-01

The activity of cytochrome P450 enzymes depends on the enzyme NADPH P450 oxidoreductase (POR). The aim of this study was to investigate the activity of the equine CYP3A94 using a system that allows to regulate the POR protein levels in mammalian cells. CYP3A94 and the equine POR were heterologously expressed in V79 cells. In the system used, the POR protein regulation is based on a destabilizing domain (DD) that transfers its instability to a fused protein. The resulting fusion protein is therefore degraded by the ubiquitin-proteasome system (UPS). Addition of “Shield-1” prevents the DD fusion protein from degradation. The change of POR levels at different Shield-1 concentrations was demonstrated by cytochrome c reduction, Western immunoblot analysis, and immunocytochemistry. The alteration of CYP3A94 activity was investigated using a substrate (BFC) known to detect CYP3A4 activity. Equine CYP3A94 was demonstrated to be metabolically active and its activity could be significantly elevated by co-expression of POR. Cytochrome c reduction was significantly increased in V79-CYP3A94/DD-POR cells compared to V79-CYP3A94 cells. Surprisingly, incubation with different Shield-1 concentrations resulted in a decrease in POR protein shown by Western immunoblot analysis. Cytochrome c reduction did not change significantly, but the CYP3A94 activity decreased more than 4-fold after incubation with 500 nM and 1 µM Shield-1 for 24 hours. No differences were obtained when V79-CYP3A94 POR cells with and without Shield-1 were compared. The basal activity levels of V79-CYP3A94/DD-POR cells were unexpectedly high, indicating that DD/POR is not degraded without Shield-1. Shield-1 decreased POR protein levels and CYP3A94 activity suggesting that Shield-1 might impair POR activity by an unknown mechanism. Although regulation of POR with the pPTuner system could not be obtained, the cell line V79-CYP3A94/DD-POR system can be used for further experiments to characterize the equine CYP3A

P450 oxidoreductase deficiency: a disorder of steroidogenesis with multiple clinical manifestations.

PubMed

Miller, Walter L

2012-10-23

Cytochrome P450 enzymes catalyze the biosynthesis of steroid hormones and metabolize drugs. There are seven human type I P450 enzymes in mitochondria and 50 type II enzymes in endoplasmic reticulum. Type II enzymes, including both drug-metabolizing and some steroidogenic enzymes, require electron donation from a two-flavin protein, P450 oxidoreductase (POR). Although knockout of the POR gene causes embryonic lethality in mice, we discovered human POR deficiency as a disorder of steroidogenesis associated with the Antley-Bixler skeletal malformation syndrome and found mild POR mutations in phenotypically normal adults with infertility. Assay results of mutant forms of POR using the traditional but nonphysiologic assay (reduction of cytochrome c) did not correlate with patient phenotypes; assays based on the 17,20 lyase activity of P450c17 (CYP17) correlated with clinical phenotypes. The POR sequence in 842 normal individuals revealed many polymorphisms; amino acid sequence variant A503V is encoded by ~28% of human alleles. POR A503V has about 60% of wild-type activity in assays with CYP17, CYP2D6, and CYP3A4, but nearly wild-type activity with P450c21, CYP1A2, and CYP2C19. Activity of a particular POR variant with one P450 enzyme will not predict its activity with another P450 enzyme: Each POR-P450 combination must be studied individually. Human POR transcription, initiated from an untranslated exon, is regulated by Smad3/4, thyroid receptors, and the transcription factor AP-2. A promoter polymorphism reduces transcription to 60% in liver cells and to 35% in adrenal cells. POR deficiency is a newly described disorder of steroidogenesis, and POR variants may account for some genetic variation in drug metabolism.

Patterns of coral disease across the Hawaiian Archipelago: Relating disease to environment

USGS Publications Warehouse

Aeby, G.S.; Williams, G.J.; Franklin, E.C.; Kenyon, J.; Cox, E.F.; Coles, S.; Work, Thierry M.

2011-01-01

In Hawaii, coral reefs occur across a gradient of biological (host abundance), climatic (sea surface temperature anomalies) and anthropogenic conditions from the human-impacted reefs of the main Hawaiian Islands (MHI) to the pristine reefs of the northwestern Hawaiian Islands (NWHI). Coral disease surveys were conducted at 142 sites from across the Archipelago and disease patterns examined. Twelve diseases were recorded from three coral genera (Porites, Montipora, Acropora) with Porites having the highest prevalence. Porites growth anomalies (PorGAs) were significantly more prevalent within and indicative of reefs in the MHI and Porites trematodiasis (PorTrm) was significantly more prevalent within and indicative of reefs in the NWHI. Porites tissue loss syndrome (PorTLS) was also important in driving regional differences but that relationship was less clear. These results highlight the importance of understanding disease ecology when interpreting patterns of disease occurrence. PorTrm is caused by a parasitic flatworm that utilizes multiple hosts during its life cycle (fish, mollusk and coral). All three hosts must be present for the disease to occur and higher host abundance leads to higher disease prevalence. Thus, a high prevalence of PorTrm on Hawaiian reefs would be an indicator of a healthy coral reef ecosystem. In contrast, the high occurrence of PorGAs within the MHI suggests that PorGAs are related, directly or indirectly, to some environmental co-factor associated with increased human population sizes. Focusing on the three indicator diseases (PorGAs, PorTrm, PorTLS) we used statistical modeling to examine the underlying associations between disease prevalence and 14 different predictor variables (biotic and abiotic). All three diseases showed positive associations with host abundance and negative associations with thermal stress. The association with human population density differed among disease states with PorGAs showing a positive and PorTrm showing

Patterns of Coral Disease across the Hawaiian Archipelago: Relating Disease to Environment

PubMed Central

Aeby, Greta S.; Williams, Gareth J.; Franklin, Erik C.; Kenyon, Jean; Cox, Evelyn F.; Coles, Steve; Work, Thierry M.

2011-01-01

In Hawaii, coral reefs occur across a gradient of biological (host abundance), climatic (sea surface temperature anomalies) and anthropogenic conditions from the human-impacted reefs of the main Hawaiian Islands (MHI) to the pristine reefs of the northwestern Hawaiian Islands (NWHI). Coral disease surveys were conducted at 142 sites from across the Archipelago and disease patterns examined. Twelve diseases were recorded from three coral genera (Porites, Montipora, Acropora) with Porites having the highest prevalence. Porites growth anomalies (PorGAs) were significantly more prevalent within and indicative of reefs in the MHI and Porites trematodiasis (PorTrm) was significantly more prevalent within and indicative of reefs in the NWHI. Porites tissue loss syndrome (PorTLS) was also important in driving regional differences but that relationship was less clear. These results highlight the importance of understanding disease ecology when interpreting patterns of disease occurrence. PorTrm is caused by a parasitic flatworm that utilizes multiple hosts during its life cycle (fish, mollusk and coral). All three hosts must be present for the disease to occur and higher host abundance leads to higher disease prevalence. Thus, a high prevalence of PorTrm on Hawaiian reefs would be an indicator of a healthy coral reef ecosystem. In contrast, the high occurrence of PorGAs within the MHI suggests that PorGAs are related, directly or indirectly, to some environmental co-factor associated with increased human population sizes. Focusing on the three indicator diseases (PorGAs, PorTrm, PorTLS) we used statistical modeling to examine the underlying associations between disease prevalence and 14 different predictor variables (biotic and abiotic). All three diseases showed positive associations with host abundance and negative associations with thermal stress. The association with human population density differed among disease states with PorGAs showing a positive and PorTrm showing

Evaluation of six nucleic acid amplification tests used for diagnosis of Neisseria gonorrhoeae in Russia compared with an international strictly validated real-time porA pseudogene polymerase chain reaction.

PubMed

Shipitsyna, E; Zolotoverkhaya, E; Hjelmevoll, S O; Maximova, A; Savicheva, A; Sokolovsky, E; Skogen, V; Domeika, M; Unemo, M

2009-11-01

In Russia, laboratory diagnosis of gonorrhoea has been mainly based on microscopy only and, in some settings, relatively rare suboptimal culturing. In recent years, Russian developed and manufactured nucleic acid amplification tests (NAAT) have been implemented for routine diagnosis of Neisseria gonorrhoeae. However, these NAATs have never been validated to any international well-recognized diagnostic NAAT. This study aims to evaluate the performance characteristics of six Russian NAATs for N. gonorrhoeae diagnostics. In total, 496 symptomatic patients were included. Five polymerase chain reaction (PCR) assays and one real-time nucleic acid sequence based amplification (NASBA) assay, developed by three Russian companies, were evaluated on urogenital samples, i.e. cervical and first voided urine (FVU) samples from females (n = 319), urethral and FVU samples from males (n = 127), and extragenital samples, i.e. rectal and pharyngeal samples, from 50 additional female patients with suspicion of gonorrhoea. As reference method, an international strictly validated real-time porA pseudogene PCR was applied. The prevalence of N. gonorrhoeae was 2.7% and 16% among the patients providing urogenital and extragenital samples, respectively. The Russian NAATs and the reference method displayed high level of concordance (99.4-100%). The sensitivities, specificities, positive predictive values and negative predictive values of the Russian tests in different specimens were 66.7-100%, 100%, 100%, and 99.4-100%, respectively. Russian N. gonorrhoeae diagnostic NAATs comprise relatively good performance characteristics. However, larger studies are crucial and, beneficially, the Russian assays should also be evaluated to other international highly sensitive and specific, and ideally Food and Drug Administration approved, NAATs such as Aptima Combo 2 (Gen-Probe).

Alerta De Insecto-Escarabajo asiatico de antenoas largas

Treesearch

Marco A. Fonseca; Ronald F. Billings

Hay probablemente una sola generacion de ALB por a'o. Los escarabajos adultos por lo general estan presentes de mayo a octubre, pero se pueden encontrar mas temprano en la primavera o mas tarde en el oto?o si las temperaturas son calidas. Los adultos por lo general permanecen en el arbol del que emergieron o se pueden desplazar por distancias cortas hacia un...

Geographical variation of overweight, obesity and related risk factors: Findings from the European Health Examination Survey in Luxembourg, 2013-2015.

PubMed

Samouda, Hanen; Ruiz-Castell, Maria; Bocquet, Valery; Kuemmerle, Andrea; Chioti, Anna; Dadoun, Frédéric; Kandala, Ngianga-Bakwin; Stranges, Saverio

2018-01-01

The analyses of geographic variations in the prevalence of major chronic conditions, such as overweight and obesity, are an important public health tool to identify "hot spots" and inform allocation of funding for policy and health promotion campaigns, yet rarely performed. Here we aimed at exploring, for the first time in Luxembourg, potential geographic patterns in overweight/obesity prevalence in the country, adjusted for several demographic, socioeconomic, behavioural and health status characteristics. Data came from 720 men and 764 women, 25-64 years old, who participated in the European Health Examination Survey in Luxembourg (2013-2015). To investigate the geographical variation, geo-additive semi-parametric mixed model and Bayesian modelisations based on Markov Chain Monte Carlo techniques for inference were performed. Large disparities in the prevalence of overweight and obesity were found between municipalities, with the highest rates of obesity found in 3 municipalities located in the South-West of the country. Bayesian approach also underlined a nonlinear effect of age on overweight and obesity in both genders (significant in men) and highlighted the following risk factors: 1. country of birth for overweight in men born in a non-European country (Posterior Odds Ratio (POR): 3.24 [1.61-8.69]) and women born in Portugal (POR: 2.44 [1.25-4.43]), 2. low educational level (secondary or below) for overweight (POR: 1.66 (1.06-2.72)] and obesity (POR:2.09 [1.05-3.65]) in men, 3. single marital status for obesity in women (POR: 2.20 [1.24-3.91]), 4.fair (men: POR: 3.19 [1.58-6.79], women: POR: 2.24 [1.33-3.73]) to very bad health perception (men: POR: 15.01 [2.16-98.09]) for obesity, 5. sleeping more than 6 hours for obesity in unemployed men (POR: 3.66 [2.02-8.03]). Protective factors highlighted were: 1. single marital status against overweight (POR: [0.60 (0.38-0.96)]) and obesity (POR: 0.39 [0.16-0.84]) in men, 2. the fact to be widowed against overweight in

The Understanding of Astronomy Concepts by Students from Basic Education of a Public School. (Spanish Title: El Entendimiento de Conceptos de Aastronmía Por Los Alumnos de Educación Básica en Una Escuela Pública.) O Entendimento de Conceitos de Astronomia Por Alunos da Educação Básica: O Caso de Uma Escola Pública Brasileira

NASA Astrophysics Data System (ADS)

Iria Machado, Daniel; dos Santos, Carlos

2011-07-01

We present the results obtained in a research on the comprehension of basic astronomical concepts, in which 561 students from fifth grade middle school to third grade high school of a public school of the city of Foz do Iguaçu (Brazil) took part. A test with 20 multiple-choice questions was applied to indentify the most common conceptions expressed by the students. This test was elaborated based on the literature about misconceptions and covered the following topics: the day-night cycle; the time zones; the seasons of the year; the phases of the Moon; the movement of the Moon; the apparent movement of the Sun in the celestial sphere; the eclipses; the dimensions and distances in the Universe; the brightness of the stars and its observation from Earth. Though a small progress was verified in the proportion of scientifically acceptable answers when comparing the eighth grade of middle school to the fifth, and the third grade of high school to the first, there was an overall predominance of alternative conceptions regarding most of the explored subjects, which persisted up to the last year of secondary school. The comparison to data found in this research made in other socio-cultural contexts revealed, in many aspects, similar notions and difficulties revealed by the students. Se presentan los resultados de una investigación sobre la comprensión de conceptos astronómicos básicos, en la cual participaron 561 estudiantes que cursaban entre el quinto grado de la enseñanza primaria y el tercer año de la enseñanza secundaria de una escuela pública de la ciudad de Foz do Iguaçu (Brasil). Se utilizó un test de 20 preguntas de opción múltiple para identificar las concepciones más comunes expresadas por los estudiantes. Este instrumento de recolección de datos se desarrolló en base a la literatura sobre las concepciones alternativas y trató los siguientes temas: el ciclo día-noche, los husos horarios, las estaciones del año, las fases de la Luna, el

Eficacia de la detección sistemática de la gripe en las fronteras en los viajeros que llegan por vía aérea*

PubMed Central

Priest, Patricia C.; Jennings, Lance C.; Duncan, Alasdair R.; Brunton, Cheryl R.; Baker, Michael G.

2015-01-01

Objetivos. Se midieron los síntomas y la prevalencia de la gripe (también llamada influenza), así como la eficacia del mecanismo de detección sistemática basado en los síntomas y la temperatura para diagnosticar la gripe en viajeros internacionales que llegaban por vía aérea. Métodos. El presente estudio transversal recopiló datos de viajeros que llegaron al aeropuerto internacional de Christchurch (Nueva Zelandia) en el invierno del 2008 mediante un cuestionario de salud, medición de la temperatura y toma de muestras de las vías respiratorias. Resultados. De los viajeros, 15 976 (68%) entregaron los formularios completos. De ellos, 17% notificaron al menos un síntoma de gripe; los síntomas más comunes fueron rinorrea o congestión nasal (10%) y tos (8%). Se tomaron muestras de las vías respiratorias de 3 769 viajeros. La prevalencia estimada de la gripe fue de 1,1% (4% en las personas sintomáticas, 0,2% en las asintomáticas). La sensibilidad de los criterios de detección varió de 84% para “cualquier síntoma” a 3% para la fiebre de 37,8 °C o mayor. El valor predictivo positivo fue bajo para todos los criterios. Conclusiones. El método de detección sistemática en las fronteras mediante la autonotificación de síntomas y la toma de la temperatura presenta limitaciones para impedir que una gripe pandémica entre en un país. Basarse en criterios como “cualquier síntoma” o la tos haría que se investigara a varias personas no infectadas, mientras que algunas personas infectadas pasarían inadvertidas. Si se usaran criterios más específicos como la fiebre, la mayoría de las personas infectadas entrarían en el país a pesar del mecanismo de detección.

Risk factors associated with human Rift Valley fever infection: systematic review and meta-analysis.

PubMed

Nicholas, Dennis E; Jacobsen, Kathryn H; Waters, Nigel M

2014-12-01

To identify risk factors for human Rift Valley fever virus (RVFV) infection. A systematic review identified 17 articles reporting on 16 studies examining risk factors for RVFV. Pooled odds ratios (pOR) were calculated for exposures examined in four or more studies. Being male [pOR = 1.4 (1.0, 1.8)], contact with aborted animal tissue [pOR = 3.4 (1.6, 7.3)], birthing an animal [pOR = 3.2 (2.4, 4.2)], skinning an animal [pOR = 2.5 (1.9, 3.2)], slaughtering an animal [pOR = 2.4 (1.4, 4.1)] and drinking raw milk [pOR = 1.8 (1.2, 2.6)] were significantly associated with RVF infection after meta-analysis. Other potential risk factors include sheltering animals in the home and milking an animal, which may both involve contact with animal body fluids. Based on the identified risk factors, use of personal protective equipment and disinfectants by animal handlers may help reduce RVFV transmission during outbreaks. Milk pasteurisation and other possible preventive methods require further investigation. © 2014 John Wiley & Sons Ltd.

Camina por Salud: Walking in Mexican-American Women

PubMed Central

Keller, Colleen S.; Gonzales, Adelita

2008-01-01

Forty-six percent of older Mexican-American women report no leisure time physical activity (PA); 38.1% are obese. This study (1) evaluated a PA intervention on reduction of risk for coronary heart disease (CHD) and (2) determined which variables affected adherence to PA. For 36 weeks, Group I walked 3 days/week; Group II walked 5 days/week. The investigators measured total body fat, regional fat, blood lipids, and adherence to PA The walking interventions favorably affected body fat, with significant differences in body mass index (BMI) reductions[F (2, 16) = 12.86, p = .001]. No statistical differences were noted in the anthropometric and blood lipid results from baseline to the 36-week measures. PMID:18457751

Desigualdad social y tendencias de mortalidad por diabetes.

PubMed

Medina-Gómez, Oswaldo; Medina-Reyes, E Ismael Seth

2017-01-01

To identify the trend of national diabetes mortality by level of marginality at the state and municipal levels. A descriptive study was conducted with records of deaths from diabetes in over 20 years from 1990 to 2013. The national mortality rate was calculated standardized by age according to the 2000 world population and the state level 2013 saw the projected naational population by join point analysis for trend analysis was performed. For the general population, the annual percentage change between 1990 and 1996 was 2.2, from 1996 to 2005 was 4.3, and from 2005 to 2013 was 0.1. The largest increase among women occurred between 1998 and 2005 while among men occurred between 1995 and 2006. At the state level was found higher annual percentage change between the towns with the highest degree of marginalization. The mortality of diabetes in women shows a significant decrease since 2004, among men, the mortality with a continuous upward trend, consistent with the trend that the disease has had in recent years. Copyright: © 2017 SecretarÍa de Salud

Disaster-related exposures and health effects among US Coast Guard responders to Hurricanes Katrina and Rita: a cross-sectional study.

PubMed

Rusiecki, Jennifer A; Thomas, Dana L; Chen, Ligong; Funk, Renée; McKibben, Jodi; Dayton, Melburn R

2014-08-01

Disaster responders work among poorly characterized physical and psychological hazards with little understood regarding health consequences of their work. A survey administered to 2834 US Coast Guard responders to Hurricanes Katrina and Rita provided data on exposures and health effects. Prevalence odds ratios (PORs) evaluated associations between baseline characteristics, missions, exposures, and health effects. Most frequent exposures were animal/insect vector (n = 1309; 46%) and floodwater (n = 817; 29%). Most frequent health effects were sunburn (n = 1119; 39%) and heat stress (n = 810; 30%). Significant positive associations were for mold exposure and sinus infection (POR = 10.39); carbon monoxide and confusion (POR = 6.27); lack of sleep and slips, trips, falls (POR = 3.34) and depression (POR = 3.01); being a Gulf-state responder and depression (POR = 3.22). Increasing protection for disaster responders requires provisions for adequate sleep, personal protective equipment, and access to medical and psychological support.

Making the invisible visible: improved electrospray ion formation of metalloporphyrins/-phthalocyanines by attachment of the formate anion (HCOO(-)).

PubMed

Hitzenberger, Jakob Felix; Dammann, Claudia; Lang, Nina; Lungerich, Dominik; García-Iglesias, Miguel; Bottari, Giovanni; Torres, Tomás; Jux, Norbert; Drewello, Thomas

2016-02-21

A protocol is developed for the coordination of the formate anion (HCOO(-)) to neutral metalloporphyrins (Pors) and -phthalocyanines (Pcs) containing divalent metals as a means to improve their ion formation in electrospray ionization (ESI). This method is particularly useful when the oxidation of the neutral metallomacrocycle fails. While focusing on Zn(II)Pors and Zn(II)Pcs, we show that formate is also readily attached to Mn(II), Mg(II) and Co(II)Pcs. However, for the Co(II)Pc secondary reactions can be observed. Upon collision-induced dissociation (CID), Zn(II)Por/Pc·formate supramolecular complexes can undergo the loss of CO2 in combination with transfer of a hydride anion (H(-)) to the zinc metal center. Further dissociation leads to electron transfer and hydrogen atom loss, generating a route to the radical anion of the Zn(II)Por/Pc without the need for electrochemical reduction, although the Zn(II)Por/Pc may have a too low electron affinity to allow electron transfer directly from the formate anion. In addition to single Por molecules, multi Por arrays were successfully analyzed by this method. In this case, multiple addition of formate occurs, giving rise to multiply charged species. In these multi Por arrays, complexation of the formate anion occurs by two surrounding Por units (sandwich). Therefore, the maximum attainment of formate anions in these arrays corresponds to the number of such sandwich complexes rather than the number of porphyrin moieties. The same bonding motif leads to dimers of the composition [(Zn(II)Por/Pc)2·HCOO](-). In these, the formate anion can act as a structural probe, allowing the distinction of isomeric ions with the formate bridging two macrocycles or being attached to a dimer of directly connected macrocycles.

Hydrolysis of clavulanate by Mycobacterium tuberculosis β-lactamase BlaC harboring a canonical SDN motif.

PubMed

Soroka, Daria; Li de la Sierra-Gallay, Inès; Dubée, Vincent; Triboulet, Sébastien; van Tilbeurgh, Herman; Compain, Fabrice; Ballell, Lluis; Barros, David; Mainardi, Jean-Luc; Hugonnet, Jean-Emmanuel; Arthur, Michel

2015-09-01

Combinations of β-lactams with clavulanate are currently being investigated for tuberculosis treatment. Since Mycobacterium tuberculosis produces a broad spectrum β-lactamase, BlaC, the success of this approach could be compromised by the emergence of clavulanate-resistant variants, as observed for inhibitor-resistant TEM variants in enterobacteria. Previous analyses based on site-directed mutagenesis of BlaC have led to the conclusion that this risk was limited. Here, we used a different approach based on determination of the crystal structure of β-lactamase BlaMAb of Mycobacterium abscessus, which efficiently hydrolyzes clavulanate. Comparison of BlaMAb and BlaC allowed for structure-assisted site-directed mutagenesis of BlaC and identification of the G(132)N substitution that was sufficient to switch the interaction of BlaC with clavulanate from irreversible inactivation to efficient hydrolysis. The substitution, which restored the canonical SDN motif (SDG→SDN), allowed for efficient hydrolysis of clavulanate, with a more than 10(4)-fold increase in k cat (0.41 s(-1)), without affecting the hydrolysis of other β-lactams. Mass spectrometry revealed that acylation of BlaC and of its G(132)N variant by clavulanate follows similar paths, involving sequential formation of two acylenzymes. Decarboxylation of the first acylenzyme results in a stable secondary acylenzyme in BlaC, whereas hydrolysis occurs in the G(132)N variant. The SDN/SDG polymorphism defines two mycobacterial lineages comprising rapidly and slowly growing species, respectively. Together, these results suggest that the efficacy of β-lactam-clavulanate combinations may be limited by the emergence of resistance. β-Lactams active without clavulanate, such as faropenem, should be prioritized for the development of new therapies. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

AraC/XylS Family Stress Response Regulators Rob, SoxS, PliA, and OpiA in the Fire Blight Pathogen Erwinia amylovora

PubMed Central

Pletzer, Daniel; Schweizer, Gabriel

2014-01-01

Transcriptional regulators of the AraC/XylS family have been associated with multidrug resistance, organic solvent tolerance, oxidative stress, and virulence in clinically relevant enterobacteria. In the present study, we identified four homologous AraC/XylS regulators, Rob, SoxS, PliA, and OpiA, from the fire blight pathogen Erwinia amylovora Ea1189. Previous studies have shown that the regulators MarA, Rob, and SoxS from Escherichia coli mediate multiple-antibiotic resistance, primarily by upregulating the AcrAB-TolC efflux system. However, none of the four AraC/XylS regulators from E. amylovora was able to induce a multidrug resistance phenotype in the plant pathogen. Overexpression of rob led to a 2-fold increased expression of the acrA gene. However, the rob-overexpressing strain showed increased resistance to only a limited number of antibiotics. Furthermore, Rob was able to induce tolerance to organic solvents in E. amylovora by mechanisms other than efflux. We demonstrated that SoxS from E. amylovora is involved in superoxide resistance. A soxS-deficient mutant of Ea1189 was not able to grow on agar plates supplemented with the superoxide-generating agent paraquat. Furthermore, expression of soxS was induced by redox cycling agents. We identified two novel members of the AraC/XylS family in E. amylovora. PliA was highly upregulated during the early infection phase in apple rootstock and immature pear fruits. Multiple compounds were able to induce the expression of pliA, including apple leaf extracts, phenolic compounds, redox cycling agents, heavy metals, and decanoate. OpiA was shown to play a role in the regulation of osmotic and alkaline pH stress responses. PMID:24936054

AraC/XylS family stress response regulators Rob, SoxS, PliA, and OpiA in the fire blight pathogen Erwinia amylovora.

PubMed

Pletzer, Daniel; Schweizer, Gabriel; Weingart, Helge

2014-09-01

Transcriptional regulators of the AraC/XylS family have been associated with multidrug resistance, organic solvent tolerance, oxidative stress, and virulence in clinically relevant enterobacteria. In the present study, we identified four homologous AraC/XylS regulators, Rob, SoxS, PliA, and OpiA, from the fire blight pathogen Erwinia amylovora Ea1189. Previous studies have shown that the regulators MarA, Rob, and SoxS from Escherichia coli mediate multiple-antibiotic resistance, primarily by upregulating the AcrAB-TolC efflux system. However, none of the four AraC/XylS regulators from E. amylovora was able to induce a multidrug resistance phenotype in the plant pathogen. Overexpression of rob led to a 2-fold increased expression of the acrA gene. However, the rob-overexpressing strain showed increased resistance to only a limited number of antibiotics. Furthermore, Rob was able to induce tolerance to organic solvents in E. amylovora by mechanisms other than efflux. We demonstrated that SoxS from E. amylovora is involved in superoxide resistance. A soxS-deficient mutant of Ea1189 was not able to grow on agar plates supplemented with the superoxide-generating agent paraquat. Furthermore, expression of soxS was induced by redox cycling agents. We identified two novel members of the AraC/XylS family in E. amylovora. PliA was highly upregulated during the early infection phase in apple rootstock and immature pear fruits. Multiple compounds were able to induce the expression of pliA, including apple leaf extracts, phenolic compounds, redox cycling agents, heavy metals, and decanoate. OpiA was shown to play a role in the regulation of osmotic and alkaline pH stress responses. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

[Waterborne outbreak of gastroenteritis transmitted through the public water supply].

