Incidence, causes, severity and treatment of throat discomfort: a four-region online questionnaire survey

PubMed Central

2012-01-01

Background Acute sore throat is commonly associated with viral infections. Consumers typically rely on over-the-counter treatments and other remedies to treat symptoms; however, limited information is available regarding consumer perceptions of sore throat or treatment needs. The aim of this study was to investigate perceptions of throat discomfort and how these influence attitudes and consumer behaviour with regard to treatment. Methods Online consumer surveys were completed by participants invited by email between 2003 and 2004 in four markets: the UK, France, Poland, and Malaysia. The questionnaire consisted of 24 questions that covered key issues surrounding throat discomfort including incidence in the past 12 months, causes, severity, effects on functionality and quality of life, actions taken to relieve throat discomfort, the efficacy of these approaches and the reasons behind using specific products. Results In total, 6465 men and women aged ≥18 years were surveyed, identifying 3514 participants who had suffered throat discomfort/irritation in the past 12 months (response rate of 54%). These participants completed the full survey. The breakdown of throat discomfort sufferers was: UK, 912; France, 899; Poland, 871; Malaysia, 832. A high proportion of respondents experienced one or more instances of throat discomfort in the previous 12 months, with an overall incidence of 54%. Infections including the common cold/influenza and other bacteria/viruses were commonly perceived causes of throat discomfort (72% and 46%, respectively). Physical and environmental factors were also perceived to be causative, including airborne pollution (28%), smoking (23%), and air conditioning (31%). Symptoms perceived to be caused by an infection were associated with a higher degree of suffering (mean degree of suffering for bacteria/virus and common cold/influenza; 3.4 and 3.0, respectively). Medicinal products were used for all perceived causes, but more commonly for sore

Anaerobic bacteria

MedlinePlus

Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these bacteria ... Brook I. Diseases caused by non-spore-forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman-Cecil ...

Behaviour of co-inoculated pathogenic and spoilage bacteria on poultry following several decontamination treatments.

PubMed

Alonso-Hernando, Alicia; Capita, Rosa; Alonso-Calleja, Carlos

2012-10-01

The potential of chemical decontaminants to cause harmful effects on human health is among the causes of the rejection of antimicrobial treatments for removing surface contamination from poultry carcasses in the European Union. This study was undertaken to determine whether decontaminants might give a competitive advantage to pathogenic bacteria on poultry and involve a potential risk to consumer. A total of 144 chicken legs were co-inoculated with similar concentrations of pathogenic bacteria (Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica serotype Enteritidis or Escherichia coli) and spoilage bacteria (Brochothrix thermosphacta or Pseudomonas fluorescens). Samples were dipped for 15min in solutions (w/v) of trisodium phosphate (12%; TSP), acidified sodium chlorite (1200ppm; ASC), citric acid (2%; CA), peroxyacids (220ppm; PA) or chlorine dioxide (50ppm; CD), or were left untreated (control). Microbiological analyses were carried out on day 0 and every 24h until day 7 of storage (at 10±1°C). The modified Gompertz equation was used as the primary model to fit observed data. TSP, ASC and CA were effective in extending the lag phase (L, ranging from 1.47±1.34days to 4.06±1.16days) and in decreasing the concentration of bacteria during the stationary phase (D, ranging from 2.46±0.51 log(10) cfu/cm(2) to 8.64±0.53 log(10) cfu/cm(2)), relative to the control samples (L values ranging from 0.59±0.38days and 2.52±2.28days, and D values ranging from 6.32±0.89 log(10) cfu/cm(2) to 9.39±0.39 log(10) cfu/cm(2), respectively). Both on untreated and on most decontaminated samples the overgrowth of spoilage bacteria among the species tested was observed throughout storage, suggesting that spoilage would occur prior to any noteworthy increase in the levels of pathogenic microorganisms. However, L. monocytogenes counts similar to, or higher than, those for spoilage bacteria were observed on samples treated with TSP, ASC or CA, suggesting that these

Bacteria entombed in the center of cholesterol gallstones induce fewer infectious manifestations than bacteria in the matrix of pigment stones.

PubMed

Stewart, Lygia; Griffiss, J McLeod; Jarvis, Gary A; Way, Lawrence W

2007-10-01

The clinical significance of bacteria in the pigment centers of cholesterol stones is unknown. We compared the infectious manifestations and characteristics of bacteria from pigment stones and predominantly cholesterol stones. Three hundred forty patients were studied. Bile was cultured. Gallstones were cultured and examined with scanning electron microscopy. Level of bacterial immunoglobulin G (bile, serum), complement killing, and tumor necrosis factor-alpha production were determined. Twenty-three percent of cholesterol stones and 68% of pigment stones contained bacteria (P < 0.0001). Stone culture correlated with scanning electron microscopy results. Pigment stone bacteria were more often present in bile and blood. Cholesterol stone bacteria caused more severe infections (19%) than sterile stones (0%), but less than pigment stone bacteria (57%) (P < 0.0001). Serum and bile from patients with cholesterol stone bacteria had less bacterial-specific immunoglobulin G. Cholesterol stone bacteria produced more slime. Pigment stone bacteria were more often killed by a patient's serum. Tumor necrosis factor-alpha production of the groups was similar. Bacteria are readily cultured from cholesterol stones with pigment centers, allowing for analysis of their virulence factors. Bacteria sequestered in cholesterol stones cause infectious manifestations, but less than bacteria in pigment stones. Possibly because of their isolation, cholesterol stone bacteria were less often present in bile and blood, induced less immunoglobulin G, were less often killed by a patient's serum, and demonstrated fewer infectious manifestations than pigment stone bacteria. This is the first study to analyze the clinical relevance of bacteria within cholesterol gallstones.

Efficacy of epiphytic bacteria to prevent northern leaf blight caused by Exserohilum turcicum in maize.

PubMed

Sartori, Melina; Nesci, Andrea; García, Julián; Passone, María A; Montemarani, Analía; Etcheverry, Miriam

Eight potential biological control agents (BCAs) were evaluated in planta in order to assess their effectiveness in reducing disease severity of northern leaf blight caused by Exserohilum turcicum. The assay was carried out in greenhouse. Twenty-six-day-old plants, V4 phenological stage, were inoculated with antagonists by foliar spray. Only one biocontrol agent was used per treatment. Ten days after this procedure, all treatments were inoculated with E. turcicum by foliar application. Treatments performed were: C-Et: control of E. turcicum; T1: isolate 1 (Enterococcus genus)+E. turcicum; T2: isolate 2 (Corynebacterium genus)+E. turcicum; T3: isolate 3 (Pantoea genus)+E. turcicum; T4: isolate 4 (Corynebacterium genus)+E. turcicum; T5: isolate 5 (Pantoea genus)+E. turcicum; T6: isolate 6 (Bacillus genus)+E. turcicum; T7: isolate 7 (Bacillus genus)+E. turcicum; T8: isolate 8 (Bacillus genus)+E. turcicum. Monitoring of antagonists on the phyllosphere was performed at different times. Furthermore, the percentage of infected leaves and, plant and leaf incidence were determined. Foliar application of different bacteria significantly reduced the leaf blight between 30-78% and 39-56% at 20 and 39 days respectively. It was observed that in the V10 stage of maize plants, isolate 8 (Bacillus spp.) caused the greatest effect on reducing the severity of northern leaf blight. Moreover, isolate 8 was the potential BCA that showed more stability in the phyllosphere. At 39 days, all potential biocontrol agents had a significant effect on controlling the disease caused by E. turcicum. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

[A Case of Hyperammonemia Caused by Urinary Tract Infection Due to Urease-Producing Bacteria].

PubMed

Emura, Masahiro; Tsuchihashi, Kazunari; Shimizu, Yosuke; Kanamaru, Sojun; Matoba, Shun; Ito, Noriyuki

2016-08-01

We present here a rare case of hyperammonemia without liver dysfunction or portal-systemic shunting. The patient was an 80-year-old woman with a history of neurogenic bladder. She was admitted to a nearby hospital for vomiting, diarrhea and consciousness disturbance. Two days after admission, she was transferred to our hospital because of persistant consciousness disturbance. Laboratory data revealed hyperammonemia, but there was no indication of liver dysfunction. Moreover abdominal computed tomography did not reveal any clear finding of liver disease or portal-systemic shunting, but we noted multiple large bladder diverticula. Antibiotic therapy, tracheal intubation, ventilator management and bladder catheterization were performed. The patient's level of consciousness improved rapidly. Urinary culture revealed Bacteroides ureolyticus (urease-producing bacteria). The patient was diagnosed with hyperammonemia and a urinary tract infection due to urease-producing bacteria. Thus, physicians should be aware that obstructive urinary tract infections due to urease-producing bacteria can also be the cause of hyperammonemia.

[Outbreaks caused by diarrheagenic Escherichia coli].

PubMed

Vila Estapé, Jordi; Zboromyrska, Yuliya

2012-02-01

Escherichia coli are ubiquitous bacteria from a wide variety of ecosystems including the gastrointestinal tract of humans and warm-blooded animals. E. coli can play a role as an opportunistic bacteria causing a variety of infectious diseases including, among many others, sepsis, urinary tract infections, meningitis, and wound infections. Moreover, these bacteria can also act as primary pathogens in the intestinal tract. There are several pathotypes of E. coli that cause enteritis, and both sporadic cases and outbreaks have been reported. In this article, we review the pathogenicity and epidemiology of enteritis caused by these E. coli pathotypes, and provide some examples of outbreaks described in the scientific literature and the measures required to prevent them. Copyright © 2011 Elsevier España, S.L. All rights reserved.

Bacteriophages to combat foodborne infections caused by food contamination by bacteria of the Campylobacter genus.

PubMed

Myga-Nowak, Magdalena; Godela, Agnieszka; Głąb, Tomasz; Lewańska, Monika; Boratyński, Janusz

2016-09-26

It is estimated that each year more than 2 million people suffer from diarrheal diseases, resulting from the consumption of contaminated meat. Foodborne infections are most frequently caused by small Gram-negative rods Campylobacter. The hosts of these bacteria are mainly birds wherein they are part of the normal intestinal flora. During the commercial slaughter, there is a likelihood of contamination of carcasses by the bacteria found in the intestinal content. In Europe, up to 90% of poultry flocks can be a reservoir of the pathogen. According to the European Food Safety Authority report from 2015, the number of reported and confirmed cases of human campylobacteriosis exceeds 200 thousands per year, and such trend remains at constant level for several years. The occurrence of growing antibiotic resistance in bacteria forces the limitation of antibiotic use in the animal production. Therefore, the European Union allows only using stringent preventive and hygienic treatment on farms. Achieving Campylobacter free chickens using these methods is possible, but difficult to implement and expensive. Utilization of bacterial viruses - bacteriophages, can be a path to provide the hygienic conditions of poultry production and food processing. Formulations applied in the food protection should contain strictly lytic bacteriophages, be non-pyrogenic and retain long lasting biological activity. Currently, on the market there are available commercial bacteriophage preparations for agricultural use, but neither includes phages against Campylobacter. However, papers on the application of bacteriophages against Campylobacter in chickens and poultry products were published in the last few years. In accordance with the estimates, 2-logarithm reduction of Campylobacter in poultry carcases will contribute to the 30-fold reduction in the incidence of campylobacteriosis in humans. Research on bacteriophages against Campylobacter have cognitive and economic importance. The paper

16S rDNA-based metagenomic analysis of dental plaque and lung bacteria in patients with severe acute exacerbations of chronic obstructive pulmonary disease.

PubMed

Tan, L; Wang, H; Li, C; Pan, Y

2014-12-01

Acute exacerbations of chronic obstructive pulmonary disease (AE-COPD) are leading causes of mortality in hospital intensive care units. We sought to determine whether dental plaque biofilms might harbor pathogenic bacteria that can eventually cause lung infections in patients with severe AE-COPD. Paired samples of subgingival plaque biofilm and tracheal aspirate were collected from 53 patients with severe AE-COPD. Total bacterial DNA was extracted from each sample individually for polymerase chain reaction amplification and/or generation of bacterial 16S rDNA sequences and cDNA libraries. We used a metagenomic approach, based on bacterial 16S rDNA sequences, to compare the distribution of species present in dental plaque and lung. Analysis of 1060 sequences (20 clones per patient) revealed a wide range of aerobic, anaerobic, pathogenic, opportunistic, novel and uncultivable bacterial species. Species indistinguishable between the paired subgingival plaque and tracheal aspirate samples (97-100% similarity in 16S rDNA sequence) were dental plaque pathogens (Aggregatibacter actinomycetemcomitans, Capnocytophaga sputigena, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola) and lung pathogens (Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa and Streptococcus pneumoniae). Real-time polymerase chain reaction of 16S rDNA indicated lower levels of Pseudomonas aeruginosa and Porphyromonas gingivalis colonizing the dental plaques compared with the paired tracheal aspirate samples. These results support the hypothesis that dental bacteria may contribute to the pathology of severe AE-COPD. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Gram-negative bacteria that produce carbapenemases causing death attributed to recent foreign hospitalization.

PubMed

Ahmed-Bentley, Jasmine; Chandran, A Uma; Joffe, A Mark; French, Desiree; Peirano, Gisele; Pitout, Johann D D

2013-07-01

Overseas travel, as a risk factor for the acquisition of infections due to antimicrobial-resistant organisms, has recently been linked to carbapenemase-producing Gram-negative bacteria. Multiresistant Klebsiella pneumoniae, Escherichia coli, and Acinetobacter baumannii strains were isolated from a wound of a Canadian patient with a recent history of hospitalization in India. This resulted in the initiation of outbreak management that included surveillance cultures. Epidemiological and molecular investigations showed that NDM-1-producing K. pneumoniae ST16 and OXA-23-producing A. baumannii ST10 strains were transmitted to 5 other patients, resulting in the colonization of 4 patients and the death of 1 patient due to septic shock caused by the OXA-23-producing A. baumannii strain. The high rate of false positivity of the screening cultures resulted in additional workloads and increased costs for infection control and clinical laboratory work. We believe that this is the first report of an infection with carbapenemase-producing Gram-negative bacteria resulting in death attributed to a patient with recent foreign hospitalization. We recommend routine rectal and wound screening for colonization with multiresistant bacteria for patients who have recently been admitted to hospitals outside Canada.

Science 101: What Causes Severe Thunderstorms and Tornadoes?

ERIC Educational Resources Information Center

Robertson, Bill

2016-01-01

What causes severe thunderstorms and tornadoes? Tornadoes, often accompanied by severe thunderstorms and hail, form in pretty much the same way as severe thunderstorms. In the continental United States, tornadoes usually form in spring and summer, when warm, humid air from the Gulf of Mexico moves across the continent from southeast to northwest…

Urinary tract infection caused by community-acquired extended-spectrum β-lactamase-producing bacteria in infants.

PubMed

Kim, Yun Hee; Yang, Eun Mi; Kim, Chan Jong

Urinary tract infection (UTI) caused by resistant strains of bacteria is increasingly prevalent in children. The aim of this study was to investigate the clinical characteristics and risk factors for UTI caused by community-acquired extended-spectrum β-lactamase (CA-ESBL)-producing bacteria in infants. This was a retrospective study performed over 5 years in a single Korean center. Hospitalized infants with febrile UTI were enrolled and divided into two groups (CA-ESBL vs. CA non-ESBL UTI). The yearly prevalence was calculated. Baseline characteristics and clinical course such as fever duration, laboratory and radiological findings were compared between the two groups. Risk factors associated with the CA-ESBL UTI were investigated. Among the enrolled infants (n=185), 31 (17%) had CA-ESBL UTI. The yearly prevalence of ESBL of CA-ESBL UTI increased during the study (0% in 2010, 22.2% in 2015). Infants with CA-ESBL UTI had a longer duration of fever after initiating antibiotics (2.0±1.1 vs. 1.5±0.6 days, p=0.020). Cortical defects on renal scan and early treatment failure were more frequent in CA-ESBL (64.5 vs. 42.2%, p=0.023; 22.6 vs. 4.5%, p=0.001). A logistic regression analysis revealed that urinary tract abnormalities and previous UTI were independent risk factors for CA-EBSL UTI (odds ratio, 2.7; p=0.025; 10.3; p=0.022). The incidence of UTI caused by ESBL-producing bacteria has increased in Korean infants. Recognition of the clinical course and risk factors for ESLB-producing UTI may help to determine appropriate guidelines for its management. Copyright © 2016. Published by Elsevier Editora Ltda.

Influence of several feeds on bacteria in sheep and goat rumen liquor in vitro.

PubMed

Gonzalez-Lopez, J; Salmeron, V; Ramos-Cormenzana, A; Silva-Colomer, J; Boza, J

1990-01-01

Bacteriological studies were made with in vitro sheep and goat ruminal fluids supplemented with several feeds (alfalfa hay, wheat straw, Agave americana, Opuntia ficus indica and Atriplex nummularia) during anaerobic incubation at 38-39 degrees C. Drastic changes in the bacterial population of sheep ruminal fluids occurred in the presence of different feeds, particularly with addition of feeds of low nutritional quality (wheat straw, A. americana and O. ficus indica). However, the bacterial population in goat rumen liquor was little affected by the addition of the same feeds. These results, which suggest that the rumen bacteria in goats are less affected by different nutritional conditions than the rumen bacteria in sheep, are discussed.

Dissemination of Persistent Intestinal Bacteria via the Mesenteric Lymph Nodes Causes Typhoid Relapse▿

PubMed Central

Griffin, Amanda J.; Li, Lin-Xi; Voedisch, Sabrina; Pabst, Oliver; McSorley, Stephen J.

2011-01-01

Enteric pathogens can cause relapsing infections in a proportion of treated patients, but greater understanding of this phenomenon is hindered by the lack of appropriate animal models. We report here a robust animal model of relapsing primary typhoid that initiates after apparently successful antibiotic treatment of susceptible mice. Four days of enrofloxacin treatment were sufficient to reduce bacterial loads below detectable levels in all major organs, and mice appeared otherwise healthy. However, any interruption of further antibiotic therapy allowed renewed fecal shedding and renewed bacterial growth in systemic tissues to occur, and mice eventually succumbed to relapsing infection. In vivo imaging of luminescent Salmonella identified the mesenteric lymph nodes (MLNs) as a major reservoir of relapsing infection. A magnetic-bead enrichment strategy isolated MLN-resident CD11b+ Gr-1− monocytes associated with low numbers of persistent Salmonella. However, the removal of MLNs increased the severity of typhoid relapse, demonstrating that this organ serves as a protective filter to restrain the dissemination of bacteria during antibiotic therapy. Together, these data describe a robust animal model of typhoid relapse and identify an important intestinal phagocyte subset involved in protection against the systemic spread of enteric infection. PMID:21263018

Evaluation of the antibacterial potential of Petroselinum crispum and Rosmarinus officinalis against bacteria that cause urinary tract infections

PubMed Central

Petrolini, Fernanda Villas Boas; Lucarini, Rodrigo; de Souza, Maria Gorete Mendes; Pires, Regina Helena; Cunha, Wilson Roberto; Martins, Carlos Henrique Gomes

2013-01-01

In this study we evaluated the antibacterial activity of the crude hydroalcoholic extracts, fractions, and compounds of two plant species, namely Rosmarinus officinalis and Petroselinum crispum, against the bacteria that cause urinary tract infection. The microdilution method was used for determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The crude hydroalcoholic extract of R. officinalis displayed in vitro activity against Gram-positive bacteria, with satisfactory MBC for the clinical isolate S. saprophyticus. The fractions and the pure compound rosmarinic acid did not furnish promising results for Gram-negative bacteria, whereas fractions 2, 3, and 4 gave encouraging results for Gram-positive bacteria and acted as bactericide against S. epidermidis as well as E. faecalis (ATCC 29212) and its clinical isolate. R. officinalis led to promising results in the case of Gram-positive bacteria, resulting in a considerable interest in the development of reliable alternatives for the treatment of urinary infections. PMID:24516424

Evaluation of the antibacterial potential of Petroselinum crispum and Rosmarinus officinalis against bacteria that cause urinary tract infections.

PubMed

Petrolini, Fernanda Villas Boas; Lucarini, Rodrigo; de Souza, Maria Gorete Mendes; Pires, Regina Helena; Cunha, Wilson Roberto; Martins, Carlos Henrique Gomes

2013-01-01

In this study we evaluated the antibacterial activity of the crude hydroalcoholic extracts, fractions, and compounds of two plant species, namely Rosmarinus officinalis and Petroselinum crispum, against the bacteria that cause urinary tract infection. The microdilution method was used for determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The crude hydroalcoholic extract of R. officinalis displayed in vitro activity against Gram-positive bacteria, with satisfactory MBC for the clinical isolate S. saprophyticus. The fractions and the pure compound rosmarinic acid did not furnish promising results for Gram-negative bacteria, whereas fractions 2, 3, and 4 gave encouraging results for Gram-positive bacteria and acted as bactericide against S. epidermidis as well as E. faecalis (ATCC 29212) and its clinical isolate. R. officinalis led to promising results in the case of Gram-positive bacteria, resulting in a considerable interest in the development of reliable alternatives for the treatment of urinary infections.

[Fatal acute pancreatitis caused by severe hypertriglyceridaemia].

PubMed

Abed, Osama Karim; Lindberg, Mats; Andos, Shadi

2014-04-14

We report a case of fatal acute pancreatitis caused by severe hypertriglyceridaemia in a 27-year-old male who was treated with quetiapine. The blood samples were milk-like with markedly elevated triglycerides (> 55 mmol/l). Computer tomography revealed a severe pancreatitis without bile stones or cholestasis. In spite of treatment the patient's condition rapidly worsened and he died 48 hours after admission. We discuss the option of treating hypertriglyceridaemia-induced pancreatitis with apheresis.

Understanding pine wilt disease: roles of the pine endophytic bacteria and of the bacteria carried by the disease-causing pinewood nematode.

PubMed

Proença, Diogo N; Grass, Gregor; Morais, Paula V

2017-04-01

Pine wilt disease (PWD) is one of the most destructive diseases in trees of the genus Pinus and is responsible for environmental and economic losses around the world. The only known causal agent of the disease is the pinewood nematode (PWN) Bursaphelenchus xylophilus. Despite that, bacteria belonging to several different genera have been found associated with PWN and their roles in the development of PWD have been suggested. Molecular methodologies and the new era of genomics have revealed different perspectives to the problem, recognizing the manifold interactions between different organisms involved in the disease. Here, we reviewed the possible roles of nematode-carried bacteria in PWD, what could be the definition of this group of microorganisms and questioned their origin as possible endophytes, discussing their relation within the endophytic community of pine trees. The diversity of the nematode-carried bacteria and the diversity of pine tree endophytes, reported until now, is revised in detail in this review. What could signify a synergetic effect with PWN harming the plant, or what could equip bacteria with functions to control the presence of nematodes inside the tree, is outlined as two possible roles of the microbial community in the etiology of this disease. An emphasis is put on the potential revealed by the genomic data of isolated organisms in their potential activities as effective tools in PWD management. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Helicobacter suis causes severe gastric pathology in mouse and mongolian gerbil models of human gastric disease.

PubMed

Flahou, Bram; Haesebrouck, Freddy; Pasmans, Frank; D'Herde, Katharina; Driessen, Ann; Van Deun, Kim; Smet, Annemieke; Duchateau, Luc; Chiers, Koen; Ducatelle, Richard

2010-11-22

"Helicobacter (H.) heilmannii" type 1 is the most prevalent gastric non-H. pylori Helicobacter species in humans suffering from gastric disease. It has been shown to be identical to H. suis, a bacterium which is mainly associated with pigs. To obtain better insights into the long-term pathogenesis of infections with this micro-organism, experimental infections were carried out in different rodent models. Mongolian gerbils and mice of two strains (BALB/c and C57BL/6) were infected with H. suis and sacrificed at 3 weeks, 9 weeks and 8 months after infection. Gastric tissue samples were collected for PCR analysis, histological and ultrastructural examination. In gerbils, bacteria mainly colonized the antrum and a narrow zone in the fundus near the forestomach/stomach transition zone. In both mice strains, bacteria colonized the entire glandular stomach. Colonization with H. suis was associated with necrosis of parietal cells in all three animal strains. From 9 weeks after infection onwards, an increased proliferation rate of mucosal epithelial cells was detected in the stomach regions colonized with H. suis. Most gerbils showed a marked lymphocytic infiltration in the antrum and in the forestomach/stomach transition zone, becoming more pronounced in the course of time. At 8 months post infection, severe destruction of the normal antral architecture at the inflamed sites and development of mucosa-associated lymphoid tissue (MALT) lymphoma-like lesions were observed in some gerbils. In mice, the inflammatory response was less pronounced than in gerbils, consisting mainly of mononuclear cell infiltration and being most severe in the fundus. H. suis causes death of parietal cells, epithelial cell hyperproliferation and severe inflammation in mice and Mongolian gerbil models of human gastric disease. Moreover, MALT lymphoma-like lesions were induced in H. suis-infected Mongolian gerbils. Therefore, the possible involvement of this micro-organism in human gastric disease

Bacteriological Assessment of Pneumonia Caused by Gram-Negative Bacteria in Patients Hospitalized in Intensive Care Unit.

PubMed

Guzek, A; Korzeniewski, K; Tomaszewski, D; Rybicki, Z; Zwolińska, E

2017-01-01

The article presents the results of 11-year study (2005-2015) of Gram-negative bacteria responsible for pneumonia in 2033 mechanically ventilated patients hospitalized in Intensive Care Unit. Of 8796 biological samples, consisting mainly of bronchial aspirate (97.9 %), 2056 bacterial strains were isolated and subjected to identification. VITEK 2 was used to determine drug susceptibility (classified according to the EUCAST criteria). ESBL, MBL and KPC-producing strains were identified by means of phenotypic methods using appropriate discs. The findings were that the predominant bacteria responsible for infections consisted of Enterobacteriaceae (42.0 %), Acinetobacter baumannii (37.2 %), Pseudomonas aeruginosa (16.1 %), and Stenotrophomonas maltophila (4.7 %). We observed a rise in the number of bacteria causing pneumonia throughout the study period, especially in S. maltophila and Enterobacteriaceae ESBL (+). Gram-negative bacilli were 100 % susceptible to colistin, apart from naturally resistant strains such as Proteus mirabilis, Serratia marcescens, whereas Enterobacteriaceae ESBL (+) were susceptible to imipenem and meropenem. Acinetobacter baumannii strains exhibited the lowest drug susceptibility. In conclusion, we report an increase in the prevalence of pneumonia associated with Gram-negative bacteria in mechanically ventilated intensive care patients. Colistin remains the most effective drug against the majority of Gram-negative bacteria. Therapeutic problems are common in the course of treatment of Acinetobacter baumannii infections.

Antibacterial Activity of Ethanolic Extract of Cinnamon Bark, Honey, and Their Combination Effects against Acne-Causing Bacteria

PubMed Central

Julianti, Elin; Rajah, Kasturi K.; Fidrianny, Irda

2017-01-01

Propionibacterium acnes and Staphylococcus epidermidis are the major skin bacteria that cause the formation of acne. The present study was conducted to investigate antibacterial activity of ethanolic extract of cinnamon bark, honey, and their combination against acne bacteria. The antibacterial activity of extract of cinnamon bark and honey were investigated against P. acnes and S. epidermidis using disc diffusion. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were attained using Clinical and Laboratory Standard Institute (CLSI) methods. The interaction between cinnamon bark extract and honey was determined using a checkerboards method. The results showed that the MICs of cinnamon bark extract and honey against P. acne were 256 µg/mL and 50% v/v, respectively, while those against S. epidermidis were 1024 µg/mL and 50% v/v, respectively. The MBC of cinnamon bark extract against P. acnes and S. epidermidis were more than 2048 µg/mL, whereas the MBC for honey against P. acnes and S. epidermidis were 100%. The combination of cinnamon bark extract and honey against P. acnes and S. epidermidis showed additive activity with a fractional inhibitory concentration index (FICI) value of 0.625. Therefore, the combination of cinnamon bark extract and honey has potential activity against acne-causing bacteria. PMID:28398231

Polymicrobial Amniotic Fluid Infection with Mycoplasma/Ureaplasma and Other Bacteria Induces Severe Intra-Amniotic Inflammation Associated with Poor Perinatal Prognosis in Preterm Labor.

PubMed

Yoneda, Noriko; Yoneda, Satoshi; Niimi, Hideki; Ueno, Tomohiro; Hayashi, Shirou; Ito, Mika; Shiozaki, Arihiro; Urushiyama, Daichi; Hata, Kenichiro; Suda, Wataru; Hattori, Masahira; Kigawa, Mika; Kitajima, Isao; Saito, Shigeru

2016-02-01

To study the relationship between perinatal prognosis in cases of preterm labor (PTL) and polymicrobial infection in amniotic fluid (AF) and intra-amniotic (IA) inflammation using a highly sensitive and reliable PCR-based method. To detect prokaryotes using a nested PCR-based method, eukaryote-made thermostable DNA polymerase without bacterial DNA contamination was used in combination with bacterial universal primers. We collected AF aseptically from 118 PTL cases and 50 term subjects. The prevalence of microorganisms was 33% (39/118) by PCR and only 7.6% (9/118) by culture. PTL caused by a combination of positive Mycoplasma/Ureaplasma and other bacteria had significantly higher AF IL-8 levels and a significantly shorter amniocentesis-to-delivery interval. Our newly established PCR method is useful for detecting IA microorganisms. Polymicrobial infection with Mycoplasma/Ureaplasma and other bacteria induces severe IA inflammation associated with poor perinatal prognosis in PTL. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Assessment of pathogenesis of infective endocarditis by plasma IgG antibody titer test against periodontal bacteria.

PubMed

Isoshima, Daichi; Yamashiro, Keisuke; Matsunaga, Kazuyuki; Shinobe, Michitaka; Nakanishi, Nagako; Nakanishi, Izumi; Omori, Kazuhiro; Yamamoto, Tadashi; Takashiba, Shogo

2017-10-01

Oral bacteria cause infective endocarditis (IE), so severe periodontitis is thought to be high risk for IE. We suggest the identification of high-risk patients by an IgG antibody titer test against periodontal bacteria might become common screening test.

Genes and Gut Bacteria Involved in Luminal Butyrate Reduction Caused by Diet and Loperamide.

PubMed

Hwang, Nakwon; Eom, Taekil; Gupta, Sachin K; Jeong, Seong-Yeop; Jeong, Do-Youn; Kim, Yong Sung; Lee, Ji-Hoon; Sadowsky, Michael J; Unno, Tatsuya

2017-11-28

Unbalanced dietary habits and gut dysmotility are causative factors in metabolic and functional gut disorders, including obesity, diabetes, and constipation. Reduction in luminal butyrate synthesis is known to be associated with gut dysbioses, and studies have suggested that restoring butyrate formation in the colon may improve gut health. In contrast, shifts in different types of gut microbiota may inhibit luminal butyrate synthesis, requiring different treatments to restore colonic bacterial butyrate synthesis. We investigated the influence of high-fat diets (HFD) and low-fiber diets (LFD), and loperamide (LPM) administration, on key bacteria and genes involved in reduction of butyrate synthesis in mice. MiSeq-based microbiota analysis and HiSeq-based differential gene analysis indicated that different types of bacteria and genes were involved in butyrate metabolism in each treatment. Dietary modulation depleted butyrate kinase and phosphate butyryl transferase by decreasing members of the Bacteroidales and Parabacteroides . The HFD also depleted genes involved in succinate synthesis by decreasing Lactobacillus . The LFD and LPM treatments depleted genes involved in crotonoyl-CoA synthesis by decreasing Roseburia and Oscilllibacter . Taken together, our results suggest that different types of bacteria and genes were involved in gut dysbiosis, and that selected treatments may be needed depending on the cause of gut dysfunction.

Severe hypertriglyceridemia in Japan: Differences in causes and therapeutic responses.

PubMed

Murase, Toshio; Okubo, Minoru; Ebara, Tetsu; Mori, Yasumichi

Severe hypertriglyceridemia (>1000 mg/dL) has a variety of causes and frequently leads to life-threating acute pancreatitis. However, the origins of this disorder are unclear for many patients. We aimed to characterize the causes of and responses to therapy in rare cases of severe hypertriglyceridemia in a group of Japanese patients. We enrolled 121 patients from a series of case studies that spanned 30 years. Subjects were divided into 3 groups: (1) primary (genetic causes); (2) secondary (acquired); and (3) disorders of uncertain causes. In the last group, we focused on 3 possible risks factors for hypertriglyceridemia: obesity, diabetes mellitus, and heavy alcohol intake. Group A (n = 20) included 13 patients with familial lipoprotein lipase deficiency, 3 patients with apolipoprotein CII deficiency, and other genetic disorders in the rest of the group. Group B patients (n = 15) had various metabolic and endocrine diseases. In Group C (uncertain causes; n = 86), there was conspicuous gender imbalance (79 males, 3 females) and most male subjects were heavy alcohol drinkers. In addition, 18 of 105 adult patients (17%) had histories of acute pancreatitis. The cause of severe hypertriglyceridemia is uncertain in many patients. In primary genetic forms of severe hypertriglyceridemia, genetic diversity between populations is unknown. In the acquired forms, we found fewer cases of estrogen-induced hypertriglyceridemia than in Western countries. In our clinical experience, the cause of most hypertriglyceridemia is uncertain. Our work suggests that genetic factors for plasma triglyceride sensitivity to alcohol should be explored. Copyright © 2017 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Tyramine and phenylethylamine biosynthesis by food bacteria.

PubMed

Marcobal, Angela; De las Rivas, Blanca; Landete, José María; Tabera, Laura; Muñoz, Rosario

2012-01-01

Tyramine poisoning is caused by the ingestion of food containing high levels of tyramine, a biogenic amine. Any foods containing free tyrosine are subject to tyramine formation if poor sanitation and low quality foods are used or if the food is subject to temperature abuse or extended storage time. Tyramine is generated by decarboxylation of the tyrosine through tyrosine decarboxylase (TDC) enzymes derived from the bacteria present in the food. Bacterial TDC have been only unequivocally identified and characterized in Gram-positive bacteria, especially in lactic acid bacteria. Pyridoxal phosphate (PLP)-dependent TDC encoding genes (tyrDC) appeared flanked by a similar genetic organization in several species of lactic acid bacteria, suggesting a common origin by a single mobile genetic element. Bacterial TDC are also able to decarboxylate phenylalanine to produce phenylethylamine (PEA), another biogenic amine. The molecular knowledge of the genes involved in tyramine production has led to the development of molecular methods for the detection of bacteria able to produce tyramine and PEA. These rapid and simple methods could be used for the analysis of the ability to form tyramine by bacteria in order to evaluate the potential risk of tyramine biosynthesis in food products.

Prevalence of bacteria and fungi in athlete's foot of varying severity and response to topical antibacterial and antifungal therapies.

PubMed

Talwar, P; Kumar, B; Ayyagiri, A; Kaur, S

1985-08-01

Ninety-six patients with clinical evidence of interdigital lesions classified as mild, moderate and severe athlete's foot were investigated for bacterial and fungal populations in the interspaces. Gram-negative bacteria, which were not found in the toe spaces of 50 normal controls, were grown in increasing numbers and with increasing frequency as the symptoms progressed from mild to severe. Gram-positive bacteria were also isolated regularly and in increasing numbers commensurate with the severity of the disease. Similarly the isolation rates of dermatophytes and Candida species were higher in patients with moderate and severe disease compared to those with mild disease. Clinical and culture responses to topical applications with framycetin, tolnaftate, miconazole and clotrimazole were also studied. In some patients the prevalence of pathogenic fungi increased as bacterial numbers decreased. The pure antibacterial framycetin brought symptomatic relief, as did the purely anti-dermatophyte substance tolnaftate, but best results were seen with two azole compounds having mixed antibacterial and antifungal properties.

[Rare cause for severe hypertriglyceridemia - case 9/2013].

PubMed

Kahl, Sabine; Roden, Michael; Mörike, Klaus; Müssig, Karsten

2013-11-01

We report on a 48-year-old female patient with recently developed severe hypertriglyceridemia. Medical history was remarkable for breast cancer with breast-preserving surgery and chemoradiotherapy. The patient has been treated with 20 mg tamoxifen per day for three months. Laboratory results showed hypertriglyeridemia, hypercholesterolemia and lowered HDL-cholesterol. Findings were consistent with a drug-induced hypertriglyceridemia caused by anti-estrogenic therapy with tamoxifen. After consulting the patient's gynaecologist, we discontinued tamoxifen treatment. Thereupon, triglyceride levels fell consistently. There were no signs of pancreatitis, serum amylase and lipase were in the normal range. Patients with pre-diagnosed metabolic disorders, especially dyslipidemia and type 2 diabetes, should undergo regular controls of serum triglycerides during tamoxifen treatment. Also, one should keep in mind that a subacute, severe rise in serum triglyceride levels may be caused, in rare cases, by tamoxifen treatment. © Georg Thieme Verlag KG Stuttgart · New York.

[The frequency of bacteria in human gallstones].

PubMed

Lévay, Bernadett; Szabó, Györgyi; Szijártó, Attila; Gamal, Eldin Mohamed

2013-12-01

Complications caused by lost gallstones within the abdominal cavity are well known. Abscesses, perforation of the gastro-intestinal tract were all described in the literature, but gallstones were found in hernial sac, or even in sputum after it penetrated through the diaphragm into the respiratory tract. These complications can develop between several weeks to several years postoperatively. Most complications can be treated surgically only. Fifty gallstones and bile samples were collected from 50 patients who underwent cholecystectomy (36 female / 14 male, avarge age: 60.8 ± 6.8 years). All samples were sent for microbiological examination. bacterial colonization of the gallstone and the bile were found in 16 cases. Four of them showed acute inflammation in the gallbladder while pathological signs of chronic inflammation in the gallbladder wall were detected in eight cases. Empyema was found in four cases. Bacteria from enteral origin (Esherichia coli, Enterococcus faecalis, Enterobacter cloacae) was detected in 13 cases, while non-enteral (Klebsiella penumoniae, Streptococcus alfa-haemoliticus) colony were detected in three cases. Positive bacterial cultures were identified in twelve female and fourmale patients. Different types of bacteria can be found in the gallstones, which may cause various complications.

Synergistic interaction and mode of action of Citrus hystrix essential oil against bacteria causing periodontal diseases.

PubMed

Wongsariya, Karn; Phanthong, Phanida; Bunyapraphatsara, Nuntavan; Srisukh, Vimol; Chomnawang, Mullika Traidej

2014-03-01

Citrus hystrix de Candolle (Rutaceae), an edible plant regularly used as a food ingredient, possesses antibacterial activity, but there is no current data on the activity against bacteria causing periodontal diseases. C. hystrix essential oil from leaves and peel were investigated for antibiofilm formation and mode of action against bacteria causing periodontal diseases. In vitro antibacterial and antibiofilm formation activities were determined by broth microdilution and time kill assay. Mode of action of essential oil was observed by SEM and the active component was identified by bioautography and GC/MS. C. hystrix leaves oil exhibited antibacterial activity at the MICs of 1.06 mg/mL for P. gingivalis and S. mutans and 2.12 mg/mL for S. sanguinis. Leaf oil at 4.25 mg/mL showed antibiofilm formation activity with 99% inhibition. The lethal effects on P. gingivalis were observed within 2 and 4 h after treated with 4 × MIC and 2 × MIC, respectively. S. sanguinis and S. mutans were completely killed within 4 and 8 h after exposed to 4 × MIC and 2 × MIC of oil. MICs of tested strains showed 4 times reduction suggesting synergistic interaction of oil and chlorhexidine. Bacterial outer membrane was disrupted after treatment with leaves oil. Additionally, citronellal was identified as the major active compound of C. hystrix oil. C. hystrix leaf oil could be used as a natural active compound or in combination with chlorhexidine in mouthwash preparations to prevent the growth of bacteria associated with periodontal diseases and biofilm formation.

[Causes and management of severe acute liver damage during pregnancy].

PubMed

Sepulveda-Martinez, Alvaro; Romero, Carlos; Juarez, Guido; Hasbun, Jorge; Parra-Cordero, Mauro

2015-05-01

Abnormalities in liver function tests appear in 3% of pregnancies. Severe acute liver damage can be an exclusive condition of pregnancy (dependent or independent of pre-eclampsia) or a concomitant disease. HELLP syndrome and acute fatty liver of pregnancy are the most severe liver diseases associated with pregnancy. Both appear during the third trimester and have a similar clinical presentation. Acute fatty liver may be associated with hypoglycemia and HELLP syndrome is closely linked with pre-eclampsia. Among concomitant conditions, fulminant acute hepatitis caused by medications or virus is the most severe disease. Its clinical presentation may be hyper-acute with neurological involvement and severe coagulation disorders. It has a high mortality and patients should be transplanted. Fulminant hepatic failure caused by acetaminophen overdose can be managed with n-acetyl cysteine. Because of the high fetal mortality rate, the gestational age at diagnosis is crucial.

Human bocavirus infection as a cause of severe acute respiratory tract infection in children.

PubMed

Moesker, F M; van Kampen, J J A; van der Eijk, A A; van Rossum, A M C; de Hoog, M; Schutten, M; Smits, S L; Bodewes, R; Osterhaus, A D M E; Fraaij, P L A

2015-10-01

In 2005 human bocavirus (HBoV) was discovered in respiratory tract samples of children. The role of HBoV as the single causative agent for respiratory tract infections remains unclear. Detection of HBoV in children with respiratory disease is frequently in combination with other viruses or bacteria. We set up an algorithm to study whether HBoV alone can cause severe acute respiratory tract infection (SARI) in children. The algorithm was developed to exclude cases with no other likely cause than HBoV for the need for admission to the paediatric intensive care unit (PICU) with SARI. We searched for other viruses by next-generation sequencing (NGS) in these cases and studied their HBoV viral loads. To benchmark our algorithm, the same was applied to respiratory syncytial virus (RSV)-positive patients. From our total group of 990 patients who tested positive for a respiratory virus by means of RT-PCR, HBoV and RSV were detected in 178 and 366 children admitted to our hospital. Forty-nine HBoV-positive patients and 72 RSV-positive patients were admitted to the PICU. We found seven single HBoV-infected cases with SARI admitted to PICU (7/49, 14%). They had no other detectable virus by NGS. They had much higher HBoV loads than other patients positive for HBoV. We identified 14 RSV-infected SARI patients with a single RSV infection (14/72, 19%). We conclude that our study provides strong support that HBoV can cause SARI in children in the absence of viral and bacterial co-infections. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Biodegradation of chlorobenzene by indigenous bacteria

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

Nishino, S.F.; Spain, J.C.; Pettigrew, C.A.

Soil and ground water from four sites chronically contaminated with chlorobenzenes were examined to determine whether indigenous bacteria could degrade the contaminants and whether the addition of specific chlorobenzene-degrading bacteria enhanced the degradation rate. At each site, chlorobenzene-degrading bacteria were readily isolated from chlorobenzene-contaminated wells, whereas similar samples from noncontaminated wells yielded no chlorobenzene-degrading bacteria. Isolates were tested for growth on a variety of substrates. At a site contaminated with several solvents, a bioreactor was inoculated with the chlorobenzene-degrading Pseudomonas sp. strain JS150. Contaminated water was pumped through this bioreactor and a control bioreactor that had been colonized by inmore » indigenous microorganisms. The contaminants were removed from both bioreactors; however, JS150 could not be recovered from the inoculated bioreactor after three weeks of operation. A follow-up lab study using ground water from the contaminated site confirmed the field results. The authors conclude that chlorobenzene contamination of soil causes the development of indigenous degradative populations that have a competitive advantage over inoculated strains. The mechanism and time course of this acclimation are poorly understood and require additional study.« less

Mechanistic modeling of biocorrosion caused by biofilms of sulfate reducing bacteria and acid producing bacteria.

PubMed

Xu, Dake; Li, Yingchao; Gu, Tingyue

2016-08-01

Biocorrosion is also known as microbiologically influenced corrosion (MIC). Most anaerobic MIC cases can be classified into two major types. Type I MIC involves non-oxygen oxidants such as sulfate and nitrate that require biocatalysis for their reduction in the cytoplasm of microbes such as sulfate reducing bacteria (SRB) and nitrate reducing bacteria (NRB). This means that the extracellular electrons from the oxidation of metal such as iron must be transported across cell walls into the cytoplasm. Type II MIC involves oxidants such as protons that are secreted by microbes such as acid producing bacteria (APB). The biofilms in this case supply the locally high concentrations of oxidants that are corrosive without biocatalysis. This work describes a mechanistic model that is based on the biocatalytic cathodic sulfate reduction (BCSR) theory. The model utilizes charge transfer and mass transfer concepts to describe the SRB biocorrosion process. The model also includes a mechanism to describe APB attack based on the local acidic pH at a pit bottom. A pitting prediction software package has been created based on the mechanisms. It predicts long-term pitting rates and worst-case scenarios after calibration using SRB short-term pit depth data. Various parameters can be investigated through computer simulation. Copyright © 2016 Elsevier B.V. All rights reserved.

Systematic review of severe acute liver injury caused by terbinafine.

PubMed

Yan, Jun; Wang, Xiaolin; Chen, Shengli

2014-08-01

Terbinafine is an effective antimicrobial agent against dermatophytes, cryptococcus and other fungi. It is the preferred drug to treat onychomycosis. However, severe acute hepatitis from oral terbinafine administration has been recently reported. To describe a representative case, and review the literature regarding the best evidence on treatment and prognosis of severe acute hepatitis caused by oral terbinafine. The literature was searched for publications on severe hepatitis caused by terbinafine using MEDLINE, China Biology Medicine Disc, and the VIP Medical Information Resource System. Related references were searched manually. Seventeen English and three Chinese references of case reports were included after eliminating duplicate publications. No randomized control studies were found. Liver enzyme levels were found to have been increased significantly. Abdominal ultrasound demonstrated cholestasis. Severe acute liver injury is a known, but unusual complication of terbinafine exposure. The prognosis is often good with appropriate treatment. Liver function assessment before treatment and periodic monitoring 4-6 weeks after initiation of treatment is recommended.

Sociomicrobiology and Pathogenic Bacteria.

PubMed

Xavier, Joao B

2016-06-01

The study of microbial pathogenesis has been primarily a reductionist science since Koch's principles. Reductionist approaches are essential to identify the causal agents of infectious disease, their molecular mechanisms of action, and potential drug targets, and much of medicine's success in the treatment of infectious disease stems from that approach. But many bacteria-caused diseases cannot be explained by a single bacterium. Several aspects of bacterial pathogenesis will benefit from a more holistic approach that takes into account social interaction among bacteria of the same species and between species in consortia such as the human microbiome. The emerging discipline of sociomicrobiology provides a framework to dissect microbial interactions in single and multi-species communities without compromising mechanistic detail. The study of bacterial pathogenesis can benefit greatly from incorporating concepts from other disciplines such as social evolution theory and microbial ecology, where communities, their interactions with hosts, and with the environment play key roles.

Bacteria isolated from bats inhibit the growth of Pseudogymnoascus destructans, the causative agent of white-nose syndrome.

PubMed

Hoyt, Joseph R; Cheng, Tina L; Langwig, Kate E; Hee, Mallory M; Frick, Winifred F; Kilpatrick, A Marm

2015-01-01

Emerging infectious diseases are a key threat to wildlife. Several fungal skin pathogens have recently emerged and caused widespread mortality in several vertebrate groups, including amphibians, bats, rattlesnakes and humans. White-nose syndrome, caused by the fungal skin pathogen Pseudogymnoascus destructans, threatens several hibernating bat species with extinction and there are few effective treatment strategies. The skin microbiome is increasingly understood to play a large role in determining disease outcome. We isolated bacteria from the skin of four bat species, and co-cultured these isolates with P. destructans to identify bacteria that might inhibit or kill P. destructans. We then conducted two reciprocal challenge experiments in vitro with six bacterial isolates (all in the genus Pseudomonas) to quantify the effect of these bacteria on the growth of P. destructans. All six Pseudomonas isolates significantly inhibited growth of P. destructans compared to non-inhibitory control bacteria, and two isolates performed significantly better than others in suppressing P. destructans growth for at least 35 days. In both challenge experiments, the extent of suppression of P. destructans growth was dependent on the initial concentration of P. destructans and the initial concentration of the bacterial isolate. These results show that bacteria found naturally occurring on bats can inhibit the growth of P. destructans in vitro and should be studied further as a possible probiotic to protect bats from white-nose syndrome. In addition, the presence of these bacteria may influence disease outcomes among individuals, populations, and species.

Bacteria Isolated from Bats Inhibit the Growth of Pseudogymnoascus destructans, the Causative Agent of White-Nose Syndrome

PubMed Central

Hoyt, Joseph R.; Cheng, Tina L.; Langwig, Kate E.; Hee, Mallory M.; Frick, Winifred F.; Kilpatrick, A. Marm

2015-01-01

Emerging infectious diseases are a key threat to wildlife. Several fungal skin pathogens have recently emerged and caused widespread mortality in several vertebrate groups, including amphibians, bats, rattlesnakes and humans. White-nose syndrome, caused by the fungal skin pathogen Pseudogymnoascus destructans, threatens several hibernating bat species with extinction and there are few effective treatment strategies. The skin microbiome is increasingly understood to play a large role in determining disease outcome. We isolated bacteria from the skin of four bat species, and co-cultured these isolates with P. destructans to identify bacteria that might inhibit or kill P. destructans. We then conducted two reciprocal challenge experiments in vitro with six bacterial isolates (all in the genus Pseudomonas) to quantify the effect of these bacteria on the growth of P. destructans. All six Pseudomonas isolates significantly inhibited growth of P. destructans compared to non-inhibitory control bacteria, and two isolates performed significantly better than others in suppressing P. destructans growth for at least 35 days. In both challenge experiments, the extent of suppression of P. destructans growth was dependent on the initial concentration of P. destructans and the initial concentration of the bacterial isolate. These results show that bacteria found naturally occurring on bats can inhibit the growth of P. destructans in vitro and should be studied further as a possible probiotic to protect bats from white-nose syndrome. In addition, the presence of these bacteria may influence disease outcomes among individuals, populations, and species. PMID:25853558

Anaemia in pet rabbits: causes, severity and reticulocyte response.

PubMed

Dettweiler, Alexandra; Klopfleisch, Robert; Müller, Kerstin

2017-12-16

The objective of the study was to determine the causes and the severity of anaemia in pet rabbits ( Oryctolagus cuniculus ), to classify anaemia and to compare the reticulocyte counts from healthy and anaemic rabbits. Over a time period of 11 years (2000-2011) a retrospective and prospective study of 223 pet rabbits was performed. Based on the clinic's own reference range for healthy pet rabbits (packed cell volume [PCV] levels 0.33-0.45 l/l), animals with a PCV level below 0.33 l/l were considered anaemic. Anaemia was mostly caused by inflammation (65/223, 29 per cent) and bleeding (54/223, 24 per cent). Seven per cent (15/223) of the rabbits suffered from renal diseases and one rabbit got diagnosed with haemolysis caused by liver lobe torsion. In 14 per cent (32/223) of the rabbits more than one underlying pathomechanism, like inflammation and bleeding, was diagnosed as possible cause of anaemia. In 25 per cent (56/223) of the anaemic rabbits no cause was found. Most anaemias were mild (156/223, 70 per cent). Moderate (43/223, 19 per cent) or severe (24/223, 11 per cent) anaemia was diagnosed more rarely. Anaemic rabbits showed similar reticulocyte counts to healthy rabbits with no significant difference. Therefore, a differentiation of regenerative and non-regenerative anaemia was not possible. © British Veterinary Association (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Gene switching in Amoeba proteus caused by endosymbiotic bacteria.

PubMed

Jeon, Taeck J; Jeon, Kwang W

2004-02-01

The expression of genes for S-adenosylmethionine synthetase (SAMS), which catalyzes the synthesis of S-adenosylmethionine (AdoMet), a major methyl donor in cells, was studied in symbiont-free (D) and symbiont-bearing (xD) amoeba strains to determine the effect of bacterial endosymbionts. The symbionts suppressed the expression of the gene in host xD amoebae, but amoebae still exhibited about half the enzyme activity found in symbiont-free D amoebae. The study was aimed at elucidating mechanisms of the suppression of the amoeba's gene and determining the alternative source for the gene product. Unexpectedly, we found a second sams (sams2) gene in amoebae, which encoded 390 amino acids. Results of experiments measuring SAMS activities and amounts of AdoMet in D and xD amoebae showed that the half SAMS activity found in xD amoebae came from the amoeba's SAMS2 and not from their endosymbionts. The expression of amoeba sams genes was switched from sams1 to sams2 as a result of infection with X-bacteria, raising the possibility that the switch in the expression of sams genes by bacteria plays a role in the development of symbiosis and the host-pathogen interactions. This is the first report showing such a switch in the expression of host sams genes by infecting bacteria.

PPIB mutations cause severe osteogenesis imperfecta.

PubMed

van Dijk, Fleur S; Nesbitt, Isabel M; Zwikstra, Eline H; Nikkels, Peter G J; Piersma, Sander R; Fratantoni, Silvina A; Jimenez, Connie R; Huizer, Margriet; Morsman, Alice C; Cobben, Jan M; van Roij, Mirjam H H; Elting, Mariet W; Verbeke, Jonathan I M L; Wijnaendts, Liliane C D; Shaw, Nick J; Högler, Wolfgang; McKeown, Carole; Sistermans, Erik A; Dalton, Ann; Meijers-Heijboer, Hanne; Pals, Gerard

2009-10-01

Deficiency of cartilage-associated protein (CRTAP) or prolyl 3-hydroxylase 1(P3H1) has been reported in autosomal-recessive lethal or severe osteogenesis imperfecta (OI). CRTAP, P3H1, and cyclophilin B (CyPB) form an intracellular collagen-modifying complex that 3-hydroxylates proline at position 986 (P986) in the alpha1 chains of collagen type I. This 3-prolyl hydroxylation is decreased in patients with CRTAP and P3H1 deficiency. It was suspected that mutations in the PPIB gene encoding CyPB would also cause OI with decreased collagen 3-prolyl hydroxylation. To our knowledge we present the first two families with recessive OI caused by PPIB gene mutations. The clinical phenotype is compatible with OI Sillence type II-B/III as seen with COL1A1/2, CRTAP, and LEPRE1 mutations. The percentage of 3-hydroxylated P986 residues in patients with PPIB mutations is decreased in comparison to normal, but it is higher than in patients with CRTAP and LEPRE1 mutations. This result and the fact that CyPB is demonstrable independent of CRTAP and P3H1, along with reported decreased 3-prolyl hydroxylation due to deficiency of CRTAP lacking the catalytic hydroxylation domain and the known function of CyPB as a cis-trans isomerase, suggest that recessive OI is caused by a dysfunctional P3H1/CRTAP/CyPB complex rather than by the lack of 3-prolyl hydroxylation of a single proline residue in the alpha1 chains of collagen type I.

Diet and caries-associated bacteria in severe early childhood caries.

PubMed

Palmer, C A; Kent, R; Loo, C Y; Hughes, C V; Stutius, E; Pradhan, N; Dahlan, M; Kanasi, E; Arevalo Vasquez, S S; Tanner, A C R

2010-11-01

Frequent consumption of cariogenic foods and bacterial infection are risk factors for early childhood caries (ECC). This study hypothesized that a short diet survey focused on frequency of foods, categorized by putative cariogenicity, would differentiate severe ECC (S-ECC) from caries-free children. Children's diets were obtained by survey and plaque bacteria detected by PCR from 72 S-ECC and 38 caries-free children. S-ECC children had higher scores for between-meal juice (p < 0.01), solid-retentive foods (p < 0.001), eating frequency (p < 0.005), and estimated food cariogenicity (p < 0.0001) than caries-free children. S-ECC children with lesion recurrence ate fewer putative caries-protective foods than children without new lesions. Streptococcus mutans (p < 0.005), Streptococcus sobrinus (p < 0.005), and Bifidobacteria (p < 0.0001) were associated with S-ECC, and S. mutans with S. sobrinus was associated with lesion recurrence (p < 0.05). S. mutans-positive children had higher food cariogenicity scores. Food frequency, putative cariogenicity, and S. mutans were associated with S-ECC individually and in combination.

Diet and Caries-associated Bacteria in Severe Early Childhood Caries

PubMed Central

Palmer, C.A.; Kent, R.; Loo, C.Y.; Hughes, C.V.; Stutius, E.; Pradhan, N.; Dahlan, M.; Kanasi, E.; Arevalo Vasquez, S.S.; Tanner, A.C.R.

2010-01-01

Frequent consumption of cariogenic foods and bacterial infection are risk factors for early childhood caries (ECC). This study hypothesized that a short diet survey focused on frequency of foods, categorized by putative cariogenicity, would differentiate severe ECC (S-ECC) from caries-free children. Children’s diets were obtained by survey and plaque bacteria detected by PCR from 72 S-ECC and 38 caries-free children. S-ECC children had higher scores for between-meal juice (p < 0.01), solid-retentive foods (p < 0.001), eating frequency (p < 0.005), and estimated food cariogenicity (p < 0.0001) than caries-free children. S-ECC children with lesion recurrence ate fewer putative caries-protective foods than children without new lesions. Streptococcus mutans (p < 0.005), Streptococcus sobrinus (p < 0.005), and Bifidobacteria (p < 0.0001) were associated with S-ECC, and S. mutans with S. sobrinus was associated with lesion recurrence (p < 0.05). S. mutans-positive children had higher food cariogenicity scores. Food frequency, putative cariogenicity, and S. mutans were associated with S-ECC individually and in combination. PMID:20858780

Typhlitis Caused by Intestinal Serpulina-Like Bacteria in Domestic Guinea Pigs (Cavia porcellus)

PubMed Central

Vanrobaeys, Mia; De Herdt, Peter; Ducatelle, Richard; Devriese, Luc A.; Charlier, Gerard; Haesebrouck, Freddy

1998-01-01

Between January 1992 and December 1996, Serpulina-like bacteria were demonstrated in intestinal tract lesions from 37 of 88 guinea pigs submitted to the University of Ghent in Ghent, Belgium, for necropsy because of disease and death from different unknown causes. All infected animals had a history of sudden death with minimal introductory clinical signs. Occasionally, they produced yellow, slimy feces or showed nervous signs, but the condition always had a fatal outcome within 24 h. When larger colonies of guinea pigs were involved, the disease spread very rapidly unless treatment with ronidazole was initiated. Lesions consisted of a catarrhal or hemorrhagic inflammation of the colon and cecum (typhlitis). Electron microscopy demonstrated the presence of large numbers of Serpulina-like organisms adhering to the cecal mucosae of these animals. Attempts to isolate the agents failed. The organisms did not stain by an immunofluorescence technique for the detection of Serpulina hyodysenteriae. The present data provide evidence that intestinal Serpulina-like organisms can be important as a cause of disease in guinea pigs. PMID:9508297

Did Zika Virus Mutate to Cause Severe Outbreaks?

PubMed

Rossi, Shannan L; Ebel, Gregory D; Shan, Chao; Shi, Pei-Yong; Vasilakis, Nikos

2018-06-11

Zika virus (ZIKV) has challenged the assumed knowledge regarding the pathobiology of flaviviruses. Despite causing sporadic and mild disease in the 50 years since its discovery, Zika virus has now caused multiple outbreaks in dozens of countries worldwide. Moreover, the disease severity in recent outbreaks, with neurological disease in adult and devastating congenital malformations in fetuses, was not previously seen. One hypothesis is that the virus has acquired mutations that have increased its virulence. Indeed, mutations in other arboviruses, such as West Nile virus (WNV), chikungunya virus (CHIKV), and Venezuelan equine encephalitis virus (VEEV), have enhanced outbreaks. This possibility, as well as alternative hypotheses, are explored here. Copyright © 2018 Elsevier Ltd. All rights reserved.

Heterologous expression of enterocin AS-48 in several strains of lactic acid bacteria.

PubMed

Fernández, M; Martínez-Bueno, M; Martín, M C; Valdivia, E; Maqueda, M

2007-05-01

Enterococcus faecalis produces a cationic and circular enterocin, AS-48, of 7149 Da, the genetic determinants of which are located within the pMB2 plasmid. We have compared enterocin AS-48 production by different enterococci species with that of other 'safe' lactic acid bacteris (LAB) (GRAS status) and looked into the subsequent application of this enterocin in food production. In an effort to exploit this system for the heterologous expression of enterocin AS-48, a number of vectors containing the as-48 cluster were constructed and used to transform several LAB strains (genera Enterococcus, Lactococcus and Lactobacillus) Heterologous production of enterocin AS-48 failed when bacteria other than those belonging to the genus Enterococcus were used as hosts, although expression of a partial level of resistance against AS-48 were always detected, ruling out the possibility of a lack of recognition of the enterococcal promoters. Our results reveal the special capacity of species from the genus Enterococcus to produce AS-48, an enterocin that requires a post-transcriptional modification to generate a circular peptide with a wide range of inhibitory activity against pathogenic and spoilage bacteria. Preliminary experiments in foodstuffs using nonvirulent enterococci with interesting functional properties reveal the possibility of a biotechnological application of these transformants.

Lactic acid bacteria of meat and meat products.

PubMed

Egan, A F

1983-09-01

When the growth of aerobic spoilage bacteria is inhibited, lactic acid bacteria may become the dominant component of the microbial flora of meats. This occurs with cured meats and with meats packaged in films of low gas permeability. The presence of a flora of psychrotrophic lactic acid bacteria on vacuum-packaged fresh chilled meats usually ensures that shelf-life is maximal. When these organisms spoil meats it is generally by causing souring, however other specific types of spoilage do occur. Some strains cause slime formation and greening of cured meats, and others may produce hydrogen sulphide during growth on vacuum-packaged beef. The safety and stability of fermented sausages depends upon fermentation caused by lactic acid bacteria. Overall the presence on meats of lactic acid bacteria is more desirable than that of the types of bacteria they have replaced.

Rapid differentiation among bacteria that cause gastroenteritis by use of low-resolution Raman spectroscopy and PLS discriminant analysis.

PubMed

Mello, Cesar; Ribeiro, Diórginis; Novaes, Fábio; Poppi, Ronei J

2005-10-01

Use of classical microbiological methods to differentiate bacteria that cause gastroenteritis is cumbersome but usually very efficient. The high cost of reagents and the time required for such identifications, approximately four days, could have serious consequences, however, mainly when the patients are children, the elderly, or adults with low resistance. The search for new methods enabling rapid and reagentless differentiation of these microorganisms is, therefore, extremely relevant. In this work the main microorganisms responsible for gastroenteritis, Escherichia coli, Salmonella choleraesuis, and Shigella flexneri, were studied. For each microorganism sixty different dispersions were prepared in physiological solution. The Raman spectra of these dispersions were recorded using a diode laser operating in the near infrared region. Partial least-squares (PLS) discriminant analysis was used to differentiate among the bacteria by use of their respective Raman spectra. This approach enabled correct classification of 100% of the bacteria evaluated and unknown samples from the clinical environment, in less time ( approximately 10 h), by use of a low-cost, portable Raman spectrometer, which can be easily used in intensive care units and clinical environments.

Suppurative parotitis caused by anaerobic bacteria in newborns.

PubMed

Brook, Itzhak

2002-01-01

Staphylococci are the usual bacterial etiology of suppurative parotitis in newborns. This report describes for the first time recovery of anaerobic bacteria from aspirates of the infected gland in two infants with suppurative parotitis. Peptostreptococcus intermedius and Prevotella melaninogenica were isolated from one child and Prevotella intermedia from the other patient. Complete recovery occurred after 4 weeks of antimicrobial therapy.

Recovery of anaerobic bacteria from wounds after lawn-mower injuries.

PubMed

Brook, Itzhak

2005-02-01

Accidental injury while using lawn mowers can cause serious infectious complications in the injured extremity. Anaerobic bacteria were rarely recovered from this infection. Two children who sustained injury in their foot by a lawn mower developed severe wound infection. Culture of the wound from 1 patient had heavy growth of Clostridium bifermentans and Peptostreptococcus magnus, and the culture from the other child grew Clostridium perfringens. Antimicrobial therapy directed at the pathogens and vigorous surgical irrigation and debridement led to complete recovery from the infection. This report illustrates the recovery of anaerobic bacteria from children that had wound infection after lawn-mower injury.

White Band Disease (type I) of endangered caribbean acroporid corals is caused by pathogenic bacteria.

PubMed

Kline, David I; Vollmer, Steven V

2011-01-01

Diseases affecting coral reefs have increased exponentially over the last three decades and contributed to their decline, particularly in the Caribbean. In most cases, the responsible pathogens have not been isolated, often due to the difficulty in isolating and culturing marine bacteria. White Band Disease (WBD) has caused unprecedented declines in the Caribbean acroporid corals, resulting in their listings as threatened on the US Threatened and Endangered Species List and critically endangered on the IUCN Red List. Yet, despite the importance of WBD, the probable pathogen(s) have not yet been determined. Here we present in situ transmission data from a series of filtrate and antibiotic treatments of disease tissue that indicate that WBD is contagious and caused by bacterial pathogen(s). Additionally our data suggest that Ampicillin could be considered as a treatment for WBD (type I).

Identifying the major bacteria causing intramammary infections in individual milk samples of sheep and goats using traditional bacteria culturing and real-time polymerase chain reaction.

PubMed

Rovai, M; Caja, G; Salama, A A K; Jubert, A; Lázaro, B; Lázaro, M; Leitner, G

2014-09-01

Use of DNA-based methods, such as real-time PCR, has increased the sensitivity and shortened the time for bacterial identification, compared with traditional bacteriology; however, results should be interpreted carefully because a positive PCR result does not necessarily mean that an infection exists. One hundred eight lactating dairy ewes (56 Manchega and 52 Lacaune) and 24 Murciano-Granadina dairy goats were used for identifying the main bacteria causing intramammary infections (IMI) using traditional bacterial culturing and real-time PCR and their effects on milk performance. Udder-half milk samples were taken for bacterial culturing and somatic cell count (SCC) 3 times throughout lactation. Intramammary infections were assessed based on bacteria isolated in ≥2 samplings accompanied by increased SCC. Prevalence of subclinical IMI was 42.9% in Manchega and 50.0% in Lacaune ewes and 41.7% in goats, with the estimated milk yield loss being 13.1, 17.9, and 18.0%, respectively. According to bacteriology results, 87% of the identified single bacteria species (with more than 3 colonies/plate) or culture-negative growth were identical throughout samplings, which agreed 98.9% with the PCR results. Nevertheless, the study emphasized that 1 sampling may not be sufficient to determine IMI and, therefore, other inflammatory responses such as increased SCC should be monitored to identify true infections. Moreover, when PCR methodology is used, aseptic and precise milk sampling procedures are key for avoiding false-positive amplifications. In conclusion, both PCR and bacterial culture methods proved to have similar accuracy for identifying infective bacteria in sheep and goats. The final choice will depend on their response time and cost analysis, according to the requirements and farm management strategy. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Re-engineering bacteria for ethanol production

DOEpatents

Yomano, Lorraine P; York, Sean W; Zhou, Shengde; Shanmugam, Keelnatham; Ingram, Lonnie O

2014-05-06

The invention provides recombinant bacteria, which comprise a full complement of heterologous ethanol production genes. Expression of the full complement of heterologous ethanol production genes causes the recombinant bacteria to produce ethanol as the primary fermentation product when grown in mineral salts medium, without the addition of complex nutrients. Methods for producing the recombinant bacteria and methods for producing ethanol using the recombinant bacteria are also disclosed.

Idiopathic annular dilation: a rare cause of isolated severe tricuspid regurgitation.

PubMed

Girard, S E; Nishimura, R A; Warnes, C A; Dearani, J A; Puga, F J

2000-03-01

The management of patients with severe tricuspid regurgitation (TR) requires the clinician to clarify the mechanism of regurgitation. Primary disorders of the tricuspid valve, either congenital or acquired, may be readily identified by echocardiography. Severe TR most often results from left-sided heart disease and secondary pulmonary hypertension. Cardiomyopathic processes may also cause right ventricular failure and functional TR. We report three patients with severe TR due to idiopathic annular dilation. The tricuspid valves were otherwise normal on surgical inspection, and the pulmonary pressures were not significantly elevated. Each patient was aged over 65 years and had chronic atrial fibrillation with preserved left ventricular systolic function. Surgical treatment was associated with marked clinical improvement. Clinicians should recognize this unusual but treatable cause of right-sided congestive heart failure.

