The in vitro effect of six antimicrobials against Mycoplasma putrefaciens, Mycoplasma mycoides subsp. mycoides LC and Mycoplasma capricolum subsp. capricolum isolated from sheep and goats in Jordan.

PubMed

Al-Momani, W; Nicholas, R A J; Janakat, S; Abu-Basha, E; Ayling, R D

2006-01-01

Respiratory disease in sheep and goats is a major problem in Jordan and is often associated with Mycoplasma species. Without effective vaccines, control is mainly by chemotherapy, but the uncontrolled use of antimicrobials has led to concerns about the potential development of antimicrobial resistance. The in vitro effect of chloramphenicol, florfenicol, enrofloxacin, tylosin, erythromycin and oxytetracycline was determined against 32 isolates of Mycoplasma species-M. mycoides subsp. mycoides LC (6), M. capricolum subsp. capricolum (8) and M. putrefaciens (18), all isolated from either nasal swabs or milk, from sheep and goats in different regions of Jordan. The antimicrobial susceptibility showed some Mycoplasma species-specific differences, with M. capricolum subsp. capricolum being more susceptible to tylosin and erythromycin. Chloramphenicol and florfenicol were the least effective for all three Mycoplasma species. No trends or significant differences in antimicrobial susceptibilities were observed between sheep and goat isolates, between milk or nasal swab isolates, or between isolates from different regions of Jordan. Some isolates of M. capricolum subsp. capricolum and M. putrefaciens showed higher MIC levels with oxytetracycline, as did two isolates of M. mycoides subsp. mycoides LC with tylosin, possibly indicating signs of development of antimicrobial resistance.

Evasion of Complement-Mediated Lysis and Complement C3 Deposition Are Regulated by Francisella tularensis Lipopolysaccharide O Antigen1

PubMed Central

Clay, Corey D.; Soni, Shilpa; Gunn, John S.; Schlesinger, Larry S.

2009-01-01

The bacterium Francisella tularensis (Ft) is a potential weapon of bioterrorism when aerosolized. Macrophage infection is necessary for disease progression and efficient phagocytosis by human macrophages requires serum opsonization by complement. Microbial complement activation leads to surface deposition of a highly regulated protein complex resulting in opsonization or membrane lysis. The nature of complement component C3 deposition, i.e., C3b (opsonization and lysis) or C3bi (opsonization only) fragment deposition, is central to the outcome of activation. In this study, we examine the mechanisms of Ft resistance to complement-mediated lysis, C3 component deposition on the Ft surface, and complement activation. Upon incubation in fresh nonimmune human serum, Schu S4 (Ft subsp. tularensis), Fn (Ft subsp. novicida), and LVS (Ft subsp. holarctica live vaccine strain) were resistant to complement-mediated lysis, but LVSG and LVSR (LVS strains altered in surface carbohydrate structures) were susceptible. C3 deposition, however, occurred on all strains. Complement-susceptible strains had markedly increased C3 fragment deposition, including the persistent presence of C3b compared with C3bi, which indicates that C3b inactivation results in survival of complement-resistant strains. C1q, an essential component of the classical activation pathway, was necessary for lysis of complement-susceptible strains and optimal C3 deposition on all strains. Finally, use of Francisella LPS mutants confirmed O Ag as a major regulator of complement resistance. These data provide evidence that pathogenic Francisella activate complement, but are resistant to complement-mediated lysis in part due to limited C3 deposition, rapid conversion of surface-bound C3b to C3bi, and the presence of LPS O Ag. PMID:18832715

Campylobacter pinnipediorum sp. nov., isolated from pinnipeds, comprising Campylobacter pinnipediorum subsp. pinnipediorum subsp. nov. and Campylobacter pinnipediorum subsp. caledonicus subsp. nov.

USDA-ARS?s Scientific Manuscript database

During independent diagnostic screenings of otariid seals in California (US) and phocid seals in Scotland (UK), Campylobacter-like isolates, which differed from the established Campylobacter taxa, were cultured from abscesses and internal organs of different seal species. A polyphasic study was unde...

Identification and characterization of lactic acid bacteria isolated from mixed pasture of timothy and orchardgrass, and its badly preserved silage.