PubMed

Godoy, P; Borrull, C; Palà, M; Caubet, I; Bach, P; Nuín, C; Espinet, L; Torres, J; Mirada, G

2003-01-01

The chlorination of public water supplies has led researchers to largely discard drinking water as a potential source of gastroenteritis outbreaks. The aim of this study was to investigate an outbreak of waterborne disease associated with drinking water from public supplies. A historical cohort study was carried out following notification of a gastroenteritis outbreak in Baqueira (Valle de Arán, Spain). We used systematic sampling to select 87 individuals staying at hotels and 67 staying in apartments in the target area. Information was gathered on four factors (consumption of water from the public water supply, sandwiches, water and food in the ski resorts) as well as on symptoms. We assessed residual chlorine in drinking water, analyzed samples of drinking water, and studied stool cultures from 4 patients. The risk associated with each water source and food type was assessed by means of relative risk (RR) and 95% confidence intervals (CI). The overall attack rate was 51.0% (76/149). The main symptoms were diarrhea 87.5%, abdominal pain 80.0%, nausea 50.7%, vomiting 30.3%, and fever 27.0%. The only factor associated with a statistically significant risk of disease was consumption of drinking water (RR = 11.0; 95% CI, 1.6-74.7). No residual chlorine was detected in the drinking water, which was judged acceptable. A problem associated with the location of the chlorinator was observed and corrected. We also recommended an increase in chlorine levels, which was followed by a reduction in the number of cases. The results of stool cultures of the four patients were negative for enterobacteria. This study highlights the potential importance of waterborne outbreaks of gastroenteritis transmitted through drinking water considered acceptable and suggests the need to improve microbiological research into these outbreaks (viruses and protozoa detection).

Virulence Factors of Escherichia coli Isolated From Female Reproductive Tract Infections and Neonatal Sepsis

PubMed Central

Cook, Susan W.; Hammill, Hunter A.

2001-01-01

Objective: The presence of enterobacteria such as Escherichia coli in the vagina of normal women is not synonymous with infection. However, vaginal E. coli may also cause symptomatic infections. We examined bacterial virulenceproperties that may promote symptomatic female reproductive tract infections (RTI) and neonatal sepsis. Methods: E. coli isolated as the causative agent from cases of vaginitis (n = 50), tubo-ovarian abscess (n = 45) and neonatal sepsis (n = 45) was examined for selected phenotypic and genetic virulence properties. Results were compared with the frequency of the same properties among fecal E. coli not associated with disease. Results: A significantly greater proportion of infection E. coli exhibited D-mannose resistant hemagglutination compared with fecal E. coli (p < 0.01). This adherence phenotype was associated with the presence of P fimbriae (pap) genes which were also significantly more prevalent among isolates from all three infection sites (p < 0.01). The majority of pap+ isolates contained the papG3 allele (Class II) regardless of infection type. Increased frequency of Type 1C genes among vaginitis and abscess isolates was also noted. No significant differences in frequency of other bacterial adherence genes, fim, sfa, uca (gaf) or dra were observed. E. coli associated with vaginitis was significantly more likely to be hemolytic ( HIy+) than were fecal isolates (p < 0.05). The HIy+ phenotype was also more prevalent among tubo-ovarian abscess and neonatal sepsis isolates (p < 0.08). Conclusions: E. coli isolated from female RTI and neonatal sepses possess unique properties that may enhance their virulence. These properties are similar to those associated with other E. coli extra-intestinal infections, indicating that strategies such as vaccination or bacterial interference that may be developed against urinary tract infections (UTI) and other E. coli extra-intestinal infections may also prevent selected female RTI. PMID:11916176

Changes in the microbial composition of raw milk induced by thermization treatments applied prior to traditional Greek hard cheese processing.

PubMed

Samelis, John; Lianou, Alexandra; Kakouri, Athanasia; Delbès, Céline; Rogelj, Irena; Bogovic-Matijasić, Bojana; Montel, Marie-Christine

2009-04-01

The microbiological quality, safety, and composition of mixtures of ewe's and goat's milk (90:10) used for cheesemaking were evaluated before and after thermization at 60 and 67 degrees C for 30 s. Such mild thermal treatments are commonly applied to reduce natural contaminants of raw milk before processing for traditional hard Greek cheeses. Raw milk samples had an average total bacterial count of 7.3 log CFU/ml; most of these bacteria were lactic acid bacteria (LAB) and pseudomonads. The LAB flora of raw milk was dominated by enterococci (40.8%), followed by lactococci (20.4%), leuconostocs (18.4%), and mesophilic lactobacilli (10.2%). Enterococcus faecalis (30.1%) and Enterococcus faecium (13.7%) were the most common LAB isolates, followed by Enterococcus durans, Lactococcus lactis subsp. lactis, Lactobacillus plantarum, and Leuconostoc lactis. Thermization at 60 degrees C for 30 s was effective for reducing raw milk contamination by enterobacteria (5.1 log CFU/ml), coagulase-positive staphylococci (3.3 log CFU/ml), and Listeria (present in 25-ml samples) to safe levels, but it also reduced mesophilic lactococci, leuconostocs, lactobacilli, and selected enterococci (72.0%) in thermized milk. Thermization at 67 degrees C for 30 s had a major inactivation effect on all bacterial groups. Two nisin-producing L. lactis subsp. lactis strains (M78 and M104) were isolated from raw milk, but neither nisin-producing nor other bacteriocin-producing LAB strains were isolated from thermized milk. Thus, thermization treatments control harmful bacteria but also may have a negative impact on milk quality by reducing desirable LAB and the biodiversity of raw milk bacteria overall, inactivating potentially protective LAB strains and enhancing the ability of potentially pathogenic enterococci to grow in fresh cheese curds.

Genomic Diversity of Erwinia carotovora subsp. carotovora and Its Correlation with Virulence

PubMed Central

Yap, Mee-Ngan; Barak, Jeri D.; Charkowski, Amy O.

2004-01-01

We used genetic and biochemical methods to examine the genomic diversity of the enterobacterial plant pathogen Erwinia carotovora subsp. carotovora. The results obtained with each method showed that E. carotovora subsp. carotovora strains isolated from one ecological niche, potato plants, are surprisingly diverse compared to related pathogens. A comparison of 23 partial mdh sequences revealed a maximum pairwise difference of 10.49% and an average pairwise difference of 2.13%, values which are much greater than the maximum variation (1.81%) and average variation (0.75%) previously reported for Escherichia coli. Pulsed-field gel electrophoresis analysis of I-CeuI-digested genomic DNA revealed seven rrn operons in all E. carotovora subsp. carotovora strains examined except strain WPP17, which had only six copies. We identified 26 I-CeuI restriction fragment length polymorphism patterns and observed significant polymorphism in fragment sizes ranging from 100 to 450 kb for all strains. We detected large plasmids in two strains, including the model strain E. carotovora subsp. carotovora 71. The two least virulent strains had an unusual chromosomal structure, suggesting that a particular pulsotype is correlated with virulence. To compare chromosomal organization of multiple enterobacterial genomes, several genes were mapped onto I-CeuI fragments. We identified portions of the genome that appear to be conserved across enterobacteria and portions that have undergone genome rearrangements. We found that the least virulent strain, WPP17, failed to oxidize cellobiose and was missing several hrp and hrc genes. The unexpected variability among isolates obtained from clonal hosts in one region and in one season suggests that factors other than the host plant, potato, drive the evolution of this common environmental bacterium and key plant pathogen. PMID:15128563

Enterobacter and Klebsiella species isolated from fresh vegetables marketed in Valencia (Spain) and their clinically relevant resistances to chemotherapeutic agents.

PubMed

Falomir, María Pilar; Rico, Hortensia; Gozalbo, Daniel

2013-12-01

Occurrence of antibiotic-resistant pathogenic or commensal enterobacteria in marketed agricultural foodstuffs may contribute to their incorporation into the food chain and constitutes an additional food safety concern. In this work, we have determined the clinically relevant resistances to 11 common chemotherapeutic agents in Enterobacter and Klebsiella isolates from fresh vegetables from various sources (supermarkets and greengrocers' shops in Valencia, Spain). A total of 96 isolates were obtained from 160 vegetables analyzed (50% positive samples): 68 Enterobacter isolates (59 E. cloacae, two E. aerogenes, two E. cancerogenus, one E. gergoviae, and four E. sakazakii, currently Cronobacter spp.), and 28 Klebsiella isolates (19 K. oxytoca and 9 K. pneumoniae). Only seven isolates were susceptible to all agents tested, and no resistances to ceftazidime, ciprofloxacin, gentamicin, and chloramphenicol were detected. Most isolates were resistant to amoxicillin/clavulanic acid (74 [58 Enterobacter and 16 Klebsiella]) or to ampicillin (80 [55/25]). Other resistances were less frequent: nitrofurantoin (13 isolates [12/1]), tetracycline (6 [5/1]), co-trimoxazole (3 [3/0]), cefotaxime (1 [1/0]), and streptomycin (2 [1/1]). Multiresistant isolates to two (56 [41/15]), three (10 E. cloacae isolates), four (one E. cloacae and one K. pneumoniae isolate), and five (two E. cloacae isolates) chemotherapeutic agents were also detected. The presence of potential pathogens points to marketed fresh produce, which often is eaten raw, as a risk factor for consumer health. In addition, these results support the usefulness of these bacterial species as indicators of the spreading of antibiotic resistances into the environment, particularly in the food chain, and suggest their role as carriers of resistance determinants from farms to consumers, which may constitute an additional "silent" food safety concern. Therefore, there is a need to improve the hygienic quality of marketed fresh

Understanding gut microbiota in elderly's health will enable intervention through probiotics.

PubMed

Pérez Martínez, G; Bäuerl, C; Collado, M C

2014-09-01

Today, advances in the public health system of most countries have managed to extend notably life expectancy, however, elderly's health remain as a very serious concern. The lifelong stimulation of innate and adaptive immune systems leads to immunosenescence and, as result, to a low ability to produce immunoglobulins against pathogens but also to a low-grade chronic inflammatory state (inflammaging) that is linked to most age-related health problems, such as dementia, Alzheimer or atherosclerosis. This inflammatory state could make the host more sensitive to intestinal microbes, or vice versa, as changes in the gut microbiota composition are related to the progression of diseases and frailty in the elderly population. It was considered that gut microbiota changed during aging, with an increase of Bacteroidetes vs. Firmicutes proportion and a reduction of bifidobacterial counts, however recent studies reported a great inter-individual variation among elderly and a significant relationship between gut microbiota, diet and institution or community living. Intervention studies of probiotics and prebiotics in elderly are not very abundant, but most cases showed that Bifidobacterium populations can efficiently be stimulated with a concomitant decrease of Enterobacteria. Furthermore, also some studies demonstrated that probiotics decreased the synthesis of pro-inflammatory cytokines which are upregulated in the elderly, such as interleukin (IL)-8, IL-6 or tumour necrosis factor ?, among others, and they increased the levels of activated lymphocytes, natural killer cells, phagocytic activity and even showed a greater response to influenza vaccination. This suggests that direct manipulation of the gut microbiota may improve adaptive immune response and reduce inflammatory secretions, therefore compensating immunosenescence effects, however, there are no records of their effect on clinical symptoms or risk for disease. Those facts reveal that this is an open research field

An in vitro model to study interactions between Escherichia coli and lactic acid bacterial inoculants for silage in rumen fluid.

PubMed

Weinberg, Z G; Chen, Y; Volchinski, V; Sela, S; Ogunade, I M; Adesogan, A

2016-07-01

Previous studies have shown that silages treated with lactic acid bacteria (LAB) inoculants enhance ruminants' performance. The objective of the current experiments was to develop an in vitro model to study interactions between LAB silage inoculants and inoculated silages and Escherichia coli (EC) in rumen fluid (RF). Our hypothesis was that some inoculants inhibit EC in RF. For that purpose buffered RF was incubated under anaerobic conditions at 39°C with commercial strains of LAB silage inoculants or with laboratory corn and wheat silages treated with these LAB, an EC strain and with various ruminant feed ingredients. The EC strain was originally isolated from cattle manure and tagged with a plasmid expressing the green fluorescence protein and kanamycin and streptomycin resistance. Results indicate that the LAB or the treated silages did not suppress EC numbers in the RF. When the pH of the RF decreased below 5·0 the EC disappeared. We conclude that both LAB inoculants for silage and EC survived in RF for several days; however, the inoculants and silages treated with such inoculants did not inhibit EC in RF in vitro. Forage crops, silage and hay are initial stages of the food chain for humans. Cattle harbours and sheds enterobacteria regularly, some strains of which are pathogens. These can contaminate forage crops through field fertilization with cattle manure. The objective of this study was to develop an in vitro model to test whether lactic acid bacteria, which are used in silage inoculants, alone or in treated silages can inhibit Escherichia coli in rumen fluid. This study presents safety aspects and it is also part of a broad research effort aimed at finding out how LAB silage inoculants and inoculated silages enhance ruminant performance or exert probiotic effects in ruminants. © 2016 The Society for Applied Microbiology.

Different fecal microbiotas and volatile organic compounds in treated and untreated children with celiac disease.

PubMed

Di Cagno, Raffaella; Rizzello, Carlo G; Gagliardi, Francesca; Ricciuti, Patrizia; Ndagijimana, Maurice; Francavilla, Ruggiero; Guerzoni, M Elisabetta; Crecchio, Carmine; Gobbetti, Marco; De Angelis, Maria

2009-06-01

This study aimed at investigating the fecal microbiotas of children with celiac disease (CD) before (U-CD) and after (T-CD) they were fed a gluten-free diet and of healthy children (HC). Brothers or sisters of T-CD were enrolled as HC. Each group consisted of seven children. PCR-denaturing gradient gel electrophoresis (DGGE) analysis with V3 universal primers revealed a unique profile for each fecal sample. PCR-DGGE analysis with group- or genus-specific 16S rRNA gene primers showed that the Lactobacillus community of U-CD changed significantly, while the diversity of the Lactobacillus community of T-CD was quite comparable to that of HC. Compared to HC, the ratio of cultivable lactic acid bacteria and Bifidobacterium to Bacteroides and enterobacteria was lower in T-CD and even lower in U-CD. The percentages of strains identified as lactobacilli differed as follows: HC (ca. 38%) > T-CD (ca. 17%) > U-CD (ca. 10%). Lactobacillus brevis, Lactobacillus rossiae, and Lactobacillus pentosus were identified only in fecal samples from T-CD and HC. Lactobacillus fermentum, Lactobacillus delbrueckii subsp. bulgaricus, and Lactobacillus gasseri were identified only in several fecal samples from HC. Compared to HC, the composition of Bifidobacterium species of T-CD varied, and it varied even more for U-CD. Forty-seven volatile organic compounds (VOCs) belonging to different chemical classes were identified using gas-chromatography mass spectrometry-solid-phase microextraction analysis. The median concentrations varied markedly for HC, T-CD, and U-CD. Overall, the r(2) values for VOC data for brothers and sisters were equal to or lower than those for unrelated HC and T-CD. This study shows the effect of CD pathology on the fecal microbiotas of children.

Novel Thermotolerant Siderophilic Filamentous Cyanobacterium that Produces Intracellular Iron-Rich Phases

NASA Technical Reports Server (NTRS)

Broun, Igor I.; Bryant, Donald A.; Casamatta, Dale; Thomas-Keprta, Kathie L.; Sarkisova, Svetlana A.; Shen, Gaozhang; Graham, Joel E.; Boyd, Eric S.; Peters, John W.; Garrison, Daniel H.;

In vitro activity of rifaximin against isolates from patients with small intestinal bacterial overgrowth.

PubMed

Pistiki, Aikaterini; Galani, Irene; Pyleris, Emmanouel; Barbatzas, Charalambos; Pimentel, Mark; Giamarellos-Bourboulis, Evangelos J

2014-03-01

Rifaximin, a non-absorbable rifamycin derivative, has published clinical efficacy in the alleviation of symptoms in patients with irritable bowel syndrome (IBS). Small intestinal bacterial overgrowth (SIBO) is associated with the pathogenesis of IBS. This study describes for the first time the antimicrobial effect of rifaximin against SIBO micro-organisms from humans. Fluid was aspirated from the third part of the duodenum from 567 consecutive patients; quantitative cultures diagnosed SIBO in 117 patients (20.6%). A total of 170 aerobic micro-organisms were isolated and the in vitro efficacy of rifaximin was studied by (i) minimum inhibitory concentration (MIC) testing by a microdilution technique and (ii) time-kill assays using bile to simulate the small intestinal environment. At a breakpoint of 32 μg/mL, rifaximin inhibited in vitro 85.4% of Escherichia coli, 43.6% of Klebsiella spp., 34.8% of Enterobacter spp., 54.5% of other Enterobacteriaceae spp., 82.6% of non-Enterobacteriaceae Gram-negative spp., 100% of Enterococcus faecalis, 100% of Enterococcus faecium and 100% of Staphylococcus aureus. For the time-kill assays, 11 E. coli, 15 non-E. coli Gram-negative enterobacteria and three E. faecalis isolates were studied. Rifaximin produced a >3 log10 decrease in the starting inoculum against most of the tested isolates at 500 μg/mL after 24h of growth. The results indicate that rifaximin has a potent effect on specific small bowel flora associated with SIBO. This conclusion should be regarded in light of the considerable time-kill effect at concentrations lower than those achieved in the bowel lumen after administration of conventional doses in humans. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Structural and Functional Characterization of Pseudomonas aeruginosa Global Regulator AmpR

PubMed Central

Caille, Olivier; Zincke, Diansy; Merighi, Massimo; Balasubramanian, Deepak; Kumari, Hansi; Kong, Kok-Fai; Silva-Herzog, Eugenia; Narasimhan, Giri; Schneper, Lisa; Lory, Stephen

2014-01-01

Pseudomonas aeruginosa is a dreaded pathogen in many clinical settings. Its inherent and acquired antibiotic resistance thwarts therapy. In particular, derepression of the AmpC β-lactamase is a common mechanism of β-lactam resistance among clinical isolates. The inducible expression of ampC is controlled by the global LysR-type transcriptional regulator (LTTR) AmpR. In the present study, we investigated the genetic and structural elements that are important for ampC induction. Specifically, the ampC (PampC) and ampR (PampR) promoters and the AmpR protein were characterized. The transcription start sites (TSSs) of the divergent transcripts were mapped using 5′ rapid amplification of cDNA ends-PCR (RACE-PCR), and strong σ54 and σ70 consensus sequences were identified at PampR and PampC, respectively. Sigma factor RpoN was found to negatively regulate ampR expression, possibly through promoter blocking. Deletion mapping revealed that the minimal PampC extends 98 bp upstream of the TSS. Gel shifts using membrane fractions showed that AmpR binds to PampC in vitro whereas in vivo binding was demonstrated using chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR). Additionally, site-directed mutagenesis of the AmpR helix-turn-helix (HTH) motif identified residues critical for binding and function (Ser38 and Lys42) and critical for function but not binding (His39). Amino acids Gly102 and Asp135, previously implicated in the repression state of AmpR in the enterobacteria, were also shown to play a structural role in P. aeruginosa AmpR. Alkaline phosphatase fusion and shaving experiments suggest that AmpR is likely to be membrane associated. Lastly, an in vivo cross-linking study shows that AmpR dimerizes. In conclusion, a potential membrane-associated AmpR dimer regulates ampC expression by direct binding. PMID:25182487

[Nosocomial infection in patients receiving a solid organ transplant or haematopoietic stem cell transplant].

PubMed

Moreno Camacho, Asunción; Ruiz Camps, Isabel

2014-01-01

Bacterial infections are the most common infections in solid organ transplant recipients. These infections occur mainly in the first month after transplantation and are hospital-acquired. Nosocomial infections cause significant morbidity and are the most common cause of mortality in this early period of transplantation. These infections are caused by multi-drug resistant (MDR) microorganisms, mainly Gram-negative enterobacteria, non-fermentative Gram-negative bacilli, enterococci, and staphylococci. The patients at risk of developing nosocomial bacterial infections are those previously colonized with MDR bacteria while on the transplant waiting list. Intravascular catheters, the urinary tract, the lungs, and surgical wounds are the most frequent sources of infection. Preventive measures are the same as those applied in non-immunocompromised, hospitalized patients except in patients at high risk for developing fungal infection. These patients need antifungal therapy during their hospitalization, and for preventing some bacterial infections in the early transplant period, patients need vaccinations on the waiting list according to the current recommendations. Although morbidity and mortality related to infectious diseases have decreased during the last few years in haematopoietic stem cell transplant recipients, they are still one of the most important complications in this population. Furthermore, as occurs in the general population, the incidence of nosocomial infections has increased during the different phases of transplantation. It is difficult to establish general preventive measures in these patients, as there are many risk factors conditioning these infections. Firstly, they undergo multiple antibiotic treatments and interventions; secondly, there is a wide variability in the degree of neutropenia and immunosuppression among patients, and finally they combine hospital and home stay during the transplant process. However, some simple measures could be

Effects of lipid sources, lysophospholipids and organic acids in maize-based broiler diets on nutrient balance, liver concentration of fat-soluble vitamins, jejunal microbiota and performance.

PubMed

Polycarpo, G V; Burbarelli, M F C; CarÃo, A C P; Merseguel, C E B; Dadalt, J C; Maganha, S R L; Sousa, R L M; Cruz-Polycarpo, V C; Albuquerque, R

2016-12-01

Three experiments with a 2 × 2 × 2 factorial arrangement were conducted to evaluate maize-based diets for broilers containing different lipid sources [soybean oil (S) or beef tallow (T)] supplemented with or without lysophospholipids and organic acids on nutrient balance (Experiment I, evaluation period of 10-14 d), on liver concentration of fat-soluble vitamins, on jejunal microbiota (Experiment II, sampling at d 14) and on performance (Experiment III, accumulated periods of 1-14, 1-21 and 1-42 d). A total of 1344 male chicks were used. In each experiment, the birds were allotted in a completely randomised design with 8 replications. The lysophospholipids were mainly composed of lysolecithins and the organic acids blend was constituted by lactic (40%), acetic (7%) and butyric acids (1%). An interaction between lipid sources and lysophospholipids was observed on faecal apparent digestibility of lipid (ADL), which improved with lysophospholipids addition in T diets. Broilers fed on S had higher ADL and faecal apparent digestibility of nitrogen-corrected gross energy (ADGE N ). It was not possible to demonstrate a significant treatment effect on the liver concentration of vitamins A and E, even with the differences in fatty acid profile between S and T. Enterobacteria values were below the detection threshold. Lysophospholipid supplementation reduced gram-positive cocci in T-fed birds. S diets promoted lower total anaerobe counts compared with T diets, independent of additives. S diets increased BW gain and feed:gain ratio in all evaluation periods. Lysophospholipids and organic acids improved feed:gain ratio at 1-21 d in T diets. Furthermore, main effects were observed for lysophospholipids and organic acids at 1-42 d, which increased BW gain and improved feed:gain ratio, respectively. No positive interactions between additives were found.

Antimicrobial packaging of chicken fillets based on the release of carvacrol from chitosan/cyclodextrin films.

PubMed

Higueras, Laura; López-Carballo, Gracia; Hernández-Muñoz, Pilar; Catalá, Ramón; Gavara, Rafael

2014-10-01

Chitosan/cyclodextrin films (CS:CD) incorporating carvacrol were obtained by casting, and conditioned at 23°C and 75% relative humidity prior to being immersed in liquid carvacrol until they reached sorption equilibrium. In a previous work, the in vitro antimicrobial activity of these films was studied. In this work, active films were used to inhibit microbial growth in packaged chicken breast fillets. Samples of CS:CD films loaded with carvacrol, of different sizes and thus with different quantities of antimicrobial agent, were stuck to the aluminium lid used to seal PP/EVOH/PP cups containing 25g of chicken fillets. These samples were stored for 9days at 4°C. The packages were hermetically sealed and it was confirmed that they provided an infinite barrier to carvacrol. The partition of the antimicrobial agent within the food/packaging system was analysed. The antimicrobial devices rapidly released a large percentage of the agent load, amounts that were gained by the adhesive coating of the lid and especially by the chicken fillets. The latter were the main sorbent phase, with average concentrations ranging between 200 and 5000mg/Kg during the period of storage. The microbiota of the packaged fresh chicken fillets - mesophiles, psychrophiles, Pseudomonas spp., enterobacteria, lactic acid bacteria and yeasts and fungi - were analysed and monitored during storage. A general microbial inhibition was observed, increasing with the size of the active device. Inhibition with a 24cm(2) device ranged from 0.3 log reductions against lactic acid bacteria to 1.8logs against yeasts and fungi. However, the large amount of antimicrobial that was sorbed or that reacted with the fillet caused an unacceptable sensory deterioration. These high sorption values are probably due to a great chemical compatibility between chicken proteins and carvacrol. Copyright © 2014 Elsevier B.V. All rights reserved.

Microbial Community Dynamics during Production of the Mexican Fermented Maize Dough Pozol

PubMed Central

ben Omar, Nabil; Ampe, Frédéric

2000-01-01

The dynamics of the microbial community responsible for the traditional fermentation of maize in the production of Mexican pozol was investigated by using a polyphasic approach combining (i) microbial enumerations with culture media, (ii) denaturing gradient gel electrophoresis (DGGE) fingerprinting of total community DNA with bacterial and eukaryotic primers and sequencing of partial 16S ribosomal DNA (rDNA) genes, (iii) quantification of rRNAs from dominant microbial taxa by using phylogenetic oligonucleotide probes, and (iv) analysis of sugars and fermentation products. A Streptococcus species dominated the fermentation and accounted for between 25 and 75% of the total flora throughout the process. Results also showed that the initial epiphytic aerobic microflora was replaced in the first 2 days by heterofermentative lactic acid bacteria (LAB), including a close relative of Lactobacillus fermentum, producing lactic acid and ethanol; this heterolactic flora was then progressively replaced by homofermentative LAB (mainly close relatives of L. plantarum, L. casei, and L. delbrueckii) which continued acidification of the maize dough. At the same time, a very diverse community of yeasts and fungi developed, mainly at the periphery of the dough. The analysis of the DGGE patterns obtained with bacterial and eukaryotic primers targeting the 16S and 18S rDNA genes clearly demonstrated that there was a major shift in the community structure after 24 h and that high biodiversity—according to the Shannon-Weaver index—was maintained throughout the process. These results proved that a relatively high number of species, at least six to eight, are needed to perform this traditional lactic acid fermentation. The presence of Bifidobacterium, Enterococcus, and enterobacteria suggests a fecal origin of some important pozol microorganisms. Overall, the results obtained with different culture-dependent or -independent techniques clearly confirmed the importance of developing a

Entner–Doudoroff pathway for sulfoquinovose degradation in Pseudomonas putida SQ1

PubMed Central

Felux, Ann-Katrin; Spiteller, Dieter; Klebensberger, Janosch; Schleheck, David

2015-01-01

Sulfoquinovose (SQ; 6-deoxy-6-sulfoglucose) is the polar head group of the plant sulfolipid SQ-diacylglycerol, and SQ comprises a major proportion of the organosulfur in nature, where it is degraded by bacteria. A first degradation pathway for SQ has been demonstrated recently, a “sulfoglycolytic” pathway, in addition to the classical glycolytic (Embden–Meyerhof) pathway in Escherichia coli K-12; half of the carbon of SQ is abstracted as dihydroxyacetonephosphate (DHAP) and used for growth, whereas a C3-organosulfonate, 2,3-dihydroxypropane sulfonate (DHPS), is excreted. The environmental isolate Pseudomonas putida SQ1 is also able to use SQ for growth, and excretes a different C3-organosulfonate, 3-sulfolactate (SL). In this study, we revealed the catabolic pathway for SQ in P. putida SQ1 through differential proteomics and transcriptional analyses, by in vitro reconstitution of the complete pathway by five heterologously produced enzymes, and by identification of all four organosulfonate intermediates. The pathway follows a reaction sequence analogous to the Entner–Doudoroff pathway for glucose-6-phosphate: It involves an NAD+-dependent SQ dehydrogenase, 6-deoxy-6-sulfogluconolactone (SGL) lactonase, 6-deoxy-6-sulfogluconate (SG) dehydratase, and 2-keto-3,6-dideoxy-6-sulfogluconate (KDSG) aldolase. The aldolase reaction yields pyruvate, which supports growth of P. putida, and 3-sulfolactaldehyde (SLA), which is oxidized to SL by an NAD(P)+-dependent SLA dehydrogenase. All five enzymes are encoded in a single gene cluster that includes, for example, genes for transport and regulation. Homologous gene clusters were found in genomes of other P. putida strains, in other gamma-Proteobacteria, and in beta- and alpha-Proteobacteria, for example, in genomes of Enterobacteria, Vibrio, and Halomonas species, and in typical soil bacteria, such as Burkholderia, Herbaspirillum, and Rhizobium. PMID:26195800

Simultaneous occurrence of MRSA and ESBL-producing Enterobacteriaceae on pig farms and in nasal and stool samples from farmers.