Curative Treatment of Severe Gram-Negative Bacterial Infections by a New Class of Antibiotics Targeting LpxC

PubMed Central

Lemaître, Nadine; Liang, Xiaofei; Najeeb, Javaria; Lee, Chul-Jin; Titecat, Marie; Leteurtre, Emmanuelle; Simonet, Michel; Toone, Eric J.

2017-01-01

ABSTRACT The infectious diseases caused by multidrug-resistant bacteria pose serious threats to humankind. It has been suggested that an antibiotic targeting LpxC of the lipid A biosynthetic pathway in Gram-negative bacteria is a promising strategy for curing Gram-negative bacterial infections. However, experimental proof of this concept is lacking. Here, we describe our discovery and characterization of a biphenylacetylene-based inhibitor of LpxC, an essential enzyme in the biosynthesis of the lipid A component of the outer membrane of Gram-negative bacteria. The compound LPC-069 has no known adverse effects in mice and is effective in vitro against a broad panel of Gram-negative clinical isolates, including several multiresistant and extremely drug-resistant strains involved in nosocomial infections. Furthermore, LPC-069 is curative in a murine model of one of the most severe human diseases, bubonic plague, which is caused by the Gram-negative bacterium Yersinia pestis. Our results demonstrate the safety and efficacy of LpxC inhibitors as a new class of antibiotic against fatal infections caused by extremely virulent pathogens. The present findings also highlight the potential of LpxC inhibitors for clinical development as therapeutics for infections caused by multidrug-resistant bacteria. PMID:28743813

A case of fetal intestinal volvulus without malrotation causing severe anemia.

PubMed

Nakagawa, Tomoko; Tachibana, Daisuke; Kitada, Kohei; Kurihara, Yasushi; Terada, Hiroyuki; Koyama, Masayasu; Sakae, Yukari; Morotomi, Yoshiki; Nomura, Shiho; Saito, Mika

2015-01-01

Fetal intestinal volvulus without malrotation is a rare, life-threatening disease. Left untreated, hemorrhage from necrotic bowel tissue will lead to severe fetal anemia and even intrauterine death. We encountered a case of fetal intestinal volvulus causing severe anemia, which was diagnosed postnatally and successfully treated with surgical intervention.

Phylogeny of pectolytic bacteria associated with recent outbreaks of potato soft rot and blackleg in the United States

USDA-ARS?s Scientific Manuscript database

Soft rot diseases of potato are caused by several species of bacteria belonging to the newly described family Pectobacteriaceae. Multiple species of Pectobacterium are known to cause soft rot diseases during field production and storage of potatoes. Recently, the genus Dickeya has been connected wi...

A Case of Fetal Intestinal Volvulus Without Malrotation Causing Severe Anemia

PubMed Central

Nakagawa, Tomoko; Tachibana, Daisuke; Kitada, Kohei; Kurihara, Yasushi; Terada, Hiroyuki; Koyama, Masayasu; Sakae, Yukari; Morotomi, Yoshiki; Nomura, Shiho; Saito, Mika

2015-01-01

Fetal intestinal volvulus without malrotation is a rare, life-threatening disease. Left untreated, hemorrhage from necrotic bowel tissue will lead to severe fetal anemia and even intrauterine death. We encountered a case of fetal intestinal volvulus causing severe anemia, which was diagnosed postnatally and successfully treated with surgical intervention. PMID:25628516

Potentially pathogenic airway bacteria and neutrophilic inflammation in treatment resistant severe asthma.

PubMed

Green, Benjamin J; Wiriyachaiporn, Surasa; Grainge, Christopher; Rogers, Geraint B; Kehagia, Valia; Lau, Laurie; Carroll, Mary P; Bruce, Kenneth D; Howarth, Peter H

2014-01-01

Molecular microbiological analysis of airway samples in asthma has demonstrated an altered microbiome in comparison to healthy controls. Such changes may have relevance to treatment-resistant severe asthma, particularly those with neutrophilic airway inflammation, as bacteria might be anticipated to activate the innate immune response, a process that is poorly steroid responsive. An understanding of the relationship between airway bacterial presence and dominance in severe asthma may help direct alternative treatment approaches. We aimed to use a culture independent analysis strategy to describe the presence, dominance and abundance of bacterial taxa in induced sputum from treatment resistant severe asthmatics and correlate findings with clinical characteristics and airway inflammatory markers. Induced sputum was obtained from 28 stable treatment-resistant severe asthmatics. The samples were divided for supernatant IL-8 measurement, cytospin preparation for differential cell count and Terminal Restriction Fragment Length Polymorphism (T-RFLP) profiling for bacterial community analysis. In 17/28 patients, the dominant species within the airway bacterial community was Moraxella catarrhalis or a member of the Haemophilus or Streptococcus genera. Colonisation with these species was associated with longer asthma disease duration (mean (SD) 31.8 years (16.7) vs 15.6 years (8.0), p = 0.008), worse post-bronchodilator percent predicted FEV1 (68.0% (24.0) vs 85.5% (19.7), p = 0.025) and higher sputum neutrophil differential cell counts (median (IQR) 80% (67-83) vs 43% (29-67), p = 0.001). Total abundance of these organisms significantly and positively correlated with sputum IL-8 concentration and neutrophil count. Airway colonisation with potentially pathogenic micro-organisms in asthma is associated with more severe airways obstruction and neutrophilic airway inflammation. This altered colonisation may have a role in the development of an asthma phenotype that

Do Low Molecular Weight Agents Cause More Severe Asthma than High Molecular Weight Agents?

PubMed

Meca, Olga; Cruz, María-Jesús; Sánchez-Ortiz, Mónica; González-Barcala, Francisco-Javier; Ojanguren, Iñigo; Munoz, Xavier

2016-01-01

The aim of this study was to analyse whether patients with occupational asthma (OA) caused by low molecular weight (LMW) agents differed from patients with OA caused by high molecular weight (HMW) with regard to risk factors, asthma presentation and severity, and response to various diagnostic tests. Seventy-eight patients with OA diagnosed by positive specific inhalation challenge (SIC) were included. Anthropometric characteristics, atopic status, occupation, latency periods, asthma severity according to the Global Initiative for Asthma (GINA) control classification, lung function tests and SIC results were analysed. OA was induced by an HMW agent in 23 patients (29%) and by an LMW agent in 55 (71%). A logistic regression analysis confirmed that patients with OA caused by LMW agents had a significantly higher risk of severity according to the GINA classification after adjusting for potential confounders (OR = 3.579, 95% CI 1.136-11.280; p = 0.029). During the SIC, most patients with OA caused by HMW agents presented an early reaction (82%), while in patients with OA caused by LMW agents the response was mainly late (73%) (p = 0.0001). Similarly, patients with OA caused by LMW agents experienced a greater degree of bronchial hyperresponsiveness, measured as the difference in the methacholine dose-response ratio (DRR) before and after SIC (1.77, range 0-16), compared with patients with OA caused by HMW agents (0.87, range 0-72), (p = 0.024). OA caused by LMW agents may be more severe than that caused by HMW agents. The severity of the condition may be determined by the different mechanisms of action of these agents.

Modeling studying on ice formation by bacteria in warm-based convective cloud

NASA Astrophysics Data System (ADS)

Sun, J.

2005-12-01

Bacteria have been recognized as cloud condensation nuclei (CCN), and certain bacteria, commonly found in plants, have exhibited capacity to act as ice nuclei (IN) at temperatures as warm as -2 °C. These ice nucleating bacteria are readily disseminated into the atmosphere and have been observed in clouds at altitudes of several kilometres. It is noteworthy that over 20 years ago, one assumed the possibility of bacterial transport and their importance into cloud formation process, rain and precipitation, as well as causing disease in plants and animal kingdom. We used a 1-D cumulus cloud model with the CCOPE 19th July 1981 case and the observed field profile of bacterial concentration, to simulate the significance of bacteria as IN through condensation freezing mechanism. In this paper, we will present our results on the role of bacteria as active ice nuclei in the developing stage of cumulus clouds, and their potential significance in atmospheric sciences.

Plants as sources of airborne bacteria, including ice nucleation-active bacteria.

PubMed

Lindemann, J; Constantinidou, H A; Barchet, W R; Upper, C D

1982-11-01

Vertical wind shear and concentration gradients of viable, airborne bacteria were used to calculate the upward flux of viable cells above bare soil and canopies of several crops. Concentrations at soil or canopy height varied from 46 colony-forming units per m over young corn and wet soil to 663 colony-forming units per m over dry soil and 6,500 colony-forming units per m over a closed wheat canopy. In simultaneous samples, concentrations of viable bacteria in the air 10 m inside an alfalfa field were fourfold higher than those over a field with dry, bare soil immediately upwind. The upward flux of viable bacteria over alfalfa was three- to fourfold greater than over dry soil. Concentrations of ice nucleation-active bacteria were higher over plants than over soil. Thus, plant canopies may constitute a major source of bacteria, including ice nucleation-active bacteria, in the air.

Antibacterial activity of extracts from five medicinal plants and their formula against bacteria that cause chronic wound infection.

PubMed

Temrangsee, Pornthep; Kondo, Sumalee; Itharat, Arunporn

2011-12-01

Chronic wound is caused by various factors such as chemotherapy, gene damage, treatment with steroids, diabetes mellitus, renal failure, blood pressure, infection and nutritional factors. One of the most common causes is bacterial infection. Antibacterial activity of several herbal plants has been reported. Thai medicinal plants which possess biological activities are potential to develop an alternative treatment of bacterial infection. To study efficiency of extracts from medicinal plants and their formula against bacteria that cause chronic wound infection. Extraction of Thai medicinal plants including Curcuma longa Linn, Rhinacanthus nasutus Linn, Garcinia mangostana Linn, Caesalpinia sappan Linn and Centellia asiatica Linn was performed by maceration with 95% ethanol and decoction followed by freeze dry. Formulation was conducted by varying the ratio of each components. Antibacterial activity were determined disk diffusion and broth dilution against Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Acinetobacter baumanii, Escherichia coli and Klebsiella pneumoniae. Ethanolic extracts exhibited better antibacterial activity against tested strains than water extracts. Antibacterial activity of Caesalpinia sappan Linn. against S. aureus and MRSA showed the most effective with MIC value of 0.625 mg/ml. One of the five different formulas which contained two times proportion of C. sappan revealed that this formula was able to inhibit all tested strains with the MIC ranging between 0.156 mg/ml and 10 mg/ml. C. sappan is the most effective herbal plant. The formula with two times proportion of C. sappan is potentially best formula for development of medicinal product of chronic wound infection. The potential active compound of C. sappan is suggested for further investigation of antimicrobial activity and other biological properties.

Bacteriophages: the possible solution to treat infections caused by pathogenic bacteria.

PubMed

El-Shibiny, Ayman; El-Sahhar, Salma

2017-11-01

Since their discovery in 1915, bacteriophages have been used to treat bacterial infections in animals and humans because of their unique ability to infect their specific bacterial hosts without affecting other bacterial populations. The research carried out in this field throughout the 20th century, largely in Georgia, part of USSR and Poland, led to the establishment of phage therapy protocols. However, the discovery of penicillin and sulfonamide antibiotics in the Western World during the 1930s was a setback in the advancement of phage therapy. The misuse of antibiotics has reduced their efficacy in controlling pathogens and has led to an increase in the number of antibiotic-resistant bacteria. As an alternative to antibiotics, bacteriophages have become a topic of interest with the emergence of multidrug-resistant bacteria, which are a threat to public health. Recent studies have indicated that bacteriophages can be used indirectly to detect pathogenic bacteria or directly as biocontrol agents. Moreover, they can be used to develop new molecules for clinical applications, vaccine production, drug design, and in the nanomedicine field via phage display.

Measurements of water temperature in fountains as an indicator of potential secondary water pollution caused by Legionella bacteria

NASA Astrophysics Data System (ADS)

Bąk, Joanna

2018-02-01

At high air temperatures persisting for a long time, water temperature in the fountains may also increase significantly. This can cause a sudden and significant increase in Legionella bacteria, which results in secondary water contamination. This phenomenon with water - air aerosol generated by fountains can be very dangerous for people. During the test, water temperature measurements in fountains in Poland were made. These research tests was conducted in the spring and summer. The research was conducted in order to determine whether there is a possibility of growth of Legionella bacteria. One of the aims of the study was to determine what temperature range occurs in the fountains and how the temperature changes in the basin of the fountain and when the highest temperature occurs. Single temperature measurements were made and also the temperature distribution was measured during daylight hours. The water temperature in most cases was greater than 20°C, but in no case exceed 26°C. The paper presents also the review about the effect of water temperature on the presence and bacterial growth. The study confirmed the existence of the risk of increasing the number of bacteria of the genus Legionella in the water in the fountains.

The influence of bacteria on multitrophic interactions among plants, psyllids, and pathogen.

PubMed

Tamborindeguy, Cecilia; Huot, Ordom Brian; Ibanez, Freddy; Levy, Julien

2017-12-01

The recent emergence of several plant diseases caused by psyllid-borne bacterial pathogens worldwide (Candidatus Liberibacter spp.) has created renewed interest on the interaction between psyllids and bacteria. In spite of these efforts to understand psyllid association with bacteria, many aspects of their interactions remain poorly understood. As more organisms are studied, subtleties on the molecular interactions as well as on the effects of the bacteria on the psyllid host are being uncovered. Additionally, psyllid-borne bacterial phytopathogens can also affect the host plant, which in turn can impact psyllid physiology and behavior. Here, we review the current literature on different aspects of the influence of bacteria on multitrophic interactions among plants, psyllids, and pathogens. We then highlight gaps that need to be addressed to advance this field, which can have significant implications for controlling these newly emergent and other plant diseases. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Denitrification by extremely halophilic bacteria

NASA Technical Reports Server (NTRS)

Hochstein, L. I.; Tomlinson, G. A.

1985-01-01

Extremely halophilic bacteria were isolated from widely separated sites by anaerobic enrichment in the presence of nitrate. The anaerobic growth of several of these isolates was accompanied by the production of nitrite, nitrous oxide, and dinitrogen. These results are a direct confirmation of the existence of extremely halophilic denitrifying bacteria, and suggest that such bacteria may be common inhabitants of hypersaline environments.

Intrinsic, adaptive and acquired antimicrobial resistance in Gram-negative bacteria.

PubMed

Arzanlou, Mohsen; Chai, Wern Chern; Venter, Henrietta

2017-02-28

Gram-negative bacteria are responsible for a large proportion of antimicrobial-resistant infections in humans and animals. Among this class of bacteria are also some of the most successful environmental organisms. Part of this success is their adaptability to a variety of different niches, their intrinsic resistance to antimicrobial drugs and their ability to rapidly acquire resistance mechanisms. These mechanisms of resistance are not exclusive and the interplay of several mechanisms causes high levels of resistance. In this review, we explore the molecular mechanisms underlying resistance in Gram-negative organisms and how these different mechanisms enable them to survive many different stress conditions. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Bacteria permeabilization and disruption caused by sludge reduction technologies evaluated by flow cytometry.

PubMed

Foladori, P; Tamburini, S; Bruni, L

2010-09-01

Technologies proposed in the last decades for the reduction of the sludge production in wastewater treatment plants and based on the mechanism of cell lysis-cryptic growth (physical, mechanical, thermal, chemical, oxidative treatments) have been widely investigated at lab-, pilot- and, in some cases, at full-scale but the effects on cellular lysis have not always been demonstrated in depth. The research presented in this paper aims to investigate how these sludge reduction technologies affect the integrity and permeabilization of bacterial cells in sludge using flow cytometry (FCM), which permits the rapid and statistically accurate quantification of intact, permeabilised or disrupted bacteria in the sludge using a double fluorescent DNA-staining instead of using conventional methods like plate counts and microscope. Physical/mechanical treatments (ultrasonication and high pressure homogenisation) caused moderate effects on cell integrity and caused significant cell disruption only at high specific energy levels. Conversely, thermal treatment caused significant damage of bacterial membranes even at moderate temperatures (45-55 °C). Ozonation significantly affected cell integrity, even at low ozone dosages, below 10 mgO(3)/gTSS, causing an increase of permeabilised and disrupted cells. At higher ozone dosages the compounds solubilised after cell lysis act as scavengers in the competition between soluble compounds and (particulate) bacterial cells. An original aspect of this paper, not yet reported in the literature, is the comparison of the effects of these sludge reduction technologies on bacterial cell integrity and permeabilization by converting pressure, temperature and ozone dosage to an equivalent value of specific energy. Among these technologies, comparison of the applied specific energy demonstrates that achieving the complete disruption of bacterial cells is not always economically advantageous because excessive energy levels may be required. Copyright �

Symbiotic interaction of endophytic bacteria with arbuscular mycorrhizal fungi and its antagonistic effect on Ganoderma boninense.

PubMed

Sundram, Shamala; Meon, Sariah; Seman, Idris Abu; Othman, Radziah

2011-08-01

Endophytic bacteria (Pseudomonas aeruginosa UPMP3 and Burkholderia cepacia UMPB3), isolated from within roots of oil palm (Elaeis guineensis Jacq.) were tested for their presymbiotic effects on two arbuscular mcorrhizal fungi, Glomus intraradices UT126 and Glomus clarum BR152B). These endophytic bacteria were also tested for antagonistic effects on Ganoderma boninense PER 71, a white wood rot fungal pathogen that causes a serious disease in oil palm. Spore germination and hyphal length of each arbuscular mycorrhizal fungal (AMF) pairing with endophytic bacteria was found to be significantly higher than spores plated in the absence of bacteria. Scanning electron microscopy (SEM) showed that the endophytic bacteria were scattered, resting or embedded on the surface hyaline layer or on the degraded walls of AMF spores, possibly feeding on the outer hyaline spore wall. The antagonistic effect of the endophytic bacteria was expressed as severe morphological abnormalities in the hyphal structures of G. boninense PER 71. The effects of the endophytic bacteria on G. boninense PER 71 hyphal structures were observed clearly under SEM. Severe inter-twisting, distortion, lysis and shriveling of the hyphal structures were observed. This study found that the effect of endophytic bacteria on G. intraradices UT126 and G. clarum BR152B resembled that of a mycorrhiza helper bacteria (MHB) association because the association significantly promoted AMF spore germination and hyphal length. However, the endophytic bacteria were extremely damaging to G. boninense PER 71.

Combination Therapy for Treatment of Infections with Gram-Negative Bacteria

PubMed Central

Cosgrove, Sara E.; Maragakis, Lisa L.

2012-01-01

Summary: Combination antibiotic therapy for invasive infections with Gram-negative bacteria is employed in many health care facilities, especially for certain subgroups of patients, including those with neutropenia, those with infections caused by Pseudomonas aeruginosa, those with ventilator-associated pneumonia, and the severely ill. An argument can be made for empiric combination therapy, as we are witnessing a rise in infections caused by multidrug-resistant Gram-negative organisms. The wisdom of continued combination therapy after an organism is isolated and antimicrobial susceptibility data are known, however, is more controversial. The available evidence suggests that the greatest benefit of combination antibiotic therapy stems from the increased likelihood of choosing an effective agent during empiric therapy, rather than exploitation of in vitro synergy or the prevention of resistance during definitive treatment. In this review, we summarize the available data comparing monotherapy versus combination antimicrobial therapy for the treatment of infections with Gram-negative bacteria. PMID:22763634

Curative Treatment of Severe Gram-Negative Bacterial Infections by a New Class of Antibiotics Targeting LpxC

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

Lemaître, Nadine; Liang, Xiaofei; Najeeb, Javaria

ABSTRACT The infectious diseases caused by multidrug-resistant bacteria pose serious threats to humankind. It has been suggested that an antibiotic targeting LpxC of the lipid A biosynthetic pathway in Gram-negative bacteria is a promising strategy for curing Gram-negative bacterial infections. However, experimental proof of this concept is lacking. Here, we describe our discovery and characterization of a biphenylacetylene-based inhibitor of LpxC, an essential enzyme in the biosynthesis of the lipid A component of the outer membrane of Gram-negative bacteria. The compound LPC-069 has no known adverse effects in mice and is effectivein vitroagainst a broad panel of Gram-negative clinical isolates,more » including several multiresistant and extremely drug-resistant strains involved in nosocomial infections. Furthermore, LPC-069 is curative in a murine model of one of the most severe human diseases, bubonic plague, which is caused by the Gram-negative bacteriumYersinia pestis. Our results demonstrate the safety and efficacy of LpxC inhibitors as a new class of antibiotic against fatal infections caused by extremely virulent pathogens. The present findings also highlight the potential of LpxC inhibitors for clinical development as therapeutics for infections caused by multidrug-resistant bacteria. IMPORTANCEThe rapid spread of antimicrobial resistance among Gram-negative bacilli highlights the urgent need for new antibiotics. Here, we describe a new class of antibiotics lacking cross-resistance with conventional antibiotics. The compounds inhibit LpxC, a key enzyme in the lipid A biosynthetic pathway in Gram-negative bacteria, and are activein vitroagainst a broad panel of clinical isolates of Gram-negative bacilli involved in nosocomial and community infections. The present study also constitutes the first demonstration of the curative treatment of bubonic plague by a novel, broad-spectrum antibiotic targeting LpxC. Hence, the data highlight the therapeutic

Linezolid in late-chronic prosthetic joint infection caused by gram-positive bacteria.

PubMed

Cobo, Javier; Lora-Tamayo, Jaime; Euba, Gorane; Jover-Sáenz, Alfredo; Palomino, Julián; del Toro, Ma Dolores; Rodríguez-Pardo, Dolors; Riera, Melchor; Ariza, Javier

2013-05-01

Linezolid may be an interesting alternative for prosthetic joint infection (PJI) due to its bioavailability and its antimicrobial spectrum. However, experience in this setting is scarce. The aim of the study was to assess linezolid's clinical and microbiological efficacy, and also its tolerance. This was a prospective, multicenter, open-label, non-comparative study of 25 patients with late-chronic PJI caused by Gram-positive bacteria managed with a two-step exchange procedure plus 6 weeks of linezolid. Twenty-two (88%) patients tolerated linezolid without major adverse effects, although a global decrease in the platelet count was observed. Three patients were withdrawn because of major toxicity, which reversed after linezolid stoppage. Among patients who completed treatment, 19 (86%) demonstrated clinical and microbiological cure. Two patients presented with clinical and microbiological failure, and one showed clinical cure and microbiological failure. In conclusion, linezolid showed good results in chronic PJI managed with a two-step exchange procedure. Tolerance seems acceptable, though close surveillance is required. Copyright © 2013 Elsevier Inc. All rights reserved.

Genomic analysis of bifunctional Class C-Class D β-lactamases in environmental bacteria.

PubMed

Silveira, Melise Chaves; Catanho, Marcos; Miranda, Antônio Basílio de

2018-01-01

β-lactamases, which are found in several bacterial species and environments, are the main cause of resistance to β-lactams in Gram-negative bacteria. In 2009, a protein (LRA-13) with two β-lactamase domains (one class C domain and one class D domain) was experimentally characterised, and an extended action spectrum against β-lactams consistent with two functional domains was found. Here, we present the results of searches in the non-redundant NCBI protein database that revealed the existence of a group of homologous bifunctional β-lactamases in the genomes of environmental bacteria. These findings suggest that bifunctional β-lactamases are widespread in nature; these findings also raise concern that bifunctional β-lactamases may be transferred to bacteria of clinical importance through lateral gene transfer mechanisms.

Mortality caused by intracranial bleeding in non-severe hemophilia A patients.

PubMed

Loomans, J I; Eckhardt, C L; Reitter-Pfoertner, S E; Holmström, M; van Gorkom, B Laros; Leebeek, F W G; Santoro, C; Haya, S; Meijer, K; Nijziel, M R; van der Bom, J G; Fijnvandraat, K

2017-06-01

Essentials Data on bleeding-related causes of death in non-severe hemophilia A (HA) patients are scarce. Such data may provide new insights into areas of care that can be improved. Non-severe HA patients have an increased risk of dying from intracranial bleeding. This demonstrates the need for specialized care for non-severe HA patients. Background Non-severe hemophilia (factor VIII concentration [FVIII:C] of 2-40 IU dL -1 ) is characterized by a milder bleeding phenotype than severe hemophilia A. However, some patients with non-severe hemophilia A suffer from severe bleeding complications that may result in death. Data on bleeding-related causes of death, such as fatal intracranial bleeding, in non-severe patients are scarce. Such data may provide new insights into areas of care that can be improved. Aims To describe mortality rates, risk factors and comorbidities associated with fatal intracranial bleeding in non-severe hemophilia A patients. Methods We analyzed data from the INSIGHT study, an international cohort study of all non-severe hemophilia A patients treated with FVIII concentrates during the observation period between 1980 and 2010 in 34 participating centers across Europe and Australia. Clinical data and vital status were collected from 2709 patients. We report the standardized mortality rate for patients who suffered from fatal intracranial bleeding, using a general European male population as a control population. Results Twelve per cent of the 148 deceased patients in our cohort of 2709 patients died from intracranial bleeding. The mortality rate between 1996 and 2010 for all ages was 3.5-fold higher than that in the general population (95% confidence interval [CI] 2.0-5.8). Patients who died from intracranial bleeding mostly presented with mild hemophilia without clear comorbidities. Conclusion Non-severe hemophilia A patients have an increased risk of dying from intracranial bleeding in comparison with the general population. This demonstrates the

Causes, types and severity of injury among army soldiers hospitalized with alcohol comorbidity.

PubMed

Howland, Jonathan; Bell, Nicole S; Hollander, Ilyssa E

2007-09-01

To examine the relationship between alcohol use and the cause, type and severity of hospitalized injuries. We used the Total Army Injury and Health Outcomes Database (TAIHOD) to conduct cross-sectional analyses of the association between alcohol comorbidity and the cause, type and severity of soldiers' non-combat injuries requiring hospitalization. Subjects were active-duty US army soldiers (n = 211 790) hospitalized with a primary diagnosis of injury between 1980 and 2002. Alcohol comorbidity was positively associated with hospitalized injuries resulting from fights and falls and negatively associated with sports injuries; positively associated with hospitalized cases of head injury, open wounds and poisonings and negatively associated with musculoskeletal injury; and, overall, associated with shorter length of stay. Controlling for demographic factors did not moderate the association between alcohol and cause, type or severity of injury. Alcohol comorbidity is specifically associated with injuries related to impairment and antisocial behavior.

Ice-Nucleating Bacteria

NASA Astrophysics Data System (ADS)

Obata, Hitoshi

Since the discovery of ice-nucleating bacteria in 1974 by Maki et al., a large number of studies on the biological characteristics, ice-nucleating substance, ice nucleation gene and frost damage etc. of the bacteria have been carried out. Ice-nucleating bacteria can cause the freezing of water at relatively warm temperature (-2.3°C). Tween 20 was good substrates for ice-nucleating activity of Pseudomonas fluorescens KUIN-1. Major fatty acids of Isolate (Pseudomonas fluorescens) W-11 grown at 30°C were palmitic, cis-9-hexadecenoic and cis-11-octadecenoic which amounted to 90% of the total fatty acids. Sequence analysis shows that an ice nucleation gene from Pseudomonas fluorescens is related to the gene of Pseudomonas syringae.

Electro-responsive supramolecular graphene oxide hydrogels for active bacteria adsorption and removal

NASA Astrophysics Data System (ADS)

Xue, Bin; Cao, Yi; Wang, Wei

Bacteria are major contaminations in drinking water and healthcare products. Bacteria contamination may cause severe health problems, including food poisoning and diseases. Currently water sterilization and purification methods to remove contaminated bacteria are mainly based on the size-exclusion mechanism. In order to completely remove all bacteria in water, the pore sizes of the membranes or cartilages should be comparable to the size of bacteria, which inevitable leads to high cross-membrane water pressure and slow purification speed. Moreover, the membranes can easily get clogged. Therefore it is highly demanded to develop efficient methods and novel materials for water purification. Recently, Cui and coworker have introduced a bacteria inactivation method with high efficiency and fast purification speed based on a kind of complex materials made of silver nanofibers, carbon nanotubes and cotton, operating in an electric field. With the help of electric field, the bacteria can be efficiently kill when passing through the membrance even the pore sizes are larger than bacteria. Inspired by their work, here we report a proof-of-principle demonstration of bacteria removal using electro-reponsive hydrogels. This work is funded by Six talent peaks project in Jiangsu Province, the National Natural Science Foundation of China (Nos. 11304156, 11334004, 31170813, 81421091 and 91127026), the 973 Program of China (No. 2012CB921801 and 2013CB834100), the Priority Ac.

Identification and antimicrobial suceptibility profile of bacteria causing bovine mastitis from dairy farms in Pelotas, Rio Grande do Sul.

PubMed

Freitas, C H; Mendes, J F; Villarreal, P V; Santos, P R; Gonçalves, C L; Gonzales, H L; Nascente, P S

2018-01-08

Mastitis is an inflammatory process of the udder tissue caused mainly by the bacteria Staphylococcus aureus. The indiscriminate use of antibiotics fosters conditions that favor the selection of resistant microorganisms, suppressing at the same time susceptible forms, causing a serious problem in dairy cattle. Given the importance in performing an antibiogram to select the most adequate antimicrobial therapy, the aim of this study was to identify bacteria isolated from cow's milk with mastitis, in dairy farms situated in the city of Pelotas, Rio Grande do Sul, and to determinate the susceptibility profile of these isolates against the antibiotics used to treat this illness. A total of 30 isolates of Staphylococcus spp., were selected from milk samples from the udder quarters with subclinical mastitis whose species were identified through the Vitek system. The susceptibility profile was performed by the disk diffusion assay, against: ampicillin, amoxicillin, bacitracin, cephalexin, ceftiofur, enrofloxacin, gentamicin, neomycin, norfloxacin, penicillin G, tetracycline and trimethoprim. In the antibiogram, 100.0% of the isolates were resistant to trimethoprim and 96.7% to tetracycline and neomycin, three strains of Staphylococcus spp., (10.0%) presented resistance to the 12 antibiotics tested and 24 (80.0%) to at least eight. These results showed the difficulty in treating mastitis, due to the pathogens' resistance.

Gut microbiota trajectory in patients with severe burn: A time series study.

PubMed

Wang, Xinying; Yang, Jianbo; Tian, Feng; Zhang, Li; Lei, Qiucheng; Jiang, Tingting; Zhou, Jihong; Yuan, Siming; Wang, Jun; Feng, Zhijian; Li, Jieshou

2017-12-01

This time series experiments aimed to investigate the dynamic change of gut microbiomes after severe burn and its association with enteral nutrition (EN). Seven severely burned patients who suffered from a severe metal dust explosion injury were recruited in this study. The dynamic changes of gut microbiome of fecal samples at six time points (1-3days, 2, 3, 4, 5 and 6weeks after severe burn) were detected using 16S ribosomal RNA pyrosequencing technology. Following the post-burn temporal order, gut microbiota dysbiosis was detected in the gut microbiome after severe burn, then it was gradually resolved. The bio-diversity of gut bacteria was initially decreased, and then returned to normal level. In addition, at the early stage (from 2 to 4weeks), the majority of those patients' gut microbiome were opportunistic pathogen genus, Enterococcus and Escherichia; while at the end of this study, the majority was a beneficial genus, Bacteroides. EN can promote the recovery of gut microbiota, especially in EN well-tolerated patients. Severe burn injury can cause a dramatic dysbiosis of gut microbiota. A trend of enriched beneficial bacteria and diminished opportunistic pathogen bacteria may serve as prognosis microbiome biomarkers of severe burn patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Several methods for concentrating bacteria in fluid samples

NASA Technical Reports Server (NTRS)

Thomas, R. R.

1976-01-01

The sensitivities of the firefly luciferase - ATP flow system and luminol flow system were established as 300,000 E. coli per milliliter and 10,000 E. coli per milliliter respectively. To achieve the detection limit of 1,000 bacteria per milliliter previously established, a method of concentrating microorganisms using a sartorius membrane filter system is investigated. Catalase in 50% ethanol is found to be a stable luminol standard and can be used up to 24 hours with only a 10% loss of activity. The luminol reagent is also stable over a 24 hour period. A method of preparing relatively inexpensive luciferase from desiccated firefly tails is developed.

Seasonal variation of fecal indicator bacteria in storm events within the US stormwater database.

PubMed

Pan, Xubin; Jones, Kim D

2012-01-01

Bacteria are one of the major causes of surface water impairments in the USA. Over the past several years, best management practices, including detention basins, manufactured devices, grass swales, filters and bioretention cells have been used to remove bacteria and other pollutants from stormwater runoff. However, there are data gaps in the comprehensive studies of bacteria concentrations in stormwater runoff. In this paper, the event mean concentration (EMC) of fecal indicator bacteria (Enterococcus, Escherichia coli, fecal Streptococcus group bacteria, and fecal coliform) across the USA was retrieved from the international stormwater best management practices database to analyze the seasonal variations of inflow and outflow event mean concentrations and removal efficiencies. The Kruskal-Wallis test was employed to determine the seasonal variations of bacteria indicator concentrations and removals, and the two-sample Kolmogorov-Smirnov test was used for comparing different seasonal outcomes. The results indicate that all the inflow EMC of FIB in stormwater runoff is above the water quality criteria. The seasonal differences of fecal Streptococcus group bacteria and fecal coliform are significant. Summer has the potential to increase the bacteria EMC and illustrate the seasonal differences.

[A case of hyperammonemia resulting from urinary tract infection caused by urease-producing bacteria in a Parkinson's disease patient with drug-induced urinary retention].

PubMed

Yasunishi, Masahiro; Koumura, Akihiro; Hayashi, Yuichi; Nishida, Shohei; Inuzuka, Takashi

2017-01-01

A 71-year-old woman with a 9-year history of Parkinson's disease was admitted to our hospital emergently because of consciousness disturbance. Her consciousness level was 200 on the Japan coma scale (JCS), and she presented with tenderness and distension of the lower abdomen. Brain computed tomography showed normal findings. Blood tests showed an increased ammonia level (209 μg/dl) with normal AST and ALT levels. We catheterized the bladder for urinary retention. Five hours after admission, the blood ammonia level decreased to 38 μg/dl, and her consciousness level improved dramatically. Corynebacterium urearyticum, a bacterial species that produces urease, was detected by urine culture. Therefore, she was diagnosed with hyperammonemic encephalopathy resulting from urinary tract infection caused by urease-producing bacteria. In this case, urologic active agents had been administered to treat neurogenic bladder. We suspect that these drugs caused urinary obstruction and urinary tract infection. It is important to recognize that obstructive urinary tract infection caused by urease-producing bacteria can cause hyperammonemia. Neurological disorders, such as Parkinson's disease, tend to complicate neurogenic bladder. This disease should be considered in elderly patients with Parkinson's disease who are receiving urologic active drugs.

Causes, types and severity of injury among army soldiers hospitalized with alcohol comorbidity*

PubMed Central

Howland, Jonathan; Bell, Nicole S.; Hollander, Ilyssa E.

2007-01-01

Aim To examine the relationship between alcohol use and the cause, type and severity of hospitalized injuries. Design/setting We used the Total Army Injury and Health Outcomes Database (TAIHOD) to conduct cross-sectional analyses of the association between alcohol comorbidity and the cause, type and severity of soldiers’ non-combat injuries requiring hospitalization. Participants Subjects were active-duty US army soldiers (n = 211 790) hospitalized with a primary diagnosis of injury between 1980 and 2002. Findings Alcohol comorbidity was positively associated with hospitalized injuries resulting from fights and falls and negatively associated with sports injuries; positively associated with hospitalized cases of head injury, open wounds and poisonings and negatively associated with musculoskeletal injury; and, overall, associated with shorter length of stay. Controlling for demographic factors did not moderate the association between alcohol and cause, type or severity of injury. Conclusion Alcohol comorbidity is specifically associated with injuries related to impairment and antisocial behavior. PMID:17697276

Antimicrobial-resistant Gram-negative bacteria in febrile neutropenic patients with cancer: current epidemiology and clinical impact.

PubMed

Trecarichi, Enrico M; Tumbarello, Mario

2014-04-01

In the recent years, several studies involving cancer patients have demonstrated a clear trend in the epidemiology of bacterial infections showing a shift in the prevalence from Gram-positive to Gram-negative bacteria and the extensive emergence of antimicrobial-resistant strains among Gram-negatives isolated from the blood. The aim of this systematic review was to examine the recent trends in epidemiology and antimicrobial resistance in Gram-negatives recovered from neutropenic cancer patients, with particular emphasis on the impact of antimicrobial resistance on the clinical outcome of severe infections caused by such microorganisms. Overall, from 2007 to date, the rate of Gram-negative bacteria recovery ranged from 24.7 to 75.8% (mean 51.3%) in cancer patient cohorts. Escherichia coli represented the most common species (mean frequency of isolation 32.1%) among the Gram-negatives, followed by Pseudomonas aeruginosa (mean frequency of isolation 20.1%). An increasing frequency of Acinetobacter spp. and Stenotrophomonas maltophilia was also reported. Increased rates of multidrug-resistant Gram-negative strains have been highlighted among Enterobacteriaceae and nonfermenting Gram-negative rods, despite discontinuation of fluoroquinolone-based antibacterial prophylaxis for neutropenic patients. In addition, antimicrobial resistance and/or the inadequacy of empirical antibiotic treatment have been frequently linked to a worse outcome in cancer patients with bloodstream infections caused by Gram-negative isolates. Sound knowledge of the local distribution of pathogens and their susceptibility patterns and prompt initiation of effective antimicrobial treatment for severe infections caused by Gram-negative bacteria are essential in cancer patients.

Immature platelet fraction in bacterial sepsis severity assessment

NASA Astrophysics Data System (ADS)

Djuang, M. H.; Ginting, F.; Hariman, H.

2018-03-01

Sepsis is an infection-induced syndrome, mostly caused by bacteria, of organ dysfunctions that caused by host response dysregulations. One of the simplest sepsis-indicator is platelet and its indexes. A new platelet parameter called immature platelet count (IPF) became theinterest in this study. The study aims to see whether IPF could assess sepsis severity by procalcitonin (PCT).Sixty-four of seventy-one patients with increased PCT were included in this cross-sectional study and separated into three groups based on their PCT levels. IPF showed no significance among the three groups (p-value>0.05) while platelet count was significant (p-value<0.05). Mean Platelet Volume (MPV) and Platelet Distribution Width (PDW) showed a strongpositive correlation with IPF. Higher sepsis severity based on PCT showed larger platelet count, as the result of platelet destructions caused by pro-inflammatory cytokines and endotoxins.

[Zoonotic diseases caused by bacteria of the genus Bartonella genus: new reservoirs ? New vectors?].

PubMed

Chomel, Bruno B; Boulouis, Henri-Jean

2005-03-01

Domestic animals and wildlife represent a large reservoir for bartonellae, at least eight species or subspecies of which have been reported to cause zoonotic infections. In addition, numerous orphan clinical syndromes are now being attributed to Bartonella henselae infection. Many mammalian species, including cats, dogs, rodents and ruminants are the main bartonellae reservoirs. Cats are the main reservoir for B. henselae. It appears that domestic dogs, at least in non tropical regions, are more likely to be accidental hosts than reservoirs, and constitute excellent sentinels for human infections. Bartonellae are vector-borne bacteria. The mode of B. henselae transmission by cat fleas is now better understood, but new potential vectors have recently been identified, including ticks and biting flies. This articles summarizes current knowledge of the etiology, new clinical features and epidemiological characteristics of these emerging zoonoses.

Primary prostatic haemangiosarcoma causing severe haematuria in a dog.

PubMed

Della Santa, D; Dandrieux, J; Psalla, D; Gorgas, D; Lang, J; Geissbuehler, U; Howard, J

2008-05-01

A 10-year-old, entire, male, mixed-breed dog was presented for severe haematuria and stranguria. Ultrasound revealed a large intraluminal urinary bladder blood clot and a prostatic space-occupying lesion. Invasion of the lesion into the prostatic urethra was detected ultrasonographically during compression of the urinary bladder. Post-mortem examination revealed primary prostatic haemangiosarcoma infiltrating the urethra. Haemangiosarcoma should be considered as a rare cause of prostatic mass lesions, haematuria or lower urinary tract signs in dogs.

Bacterial communities found in placental tissues are associated with severe chorioamnionitis and adverse birth outcomes

PubMed Central

Harris, Kathryn; Kamiza, Steve; Harjunmaa, Ulla; Ashorn, Ulla; Nkhoma, Minyanga; Dewey, Kathryn G.; Maleta, Kenneth; Ashorn, Per; Klein, Nigel

2017-01-01

Preterm birth is a major cause of neonatal mortality and morbidity worldwide. Bacterial infection and the subsequent inflammatory response are recognised as an important cause of preterm birth. It is hypothesised that these organisms ascend the cervical canal, colonise placental tissues, cause chorioamnionitis and in severe cases infect amniotic fluid and the foetus. However, the presence of bacteria within the intrauterine cavity does not always precede chorioamnionitis or preterm birth. Whereas previous studies observing the types of bacteria present have been limited in size and the specificity of a few predetermined organisms, in this study we characterised bacteria found in placental tissues from a cohort of 1391 women in rural Malawi using 16S ribosomal RNA gene sequencing. We found that specific bacteria found concurrently on placental tissues associate with chorioamnionitis and delivery of a smaller newborn. Severe chorioamnionitis was associated with a distinct difference in community members, a higher bacterial load and lower species richness. Furthermore, Sneathia sanguinengens and Peptostreptococcus anaerobius found in both matched participant vaginal and placental samples were associated with a lower newborn length-for-age Z-score. This is the largest study to date to examine the placental microbiome and its impact of birth outcomes. Our results provide data on the role of the vaginal microbiome as a source of placental infection as well as the possibility of therapeutic interventions against targeted organisms during pregnancy. PMID:28700642

Investigational drugs for the treatment of infections caused by multidrug-resistant Gram-negative bacteria.

PubMed

Avery, Lindsay M; Nicolau, David P

2018-04-01

Infections caused by multidrug-resistant Gram-negative bacteria (MDR-GNB) are associated with significant mortality and costs. New drugs in development to combat these difficult-to-treat infections primarily target carbapenem-resistant Enterobacteriaceae, MDR Pseudomonas aeruginosa, and MDR Acinetobacter baumannii. Areas covered: The authors summarize in vitro and in vivo efficacy studies, as well as available clinical trial findings, for new agents in development for treatment of infection caused by MDR-GNB. Information regarding dosage regimens utilized in clinical trials and key pharmacokinetic and pharmacodynamic considerations are provided if available. A summary of recently approved agents, delafloxacin and meropenem/vaborbactam, is also included. Expert opinion: The development of multiple novel agents to fight MDR-GNB is promising to help save the lives of patients who acquire infection, and judicious use of these agents is imperative once they come to market to prevent the development of resistance. The other component paramount to this field of research is implementation of effective infection control policies and carbapenem-resistant Enterobacteriaceae (CRE) carrier screening protocols to mitigate the worldwide spread of MDR-GNB. Further investigation of anti-infective synergistic combinations will also be important, as well as support for economic research to reveal the true cost-benefit of utilization of the new agents discussed herein.

STUDIES ON LUMINOUS BACTERIA

PubMed Central

Morrison, Thomas F.

1925-01-01

1. A method has been described whereby the intensity of the light of luminous bacteria may be measured in a quantitative manner. 2. It is pointed out that the temperature coefficients for light intensity do not follow the van't Hoff rule, but are higher and vary with each 10° temperature interval. 3. From a comparison with other data it is found that the process is not a simple one, but that the observed curve is the resultant of several reactions which proceed simultaneously. 4. The discrepancies in the temperature coefficients in the neighborhood of the "optimum temperature" may be due to a process of coagulation of the colloidal particles of the enzyme. This coagulation will tend to cause a deviation of the curve away from that normal for chemical reactions. PMID:19872179

Root causes and impacts of severe accidents at large nuclear power plants.

PubMed

Högberg, Lars

2013-04-01

The root causes and impacts of three severe accidents at large civilian nuclear power plants are reviewed: the Three Mile Island accident in 1979, the Chernobyl accident in 1986, and the Fukushima Daiichi accident in 2011. Impacts include health effects, evacuation of contaminated areas as well as cost estimates and impacts on energy policies and nuclear safety work in various countries. It is concluded that essential objectives for reactor safety work must be: (1) to prevent accidents from developing into severe core damage, even if they are initiated by very unlikely natural or man-made events, and, recognizing that accidents with severe core damage may nevertheless occur; (2) to prevent large-scale and long-lived ground contamination by limiting releases of radioactive nuclides such as cesium to less than about 100 TBq. To achieve these objectives the importance of maintaining high global standards of safety management and safety culture cannot be emphasized enough. All three severe accidents discussed in this paper had their root causes in system deficiencies indicative of poor safety management and poor safety culture in both the nuclear industry and government authorities.

Photocatalytic inactivation of bacteria from spoiled raw chicken carcasses in aqueous suspensions by TiO2 nanoparticles

USDA-ARS?s Scientific Manuscript database

Bacterial spoilage is a major cause of reduced shelf life of fresh poultry; therefore, decreasing contamination by spoilage bacteria could increase the shelf life of these products. Titanium dioxide (TiO2) nanoparticles in the presence of UVA light possess antibacterial activities towards several ba...

A systematic review of causes of sudden and severe headache (Thunderclap Headache): should lists be evidence based?

PubMed Central

2014-01-01

Background There are many potential causes of sudden and severe headache (thunderclap headache), the most important of which is aneurysmal subarachnoid haemorrhage. Published academic reviews report a wide range of causes. We sought to create a definitive list of causes, other than aneurysmal subarachnoid haemorrhage, using a systematic review. Methods Systematic Review of EMBASE and MEDLINE databases using pre-defined search criteria up to September 2009. We extracted data from any original research paper or case report describing a case of someone presenting with a sudden and severe headache, and summarized the published causes. Results Our search identified over 21,000 titles, of which 1224 articles were scrutinized in full. 213 articles described 2345 people with sudden and severe headache, and we identified 6 English language academic review articles. A total of 119 causes were identified, of which 46 (38%) were not mentioned in published academic review articles. Using capture-recapture analysis, we estimate that our search was 98% complete. There is only one population-based estimate of the incidence of sudden and severe headache at 43 cases per 100,000. In cohort studies, the most common causes identified were primary headaches or headaches of uncertain cause. Vasoconstriction syndromes are commonly mentioned in case reports or case series. The most common cause not mentioned in academic reviews was pneumocephalus. 70 non-English language articles were identified but these did not contain additional causes. Conclusions There are over 100 different published causes of sudden and severe headache, other than aneurysmal subarachnoid haemorrhage. We have now made a definitive list of causes for future reference which we intend to maintain. There is a need for an up to date population based description of cause of sudden and severe headache as the modern epidemiology of thunderclap headache may require updating in the light of research on cerebral

Weakening effect of cell permeabilizers on gram-negative bacteria causing biodeterioration.

PubMed

Alakomi, H-L; Paananen, A; Suihko, M-L; Helander, I M; Saarela, M

2006-07-01

Gram-negative bacteria play an important role in the formation and stabilization of biofilm structures on stone surfaces. Therefore, the control of growth of gram-negative bacteria offers a way to diminish biodeterioration of stone materials. The effect of potential permeabilizers on the outer membrane (OM) properties of gram-negative bacteria was investigated and further characterized. In addition, efficacy of the agents in enhancing the activity of a biocide (benzalkonium chloride) was assessed. EDTA, polyethylenimine (PEI), and succimer (meso-2,3-dimercaptosuccinic) were shown to be efficient permeabilizers of the members of Pseudomonas and Stenotrophomonas genera, as indicated by an increase in the uptake of a hydrophobic probe (1-N-phenylnaphthylamine) and sensitization to hydrophobic antibiotics. Visualization of Pseudomonas cells treated with EDTA or PEI by atomic force microscopy revealed damage in the outer membrane structure. PEI especially increased the surface area and bulges of the cells. Topographic images of EDTA-treated cells were compatible with events assigned for the effect of EDTA on outer membranes, i.e., release of lipopolysaccharide and disintegration of OM structure. In addition, the effect of EDTA treatment was visualized in phase-contrast images as large areas with varying hydrophilicity on cell surfaces. In liquid culture tests, EDTA and PEI supplementation enhanced the activity of benzalkonium chloride toward the target strains. Use of permeabilizers in biocide formulations would enable the use of decreased concentrations of the active biocide ingredient, thereby providing environmentally friendlier products.

Pulmonary inflammation induced by bacteria-free outer membrane vesicles from Pseudomonas aeruginosa.

PubMed

Park, Kyong-Su; Lee, Jaewook; Jang, Su Chul; Kim, Sae Rom; Jang, Myoung Ho; Lötvall, Jan; Kim, Yoon-Keun; Gho, Yong Song

2013-10-01

Pseudomonas aeruginosa is often involved in lung diseases such as cystic fibrosis. These bacteria can release outer membrane vesicles (OMVs), which are bilayered proteolipids with diameters of approximately 20 to 250 nm. In vitro, these OMVs activate macrophages and airway epithelial cells. The aim of this study was to determine whether OMVs from P. aeruginosa can induce pulmonary inflammation in vivo and to elucidate the mechanisms involved. Bacteria-free OMVs were isolated from P. aeruginosa cultures. Wild-type, Toll-like receptor (TLR)2 and TLR4 knockout mice were exposed to OMVs by the airway, and inflammation in the lung was assessed using differential counts, histology, and quantification of chemokines and cytokines. The involvement of the TLR2 and TLR4 pathways was studied in human cells using transfection. OMVs given to the mouse lung caused dose- and time-dependent pulmonary cellular inflammation. Furthermore, OMVs increased concentrations of several chemokines and cytokines in the mouse lungs and mouse alveolar macrophages. The inflammatory responses to OMVs were comparable to those of live bacteria and were only partly regulated by the TLR2 and TLR4 pathways, according to studies in knockout mice. This study shows that OMVs from P. aeruginosa cause pulmonary inflammation without live bacteria in vivo. This effect is only partly controlled by TLR2 and TLR4. The role of OMVs in clinical disease warrants further studies because targeting of OMVs in addition to live bacteria may add clinical benefit compared with treating with antibiotics alone.

Differentiating sepsis from non-infectious systemic inflammation based on microvesicle-bacteria aggregation

NASA Astrophysics Data System (ADS)

Herrmann, I. K.; Bertazzo, S.; O'Callaghan, D. J. P.; Schlegel, A. A.; Kallepitis, C.; Antcliffe, D. B.; Gordon, A. C.; Stevens, M. M.

2015-08-01

Sepsis is a severe medical condition and a leading cause of hospital mortality. Prompt diagnosis and early treatment has a significant, positive impact on patient outcome. However, sepsis is not always easy to diagnose, especially in critically ill patients. Here, we present a conceptionally new approach for the rapid diagnostic differentiation of sepsis from non-septic intensive care unit patients. Using advanced microscopy and spectroscopy techniques, we measure infection-specific changes in the activity of nano-sized cell-derived microvesicles to bind bacteria. We report on the use of a point-of-care-compatible microfluidic chip to measure microvesicle-bacteria aggregation and demonstrate rapid (<=1.5 hour) and reliable diagnostic differentiation of bacterial infection from non-infectious inflammation in a double-blind pilot study. Our study demonstrates the potential of microvesicle activities for sepsis diagnosis and introduces microvesicle-bacteria aggregation as a potentially useful parameter for making early clinical management decisions.Sepsis is a severe medical condition and a leading cause of hospital mortality. Prompt diagnosis and early treatment has a significant, positive impact on patient outcome. However, sepsis is not always easy to diagnose, especially in critically ill patients. Here, we present a conceptionally new approach for the rapid diagnostic differentiation of sepsis from non-septic intensive care unit patients. Using advanced microscopy and spectroscopy techniques, we measure infection-specific changes in the activity of nano-sized cell-derived microvesicles to bind bacteria. We report on the use of a point-of-care-compatible microfluidic chip to measure microvesicle-bacteria aggregation and demonstrate rapid (<=1.5 hour) and reliable diagnostic differentiation of bacterial infection from non-infectious inflammation in a double-blind pilot study. Our study demonstrates the potential of microvesicle activities for sepsis diagnosis and

Curative Treatment of Severe Gram-Negative Bacterial Infections by a New Class of Antibiotics Targeting LpxC.

PubMed

Lemaître, Nadine; Liang, Xiaofei; Najeeb, Javaria; Lee, Chul-Jin; Titecat, Marie; Leteurtre, Emmanuelle; Simonet, Michel; Toone, Eric J; Zhou, Pei; Sebbane, Florent

2017-07-25

The infectious diseases caused by multidrug-resistant bacteria pose serious threats to humankind. It has been suggested that an antibiotic targeting LpxC of the lipid A biosynthetic pathway in Gram-negative bacteria is a promising strategy for curing Gram-negative bacterial infections. However, experimental proof of this concept is lacking. Here, we describe our discovery and characterization of a biphenylacetylene-based inhibitor of LpxC, an essential enzyme in the biosynthesis of the lipid A component of the outer membrane of Gram-negative bacteria. The compound LPC-069 has no known adverse effects in mice and is effective in vitro against a broad panel of Gram-negative clinical isolates, including several multiresistant and extremely drug-resistant strains involved in nosocomial infections. Furthermore, LPC-069 is curative in a murine model of one of the most severe human diseases, bubonic plague, which is caused by the Gram-negative bacterium Yersinia pestis Our results demonstrate the safety and efficacy of LpxC inhibitors as a new class of antibiotic against fatal infections caused by extremely virulent pathogens. The present findings also highlight the potential of LpxC inhibitors for clinical development as therapeutics for infections caused by multidrug-resistant bacteria. IMPORTANCE The rapid spread of antimicrobial resistance among Gram-negative bacilli highlights the urgent need for new antibiotics. Here, we describe a new class of antibiotics lacking cross-resistance with conventional antibiotics. The compounds inhibit LpxC, a key enzyme in the lipid A biosynthetic pathway in Gram-negative bacteria, and are active in vitro against a broad panel of clinical isolates of Gram-negative bacilli involved in nosocomial and community infections. The present study also constitutes the first demonstration of the curative treatment of bubonic plague by a novel, broad-spectrum antibiotic targeting LpxC. Hence, the data highlight the therapeutic potential of Lpx

Antibacterial activity of silver nanoparticle-coated fabric and leather against odor and skin infection causing bacteria.

PubMed

Velmurugan, Palanivel; Lee, Sang-Myeong; Cho, Min; Park, Jung-Hee; Seo, Sang-Ki; Myung, Hyun; Bang, Keuk-Soo; Oh, Byung-Taek

2014-10-01

We present a simple, eco-friendly synthesis of silver and gold nanoparticles using a natural polymer pine gum solution as the reducing and capping agent. The pine gum solution was combined with silver nitrate (AgNO3) or a chloroauric acid (HAuCl4) solution to produce silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs), respectively. The reaction process was simple; formation of the nanoparticles was achieved by autoclaving the silver and gold ions with the pine gum. UV-Vis spectra showed surface plasmon resonance (SPR) for silver and gold nanoparticles at 432 and 539 nm, respectively. The elemental forms of AgNPs and AuNPs were confirmed by energy-dispersive X-ray spectroscopy (EDX). Fourier transform infrared spectroscopy (FTIR) showed the biomolecules present in the pine gum, AgNPs, and AuNPs. Transmission electron microscopy (TEM) images showed the shape and size of AgNPs and AuNPs. The crystalline nature of synthesized AgNPs and AuNPs was confirmed by X-ray crystallography [X-ray diffraction (XRD)]. Application of synthesized AgNPs onto cotton fabrics and leather, in order to evaluate their antibacterial properties against odor- or skin infection-causing bacteria, is also discussed. Among the four tested bacteria, AgNP-coated cotton fabric and leather samples displayed excellent antibacterial activity against Brevibacterium linens.

Development and transmission of antimicrobial resistance among Gram-negative bacteria in animals and their public health impact.

PubMed

Mukerji, Shewli; O'Dea, Mark; Barton, Mary; Kirkwood, Roy; Lee, Terence; Abraham, Sam

2017-02-28

Gram-negative bacteria are known to cause severe infections in both humans and animals. Antimicrobial resistance (AMR) in Gram-negative bacteria is a major challenge in the treatment of clinical infections globally due to the propensity of these organisms to rapidly develop resistance against antimicrobials in use. In addition, Gram-negative bacteria possess highly efficient mechanisms through which the AMR can be disseminated between pathogenic and commensal bacteria of the same or different species. These unique traits of Gram-negative bacteria have resulted in evolution of Gram-negative bacterial strains demonstrating resistance to multiple classes of antimicrobials. The evergrowing resistance issue has not only resulted in limitation of treatment options but also led to increased treatment costs and mortality rates in humans and animals. With few or no new antimicrobials in production to combat severe life-threatening infections, AMR has been described as the one of the most severe, long-term threats to human health. Aside from overuse and misuse of antimicrobials in humans, another factor that has exacerbated the emergence of AMR in Gram-negative bacteria is the veterinary use of antimicrobials that belong to the same classes considered to be critically important for treating serious life-threatening infections in humans. Despite the fact that development of AMR dates back to before the introduction of antimicrobials, the recent surge in the resistance towards all available critically important antimicrobials has emerged as a major public health issue. This review thus focuses on discussing the development, transmission and public health impact of AMR in Gram-negative bacteria in animals. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Causes, Patterns, and Severity of Androgen Excess in 1205 Consecutively Recruited Women.

PubMed

Elhassan, Yasir S; Idkowiak, Jan; Smith, Karen; Asia, Miriam; Gleeson, Helena; Webster, Rachel; Arlt, Wiebke; O'Reilly, Michael W

2018-03-01

Androgen excess in women is predominantly due to underlying polycystic ovary syndrome (PCOS). However, there is a lack of clarity regarding patterns and severity of androgen excess that should be considered predictive of non-PCOS pathology. We examined the diagnostic utility of simultaneous measurement of serum dehydroepiandrosterone sulfate (DHEAS), androstenedione (A4), and testosterone (T) to delineate biochemical signatures and cutoffs predictive of non-PCOS disorders in women with androgen excess. Retrospective review of all women undergoing serum androgen measurement at a large tertiary referral center between 2012 and 2016. Serum A4 and T were measured by tandem mass spectrometry and DHEAS by immunoassay. Patients with at least one increased serum androgen underwent phenotyping by clinical notes review. In 1205 women, DHEAS, A4, and T were measured simultaneously. PCOS was the most common diagnosis in premenopausal (89%) and postmenopausal women (29%). A4 was increased in all adrenocortical carcinoma (ACC) cases (n = 15) and T in all ovarian hyperthecosis (OHT) cases (n = 7); all but one case of congenital adrenal hyperplasia (CAH; n = 18) were identified by increased levels of A4 and/or T. In premenopausal women, CAH was a prevalent cause of severe A4 (59%) and T (43%) excess; severe DHEAS excess was predominantly due to PCOS (80%). In postmenopausal women, all cases of severe DHEAS and A4 excess were caused by ACC and severe T excess equally by ACC and OHT. Pattern and severity of androgen excess are important predictors of non-PCOS pathology and may be used to guide further investigations as appropriate.

Biotechnology of Anoxygenic Phototrophic Bacteria.

PubMed

Frigaard, Niels-Ulrik

Anoxygenic phototrophic bacteria are a diverse collection of organisms that are defined by their ability to grow using energy from light without evolving oxygen. The dominant groups are purple sulfur bacteria, purple nonsulfur bacteria, green sulfur bacteria, and green and red filamentous anoxygenic phototrophic bacteria. They represent several bacterial phyla but they all have bacteriochlorophylls and carotenoids and photochemical reaction centers which generate ATP and cellular reductants used for CO 2 fixation. They typically have an anaerobic lifestyle in the light, although some grow aerobically in the dark. Some of them oxidize inorganic sulfur compounds for light-dependent CO 2 fixation; this ability can be exploited for photobiological removal of hydrogen sulfide from wastewater and biogas. The anoxygenic phototrophic bacteria also perform bioremediation of recalcitrant dyes, pesticides, and heavy metals under anaerobic conditions. Finally, these organisms may be useful for overexpression of membrane proteins and photobiological production of H 2 and other valuable compounds.

Severe leaching of calcium ions from fir needles caused by acid fog.

PubMed

Igawa, Manabu; Kase, Toshiyuki; Satake, Kosuke; Okochi, Hiroshi

2002-01-01

We have measured the components of the throughfall under fir trees (Abies firma) in the field around Mt. Oyama, where the forest appears to be declining, for the period 1994-1998. Exposure experiments of a simulated acid fog to fir twigs were performed under field conditions. There was a similarity between the acid response in the field and that in the laboratory. In both studies, the severe leaching of calcium ions from the needle surface was caused by exposure to acid fog. We also applied acid fog to fir seedlings over 1 year and observed a decrease in the growth of the seedlings due to this application in the dormant season. These results suggest that the severe leaching of calcium ions due to acid fog may cause the deficiency of calcium and be responsible for the decline of the fir trees.

Upper gastrointestinal bleeding caused by severe esophagitis: a unique clinical syndrome.

PubMed

Guntipalli, Prathima; Chason, Rebecca; Elliott, Alan; Rockey, Don C

2014-12-01

We have recognized a unique clinical syndrome in patients with upper gastrointestinal bleeding who are found to have severe esophagitis. We aimed to more clearly describe the clinical entity of upper gastrointestinal bleeding in patients with severe esophagitis. We conducted a retrospective matched case-control study designed to investigate clinical features in patients with carefully defined upper gastrointestinal bleeding and severe esophagitis. Patient data were captured prospectively via a Gastrointestinal Bleeding Healthcare Registry, which collects data on all patients admitted with gastrointestinal bleeding. Patients with endoscopically documented esophagitis (cases) were matched with randomly selected controls that had upper gastrointestinal bleeding caused by other lesions. Epidemiologic features in patients with esophagitis were similar to those with other causes of upper gastrointestinal bleeding. However, hematemesis was more common in patients with esophagitis 86% (102/119) than in controls 55% (196/357) (p < 0.0001), while melena was less common in patients with esophagitis 38% (45/119) than in controls 68% (244/357) (p < 0.0001). Additionally, the more severe the esophagitis, the more frequent was melena. Patients with esophagitis had less abnormal vital signs, lesser decreases in hematocrit, and lesser increases in BUN. Both pre- and postRockall scores were lower in patients with esophagitis compared with controls (p = 0.01, and p < 0.0001, respectively). Length of hospital stay (p = 0.002), rebleeding rate at 42 days (p = 0.0007), and mortality were less in patients with esophagitis than controls. Finally, analysis of patients with esophagitis and cirrhosis suggested that this group of patients had more severe bleeding than those without cirrhosis. We have described a unique clinical syndrome in patients with upper gastrointestinal bleeding who have erosive esophagitis. This syndrome is manifest by typical clinical features and is associated with

Lipopolysaccharides in diazotrophic bacteria.

PubMed

Serrato, Rodrigo V

2014-01-01

Biological nitrogen fixation (BNF) is a process in which the atmospheric nitrogen (N2) is transformed into ammonia (NH3) by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are found between associative diazotrophs and plants, resulting in plant infection and colonization of internal tissues. Independent of the type of ecological interaction, glycans, and glycoconjugates produced by these bacteria play an important role in the molecular communication prior and during colonization. Even though exopolysaccharides (EPS) and lipochitooligosaccharides (LCO) produced by diazotrophic bacteria and released onto the environment have their importance in the microbe-plant interaction, it is the lipopolysaccharides (LPS), anchored on the external membrane of these bacteria, that mediates the direct contact of the diazotroph with the host cells. These molecules are extremely variable among the several species of nitrogen fixing-bacteria, and there are evidences of the mechanisms of infection being closely related to their structure.

Lipopolysaccharides in diazotrophic bacteria

PubMed Central

Serrato, Rodrigo V.

2014-01-01

Biological nitrogen fixation (BNF) is a process in which the atmospheric nitrogen (N2) is transformed into ammonia (NH3) by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are found between associative diazotrophs and plants, resulting in plant infection and colonization of internal tissues. Independent of the type of ecological interaction, glycans, and glycoconjugates produced by these bacteria play an important role in the molecular communication prior and during colonization. Even though exopolysaccharides (EPS) and lipochitooligosaccharides (LCO) produced by diazotrophic bacteria and released onto the environment have their importance in the microbe-plant interaction, it is the lipopolysaccharides (LPS), anchored on the external membrane of these bacteria, that mediates the direct contact of the diazotroph with the host cells. These molecules are extremely variable among the several species of nitrogen fixing-bacteria, and there are evidences of the mechanisms of infection being closely related to their structure. PMID:25232535

Sensor node for remote monitoring of waterborne disease-causing bacteria.

PubMed

Kim, Kyukwang; Myung, Hyun

2015-05-05

A sensor node for sampling water and checking for the presence of harmful bacteria such as E. coli in water sources was developed in this research. A chromogenic enzyme substrate assay method was used to easily detect coliform bacteria by monitoring the color change of the sampled water mixed with a reagent. Live webcam image streaming to the web browser of the end user with a Wi-Fi connected sensor node shows the water color changes in real time. The liquid can be manipulated on the web-based user interface, and also can be observed by webcam feeds. Image streaming and web console servers run on an embedded processor with an expansion board. The UART channel of the expansion board is connected to an external Arduino board and a motor driver to control self-priming water pumps to sample the water, mix the reagent, and remove the water sample after the test is completed. The sensor node can repeat water testing until the test reagent is depleted. The authors anticipate that the use of the sensor node developed in this research can decrease the cost and required labor for testing samples in a factory environment and checking the water quality of local water sources in developing countries.

Rock-degrading endophytic bacteria in cacti

Treesearch

M. Esther Puente; Ching Y. Li; Yoav Bashan

2009-01-01

A plant-bacterium association of the cardon cactus (Pachycereus pringlei) and endophytic bacteria promotes establishment of seedlings and growth on igneous rocks without soil. These bacteria weather several rock types and minerals, unbind significant amounts of useful minerals for plants from the rocks, fix in vitro N2. produce...

Comparison of Biocorrosion due to Desulfovibrio desulfuricans and Desulfotomaculum nigrificans Bacteria

NASA Astrophysics Data System (ADS)

Lata, Suman; Sharma, Chhaya; Singh, Ajay K.

2013-02-01

One observes several species of sulfate-reducing bacteria in nature. Presence of these species in a media may cause microbial influenced corrosion (MIC) of materials differently. To investigate this aspect of MIC, corrosion tests were performed on three types of stainless steels. The tests were done in modified Baar's media inoculated separately by the two species of SRB namely Desulfovibrio desulfuricans (DD) and Desulfotomaculum nigrificans (DN). Electrochemical and immersion tests were performed to assess the extent of uniform and localized corrosion of these steels. Biofilms formed on the corroded samples were analyzed for estimating various components of its extracellular polymeric substances. Hydrogenase enzyme of these bacteria was tested to determine its nature and activity. Higher degree of corrosivity was observed in case of media inoculated with DD as compared to DN. More active nature of hydrogenase enzyme, its location in the periplasmic phase in DD and higher fraction of carbohydrate in biofilm formed due to DD have been suggested to be responsible for higher degree of corrosivity caused by them.

Laser-Based Identification of Pathogenic Bacteria

NASA Astrophysics Data System (ADS)

Rehse, Steven J.

2009-03-01

Bacteria are ubiquitous in our world. From our homes, to our work environment, to our own bodies, bacteria are the omnipresent although often unobserved companions to human life. Physicists are typically untroubled professionally by the presence of these bacteria, as their study usually falls safely outside the realm of our typical domain. In the last 10 years, however, several events have occurred that demand the attention of the general populace — including the ranks of physicists among them.

Membrane-active macromolecules kill antibiotic-tolerant bacteria and potentiate antibiotics towards Gram-negative bacteria

PubMed Central

Uppu, Divakara S. S. M.; Konai, Mohini M.; Sarkar, Paramita; Samaddar, Sandip; Fensterseifer, Isabel C. M.; Farias-Junior, Celio; Krishnamoorthy, Paramanandam; Shome, Bibek R.; Franco, Octávio L.