PubMed

Tohno, Masanori; Kobayashi, Hisami; Nomura, Masaru; Uegaki, Ryuichi; Cai, Yimin

2012-04-01

In order to understand the relationship between lactic acid bacteria (LAB) species and silage fermentation, a total of 65 LAB strains isolated from mixed pasture of timothy (Phleum pratense L.) and orchardgrass (Dactylis glomerata L.), and its badly preserved silages were subjected to phenotypic and genetic analysis. According to these analyses, the isolates were divided into 13 groups, including Enterococcus gallinarum, Lactobacillus acidipiscis, L. coryniformis subsp. coryniformis, L. coryniformis subsp. torquens, L. curvatus, L. paraplantarum, L. plantarum subsp. argentoratensis, L. plantarum subsp. plantarum, L. sakei subsp. carnosus, Lactococcus garvieae, Lactococcus lactis subsp. cremoris, Leuconostoc pseudomesenteroides, Pediococcus acidilactici, Pediococcus pentosaceus, Weissella hellenica, Weissella paramesenteroides and Carnobacterium divergens. This is the first report to document that C. divergens, L. acidipiscis, L. sakei subsp. carnosus, L. garvieae, phenotypically novel L. lactis subsp. cremoris, E. gallinarum and W. hellenica are present in vegetative forage crops. L. plantarum group strains were most frequently isolated from the badly preserved silages. Some isolates showed a wide range of growth preferences for carbohydrate utilization, optimal growth pH and temperature in vitro, indicating that they have a high growth potential. These results are useful in understanding the diversity of LAB associated with decayed silage of timothy and orchardgrass. © 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.

Isolation of Bartonella henselae and Two New Bartonella Subspecies, Bartonella koehlerae Subspecies boulouisii subsp. nov. and Bartonella koehlerae Subspecies bothieri subsp. nov. from Free-Ranging Californian Mountain Lions and Bobcats

PubMed Central

Chomel, Bruno B.; Molia, Sophie; Kasten, Rickie W.; Borgo, Gina M.; Stuckey, Matthew J.; Maruyama, Soichi; Chang, Chao-chin; Haddad, Nadia; Koehler, Jane E.

2016-01-01

Domestic cats are the natural reservoir of Bartonella henselae, B. clarridgeiae and B. koehlerae. To determine the role of wild felids in the epidemiology of Bartonella infections, blood was collected from 14 free-ranging California mountain lions (Puma concolor) and 19 bobcats (Lynx rufus). Bartonella spp. were isolated from four (29%) mountain lions and seven (37%) bobcats. These isolates were characterized using growth characteristics, biochemical reactions, molecular techniques, including PCR-RFLP of selected genes or interspacer region, pulsed-field gel electrophoresis (PFGE), partial sequencing of several genes, and DNA-DNA hybridization. Two isolates were identical to B. henselae genotype II. All other isolates were distinguished from B. henselae and B. koehlerae by PCR-RFLP of the gltA gene using endonucleases HhaI, TaqI and AciI, with the latter two discriminating between the mountain lion and the bobcat isolates. These two novel isolates displayed specific PFGE profiles distinct from B. henselae, B. koehlerae and B. clarridgeiae. Sequences of amplified gene fragments from the three mountain lion and six bobcat isolates were closely related to, but distinct from, B. henselae and B. koehlerae. Finally, DNA-DNA hybridization studies demonstrated that the mountain lion and bobcat strains are most closely related to B. koehlerae. We propose naming the mountain lion isolates B. koehlerae subsp. boulouisii subsp. nov. (type strain: L-42-94), and the bobcat isolates B. koehlerae subsp. bothieri subsp. nov. (type strain: L-17-96), and to emend B. koehlerae as B. koehlerae subsp. koehlerae. The mode of transmission and the zoonotic potential of these new Bartonella subspecies remain to be determined. PMID:26981874

Complete genome sequence of Mycobacterium avium subsp. paratuberculosis, isolated from human breast milk

USDA-ARS?s Scientific Manuscript database

Mycobacterium avium subsp paratuberculosis is the etiologic agent of Johne’s disease. We report the draft genome sequences of six M. avium subsp paratuberculosis isolates obtained from diverse hosts including bison, cattle and sheep. These sequences will deepen our understanding of host association ...

Identification of Mycobacterium avium subsp. hominissuis Isolated From Drinking Water

EPA Science Inventory

Mycobacterium avium (MA) is divided into four subspecies based primarily on host-range and consists of MA subsp. avium (birds), MA subsp. silvaticum (wood pigeons), MA subsp. paratuberculosis (broad, poorly-defined host range), and the recently described MA subsp. hominissuis (hu...