PubMed

Fischer, Julia; Hille, Katja; Ruddat, Inga; Mellmann, Alexander; Köck, Robin; Kreienbrock, Lothar

2017-02-01

Methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL) producing enterobacteria (ESBL-E) have emerged in livestock. This study prospectively investigates the prevalence of MRSA and ESBL-E on pig farms and in nasal and stool samples from farmers and compares molecular characteristics of these ESBL-E isolates. In 2014, samples were derived at 51 pig farms in Germany. Per farm, five dust and five fecal samples were collected; one nasal and one stool sample were retrieved from farmers. ESBL-E isolates from humans and environmental isolates from the respective farms were characterized using whole genome sequencing for classical multilocus sequence typing (MLST), determination of ESBL-encoding genes and an ad hoc core genome MLST (cgMLST) analysis. MRSA and ESBL-E were detected on 49 (96%) and 31 (61%) of the farms, respectively; in most cases (59%) simultaneously. Nasal MRSA carriage was detected in 72 of 85 (84.7%) farmers and five of 84 (6.0%) farmers carried ESBL-E. ESBL-Escherichia coli isolates from farmers belonged to MLST STs/ESBL-genes ST10/CTX-M-1, ST196/TEM-52, ST278/TEM-52, ST410/CTX-M-15 and ST453/CTX-M-1. In one case, the human ESBL-E isolate was clonally identical to isolates from the farm environment; in the other four cases typing results indicated potential exchange of resistance determinants between human and environmental isolates, but, comparing the isolates within a minimum spanning tree indicated differences in cgMLST-patterns between the farms (p=0.076). This study demonstrated rectal ESBL-E carriage rates among farmers, which were similar to those in the general population. Molecular typing suggested that cross-transmission between the farmers and the farm environment is possible. Copyright © 2016 Elsevier B.V. All rights reserved.

Clinical mastitis in ewes; bacteriology, epidemiology and clinical features.

PubMed

Mørk, Tormod; Waage, Steinar; Tollersrud, Tore; Kvitle, Bjørg; Sviland, Ståle

2007-09-24

Clinical mastitis is an important disease in sheep. The objective of this work was to identify causal bacteria and study certain epidemiological and clinical features of clinical mastitis in ewes kept for meat and wool production. The study included 509 ewes with clinical mastitis from 353 flocks located in 14 of the 19 counties in Norway. Clinical examination and collection of udder secretions were carried out by veterinarians. Pulsed-field gel electrophoresis (PFGE) was performed on 92 Staphylococcus aureus isolates from 64 ewes. S. aureus was recovered from 65.3% of 547 clinically affected mammary glands, coagulase-negative staphylococci from 2.9%, enterobacteria, mainly Escherichia coli, from 7.3%, Streptococcus spp. from 4.6%, Mannheimia haemolytica from 1.8% and various other bacteria from 4.9%, while no bacteria were cultured from 13.2% of the samples. Forty percent of the ewes with unilateral clinical S. aureus mastitis also had a subclinical S. aureus infection in the other mammary gland. Twenty-four of 28 (86%) pairs of S. aureus isolates obtained from clinically and subclinically affected mammary glands of the same ewe were indistinguishable by PFGE. The number of identical pairs was significantly greater than expected, based on the distribution of different S. aureus types within the flocks. One-third of the cases occurred during the first week after lambing, while a second peak was observed in the third week of lactation. Gangrene was present in 8.8% of the clinically affected glands; S. aureus was recovered from 72.9%, Clostridium perfringens from 6.3% and E. coli from 6.3% of the secretions from such glands. This study shows that S. aureus predominates as a cause of clinical ovine mastitis in Norway, also in very severe cases. Results also indicate that S. aureus is frequently spread between udder halves of infected ewes.

Splenda alters gut microflora and increases intestinal p-glycoprotein and cytochrome p-450 in male rats.

PubMed

Abou-Donia, Mohamed B; El-Masry, Eman M; Abdel-Rahman, Ali A; McLendon, Roger E; Schiffman, Susan S

2008-01-01

Splenda is comprised of the high-potency artificial sweetener sucralose (1.1%) and the fillers maltodextrin and glucose. Splenda was administered by oral gavage at 100, 300, 500, or 1000 mg/kg to male Sprague-Dawley rats for 12-wk, during which fecal samples were collected weekly for bacterial analysis and measurement of fecal pH. After 12-wk, half of the animals from each treatment group were sacrificed to determine the intestinal expression of the membrane efflux transporter P-glycoprotein (P-gp) and the cytochrome P-450 (CYP) metabolism system by Western blot. The remaining animals were allowed to recover for an additional 12-wk, and further assessments of fecal microflora, fecal pH, and expression of P-gp and CYP were determined. At the end of the 12-wk treatment period, the numbers of total anaerobes, bifidobacteria, lactobacilli, Bacteroides, clostridia, and total aerobic bacteria were significantly decreased; however, there was no significant treatment effect on enterobacteria. Splenda also increased fecal pH and enhanced the expression of P-gp by 2.43-fold, CYP3A4 by 2.51-fold, and CYP2D1 by 3.49-fold. Following the 12-wk recovery period, only the total anaerobes and bifidobacteria remained significantly depressed, whereas pH values, P-gp, and CYP3A4 and CYP2D1 remained elevated. These changes occurred at Splenda dosages that contained sucralose at 1.1-11 mg/kg (the US FDA Acceptable Daily Intake for sucralose is 5 mg/kg). Evidence indicates that a 12-wk administration of Splenda exerted numerous adverse effects, including (1) reduction in beneficial fecal microflora, (2) increased fecal pH, and (3) enhanced expression levels of P-gp, CYP3A4, and CYP2D1, which are known to limit the bioavailability of orally administered drugs.

Retrospective and prospective evaluation of the Carbapenem inactivation method for the detection of carbapenemase-producing Enterobacteriaceae

PubMed Central

Gauthier, Lauraine; Dortet, Laurent; Naas, Thierry

2017-01-01

Background There is an urgent need for accurate and rapid diagnostic tests to identify carbapenemase producing enterobacteria (CPE). Here, we have evaluated the Carbapenem Inactivation Method (CIM) test to detect CPEs from cultured colonies. Methods A total of 256 enterobacterial isolates were used to evaluate the performance of the CIM in comparison to Carba NP test and molecular detection used a reference method. Ninety three well-characterized isolates (including 29 non-CPE and 63 CPEs of worldwide origin) with decreased susceptibility to at least one carbapenem were used to (i) evaluate the efficacy of CIM test and (ii) to compare it to the Carba NP test. We also tested different carbapenems to determine the best substrate for this test. Finally, the CIM test was then evaluated prospectively against 164 isolates referred to the French National Reference Center (NRC) for Antimicrobial Resistance from may 2016 to july 2016. Results Based on the results of this retrospective study, sensitivity and specificity of the CIM and the Carba NP test were 92.1% and 100%, respectively. We demonstrated that the meropenem was the best substrate to perform the CIM test since sensitivity and specificity were 81.1% and 100% using ertapenem disk, and 100% and 65,6% using imipenem disk, and respectively. Taking in account the results of retrospective and prospective studies, CIM and Carba NP tests have similar sensitivity, specificity, positive predictive value and negative predictive values being 96.3%, 98.9%, 99.0% and 98.4% for the CIM test versus 96.9%, 100%, 100% and 100% for the Carba NP test. Conclusions Our results confirm that the CIM test may be a useful tool for the reliable confirmation of carbapenemase-activity in enterobacterial isolates, especially in clinical microbiological laboratories with limited resources, no trained personnel, and no specialized equipment. PMID:28158310

Fermentation of African kale (Brassica carinata) using L. plantarum BFE 5092 and L. fermentum BFE 6620 starter strains.

PubMed

Oguntoyinbo, Folarin A; Cho, Gyu-Sung; Trierweiler, Bernhard; Kabisch, Jan; Rösch, Niels; Neve, Horst; Bockelmann, Wilhelm; Frommherz, Lara; Nielsen, Dennis S; Krych, Lukasz; Franz, Charles M A P

2016-12-05

Vegetables produced in Africa are sources of much needed micronutrients and fermentation is one way to enhance the shelf life of these perishable products. To prevent post-harvest losses and preserve African leafy vegetables, Lactobacillus plantarum BFE 5092 and Lactobacillus fermentum BFE 6620 starter strains were investigated for their application in fermentation of African kale (Brassica carinata) leaves. They were inoculated at 1×10 7 cfu/ml and grew to a maximum level of 10 8 cfu/ml during 24h submerged fermentation. The strains utilized simple sugars (i.e., glucose, fructose, and sucrose) in the kale to quickly reduce the pH from pH6.0 to pH3.6 within 24h. The strains continued to produce both d and l lactic acid up to 144h, reaching a maximum concentration of 4.0g/l. Fermentations with pathogens inoculated at 10 4 cfu/ml showed that the quick growth of the starters inhibited the growth of Listeria monocytogenes and Salmonella Enteritidis, as well as other enterobacteria. Denaturing gradient gel electrophoresis and 16S rRNA gene (V3-V4-region) amplicon sequencing showed that in the spontaneous fermentations a microbial succession took place, though with marked differences in biodiversity from fermentation to fermentation. The fermentations inoculated with starters however were clearly dominated by both the inoculated strains throughout the fermentations. RAPD-PCR fingerprinting showed that the strains established themselves at approx. equal proportions. Although vitamins C, B 1 and B 2 decreased during the fermentation, the final level of vitamin C in the product was an appreciable concentration of 35mg/100g. In conclusion, controlled fermentation of kale offers a promising avenue to prevent spoilage and improve the shelf life and safety. Copyright © 2016 Elsevier B.V. All rights reserved.

Oral and Anal Vaccination Confers Full Protection against Enteric Redmouth Disease (ERM) in Rainbow Trout

PubMed Central

Ohtani, Maki; Strøm, Helene Kragelund; Raida, Martin Kristian

2014-01-01

The effect of oral vaccines against bacterial fish diseases has been a topic for debate for decades. Recently both M-like cells and dendritic cells have been discovered in the intestine of rainbow trout. It is therefore likely that antigens reaching the intestine can be taken up and thereby induce immunity in orally vaccinated fish. The objective of this project was to investigate whether oral and anal vaccination of rainbow trout induces protection against an experimental waterborne infection with the pathogenic enterobacteria Yersinia ruckeri O1 biotype 1 the causative agent of enteric redmouth disease (ERM). Rainbow trout were orally vaccinated with AquaVac ERM Oral (MERCK Animal Health) or an experimental vaccine bacterin of Y. ruckeri O1. Both vaccines were tested with and without a booster vaccination four months post the primary vaccination. Furthermore, two groups of positive controls were included, one group receiving the experimental oral vaccine in a 50 times higher dose, and the other group receiving a single dose administered anally in order to bypass the stomach. Each group was bath challenged with 6.3×108 CFU/ml Y. ruckeri, six months post the primary vaccination. The challenge induced significant mortality in all the infected groups except for the groups vaccinated anally with a single dose or orally with the high dose of bacterin. Both of these groups had 100% survival. These results show that a low dose of Y. ruckeri bacterin induces full protection when the bacterin is administered anally. Oral vaccination also induces full protection, however, at a dose 50 times higher than if the fish were to be vaccinated anally. This indicates that much of the orally fed antigen is digested in the stomach before it reaches the second segment of the intestine where it can be taken up as immunogenic antigens and presented to lymphocytes. PMID:24705460

Multiparametric Profiling for Identification of Chemosensitizers against Gram-Negative Bacteria

PubMed Central

Lôme, Vincent; Brunel, Jean-Michel; Pagès, Jean-Marie; Bolla, Jean-Michel

2018-01-01

Antibiotic resistance is now a worldwide therapeutic problem. Since the beginning of anti-infectious treatment bacteria have rapidly shown an incredible ability to develop and transfer resistance mechanisms. In the last decades, the design variation of pioneer bioactive molecules has strongly improved their activity and the pharmaceutical companies partly won the race against the clock. Since the 1980s, the new classes of antibiotics that emerged were mainly directed to Gram-positive bacteria. Thus, we are now facing to multidrug-resistant Gram-negative bacteria, with no therapeutic options to deal with them. These bacteria are mainly resistant because of their double membrane that conjointly impairs antibiotic accumulation and extrudes these molecules when entered. The main challenge is to allow antibiotics to cross the impermeable envelope and reach their targets. One promising solution would be to associate, in a combination therapy, a usual antibiotic with a non-antibiotic chemosensitizer. Nevertheless, for effective drug discovery, there is a prominent lack of tools required to understand the rules of permeation and accumulation into Gram-negative bacteria. By the use of a multidrug-resistant enterobacteria, we introduce a high-content screening procedure for chemosensitizers discovery by quantitative assessment of drug accumulation, alteration of barriers, and deduction of their activity profile. We assembled and analyzed a control chemicals library to perform the proof of concept. The analysis was based on real-time monitoring of the efflux alteration and measure of the influx increase in the presence of studied compounds in an automatized bio-assay. Then, synergistic activity of compounds with an antibiotic was studied and kinetic data reduction was performed which led to the calculation of a score for each barrier to be altered. PMID:29556218

Protective effect of lafutidine, a histamine H2 receptor antagonist, against loxoprofen-induced small intestinal lesions in rats.

PubMed

Amagase, Kikuko; Ochi, Akimu; Sugihara, Tetsuya; Kato, Shinichi; Takeuchi, Koji

2010-05-01

We examined the effect of lafutidine, a histamine H(2) receptor antagonist with a mucosal protective action mediated by capsaicin-sensitive sensory neurons (CSN), on intestinal lesions produced by loxoprofen administration in rats. Animals were given loxoprofen (10-100 mg/kg p.o.) and killed 24 h later. Lafutidine (10 and 30 mg/kg), cimetidine (100 mg/kg) or famotidine (30 mg/kg) was given twice p.o. at 0.5 h before and 6 h after loxoprofen. Omeprazole (100 mg/kg) was given p.o. once 0.5 h before. Ampicillin (800 mg/kg) was given p.o. twice at 24 h and 0.5 h before loxoprofen, while 16,16-dimethyl prostaglandin E(2) (dmPGE(2); 0.01 mg/kg) was given i.v. twice at 5 min before and 6 h after. Loxoprofen dose-dependently produced hemorrhagic lesions in the small intestine, accompanied by invasion of enterobacteria and increased inducible nitric oxide synthase (iNOS) expression as well as myeloperoxidase activity in the mucosa. The ulcerogenic response to loxoprofen (60 mg/kg) was significantly prevented by lafutidine (30 mg/kg), similar to dmPGE(2) and ampicillin, and the effect of lafutidine was totally attenuated by ablation of CSN. Neither cimetidine, famotidine nor omeprazole had a significant effect against these lesions. Lafutidine alone increased mucus secretion and reverted the decreased mucus response to loxoprofen, resulting in suppression of bacterial invasion and iNOS expression. In addition, loxoprofen downregulated Muc2 expression, and this response was totally reversed by lafutidine mediated by CSN. Lafutidine protects the small intestine against loxoprofen-induced lesions, essentially mediated by the CSN, and this effect may be functionally associated with increased Muc2 expression/mucus secretion, an important factor in the suppression of bacterial invasion.

Isolation, genome sequencing and functional analysis of two T7-like coliphages of avian pathogenic Escherichia coli.

PubMed

Chen, Mianmian; Xu, Juntian; Yao, Huochun; Lu, Chengping; Zhang, Wei

2016-05-10

Avian pathogenic Escherichia coli (APEC) causes colibacillosis, which results in significant economic losses to the poultry industry worldwide. Due to the drug residues and increased antibiotic resistance caused by antibiotic use, bacteriophages and other alternative therapeutic agents are expected to control APEC infection in poultry. Two APEC phages, named P483 and P694, were isolated from the feces from the farmers market in China. We then studied their biological properties, and carried out high-throughput genome sequencing and homology analyses of these phages. Assembly results of high-throughput sequencing showed that the structures of both P483 and P694 genomes consist of linear and double-stranded DNA. Results of the electron microscopy and homology analysis revealed that both P483 and P694 belong to T7-like virus which is a member of the Podoviridae family of the Caudovirales order. Comparative genomic analysis showed that most of the predicted proteins of these two phages showed strongest sequence similarity to the Enterobacteria phages BA14 and 285P, Erwinia phage FE44, and Kluyvera phage Kvp1; however, some proteins such as gp0.6a, gp1.7 and gp17 showed lower similarity (<85%) with the homologs of other phages in the T7 subgroup. We also found some unique characteristics of P483 and P694, such as the two types of the genes of P694 and no lytic activity of P694 against its host bacteria in liquid medium. Our results serve to further our understanding of phage evolution of T7-like coliphages and provide the potential application of the phages as therapeutic agents for the treatment of diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

Fecal Calprotectin Levels Are Closely Correlated with the Absence of Relevant Mucosal Lesions in Postoperative Crohn's Disease.

PubMed

Garcia-Planella, Esther; Mañosa, Míriam; Cabré, Eduard; Marín, Laura; Gordillo, Jordi; Zabana, Yamile; Boix, Jaume; Sáinz, Sergio; Domènech, Eugeni

2016-12-01

Fecal calprotectin (FC) is the best noninvasive biomarker of disease activity in inflammatory bowel disease. Its correlation with endoscopic mucosal lesions could save inconvenient, expensive, and repeated endoscopic examinations in particular clinical settings. To assess the correlation between FC and the existence and severity of endoscopic postoperative recurrence (POR), a group of clinically stable outpatients with Crohn's disease for whom an ileocolonoscopy was routinely planned to assess POR were invited to collect a stool sample before starting bowel cleansing to measure FC. POR was graded by means of Rutgeerts endoscopic score. One hundred nineteen ileocolonoscopies were included, 42% with endoscopic POR. FC was significantly lower in the absence of endoscopic POR and in the absence of any endoscopic lesion. The area under the receiver operating characteristic curve was 0.76 (95% confidence interval, 0.68-0.85) for the diagnosis of the absence of lesions and 0.75 (95% confidence interval, 0.66-0.84) for endoscopic POR. Better sensitivity and negative predictive value were observed when combining FC and serum C-reactive protein (CRP), leading to a sensitivity of 82%, a specificity of 53%, and negative and positive predictive values of 81% and 54%, respectively, for the prediction of endoscopic POR with a combination of FC 100 μg/g and CRP 5 mg/L cutoff values. FC correlates closely with endoscopic POR in clinically stable postoperative patients with Crohn's disease and, when used in combination with CRP, might save endoscopic examinations and allow for a high-grade suspicion of endoscopic POR in the long-term monitoring of these patients.

Anti-inflammatory, Analgesic and Antiulcer properties of Porphyra vietnamensis.

PubMed

Bhatia, Saurabh; Sharma, Kiran; Sharma, Ajay; Nagpal, Kalpana; Bera, Tanmoy

2015-01-01

Aim of the present work was to investigate the anti-inflammatory, analgesic and antiulcer effects of red seaweed Porphyra vietnamensis (P. vietnamenis). Aqueous (POR) and alcoholic (PE) fractions were successfully isolated from P. vietnamenis. Further biological investigations were performed using a classic test of paw edema induced by carrageenan, writhing induced by acetic acid, hot plate method and naproxen induced gastro-duodenal ulcer. Among the fractions POR showed better activity. POR and PE significantly (p < 0.05) reduced carrageenan induced paw edema in a dose dependent manner. In the writhing test POR significantly (p < 0.05) reduced abdominal writhes than PE. In hot plate method POR showed better analgesic activity than PE. POR showed comparable ulcers reducing potential (p<0.01) to that of omeprazole, and has more ulcer reducing potential then PE. The results of this study demonstrated that P. vietnamenis aqueous fraction possesses biological activity that is close to the standards taken for the treatment of peripheral painful or/and inflammatory and ulcer conditions.

76 FR 24857 - Fresh Garlic From the People's Republic of China: Preliminary Intent To Rescind New Shipper Reviews

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-03

... sales are not bona fide. As such, we are preliminarily rescinding the NSR for Shenzhen Bainong and... sale or entry during the original, unextended POR, and therefore we are preliminarily rescinding the...-annual NSR POR. When the sale of the subject merchandise occurs within the POR specified by the...

The production process of "Étude sur le Rein des Urinaires", doctoral thesis of Joaquin María Albarrán at the Faculty of Medicine in Paris.

PubMed

Fernández-Arias, M; Otero, I; Pérez-Albacete, M; Fariña, L A; Angulo, J C

2014-01-01

infection, bacteriemia, renal failure sepsis and patient death. The evolution of pyelonephritis to perinephritis and perinephric abscess was masterly interpreted, with new description of ascending infection and lymphatic peritubular dissemination of bacteria. The differences detected between written and printed work are numerous and can be explained by the corrections of Prof. Guyon before definite presentation and the technical process to perform the lithographs. Copyright © 2013 AEU. Published by Elsevier Espana. All rights reserved.

An ortholog of farA of Aspergillus nidulans is implicated in the transcriptional activation of genes involved in fatty acid utilization in the yeast Yarrowia lipolytica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poopanitpan, Napapol; Kobayashi, Satoshi; Fukuda, Ryouichi

2010-11-26

Research highlights: {yields} POR1 is a Yarrowia lipolytica ortholog of farA involved in fatty acid response in A. nidulans. {yields} Deletion of POR1 caused growth defects on fatty acids. {yields} {Delta}por1 strain exhibited defects in the induction of genes involved in fatty acid utilization. -- Abstract: The yeast Yarrowia lipolytica effectively utilizes hydrophobic substrates such as fatty acids and n-alkanes. To identify a gene(s) regulating fatty acid utilization in Y. lipolytica, we first studied homologous genes to OAF1 and PIP2 of Saccharomyces cerevisiae, but their disruption did not change growth on oleic acid at all. We next characterized a Y.more » lipolytica gene, POR1 (primary oleate regulator 1), an ortholog of farA encoding a transcriptional activator that regulates fatty acid utilization in Aspergillus nidulans. The deletion mutant of POR1 was defective in the growth on various fatty acids, but not on glucose, glycerol, or n-hexadecane. It exhibited slight defect on n-decane. The transcriptional induction of genes involved in {beta}-oxidation and peroxisome proliferation by oleate was distinctly diminished in the {Delta}por1 strains. These data suggest that POR1 encodes a transcriptional activator widely regulating fatty acid metabolism in Y. lipolytica.« less

NADPH–Cytochrome P450 Oxidoreductase: Roles in Physiology, Pharmacology, and Toxicology

PubMed Central

Ding, Xinxin; Wolf, C. Roland; Porter, Todd D.; Pandey, Amit V.; Zhang, Qing-Yu; Gu, Jun; Finn, Robert D.; Ronseaux, Sebastien; McLaughlin, Lesley A.; Henderson, Colin J.; Zou, Ling; Flück, Christa E.

2013-01-01

This is a report on a symposium sponsored by the American Society for Pharmacology and Experimental Therapeutics and held at the Experimental Biology 2012 meeting in San Diego, California, on April 25, 2012. The symposium speakers summarized and critically evaluated our current understanding of the physiologic, pharmacological, and toxicological roles of NADPH–cytochrome P450 oxidoreductase (POR), a flavoprotein involved in electron transfer to microsomal cytochromes P450 (P450), cytochrome b5, squalene mono-oxygenase, and heme oxygenase. Considerable insight has been derived from the development and characterization of mouse models with conditional Por deletion in particular tissues or partial suppression of POR expression in all tissues. Additional mouse models with global or conditional hepatic deletion of cytochrome b5 are helping to clarify the P450 isoform- and substrate-specific influences of cytochrome b5 on P450 electron transfer and catalytic function. This symposium also considered studies using siRNA to suppress POR expression in a hepatoma cell–culture model to explore the basis of the hepatic lipidosis phenotype observed in mice with conditional deletion of Por in liver. The symposium concluded with a strong translational perspective, relating the basic science of human POR structure and function to the impacts of POR genetic variation on human drug and steroid metabolism. PMID:23086197

Influence of cytochrome P450 oxidoreductase genetic polymorphisms on CYP1A2 activity and inducibility by smoking.

PubMed

Dobrinas, Maria; Cornuz, Jacques; Pedrido, Leticia; Eap, Chin B

2012-02-01

Cytochrome P4501A2 (CYP1A2) presents a high interindividual variability in its activity and also in its inducibility by smoking. Cytochrome P450 oxidoreductase (POR) is an electron transfer protein that catalyzes the activity of several cytochromes P450. We aimed to study the influence of POR genetic polymorphisms on CYP1A2 activity while smoking and after smoking cessation, as well as on CYP1A2 inducibility. CYP1A2 activity was determined by the paraxanthine/caffeine ratio in 184 smokers and in 113 of these smokers who were abstinent during a 4-week period. Participants were genotyped for POR rs17148944G>A, rs10239977C>T, rs3815455C>T, rs2286823G>A, rs2302429G>A, and rs1057868C>T (POR*28) polymorphisms. While smoking, none of the tested POR polymorphisms showed a significant influence on CYP1A2 activity. After smoking cessation, significantly higher CYP1A2 activity was found in POR rs2302429A carriers (P=0.038) and in carriers of rs17148944G-rs10239977C-rs3815455T-rs2286823G-rs2302429A-rs1057868T haplotype (P=0.038), whereas carriers of POR rs2286823A (P=0.031) and of the rs17148944G-rs10239977C-rs3815455C-rs2286823A-rs2302429G-rs1057868C haplotype (P=0.031) had decreased CYP1A2 activity. In the complete regression model, only POR rs2302429G>A showed a significant effect (P=0.017). No influence of POR genotypes or haplotypes was observed on the inducibility of CYP1A2. POR genetic polymorphisms influence CYP1A2 basal but not induced activity and do not seem to influence CYP1A2 inducibility. Future work is warranted to identify other clinical and genetic factors that may explain the variability in CYP1A2 activity and inducibility by smoking.

Deletion of P399{sub E}401 in NADPH cytochrome P450 oxidoreductase results in partial mixed oxidase deficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flueck, Christa E., E-mail: christa.flueck@dkf.unibe.ch; Mallet, Delphine; Hofer, Gaby

2011-09-09

Highlights: {yields} Mutations in human POR cause congenital adrenal hyperplasia. {yields} We are reporting a novel 3 amino acid deletion mutation in POR P399{sub E}401del. {yields} POR mutation P399{sub E}401del decreased P450 activities by 60-85%. {yields} Impairment of steroid metabolism may be caused by multiple hits. {yields} Severity of aromatase inhibition is related to degree of in utero virilization. -- Abstract: P450 oxidoreductase (POR) is the electron donor for all microsomal P450s including steroidogenic enzymes CYP17A1, CYP19A1 and CYP21A2. We found a novel POR mutation P399{sub E}401del in two unrelated Turkish patients with 46,XX disorder of sexual development. Recombinant PORmore » proteins were produced in yeast and tested for their ability to support steroid metabolizing P450 activities. In comparison to wild-type POR, the P399{sub E}401del protein was found to decrease catalytic efficiency of 21-hydroxylation of progesterone by 68%, 17{alpha}-hydroxylation of progesterone by 76%, 17,20-lyase action on 17OH-pregnenolone by 69%, aromatization of androstenedione by 85% and cytochrome c reduction activity by 80%. Protein structure analysis of the three amino acid deletion P399{sub E}401 revealed reduced stability and flexibility of the mutant. In conclusion, P399{sub E}401del is a novel mutation in POR that provides valuable genotype-phenotype and structure-function correlation for mutations in a different region of POR compared to previous studies. Characterization of P399{sub E}401del provides further insight into specificity of different P450s for interaction with POR as well as nature of metabolic disruptions caused by more pronounced effect on specific P450s like CYP17A1 and aromatase.« less

"Spider"-shaped porphyrins with conjugated pyridyl anchoring groups as efficient sensitizers for dye-sensitized solar cells.