2017-01-01

Chronic bacterial biofilms place a massive burden on healthcare due to the presence of antibiotic-tolerant dormant bacteria. Some of the conventional antibiotics such as erythromycin, vancomycin, linezolid, rifampicin etc. are inherently ineffective against Gram-negative bacteria, particularly in their biofilms. Here, we report membrane-active macromolecules that kill slow dividing stationary-phase and antibiotic tolerant cells of Gram-negative bacteria. More importantly, these molecules potentiate antibiotics (erythromycin and rifampicin) to biofilms of Gram-negative bacteria. These molecules eliminate planktonic bacteria that are liberated after dispersion of biofilms (dispersed cells). The membrane-active mechanism of these molecules forms the key for potentiating the established antibiotics. Further, we demonstrate that the combination of macromolecules and antibiotics significantly reduces bacterial burden in mouse burn and surgical wound infection models caused by Acinetobacter baumannii and Carbapenemase producing Klebsiella pneumoniae (KPC) clinical isolate respectively. Colistin, a well-known antibiotic targeting the lipopolysaccharide (LPS) of Gram-negative bacteria fails to kill antibiotic tolerant cells and dispersed cells (from biofilms) and bacteria develop resistance to it. On the contrary, these macromolecules prevent or delay the development of bacterial resistance to known antibiotics. Our findings emphasize the potential of targeting the bacterial membrane in antibiotic potentiation for disruption of biofilms and suggest a promising strategy towards developing therapies for topical treatment of Gram-negative infections. PMID:28837596

Traditional healers in Nigeria: perception of cause, treatment and referral practices for severe malaria.

PubMed

Okeke, T A; Okafor, H U; Uzochukwu, B S C

2006-07-01

Malaria remains one of the main causes of mortality among young children in sub-Saharan Africa. In Nigeria traditional healers play an important role in health care delivery and the majority of the population depend on them for most of their ailments. The aim of this study was to investigate the perceptions of traditional healers regarding causes, symptoms, treatment of uncomplicated malaria and referral practices for severe malaria with a view to developing appropriate intervention strategies aimed at improving referral practices for severe malaria. A qualitative study was carried out in Ugwogo-Nike, a rural community in south-east Nigeria, which included in-depth interviews with 23 traditional healers. The traditional healers believed that the treatment of severe malaria, especially convulsions, with herbal remedies was very effective. Some traditional healers were familiar with the signs and symptoms of malaria, but malaria was perceived as an environmentally related disease caused by heat from the scorching sun. The majority of traditional healers believed that convulsions are inherited from parents, while a minority attributed them to evil spirits. Most (16/23) will not refer cases to a health facility because they believe in the efficacy of their herbal remedies. The few that did refer did so after several stages of traditional treatment, which resulted in long delays of about two weeks before appropriate treatment was received. The fact that traditional healers are important providers of treatment for severe malaria, especially convulsions, underlines the need to enlist their support in efforts to improve referral practices for severe malaria.

Genetically engineered acidophilic heterotrophic bacteria by bacteriophage transduction

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

Ward, T.E.; Bruhn, D.F.; Bulmer, D.F.

1989-05-10

A bacteriophage capable of infecting acidophilic heterotrophic bacteria and processes for genetically engineering acidophilic bacteria for biomining or sulfur removal from coal are disclosed. The bacteriophage is capable of growth in cells existing at pH at or below 3.0. Lytic forms of the phage introduced into areas experiencing acid drainage kill the bacteria causing such drainage. Lysogenic forms of the phage having genes for selective removal of metallic or nonmetallic elements can be introduced into acidophilic bacteria to effect removal of the desired element from ore or coal. 1 fig., 1 tab.

Isolation and Molecular Detection of Gram Negative Bacteria Causing Urinary Tract Infection in Patients Referred to Shahrekord Hospitals, Iran.

PubMed

Tajbakhsh, Elahe; Tajbakhsh, Sara; Khamesipour, Faham

2015-05-01

Urinary Tract Infections (UTI), and their complications, cause serious health problems, which affect millions of people every year. Infections of the urinary tract are the second most common type of infection in the body and approximately 20% of women are especially prone to UTIs for reasons not yet well understood. Urinary Tract Infections in men are not as common as in women yet can be very serious when they do occur. Accurate identification of bacterial isolates is an essential task of the clinical microbiology laboratory. The purpose of this study was to determine the incidence and variety of the causative microbial agents of UTIs in patients who had referred to a medical laboratory of Kashani and Hajar hospital in Shahrekord, Iran. In this cross-sectional study 147 urine samples of patients (urine test results were positive for UTIs) were examined during April to September 2013. A total of 147 urine samples of patients with clinical symptoms of UTI who had been referred to a medical laboratory of Kashani and Hajar hospital in Shahrekord (Iran), were collected and processed immediately for laboratory analysis. Escherichia coli was identified as the most common causative agent of UTIs (51.70% of total isolates in both sexes), followed by Klebsiella pneumoniae (K. Pneumoniae) (16.32%). Frequency of Proteus spp., Acinetobacter spp., Entrobacter spp., Citrobacter spp., Pseudomonas aeruginosa (P. aeruginosa) and Providencia spp. was 10.88%, 6.12%, 5.44%, 4.08%, 3.40% and 2.04%, respectively. Statistical analysis by Fisher exact test showed that there was no significant relationship between the type of bacteria and gender (P > 0.05). Chi square test showed that there was no significant relationship between the type of bacteria and the use of catheter and age group (P > 0.05). However, there was a significant relationship between the type of bacteria and the history of hospitalization (P > 0.05). Our findings implied that a wide range of bacteria could be involved in

All-Cause Mortality in Women With Severe Postpartum Psychiatric Disorders

PubMed Central

Johannsen, Benedicte Marie Winther; Larsen, Janne Tidselbak; Laursen, Thomas Munk; Bergink, Veerle; Meltzer-Brody, Samantha; Munk-Olsen, Trine

2017-01-01

Objective The postpartum period is associated with a high risk of psychiatric episodes. The authors studied mortality in women with first-onset severe psychiatric disorders following childbirth and compared their mortality rates with those in women from the background population including other female psychiatric patients (mothers and childless women). Method In a register-based cohort study with linked information from Danish population registers, the authors identified women with first psychiatric inpatient or outpatient contacts 0–3 months postpartum. The main outcome measure was mortality rate ratios (MRRs): deaths from natural causes (diseases and medical conditions) or unnatural causes (suicides, accidents, and homicides). The cohort included 1,545,857 women representing 68,473,423 person-years at risk. Results In total, 2,699 women had first-onset psychiatric disorders 0–3 months postpartum, and 96 of these died during follow-up. Women with postpartum psychiatric disorders had a higher MRR (3.74; 95% CI=3.06–4.57) than non-postpartum-onset mothers (MRR=2.73; 95% CI=2.67–2.79) when compared with mothers with no psychiatric history. However, childless women with psychiatric diagnoses had the highest MRR (6.15; 95% CI=5.94–6.38). Unnatural cause of death represented 40.6% of fatalities among women with postpartum psychiatric disorders, and within the first year after diagnosis, suicide risk was drastically increased (MRR=289.42; 95% CI=144.02–581.62) when compared with mothers with no psychiatric history. Conclusions Women with severe postpartum psychiatric disorders had increased MRRs compared with mothers without psychiatric diagnoses, and the first year after diagnosis represents a time of particularly high relative risk for suicide in this vulnerable group. PMID:26940804

Causes of severe visual impairment and blindness in children in the Republic of Suriname.

PubMed

Heijthuijsen, Astrid Anna Maria; Beunders, Victoria Apollonia Annemarie; Jiawan, Dinesh; de Mesquita-Voigt, Anne-Marie Bueno; Pawiroredjo, Jerrel; Mourits, Maarten; Tanck, Michael; Verhoeff, Joost; Saeed, Peerooz

2013-07-01

To determine the causes of severe visual impairment and blindness (SVI/BL) in children in Suriname (Dutch Guyana) and to identify preventable and treatable causes. 4643 children under 16 years of age were recruited from two locations: 33 children attending the only school for the blind were examined and 4610 medical records were analysed at an eye clinic. Data have been collected using the WHO Prevention of Blindness Programme eye examination record for children. 65 children were identified with SVI/BL, 58.5% were blind and 41.5% were severely visually impaired (SVI). The major anatomical site of SVI/BL was the retina in 33.8%, lens in 15.4% and normal appearing globe in 15.4%. The major underlying aetiology of SVI/BL was undetermined in 56.9% (mainly cataract and abnormality since birth) and perinatal factors 21.5% (mainly retinopathy of prematurity (ROP)). Avoidable causes of SVI/BL accounted for 40% of cases; 7.7% were preventable and 32.3% were treatable with cataracts and ROP the most common causes (15.4% and 12.3%, respectively). More than a third of the SVI/BL causes are potentially avoidable, with childhood cataract and ROP the leading causes. Corneal scarring from vitamin A deficiency does not seem to be a continuing issue in Suriname.

Antagonism of Lactic Acid Bacteria against Phytopathogenic Bacteria

PubMed Central

Visser, Ronèl; Holzapfel, Wilhelm H.; Bezuidenhout, Johannes J.; Kotzé, Johannes M.

1986-01-01

A variety of lactic acid bacteria, isolated from plant surfaces and plant-associated products, were found to be antagonistic to test strains of the phytopathogens Xanthomonas campestris, Erwinia carotovora, and Pseudomonas syringae. Effective “in vitro” inhibition was found both on agar plates and in broth cultures. In pot trials, treatment of bean plants with a Lactobacillus plantarum strain before inoculation with P. syringae caused a significant reduction of the disease incidence. Images PMID:16347150

[Severe Eyeball and Facial Skeletal Injuries Caused by Firefighting Sport].

PubMed

Rusňák, Š; Maranová, Z; Kasl, Z; Hecová, L; Voigt, E; Raiskup, F

2017-07-01

The aim of this work is to draw attention to possible injuries of the eye and the facial skeleton caused by firefighting sport. There was a group of 9 patients presented who were treated from 2006 to 2015 in the Department of Ophthalmology at the University Hospital in Pilsen and diagnosed with severe eyeball contusion after being hit by a jet of water and/or a water pipe. Three cases are presented in detail. Georg Thieme Verlag KG Stuttgart · New York.

[Nationwide sensitivity surveillance of ciprofloxacin and various parenteral antibiotics against bacteria isolated from patients with severe infections--the first Ciproxan IV special investigation in 2001].

PubMed

Yamaguchi, Keizo; Ishii, Yoshikazu; Iinuma, Yoshitsugu; Yamanaka, Kiyoharu; Ichiyama, Satoshi; Watanabe, Naoki; Uehara, Nobuyuki; Kaku, Mitsuo; Kurokawa, Yukinori; Hayashi, Mutsumu; Hirakata, Yoichi

2003-12-01

The parenteral injection of ciprofloxacin (CPFX), a fluoroquinolone antimicrobial drug, was approved in September 2000 and a re-examination period of 6 years was set at that time. As a special investigation to apply for re-examination of this drug, it has been planned to conduct 3 nationwide surveillances during the re-examination period by collecting clinically isolated bacteria from patients with severe infections, to whom the drug was mainly indicated, and examining drug susceptibilities of the bacteria to various parenteral antimicrobial drugs including CPFX. This time, we determined the minimum inhibitory concentrations (MICs) of various parenteral antimicrobial drugs including CPFX against 1,220 strains isolated from patients with severe infections by the micro-liquid dilution method and compared susceptibilities of various clinically isolated bacteria to CPFX with those to other antimicrobial drugs. Gram-positive bacteria were less susceptible to CPFX than to carbapenems except 2 bacterial species, Enterococcus faecium and Enterococcus avium but susceptibilities of methicillin-susceptible Staphylococcus aureus (MSSA), Staphylococcus epidermidis and Enterococcus faecalis to CPFX were comparable to those to cefozopran. Susceptibility of Streptococcus pneumoniae to CPFX did not differ among ampicillin (ABPC)-susceptible Streptococcus pneumoniae (MIC of ABPC: < 0.25 microgram/ml), ABPC-intermediate S. pneumoniae (MIC of ABPC: 0.25-2 micrograms/ml) and ABPC-resistant S. pneumoniae (MIC of ABPC: > or = 4 micrograms/ml) MIC90 of CPFX: 1 microgram/ml) and a decrease in the antimicrobial activity seen among cephem and carbapenem antimicrobial drugs against penicillin-intermediate strains was not noted with CPFX. Gram-negative bacteria were susceptible to CPFX similarly to carbapenems and the MIC90 values of CPFX were in the range from < or = 0.063 to 2 micrograms/ml against strains except Stenotrophomonas maltophilia and Burkholderia cepacia. Pseudomonas aeruginosa

Sulfasalazine-Induced Crystalluria Causing Severe Acute Kidney Injury.

PubMed

Durando, Michael; Tiu, Hannah; Kim, James Soo

2017-12-01

Sulfasalazine is an anti-inflammatory agent commonly used in the treatment of autoimmune conditions such as inflammatory bowel disease and rheumatoid arthritis. Sulfasalazine is converted by gut bacteria into sulfapyridine and the clinically active metabolite 5-aminosalicylic acid (5-ASA), and its efficacy is proportional to the 5-ASA concentration within the intestinal lumen. Renal complications are commonly reported for the chemically similar 5-ASA derivative mesalamine, but are not well-known side effects of sulfasalazine therapy. We report a 72-year-old patient with Crohn's disease managed with sulfasalazine for more than 10 years who presented with severe acute kidney injury (serum creatinine, 9.7mg/dL). Renal ultrasound revealed calculi and he subsequently spontaneously voided innumerable stones, which were composed of sulfasalazine metabolites. His renal calculi cleared and serum creatinine concentration improved to 3.1mg/dL after discontinuing sulfasalazine therapy and intravenous fluid hydration. His kidney function eventually returned to baseline. This case demonstrates that renal complications, in particular nephrolithiasis, may be an under-reported but potentially serious phenomenon in patients with inflammatory bowel disease treated with sulfasalazine and that their hydration status may play an important role in this process. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Antibiotic-Resistant Bacteria.

ERIC Educational Resources Information Center

Longenecker, Nevin E.; Oppenheimer, Dan

1982-01-01

A study conducted by high school advanced bacteriology students appears to confirm the hypothesis that the incremental administration of antibiotics on several species of bacteria (Escherichia coli, Staphylococcus epidermis, Bacillus sublitus, Bacillus megaterium) will allow for the development of antibiotic-resistant strains. (PEB)

In vitro activity of daptomycin against clinical isolates of Gram-positive bacteria.

PubMed

Piper, Kerryl E; Steckelberg, James M; Patel, Robin

2005-08-01

We determined the activity of daptomycin, a recently FDA-approved antimicrobial agent, against clinical isolates of Gram-positive bacteria, including viridans group streptococci (16 Streptococcus mitis species group, 12 S. mutans species group, 9 S. anginosus species group, 8 S. sanguinis species group, 5 S. salivarius species group) from patients with infective endocarditis, 32 methicillin-resistant Staphylococcus aureus, 32 high-level penicillin-resistant Streptococcus pneumoniae, 38 vancomycin-resistant enterococci (including 1 linezolid-resistant isolate), and the following unusual Gram-positive bacteria: 3 Listeria monocytogenes, 4 Erysipelothrix rhusiopathiae, 9 Corynebacterium species, 10 Abiotrophia/Granulicatella species, 2 Rothia (Stomatococcus) mucilaginosus, and 4 Gemella morbillorum. Daptomycin minimum inhibitory concentration (MIC)(90) values for the viridans group streptococci, methicillin-resistant S. aureus, penicillin-resistant S. pneumoniae, and Enterococcus species were 0.5, 0.5, < or =0.125, and 4 microg/ml, respectively. The daptomycin MIC range for the unusual Gram-positive bacteria was < or =0.125-2 microg/ml. We conclude that daptomycin has in vitro activity against viridans group streptococci associated with endocarditis as well as against several types of unusual Gram-positive bacteria that can cause endocarditis.

X-ray photoelectron spectroscopic evidence for bacteria-enhanced dissolution of hornblende

NASA Astrophysics Data System (ADS)

Kalinowski, B. E.; Liermann, L. J.; Brantley, S. L.; Barnes, A.; Pantano, C. G.

2000-04-01

An Arthrobacter species capable of extracting Fe from hornblende was isolated from a soil from the Adirondacks, NY (USA). This bacteria isolate, used in batch experiments with hornblende, accelerated the release of Fe from hornblende without measurably affecting Al release. The isolate produces both low molecular weight organic acids (LMWOA) and a catecholate siderophore. Polished hornblende (glass and crystal) discs were analyzed with X-ray photoelectron spectroscopy (XPS) before and after incubation with growing Arthrobacter sp. to investigate whether the bacteria caused a distinguishable chemical signature on the upper 100 Å of mineral surface. After removal of the arthrobacter grown on hornblende crystal or glass substrates using lysozyme, XPS revealed surface depletion of Fe for samples grown for several days in buffered (crystal) and unbuffered (crystal and glass) media. Fe/Si ratios of hornblende surfaces dissolved under biotic conditions are significantly lower than Fe/Si ratios on surfaces dissolved under abiotic conditions for similar amounts of time. Enhanced Fe release and the formation of Fe-depleted surfaces is inferred to be caused by catechol complexation at the mineral surface. Because natural siderophore was not isolated in sufficient quantities to run bacteria-free leaching experiments, parallel investigations were run with a commercially available siderophore (desferrioxamine B). Desferrioxamine B was observed to enhance release of Fe, Si, and Al from hornblende both with and without added bacteria. Formation of desferrioxamine-Fe surface complexes were probed by studying the multiple splitting and shift in intensities of the N 1s line analyzed by XPS on siderophore ± Fe on gold surfaces and siderophore + hornblende crystal surfaces. Based upon the observed formation of an hydroxamate (desferrioxamine) surface complex on hornblende, we infer that catecholate siderophores, such as those produced by the arthrobacter, also complex on the

Effects of Combinations of Substrates on Maximum Growth Rates of Several Rumen Bacteria

PubMed Central

Russell, James B.; Delfino, Frank J.; Baldwin, R. L.

1979-01-01

Five rumen bacteria, Selenomonas ruminantium, Bacteroides ruminicola, Megasphaera elsdenii, Butyrivibrio fibrisolvens, and Streptococcus bovis were grown in media containing nonlimiting concentrations of glucose, sucrose, maltose, cellobiose, xylose and/or lactate. Each bacterium was grown with every substrate that it could ferment in every possible two-way combination. Only once did a combination of substrates result in a higher maximum growth rate than that observed with either substrate alone. Such stimulations of growth rate would be expected if specific factors unique to individual substrates (transport proteins and/or enzymes) were limiting. Since such synergisms were rare, it was concluded that more general factors limit maximum growth rates in these five bacteria. PMID:16345360

Isolation of marine fungi Aspergillus sp. and its in vitro antifouling activity against marine bacteria.

PubMed

Thiyagarajan, Santhananmari; Bavya, Manoharan; Jamal, Alruwaili

2016-09-01

Biofouling is considered as a main issue of concern in aquatic environment causing severe economic loss and pollution. The aim of the present study was to isolate marine fungus antagonistic to biofouling bacteria and to define antifouling compounds present in it. Using standard plate method five predominant biofouling bacteria viz., Methylococcus sp., Flavobacterium sp., Marinococcus sp., Serratia sp. and Pseudomonas sp. were isolated from marine solid substances on Zobell's agar. Tolerance range of these bacteria to NaCl was 2-10%. Isolation of fungi from mangrove and estuarine sediments and their screening identified Aspergillus sp. EF4 as a potential isolate. This isolate caused inhibition of all the five test bacterial cultures measuring zone diameters respectively of 11, 16, 12, 13 and 11mm.? Subsequent to submerged fermentation using shaking flask method this fungus produced bioactive compounds within 5 days. The culture parameters optimized were raffinose as carbon source, yeast extract as lone nitrogen source, pH up to 9.0 and temperature up to 40?C. Antifouling compounds of culture filtrate were separated and detected by a three-step procedure involving thin layer chromatography, bioautography and preparative TLC. The in vitro assay involving glass slide-wooden stick-biofilm method revealed that these compounds could cause inhibition and destruction of bacteria to an extent of 2.16 x 104 CFU ml-1 and 2.46 x 104 CFU ml-1 respectively while growth of bacteria in control beaker was enumerated to be 4.41 x 104 CFU ml-1. High performance liquid chromatography of culture filtrate indicated probable principal antifouling compound as Fumonisin B2. Isolation of antagonistic marine fungus from Indian coast and detection of its antifouling compound would help in planning effective strategies for controlling biofouling in marine environment.

Causes of severe visual impairment and blindness in children in the Republic of Suriname

PubMed Central

Heijthuijsen, Astrid Anna Maria; Beunders, Victoria Apollonia Annemarie; Jiawan, Dinesh; de Mesquita-Voigt, Anne-Marie Bueno; Pawiroredjo, Jerrel; Mourits, Maarten; Tanck, Michael; Verhoeff, Joost; Saeed, Peerooz

2013-01-01

Aims To determine the causes of severe visual impairment and blindness (SVI/BL) in children in Suriname (Dutch Guyana) and to identify preventable and treatable causes. Methods 4643 children under 16 years of age were recruited from two locations: 33 children attending the only school for the blind were examined and 4610 medical records were analysed at an eye clinic. Data have been collected using the WHO Prevention of Blindness Programme eye examination record for children. Results 65 children were identified with SVI/BL, 58.5% were blind and 41.5% were severely visually impaired (SVI). The major anatomical site of SVI/BL was the retina in 33.8%, lens in 15.4% and normal appearing globe in 15.4%. The major underlying aetiology of SVI/BL was undetermined in 56.9% (mainly cataract and abnormality since birth) and perinatal factors 21.5% (mainly retinopathy of prematurity (ROP)). Avoidable causes of SVI/BL accounted for 40% of cases; 7.7% were preventable and 32.3% were treatable with cataracts and ROP the most common causes (15.4% and 12.3%, respectively). Conclusions More than a third of the SVI/BL causes are potentially avoidable, with childhood cataract and ROP the leading causes. Corneal scarring from vitamin A deficiency does not seem to be a continuing issue in Suriname. PMID:23603759

Detection of rotor imbalance, including root cause, severity and location

NASA Astrophysics Data System (ADS)

Cacciola, S.; Munduate Agud, I.; Bottasso, C. L.

2016-09-01

This paper presents a new way of detecting imbalances on wind turbine rotors, by using a harmonic analysis of the rotor response in the fixed frame. The method is capable of distinguishing among different root causes of the imbalance. In addition, the imbalance severity and location, i.e. the affected blade, can be identified. The automatic classification of the imbalance problem is obtained by using a neural network. The performance of the method is illustrated with the help of different fault scenarios, within a high-fidelity simulation environment.

Interactions between amphibians' symbiotic bacteria cause the production of emergent anti-fungal metabolites

PubMed Central

Loudon, Andrew H.; Holland, Jessica A.; Umile, Thomas P.; Burzynski, Elizabeth A.; Minbiole, Kevin P. C.; Harris, Reid N.

2014-01-01

Amphibians possess beneficial skin bacteria that protect against the disease chytridiomycosis by producing secondary metabolites that inhibit the pathogen Batrachochytrium dendrobatidis (Bd). Metabolite production may be a mechanism of competition between bacterial species that results in host protection as a by-product. We expect that some co-cultures of bacterial species or strains will result in greater Bd inhibition than mono-cultures. To test this, we cultured four bacterial isolates (Bacillus sp., Janthinobacterium sp., Pseudomonas sp. and Chitinophaga arvensicola) from red-backed salamanders (Plethodon cinereus) and cultured isolates both alone and together to collect their cell-free supernatants (CFS). We challenged Bd with CFSs from four bacterial species in varying combinations. This resulted in three experimental treatments: (1) CFSs of single isolates; (2) combined CFSs of two isolates; and (3) CFSs from co-cultures. Pair-wise combinations of four bacterial isolates CFSs were assayed against Bd and revealed additive Bd inhibition in 42.2% of trials, synergistic inhibition in 42.2% and no effect in 16.6% of trials. When bacteria isolates were grown in co-cultures, complete Bd inhibition was generally observed, and synergistic inhibition occurred in four out of six trials. A metabolite profile of the most potent co-culture, Bacillus sp. and Chitinophaga arvensicola, was determined with LC-MS and compared with the profiles of each isolate in mono-culture. Emergent metabolites appearing in the co-culture were inhibitory to Bd, and the most potent inhibitor was identified as tryptophol. Thus mono-cultures of bacteria cultured from red-backed salamanders interacted synergistically and additively to inhibit Bd, and such bacteria produced emergent metabolites when cultured together, with even greater pathogen inhibition. Knowledge of how bacterial species interact to inhibit Bd can be used to select probiotics to provide amphibians with protection against Bd

Amoeba-Resisting Bacteria and Ventilator-Associated Pneumonia

PubMed Central

La Scola, Bernard; Boyadjiev, Ioanna; Greub, Gilbert; Khamis, Atieh; Martin, Claude

2003-01-01

To evaluate the role of amoeba-associated bacteria as agents of ventilator-associated pneumonia (VAP), we tested the water from an intensive care unit (ICU) every week for 6 months for such bacteria isolates; serum samples and bronchoalveolar lavage samples (BAL) were also obtained from 30 ICU patients. BAL samples were examined for amoeba-associated bacteria DNA by suicide-polymerase chain reaction, and serum samples were tested against ICU amoeba-associated bacteria. A total of 310 amoeba-associated bacteria from10 species were isolated. Twelve of 30 serum samples seroconverted to one amoeba-associated bacterium isolated in the ICU, mainly Legionella anisa and Bosea massiliensis, the most common isolates from water (p=0.021). Amoeba-associated bacteria DNA was detected in BAL samples from two patients whose samples later seroconverted. Seroconversion was significantly associated with VAP and systemic inflammatory response syndrome, especially in patients for whom no etiologic agent was found by usual microbiologic investigations. Amoeba-associated bacteria might be a cause of VAP in ICUs, especially when microbiologic investigations are negative. PMID:12890321

Streptococcus mitis Strains Causing Severe Clinical Disease in Cancer Patients

PubMed Central

Sahasrabhojane, Pranoti; Saldana, Miguel; Yao, Hui; Su, Xiaoping; Horstmann, Nicola; Thompson, Erika; Flores, Anthony R.

2014-01-01

The genetically diverse viridans group streptococci (VGS) are increasingly recognized as the cause of a variety of human diseases. We used a recently developed multilocus sequence analysis scheme to define the species of 118 unique VGS strains causing bacteremia in patients with cancer; Streptococcus mitis (68 patients) and S. oralis (22 patients) were the most frequently identified strains. Compared with patients infected with non–S. mitis strains, patients infected with S. mitis strains were more likely to have moderate or severe clinical disease (e.g., VGS shock syndrome). Combined with the sequence data, whole-genome analyses showed that S. mitis strains may more precisely be considered as >2 species. Furthermore, we found that multiple S. mitis strains induced disease in neutropenic mice in a dose-dependent fashion. Our data define the prominent clinical effect of the group of organisms currently classified as S. mitis and lay the groundwork for increased understanding of this understudied pathogen. PMID:24750901

Factors of bacteria and virus transport in groundwater

NASA Astrophysics Data System (ADS)

Pekdeger, A.; Matthess, G.

1983-06-01

The underground transport of pathogenic bacteria and viruses may be described by the general transport equation considering dispersion, adsorption, and biological elimination. The survival time of bacteria and viruses in groundwater is different for the specific species and for the specific groundwater environment. Dispersion causes a distribution of pollutants in time and space, thus their concentration decreases over time and with transport distance. Microorganisms are reversibly adsorbed on underground particles, which causes a retardation of their transport velocity with respect to groundwater flow velocity. An additional approach is provided by the filter theory.

[Solitary Fibrous Tumor: a Rare Cause of Recurrent Severe Hypoglycemia].

PubMed

Kühn-Velten, Ute; Hohmann, Christian; Strauss, Tim; Heizmann, Oleg; Klöppel, Günter

2018-06-01

 A 73-year-old woman was admitted to hospital early in the morning by an emergency doctor in initially unclear comatose conditions with a blood glucose of 24 mg/dl. There were no important previous diseases requiring any medication. She was in good physical state.  Except for a lowered breath sound on the right side of the chest the physical findings were normal. Endocrinologic tests, diagnostic imaging (Chest-x-ray, ultrasonography of abdomen and pleura, abdominal and thoracic CT) and fine needle biopsy suggested a non-islet-cell-tumor on the right side of the pleura as cause of hypoglycemia.  Resection of the tumor resulted in normoglycemia and the pathologic examination of the tumor specimen revealed a solid fibrous tumor. A solid fibrous tumor is a relatively common cause of the rare syndrome of non-islet-cell-tumor hypoglycemia. It shows typical endocrinologic findings, which immediately help to clarify the differential diagnosis with other causes of severe hypoglycemia. Early thorough endocrinologic testing is therefore paramount for the recognition of this distinct hypoglycemic disease which is related to the release of IGF-2, respectively Big-IGF-2, from the tumor cells. © Georg Thieme Verlag KG Stuttgart · New York.

Physical mechanisms for chemotactic pattern formation by bacteria.

PubMed Central

Brenner, M P; Levitov, L S; Budrene, E O

1998-01-01

This paper formulates a theory for chemotactic pattern formation by the bacteria Escherichia coli in the presence of excreted attractant. In a chemotactically neutral background, through chemoattractant signaling, the bacteria organize into swarm rings and aggregates. The analysis invokes only those physical processes that are both justifiable by known biochemistry and necessary and sufficient for swarm ring migration and aggregate formation. Swarm rings migrate in the absence of an external chemoattractant gradient. The ring motion is caused by the depletion of a substrate that is necessary to produce attractant. Several scaling laws are proposed and are demonstrated to be consistent with experimental data. Aggregate formation corresponds to finite time singularities in which the bacterial density diverges at a point. Instabilities of swarm rings leading to aggregate formation occur via a mechanism similar to aggregate formation itself: when the mass density of the swarm ring exceeds a threshold, the ring collapses cylindrically and then destabilizes into aggregates. This sequence of events is demonstrated both in the theoretical model and in the experiments. PMID:9545032

Microbial Transformation of Dicarboxylic Acids by Airborne Bacteria

NASA Astrophysics Data System (ADS)

Cote, V.; Ariya, P.

2004-05-01

Organic aerosols are assumed to be key players in driving climatic changes and can cause health problems for human. Dicarboxylic acids (DCA) include a large fraction of identified important class of organic aerosols. In addition to direct sources, DCA are partly formed as the result of ozonolysis of terpenes and cyclic alkenes. Previous works in our laboratory show that airborne fungi collected from urban and suburban air play an important role in the transformation of severals organic aerosols such as DCA. Our present study focuses on understanding the potential chemical transformation induced by airborne bacteria and on identification of the transformation products. Airborne bacteria have been collected using a biosampler and cultivated on a solid media. Each bacterial colony is being tested by HPLC for their ability to transform DCA in liquid cultures. Also, GC-MS, SPME and NMR are being used to identify the metabolites generated from the transformation. We will present our preliminary results and we will discuss the application of bacterial activities on the chemical transformation of organics in atmosphere.

[Severe hypertriglyceridemia--an important cause of pancreatitis].

PubMed

Graesdal, Asgeir

2008-05-01

Moderate hypertriglyceridaemia is a risk factor for cardiovascular disease and serious hypertriglyceridaemia, with triglyceride values above 10 mmol/L, increases the risk of pancreatitis. Gallstones and alcohol abuse are regarded as the two most important causes of acute pancreatitis, but the considerable risk posed by hypertriglyceridaemia has probably been underrated. It is therefore crucial to acquire updated knowledge and awareness of the fact that high levels of triglycerides can cause pancreatitis. This article is based on current literature retrieved though a search on the topic and clinical experience. Serious hypertriglyceridaemia is a relatively rare condition and its usual cause is genetic predisposition combined with obesity, diabetes or alcohol abuse. Certain types of medication, as well as pregnancy, are also well known causes. Current literature suggests that hypertriglyceridaemia is the cause of pancreatitis in 1-38% of the cases--a substantial variation. The condition is often accompanied by low amylase values and may therefore be underrated as a cause. Our case reports illustrate that the etiology is complex. Plasmapheresis or LDL-apheresis may be indicated when conservative treatment proves insufficient.

Bacteria causing important diseases of citrus utilise distinct modes of pathogenesis to attack a common host.

PubMed

Vojnov, Adrián Alberto; do Amaral, Alexandre Morais; Dow, John Maxwell; Castagnaro, Atilio Pedro; Marano, Marìa Rosa

2010-06-01

In this review, we summarise the current knowledge on three pathogens that exhibit distinct tissue specificity and modes of pathogenesis in citrus plants. Xanthomonas axonopodis pv. citri causes canker disease and invades the host leaf mesophyll tissue through natural openings and can also survive as an epiphyte. Xylella fastidiosa and Candidatus Liberibacter are vectored by insects and proliferate in the vascular system of the host, either in the phloem (Candidatus Liberibacter) or xylem (X. fastidiosa) causing variegated chlorosis and huanglongbing diseases, respectively. Candidatus Liberibacter can be found within host cells and is thus unique as an intracellular phytopathogenic bacterium. Genome sequence comparisons have identified groups of species-specific genes that may be associated with the particular lifestyle, mode of transmission or symptoms produced by each phytopathogen. In addition, components that are conserved amongst bacteria may have diverse regulatory actions underpinning the different bacterial lifestyles; one example is the divergent role of the Rpf/DSF cell-cell signalling system in X. citri and X. fastidiosa. Biofilm plays a key role in epiphytic fitness and canker development in X. citri and in the symptoms produced by X. fastidiosa. Bacterial aggregation may be associated with vascular occlusion of the xylem vessels and symptomatology of variegated chlorosis.

Causes of non-adherence to therapeutic guidelines in severe community-acquired pneumonia

PubMed Central

Gattarello, Simone; Ramírez, Sergio; Almarales, José Rafael; Borgatta, Bárbara; Lagunes, Leonel; Encina, Belén; Rello, Jordi

2015-01-01

Objective To assess the adherence to Infectious Disease Society of America/American Thoracic Society guidelines and the causes of lack of adherence during empirical antibiotic prescription in severe pneumonia in Latin America. Methods A clinical questionnaire was submitted to 36 physicians from Latin America; they were asked to indicate the empirical treatment in two fictitious cases of severe respiratory infection: community-acquired pneumonia and nosocomial pneumonia. Results In the case of communityacquired pneumonia, 11 prescriptions of 36 (30.6%) were compliant with international guidelines. The causes for non-compliant treatment were monotherapy (16.0%), the unnecessary prescription of broad-spectrum antibiotics (40.0%) and the use of non-recommended antibiotics (44.0%). In the case of nosocomial pneumonia, the rate of adherence to the Infectious Disease Society of America/American Thoracic Society guidelines was 2.8% (1 patient of 36). The reasons for lack of compliance were monotherapy (14.3%) and a lack of dual antibiotic coverage against Pseudomonas aeruginosa (85.7%). If monotherapy with an antipseudomonal antibiotic was considered adequate, the antibiotic treatment would be adequate in 100% of the total prescriptions. Conclusion The compliance rate with the Infectious Disease Society of America/American Thoracic Society guidelines in the community-acquired pneumonia scenario was 30.6%; the most frequent cause of lack of compliance was the indication of monotherapy. In the case of nosocomial pneumonia, the compliance rate with the guidelines was 2.8%, and the most important cause of non-adherence was lack of combined antipseudomonal therapy. If the use of monotherapy with an antipseudomonal antibiotic was considered the correct option, the treatment would be adequate in 100% of the prescriptions. PMID:25909312

Frozen chips: an unusual cause of severe frostbite injury

PubMed Central

Graham, C.; Stevenson, J.

2000-01-01

A case of severe frostbite injury to the right foot is presented. This was caused by the inappropriate application of a bag of frozen chips to the foot in an attempt to ease non-specific pain. No specific acute traumatic injury was identified. As the patient was a teacher of physical education, the pain had initially been assumed to originate from a minor musculoskeletal injury. Full recovery ensued after surgical excision of necrotic tissue and split skin grafting. The danger of inappropriate overenthusiastic use of ice packs or other frozen material to treat soft tissue injuries is emphasised. The need for education to prevent similar future injuries is discussed. Key Words: cold injury; frostbite; ice pack; skin; necrosis PMID:11049150

Regional Variations in the Risk and Severity of Ciguatera Caused by Eating Moray Eels

PubMed Central

Chan, Thomas Y. K.

2017-01-01

Moray eels (Gymnothorax species) from tropical waters have long been known to be high-risk species, and the consumption of particularly the viscera or ungutted eels can result in severe ciguatera (known as Gymnothorax or moray eel poisoning), characterized by prominent neurological features. In this review, the main objective was to describe the risk and severity of ciguatera caused by eating moray eels in different parts of the world. Moray eels can accumulate very high ciguatoxin (CTX) levels in the flesh and particularly the liver. Therefore, even the smaller ones can be toxic and the consumption of an average portion (particularly liver) can result in severe or fatal ciguatera. Moray eels (particularly when ungutted) must never be served in gatherings since they can cause mass poisoning because of their large sizes and high CTX levels. Apart from regulatory measures restricting or excluding access, the public should be repeatedly warned to avoid eating moray eels. PMID:28672845

Regional Variations in the Risk and Severity of Ciguatera Caused by Eating Moray Eels.

PubMed

Chan, Thomas Y K

2017-06-26

Moray eels ( Gymnothorax species) from tropical waters have long been known to be high-risk species, and the consumption of particularly the viscera or ungutted eels can result in severe ciguatera (known as Gymnothorax or moray eel poisoning), characterized by prominent neurological features. In this review, the main objective was to describe the risk and severity of ciguatera caused by eating moray eels in different parts of the world. Moray eels can accumulate very high ciguatoxin (CTX) levels in the flesh and particularly the liver. Therefore, even the smaller ones can be toxic and the consumption of an average portion (particularly liver) can result in severe or fatal ciguatera. Moray eels (particularly when ungutted) must never be served in gatherings since they can cause mass poisoning because of their large sizes and high CTX levels. Apart from regulatory measures restricting or excluding access, the public should be repeatedly warned to avoid eating moray eels.

Bisphosphocins: novel antimicrobials for enhanced killing of drug-resistant and biofilm-forming bacteria.

PubMed

Wong, Jonathan P; DiTullio, Paul; Parkinson, Steve

2015-01-01

The global prevalence of antibiotic resistance and the threat posed by drug-resistant superbugs are a leading challenge confronting modern medicine in the 21st century. However, the progress on the development of novel antibiotics to combat this problem is severely lagging. A more concerted effort to develop novel therapeutic agents with robust activity and unique mechanisms of action will be needed to overcome the problem of drug resistance. Furthermore, biofilm forming bacteria are known to be increasingly resistant to the actions of antibiotics and are a leading cause of mortality or morbidity in nosocomial infections. Bisphosphocins (also scientifically known as nubiotics) are novel small protonated deoxynucleotide molecules, and exert their antibacterial activity by depolarization of the bacterial cell membrane, causing bacterial cell death. Bisphosphocins may represent an effective weapon against antibiotic-resistant and biofilm-forming pathogenic bacteria. Preclinical efficacy studies in animals have shown that the compounds are safe and, efficacious against various bacterial infections, including drug-resistant pathogens. In vitro biochemical analysis confirmed that the bactericidal activity of bisphosphocins is mediated by depolarization of the bacterial cell membrane, and these compounds are better able to penetrate through bacterial biofilm and kill the biofilm encased bacteria. This article will cover the structure, mode of action, safety, efficacy and the current state of development of bisphosphocins. Together, the information presented here will present a strong case for bisphosphocins to be considered for use as new weapons to complement the existing arsenal of antimicrobial drugs and as a first line defence against drug-resistant and biofilm-forming bacteria.

The antibiotic pipeline for multi-drug resistant gram negative bacteria: what can we expect?

PubMed

Falagas, Matthew E; Mavroudis, Andreas D; Vardakas, Konstantinos Z

2016-08-01

A real concern in the medical community is the increasing resistance of bacteria, especially that of Gram-negative types. New antibiotics are currently under clinical development, promising to tackle severe infections caused, especially, by multi-drug resistant (MDR) bacteria and broaden the armamentarium of clinicians. We searched PUBMED and GOOGLE databases. Combinations of already approved β-lactams or monobactams with new β-lactamase inhibitors [imipenem-cilastatin/MK-7655 (relebactam), meropenem/RPX7009 (vaborbactam), ceftaroline/avibactam, aztreonam/avibactam], new β-lactams (S-649266, BAL30072), aminoglycosides (plazomicin), quinolones (finafloxacin) and tetracyclines (eravacycline) were included in the review. Expert commentary: For the majority of the upcoming antibiotics the currently available data is limited to their microbiology and pharmacokinetics. Their effectiveness and safety against infections due to MDR bacteria remain to be proved. Significant issues are also the impact of these antibiotics on the human intestinal microbiota and their possible co-administration with already-known antimicrobial agents in difficult-to-treat-infections; further studies should be conducted for these objectives.

Bioautography-guided isolation of antibacterial compounds of essential oils from Thai spices against histamine-producing bacteria.

PubMed

Lomarat, Pattamapan; Phanthong, Phanida; Wongsariya, Karn; Chomnawang, Mullika Traidej; Bunyapraphatsara, Nuntavan

2013-05-01

The outbreak of histamine fish poisoning has been being an issue in food safety and international trade. The growth of contaminated bacterial species including Morganella morganii which produce histidine decarboxylase causes histamine formation in fish during storage. Histamine, the main toxin, causes mild to severe allergic reaction. At present, there is no well-established solution for histamine fish poisoning. This study was performed to determine the antibacterial activity of essential oils from Thai spices against histamine-producing bacteria. Among the essential oils tested, clove, lemongrass and sweet basil oils were found to possess the antibacterial activity. Clove oil showed the strongest inhibitory activity against Morganella morganii, followed by lemongrass and sweet basil oils. The results indicated that clove, lemongrass and sweet basil oils could be useful for the control of histamine-producing bacteria. The attempt to identify the active components using preparative TLC and GC/MS found eugenol, citral and methyl chavicol as the active components of clove, lemongrass and sweet basil oils, respectively. The information from this study would be useful in the research and development for the control of histamine-producing bacteria in fish or seafood products to reduce the incidence of histamine fish poisoning.

Micro-Raman spectroscopy for identification and classification of UTI bacteria

NASA Astrophysics Data System (ADS)

Yogesha, M.; Chawla, Kiran; Acharya, Mahendra; Chidangil, Santhosh; Bankapur, Aseefhali

2017-07-01

Urinary tract infection (UTI) is one of the major clinical problems known to mankind, especially among adult women. Conventional methods for identification of UTI causing bacteria are time consuming and expensive. Therefore, a rapid and cost-effective method is desired. In the present study, five bacteria (one Gram-positive and four Gram-negative), most commonly known to cause UTI, have been identified and classified using micro-Raman spectroscopy combined with principal component analysis (PCA).

Quantitative assessment of salivary oral bacteria according to the severity of dental caries in childhood.

PubMed

Colombo, Natália H; Kreling, Paula F; Ribas, Laís F F; Pereira, Jesse A; Kressirer, Christine A; Klein, Marlise I; Tanner, Anne C R; Duque, Cristiane

2017-11-01

This study aimed to assess differences in selected oral bacteria in children according to the severity of dental caries. One hundred and thirty-six children, 36-60 months old were divided into three groups according to caries status: caries-free (CF) (n=47), early childhood caries (ECC) (n=40) and severe-early childhood caries (S-ECC) (n=49). Saliva was collected for detection and quantification of selected oral streptococci, Actinomyces naeslundii, Lactobacillus spp., Bifidobacterium spp., and Scardovia wiggsiae by quantitative-polymerase chain reaction. The results showed that the detection and quantitative levels of S. mutans, S. sobrinus, Bifidobacterium spp. and S. wiggsiae were significantly higher in S-ECC children compared to CF and ECC children, while for S. salivarius were significantly higher in CF compared to ECC and S-ECC children. There was no statistical difference among the clinical groups for S. mitis, S. oralis, A. naeslundii and Lactobacillus spp. levels and detection. S-ECC children had a lower monthly family income, started tooth brushing later and were breastfeed for a longer duration compared to CF children. S. mutans levels were positively correlated with S. wiggsiae and Bifidobacterium spp. levels, lower mother's education and child bottle-feeding before sleeping and negatively correlated with S. salivarius. It was concluded that in addition to S. mutans, other bacterial species, including bifidobacteria, Scardovia wiggsiae and S. sobrinus, are associated with severity of early childhood caries, although their role in the progress of dental caries remains unclear. Copyright © 2017 Elsevier Ltd. All rights reserved.

Responses, applications, and analysis of microgravity effects on bacteria

NASA Astrophysics Data System (ADS)

Benoit, Michael Robert

Spaceflight causes many changes to the growth and behavior of bacteria, most likely because of microgravity. However, we do not fully understand the gravity-dependent mechanisms that alter bacterial cell physiology. Furthermore, the literature consists of many contradictory results, creating controversy over the mechanisms by which spaceflight affects bacterial cultures. The research described in this dissertation combines empirical, analytical, and numerical modeling techniques aimed at characterizing the various gravity-dependent phenomena that act on bacteria. While reviewing the literature, I identified an interesting trend in prior experimental results regarding bacterial motility. With this information, we can begin to explain some of the seemingly contradictory findings. This discovery should help to resolve several controversial theories in the field of space microbiology. Chapter 3 describes a microbial antibiotic production experiment conducted onboard the International Space Station. The results corroborated earlier findings of increased antibiotic production for samples taken during the first two weeks of spaceflight. For later samples, however, a reversal occurred, showing decreased production in the spaceflight samples. This insight highlights the benefit of conducting long duration experiments in space to fully evaluate biological responses. Chapter 4 describes a novel technique for preventing bacterial cell sedimentation to partially simulate microgravity in ground-based experiments. The results of this study showed a correlation between cell sedimentation and bacterial growth. As documented in Chapter 5, I investigated the use of digital holographic interferometry to measure extracellular fluid density changes caused by bacterial metabolism. The results showed that fluid density changes surrounding individual bacteria were too small to measure directly. Therefore, I used mathematical analyses and numerical model simulations (described in Chapter 6

Isolation and identification of bacteria causing mastitis in small ruminants and their susceptibility to antibiotics, honey, essential oils, and plant extracts

PubMed Central

Abdalhamed, Abeer Mostafa; Zeedan, Gamil Sayed Gamil; Zeina, Hala Abdoula Ahmed Abou

2018-01-01

Aim: The present work aims to isolate and identify bacteria that cause mastitis in small ruminants and evaluates the antibacterial activity of some antibiotics, honey, essential oils, and plant extracts. Materials and Methods: A total of 289 milk samples were collected from udder secretions of sheep (n=189) and goat (n=100) from El-Fayoum, Beni-Suef, and Giza governorates. Screening subclinical mastitis (SCM) was done using California Mastitis Test (CMT); identification of the isolates was achieved using Gram’s staining, hemolytic pattern, colony morphology, and biochemical tests using Analytical Profile Index. Results: On clinical examination, the incidence of clinical mastitis (CM) was found to be 5.88% and 7% in sheep and goat, respectively. On CMT, SCM was found to be 25 (13.23%) and 11 (10%) in sheep and goat, respectively. Bacteriological examination of all milk samples found the presence of Staphylococcus aureus (SA) (31.1%), coagulase-negative staphylococci (CNS) (19.5%), Escherichia coli (EC) (8.3%), Streptococcus spp. (5.6%), Klebsiella spp. (3.77%), and Pseudomonas spp. (1.89%), while no bacteria were cultured from 81.66% of the samples. Identification of 9 isolates of CNS was achieved by using API staph test to Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus cohnii, and Staphylococcus saprophyticus. The highest bacterial resistance was found in EC (67.14%) followed by Kp (45.28%) and SA (26.57%). Conclusion: Onion and black cumin essential oils followed by Egyptian honey showed strong antibacterial effects against multidrug-resistant bacteria. Finally, our study proved that Egyptian honey, onion, and black cumin essential oils have a marked strong antibacterial effect against bacteria isolated from small ruminant mastitis, but still further extensive studies are needed to discover the therapeutic properties of these plant extracts and honey. PMID:29657429

Indirect causes of severe adverse maternal outcomes: a secondary analysis of the WHO Multicountry Survey on Maternal and Newborn Health.

PubMed

Lumbiganon, P; Laopaiboon, M; Intarut, N; Vogel, J P; Souza, J P; Gülmezoglu, A M; Mori, R

2014-03-01

To assess the proportion of severe maternal outcomes resulting from indirect causes, and to determine pregnancy outcomes of women with indirect causes. Secondary analysis of the WHO Multicountry Survey on Maternal and Newborn Health. A total of 359 health facilities in 29 countries in Africa, Asia, Latin America, and the Middle East. A total of 314 623 pregnant women admitted to the participating facilities. We identified the percentage of women with severe maternal outcomes arising from indirect causes. We evaluated the risk of severe maternal and perinatal outcomes in women with, versus without, underlying indirect causes, using adjusted odds ratios and 95% confidence intervals, by a multilevel, multivariate logistic regression model, accounting for clustering effects within countries and health facilities. Severe maternal outcomes and preterm birth, fetal mortality, early neonatal mortality, perinatal mortality, low birthweight, and neonatal intensive care unit admission. Amongst 314 623 included women, 2822 were reported to suffer from severe maternal outcomes, out of which 20.9% (589/2822; 95% CI 20.1-21.6%) were associated with indirect causes. The most common indirect cause was anaemia (50%). Women with underlying indirect causes showed significantly higher risk of obstetric complications (adjusted odds ratio, aOR, 7.0; 95% CI 6.6-7.4), severe maternal outcomes (aOR 27.9; 95% CI 24.7-31.6), and perinatal mortality (aOR 3.8; 95% CI 3.5-4.1). Indirect causes were responsible for about one-fifth of severe maternal outcomes. Women with underlying indirect causes had significantly increased risks of severe maternal and perinatal outcomes. © 2014 RCOG The World Health Organization retains copyright and all other rights in the manuscript of this article as submitted for publication.

Antibacterial activity of GUAVA, Psidium guajava Linnaeus, leaf extracts on diarrhea-causing enteric bacteria isolated from Seabob shrimp, Xiphopenaeus kroyeri (Heller).

PubMed

Gonçalves, Flávia A; Andrade Neto, Manoel; Bezerra, José N S; Macrae, Andrew; Sousa, Oscarina Viana de; Fonteles-Filho, Antonio A; Vieira, Regine H S F

2008-01-01

Guava leaf tea of Psidium guajava Linnaeus is commonly used as a medicine against gastroenteritis and child diarrhea by those who cannot afford or do not have access to antibiotics. This study screened the antimicrobial effect of essential oils and methanol, hexane, ethyl acetate extracts from guava leaves. The extracts were tested against diarrhea-causing bacteria: Staphylococcus aureus, Salmonella spp. and Escherichia coli. Strains that were screened included isolates from seabob shrimp, Xiphopenaeus kroyeri (Heller) and laboratory-type strains. Of the bacteria tested, Staphylococcus aureus strains were most inhibited by the extracts. The methanol extract showed greatest bacterial inhibition. No statistically significant differences were observed between the tested extract concentrations and their effect. The essential oil extract showed inhibitory activity against S. aureus and Salmonella spp. The strains isolated from the shrimp showed some resistance to commercially available antibiotics. These data support the use of guava leaf-made medicines in diarrhea cases where access to commercial antibiotics is restricted. In conclusion, guava leaf extracts and essential oil are very active against S. aureus, thus making up important potential sources of new antimicrobial compounds.

Influence of a new surface modification of intraocular lenses with fluoroalkylsilan on the adherence of endophthalmitis-causing bacteria in vitro.

PubMed

Kienast, Antonia; Kämmerer, Regine; Weiss, Claudia; Klinger, Matthias; Menz, Dirk-Henning; Dresp, Joachim; Ohgke, Helge; Solbach, Werner; Laqua, Horst; Hoerauf, Hans

2006-09-01

Dynasilan is a fluoroalkylsilan that is able to interact with surface active centres on intraocular lenses (IOL), offering a new way for surface modification of different IOL materials. The purpose of this in vitro study was to investigate the influence of this new surface modification on the adherence of two typical endophthalmitis causing bacteria (Staphylococcus epidermidis, Propionibacterium acnes). In a pilot experiment, the effect of Dynasilan coating on the adherence of S. epidermidis was tested on glass slides. Forty-two Dynasilan-modified and 42 unmodified IOL (14 PMMA, 14 silicone and 14 hydrogel) were incubated at 37 degrees C in brain heart infusion broth (10(8) CFU/ml) with either S. epidermidis for 24 h or with P. acnes for 1 h. Subsequently, the adherent bacteria were resuspended using ultrasonification at 35 kHz for 3x45 s. After dilution series and incubation at 37 degrees C on Petri dishes for 24 h and 3 days, respectively, the colonies were counted. In the pilot experiment, a markedly lower number of adherent S. epidermidis was observed on Dynasilan-modified glass slides. Of all IOL materials incubated with S. epidermidis, those modified with Dynasilan showed a lower mean number of adherent bacteria (mean 1.37x10(7); SD 2.37x10(7)) than those untreated (2.43x10(7); SD 3.04x10(7)). IOLs incubated with P. acnes showed a significantly lower mean number of adherent bacteria of 2.51x10(4) (SD 2.71x10(4)) on Dynasilan-modified IOLs versus 6.27x10(4) (SD 7.70x10(4)) on untreated IOLs. The presented in vitro results indicate that Dynasilan surface modification is able to reduce the adherence of S. epidermidis and P. acnes on all IOL materials tested. Further studies regarding the stability of this modification and its biocompatibility must be performed.

Bacteremic Urinary Tract Infection Caused by Multidrug-Resistant Enterobacteriaceae Are Associated With Severe Sepsis at Admission

PubMed Central

Lee, Yi-Chien; Hsiao, Chih-Yen; Hung, Miao-Chiu; Hung, Sheng-Che; Wang, Hung-Ping; Huang, Yun-Jhong; Wang, Jann-Tay

2016-01-01

Abstract The purpose of this study is to compare the clinical features and treatment outcomes among patients with bacteremic urinary tract infection (UTI) caused by multidrug-resistant (MDR) and non-MDR Enterobacteriaceae and to identify whether MDR pathogens were independently associated with severe sepsis or septic shock at presentation. The clinical data of adult patients visiting and being treated at Chia-Yi Christian Hospital due to bacteremic UTI caused by Enterobacteriaceae from January 2006 to August 2015 were retrospectively analyzed. A total of 585 patients were enrolled. Among them, 220 (37.6%) were caused by the MDR Enterobacteriaceae. A total of 206 patients (35.2%) developed severe sepsis or septic shock at presentation. Patients in the MDR group tend to be male and have a past history of gout, recurrent UTI, prior hospitalization, hydronephrosis, renal stone, ureteral stone, indwelling urinary catheter, newly development of renal dysfunction, severe sepsis or septic shock, intensive care unit (ICU) admission, receipt of ineffective empirical therapy, longer hospital stay, and higher in-hospital mortality (2.7% vs 1.9%, P = 0.569). Using multivariate logistic regression analysis, it is revealed that independent predictors associated with severe sepsis or septic shock at presentation were liver cirrhosis (OR 2.868; 95% CI 1.439–5.716; P = 0.003), indwelling urinary catheter (OR 1.936; 95% CI 1.238–3.027; P = 0.004), and MDR Enterobacteriaceae (OR 1.447; 95% CI 1.002–2.090; P = 0.049). Multidrug resistance was associated with the development of severe sepsis or septic shock upon presentation among patients with bacteremic UTI caused by Enterobacteriaceae. Therefore, empirical antibiotics therapy for patients with UTI presented with severe sepsis and/or septic shock should be more broad-spectrum to effectively cover MDR Enterobacteriaceae. PMID:27196480

Unusual multifocal granulomatous disease caused by actinomycetous bacteria in a nestling Derbyan parrot (Psittacula derbiana).

PubMed

Park, F J; Jaensch, S

2009-01-01

A nestling Derbyan parrot (Psittacula derbiana) was presented with unusual subcutaneous swellings of the thigh regions, and poor growth. Histological examination revealed actinomycetous bacteria associated with multifocal systemic granulomas. The clinical and pathological findings of the case are presented, and some relevant aspects of actinomycetous bacterial infections in mammals and birds are discussed. Although granulomatous disease is encountered at times in avian species, the actinomycetous bacteria (Nocardia and Actinomyces spp.) have rarely been reported in association with multifocal granulomatous disease in birds.

Endophytic bacteria and their potential to enhance heavy metal phytoextraction.

PubMed

Rajkumar, Mani; Ae, Noriharu; Freitas, Helena

2009-09-01

Pollution of soils with heavy metals is becoming one of the most severe environmental and human health hazards. Due to its widespread contamination finding innovative ways to clean metal pollutant has become a priority in the remediation field. Phytoremediation, the use of plants for the restoration of environments contaminated with pollutants is a relatively new technology that is more benign than current engineering solutions to treat contaminated sites. Recently, the benefits of combining endophytic bacteria with plants for increased remediation of pollutants have been successfully tried for toxic metal removal from contaminated soils. Endophytic bacteria reside within plant hosts without causing disease symptoms. Further, the metal resistant endophytes are reported to be present in various hyperaccumulator plants growing on heavy metal contaminated soils and play an important role in successful survival and growth of plants. Moreover, the metal resistant endophytes are reported to promote plant growth by various mechanisms such as nitrogen fixation, solubilization of minerals, production of phytohormones, siderophores, utilization of 1-aminocyclopropane-1-carboxylic acid as a sole N source and transformation of nutrient elements. In this review we highlight the diversity and plant growth promoting features of metal resistant endophytic bacteria and discuss their potential in phytoextraction of heavy metals from contaminated soils.

Legionella waltersii--a novel cause of pneumonia?

PubMed

König, Corinne; Hebestreit, Helge; Valenza, Guiseppe; Abele-Horn, Marianne; Speer, Christian P

2005-10-01

A 5-y-old girl was admitted to our hospital with fever, cough, respiratory distress and rapidly increasing oxygen requirements. A chest radiograph showed bilateral central infiltrates. PCR was performed with pharyngeal washings and revealed Legionella DNA, while no genetic materials of other pathogens such as respiratory viruses, Mycoplasma and Chlamydia were detected. The clinical condition improved gradually after administration of steroids and therapy with clarithromycin. Further sequencing of Legionella DNA led to the identification of Legionella waltersii. This Legionella species has never been described as a human pathogen before. For the first time, L. waltersii was identified as a cause of severe pneumonia. Since L. waltersii is not detected by routine laboratory tests, it may be speculated that these bacteria, like other Legionella species, are underestimated as a probable cause of community-acquired pneumonia.

Affinity sensor using 3-aminophenylboronic acid for bacteria detection.

PubMed

Wannapob, Rodtichoti; Kanatharana, Proespichaya; Limbut, Warakorn; Numnuam, Apon; Asawatreratanakul, Punnee; Thammakhet, Chongdee; Thavarungkul, Panote

2010-10-15

Boronic acid that can reversibly bind to diols was used to detect bacteria through its affinity binding reaction with diol-groups on bacterial cell walls. 3-aminophenylboronic acid (3-APBA) was immobilized on a gold electrode via a self-assembled monolayer. The change in capacitance of the sensing surface caused by the binding between 3-APBA and bacteria in a flow system was detected by a potentiostatic step method. Under optimal conditions the linear range of 1.5×10(2)-1.5×10(6) CFU ml(-1) and the detection limit of 1.0×10(2) CFU ml(-1) was obtained. The sensing surface can be regenerated and reused up to 58 times. The method was used for the analysis of bacteria in several types of water, i.e., bottled, well, tap, reservoir and wastewater. Compared with the standard plate count method, the results were within one standard deviation of each other. The proposed method can save both time and cost of analysis. The electrode modified with 3-APBA would also be applicable to the detection of other cis-diol-containing analytes. The concept could be extended to other chemoselective ligands, offering less expensive and more robust affinity sensors for a wide range of compounds. Copyright © 2010 Elsevier B.V. All rights reserved.

Acetic acid bacteria: A group of bacteria with versatile biotechnological applications.

PubMed

Saichana, Natsaran; Matsushita, Kazunobu; Adachi, Osao; Frébort, Ivo; Frebortova, Jitka

2015-11-01

Acetic acid bacteria are gram-negative obligate aerobic bacteria assigned to the family Acetobacteraceae of Alphaproteobacteria. They are members of the genera Acetobacter, Gluconobacter, Gluconacetobacter, Acidomonas, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia, Granulibacter, Tanticharoenia, Ameyamaea, Neokomagataea, and Komagataeibacter. Many strains of Acetobacter and Komagataeibacter have been known to possess high acetic acid fermentation ability as well as the acetic acid and ethanol resistance, which are considered to be useful features for industrial production of acetic acid and vinegar, the commercial product. On the other hand, Gluconobacter strains have the ability to perform oxidative fermentation of various sugars, sugar alcohols, and sugar acids leading to the formation of several valuable products. Thermotolerant strains of acetic acid bacteria were isolated in order to serve as the new strains of choice for industrial fermentations, in which the cooling costs for maintaining optimum growth and production temperature in the fermentation vessels could be significantly reduced. Genetic modifications by adaptation and genetic engineering were also applied to improve their properties, such as productivity and heat resistance. Copyright © 2014 Elsevier Inc. All rights reserved.

SOS, the formidable strategy of bacteria against aggressions.

PubMed

Baharoglu, Zeynep; Mazel, Didier

2014-11-01

The presence of an abnormal amount of single-stranded DNA in the bacterial cell constitutes a genotoxic alarm signal that induces the SOS response, a broad regulatory network found in most bacterial species to address DNA damage. The aim of this review was to point out that beyond being a repair process, SOS induction leads to a very strong but transient response to genotoxic stress, during which bacteria can rearrange and mutate their genome, induce several phenotypic changes through differential regulation of genes, and sometimes acquire characteristics that potentiate bacterial survival and adaptation to changing environments. We review here the causes and consequences of SOS induction, but also how this response can be modulated under various circumstances and how it is connected to the network of other important stress responses. In the first section, we review articles describing the induction of the SOS response at the molecular level. The second section discusses consequences of this induction in terms of DNA repair, changes in the genome and gene expression, and sharing of genomic information, with their effects on the bacteria's life and evolution. The third section is about the fine tuning of this response to fit with the bacteria's 'needs'. Finally, we discuss recent findings linking the SOS response to other stress responses. Under these perspectives, SOS can be perceived as a powerful bacterial strategy against aggressions. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Background sequence characteristics influence the occurrence and severity of disease-causing mtDNA mutations

PubMed Central

Wei, Wei; Hudson, Gavin

2017-01-01

Inherited mitochondrial DNA (mtDNA) mutations have emerged as a common cause of human disease, with mutations occurring multiple times in the world population. The clinical presentation of three pathogenic mtDNA mutations is strongly associated with a background mtDNA haplogroup, but it is not clear whether this is limited to a handful of examples or is a more general phenomenon. To address this, we determined the characteristics of 30,506 mtDNA sequences sampled globally. After performing several quality control steps, we ascribed an established pathogenicity score to the major alleles for each sequence. The mean pathogenicity score for known disease-causing mutations was significantly different between mtDNA macro-haplogroups. Several mutations were observed across all haplogroup backgrounds, whereas others were only observed on specific clades. In some instances this reflected a founder effect, but in others, the mutation recurred but only within the same phylogenetic cluster. Sequence diversity estimates showed that disease-causing mutations were more frequent on young sequences, and genomes with two or more disease-causing mutations were more common than expected by chance. These findings implicate the mtDNA background more generally in recurrent mutation events that have been purified through natural selection in older populations. This provides an explanation for the low frequency of mtDNA disease reported in specific ethnic groups. PMID:29253894

Causes and Severity of Ischemic Stroke in Patients with Symptomatic Intracranial Arterial Stenosis

PubMed Central

Famakin, Bolanle M; Chimowitz, Marc I; Lynn, Michael J; Stern, Barney J; George, Mary G.

2009-01-01

Background and purpose There are limited data on the causes and severity of subsequent stroke in patients presenting initially with TIA or stroke attributed to intracranial arterial stenosis. Methods We evaluated the location, type (lacunar vs. non-lacunar), cause, and severity of stroke in patients who had an ischemic stroke endpoint in the Warfarin Aspirin Symptomatic Intracranial Disease (WASID) trial. Results Of the 569 patients enrolled in the WASID trial, 106 patients (18.6%) had an ischemic stroke during a mean follow-up of 1.8 years. Stroke occurred in the territory of the symptomatic artery in 77 (73%) of 106 patients. Among the 77 strokes in the territory, 70 (91%) were non-lacunar and 34 (44%) were disabling. Stroke out of the territory of the symptomatic artery occurred in 29 (27%) of 106 patients. Among these 29 strokes, 24 (83%) were non-lacunar, 14 (48%) were due to previously asymptomatic intracranial stenosis, and 9 (31%) were disabling. Conclusions Most subsequent strokes in patients with symptomatic intracranial artery stenosis are in the same territory and non-lacunar, and nearly half of the strokes in the territory are disabling. The most commonly identified cause of stroke out of the territory was a previously asymptomatic intracranial stenosis. Penetrating artery disease was responsible for a low number of strokes. PMID:19407228

Role of dissolved organic carbon upon re-entrainment and surface properties of aquifer bacteria and bacteria-sized microspheres during subsurface transport (Invited)

NASA Astrophysics Data System (ADS)

Harvey, R. W.; Metge, D. W.; Mohanram, A.; Gao, X.; Chorover, J.

2010-12-01

Susceptibilities for in-situ re-entrainment of attached 0.2 and 1.0 μm (diameter) microspheres and groundwater bacteria (Pseudomonas stuzeri and uncultured, native bacteria) were assessed during transport studies involving an organically contaminated, sandy aquifer in Cape Cod, MA. Aquifer sediments between pairs of injection and sampling wells were initially loaded with fluorescently labeled, carboxylated microspheres and bacteria that had been stained with the DNA-specific fluorochrome 4',6-diamidino-2-phenylindole. In response to subsequent hydrodynamic perturbations and injections of deionized water (ionic strength reduction), anionic surfactants (77 μM linear alkylbenzene sulfonates, LAS) and non-ionic surfactant (76 μM polyoxyethylene sorbitan monooleate, Tween 80), differing patterns of re-entrainment were evident for the two colloids. Injections of anionic surfactant and deionized water were the most efficient in causing detachment of the highly hydrophilic and negatively charged microspheres, but largely ineffective in causing re-entrainment of bacteria. In contrast, the nonionic surfactant was highly effective in re-entraining bacteria, but not microspheres. The hydrophobicities and zeta potentials of the indigenous bacteria were highly sensitive to modest concentration changes (0.6 to 1.3 mg L-1) in groundwater dissolved organic carbon (DOC), whereas the microspheres were largely unaffected. The most hydrophilic and negatively charged bacterial community was isolated from groundwater having the lowest DOC. FTIR spectra indicated that the community from the lowest DOC groundwater also had the highest average density of surface carboxyl groups. This indicates that DOC may have a biological effect on native bacteria resulting in changes to surface structures or changes in the makeup of the bacterial community.

Numerical taxonomy of phenanthrene-degrading bacteria isolated from the Chesapeake Bay

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

West, P.A.; Okpokwasili, G.C.; Brayton, P.R.

1984-11-01

Phenanthrene-degrading bacteria were isolated from Chesapeake Bay samples by the use of a solid medium which had been overlaid with an ethanol solution of phenanthrene before inoculation. Eighteen representative strains of phenanthrene-degrading bacteria with 21 type and reference bacteria were examined for 123 characteristics representing physiological, biochemical, and nutritional properties. Relationships between strains were computed with several similarity coefficients. The phenogram constructed by unweighted-pair-group arithmetic average linkage and use of the simple Jaccard (S/sub J/) coefficient was used to identify seven phena. Phenanthrene-degrading bacteria were identified as Vibrio parahaemolyticus and Vibrio fluvialis by their clustering with type and reference strains.more » Several phenanthrene-degrading bacteria resembled Enterobacteriaceae family members, although some Vibrio-like phenanthrene degraders could not be identified. 22 references, 1 figure, 2 tables.« less

Antibacterial Activities of Endophytic Bacteria Isolated from Taxus brevifolia Against Foodborne Pathogenic Bacteria.