PubMed

Stangel, Christina; Bagaki, Anthi; Angaridis, Panagiotis A; Charalambidis, Georgios; Sharma, Ganesh D; Coutsolelos, Athanasios G

2014-11-17

Two novel "spider-shaped" porphyrins, meso-tetraaryl-substituted 1PV-Por and zinc-metalated 1PV-Zn-Por, bearing four oligo(p-phenylenevinylene) (oPPV) pyridyl groups with long dodecyloxy chains on the phenyl groups, have been synthesized. The presence of four pyridyl groups in both porphyrins, which allow them to act as anchoring groups upon coordination to various Lewis acid sites, the conjugated oPPV bridges, which offer the possibility of electronic communication between the porphyrin core and the pyridyl groups, and the dodecyloxy groups, which offer the advantage of high solubility in a variety of organic solvents of different polarities and could prevent porphyrin aggregation, renders porphyrins 1PV-Por and 1PV-Zn-Por very promising sensitizers for dye-sensitized solar cells (DSSCs). Photophysical measurements, together with electrochemistry experiments and density functional theory calculations, suggest that both porphyrins have frontier molecular orbital energy levels that favor electron injection and dye regeneration in DSSCs. Solar cells sensitized by 1PV-Por and 1PV-Zn-Por were fabricated, and it was found that they show power conversion efficiencies (PCEs) of 3.28 and 5.12%, respectively. Photovoltaic measurements (J-V curves) together with incident photon-to-electron conversion efficiency spectra of the two cells reveal that the higher PCE value of the DSSC based on 1PV-Zn-Por is ascribed to higher short-circuit current (Jsc), open-circuit voltage (Voc), and dye loading values. Emission spectra and electrochemistry experiments suggest a greater driving force for injection of the photogenerated electrons into the TiO2 conduction band for 1PV-Zn-Por rather than its free-base analogue. Furthermore, electrochemical impedance spectroscopy measurements prove that the utilization of 1PV-Zn-Por as a sensitizer offers a high charge recombination resistance and, therefore, leads to a longer electron lifetime.

Anti-inflammatory, Analgesic and Antiulcer properties of Porphyra vietnamensis

PubMed Central

Bhatia, Saurabh; Sharma, Kiran; Sharma, Ajay; Nagpal, Kalpana; Bera, Tanmoy

2015-01-01

Objectives: Aim of the present work was to investigate the anti-inflammatory, analgesic and antiulcer effects of red seaweed Porphyra vietnamensis (P. vietnamenis). Materials and Methods: Aqueous (POR) and alcoholic (PE) fractions were successfully isolated from P. vietnamenis. Further biological investigations were performed using a classic test of paw edema induced by carrageenan, writhing induced by acetic acid, hot plate method and naproxen induced gastro-duodenal ulcer. Results: Among the fractions POR showed better activity. POR and PE significantly (p < 0.05) reduced carrageenan induced paw edema in a dose dependent manner. In the writhing test POR significantly (p < 0.05) reduced abdominal writhes than PE. In hot plate method POR showed better analgesic activity than PE. POR showed comparable ulcers reducing potential (p<0.01) to that of omeprazole, and has more ulcer reducing potential then PE. Conclusions: The results of this study demonstrated that P. vietnamenis aqueous fraction possesses biological activity that is close to the standards taken for the treatment of peripheral painful or/and inflammatory and ulcer conditions. PMID:25767759

La Resonancia J/$$\\psi$$ y Sus Implicaciones Para La Masa Del W (in Spanish)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanchez-Hernandez, Alberto

Es un placer agradecer a mi asesor el doctor Heriberto Castilla Valdez por brindarme sus conocimientos, experiencia y paciencia en el desarrollo de esta tesis; tambien quiero agradecer al profesor H.E. Fisk, por su apoyo econemico en mi estancia en Fermilab. De igual forma agradezco a los doctores Arturo Fernandez Telles, Miguel Angel Perez Angen y Rebeca Juarez Wisozka quienes me introdujeron al campo de la fisica experimental de altas energfas. Agradezco tambien a Maribel Rios Cruz, Ruben Flores Mendieta, Juan Morales Corona, Fabiola Vazquez Valencia, Salvador Carrillo Moreno y Cecilia Uribe Estrada por su amistad y compaiierismo durante elmore » desarrollo de mi maestria. Un especial agradecimiento a Ian Adam y Kina Denisenko por su valiosa ayuda, comentarios y discusiones durante mi estancia en Fermilab. Por ultimo quisiera agradecer a mis profesores, amigos y familiares quienes siempre me apoyaron y alentaron y al Consejo N acional de Ciencia y Tecnologfa asf como al Departamento de Fisica de Cinvestav por su apoyo econemlco.« less

Influence of the doping type and level on the morphology of porous Si formed by galvanic etching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pyatilova, O. V., E-mail: 5ilova87@gmail.com; Gavrilov, S. A.; Shilyaeva, Yu. I.

The formation of porous silicon (por-Si) layers by the galvanic etching of single-crystal Si samples (doped with boron or phosphorus) in an HF/C{sub 2}H{sub 5}OH/H{sub 2}O{sub 2} solution is investigated. The por-Si layers are analyzed by the capillary condensation of nitrogen and scanning electron microscopy (SEM). The dependences of the morphological characteristics of por-Si (pore diameter, specific surface area, pore volume, and thickness of the pore walls), which determine the por-Si combustion kinetics, on the dopant type and initial wafer resistivity are established.

Evidence for the bacterial origin of genes encoding fermentation enzymes of the amitochondriate protozoan parasite Entamoeba histolytica.

PubMed

Rosenthal, B; Mai, Z; Caplivski, D; Ghosh, S; de la Vega, H; Graf, T; Samuelson, J

1997-06-01

Entamoeba histolytica is an amitochondriate protozoan parasite with numerous bacterium-like fermentation enzymes including the pyruvate:ferredoxin oxidoreductase (POR), ferredoxin (FD), and alcohol dehydrogenase E (ADHE). The goal of this study was to determine whether the genes encoding these cytosolic E. histolytica fermentation enzymes might derive from a bacterium by horizontal transfer, as has previously been suggested for E. histolytica genes encoding heat shock protein 60, nicotinamide nucleotide transhydrogenase, and superoxide dismutase. In this study, the E. histolytica por gene and the adhE gene of a second amitochondriate protozoan parasite, Giardia lamblia, were sequenced, and their phylogenetic positions were estimated in relation to POR, ADHE, and FD cloned from eukaryotic and eubacterial organisms. The E. histolytica por gene encodes a 1,620-amino-acid peptide that contained conserved iron-sulfur- and thiamine pyrophosphate-binding sites. The predicted E. histolytica POR showed fewer positional identities to the POR of G. lamblia (34%) than to the POR of the enterobacterium Klebsiella pneumoniae (49%), the cyanobacterium Anabaena sp. (44%), and the protozoan Trichomonas vaginalis (46%), which targets its POR to anaerobic organelles called hydrogenosomes. Maximum-likelihood, neighbor-joining, and parsimony analyses also suggested as less likely E. histolytica POR sharing more recent common ancestry with G. lamblia POR than with POR of bacteria and the T. vaginalis hydrogenosome. The G. lamblia adhE encodes an 888-amino-acid fusion peptide with an aldehyde dehydrogenase at its amino half and an iron-dependent (class 3) ADH at its carboxy half. The predicted G. lamblia ADHE showed extensive positional identities to ADHE of Escherichia coli (49%), Clostridium acetobutylicum (44%), and E. histolytica (43%) and lesser identities to the class 3 ADH of eubacteria and yeast (19 to 36%). Phylogenetic analyses inferred a closer relationship of the E

First example of a modular porphyrinoid assembly capable of stabilizing different metal ions in a single molecular scaffold.

PubMed

Murugavel, Muthuchamy; Reddy, R V Ramana; Dey, Dhananjay; Sankar, Jeyaraman

2015-10-05

We report the synthesis and characterization of porphyrin-corrole-porphyrin (Por-Cor-Por) hybrids directly linked at the meso-meso positions for the first time. The stability and solubility of the trimer are carefully balanced by adding electron-withdrawing substituents to the corrole ring and sterically bulky groups on the porphyrins. The new hybrids are capable of stabilizing more than one metal ion in a single molecular scaffold. The versatility of the triad has been demonstrated by successfully stabilizing homo- (Ni) and heterotrinuclear (Ni-Cu-Ni) coordination motifs. The solid-state structure of the NiPor-CuCor-PorNi hybrid was revealed by single-crystal X-ray diffraction studies. The Ni(II) porphyrins are significantly ruffled and tilted by 83° from the plane of corrole. The robustness of the synthesized hybrids was reflected in the electrochemical investigations and the redox behaviour of the hybrids show that the oxidation processes are mostly corrole-centred. In particular it is worth noting that the Por-Cor-Por hybrid can further be manipulated due to the presence of substituent-free meso-positions on both the terminals. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Management of post-operative Crohn's disease in 2017: where do we go from here?

PubMed

Nguyen, Vu; Kanth, Rajan; Gazo, Joshua; Sorrentino, Dario

2016-11-01

Postoperative recurrence (POR) of Crohn's disease is common after surgical resection. How to best manage POR remains uncertain. Areas covered: In this review, we will first describe the natural course and the best modalities to diagnose this surgical sequela. We will then focus on the potential risk factors for relapse and highlight the main shortcomings in the current study designs and endoscopic and clinical scoring systems, which may partly explain the unexpected outcomes of recent clinical trials. Finally, we will propose a strategy to address the management of POR. Expert commentary: Anti-tumor necrosis factor (Anti-TNF) agents are the most effective therapy to prevent POR in Crohn's disease. Patient risk stratification and active monitoring with scheduled ileocolonoscopy are cornerstones of optimal POR management. Further studies are needed to address areas of uncertainty including timing and duration of therapy and the role of therapeutic drug monitoring in this setting.

Developing a military nurse scientist program of research: A military women's health exemplar.

PubMed

Trego, Lori Lyn

Developing a feasible, fundable, and sustainable program of research (POR) is an essential career goal in research. Nurse scientists can lay the foundation for a salient POR as early as during their doctoral studies. The ensuing years of postdoctoral experiences are informative as they expand their research skills and knowledge around their research area of interest. Following graduation from a doctoral research program, novice military nurse scientists (MNS) are placed in positions that are conducive to fostering a POR. Military organizational support and the rich experiences of peers and mentors facilitate early career development of MNS. The purpose of this article is to present a conceptual framework for research career development of the novice MNS. Using an exemplar POR in military women's health, the concepts are operationalized to illustrate how the military environment enhances the development of a successful POR. Copyright © 2017 Elsevier Inc. All rights reserved.

Association between arsenic exposure from drinking water and proteinuria: results from the Health Effects of Arsenic Longitudinal Study

PubMed Central

Chen, Yu; Parvez, Faruque; Liu, Mengling; Pesola, Gene R; Gamble, Mary V; Slavkovich, Vesna; Islam, Tariqul; Ahmed, Alauddin; Hasan, Rabiul; Graziano, Joseph H; Ahsan, Habibul

2011-01-01

Background Proteinuria has been recognized as a marker for an increased risk of chronic renal disease. It is unclear whether arsenic (As) exposure from drinking water is associated with proteinuria. Methods We evaluated the association between As exposure from drinking water and proteinuria in 11 122 participants in the Health Effects of Arsenic Longitudinal Study (HEALS). Proteinuria was detected by urinary dipstick tests at baseline and at 2-year intervals. As exposure variables included baseline well As and changes in urinary As during follow-up modelled as time-dependent variables in the analyses. Results At baseline, well As was positively related to prevalence of proteinuria; prevalence odds ratios (PORs) for proteinuria in increasing quintiles of well As (≤7, 8–39, 40–91, 92–179 and 180–864 µg/l) were 1.00 (ref), POR 0.99 [95% confidence interval (CI) 0.77–1.27], POR 1.23 (95% CI 0.97–1.57), POR 1.50 (95% CI 1.18–1.89) and POR 1.59 (95% CI 1.26–2.00) (P for trend <0.01). Hazard ratios for incidence of proteinuria were POR 0.83 (95% CI 0.67–1.03) and POR 0.91 (95% CI 0.74–1.12) for participants with a decreasing level of >70 and 17–70 µg/l in urinary As over time, respectively, and were POR 1.17 (95% CI 0.97–1.42) and POR 1.42 (95% CI 1.16–1.73) for participants with an increasing level of 16–68 and >68 µg/l in urinary As over time, respectively, compared with the group with relatively little changes in urinary As as the reference group (urinary As −16 to 15 µg/l). Conclusion The findings suggest that there are adverse effects of As exposure on the risk of proteinuria and the effects are modifiable by recent changes in As exposure. PMID:21343184

Recombinant Salivary Proteins of Phlebotomus orientalis are Suitable Antigens to Measure Exposure of Domestic Animals to Sand Fly Bites

PubMed Central

Sima, Michal; Ferencova, Blanka; Warburg, Alon; Rohousova, Iva; Volf, Petr

2016-01-01

Background Certain salivary proteins of phlebotomine sand flies injected into the host skin during blood-feeding are highly antigenic and elicit strong antibody-mediated immune responses in repeatedly-exposed hosts. These antibodies can be measured by enzyme-linked immuno sorbent assays (ELISAs) using salivary gland homogenates (SGHs) as the source of antigens and serve as a markers for exposure to biting sand flies. Large-scale screening for anti-sand fly saliva antibodies requires replacement of SGH with recombinant salivary proteins. In East Africa, Phlebotomus orientalis is the main vector of Leishmania donovani, a trypanosomatid parasite causing visceral leishmaniasis. We tested recombinant salivary proteins derived from Ph. orientalis saliva to study exposure of domestic animals to this sand fly species. Methodology/Principal Findings Antigenic salivary proteins from Ph. orientalis were identified by immunoblot and mass spectrometry. Recombinant apyrase rPorSP15, yellow-related protein rPorSP24, ParSP25-like protein rPorSP65, D7-related protein rPorSP67, and antigen 5-related protein rPorSP76 were tested using ELISA with sera of domestic animals from L. donovani foci in Ethiopia where Ph. orientalis is present. Our results highlighted recombinant yellow-related protein rPorSP24 as the most promising antigen, displaying a high positive correlation coefficient as well as good sensitivity and specificity when compared to SGH. This recombinant protein was the most suitable one for testing sera of dogs, sheep, and goats. In addition, a different antigen, rPorSP65 was found efficacious for testing canine sera. Conclusions/Significance Recombinant salivary proteins of Ph. orientalis, specifically rPorSP24, were shown to successfully substitute SGH in serological experiments to measure exposure of domestic animals to Ph. orientalis, the vector of L. donovani. The results suggest that rPorSP24 might be a suitable antigen for detecting anti-Ph. orientalis antibody

Recombinant Salivary Proteins of Phlebotomus orientalis are Suitable Antigens to Measure Exposure of Domestic Animals to Sand Fly Bites.

PubMed

Sima, Michal; Ferencova, Blanka; Warburg, Alon; Rohousova, Iva; Volf, Petr

2016-03-01

Certain salivary proteins of phlebotomine sand flies injected into the host skin during blood-feeding are highly antigenic and elicit strong antibody-mediated immune responses in repeatedly-exposed hosts. These antibodies can be measured by enzyme-linked immuno sorbent assays (ELISAs) using salivary gland homogenates (SGHs) as the source of antigens and serve as a markers for exposure to biting sand flies. Large-scale screening for anti-sand fly saliva antibodies requires replacement of SGH with recombinant salivary proteins. In East Africa, Phlebotomus orientalis is the main vector of Leishmania donovani, a trypanosomatid parasite causing visceral leishmaniasis. We tested recombinant salivary proteins derived from Ph. orientalis saliva to study exposure of domestic animals to this sand fly species. Antigenic salivary proteins from Ph. orientalis were identified by immunoblot and mass spectrometry. Recombinant apyrase rPorSP15, yellow-related protein rPorSP24, ParSP25-like protein rPorSP65, D7-related protein rPorSP67, and antigen 5-related protein rPorSP76 were tested using ELISA with sera of domestic animals from L. donovani foci in Ethiopia where Ph. orientalis is present. Our results highlighted recombinant yellow-related protein rPorSP24 as the most promising antigen, displaying a high positive correlation coefficient as well as good sensitivity and specificity when compared to SGH. This recombinant protein was the most suitable one for testing sera of dogs, sheep, and goats. In addition, a different antigen, rPorSP65 was found efficacious for testing canine sera. Recombinant salivary proteins of Ph. orientalis, specifically rPorSP24, were shown to successfully substitute SGH in serological experiments to measure exposure of domestic animals to Ph. orientalis, the vector of L. donovani. The results suggest that rPorSP24 might be a suitable antigen for detecting anti-Ph. orientalis antibody-mediated reactions also in other host species.

A Comparison Between PSRK and GERG-2004 Equation of State for Simulation of Non-Isothermal Compressible Natural Gases Mixed with Hydrogen in Pipelines / Porównanie równań stanu opracowanych według metody PSRK oraz GERG-2004 wykorzystanych do symulacji zachowania ściśliwych mieszanin gazu ziemnego i wodoru w rurociągach, w warunkach przepływów nie-izotermicznych

NASA Astrophysics Data System (ADS)

Uilhoorn, Frits E.

2013-06-01

In this work, the GERG-2004 equation of state based on a multi-fluid approximation explicit in the reduced Helmholtz energy is compared with the predictive Soave-Redlich-Kwong group contribution method. In the analysis, both equations of state are compared by simulating a non-isothermal transient flow of natural gas and mixed hydrogen-natural gas in pipelines. Besides the flow conditions also linepack-energy and energy consumption of the compressor station are computed. The gas flow is described by a set of partial differential equations resulting from the conservation of mass, momentum and energy. A pipeline section of the Yamal-Europe gas pipeline on Polish territory has been selected for the case study. W artykule dokonano porównania wyników uzyskanych przy wykorzystaniu równania stanu GERG- 2004 opartego na jawnym przybliżeniu wyników dla wielu cieczy w oparciu o zredukowaną energię Helmhotza oraz wyników uzyskanych w oparciu o metodę Soave-Redlich Kwonga. Obydwa równania stanu porównano poprzez przeprowadzenie symulacji stanów przejściowych przepływów gazu ziemnego oraz mieszanin gazu ziemnego i wodoru w rurociągach w warunkach przepływów nie-izotermicznych. Oprócz warunków przepływu, określono energię w napełnionym układzie oraz zużycie energii przez stację kompresora. Przepływ gazu opisano zbiorem równań różniczkowych cząstkowych, wyprowadzonych w oparciu o prawa zachowania masy, pędu i energii. Jako studium przypadku wybrano fragment rurociągu jamalskiego (Yamal- Europa) przebiegającego przez terytorium Polski.

Weathering resistance of thin plasma polymer films on pre-coated steel =

NASA Astrophysics Data System (ADS)

Serra, Ricardo Gil Henriques

O trabalho apresentado teve origem no projecto de investigacao “Tailored Thin Plasma Polymers Films for Surface Engineering of Coil Coated Steel”, financiado pelo Programa Europeu ECSC Steel Research. Sistemas de aco galvanizado pre-pintado em banda a base de poliester e poliuretano foram submetidos a um processo de polimerizacao por plasma onde um filme fino foi depositado de modo a modificar as propriedades de superficie. Foram usados reactores de catodo oco, microondas e radio frequencia para a deposicao do polimero fino. Os sistemas preparados foram analisados de modo a verificar a influencia do processo de polimerizacao por plasma na alteracao das propriedades barreira dos sistemas pre-pintados em banda. Foi estudado o efeito dos diferentes passos do processo de polimerizacao por plasma, bem como o efeito de diferentes variaveis operatorias. A mistura precursora foi variada de modo a modificar as propriedades da superficie de modo a poder vir a obter maior hidrofobicidade, maior resistencia a marcas digitais, bem como maior facilidade de limpeza. Os testes foram conduzidos em solucao de NaCl 0,5 M. Para o trabalho foram usadas tecnicas de analise da morfologia da superficie como Microscopia de Forca Atomica e Microscopia Electronica de Varrimento. As propriedades electroquimicas dos sistemas foram estudadas por Espectroscopia de Impedancia Electroquimica. A estrutura dos filmes gerados no processo de polimerizacao por plasma foi caracterizada por Microscopia de Transmissao Electronica. A modificacao das propriedades opticas devido ao processo de polimerizacao por plasma foi tambem obtida.

Prognosis and cost-effectiveness of IVF in poor responders according to the Bologna Criteria.

PubMed

Busnelli, Andrea; Somigliana, Edgardo

2018-02-01

Poor ovarian response (POR) to controlled ovarian hyperstimulation for in vitro fertilization (IVF) is one of the most challenging issue in the field of reproductive medicine. However, even if improving IVF outcome in poor responders (PORs) represents a main priority, the lack of a unique definition of POR has hampered research in this area. In order to overcome this impediment, an ESHRE Campus Workshop was organized in Bologna in 2010 and reached a consensus on the criteria for the diagnosis of POR ("Bologna Criteria"). In this review we aimed to estimate the prognostic potential of the ESHRE definition, to elucidate its possible weaknesses and to analyze the economic aspects of IVF in a population of poor responders (PORs). Available evidence confirmed that the Bologna criteria are able to select a population with a poor IVF prognosis thus supporting their validity. Nonetheless, different aspects of the definition have been criticized. The main points of debate concern the homogeneity of the population identified, the cut-off values chosen for the ovarian reserve tests and the risks factors other than age associated with POR. Data concerning the economic profile of IVF in PORs are scanty. The only published study on the argument showed that IVF in these cases is not cost-effective. However, considering the potential substantial impact of cost-effectiveness analyses on public health policies, there is the need for further and independent validations.

Estimación de pequeñas perturbaciones en satélites geocéntricos como un problema inverso

NASA Astrophysics Data System (ADS)

Zadunaisky, P. E.

El movimiento geocéntrico de un satélite artificial es simulado automáticamente por un sistema de ecuaciones diferenciales de segundo orden que incluyen dos funciones perturbadoras. La primera representa el segundo término del potencial gravitatorio de la Tierra y la segunda corresponde al frenado atmosférico. Asumiendo como conocidas, por hipótesis o por mediciones, la posición y velocidad del satélite en instantes sucesivos se estiman las perturbaciones a intervalos sucesivos por un método determinístico. Para ilustrar el método y comprobar la precisión de nuestros resultados hemos simulado dos ejemplos incluyendo valores conocidos de las perturbaciones que luego comparamos con los resultados de nuestro método. El método puede aplicarse por ejemplo para el intervalo de una revolución satelital lo cual permitiría el diseño inmediato de una maniobra correctiva de la órbita satelital.

El Estado de los Bosques de Puerto Rico, 2003

Treesearch

Thomas J. Brandeis; Eileen H. Helmer; Sonja N. Oswalt

2003-01-01

La cobertura forestal de Puerto Rico sigue aumentando y ahora asciende a un 57 por ciento en la isla de Puerto Rico, 85 por ciento en Vieques y 88 por ciento en Culebra. Los bosques subtropicales secos ocupan 50 346 ha, 6832 ha, 2591 ha y 6217 ha en las islas de Puerto Rico, Vieques, Culebra y Mona, respectivamente. El bosque subtropical húmedo, la zona de vida...

"Power-on resets" in cardiac implantable electronic devices during magnetic resonance imaging.

PubMed

Higgins, John V; Sheldon, Seth H; Watson, Robert E; Dalzell, Connie; Acker, Nancy; Cha, Yong-Mei; Asirvatham, Samuel J; Kapa, Suraj; Felmlee, Joel P; Friedman, Paul A

2015-03-01

Magnetic resonance imaging (MRI) has been safely performed in some patients with cardiac implantable electronic devices (CIEDs) under careful monitoring and prespecified conditions. Pacemaker-dependent patients are often excluded, partly because of the potential for "power-on reset" (PoR), which can lead to a change from asynchronous to inhibited pacing with consequent inhibition of pacing due to electromagnetic interference during MRI. The purpose of this study was to review risk factors for PoR during MRI. A prospective study was performed between January 2008 and May 2013 in patients with CIEDs undergoing clinically indicated MRI. Eligible patients were not pacemaker dependent. Devices were interrogated before and after MRI, programmed to an asynchronous mode or an inhibition mode with tachyarrhythmia therapies turned off, and reprogrammed to their original settings after MRI. MRI scans (n = 256) were performed in 198 patients with non-MRI-conditional CIEDs between 2008 and 2013 (median age 66 years; interquartile range 57-77 years; 59% men). PoR occurred during 9 MRI scans (3.5%) in 8 patients. PoR was more frequent with Medtronic devices than with other generator brands (n = 9/139 vs 0/117 [6% vs 0%]; P = .005). Devices with PoR were all released before 2002 and were implanted from 1999 to 2004. Effects of PoR included a decrease in heart rate during MRI (n = 4) and transient anomalous battery life indication (n = 1). All devices functioned normally after MRI. PoR occurs infrequently but can cause deleterious changes in pacing mode and heart rate. MRI should not be performed in pacemaker-dependent patients with older at-risk generators. Continuous monitoring during MRI is essential because unrecognized PoR may inhibit pacing or accelerate battery depletion due to high pacing output. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Hospitalization costs of severe bacterial pneumonia in children: comparative analysis considering different costing methods.

PubMed

Nunes, Sheila Elke Araujo; Minamisava, Ruth; Vieira, Maria Aparecida da Silva; Itria, Alexander; Pessoa, Vicente Porfirio; Andrade, Ana Lúcia Sampaio Sgambatti de; Toscano, Cristiana Maria

2017-01-01

To determine and compare hospitalization costs of bacterial community-acquired pneumonia cases via different costing methods under the Brazilian Public Unified Health System perspective. Cost-of-illness study based on primary data collected from a sample of 59 children aged between 28 days and 35 months and hospitalized due to bacterial pneumonia. Direct medical and non-medical costs were considered and three costing methods employed: micro-costing based on medical record review, micro-costing based on therapeutic guidelines and gross-costing based on the Brazilian Public Unified Health System reimbursement rates. Costs estimates obtained via different methods were compared using the Friedman test. Cost estimates of inpatient cases of severe pneumonia amounted to R$ 780,70/$Int. 858.7 (medical record review), R$ 641,90/$Int. 706.90 (therapeutic guidelines) and R$ 594,80/$Int. 654.28 (Brazilian Public Unified Health System reimbursement rates). Costs estimated via micro-costing (medical record review or therapeutic guidelines) did not differ significantly (p=0.405), while estimates based on reimbursement rates were significantly lower compared to estimates based on therapeutic guidelines (p<0.001) or record review (p=0.006). Brazilian Public Unified Health System costs estimated via different costing methods differ significantly, with gross-costing yielding lower cost estimates. Given costs estimated by different micro-costing methods are similar and costing methods based on therapeutic guidelines are easier to apply and less expensive, this method may be a valuable alternative for estimation of hospitalization costs of bacterial community-acquired pneumonia in children. Determinar e comparar custos hospitalares no tratamento da pneumonia bacteriana adquirida na comunidade por diferentes metodologias de custeio, na perspectiva do Sistema Único de Saúde. Estudo de custo, com coleta de dados primários de uma amostra de 59 crianças com 28 dias a 35 meses de idade

The role of galectin-1 in in vitro and in vivo photodynamic therapy with a galactodendritic porphyrin.

PubMed

Pereira, Patrícia M R; Silva, Sandrina; Ramalho, José S; Gomes, Célia M; Girão, Henrique; Cavaleiro, José A S; Ribeiro, Carlos A F; Tomé, João P C; Fernandes, Rosa

2016-11-01

Conventional photodynamic agents used in clinic are porphyrin-based photosensitizers. However, they have low tumour selectivity, which may induce unwanted side-effects and damage to healthy tissues. In this study, we used a porphyrin with dendritic units of galactose (PorGal 8 ) developed by us, which can target the galactose-binding protein, galectin-1, known to be overexpressed in many tumour tissues. In vitro and in vivo studies had been conducted for the validation of PorGal 8 effectiveness. We showed a specific uptake of PorGal 8 and induction of apoptotic cell death by generating oxidative stress and alterations in the cytoskeleton of bladder cancer cells overexpressing galectin-1. We further validated the photodynamic efficiency of PorGal 8 in athymic nude mice (Balb/c nu/nu) bearing subcutaneously implanted luciferase-positive bladder cancer xenografts, overexpressing galectin-1 protein. PorGal 8 (5 μmol/kg, intraperitoneal), injected 24 h before light delivery (50.4 J/cm 2 ), inhibited tumour growth. We conclude that the use of PorGal 8 enables selective target and cytotoxicity by photodynamic therapy in cancer cells overexpressing galectin-1, preventing undesired phototoxicity in the surrounding healthy tissues. Copyright © 2016 Elsevier Ltd. All rights reserved.

Empirical Analysis of Using Erasure Coding in Outsourcing Data Storage With Provable Security

DTIC Science & Technology

2016-06-01

the fastest encoding performance among the four tested schemes. We expected to observe that Cauchy Reed-Solomonwould be faster than Reed- Solomon for all...providing recoverability for POR. We survey MDS codes and select Reed- Solomon and Cauchy Reed- Solomon MDS codes to be implemented into a prototype POR...tools providing recoverability for POR. We survey MDS codes and select Reed- Solomon and Cauchy Reed- Solomon MDS codes to be implemented into a

Co-infection of classic swine H1N1 influenza virus in pigs persistently infected with porcine rubulavirus.

PubMed

Rivera-Benitez, José Francisco; De la Luz-Armendáriz, Jazmín; Saavedra-Montañez, Manuel; Jasso-Escutia, Miguel Ángel; Sánchez-Betancourt, Ivan; Pérez-Torres, Armando; Reyes-Leyva, Julio; Hernández, Jesús; Martínez-Lara, Atalo; Ramírez-Mendoza, Humberto

2016-02-29

Porcine rubulavirus (PorPV) and swine influenza virus infection causes respiratory disease in pigs. PorPV persistent infection could facilitate the establishment of secondary infections. The aim of this study was to analyse the pathogenicity of classic swine H1N1 influenza virus (swH1N1) in growing pigs persistently infected with porcine rubulavirus. Conventional six-week-old pigs were intranasally inoculated with PorPV, swH1N1, or PorPV/swH1N1. A mock-infected group was included. The co-infection with swH1N1 was at 44 days post-infection (DPI), right after clinical signs of PorPV infection had stopped. The pigs of the co-infection group presented an increase of clinical signs compared to the simple infection groups. In all infected groups, the most recurrent lung lesion was hyperplasia of the bronchiolar-associated lymphoid tissue and interstitial pneumonia. By means of immunohistochemical evaluation it was possible to demonstrate the presence of the two viral agents infecting simultaneously the bronchiolar epithelium. Viral excretion of PorPV in nasal and oral fluid was recorded at 28 and 52 DPI, respectively. PorPV persisted in several samples from respiratory tissues (RT), secondary lymphoid organs (SLO), and bronchoalveolar lavage fluid (BALF). For swH1N1, the viral excretion in nasal fluids was significantly higher in single-infected swH1N1 pigs than in the co-infected group. However, the co-infection group exhibited an increase in the presence of swH1N1 in RT, SLO, and BALF at two days after co-infection. In conclusion, the results obtained confirm an increase in the clinical signs of infection, and PorPV was observed to impact the spread of swH1N1 in analysed tissues in the early stage of co-infection, although viral shedding was not enhanced. In the present study, the interaction of swH1N1 infection is demonstrated in pigs persistently infected with PorPV. Copyright © 2016 Elsevier B.V. All rights reserved.

Monóxido de carbono

EPA Pesticide Factsheets

La mayoria de los accidentes causados por envenenamiento por monoxido de carbono (CO) se producen en los hogares y estan relacionados a nuestras actividades diarias como cocinar y usar la calefaccion.

Genetic variations in NADPH-CYP450 oxidoreductase in a Czech Slavic cohort

PubMed Central

Tomková, Mária; Panda, Satya Prakash; Šeda, Ondřej; Baxová, Alice; Hůlková, Martina; Masters, Bettie Sue Siler; Martásek, Pavel

2015-01-01

Background Gene polymorphisms encoding the enzyme NADPH–cytochrome P450 oxidoreductase (POR) contribute to inter-individual differences in drug response. Aim To estimate polymorphic allele frequencies of the POR gene in a Czech Slavic population. Materials & Methods The gene POR was analyzed in 322 Czech Slavic individuals from a control cohort by sequencing and HRM analysis. Results Twenty-five SNP genetic variations were identified. Of these variants, 7 were new, unreported SNPs, including two SNPs in the 5´flanking region (g.4965 C>T and g.4994 G>T), one intronic variant (c.1899 −20C>T), one synonymous SNP (p.20Ala=) and three nonsynonymous SNPs (p.Thr29Ser, p.Pro384Leu and p.Thr529Met). The p.Pro384Leu variant exhibited reduced enzymatic activities compared to wild type. Conclusion New POR variant identification indicates that the number of uncommon variants might be specific for each subpopulation being investigated, particularly germane to the singular role that POR plays in providing reducing equivalents to all CYPs in the endoplasmic reticulum. PMID:25712184

Completing the surrogate motherhood process: parental order reporters' attitudes towards surrogacy arrangements, role ambiguity and role conflict.

PubMed

Purewal, Satvinder; Crawshaw, Marilyn; van den Akker, Olga

2012-06-01

This study investigated the attitudes of parental order reporters (PORs) towards their work with surrogacy arrangements and their experiences of role conflict and role ambiguity. A questionnaire was used to assess PORs' perceptions of their role in parental order [PO] applications, attitudes towards surrogacy arrangements and the legal process and the influence of role ambiguity or conflict. Questionnaires were distributed to all PORs employed by the Children and Family Court Advisory and Support Service in England. Thirty-three PORs participated (response rate 46%) who, on average, had each completed five PO applications (range 1-40). Positive attitudes towards surrogacy and the child's needs for openness about origins were found. Concerns about the inadequacy of preparation and assessment arrangements, overseas arrangements and non-regulation of surrogacy agencies were evident. PORs with high-role ambiguity were more likely to report less positive attitudes towards the emotional consequence of surrogacy on offspring. High scores on role ambiguity and role conflict were reflected in less positive attitudes towards the parties' preparation towards parenthood. These results have implications for training, policy and practice in this area.

Neuraminidase activity of blue eye disease porcine rubulavirus: Specificity, affinity and inhibition studies.

PubMed

Santos-López, Gerardo; Borraz-Argüello, María T; Márquez-Domínguez, Luis; Flores-Alonso, Juan Carlos; Ramírez-Mendoza, Humberto; Priem, Bernard; Fort, Sébastien; Vallejo-Ruiz, Verónica; Reyes-Leyva, Julio; Herrera-Camacho, Irma

2017-10-01

Porcine rubulavirus (PorPV), also known as La Piedad Michoacan Virus (LPMV) causes encephalitis and reproductive failure in newborn and adult pigs, respectively. The hemagglutinin-neuraminidase (HN) glycoprotein is the most exposed and antigenic of the virus proteins. HN plays central roles in PorPV infection; i.e., it recognizes sialic acid-containing cell receptors that mediate virus attachment and penetration; in addition, its neuraminidase (sialic acid releasing) activity has been proposed as a virulence factor. This work describes the purification and characterization of PorPV HN protein (isolate PAC1). The specificity of neuraminidase is restricted to sialyl(α2,3)lactose (3SL). HN showed typical Michaelis-Menten kinetics with fetuin as substrate (km=0.029μM, Vmax=522.8nmolmin -1 mg -1 ). When 3SL was used as substrate, typical cooperative kinetics were found (S 50 =0.15μM, Vmax=154.3nmolmin -1 mg -1 ). The influenza inhibitor zanamivir inhibited the PorPV neuraminidase with IC 50 of 0.24μM. PorPV neuraminidase was activated by Ca 2+ and inhibited by nucleoside triphosphates with the level of inhibition depending on phosphorylation level. The present results open possibilities to study the role of neuraminidase in the pathogenicity of PorPV infection and its potential inhibitors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prevalence of asthma and chronic obstructive pulmonary disease in Aboriginal and non-Aboriginal populations: A systematic review and meta-analysis of epidemiological studies

PubMed Central

Ospina, Maria B; Voaklander, Donald C; Stickland, Michael K; King, Malcolm; Senthilselvan, Ambikaipakan; Rowe, Brian H

2012-01-01

BACKGROUND: Asthma and chronic obstructive pulmonary disease (COPD) have considerable potential for inequities in diagnosis and treatment, thereby affecting vulnerable groups. OBJECTIVE: To evaluate differences in asthma and COPD prevalence between adult Aboriginal and non-Aboriginal populations. METHODS: MEDLINE, EMBASE, specialized databases and the grey literature up to October 2011 were searched to identify epidemiological studies comparing asthma and COPD prevalence between Aboriginal and non-Aboriginal adult populations. Prevalence ORs (PORs) and 95% CIs were calculated in a random-effects meta-analysis. RESULTS: Of 132 studies, eight contained relevant data. Aboriginal populations included Native Americans, Canadian Aboriginals, Australian Aboriginals and New Zealand Maori. Overall, Aboriginals were more likely to report having asthma than non-Aboriginals (POR 1.41 [95% CI 1.23 to 1.60]), particularly among Canadian Aboriginals (POR 1.80 [95% CI 1.68 to 1.93]), Native Americans (POR 1.41 [95% CI 1.13 to 1.76]) and Maori (POR 1.64 [95% CI 1.40 to 1.91]). Australian Aboriginals were less likely to report asthma (POR 0.49 [95% CI 0.28 to 0.86]). Sex differences in asthma prevalence between Aboriginals and their non-Aboriginal counterparts were not identified. One study compared COPD prevalence between Native and non-Native Americans, with similar rates in both groups (POR 1.08 [95% CI 0.81 to 1.44]). CONCLUSIONS: Differences in asthma prevalence between Aboriginal and non-Aboriginal populations exist in a variety of countries. Studies comparing COPD prevalence between Aboriginal and non-Aboriginal populations are scarce. Further investigation is needed to identify and account for factors associated with respiratory health inequalities among Aboriginal peoples. PMID:23248798

Disconnection of the Perirhinal and Postrhinal Cortices Impairs Recognition of Objects in Context But Not Contextual Fear Conditioning

PubMed Central

2017-01-01

The perirhinal cortex (PER) is known to process object information, whereas the rodent postrhinal cortex (POR), homolog to the parahippocampal cortex in primates, is thought to process spatial information. A number of studies, however, provide evidence that both areas are involved in processing contextual information. In this study, we tested the hypothesis that the rat POR relies on object information received from the PER to form complex representations of context. Using three fear-conditioning (FC) paradigms (signaled, unsignaled, and renewal) and two context-guided object recognition tasks (with 3D and 2D objects), we examined the effects of crossed excitotoxic lesions to the POR and the contralateral PER. Performance of rats with crossed lesions was compared with that of rats with ipsilateral POR plus PER lesions and sham-operated rats. We found that rats with contralateral PER–POR lesions were impaired in object–context recognition but not in contextual FC. Therefore, interaction between the POR and PER is necessary for context-guided exploratory behavior but not for associating fear with context. Our results provide evidence for the hypothesis that the POR relies on object and pattern information from the PER to encode representations of context. The association of fear with a context, however, may be supported by alternate cortical and/or subcortical pathways when PER–POR interaction is not available. Our results suggest that contextual FC may represent a special case of context-guided behavior. SIGNIFICANCE STATEMENT Representations of context are important for perception, memory, decision making, and other cognitive processes. Moreover, there is extensive evidence that the use of contextual representations to guide appropriate behavior is disrupted in neuropsychiatric and neurological disorders including developmental disorders, schizophrenia, affective disorders, and Alzheimer's disease. Many of these disorders are accompanied by changes in

Paleoenvironmental implications of taxonomic variation among δ 15 N values of chloropigments

NASA Astrophysics Data System (ADS)

Higgins, Meytal B.; Wolfe-Simon, Felisa; Robinson, Rebecca S.; Qin, Yelun; Saito, Mak A.; Pearson, Ann

2011-11-01

Natural variations in the ratios of nitrogen isotopes in biomass reflect variations in nutrient sources utilized for growth. In order to use δ 15N values of chloropigments of photosynthetic organisms to determine the corresponding δ 15N values of biomass - and by extension, surface waters - the isotopic offset between chlorophyll and biomass must be constrained. Here we examine this offset in various geologically-relevant taxa, grown using nutrient sources that may approximate ocean conditions at different times in Earth's history. Phytoplankton in this study include cyanobacteria (diazotrophic and non-diazotrophic), eukaryotic algae (red and green), and anoxygenic photosynthetic bacteria (Proteobacteria), as well as environmental samples from sulfidic lake water. Cultures were grown using N 2, NO 3-, and NH 4+ as nitrogen sources, and were examined under different light regimes and growth conditions. We find surprisingly high variability in the isotopic difference (δ 15N biomass - δ 15N chloropigment) for prokaryotes, with average values for species ranging from -12.2‰ to +11.7‰. We define this difference as ɛpor, a term that encompasses diagenetic porphyrins and chlorins, as well as chlorophyll. Negative values of ɛpor reflect chloropigments that are 15N-enriched relative to biomass. Notably, this enrichment appears to occur only in cyanobacteria. The average value of ɛpor for freshwater cyanobacterial species is -9.8 ± 1.8‰, while for marine cyanobacteria it is -0.9 ± 1.3‰. These isotopic effects group environmentally but not phylogenetically, e.g., ɛpor values for freshwater Chroococcales resemble those of freshwater Nostocales but differ from those of marine Chroococcales. Our measured values of ɛpor for eukaryotic algae (range = 4.7-8.7‰) are similar to previous reports for pure cultures. For all taxa studied, values of ɛpor do not depend on the type of nitrogen substrate used for growth. The observed environmental control of ɛpor

Disconnection of the Perirhinal and Postrhinal Cortices Impairs Recognition of Objects in Context But Not Contextual Fear Conditioning.

PubMed

Heimer-McGinn, Victoria R; Poeta, Devon L; Aghi, Krishan; Udawatta, Methma; Burwell, Rebecca D

2017-05-03

The perirhinal cortex (PER) is known to process object information, whereas the rodent postrhinal cortex (POR), homolog to the parahippocampal cortex in primates, is thought to process spatial information. A number of studies, however, provide evidence that both areas are involved in processing contextual information. In this study, we tested the hypothesis that the rat POR relies on object information received from the PER to form complex representations of context. Using three fear-conditioning (FC) paradigms (signaled, unsignaled, and renewal) and two context-guided object recognition tasks (with 3D and 2D objects), we examined the effects of crossed excitotoxic lesions to the POR and the contralateral PER. Performance of rats with crossed lesions was compared with that of rats with ipsilateral POR plus PER lesions and sham-operated rats. We found that rats with contralateral PER-POR lesions were impaired in object-context recognition but not in contextual FC. Therefore, interaction between the POR and PER is necessary for context-guided exploratory behavior but not for associating fear with context. Our results provide evidence for the hypothesis that the POR relies on object and pattern information from the PER to encode representations of context. The association of fear with a context, however, may be supported by alternate cortical and/or subcortical pathways when PER-POR interaction is not available. Our results suggest that contextual FC may represent a special case of context-guided behavior. SIGNIFICANCE STATEMENT Representations of context are important for perception, memory, decision making, and other cognitive processes. Moreover, there is extensive evidence that the use of contextual representations to guide appropriate behavior is disrupted in neuropsychiatric and neurological disorders including developmental disorders, schizophrenia, affective disorders, and Alzheimer's disease. Many of these disorders are accompanied by changes in

Porous silicon for drug delivery systems

NASA Astrophysics Data System (ADS)

Abramova, E. N.; Khort, A. M.; Yakovenko, A. G.; Kornilova, D. S.; Slipchenko, E. A.; Prokhorov, D. I.; Shvets, V. I.

2018-01-01

The article deals with main principles of the formation of porous silicon (por-Si) to produce containers for drug delivery systems. Most important por-Si characteristics to produce nanocontainers with required parameters are determined.

Intestinal, extra-intestinal and systemic sequelae of Toxoplasma gondii induced acute ileitis in mice harboring a human gut microbiota

PubMed Central

von Klitzing, Eliane; Ekmekciu, Ira; Kühl, Anja A.; Bereswill, Stefan

2017-01-01

Background Within seven days following peroral high dose infection with Toxoplasma gondii susceptible conventionally colonized mice develop acute ileitis due to an underlying T helper cell (Th) -1 type immunopathology. We here addressed whether mice harboring a human intestinal microbiota developed intestinal, extra-intestinal and systemic sequelae upon ileitis induction. Methodology/Principal findings Secondary abiotic mice were generated by broad-spectrum antibiotic treatment and associated with a complex human intestinal microbiota following peroral fecal microbiota transplantation. Within three weeks the human microbiota had stably established in the murine intestinal tract as assessed by quantitative cultural and culture-independent (i.e. molecular 16S rRNA based) methods. At day 7 post infection (p.i.) with 50 cysts of T. gondii strain ME49 by gavage human microbiota associated (hma) mice displayed severe clinical, macroscopic and microscopic sequelae indicating acute ileitis. In diseased hma mice increased numbers of innate and adaptive immune cells within the ileal mucosa and lamina propria and elevated intestinal secretion of pro-inflammatory mediators including IFN-γ, IL-12 and nitric oxide could be observed at day 7 p.i. Ileitis development was accompanied by substantial shifts in intestinal microbiota composition of hma mice characterized by elevated total bacterial loads and increased numbers of intestinal Gram-negative commensals such as enterobacteria and Bacteroides / Prevotella species overgrowing the small and large intestinal lumen. Furthermore, viable bacteria translocated from the inflamed ileum to extra-intestinal including systemic compartments. Notably, pro-inflammatory immune responses were not restricted to the intestinal tract as indicated by increased pro-inflammatory cytokine secretion in extra-intestinal (i.e. liver and kidney) and systemic compartments including spleen and serum. Conclusion/Significance With respect to the intestinal

Intestinal, extra-intestinal and systemic sequelae of Toxoplasma gondii induced acute ileitis in mice harboring a human gut microbiota.

PubMed

von Klitzing, Eliane; Ekmekciu, Ira; Kühl, Anja A; Bereswill, Stefan; Heimesaat, Markus M

2017-01-01

Within seven days following peroral high dose infection with Toxoplasma gondii susceptible conventionally colonized mice develop acute ileitis due to an underlying T helper cell (Th) -1 type immunopathology. We here addressed whether mice harboring a human intestinal microbiota developed intestinal, extra-intestinal and systemic sequelae upon ileitis induction. Secondary abiotic mice were generated by broad-spectrum antibiotic treatment and associated with a complex human intestinal microbiota following peroral fecal microbiota transplantation. Within three weeks the human microbiota had stably established in the murine intestinal tract as assessed by quantitative cultural and culture-independent (i.e. molecular 16S rRNA based) methods. At day 7 post infection (p.i.) with 50 cysts of T. gondii strain ME49 by gavage human microbiota associated (hma) mice displayed severe clinical, macroscopic and microscopic sequelae indicating acute ileitis. In diseased hma mice increased numbers of innate and adaptive immune cells within the ileal mucosa and lamina propria and elevated intestinal secretion of pro-inflammatory mediators including IFN-γ, IL-12 and nitric oxide could be observed at day 7 p.i. Ileitis development was accompanied by substantial shifts in intestinal microbiota composition of hma mice characterized by elevated total bacterial loads and increased numbers of intestinal Gram-negative commensals such as enterobacteria and Bacteroides / Prevotella species overgrowing the small and large intestinal lumen. Furthermore, viable bacteria translocated from the inflamed ileum to extra-intestinal including systemic compartments. Notably, pro-inflammatory immune responses were not restricted to the intestinal tract as indicated by increased pro-inflammatory cytokine secretion in extra-intestinal (i.e. liver and kidney) and systemic compartments including spleen and serum. With respect to the intestinal microbiota composition "humanized" mice display acute ileitis

Bacterial epidemiology of osteoarticular infections in a referent center: 10-year study.

PubMed

Titécat, M; Senneville, E; Wallet, F; Dezèque, H; Migaud, H; Courcol, R-J; Loïez, C

2013-10-01

Management of osteoarticular infections combines surgical treatment with antibiotic therapy. For some teams the immediate postoperative regimen requires at least partly wide-spectrum probabilistic treatment while waiting for the microbiological results. This protocol exposes the patient to the selection of resistant bacteria and the hospital unit to a modification of its bacterial ecology. The objective of this study was to retrospectively describe the microbial epidemiology of the Traumatology and Orthopaedics Department of the Lille University Hospital over 10 years (2002-2011). The bacterial species isolated in culture of osteoarticular samples were listed, after removing any duplicates. The antibiotics retained for follow-up were those used in treatment of these infections as well as those recognized as markers of resistance. For Gram-positive species, the antibiotics considered were methicillin, rifampicin, fluoroquinolones, glycopeptides, and linezolid; for the Gram-negative species, cefotaxime, cefepime, imipenem, and fluoroquinolones were considered. Of the 5006 strains isolated between 2002 and 2011, Gram-positive cocci accounted for more than 71%; Staphylococcus aureus 27%, and coagulase-negative staphylococci (CoNS) 54%. Contrary to S. aureus, resistance to methicillin, fluoroquinolones, and teicoplanin significantly increased in CoNS, reaching 44%, 34%, and 22%, respectively, of the strains in 2011. The proportion of streptococcal and enterococcal infections remained stable, a mean 7.4% and 5.3%, respectively, per year. Enterobacteria (12.5% of the isolates) were producers of extended-spectrum beta-lactamase in 7.8% of the cases. Pseudomonas aeruginosa was involved in 3.6% of the infections, and 12% of the strains remained resistant to ceftazidime. Propionibacterium acnes accounted for 5.8% of the bacteria isolated and showed few antibiotic resistance problems. Stability in the distribution and the susceptibility of different bacterial species was noted

Dissimilatory Metabolism of Nitrogen Oxides in Bacteria:Comparative Reconstruction of Transcriptional Networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodionov, Dmitry A.; Dubchak, Inna L.; Arkin, Adam P.

2005-09-01

Bacterial response to nitric oxide (NO) is of major importance since NO is an obligatory intermediate of the nitrogen cycle. Transcriptional regulation of the dissimilatory nitric oxides metabolism in bacteria is diverse and involves FNR-like transcription factors HcpR, DNR and NnrR, two-component systems NarXL and NarQP, NO-responsive activator NorR, and nitrite sensitive repressor NsrR. Using comparative genomics approaches we predict DNA-binding signals for these transcriptional factors and describe corresponding regulons in available bacterial genomes. Within the FNR family of regulators, we observed a correlation of two specificity-determining amino acids and contacting bases in corresponding DNA signal. Highly conserved regulon HcpRmore » for the hybrid cluster protein and some other redox enzymes is present in diverse anaerobic bacteria including Clostridia, Thermotogales and delta-proteobacteria. NnrR and DNR control denitrification in alpha- and beta-proteobacteria, respectively. Sigma-54-dependent NorR regulon found in some gamma- and beta-proteobacteria contains various enzymes involved in the NO detoxification. Repressor NsrR, which was previously known to control only nitrite reductase operon in Nitrosomonas spp., appears to be the master regulator of the nitric oxides metabolism not only in most gamma- and beta-proteobacteria (including well-studied species like Escherichia coli), but also in Gram-positive Bacillus and Streptomyces species. Positional analysis and comparison of regulatory regions of NO detoxification genes allows us to propose the candidate NsrR-binding signal. The most conserved member of the predicted NsrR regulon is the NO-detoxifying flavohemoglobin Hmp. In enterobacteria, the regulon includes also two nitrite-responsive loci, nipAB (hcp-hcr) and nipC(dnrN), thus confirming the identity of the effector, i.e., nitrite. The proposed NsrR regulons in Neisseria and some other species are extended to include denitrification genes. As

Monitoring and evaluation of antibiotic-resistant bacteria at a municipal wastewater treatment plant in China.

PubMed

Huang, Jing-Jing; Hu, Hong-Ying; Lu, Sun-Qin; Li, Yi; Tang, Fang; Lu, Yun; Wei, Bin

2012-07-01

The prevalence of antibiotic-resistant bacteria in municipal wastewater treatment plants (WWTPs) is becoming a concern of public health. In order to acquire information on the emission of antibiotic-resistant bacteria from WWTP effluents into natural waters, both average antibiotic tolerance and concentrations of antibiotic-resistant bacteria in the effluent of a WWTP in Beijing, China were investigated. A new index of IC(50)/MIC ratio (the antibiotic concentration required to inhibit 50% of total heterotrophic bacteria compared to the highest minimum inhibitory concentration value of a group of pathogens according to a specific antibiotic, as defined by CLSI) was used to reflect the average antibiotic tolerance of total heterotrophic bacteria in the secondary effluent. The results showed that the IC(50)/MIC ratios of heterotrophic bacteria in the secondary effluent to penicillin, ampicillin, cephalothin, chloramphenicol and rifampicin were >2, >1, >1, and 1.08, respectively, which reflected a significantly high general level of heterotrophic bacteria found in the secondary effluent resistant to these five antibiotics. The concentrations of penicillin-, ampicillin-, cephalothin-, and chloramphenicol-resistant bacteria were as high as 1.5×10(4)-1.9×10(5), 1.2×10(4)-1.5×10(5), 8.9×10(3)-1.9×10(5) and 2.6×10(4)-2.0×10(5) CFU/mL, and the average percentages in relation to total heterotrophic bacteria were 63%, 47%, 55%, and 69%, respectively. The concentrations of tetracycline- and rifampicin-resistant bacteria were 840-6.1×10(3) and 310-6.1×10(4) CFU/mL with average percentages of 2.6% and 11%, respectively. Furthermore, our study found that five- and six-antibiotic-resistant bacteria were widely distributed in four types of enterobacteria from the secondary effluent. The presence of multiple-antibiotic-resistant bacteria from effluents of WWTPs into natural waters could pose a serious problem as a secondary pollutant of drinking water. Copyright © 2011

Global Systems-Level Analysis of Hfq and SmpB Deletion Mutants in Salmonella: Implications for Virulence and Global Protein Translation

PubMed Central

Porwollik, Steffen; Mottaz-Brewer, Heather; Petritis, Brianne O.; Jaitly, Navdeep; Adkins, Joshua N.; McClelland, Michael; Heffron, Fred; Smith, Richard D.