PubMed

Islam, Nurul; Choi, Jaehyuk; Baek, Kwang-Hyun

2018-05-01

Endophytes are a potential source of novel bioactive compounds with medicinal properties. In this study, 41 endophytic bacteria (EB) were isolated from tissues of a medicinally important plant Taxus brevifolia (Pacific yew). The objective was to screen all the EB isolates for their antibacterial effects against five foodborne pathogenic bacteria: Bacillus cereus ATCC10876, Staphylococcus aureus ATCC12600, Listeria monocytogenes ATCC19115, Escherichia coli ATCC43890, and Salmonella Typhimurium ATCC19585. Among the EB isolates, T. brevifolia seed (TbS)-8, T. brevifolia fleshy part of fruit (TbFl)-10, T. brevifolia leaf (TbL)-22, TbS-29, and TbL-34 exerted significant antibacterial activity against the tested foodborne pathogens. Especially TbFl-10 showed the highest antibacterial activity against all the tested bacteria and was identified as Paenibacillus kribbensis (Pk). Furthermore, an ethyl acetate extract of Pk-TbFl-10 possessed antibacterial activities against the tested five foodborne pathogenic bacteria, with zones of inhibition from 15.71 ± 2.85 to 13.01 ± 2.12 mm. Scanning electron microscopy analysis revealed ruptured, lysed, shrunk, and swollen cells of all the tested foodborne pathogens treated with the ethyl acetate extract of Pk-TbFl-10, suggesting that a metabolite(s) of Pk-TbFl-10 penetrates the cell membrane and causes cell lysis leading to cell death. Our results indicate that Pk-TbFl-10 isolated from T. brevifolia can serve as a novel source of natural antibacterial agents against foodborne pathogenic bacteria, with potential applications in the pharmaceutical industry.

Microfluidic Transducer for Detecting Nanomechanical Movements of Bacteria

NASA Astrophysics Data System (ADS)

Kara, Vural; Ekinci, Kamil

2017-11-01

Various nanomechanical movements of bacteria are currently being explored as an indication of bacterial viability. Most notably, these movements have been observed to subside rapidly and dramatically when the bacteria are exposed to an effective antibiotic. This suggests that monitoring bacterial movements, if performed with high fidelity, can offer a path to various clinical microbiological applications, including antibiotic susceptibility tests. Here, we introduce a robust and sensitive microfluidic transduction technique for detecting the nanomechanical movements of bacteria. The technique is based on measuring the electrical fluctuations in a microchannel which the bacteria populate. These electrical fluctuations are caused by the swimming of motile, planktonic bacteria and random oscillations of surface-immobilized bacteria. The technique provides enough sensitivity to detect even the slightest movements of a single cell and lends itself to smooth integration with other microfluidic methods and devices; it may eventually be used for rapid antibiotic susceptibility testing. We acknowledge support from Boston University Office of Technology Development, Boston University College of Engineering, NIH (1R03AI126168-01) and The Wallace H. Coulter Foundation.

A prophage tail-like protein is deployed by Burkholderia bacteria to feed on fungi.

PubMed

Swain, Durga Madhab; Yadav, Sunil Kumar; Tyagi, Isha; Kumar, Rahul; Kumar, Rajeev; Ghosh, Srayan; Das, Joyati; Jha, Gopaljee

2017-09-01

Some bacteria can feed on fungi, a phenomenon known as mycophagy. Here we show that a prophage tail-like protein (Bg_9562) is essential for mycophagy in Burkholderia gladioli strain NGJ1. The purified protein causes hyphal disintegration and inhibits growth of several fungal species. Disruption of the Bg_9562 gene abolishes mycophagy. Bg_9562 is a potential effector secreted by a type III secretion system (T3SS) and is translocated into fungal mycelia during confrontation. Heterologous expression of Bg_9562 in another bacterial species, Ralstonia solanacearum, confers mycophagous ability in a T3SS-dependent manner. We propose that the ability to feed on fungi conferred by Bg_9562 may help the bacteria to survive in certain ecological niches. Furthermore, considering its broad-spectrum antifungal activity, the protein may be potentially useful in biotechnological applications to control fungal diseases.Some bacteria can feed on live fungi through unclear mechanisms. Here, the authors show that a T3SS-secreted protein, which is homologous to phage tail proteins, allows a Burkholderia gladioli strain to kill and feed on various fungal species.

Antibacterial activity of caffeine against plant pathogenic bacteria.

PubMed

Sledz, Wojciech; Los, Emilia; Paczek, Agnieszka; Rischka, Jacek; Motyka, Agata; Zoledowska, Sabina; Piosik, Jacek; Lojkowska, Ewa

2015-01-01

The objective of the present study was to evaluate the antibacterial properties of a plant secondary metabolite - caffeine. Caffeine is present in over 100 plant species. Antibacterial activity of caffeine was examined against the following plant-pathogenic bacteria: Ralstonia solanacearum (Rsol), Clavibacter michiganesis subsp. sepedonicus (Cms), Dickeya solani (Dsol), Pectobacterium atrosepticum (Pba), Pectobacterium carotovorum subsp. carotovorum (Pcc), Pseudomonas syringae pv. tomato (Pst), and Xanthomonas campestris subsp. campestris (Xcc). MIC and MBC values ranged from 5 to 20 mM and from 43 to 100 mM, respectively. Caffeine increased the bacterial generation time of all tested species and caused changes in cell morphology. The influence of caffeine on the synthesis of DNA, RNA and proteins was investigated in cultures of plant pathogenic bacteria with labelled precursors: [(3)H]thymidine, [(3)H]uridine or (14)C leucine, respectively. RNA biosynthesis was more affected than DNA or protein biosynthesis in bacterial cells treated with caffeine. Treatment of Pba with caffeine for 336 h did not induce resistance to this compound. Caffeine application reduced disease symptoms caused by Dsol on chicory leaves, potato slices, and whole potato tubers. The data presented indicate caffeine as a potential tool for the control of diseases caused by plant-pathogenic bacteria, especially under storage conditions.

Emerging role of bacteria in oral carcinogenesis: a review with special reference to perio-pathogenic bacteria.

PubMed

Perera, Manosha; Al-Hebshi, Nezar Noor; Speicher, David J; Perera, Irosha; Johnson, Newell W

2016-01-01

Oral cancer, primarily oral squamous cell carcinoma (OSCC), continues to be a major global health problem with high incidence and low survival rates. While the major risk factors for this malignancy, mostly lifestyle related, have been identified, around 15% of oral cancer cases remain unexplained. In light of evidence implicating bacteria in the aetiology of some cancer types, several epidemiological studies have been conducted in the last decade, employing methodologies ranging from traditional culture techniques to 16S rRNA metagenomics, to assess the possible role of bacteria in OSCC. While these studies have demonstrated differences in microbial composition between cancerous and healthy tissues, they have failed to agree on specific bacteria or patterns of oral microbial dysbiosis to implicate in OSCC. On the contrary, some oral taxa, particularly Porphyromonas gingivalis and Fusobacterium nucleatum, show strong oral carcinogenic potential in vitro and in animal studies. Bacteria are thought to contribute to oral carcinogenesis via inhibition of apoptosis, activation of cell proliferation, promotion of cellular invasion, induction of chronic inflammation, and production of carcinogens. This narrative review provides a critical analysis of and an update on the association between bacteria and oral carcinogenesis and the possible mechanisms underlying it.

Chemotactic selection of pollutant degrading soil bacteria

DOEpatents

Hazen, Terry C.

1994-01-01

A method for identifying soil microbial strains which may be bacterial degraders of pollutants comprising the steps of placing a concentration of a pollutant in a substantially closed container, placing the container in a sample of soil for a period of time ranging from one minute to several hours, retrieving the container, collecting the contents of the container, and microscopically determining the identity of the bacteria present. Different concentrations of the pollutant can be used to determine which bacteria respond to each concentration. The method can be used for characterizing a polluted site or for looking for naturally occurring biological degraders of the pollutant. Then bacteria identified as degraders of the pollutant and as chemotactically attracted to the pollutant are used to inoculate contaminated soil. To enhance the effect of the bacteria on the pollutant, nutrients are cyclicly provided to the bacteria then withheld to alternately build up the size of the bacterial colony or community and then allow it to degrade the pollutant.

Chemotactic selection of pollutant degrading soil bacteria

DOEpatents

Hazen, T.C.

1991-03-04

A method is described for identifying soil microbial strains which may be bacterial degraders of pollutants. This method includes: Placing a concentration of a pollutant in a substantially closed container; placing the container in a sample of soil for a period of time ranging from one minute to several hours; retrieving the container and collecting its contents; microscopically determining the identity of the bacteria present. Different concentrations of the pollutant can be used to determine which bacteria respond to each concentration. The method can be used for characterizing a polluted site or for looking for naturally occurring biological degraders of the pollutant. Then bacteria identified as degraders of the pollutant and as chemotactically attracted to the pollutant are used to innoculate contaminated soil. To enhance the effect of the bacteria on the pollutant, nutrients are cyclicly provided to the bacteria then withheld to alternately build up the size of the bacterial colony or community and then allow it to degrade the pollutant.

Incidence of Bacteriocins Produced by Food-Related Lactic Acid Bacteria Active towards Oral Pathogens

PubMed Central

Zoumpopoulou, Georgia; Pepelassi, Eudoxie; Papaioannou, William; Georgalaki, Marina; Maragkoudakis, Petros A.; Tarantilis, Petros A.; Polissiou, Moschos; Tsakalidou, Effie; Papadimitriou, Konstantinos

2013-01-01

In the present study we investigated the incidence of bacteriocins produced by 236 lactic acid bacteria (LAB) food isolates against pathogenic or opportunistic pathogenic oral bacteria. This set of LAB contained several strains (≥17%) producing bacteriocins active against food-related bacteria. Interestingly only Streptococcus macedonicus ACA-DC 198 was able to inhibit the growth of Streptococcus oralis, Streptococcus sanguinis and Streptococcus gordonii, while Lactobacillus fermentum ACA-DC 179 and Lactobacillus plantarun ACA-DC 269 produced bacteriocins solely against Streptococcus oralis. Thus, the percentage of strains that were found to produce bacteriocins against oral bacteria was ~1.3%. The rarity of bacteriocins active against oral LAB pathogens produced by food-related LAB was unexpected given their close phylogenetic relationship. Nevertheless, when tested in inhibition assays, the potency of the bacteriocin(s) of S. macedonicus ACA-DC 198 against the three oral streptococci was high. Fourier-transform infrared spectroscopy combined with principal component analysis revealed that exposure of the target cells to the antimicrobial compounds caused major alterations of key cellular constituents. Our findings indicate that bacteriocins produced by food-related LAB against oral LAB may be rare, but deserve further investigation since, when discovered, they can be effective antimicrobials. PMID:23443163

An active principle of Nigella sativa L., thymoquinone, showing significant antimicrobial activity against anaerobic bacteria.

PubMed

Randhawa, Mohammad Akram; Alenazy, Awwad Khalaf; Alrowaili, Majed Gorayan; Basha, Jamith

2017-01-01

Thymoquinone (TQ) is the major active principle of Nigella sativa seed (black seed) and is known to control many fungi, bacteria, and some viruses. However, the activity of TQ against anaerobic bacteria is not well demonstrated. Anaerobic bacteria can cause severe infections, including diarrhea, aspiration pneumonia, and brain abscess, particularly in immunodeficient individuals. The present study aimed to investigate the in vitro antimicrobial activity of TQ against some anaerobic pathogens in comparison to metronidazole. Standard, ATCC, strains of four anaerobic bacteria ( Clostridium difficile , Clostridium perfringens , Bacteroides fragilis , and Bacteroides thetaiotaomicron ), were initially isolated on special Brucella agar base (with hemin and vitamin K). Then, minimum inhibitory concentrations (MICs) of TQ and metronidazole were determined against these anaerobes when grown in Brucella agar, using serial agar dilution method according to the recommended guidelines for anaerobic organisms instructed by the Clinical and Laboratory Standards Institute. TQ showed a significant antimicrobial activity against anaerobic bacteria although much weaker than metronidazole. MICs of TQ and metronidazole against various anaerobic human pathogens tested were found to be between 10-160 mg/L and 0.19-6.25 mg/L, respectively. TQ controlled the anaerobic human pathogenic bacteria, which supports the use of N. sativa in the treatment of diarrhea in folk medicine. Further investigations are in need for determination of the synergistic effect of TQ in combination with metronidazole and the activity of derivatives of TQ against anaerobic infections.

Number of Bacteria and Time of Coincubation With Bacteria Required for the Development of Acanthamoeba Keratitis.

PubMed

Nakagawa, Hayate; Hattori, Takaaki; Koike, Naohito; Ehara, Tomoko; Narimatsu, Akitomo; Kumakura, Shigeto; Matsumoto, Tetsuya; Goto, Hiroshi

2017-03-01

We hypothesized that bacteria may be a factor contributing to the development of Acanthamoeba keratitis (AK). We investigated interactions between Acanthamoeba and Pseudomonas aeruginosa for the development of keratitis in rabbit corneas. Acanthamoeba castellanii (ATCC50492) and P. aeruginosa (PAO-1) were used. Two densities of P. aeruginosa (high, 1 × 10/mL; low, 3 × 10/mL) and 2 durations of coincubation (long, 6 h; short, 2 h) of Acanthamoeba with 1 × 10/mL of P. aeruginosa were tested. Acanthamoeba alone or Acanthamoeba coincubated with P. aeruginosa was inoculated into rabbit corneas. After inoculation, levofloxacin (LVFX) eye drops were administered. The clinical score of the cornea was evaluated after inoculation. Acanthamoeba alone did not produce keratitis during a 5-day observation period. Rabbit corneas inoculated with Acanthamoeba coincubated with low-density P. aeruginosa followed by topical LVFX were clear with few infiltrates. Corneas inoculated with Acanthamoeba coincubated with high-density P. aeruginosa followed by LVFX treatment developed severe keratitis, and clinical scores were significantly higher compared with high-density P. aeruginosa alone followed by LVFX treatment (scores 7, 9.6, 8.5 vs. 3, 3.5, 3.25 on days 1-3, all P < 0.01). The long (6 h) coincubation time of Acanthamoeba with high-density P. aeruginosa resulted in more severe keratitis compared with short (2 h) coincubation (scores, 9.7, 12.7, 12.1, 9.8, 8.7 vs. 7, 9.6, 8.5, 6.9, 5.6 on days 1-5, all P < 0.01). These results suggest that the presence of bacteria is essential and a critical number of bacteria is required for the development of AK. The time of coexistence with bacteria may be an important determinant of the severity of AK.

Isolation, characterization, and formulation of antagonistic bacteria for the management of seedlings damping-off and root rot disease of cucumber.

PubMed

Khabbaz, Salah Eddin; Abbasi, Pervaiz A

2014-01-01

Antagonistic bacteria are common soil inhabitants with potential to be developed into biofungicides for the management of seedling damping-off, root rot, and other soil-borne diseases of various crops. In this study, antagonistic bacteria were isolated from a commercial potato field and screened for their growth inhibition of fungal and oomycete pathogens in laboratory tests. The biocontrol potential of the 3 most effective antagonistic bacteria from the in vitro tests was evaluated against seedling damping-off and root rot of cucumber caused by Pythium ultimum. Based on phenotypic characteristics, biochemical tests, and sequence analysis of 16S-23S rDNA gene, the 3 antagonistic bacteria were identified as Pseudomonas fluorescens (isolate 9A-14), Pseudomonas sp. (isolate 8D-45), and Bacillus subtilis (isolate 8B-1). All 3 bacteria promoted plant growth and suppressed Pythium damping-off and root rot of cucumber seedlings in growth-room assays. Both pre- and post-planting application of these bacteria to an infested peat mix significantly increased plant fresh masses by 113%-184% and percentage of healthy seedlings by 100%-290%, and decreased damping-off and root rot severity by 27%-50%. The peat and talc formulations of these antagonistic bacteria applied as seed or amendment treatments to the infested peat mix effectively controlled Pythium damping-off and root rot of cucumber seedlings and enhanced plant growth. The survival of all 3 antagonistic bacteria in peat and talc formulations decreased over time at room temperature, but the populations remained above 10(8) CFU/g during the 180-day storage period. The peat formulation of a mixture of 3 bacteria was the best seed treatment, significantly increasing the plant fresh masses by 245% as compared with the Pythium control, and by 61.4% as compared with the noninfested control. This study suggests that the indigenous bacteria from agricultural soils can be developed and formulated as biofungicides for minimizing

Decreased waterborne pathogenic bacteria in an urban aquifer related to intense shallow geothermal exploitation.

PubMed

García-Gil, Alejandro; Gasco-Cavero, Samanta; Garrido, Eduardo; Mejías, Miguel; Epting, Jannis; Navarro-Elipe, Mercedes; Alejandre, Carmen; Sevilla-Alcaine, Elena

2018-08-15

The implications of intensive use of shallow geothermal energy resources in shallow urban aquifers are still not known for waterborne pathogens relevant to human health. Firstly, we hypothesized that waterborne enteric pathogens would be relatively increased in heated groundwater plumes. To prove this, microbiological sampling of 31 piezometers covering the domain of an urban groundwater body affected by microbiological contamination and energetically exploited by 70 groundwater heat pump systems was performed. Mean differences of pathogenic bacteria contents between impacted and non-impacted monitoring points were assessed with a two-tailed independent Student's t-test or Mann-Whitney U and correlation coefficients were also calculated. Surprisingly, the results obtained revealed a significant and generalized decrease in waterborne pathogen contents in thermally impacted piezometers compared to that of non-impacted piezometers. This decrease is hypothesized to be caused by a heat shock to bacteria within the heat exchangers. The statistically significant negative correlations obtained between waterborne pathogen counts and temperature could be explained by the spatial distribution of the bacteria, finding that bacteria start to recover with increasing distance from the injection point. Also, different behavior groups fitting exponential regression models were found for the bacteria species studied, justified by the different presence and influence of several aquifer parameters and major, minor and trace elements studied, as well as the coexistence with other bacteria species. The results obtained from this work reinforce the concept of shallow geothermal resources as a clean energy source, as they could also provide the basis to control the pathogenic bacteria contents in groundwater bodies. Copyright © 2018 Elsevier B.V. All rights reserved.

THE FINE STRUCTURE OF GREEN BACTERIA

PubMed Central

Cohen-Bazire, Germaine; Pfennig, Norbert; Kunisawa, Riyo

1964-01-01

The fine structure of several strains of green bacteria belonging to the genus Chlorobium has been studied in thin sections with the electron microscope. In addition to having general cytological features typical of Gram-negative bacteria, the cells of these organisms always contain membranous mesosomal elements, connected with the cytoplasmic membrane, and an elaborate system of isolated cortical vesicles, some 300 to 400 A wide and 1000 to 1500 A long. The latter structures, chlorobium vesicles, have been isolated in a partly purified state by differential centrifugation of cell-free extracts. They are associated with a centrifugal fraction that has a very high specific chlorophyll content. In all probability, therefore, the chlorobium vesicles are the site of the photosynthetic apparatus of green bacteria. PMID:14195611

Occupant Injury Severity and Accident Causes in Helicopter Emergency Medical Services (1983-2014).

PubMed

Boyd, Douglas D; Macchiarella, Nickolas D

2016-01-01

Helicopter emergency medical services (HEMS) transport critically ill patients to/between emergency care facilities and operate in a hazardous environment: the destination site is often encumbered with obstacles, difficult to visualize at night, and lack instrument approaches for degraded visibility. The study objectives were to determine 1) HEMS accident rates and causes; 2) occupant injury severity profiles; and 3) whether accident aircraft were certified to the more stringent crashworthiness standards implemented two decades ago. The National Transportation Safety Board (NTSB) aviation accident database was used to identify HEMS mishaps for the years spanning 1983-2014. Contingency tables (Pearson Chi-square or Fisher's exact test) were used to determine differences in proportions. A generalized linear model (Poisson distribution) was used to determine if accident rates differed over time. While the HEMS accident rate decreased by 71% across the study period, the fraction of fatal accidents (36-50%) and the injury severity profiles were unchanged. None of the accident aircraft fully satisfied the current crashworthiness standards. Failure to clear obstacles and visual-to-instrument flight, the most frequent accident causes (37 and 26%, respectively), showed a downward trend, whereas accidents ascribed to aircraft malfunction showed an upward trend over time. HEMS operators should consider updating their fleet to the current, more stringent crashworthiness standards in an attempt to reduce injury severity. Additionally, toward further mitigating accidents ascribed to inadvertent visual-to-instrument conditions, HEMS aircraft should be avionics-equipped for instrument flight rules flight.

Development of a multiplex PCR assay for rapid and simultaneous detection of four genera of fish pathogenic bacteria.

PubMed

Zhang, D F; Zhang, Q Q; Li, A H

2014-11-01

Species of genus Aeromonas, Vibrio, Edwardsiella and Streptococcus are the most common fish pathogenic bacteria that cause economically devastating losses in aquaculture. A multiplex polymerase chain reaction (mPCR) was developed for the simultaneous detection and differentiation of the four genera of fish pathogenic bacteria. Through the use of genus-specific primers instead of species-specific ones, the current mPCR covered much more target bacterial species compared with previously reported species-specific mPCR methods. The specificity of the four putative genus-specific primers was validated experimentally while used exclusively (uniplex PCR) or combined (mPCR) against bacterial genomic DNA templates of the target bacteria and nontarget bacteria. The PCR amplicons for the following genera were obtained as expected: Aeromonas (875 bp), Vibrio (524 bp), Edwardsiella (302 bp) and Streptococcus (197 bp), and the fragments could be separated clearly on the agarose gel electrophoresis. The mPCR did not produce nonspecific amplification products when used to amplify 21 nontarget species of bacteria. The mPCR detection limits for each target bacterial genera were 50 colony-forming units (CFU) in pure culture and 100 CFU in fish tissue samples. In conclusion, the mPCR assay was proven to be a powerful alternative to the conventional culture-based method, given its rapid, specific, sensitive and reliable detection of target pathogens. The fish pathogenic bacteria of genus Aeromonas, Vibrio, Edwardsiella and Streptococcus frequently cause severe outbreaks of diseases in cultured fish, and the genus-specific multiplex PCR assay developed in this study can detect the bacteria of the four genera when present in the samples either alone or mixed. The mPCR assay is expected to identify the causative agents more efficiently than uniplex PCR or species-specific multiplex PCR for clinical diagnosis, resulting in the earlier implementation of control measures. This m

Identification of active fluorescence stained bacteria by Raman spectroscopy

NASA Astrophysics Data System (ADS)

Krause, Mario; Beyer, Beatrice; Pietsch, Christian; Radt, Benno; Harz, Michaela; Rösch, Petra; Popp, Jürgen

2008-04-01

Microorganisms can be found everywhere e.g. in food both as useful ingredients or harmful contaminations causing food spoilage. Therefore, a fast and easy to handle analysis method is needed to detect bacteria in different kinds of samples like meat, juice or air to decide if the sample is contaminated by harmful microorganisms. Conventional identification methods in microbiology require always cultivation and therefore are time consuming. In this contribution we present an analysis approach to identify fluorescence stained bacteria on strain level by means of Raman spectroscopy. The stained bacteria are highlighted and can be localized easier against a complex sample environment e.g. in food. The use of Raman spectroscopy in combination with chemometrical methods allows the identification of single bacteria within minutes.

Severe maternal morbidity from direct obstetric causes in West Africa: incidence and case fatality rates.

PubMed Central

Prual, A.; Bouvier-Colle, M. H.; de Bernis, L.; Bréart, G.

2000-01-01

Data on maternal morbidity make it possible to assess how many women are likely to need essential obstetric care, and permit the organization, monitoring and evaluation of safe motherhood programmes. In the present paper we propose operational definitions of severe maternal morbidity and report the frequency of such morbidity as revealed in a population-based survey of a cohort of 20,326 pregnant women in six West African countries. The methodology and questionnaires were the same in all areas. Each pregnant woman had four contacts with the obstetric survey team: at inclusion, between 32 and 36 weeks of amenorrhoea, during delivery and 60 days postpartum. Direct obstetric causes of severe morbidity were observed in 1215 women (6.17 cases per 100 live births). This ratio varied significantly between areas, from 3.01% in Bamako to 9.05% in Saint-Louis. The main direct causes of severe maternal morbidity were: haemorrhage (3.05 per 100 live births); obstructed labour (2.05 per 100), 23 cases of which involved uterine rupture (0.12 per 100); hypertensive disorders of pregnancy (0.64 per 100), 38 cases of which involved eclampsia (0.19 per 100); and sepsis (0.09 per 100). Other direct obstetric causes accounted for 12.2% of cases. Case fatality rates were very high for sepsis (33.3%), uterine rupture (30.4%) and eclampsia (18.4%); those for haemorrhage varied from 1.9% for antepartum or peripartum haemorrhage to 3.7% for abruptio placentae. Thus at least 3-9% of pregnant women required essential obstetric care. The high case fatality rates of several complications reflected a poor quality of obstetric care. PMID:10859853

Isolation and characterization of pigmented algicidal bacteria from seawater

NASA Astrophysics Data System (ADS)

Shaima, A.; Gires, U.; Asmat, A.

2014-09-01

Some dinoflagellate species are toxic and widely distributed in Malaysian marines ecosystems. They can cause many problems to aquatic life due to the production of various potential and natural toxins that accumulate in filter feeding shellfish and cause food poisoning to human. In recent decades, bacteria have been widely used as a biological control against these harmful algae. In the present study, pigmented bacteria isolated from marine water of Port Dickson beach was studied for their anti-algal activity towards toxic dinoflagellate Alexandrium minutum. Four isolates were studied and only one was capable of inhibiting algal growth when treated with bacterial culture. The algilytic effect on dinoflagellate was evaluated based on direct cell count under the microscope. Results showed that only isolate Sdpd-310 with orange colour has an inhibitory effect on A. minutum growth. This study demonstrated the rapid algicidal activity of a marine pigmented bacteria against the toxic dinoflagellate A. minutum.

Mutations in DYNC1H1 cause severe intellectual disability with neuronal migration defects.

PubMed

Willemsen, Marjolein H; Vissers, Lisenka E L; Willemsen, Michèl A A P; van Bon, Bregje W M; Kroes, Thessa; de Ligt, Joep; de Vries, Bert B; Schoots, Jeroen; Lugtenberg, Dorien; Hamel, Ben C J; van Bokhoven, Hans; Brunner, Han G; Veltman, Joris A; Kleefstra, Tjitske

2012-03-01

DYNC1H1 encodes the heavy chain protein of the cytoplasmic dynein 1 motor protein complex that plays a key role in retrograde axonal transport in neurons. Furthermore, it interacts with the LIS1 gene of which haploinsufficiency causes a severe neuronal migration disorder in humans, known as classical lissencephaly or Miller-Dieker syndrome. To describe the clinical spectrum and molecular characteristics of DYNC1H1 mutations. A family based exome sequencing approach was used to identify de novo mutations in patients with severe intellectual disability. In this report the identification of two de novo missense mutations in DYNC1H1 (p.Glu1518Lys and p.His3822Pro) in two patients with severe intellectual disability and variable neuronal migration defects is described. Since an autosomal dominant mutation in DYNC1H1 was previously identified in a family with the axonal (type 2) form of Charcot- Marie-Tooth (CMT2) disease and mutations in Dync1h1 in mice also cause impaired neuronal migration in addition to neuropathy, these data together suggest that mutations in DYNC1H1 can lead to a broad phenotypic spectrum and confirm the importance of DYNC1H1 in both central and peripheral neuronal functions.

Novel pharmacotherapy for the treatment of hospital-acquired and ventilator-associated pneumonia caused by resistant gram-negative bacteria.

PubMed

Kidd, James M; Kuti, Joseph L; Nicolau, David P

2018-03-01

Hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP) are among the most prevalent infections in hospitalized patients, particularly those in the intensive care unit. Importantly, the frequency of multidrug resistant (MDR) Gram-negative (GN) bacteria as the bacteriologic cause of HABP/VABP is increasing. These include MDR Pseudomonas aeruginosa, Acinetobacter baumannii, and carbapenem resistant Enterobacteriaceae (CRE). Few antibiotics are currently available when such MDR Gram-negatives are encountered and older agents such as polymyxin B, colistin (polymyxin E), and tigecycline have typically performed poorly in HABP/VABP. Areas covered: In this review, the authors summarize novel antibiotics which have reached phase 3 clinical trials including patients with HABP/VABP. For each agent, the spectrum of activity, pertinent pharmacological characteristics, clinical trial data, and potential utility in the treatment of MDR-GN HABP/VABP is discussed. Expert opinion: Novel antibiotics currently available, and those soon to be, will expand opportunities to treat HABP/VABP caused by MDR-GN organisms and minimize the use of more toxic, less effective drugs. However, with sparse clinical data available, defining the appropriate role for each of the new agents is challenging. In order to maximize the utility of these antibiotics, combination therapy and the role of therapeutic drug monitoring should be investigated.

Chloroform ingestion causing severe gastrointestinal injury, hepatotoxicity and dermatitis confirmed with plasma chloroform concentrations.

PubMed

Jayaweera, Dushan; Islam, Shawkat; Gunja, Naren; Cowie, Chris; Broska, James; Poojara, Latesh; Roberts, Michael S; Isbister, Geoffrey K

2017-02-01

Poisoning due to chloroform ingestion is rare. The classic features of acute chloroform toxicity include central nervous system (CNS) and respiratory depression, and delayed hepatotoxicity. A 30-year-old female ingested 20-30 mL of 99% chloroform solution, which caused rapid loss of consciousness, transient hypotension and severe respiratory depression requiring endotracheal intubation and ventilation. She was alert by 12 h and extubated 16 h post-overdose. At 38-h post-ingestion, her liver function tests started to rise and she was commenced on intravenous acetylcysteine. Her alanine transaminase (1283 U/L), aspartate transaminase (734 U/L) and international normalized ratio (2.3) peaked 67- to 72-h post-ingestion. She also developed severe abdominal pain, vomiting and diarrhoea. An abdominal CT scan was consistent with severe enterocolitis, and an upper gastrointestinal endoscopy showed erosive oesophagitis, severe erosive gastritis and ulceration. She was treated with opioid analgesia, proton pump inhibitors, sucralfate and total parenteral nutrition. Secretions caused a contact dermatitis of her face and back. Nine days post-ingestion she was able to tolerate food. Her liver function tests normalized and the dermatitis resolved. Chloroform was measured using headspace gas chromatograph mass spectrometry, with a peak concentration of 2.00 μg/mL, 4 h 20 min post-ingestion. The concentration-time data fitted a 1-compartment model with elimination half-life 6.5 h. In addition to early CNS depression and delayed hepatotoxicity, we report severe gastrointestinal injury and dermatitis with chloroform ingestion. Recovery occurred with good supportive care, acetylcysteine and management of gastrointestinal complications.

Copper tolerance and virulence in bacteria

PubMed Central

Ladomersky, Erik; Petris, Michael J.

2015-01-01

Copper (Cu) is an essential trace element for all aerobic organisms. It functions as a cofactor in enzymes that catalyze a wide variety of redox reactions due to its ability to cycle between two oxidation states, Cu(I) and Cu(II). This same redox property of copper has the potential to cause toxicity if copper homeostasis is not maintained. Studies suggest that the toxic properties of copper are harnessed by the innate immune system of the host to kill bacteria. To counter such defenses, bacteria rely on copper tolerance genes for virulence within the host. These discoveries suggest bacterial copper intoxication is a component of host nutritional immunity, thus expanding our knowledge of the roles of copper in biology. This review summarizes our current understanding of copper tolerance in bacteria, and the extent to which these pathways contribute to bacterial virulence within the host. PMID:25652326

Extended spectrum β-lactamases, carbapenemases and mobile genetic elements responsible for antibiotics resistance in Gram-negative bacteria.

PubMed

El Salabi, Allaaeddin; Walsh, Timothey R; Chouchani, Chedly

2013-05-01

Infectious diseases due to Gram-negative bacteria are a leading cause of morbidity and mortality worldwide. Antimicrobial agents represent one major therapeutic tools implicated to treat these infections. The misuse of antimicrobial agents has resulted in the emergence of resistant strains of Gram-negatives in particular Enterobacteriaceae and non-fermenters; they have an effect not only on a human but on the public health when bacteria use the resistance mechanisms to spread in the hospital environment and to the community outside the hospitals by means of mobile genetic elements. Gram-negative bacteria have become increasingly resistant to antimicrobial agents. They have developed several mechanisms by which they can withstand to antimicrobials, these mechanisms include the production of Extended-spectrum β-lactamases (ESBLs) and carbapenemases, furthermore, Gram-negative bacteria are now capable of spreading such resistance between members of the family Enterobacteriaceae and non-fermenters using mobile genetic elements as vehicles for such resistance mechanisms rendering antibiotics useless. Therefore, addressing the issue of mechanisms of antimicrobial resistance is considered one of most urgent priorities. This review will help to illustrate different resistance mechanisms; ESBLs, carbapenemases encoded by genes carried by mobile genetic elements, which are used by Gram-negative bacteria to escape antimicrobial effect.

Transfer of Multidrug-Resistant Bacteria between Intermingled Ecological Niches: The Interface between Humans, Animals and the Environment

PubMed Central

da Costa, Paulo Martins; Loureiro, Luís; Matos, Augusto J. F.

2013-01-01

The use of antimicrobial agents has been claimed to be the driving force for the emergence and spread of microbial resistance. However, several studies have reported the presence of multidrug-resistant bacteria in populations exposed to low levels of antimicrobial drugs or even never exposed. For many pathogens, especially those organisms for which asymptomatic colonization typically precedes infection (e.g., Enterococcus spp. and Escherichia coli), the selective effects of antimicrobial use can only be understood if we considerer all biological and environmental pathways which enable these bacteria, and the genes they carry, to spread between different biomes. This ecological framework provides an essential perspective for formulating antimicrobial use policies, precisely because it encompasses the root causes of these problems rather than merely their consequences. PMID:23343983

Bartonella Species, an Emerging Cause of Blood-Culture-Negative Endocarditis.

PubMed

Okaro, Udoka; Addisu, Anteneh; Casanas, Beata; Anderson, Burt

2017-07-01

Since the reclassification of the genus Bartonella in 1993, the number of species has grown from 1 to 45 currently designated members. Likewise, the association of different Bartonella species with human disease continues to grow, as does the range of clinical presentations associated with these bacteria. Among these, blood-culture-negative endocarditis stands out as a common, often undiagnosed, clinical presentation of infection with several different Bartonella species. The limitations of laboratory tests resulting in this underdiagnosis of Bartonella endocarditis are discussed. The varied clinical picture of Bartonella infection and a review of clinical aspects of endocarditis caused by Bartonella are presented. We also summarize the current knowledge of the molecular basis of Bartonella pathogenesis, focusing on surface adhesins in the two Bartonella species that most commonly cause endocarditis, B. henselae and B. quintana . We discuss evidence that surface adhesins are important factors for autoaggregation and biofilm formation by Bartonella species. Finally, we propose that biofilm formation is a critical step in the formation of vegetative masses during Bartonella -mediated endocarditis and represents a potential reservoir for persistence by these bacteria. Copyright © 2017 American Society for Microbiology.

Treatment with Botulinum Toxin for Refractory Fever Caused by Severe Spasticity: A Case Series.

PubMed

Lester, Jacobo; Alvarez-Resendiz, Gerardo Esteban; Klériga, Enrique; Videgaray, Fernando; Zambito, Gerardo

2018-06-01

Brain and spinal cord injuries may cause very severe spasticity that occasionally may be associated with persistent fever. We present 14 patients with spasticity and persistent fever, treated with botulinum toxin type A. Their spasticity improved and the fever resolved within a period no greater than 48 h. In all cases, infectious and other non-infectious causes were ruled out. When sustained tonic muscular activity is associated with a significant increase in body temperature and is refractory to the usual drugs used for hyperpyrexia, type A botulinum toxin may be an effective treatment option to control both spasticity and fever.

Two novel mutations in thymidine kinase-2 cause early onset fatal encephalomyopathy and severe mtDNA depletion.

PubMed

Lesko, Nicole; Naess, Karin; Wibom, Rolf; Solaroli, Nicola; Nennesmo, Inger; von Döbeln, Ulrika; Karlsson, Anna; Larsson, Nils-Göran

2010-03-01

Deficiency of thymidine kinase-2 (TK2) has been described in children with early onset fatal skeletal myopathy. TK2 is a mitochondrial deoxyribonucleoside kinase required for the phosphorylation of deoxycytidine and deoxythymidine and hence is vital for the maintenance of a balanced mitochondrial dNTP pool in post-mitotic tissues. We describe a patient with two novel TK2 mutations, which caused disease onset shortly after birth and death at the age of three months. One mutation (219insCG) generated an early stop codon, thus preventing the synthesis of a functional protein. The second mutation (R130W) resulted in an amino acid substitution, which caused a severe reduction (<3%) of TK2 enzyme activity. These two novel TK2 mutations cause an extremely severe phenotype with overwhelming central nervous system symptoms not commonly seen in patients with TK2-deficiency. We conclude that the severe clinical presentation in this patient was due to a virtual lack of mitochondrial TK2 activity. Copyright 2009 Elsevier B.V. All rights reserved.

[The effect of physical therapy on the most severe forms of knee structral changes caused by osteoarthritis].

PubMed

Kapidzić-Basić, Nedima; Dzananović, Dzevad; Kapidzić-Duraković, Suada; Kikanović, Sahza; Mulić-Bacić, Suada; Hotić-Hadziefendić, Asja

2011-01-01

In the most severe form of structural changes on knee caused by osteoarthritis non-surgical treatment provide minimal results and a question of its purpose is being raised. Aim of the study was to examine the possibilities of physical treatment of patients with the most severe degree of structural changes caused by knee osteoarthritis. Examination was conducted on 60 patients that were on physical treatment because of the knee OA. Structural changes are evaluated by Kellgren-Lawrence scale, functional ability by Lequesne index, and pain by Visual analog scale. Physical treatment lasted for 4 weeks. After the physical treatment there was a significant improvement of functional ability (p = 1.78E-07), but the size of improvement was reduced by the level of structural changes. It was significantly lower in IV class in relation to III and II class (p < 0.05). Physical treatment has lower affect by patients with the most severe form of structural changes caused by knee osteoarthritis, but it still can help patients to ease the appearance of complete dependence on other people's help.

Atypical amyoplasia congenita in an infant with Leigh syndrome: a mitochondrial cause of severe contractures?

PubMed

Wilnai, Yael; Seaver, Laurie H; Enns, Gregory M

2012-09-01

Amyoplasia congenita is a distinct form of arthrogryposis with characteristic features including internally rotated and adducted shoulders, extended elbows, flexion, and ulnar deviation of the wrists, and adducted thumbs. Fetal hypokinesia, secondary to a variety of genetic conditions, neuromuscular disorders, and environmental agents, is associated with contractures. In order to increase our understanding of the phenotypic spectrum associated with SURF 1 deficiency, a common cause of mitochondrial respiratory chain complex IV deficiency and Leigh syndrome, we describe a now 6-year-old boy who presented in the neonatal period with amyoplasia congenita. His development was normal until age 10.5 months, at which time he developed severe hypotonia and choreoathetosis following an episode of viral gastroenteritis. Following the onset of neurological symptoms, he gradually developed severe kyphosis and lower limb contractures. Blood and cerebrospinal fluid lactate levels were elevated and head imaging showed characteristic features of Leigh syndrome. He was found to harbor two pathogenic heterozygous mutations in the SURF 1 gene. In this case, mitochondrial dysfunction and the resultant energy deficiency may have played a role in causing abnormal neuronal development during embryogenesis, causing arthrogryposis. A variety of mitochondrial respiratory chain complex deficiencies have been associated with contractures of varying severity. Therefore, mitochondrial disorders should be considered in the differential diagnosis of neonatal arthrogryposis, especially if other characteristic findings such as lactic acidemia or basal ganglia abnormalities are present. Copyright © 2012 Wiley Periodicals, Inc.

Staphylococcus aureus seroproteomes discriminate ruminant isolates causing mild or severe mastitis

PubMed Central

2011-01-01

Staphylococcus aureus is a major cause of mastitis in ruminants. In ewe mastitis, symptoms range from subclinical to gangrenous mastitis. S. aureus factors or host-factors contributing to the different outcomes are not completely elucidated. In this study, experimental mastitis was induced on primiparous ewes using two S. aureus strains, isolated from gangrenous (strain O11) or subclinical (strain O46) mastitis. Strains induced drastically distinct clinical symptoms when tested in ewe and mice experimental mastitis. Notably, they reproduced mild (O46) or severe (O11) mastitis in ewes. Ewe sera were used to identify staphylococcal immunoreactive proteins commonly or differentially produced during infections of variable severity and to define core and accessory seroproteomes. Such SERological Proteome Analysis (SERPA) allowed the identification of 89 immunoreactive proteins, of which only 52 (58.4%) were previously identified as immunogenic proteins in other staphylococcal infections. Among the 89 proteins identified, 74 appear to constitute the core seroproteome. Among the 15 remaining proteins defining the accessory seroproteome, 12 were specific for strain O11, 3 were specific for O46. Distribution of one protein specific for each mastitis severity was investigated in ten other strains isolated from subclinical or clinical mastitis. We report here for the first time the identification of staphylococcal immunogenic proteins common or specific to S. aureus strains responsible for mild or severe mastitis. These findings open avenues in S. aureus mastitis studies as some of these proteins, expressed in vivo, are likely to account for the success of S. aureus as a pathogen of the ruminant mammary gland. PMID:21324116

Heterotrophic bacteria in drinking water distribution system: a review.

PubMed

Chowdhury, Shakhawat

2012-10-01

The microbiological quality of drinking water in municipal water distribution systems (WDS) depends on several factors. Free residual chlorine and/or chloramines are typically used to minimize bacterial recontamination and/or regrowth in WDS. Despite such preventive measures, regrowth of heterotrophic (HPC) and opportunistic bacteria in bulk water and biofilms has yet to be controlled completely. No approach has shown complete success in eliminating biofilms or HPC bacteria from bulk water and pipe surfaces. Biofilms can provide shelter for pathogenic bacteria and protect these bacteria from disinfectants. Some HPC bacteria may be associated with aesthetic and non-life threatening diseases. Research to date has achieved important success in understanding occurrence and regrowth of bacteria in bulk water and biofilms in WDS. To achieve comprehensive understanding and to provide efficient control against bacteria regrowth, future research on bacteria regrowth dynamics and their implications is warranted. In this study, a review was performed on the literature published in this area. The findings and limitations of these papers are summarized. Occurrences of bacteria in WDS, factors affecting bacteria regrowth in bulk water and biofilms, bacteria control strategies, sources of nutrients, human health risks from bacterial exposure, modelling of bacteria regrowth and methods of bacteria sampling and detection and quantification are investigated. Advances to date are noted, and future research needs are identified. Finally, research directions are proposed to effectively control HPC and opportunistic bacteria in bulk water and biofilms in WDS.

A recurrent mutation causing Melnick-Needles syndrome in females confers a severe, lethal phenotype in males.

PubMed

Spencer, Careni; Lombaard, Hendrik; Wise, Amy; Krause, Amanda; Robertson, Stephen P

2018-04-01

Melnick-Needles syndrome (MNS; MIM 309350) is an X-linked skeletal dysplasia caused by mutations in FLNA. Females with the condition present with characteristic facial features, short stature, skeletal anomalies, including poorly modeled and sclerotic bones, and structural abnormalities such as cardiac and urological defects. Previously males were thought to present with either a mild phenotype compatible with life or a severe lethal presentation depending on the maternal phenotype. The discovery of a limited number of mutations in FLNA as the cause of the condition has clarified the molecular basis of the disorder, but only a very small number of severely affected males have been reported with MNS. Furthermore, no mildly affected males have been described with a molecular confirmation of the condition. In this report, we describe the clinical and molecular findings of a mildly affected mother with MNS and her severely affected son. They shared a well-documented disease-causing variant in FLNA, p.(Ala1188Thr), one of two highly recurrent mutations leading to the disorder. This is only the fourth report of a male with perinatal lethal MNS and a molecular confirmation; it is the first description of this specific mutation in a male. © 2018 Wiley Periodicals, Inc.

Meningitis caused by Oerskovia xanthineolytica.

PubMed

Kailath, E J; Goldstein, E; Wagner, F H

1988-03-01

In summary, we describe a case of central nervous system infection with O. xanthineolytica in which the infecting microbe probably was engrafted on a ventricular shunt. The bacteria caused a smoldering meningitis that did not respond to penicillin and rifampin despite in vitro sensitivity, presumably because of inadequate cerebrospinal fluid penetration of the penicillin and the recognized difficulty of eradicating bacteria from contaminated shunts. Removal of the shunt and continued treatment with penicillin and rifampin resulted in cure.

Physiological assessment of bacteria using fluorochromes

NASA Technical Reports Server (NTRS)

McFeters, G. A.; Yu, F. P.; Pyle, B. H.; Stewart, P. S.

1995-01-01

This minireview focuses on the application of fluorogenic compounds in the detection of bacteria with particular emphasis on the assessment of physiological activity using epifluorescence microscopy. Microbiological applications of several related methods will also be reviewed.

All-Cause and Acute Pancreatitis Health Care Costs in Patients With Severe Hypertriglyceridemia.

PubMed

Rashid, Nazia; Sharma, Puza P; Scott, Ronald D; Lin, Kathy J; Toth, Peter P

2017-01-01

The aim of this study was to assess health care utilization and costs related to acute pancreatitis (AP) in patients with severe hypertriglyceridemia (sHTG) levels. Patients with sHTG levels 1000 mg/dL or higher were identified from January 1, 2007, to June 30, 2013. The first identified incident triglyceride level was labeled as index date. All-cause, AP-related health care visits, and mean total all-cause costs in patients with and without AP were compared during 12 months postindex. A generalized linear model regression was used to compare costs while controlling for patient characteristics and comorbidities. Five thousand five hundred fifty sHTG patients were identified, and 5.4% of these patients developed AP during postindex. Patients with AP had significantly (P < 0.05) more all-cause outpatient visits, hospitalizations, longer length of stays during the hospital visits, and emergency department visits versus patients without AP. Mean (SD) unadjusted all-cause health care costs in the 12 months postindex were $25,343 ($33,139) for patients with AP compared with $15,195 ($24,040) for patients with no AP. The regression showed annual all-cause costs were 49.9% higher (P < 0.01) for patients with AP versus without AP. Patients who developed AP were associated with higher costs; managing patients with sHTG at risk of developing AP may help reduce unnecessary costs.

Antimicrobial activity of essential oils from Mediterranean aromatic plants against several foodborne and spoilage bacteria.

PubMed

Silva, Nuno; Alves, Sofia; Gonçalves, Alexandre; Amaral, Joana S; Poeta, Patrícia

2013-12-01

The antimicrobial activity of essential oils extracted from a variety of aromatic plants, often used in the Portuguese gastronomy was studied in vitro by the agar diffusion method. The essential oils of thyme, oregano, rosemary, verbena, basil, peppermint, pennyroyal and mint were tested against Gram-positive (Listeria monocytogenes, Clostridium perfringens, Bacillus cereus, Staphylococcus aureus, Enterococcus faecium, Enterococcus faecalis, and Staphylococcus epidermidis) and Gram-negative strains (Salmonella enterica, Escherichia coli, and Pseudomonas aeruginosa). For most essential oils examined, S. aureus, was the most susceptible bacteria, while P. aeruginosa showed, in general, least susceptibility. Among the eight essential oils evaluated, thyme, oregano and pennyroyal oils showed the greatest antimicrobial activity, followed by rosemary, peppermint and verbena, while basil and mint showed the weakest antimicrobial activity. Most of the essential oils considered in this study exhibited a significant inhibitory effect. Thyme oil showed a promising inhibitory activity even at low concentration, thus revealing its potential as a natural preservative in food products against several causal agents of foodborne diseases and food spoilage. In general, the results demonstrate that, besides flavoring the food, the use of aromatic herbs in gastronomy can also contribute to a bacteriostatic effect against pathogens.

Emerging role of bacteria in oral carcinogenesis: a review with special reference to perio-pathogenic bacteria

PubMed Central

Perera, Manosha; Al-hebshi, Nezar Noor; Speicher, David J.; Perera, Irosha; Johnson, Newell W.

2016-01-01

Oral cancer, primarily oral squamous cell carcinoma (OSCC), continues to be a major global health problem with high incidence and low survival rates. While the major risk factors for this malignancy, mostly lifestyle related, have been identified, around 15% of oral cancer cases remain unexplained. In light of evidence implicating bacteria in the aetiology of some cancer types, several epidemiological studies have been conducted in the last decade, employing methodologies ranging from traditional culture techniques to 16S rRNA metagenomics, to assess the possible role of bacteria in OSCC. While these studies have demonstrated differences in microbial composition between cancerous and healthy tissues, they have failed to agree on specific bacteria or patterns of oral microbial dysbiosis to implicate in OSCC. On the contrary, some oral taxa, particularly Porphyromonas gingivalis and Fusobacterium nucleatum, show strong oral carcinogenic potential in vitro and in animal studies. Bacteria are thought to contribute to oral carcinogenesis via inhibition of apoptosis, activation of cell proliferation, promotion of cellular invasion, induction of chronic inflammation, and production of carcinogens. This narrative review provides a critical analysis of and an update on the association between bacteria and oral carcinogenesis and the possible mechanisms underlying it. PMID:27677454

Deletion of the hfsB gene increases ethanol production in Thermoanaerobacterium saccharolyticum and several other thermophilic anaerobic bacteria.

PubMed

Eminoğlu, Ayşenur; Murphy, Sean Jean-Loup; Maloney, Marybeth; Lanahan, Anthony; Giannone, Richard J; Hettich, Robert L; Tripathi, Shital A; Beldüz, Ali Osman; Lynd, Lee R; Olson, Daniel G

2017-01-01

With the discovery of interspecies hydrogen transfer in the late 1960s (Bryant et al. in Arch Microbiol 59:20-31, 1967), it was shown that reducing the partial pressure of hydrogen could cause mixed acid fermenting organisms to produce acetate at the expense of ethanol. Hydrogen and ethanol are both more reduced than glucose. Thus there is a tradeoff between production of these compounds imposed by electron balancing requirements; however, the mechanism is not fully known. Deletion of the hfsA or B subunits resulted in a roughly 1.8-fold increase in ethanol yield. The increase in ethanol production appears to be associated with an increase in alcohol dehydrogenase activity, which appears to be due, at least in part, to increased expression of the adhE gene, and may suggest a regulatory linkage between hfsB and adhE . We studied this system most intensively in the organism Thermoanaerobacterium saccharolyticum ; however, deletion of hfsB also increases ethanol production in other thermophilic bacteria suggesting that this could be used as a general technique for engineering thermophilic bacteria for improved ethanol production in organisms with hfs -type hydrogenases. Since its discovery by Shaw et al. (JAMA 191:6457-64, 2009), the hfs hydrogenase has been suspected to act as a regulator due to the presence of a PAS domain. We provide additional support for the presence of a regulatory phenomenon. In addition, we find a practical application for this scientific insight, namely increasing ethanol yield in strains that are of interest for ethanol production from cellulose or hemicellulose. In two of these organisms ( T. xylanolyticum and T. thermosaccharolyticum ), the ethanol yields are the highest reported to date.

Effect of two organophosphorus insecticides on the phosphate-dissolving soil bacteria.

PubMed Central

Congregado, F; Simon-Pujol, D; Juárez, A

1979-01-01

Dimethoate and malathion added to soil at 10 and 100 microgram/g caused an initial stimulation of CO2 production. Total counts of bacterial propagules were increased. All insecticide applications increased bacteria producing phospholipases from week 1 until week 4 after the application; bacteria then returned to the original levels. PMID:760634

Communication among Oral Bacteria

PubMed Central

Kolenbrander, Paul E.; Andersen, Roxanna N.; Blehert, David S.; Egland, Paul G.; Foster, Jamie S.; Palmer, Robert J.

2002-01-01

Human oral bacteria interact with their environment by attaching to surfaces and establishing mixed-species communities. As each bacterial cell attaches, it forms a new surface to which other cells can adhere. Adherence and community development are spatiotemporal; such order requires communication. The discovery of soluble signals, such as autoinducer-2, that may be exchanged within multispecies communities to convey information between organisms has emerged as a new research direction. Direct-contact signals, such as adhesins and receptors, that elicit changes in gene expression after cell-cell contact and biofilm growth are also an active research area. Considering that the majority of oral bacteria are organized in dense three-dimensional biofilms on teeth, confocal microscopy and fluorescently labeled probes provide valuable approaches for investigating the architecture of these organized communities in situ. Oral biofilms are readily accessible to microbiologists and are excellent model systems for studies of microbial communication. One attractive model system is a saliva-coated flowcell with oral bacterial biofilms growing on saliva as the sole nutrient source; an intergeneric mutualism is discussed. Several oral bacterial species are amenable to genetic manipulation for molecular characterization of communication both among bacteria and between bacteria and the host. A successful search for genes critical for mixed-species community organization will be accomplished only when it is conducted with mixed-species communities. PMID:12209001

Impacts of Gut Bacteria on Human Health and Diseases

PubMed Central

Zhang, Yu-Jie; Li, Sha; Gan, Ren-You; Zhou, Tong; Xu, Dong-Ping; Li, Hua-Bin

2015-01-01

Gut bacteria are an important component of the microbiota ecosystem in the human gut, which is colonized by 1014 microbes, ten times more than the human cells. Gut bacteria play an important role in human health, such as supplying essential nutrients, synthesizing vitamin K, aiding in the digestion of cellulose, and promoting angiogenesis and enteric nerve function. However, they can also be potentially harmful due to the change of their composition when the gut ecosystem undergoes abnormal changes in the light of the use of antibiotics, illness, stress, aging, bad dietary habits, and lifestyle. Dysbiosis of the gut bacteria communities can cause many chronic diseases, such as inflammatory bowel disease, obesity, cancer, and autism. This review summarizes and discusses the roles and potential mechanisms of gut bacteria in human health and diseases. PMID:25849657

Cuticular bacteria appear detrimental to social spiders in mixed but not monoculture exposure

PubMed Central

Keiser, Carl N.; Shearer, Taylor A.; DeMarco, Alexander E.; Brittingham, Hayley A.; Knutson, Karen A.; Kuo, Candice; Zhao, Katherine; Pruitt, Jonathan N.

2016-01-01

Abstract Much of an animal’s health status, life history, and behavior are dictated by interactions with its endogenous and exogenous bacterial communities. Unfortunately, interactions between hosts and members of their resident bacterial community are often ignored in animal behavior and behavioral ecology. Here, we aim to identify the nature of host–microbe interactions in a nonmodel organism, the African social spider Stegodyphus dumicola. We collected and identified bacteria from the cuticles of spiders in situ and then exposed spiders to bacterial monocultures cultures via topical application or injection. We also topically inoculated spiders with a concomitant “cocktail” of bacteria and measured the behavior of spiders daily for 24 days after inoculation. Lastly, we collected and identified bacteria from the cuticles of prey items in the capture webs of spiders, and then fed spiders domestic crickets which had been injected with these bacteria. We also injected 1 species of prey-borne bacteria into the hemolymph of spiders. Only Bacillus thuringiensis caused increased mortality when injected into the hemolymph of spiders, whereas no bacterial monocultures caused increased mortality when applied topically, relative to control solutions. However, a bacterial cocktail of cuticular bacteria caused weight loss and mortality when applied topically, yet did not detectibly alter spider behavior. Consuming prey injected with prey-borne bacteria was associated with an elongated lifespan in spiders. Thus, indirect evidence from multiple experiments suggests that the effects of these bacteria on spider survivorship appear contingent on their mode of colonization and whether they are applied in monoculture or within a mixed cocktail. We urge that follow-up studies should test these host–microbe interactions across different social contexts to determine the role that microbes play in colony performance. PMID:29491926

Symptoms and Causes of Peptic Ulcer Disease

MedlinePlus

... ulcer. How do H. pylori cause a peptic ulcer and peptic ulcer disease? H. pylori are spiral-shaped bacteria that ... peptic ulcer. How do tumors from ZES cause peptic ulcers? Zollinger-Ellison syndrome is a rare disorder that ...

Activities of different types of Thai honey on pathogenic bacteria causing skin diseases, tyrosinase enzyme and generating free radicals.

PubMed

Jantakee, Kanyaluck; Tragoolpua, Yingmanee

2015-01-16

Honey is a natural product obtained from the nectar that is collected from flowers by bees. It has several properties, including those of being food and supplementary diet, and it can be used in cosmetic products. Honey imparts pharmaceutical properties since it has antibacterial and antioxidant activities. The antibacterial and antioxidant activities of Thai honey were investigated in this study. The honey from longan flower (source No. 1) gave the highest activity on MRSA when compared to the other types of honey, with a minimum inhibitory concentration of 12.5% (v/v) and minimum bactericidal concentration of 25% (v/v). Moreover, it was found that MRSA isolate 49 and S. aureus were completely inhibited by the 50% (v/v) longan honey (source No. 1) at 8 and 20 hours of treatment, respectively. Furthermore, it was observed that the honey from coffee pollen (source No. 4) showed the highest phenolic and flavonoid compounds by 734.76 mg gallic/kg of honey and 178.31 mg quercetin/kg of honey, respectively. The antioxidant activity of the honey obtained from coffee pollen was also found to be the highest, when investigated using FRAP and DPPH assay, with 1781.77 mg FeSO4•7H2O/kg of honey and 86.20 mg gallic/kg of honey, respectively. Additionally, inhibition of tyrosinase enzyme was found that honey from coffee flower showed highest inhibition by 63.46%. Honey demonstrates tremendous potential as a useful source that provides anti-free radicals, anti-tyrosinase and anti-bacterial activity against pathogenic bacteria causing skin diseases.

Impalement of an unusual foreign body on the temporomandibular joint causing severe trismus.

PubMed

Ito, Ryohei; Kubota, Kosei; Furudate, Ken; Nakagawa, Hiroshi; Kon, Takao; Tamura, Yoshihiro; Kobayashi, Wataru

2016-12-01

A penetrating injury by a foreign body is comparatively common in the oral and maxillofacial region. On the other hand, injury to the temporomandibular joint (TMJ) by a foreign object is very rare. The TMJ is an anatomically narrow space surrounded by hard bony processes. An unusual case of trauma with severe trismus caused by a foreign body that impaled the TMJ is reported. A 55-year-old man presented with a 5 × 1-cm laceration to the right cheek caused by a flying object propelled during the use of a lawn mower. The edge of the foreign body had a metallic wire, which became imbedded in the wound. His jaw opening was severely limited. Computed tomography revealed that the foreign body was 3 mm in diameter and was impaled on the articular capsule. The object was successfully removed, and the wound and interior of the TMJ were irrigated. Rehabilitation of mouth opening was started on postoperative day 3. On day 9, mouth opening had improved to 35 mm, and he was discharged. After 1 year, mouth opening was 45 mm with no sign of any TMJ disorders. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Causes and anatomical site of blindness and severe visual loss in Isfahan, Islamic Republic of Iran.

PubMed

Dehghan, A; Kianersi, F; Moazam, E; Ghanbari, H

2010-02-01

This study in 2005 evaluated the causes and major anatomical site of blindness and severe visual loss at a school for blind children in Isfahan province, Islamic Republic of Iran. All 211 students were examined according to the modified WHO/PBL eye examination record: 70.4% were blind, 24.3% had severe visual loss and 5.3% were visually impaired. The major causes of abnormality were hereditary factors (42.7%), prenatal/neonatal (18.5%) and unknown etiology (35.5%). The main sites of abnormality were the retina (62.6%), whole globe (17.5%), lens (7.1%) and optic nerve (7.1%). A high proportion of parents were in a consanguineous marriage (49.2%). The pattern of blindness in Isfahan encompasses characteristics of both developed and developing countries.

Probiotic viability and storage stability of yogurts and fermented milks prepared with several mixtures of lactic acid bacteria.

PubMed

Mani-López, E; Palou, E; López-Malo, A

2014-05-01

Currently, the food industry wants to expand the range of probiotic yogurts but each probiotic bacteria offers different and specific health benefits. Little information exists on the influence of probiotic strains on physicochemical properties and sensory characteristics of yogurts and fermented milks. Six probiotic yogurts or fermented milks and 1 control yogurt were prepared, and we evaluated several physicochemical properties (pH, titratable acidity, texture, color, and syneresis), microbial viability of starter cultures (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) and probiotics (Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus reuteri) during fermentation and storage (35 d at 5°C), as well as sensory preference among them. Decreases in pH (0.17 to 0.50 units) and increases in titratable acidity (0.09 to 0.29%) were observed during storage. Only the yogurt with S. thermophilus, L. delbrueckii ssp. bulgaricus, and L. reuteri differed in firmness. No differences in adhesiveness were determined among the tested yogurts, fermented milks, and the control. Syneresis was in the range of 45 to 58%. No changes in color during storage were observed and no color differences were detected among the evaluated fermented milk products. Counts of S. thermophilus decreased from 1.8 to 3.5 log during storage. Counts of L. delbrueckii ssp. bulgaricus also decreased in probiotic yogurts and varied from 30 to 50% of initial population. Probiotic bacteria also lost viability throughout storage, although the 3 probiotic fermented milks maintained counts ≥ 10(7)cfu/mL for 3 wk. Probiotic bacteria had variable viability in yogurts, maintaining counts of L. acidophilus ≥ 10(7) cfu/mL for 35 d, of L. casei for 7d, and of L. reuteri for 14 d. We found no significant sensory preference among the 6 probiotic yogurts and fermented milks or the control. However, the yogurt and fermented milk made with L. casei were better accepted. This

Allergic sinusitis and severe asthma caused by occupational exposure to locust bean gum: Case report

PubMed Central

Hawley, Brie; Cummings, Kristin J.; Mohammed, Mohammed; Dimmock, Anne E.; Bascom, Rebecca

2017-01-01

We present a case that highlights the difficulties with diagnosis and the dangers of occupational allergic sinusitis and asthma left unrecognized. We describe the case history of a man who experienced work-related symptoms 1 year after beginning work as a cheesemaker at a creamery, and whose respiratory symptoms progressively worsened over 16 years before an occupational cause of his asthma was identified. His initial discrete episodes of sinusitis and acute bronchitis evolved into persistent asthma of increasing severity with exacerbations requiring repeated emergency room treatment. The case described in our report emphasizes the importance of clinician diagnosis of OA, and subsequent removal from exposure, such that asthma severity does not progress to near-fatal or fatal asthma in the sensitized worker. As demonstrated by this case report, identification of an occupational cause of asthma relies on a high degree of suspicion and excellent detective work by the clinician. PMID:28497854

Impact of succinate on growth of cultures of cecal bacteria from commercial broilers

USDA-ARS?s Scientific Manuscript database

Beneficial bacteria in probiotics produce and utilize several organic acids that may play a role in the ability of these bacteria to inhibit colonization of poultry by enteropathogens. Since cecal contents of adult poultry contain many of these beneficial bacteria, 3 experiments were conducted to ex...

Streptomyces lunalinharesii strain 235 shows the potential to inhibit bacteria involved in biocorrosion processes.

PubMed

Pacheco da Rosa, Juliana; Korenblum, Elisa; Franco-Cirigliano, Marcella Novaes; Abreu, Fernanda; Lins, Ulysses; Soares, Rosângela M A; Macrae, Andrew; Seldin, Lucy; Coelho, Rosalie R R

2013-01-01

Four actinomycete strains previously isolated from Brazilian soils were tested for their antimicrobial activity against Bacillus pumilus LF-4 and Desulfovibrio alaskensis NCIMB 13491, bacteria that are well known to be involved in biofilm formation and biocorrosion. Strain 235, belonging to the species Streptomyces lunalinharesii, inhibited the growth of both bacteria. The antimicrobial activity was seen over a wide range of pH, and after treatment with several chemicals and heat but not with proteinase K and trypsin. The antimicrobial substances present in the concentrated supernatant from growth media were partially characterized by SDS-PAGE and extracellular polypeptides were seen. Bands in the size range of 12 to 14.4 kDa caused antimicrobial activity. Transmission electron microscopy of D. alaskensis cells treated with the concentrated supernatant containing the antimicrobial substances revealed the formation of prominent bubbles, the spherical double-layered structures on the cell membrane, and the periplasmic space completely filled with electron-dense material. This is the first report on the production of antimicrobial substances by actinomycetes against bacteria involved in biocorrosion processes, and these findings may be of great relevance as an alternative source of biocides to those currently employed in the petroleum industry.

Homozygous SLC2A9 Mutations Cause Severe Renal Hypouricemia

PubMed Central

Gray, Nicola K.; Campbell, Susan; Shu, Xinhua; Sawyer, Lindsay; Richardson, William; Rechavi, Gideon; Amariglio, Ninette; Ganon, Liat; Sela, Ben-Ami; Bahat, Hilla; Goldman, Michael; Weissgarten, Joshua; Millar, Michael R.; Wright, Alan F.; Holtzman, Eliezer J.

2010-01-01

Hereditary hypouricemia may result from mutations in the renal tubular uric acid transporter URAT1. Whether mutation of other uric acid transporters produces a similar phenotype is unknown. We studied two families who had severe hereditary hypouricemia and did not have a URAT1 defect. We performed a genome-wide homozygosity screen and linkage analysis and identified the candidate gene SLC2A9, which encodes the glucose transporter 9 (GLUT9). Both families had homozygous SLC2A9 mutations: A missense mutation (L75R) in six affected members of one family and a 36-kb deletion, resulting in a truncated protein, in the other. In vitro, the L75R mutation dramatically impaired transport of uric acid. The mean concentration of serum uric acid of seven homozygous individuals was 0.17 ± 0.2 mg/dl, and all had a fractional excretion of uric acid >150%. Three individuals had nephrolithiasis, and three had a history of exercise-induced acute renal failure. In conclusion, homozygous loss-of-function mutations of GLUT9 cause a total defect of uric acid absorption, leading to severe renal hypouricemia complicated by nephrolithiasis and exercise-induced acute renal failure. In addition to clarifying renal handling of uric acid, our findings may provide a better understanding of the pathophysiology of acute renal failure, nephrolithiasis, hyperuricemia, and gout. PMID:19926891

Diagnosing the Causes and Severity of One-sided Message Contention

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

Tallent, Nathan R.; Vishnu, Abhinav; van Dam, Hubertus

Two trends suggest network contention for one-sided messages is poised to become a performance problem that concerns application developers: an increased interest in one-sided programming models and a rising ratio of hardware threads to network injection bandwidth. Unfortunately, it is difficult to reason about network contention and one-sided messages because one-sided tasks can either decrease or increase contention. We present effective and portable techniques for diagnosing the causes and severity of one-sided message contention. To detect that a message is affected by contention, we maintain statistics representing instantaneous (non-local) network resource demand. Using lightweight measurement and modeling, we identify themore » portion of a message's latency that is due to contention and whether contention occurs at the initiator or target. We attribute these metrics to program statements in their full static and dynamic context. We characterize contention for an important computational chemistry benchmark on InfiniBand, Cray Aries, and IBM Blue Gene/Q interconnects. We pinpoint the sources of contention, estimate their severity, and show that when message delivery time deviates from an ideal model, there are other messages contending for the same network links. With a small change to the benchmark, we reduce contention up to 50% and improve total runtime as much as 20%.« less

Bacteria-based concrete: from concept to market

NASA Astrophysics Data System (ADS)

Wiktor, V.; Jonkers, H. M.

2016-08-01

The concept of self-healing concrete—a concrete which can autonomously repair itself after crack formation, with no or limited human intervention—has received a lot of attention over the past 10 years as it could help structures to last longer and at a lower maintenance cost. This paper gives an overview on the key aspects and recent advances in the development of the bacteria-based self-healing concrete developed at the University of Technology of Delft (The Netherlands). Research started with the screening and selection of concrete compatible bacteria and nutrients. Several types of encapsulated bacteria and nutrients have been developed and tested. The functionality of these healing agents was demonstrated by showing metabolic activity of activated bacterial spores by oxygen consumption measurements and by regain of material functionality in form of regain of water tightness. Besides development of bacteria-based self-healing concrete, a bacteria-based repair mortar and liquid system were developed for the treatment of aged concrete structures. Field trials have been carried out with either type of bacteria-based systems and the promising results have led to a spinoff company Basilisk Self-Healing Concrete with the aim to further develop these systems and bring them to the market.

Characterisation of the Cullin-3 mutation that causes a severe form of familial hypertension and hyperkalaemia

PubMed Central

Schumacher, Frances-Rose; Siew, Keith; Zhang, Jinwei; Johnson, Clare; Wood, Nicola; Cleary, Sarah E; Al Maskari, Raya S; Ferryman, James T; Hardege, Iris; Figg, Nichola L; Enchev, Radoslav; Knebel, Axel; O’Shaughnessy, Kevin M; Kurz, Thimo

2015-01-01

Deletion of exon 9 from Cullin-3 (CUL3, residues 403–459: CUL3Δ403–459) causes pseudohypoaldosteronism type IIE (PHA2E), a severe form of familial hyperkalaemia and hypertension (FHHt). CUL3 binds the RING protein RBX1 and various substrate adaptors to form Cullin-RING-ubiquitin-ligase complexes. Bound to KLHL3, CUL3-RBX1 ubiquitylates WNK kinases, promoting their ubiquitin-mediated proteasomal degradation. Since WNK kinases activate Na/Cl co-transporters to promote salt retention, CUL3 regulates blood pressure. Mutations in both KLHL3 and WNK kinases cause PHA2 by disrupting Cullin-RING-ligase formation. We report here that the PHA2E mutant, CUL3Δ403–459, is severely compromised in its ability to ubiquitylate WNKs, possibly due to altered structural flexibility. Instead, CUL3Δ403–459 auto-ubiquitylates and loses interaction with two important Cullin regulators: the COP9-signalosome and CAND1. A novel knock-in mouse model of CUL3WT/Δ403–459 closely recapitulates the human PHA2E phenotype. These mice also show changes in the arterial pulse waveform, suggesting a vascular contribution to their hypertension not reported in previous FHHt models. These findings may explain the severity of the FHHt phenotype caused by CUL3 mutations compared to those reported in KLHL3 or WNK kinases. PMID:26286618

Clinical characteristics and outcomes of prosthetic joint infection caused by small colony variant staphylococci.

PubMed

Tande, Aaron J; Osmon, Douglas R; Greenwood-Quaintance, Kerryl E; Mabry, Tad M; Hanssen, Arlen D; Patel, Robin

2014-09-30

Small colony variants (SCVs) are naturally occurring subpopulations of bacteria. The clinical characteristics and treatment outcomes of patients with prosthetic joint infection (PJI) caused by staphylococcal SCVs are unknown. This study was a retrospective series of 113 patients with staphylococcal PJI, with prospective testing of archived sonicate fluid samples. SCVs were defined using two-investigator review. Treatment failure was defined as (i) subsequent revision surgery for any reason, (ii) PJI after the index surgery, (iii) prosthesis nonreimplantation due to ongoing infection, or (iv) amputation of the affected limb. There were 38 subjects (34%) with SCVs and 75 (66%) with only normal-phenotype (NP) bacteria. Subjects with SCVs were more likely to have been on chronic antimicrobials prior to surgery (P = 0.048), have had prior surgery for PJI (P = 0.03), have had a longer duration of symptoms (P = 0.0003), and have had a longer time since joint implantation (P = 0.007), compared to those with only NP bacteria. Over a median follow-up of 30.6 months, 9 subjects (24%) with SCVs and 23 (32%) with only NP bacteria experienced treatment failure (P = 0.51). Subjects infected with Staphylococcus aureus were more likely to fail than were those infected with Staphylococcus epidermidis (hazard ratio [HR], 4.03; 95% confidence interval [CI], 1.80 to 9.04). While frequently identified in subjects with PJI and associated with several potential predisposing factors, SCVs were not associated with excess treatment failure compared to NP infections in this study, where they were primarily managed with two-stage arthroplasty exchange. Bacteria with the small colony variant (SCV) phenotype are described in small case series as causing persistent or relapsing infection, but there are insufficient data to suggest that they should be managed differently than infection with normal-phenotype bacteria. In an effort to investigate the clinical importance of this phenotype, we

Periodontal disease bacteria specific to tonsil in IgA nephropathy patients predicts the remission by the treatment.

PubMed

Nagasawa, Yasuyuki; Iio, Kenichiro; Fukuda, Shinji; Date, Yasuhiro; Iwatani, Hirotsugu; Yamamoto, Ryohei; Horii, Arata; Inohara, Hidenori; Imai, Enyu; Nakanishi, Takeshi; Ohno, Hiroshi; Rakugi, Hiromi; Isaka, Yoshitaka

2014-01-01

Immunoglobulin (Ig)A nephropathy (IgAN) is the most common form of primary glomerulonephritis in the world. Some bacteria were reported to be the candidate of the antigen or the pathogenesis of IgAN, but systematic analysis of bacterial flora in tonsil with IgAN has not been reported. Moreover, these bacteria specific to IgAN might be candidate for the indicator which can predict the remission of IgAN treated by the combination of tonsillectomy and steroid pulse. We made a comprehensive analysis of tonsil flora in 68 IgAN patients and 28 control patients using Denaturing gradient gel electrophoresis methods. We also analyzed the relationship between several bacteria specific to the IgAN and the prognosis of the IgAN. Treponema sp. were identified in 24% IgAN patients, while in 7% control patients (P = 0.062). Haemophilus segnis were detected in 53% IgAN patients, while in 25% control patients (P = 0.012). Campylobacter rectus were identified in 49% IgAN patients, while in 14% control patients (P = 0.002). Multiple Cox proportional-hazards model revealed that Treponema sp. or Campylobactor rectus are significant for the remission of proteinuria (Hazard ratio 2.35, p = 0.019). There was significant difference in remission rates between IgAN patients with Treponema sp. and those without the bacterium (p = 0.046), and in remission rates between IgAN patients with Campylobacter rectus and those without the bacterium (p = 0.037) by Kaplan-Meier analysis. Those bacteria are well known to be related with the periodontal disease. Periodontal bacteria has known to cause immune reaction and many diseases, and also might cause IgA nephropathy. This insight into IgAN might be useful for diagnosis of the IgAN patients and the decision of treatment of IgAN.

Severe pain as a possible cause of dropped head syndrome that was attenuated after amputation of an ischemic lower limb.

PubMed

Maki, Satoshi; Koda, Masao; Furuya, Takeo; Takahashi, Kazuhisa; Yamazaki, Masashi

2016-03-02

Dropped head syndrome (DHS) is defined as weakness of the neck extensor muscles causing a correctable chin-on-the-chest deformity. Here we report the case of a patient with severe pain from lower leg ischemia showing DHS whose symptoms were attenuated by pain relief after amputation of the severely ischemic lower leg. To our knowledge this is the first report indicating that severe pain can cause DHS. A 64-year-old Asian woman was referred to our department with a 1-month history of DHS. She also suffered from severe right foot pain because of limb ischemia. She began to complain of DHS as her gangrenous foot pain worsened. She had neck pain and difficulty with forward gaze. We found no clinical or laboratory findings of neuromuscular disorder or isolated neck extensor myopathy. We amputated her leg below the knee because of progressive foot gangrene. Her severe foot pain resolved after the surgery and her DHS was attenuated. Severe pain can cause DHS. If a patient with DHS has severe pain in another part of the body, we recommend considering aggressive pain relief as a treatment option.

Expulsion of swimming bacteria by a circular flow

NASA Astrophysics Data System (ADS)

Sokolov, Andrey; Aronson, Igor

Macroscopic shear flow alters swimming trajectories in a highly nontrivial way and results in dramatic reduction of viscosity and heterogeneous bacterial distributions. We report on experimental and theoretical studies of rapid expulsion of microswimmers, such as motile bacteria, by a circular flow created by a rotating microparticle. We observed a formation of a macroscopic depletion area in a high-shear region, in the vicinity of a microparticle. The rapid migration of bacteria from the shear-rich area is caused by a circular structure of the flow rather than intrinsic random fluctuations of bacteria orientations, in stark contrast to planar shear flow. Our mathematical model revealed that expulsion is a combined effect of motility and alignment by a vortical flow. Our findings offer a novel approach for manipulation of motile microorganisms and shed new light on bacteria-flow interactions. Was supported by the US DOE, Office of Basic Energy Sciences, Division of Materials Science And Engineering, under Contract No. DE AC02-06CH11357.

Appropriateness of antibiotic prescription for targeted therapy of infections caused by multidrug-resistant bacteria: assessment of the most common improper uses in a tertiary hospital in southern Italy.

PubMed

Viceconte, Giulio; Maraolo, Alberto Enrico; Iula, Vita Dora; Catania, Maria Rosaria; Tosone, Grazia; Orlando, Raffaele

2017-09-01

A huge proportion of antibiotic therapies for infections caused by multidrug-resistant bacteria (MDR) are inappropriate. In this study, we described the most common causes of inappropriateness of definitive antibiotic regimes in a large university hospital in southern Italy and we evaluated the impact on microbial eradication, length of stay, 30-day readmission and mortality. We retrospectively assessed 45 patients who received a definitive antibiotic therapy after isolation of multidrug-resistant Staphylococcus aureus, Enterococcus spp., Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter spp. strains between 2014 and 2015. From the literature, we set a series of criteria to retrospectively determine the appropriateness of the therapy. In all, 61% of the prescribed antibiotic regimes were found to be inappropriate, especially due to incorrect drug dosage. It emerged that meropenem was the antibiotic most frequently inappropriately used. In 46% of infections caused by MDR but not extended-spectrum β-lactamase-producing Enterobacteriaceae, carbapenems were inappropriately administered. Microbial eradication was achieved in 87% of the appropriate therapy group compared to 31% of the inappropriate therapy group (chi-square=6.750, p<0.027). No statistically significant association was found between inappropriate therapy and the length of stay (chi-square=3.084, p=0.101) and 30-day readmission (p=0.103). Definitive antibiotic therapy in infections caused by multidrug-resistant bacteria in a large university hospital is often inappropriate, especially due to the drug dosing regimen, particularly in the case of meropenem and colistin. This inappropriateness has a significant impact on post-treatment microbial eradication in specimens collected after antibiotic therapy.

Antibacterial activity of plant extracts on foodborne bacterial pathogens and food spoilage bacteria

USDA-ARS?s Scientific Manuscript database

Bacterial foodborne diseases are caused by consumption of foods contaminated with bacteria and/or their toxins. In this study, we evaluated antibacterial properties of twelve different extracts including turmeric, lemon and different kinds of teas against four major pathogenic foodborne bacteria inc...

Quantification and Qualification of Bacteria Trapped in Chewed Gum

PubMed Central

Wessel, Stefan W.; van der Mei, Henny C.; Morando, David; Slomp, Anje M.; van de Belt-Gritter, Betsy; Maitra, Amarnath; Busscher, Henk J.

2015-01-01

Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and remove them from the oral cavity. To test this hypothesis, we developed two methods to quantify numbers of bacteria trapped in chewed gum. In the first method, known numbers of bacteria were finger-chewed into gum and chewed gums were molded to standard dimensions, sonicated and plated to determine numbers of colony-forming-units incorporated, yielding calibration curves of colony-forming-units retrieved versus finger-chewed in. In a second method, calibration curves were created by finger-chewing known numbers of bacteria into gum and subsequently dissolving the gum in a mixture of chloroform and tris-ethylenediaminetetraacetic-acid (TE)-buffer. The TE-buffer was analyzed using quantitative Polymerase-Chain-Reaction (qPCR), yielding calibration curves of total numbers of bacteria versus finger-chewed in. Next, five volunteers were requested to chew gum up to 10 min after which numbers of colony-forming-units and total numbers of bacteria trapped in chewed gum were determined using the above methods. The qPCR method, involving both dead and live bacteria yielded higher numbers of retrieved bacteria than plating, involving only viable bacteria. Numbers of trapped bacteria were maximal during initial chewing after which a slow decrease over time up to 10 min was observed. Around 108 bacteria were detected per gum piece depending on the method and gum considered. The number of species trapped in chewed gum increased with chewing time. Trapped bacteria were clearly visualized in chewed gum using scanning-electron-microscopy. Summarizing, using novel methods to quantify and qualify oral bacteria trapped in chewed gum, the hypothesis is confirmed that chewing of gum can trap

Rapid separation of bacteria from blood — Chemical aspects

PubMed Central

Alizadeh, Mahsa; Wood, Ryan L.; Buchanan, Clara M.; Bledsoe, Colin G.; Wood, Madison E.; McClellan, Daniel S.; Blanco, Rae; Ravsten, Tanner V.; Husseini, Ghaleb A.; Hickey, Caroline L.; Robison, Richard A.; Pitt, William G.

2017-01-01

To rapidly diagnose infectious organisms causing blood sepsis, bacteria must be rapidly separated from blood, a very difficult process considering that concentrations of bacteria are many orders of magnitude lower than concentrations of blood cells. We have successfully separated bacteria from red and white blood cells using a sedimentation process in which the separation is driven by differences in density and size. Seven mL of whole human blood spiked with bacteria is placed in a 12-cm hollow disk and spun at 3000 rpm for 1 min. The red and white cells sediment more than 30-fold faster than bacteria, leaving much of the bacteria in the plasma. When the disk is slowly decelerated, the plasma flows to a collection site and the red and white cells are trapped in the disk. Analysis of the recovered plasma shows that about 36% of the bacteria is recovered in the plasma. The plasma is not perfectly clear of red blood cells, but about 94% have been removed. This paper describes the effects of various chemical aspects of this process, including the influence of anticoagulant chemistry on the separation efficiency and the use of wetting agents and platelet aggregators that may influence the bacterial recovery. In a clinical scenario, the recovered bacteria can be subsequently analyzed to determine their species and resistance to various antibiotics. PMID:28365426

In Silico Evidence for the Horizontal Transfer of gsiB, a σΒ-Regulated Gene in Gram-Positive Bacteria, to Lactic Acid Bacteria ▿

PubMed Central

Asteri, Ioanna-Areti; Boutou, Effrossyni; Anastasiou, Rania; Pot, Bruno; Vorgias, Constantinos E.; Tsakalidou, Effie; Papadimitriou, Konstantinos

2011-01-01

gsiB, coding for glucose starvation-inducible protein B, is a characteristic member of the σΒ stress regulon of Bacillus subtilis and several other Gram-positive bacteria. Here we provide in silico evidence for the horizontal transfer of gsiB in lactic acid bacteria that are devoid of the σΒ factor. PMID:21421783

Thermal control of virulence factors in bacteria: A hot topic

PubMed Central

Lam, Oliver; Wheeler, Jun; Tang, Christoph M

2014-01-01

Pathogenic bacteria sense environmental cues, including the local temperature, to control the production of key virulence factors. Thermal regulation can be achieved at the level of DNA, RNA or protein and although many virulence factors are subject to thermal regulation, the exact mechanisms of control are yet to be elucidated in many instances. Understanding how virulence factors are regulated by temperature presents a significant challenge, as gene expression and protein production are often influenced by complex regulatory networks involving multiple transcription factors in bacteria. Here we highlight some recent insights into thermal regulation of virulence in pathogenic bacteria. We focus on bacteria which cause disease in mammalian hosts, which are at a significantly higher temperature than the outside environment. We outline the mechanisms of thermal regulation and how understanding this fundamental aspect of the biology of bacteria has implications for pathogenesis and human health. PMID:25494856

Distinct growth strategies of soil bacteria as revealed by large-scale colony tracking.

PubMed

Ernebjerg, Morten; Kishony, Roy

2012-03-01

Our understanding of microbial ecology has been significantly furthered in recent years by advances in sequencing techniques, but comprehensive surveys of the phenotypic characteristics of environmental bacteria remain rare. Such phenotypic data are crucial for understanding the microbial strategies for growth and the diversity of microbial ecosystems. Here, we describe a high-throughput measurement of the growth of thousands of bacterial colonies using an array of flat-bed scanners coupled with automated image analysis. We used this system to investigate the growth properties of members of a microbial community from untreated soil. The system provides high-quality measurements of the number of CFU, colony growth rates, and appearance times, allowing us to directly study the distribution of these properties in mixed environmental samples. We find that soil bacteria display a wide range of growth strategies which can be grouped into several clusters that cannot be reduced to any of the classical dichotomous divisions of soil bacteria, e.g., into copiotophs and oligotrophs. We also find that, at early times, cells are most likely to form colonies when other, nearby colonies are present but not too dense. This maximization of culturability at intermediate plating densities suggests that the previously observed tendency for high density to lead to fewer colonies is partly offset by the induction of colony formation caused by interactions between microbes. These results suggest new types of growth classification of soil bacteria and potential effects of species interactions on colony growth.

A combined deficiency of vitamins E and C causes severe central nervous system damage in guinea pigs.

PubMed

Burk, Raymond F; Christensen, Joani M; Maguire, Mark J; Austin, Lori M; Whetsell, William O; May, James M; Hill, Kristina E; Ebner, Ford F

2006-06-01

A short period of combined deficiency of vitamins E and C causes profound central nervous system (CNS) dysfunction in guinea pigs. For this report, CNS histopathology was studied to define the nature and extent of injury caused by this double deficiency. Weanling guinea pigs were fed a vitamin E-deficient or -replete diet for 14 d. Then vitamin C was withdrawn from the diet of some guinea pigs. Four diet groups were thus formed: replete, vitamin E deficient, vitamin C deficient, and both vitamin E and C deficient. From 5 to 11 d after institution of the doubly deficient diet, 9 of 12 guinea pigs developed paralysis, and 2 more were found dead. The remaining guinea pig in the doubly deficient group and all animals in the other 3 groups survived without clinical impairment until the experiment was terminated at 13-15 d. Brains and spinal cords were serially sectioned and stained for examination. Only the combined deficiency produced damage in the CNS. The damage consisted mainly of nerve cell death, axonal degeneration, vascular injury, and associated glial cell responses. The spinal cord and the ventral pons in the brainstem were most severely affected, often exhibiting asymmetric cystic lesions. Several features of the lesions suggest that the primary damage was to blood vessels. These results indicate that the paralysis and death caused by combined deficiency of vitamins E and C in guinea pigs is caused by severe damage in the brainstem and spinal cord.

Colonisation of antibiotic resistant bacteria in a cohort of HIV infected children in Ghana.

PubMed

Sampane-Donkor, Eric; Badoe, Ebenezer Vincent; Annan, Jennifer Adoley; Nii-Trebi, Nicholas

2017-01-01

Antibiotic use not only selects for resistance in pathogenic bacteria, but also in commensal flora of exposed individuals. Little is known epidemiologically about antibiotic resistance in relation to people with HIV infection in sub-Saharan Africa. This study investigated the carriage of antibiotic resistant bacteria among HIV infected children at a tertiary hospital in Ghana. One hundred and eighteen HIV positive children were recruited at the Korle-Bu Teaching Hospital in Ghana and nasopharyngeal specimens were collected from them. The specimens were cultured for bacteria, and the isolates were identified by standard microbiological methods. Antibiotic susceptibility tests were carried out on selected bacterial organisms by the Kirby Bauer method. Bacteria isolated from the study subjects included Moraxella catarrhalis (39.8%), coagulase negative staphylococci (33.1%), Streptococcus pneumoniae (30.5%), diptheroids (29.7%), viridian streptococci (27.1%), Staphylococcus aureus (22.0%), Citrobacter spp. (4.2%) and Neisseria meningitidis (0.9%). Prevalence of antibiotic resistance of S. pneumoniae ranged from 5.6% (ceftriaxone) to 58.3% (cotrimoxazole), M. catarrhalis ranged from 2.1% (gentamicin) to 80.6% (ampicillin), and S. aureus ranged from 7.7% (cefoxitin) to 100% (penicillin). The prevalence of multiple drug resistance was 16.7% for S. pneumoniae, 57.4% for M. catarrhalis and 84.6% for S. aureus. HIV infected children in the study area commonly carry multi-drug resistant isolates of several pathogenic bacteria such as S. aureus and S. pneumoniae. Infections arising in these patients that are caused by S. aureus and S. pneumoniae could be treated with ceftriaxone and cefoxitin respectively.

Using wavelength-normalized optical spectroscopy to improve the accuracy of bacteria growth rate quantification

NASA Astrophysics Data System (ADS)

McBirney, Samantha E.; Trinh, Kristy; Wong-Beringer, Annie; Armani, Andrea M.

2017-02-01

One of the fundamental analytical measurements performed in microbiology is monitoring and characterizing cell concentration in culture media. Measurement error will give rise to reproducibility problems in a wide range of applications, from biomanufacturing to basic research. Therefore, it is critical that the generated results are consistent. Single wavelength optical density (OD) measurements have become the preferred approach. Here, we compare the conventional OD600 technique with a multi-wavelength normalized scattering optical spectroscopy method to measure the growth rates of Pseudomonas aeruginosa and Staphylococcus aureus, two of the leading nosocomial pathogens with proven abilities to develop resistance. The multi-wavelength normalization process minimizes the impact of bacteria byproducts and environmental noise on the signal, thereby accurately quantifying growth rates with high fidelity at low concentrations. In contrast, due to poor absorbance and scattering at 600 nm, the classic OD600 measurement method is able to detect bacteria but cannot quantify the growth rate reliably. Our wavelength-normalization protocol to detect bacteria growth rates can be readily and easily adopted by research labs, given that it only requires the use of a standard spectrophotometer and implementation of straightforward data analysis. Measuring and monitoring bacteria growth rates play a critical role in a wide range of settings, spanning from therapeutic design and development to diagnostics and disease prevention. Having a full understanding of the growth cycles of bacteria known to cause severe infections and diseases will lead to a better understanding of the pathogenesis of these illnesses, leading to better treatment and, ultimately, the development of a cure.

Colonisation of antibiotic resistant bacteria in a cohort of HIV infected children in Ghana

PubMed Central

Sampane-Donkor, Eric; Badoe, Ebenezer Vincent; Annan, Jennifer Adoley; Nii-Trebi, Nicholas

2017-01-01

Antibiotic use not only selects for resistance in pathogenic bacteria, but also in commensal flora of exposed individuals. Little is known epidemiologically about antibiotic resistance in relation to people with HIV infection in sub-Saharan Africa. This study investigated the carriage of antibiotic resistant bacteria among HIV infected children at a tertiary hospital in Ghana. One hundred and eighteen HIV positive children were recruited at the Korle-Bu Teaching Hospital in Ghana and nasopharyngeal specimens were collected from them. The specimens were cultured for bacteria, and the isolates were identified by standard microbiological methods. Antibiotic susceptibility tests were carried out on selected bacterial organisms by the Kirby Bauer method. Bacteria isolated from the study subjects included Moraxella catarrhalis (39.8%), coagulase negative staphylococci (33.1%), Streptococcus pneumoniae (30.5%), diptheroids (29.7%), viridian streptococci (27.1%), Staphylococcus aureus (22.0%), Citrobacter spp. (4.2%) and Neisseria meningitidis (0.9%). Prevalence of antibiotic resistance of S. pneumoniae ranged from 5.6% (ceftriaxone) to 58.3% (cotrimoxazole), M. catarrhalis ranged from 2.1% (gentamicin) to 80.6% (ampicillin), and S. aureus ranged from 7.7% (cefoxitin) to 100% (penicillin). The prevalence of multiple drug resistance was 16.7% for S. pneumoniae, 57.4% for M. catarrhalis and 84.6% for S. aureus. HIV infected children in the study area commonly carry multi-drug resistant isolates of several pathogenic bacteria such as S. aureus and S. pneumoniae. Infections arising in these patients that are caused by S. aureus and S. pneumoniae could be treated with ceftriaxone and cefoxitin respectively. PMID:28451037

Deletion of the hfsB gene increases ethanol production in Thermoanaerobacterium saccharolyticum and several other thermophilic anaerobic bacteria

DOE PAGES

Eminoglu, Aysenur; Murphy, Sean Jean-Loup; Maloney, Marybeth; ...

2017-11-30

With the discovery of interspecies hydrogen transfer in the late 1960s (Bryant et al. in Arch Microbiol 59:20–31, 1967), it was shown that reducing the partial pressure of hydrogen could cause mixed acid fermenting organisms to produce acetate at the expense of ethanol. Hydrogen and ethanol are both more reduced than glucose. Thus there is a tradeoff between production of these compounds imposed by electron balancing requirements; however, the mechanism is not fully known. Deletion of the hfsA or B subunits resulted in a roughly 1.8-fold increase in ethanol yield. The increase in ethanol production appears to be associated withmore » an increase in alcohol dehydrogenase activity, which appears to be due, at least in part, to increased expression of the adhE gene, and may suggest a regulatory linkage between hfsB and adhE. We studied this system most intensively in the organism Thermoanaerobacterium saccharolyticum; however, deletion of hfsB also increases ethanol production in other thermophilic bacteria suggesting that this could be used as a general technique for engineering thermophilic bacteria for improved ethanol production in organisms with hfs-type hydrogenases. Since its discovery by Shaw et al. (JAMA 191:6457–64, 2009), the hfs hydrogenase has been suspected to act as a regulator due to the presence of a PAS domain. We provide additional support for the presence of a regulatory phenomenon. In addition, we find a practical application for this scientific insight, namely increasing ethanol yield in strains that are of interest for ethanol production from cellulose or hemicellulose. In two of these organisms (T. xylanolyticum and T. thermosaccharolyticum), the ethanol yields are the highest reported to date.« less

Deletion of the hfsB gene increases ethanol production in Thermoanaerobacterium saccharolyticum and several other thermophilic anaerobic bacteria

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

Eminoglu, Aysenur; Murphy, Sean Jean-Loup; Maloney, Marybeth

With the discovery of interspecies hydrogen transfer in the late 1960s (Bryant et al. in Arch Microbiol 59:20–31, 1967), it was shown that reducing the partial pressure of hydrogen could cause mixed acid fermenting organisms to produce acetate at the expense of ethanol. Hydrogen and ethanol are both more reduced than glucose. Thus there is a tradeoff between production of these compounds imposed by electron balancing requirements; however, the mechanism is not fully known. Deletion of the hfsA or B subunits resulted in a roughly 1.8-fold increase in ethanol yield. The increase in ethanol production appears to be associated withmore » an increase in alcohol dehydrogenase activity, which appears to be due, at least in part, to increased expression of the adhE gene, and may suggest a regulatory linkage between hfsB and adhE. We studied this system most intensively in the organism Thermoanaerobacterium saccharolyticum; however, deletion of hfsB also increases ethanol production in other thermophilic bacteria suggesting that this could be used as a general technique for engineering thermophilic bacteria for improved ethanol production in organisms with hfs-type hydrogenases. Since its discovery by Shaw et al. (JAMA 191:6457–64, 2009), the hfs hydrogenase has been suspected to act as a regulator due to the presence of a PAS domain. We provide additional support for the presence of a regulatory phenomenon. In addition, we find a practical application for this scientific insight, namely increasing ethanol yield in strains that are of interest for ethanol production from cellulose or hemicellulose. In two of these organisms (T. xylanolyticum and T. thermosaccharolyticum), the ethanol yields are the highest reported to date.« less

Endodontic pathogens causing deep neck space infections: clinical impact of different sampling techniques and antibiotic susceptibility.

PubMed

Poeschl, Paul W; Crepaz, Valentina; Russmueller, Guenter; Seemann, Rudolf; Hirschl, Alexander M; Ewers, Rolf

2011-09-01

The aims of the present study were to compare microbial populations in patients suffering from deep neck space abscesses caused by primary endodontic infections by sampling the infections with aspiration or swabbing techniques and to determine the susceptibility rates of the isolated bacteria to commonly used antibiotics. A total of 89 patients with deep neck space abscesses caused by primary endodontic infections requiring extraoral incision and drainage under general anesthesia were included. Either aspiration or swabbing was used to sample microbial pus specimens. The culture of the microbial specimens and susceptibility testing were performed following standard procedures. A total of 142 strains were recovered from 76 patients. In 13 patients, no bacteria were found. The predominant bacteria observed were streptococci (36%), staphylococci (13%), Prevotella (8%), and Peptostreptococcus (6%). A statistically significant greater number of obligate anaerobes were found in the aspiration group. The majority of patients presented a mixed aerobic-anaerobic population of bacterial flora (62%). The antibiotic resistance rates for the predominant bacteria were 10% for penicillin G, 9% for amoxicillin, 0% for amoxicillin clavulanate, 24% for clindamycin, and 24% for erythromycin. The results of our study indicated that a greater number of anaerobes were found when sampling using the aspiration technique. Penicillin G and aminopenicillins alone are not always sufficient for the treatment of severe deep neck space abscesses; beta-lactamase inhibitor combinations are more effective. Bacteria showed significant resistant rates to clindamycin. Thus, its single use in penicillin-allergic patients has to be carefully considered. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

How to isolate, identify and determine antimicrobial susceptibility of anaerobic bacteria in routine laboratories?

PubMed

Nagy, E; Boyanova, L; Justesen, U S

2018-02-17

There has been increased interest in the study of anaerobic bacteria that cause human infection during the past decade. Many new genera and species have been described using 16S rRNA gene sequencing of clinical isolates obtained from different infection sites with commercially available special culture media to support the growth of anaerobes. Several systems, such as anaerobic pouches, boxes, jars and chambers provide suitable anaerobic culture conditions to isolate even strict anaerobic bacteria successfully from clinical specimens. Beside the classical, time-consuming identification methods and automated biochemical tests, the use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry has revolutionized identification of even unusual and slow-growing anaerobes directly from culture plates, providing the possibility of providing timely information about anaerobic infections. The aim of this review article is to present methods for routine laboratories, which carry out anaerobic diagnostics on different levels. Relevant data from the literature mostly published during the last 7 years are encompassed and discussed. The review involves topics on the anaerobes that are members of the commensal microbiota and their role causing infection, the key requirements for collection and transport of specimens, processing of specimens in the laboratory, incubation techniques, identification and antimicrobial susceptibility testing of anaerobic bacteria. Advantages, drawbacks and specific benefits of the methods are highlighted. The present review aims to update and improve anaerobic microbiology in laboratories with optimal conditions as well as encourage its routine implementation in laboratories with restricted resources. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

A severe red tide (Tampa Bay, 2005) causes an anomalous decrease in biological sound.

PubMed

Indeck, Katherine L; Simard, Peter; Gowans, Shannon; Lowerre-Barbieri, Susan; Mann, David A

2015-09-01

Although harmful algal blooms (HABs) are known to cause morbidity and mortality in marine organisms, their sublethal effects are poorly understood. The purpose of this study was to compare ambient noise levels during a severe HAB event in Tampa Bay, Florida, to those during non-HAB periods. Passive acoustic monitoring was conducted using bottom-mounted autonomous acoustic recorders during a severe HAB in summer 2005, and in summers 2006, 2011 and 2012 (non-severe HAB years). Ambient noise levels were significantly higher during the non-HAB years due to an abundance of snapping shrimp (Alpheidae) sounds and fish chorusing. The difference of sound intensity between the study years is most likely attributable to effects of the HAB on the abundance and/or behaviour of fish and snapping shrimp as a result of mortality and stress-induced behavioural modifications.

Celiac disease causing severe osteomalacia: an association still present in Morocco!

PubMed

Tahiri, Latifa; Azzouzi, Hamida; Squalli, Ghita; Abourazzak, Fatimazahra; Harzy, Taoufik

2014-01-01

Celiac disease (CD), a malabsorption syndrome caused by hypersensitivity to gliadin fraction of gluten. CD can manifest with classic symptoms; however, significant myopathy and multiple fractures are rarely the predominant presentation of untreated celiac disease. Osteomalacia complicating celiac disease had become more and more rare. We describe here a case of osteomalacia secondary to a longstanding untreated celiac disease. This patient complained about progressive bone and muscular pain, weakness, fractures and skeletal deformities. Radiological and laboratory findings were all in favor of severe osteomalacia. Improvement of patient's weakness and laboratory abnormalities was obvious after treatment with gluten free diet, vitamin D, calcium and iron. This case affirms that chronic untreated celiac disease, can lead to an important bone loss and irreversible complications like skeletal deformities.

Celiac disease causing severe osteomalacia: an association still present in Morocco!

PubMed Central

Tahiri, Latifa; Azzouzi, Hamida; Squalli, Ghita; Abourazzak, Fatimazahra; Harzy, Taoufik

2014-01-01

Celiac disease (CD), a malabsorption syndrome caused by hypersensitivity to gliadin fraction of gluten. CD can manifest with classic symptoms; however, significant myopathy and multiple fractures are rarely the predominant presentation of untreated celiac disease. Osteomalacia complicating celiac disease had become more and more rare. We describe here a case of osteomalacia secondary to a longstanding untreated celiac disease. This patient complained about progressive bone and muscular pain, weakness, fractures and skeletal deformities. Radiological and laboratory findings were all in favor of severe osteomalacia. Improvement of patient's weakness and laboratory abnormalities was obvious after treatment with gluten free diet, vitamin D, calcium and iron. This case affirms that chronic untreated celiac disease, can lead to an important bone loss and irreversible complications like skeletal deformities. PMID:25667705

Inactivation mechanisms of pathogenic bacteria in several matrixes during the composting process in a composting toilet.

PubMed

Sossou, S K; Hijikata, N; Sou, M; Tezuka, R; Maiga, A H; Funamizu, N

2014-01-01

This study aimed to compare the inactivation rate and the mechanisms of pathogenic bacteria in three matrixes (sawdust, rice husk and charcoal) during the composting process. The inactivation rate was evaluated with Escherichia coli strain and the damaged parts and/or functions were evaluated with three different media. Normalized inactivation rate constant in three media and from three matrixes had no significant difference in each process (pure, 1 month and 2 months). The value in rice husk was relatively increased during 2 months but there was no significant difference. The inactivation rate constants of Tryptic Soy Agar (TSA) and Compact Dry E. coli/Coliform in pure sawdust and rice husk were relatively lower than that of Desoxycholate Agar, but increased in 2 months. This indicated that damaging part was changed from outer membrane to enzymes and metabolisms during the 2-month composting process. In the case of charcoal, only the TSA value in apure matrix was relatively lower than that of others, but it increased in 2 months. This indicated that damaging part was changed from outer membrane and enzyme to metabolisms during the composting process. Composting matrix and composting process did not significantly affect inactivation rate of pathogenic bacteria during the process but affected the damaging part of the bacteria.

Plant-bacteria partnerships for the remediation of persistent organic pollutants.

PubMed

Arslan, Muhammad; Imran, Asma; Khan, Qaiser Mahmood; Afzal, Muhammad

2017-02-01

High toxicity, bioaccumulation factor and widespread dispersal of persistent organic pollutants (POPs) cause environmental and human health hazards. The combined use of plants and bacteria is a promising approach for the remediation of soil and water contaminated with POPs. Plants provide residency and nutrients to their associated rhizosphere and endophytic bacteria. In return, the bacteria support plant growth by the degradation and detoxification of POPs. Moreover, they improve plant growth and health due to their innate plant growth-promoting mechanisms. This review provides a critical view of factors that affect absorption and translocation of POPs in plants and the limitations that plant have to deal with during the remediation of POPs. Moreover, the synergistic effects of plant-bacteria interactions in the phytoremediation of organic pollutants with special reference to POPs are discussed.

Antimicrobial Photodynamic Therapy to Kill Gram-negative Bacteria

PubMed Central

Sperandio, Felipe F; Huang, Ying-Ying; Hamblin, Michael R

2013-01-01

Antimicrobial photodynamic therapy (PDT) or photodynamic inactivation (PDI) is a new promising strategy to eradicate pathogenic microorganisms such as Gram-positive and Gram-negative bacteria, yeasts and fungi. The search for new approaches that can kill bacteria but do not induce the appearance of undesired drug-resistant strains suggests that PDT may have advantages over traditional antibiotic therapy. PDT is a non-thermal photochemical reaction that involves the simultaneous presence of visible light, oxygen and a dye or photosensitizer (PS). Several PS have been studied for their ability to bind to bacteria and efficiently generate reactive oxygen species (ROS) upon photostimulation. ROS are formed through type I or II mechanisms and may inactivate several classes of microbial cells including Gram-negative bacteria such as Pseudomonas aeruginosa, which are typically characterized by an impermeable outer cell membrane that contains endotoxins and blocks antibiotics, dyes, and detergents, protecting the sensitive inner membrane and cell wall. This review covers significant peer-reviewed articles together with US and World patents that were filed within the past few years and that relate to the eradication of Gram-negative bacteria via PDI or PDT. It is organized mainly according to the nature of the PS involved and includes natural or synthetic food dyes; cationic dyes such as methylene blue and toluidine blue; tetrapyrrole derivatives such as phthalocyanines, chlorins, porphyrins, chlorophyll and bacteriochlorophyll derivatives; functionalized fullerenes; nanoparticles combined with different PS; other formulations designed to target PS to bacteria; photoactive materials and surfaces; conjugates between PS and polycationic polymers or antibodies; and permeabilizing agents such as EDTA, PMNP and CaCl2. The present review also covers the different laboratory animal models normally used to treat Gram-negative bacterial infections with antimicrobial PDT. PMID

Multidrug resistance in enteric and other gram-negative bacteria.

PubMed

George, A M

1996-05-15

In Gram-negative bacteria, multidrug resistance is a term that is used to describe mechanisms of resistance by chromosomal genes that are activated by induction or mutation caused by the stress of exposure to antibiotics in natural and clinical environments. Unlike plasmid-borne resistance genes, there is no alteration or degradation of drugs or need for genetic transfer. Exposure to a single drug leads to cross-resistance to many other structurally and functionally unrelated drugs. The only mechanism identified for multidrug resistance in bacteria is drug efflux by membrane transporters, even though many of these transporters remain to be identified. The enteric bacteria exhibit mostly complex multidrug resistance systems which are often regulated by operons or regulons. The purpose of this review is to survey molecular mechanisms of multidrug resistance in enteric and other Gram-negative bacteria, and to speculate on the origins and natural physiological functions of the genes involved.

Genetic basis and importance of metal resistant genes in bacteria for bioremediation of contaminated environments with toxic metal pollutants.

PubMed

Das, Surajit; Dash, Hirak R; Chakraborty, Jaya

2016-04-01

Metal pollution is one of the most persistent and complex environmental issues, causing threat to the ecosystem and human health. On exposure to several toxic metals such as arsenic, cadmium, chromium, copper, lead, and mercury, several bacteria has evolved with many metal-resistant genes as a means of their adaptation. These genes can be further exploited for bioremediation of the metal-contaminated environments. Many operon-clustered metal-resistant genes such as cadB, chrA, copAB, pbrA, merA, and NiCoT have been reported in bacterial systems for cadmium, chromium, copper, lead, mercury, and nickel resistance and detoxification, respectively. The field of environmental bioremediation has been ameliorated by exploiting diverse bacterial detoxification genes. Genetic engineering integrated with bioremediation assists in manipulation of bacterial genome which can enhance toxic metal detoxification that is not usually performed by normal bacteria. These techniques include genetic engineering with single genes or operons, pathway construction, and alternations of the sequences of existing genes. However, numerous facets of bacterial novel metal-resistant genes are yet to be explored for application in microbial bioremediation practices. This review describes the role of bacteria and their adaptive mechanisms for toxic metal detoxification and restoration of contaminated sites.

Selection and Transmission of Antibiotic-Resistant Bacteria.

PubMed

Andersson, Dan I; Hughes, Diarmaid

2017-07-01

Ever since antibiotics were introduced into human and veterinary medicine to treat and prevent bacterial infections there has been a steady selection and increase in the frequency of antibiotic resistant bacteria. To be able to reduce the rate of resistance evolution, we need to understand how various biotic and abiotic factors interact to drive the complex processes of resistance emergence and transmission. We describe several of the fundamental factors that underlay resistance evolution, including rates and niches of emergence and persistence of resistant bacteria, time- and space-gradients of various selective agents, and rates and routes of transmission of resistant bacteria between humans, animals and other environments. Furthermore, we discuss the options available to reduce the rate of resistance evolution and/ or transmission and their advantages and disadvantages.

Algicidal bacteria in the sea and their impact on algal blooms.

PubMed

Mayali, Xavier; Azam, Farooq

2004-01-01

Over the past two decades, many reports have revealed the existence of bacteria capable of killing phytoplankton. These algicidal bacteria sometimes increase in abundance concurrently with the decline of algal blooms, suggesting that they may affect algal bloom dynamics. Here, we synthesize the existing knowledge on algicidal bacteria interactions with marine eukaryotic microalgae. We discuss the effectiveness of the current methods to characterize the algicidal phenotype in an ecosystem context. We briefly consider the literature on the phylogenetic identification of algicidal bacteria, their interaction with their algal prey, the characterization of algicidal molecules, and the enumeration of algicidal bacteria during algal blooms. We conclude that, due to limitations of current methods, the evidence for algicidal bacteria causing algal bloom decline is circumstantial. New methods and an ecosystem approach are needed to test hypotheses on the impact of algicidal bacteria in algal bloom dynamics. This will require enlarging the scope of inquiry from its current focus on the potential utility of algicidal bacteria in the control of harmful algal blooms. We suggest conceptualizing bacterial algicidy within the general problem of bacterial regulation of algal community structure in the ocean.

Quantification of microbial risks to human health caused by waterborne viruses and bacteria in an urban slum.

PubMed

Katukiza, A Y; Ronteltap, M; van der Steen, P; Foppen, J W A; Lens, P N L

2014-02-01

To determine the magnitude of microbial risks from waterborne viruses and bacteria in Bwaise III in Kampala (Uganda), a typical slum in Sub-Saharan Africa. A quantitative microbial risk assessment (QMRA) was carried out to determine the magnitude of microbial risks from waterborne pathogens through various exposure pathways in Bwaise III in Kampala (Uganda). This was based on the concentration of Escherichia coli O157:H7, Salmonella spp., rotavirus (RV) and human adenoviruses F and G (HAdV) in spring water, tap water, surface water, grey water and contaminated soil samples. The total disease burden was 680 disability-adjusted life years (DALYs) per 1000 persons per year. The highest disease burden contribution was caused by exposure to surface water open drainage channels (39%) followed by exposure to grey water in tertiary drains (24%), storage containers (22%), unprotected springs (8%), contaminated soil (7%) and tap water (0.02%). The highest percentage of the mean estimated infections was caused by E. coli O157:H7 (41%) followed by HAdV (32%), RV (20%) and Salmonella spp. (7%). In addition, the highest infection risk was 1 caused by HAdV in surface water at the slum outlet, while the lowest infection risk was 2.71 × 10(-6) caused by E. coli O157:H7 in tap water. The results show that the slum environment is polluted, and the disease burden from each of the exposure routes in Bwaise III slum, with the exception of tap water, was much higher than the WHO reference level of tolerable risk of 1 × 10(-6) DALYs per person per year. The findings of this study provide guidance to governments, local authorities and nongovernment organizations in making decisions on measures to reduce infection risk and the disease burden by 10(2) to 10(5) depending on the source of exposure to achieve the desired health impacts. The infection risk may be reduced by sustainable management of human excreta and grey water, coupled with risk communication during hygiene awareness

Endophytic Bacteria Improve Plant Growth, Symbiotic Performance of Chickpea (Cicer arietinum L.) and Induce Suppression of Root Rot Caused by Fusarium solani under Salt Stress.

PubMed

Egamberdieva, Dilfuza; Wirth, Stephan J; Shurigin, Vyacheslav V; Hashem, Abeer; Abd Allah, Elsayed F

2017-01-01

Salinity causes disturbance in symbiotic performance of plants, and increases susceptibility of plants to soil-borne pathogens. Endophytic bacteria are an essential determinant of cross-tolerance to biotic and abiotic stresses in plants. The aim of this study was to isolate non-rhizobial endophytic bacteria from the root nodules of chickpea ( Cicer arietinum L.), and to assess their ability to improve plant growth and symbiotic performance, and to control root rot in chickpea under saline soil conditions. A total of 40 bacterial isolates from internal root tissues of chickpea grown in salinated soil were isolated. Four bacterial isolates, namely Bacillus cereus NUU1 , Achromobacter xylosoxidans NUU2, Bacillus thuringiensis NUU3, and Bacillus subtilis NUU4 colonizing root tissue demonstrated plant beneficial traits and/or antagonistic activity against F. solani and thus were characterized in more detail. The strain B. subtilis NUU4 proved significant plant growth promotion capabilities, improved symbiotic performance of host plant with rhizobia, and promoted yield under saline soil as compared to untreated control plants under field conditions. A combined inoculation of chickpea with M. ciceri IC53 and B. subtilis NUU4 decreased H 2 O 2 concentrations and increased proline contents compared to the un-inoculated plants indicating an alleviation of adverse effects of salt stress. Furthermore, the bacterial isolate was capable to reduce the infection rate of root rot in chickpea caused by F. solani . This is the first report of F. solani causing root rot of chickpea in a salinated soil of Uzbekistan. Our findings demonstrated that the endophytic B. subtilis strain NUU4 provides high potentials as a stimulator for plant growth and as biological control agent of chickpea root rot under saline soil conditions. These multiple relationships could provide promising practical approaches to increase the productivity of legumes under salt stress.

Endophytic Bacteria Improve Plant Growth, Symbiotic Performance of Chickpea (Cicer arietinum L.) and Induce Suppression of Root Rot Caused by Fusarium solani under Salt Stress

PubMed Central

Egamberdieva, Dilfuza; Wirth, Stephan J.; Shurigin, Vyacheslav V.; Hashem, Abeer; Abd_Allah, Elsayed F.

2017-01-01

Salinity causes disturbance in symbiotic performance of plants, and increases susceptibility of plants to soil-borne pathogens. Endophytic bacteria are an essential determinant of cross-tolerance to biotic and abiotic stresses in plants. The aim of this study was to isolate non–rhizobial endophytic bacteria from the root nodules of chickpea (Cicer arietinum L.), and to assess their ability to improve plant growth and symbiotic performance, and to control root rot in chickpea under saline soil conditions. A total of 40 bacterial isolates from internal root tissues of chickpea grown in salinated soil were isolated. Four bacterial isolates, namely Bacillus cereus NUU1, Achromobacter xylosoxidans NUU2, Bacillus thuringiensis NUU3, and Bacillus subtilis NUU4 colonizing root tissue demonstrated plant beneficial traits and/or antagonistic activity against F. solani and thus were characterized in more detail. The strain B. subtilis NUU4 proved significant plant growth promotion capabilities, improved symbiotic performance of host plant with rhizobia, and promoted yield under saline soil as compared to untreated control plants under field conditions. A combined inoculation of chickpea with M. ciceri IC53 and B. subtilis NUU4 decreased H2O2 concentrations and increased proline contents compared to the un-inoculated plants indicating an alleviation of adverse effects of salt stress. Furthermore, the bacterial isolate was capable to reduce the infection rate of root rot in chickpea caused by F. solani. This is the first report of F. solani causing root rot of chickpea in a salinated soil of Uzbekistan. Our findings demonstrated that the endophytic B. subtilis strain NUU4 provides high potentials as a stimulator for plant growth and as biological control agent of chickpea root rot under saline soil conditions. These multiple relationships could provide promising practical approaches to increase the productivity of legumes under salt stress. PMID:29033922

Effect of autochthonous bacteriocin-producing Lactococcus lactis on bacterial population dynamics and growth of halotolerant bacteria in Brazilian charqui.

PubMed

Biscola, Vanessa; Abriouel, Hikmate; Todorov, Svetoslav Dimitrov; Capuano, Verena Sant'Anna Cabral; Gálvez, Antonio; Franco, Bernadette Dora Gombossy de Melo

2014-12-01

Charqui is a fermented, salted and sun-dried meat product, widely consumed in Brazil and exported to several countries. Growth of microorganisms in this product is unlikely due to reduced Aw, but halophilic and halotolerant bacteria may grow and cause spoilage. Charqui is a good source of lactic acid bacteria able to produce antimicrobial bacteriocins. In this study, an autochthonous bacteriocinogenic strain (Lactococcus lactis subsp. lactis 69), isolated from charqui, was added to the meat used for charqui manufacture and evaluated for its capability to prevent the growth of spoilage bacteria during storage up to 45 days. The influence of L. lactis 69 on the bacterial diversity during the manufacturing of the product was also studied, using denaturing gradient gel electrophoresis (DGGE). L. lactis 69 did not affect the counts and diversity of lactic acid bacteria during manufacturing and storage, but influenced negatively the populations of halotolerant microorganisms, reducing the spoilage potential. The majority of tested virulence genes was absent, evidencing the safety and potential technological application of this strain as an additional hurdle to inhibit undesirable microbial growth in this and similar fermented meat products. Copyright © 2014 Elsevier Ltd. All rights reserved.

Bacteria isolated from amoebae/bacteria consortium

DOEpatents

Tyndall, R.L.

1995-05-30

New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

Bacteria isolated from amoebae/bacteria consortium

DOEpatents

Tyndall, Richard L.

1995-01-01

New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

Perceived causes of severe mental disturbance and preferred interventions by the Borana semi-nomadic population in southern Ethiopia: a qualitative study

PubMed Central

2012-01-01

Background Culture affects the way people conceptualize causes of severe mental disturbance which may lead to a variation in the preferred intervention methods. There is a seemingly dichotomous belief regarding what causes severe mental disturbance: people living in western countries tend to focus mainly on biological and psychosocial risk factors; whereas, in non-western countries the focus is mainly on supernatural and religious factors. These belief systems about causation potentially dictate the type of intervention preferred. Studying such belief systems in any society is expected to help in planning and implementation of appropriate mental health services. Methods A qualitative study was conducted among the Borana semi-nomadic population in southern Ethiopia to explore perceived causes of severe mental disturbance and preferred interventions. We selected, using purposive sampling, key informants from three villages and conducted a total of six focus group discussions: three for males and three for females. Results The views expressed regarding the causes of mental disturbance were heterogeneous encompassing supernatural causes such as possession by evil spirits, curse, bewitchment, ‘exposure to wind’ and subsequent attack by evil spirit in postnatal women and biopsychosocial causes such as infections (malaria), loss, ‘thinking too much’, and alcohol and khat abuse. The preferred interventions for severe mental disturbance included mainly indigenous approaches, such as consulting Borana wise men or indigenous healers, prayer, holy water treatment and seeking modern mental health care as a last resort. Conclusions These findings will be of value for health care planners who wish to expand modern mental health care to this population, indicating the need to increase awareness about the causes of severe mental disturbance and their interventions and collaborate with influential people and indigenous healers to increase acceptability of modern mental

Global Regulatory Mutations in csrA and rpoS Cause Severe Central Carbon Stress in Escherichia coli in the Presence of Acetate

PubMed Central

Wei, Bangdong; Shin, Sooan; LaPorte, David; Wolfe, Alan J.; Romeo, Tony

2000-01-01

The csrA gene encodes a small RNA-binding protein, which acts as a global regulator in Escherichia coli and other bacteria (T. Romeo, Mol. Microbiol. 29:1321–1330, 1998). Its key regulatory role in central carbon metabolism, both as an activator of glycolysis and as a potent repressor of glycogen biosynthesis and gluconeogenesis, prompted us to examine the involvement of csrA in acetate metabolism and the tricarboxylic acid (TCA) cycle. We found that growth of csrA rpoS mutant strains was very poor on acetate as a sole carbon source. Surprisingly, growth also was inhibited specifically by the addition of modest amounts of acetate to rich media (e.g., tryptone broth). Cultures grown in the presence of ≥25 mM acetate consisted substantially of glycogen biosynthesis (glg) mutants, which were no longer inhibited by acetate. Several classes of glg mutations were mapped to known and novel loci. Several hypotheses were examined to provide further insight into the effects of acetate on growth and metabolism in these strains. We determined that csrA positively regulates acs (acetyl-coenzyme A synthetase; Acs) expression and isocitrate lyase activity without affecting key TCA cycle enzymes or phosphotransacetylase. TCA cycle intermediates or pyruvate, but not glucose, galactose, or glycerol, restored growth and prevented the glg mutations in the presence of acetate. Furthermore, amino acid uptake was inhibited by acetate specifically in the csrA rpoS strain. We conclude that central carbon flux imbalance, inhibition of amino acid uptake, and a deficiency in acetate metabolism apparently are combined to cause metabolic stress by depleting the TCA cycle. PMID:10692369

Chronic plus binge ethanol exposure causes more severe pancreatic injury and inflammation

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

Ren, Zhenhua

Alcohol abuse increases the risk for pancreatitis. The pattern of alcohol drinking may impact its effect. We tested a hypothesis that chronic ethanol consumption in combination with binge exposure imposes more severe damage to the pancreas. C57BL/6 mice were divided into four groups: control, chronic ethanol exposure, binge ethanol exposure and chronic plus binge ethanol exposure. For the control group, mice were fed with a liquid diet for two weeks. For the chronic ethanol exposure group, mice were fed with a liquid diet containing 5% ethanol for two weeks. In the binge ethanol exposure group, mice were treated with ethanolmore » by gavage (5 g/kg, 25% ethanol w/v) daily for 3 days. For the chronic plus binge exposure group, mice were fed with a liquid diet containing 5% ethanol for two weeks and exposed to ethanol by gavage during the last 3 days. Chronic and binge exposure alone caused minimal pancreatic injury. However, chronic plus binge ethanol exposure induced significant apoptotic cell death. Chronic plus binge ethanol exposure altered the levels of alpha-amylase, glucose and insulin. Chronic plus binge ethanol exposure caused pancreatic inflammation which was shown by the macrophages infiltration and the increase of cytokines and chemokines. Chronic plus binge ethanol exposure increased the expression of ADH1 and CYP2E1. It also induced endoplasmic reticulum stress which was demonstrated by the unfolded protein response. In addition, chronic plus binge ethanol exposure increased protein oxidation and lipid peroxidation, indicating oxidative stress. Therefore, chronic plus binge ethanol exposure is more detrimental to the pancreas. - Highlights: • Chronic plus binge alcohol drinking causes more pancreatic injury. • Chronic plus binge alcohol drinking induces more pancreatic inflammation. • Chronic plus binge alcohol causes more endoplasmic reticulum stress and oxidative stress.« less

Isolation, Characterisation and Antagonistic Activity of Bacteria Symbionts Hardcoral Pavona sp. Isolated from Panjang Island, Jepara Against Infectious Multi-drug Resistant (MDR) Bacteria

NASA Astrophysics Data System (ADS)

Ayuningrum, D.; Kristiana, R.; Asagabaldan, M. A.; Sabdono, A.; Radjasa, O. K.; Nuryadi, H.; Trianto, A.

2017-02-01

Pavona sp. is highly spread over Indonesian waters including Panjang Island. Several studies showed that bacteria symbionts hardcoral were the big source of antibiotic product, but there was limited research of the bacteria symbionts with hardcoral Pavona sp. In this research bacteria symbionts from hardcoral Pavona sp. had been collected from Panjang Island, Jepara. Marine bacteria symbionts were isolated by serial dillution method, while antibacterial activity was performed by using overlay and agar block method. The total of 2 from 5 isolates were active to MDR bacteria such as Enterobacter aerogenes and Acinetobacter baumanii, the code were PHC 44/04 and PHC 44/05. Then both of them were identified by morphological and molecular DNA characterization using 16 S rRNA gene sequence. The result of 16 S rRNA identification shows PHC 44/04 has 99% similarities with Virgibacillus salarius strain sa-Vb 1, while PHC 44/05 shows 99% similarities with Pseudoalteromonas flavipulchra strain NCIMB 2033.

The aerobic activity of metronidazole against anaerobic bacteria.

PubMed

Dione, Niokhor; Khelaifia, Saber; Lagier, Jean-Christophe; Raoult, Didier

2015-05-01

Recently, the aerobic growth of strictly anaerobic bacteria was demonstrated using antioxidants. Metronidazole is frequently used to treat infections caused by anaerobic bacteria; however, to date its antibacterial activity was only tested in anaerobic conditions. Here we aerobically tested using antioxidants the in vitro activities of metronidazole, gentamicin, doxycycline and imipenem against 10 common anaerobic and aerobic bacteria. In vitro susceptibility testing was performed by the disk diffusion method, and minimum inhibitory concentrations (MICs) were determined by Etest. Aerobic culture of the bacteria was performed at 37°C using Schaedler agar medium supplemented with 1mg/mL ascorbic acid and 0.1mg/mL glutathione; the pH was adjusted to 7.2 by 10M KOH. Growth of anaerobic bacteria cultured aerobically using antioxidants was inhibited by metronidazole after 72h of incubation at 37°C, with a mean inhibition diameter of 37.76mm and an MIC of 1μg/mL; however, strains remained non-sensitive to gentamicin. No growth inhibition of aerobic bacteria was observed after 24h of incubation at 37°C with metronidazole; however, inhibition was observed with doxycycline and imipenem used as controls. These results indicate that bacterial sensitivity to metronidazole is not related to the oxygen tension but is a result of the sensitivity of the micro-organism. In future, both culture and antibiotic susceptibility testing of strictly anaerobic bacteria will be performed in an aerobic atmosphere using antioxidants in clinical microbiology laboratories. Copyright © 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

In Vitro Antibacterial Activity of Several Plant Extracts and Oils against Some Gram-Negative Bacteria

PubMed Central

Al-Mariri, Ayman; Safi, Mazen

2014-01-01

Background: Medicinal plants are considered new resources for producing agents that could act as alternatives to antibiotics in the treatment of antibiotic-resistant bacteria. The aim of this study was to evaluate the antibacterial activity of 28 plant extracts and oils against four Gram-negative bacterial species. Methods: Experimental, in vitro, evaluation of the activities of 28 plant extracts and oils as well as some antibiotics against E. coli O157:H7, Yersinia enterocolitica O9, Proteus spp., and Klebsiella pneumoniae was performed. The activity against 15 isolates of each bacterium was determined by disc diffusion method at a concentration of 5%. Microdilution susceptibility assay was used in order to determine the minimal inhibitory concentrations (MICs) of the plant extracts, oils, and antibiotics. Results: Among the evaluated herbs, only Origanum syriacum L., Thymus syriacus Boiss., Syzygium aromaticum L., Juniperus foetidissima Wild, Allium sativum L., Myristica fragrans Houtt, and Cinnamomum zeylanicum L. essential oils and Laurus nobilis L. plant extract showed anti-bacterial activity. The MIC50 values of these products against the Gram-negative organisms varied from 1.5 (Proteus spp. and K. pneumoniae( and 6.25 µl/ml (Yersinia enterocolitica O9 ) to 12.5 µl/ml (E. coli O:157). Conclusion: Among the studied essential oils, O. syriacum L., T. syriacus Boiss., C. zeylanicum L., and S. aromaticum L. essential oils were the most effective. Moreover, Cephalosporin and Ciprofloxacin were the most effective antibiotics against almost all the studied bacteria. Therefore, O. syriacum L., T. syriacus Boiss., C. zeylanicum L., and S. aromaticum L. could act as bactericidal agents against Gram-negative bacteria. PMID:24453392

Acoustic impedance matched buffers enable separation of bacteria from blood cells at high cell concentrations.

PubMed

Ohlsson, Pelle; Petersson, Klara; Augustsson, Per; Laurell, Thomas

2018-06-14

Sepsis is a common and often deadly systemic response to an infection, usually caused by bacteria. The gold standard for finding the causing pathogen in a blood sample is blood culture, which may take hours to days. Shortening the time to diagnosis would significantly reduce mortality. To replace the time-consuming blood culture we are developing a method to directly separate bacteria from red and white blood cells to enable faster bacteria identification. The blood cells are moved from the sample flow into a parallel stream using acoustophoresis. Due to their smaller size, the bacteria are not affected by the acoustic field and therefore remain in the blood plasma flow and can be directed to a separate outlet. When optimizing for sample throughput, 1 ml of undiluted whole blood equivalent can be processed within 12.5 min, while maintaining the bacteria recovery at 90% and the blood cell removal above 99%. That makes this the fastest label-free microfluidic continuous flow method per channel to separate bacteria from blood with high bacteria recovery (>80%). The high throughput was achieved by matching the acoustic impedance of the parallel stream to that of the blood sample, to avoid that acoustic forces relocate the fluid streams.

Streptomyces lunalinharesii Strain 235 Shows the Potential to Inhibit Bacteria Involved in Biocorrosion Processes

PubMed Central

Pacheco da Rosa, Juliana; Korenblum, Elisa; Franco-Cirigliano, Marcella Novaes; Abreu, Fernanda; Lins, Ulysses; Soares, Rosângela M. A.; Macrae, Andrew; Seldin, Lucy; Coelho, Rosalie R. R.

2013-01-01

Four actinomycete strains previously isolated from Brazilian soils were tested for their antimicrobial activity against Bacillus pumilus LF-4 and Desulfovibrio alaskensis NCIMB 13491, bacteria that are well known to be involved in biofilm formation and biocorrosion. Strain 235, belonging to the species Streptomyces lunalinharesii, inhibited the growth of both bacteria. The antimicrobial activity was seen over a wide range of pH, and after treatment with several chemicals and heat but not with proteinase K and trypsin. The antimicrobial substances present in the concentrated supernatant from growth media were partially characterized by SDS-PAGE and extracellular polypeptides were seen. Bands in the size range of 12 to 14.4 kDa caused antimicrobial activity. Transmission electron microscopy of D. alaskensis cells treated with the concentrated supernatant containing the antimicrobial substances revealed the formation of prominent bubbles, the spherical double-layered structures on the cell membrane, and the periplasmic space completely filled with electron-dense material. This is the first report on the production of antimicrobial substances by actinomycetes against bacteria involved in biocorrosion processes, and these findings may be of great relevance as an alternative source of biocides to those currently employed in the petroleum industry. PMID:23484107

[The very severe sensorineural deafness patients caused by rubella virus infection: two cases report].

PubMed

Ma, Jing; Wan, Lang; Xu, Fen

2015-09-01

To explore the audiological features in children who were sever sensorineural hearing loss infected with rubella virus. There were two cases of rubella virus infection in children who were deaf, they conducted the distortion product otoacoustic emission, ABR and auditory steady-state evoked response (ASSR) examination, then analyzed the results comprehensively. Two patients' mothers were prompted to have infected rubella virus during the early three months pregnant period by history and laboratory tests. The two patients were not detected deafness gene mutation. Audiology results implied the two patients were very severe binaural sensorineural deafness, so they were recommended to equipped with hearing aids and cochlear implant surgery. Early pregnancy women infected with rubella virus can cause very severe offspring sensorineural deafness. The crowd whose mother were suspected to infect with rubella virus in early pregnancy, that should be tracked and detected hearing in order to achieve early detection, early intervention and early treatment.

Global loss of Leucine Carboxyl Methyltransferase-1 causes severe defects in fetal liver hematopoiesis.

PubMed

Lee, Jocelyn A; Wang, Zhengqi; Sambo, Danielle; Bunting, Kevin D; Pallas, David C

2018-05-07

Leucine Carboxyl Methyltransferase-1 (LCMT-1) 3 methylates the carboxy-terminal leucine α-carboxyl group of the catalytic subunits of the protein phosphatase 2A (PP2A) subfamily of protein phosphatases, PP2Ac, PP4c, and PP6c. LCMT-1 differentially regulates the formation and function of a subset of the heterotrimeric complexes that PP2A and PP4 form with their regulatory subunits. Global LCMT-1 knockout causes embryonic lethality in mice, but LCMT-1 function in development is unknown. In the current study, we analyzed the effects of global LCMT-1 loss on embryonic development. LCMT-1 knockout causes loss of PP2Ac methylation, indicating that LCMT-1 is the sole PP2Ac methyltransferase. PP2A heterotrimers containing the Bα and Bδ B-type subunits are dramatically reduced in whole embryos, and the steady-state levels of PP2Ac and the PP2A structural A subunit are also down ~30%. Strikingly, global loss of LCMT-1 causes severe defects in fetal hematopoiesis and death by embryonic day 16.5 (E16.5). Fetal livers of homozygous lcmt-1 knockout embryos display hypocellularity, elevated apoptosis, and greatly reduced numbers of hematopoietic stem and progenitor cell-enriched Kit + Lin - Sca1 + (KLS) cells. The percent cycling cells and mitotic indexes of wild-type and lcmt-1 knockout fetal liver cells are similar, suggesting that hypocellularity may be due to a combination of apoptosis and/or defects in specification, self-renewal, or survival of stem cells. Indicative of a possible intrinsic defect in stem cells, non-competitive and competitive transplantation experiments reveal that lcmt-1 loss causes a severe multi-lineage hematopoietic repopulating defect. Therefore, this study reveals a novel role for LCMT-1 as a key player in fetal liver hematopoiesis. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Reprogrammable microbial cell-based therapeutics against antibiotic-resistant bacteria.

PubMed

Hwang, In Young; Koh, Elvin; Kim, Hye Rim; Yew, Wen Shan; Chang, Matthew Wook

2016-07-01

The discovery of antimicrobial drugs and their subsequent use has offered an effective treatment option for bacterial infections, reducing morbidity and mortality over the past 60 years. However, the indiscriminate use of antimicrobials in the clinical, community and agricultural settings has resulted in selection for multidrug-resistant bacteria, which has led to the prediction of possible re-entrance to the pre-antibiotic era. The situation is further exacerbated by significantly reduced antimicrobial drug discovery efforts by large pharmaceutical companies, resulting in a steady decline in the number of new antimicrobial agents brought to the market in the past several decades. Consequently, there is a pressing need for new antimicrobial therapies that can be readily designed and implemented. Recently, it has become clear that the administration of broad-spectrum antibiotics can lead to collateral damage to the human commensal microbiota, which plays several key roles in host health. Advances in genetic engineering have opened the possibility of reprogramming commensal bacteria that are in symbiotic existence throughout the human body to implement antimicrobial drugs with high versatility and efficacy against pathogenic bacteria. In this review, we discuss recent advances and potentialities of engineered bacteria in providing a novel antimicrobial strategy against antibiotic resistance. Copyright © 2016 Elsevier Ltd. All rights reserved.

A novel mutation in the EDAR gene causes severe autosomal recessive hypohidrotic ectodermal dysplasia.

PubMed

Henningsen, Emil; Svendsen, Mathias Tiedemann; Lildballe, Dorte Launholt; Jensen, Peter Kjestrup Axel

2014-08-01

We report on a 2-year-old girl presenting with a severe form of hypohidrotic ectodermal dysplasia (HED). The patient presented with hypotrichosis, anodontia, hypohidrosis, frontal bossing, prominent lips and ears, dry, pale skin, and dermatitis. The patient had chronic rhinitis with malodorous nasal discharge. The girl was the second born child of first-cousin immigrants from Northern Iraq. A novel homozygous mutation (c.84delC) in the EDAR gene was identified. This mutation most likely causes a frameshift in the protein product (p.S29fs*74). This results in abolition of all ectodysplasin-mediated NF-kB signalling. This complete loss-of-function mutation likely accounts for the severe clinical abnormalities in ectodermal structures in the described patient. © 2014 Wiley Periodicals, Inc.

Bacteriocins from Gram-Negative Bacteria: A Classification?

NASA Astrophysics Data System (ADS)

Rebuffat, Sylvie

Bacteria produce an arsenal of toxic peptides and proteins, which are termed bacteriocins and play a role in mediating the dynamics of microbial populations and communities. Bacteriocins from Gram-negative bacteria arise mainly from Enterobacteriaceae. They assemble into two main families: high molecular mass modular proteins (30-80 kDa) termed colicins and low molecular mass peptides (between 1 and 10 kDa) termed microcins. The production of colicins is mediated by the SOS response regulon, which plays a role in the response of many bacteria to DNA damages. Microcins are highly stable hydrophobic peptides that are produced under stress conditions, particularly nutrient depletion. Colicins and microcins are found essentially in Escherichia coli, but several other Gram-negative species also produce bacteriocin-like substances. This chapter presents the basis of a classification of colicins and microcins.

Molecular and chemical dialogues in bacteria-protozoa interactions.

PubMed

Song, Chunxu; Mazzola, Mark; Cheng, Xu; Oetjen, Janina; Alexandrov, Theodore; Dorrestein, Pieter; Watrous, Jeramie; van der Voort, Menno; Raaijmakers, Jos M

2015-08-06

Protozoan predation of bacteria can significantly affect soil microbial community composition and ecosystem functioning. Bacteria possess diverse defense strategies to resist or evade protozoan predation. For soil-dwelling Pseudomonas species, several secondary metabolites were proposed to provide protection against different protozoan genera. By combining whole-genome transcriptome analyses with (live) imaging mass spectrometry (IMS), we observed multiple changes in the molecular and chemical dialogues between Pseudomonas fluorescens and the protist Naegleria americana. Lipopeptide (LP) biosynthesis was induced in Pseudomonas upon protozoan grazing and LP accumulation transitioned from homogeneous distributions across bacterial colonies to site-specific accumulation at the bacteria-protist interface. Also putrescine biosynthesis was upregulated in P. fluorescens upon predation. We demonstrated that putrescine induces protozoan trophozoite encystment and adversely affects cyst viability. This multifaceted study provides new insights in common and strain-specific responses in bacteria-protozoa interactions, including responses that contribute to bacterial survival in highly competitive soil and rhizosphere environments.