2009-01-01

Using sample-matched transcriptomics and proteomics measurements it is now possible to begin to understand the impact of post-transcriptional regulatory programs in Enterobacteria. In bacteria post-transcriptional regulation is mediated by relatively few identified RNA-binding protein factors including CsrA, Hfq and SmpB. A mutation in any one of these three genes, csrA, hfq, and smpB, in Salmonella is attenuated for mouse virulence and unable to survive in macrophages. CsrA has a clearly defined specificity based on binding to a specific mRNA sequence to inhibit translation. However, the proteins regulated by Hfq and SmpB are not as clearly defined. Previous work identified proteins regulated by hfq using purification of the RNA-protein complex with direct sequencing of the bound RNAs and found binding to a surprisingly large number of transcripts. In this report we have used global proteomics to directly identify proteins regulated by Hfq or SmpB by comparing protein abundance in the parent and isogenic hfq or smpB mutant. From these same samples we also prepared RNA for microarray analysis to determine if alteration of protein expression was mediated post-transcriptionally. Samples were analyzed from bacteria grown under four different conditions; two laboratory conditions and two that are thought to mimic the intracellular environment. We show that mutants of hfq and smpB directly or indirectly modulate at least 20% and 4% of all possible Salmonella proteins, respectively, with limited correlation between transcription and protein expression. These proteins represent a broad spectrum of Salmonella proteins required for many biological processes including host cell invasion, motility, central metabolism, LPS biosynthesis, two-component regulatory systems, and fatty acid metabolism. Our results represent one of the first global analyses of post-transcriptional regulons in any organism and suggest that regulation at the translational level is widespread and plays

Use of wildlife rehabilitation centres in pathogen surveillance: A case study in white storks (Ciconia ciconia).

PubMed

Camacho, MariaCruz; Hernández, Jose Manuel; Lima-Barbero, Jose Francisco; Höfle, Ursula

2016-08-01

More than 70% of new human pathogens are zoonotic and many originate from the wildlife reservoir. Wildlife rehabilitation centres (WRC) are an easily accessible source for sample and data collection for preventive surveillance, but data collected this way may be biased. We use white storks (Ciconia ciconia) as a model to compare pathogen prevalence obtained in the field and WRC. We address factors that may affect disease prevalence data like origin, the age group and the "diseased" state of WRC admissions. In this study we compared prevalence of Escherichia coli and Salmonella spp. in the digestive tract; antibodies against West Nile virus, avian influenza and Newcastle disease virus, and antimicrobial resistance patterns of E. coli between nestling and adult wild storks established in different habitats (n=90) and storks admitted to two different WRC (n=30) in the same region. When age groups and colonies of origin were disregarded, the mean enterobacteria (E. coli, Salmonella) and viral antibody prevalence of the wild population (n=90) were similar to prevalence observed in the individuals admitted to WRC (n=30). However, in fledgling juvenile storks admitted to WRC, the prevalence of Salmonella spp. (13.3%), E. coli showing resistance to cefotaxime (37.9%) and against two antimicrobials at once (41.4%) were more similar to the prevalence in stork nestlings from landfill-associated colonies (7.9%, 37.1% and 48.6%, respectively for prevalence of Salmonella spp. and E. coli displaying, cefotaxime resistance and resistance against two antimicrobials), and significantly higher than in colonies located in natural habitats (0%; 10.5% and 15.8%, respectively). Thus, pathogen surveillance in individuals from an abundant species admitted to WRC is useful to monitor overall mean prevalence, but for certain pathogens may not be sufficient to detect differences between local populations. In addition, the ecology of the tested species and the specific temporal, spatial and

Diversity of Somatic Coliphages in Coastal Regions with Different Levels of Anthropogenic Activity in São Paulo State, Brazil ▿

PubMed Central

Burbano-Rosero, E. M.; Ueda-Ito, M.; Kisielius, J. J.; Nagasse-Sugahara, T. K.; Almeida, B. C.; Souza, C. P.; Markman, C.; Martins, G. G.; Albertini, L.; Rivera, I. N. G.

2011-01-01

Bacteriophages are the most abundant and genetically diverse viruses on Earth, with complex ecology in both quantitative and qualitative terms. Somatic coliphages (SC) have been reported to be good indicators of fecal pollution in seawater. This study focused on determining the concentration of SC and their diversity by electron microscopy of seawater, plankton, and bivalve samples collected at three coastal regions in São Paulo, Brazil. The SC counts varied from <1 to 3.4 × 103 PFU/100 ml in seawater (73 samples tested), from <1 to 4.7 × 102 PFU/g in plankton (46 samples tested), and from <1 to 2.2 × 101 PFU/g in bivalves (11 samples tested). In seawater samples, a relationship between the thermotolerant coliforms and Escherichia coli and SC was observed at the three regions (P = 0.0001) according to the anthropogenic activities present at each region. However, SC were found in plankton samples from three regions: Baixada Santista (17/20), Canal de São Sebastião (6/14), and Ubatuba (3/12). In seawater samples collected from Baixada Santista, four morphotypes were observed: A1 (4.5%), B1 (50%), C1 (36.4%), and D1 (9.1%). One coliphage, Siphoviridae type T1, had the longest tail: between 939 and 995 nm. In plankton samples, Siphoviridae (65.8%), Podoviridae (15.8%), Microviridae (15.8%), and Myoviridae (2.6%) were found. In bivalves, only the morphotype B1 was observed. These SC were associated with enteric hosts: enterobacteria, E. coli, Proteus, Salmonella, and Yersinia. Baixada Santista is an area containing a high level of fecal pollution compared to those in the Canal de São Sebastião and Ubatuba. This is the first report of coliphage diversity in seawater, plankton, and bivalve samples collected from São Paulo coastal regions. A better characterization of SC diversity in coastal environments will help with the management and evaluation of the microbiological risks for recreation, seafood cultivation, and consumption. PMID:21531842

Feed supplemented with 3 different antibiotics improved food intake and decreased the activation of the humoral immune response in healthy weaned pigs but had differing effects on intestinal microbiota.

PubMed

Bosi, P; Merialdi, G; Scandurra, S; Messori, S; Bardasi, L; Nisi, I; Russo, D; Casini, L; Trevisi, P

2011-12-01

The aim of this study was to determine the effects of 3 antibiotics used for pulmonary pathologies added in the feed of weaned pigs on growth performance, commensal microbiota, and immune response. At weaning, a total of 72 pigs were randomly assigned by BW and litter to 1 of the following diets: control (typical weaning diet), control + 400 mg of tilmicosin/kg, control + 600 mg of amoxicillin/kg, and control + 300 mg of doxycycline/kg. Individually penned pigs were slaughtered after 3 wk (12 pigs/treatment) or 4 wk (6 pigs/treatment). During the fourth week, all pigs received the control diet to test the residual effect of the antimicrobial supplementation. The antibiotic supplementation increased growth and feed intake during the first week (P < 0.01) and over the first 3 wk combined (P < 0.05). Gain-to-feed ratio tended to improve during the first week (P = 0.076) by the antibiotics compared with the control. Among the antibiotic treatments, no difference was observed in ADG and feed intake, which were also unchanged by the diet in the fourth week. The fecal enterobacteria counts were increased by amoxicillin on d 14 and 21 (P < 0.05 and 0.01, respectively) and were decreased by tilmicosin (P < 0.001) compared with the control. Amoxicillin decreased lactic acid bacteria (P < 0.01) counts compared with the control. The antibiotic supplementation tended to decrease total bacteria variability in the jejunum (Shannon index, P = 0.091) compared with the control. The antibiotic treatment decreased the mean total serum IgM concentration (P = 0.016) after 3 wk and did not change the mucosal histomorphometry of the small intestine. For tilmicosin, the observed positive action on piglet performance and feed intake can originate by the decreased costs of immune activation determined by the action on intestinal microbiota. For amoxicillin and doxycycline, the observation on intestinal and fecal microbiota seems to be not sufficient to explain their growth-promoting effect.

The temperate Burkholderia phage AP3 of the Peduovirinae shows efficient antimicrobial activity against B. cenocepacia of the IIIA lineage.

PubMed

Roszniowski, Bartosz; Latka, Agnieszka; Maciejewska, Barbara; Vandenheuvel, Dieter; Olszak, Tomasz; Briers, Yves; Holt, Giles S; Valvano, Miguel A; Lavigne, Rob; Smith, Darren L; Drulis-Kawa, Zuzanna

2017-02-01

Burkholderia phage AP3 (vB_BceM_AP3) is a temperate virus of the Myoviridae and the Peduovirinae subfamily (P2likevirus genus). This phage specifically infects multidrug-resistant clinical Burkholderia cenocepacia lineage IIIA strains commonly isolated from cystic fibrosis patients. AP3 exhibits high pairwise nucleotide identity (61.7 %) to Burkholderia phage KS5, specific to the same B. cenocepacia host, and has 46.7-49.5 % identity to phages infecting other species of Burkholderia. The lysis cassette of these related phages has a similar organization (putative antiholin, putative holin, endolysin, and spanins) and shows 29-98 % homology between specific lysis genes, in contrast to Enterobacteria phage P2, the hallmark phage of this genus. The AP3 and KS5 lysis genes have conserved locations and high amino acid sequence similarity. The AP3 bacteriophage particles remain infective up to 5 h at pH 4-10 and are stable at 60 °C for 30 min, but are sensitive to chloroform, with no remaining infective particles after 24 h of treatment. AP3 lysogeny can occur by stable genomic integration and by pseudo-lysogeny. The lysogenic bacterial mutants did not exhibit any significant changes in virulence compared to wild-type host strain when tested in the Galleria mellonella moth wax model. Moreover, AP3 treatment of larvae infected with B. cenocepacia revealed a significant increase (P < 0.0001) in larvae survival in comparison to AP3-untreated infected larvae. AP3 showed robust lytic activity, as evidenced by its broad host range, the absence of increased virulence in lysogenic isolates, the lack of bacterial gene disruption conditioned by bacterial tRNA downstream integration site, and the absence of detected toxin sequences. These data suggest that the AP3 phage is a promising potent agent against bacteria belonging to the most common B. cenocepacia IIIA lineage strains.

Feeding Jerusalem artichoke reduced skatole level and changed intestinal microbiota in the gut of entire male pigs.

PubMed

Vhile, S G; Kjos, N P; Sørum, H; Overland, M

2012-05-01

Different levels of dried Jerusalem artichoke were fed to entire male pigs 1 week before slaughter. The objective was to investigate the effect on skatole level in the hindgut and in adipose tissue, as well as the effect on microflora and short-chain fatty acids (SCFA) in the hindgut. Five experimental groups (n = 11) were given different dietary treatments 7 days before slaughtering: negative control (basal diet), positive control (basal diet + 9% chicory-inulin), basal diet + 4.1% Jerusalem artichoke, basal diet + 8.1% Jerusalem artichoke and basal diet + 12.2% Jerusalem artichoke. Samples from colon, rectum, faeces and adipose tissue were collected. Effect of dietary treatment on skatole, indole and androstenone levels in adipose tissue and on skatole, indole, pH, dry matter (DM), microbiota and SCFA in the hindgut was evaluated. Feeding increasing levels of Jerusalem artichoke to entire male pigs reduced skatole in digesta from colon and in faeces (linear, P < 0.01). There was also a tendency towards a decreased level of skatole in adipose tissue (linear, P = 0.06). Feeding Jerusalem artichoke decreased DM content in colon and faeces and pH in colon (linear, P < 0.01). Increasing levels of Jerusalem artichoke resulted in a reduced level of Clostridium perfringens in both colon and rectum (linear, P < 0.05) and a tendency towards decreased levels of enterobacteria in colon (linear, P = 0.05). Further, there was an increase in total amount of SCFA (linear, P < 0.05), acetic acid (linear, P < 0.05) and valerianic acid (linear, P < 0.01) in faeces. In conclusion, adding dried Jerusalem artichoke to diets for entire male pigs 1 week before slaughter resulted in a dose-dependent decrease in skatole levels in the hindgut and adipose tissue. The reduced skatole levels might be related to the decrease in C. perfringens and the increase in SCFA with subsequent reduction in pH.

Fecal microbiome of growing pigs fed a cereal based diet including chicory (Cichorium intybus L.) or ribwort (Plantago lanceolata L.) forage.

PubMed

Dicksved, Johan; Jansson, Janet K; Lindberg, Jan Erik

2015-01-01

The purpose of this study was to investigate how inclusion of chicory forage or ribwort forage in a cereal-based diet influenced the fecal microbial community (microbiome) in newly weaned (35 days of age) piglets. The piglets were fed a cereal-based diet without (B) and with inclusion (80 and 160 g/kg air-dry forage) of vegetative shoots of chicory (C) and leaves of ribwort (R) forage in a 35-day growth trial. Fecal samples were collected at the start (D0), 17 (D17) and 35 (D35) days after weaning and profiles of the microbial consortia were generated using terminal restriction fragment length polymorphism (T-RFLP). 454-FLX pyrosequencing of 16S rRNA gene amplicons was used to analyze the microbial composition in a subset of the samples already analyzed with T-RFLP. The microbial clustering pattern was primarily dependent on age of the pigs, but diet effects could also be observed. Lactobacilli and enterobacteria were more abundant at D0, whereas the genera Streptococcus, Treponema, Clostridium, Clostridiaceae1 and Coprococcus were present in higher abundances at D35. Pigs fed ribwort had an increased abundance of sequences classified as Treponema and a reduction in lactobacilli. However, the abundance of Prevotellaceae increased with age in on both the chicory and the ribwort diet. Moreover, there were significant correlations between the abundance of Bacteroides and the digested amount of galactose, uronic acids and total non-starch polysaccharides, and between the abundance of Bacteroidales and the digested amount of xylose. This study demonstrated that both chicory and ribwort inclusion in the diet of newly weaned pigs influenced the composition of the fecal microbiota and that digestion of specific dietary components was correlated with species composition of the microbiota. Moreover, this study showed that the gut will be exposed to a dramatic shift in the microbial community structure several weeks after weaning.

Fecal microbiome of growing pigs fed a cereal based diet including chicory (Cichorium intybus L.) or ribwort (Plantago lanceolata L.) forage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dicksved, Johan; Jansson, Janet K.; Lindberg, Jan Erik

BACKGROUND: The purpose of this study was to investigate how inclusion of chicory forage or ribwort forage in a cereal-based diet influenced the fecal microbial community (microbiome) in newly weaned (35 days of age) piglets. The piglets were fed a cereal-based diet without (B) and with inclusion (80 and 160 g/kg air-dry forage) of vegetative shoots of chicory (C) and leaves of ribwort (R) forage in a 35-day growth trial. Fecal samples were collected at the start (D0), 17 (D17) and 35 (D35) days after weaning and profiles of the microbial consortia were generated using terminal restriction fragment length polymorphismmore » (T-RFLP). 454-FLX pyrosequencing of 16S rRNA gene amplicons was used to analyze the microbial composition in a subset of the samples already analyzed with T-RFLP. RESULTS: The microbial clustering pattern was primarily dependent on age of the pigs, but diet effects could also be observed. Lactobacilli and enterobacteria were more abundant at D0, whereas the genera Streptococcus, Treponema, Clostridium, Clostridiaceae1 and Coprococcus were present in higher abundances at D35. Pigs fed ribwort had an increased abundance of sequences classified as Treponema and a reduction in lactobacilli. However, the abundance of Prevotellaceae increased with age in on both the chicory and the ribwort diet. Moreover, there were significant correlations between the abundance of Bacteroides and the digested amount of galactose, uronic acids and total non-starch polysaccharides, and between the abundance of Bacteroidales and the digested amount of xylose. CONCLUSION: This study demonstrated that both chicory and ribwort inclusion in the diet of newly weaned pigs influenced the composition of the fecal microbiota and that digestion of specific dietary components was correlated with species composition of the microbiota. Moreover, this study showed that the gut will be exposed to a dramatic shift in the microbial community structure several weeks after weaning.« less

Use of bacteriocin-producing, probiotic strain Enterococcus faecium AL41 to control intestinal microbiota in farm ostriches.

PubMed

Lauková, A; Kandričáková, A; Ščerbová, J

2015-06-01

Probiotic enterococci can produce bacteriocins. Enterococcus faecium AL41 is an Enterocin M-producing, probiotic strain which has previously shown beneficial effect in broiler chickens. In this study, it was used to control intestinal microbiota in farm ostriches in a 42-day experiment with an experimental group (EG, 40 ostriches) and a control group (CG, 46). In addition to feed mixture, the ostriches in EG received Ent. faecium AL41 (10(9) CFU ml(-1); by rifampicin-marked variant) 400 μl per animal per day in their drinking water for 21 days. Sampling was carried out at the start of the experiment (at day 0/1), at day 21 (after 21 days of AL41 application) and at day 42 (21 days after AL41 cessation). Faeces (mixture, n = 6) were treated using the standard microbiological dilution method and cultivated on selective media (ISO). The highest count of AL41 was found at day 42. Its identity was confirmed with PCR and Maldi-Tof. The ostriches were free of Salmonella and Campylobacter cells. At day 21, antimicrobial effect was demonstrated by significant reduction in coagulase-positive and negative staphylococci in EG compared to CG (P < 0·001) and coliforms, Enterobacteria and Pseudomonas-like bacteria (P < 0·001). We conclude that AL41 can be used to control intestinal microbiota in farm ostriches. Significance and impact of the study: Ostriches are excellent for high intensity farming in a wide range of climates, requiring only limited space and giving high yields per hectare. They are reared mainly for their meat. Although adult birds possess quite good immunity, young birds can be threatened by spoilage bacteria, especially when they are transferred from the nests to the farm area. Based on our previous results related to the beneficial effect of bacteriocin-producing, probiotic strain Enterococcus faecium AL41 in poultry or rabbits, we decided to test its ability to control intestinal microbiota in farming ostriches which has never been tested previously. �

Identification and characterization of plasmid-mediated quinolone resistance determinants in Enterobacteriaceae isolated from healthy poultry in Brazil.

PubMed

Ferreira, Joseane Cristina; Penha Filho, Rafael Antonio Casarin; Kuaye, Ana Paula Yorika; Andrade, Leonardo Neves; Berchieri Junior, Angelo; Darini, Ana Lúcia da Costa

2018-06-01

The expression of plasmid-mediated quinolone resistance (PMQR) genes confers low-level quinolone and fluoroquinolones resistance alone. However, the association to chromosomal resistance mechanisms determines an expressively higher resistance in Enterobacteriaceae. These mechanisms are horizontally disseminated within plasmids and have contributed to the emergence of bacteria with reduced susceptibility or resistant to therapies worldwide. The epidemiological characterization of PMQR dissemination is highly relevant in the scientific and medical context, to investigate the dissemination within enterobacteria, from different populations, including humans and food-producing animals. In the present study, 200 Enterobacteriaceae isolates were harvested from poultry with cloacal swabs and identified as Escherichia coli (90.5%), Escherichia fergusonii (5.5%), Klebsiella oxytoca (2.5%) and Klebsiella pneumoniae (1.5%). Among isolates evaluated, 46 (23%) harboured PMQR genes including qnrB (43/200), qnrS (2/200) and aac(6')-Ib-cr (1/200). All isolates carrying PMQR genes showed multidrug-resistance phenotype. The 36 E. coli isolates showed 18 different PFGE types. All E. fergusonii isolates showed the same PFGE type. The two Klebsiella oxytoca belonged to two different PFGE types. The phylogenetic groups A, B1, and D were found among the E. coli harboring PMQR genes. Based on the phylogenetic analysis and PFGE, the population structure of E. coli isolates was diverse, even within the same farm. All isolates carrying qnrB and qnrS genes also harboured ColE-like plasmids. The Southern blot hybridization using the S1-PFGE revealed that the qnrB genes were located on low molecular weight plasmids, smaller than 10Kb. Resistance plasmids were sequenced and showed 100% identity with plasmid pPAB19-3. The association of PMQR genes with mobile genetic elements, such as transferable plasmids, favours the selection and dissemination of (fluoro) quinolones resistant bacteria among

Moléculas orgánicas obtenidas en simulaciones experimentales del medio interestelar.

NASA Astrophysics Data System (ADS)

Muñoz-Caro, Guillermo Manuel

Las nubes moleculares son regiones de formación de estrellas, con temperaturas cinéticas entre 10-50 K y densidades de 103-106 átomos cm-3. Su materia está formada por gas y polvo interestelar. Estas partículas de polvo están cubiertas por una fina capa de hielo, de unos 0.01 μm, que contiene H2O y a menudo CO, CO2, CH3OH y NH3. El hielo es presumiblemente irradiado por fotones ultravioleta y rayos cósmicos en las zonas poco profundas de las nubes moleculares y las regiones circunestelares. En un sistema de vacío, P ˜ 10-7 mbar, simulamos la deposición de hielo a partir de 10 K y la irradiación ultravioleta por medio de una lámpara de descarga de hidrógeno activada con microondas. La evolución del hielo se observa por medio de un espectrómetro infrarrojo. De este modo es posible determinar la composición del hielo observado en el medio interestelar y predecir la presencia de moléculas aún no detectadas en el espacio, que han sido producto del procesamiento del hielo en nuestros experimentos. También es posible calentar el sistema hasta temperatura ambiente para sublimar el hielo depositado. Cuando el hielo ha sido previamente irradiado, se observa un residuo compuesto por moléculas orgánicas complejas, algunas prebióticas, como varios ácidos carboxílicos, aminas, amidas, ésteres y en menor proporción moléculas heterocíclicas y aminoácidos. Algunas de estas moléculas podrían detectarse en estado gaseoso por medio de observaciones milimétricas y de radio. También podrían estar presentes en el polvo cometario, cuyo análisis químico está planeado por las misiones Stardust y Rosetta. Mientras tanto, nuestro grupo está llevando a cabo el análisis de partículas de polvo interplanetario (IDPs), algunas de las cuales pueden ser de origen cometario. Al igual que ocurre con los productos obtenidos por irradiación del hielo en nuestros experimentos, algunas IDPs son ricas en material orgánico que contiene oxígeno.

PubMed

Scotta, Ana Verónica; Bongiovanni, Guillermina Azucena; Soria, Elio Andrés

2018-03-21

Antecedentes: Clorpirifos es un pesticida altamente tóxico, que puede producir inmunotoxicidad con efectos deletéreos sobre la salud a nivel mundial. Por otro lado, las plantas americanas pueden tener derivados con actividad protectora e inmunoestimulante. Por lo tanto, debe evaluarse el potencial de estas plantas frente a clorpirifos. Objetivo: Identificar extractos acuosos bioactivos de Lantana grisebachii (LG), Aspidosperma quebracho-blanco (AQ), Peumus boldus (PB), e Ilex paraguariensis (IP), contra la toxicidad de clorpirifos sobre esplenocitos de hembras Balb/c. Materiales y Métodos: Esplenocitos fueron tratados in vitro por 72 horas con 0-35 µg/mL de clorpirifos, 0-100 µg/mL de cada extracto (LG, AQ, PB, IP) y 0-5 µg/mL de concanavalina A. Luego, se midió y analizó estadísticamente viabilidad y muerte celular (tinciones de resazurina y yoduro de propidio), hidroperóxidos, lipoperóxidos (ensayos basados en naranja de xilenol), actividad de la ?-glutamiltranspeptidasa (método de Szasz). Resultados: Clorpirifos redujo la viabilidad celular de forma dosis dependiente, lo que fue contrarrestado por AQ e IP, los que fueron menos activos en las células inducibles por concanavalina A (p<0,05). La toxicidad por clorpirifos implicó la inducción de la ?-glutamiltranspeptidasa con la consecuente reducción de los peróxidos, mientras que AQ y principalmente IP antagonizaron dichas respuestas (p<0,05). Conclusiones: Los extractos de Ilex paraguariensis y Aspidosperma quebracho-blanco protegieron in vitro a los esplenocitos frente a clorpirifos. Este efecto dependió del tipo celular, dado que las células inducibles por concanavalina A fueron más susceptibles a este tóxico.

Sistemas de transporte inteligentes en cruces fronterizos internacionales : un estudio abarcador : facilitando el comercio y mejorando la seguridad en el transporte

DOT National Transportation Integrated Search

2001-04-01

El Programa de Permisosen Fronteras Internacionales (IBC por sus siglas en ingls) fue iniciado bajo la previsin del Acta de Eficiencia de Transporte Terrestre Intermodal (ISTEA por sus siglas en ingls) en 1991. El programa fue concebido origina...

Evaluation of a 3year intervention to increase adoption of safer nursery crop production practices.

PubMed

Chapman, Larry J; Newenhouse, Astrid C; Karsh, Ben-Tzion

2010-01-01

We conducted a 3year intervention to increase awareness and adoption of eight more profitable nursery crop production practices that reduced certain traumatic and musculoskeletal injury hazards. We disseminated information to nursery managers across seven states using information channels they were known to rely on (e.g. trade publications, public events, university Extension, other managers). We evaluated rolling, independent, probability samples (n=1200) with mail questionnaires before the intervention and after each of 3 intervention years. We also evaluated samples (n=250) from a comparison group of New Zealand nursery managers. The intervention was associated with increased awareness of four of the eight practices among US managers after year 3 compared to their baseline: zippers (20 vs. 32%, p=0.000), stools (11 vs. 22%, p=0.001), pruners (29 vs. 40%, p=0.014), and tarps (24 vs. 33%, p=0.009). There were no changes in adoption. New Zealand manager awareness was increased for hoes after year 2 compared to their baseline (35 vs. 52%, p=0.010). A modest, regionwide information dissemination intervention was associated with increased awareness, but not adoption.

Nuevos sistemas de frecuencia intermedia para el IAR

NASA Astrophysics Data System (ADS)

Olalde, J. C.; Perilli, D.; Larrarte, J. J.

Se presenta el diagrama en bloques de los nuevos sistemas de Frecuencia Intermedia para los dos radiómetros instalados en el IAR. Entre las características más importantes del sistema podemos mencionar la posibilidad de conectar cualquiera de las dos antenas a los ``backend" disponibles: analizador espectral de alta resolución (META II) de 0,05 Hz, autocorrelador de 1008 canales y contínuo. Se incorporan al sistema nuevos sintetizadores de frecuencia implementados con PLL y la moderna técnica de síntesis digital directa. Por último, el conjunto del sistema es susceptible de ser configurado por las computadoras de adquisición de datos, supervisadas por otra, que entrega el estado de funcionamiento actual y evita la selección de configuraciones incorrectas por parte del usuario.

Novel approach for III-N on Si (111) templates fabrication by low-temperature PA MBE using porous Si layer

NASA Astrophysics Data System (ADS)

Zolotukhin, D.; Seredin, P.; Lenshin, A.; Goloshchapov, D.; Mizerov, A.

2017-11-01

We report on successful growth of GaN nanorods by low-temperature plasma-assisted molecular beam epitaxy on a Si(111) substrate with and without preformed thin porous Si layer (por-Si). The deposited GaN initially forms islands which act as a seed for the wires. Porous structure of the por-Si layer helps to control nucleation islands sizes and achieve homogeneous distribution of the nanorods diameters. In addition 850 nm-thick crack-free GaN layer was formed on Si(111) substrate with preformed por-Si layer.