Marine Sponges and Bacteria as Challenging Sources of Enzyme Inhibitors for Pharmacological Applications

PubMed Central

Ruocco, Nadia; Costantini, Susan; Palumbo, Flora; Costantini, Maria

2017-01-01

Enzymes play key roles in different cellular processes, for example, in signal transduction, cell differentiation and proliferation, metabolic processes, DNA damage repair, apoptosis, and response to stress. A deregulation of enzymes has been considered one of the first causes of several diseases, including cancers. In the last several years, enzyme inhibitors, being good candidates as drugs in the pathogenic processes, have received an increasing amount of attention for their potential application in pharmacology. The marine environment is considered a challenging source of enzyme inhibitors for pharmacological applications. In this review, we report on secondary metabolites with enzyme inhibitory activity, focusing our attention on marine sponges and bacteria as promising sources. In the case of sponges, we only reported the kinase inhibitors, because this class was the most representative isolated so far from these marine organisms. PMID:28604647

Enumeration and Identification of Coliform Bacteria Injured by Chlorine or Fungicide Mixed with Agricultural Water.

PubMed

Izumi, Hidemi; Nakata, Yuji; Inoue, Ayano

2016-10-01

Chemical sanitizers may induce no injury (bacteria survive), sublethal injury (bacteria are injured), or lethal injury (bacteria die). The proportion of coliform bacteria that were injured sublethally by chlorine and fungicide mixed with agricultural water (pond water), which was used to dilute the pesticide solution, was evaluated using the thin agar layer (TAL) method. In pure cultures of Enterobacter cloacae , Escherichia coli , and E. coli O157:H7 (representing a human pathogen), the percentage of chlorine-injured cells was 69 to 77% for dilute electrolyzed water containing an available chlorine level of 2 ppm. When agricultural water was mixed with electrolyzed water, the percentage of injured coliforms in agricultural water was 75%. The isolation and identification of bacteria on TAL and selective media suggested that the chlorine stress caused injury to Enterobacter kobei . Of the four fungicide products tested, diluted to their recommended concentrations, Topsin-M, Sumilex, and Oxirane caused injury to coliform bacteria in pure cultures and in agricultural water following their mixture with each pesticide, whereas Streptomycin did not induce any injury to the bacteria. The percentage of injury was 45 to 97% for Topsin-M, 80 to 87% for Sumilex, and 50 to 97% for Oxirane. A comparison of the coliforms isolated from the pesticide solutions and then grown on either TAL or selective media indicated the possibility of fungicide-injured Rahnella aquatilis , Yersinia mollaretii , and E. coli . These results suggest the importance of selecting a suitable sanitizer and the necessity of adjusting the sanitizer concentration to a level that will kill the coliforms rather than cause sanitizer-induced cell injury that can result in the recovery of the coliforms.

Fungal Disease Prevention in Seedlings of Rice (Oryza sativa) and Other Grasses by Growth-Promoting Seed-Associated Endophytic Bacteria from Invasive Phragmites australis

PubMed Central

Verma, Satish K.; Kingsley, Kathryn L.; Bergen, Marshall S.; White, James F.

2018-01-01

Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium, Pythium and other water moulds cause seed rots during germination. Fusarium blights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass (Cynodon dactylon), or annual bluegrass (Poa annua) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum. We found that three bacteria belonging to genus Pseudomonas spp. (SLB4-P. fluorescens, SLB6-Pseudomonas sp. and SY1-Pseudomonas sp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum, 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production suggested presence of

Fungal Disease Prevention in Seedlings of Rice (Oryza sativa) and Other Grasses by Growth-Promoting Seed-Associated Endophytic Bacteria from Invasive Phragmites australis.

PubMed

Verma, Satish K; Kingsley, Kathryn L; Bergen, Marshall S; Kowalski, Kurt P; White, James F

2018-03-08

Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium , Pythium and other water moulds cause seed rots during germination. Fusarium blights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass ( Cynodon dactylon ), or annual bluegrass ( Poa annua ) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum . We found that three bacteria belonging to genus Pseudomonas spp. (SLB4- P. fluorescens , SLB6- Pseudomonas sp. and SY1- Pseudomonas sp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum , 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production suggested

Effects of Interactions of Auxin-Producing Bacteria and Bacterial-Feeding Nematodes on Regulation of Peanut Growths

PubMed Central

Xu, Li; Xu, Wensi; Jiang, Ying; Hu, Feng; Li, Huixin

2015-01-01

The influences of an IAA (indole-3-acetic acid)-producing bacterium (Bacillus megaterium) and two bacterial-feeding nematodes (Cephalobus sp. or Mesorhabditis sp.) on the growth of peanut (Arachis hypogaea L. cv. Haihua 1) after various durations of time were investigated in natural soils. The addition of bacteria and nematodes and incubation time all significantly affected plant growth, plant root growth, plant nutrient concentrations, soil nutrient concentrations, soil microorganisms and soil auxin concentration. The addition of nematodes caused greater increases in these indices than those of bacteria, while the addition of the combination of bacteria and nematodes caused further increases. After 42-day growth, the increases in soil respiration differed between the additions of two kinds of nematodes because of differences in their life strategies. The effects of the bacteria and nematodes on the nutrient and hormone concentrations were responsible for the increases in plant growth. These results indicate the potential for promoting plant growth via the addition of nematodes and bacteria to soil. PMID:25867954

Effects of interactions of auxin-producing bacteria and bacterial-feeding nematodes on regulation of peanut growths.

PubMed

Xu, Li; Xu, Wensi; Jiang, Ying; Hu, Feng; Li, Huixin

2015-01-01

The influences of an IAA (indole-3-acetic acid)-producing bacterium (Bacillus megaterium) and two bacterial-feeding nematodes (Cephalobus sp. or Mesorhabditis sp.) on the growth of peanut (Arachis hypogaea L. cv. Haihua 1) after various durations of time were investigated in natural soils. The addition of bacteria and nematodes and incubation time all significantly affected plant growth, plant root growth, plant nutrient concentrations, soil nutrient concentrations, soil microorganisms and soil auxin concentration. The addition of nematodes caused greater increases in these indices than those of bacteria, while the addition of the combination of bacteria and nematodes caused further increases. After 42-day growth, the increases in soil respiration differed between the additions of two kinds of nematodes because of differences in their life strategies. The effects of the bacteria and nematodes on the nutrient and hormone concentrations were responsible for the increases in plant growth. These results indicate the potential for promoting plant growth via the addition of nematodes and bacteria to soil.

A novel sponge disease caused by a consortium of micro-organisms

NASA Astrophysics Data System (ADS)

Sweet, Michael; Bulling, Mark; Cerrano, Carlo

2015-09-01

In healthy sponges, microbes have been shown to account for up to 40 % of tissues. The majority of these are thought to originate from survivors evading digestion and immune responses of the sponge and growing and residing in the microenvironments of the mesophyll. Although a large percentage of these microbes are likely commensals, they may also include potentially pathogenic agents, which under specific conditions, such as temperature stress, may cause disease. Here we report a novel disease (sponge necrosis syndrome) that is severely affecting populations of the sponge Callyspongia ( Euplacella) aff biru. Both ITS fungal and 16S rDNA bacterial diversities were assessed in healthy and diseased individuals, highlighting six potential primary causal agents for this new disease: two bacteria, a Rhodobacteraceae sp. and a cyanobacterium, Hormoscilla spongeliae (formally identified as Oscillatoria spongeliae), and four fungi, a Ascomycota sp., a Pleosporales sp., a Rhabdocline sp., and a Clasosporium sp. Furthermore, histological analysis showed the dominance of fungal hyphae rather than bacteria throughout the disease lesion, which was absent or rare in healthy tissues. Inoculation trails showed that only a combination of one bacterium and one fungus could replicate the disease, fulfilling Henle-Koch's postulates and showing that this sponge disease is caused by a poly-microbial consortium.

Mucosal immunity to pathogenic intestinal bacteria.

PubMed

Perez-Lopez, Araceli; Behnsen, Judith; Nuccio, Sean-Paul; Raffatellu, Manuela

2016-03-01

The intestinal mucosa is a particularly dynamic environment in which the host constantly interacts with trillions of commensal microorganisms, known as the microbiota, and periodically interacts with pathogens of diverse nature. In this Review, we discuss how mucosal immunity is controlled in response to enteric bacterial pathogens, with a focus on the species that cause morbidity and mortality in humans. We explain how the microbiota can shape the immune response to pathogenic bacteria, and we detail innate and adaptive immune mechanisms that drive protective immunity against these pathogens. The vast diversity of the microbiota, pathogens and immune responses encountered in the intestines precludes discussion of all of the relevant players in this Review. Instead, we aim to provide a representative overview of how the intestinal immune system responds to pathogenic bacteria.

Surveillance of multidrug resistant uropathogenic bacteria in hospitalized patients in Indian

PubMed Central

Mishra, Monali Priyadarsini; Debata, Nagen Kumar; Padhy, Rabindra Nath

2013-01-01

Objective To record surveillance, antibiotic resistance of uropathogens of hospitalized patients over a period of 18 months. Methods Urine samples from wards and cabins were used for isolating urinary tract infection (UTI)-causing bacteria that were cultured on suitable selective media and identified by biochemical tests; and their antibiograms were ascertained by Kirby-Bauer's disc diffusion method, in each 6-month interval of the study period, using 18 antibiotics of five different classes. Results From wards and cabins, 1 245 samples were collected, from which 996 strains of bacteria belonging to 11 species were isolated, during April 2011 to September 2012. Two Gram-positive, Staphylococcus aureus (S. aureus) and Enterococcus faecalis (E. faecalis), and nine Gram-negative bacteria, Acinetobacter baumannii, Citrobacter sp., Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis, Proteus vulgaris and Pseudomonas aeruginosa were isolated. Both S. aureus and E. faecalis were vancomycin resistant, and resistant-strains of all pathogens increased in each 6-month period of study. Particularly, all Gram-negatives were resistant to nitrofurantoin and co-trimoxazole, the most preferred antibiotics of empiric therapy for UTI. Conclusions Antibiograms of 11 UTI-causing bacteria recorded in this study indicated moderately higher numbers of strains resistant to each antibiotic studied, generating the fear of precipitating fervent episodes in public health particularly with bacteria, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and S. aureus. Moreover, vancomycin resistance in strains of S. aureus and E. faecalis is a matter of concern. PMID:23620859

Isolation and whole genome analysis of endospore-forming bacteria from heroin.

PubMed

Kalinowski, Jörn; Ahrens, Björn; Al-Dilaimi, Arwa; Winkler, Anika; Wibberg, Daniel; Schleenbecker, Uwe; Rückert, Christian; Wölfel, Roman; Grass, Gregor

2018-01-01

Infections caused by endospore-forming bacteria have been associated with severe illness and death among persons who inject drugs. Analysis of the bacteria residing in heroin has thus been biased towards species that affect human health. Similarly, exploration of the bacterial diversity of seized street market heroin correlated with the skin microflora of recreational heroin users insofar as different Staphylococus spp. or typical environmental endospore formers including Bacillus cereus and other Bacilli outside the B. cereus sensu lato group as well as diverse Clostridia were identified. In this work 82 samples of non-street market ("wholesale") heroin originating from the German Federal Criminal Police Office's heroin analysis program seized during the period between 2009 and 2014 were analyzed for contaminating bacteria. Without contact with the end user and with only little contaminations introduced by final processing, adulteration and cutting this heroin likely harbors original microbiota from the drug's original source or trafficking route. We found this drug to be only sparsely populated with retrievable heterotrophic, aerobic bacteria. In total, 68 isolates were retrieved from 49 out of 82 samples analyzed (60% culture positive). All isolates were endospore-forming, Gram-positive Bacilli. Completely absent were non-endospore-formers or Gram-negatives. The three most predominant species were Bacillus clausii, Bacillus (para)licheniformis, and Terribacillus saccharophilus. Whole genome sequencing of these 68 isolates was performed using Illumina technology. Sequence data sets were assembled and annotated using an automated bioinformatics pipeline. Average nucleotide identity (ANI) values were calculated for all draft genomes and all close to identical genomes (ANI>99.5%) were compared to the forensic data of the seized drug, showing positive correlations that strongly warrant further research on this subject. Copyright © 2017 Elsevier B.V. All rights

Clonal Clusters and Virulence Factors of Group C and G Streptococcus Causing Severe Infections, Manitoba, Canada, 2012-2014.

PubMed

Lother, Sylvain A; Demczuk, Walter; Martin, Irene; Mulvey, Michael; Dufault, Brenden; Lagacé-Wiens, Philippe; Keynan, Yoav

2017-07-01

The incidence of group C and G Streptococcus (GCGS) bacteremia, which is associated with severe disease and death, is increasing. We characterized clinical features, outcomes, and genetic determinants of GCGS bacteremia for 89 patients in Winnipeg, Manitoba, Canada, who had GCGS bacteremia during 2012-2014. Of the 89 patients, 51% had bacteremia from skin and soft tissue, 70% had severe disease features, and 20% died. Whole-genome sequencing analysis was performed on isolates derived from 89 blood samples and 33 respiratory sample controls: 5 closely related genetic lineages were identified as being more likely to cause invasive disease than non-clade isolates (83% vs. 57%, p = 0.002). Virulence factors cbp, fbp, speG, sicG, gfbA, and bca clustered clonally into these clades. A clonal distribution of virulence factors may account for severe and fatal cases of bacteremia caused by invasive GCGS.

Virulence of plant pathogenic bacteria attenuated by degradation of fatty acid cell-to-cell signaling factors.

PubMed

Newman, Karyn L; Chatterjee, Subhadeep; Ho, Kimberly A; Lindow, Steven E

2008-03-01

Diffusible signal factor (DSF) is a fatty acid signal molecule involved in regulation of virulence in several Xanthomonas species as well as Xylella fastidiosa. In this study, we identified a variety of bacteria that could disrupt DSF-mediated induction of virulence factors in Xanthomonas campestris pv. campestris. While many bacteria had the ability to degrade DSF, several bacterial strains belonging to genera Bacillus, Paenibacillus, Microbacterium, Staphylococcus, and Pseudomonas were identified that were capable of particularly rapid degradation of DSF. The molecular determinants for rapid degradation of DSF in Pseudomonas spp. strain G were elucidated. Random transposon mutants of strain G lacking the ability to degrade DSF were isolated. Cloning and characterization of disrupted genes in these strains revealed that carAB, required for the synthesis of carbamoylphosphate, a precursor for pyrimidine and arginine biosynthesis is required for rapid degradation of DSF in strain G. Complementation of carAB mutants restored both pyrimidine prototrophy and DSF degradation ability of the strain G mutant. An Escherichia coli strain harboring carAB of Pseudomonas spp. strain G degrades DSF more rapidly than the parental strain, and overexpression of carAB in trans increased the ability of Pseudomonas spp. strain G to degrade as compared with the parental strain. Coinoculation of X. campestris pv. campestris with DSF-degrading bacteria into mustard and cabbage leaves reduced disease severity up to twofold compared with plants inoculated only with the pathogen. Likewise, disease incidence and severity in grape stems coinoculated with Xylella fastidiosa and DSF-degrading strains were significantly reduced compared with plants inoculated with the pathogen alone. Coinoculation of grape plants with a carAB mutant of Pseudomonas spp. strain G complemented with carAB in trans reduced disease severity as well or better than the parental strain. These results indicate that

Respiration and carbon dynamics of free-living and particle-attached bacteria in coastal waters of NE Pacific

NASA Astrophysics Data System (ADS)

Guo, C.; Ke, Y.; Liu, H.

2016-02-01

Bacterial respiration (BR) rates are fundamental to understand the role of bacteria in carbon flow in aquatic ecosystem, and therefore it is critical to obtain reliable measurements. Prefiltration- (mostly 1-3μm) and dark-incubation- (mostly 24 h) based direct measurements of oxygen consumption have been the most commonly used method for BR. However, the prefiltration procedure and long incubation time may cause change of the bacterial abundance and structure, leading to inaccurate measurements. In this study, by measuring bacterial abundance, production and respiration of both particle-attached (PA) and free-living (FL) bacteria at two contrasting site in coastal NE Pacific from Nov 2014 to Mar 2015, we found that the 24 h growth rate of FL bacteria in the traditional BR incubations were significantly higher for 30% and 54% than those obtained for FL and total (FL+PA) bacteria in unfiltered incubations respectively, suggesting removal of protist grazers could cause a significant biomass accumulation during 24 h incubation than the in situ condition. This biomass overestimation resulted in 40% (±12%) overestimation of measured FL BR rates compared with the corrected in situ FL BR. Nevertheless, for the corrected in situ total BR, the rates were overestimated by traditional method in three measurements over nine for 6-46%, and were underestimated in the rest six measurements for 7-67%. Interestingly, those underestimations were attributed to the ignorance of PA bacteria due to prefiltration, which had larger cell size than the FL bacteria, accounted for 19% (±16%) in total bacterial abundance, and contributed to 50% (±19%) of total bacterial production. The average bacterial growth efficiency calculated by comparable 24 h integrated bacterial production and respiration was 0.42 (±0.24). Our results confirmed two major flaws in the current BR methodology, i.e., 1) it only measures the respiration of FL bacteria, and 2) the removal of grazers causing dramatic

Biotransformation of geosmin by terpene-degrading bacteria.

USDA-ARS?s Scientific Manuscript database

Two terpene-degrading bacteria that are able to transform geosmin have been identified. Pseudomonas sp. SBR3-tpnb, isolated on -terpinene, converts geosmin to several products; the major products are keto-geosmins. This geosmin transformation ability is inducible by -terpinene. Rhodococcus wratisl...

Effects of Caesalpinia sappan on pathogenic bacteria causing dental caries and gingivitis.

PubMed

Puttipan, Rinrampai; Wanachantararak, Penpicha; Khongkhunthian, Sakornrat; Okonogi, Siriporn

2017-01-01

The present study explores antimicrobial activities of Caesalpinia sappan extracts against three strains of oral pathogenic bacteria; Streptococcus mutans DMST9567 (Smu9), Streptococcus mutans DMST41283 (Smu4), and Streptococcus intermedius DMST42700 (Si). Ethanol crude extract of C. sappan (Cs-EtOH) was firstly compared to that of other medicinal plants using disc diffusion method. Cs-EtOH showed significantly higher effective inhibition against all tested strains than other extracts and 0.12% chlorhexidine with the inhibition zone of 17.5 ± 0.5, 18.5 ± 0.0, and 17.0 ± 0.0 mm against Smu9, Smu4, and Si, respectively. Three fractionated extracts of C. sappan using hexane, ethyl acetate, and ethanol, respectively, were further investigated. The fractionated extract from ethanol (F-EtOH) presented the strongest activities with the minimum bactericidal concentration (MBC) of 125-250 µg/mL. Killing kinetics of F-EtOH was depended on the bacterial species and the concentration of F-EtOH. Two-fold MBC of F-EtOH could kill all tested strains within 12 h whereas its 4-fold MBC showed killing effect against Si within 6 h. Separation of F-EtOH by column chromatography using chloroform/methanol mixture as an eluent yielded 11 fractions (F1-F11). The fingerprints of these fractions by high-performance liquid chromatography at 280 nm revealed that F-EtOH consisted of at least 5 compounds. F6 possessed the significantly highest antimicrobial activity among 11 fractions, however less than F-EtOH. It is considered that F-EtOH is the promising extract of C. sappan for inhibiting oral pathogenic bacteria and appropriate as natural antiseptic for further develop of oral hygiene products.

Stop the Spread of Superbugs: Help Fight Drug Resistant Bacteria

MedlinePlus

... those that cause colds or flu. Unfortunately, many antibiotics prescribed to people and to animals are unnecessary. And the overuse and misuse of antibiotics helps to create drug-resistant bacteria. Here’s how ...

Severe peripheral neuropathy and elevated plantar pressures causing foot ulceration in pituitary gigantism.

PubMed

Jennings, A M; Robinson, A; Kandler, R H; Betts, R P; Ryder, R E; Cullen, D R

1993-07-01

We report two patients with treated pituitary gigantism and peripheral neuropathy, one of whom has chronic foot ulceration. Detailed neurophysiological assessment was performed on both patients. The patient with foot ulceration had clinical and neurophysiological evidence of severe neuropathy, whereas the patient without ulceration had only neurophysiological abnormalities. The sweating response to acetylcholine was markedly impaired in the feet of both patients, suggesting pedal autonomic denervation. Neither patient had evidence of diabetes mellitus and detailed investigation failed to reveal an alternative cause of peripheral neuropathy. Optical pedobarography revealed abnormally high pressure (> 10 kg/cm2) under the metatarsal heads of both patients, one such area coinciding with the area of ulceration. Thus in pituitary gigantism elevated plantar pressures may contribute to the development of foot ulceration when severe peripheral neuropathy is present. Furthermore, as in diabetes mellitus, impaired sweating may also increase the risk of ulceration as the resultant dry skin may develop fissures.

[From the discovery of antibiotics to emerging highly drug-resistant bacteria].

PubMed

Meunier, Olivier

2015-01-01

The discovery of antibiotics has enabled serious infections to be treated. However, bacteria resistant to several families of antibiotics and the emergence of new highly drug-resistant bacteria constitute a public health issue in France and across the world. Actions to prevent their transmission are being put in place. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Causes of severe visual impairment and blindness in students in schools for the blind in Northwest Ethiopia.

PubMed

Asferaw, Mulusew; Woodruff, Geoffrey; Gilbert, Clare

2017-01-01

To determine the causes of severe visual impairment and blindness (SVI/BL) among students in schools for the blind in Northwest Ethiopia and to identify preventable and treatable causes. Students attending nine schools for the blind in Northwest Ethiopia were examined and causes assigned using the standard WHO record form for children with blindness and low vision in May and June 2015. 383 students were examined, 357 (93%) of whom were severely visually impaired or blind (<6/60 in their better eye). 253 (70.9%) were aged 16 years or above and 228 (63.9%) were males. 100 students aged <16 years were blind and four were SVI, total 104. The major anatomical site of visual loss among those 0-15 years was cornea/phthisis (47.1%), usually due to measles and vitamin A deficiency, followed by whole globe (22.1%), lens (9.6%) and uvea (8.7%). Among students aged 16 years and above, corneal/phthisis (76.3%) was the major anatomical cause, followed by lens (6.3%), whole globe (4.7%), uvea (3.6%) and optic nerve (3.2%). The leading underlying aetiology among students aged <16 years was childhood factors (39.4%) (13.5% measles, 10.6% vitamin A deficiency), followed by unknown aetiology (54.8%), perinatal (2.9%) and hereditary factors (2.9%). In the older group, childhood factors (72.3%) (25% measles, 15% vitamin A deficiency) were major causes, followed by unknown aetiology (24.1%), perinatal (2.4%) and hereditary factors (0.8%). Over 80% of the causes were avoidable with majority being potentially preventable (65%). Corneal blindness, mainly as the result of measles and vitamin A deficiency, is still a public health problem in Northwest Ethiopia, and this has not changed as observed in other low-income countries. More than three-fourth of causes of SVI/BL in students in schools for the blind are potentially avoidable, with measles/vitamin A deficiency and cataract being the leading causes.

Bacteria-Targeting Nanoparticles for Managing Infections

NASA Astrophysics Data System (ADS)

Radovic-Moreno, Aleksandar Filip

Bacterial infections continue to be a significant concern particularly in healthcare settings and in the developing world. Current challenges include the increasing spread of drug resistant (DR) organisms, the side effects of antibiotic therapy, the negative consequences of clearing the commensal bacterial flora, and difficulties in developing prophylactic vaccines. This thesis was an investigation of the potential of a class of polymeric nanoparticles (NP) to contribute to the management of bacterial infections. More specifically, steps were taken towards using these NPs (1) to achieve greater spatiotemporal control over drug therapy by more targeted antibiotic delivery to bacteria, and (2) to develop a prophylactic vaccine formulation against the common bacterial sexually transmitted disease (STD) caused by Chlamydia trachomatis. In the first part, we synthesized polymeric NPs containing poly(lactic-co-glycolic acid)-block-poly(L-histidine)-block-poly(ethylene glycol) (PLGA-PLH-PEG). We show that these NPs are able to bind to bacteria under model acidic infection conditions and are able to encapsulate and deliver vancomycin to inhibit the growth of Staphylococcus aureus bacteria in vitro. Further work showed that the PLGA-PLH-PEG-based NPs demonstrated the potential for competition for binding bacteria at a site of infection from soluble protein and model phagocytic and tissue-resident cells in a NP composition dependent manner. The NPs demonstrated low toxicity in vitro, were well tolerated by mice in vivo, and circulated in the blood on timescales comparable to control PLGA-PEG NPs. In the second part, we used PLGA-PLH-PEG-based NPs to design a prophylactic vaccine against the obligate intracellular bacterium Chlamydia trachomatis, the most common cause of bacterial STD in the world. Currently, no vaccines against this pathogen are approved for use in humans. We first formulated NPs encapsulating the TLR7 agonist R848 conjugated to poly(lactic acid) (R848-PLA

Effects of bovine milk lactoperoxidase system on some bacteria.

PubMed

Cankaya, M; Sişecioğlu, M; Bariş, O; Güllüce, M; Ozdemir, H

2010-01-01

Bovine lactoperoxidase (LPO) was purified from skimmed milk using amberlite CG-50-H+ resin, CM sephadex C-50 ion-exchange chromatography, and sephadex G-100 gel filtration chromatography. Lactoperoxidase was purified 20.45-fold with a yield of 28.8%. Purity of enzyme checked by sodium dodecyl sulphate-polyacrylamide gel electrophoresis method and a single band was observed. Km was 0.25 mM at 20 degrees C, Vmax value was 7.95 micromol/ml min at 20 degrees C (pH 6.0). Antibacterial study was done by disk diffusion method of Kir-by-Bauer using Mueller-Hinton agar medium with slight modification. Bovine LPO showed high antibacterial activity in 100 mM thiocyanate-100 mM H2O2 medium for some bacteria (Brevibacillus centrosaurus, B. choshinensis, B. lyticum, Cedecea davisae, Chryseobacterium indoltheticum, Clavibacter michiganense pv. insidiosum, Kocuria erythromyxa, K. kristinae, K. rosea, K. varians, Paenibacillus validus, Pseudomonas syringae pv. populans, Ralstonia pickettii, Rhodococcus wratislaviensis, Serratia fonticola, Streptomyces violaceusniger, Vibrio cholerae-nonO1) respectively, and compared with well known antibacterial substances (levofloxacin, netilmicin). LPO system has inhibition effects on all type bacteria and concentration is really important such as LPO-100 mM thiocyanate-100 mM H2O2 system was proposed as an effective agent against many factors causing several diseases.

Antibiotic effects against periodontal bacteria in organ cultured tissue.

PubMed

Takeshita, Masaaki; Haraguchi, Akira; Miura, Mayumi; Hamachi, Takafumi; Fukuda, Takao; Sanui, Terukazu; Takano, Aiko; Nishimura, Fusanori

2017-02-01

Mechanical reduction of infectious bacteria by using physical instruments is considered the principal therapeutic strategy for periodontal disease; addition of antibiotics is adjunctive. However, local antibiotic treatment, combined with conventional mechanical debridement, has recently been shown to be more effective in periodontitis subjects with type 2 diabetes. This suggests that some bacteria may invade the inflamed inner gingival epithelium, and mechanical debridement alone will be unable to reduce these bacteria completely. Therefore, we tried to establish infected organ culture models that mimic the inner gingival epithelium and aimed to see the effects of antibiotics in these established models. Mouse dorsal skin epithelia were isolated, and periodontal bacteria were injected into the epithelia. Infected epithelia were incubated with test antibiotics, and colony-forming ability was evaluated. Results indicated that effective antibiotics differed according to injected bacteria and the bacterial combinations tested. Overall, in organ culture model, the combination of amoxicillin or cefdinir and metronidazole compensate for the effects of less effective bacterial combinations on each other. This in vitro study would suggest effective periodontal treatment regimens, especially for severe periodontitis.

Use of thermophilic bacteria for bioremediation of petroleum contaminants

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

Al-Maghrabi, I.M.A.; Bin Aqil, A.O.; Chaalal, O.

1999-01-01

Several strains of thermophilic bacteria were isolated from the environment of the United Arab Emirates. These bacteria show extraordinary resistance to heat and have their maximum growth rate around 60--80 C. This article investigates the potential of using these facultative bacteria for both in situ and ex situ bioremediation of petroleum contaminants. In a series of batch experiments, bacterial growth was observed using a computer image analyzer following a recently developed technique. These experiments showed clearly that the growth rate is enhanced in the presence of crude oil. This is coupled with a rapid degradation of the crude oil. Thesemore » bacteria were found to be ideal for breaking down long-chain organic molecules at a temperature of 40 C, which is the typical ambient temperature of the Persian Gulf region. The same strains of bacteria are also capable of surviving in the presence of the saline environment that can prevail in both sea water and reservoir connate water. This observation prompted further investigation into the applicability of the bacteria in microbial enhanced oil recovery. In the United Arab Emirates, the reservoirs are typically at a temperature of around 85 C. Finally, the performance of the bacteria is tested in a newly developed bioreactor that uses continuous aeration through a transverse slotted pipe. This reactor also uses mixing without damaging the filamentous bacteria. In this process, the mechanisms of bioremediation are identified.« less

Corals diseases are a major cause of coral death

EPA Science Inventory

Corals, like humans, are susceptible to diseases. Some coral diseases are associated with pathogenic bacteria; however, the causes of most remain unknown. Some diseases trigger rapid and extensive mortality, while others slowly cause localized color changes or injure coral tiss...

Bacteremic Urinary Tract Infection Caused by Multidrug-Resistant Enterobacteriaceae Are Associated With Severe Sepsis at Admission: Implication for Empirical Therapy.

PubMed

Lee, Yi-Chien; Hsiao, Chih-Yen; Hung, Miao-Chiu; Hung, Sheng-Che; Wang, Hung-Ping; Huang, Yun-Jhong; Wang, Jann-Tay

2016-05-01

The purpose of this study is to compare the clinical features and treatment outcomes among patients with bacteremic urinary tract infection (UTI) caused by multidrug-resistant (MDR) and non-MDR Enterobacteriaceae and to identify whether MDR pathogens were independently associated with severe sepsis or septic shock at presentation.The clinical data of adult patients visiting and being treated at Chia-Yi Christian Hospital due to bacteremic UTI caused by Enterobacteriaceae from January 2006 to August 2015 were retrospectively analyzed.A total of 585 patients were enrolled. Among them, 220 (37.6%) were caused by the MDR Enterobacteriaceae. A total of 206 patients (35.2%) developed severe sepsis or septic shock at presentation. Patients in the MDR group tend to be male and have a past history of gout, recurrent UTI, prior hospitalization, hydronephrosis, renal stone, ureteral stone, indwelling urinary catheter, newly development of renal dysfunction, severe sepsis or septic shock, intensive care unit (ICU) admission, receipt of ineffective empirical therapy, longer hospital stay, and higher in-hospital mortality (2.7% vs 1.9%, P = 0.569). Using multivariate logistic regression analysis, it is revealed that independent predictors associated with severe sepsis or septic shock at presentation were liver cirrhosis (OR 2.868; 95% CI 1.439-5.716; P = 0.003), indwelling urinary catheter (OR 1.936; 95% CI 1.238-3.027; P = 0.004), and MDR Enterobacteriaceae (OR 1.447; 95% CI 1.002-2.090; P = 0.049).Multidrug resistance was associated with the development of severe sepsis or septic shock upon presentation among patients with bacteremic UTI caused by Enterobacteriaceae. Therefore, empirical antibiotics therapy for patients with UTI presented with severe sepsis and/or septic shock should be more broad-spectrum to effectively cover MDR Enterobacteriaceae.

Battacin (Octapeptin B5), a New Cyclic Lipopeptide Antibiotic from Paenibacillus tianmuensis Active against Multidrug-Resistant Gram-Negative Bacteria

PubMed Central

Qian, Chao-Dong; Teng, Yi; Zhao, Wen-Peng; Li, Ou; Fang, Sheng-Guo; Huang, Zhao-Hui; Gao, Hai-Chun

2012-01-01

Hospital-acquired infections caused by drug-resistant bacteria are a significant challenge to patient safety. Numerous clinical isolates resistant to almost all commercially available antibiotics have emerged. Thus, novel antimicrobial agents, specifically those for multidrug-resistant Gram-negative bacteria, are urgently needed. In the current study, we report the isolation, structure elucidation, and preliminary biological characterization of a new cationic lipopeptide antibiotic, battacin or octapeptin B5, produced from a Paenibacillus tianmuensis soil isolate. Battacin kills bacteria in vitro and has potent activity against Gram-negative bacteria, including multidrug-resistant and extremely drug-resistant clinical isolates. Hospital strains of Escherichia coli and Pseudomonas aeruginosa are the pathogens most sensitive to battacin, with MICs of 2 to 4 μg/ml. The ability of battacin to disrupt the outer membrane of Gram-negative bacteria is comparable to that of polymyxin B, the last-line therapy for infections caused by antibiotic-resistant Gram-negative bacteria. However, the capacity of battacin to permeate bacterial plasma membranes is less extensive than that of polymyxin B. The bactericidal kinetics of battacin correlate with the depolarization of the cell membrane, suggesting that battacin kills bacteria by disrupting the cytoplasmic membrane. Other studies indicate that battacin is less acutely toxic than polymyxin B and has potent in vivo biological activity against E. coli. Based on the findings of the current study, battacin may be considered a potential therapeutic agent for the treatment of infections caused by antibiotic-resistant Gram-negative bacteria. PMID:22183171

The Role of Plant Growth-Promoting Bacteria in Metal Phytoremediation.

PubMed

Kong, Zhaoyu; Glick, Bernard R

2017-01-01

Phytoremediation is a promising technology that uses plants and their associated microbes to clean up contaminants from the environment. In recent years, phytoremediation assisted by plant growth-promoting bacteria (PGPB) has been highly touted for cleaning up toxic metals from soil. PGPB include rhizospheric bacteria, endophytic bacteria and the bacteria that facilitate phytoremediation by other means. This review provides information about the traits and mechanisms possessed by PGPB that improve plant metal tolerance and growth, and illustrate mechanisms responsible for plant metal accumulation/translocation in plants. Several recent examples of phytoremediation of metals facilitated by PGPB are reviewed. Although many encouraging results have been reported in the past years, there have also been numerous challenges encountered in phytoremediation in the field. To implement PGPB-assisted phytoremediation of metals in the natural environment, there is also a need to critically assess the ecological effects of PGPB, especially for those nonnative bacteria. © 2017 Elsevier Ltd All rights reserved.

A Veritable Menagerie of Heritable Bacteria from Ants, Butterflies, and Beyond: Broad Molecular Surveys and a Systematic Review

PubMed Central

Russell, Jacob A.; Funaro, Colin F.; Giraldo, Ysabel M.; Goldman-Huertas, Benjamin; Suh, David; Kronauer, Daniel J. C.; Moreau, Corrie S.; Pierce, Naomi E.

2012-01-01

Maternally transmitted bacteria have been important players in the evolution of insects and other arthropods, affecting their nutrition, defense, development, and reproduction. Wolbachia are the best studied among these and typically the most prevalent. While several other bacteria have independently evolved a heritable lifestyle, less is known about their host ranges. Moreover, most groups of insects have not had their heritable microflora systematically surveyed across a broad range of their taxonomic diversity. To help remedy these shortcomings we used diagnostic PCR to screen for five groups of heritable symbionts—Arsenophonus spp., Cardinium hertigii, Hamiltonella defensa, Spiroplasma spp., and Wolbachia spp.—across the ants and lepidopterans (focusing, in the latter case, on two butterfly families—the Lycaenidae and Nymphalidae). We did not detect Cardinium or Hamiltonella in any host. Wolbachia were the most widespread, while Spiroplasma (ants and lepidopterans) and Arsenophonus (ants only) were present at low levels. Co-infections with different Wolbachia strains appeared especially common in ants and less so in lepidopterans. While no additional facultative heritable symbionts were found among ants using universal bacterial primers, microbes related to heritable enteric bacteria were detected in several hosts. In summary, our findings show that Wolbachia are the dominant heritable symbionts of ants and at least some lepidopterans. However, a systematic review of symbiont frequencies across host taxa revealed that this is not always the case across other arthropods. Furthermore, comparisons of symbiont frequencies revealed that the prevalence of Wolbachia and other heritable symbionts varies substantially across lower-level arthropod taxa. We discuss the correlates, potential causes, and implications of these patterns, providing hypotheses on host attributes that may shape the distributions of these influential bacteria. PMID:23284655

The determination and arrangement of a combination of enzyme lactate dehydrogenase of bacteria Acinetobacter sp. as a device the identity important bacteria agent composts

NASA Astrophysics Data System (ADS)

Sukmawati, D.; Puspitaningrum, R.; Muzajjanah

2017-07-01

The number of garbage generated by the industry or society is a usual problem encountered by almost all urban centers, especially large cities such as Jakarta. Waste prevention strategy required quickly and accurately. One strategy for tackling the Junk was getting lactic acid-producing bacteria. It has been shown that lactic acid can increase the acceleration of organic matter such as an overhaul of lignin and cellulose as well as out causing toxic compounds arising from decay. This research will be conducted on the determination and characterization of the enzyme-producing compost bacteria LDH lactate dehydrogenase LDH - which in isolation from the garbage Landfill Rawasari. Methodology: Research carried out consists: isolation of lactic acid-producing bacteria; identification of microscopic, macroscopic and staining Gram; cellulose assay, and optimization of PCR conditions LDH enzymes producing bacteria. Isolation is performed by dilution method and the direct method. As many as 5-point sampling. Each stage is conducted from 10 grams of soil from the top surface of the compost. Isolation results obtained 100 isolate the bacteria. Base on the characteristic of macroscopic and microscopic observations retrieved 14 isolates of bacteria have shaped rods and brought forth a negative kind of Gram positive staining. Bacterial isolates with codes (BK1; BK3; BK4; BK5; BK6; BK7; BK8; BK9; BK10; BK11: BK12; BK 13). The potential bacteria with ability produce lactate dehydrogenase was BK1 and BK3. Base for analysis phylogenetic there was identification bacteria bak1 and bak3 where Acinetobacter sp.

Cerebrospinal fluid PCR analysis and biochemistry in bodies with severe decomposition.

PubMed

Palmiere, Cristian; Vanhaebost, Jessica; Ventura, Francesco; Bonsignore, Alessandro; Bonetti, Luca Reggiani

2015-02-01

The aim of this study was to assess whether Neisseria meningitidis, Listeria monocytogenes, Streptococcus pneumoniae and Haemophilus influenzae can be identified using the polymerase chain reaction technique in the cerebrospinal fluid of severely decomposed bodies with known, noninfectious causes of death or whether postmortem changes can lead to false positive results and thus erroneous diagnostic information. Biochemical investigations, postmortem bacteriology and real-time polymerase chain reaction analysis in cerebrospinal fluid were performed in a series of medico-legal autopsies that included noninfectious causes of death with decomposition, bacterial meningitis without decomposition, bacterial meningitis with decomposition, low respiratory tract infections with decomposition and abdominal infections with decomposition. In noninfectious causes of death with decomposition, postmortem investigations failed to reveal results consistent with generalized inflammation or bacterial infections at the time of death. Real-time polymerase chain reaction analysis in cerebrospinal fluid did not identify the studied bacteria in any of these cases. The results of this study highlight the usefulness of molecular approaches in bacteriology as well as the use of alternative biological samples in postmortem biochemistry in order to obtain suitable information even in corpses with severe decompositional changes. Copyright © 2014 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Effects of the Essential Oil from Origanum vulgare L. on Survival of Pathogenic Bacteria and Starter Lactic Acid Bacteria in Semihard Cheese Broth and Slurry.

PubMed

de Souza, Geany Targino; de Carvalho, Rayssa Julliane; de Sousa, Jossana Pereira; Tavares, Josean Fechine; Schaffner, Donald; de Souza, Evandro Leite; Magnani, Marciane

2016-02-01

This study assessed the inhibitory effects of the essential oil from Origanum vulgare L. (OVEO) on Staphylococcus aureus, Listeria monocytogenes, and a mesophilic starter coculture composed of lactic acid bacteria (Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris) in Brazilian coalho cheese systems. The MIC of OVEO was 2.5 μl/ml against both S. aureus and L. monocytogenes and 0.6 μl/ml against the tested starter coculture. In cheese broth containing OVEO at 0.6 μl/ml, no decrease in viable cell counts (VCC) of both pathogenic bacteria was observed, whereas the initial VCC of the starter coculture decreased approximately 1.0 log CFU/ml after 24 h of exposure at 10°C. OVEO at 1.25 and 2.5 μl/ml caused reductions of up to 2.0 and 2.5 log CFU/ml in S. aureus and L. monocytogenes, respectively, after 24 h of exposure in cheese broth. At these same concentrations, OVEO caused a greater decrease of initial VCC of the starter coculture following 4 h of exposure. Higher concentrations of OVEO were required to decrease the VCC of all target bacteria in semisolid coalho cheese slurry compared with cheese broth. The VCC of Lactococcus spp. in coalho cheese slurry containing OVEO were always lower than those of pathogenic bacteria under the same conditions. These results suggest that the concentrations of OVEO used to control pathogenic bacteria in semihard cheese should be carefully evaluated because of its inhibitory effects on the growth of starter lactic acid cultures used during the production of the product.

The Use of Bacteria for Remediation of Mercury Contaminated Groundwater

EPA Science Inventory

Many processes of mercury transformation in the environment are bacteria mediated. Mercury properties cause some difficulties of remediation of mercury contaminated environment. Despite the significance of the problem of mercury pollution, methods of large scale bioremediation ...

Motile bacteria in a critical fluid mixture

NASA Astrophysics Data System (ADS)

Koumakis, Nick; Devailly, Clémence; Poon, Wilson C. K.

2018-06-01

We studied the swimming of Escherichia coli bacteria in the vicinity of the critical point in a solution of the nonionic surfactant C12E5 in buffer solution. In phase-contrast microscopy, each swimming cell produces a transient trail behind itself lasting several seconds. Comparing quantitative image analysis with simulations show that these trails are due to local phase reorganization triggered by differential adsorption. This contrasts with similar trails seen in bacteria swimming in liquid crystals, which are due to shear effects. We show how our trails are controlled, and use them to probe the structure and dynamics of critical fluctuations in the fluid medium.

Fast-Moving Bacteria Self-Organize into Active Two-Dimensional Crystals of Rotating Cells

NASA Astrophysics Data System (ADS)

Petroff, Alexander P.; Wu, Xiao-Lun; Libchaber, Albert

2015-04-01

We investigate a new form of collective dynamics displayed by Thiovulum majus, one of the fastest-swimming bacteria known. Cells spontaneously organize on a surface into a visually striking two-dimensional hexagonal lattice of rotating cells. As each constituent cell rotates its flagella, it creates a tornadolike flow that pulls neighboring cells towards and around it. As cells rotate against their neighbors, they exert forces on one another, causing the crystal to rotate and cells to reorganize. We show how these dynamics arise from hydrodynamic and steric interactions between cells. We derive the equations of motion for a crystal, show that this model explains several aspects of the observed dynamics, and discuss the stability of these active crystals.

Rhizosphere Bacteria Enhance Selenium Accumulation and Volatilization by Indian Mustard1

PubMed Central

de Souza, Mark P.; Chu, Dara; Zhao, May; Zayed, Adel M.; Ruzin, Steven E.; Schichnes, Denise; Terry, Norman

1999-01-01

Indian mustard (Brassica juncea L.) accumulates high tissue Se concentrations and volatilizes Se in relatively nontoxic forms, such as dimethylselenide. This study showed that the presence of bacteria in the rhizosphere of Indian mustard was necessary to achieve the best rates of plant Se accumulation and volatilization of selenate. Experiments with the antibiotic ampicillin showed that bacteria facilitated 35% of plant Se volatilization and 70% of plant tissue accumulation. These results were confirmed by inoculating axenic plants with rhizosphere bacteria. Compared with axenic controls, plants inoculated with rhizosphere bacteria had 5-fold higher Se concentrations in roots (the site of volatilization) and 4-fold higher rates of Se volatilization. Plants with bacteria contained a heat-labile compound in their root exudate; when this compound was added to the rhizosphere of axenic plants, Se accumulation in plant tissues increased. Plants with bacteria had an increased root surface area compared with axenic plants; the increased area was unlikely to have caused their increased tissue Se accumulation because they did not accumulate more Se when supplied with selenite or selenomethionine. Rhizosphere bacteria also possibly increased plant Se volatilization because they enabled plants to overcome a rate-limiting step in the Se volatilization pathway, i.e. Se accumulation in plant tissues. PMID:9952452

Predicting Fecal Indicator Bacteria Fate and Removal in Urban Stormwater at the Watershed Scale

NASA Astrophysics Data System (ADS)

Wolfand, J.; Hogue, T. S.; Luthy, R. G.

2016-12-01

Urban stormwater is a major cause of water quality impairment, resulting in surface waters that fail to meet water quality standards and support their designated uses. Of the many stormwater pollutants, fecal indicator bacteria are particularly important to track because they are directly linked to pathogens which jeopardize public health; yet, their fate and transport in urban stormwater is poorly understood. Monitoring fecal bacteria in stormwater is possible, but due to the high variability of fecal indicators both spatially and temporally, single grab or composite samples do not fully capture fecal indicator loading. Models have been developed to predict fecal indicator bacteria at the watershed scale, but they are often limited to agricultural areas, or areas that receive frequent rainfall. Further, it is unclear whether best management practices (BMPs), such as bioretention or engineered wetlands, are able to reduce bacteria to meet water quality standards at watershed outlets. This research seeks to develop a model to predict fecal indicator bacteria in urban stormwater in a semi-arid climate at the watershed scale. Using the highly developed Ballona Creek watershed (89 mi2) located in Los Angeles County as a case study, several existing mechanistic models are coupled with a hydrologic model to predict fecal indicator concentrations (E. coli, enterococci, fecal coliform, and total coliform) at the outfall of Ballona Creek watershed, Santa Monica Bay. The hydrologic model was developed using InfoSWMM Sustain, calibrated for flow from WY 1998-2006 (NSE = 0.94; R2 = 0.95), and validated from WY 2007-2015 (NSE = 0.93; R2 = 0.95). The developed coupled model is being used to predict fecal indicator fate and transport and evaluate how BMPs can be optimized to reduce fecal indicator loading to surface waters and recreational beaches.

Chaotic Model for Lévy Walks in Swarming Bacteria

NASA Astrophysics Data System (ADS)

Ariel, Gil; Be'er, Avraham; Reynolds, Andy

2017-06-01

We describe a new mechanism for Lévy walks, explaining the recently observed superdiffusion of swarming bacteria. The model hinges on several key physical properties of bacteria, such as an elongated cell shape, self-propulsion, and a collectively generated regular vortexlike flow. In particular, chaos and Lévy walking are a consequence of group dynamics. The model explains how cells can fine-tune the geometric properties of their trajectories. Experiments confirm the spectrum of these patterns in fluorescently labeled swarming Bacillus subtilis.

Lactic acid bacteria as oral delivery systems for biomolecules.

PubMed

Berlec, A; Ravnikar, M; Strukelj, B

2012-11-01

Lactic acid bacteria (LAB) have become increasingly studied over the last two decades as potential delivery systems for various biological molecules to the gastrointestinal tract. This article presents an overview of characteristics of LAB as delivery systems and of the applications which have already been developed. The majority of LAB strains are able to survive the intestinal passage and some are also able to persist and colonize the intestine. Several strains were in fact described as members of the human commensal flora. They can interact with their host and are able to deliver large molecular weight biomolecules across the epithelium via M-cells or dendritic cells. The most widely applied LAB species has been Lactococcus lactis; however species from genus Lactobacillus are gaining popularity and the first examples from genus Bifidobacterium are starting to emerge. Bacteria are mostly applied live and enable continuous delivery of the biomolecules. However, killed bacteria (e.g. gram-positive enhancer matrix), with bound biomolecules or as adjuvants, are also being developed. The techniques for genetic modification of LAB are well known. This review focuses on the delivery of recombinant proteins and DNA, which can cause either local or systemic effects. We divide recombinant proteins into antigens and therapeutic proteins. Delivery of antigens for the purpose of vaccination represents the most abundant application with numerous successful demonstrations of the efficacy on the animal model. Therapeutic proteins have mostly been developed for the treatment of the inflammatory bowel disease, by the delivery of anti-inflammatory cytokines, or downregulation of proinflammatory cytokines. Delivery of allergens for the modulation of allergic disorders represents the second most popular application of therapeutic proteins. The delivery of DNA by LAB was demonstrated and offers exciting opportunities, especially as a vaccine. New discoveries may eventually lead to the

[Anaerobic bacteria 150 years after their discovery by Pasteur].

PubMed

García-Sánchez, José Elías; García-Sánchez, Enrique; Martín-Del-Rey, Ángel; García-Merino, Enrique

2015-02-01

In 2011 we celebrated the 150th anniversary of the discovery of anaerobic bacteria by Louis Pasteur. The interest of the biomedical community on such bacteria is still maintained, and is particularly focused on Clostridium difficile. In the past few years important advances in taxonomy have been made due to the genetic, technological and computing developments. Thus, a significant number of new species related to human infections have been characterised, and some already known have been reclassified. At pathogenic level some specimens of anaerobic microflora, that had not been isolated from human infections, have been now isolated in some clinical conditions. There was emergence (or re-emergence) of some species and clinical conditions. Certain anaerobic bacteria have been associated with established infectious syndromes. The virulence of certain strains has increased, and some hypotheses on their participation in certain diseases have been given. In terms of diagnosis, the routine use of MALDI-TOF has led to a shortening of time and a cost reduction in the identification, with an improvement directly related to the improvement of data bases. The application of real-time PCR has been another major progress, and the sequencing of 16srRNA gene and others is currently a reality for several laboratories. Anaerobes have increased their resistance to antimicrobial agents, and the emergence of resistance to carbapenems and metronidazole, and multi-resistance is a current reality. In this situation, linezolid could be an effective alternative for Bacteroides. Fidaxomicin is the only anti-anaerobic agent introduced in the recent years, specifically for the diarrhoea caused by C.difficile. Moreover, some mathematical models have also been proposed in relation with this species. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

A subperiosteal maxillary implant causing severe osteolysis.

PubMed

Maï, Nguyen Tan; Jean-Baptiste, Caruhel; Hossein, Khonsari Roman

2018-06-22

Subperiosteal implant denture therapy was initially introduced in 1942 in Sweden and was then used worldwide for the treatment of fully edentulous maxillary or mandibular arches with advanced bone atrophy. Most authors describe decent success rates for mandibular subperiosteal implants in cases with major bone atrophy but follow-up studies for maxillary subperiosteal implants are not available. Here, we report a case of severe maxillary osteolysis secondary to the placement of a subperiosteal in-house implant. Subperiosteal implants are rarely used today but patients still carrying these devices with severe complications can be challenging to manage. New technical advances, including the use of surgical planification and additive manufacturing, may lead to a new interest in subperiosteal implants. Copyright © 2018. Published by Elsevier Masson SAS.

Antioxidant and Antimicrobial Potential of the Bifurcaria bifurcata Epiphytic Bacteria

PubMed Central

Horta, André; Pinteus, Susete; Alves, Celso; Fino, Nádia; Silva, Joana; Fernandez, Sara; Rodrigues, Américo; Pedrosa, Rui

2014-01-01

Surface-associated marine bacteria are an interesting source of new secondary metabolites. The aim of this study was the isolation and identification of epiphytic bacteria from the marine brown alga, Bifurcaria bifurcata, and the evaluation of the antioxidant and antimicrobial activity of bacteria extracts. The identification of epiphytic bacteria was determined by 16S rRNA gene sequencing. Bacteria extracts were obtained with methanol and dichloromethane (1:1) extraction. The antioxidant activity of extracts was performed by quantification of total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and oxygen radical absorbance capacity (ORAC). Antimicrobial activities were evaluated against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Salmonella enteritidis, Staphylococcus aureus, Saccharomyces cerevisiae and Candida albicans. A total of 39 Bifurcaria bifurcata-associated bacteria were isolated and 33 were identified as Vibrio sp. (48.72%), Alteromonas sp. (12.82%), Shewanella sp. (12.26%), Serratia sp. (2.56%), Citricoccus sp. (2.56%), Cellulophaga sp. (2.56%), Ruegeria sp. (2.56%) and Staphylococcus sp. (2.56%). Six (15.38%) of the 39 bacteria Bifurcaria bifurcata-associated bacteria presented less than a 90% Basic Local Alignment Search Tool (BLAST) match, and some of those could be new. The highest antioxidant activity and antimicrobial activity (against B. subtilis) was exhibited by strain 16 (Shewanella sp.). Several strains also presented high antimicrobial activity against S. aureus, mainly belonging to Alteromonas sp. and Vibrio sp. There were no positive results against fungi and Gram-negative bacteria. Bifurcaria bifurcata epiphytic bacteria were revealed to be excellent sources of natural antioxidant and antimicrobial compounds. PMID:24663118

Antioxidant and antimicrobial potential of the Bifurcaria bifurcata epiphytic bacteria.

PubMed

Horta, André; Pinteus, Susete; Alves, Celso; Fino, Nádia; Silva, Joana; Fernandez, Sara; Rodrigues, Américo; Pedrosa, Rui

2014-03-24

Surface-associated marine bacteria are an interesting source of new secondary metabolites. The aim of this study was the isolation and identification of epiphytic bacteria from the marine brown alga, Bifurcaria bifurcata, and the evaluation of the antioxidant and antimicrobial activity of bacteria extracts. The identification of epiphytic bacteria was determined by 16S rRNA gene sequencing. Bacteria extracts were obtained with methanol and dichloromethane (1:1) extraction. The antioxidant activity of extracts was performed by quantification of total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and oxygen radical absorbance capacity (ORAC). Antimicrobial activities were evaluated against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Salmonella enteritidis, Staphylococcus aureus, Saccharomyces cerevisiae and Candida albicans. A total of 39 Bifurcaria bifurcata-associated bacteria were isolated and 33 were identified as Vibrio sp. (48.72%), Alteromonas sp. (12.82%), Shewanella sp. (12.26%), Serratia sp. (2.56%), Citricoccus sp. (2.56%), Cellulophaga sp. (2.56%), Ruegeria sp. (2.56%) and Staphylococcus sp. (2.56%). Six (15.38%) of the 39 bacteria Bifurcaria bifurcata-associated bacteria presented less than a 90% Basic Local Alignment Search Tool (BLAST) match, and some of those could be new. The highest antioxidant activity and antimicrobial activity (against B. subtilis) was exhibited by strain 16 (Shewanella sp.). Several strains also presented high antimicrobial activity against S. aureus, mainly belonging to Alteromonas sp. and Vibrio sp. There were no positive results against fungi and Gram-negative bacteria. Bifurcaria bifurcata epiphytic bacteria were revealed to be excellent sources of natural antioxidant and antimicrobial compounds.

Is there, and should there be, apoptosis in bacteria?

PubMed

Häcker, Georg

2013-01-01

Apoptosis is a well-studied form of cell death in metazoans, where it has a clear role during the life of the (multicellular) animal. Some situations of cell death in unicellular eukaryotes (protozoa and yeast) have also been referred to as apoptosis. In recent years apoptosis has further been identified in bacteria several times. As a bacterial response to external stimuli, apoptosis could be important not only for the bacteria but also to the host. Here I will discuss why I believe that the term apoptosis should be avoided for these situations in bacteria, no matter how interesting the molecular background or how biologically important the underlying mechanism may be. Copyright © 2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Impact of Flood Spates on Denitrifying Bacteria in Low Order Streams

NASA Astrophysics Data System (ADS)

Herrman, K.; Stokdyk, J.

2011-12-01

The impact of flood events on channel design, macroinvertebrates, and periphyton in stream ecosystems has been well studied. Little is known, however, about how flood spates affect microorganisms found in stream sediments. Denitrifying bacteria are beneficial organisms because they convert nitrates to nitrogen gas. Providing data that describes the impact of flood events on denitrifiers and the time required after the disturbance for the bacteria to recover are crucial in understanding nitrogen dynamics in stream ecosystems. Three low order streams in central Wisconsin, USA are being monitored during several flood spates during July and August of 2011. Discharge is being continuously monitored in all three streams and sediments are being collected before and after several flood events for laboratory assays. Specifically, sediments are being processed for denitrification rates using the acetylene inhibition technique, microbial biomass carbon using chloroform fumigation, and the quantification of denitrifying bacteria (i.e., nirS, nirK, and nosZ genes) using real-time quantitative PCR. Preliminary data show that within 36 hours after a 90 mm rain event, microbial biomass carbon in all three streams (580 μg C g sediment-1) significantly increased (F1,23 = 650 ± 140; p < 0.001) compared to microbial biomass during baseflow (200 ± 27 μg C g sediment-1). These initial results suggest that contrary to our expectations flood events enhance bacteria in stream sediments. Denitrification rates and quantification of denitrifying bacteria still need to be analyzed to determine if these specific bacteria follow a similar pattern or if the bacterial recolonization of stream sediments follows a unique pattern.

Chromosomal duplications in bacteria, fruit flies, and humans

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

Lupski, J.R.; Weinstock, G.M.; Roth, J.R.

1996-01-01

Tandem duplication of chromosomal segments has been recognized as a frequent mutational mechanism in several genetic model systems. In bacteria, fruit flies, and humans, duplications form by similar molecular mechanisms and appear to be important in genome evolution. 80 refs.

Wastewater nutrient removal in a mixed microalgae-bacteria culture: effect of light and temperature on the microalgae-bacteria competition.

PubMed

González-Camejo, J; Barat, R; Pachés, M; Murgui, M; Seco, A; Ferrer, J

2018-02-01

The aim of this study was to evaluate the effect of light intensity and temperature on nutrient removal and biomass productivity in a microalgae-bacteria culture and their effects on the microalgae-bacteria competition. Three experiments were carried out at constant temperature and various light intensities: 40, 85 and 125 µE m -2  s -1 . Other two experiments were carried out at variable temperatures: 23 ± 2°C and 28 ± 2°C at light intensity of 85 and 125 µE m -2  s -1 , respectively. The photobioreactor was fed by the effluent from an anaerobic membrane bioreactor. High nitrogen and phosphorus removal efficiencies (about 99%) were achieved under the following operating conditions: 85-125 µE m -2  s -1 and 22 ± 1°C. In the microalgae-bacteria culture studied, increasing light intensity favoured microalgae growth and limited the nitrification process. However, a non-graduated temperature increase (up to 32°C) under the light intensities studied caused the proliferation of nitrifying bacteria and the nitrite and nitrate accumulation. Hence, light intensity and temperature are key parameters in the control of the microalgae-bacteria competition. Biomass productivity significantly increased with light intensity, reaching 50.5 ± 9.6, 80.3 ± 6.5 and 94.3 ± 7.9 mgVSS L -1  d -1 for a light intensity of 40, 85 and 125 µE m -2  s -1 , respectively.

Removal of bacteria Legionella pneumophila, Escherichia coli, and Bacillus subtilis by (super)cavitation.

PubMed

Šarc, Andrej; Kosel, Janez; Stopar, David; Oder, Martina; Dular, Matevž

2018-04-01

In sufficient concentrations, the pathogenic bacteria L. pneumophila can cause a respiratory illness that is known as the "Legionnaires" disease. Moreover, toxic Shiga strains of bacteria E. coli can cause life-threatening hemolytic-uremic syndrome. Because of the recent restrictions imposed on the usage of chlorine, outbreaks of these two bacterial species have become more common. In this study we have developed a novel rotation generator and its effectiveness against bacteria Legionella pneumophila and Escherichia coli was tested for various types of hydrodynamic cavitation (attached steady cavitation, developed unsteady cavitation and supercavitation). The results show that the supercavitation was the only effective form of cavitation. It enabled more than 3 logs reductions for both bacterial species and was also effective against a more persistent Gram positive bacteria, B. subtilis. The deactivation mechanism is at present unknown. It is proposed that when bacterial cells enter a supercavitation cavity, an immediate pressure drop occurs and this results in bursting of the cellular membrane. The new rotation generator that induced supercavitation proved to be economically and microbiologically far more effective than the classical Venturi section (super)cavitation. Copyright © 2017 Elsevier B.V. All rights reserved.

Prevalence and causes of severe visual impairment and blindness among children in the lorestan province of iran, using the key informant method.

PubMed

Razavi, Hessom; Kuper, Hannah; Rezvan, Farhad; Amelie, Khatere; Mahboobi-Pur, Hassan; Oladi, Mohammad Reza; Muhit, Mohammad; Hashemi, Hassan

2010-03-01

To estimate the prevalence and causes of severe visual impairment and blindness among children in Lorestan province of Iran, and to assess the feasibility of the Key Informant Method in this setting. Potential cases were identified using the Key Informant Method, in 3 counties of Lorestan province during June through August 2008, and referred for examination. Causes of severe visual impairment/blindness were determined and categorized using standard World Health Organization methods. Of 123 children referred for examination, 27 children were confirmed to have severe visual impairment/blindness or blindness. The median age was11 years (interquartile range 6-13), and 59% were girls. After adjusting for non-attenders, the estimated prevalence of severe visual impairment/blindness was 0.04% (0.03-0.05). The main site of abnormality was retina (44%), followed by disorders of the whole eye (33%). The majority of causes had a hereditary etiology (70%), which was associated with a family history of blindness (P = 0.002). Potentially avoidable causes of severe visual impairment/blindness were found in 14 children (52%). Almost all children with severe visual impairment/blindness had a history of parental consanguinity (93%). Our findings suggest a moderate prevalence of childhood blindness in the Lorestan province of Iran, a high proportion of which may be avoidable, given improved access to ophthalmic and genetic counselling services in rural areas. The Key Informant Method is feasible in Iran; future research is discussed.

Comparative Analysis of the Antimicrobial Activities of Plant Defensin-Like and Ultrashort Peptides against Food-Spoiling Bacteria.

PubMed

Kraszewska, Joanna; Beckett, Michael C; James, Tharappel C; Bond, Ursula

2016-07-15

Antimicrobial peptides offer potential as novel therapeutics to combat food spoilage and poisoning caused by pathogenic and nonpathogenic bacteria. Our previous studies identified the peptide human beta-defensin 3 (HBD3) as a potent antimicrobial agent against a wide range of beer-spoiling bacteria. Thus, HBD3 is an excellent candidate for development as an additive to prevent food and beverage spoilage. To expand the repertoire of peptides with antimicrobial activity against bacteria associated with food spoilage and/or food poisoning, we carried out an in silico discovery pipeline to identify peptides with structure and activity similar to those of HBD3, focusing on peptides of plant origin. Using a standardized assay, we compared the antimicrobial activities of nine defensin-like plant peptides to the activity of HBD3. Only two of the peptides, fabatin-2 and Cp-thionin-2, displayed antimicrobial activity; however, the peptides differed from HBD3 in being sensitive to salt and were thermostable. We also compared the activities of several ultrashort peptides to that of HBD3. One of the peptides, the synthetic tetrapeptide O3TR, displayed biphasic antimicrobial activity but had a narrower host range than HBD3. Finally, to determine if the peptides might act in concert to improve antimicrobial activity, we compared the activities of the peptides in pairwise combinations. The plant defensin-like peptides fabatin-2 and Cp-thionin-2 displayed a synergistic effect with HBD3, while O3TR was antagonistic. Thus, some plant defensin-like peptides are effective antimicrobials and may act in concert with HBD3 to control bacteria associated with food spoilage and food poisoning. Food spoilage and food poisoning caused by bacteria can have major health and economic implications for human society. With the rise in resistance to conventional antibiotics, there is a need to identify new antimicrobials to combat these outbreaks in our food supply. Here we screened plant peptide

Role of granular activated carbon in the microalgal cultivation from bacteria contamination.

PubMed

Ni, Zhi-Yi; Li, Jing-Ya; Xiong, Zhao-Zhao; Cheng, Li-Hua; Xu, Xin-Hua

2018-01-01

Microalgal wastewater treatment has been considered as one of the most promising measures to treat nitrogen and phosphorus in the municipal wastewater. While the municipal wastewater provides sufficient nitrogen and phosphorus for microalgal growth, the microalgae still faces serious biological contamination caused by bacteria in wastewater. In this study, the commercial granular activated carbon (GAC) was added into the simulated municipal wastewater to avoid the influence of bacteria on the growth of microalgae. The extracellular organic matter (EOM) in microalgal broth was then characterized to enlighten the role of GAC in reducing the bioavailability of EOM. The results showed that the GAC addition could increase the dry weight of microalgae from 0.06mgL -1 to 0.46mgL -1 under the condition of bacterial inoculation. The GAC could mitigate bacterial contamination mainly due to its adsorption of both bacteria and EOM that might contain algicidal extracellular substances. Moreover, compared to the control group, the GAC addition could mitigate the microalgal lysis caused by bacteria and thus greatly reduce the bioavailability of EOM from 2.80mgL -1 to 0.61mgL -1 , which was beneficial for the improvement of biostability and reuse of effluent after the microalgal harvesting. Copyright © 2017 Elsevier Ltd. All rights reserved.

Differentiating the growth phases of single bacteria using Raman spectroscopy

NASA Astrophysics Data System (ADS)

Strola, S. A.; Marcoux, P. R.; Schultz, E.; Perenon, R.; Simon, A.-C.; Espagnon, I.; Allier, C. P.; Dinten, J.-M.

2014-03-01

In this paper we present a longitudinal study of bacteria metabolism performed with a novel Raman spectrometer system. Longitudinal study is possible with our Raman setup since the overall procedure to localize a single bacterium and collect a Raman spectrum lasts only 1 minute. Localization and detection of single bacteria are performed by means of lensfree imaging, whereas Raman signal (from 600 to 3200 cm-1) is collected into a prototype spectrometer that allows high light throughput (HTVS technology, Tornado Spectral System). Accomplishing time-lapse Raman spectrometry during growth of bacteria, we observed variation in the net intensities for some band groups, e.g. amides and proteins. The obtained results on two different bacteria species, i.e. Escherichia coli and Bacillus subtilis clearly indicate that growth affects the Raman chemical signature. We performed a first analysis to check spectral differences and similarities. It allows distinguishing between lag, exponential and stationary growth phases. And the assignment of interest bands to vibration modes of covalent bonds enables the monitoring of metabolic changes in bacteria caused by growth and aging. Following the spectra analysis, a SVM (support vector machine) classification of the different growth phases is presented. In sum this longitudinal study by means of a compact and low-cost Raman setup is a proof of principle for routine analysis of bacteria, in a real-time and non-destructive way. Real-time Raman studies on metabolism and viability of bacteria pave the way for future antibiotic susceptibility testing.

Bacteriophages of lactic acid bacteria and their impact on milk fermentations

PubMed Central

2011-01-01

Every biotechnology process that relies on the use of bacteria to make a product or to overproduce a molecule may, at some time, struggle with the presence of virulent phages. For example, phages are the primary cause of fermentation failure in the milk transformation industry. This review focuses on the recent scientific advances in the field of lactic acid bacteria phage research. Three specific topics, namely, the sources of contamination, the detection methods and the control procedures will be discussed. PMID:21995802

Quantification of Growth of Campylobacter and Extended Spectrum β-Lactamase Producing Bacteria Sheds Light on Black Box of Enrichment Procedures.

PubMed

Hazeleger, Wilma C; Jacobs-Reitsma, Wilma F; den Besten, Heidy M W

2016-01-01

Campylobacter is well recognized as the leading cause of bacterial foodborne diarrheal disease worldwide, and is routinely found in meat originating from poultry, sheep, pigs, and cattle. Effective monitoring of Campylobacter contamination is dependent on the availability of reliable detection methods. The method of the International Organization for Standardization for the detection of Campylobacter spp. in food (ISO 10272-1:2006) recommends the use of Bolton broth (BB) as selective enrichment medium, including a pre-enrichment step of 4-6 h at 37°C to revive sublethally damaged cells prior to incubation for 2 days at 41.5°C. Recently the presence of abundantly growing extended spectrum β-lactamase producing Enterobacteriaceae (ESBL bacteria) has become one of the most important factors that interfere with the isolation of Campylobacter, resulting in false-negative detection. However, detailed growth dynamics of Campylobacter and its competitors remain unclear, where these would provide a solid base for further improvement of the enrichment procedure for Campylobacter. Other enrichment broths, such as Preston broth (PB) and BB plus clavulanic acid (BBc) have been suggested to inhibit competitive flora. Therefore, these different broths were used as enrichments to measure the growth kinetics of several strains of Campylobacter jejuni and ESBL bacteria separately, in co-culture and of strains in chicken samples. The maximum cell numbers and often the growth rates of Campylobacter in mixed culture with ESBL bacteria were significantly lower than in single cultures, indicating severe suppression of Campylobacter by ESBL bacteria, also in naturally contaminated samples. PB and BBc successfully diminished ESBL bacteria and might therefore be a better choice as enrichment medium in possibly ESBL-bacteria contaminated samples. The efficacy of a pre-enrichment step in the BB ISO-procedure was not supported for cold-stressed and non-stressed cells. Therefore, omission of

Bacteria from Animals as a Pool of Antimicrobial Resistance Genes

PubMed Central

Argudín, Maria Angeles; Deplano, Ariane; Meghraoui, Alaeddine; Dodémont, Magali; Heinrichs, Amelie; Denis, Olivier; Nonhoff, Claire; Roisin, Sandrine

2017-01-01

Antimicrobial agents are used in both veterinary and human medicine. The intensive use of antimicrobials in animals may promote the fixation of antimicrobial resistance genes in bacteria, which may be zoonotic or capable to transfer these genes to human-adapted pathogens or to human gut microbiota via direct contact, food or the environment. This review summarizes the current knowledge of the use of antimicrobial agents in animal health and explores the role of bacteria from animals as a pool of antimicrobial resistance genes for human bacteria. This review focused in relevant examples within the ESC(K)APE (Enterococcus faecium, Staphylococcus aureus, Clostridium difficile (Klebsiella pneumoniae), Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacteriaceae) group of bacterial pathogens that are the leading cause of nosocomial infections throughout the world. PMID:28587316

Kindler syndrome causing severe cicatricial ectropion.

PubMed

Lelli, Gary J

2010-01-01

A 32-year-old female with Kindler syndrome presented with a 5-year history of lower eyelid malposition, corneal exposure, and recurrent erosions. Severe anterior lamellar cicatricial changes were noted bilaterally, with bilateral lower eyelid ectropion and retraction. Tarsal eversion was noted on the left lower eyelid. The patient had repeatedly failed conservative treatments for keratopathy and was treated surgically, with resolution of corneal disease and improved lower eyelid position. A review of Kindler syndrome is provided, geared toward the oculoplastic surgeon who may participate in the care of these patients.

Variation in disease severity caused by Phytophthora cinnamomi, P. plurivora, and Pythium cryptoirregulare on two rhododendron cultivars

USDA-ARS?s Scientific Manuscript database

Rhododendrons are an important component of the ornamental nursery industry, but are prone to Phytophthora root rot. Phytophthora root rot is a continuing issue on rhododendrons despite decades of research. Several Phytophthora species are known to cause root rot, but most research has focused on P....

Characterization of recombinant Trypanosoma brucei gambiense Translationally Controlled Tumor Protein (rTbgTCTP) and its interaction with Glossina midgut bacteria.

PubMed

Bossard, Géraldine; Bartoli, Manon; Fardeau, Marie-Laure; Holzmuller, Philippe; Ollivier, Bernard; Geiger, Anne

2017-09-03

In humans, sleeping sickness (i.e. Human African Trypanosomiasis) is caused by the protozoan parasites Trypanosoma brucei gambiense (Tbg) in West and Central Africa, and T. b. rhodesiense in East Africa. We previously showed in vitro that Tbg is able to excrete/secrete a large number of proteins, including Translationally Controlled Tumor Protein (TCTP). Moreover, the tctp gene was described previously to be expressed in Tbg-infected flies. Aside from its involvement in diverse cellular processes, we have investigated a possible alternative role within the interactions occurring between the trypanosome parasite, its tsetse fly vector, and the associated midgut bacteria. In this context, the Tbg tctp gene was synthesized and cloned into the baculovirus vector pAcGHLT-A, and the corresponding protein was produced using the baculovirus Spodoptera frugicola (strain 9) / insect cell system. The purified recombinant protein rTbgTCTP was incubated together with bacteria isolated from the gut of tsetse flies, and was shown to bind to 24 out of the 39 tested bacteria strains belonging to several genera. Furthermore, it was shown to affect the growth of the majority of these bacteria, especially when cultivated under microaerobiosis and anaerobiosis. Finally, we discuss the potential for TCTP to modulate the fly microbiome composition toward favoring trypanosome survival.

Virulence properties of cariogenic bacteria

PubMed Central

Kuramitsu, Howard K; Wang, Bing-Yan

2006-01-01

The importance of Streptococcus mutans in the etiology of dental caries has been well documented. However, there is growing recognition that the cariogenic potential of dental plaque may be determined by the composite interactions of the total plaque bacteria rather than solely the virulence properties of a single organism. This study will examine how the interactions of S. mutans with other biofilm constituents may influence the cariogenicity of plaque samples. In order to begin to investigate the effects of nonmutans streptococci on the cariogenic potential of S. mutans, we have examined the effects of Streptococcus gordonii on the virulence properties of the former organisms. These studies have indicated that S.gordonii can attenuate several potential virulence properties of S. mutans including bacteriocin production, genetic transformation, and biofilm formation. Therefore, modulation of the interactions between plaque bacteria might be a novel approach for attenuating dental caries initiation. PMID:16934112

COMPOSITE SAMPLING FOR DETECTION OF COLIFORM BACTERIA IN WATER SUPPLY

EPA Science Inventory

Low densities of coliform bacteria introduced into distribution systems may survive in protected habitats. These organisms may interfere with and cause confusion in the use of the coliforms as indicators of sewage contamination of drinking water. Methods of increasing the probabi...

Plant growth-promoting bacteria as inoculants in agricultural soils

PubMed Central

de Souza, Rocheli; Ambrosini, Adriana; Passaglia, Luciane M.P.

2015-01-01

Abstract Plant-microbe interactions in the rhizosphere are the determinants of plant health, productivity and soil fertility. Plant growth-promoting bacteria (PGPB) are bacteria that can enhance plant growth and protect plants from disease and abiotic stresses through a wide variety of mechanisms; those that establish close associations with plants, such as the endophytes, could be more successful in plant growth promotion. Several important bacterial characteristics, such as biological nitrogen fixation, phosphate solubilization, ACC deaminase activity, and production of siderophores and phytohormones, can be assessed as plant growth promotion (PGP) traits. Bacterial inoculants can contribute to increase agronomic efficiency by reducing production costs and environmental pollution, once the use of chemical fertilizers can be reduced or eliminated if the inoculants are efficient. For bacterial inoculants to obtain success in improving plant growth and productivity, several processes involved can influence the efficiency of inoculation, as for example the exudation by plant roots, the bacterial colonization in the roots, and soil health. This review presents an overview of the importance of soil-plant-microbe interactions to the development of efficient inoculants, once PGPB are extensively studied microorganisms, representing a very diverse group of easily accessible beneficial bacteria. PMID:26537605

Depth-Related Changes in Community Structure of Culturable Mineral Weathering Bacteria and in Weathering Patterns Caused by Them along Two Contrasting Soil Profiles

PubMed Central

Huang, Jing; Xi, Jun; Huang, Zhi; Wang, Qi; Zhang, Zhen-Dong

2014-01-01

Bacteria play important roles in mineral weathering and soil formation. However, few reports of mineral weathering bacteria inhabiting subsurfaces of soil profiles have been published, raising the question of whether the subsurface weathering bacteria are fundamentally distinct from those in surface communities. To address this question, we isolated and characterized mineral weathering bacteria from two contrasting soil profiles with respect to their role in the weathering pattern evolution, their place in the community structure, and their depth-related changes in these two soil profiles. The effectiveness and pattern of bacterial mineral weathering were different in the two profiles and among the horizons within the respective profiles. The abundance of highly effective mineral weathering bacteria in the Changshu profile was significantly greater in the deepest horizon than in the upper horizons, whereas in the Yanting profile it was significantly greater in the upper horizons than in the deeper horizons. Most of the mineral weathering bacteria from the upper horizons of the Changshu profile and from the deeper horizons of the Yanting profile significantly acidified the culture media in the mineral weathering process. The proportion of siderophore-producing bacteria in the Changshu profile was similar in all horizons except in the Bg2 horizon, whereas the proportion of siderophore-producing bacteria in the Yanting profile was higher in the upper horizons than in the deeper horizons. Both profiles existed in different highly depth-specific culturable mineral weathering community structures. The depth-related changes in culturable weathering communities were primarily attributable to minor bacterial groups rather than to a change in the major population structure. PMID:24077700

Spatial Variability of Cyanobacteria and Heterotrophic Bacteria in Lake Taihu (China).

PubMed

Qian, Haifeng; Lu, Tao; Song, Hao; Lavoie, Michel; Xu, Jiahui; Fan, Xiaoji; Pan, Xiangliang

2017-09-01

Cyanobacterial blooms frequently occur in Lake Taihu (China), but the intertwined relationships between biotic and abiotic factors modulating the frequency and duration of the blooms remain enigmatic. To better understand the relationships between the key abiotic and biotic factors and cyanobacterial blooms, we measured the abundance and diversity of prokaryotic organisms by high-throughput sequencing, the abundance of key genes involved in microcystin production and nitrogen fixation or loss as well as several physicochemical parameters at several stations in Lake Taihu during a cyanobacterial bloom of Microcystis sp.. Measurements of the copy number of denitrification-related genes and 16S rRNA analyses show that denitrification potential and denitrifying bacteria abundance increased in concert with non-diazotrophic cyanobacteria (Microcystis sp.), suggesting limited competition between cyanobacteria and heterotrophic denitrifiers for nutrients, although potential bacteria-mediated N loss may hamper Microcystis growth. The present study provides insight into the importance of different abiotic and biotic factors in controlling cyanobacteria and heterotrophic bacteria spatial variability in Lake Taihu.

Drought delays development of the sorghum root microbiome and enriches for monoderm bacteria

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

Xu, Ling; Naylor, Dan; Dong, Zhaobin

Here, drought stress is a major obstacle to crop productivity, and the severity and frequency of drought are expected to increase in the coming century. Certain root-associated bacteria have been shown to mitigate the negative effects of drought stress on plant growth, and manipulation of the crop microbiome is an emerging strategy for overcoming drought stress in agricultural systems, yet the effect of drought on the development of the root microbiome is poorly understood. Through 16S rRNA amplicon and metatranscriptome sequencing, as well as root metabolomics, we demonstrate that drought delays the development of the early sorghum root microbiome andmore » causes increased abundance and activity of monoderm bacteria, which lack an outer cell membrane and contain thick cell walls. Our data suggest that altered plant metabolism and increased activity of bacterial ATP-binding cassette (ABC) transporter genes are correlated with these shifts in community composition. Finally, inoculation experiments with monoderm isolates indicate that increased colonization of the root during drought can positively impact plant growth. Collectively, these results demonstrate the role that drought plays in restructuring the root microbiome and highlight the importance of temporal sampling when studying plant-associated microbiomes.« less

Drought delays development of the sorghum root microbiome and enriches for monoderm bacteria

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

Xu, Ling; Naylor, Dan; Dong, Zhaobin

Drought stress is a major obstacle to crop productivity and the severity and frequency of drought are expected to increase in the coming century. Certain root-associated bacteria have been shown to mitigate the negative effects of drought stress on plant growth, and manipulation of the crop microbiome is an emerging strategy for overcoming drought stress in agricultural systems, yet the effect of drought on the development of the root microbiome is poorly understood. Through16S amplicon and metatranscriptome sequencing, as well as root metabolomics, we demonstrate that drought delays the development of the early sorghum root microbiome and causes increased abundancemore » and activity of monoderm bacteria, which lack an outer cell membrane and contain thick cell walls. Our data suggest that altered plant metabolism and increased activity of bacterial ABC (ATP-binding cassette)-transporter genes may mediate these shifts in community composition. Finally, experiments with fluorescently tagged monoderms indicate that increased colonization of the root during drought can positively impact plant growth. Collectively, these results demonstrate the role drought plays in restructuring the root microbiome and highlight the importance of temporal sampling when studying plant-associated microbiomes.« less

Drought delays development of the sorghum root microbiome and enriches for monoderm bacteria

DOE PAGES

Xu, Ling; Naylor, Dan; Dong, Zhaobin; ...

2018-04-16

Here, drought stress is a major obstacle to crop productivity, and the severity and frequency of drought are expected to increase in the coming century. Certain root-associated bacteria have been shown to mitigate the negative effects of drought stress on plant growth, and manipulation of the crop microbiome is an emerging strategy for overcoming drought stress in agricultural systems, yet the effect of drought on the development of the root microbiome is poorly understood. Through 16S rRNA amplicon and metatranscriptome sequencing, as well as root metabolomics, we demonstrate that drought delays the development of the early sorghum root microbiome andmore » causes increased abundance and activity of monoderm bacteria, which lack an outer cell membrane and contain thick cell walls. Our data suggest that altered plant metabolism and increased activity of bacterial ATP-binding cassette (ABC) transporter genes are correlated with these shifts in community composition. Finally, inoculation experiments with monoderm isolates indicate that increased colonization of the root during drought can positively impact plant growth. Collectively, these results demonstrate the role that drought plays in restructuring the root microbiome and highlight the importance of temporal sampling when studying plant-associated microbiomes.« less

More Easily Cultivated Than Identified: Classical Isolation With Molecular Identification of Vaginal Bacteria

PubMed Central

Srinivasan, Sujatha; Munch, Matthew M.; Sizova, Maria V.; Fiedler, Tina L.; Kohler, Christina M.; Hoffman, Noah G.; Liu, Congzhou; Agnew, Kathy J.; Marrazzo, Jeanne M.; Epstein, Slava S.; Fredricks, David N.

2016-01-01

Background. Women with bacterial vaginosis (BV) have complex communities of anaerobic bacteria. There are no cultivated isolates of several bacteria identified using molecular methods and associated with BV. It is unclear whether this is due to the inability to adequately propagate these bacteria or to correctly identify them in culture. Methods. Vaginal fluid from 15 women was plated on 6 different media using classical cultivation approaches. Individual isolates were identified by 16S ribosomal RNA (rRNA) gene sequencing and compared with validly described species. Bacterial community profiles in vaginal samples were determined using broad-range 16S rRNA gene polymerase chain reaction and pyrosequencing. Results. We isolated and identified 101 distinct bacterial strains spanning 6 phyla including (1) novel strains with <98% 16S rRNA sequence identity to validly described species, (2) closely related species within a genus, (3) bacteria previously isolated from body sites other than the vagina, and (4) known bacteria formerly isolated from the vagina. Pyrosequencing showed that novel strains Peptoniphilaceae DNF01163 and Prevotellaceae DNF00733 were prevalent in women with BV. Conclusions. We isolated a diverse set of novel and clinically significant anaerobes from the human vagina using conventional approaches with systematic molecular identification. Several previously “uncultivated” bacteria are amenable to conventional cultivation. PMID:27449870

Symbiotic bacteria contribute to increasing the population size of a freshwater crustacean, Daphnia magna.

PubMed

Peerakietkhajorn, Saranya; Tsukada, Koji; Kato, Yasuhiko; Matsuura, Tomoaki; Watanabe, Hajime

2015-04-01

The filter-feeding crustacean Daphnia is a key organism in freshwater ecosystems. Here, we report the effect of symbiotic bacteria on ecologically important life history traits, such as population dynamics and longevity, in Daphnia magna. By disinfection of the daphniid embryos with glutaraldehyde, aposymbiotic daphniids were prepared and cultured under bacteria-free conditions. Removal of bacteria from the daphniids was monitored by quantitative polymerase chain reaction for bacterial 16S rRNA gene. The population of aposymbiotic daphniids was reduced 10-folds compared with that of the control daphniids. Importantly, re-infection with symbiotic bacteria caused daphniids to regain bacteria and increase their fecundity to the level of the control daphniids, suggesting that symbiotic bacteria regulate Daphnia fecundity. To identify the species of symbiotic bacteria, 16S rRNA genes of bacteria in daphniids were sequenced. This revealed that 50% of sequences belonged to the Limnohabitans sp. of the Betaproteobacteria class and that the diversity of bacterial taxa was relatively low. These results suggested that symbiotic bacteria have a beneficial effect on D. magna, and that aposymbiotic Daphnia are useful tools in understanding the role of symbiotic bacteria in the environmental responses and evolution of their hosts. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

Enrichments for phototrophic bacteria and characterization by morphology and pigment analysis

NASA Technical Reports Server (NTRS)

Brune, D.

1985-01-01

The purpose of this investigation was to examine several sulfide containing environments for the presence of phototrophic bacteria and to obtain enriched cultures of some of the bacteria present. The field sites were Alum Rock State Park, the Palo Alto salt marsh, the bay area salt ponds, and Big Soda Lake (near Fallon, Nevada). Bacteria from these sites were characterized by microscopic examination, measurement of in vitro absorption spectra, and analysis of carotenoid pigments. Field observations at one of the bay area salt ponds, in which the salt concentration was saturating (about 30 percent NaCl) and the sediments along the shore of the pond covered with a gypsum crust, revealed a layer of purple photosynthetic bacteria under a green layer in the gypsum crust. Samples of this gypsum crust were taken to the laboratory to measure light transmission through the crust and to try to identify the purple photosynthetic bacteria present in this extremely saline environment.

Detecting cell division of Pseudomonas aeruginosa bacteria from bright-field microscopy images with hidden conditional random fields.

PubMed

Ong, Lee-Ling S; Xinghua Zhang; Kundukad, Binu; Dauwels, Justin; Doyle, Patrick; Asada, H Harry

2016-08-01

An approach to automatically detect bacteria division with temporal models is presented. To understand how bacteria migrate and proliferate to form complex multicellular behaviours such as biofilms, it is desirable to track individual bacteria and detect cell division events. Unlike eukaryotic cells, prokaryotic cells such as bacteria lack distinctive features, causing bacteria division difficult to detect in a single image frame. Furthermore, bacteria may detach, migrate close to other bacteria and may orientate themselves at an angle to the horizontal plane. Our system trains a hidden conditional random field (HCRF) model from tracked and aligned bacteria division sequences. The HCRF model classifies a set of image frames as division or otherwise. The performance of our HCRF model is compared with a Hidden Markov Model (HMM). The results show that a HCRF classifier outperforms a HMM classifier. From 2D bright field microscopy data, it is a challenge to separate individual bacteria and associate observations to tracks. Automatic detection of sequences with bacteria division will improve tracking accuracy.

Psychobiotics and the Manipulation of Bacteria-Gut-Brain Signals.

PubMed

Sarkar, Amar; Lehto, Soili M; Harty, Siobhán; Dinan, Timothy G; Cryan, John F; Burnet, Philip W J

2016-11-01

Psychobiotics were previously defined as live bacteria (probiotics) which, when ingested, confer mental health benefits through interactions with commensal gut bacteria. We expand this definition to encompass prebiotics, which enhance the growth of beneficial gut bacteria. We review probiotic and prebiotic effects on emotional, cognitive, systemic, and neural variables relevant to health and disease. We discuss gut-brain signalling mechanisms enabling psychobiotic effects, such as metabolite production. Overall, knowledge of how the microbiome responds to exogenous influence remains limited. We tabulate several important research questions and issues, exploration of which will generate both mechanistic insights and facilitate future psychobiotic development. We suggest the definition of psychobiotics be expanded beyond probiotics and prebiotics to include other means of influencing the microbiome. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

The effect of a plasma needle on bacteria in planktonic samples and on peripheral blood mesenchymal stem cells

NASA Astrophysics Data System (ADS)

Lazović, Saša; Puač, Nevena; Miletić, Maja; Pavlica, Dušan; Jovanović, Milena; Bugarski, Diana; Mojsilović, Slavko; Maletić, Dejan; Malović, Gordana; Milenković, Pavle; Petrović, Zoran

2010-08-01

In this paper, we study the application of a plasma needle to induce necrosis in planktonic samples containing a single breed of bacteria. Two different types of bacteria, Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922), were covered in this study. In all experiments with bacteria, the samples were liquid suspensions of several different concentrations of bacteria prepared according to the McFarland standard. The second system studied in this paper was human peripheral blood mesenchymal stem cells (hPB-MSC). In the case of hPB-MSC, two sets of experiments were performed: when cells were covered with a certain amount of liquid (indirect) and when the cell sample was in direct contact with the plasma. Most importantly, the study is made with the aim to see the effects when the living cells are in a liquid medium, which normally acts as protection against the many agents that may be released by plasmas. It was found that a good effect may be expected for a wide range of initial cell densities and operating conditions causing destruction of several orders of magnitude even under the protection of a liquid. It was established independently that a temperature increase could not affect the cells under the conditions of our experiment, so the effect could originate only from the active species produced by the plasma. In the case of those hPB-MSC that were not protected by a liquid, gas flow proved to produce a considerable effect, presumably due to poor adhesion of the cells, but in a liquid the effect was only due to the plasma. Further optimization of the operation may be attempted, opening up the possibility of localized in vivo sterilization.

The endophyte Curtobacterium flaccumfaciens reduces symptoms caused by Xylella fastidiosa in Catharanthus roseus.

PubMed

Lacava, Paulo Teixeira; Li, Wenbin; Araújo, Welington Luiz; Azevedo, João Lúcio; Hartung, John Stephen

2007-10-01

Citrus variegated chlorosis (CVC) is a disease of the sweet orange [Citrus sinensis (L.)], which is caused by Xylella fastidiosa subsp. pauca, a phytopathogenic bacterium that has been shown to infect all sweet orange cultivars. Sweet orange trees have been occasionally observed to be infected by Xylella fastidiosa without evidencing severe disease symptoms, whereas other trees in the same grove may exhibit severe disease symptoms. The principal endophytic bacterial species isolated from such CVC-asymptomatic citrus plants is Curtobacterium flaccumfaciens. The Madagascar periwinkle [Citrus sinensis (L.)] is a model plant which has been used to study X. fastidiosa in greenhouse environments. In order to characterize the interactions of X. fastidiosa and C. flaccumfaciens, periwinkle plants were inoculated separately with C. flaccumfaciens, X. fastidiosa, and both bacteria together. The number of flowers produced by the plants, the heights of the plants, and the exhibited disease symptoms were evaluated. PCR-primers for C. flaccumfaciens were designed in order to verify the presence of this endophytic bacterium in plant tissue, and to complement an existing assay for X. fastidiosa. These primers were capable of detecting C. flaccumfaciens in the periwinkle in the presence of X. fastidiosa. X. fastidiosa induced stunting and reduced the number of flowers produced by the periwinkle. When C. flaccumfaciens was inoculated together with X. fastidiosa, no stunting was observed. The number of flowers produced by our doubly- inoculated plants was an intermediate between the number produced by the plants inoculated with either of the bacteria separately. Our data indicate that C. flaccumfaciens interacted with X. fastidiosa in C. roseus, and reduced the severity of the disease symptoms induced by X. fastidiosa. Periwinkle is considered to be an excellent experimental system by which the interaction of C. flaccumfaciens and other endophytic bacteria with X. fastidiosa can be

The Effect of Bacteriophage Preparations on Intracellular Killing of Bacteria by Phagocytes

PubMed Central

Jończyk-Matysiak, Ewa; Łusiak-Szelachowska, Marzanna; Kłak, Marlena; Bubak, Barbara; Międzybrodzki, Ryszard; Weber-Dąbrowska, Beata; Żaczek, Maciej; Fortuna, Wojciech; Rogóż, Paweł; Letkiewicz, Sławomir; Szufnarowski, Krzysztof; Górski, Andrzej

2015-01-01

Intracellular killing of bacteria is one of the fundamental mechanisms against invading pathogens. Impaired intracellular killing of bacteria by phagocytes may be the reason of chronic infections and may be caused by antibiotics or substances that can be produced by some bacteria. Therefore, it was of great practical importance to examine whether phage preparations may influence the process of phagocyte intracellular killing of bacteria. It may be important especially in the case of patients qualified for experimental phage therapy (approximately half of the patients with chronic bacterial infections have their immunity impaired). Our analysis included 51 patients with chronic Gram-negative and Gram-positive bacterial infections treated with phage preparations at the Phage Therapy Unit in Wroclaw. The aim of the study was to investigate the effect of experimental phage therapy on intracellular killing of bacteria by patients' peripheral blood monocytes and polymorphonuclear neutrophils. We observed that phage therapy does not reduce patients' phagocytes' ability to kill bacteria, and it does not affect the activity of phagocytes in patients with initially reduced ability to kill bacteria intracellularly. Our results suggest that experimental phage therapy has no significant adverse effects on the bactericidal properties of phagocytes, which confirms the safety of the therapy. PMID:26783541

Evaluation of the in vitro growth of urinary tract infection-causing gram-negative and gram-positive bacteria in a proposed synthetic human urine (SHU) medium.

PubMed

Ipe, Deepak S; Ulett, Glen C

2016-08-01

Bacteriuria is a hallmark of urinary tract infection (UTI) and asymptomatic bacteriuria (ABU), which are among the most frequent infections in humans. A variety of gram-negative and gram-positive bacteria are associated with these infections but Escherichia coli contributes up to 80% of cases. Multiple bacterial species including E. coli can grow in human urine as a means to maintain colonization during infections. In vitro bacteriuria studies aimed at modeling microbial growth in urine have utilized various compositions of synthetic human urine (SHU) and a Composite SHU formulation was recently proposed. In this study, we sought to validate the recently proposed Composite SHU as a medium that supports the growth of several bacterial species that are known to grow in normal human urine and/or artificial urine. Comparative growth assays of gram-negative and gram-positive bacteria E. coli, Pseudomonas aeruginosa, Proteus mirabilis, Streptococcus agalactiae, Staphylococcus saprophyticus and Enterococcus faecalis were undertaken using viable bacterial count and optical density measurements over a 48h culture period. Three different SHU formulations were tested in various culture vessels, shaking conditions and volumes and showed that Composite SHU can support the robust growth of gram-negative bacteria but requires supplementation with 0.2% yeast extract to support the growth of gram-positive bacteria. Experiments are also presented that show an unexpected but major influence of P. mirabilis towards the ability to measure bacterial growth in generally accepted multiwell assays using absorbance readings, predicted to have a basis in the release of volatile organic compound(s) from P. mirabilis during growth in Composite SHU medium. This study represents an essential methodological validation of a more chemically defined type of synthetic urine that can be applied to study mechanisms of bacteriuria and we conclude will offer a useful in vitro model to investigate the

Elucidation of Bacterial Pneumonia-Causing Pathogens in Patients with Respiratory Viral Infection.

PubMed

Jung, Hwa Sik; Kang, Byung Ju; Ra, Seung Won; Seo, Kwang Won; Jegal, Yangjin; Jun, Jae Bum; Jung, Jiwon; Jeong, Joseph; Jeon, Hee Jeong; Ahn, Jae Sung; Lee, Taehoon; Ahn, Jong Joon

2017-10-01

Bacterial pneumonia occurring after respiratory viral infection is common. However, the predominant bacterial species causing pneumonia secondary to respiratory viral infections other than influenza remain unknown. The purpose of this study was to know whether the pathogens causing post-viral bacterial pneumonia vary according to the type of respiratory virus. Study subjects were 5,298 patients, who underwent multiplex real-time polymerase chain reaction for simultaneous detection of respiratory viruses, among who visited the emergency department or outpatient clinic with respiratory symptoms at Ulsan University Hospital between April 2013 and March 2016. The patients' medical records were retrospectively reviewed. A total of 251 clinically significant bacteria were identified in 233 patients with post-viral bacterial pneumonia. Mycoplasma pneumoniae was the most frequent bacterium in patients aged <16 years, regardless of the preceding virus type (p=0.630). In patients aged ≥16 years, the isolated bacteria varied according to the preceding virus type. The major results were as follows (p<0.001): pneumonia in patients with influenza virus (type A/B), rhinovirus, and human metapneumovirus infections was caused by similar bacteria, and the findings indicated that Staphylococcus aureus pneumonia was very common in these patients. In contrast, coronavirus, parainfluenza virus, and respiratory syncytial virus infections were associated with pneumonia caused by gram-negative bacteria. The pathogens causing post-viral bacterial pneumonia vary according to the type of preceding respiratory virus. This information could help in selecting empirical antibiotics in patients with post-viral pneumonia. Copyright©2017. The Korean Academy of Tuberculosis and Respiratory Diseases

Elucidation of Bacterial Pneumonia-Causing Pathogens in Patients with Respiratory Viral Infection

PubMed Central

Jung, Hwa Sik; Kang, Byung Ju; Ra, Seung Won; Seo, Kwang Won; Jegal, Yangjin; Jun, Jae-Bum; Jung, Jiwon; Jeong, Joseph; Jeon, Hee-Jeong; Ahn, Jae-Sung

2017-01-01

Background Bacterial pneumonia occurring after respiratory viral infection is common. However, the predominant bacterial species causing pneumonia secondary to respiratory viral infections other than influenza remain unknown. The purpose of this study was to know whether the pathogens causing post-viral bacterial pneumonia vary according to the type of respiratory virus. Methods Study subjects were 5,298 patients, who underwent multiplex real-time polymerase chain reaction for simultaneous detection of respiratory viruses, among who visited the emergency department or outpatient clinic with respiratory symptoms at Ulsan University Hospital between April 2013 and March 2016. The patients' medical records were retrospectively reviewed. Results A total of 251 clinically significant bacteria were identified in 233 patients with post-viral bacterial pneumonia. Mycoplasma pneumoniae was the most frequent bacterium in patients aged <16 years, regardless of the preceding virus type (p=0.630). In patients aged ≥16 years, the isolated bacteria varied according to the preceding virus type. The major results were as follows (p<0.001): pneumonia in patients with influenza virus (type A/B), rhinovirus, and human metapneumovirus infections was caused by similar bacteria, and the findings indicated that Staphylococcus aureus pneumonia was very common in these patients. In contrast, coronavirus, parainfluenza virus, and respiratory syncytial virus infections were associated with pneumonia caused by gram-negative bacteria. Conclusion The pathogens causing post-viral bacterial pneumonia vary according to the type of preceding respiratory virus. This information could help in selecting empirical antibiotics in patients with post-viral pneumonia. PMID:28905531

Fungal disease prevention in seedlings of rice (Oryza sativa) and other grasses by growth-promoting seed-associated endophytic bacteria from invasive Phragmites australis

USGS Publications Warehouse

Verma, Satish K.; Kingsley, Kathryn L.; Bergen, Marshall S.; Kowalski, Kurt P.; White, James F.

2018-01-01

Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium, Pythium and other water moulds cause seed rots during germination. Fusariumblights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass (Cynodon dactylon), or annual bluegrass (Poa annua) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum. We found that three bacteria belonging to genus Pseudomonas spp. (SLB4-P. fluorescens, SLB6-Pseudomonas sp. and SY1-Pseudomonassp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum, 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production

Algae-bacteria interactions: Evolution, ecology and emerging applications.

PubMed

Ramanan, Rishiram; Kim, Byung-Hyuk; Cho, Dae-Hyun; Oh, Hee-Mock; Kim, Hee-Sik

2016-01-01

Algae and bacteria have coexisted ever since the early stages of evolution. This coevolution has revolutionized life on earth in many aspects. Algae and bacteria together influence ecosystems as varied as deep seas to lichens and represent all conceivable modes of interactions - from mutualism to parasitism. Several studies have shown that algae and bacteria synergistically affect each other's physiology and metabolism, a classic case being algae-roseobacter interaction. These interactions are ubiquitous and define the primary productivity in most ecosystems. In recent years, algae have received much attention for industrial exploitation but their interaction with bacteria is often considered a contamination during commercialization. A few recent studies have shown that bacteria not only enhance algal growth but also help in flocculation, both essential processes in algal biotechnology. Hence, there is a need to understand these interactions from an evolutionary and ecological standpoint, and integrate this understanding for industrial use. Here we reflect on the diversity of such relationships and their associated mechanisms, as well as the habitats that they mutually influence. This review also outlines the role of these interactions in key evolutionary events such as endosymbiosis, besides their ecological role in biogeochemical cycles. Finally, we focus on extending such studies on algal-bacterial interactions to various environmental and bio-technological applications. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

[Severe anemia caused by haemorrhoids: the casae of a young man with toxic cirrhosis].

PubMed

Kovács, Erzsébet; Palatka, Károly; Németh, Attila; Pásztor, Éva; Pfliegler, György

2013-03-10

A 38-year-old alcoholic man with severe iron deficient anaemia, and bloody-mucous stool was found to have haemorrhoidal bleeding. In spite of intravenous iron supplements haemoglobin levels were falling. He was admitted because of deteriorating condition, jaundice, severe anaemia (haemoglobin, 38 g/l) and iron deficiency. Except of toxic (alcohol) agent all other causes of liver disease could be excluded. Sclero-, and medical therapy, and abstinence resulted in a rapid improvement in his condition and subsequently rectal bleeding also disappeared. Bleeding from the upper gastrointestinal tract is a well known and serious complication in liver cirrhosis, however, a voluminous blood loss resulting in a life-threatening anaemia from lower gastrointestinal tract or haemorrhoids, as it was detected in this patient, is quite rare. Sclerotherapy seems to be an effective method with only minor complications when compared with other invasive techniques. However, the patient's compliance even in liver cirrhosis with haemorrhoidal nodes is essential for long-term success.

Antibiotic-resistant bacteria show widespread collateral sensitivity to antimicrobial peptides.

PubMed

Lázár, Viktória; Martins, Ana; Spohn, Réka; Daruka, Lejla; Grézal, Gábor; Fekete, Gergely; Számel, Mónika; Jangir, Pramod K; Kintses, Bálint; Csörgő, Bálint; Nyerges, Ákos; Györkei, Ádám; Kincses, András; Dér, András; Walter, Fruzsina R; Deli, Mária A; Urbán, Edit; Hegedűs, Zsófia; Olajos, Gábor; Méhi, Orsolya; Bálint, Balázs; Nagy, István; Martinek, Tamás A; Papp, Balázs; Pál, Csaba

2018-06-01

Antimicrobial peptides are promising alternative antimicrobial agents. However, little is known about whether resistance to small-molecule antibiotics leads to cross-resistance (decreased sensitivity) or collateral sensitivity (increased sensitivity) to antimicrobial peptides. We systematically addressed this question by studying the susceptibilities of a comprehensive set of 60 antibiotic-resistant Escherichia coli strains towards 24 antimicrobial peptides. Strikingly, antibiotic-resistant bacteria show a high frequency of collateral sensitivity to antimicrobial peptides, whereas cross-resistance is relatively rare. We identify clinically relevant multidrug-resistance mutations that increase bacterial sensitivity to antimicrobial peptides. Collateral sensitivity in multidrug-resistant bacteria arises partly through regulatory changes shaping the lipopolysaccharide composition of the bacterial outer membrane. These advances allow the identification of antimicrobial peptide-antibiotic combinations that enhance antibiotic activity against multidrug-resistant bacteria and slow down de novo evolution of resistance. In particular, when co-administered as an adjuvant, the antimicrobial peptide glycine-leucine-amide caused up to 30-fold decrease in the antibiotic resistance level of resistant bacteria. Our work provides guidelines for the development of efficient peptide-based therapies of antibiotic-resistant infections.

Empiric systemic antibiotics for hospitalized patients with severe odontogenic infections.

PubMed

Zirk, Matthias; Buller, Johannes; Goeddertz, Peter; Rothamel, Daniel; Dreiseidler, Timo; Zöller, Joachim E; Kreppel, Matthias

2016-08-01

Odontogenic infections may lead to severe head and neck infections with potentially great health risk. Age, location of purulent affected sites and beta-lactam allergy are some mentionable factors regarding patients' in-hospital stay and course of disease. Are there new challenges regarding bacteria' antibiotic resistance for empiric treatment and what influences do they have on patients' clinical course? We analyzed in a 4-year retrospective study the medical records of 294 in-hospital patients with severe odontogenic infections. On a routine base bacteria were identified and susceptibility testing was performed. Length of stay in-hospital was evaluated regarding patients' age, beta-lactam allergy profile, affected sites and bacteria susceptibility to empiric antibiotics. Length of stay in-hospital was detected to be associated with affected space and penicillin allergy as well (p < 0.05). Isolates presented large amounts of aerobic gram-positive bacteria (64.2%), followed by facultative anaerobic bacteria (gram+/15.8%, gram-/12.7%). Tested ampicillin in combination with sulbactam (or without) and cephalosporins displayed high susceptibility rates, revealing distinguished results regarding clindamycin (p < 0.05). Co-trimoxazol and moxifloxacin showed high overall susceptibility rates (MOX: 94.7%, COTRIM: 92.6%). This study demonstrates ampicillin/sulbactam in addition to surgical intervention is a good standard in treatment of severe odontogenic neck infections. Cephalosporins seem to be a considerable option as well. If beta-lactam allergy is diagnosed co-trimoxazol and moxifloxacin represent relevant alternatives. Age, allergic profile and bacteria' resistance patterns for empiric antibiotics have an influence on patients in-hospital stay. Ampicillin/sulbactam proves itself to be good for empiric antibiosis in severe odontogenic infections. Furthermore cephalosporins could be considered as another option in treatment. However moxifloxacin and co

Essential Oils and Their Components as Modulators of Antibiotic Activity against Gram-Negative Bacteria

PubMed Central

Aelenei, Petruta; Miron, Anca; Trifan, Adriana; Bujor, Alexandra; Gille, Elvira; Aprotosoaie, Ana Clara

2016-01-01

Gram-negative bacteria cause infections that are difficult to treat due to the emergence of multidrug resistance. This review summarizes the current status of the studies investigating the capacity of essential oils and their components to modulate antibiotic activity against Gram-negative bacteria. Synergistic interactions are particularly discussed with reference to possible mechanisms by which essential oil constituents interact with antibiotics. Special emphasis is given to essential oils and volatile compounds that inhibit efflux pumps, thus reversing drug resistance in Gram-negative bacteria. In addition, indifference and antagonism between essential oils/volatile compounds and conventional antibiotics have also been reported. Overall, this literature review reveals that essential oils and their purified components enhance the efficacy of antibiotics against Gram-negative bacteria, being promising candidates for the development of new effective formulations against Gram-negative bacteria. PMID:28930130

Exploring the potential environmental functions of viable but non-culturable bacteria.

PubMed

Su, Xiaomei; Chen, Xi; Hu, Jinxing; Shen, Chaofeng; Ding, Linxian

2013-12-01

A conventional plate count is the most commonly employed method to estimate the number of living bacteria in environmental samples. In fact, judging the level of viable culture by plate count is limited, because it is often several orders of magnitude less than the number of living bacteria actually present. Most of the bacteria are in "viable but non-culturable" (VBNC) state, whose cells are intact and alive and can resuscitate when surrounding conditions are more favorable. The most exciting recent development in resuscitating VBNC bacteria is a bacterial cytokine, namely, the resuscitation-promoting factor (Rpf), secreted by Micrococcus luteus, which promotes the resuscitation and growth of high G+C Gram-positive organisms, including some species of the genus Mycobacterium. However, most of studies deal with VBNC bacteria only from the point of view of medicine and epidemiology. It is therefore of great significance to research whether these VBNC state bacteria also possess some useful environmental capabilities, such as degradation, flocculation, etc. Further studies are needed to elucidate the possible environmental role of the VBNC bacteria, rather than only considering their role as potential pathogens from the point view of epidemiology and public health. We have studied the resuscitation of these VBNC bacteria in polluted environments by adding culture supernatant containing Rpf from M. luteus, and it was found that, as a huge microbial resource, VBNC bacteria could provide important answers to dealing with existing problems of environmental pollution. This mini-review will provide new insight for considering the potentially environmental functions of VBNC bacteria.

New York City House Mice (Mus musculus) as Potential Reservoirs for Pathogenic Bacteria and Antimicrobial Resistance Determinants

PubMed Central

Williams, Simon H.; Che, Xiaoyu; Paulick, Ashley; Guo, Cheng; Lee, Bohyun; Muller, Dorothy; Uhlemann, Anne-Catrin; Lowy, Franklin D.; Corrigan, Robert M.

2018-01-01

ABSTRACT House mice (Mus musculus) thrive in large urban centers worldwide. Nonetheless, little is known about the role that they may play in contributing to environmental contamination with potentially pathogenic bacteria. Here, we describe the fecal microbiome of house mice with emphasis on detection of pathogenic bacteria and antimicrobial resistance genes by molecular methods. Four hundred sixteen mice were collected from predominantly residential buildings in seven sites across New York City over a period of 13 months. 16S rRNA sequencing identified Bacteroidetes as dominant and revealed high levels of Proteobacteria. A targeted PCR screen of 11 bacteria, as indicated by 16S rRNA analyses, found that mice are carriers of several gastrointestinal disease-causing agents, including Shigella, Salmonella, Clostridium difficile, and diarrheagenic Escherichia coli. Furthermore, genes mediating antimicrobial resistance to fluoroquinolones (qnrB) and β-lactam drugs (blaSHV and blaACT/MIR) were widely distributed. Culture and molecular strain typing of C. difficile revealed that mice harbor ribotypes associated with human disease, and screening of kidney samples demonstrated genetic evidence of pathogenic Leptospira species. In concert, these findings support the need for further research into the role of house mice as potential reservoirs for human pathogens and antimicrobial resistance in the built environment. PMID:29666289

Sharper and faster "nano darts" kill more bacteria: a study of antibacterial activity of individually dispersed pristine single-walled carbon nanotube.

PubMed

Liu, Shaobin; Wei, Li; Hao, Lin; Fang, Ning; Chang, Matthew Wook; Xu, Rong; Yang, Yanhui; Chen, Yuan

2009-12-22

To further our understanding on the antibacterial activity of single-walled carbon nanotubes (SWCNTs), high purity SWCNTs with average diameter of 0.83 nm and (7,5) chirality as dominate (n,m) structure were dispersed in a biocompatible surfactant solution. Ultraviolet-visible-near-infrared radiation absorption spectroscopy was employed to monitor the aggregation of SWCNTs. The results demonstrated that individually dispersed SWCNTs were more toxic than SWCNT aggregates toward bacteria (gram-negative Escherichia coli, Pseudomonas aeruginosa, and gram-positive Staphylococcus aureus, Bacillus subtilis). Individually dispersed SWCNTs can be visualized as numerous moving "nano darts" in the solution, constantly attacking the bacteria; thereby, degrading the bacterial cell integrity and causing the cell death. Controlled experimental results suggested that inhibiting cell growth and oxidative stress were not the major causes responsible for the death of cells. Furthermore, the detrimental effects of Co metal residues (up to 1 mug/mL) on SWCNT samples can be ruled out. Atomic force microscope study conducted in suspension proved that the death rates of bacteria were strongly correlated with their mechanical properties; soft cells were more vulnerable to SWCNT piercing. The antibacterial activity of SWCNTs can be remarkably improved by enhancing the SWCNT physical puncture on bacteria in the following ways: (1) dispersing SWCNTs individually to sharpen the nano darts; (2) increasing SWCNT concentration to raise the population density of nano darts; and (3) elevating the shaking speed of incubation to speed up the nano darts. This study elucidated several factors controlling the antibacterial activity of pristine SWCNTs and it provided an insight in developing strategies that can maximize the SWCNT application potentials while minimizing the health and environment risks.

A case of hyperammonemia with obstructive urinary tract infection by urease-producing bacteria.

PubMed

Goda, Toshiaki; Watanabe, Kotaro; Kobayashi, Junya; Nagai, Yasuharu; Ohara, Nobuyuki; Takahashi, Daisuke

2017-03-28

A 79-year-old woman was admitted emergently for disturbance of consciousness. Her consciousness level was Japan coma scale 20, and she presented with hypermyotonia. Brain magnetic resonance imaging and cerebrospinal fluid examination showed normal findings. Her blood tests showed an increased ammonia level of 291 μg/dl with normal liver function. We catheterized the bladder for urinary retention. Eight hours after admission, the blood level of ammonia decreased to 57 μg/dl and the patient's consciousness level improved. Corynebacterium pseudodiphtheriticum, which is a bacteria producing urease, was detected from a urine culture. It is important to recognize that obstructive urinary tract infection caused by urease-producing bacteria can cause hyperammonemia.

Potential application of algicidal bacteria for improved lipid recovery with specific algae.

PubMed

Lenneman, Eric M; Wang, Ping; Barney, Brett M

2014-05-01

The utility of specific strains of natural algicidal bacteria isolated from shallow wetland sediments was evaluated against several strains of algae with potential immediate or future commercial value. Two strains of bacteria, Pseudomonas pseudoalcaligenes AD6 and Aeromonas hydrophila AD9, were identified and demonstrated to have algicidal activity against the microalgae Neochloris oleoabundans and Dunaliella tertiolecta. These bacteria were further evaluated for the potential to improve lipid extraction using a mild solvent extraction approach. Aeromonas hydrophila AD9 showed a nearly 12-fold increase in lipid extraction with D. tertiolecta, while both bacteria showed a sixfold improvement in lipid extraction with N. oleoabundans. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Prions: Protein Rebels with a Cause!

ERIC Educational Resources Information Center

Marshall, Karen E.; Serpell, Louise C.

2017-01-01

Traditionally we consider infection to arise from viruses, bacteria and parasites. Prions are infectious proteins without any nucleic acids, and therefore do not represent living things. Despite this, they have the ability to replicate themselves and cause diseases such as mad cow disease (bovine spongiform encepthalopathy) and human…

Platelets and Infections – Complex Interactions with Bacteria

PubMed Central

Hamzeh-Cognasse, Hind; Damien, Pauline; Chabert, Adrien; Pozzetto, Bruno; Cognasse, Fabrice; Garraud, Olivier

2015-01-01

Platelets can be considered sentinels of vascular system due to their high number in the circulation and to the range of functional immunoreceptors they express. Platelets express a wide range of potential bacterial receptors, including complement receptors, FcγRII, Toll-like receptors but also integrins conventionally described in the hemostatic response, such as GPIIb–IIIa or GPIb. Bacteria bind these receptors either directly, or indirectly via fibrinogen, fibronectin, the first complement C1q, the von Willebrand Factor, etc. The fate of platelet-bound bacteria is questioned. Several studies reported the ability of activated platelets to internalize bacteria such as Staphylococcus aureus or Porphyromonas gingivalis, though there is no clue on what happens thereafter. Are they sheltered from the immune system in the cytoplasm of platelets or are they lysed? Indeed, while the presence of phagolysosome has not been demonstrated in platelets, they contain antimicrobial peptides that were shown to be efficient on S. aureus. Besides, the fact that bacteria can bind to platelets via receptors involved in hemostasis suggests that they may induce aggregation; this has indeed been described for Streptococcus sanguinis, S. epidermidis, or C. pneumoniae. On the other hand, platelets are able to display an inflammatory response to an infectious triggering. We, and others, have shown that platelet release soluble immunomodulatory factors upon stimulation by bacterial components. Moreover, interactions between bacteria and platelets are not limited to only these two partners. Indeed, platelets are also essential for the formation of neutrophil extracellular traps by neutrophils, resulting in bacterial clearance by trapping bacteria and concentrating antibacterial factors but in enhancing thrombosis. In conclusion, the platelet–bacteria interplay is a complex game; its fine analysis is complicated by the fact that the inflammatory component adds to the aggregation response

EXTENDED-SPECTRUM BETA-LACTAMASE PRODUCING GRAM NEGATIVE BACTERIA IN IRAN: A REVIEW

PubMed Central

Leylabadlo, Hamed Ebrahimzadeh; Pourlak, Tala; bialvaei, Abed Zahedi; Aghazadeh, Mohammad; Asgharzadeh, Mohammad; Kafil, Hossein Samadi

2017-01-01

Background: The emergence and spread of extended spectrum β-lactamase (ESBL)-producing Gram- negative bacteria (GNB), particularly in Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa, have increased all over the world. ESBLs are characterized by their ability to hydrolyze β-lactams, early cephalosporins, oxyimino-thiazolyl cephalosporins, and monobactams, but not cephamycins or carbapenems. The rate of nosocomial infections caused by ESBL-producing GNB in Asia Pacific has increased and several studies have identified their prevalence in the region. The aim of this study is to review the prevalence of ESBL-producing GNB in the West Asia and the Middle East with a particular focus on Iran. Materials and Methods: The available evidence from various studies (Microbia and clinical studies, retrieved from the PubMed, and Scopus databases) regarding the ESBL producing Gram negative bacteria in Iran were evaluated. Results: In almost all parts of the country, high resistance has been observed, especially in the central part of Iran. Up to 89.8% Escherichia coli, 72.1% Klebsiella pneumonia, 84.2% Acinetobacter baumannii, and 83.8% Pseudomonas aeruginosa isolates are ESBL positive. Conclusion: The present study showed the increasing prevalence of ESBLs in different regions of Iran, which could be useful to strategic policy towards reducing reduce their prevalence. PMID:28670639

First Report of Oryctes rhinoceros nudivirus (Coleoptera: Scarabaeidae) Causing Severe Disease in Allomyrina dichotoma in Korea

PubMed Central

Lee, Seokhyun; Park, Kwan-Ho; Nam, Sung-Hee; Kwak, Kyu-Won; Choi, Ji-Young

2015-01-01

Oryctes rhinoceros nudivirus (OrNV) has been known to cause severe disease in coconut palm rhinoceros beetle, Oryctes rhinoceros, in Southeastern Asia and is used as a biological control to reduce the pest population. Here, we report for the first time that the OrNV may have landed on Korea and may be the major pathogen for diseased larvae of Korean horn beetle, Allomyrina dichotoma. After peroral inoculation, over 60% of infected larvae perished in 6 wk. This viral disease spreads very fast in several locations throughout Korea. This threat not only makes economic loss of local farms rearing A. dichotoma larvae but also may disturb the ecosystem by transmitting to wild A. dichotoma. PMID:25765317

Salt gland adenitis associated with bacteria in Blue Penguins (Eudyptula minor) from Hauraki Gulf (auckland, New Zealand).

PubMed

Suepaul, R B; Alley, M R; van Rensburg, M Jansen

2010-01-01

Three Blue Penguins (Eudyptula minor) were rescued between July 2006 and January 2007 off the east coast of Auckland, New Zealand. They were taken to a rehabilitation center, where they subsequently died in May 2007 and were submitted for necropsy. There was unilateral enlargement of the salt glands with disseminated small, pale, and firm foci in all birds. Histologic examination of the affected glands demonstrated the presence of multifocal granulomas and areas of severe squamous metaplasia of the collecting ducts. The remaining gland had areas of hyperplasia, dysplasia, and necrosis with a severe granulomatous inflammatory reaction. Intralesional gram-negative bacteria were detected, but, unfortunately, bacterial culture was unrewarding. No further cases were observed in penguins in the subsequent year, and the primary cause of the salt gland adenitis remains uncertain.

Methanotrophic bacteria.

PubMed Central

Hanson, R S; Hanson, T E

1996-01-01

Methane-utilizing bacteria (methanotrophs) are a diverse group of gram-negative bacteria that are related to other members of the Proteobacteria. These bacteria are classified into three groups based on the pathways used for assimilation of formaldehyde, the major source of cell carbon, and other physiological and morphological features. The type I and type X methanotrophs are found within the gamma subdivision of the Proteobacteria and employ the ribulose monophosphate pathway for formaldehyde assimilation, whereas type II methanotrophs, which employ the serine pathway for formaldehyde assimilation, form a coherent cluster within the beta subdivision of the Proteobacteria. Methanotrophic bacteria are ubiquitous. The growth of type II bacteria appears to be favored in environments that contain relatively high levels of methane, low levels of dissolved oxygen, and limiting concentrations of combined nitrogen and/or copper. Type I methanotrophs appear to be dominant in environments in which methane is limiting and combined nitrogen and copper levels are relatively high. These bacteria serve as biofilters for the oxidation of methane produced in anaerobic environments, and when oxygen is present in soils, atmospheric methane is oxidized. Their activities in nature are greatly influenced by agricultural practices and other human activities. Recent evidence indicates that naturally occurring, uncultured methanotrophs represent new genera. Methanotrophs that are capable of oxidizing methane at atmospheric levels exhibit methane oxidation kinetics different from those of methanotrophs available in pure cultures. A limited number of methanotrophs have the genetic capacity to synthesize a soluble methane monooxygenase which catalyzes the rapid oxidation of environmental pollutants including trichloroethylene. PMID:8801441

A Role of Oral Bacteria in Bisphosphonate-induced Osteonecrosis of the Jaw

PubMed Central

Mawardi, H.; Giro, G.; Kajiya, M.; Ohta, K.; Almazrooa, S.; Alshwaimi, E.; Woo, S.-B.; Nishimura, I.; Kawai, T.

2011-01-01

No consensus has yet been reached to associate oral bacteria conclusively with the etio-pathogenesis of bisphosphonate-induced osteonecrosis of the jaw (BONJ). Therefore, the present study examined the effects of oral bacteria on the development of BONJ-like lesions in a mouse model. In the pamidronate (Pam)-treated mice, but not control non-drug-treated mice, tooth extraction followed by oral infection with Fusobacterium nucleatum caused BONJ-like lesions and delayed epithelial healing, both of which were completely suppressed by a broad-spectrum antibiotic cocktail. Furthermore, in both in vitro and in vivo experiments, the combination of Pam and Fusobacterium nucleatum caused the death of gingival fibroblasts (GFs) and down-regulated their production of keratinocyte growth factor (KGF), which induces epithelial cell growth and migration. Therefore, in periodontal tissues pre-exposed to bisphosphonate, bacterial infection at tooth extraction sites caused diminished KGF expression in GFs, leading to a delay in the epithelial wound-healing process that was mitigated by antibiotics. PMID:21921248

Electronic Nose Characterization of the Quality Parameters of Freeze-Dried Bacteria

NASA Astrophysics Data System (ADS)

Capuano, R.; Santonico, M.; Martinelli, E.; Paolesse, R.; Passot, S.; Fonseca, F.; Cenard, S.; Trelea, C.; Di Natale, C.

2011-09-01

Freeze-drying is the method of choice for preserving heat sensitive biological products such as microorganisms. The development of a fast analytical method for evaluating the properties of the dehydrated bacteria is then necessary for a proper utilization of the product in several food processes. In this paper, dried bacteria headspace is analyzed by a GC-MS and an electronic nose. Results indicate that headspace contains enough information to assess the products quality.

Severe rickets in a young girl caused by celiac disease: the tragedy of delayed diagnosis: a case report.

PubMed

Al-Sharafi, Butheinah A; Al-Imad, Shafiq A; Shamshair, Amani M; Al-Faqeeh, Derhim H

2014-10-08

Celiac disease is a systemic immune mediated disease which usually presents with gastrointestinal symptoms, but it may present with extra gastrointestinal manifestations such as metabolic bone disease and failure to thrive. This may lead to a delay in the diagnosis. We present a 13 year old female from the middle east with an 8 year history of severe rickets causing multiple bone deformities leaving the child crippled with bowing of both of her arms and legs. The patient was also found to have growth failure, anemia and on further workup she was found to have celiac disease. We are presenting this case because it shows a severe case of rickets after malabsorption for many years. Celiac disease should be kept in mind as a cause of rickets in patients not responding to usual forms of treatment or when associated with other manifestations of malabsorption.

Bacteria on catheters in patients undergoing peritoneal dialysis.

PubMed

Pihl, Maria; Davies, Julia R; Johansson, Ann-Cathrine; Svensäter, Gunnel

2013-01-01

Peritonitis is the leading cause of morbidity for peritoneal dialysis (PD) patients, and microbial biofilms have previously been identified on catheters from infected patients. However, few studies of catheters from patients without clinical signs of infection have been undertaken. The aim of the present study was to investigate the extent to which bacteria are present on catheters from PD patients with no symptoms of infection. Microbiologic culturing under aerobic and anaerobic conditions and confocal laser scanning microscopy were used to determine the distribution of bacteria on PD catheters from 15 patients without clinical signs of infection and on catheters from 2 infected patients. The 16S rRNA gene sequencing technique was used to identify cultured bacteria. Bacteria were detected on 12 of the 15 catheters from patients without signs of infection and on the 2 catheters from infected patients. Single-species and mixed-microbial communities containing up to 5 species were present on both the inside and the outside along the whole length of the colonized catheters. The bacterial species most commonly found were the skin commensals Staphylococcus epidermidis and Propionibacterium acnes, followed by S. warneri and S. lugdunensis. The strains of these micro-organisms, particularly those of S. epidermidis, varied in phenotype with respect to their tolerance of the major classes of antibiotics. Bacteria were common on catheters from patients without symptoms of infection. Up to 4 different bacterial species were found in close association and may represent a risk factor for the future development of peritonitis in patients hosting such micro-organisms.

Photodynamic inactivation of antibiotic-resistant bacteria and biofilms by hematoporphyrin monomethyl ether.

PubMed

Liu, Chengcheng; Hu, Min; Ma, Dandan; Lei, Jin'e; Xu, Jiru

2016-02-01

The worldwide increase in bacterial antibiotic resistance has led to a search for alternative antibacterial therapies. A promising approach to killing antibiotic-resistant bacteria is photodynamic antimicrobial chemotherapy, which uses light in combination with a photosensitizer to induce a phototoxic reaction. We evaluated the photodynamic inactivation (PDI) efficiency of hematoporphyrin monomethyl ether (HMME) on antibiotic-resistant bacteria and biofilms. HMME exhibited no significant dark toxicity and provided dose-dependent inactivation of antibiotic-resistant bacteria and biofilms. After incubation with 100-μM HMME and irradiation with 72-J cm(-2) white light, 4.19-7.59 log10 reductions in survival were achieved in planktonic suspension. Antibiotic-resistant strains were as susceptible to PDI in biofilms as in planktonic suspensions, but the inactivation of bacterial cells in biofilms was attenuated. In addition, gram-positive bacterial strains and biofilms were more susceptible than gram-negative strains and biofilms to the PDI effect of HMME. Thus, HMME is a promising photosensitizer for the treatment of infectious diseases caused by antibiotic-resistant bacteria, especially gram-positive bacteria.

More Easily Cultivated Than Identified: Classical Isolation With Molecular Identification of Vaginal Bacteria.

PubMed

Srinivasan, Sujatha; Munch, Matthew M; Sizova, Maria V; Fiedler, Tina L; Kohler, Christina M; Hoffman, Noah G; Liu, Congzhou; Agnew, Kathy J; Marrazzo, Jeanne M; Epstein, Slava S; Fredricks, David N

2016-08-15

Women with bacterial vaginosis (BV) have complex communities of anaerobic bacteria. There are no cultivated isolates of several bacteria identified using molecular methods and associated with BV. It is unclear whether this is due to the inability to adequately propagate these bacteria or to correctly identify them in culture. Vaginal fluid from 15 women was plated on 6 different media using classical cultivation approaches. Individual isolates were identified by 16S ribosomal RNA (rRNA) gene sequencing and compared with validly described species. Bacterial community profiles in vaginal samples were determined using broad-range 16S rRNA gene polymerase chain reaction and pyrosequencing. We isolated and identified 101 distinct bacterial strains spanning 6 phyla including (1) novel strains with <98% 16S rRNA sequence identity to validly described species, (2) closely related species within a genus, (3) bacteria previously isolated from body sites other than the vagina, and (4) known bacteria formerly isolated from the vagina. Pyrosequencing showed that novel strains Peptoniphilaceae DNF01163 and Prevotellaceae DNF00733 were prevalent in women with BV. We isolated a diverse set of novel and clinically significant anaerobes from the human vagina using conventional approaches with systematic molecular identification. Several previously "uncultivated" bacteria are amenable to conventional cultivation. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Do wheelchairs spread pathogenic bacteria within hospital walls?

PubMed

Peretz, Avi; Koiefman, Anna; Dinisman, Eleonora; Brodsky, Diana; Labay, Kozitta

2014-02-01

Transmission of nosocomial pathogens has been linked to transient colonization of health care workers, medical devices and other constituents of patients' environment. In this paper we present our findings concerning the presence of pathogenic bacteria on wheelchairs, and the possibility that wheelchairs constitute a reservoir of these bacteria and a means of spreading them. In this work we examined four wheelchairs, each from a different location: the internal medicine ward, the emergency department, the general surgery ward and wheelchair stockpile of the transportation unit of the hospital. The samples were collected and cultured on different media. Bacterial identification and antimicrobial sensitivity testing were carried out using accepted practices in the microbiology laboratory. We found that wheelchairs are contaminated with several pathogenic bacteria, among them antibiotic-resistant strains such as MRSA, Pseudomonas aeruginosa, Acinetobacter baumanni etc. Since there is no specific guideline protocol that deals with disinfection and cleaning frequency of wheelchairs in hospitals, we suggest each hospital to write one.

Downeast Drainage - Examining and Communicating the Dynamics of Bacteria Pollution Events in the Gulf of Maine

NASA Astrophysics Data System (ADS)

Smith, S. M.; Brady, D. C.; Cole, K. L.; Jones, S.; McGreavy, B.; Petersen, C.; Rothenheber, D.; Gerard, B.; Roy, S. G.

2015-12-01

The New England Sustainability Consortium is an interdisciplinary NSF EPSCoR funded project organized to strengthen the connections between science and decision-making and to advance the practice of sustainability science. The project uses complementary research capacity at several institutions to examine watershed and estuarine processes linked to bacteria pollution affecting shellfish harvesting and beach water quality in the Gulf of Maine. A fundamental research target is the development of a better approach for the prediction of coastal bacteria pollution events that can cause losses in tourism and shellfishery revenue. Enhanced prediction and communication of the events require a simultaneous examination of watershed pollution sources, drainage systems, estuarine residence times and bacterial survival. Our presentation will summarize initial observations from our investigations and stakeholder engagement activities at two project reference sites located in Wells and Bar Harbor, Maine. These will include field measurements, watershed and estuarine modeling outcomes, and stakeholder engagement results that are framed to quantify and explain land-sea interactions linked to bacterial pollution events in locations with varied relief, hydrodynamics, and stakeholder communities.

The association between body mass index and severe biliary infections: a multivariate analysis.

PubMed

Stewart, Lygia; Griffiss, J McLeod; Jarvis, Gary A; Way, Lawrence W

2012-11-01

Obesity has been associated with worse infectious disease outcomes. It is a risk factor for cholesterol gallstones, but little is known about associations between body mass index (BMI) and biliary infections. We studied this using factors associated with biliary infections. A total of 427 patients with gallstones were studied. Gallstones, bile, and blood (as applicable) were cultured. Illness severity was classified as follows: none (no infection or inflammation), systemic inflammatory response syndrome (fever, leukocytosis), severe (abscess, cholangitis, empyema), or multi-organ dysfunction syndrome (bacteremia, hypotension, organ failure). Associations between BMI and biliary bacteria, bacteremia, gallstone type, and illness severity were examined using bivariate and multivariate analysis. BMI inversely correlated with pigment stones, biliary bacteria, bacteremia, and increased illness severity on bivariate and multivariate analysis. Obesity correlated with less severe biliary infections. BMI inversely correlated with pigment stones and biliary bacteria; multivariate analysis showed an independent correlation between lower BMI and illness severity. Most patients with severe biliary infections had a normal BMI, suggesting that obesity may be protective in biliary infections. This study examined the correlation between BMI and biliary infection severity. Published by Elsevier Inc.

Extended-spectrum β-lactamase-producing bacteria causing community-acquired urinary tract infections in children.

PubMed

Megged, Orli

2014-09-01

Extended-spectrum β-lactamase (ESBL)-producing bacteria are infrequent pathogens of community-acquired (CA) urinary tract infections (UTIs) in children. The aim of this study was to assess the frequency of and identify risk factors for CA-UTIs due to ESBL-producing microorganisms (CA-ESBL-UTI). The medical records of all children diagnosed with CA-ESBL-UTI at our medical center between 2003 and 2013 were reviewed. Patients with non-ESBL-UTIs during the same period were included as controls. Eighty cases of CA-ESBL-UTI were identified. The incidence of ESBL-UTI increased from 2 to 3.8% during the study period. Compared to children with non-ESBL-UTI, those with ESBL were more likely to be of Arab descent, to have underlying medical conditions, to have received antibiotics in the month prior to the UTI and to have been previously hospitalized. The mean duration of hospitalization for patients with an ESBL-UTI was significantly longer than that for patients with a non-ESBL UTI (3.6 vs. 2 days; P = 0.01). In multivariate analysis, Arab ethnicity [odds ratio (OR) 6.1; 95 % confidence interval (CI) 2.7-13.6] and recent antibiotic treatment (OR 4.0; 95 % CI 1.6-10.4) were risk factors for CA-ESBL-UTI. The incidence of CA-ESBL-UTI is rising. The empiric treatment for suspected UTI in children who had been previously hospitalized and who had received antibiotics in the last month should cover ESBL-producing bacteria.

Impact of socioeconomic deprivation on rate and cause of death in severe mental illness.

PubMed

Martin, Julie Langan; McLean, Gary; Park, John; Martin, Daniel J; Connolly, Moira; Mercer, Stewart W; Smith, Daniel J

2014-09-12

Socioeconomic status has important associations with disease-specific mortality in the general population. Although individuals with Severe Mental Illnesses (SMI) experience significant premature mortality, the relationship between socioeconomic status and mortality in this group remains under investigated. We aimed to assess the impact of socioeconomic status on rate and cause of death in individuals with SMI (schizophrenia and bipolar disorder) relative to the local (Glasgow) and wider (Scottish) populations. Cause and age of death during 2006-2010 inclusive for individuals with schizophrenia or bipolar disorder registered on the Glasgow Psychosis Clinical Information System (PsyCIS) were obtained by linkage to the Scottish General Register Office (GRO). Rate and cause of death by socioeconomic status, measured by Scottish Index of Multiple Deprivation (SIMD), were compared to the Glasgow and Scottish populations. Death rates were higher in people with SMI across all socioeconomic quintiles compared to the Glasgow and Scottish populations, and persisted when suicide was excluded. Differences were largest in the most deprived quintile (794.6 per 10,000 population vs. 274.7 and 252.4 for Glasgow and Scotland respectively). Cause of death varied by socioeconomic status. For those living in the most deprived quintile, higher drug-related deaths occurred in those with SMI compared to local Glasgow and wider Scottish population rates (12.3% vs. 5.9%, p = <0.001 and 5.1% p = 0.002 respectively). A lower proportion of deaths due to cancer in those with SMI living in the most deprived quintile were also observed, relative to the local Glasgow and wider Scottish populations (12.3% vs. 25.1% p = 0.013 and 26.3% p = <0.001). The proportion of suicides was significantly higher in those with SMI living in the more affluent quintiles relative to Glasgow and Scotland (54.6% vs. 5.8%, p = <0.001 and 5.5%, p = <0.001). Excess mortality in those with SMI occurred across all

Fast Raman single bacteria identification: toward a routine in-vitro diagnostic

NASA Astrophysics Data System (ADS)

Douet, Alice; Josso, Quentin; Marchant, Adrien; Dutertre, Bertrand; Filiputti, Delphine; Novelli-Rousseau, Armelle; Espagnon, Isabelle; Kloster-Landsberg, Meike; Mallard, Frédéric; Perraut, Francois

2016-04-01

Timely microbiological results are essential to allow clinicians to optimize the prescribed treatment, ideally at the initial stage of the therapeutic process. Several approaches have been proposed to solve this issue and to provide the microbiological result in a few hours directly from the sample such as molecular biology. However fast and sensitive those methods are not based on single phenotypic information which presents several drawbacks and limitations. Optical methods have the advantage to allow single-cell sensitivity and to probe the phenotype of measured cells. Here we present a process and a prototype that allow automated single-bacteria phenotypic analysis. This prototype is based on the use of Digital In-line Holography techniques combined with a specially designed Raman spectrometer using a dedicated device to capture bacteria. The localization of single-cell is finely determined by using holograms and a proper propagation kernel. Holographic images are also used to analyze bacteria in the sample to sort potential pathogens from flora dwelling species or other biological particles. This accurate localization enables the use of a small confocal volume adapted to the measurement of single-cell. Along with the confocal volume adaptation, we also have modified every components of the spectrometer to optimize single-bacteria Raman measurements. This optimization allowed us to acquire informative single-cell spectra using an integration time of 0.5s only. Identification results obtained with this prototype are presented based on a 65144 Raman spectra database acquired automatically on 48 bacteria strains belonging to 8 species.