Microbicidas Metodo de Prevencion en VIH/SIDA Controlado por Mujeres

PubMed Central

Ruiz, Cindy; Torres, Viviana; Cianelli, Rosina; Ferrer, Lilian

2016-01-01

HIV/AIDS continues to expand throughout the world, and in recent times has had a severe impact on the number of women living with HIV. Access to methods of prevention for HIV/AIDS around the world is limited and for many women may not be feasible. Examples of such methods are sexual abstinence, which though recognized as an effective method of prevention is difficult for many women to achieve. Mutual fidelity is another option, but many women cannot control the sexual behavior of their partners. Finally, the male condom continues to be an available method of HIV prevention for sexually active people. However, in many places, gender inequality, social norms, and economic disparities severely limit women's capacity to negotiate the use of a condom with their partner. For this reason, an urgent need exists to develop a product for the prevention of HIV/AIDS that can be handled by women. Microbicides, products that can reduce HIV risk when applied intravaginally, hold promise for stopping the advance of HIV/AIDS, especially when considering that women can make their own decisions about whether to use them when other methods of prevention are not available. The objective of the current literature review was to understand the scientific advances related to microbicides in the prevention of HIV/AIDS in women through the analysis of available literature in this area. Interest in this topic emerged from the need to contribute to women's health and HIV/AIDS prevention. To achieve this review's objective, a search was carried out in multiple databases, including OVID, PUBMED, PROQUEST, and CINAHL, as well as published materials from organizations related to this area such as UNAIDS and CONASIDA, and literature available from the Internet. Upon completion of the literature review, it was concluded that microbicides are an effective method for preventing HIV/AIDS for women as well as their partners. Although they have a high level of acceptance among the female population, the majority of microbicides are still in clinical studies, requiring further evaluation for their safe use in humans. There are 3 microbicides in the final phases of clinical studies that will soon be available on the market. One of these was found to be 60% effective in protecting against the transmission of HIV and was used by women in 50% of their sexual activity, which resulted in avoiding approximately 2.5 million new HIV infections in men, women, and children over a 3-year period. PMID:28111528

Microbicidas Metodo de Prevencion en VIH/SIDA Controlado por Mujeres.

PubMed

Ruiz, Cindy; Torres, Viviana; Cianelli, Rosina; Ferrer, Lilian

2009-03-01

HIV/AIDS continues to expand throughout the world, and in recent times has had a severe impact on the number of women living with HIV. Access to methods of prevention for HIV/AIDS around the world is limited and for many women may not be feasible. Examples of such methods are sexual abstinence, which though recognized as an effective method of prevention is difficult for many women to achieve. Mutual fidelity is another option, but many women cannot control the sexual behavior of their partners. Finally, the male condom continues to be an available method of HIV prevention for sexually active people. However, in many places, gender inequality, social norms, and economic disparities severely limit women's capacity to negotiate the use of a condom with their partner. For this reason, an urgent need exists to develop a product for the prevention of HIV/AIDS that can be handled by women. Microbicides, products that can reduce HIV risk when applied intravaginally, hold promise for stopping the advance of HIV/AIDS, especially when considering that women can make their own decisions about whether to use them when other methods of prevention are not available. The objective of the current literature review was to understand the scientific advances related to microbicides in the prevention of HIV/AIDS in women through the analysis of available literature in this area. Interest in this topic emerged from the need to contribute to women's health and HIV/AIDS prevention. To achieve this review's objective, a search was carried out in multiple databases, including OVID, PUBMED, PROQUEST, and CINAHL, as well as published materials from organizations related to this area such as UNAIDS and CONASIDA, and literature available from the Internet. Upon completion of the literature review, it was concluded that microbicides are an effective method for preventing HIV/AIDS for women as well as their partners. Although they have a high level of acceptance among the female population, the majority of microbicides are still in clinical studies, requiring further evaluation for their safe use in humans. There are 3 microbicides in the final phases of clinical studies that will soon be available on the market. One of these was found to be 60% effective in protecting against the transmission of HIV and was used by women in 50% of their sexual activity, which resulted in avoiding approximately 2.5 million new HIV infections in men, women, and children over a 3-year period.

Decade of Venezuela’s President Hugo Chavez, Por Ahora

DTIC Science & Technology

2009-04-01

minor production source of opium and cocoa , Venezuela is important in the transit of narcotics between Columbia and the US. 60 61 Mindful of this, a...took over.91 To highlight the significance of oil to Venezuela , in 2006, oil represented 91% of its exports compared to 80% five years earlier.92...methodology to examine the last ten years of Venezuelas Hugo Chavez presidency and the significant aspects in terms of US security. The paper contents

On the Use of "Por" Plus Agent with "Se" Construction

ERIC Educational Resources Information Center

De Mello, George

1978-01-01

Two explanations for the role of "se" in such constructions as "Se construyen casas" are given by grammarians; one states that it is a passive interpretation ("Houses are built"), the other advocates an impersonal interpretation ("One builds houses"). Different views are presented and analyzed. (Author/NCR)

Time spent traveling in motor vehicles and its association with overweight and abdominal obesity in Colombian adults who do not own a car.

PubMed

Flórez Pregonero, Alberto; Gómez, Luis Fernando; Parra, Diana C; Cohen, Daniel D; Arango Paternina, Carlos Mario; Lobelo, Felipe

2012-06-01

This study examined associations between time spent traveling in motor vehicles per week (TSTMV) and BMI and abdominal obesity (AO) among Colombian adults residing in urban areas who do not own car. Secondary data analysis of the 2005 National Nutrition Survey of Colombia was conducted. TSTMV was assessed using the long International Physical Activity Questionnaire. Body composition was measured in 7900 adults. Polytomous and binary logistic regressions were conducted, stratified by gender and adjusted for confounders, including physical activity (PA). Forty-two percent of participants were either overweight or obese according to their BMI, and 22.4% had AO. Males in the middle (10 to 149 min) and highest (>150 min) TSTMV tertiles were more likely to be overweight (POR=1.58, 95% CI=1.13-2.21 and POR=1.55, 95% CI=1.12-2.15 respectively, p-trend=0.012), obese (POR=2.39, 95% CI=1.43-3.99 and POR=1.93, 95% CI=1.22-3.08 respectively, p trend=0.019) and to have AO (POR=1.81, 95% CI=1.18-2.78 and POR=1.73, 95% CI=1.18-2.54 respectively, p-trend=0.009). Associations were not significant in females. TSTMV was positively associated with overweight and AO in adult Colombian males even after adjusting for PA. These findings highlight the potential deleterious health effects of sedentary behaviors such as prolonged traveling time, independently of having met PA recommendations. Copyright © 2012 Elsevier Inc. All rights reserved.

[Not Available].

PubMed

San Mauro Martin, Ismael; Mendive Dubourdieu, Paula; Paredes Barato, Víctor; Garicano Vilar, Elena

2016-07-19

Introducción: la tradición de la comida picante desempeña un papel muy importante en el gusto por este tipo de comida y su tolerancia. Las preferencias alimentarias muestran influencia genética y ambiental.Objetivos: estudiar la tolerancia y el gusto por el picante de tres poblaciones, y la influencia hereditaria y del ambiente.Métodos:se realizó una encuesta a 522 sujetos, de tres continentes (Asia, Europa y Latinoamérica) en tres idiomas (español, inglés y chino) a través de Internet. Se realizaron preguntas acerca de la tolerancia al picante, el gusto por los alimentos picantes, su uso, la edad de comienzo de consumo, el gusto del padre y de la madre y si ella lo consumía durante el embarazo y/o lactancia.Resultados: existe diferencia entre el gusto por el picante del hijo y el sexo (p < 0,001), la tolerancia (p < 0,001) y, solo en el sexo femenino, el gusto de la madre por el picante (p < 0,001), su consumo durante el embarazo (p < 0,001) y la lactancia (p = 0,005) y el gusto del padre por el picante (p = 0,003). Existe correlación entre el continente de residencia (p = 0,007) y de nacimiento (p = 0,012) y la tolerancia a los alimentos picantes.Conclusión: la influencia de los progenitores, el género y la composición corporal se relacionaron con gustos y tolerancias diferentes.

Sunburn and sun-protective behaviors among adults with and without previous nonmelanoma skin cancer: a population-based study

PubMed Central

Fischer, Alexander H.; Wang, Timothy S.; Yenokyan, Gayane; Kang, Sewon; Chien, Anna L.

2016-01-01

Background Individuals with previous nonmelanoma skin cancer (NMSC) are at increased risk for subsequent skin cancer, and should therefore limit UV exposure. Objective To determine whether individuals with previous NMSC engage in better sun protection than those with no skin cancer history. Methods We pooled self-reported data (2005 and 2010 National Health Interview Surveys) from US non-Hispanic white adults (758 with and 34,161 without previous NMSC). We calculated adjusted prevalence odds ratios (aPOR) and 95% confidence intervals (95% CI), taking into account the complex survey design. Results Individuals with previous NMSC versus no history of NMSC had higher rates of frequent use of shade (44.3% versus 27.0%; aPOR=1.41; 1.16–1.71), long sleeves (20.5% versus 7.7%; aPOR=1.55; 1.21–1.98), a wide-brimmed hat (26.1% versus 10.5%; aPOR=1.52; 1.24–1.87), and sunscreen (53.7% versus 33.1%; aPOR=2.11; 95% CI=1.73–2.59), but did not have significantly lower odds of recent sunburn (29.7% versus 40.7%; aPOR=0.95; 0.77–1.17). Among subjects with previous NMSC, recent sunburn was inversely associated with age, sun avoidance, and shade but not sunscreen. Limitations Self-reported cross-sectional data and unavailable information quantifying regular sun exposure. Conclusion Physicians should emphasize sunburn prevention when counseling patients with previous NMSC, especially younger adults, focusing on shade and sun avoidance over sunscreen. PMID:27198078

Factors associated with anemia in refugee children.

PubMed

Hassan, K; Sullivan, K M; Yip, R; Woodruff, B A

1997-11-01

A nutrition survey was performed in 1990 among children 6 through 35 mo of age living in Palestinian refugee camps in Syria, Jordan, the West Bank, Gaza Strip and Lebanon. Overall, 67% [95% confidence interval (CI): 66, 68] were anemic (hemoglobin <110 g/L), ranging from 54% in the West Bank to 75% in Syria. The following factors were significantly associated with anemia in one or more of three age groups (6-11.9, 12-23.9 and 24-35.9 mo) by logistic regression: living in Syria, Lebanon, or Gaza [with prevalence odds ratios (POR) in the range of 1.4-2.6 depending on the age group and area, relative to children living in Jordan]; never having been breast-fed (POR = 1.7); male sex (POR = 1.2); maternal illiteracy (POR = 1.4 relative to those with >/=6 y of education); having a recent (within 2 wk) or current episode of fever or diarrhea; and stunting. Recent or current illness and stunting interacted in two age groups with the general trend of stunted children with recent or current illness having high POR. Early childhood anemia is associated with factors reflecting poor socioeconomic status and recent diarrheal and febrile illnesses in Palestinian refugee camps.

Risk of specific congenital abnormalities in offspring of women with diabetes.

PubMed

Nielsen, G L; Nørgard, B; Puho, E; Rothman, K J; Sørensen, H T; Czeizel, A E

2005-06-01

To assess the extent to which the increased risk of congenital abnormalities seen in women with pre-gestational insulin-treated diabetes mellitus is unspecific or related to the embryology of specific organs. Cases with congenital abnormalities were identified in the population-based Hungarian Congenital Abnormality Registry from 1980 to 1996 with two newborn children without congenital abnormality selected from the National Birth Registry as controls. We adjusted for parity, maternal age, and use of antipsychotic drugs. Among cases we found 63/22,843 babies with maternal diabetes compared with 50/38,151 in the control group [adjusted prevalence odds ratio (POR) 2.1; 95% CI 1.5-3.1]. The association was strongest for the following congenital abnormalities: renal agenesis (POR: 14.8; 95% CI, 3.5-62.1), obstructive congenital abnormalities of the urinary tract (POR: 4.3; 95% CI, 1.3-13.9), cardiovascular congenital abnormalities (POR: 3.4; 95% CI, 2.0-5.7), and multiple congenital abnormalities (POR: 5.0; 95% CI, 2.4-10.2). These data indicate that pre-gestational maternal diabetes is associated with strong teratogenic effects on the kidney, urinary tract, and heart, and strongly associated with multiple congenital abnormalities. We found no material association between diabetes and spinal congenital abnormalities and limb deficiencies.

Using MOMP typing as an epidemiological tool to investigate outbreaks caused by milkborne Campylobacter jejuni isolates in California

USDA-ARS?s Scientific Manuscript database

We describe using major outer membrane protein (MOMP) typing as a screen to compare the C. jejuni porA gene sequences of clinical outbreak strains from human stool with the porA sequences of dairy farm strains isolated during two milkborne campylobacteriosis outbreak investigations in California. Th...

Unidades generadoras de energía eléctrica para servicios públicos: Revocación del Plan de Energía Limpia: Propuesta

EPA Pesticide Factsheets

La EPA está proponiendo la revocación del Plan de Energía Limpia (CPP, por sus siglas en inglés) – después de completar una revisión minuciosa como fue dictaminada por la Orden Ejecutiva de Independencia Energética.

78 FR 29322 - Silicon Metal From the People's Republic of China: Final Results and Final No Shipments...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-20

... People's Republic of China: Final Results and Final No Shipments Determination of Antidumping Duty... the People's Republic of China (``PRC'').\\1\\ The period of review (``POR'') is June 1, 2011, through... any reviewable transactions during the POR. \\1\\ See Silicon Metal From the People's Republic of China...

77 FR 28570 - Honey From Argentina: Extension of Time Limit for the Final Results of Antidumping Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-15

... DEPARTMENT OF COMMERCE International Trade Administration [A-357-812] Honey From Argentina... administrative review for the 2009-2010 period of review (POR) of honey from Argentina. See Honey From Argentina... producers/exporters of honey from Argentina during the POR.\\1\\ \\1\\ See Preliminary Results for a detailed...

El nuevo panorama de la Dinámica Galáctica

NASA Astrophysics Data System (ADS)

Pivovaroff, Michael James

En general, la tendencia imperante en Dinámica Galáctica ha sido considerar que los movimientos estelares son básicamente regulares y que el caos no tiene mayor relevancia en los sistemas estelares. Sin embargo, en el último lustro se vienen acumulando pruebas de la importancia del movimiento caótico en ciertos sistemas estelares que existen en la naturaleza. Por una parte, sobre todo el grupo de David Merritt, lo ha mostrado en los casos de galaxias elípticas con concentraciones centrales de materia; por otra parte, en nuestro propio grupo, lo hemos mostrado para el caso de los satélites galácticos. Las consecuencias de estos hallazgos son tanto de tipo técnico, por la necesidad de construir modelos que contengan órbitas caóticas, como astrofísico, por los efectos del caos sobre la estacionariedad y evolución de los sistemas estelares en los que se presenta.

Tyrosine oxidation in heme oxygenase: examination of long-range proton-coupled electron transfer.

PubMed

Smirnov, Valeriy V; Roth, Justine P

2014-10-01

Heme oxygenase is responsible for the degradation of a histidine-ligated ferric protoporphyrin IX (Por) to biliverdin, CO, and the free ferrous ion. Described here are studies of tyrosyl radical formation reactions that occur after oxidizing Fe(III)(Por) to Fe(IV)=O(Por(·+)) in human heme oxygenase isoform-1 (hHO-1) and the structurally homologous protein from Corynebacterium diphtheriae (cdHO). Site-directed mutagenesis on hHO-1 probes the reduction of Fe(IV)=O(Por(·+)) by tyrosine residues within 11 Å of the prosthetic group. In hHO-1, Y58· is implicated as the most likely site of oxidation, based on the pH and pD dependent kinetics. The absence of solvent deuterium isotope effects in basic solutions of hHO-1 and cdHO contrasts with the behavior of these proteins in the acidic solution, suggesting that long-range proton-coupled electron transfer predominates over electron transfer.

Genetic variations in NADPH-CYP450 oxidoreductase in a Czech Slavic cohort.

PubMed

Tomková, Mária; Panda, Satya Prakash; Šeda, Ondřej; Baxová, Alice; Hůlková, Martina; Siler Masters, Bettie Sue; Martásek, Pavel

2015-01-01

Estimating polymorphic allele frequencies of the NADPH-CYP450 oxidoreductase (POR) gene in a Czech Slavic population. The POR gene was analyzed in 322 individuals from a control cohort by sequencing and high resolution melting analysis. We identified seven unreported SNP genetic variations, including two SNPs in the 5' flanking region (g.4965C>T and g.4994G>T), one intronic variant (c.1899-20C>T), one synonymous SNP (p.20Ala=) and three nonsynonymous SNPs (p.Thr29Ser, p.Pro384Leu and p.Thr529Met). The p.Pro384Leu variant exhibited reduced enzymatic activities compared with wild-type. New POR variant identification indicates the number of uncommon variants might be specific for each subpopulation being investigated, particularly germane to the singular role that POR plays in providing reducing equivalents to all CYP450s in the endoplasmic reticulum. Original submitted 15 September 2014; Revision submitted 17 November 2014.

Observational study to calculate addictive risk to opioids: a validation study of a predictive algorithm to evaluate opioid use disorder.

PubMed

Brenton, Ashley; Richeimer, Steven; Sharma, Maneesh; Lee, Chee; Kantorovich, Svetlana; Blanchard, John; Meshkin, Brian

2017-01-01

Opioid abuse in chronic pain patients is a major public health issue, with rapidly increasing addiction rates and deaths from unintentional overdose more than quadrupling since 1999. This study seeks to determine the predictability of aberrant behavior to opioids using a comprehensive scoring algorithm incorporating phenotypic risk factors and neuroscience-associated single-nucleotide polymorphisms (SNPs). The Proove Opioid Risk (POR) algorithm determines the predictability of aberrant behavior to opioids using a comprehensive scoring algorithm incorporating phenotypic risk factors and neuroscience-associated SNPs. In a validation study with 258 subjects with diagnosed opioid use disorder (OUD) and 650 controls who reported using opioids, the POR successfully categorized patients at high and moderate risks of opioid misuse or abuse with 95.7% sensitivity. Regardless of changes in the prevalence of opioid misuse or abuse, the sensitivity of POR remained >95%. The POR correctly stratifies patients into low-, moderate-, and high-risk categories to appropriately identify patients at need for additional guidance, monitoring, or treatment changes.

Transmission scenarios of major vector-borne diseases in Colombia, 1990-2016.

PubMed

Padilla, Julio César; Lizarazo, Fredy Eberto; Murillo, Olga Lucía; Mendigaña, Fernando Antonio; Pachón, Edwin; Vera, Mauricio Javier

2017-03-29

Introducción. Las enfermedades transmitidas por vectores representan más de 17 % de todas las enfermedades infecciosas y causan anualmente un millón de defunciones a nivel mundial. En Colombia, la malaria, el dengue, la enfermedad de Chagas y las leishmaniasis son condiciones endemoepidémicas persistentes.Objetivo. Determinar el comportamiento epidemiológico de las enfermedades transmitidas por vectores en zonas urbanas y rurales de Colombia entre 1990 y 2016.Materiales y métodos. Se hizo un estudio descriptivo del comportamiento epidemiológico de las principales enfermedades transmitidas por vectores en zonas urbanas y rurales de Colombia entre 1990 y 2016, con la información proveniente de fuentes oficiales secundarias.Resultados. En el periodo estudiado se registraron 5'360.134 casos de enfermedades transmitidas por vectores, de los cuales 54,7 % fueron de malaria y 24,9 % de dengue. Estos casos concentraron el 80 % de la carga acumulada de casos de enfermedades transmitidas por vectores. Las medianas de las tasas de incidencia fueron 1.371 y 188 por 100.00 habitantes para malaria y dengue, respectivamente. Además, los casos de chikungunya fueron 774.831 desde su introducción en el 2014 y, los de Zika, 117.674 desde su aparición en 2015. En las zonas rurales predominaron las enfermedades parasitarias transmitidas por vectores como la malaria, las leishmaniasis y la enfermedad de Chagas. A nivel urbano, predominaron el dengue, el chikungunya y el Zika.Conclusiones. La transmisión en Colombia de estas enfermedades es persistente en las zonas urbanas y en las rurales, y de tipo endemoepidémico en los casos de malaria, dengue, leishmaniasis y enfermedad de Chagas. Dicha transmisión se ha dado de manera focalizada y con patrones variables de intensidad. Asimismo, se mantienen las condiciones que han favorecido la transmisión emergente de nuevas arbovirosis.

76 FR 26241 - Certain Frozen Warmwater Shrimp From Thailand: Notice of Court Decision Not in Harmony With Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-06

... Shrimp From Thailand: Notice of Court Decision Not in Harmony With Final Results of Administrative Review... Thailand covering the period of review (POR) of February 1, 2006, through January 31, 2007. DATES... administrative review of certain frozen warmwater shrimp from Thailand covering the POR of February 1, 2006...

Proyecto Energético Palmdale; Decisión del Permiso Final

EPA Pesticide Factsheets

Proyecto Energético Palmdale: EPA Región 9 por el presente emite aviso de su decisión final, el cumplimiento con la Ley Federal de Aire Limpio, para la construcción de una planta generadora de electricidad de ciclo combinado y alimentada por gas natural

PubMed

Escandón-Nagel, Neli

2016-11-29

Introducción: si bien el Trastorno por Atracón es un trastorno de la conducta alimentaria que  no se da exclusivamente en personas obesas, es más común en este grupo que en sujetos con normopeso, sin embargo no todas las personas con malnutrición por exceso presentan Trastorno por Atracón. Objetivo: identificar el conocimiento actual respecto a las diferencias y semejanzas existentes entre personas con malnutrición por exceso con y sin Trastorno por Atracón.Método: para lograr el objetivo anterior, se realizó una revisión de artículos científicos en torno al tema.Resultados: primero se analizó la comorbilidad psicopatológica en obesidad y después se detectaron similitudes y diferencias entre los grupos de interés, tanto en sintomatología general, como así también en sintomatología de la conducta alimentaria. Además, se identificaron algunos aspectos controversiales, en que existe evidencia contradictoria respecto a la comparación intergrupal.Conclusión: de esta revisión se concluye que en el estudio de la obesidad se hace necesario conocer en mayor profundidad las características del subgrupo de pacientes que además presenta Trastorno por Atracón,  ya que estas personas poseen características distintivas cuyo conocimiento permitirá ofrecer tratamientos integrales más adecuados a las necesidades de los pacientes, lo que posibilitará, en consecuencia, diseñar intervenciones más eficaces.

[Not Available].

PubMed

Latorre-Román, Pedro Ángel; Martínez-López, Emilio José; Ruiz-Ariza, Alberto; Izquierdo-Rus, Tomás; Salas-Sánchez, Jesús; García-Pinillos, Felipe

2016-06-30

Objetivo: el objetivo de este estudio es evaluar las propiedades psicométricas del cuestionario de disfrute por el ejercicio físico (PACES) en adolescentes con sobrepeso y obesidad.Métodos: participaron 139 adolescentes con sobrepeso y obesidad: 91 niñas (edad = 13,85 ± 1,92 años; índice de masa corporal [IMC] = 26,83 ± 3,16 kg/m2) y 48 niños (edad = 14,29 ± 1,62 años; IMC = 28,31 ± 3,74 kg/m2). Para analizar el disfrute por la actividad física se empleó el cuestionario Physical Activity Enjoyment Scale (PACES).Resultados: los resultados del análisis factorial exploratorio y confirmatorio han mostrado una estructura de dos factores; a su vez el PACES presenta una consistencia interna muy alta (alfa de Cronbach = 0,908). La fiabilidad test-retest indica una buena concordancia temporal (Spearman rho = 0,815, p < 0,001). Por último, el PACES en adolescentes con sobrepeso y obesidad manifiesta una validez convergente adecuada con la intencionalidad de ser activo (MIFA), la atracción por la actividad física (CAPA), la resistencia cardiorrespiratoria y los pliegues suprailiacoy subescapular.Conclusión: los resultados confirman que el PACES es una medida válida y fiable del disfrute por la actividad física en adolescentes con sobrepeso y obesidad. El disfrute por la actividad física puede ser relevante en la participación de los adolescentes con sobrepeso y obesidad en estas actividades.

LIL3, a Light-Harvesting Complex Protein, Links Terpenoid and Tetrapyrrole Biosynthesis in Arabidopsis thaliana1[OPEN

PubMed Central

Rothbart, Maxi; Herbst, Josephine; Wittmann, Daniel; Gruhl, Kirsten

2017-01-01

The LIL3 protein of Arabidopsis (Arabidopsis thaliana) belongs to the light-harvesting complex (LHC) protein family, which also includes the light-harvesting chlorophyll-binding proteins of photosystems I and II, the early-light-inducible proteins, PsbS involved in nonphotochemical quenching, and the one-helix proteins and their cyanobacterial homologs designated high-light-inducible proteins. Each member of this family is characterized by one or two LHC transmembrane domains (referred to as the LHC motif) to which potential functions such as chlorophyll binding, protein interaction, and integration of interacting partners into the plastid membranes have been attributed. Initially, LIL3 was shown to interact with geranylgeranyl reductase (CHLP), an enzyme of terpene biosynthesis that supplies the hydrocarbon chain for chlorophyll and tocopherol. Here, we show another function of LIL3 for the stability of protochlorophyllide oxidoreductase (POR). Multiple protein-protein interaction analyses suggest the direct physical interaction of LIL3 with POR but not with chlorophyll synthase. Consistently, LIL3-deficient plants exhibit substantial loss of POR as well as CHLP, which is not due to defective transcription of the POR and CHLP genes but to the posttranslational modification of their protein products. Interestingly, in vitro biochemical analyses provide novel evidence that LIL3 shows high binding affinity to protochlorophyllide, the substrate of POR. Taken together, this study suggests a critical role for LIL3 in the organization of later steps in chlorophyll biosynthesis. We suggest that LIL3 associates with POR and CHLP and thus contributes to the supply of the two metabolites, chlorophyllide and phytyl pyrophosphate, required for the final step in chlorophyll a synthesis. PMID:28432258

Sunburn and sun-protective behaviors among adults with and without previous nonmelanoma skin cancer (NMSC): A population-based study.

PubMed

Fischer, Alexander H; Wang, Timothy S; Yenokyan, Gayane; Kang, Sewon; Chien, Anna L

2016-08-01

Individuals with previous nonmelanoma skin cancer (NMSC) are at increased risk for subsequent skin cancer, and should therefore limit ultraviolet exposure. We sought to determine whether individuals with previous NMSC engage in better sun protection than those with no skin cancer history. We pooled self-reported data (2005 and 2010 National Health Interview Surveys) from US non-Hispanic white adults (758 with and 34,161 without previous NMSC). We calculated adjusted prevalence odds ratios (aPOR) and 95% confidence intervals (CI), taking into account the complex survey design. Individuals with previous NMSC versus no history of NMSC had higher rates of frequent use of shade (44.3% vs 27.0%; aPOR 1.41; 95% CI 1.16-1.71), long sleeves (20.5% vs 7.7%; aPOR 1.55; 95% CI 1.21-1.98), a wide-brimmed hat (26.1% vs 10.5%; aPOR 1.52; 95% CI 1.24-1.87), and sunscreen (53.7% vs 33.1%; aPOR 2.11; 95% CI 1.73-2.59), but did not have significantly lower odds of recent sunburn (29.7% vs 40.7%; aPOR 0.95; 95% CI 0.77-1.17). Among those with previous NMSC, recent sunburn was inversely associated with age, sun avoidance, and shade but not sunscreen. Self-reported cross-sectional data and unavailable information quantifying regular sun exposure are limitations. Physicians should emphasize sunburn prevention when counseling patients with previous NMSC, especially younger adults, focusing on shade and sun avoidance over sunscreen. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

LIL3, a Light-Harvesting Complex Protein, Links Terpenoid and Tetrapyrrole Biosynthesis in Arabidopsis thaliana.