Aberrant tendinous chords with tethering of the tricuspid leaflets: a congenital anomaly causing severe tricuspid regurgitation.

PubMed

Kobza, R; Kurz, D J; Oechslin, E N; Prêtre, R; Zuber, M; Vogt, P; Jenni, R

2004-03-01

To define the entity of tricuspid regurgitation caused by tethering of the tricuspid valve leaflets by aberrant tendinous chords. Retrospective study. Tertiary care centre (university teaching hospital). 10 patients with unexplained severe tricuspid regurgitation. The last 13 500 echocardiographic studies from our facility were reviewed to identify patients with severe unexplained tricuspid regurgitation. Tethering was defined by the presence of aberrant tendinous chords to the tricuspid valve leaflets limiting the mobility of the tricuspid leaflet and resulting in incomplete coaptation and apical displacement of the regurgitant jet origin. Aberrant tendinous chords were defined as those inserting at the clear zone of the tricuspid leaflet and not originating from the papillary muscle. Patients fulfilling the diagnostic criteria for Ebstein's anomaly were excluded. 10 patients with aberrant tendinous chords tethering one or more tricuspid valve leaflets were identified. There were short non-aberrant tendinous chords in seven patients, five of whom also had right ventricular or tricuspid annulus dilatation. Tethering of the tricuspid valve leaflets by aberrant tendinous chords can be the sole mechanism of congenital tricuspid regurgitation. It is often associated with short non-aberrant tendinous chords, which may develop secondary to right ventricular or tricuspid annulus dilatation. Awareness of tethering as a cause of tricuspid regurgitation may be important in planning reconstructive surgery.

Development of a filter to prevent infections with spore-forming bacteria in injecting drug users.

PubMed

Alhusein, Nour; Scott, Jenny; Kasprzyk-Hordern, Barbara; Bolhuis, Albert

2016-12-01

In heroin injectors, there have been a number of outbreaks caused by spore-forming bacteria, causing serious infections such as anthrax or botulism. These are, most likely, caused by injecting contaminated heroin, and our aim was to develop a filter that efficiently removes these bacteria and is also likely to be acceptable for use by people who inject drugs (i.e. quick, simple and not spoil the hit). A prototype filter was designed and different filter membranes were tested to assess the volume of liquid retained, filtration time and efficiency of the filter at removing bacterial spores. Binding of active ingredients of heroin to different types of membrane filters was determined using a highly sensitive analytical chemistry technique. Heroin samples that were tested contained up to 580 bacteria per gramme, with the majority being Bacillus spp., which are spore-forming soil bacteria. To remove these bacteria, a prototype filter was designed to fit insulin-type syringes, which are commonly used by people who inject drugs (PWIDs). Efficient filtration of heroin samples was achieved by combining a prefilter to remove particles and a 0.22 μm filter to remove bacterial spores. The most suitable membrane was polyethersulfone (PES). This membrane had the shortest filtration time while efficiently removing bacterial spores. No or negligible amounts of active ingredients in heroin were retained by the PES membrane. This study successfully produced a prototype filter designed to filter bacterial spores from heroin samples. Scaled up production could produce an effective harm reduction tool, especially during outbreaks such as occurred in Europe in 2009/10 and 2012.

Vanadium removal from LD converter slag using bacteria and fungi.

PubMed

Mirazimi, S M J; Abbasalipour, Z; Rashchi, F

2015-04-15

Removal of vanadium from Linz-Donawits (LD) converter slag was investigated by means of three different species of microbial systems: Acidithiobacillus thiooxidans (autotrophic bacteria), Pseudomonas putida (heterotrophic bacteria) and Aspergillus niger (fungi). The bioleaching process was carried out in both one-step and two-step process and the leaching efficiencies in both cases were compared. Formation of inorganic and organic acids during the leaching process caused mobilization of vanadium. In order to reduce toxic effects of the metal species on the above mentioned microorganisms, a prolonged adaptation process was performed. Both bacteria, A. thiooxidans and P. putida were able to remove more than 90% of vanadium at slag concentrations of 1-5 g L(-1) after 15 days. Also, the maximum achievable vanadium removal in the fungal system was approximately 92% at a slag concentration of 1 g L(-1) after 22 days. Copyright © 2015 Elsevier Ltd. All rights reserved.

Human bactericidal/permeability-increasing protein and a recombinant NH2-terminal fragment cause killing of serum-resistant gram-negative bacteria in whole blood and inhibit tumor necrosis factor release induced by the bacteria.

PubMed Central

Weiss, J; Elsbach, P; Shu, C; Castillo, J; Grinna, L; Horwitz, A; Theofan, G

1992-01-01

The bactericidal/permeability-increasing protein (BPI) of neutrophils and BPI fragments neutralize the effects of isolated Gram-negative bacterial lipopolysaccharides both in vitro and in vivo. Since endotoxin most commonly enters the host as constituents of invading Gram-negative bacteria, we raised the question: Can BPI and its bioactive fragments also protect against whole bacteria? To determine whether the bactericidal and endotoxin-neutralizing activities of BPI/fragments are expressed when Gram-negative bacteria are introduced to the complex environment of whole blood we examined the effects of added BPI and proteolytically prepared and recombinant NH2-terminal fragments on: (a) the fate of serum-resistant encapsulated Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa that survive the antibacterial actions of whole blood and (b) the ability of these bacteria to trigger cytokine release. Added BPI in nanomolar concentrations killed each of three encapsulated strains of E. coli and in closely parallel fashion inhibited tumor necrosis factor (TNF) release. Holo-BPI and its NH2-terminal fragment were equipotent toward a rough LPS chemotype K1-encapsulated strain, but the fragment was substantially more potent than holo-BPI toward two encapsulated smooth LPS chemotype strains. TNF release induced by K. pneumoniae and P. aeruginosa was also inhibited by both holo-BPI and fragment but, at the protein concentrations tested, P. aeruginosa was killed only by the fragment and K. pneumoniae was not killed by either protein. The bactericidal action of BPI/fragment toward E. coli is inhibited by C7-depleted serum, but accelerated by normal serum, indicating that BPI, acting in synergy with late complement components, enhances extracellular killing of serum-resistant bacteria. Thus, BPI and an even more potent NH2-terminal fragment may protect against Gram-negative bacteria in the host by blocking bacterial proliferation as well as endotoxin

Human bactericidal/permeability-increasing protein and a recombinant NH2-terminal fragment cause killing of serum-resistant gram-negative bacteria in whole blood and inhibit tumor necrosis factor release induced by the bacteria.

PubMed

Weiss, J; Elsbach, P; Shu, C; Castillo, J; Grinna, L; Horwitz, A; Theofan, G

1992-09-01

The bactericidal/permeability-increasing protein (BPI) of neutrophils and BPI fragments neutralize the effects of isolated Gram-negative bacterial lipopolysaccharides both in vitro and in vivo. Since endotoxin most commonly enters the host as constituents of invading Gram-negative bacteria, we raised the question: Can BPI and its bioactive fragments also protect against whole bacteria? To determine whether the bactericidal and endotoxin-neutralizing activities of BPI/fragments are expressed when Gram-negative bacteria are introduced to the complex environment of whole blood we examined the effects of added BPI and proteolytically prepared and recombinant NH2-terminal fragments on: (a) the fate of serum-resistant encapsulated Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa that survive the antibacterial actions of whole blood and (b) the ability of these bacteria to trigger cytokine release. Added BPI in nanomolar concentrations killed each of three encapsulated strains of E. coli and in closely parallel fashion inhibited tumor necrosis factor (TNF) release. Holo-BPI and its NH2-terminal fragment were equipotent toward a rough LPS chemotype K1-encapsulated strain, but the fragment was substantially more potent than holo-BPI toward two encapsulated smooth LPS chemotype strains. TNF release induced by K. pneumoniae and P. aeruginosa was also inhibited by both holo-BPI and fragment but, at the protein concentrations tested, P. aeruginosa was killed only by the fragment and K. pneumoniae was not killed by either protein. The bactericidal action of BPI/fragment toward E. coli is inhibited by C7-depleted serum, but accelerated by normal serum, indicating that BPI, acting in synergy with late complement components, enhances extracellular killing of serum-resistant bacteria. Thus, BPI and an even more potent NH2-terminal fragment may protect against Gram-negative bacteria in the host by blocking bacterial proliferation as well as endotoxin

Effect of soil structure on the growth of bacteria in soil quantified using CARD-FISH

NASA Astrophysics Data System (ADS)

Juyal, Archana; Eickhorst, Thilo; Falconer, Ruth; Otten, Wilfred

2014-05-01

It has been reported that compaction of soil due to use of heavy machinery has resulted in the reduction of crop yield. Compaction affects the physical properties of soil such as bulk density, soil strength and porosity. This causes an alteration in the soil structure which limits the mobility of nutrients, water and air infiltration and root penetration in soil. Several studies have been conducted to explore the effect of soil compaction on plant growth and development. However, there is scant information on the effect of soil compaction on the microbial community and its activities in soil. Understanding the effect of soil compaction on microbial community is essential as microbial activities are very sensitive to abrupt environmental changes in soil. Therefore, the aim of this work was to investigate the effect of soil structure on growth of bacteria in soil. The bulk density of soil was used as a soil physical parameter to quantify the effect of soil compaction. To detect and quantify bacteria in soil the method of catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH) was used. This technique results in high intensity fluorescent signals which make it easy to quantify bacteria against high levels of autofluorescence emitted by soil particles and organic matter. In this study, bacterial strains Pseudomonas fluorescens SBW25 and Bacillus subtilis DSM10 were used. Soils of aggregate size 2-1mm were packed at five different bulk densities in polyethylene rings (4.25 cm3).The soil rings were sampled at four different days. Results showed that the total number of bacteria counts was reduced significantly (P

Bacteria versus selenium: A view from the inside out

USGS Publications Warehouse

Staicu, Lucian; Oremland, Ronald S.; Tobe, Ryuta; Mihara, Hisaaki

2017-01-01

Bacteria and selenium (Se) are closely interlinked as the element serves both essential nutrient requirements and energy generation functions. However, Se can also behave as a powerful toxicant for bacterial homeostasis. Conversely, bacteria play a tremendous role in the cycling of Se between different environmental compartments, and bacterial metabolism has been shown to participate to all valence state transformations undergone by Se in nature. Bacteria possess an extensive molecular repertoire for Se metabolism. At the end of the 1980s, a novel mode of anaerobic respiration based on Se oxyanions was experimentally documented for the first time. Following this discovery, specific enzymes capable of reducing Se oxyanions and harvesting energy were found in a number of anaerobic bacteria. The genes involved in the expression of these enzymes have later been identified and cloned. This iterative approach undertaken outside-in led to the understanding of the molecular mechanisms of Se transformations in bacteria. Based on the extensive knowledge accumulated over the years, we now have a full(er) view from the inside out, from DNA-encoding genes to enzymes and thermodynamics. Bacterial transformations of Se for assimilatory purposes have been the object of numerous studies predating the investigation of Se respiration. Remarkable contributions related to the understating of the molecular picture underlying seleno-amino acid biosynthesis are reviewed herein. Under certain circumstances, Se is a toxicant for bacterial metabolism and bacteria have evolved strategies to counteract this toxicity, most notably by the formation of elemental Se (nano)particles. Several biotechnological applications, such as the production of functional materials and the biofortification of crop species using Se-utilizing bacteria, are presented in this chapter.

BACTERICIDAL COATINGS ON TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT

DTIC Science & Technology

2017-07-07

Activity by Bacillus sp. P11” Food Bioprocess Technol. 4:822- 828. (2011) Levy, S.B and Marshal,l B.; “ Antibacterial resistance worldwide: causes...TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT by Tobyn A. Branck Courtney M. Cowell Jennifer M. Rego and...October 2011 – September 2015 4. TITLE AND SUBTITLE BACTERICIDAL COATINGS ON TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT

Bacteria between protists and phages: from antipredation strategies to the evolution of pathogenicity.

PubMed

Brüssow, Harald

2007-08-01

Bacteriophages and protists are major causes of bacterial mortality. Genomics suggests that phages evolved well before eukaryotic protists. Bacteria were thus initially only confronted with phage predators. When protists evolved, bacteria were caught between two types of predators. One successful antigrazing strategy of bacteria was the elaboration of toxins that would kill the grazer. The released cell content would feed bystander bacteria. I suggest here that, to fight grazing protists, bacteria teamed up with those phage predators that concluded at least a temporary truce with them in the form of lysogeny. Lysogeny was perhaps initially a resource management strategy of phages that could not maintain infection chains. Subsequently, lysogeny might have evolved into a bacterium-prophage coalition attacking protists, which became a food source for them. When protists evolved into multicellular animals, the lysogenic bacteria tracked their evolving food source. This hypothesis could explain why a frequent scheme of bacterial pathogenicity is the survival in phagocytes, why a significant fraction of bacterial pathogens have prophage-encoded virulence genes, and why some virulence factors of animal pathogens are active against unicellular eukaryotes. Bacterial pathogenicity might thus be one playing option of the stone-scissor-paper game played between phages-bacteria-protists, with humans getting into the crossfire.

Changes in the proteome of Mastitis-causing escherichia coli strains that affect pathogenesis

USDA-ARS?s Scientific Manuscript database

Escherichia coli is a leading cause of bacterial mastitis in dairy cattle. Milk is the environment in which bacteria must grow to establish an infection of the mammary gland. However, milk is not a rich growth media for bacteria. In fact, milk naturally contains many mechanisms to inhibit bacterial ...

Novel NEK8 Mutations Cause Severe Syndromic Renal Cystic Dysplasia through YAP Dysregulation

PubMed Central

Grampa, Valentina; Odye, Gweltas; Thomas, Sophie; Elkhartoufi, Nadia; Filhol, Emilie; Niel, Olivier; Silbermann, Flora; Lebreton, Corinne; Collardeau-Frachon, Sophie; Rouvet, Isabelle; Alessandri, Jean-Luc; Devisme, Louise; Dieux-Coeslier, Anne; Cordier, Marie-Pierre; Capri, Yline; Khung-Savatovsky, Suonavy; Sigaudy, Sabine; Salomon, Rémi; Antignac, Corinne; Gubler, Marie-Claire; Benmerah, Alexandre; Terzi, Fabiola; Attié-Bitach, Tania; Jeanpierre, Cécile; Saunier, Sophie

2016-01-01

Ciliopathies are a group of genetic multi-systemic disorders related to dysfunction of the primary cilium, a sensory organelle present at the cell surface that regulates key signaling pathways during development and tissue homeostasis. In order to identify novel genes whose mutations would cause severe developmental ciliopathies, >500 patients/fetuses were analyzed by a targeted high throughput sequencing approach allowing exome sequencing of >1200 ciliary genes. NEK8/NPHP9 mutations were identified in five cases with severe overlapping phenotypes including renal cystic dysplasia/hypodysplasia, situs inversus, cardiopathy with hypertrophic septum and bile duct paucity. These cases highlight a genotype-phenotype correlation, with missense and nonsense mutations associated with hypodysplasia and enlarged cystic organs, respectively. Functional analyses of NEK8 mutations in patient fibroblasts and mIMCD3 cells showed that these mutations differentially affect ciliogenesis, proliferation/apoptosis/DNA damage response, as well as epithelial morphogenesis. Notably, missense mutations exacerbated some of the defects due to NEK8 loss of function, highlighting their likely gain-of-function effect. We also showed that NEK8 missense and loss-of-function mutations differentially affect the regulation of the main Hippo signaling effector, YAP, as well as the expression of its target genes in patient fibroblasts and renal cells. YAP imbalance was also observed in enlarged spheroids of Nek8-invalidated renal epithelial cells grown in 3D culture, as well as in cystic kidneys of Jck mice. Moreover, co-injection of nek8 MO with WT or mutated NEK8-GFP RNA in zebrafish embryos led to shortened dorsally curved body axis, similar to embryos injected with human YAP RNA. Finally, treatment with Verteporfin, an inhibitor of YAP transcriptional activity, partially rescued the 3D spheroid defects of Nek8-invalidated cells and the abnormalities of NEK8-overexpressing zebrafish embryos

Why do lesions in the rodent anterior thalamic nuclei cause such severe spatial deficits?

PubMed Central

Aggleton, John P.; Nelson, Andrew J.D.

2015-01-01

Lesions of the rodent anterior thalamic nuclei cause severe deficits to multiple spatial learning tasks. Possible explanations for these effects are examined, with particular reference to T-maze alternation. Anterior thalamic lesions not only impair allocentric place learning but also disrupt other spatial processes, including direction learning, path integration, and relative length discriminations, as well as aspects of nonspatial learning, e.g., temporal discriminations. Working memory tasks, such as T-maze alternation, appear particularly sensitive as they combine an array of these spatial and nonspatial demands. This sensitivity partly reflects the different functions supported by individual anterior thalamic nuclei, though it is argued that anterior thalamic lesion effects also arise from covert pathology in sites distal to the thalamus, most critically in the retrosplenial cortex and hippocampus. This two-level account, involving both local and distal lesion effects, explains the range and severity of the spatial deficits following anterior thalamic lesions. These findings highlight how the anterior thalamic nuclei form a key component in a series of interdependent systems that support multiple spatial functions. PMID:25195980

Pathogenic bacteria carried by companion animals and their susceptibility to antibacterial agents.

PubMed

Buma, Ryoko; Maeda, Takuya; Kamei, Masaharu; Kourai, Hiroki

2006-03-01

Results of the investigation showed that there was a difference in the bacteria isolated from dogs, cats and their living environment. The number and species isolated from the hair and front paw samples from dogs kept outdoors and from cats were greater and more varied than those from the samples from dogs kept indoors. Staphylococcus, Micrococcus and Bacillus were frequently detected from skin surfaces. On the other hand, Escherichia, Pseudomonas, Proteus and others were detected on each sampling area on dogs kept outdoors and on cats. About 60% of the bacteria commonly causes infectious diseases and carries a risk of food poisoning. Moreover, Pasteurella multocida, which causes pasteurellasis, a kind of zoonosis, was isolated from dogs and cats. These pathogenic bacteria were transmitted from animals to humans by direct contact. This result suggests that direct contact with dogs and cats and contact with aerosols can possibly transmit infectious diseases. Most of the isolates (75.9%, 60/79) were resistant to antibacterial agents. We then investigated the effect of household detergents and pet care deodorant sprays containing antibacterial agents on isolates from dogs and cats. They were effective in preventing the transmission of pathogens from dogs and cats to humans.

Intraplaque hemorrhage, a potential consequence of periodontal bacteria gathering in human carotid atherothrombosis.

PubMed

Brun, Adrian; Rangé, Hélène; Prouvost, Bastien; Meilhac, Olivier; Mazighi, Mikael; Amarenco, Pierre; Lesèche, Guy; Bouchard, Philippe; Michel, Jean-Baptiste

2016-06-28

Periodontal diseases are multifactorial inflammatory diseases, caused by a bacterial biofilm involving both innate and adaptative immunity, characterized by the destruction of tooth-supporting tissues. In the context of periodontitis, the spread of weak pathogenic bacteria into the bloodstream has been described. These bacteria will preferentially localize to existing clot within the circulation. Atherothrombosis of the carotid arteries is a local pathology and a common cause of cerebral infarction. Intraplaque hemorrhages render the lesion more prone to clinical complications such as stroke. The main objective of this study is to explore the biological relationship between carotid intraplaque hemorrhage and periodontal diseases. This study included consecutive patients with symptomatic or asymptomatic carotid stenosis, admitted for endarterectomy surgical procedure (n=41). In conditioned media of the carotid samples collected, markers of neutrophil activation (myeloperoxidase or MPO, DNA-MPO complexes) and hemoglobin were quantified. To investigate the presence of DNA from periodontal bacteria in atherosclerotic plaque, PCR analysis using specific primers was performed. Our preliminary results indicate an association between neutrophil activation and intraplaque hemorrhages, reflected by the release of MPO (p<0,01) and MPO-DNA complexes (p<0,05). Presence of DNA from periodontitis-associated bacteria was found in 32/41 (78%) atheromatous plaque samples. More specifically, DNA from Pg, Tf, Pi, Aa was found in 46%, 24%, 34% and 68% of the samples, respectively. Hemoglobin levels were higher in conditioned media in carotid samples where the bacteria were found, but this was not statistically significant. Our data confirm the relationship between intraplaque hemorrhage and neutrophil activation. In addition, the presence of periodontal bacteria DNA in carotid atheromatous plaque, may contribute to this activation. Further analysis is needed to fully explore the

Phenotypic switching in bacteria

NASA Astrophysics Data System (ADS)

Merrin, Jack

Living matter is a non-equilibrium system in which many components work in parallel to perpetuate themselves through a fluctuating environment. Physiological states or functionalities revealed by a particular environment are called phenotypes. Transitions between phenotypes may occur either spontaneously or via interaction with the environment. Even in the same environment, genetically identical bacteria can exhibit different phenotypes of a continuous or discrete nature. In this thesis, we pursued three lines of investigation into discrete phenotypic heterogeneity in bacterial populations: the quantitative characterization of the so-called bacterial persistence, a theoretical model of phenotypic switching based on those measurements, and the design of artificial genetic networks which implement this model. Persistence is the phenotype of a subpopulation of bacteria with a reduced sensitivity to antibiotics. We developed a microfluidic apparatus, which allowed us to monitor the growth rates of individual cells while applying repeated cycles of antibiotic treatments. We were able to identify distinct phenotypes (normal and persistent) and characterize the stochastic transitions between them. We also found that phenotypic heterogeneity was present prior to any environmental cue such as antibiotic exposure. Motivated by the experiments with persisters, we formulated a theoretical model describing the dynamic behavior of several discrete phenotypes in a periodically varying environment. This theoretical framework allowed us to quantitatively predict the fitness of dynamic populations and to compare survival strategies according to environmental time-symmetries. These calculations suggested that persistence is a strategy used by bacterial populations to adapt to fluctuating environments. Knowledge of the phenotypic transition rates for persistence may provide statistical information about the typical environments of bacteria. We also describe a design of artificial

Influence of surfaces on sulphidogenic bacteria.

PubMed

Bass, C J; Webb, J S; Sanders, P F; Lappin-Scott, H M

1996-01-01

Sulphidogenic bacteria in oil reservoirs are of great economic importance in terms of souring, fouling and corrosion. Mixed cultures containing these bacteria were isolated from chalk formations in North Sea oil reservoirs. These were thermophilic cultures, growing optimally at 60°C. Oil formations are porous matrices, providing a very large surface area and ideal conditions for bacterial attachment, survival and growth. This study included assessments of sulphide production rates of thermophilic (t-)sulphidogen consortia with and without additional surfaces. The availability of a surface contributed significantly to the rate and extent of sulphide generation. Surfaces were offered in varying amounts to growing planktonic cultures: significantly more sulphide was produced from cultures in contact with a surface than from identical cultures in the absence of a surface. In another series of experiments, t-sulphidogens were added to chalk rock chips in the presence of nutrients and incubated for several months. This resulted in rapid sulphide generation, the final concentration being related to the initial nutrient concentration. Subsequent nutrient addition resulted in renewed sulphide generation. It is suggested that bacteria in reservoirs can withstand long periods of nutrient deprivation while attached within the porous rock matrix and opportunistically utilise nutrients when they become available.

Sorting and recycling of domestic waste. Review of occupational health problems and their possible causes.

PubMed

Poulsen, O M; Breum, N O; Ebbehøj, N; Hansen, A M; Ivens, U I; van Lelieveld, D; Malmros, P; Matthiasen, L; Nielsen, B H; Nielsen, E M

1995-05-19

In order to reduce the strain on the environment from the deposition of waste in landfills and combustion at incineration plants, several governments throughout the industrialized world have planned greatly increased recycling of domestic waste by the turn of the millennium. To implement the plans, new waste recycling facilities are to be built and the number of workers involved in waste sorting and recycling will increase steadily during the next decade. Several studies have reinforced the hypothesis that exposure to airborne microorganisms and the toxic products thereof are important factors causing a multitude of health problems among workers at waste sorting and recycling plants. Workers at transfer stations, landfills and incineration plants may experience an increased risk of pulmonary disorders and gastrointestinal problems. High concentrations of total airborne dust, bacteria, faecal coliform bacteria and fungal spores have been reported. The concentrations are considered to be sufficiently high to cause adverse health effects. In addition, a high incidence of lower back injuries, probably due to heavy lifting during work, has been reported among workers at landfills and incineration plants. Workers involved in manual sorting of unseparated domestic waste, as well as workers at compost plants experience more or less frequent symptoms of organic dust toxic syndrome (ODTS) (cough, chest-tightness, dyspnoea, influenza-like symptoms such as chills, fever, muscle ache, joint pain, fatigue and headache), gastrointestinal problems such as nausea and diarrhoea, irritation of the skin, eye and mucous membranes of the nose and upper airways, etc. In addition cases of severe occupational pulmonary diseases (asthma, alveolitis, bronchitis) have been reported. Manual sorting of unseparated domestic waste may be associated with exposures to large quantities of airborne bacteria and endotoxin. Several work functions in compost plants can result in very high exposure to

Metabolic interdependence of obligate intracellular bacteria and their insect hosts.

PubMed

Zientz, Evelyn; Dandekar, Thomas; Gross, Roy

2004-12-01

Mutualistic associations of obligate intracellular bacteria and insects have attracted much interest in the past few years due to the evolutionary consequences for their genome structure. However, much less attention has been paid to the metabolic ramifications for these endosymbiotic microorganisms, which have to compete with but also to adapt to another metabolism--that of the host cell. This review attempts to provide insights into the complex physiological interactions and the evolution of metabolic pathways of several mutualistic bacteria of aphids, ants, and tsetse flies and their insect hosts.

Types and severity of operated supraclavicular brachial plexus injuries caused by traffic accidents.

PubMed

Kaiser, Radek; Waldauf, Petr; Haninec, Pavel

2012-07-01

Brachial plexus injuries occur in up to 5% of polytrauma cases involving motorcycle accidents and in approximately 4% of severe winter sports injuries. One of the criteria for a successful operative therapy is the type of lesion. Upper plexus palsy has the best prognosis, whereas lower plexus palsy is surgically untreatable. The aim of this study was to evaluate a group of patients with brachial plexus injury caused by traffic accidents, categorize the injuries according to type of accident, and look for correlations between type of palsy (injury) and specific accidents. A total of 441 brachial plexus reconstruction patients from our department were evaluated retrospectively(1993 to 2011). Sex, age, neurological status, and the type and cause of injury were recorded for each case. Patients with BPI caused by a traffic accident were assessed in detail. Traffic accidents were the cause of brachial plexus injury in most cases (80.7%). The most common type of injury was avulsion of upper root(s) (45.7%) followed by rupture (28.2%), complete avulsion (16.9%) and avulsion of lower root(s) (9.2%). Of the patients, 73.9% had an upper,22.7% had a complete and only 3.4% had a lower brachial plexus palsy. The main cause was motorcycle accidents(63.2%) followed by car accidents (23.5%), bicycle accidents(10.7%) and pedestrian collisions (3.1%) (p<0.001).Patients involved in car accidents had a higher percentage of lower avulsion (22.7%) and a lower percentage of upper avulsion (29.3%), whereas cyclists had a higher percentage of upper avulsion (68.6%) based on the data from the entire group of patients (p<0.001). Lower plexus palsy was significantly increased in patients after car accidents (9.3%,p<0.05). In the two main groups (car and motorcycle accidents),significantly more upper and fewer lower palsies were present. In the bicycle accident group, upper palsy was the most common (89%). Study results indicate that the most common injury was an upper plexus palsy. It was

Taxonomic composition and physiological and biochemical properties of bacteria in the digestive tracts of earthworms

NASA Astrophysics Data System (ADS)

Byzov, B. A.; Tikhonov, V. V.; Nechitailo, T. Yu.; Demin, V. V.; Zvyagintsev, D. G.

2015-03-01

Several hundred bacterial strains belonging to different taxa were isolated and identified from the digestive tracts of soil and compost earthworms. Some physiological and biochemical properties of the bacteria were characterized. The majority of intestinal bacteria in the earthworms were found to be facultative anaerobes. The intestinal isolates as compared to the soil ones had elevated activity of proteases and dehydrogenases. In addition, bacteria associated with earthworms' intestines are capable of growth on humic acids as a sole carbon source. Humic acid stimulated the growth of the intestinal bacteria to a greater extent than those of the soil ones. In the digestive tracts, polyphenol oxidase activity was found. Along with the data on the taxonomic separation of the intestinal bacteria, the features described testified to the presence of a group of bacteria in the earthworms intestines that is functionally characteristic and is different from the soil bacteria.

Label-Free in Situ Discrimination of Live and Dead Bacteria by Surface-Enhanced Raman Scattering.

PubMed

Zhou, Haibo; Yang, Danting; Ivleva, Natalia P; Mircescu, Nicoleta E; Schubert, Sören; Niessner, Reinhard; Wieser, Andreas; Haisch, Christoph

2015-07-07

Techniques to distinguish between live and dead bacteria in a quantitative manner are in high demand in numerous fields including medical care, food safety, and public security as well as basic science research. This work demonstrates new nanostructures (silver nanoparticles coating bacteria structure, Bacteria@AgNPs) and their utility for rapid counting of live and dead bacteria by surface-enhanced Raman scattering (SERS). We found that suspensions containing Gram-negative organisms as well as AgNPs give strong SERS signals of live bacteria when generated selectively on the particle surface. However, almost no SERS signals can be detected from Bacteria@AgNPs suspensions containing dead bacteria. We demonstrate successful quantification of different percentages of dead bacteria both in bulk liquid and on glass surfaces by using SERS mapping on a single cell basis. Furthermore, different chemicals have been used to elucidate the mechanism involved in this observation. Finally, we used the Bacteria@AgNPs method to detect antibiotic resistance of E. coli strains against several antibiotics used in human medicine.

Association between all-cause mortality and severity of depressive symptoms in patients with type 2 diabetes: Analysis from the Japan Diabetes Complications Study (JDCS).

PubMed

Matsunaga, Satoshi; Tanaka, Shiro; Fujihara, Kazuya; Horikawa, Chika; Iimuro, Satoshi; Kitaoka, Masafumi; Sato, Asako; Nakamura, Jiro; Haneda, Masakazu; Shimano, Hitoshi; Akanuma, Yasuo; Ohashi, Yasuo; Sone, Hirohito

2017-08-01

The aims of this study are to confirm whether the excess mortality caused by depressive symptoms is independent of severe hypoglycemia in patients with type 2 diabetes mellitus (T2DM) and to evaluate the association between all-cause mortality and degrees of severity of depressive symptoms in Japanese patients with T2DM. A total of 1160 Japanese patients with T2DM were eligible for this analysis. Participants were followed prospectively for 3years and their depressive states were evaluated at baseline by the Center for Epidemiologic Studies Depression Scale (CES-D). Cox proportional hazards model was used to evaluate the relative risk of all-cause mortality and was adjusted by possible confounding factors, including severe hypoglycemia, all of which are known as risk factors for both depression and mortality. After adjustment for severe hypoglycemia, each 5-point increase in the CES-D score was significantly associated with excess all-cause mortality (hazard ratio 1.69 [95% CI 1.26-2.17]). The spline curve of HRs for mortality according to total CES-D scores showed that mortality risk was slightly increased at lower scores but was sharply elevated at higher scores. A high score on the CES-D at baseline was significantly associated with all-cause mortality in patients with T2DM after adjusting for confounders including severe hypoglycemia. However, only a small effect on mortality risk was found at relatively lower levels of depressive symptoms in this population. Further research is needed to confirm this relationship between the severity of depressive symptoms and mortality in patients with T2DM. Copyright © 2017 Elsevier Inc. All rights reserved.

Dynamic left ventricular dyssynchrony and severe mitral regurgitation caused by exercise: should we go beyond the guidelines?

PubMed

Laflamme, Emilie; Philippon, François; O'Connor, Kim; Sarrazin, Jean-François; Auffret, Vincent; Chauvette, Vincent; Dubois, Michelle; Voisine, Pierre; Bergeron, Sébastien; Sénéchal, Mario

2018-01-01

Guidelines for cardiac resynchronization therapy (CRT) have been established, but there may be a subgroup of patients not identified in these guidelines who may benefit from this therapy. We report a patient with a dynamic left ventricular dyssynchrony and severe mitral regurgitation caused by exercise successfully treated with CRT. Exercise testing should be considered in patients with left ventricular ejection fraction <35% and QRS <130 ms with severe heart failure symptoms that are unexplained by rest echocardiography evaluation in order to rule out ischemia and/or dynamic left ventricular dyssynchrony. In the presence of exercise-induced left ventricular bundle branch block, the implantation of CRT should be contemplated.

The role of anaerobic bacteria in the cystic fibrosis airway.

PubMed

Sherrard, Laura J; Bell, Scott C; Tunney, Michael M

2016-11-01

Anaerobic bacteria are not only normal commensals, but are also considered opportunistic pathogens and have been identified as persistent members of the lower airway community in people with cystic fibrosis of all ages and stages of disease. Currently, the role of anaerobic bacteria in cystic fibrosis lower airway disease is not well understood. Therefore, this review describes the recent studies relating to the potential pathophysiological role(s) of anaerobes within the cystic fibrosis lungs. The most frequently identified anaerobic bacteria in the lower airways are common to both cystic fibrosis and healthy lungs. Studies have shown that in cystic fibrosis, the relative abundance of anaerobes fluctuates in the lower airways with reduced lung function and increased inflammation associated with a decreased anaerobic load. However, anaerobes found within the lower airways also produce virulence factors, may cause a host inflammatory response and interact synergistically with recognized pathogens. Anaerobic bacteria are potentially members of the airway microbiota in health but could also contribute to the pathogenesis of lower airway disease in cystic fibrosis via both direct and indirect mechanisms. A personalized treatment strategy that maintains a normal microbial community may be possible in the future.

Back To Bacteria.

ERIC Educational Resources Information Center

Flannery, Maura C.

1997-01-01

Explores new research about bacteria. Discusses bacterial genomes, archaea, unusual environments, evolution, pathogens, bacterial movement, biofilms, bacteria in the body, and a bacterial obsession. Contains 29 references. (JRH)

A cultured greigite-producing magnetotactic bacterium in a novel group of sulfate-reducing bacteria.

PubMed

Lefèvre, Christopher T; Menguy, Nicolas; Abreu, Fernanda; Lins, Ulysses; Pósfai, Mihály; Prozorov, Tanya; Pignol, David; Frankel, Richard B; Bazylinski, Dennis A

2011-12-23

Magnetotactic bacteria contain magnetosomes--intracellular, membrane-bounded, magnetic nanocrystals of magnetite (Fe(3)O(4)) or greigite (Fe(3)S(4))--that cause the bacteria to swim along geomagnetic field lines. We isolated a greigite-producing magnetotactic bacterium from a brackish spring in Death Valley National Park, California, USA, strain BW-1, that is able to biomineralize greigite and magnetite depending on culture conditions. A phylogenetic comparison of BW-1 and similar uncultured greigite- and/or magnetite-producing magnetotactic bacteria from freshwater to hypersaline habitats shows that these organisms represent a previously unknown group of sulfate-reducing bacteria in the Deltaproteobacteria. Genomic analysis of BW-1 reveals the presence of two different magnetosome gene clusters, suggesting that one may be responsible for greigite biomineralization and the other for magnetite.

Antibiotics from Gram-negative bacteria: a comprehensive overview and selected biosynthetic highlights.

PubMed

Masschelein, J; Jenner, M; Challis, G L

2017-07-01

Covering: up to 2017The overwhelming majority of antibiotics in clinical use originate from Gram-positive Actinobacteria. In recent years, however, Gram-negative bacteria have become increasingly recognised as a rich yet underexplored source of novel antimicrobials, with the potential to combat the looming health threat posed by antibiotic resistance. In this article, we have compiled a comprehensive list of natural products with antimicrobial activity from Gram-negative bacteria, including information on their biosynthetic origin(s) and molecular target(s), where known. We also provide a detailed discussion of several unusual pathways for antibiotic biosynthesis in Gram-negative bacteria, serving to highlight the exceptional biocatalytic repertoire of this group of microorganisms.

Marine Pseudomonas putida: a potential source of antimicrobial substances against antibiotic-resistant bacteria.

PubMed

Marinho, Palloma Rodrigues; Moreira, Ana Paula Barbosa; Pellegrino, Flávia Lúcia Piffano Costa; Muricy, Guilherme; Bastos, Maria do Carmo de Freire; Santos, Kátia Regina Netto dos; Giambiagi-deMarval, Marcia; Laport, Marinella Silva

2009-08-01

Bacteria isolated from marine sponges found off the coast of Rio de Janeiro, Brazil, were screened for the production of antimicrobial substances. We report a new Pseudomonas putida strain (designated P. putida Mm3) isolated from the sponge Mycale microsigmatosa that produces a powerful antimicrobial substance active against multidrug-resistant bacteria. P. putida Mm3 was identified on the basis of 16S rRNA gene sequencing and phenotypic tests. Molecular typing for Mm3 was performed by RAPD-PCR and comparison of the results to other Pseudomonas strains. Our results contribute to the search for new antimicrobial agents, an important strategy for developing alternative therapies to treat infections caused by multidrug-resistant bacteria.

Mechanism of quinolone resistance in anaerobic bacteria.

PubMed

Oh, H; Edlund, C

2003-06-01

Several recently developed quinolones have excellent activity against a broad range of aerobic and anaerobic bacteria and are thus potential drugs for the treatment of serious anaerobic and mixed infections. Resistance to quinolones is increasing worldwide, but is still relatively infrequent among anaerobes. Two main mechanisms, alteration of target enzymes (gyrase and topoisomerase IV) caused by chromosomal mutations in encoding genes, or reduced intracellular accumulation due to increased efflux of the drug, are associated with quinolone resistance. These mechanisms have also been found in anaerobic species. High-level resistance to the newer broad-spectrum quinolones often requires stepwise mutations in target genes. The increasing emergence of resistance among anaerobes may be a consequence of previous widespread use of quinolones, which may have enriched first-step mutants in the intestinal tract. Quinolone resistance in the Bacteroides fragilis group strains is strongly correlated with amino acid substitutions at positions 82 and 86 in GyrA (equivalent to positions 83 and 87 of Escherichia coli). Several studies have indicated that B. fragilis group strains possess efflux pump systems that actively expel quinolones, leading to resistance. DNA gyrase seems also to be the primary target for quinolones in Clostridium difficile, since amino acid substitutions in GyrA and GyrB have been detected in resistant strains. To what extent other mechanisms, such as mutational events in other target genes or alterations in outer-membrane proteins, contribute to resistance among anaerobes needs to be further investigated.

Respiratory viruses from hospitalized children with severe pneumonia in the Philippines

PubMed Central

2012-01-01

Background Pneumonia remains a leading cause of child death in developing countries. The viruses in severe pneumonia remain poorly defined. Methods The study was conducted at the Eastern Visayas Regional Medical Center in Tacloban City, Philippines from May 2008 to May 2009. Patients aged 8 days to 13 years old who were admitted to the Department of Pediatrics with severe pneumonia were enrolled for the study. Upon admission, polymerase chain reaction was performed using nasopharyngeal swabs and blood cultures to detect respiratory viruses and bacteria, respectively. Result Among the 819 patients enrolled, at least one virus was detected in 501 cases (61.2%). In addition, 423 cases were positive for a single virus while bacteria were detected in the blood culture sample of 31 cases. The most commonly detected viruses were human rhinoviruses (n = 189), including types A (n = 103), B (n = 17), and C (n = 69), and respiratory syncytial virus (RSV) (n = 165). Novel viruses such as human metapneumovirus, human coronavirus NL63, human bocavirus, and human polyomaviruses WU and KI were also detected. There were 70 deaths, and one or more viruses were detected in 35 (50%) of these cases. Positivity only for influenza A virus (OR = 4.3, 95% CI = 1.3-14.6) was significantly associated with fatal outcome. From the blood culture, Burkholderia cepacia group (n = 9), Streptococcus pneumoniae (n = 4), Staphylococcus aureus (n = 4), Haemophilus influenzae (n = 1), and Salmonella C1 (n = 1) were also isolated. Conclusion Viruses were commonly detected in children with severe pneumonia in the Philippines. Hence, viral etiologies should be considered while developing better effective strategies to reduce child pneumonia-related deaths in developing countries. PMID:23092190

Effect of extremely low frequency electromagnetic fields on growth rate and morphology of bacteria.

PubMed

Inhan-Garip, Ayse; Aksu, Burak; Akan, Zafer; Akakin, Dilek; Ozaydin, A Nilufer; San, Tangul

2011-12-01

To determine the effect of extremely low frequency (<300 Hz) electromagnetic fields (ELF-EMF) on the growth rate of Gram-positive and Gram-negative bacteria and to determine any morphological changes that might have been caused by ELF-EMF. Six bacterial strains, three Gram-negative and three Gram-positive were subjected to 50 Hz, 0.5 mT ELF-EMF for 6 h. To determine growth rate after ELF-EMF application, bacteria exposed to ELF-EMF for 3 h were collected, transferred to fresh medium and cultured without field application for another 4 h. Growth-rate was determined by optical density (OD) measurements made every hour. Morphological changes were determined with Transmission electron microscopy (TEM) for two gram-negative and two gram-positive strains collected after 3 h of field application. A decrease in growth rate with respect to control samples was observed for all strains during ELF-EMF application. The decrease in growth-rate continued when exposed bacteria were cultured without field application. Significant ultrastructural changes were observed in all bacterial strains, which were seen to resemble the alterations caused by cationic peptides. This study shows that ELF-EMF induces a decrease in growth rate and morphological changes for both Gram-negative and Gram-positive bacteria.

A prospective study from south India to compare the severity of malaria caused by Plasmodium vivax, P. falciparum and dual infection.

PubMed

Mitra, Shubhanker; Abhilash, Kpp; Arora, Shalabh; Miraclin, Angel

2015-12-01

Traditionally, Plasmodium falciparum has been attributed to cause severe malaria, whereas P. vivax is considered to cause "benign" tertian malaria. Recently, there has been an increasing body of evidence challenging this conviction. However, the spectrum and degree of severity of the disease caused by P. vivax, as per World Health Organization (2012) remains unclear. Thus, in this prospective study, we aimed at comparing the severity of malaria caused by P. vivax, P. falciparum and dual infection. Adult patients presenting to Christian Medical College, Vellore from October 2012 to September 2013 with microscopically confirmed malaria were included in the study. Their clinical and laboratory parameters were recorded and analyzed. Paired t-test and chi-square with 95% CI and post-hoc analyses using the Scheffι post-hoc criterion were used to assess the statistical significance at the level of α <0.05. In total, 131 cases of malaria were identified during the study period, comprising 83 cases of P. vivax, 35 cases of P. falciparum and 13 cases of mixed vivax and falciparum infections. The spectrum and degree of hematological, hepatic, renal, metabolic, central nervous system complications of vivax malaria was not different from that of falciparum group. Thrombocytopenia and hyperbilirubinemia were the most common laboratory abnormalities identified in all the groups. This cross-sectional comparative study clearly demonstrates that clinical features, complications and case-fatality rates in vivax malaria can be as severe as in falciparum malaria. Hence, vivax malaria could not be considered benign; and appropriate preventive strategies along with antimalarial therapies should be adopted for control and elimination of this disease.

Interdigital athlete's foot. The interaction of dermatophytes and resident bacteria.

PubMed

Leyden, J J; Kligman, A M

1978-10-01

Quantitative cultures in 140 cases of interdigital "athlete's foot" established the following clinical-microbiological correlations. In 39 cases of mild, scaling, relatively asymptomatic variety, fungi were recovered in 84% of cases. As the disease progressed to maceration, hyperkeratosis, and increased symptoms, recovery of fungi fell to 55% in moderately symptomatic and to 36% in severe cases. Symptomatic cases had increasing numbers of resident aerobic organisms, particularly large colony diphtheroids. Experimental manipulations of the interspace microflora in volunteers, monitored with quantitative cultures, demonstrated that symptomatic, macerated, hyperkeratotic process results from an overgrowth of resident organisms if the stratum corneum barrier is damaged by preexisting fungi, while overgrowth of the same organisms in normal, fungus-free interspaces does not produce lesions. These experiments support the conclusion that athlete's foot represents a continuum from a relatively asymptomatic, scaling eruption produced by fungi to a symptomatic, macerated, hyperkeratotic variety that is caused by an overgrowth of bacteria.

High abundances of aerobic anoxygenic photosynthetic bacteria in the South Pacific Ocean.

PubMed

Lami, Raphaël; Cottrell, Matthew T; Ras, Joséphine; Ulloa, Osvaldo; Obernosterer, Ingrid; Claustre, Hervé; Kirchman, David L; Lebaron, Philippe

2007-07-01

Little is known about the abundance, distribution, and ecology of aerobic anoxygenic phototrophic (AAP) bacteria, particularly in oligotrophic environments, which represent 60% of the ocean. We investigated the abundance of AAP bacteria across the South Pacific Ocean, including the center of the gyre, the most oligotrophic water body of the world ocean. AAP bacteria, Prochlorococcus, and total prokaryotic abundances, as well as bacteriochlorophyll a (BChl a) and divinyl-chlorophyll a concentrations, were measured at several depths in the photic zone along a gradient of oligotrophic conditions. The abundances of AAP bacteria and Prochlorococcus were high, together accounting for up to 58% of the total prokaryotic community. The abundance of AAP bacteria alone was up to 1.94 x 10(5) cells ml(-1) and as high as 24% of the overall community. These measurements were consistent with the high BChl a concentrations (up to 3.32 x 10(-3) microg liter(-1)) found at all stations. However, the BChl a content per AAP bacterial cell was low, suggesting that AAP bacteria are mostly heterotrophic organisms. Interestingly, the biovolume and therefore biomass of AAP bacteria was on average twofold higher than that of other prokaryotic cells. This study demonstrates that AAP bacteria can be abundant in various oligotrophic conditions, including the most oligotrophic regime of the world ocean, and can account for a large part of the bacterioplanktonic carbon stock.

Changes in Bacteria Induce Inflammatory Skin Diseases | Center for Cancer Research

Cancer.gov

Atopic dermatitis (AD) is a chronic inflammatory skin disease that manifests as dry skin with a relentless itch and eczema. AD is considered an allergic disease in which the skin inflammation manifests in response to chronic exposure to contact allergens. However, identification of a responsible allergen is uncommon. Meanwhile, analyses have demonstrated that the surface of the human body is colonized by large numbers of diverse bacteria. This observation has led researchers to examine the roles these bacteria play in healthy and diseased skin. In a variety of genetic and chronic inflammatory skin diseases, including in patients with AD or with cancer who receive epidermal growth factor receptor (EGFR) inhibitors, Staphylococcus aureus and Corynebacterium species are the predominant bacteria isolated from the skin. However, the cause-and-effect relationship between this microbial imbalance and skin inflammation has not been determined.

A metagenomic assessment of the bacteria associated with Lucilia sericata and Lucilia cuprina (Diptera: Calliphoridae)

USDA-ARS?s Scientific Manuscript database

Lucilia Robineau-Desvoidy (Diptera: Calliphoridae), is a blow fly genus of forensic, medical, veterinary, and agricultural importance. Both species of this genus causes myiasis and are vectors of disease causing bacteria. This genus is also famous because of its beneficial uses in maggot therapy. ...

Successful management of a hydropic fetus with severe anemia and thrombocytopenia caused by anti-CD36 antibody.

PubMed

Xu, Xiuzhang; Li, Lin; Xia, Wenjie; Ding, Haoqiang; Chen, Dawei; Liu, Jing; Deng, Jing; Chen, Yangkai; He, Zhiming; Wang, Jiali; Shao, Yuan; Santoso, Sentot; Ye, Xin; Fang, Qun

2018-02-01

Cases of CD36 deficiency are not rare in Asian populations, foetal and neonatal alloimmune thrombocytopenia (FNAIT) caused by anti-CD36 isoantibodies appears more frequent than other HPA alloantibodies. However, little is known about the treatment of anti-CD36 mediated FNAIT in this region. A Chinese male foetus, whose mother had a history of multiple intrauterine foetal demise and/or hydrops, was diagnosed with severe FNAIT at 27 weeks of gestational age. Immunological analysis revealed total absence of CD36 on platelets and monocytes from mother, caused by a 329-330delAC mutation of the CD36 gene. Anti-CD36 and anti-HLA class I antibodies were detected in the maternal serum, whereas only anti-CD36 isoantibodies were detectable in the foetal blood sample. Serial intrauterine transfusions with red blood cells (RBC) and platelets from a CD36null donor were performed to improve the severe anaemia and thrombocytopenia. The baby (2250 g; Apgar scores 10) was delivered vaginally at 32 weeks of gestation with normal haemoglobin (186 g/L) but low platelet count (48 × 10 9 /L). After 2 days the platelet count rose to 121 × 10 9 /L. This report suggests that intrauterine transfusions with compatible RBC and CD36null platelets are useful in preventing the deleterious clinical effects of anti-CD36-mediated severe FNAIT.

Agriculture and food animals as a source of antimicrobial-resistant bacteria

PubMed Central

Economou, Vangelis; Gousia, Panagiota

2015-01-01

One of the major breakthroughs in the history of medicine is undoubtedly the discovery of antibiotics. Their use in animal husbandry and veterinary medicine has resulted in healthier and more productive farm animals, ensuring the welfare and health of both animals and humans. Unfortunately, from the first use of penicillin, the resistance countdown started to tick. Nowadays, the infections caused by antibiotic-resistant bacteria are increasing, and resistance to antibiotics is probably the major public health problem. Antibiotic use in farm animals has been criticized for contributing to the emergence of resistance. The use and misuse of antibiotics in farm animal settings as growth promoters or as nonspecific means of infection prevention and treatment has boosted antibiotic consumption and resistance among bacteria in the animal habitat. This reservoir of resistance can be transmitted directly or indirectly to humans through food consumption and direct or indirect contact. Resistant bacteria can cause serious health effects directly or via the transmission of the antibiotic resistance traits to pathogens, causing illnesses that are difficult to treat and that therefore have higher morbidity and mortality rates. In addition, the selection and proliferation of antibiotic-resistant strains can be disseminated to the environment via animal waste, enhancing the resistance reservoir that exists in the environmental microbiome. In this review, an effort is made to highlight the various factors that contribute to the emergence of antibiotic resistance in farm animals and to provide some insights into possible solutions to this major health issue. PMID:25878509

Small molecule inhibitor of lipoteichoic acid synthesis is an antibiotic for Gram-positive bacteria

PubMed Central

Richter, Stefan G.; Elli, Derek; Kim, Hwan Keun; Hendrickx, Antoni P. A.; Sorg, Joseph A.; Schneewind, Olaf; Missiakas, Dominique

2013-01-01

The current epidemic of infections caused by antibiotic-resistant Gram-positive bacteria requires the discovery of new drug targets and the development of new therapeutics. Lipoteichoic acid (LTA), a cell wall polymer of Gram-positive bacteria, consists of 1,3-polyglycerol-phosphate linked to glycolipid. LTA synthase (LtaS) polymerizes polyglycerol-phosphate from phosphatidylglycerol, a reaction that is essential for the growth of Gram-positive bacteria. We screened small molecule libraries for compounds inhibiting growth of Staphylococcus aureus but not of Gram-negative bacteria. Compound 1771 [2-oxo-2-(5-phenyl-1,3,4-oxadiazol-2-ylamino)ethyl 2-naphtho[2,1-b]furan-1-ylacetate] blocked phosphatidylglycerol binding to LtaS and inhibited LTA synthesis in S. aureus and in Escherichia coli expressing ltaS. Compound 1771 inhibited the growth of antibiotic-resistant Gram-positive bacteria and prolonged the survival of mice with lethal S. aureus challenge, validating LtaS as a target for the development of antibiotics. PMID:23401520

Microfluidic cantilever detects bacteria and measures their susceptibility to antibiotics in small confined volumes

NASA Astrophysics Data System (ADS)

Etayash, Hashem; Khan, M. F.; Kaur, Kamaljit; Thundat, Thomas

2016-10-01

In the fight against drug-resistant bacteria, accurate and high-throughput detection is essential. Here, a bimaterial microcantilever with an embedded microfluidic channel with internal surfaces chemically or physically functionalized with receptors selectively captures the bacteria passing through the channel. Bacterial adsorption inside the cantilever results in changes in the resonance frequency (mass) and cantilever deflection (adsorption stress). The excitation of trapped bacteria using infrared radiation (IR) causes the cantilever to deflect in proportion to the infrared absorption of the bacteria, providing a nanomechanical infrared spectrum for selective identification. We demonstrate the in situ detection and discrimination of Listeria monocytogenes at a concentration of single cell per μl. Trapped Escherichia coli in the microchannel shows a distinct nanomechanical response when exposed to antibiotics. This approach, which combines enrichment with three different modes of detection, can serve as a platform for the development of a portable, high-throughput device for use in the real-time detection of bacteria and their response to antibiotics.

Diversity of ionizing radiation-resistant bacteria obtained from the Taklimakan Desert.

PubMed

Yu, Li Zhi-Han; Luo, Xue-Song; Liu, Ming; Huang, Qiaoyun

2015-01-01

So far, little is known about the diversity of the radiation-resistant microbes of the hyperarid Taklimakan Desert. In this study, ionizing radiation (IR)-resistant bacteria from two sites in Xinjiang were investigated. After exposing the arid (water content of 0.8 ± 0.3%) and non-arid (water content of 21.3 ± 0.9%) sediment samples to IR of 3000 Gy using a (60)Co source, a total of 52 γ-radiation-resistant bacteria were isolated from the desert sample. The 16S rRNA genes of all isolates were sequenced. The phylogenetic tree places these isolates into five groups: Cytophaga-Flavobacterium-Bacteroides, Proteobacteria, Deinococcus-Thermus, Firmicutes, and Actinobacteria. Interestingly, this is the first report of radiation-resistant bacteria belonging to the genera Knoellia, Lysobacter, Nocardioides, Paracoccus, Pontibacter, Rufibacter and Microvirga. The 16s rRNA genes of four isolates showed low sequence similarities to those of the published species. Phenotypic analysis showed that all bacteria in this study are able to produce catalase, suggesting that these bacteria possess reactive oxygen species (ROS)-scavenging enzymes. These radiation-resistant bacteria also displayed diverse metabolic properties. Moreover, their radiation resistances were found to differ. The diversity of the radiation-resistant bacteria in the desert provides further ecological support for the hypothesis that the ionizing-radiation resistance phenotype is a consequence of the evolution of ROS-scavenging systems that protect cells against oxidative damage caused by desiccation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Drought delays development of the sorghum root microbiome and enriches for monoderm bacteria.

PubMed

Xu, Ling; Naylor, Dan; Dong, Zhaobin; Simmons, Tuesday; Pierroz, Grady; Hixson, Kim K; Kim, Young-Mo; Zink, Erika M; Engbrecht, Kristin M; Wang, Yi; Gao, Cheng; DeGraaf, Stephanie; Madera, Mary A; Sievert, Julie A; Hollingsworth, Joy; Birdseye, Devon; Scheller, Henrik V; Hutmacher, Robert; Dahlberg, Jeffery; Jansson, Christer; Taylor, John W; Lemaux, Peggy G; Coleman-Derr, Devin

2018-05-01

Drought stress is a major obstacle to crop productivity, and the severity and frequency of drought are expected to increase in the coming century. Certain root-associated bacteria have been shown to mitigate the negative effects of drought stress on plant growth, and manipulation of the crop microbiome is an emerging strategy for overcoming drought stress in agricultural systems, yet the effect of drought on the development of the root microbiome is poorly understood. Through 16S rRNA amplicon and metatranscriptome sequencing, as well as root metabolomics, we demonstrate that drought delays the development of the early sorghum root microbiome and causes increased abundance and activity of monoderm bacteria, which lack an outer cell membrane and contain thick cell walls. Our data suggest that altered plant metabolism and increased activity of bacterial ATP-binding cassette (ABC) transporter genes are correlated with these shifts in community composition. Finally, inoculation experiments with monoderm isolates indicate that increased colonization of the root during drought can positively impact plant growth. Collectively, these results demonstrate the role that drought plays in restructuring the root microbiome and highlight the importance of temporal sampling when studying plant-associated microbiomes. Copyright © 2018 the Author(s). Published by PNAS.

White Paper: Recommendations on the Conduct of Superiority and Organism-Specific Clinical Trials of Antibacterial Agents for the Treatment of Infections Caused by Drug-Resistant Bacterial Pathogens

PubMed Central

2012-01-01

There is a critical need for new pathways to develop antibacterial agents to treat life-threatening infections caused by highly resistant bacteria. Traditionally, antibacterial agents have been studied in noninferiority clinical trials that focus on one site of infection (eg, pneumonia, intra-abdominal infection). Conduct of superiority trials for infections caused by highly antibiotic-resistant bacteria represents a new, and as yet, untested paradigm for antibacterial drug development. We sought to define feasible trial designs of antibacterial agents that could enable conduct of superiority and organism-specific clinical trials. These recommendations are the results of several years of active dialogue among the white paper's drafters as well as external collaborators and regulatory officials. Our goal is to facilitate conduct of new types of antibacterial clinical trials to enable development and ultimately approval of critically needed new antibacterial agents. PMID:22891041

New York City House Mice (Mus musculus) as Potential Reservoirs for Pathogenic Bacteria and Antimicrobial Resistance Determinants.

PubMed

Williams, Simon H; Che, Xiaoyu; Paulick, Ashley; Guo, Cheng; Lee, Bohyun; Muller, Dorothy; Uhlemann, Anne-Catrin; Lowy, Franklin D; Corrigan, Robert M; Lipkin, W Ian

2018-04-17

House mice ( Mus musculus ) thrive in large urban centers worldwide. Nonetheless, little is known about the role that they may play in contributing to environmental contamination with potentially pathogenic bacteria. Here, we describe the fecal microbiome of house mice with emphasis on detection of pathogenic bacteria and antimicrobial resistance genes by molecular methods. Four hundred sixteen mice were collected from predominantly residential buildings in seven sites across New York City over a period of 13 months. 16S rRNA sequencing identified Bacteroidetes as dominant and revealed high levels of Proteobacteria A targeted PCR screen of 11 bacteria, as indicated by 16S rRNA analyses, found that mice are carriers of several gastrointestinal disease-causing agents, including Shigella , Salmonella , Clostridium difficile , and diarrheagenic Escherichia coli Furthermore, genes mediating antimicrobial resistance to fluoroquinolones ( qnrB ) and β-lactam drugs ( bla SHV and bla ACT/MIR ) were widely distributed. Culture and molecular strain typing of C. difficile revealed that mice harbor ribotypes associated with human disease, and screening of kidney samples demonstrated genetic evidence of pathogenic Leptospira species. In concert, these findings support the need for further research into the role of house mice as potential reservoirs for human pathogens and antimicrobial resistance in the built environment. IMPORTANCE Mice are commensal pests often found in close proximity to humans, especially in urban centers. We surveyed mice from seven sites across New York City and found multiple pathogenic bacteria associated with febrile and gastrointestinal disease as well as an array of antimicrobial resistance genes. Copyright © 2018 Williams et al.

Flagella and motility behaviour of square bacteria.

PubMed Central

Alam, M; Claviez, M; Oesterhelt, D; Kessel, M

1984-01-01

Square bacteria are shown to have right-handed helical (RH) flagella. They swim forward by clockwise (CW), and backwards by counterclockwise (CCW) rotation of their flagella. They are propelled by several or single filaments arising at several or single points on the cell surface. When there are several filaments a stable bundle is formed that does not fly apart during the change from clockwise to counterclockwise rotation or vice versa. In addition to the flagella attached to the cells, large amounts of detached flagella aggregated into thick super-flagella, can be observed at all phases of growth. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:6526006

Evolution of the Kdo2-lipid A Biosynthesis in Bacteria

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

S Opiyo; R Pardy; H Moriyama

BACKGROUND: Lipid A is the highly immunoreactive endotoxic center of lipopolysaccharide (LPS). It anchors the LPS into the outer membrane of most Gram-negative bacteria. Lipid A can be recognized by animal cells, triggers defense-related responses, and causes Gram-negative sepsis. The biosynthesis of Kdo2-lipid A, the LPS substructure, involves with nine enzymatic steps. RESULTS: In order to elucidate the evolutionary pathway of Kdo2-lipid A biosynthesis, we examined the distribution of genes encoding the nine enzymes across bacteria. We found that not all Gram-negative bacteria have all nine enzymes. Some Gram-negative bacteria have no genes encoding these enzymes and others have genesmore » only for the first four enzymes (LpxA, LpxC, LpxD, and LpxB). Among the nine enzymes, five appeared to have arisen from three independent gene duplication events. Two of such events happened within the Proteobacteria lineage, followed by functional specialization of the duplicated genes and pathway optimization in these bacteria. CONCLUSIONS: The nine-enzyme pathway, which was established based on the studies mainly in Escherichia coli K12, appears to be the most derived and optimized form. It is found only in E. coli and related Proteobacteria. Simpler and probably less efficient pathways are found in other bacterial groups, with Kdo2-lipid A variants as the likely end products. The Kdo2-lipid A biosynthetic pathway exemplifies extremely plastic evolution of bacterial genomes, especially those of Proteobacteria, and how these mainly pathogenic bacteria have adapted to their environment.« less

Inactivation of biofilm bacteria.

PubMed Central

LeChevallier, M W; Cawthon, C D; Lee, R G

1988-01-01

The current project was developed to examine inactivation of biofilm bacteria and to characterize the interaction of biocides with pipe surfaces. Unattached bacteria were quite susceptible to the variety of disinfectants tested. Viable bacterial counts were reduced 99% by exposure to 0.08 mg of hypochlorous acid (pH 7.0) per liter (1 to 2 degrees C) for 1 min. For monochloramine, 94 mg/liter was required to kill 99% of the bacteria within 1 min. These results were consistent with those found by other investigators. Biofilm bacteria grown on the surfaces of granular activated carbon particles, metal coupons, or glass microscope slides were 150 to more than 3,000 times more resistant to hypochlorous acid (free chlorine, pH 7.0) than were unattached cells. In contrast, resistance of biofilm bacteria to monochloramine disinfection ranged from 2- to 100-fold more than that of unattached cells. The results suggested that, relative to inactivation of unattached bacteria, monochloramine was better able to penetrate and kill biofilm bacteria than free chlorine. For free chlorine, the data indicated that transport of the disinfectant into the biofilm was a major rate-limiting factor. Because of this phenomenon, increasing the level of free chlorine did not increase disinfection efficiency. Experiments where equal weights of disinfectants were used suggested that the greater penetrating power of monochloramine compensated for its limited disinfection activity. These studies showed that monochloramine was as effective as free chlorine for inactivation of biofilm bacteria. The research provides important insights into strategies for control of biofilm bacteria. Images PMID:2849380

[Analysis of the causes and determinants of reaction to severe stress and adjustment disorder patients on mental health clinics].

PubMed

Golinowska, Danuta; Florkowski, Antoni; Juszczak, Dariusz

2010-05-01

In everyday life there are many obstacles that prevent the creation of many important needs. They require a skillful adaptation and may be the cause of stress. Stress of considerable intensity can receive the joy of life and even lead to a temporary mental disorder. To present the main causes and frequency of disturbance determined according to the ICD-10 as a reaction to severe stress and adaptive disorders among patients in psychiatric and psychological counseling and to establish whether the causes of the disorder are dependent on factors such as age, sex or level of education. Analysis was done on a separate group of 754 persons from among patients seeking psychiatric counseling--Psychological Outpatient Mental Health in the 10th Military Clinical Hospital in Bydgoszcz, in 2005. This group were qualified person, who according to the criteria of ICD-10 were found to respond to severe stress and abnormal adaptation. In addition, during the interview determines whether they are long-term somatic illness. They have not been included in the study group. Also excluded persons who were found difficulties in operation prior to the stressful situation and those that have already been treated with psychiatric or psychological benefit from therapy. The collected data were statistically analyzed. The analysis identifies three main causes of adjustment disorder. The first group of reasons is related to difficulties in the workplace, which represents 59% of all patients with the disorder described. In this group identifies three major stressful situations: bullying, job loss, unemployment. Another reason relates to family problems. They are the reason for the emergence of abnormalities in 23% of patients analyzed group. Among these difficulties was divided into four main types of situation causing disorder presented. There are family conflicts, death of spouse, parent death, divorce. The last group of factors are stressful events or incidents which contributed to the

Acute quadriplegia caused by necrotizing myopathy in a renal transplant recipient with severe pneumonia: acute onset and complete recovery.

PubMed

Tu, Guo-Wei; Song, Jie-Qiong; Ting, Simon Kang Seng; Ju, Min-Jie; He, Hong-Yu; Dong, Ji-Hong; Luo, Zhe

2015-02-03

Critical illness polyneuropathy and myopathy are multifaceted complications that follow severe illnesses involving the sensorimotor axons and proximal skeletal muscles. These syndromes have rarely been reported among renal transplant recipients. In this paper, we report a case of acute quadriplegia caused by necrotizing myopathy in a renal transplant recipient with severe pneumonia. The muscle strength in the patient's extremities improved gradually after four weeks of comprehensive treatment, and his daily life activities were normal a year after being discharged.

Optical microcavities for real-time detection of bacteria

NASA Astrophysics Data System (ADS)

Ghali, Hala

Researchers showed a lot of interest in studying whispering gallery microcavities as a tool for biosensing in the last decade. Optical microcavities are structures that confine light at the microscale due to total internal reflection of light at the interface between the cavity and its surrounding medium. If a molecule binds to the surface of the microcavity, light can interact with it several times, making optical microcavities very sensitive tools for label-free sensing. During this Ph.D. project, optical microdisks are used to detect the presence of Staphylococcus aureus (S. aureus) bacteria. To our knowledge, this is the first time optical microdisks are used to specifically detect bacteria. In order to have a reliable and efficient biosensor, it needs to be highly specific. Specificity is achieved by choosing an appropriate functionalization process. The functionalization process uses the antibody that is specific to the antigen of interest. In this case, the choice of a specific bacteriophage to bind S. aureus bacteria is crucial to obtain a specific sensor, and many experiences were done in order to identify the most appropriate. However, the purification of bacteriophages can be long and complex. An alternative to working with whole bacteriophages is the use of purified protein phages that can be easier to prepare. The functionalization process used in this thesis was developed in collaboration with professor Jay L. Nadeau's group from the biomedical engineering department at McGill university. LysK protein phage is added to the microdisk and will attach S. aureus bacteria during the real-time detection experiments. In order to demonstrate the specificity of the functionalization process, LysK was used with E. coli bacteria. As predicted, since LysK is only specific to S. aureus strains, it did not attach any E. coli. The binding of bacteria to the microdisk surface is observed through the reactive sensing mechanism. When bacteria bind to the surface of the

Acute sensitivity of activated sludge bacteria to erythromycin.

PubMed

Alighardashi, A; Pandolfi, D; Potier, O; Pons, M N

2009-12-30

The presence of antibiotics in water resources has been disturbing news for the stakeholders who are responsible for public health and the drinking water supply. In many cases, biological wastewater treatment plants are the final opportunity in the water cycle to trap these substances. The sensitivity of activated sludge bacteria to erythromycin, a macrolide widely used in human medicine was investigated in batch toxicity tests using a concentration range of 1-300 mg L(-1). Erythromycin, a protein synthesis inhibitor, has been found to significantly inhibit ammonification, nitritation and nitratation at concentrations higher than 20 mg L(-1). The degree of inhibition increased with greater concentrations of the antibiotic. Exposure to erythromycin also clearly affected heterotrophs, particularly filamentous bacteria, causing floc disintegration and breakage of filaments. Cell lysis was observed with the concomitant release of organic nitrogen (intracellular proteins) and soluble COD. Although erythromycin exhibits properties of a surfactant, this characteristic alone cannot explain the damage to heterotrophs: the effects from erythromycin were greater than those of Tween 80, a commonly used surfactant. Floc disruption can lead to the release of isolated bacteria, and possibly antibiotic resistance genes, into the environment.

A method for the specific detection of resident bacteria in brine shrimp larvae.

PubMed