PubMed

Hey, Daniel; Rothbart, Maxi; Herbst, Josephine; Wang, Peng; Müller, Jakob; Wittmann, Daniel; Gruhl, Kirsten; Grimm, Bernhard

2017-06-01

The LIL3 protein of Arabidopsis ( Arabidopsis thaliana ) belongs to the light-harvesting complex (LHC) protein family, which also includes the light-harvesting chlorophyll-binding proteins of photosystems I and II, the early-light-inducible proteins, PsbS involved in nonphotochemical quenching, and the one-helix proteins and their cyanobacterial homologs designated high-light-inducible proteins. Each member of this family is characterized by one or two LHC transmembrane domains (referred to as the LHC motif) to which potential functions such as chlorophyll binding, protein interaction, and integration of interacting partners into the plastid membranes have been attributed. Initially, LIL3 was shown to interact with geranylgeranyl reductase (CHLP), an enzyme of terpene biosynthesis that supplies the hydrocarbon chain for chlorophyll and tocopherol. Here, we show another function of LIL3 for the stability of protochlorophyllide oxidoreductase (POR). Multiple protein-protein interaction analyses suggest the direct physical interaction of LIL3 with POR but not with chlorophyll synthase. Consistently, LIL3-deficient plants exhibit substantial loss of POR as well as CHLP, which is not due to defective transcription of the POR and CHLP genes but to the posttranslational modification of their protein products. Interestingly, in vitro biochemical analyses provide novel evidence that LIL3 shows high binding affinity to protochlorophyllide, the substrate of POR. Taken together, this study suggests a critical role for LIL3 in the organization of later steps in chlorophyll biosynthesis. We suggest that LIL3 associates with POR and CHLP and thus contributes to the supply of the two metabolites, chlorophyllide and phytyl pyrophosphate, required for the final step in chlorophyll a synthesis. © 2017 American Society of Plant Biologists. All Rights Reserved.

Faecal calprotectin and magnetic resonance imaging in detecting Crohn's disease endoscopic postoperative recurrence.

PubMed

Baillet, Pierre; Cadiot, Guillaume; Goutte, Marion; Goutorbe, Felix; Brixi, Hedia; Hoeffel, Christine; Allimant, Christophe; Reymond, Maud; Obritin-Guilhen, Hélène; Magnin, Benoit; Bommelaer, Gilles; Pereira, Bruno; Hordonneau, Constance; Buisson, Anthony

2018-02-07

To assess magnetic resonance imaging (MRI) and faecal calprotectin to detect endoscopic postoperative recurrence in patients with Crohn's disease (CD). From two tertiary centers, all patients with CD who underwent ileocolonic resection were consecutively and prospectively included. All the patients underwent MRI and endoscopy within the first year after surgery or after the restoration of intestinal continuity [median = 6 mo (5.0-9.3)]. The stools were collected the day before the colonoscopy to evaluate faecal calprotectin level. Endoscopic postoperative recurrence (POR) was defined as Rutgeerts' index ≥ i2b. The MRI was analyzed independently by two radiologists blinded from clinical data. Apparent diffusion coefficient (ADC) was lower in patients with endoscopic POR compared to those with no recurrence (2.03 ± 0.32 vs 2.27 ± 0.38 × 10 -3 mm²/s, P = 0.032). Clermont score (10.4 ± 5.8 vs 7.4 ± 4.5, P = 0.038) and relative contrast enhancement (RCE) (129.4% ± 62.8% vs 76.4% ± 32.6%, P = 0.007) were significantly associated with endoscopic POR contrary to the magnetic resonance index of activity (MaRIA) (7.3 ± 4.5 vs 4.8 ± 3.7; P = 0.15) and MR scoring system ( P = 0.056). ADC < 2.35 × 10 -3 mm²/s [sensitivity = 0.85, specificity = 0.65, positive predictive value (PPV) = 0.85, negative predictive value (NPV) = 0.65] and RCE > 100% (sensitivity = 0.75, specificity = 0.81, PPV = 0.75, NPV = 0.81) were the best cut-off values to identify endoscopic POR. Clermont score > 6.4 (sensitivity = 0.61, specificity = 0.82, PPV = 0.73, NPV = 0.74), MaRIA > 3.76 (sensitivity = 0.61, specificity = 0.82, PPV = 0.73, NPV = 0.74) and a MR scoring system ≥ MR1 (sensitivity = 0.54, specificity = 0.82, PPV = 0.70, and NPV = 0.70) demonstrated interesting performances to detect endoscopic POR. Faecal calprotectin values were significantly higher in patients with endoscopic POR (114 ± 54.5 μg/g vs 354.8 ± 432.5 μg/g; P = 0.0075). Faecal calprotectin > 100 �

Faecal calprotectin and magnetic resonance imaging in detecting Crohn’s disease endoscopic postoperative recurrence

PubMed Central

Baillet, Pierre; Cadiot, Guillaume; Goutte, Marion; Goutorbe, Felix; Brixi, Hedia; Hoeffel, Christine; Allimant, Christophe; Reymond, Maud; Obritin-Guilhen, Hélène; Magnin, Benoit; Bommelaer, Gilles; Pereira, Bruno; Hordonneau, Constance; Buisson, Anthony

2018-01-01

AIM To assess magnetic resonance imaging (MRI) and faecal calprotectin to detect endoscopic postoperative recurrence in patients with Crohn’s disease (CD). METHODS From two tertiary centers, all patients with CD who underwent ileocolonic resection were consecutively and prospectively included. All the patients underwent MRI and endoscopy within the first year after surgery or after the restoration of intestinal continuity [median = 6 mo (5.0-9.3)]. The stools were collected the day before the colonoscopy to evaluate faecal calprotectin level. Endoscopic postoperative recurrence (POR) was defined as Rutgeerts’ index ≥ i2b. The MRI was analyzed independently by two radiologists blinded from clinical data. RESULTS Apparent diffusion coefficient (ADC) was lower in patients with endoscopic POR compared to those with no recurrence (2.03 ± 0.32 vs 2.27 ± 0.38 × 10-3 mm²/s, P = 0.032). Clermont score (10.4 ± 5.8 vs 7.4 ± 4.5, P = 0.038) and relative contrast enhancement (RCE) (129.4% ± 62.8% vs 76.4% ± 32.6%, P = 0.007) were significantly associated with endoscopic POR contrary to the magnetic resonance index of activity (MaRIA) (7.3 ± 4.5 vs 4.8 ± 3.7; P = 0.15) and MR scoring system (P = 0.056). ADC < 2.35 × 10-3 mm²/s [sensitivity = 0.85, specificity = 0.65, positive predictive value (PPV) = 0.85, negative predictive value (NPV) = 0.65] and RCE > 100% (sensitivity = 0.75, specificity = 0.81, PPV = 0.75, NPV = 0.81) were the best cut-off values to identify endoscopic POR. Clermont score > 6.4 (sensitivity = 0.61, specificity = 0.82, PPV = 0.73, NPV = 0.74), MaRIA > 3.76 (sensitivity = 0.61, specificity = 0.82, PPV = 0.73, NPV = 0.74) and a MR scoring system ≥ MR1 (sensitivity = 0.54, specificity = 0.82, PPV = 0.70, and NPV = 0.70) demonstrated interesting performances to detect endoscopic POR. Faecal calprotectin values were significantly higher in patients with endoscopic POR (114 ± 54.5 μg/g vs 354.8 ± 432.5 μg/g; P = 0.0075). Faecal

76 FR 34296 - Proposed Collection; Comment Request for Forms 1040-PR and 1040-SS

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-13

... Form 1040-PR, Planilla para la Declaraci[oacute]n de la Contribuci[oacute]n Federal sobre el Trabajo... Trabajo por Cuenta Propia (Incluyendo el Cr[eacute]dito Tributario Adicional por Hijos para Residentes... Subtitle A, and provide credit to the taxpayer's social security account. Anejo H-PR is used to compute...

77 FR 77017 - Certain Orange Juice From Brazil: Notice of Court Decision Not in Harmony With Final Results of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-31

..., International Trade Administration, Department of Commerce. SUMMARY: On October 24, 2012, the United States... juice (OJ) from Brazil covering the period of review (POR) of March 1, 2008, through February 28, 2009... administrative review of OJ from Brazil covering the POR of March 1, 2008, through February 28, 2009. See Certain...

La EPA ayuda a restaurar el laboratorio de ciencias de Puerto Rico y las capacidades de monitorear la calidad del aire

EPA Pesticide Factsheets

La EPA continúa ayudando a Puerto Rico a responder tras los daños causados por los huracanes Irma y María. La EPA, conforme a una misión asignada por FEMA, y en estrecha cooperación con el gobierno de Puerto Rico, se encuentra apoya

Two dimensional self-assembly zinc porphyrins and zinc phthalocyanines heterojunctions with record high power conversion efficiencies.

PubMed

Yu, Junting; Jiang, Zhou; Hao, Yifan; Zhu, Qianhong; Zhao, Mingliang; Jiang, Xue; Zhao, Jijun

2018-05-15

Compared to inorganic solar cells, the power conversion efficiencies (PCEs) of organic solar cells are much lower, but they are compensated by many merits such as lower cost, less weight, and tunable structures, making them prospective for further applications. Porphyrin and phthalocyanine are the two most significant materials for organic solar cells due to their strong light-absorbing properties and semiconductor characteristics. However, there is little research on the 2D heterojunction solar cells based on these two materials, meanwhile the PCEs of them are still low. Here we have self-assembled several 2D Zinc-porphyrins (ZnPors) and performed first-principles simulation to demonstrate their good stability, suitable light harvesting, and high charge carrier mobility. By perfectly matching lattice constants and band levels between those 2D ZnPors and our previous proposed ZnPcs, eleven type-II organic heterojunctions are constructed to further improve their charge separation capability. Those advantages endow 2D ZnPors and ZnPcs appreciable PCEs for solar cell. Among them, the theoretical PCE of 2D ZnPors/ZnPcs heterojunctions achieves as high as 19.84%, which prevails all reported organic solar cells, and even approaches the PCEs of inorganic solar cells. These results indicate that our 2D ZnPors and 2D ZnPcs are good candidate materials for future organic solar cells. © 2018 IOP Publishing Ltd.

Two dimensional self-assembly zinc porphyrin and zinc phthalocyanine heterojunctions with record high power conversion efficiencies

NASA Astrophysics Data System (ADS)

Yu, Junting; Jiang, Zhou; Hao, Yifan; Zhu, Qianhong; Zhao, Mingliang; Jiang, Xue; Zhao, Jijun

2018-06-01

Compared to inorganic solar cells, the power conversion efficiencies (PCEs) of organic solar cells are much lower, but they are compensated by many merits such as lower cost, less weight, and tunable structures, making them prospective for further applications. Porphyrin and phthalocyanine are the two most significant materials for organic solar cells due to their strong light-absorbing properties and semiconductor characteristics. However, there is little research on the 2D heterojunction solar cells based on these two materials, meanwhile the PCEs of them are still low. Here we have self-assembled several 2D zinc porphyrins (ZnPors) and performed first-principles simulation to demonstrate their good stability, suitable light harvesting, and high charge carrier mobility. By perfectly matching lattice constants and molecular energy levels between those 2D ZnPors and our previous proposed zinc phthalocyanines (ZnPcs), 11 type-II organic heterojunctions are constructed to further improve their charge separation capability. Those advantages endow 2D ZnPors and ZnPcs appreciable PCEs for solar cells. Among them, the theoretical PCE of 2D ZnPors/ZnPcs heterojunctions achieves as high as 19.84%, which exceeds all reported organic solar cells, and even approaches the PCEs of inorganic solar cells. These results indicate that our 2D ZnPors and 2D ZnPcs are good candidate materials for future organic solar cells.

78 FR 79665 - Welded Carbon Steel Standard Pipe and Tube Products From Turkey: Final Results of Antidumping...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-31

... Pipe and Tube Products From Turkey: Final Results of Antidumping Duty Administrative Review; 2011-2012... pipe and tube products (welded pipe and tube) from Turkey.\\1\\ The period of review (POR) is May 1, 2011... during the POR.\\2\\ \\1\\ See Welded Carbon Steel Standard Pipe and Tube Products from Turkey: Preliminary...

Differentiation‐associated urothelial cytochrome P450 oxidoreductase predicates the xenobiotic‐metabolizing activity of “luminal” muscle‐invasive bladder cancers

PubMed Central

Arlt, Volker M.; Indra, Radek; Joel, Madeleine; Stiborová, Marie; Eardley, Ian; Ahmad, Niaz; Otto, Wolfgang; Burger, Maximilian; Rubenwolf, Peter; Phillips, David H.; Southgate, Jennifer

2018-01-01

Extra‐hepatic metabolism of xenobiotics by epithelial tissues has evolved as a self‐defence mechanism but has potential to contribute to the local activation of carcinogens. Bladder epithelium (urothelium) is bathed in excreted urinary toxicants and pro‐carcinogens. This study reveals how differentiation affects cytochrome P450 (CYP) activity and the role of NADPH:P450 oxidoreductase (POR). CYP1A1 and CYP1B1 transcripts were inducible in normal human urothelial (NHU) cells maintained in both undifferentiated and functional barrier‐forming differentiated states in vitro. However, ethoxyresorufin O‐deethylation (EROD) activity, the generation of reactive BaP metabolites and BaP‐DNA adducts, were predominantly detected in differentiated NHU cell cultures. This gain‐of‐function was attributable to the expression of POR, an essential electron donor for all CYPs, which was significantly upregulated as part of urothelial differentiation. Immunohistology of muscle‐invasive bladder cancer (MIBC) revealed significant overall suppression of POR expression. Stratification of MIBC biopsies into “luminal” and “basal” groups, based on GATA3 and cytokeratin 5/6 labeling, showed POR over‐expression by a subgroup of the differentiated luminal tumors. In bladder cancer cell lines, CYP1‐activity was undetectable/low in basal PORlo T24 and SCaBER cells and higher in the luminal POR over‐expressing RT4 and RT112 cells than in differentiated NHU cells, indicating that CYP‐function is related to differentiation status in bladder cancers. This study establishes POR as a predictive biomarker of metabolic potential. This has implications in bladder carcinogenesis for the hepatic versus local activation of carcinogens and as a functional predictor of the potential for MIBC to respond to prodrug therapies. PMID:29323757

Association of low dietary intake of fiber and liquids with constipation: evidence from the National Health and Nutrition Examination Survey.

PubMed

Markland, Alayne D; Palsson, Olafur; Goode, Patricia S; Burgio, Kathryn L; Busby-Whitehead, Jan; Whitehead, William E

2013-05-01

Epidemiological studies support an association of self-defined constipation with fiber and physical activity, but not liquid intake. The aims of this study were to assess the prevalence and associations of dietary fiber and liquid intake to constipation. Analyses were based on data from 10,914 adults (≥20 years) from the 2005-2008 cycles of the National Health and Nutrition Examination Surveys. Constipation was defined as hard or lumpy stools (Bristol Stool Scale type 1 or 2) as the "usual or most common stool type." Dietary fiber and liquid intake from total moisture content were obtained from dietary recall. Co-variables included: age, race, education, poverty income ratio, body mass index, self-reported general health status, chronic illnesses, and physical activity. Prevalence estimates and prevalence odds ratios (POR) were analyzed in adjusted multivariable models using appropriate sampling weights. Overall, 9,373 (85.9%) adults (4,787 women and 4,586 men) had complete stool consistency and dietary data. Constipation rates were 10.2% (95% confidence interval (CI): 9.6, 10.9) for women and 4.0% (95% CI: 3.2, 5.0) for men (P<.001). After multivariable adjustment, low liquid consumption remained a predictor of constipation among women (POR: 1.3, 95% CI: 1.0, 1.6) and men (POR: 2.4, 95% CI: 1.5, 3.9); however, dietary fiber was not a predictor. Among women, African-American race/ethnicity (POR: 1.4, 95% CI: 1.0, 1.9), being obese (POR: 0.7, 95% CI: 0.5,0.9), and having a higher education level (POR: 0.8, 95% CI: 0.7, 0.9) were significantly associated with constipation. The findings support clinical recommendations to treat constipation with increased liquid, but not fiber or exercise.

Association of Low Dietary Intake of Fiber and Liquids with Constipation: Evidence from the National Health and Nutrition Examination Survey (NHANES)

PubMed Central

Markland, Alayne D.; Palsson, Olafur; Goode, Patricia S.; Burgio, Kathryn L.; Busby-Whitehead, Jan; Whitehead, William E.

2013-01-01

Objective Epidemiological studies support an association of self-defined constipation with fiber and physical activity, but not liquid intake. The aims of this study were to assess the prevalence and associations of dietary fiber and liquid intake to constipation. Methods Analyses were based on data from 10,914 adults (≥20 years) from the 2005-2008 cycles of the National Health and Nutrition Examination Surveys (NHANES). Constipation was defined as hard or lumpy stools (Bristol Stool Scale types 1 or 2) as the “usual or most common stool type.” Dietary fiber and liquid intake from total moisture content were obtained from dietary recall. Co-variables included: age, race, education, poverty income ratio, body mass index, self-reported general health status, chronic illnesses, and physical activity. Prevalence estimates and prevalence odds ratios (POR) were analyzed in adjusted multivariable models using appropriate sampling weights. Results Overall, 9,373 (85.9%) adults (4,787 women and 4,586 men) had complete stool consistency and dietary data. Constipation rates were 10.2% (95% CI: 9.6,10.9) for women and 4.0 (95% CI: 3.2,5.0) for men (p<.001). After multivariable adjustment, low liquid consumption remained a predictor of constipation among women (POR: 1.3, 95% CI: 1.0,1.6) and men (POR: 2.4, 95% CI: 1.5,3.9); however, dietary fiber was not a predictor. Among women, African-American race/ethnicity (POR: 1.4, 95% CI: 1.0,1.9), being obese (POR: 0.7, 95% CI: 0.5,0.9), and having a higher education level (POR: 0.8, 95% CI: 0.7,0.9) were significantly associated with constipation. Conclusions The findings support clinical recommendations to treat constipation with increased liquid, but not fiber or exercise. PMID:23567352

Factors associated with the incidence of pressure ulcer during hospital stay.

PubMed

Matozinhos, Fernanda Penido; Velasquez-Melendez, Gustavo; Tiensoli, Sabrina Daros; Moreira, Alexandra Dias; Gomes, Flávia Sampaio Latini

2017-05-25

Estimating the incidence rate of pressure ulcers and verifying factors associated with this occurrence in a cohort of hospitalized patients. This is a cohort study in which the considered outcome was the time until pressure ulcer occurrence. Estimated effect of the variables on the cumulative incidence ratio of the outcome was performed using the Cox proportional hazards model. Variable selection occurred via the Logrank hypothesis test. The sample consisted of 442 adults, with 25 incidents of pressure ulcers. Patients with high scores on the Braden scale presented a higher risk of pressure ulcer incidence when compared to those classified into the low score category. These results reinforce the importance of using the Braden Scale to assist in identifying patients more likely to develop pressure ulcers. Estimar a taxa de incidência de úlcera por pressão e verificar fatores associados a essa ocorrência em uma coorte de pacientes hospitalizados. Trata-se de estudo de coorte no qual o desfecho foi a ocorrência da úlcera por pressão. A estimativa do efeito das variáveis para a proporção de incidência acumulada do desfecho foi realizada utilizando o modelo de riscos proporcionais de Cox. A seleção das variáveis ocorreu por meio do teste de hipóteses Logrank. A amostra foi composta de 442 adultos, com 25 casos incidentes de úlcera por pressão. Pacientes com altos escores na escala de Braden apresentaram maior risco de incidência de úlcera por pressão quando comparados com aqueles classificados na categoria de baixo escore. Os resultados reforçam a importância do uso da Escala de Braden para auxiliar na identificação dos pacientes com maior probabilidade de desenvolver úlcera por pressão.

Missed Opportunities for Human Immunodeficiency Virus and Syphilis Testing Among Men Who Have Sex With Men in China: A Cross-Sectional Study.

PubMed

Ong, Jason J; Fu, Hongyun; Pan, Stephen; Smith, M Kumi; Wu, Dan; Wei, Chongyi; Cao, Bolin; Ma, Wei; Yang, Ligang; Tang, Weiming; Tucker, Joseph D

2018-06-01

Men who have sex with men (MSM) are at high risk of human immunodeficiency virus (HIV)/syphilis. To inform strategies for dual testing, we describe patterns of HIV/syphilis testing, and examine factors associated with never testing for HIV/syphilis in China. An online survey (2016) was completed by MSM from 8 cities: men born biologically male, 16 years or older, and had sex with another man at least once during their lifetime. Demographic, sexual behavioral, and HIV/syphilis testing data were collected. Multivariable multinomial logistic regression identified characteristics associated with men who never tested for HIV/syphilis compared with men who ever tested for both infections. Overall, 2105 men participated. Among them, 35.1% (738/2105) never tested for HIV/syphilis, and in those ever tested for HIV, only half (54.0%, 709/1312) had tested for syphilis. Relative to men who had ever tested for both infections, those with increased probability of never testing for HIV/syphilis include non-gay sexual identity (prevalence odds ratio [POR] 1.86; 95% confidence interval [CI], 1.45-2.37), not disclosed their sexuality/sexual history with men other than their regular partner (POR, 2.22; 95% CI, 1.75-2.78]) or with health professionals (POR, 11.11; 95% CI, 7.69-14.29), no condomless sex with casual partners in the last 3 months (POR, 1.89; 95% CI, 1.37-2.56), no community engagement in sexual health (POR, 15.16; 95% CI, 9.40-24.45), and mainly met partners offline (POR, 1.49; 95% CI, 1.16-1.92). There are significant gaps in lifetime testing for HIV/syphilis among Chinese MSM. Strategies to target never testers and integrate syphilis testing within HIV testing services are urgently needed. Future opportunities include point-of-care dual test kits, and testing in China's expanding primary healthcare system.

Does open-air exposure to volatile organic compounds near a plastic recycling factory cause health effects?

PubMed

Yorifuji, Takashi; Noguchi, Miyuki; Tsuda, Toshihide; Suzuki, Etsuji; Takao, Soshi; Kashima, Saori; Yanagisawa, Yukio

2012-01-01

After a plastic reprocessing factory began to operate in August 2004, the residents around the factory in Neyagawa, Osaka, Japan, began to complain of symptoms. Therefore, we conducted an exposure assessment and a population-based epidemiological study in 2006. To assess exposure, volatile organic compounds (VOCs) and total VOCs were measured at two locations in the vicinity of the factory. In the population-based study, a total of 3,950 residents were targeted. A self-administered questionnaire was used to collect information about subjects' mucocutaneous or respiratory symptoms. Using logistic regression models, we compared the prevalence of symptoms in July 2006 by employing the farthest area from the factory as a reference, and prevalence odds ratios (PORs) and their 95% confidence intervals (CIs) were estimated. The concentration of total VOCs was higher in the vicinity of the factory. The prevalence of mucocutaneous and respiratory symptoms was the highest among the residents in the closest area to the factory. Some symptoms were significantly increased among the residents within 500 m of the factory compared with residents of an area 2800 m from the factory: e.g., sore throat (POR=3.2, 95% CI: 1.3-8.0), eye itch (POR=3.0, 95% CI: 1.5-6.0), eye discharge (POR=6.0, 95% CI: 2.3-15.9), eczema (POR=3.0, 95% CI: 1.1-7.9) and sputum (POR=2.4, 95% CI: 1.1-5.1). Despite of the limitations of this study, these results imply a possible association of open-air VOCs with mucocutaneous and respiratory symptoms. Because this kind of plasticre cycling factory only recently came into operation, more attention should be paid to the operation of plastic recycling factories in the environment.

PubMed

Dipierri, José Edgardo; Bronberg, Rubén Adrian

2017-09-08

Debido al incremento de casos de microcefalia por virus Zika en Brasil el Ministerio de Salud de Argentina recomienda incrementar la vigilancia de esta malformación. A fin de profundizar el conocimiento del comportamiento epidemiológico de microcefalia en el país se analiza la mortalidad infantil por microcefalia entre 1998-2012. Los datos proceden de la Dirección de Estadísticas e Información de Salud (DEIS). Se calculó por provincias y regiones la tasa de mortalidad infantil por microcefalia (TMI-M) y se realizó un análisis de agrupamiento a nivel departamental. Las tasas más elevadas se observaron en las regiones y provincias del norte del país. La distribución espacial de la TMI-M guarda relación con las prevalencias de microcefalia en recién nacidos. Esta distribución se relaciona con la mayor pobreza y consanguinidad del norte de la Argentina, factores sinérgicos predisponentes de la ocurrencia de malformaciones congénitas en general y de microcefalia en particular.

Long-term follow-up of a female with congenital adrenal hyperplasia due to P450-oxidoreductase deficiency.

PubMed

Bonamichi, Beatriz D S F; Santiago, Stella L M; Bertola, Débora R; Kim, Chong A; Alonso, Nivaldo; Mendonca, Berenice B; Bachega, Tania A S S; Gomes, Larissa G

2016-10-01

P450 oxidoreductase deficiency (PORD) is a variant of congenital adrenal hyperplasia that is caused by POR gene mutations. The POR gene encodes a flavor protein that transfers electrons from nicotinamide adenine dinucleotide phosphate (NADPH) to all microsomal cytochrome P450 type II (including 21-hydroxylase, 17α-hydroxylase 17,20 lyase and aromatase), which is fundamental for their enzymatic activity. POR mutations cause variable impairments in steroidogenic enzyme activities that result in wide phenotypic variability ranging from 46,XX or 46,XY disorders of sexual differentiation, glucocorticoid deficiency, with or without skeletal malformations similar to Antley-Bixler syndrome to asymptomatic newborns diagnosed during neonatal screening test. Little is known about the PORD long-term evolution. We described a 46,XX patient with mild atypical genitalia associated with severe bone malformation, who was diagnosed after 13 years due to sexual infantilism. She developed large ovarian cysts and late onset adrenal insufficiency during follow-up, both of each regressed after hormone replacement therapies. We also described a late surgical approach for the correction of facial hypoplasia in a POR patient.

Observational study to calculate addictive risk to opioids: a validation study of a predictive algorithm to evaluate opioid use disorder

PubMed Central

Brenton, Ashley; Richeimer, Steven; Sharma, Maneesh; Lee, Chee; Kantorovich, Svetlana; Blanchard, John; Meshkin, Brian

2017-01-01

Background Opioid abuse in chronic pain patients is a major public health issue, with rapidly increasing addiction rates and deaths from unintentional overdose more than quadrupling since 1999. Purpose This study seeks to determine the predictability of aberrant behavior to opioids using a comprehensive scoring algorithm incorporating phenotypic risk factors and neuroscience-associated single-nucleotide polymorphisms (SNPs). Patients and methods The Proove Opioid Risk (POR) algorithm determines the predictability of aberrant behavior to opioids using a comprehensive scoring algorithm incorporating phenotypic risk factors and neuroscience-associated SNPs. In a validation study with 258 subjects with diagnosed opioid use disorder (OUD) and 650 controls who reported using opioids, the POR successfully categorized patients at high and moderate risks of opioid misuse or abuse with 95.7% sensitivity. Regardless of changes in the prevalence of opioid misuse or abuse, the sensitivity of POR remained >95%. Conclusion The POR correctly stratifies patients into low-, moderate-, and high-risk categories to appropriately identify patients at need for additional guidance, monitoring, or treatment changes. PMID:28572737

[Not Available].

PubMed

Ortega, Rosa M

2016-07-19

El artículo de San Mauro y cols. profundiza en un tema de interés prioritario como es el estudio de los hábitos de ingesta de fluidos en personas de cuatro países: España, Portugal, México y Uruguay, para analizar si se cumplen (y si se conocen) las pautas de hidratación marcadas como adecuadas por organismos oficiales y, en concreto, por la EFSA. Es indudable la importancia de una correcta hidratación pues mientras que se puede vivir meses, o años, con una alimentación incorrecta, la deshidratación puede llevar a la muerte en un escaso periodo de tiempo. Por otra parte, un aporte ligeramente insuficiente de fluidos perjudica la salud, capacidad funcional y calidad de vida del individuo, por lo que debe ser evitada. Incluso algunos estudios encuentran hábitos y estilo de vida menos saludables en individuos con menor consumo de fluidos y pautas de hidratación más incorrectas.