Importance of Branched-Chain Amino Acid Utilization in Francisella Intracellular Adaptation

PubMed Central

Gesbert, Gael; Ramond, Elodie; Tros, Fabiola; Dairou, Julien; Frapy, Eric; Barel, Monique

2014-01-01

Intracellular bacterial pathogens have adapted their metabolism to optimally utilize the nutrients available in infected host cells. We recently reported the identification of an asparagine transporter required specifically for cytosolic multiplication of Francisella. In the present work, we characterized a new member of the major super family (MSF) of transporters, involved in isoleucine uptake. We show that this transporter (here designated IleP) plays a critical role in intracellular metabolic adaptation of Francisella. Inactivation of IleP severely impaired intracellular F. tularensis subsp. novicida multiplication in all cell types tested and reduced bacterial virulence in the mouse model. To further establish the importance of the ileP gene in F. tularensis pathogenesis, we constructed a chromosomal deletion mutant of ileP (ΔFTL_1803) in the F. tularensis subsp. holarctica live vaccine strain (LVS). Inactivation of IleP in the F. tularensis LVS provoked comparable intracellular growth defects, confirming the critical role of this transporter in isoleucine uptake. The data presented establish, for the first time, the importance of isoleucine utilization for efficient phagosomal escape and cytosolic multiplication of Francisella and suggest that virulent F. tularensis subspecies have lost their branched-chain amino acid biosynthetic pathways and rely exclusively on dedicated uptake systems. This loss of function is likely to reflect an evolution toward a predominantly intracellular life style of the pathogen. Amino acid transporters should be thus considered major players in the adaptation of intracellular pathogens. PMID:25332124

Genome sequencing identifies Listeria fleischmannii subsp. coloradonensis subsp. nov., isolated from a ranch.

PubMed

den Bakker, Henk C; Manuel, Clyde S; Fortes, Esther D; Wiedmann, Martin; Nightingale, Kendra K

2013-09-01

Twenty Listeria-like isolates were obtained from environmental samples collected on a cattle ranch in northern Colorado; all of these isolates were found to share an identical partial sigB sequence, suggesting close relatedness. The isolates were similar to members of the genus Listeria in that they were Gram-stain-positive, short rods, oxidase-negative and catalase-positive; the isolates were similar to Listeria fleischmannii because they were non-motile at 25 °C. 16S rRNA gene sequencing for representative isolates and whole genome sequencing for one isolate was performed. The genome of the type strain of Listeria fleischmannii (strain LU2006-1(T)) was also sequenced. The draft genomes were very similar in size and the average MUMmer nucleotide identity across 91% of the genomes was 95.16%. Genome sequence data were used to design primers for a six-gene multi-locus sequence analysis (MLSA) scheme. Phylogenies based on (i) the near-complete 16S rRNA gene, (ii) 31 core genes and (iii) six housekeeping genes illustrated the close relationship of these Listeria-like isolates to Listeria fleischmannii LU2006-1(T). Sufficient genetic divergence of the Listeria-like isolates from the type strain of Listeria fleischmannii and differing phenotypic characteristics warrant these isolates to be classified as members of a distinct infraspecific taxon, for which the name Listeria fleischmannii subsp. coloradonensis subsp. nov. is proposed. The type strain is TTU M1-001(T) ( =BAA-2414(T) =DSM 25391(T)). The isolates of Listeria fleischmannii subsp. coloradonensis subsp. nov. differ from the nominate subspecies by the inability to utilize melezitose, turanose and sucrose, and the ability to utilize inositol. The results also demonstrate the utility of whole genome sequencing to facilitate identification of novel taxa within a well-described genus. The genomes of both subspecies of Listeria fleischmannii contained putative enhancin genes; the Listeria fleischmannii subsp. coloradonensis subsp. nov. genome also encoded a putative mosquitocidal toxin. The presence of these genes suggests possible adaptation to an insect host, and further studies are needed to probe niche adaptation of Listeria fleischmannii.

Pork Meat as a Potential Source of Salmonella enterica subsp. arizonae Infection in Humans

PubMed Central

Kritas, Spyridon; Govaris, Alexander; Burriel, Angeliki R.

2014-01-01

Salmonella enterica subsp. arizonae was isolated from 13 of 123 slaughtered pigs in central Greece. The samples cultured were feces, ileum tissue, mesenteric lymph nodes, and gallbladder swabs. A total of 74 isolates from 492 samples were identified as Salmonella spp. by use of standard laboratory culture media and two commercial micromethods and by use of a polyvalent slide agglutination test for the detection of O and H antigens. Among them were 19 (25.68%) suspected to be S. enterica subsp. arizonae according to analysis with standard laboratory culture media. Of those, 14 were identified as S. enterica subsp. arizonae by the API 20E (bioMérieux, France) and the Microgen GnA+B-ID (Microgen Bioproducts, Ltd., United Kingdom) identification systems. All the isolates were tested for resistance to 23 antimicrobials. Strains identified as S. enterica subsp. arizonae were resistant to 17 (70.8%) antibiotics. The highest proportions of resistance were observed for sulfamethoxazole-trimethoprim (71.4%), tetracycline (71.4%), ampicillin (64.3%), and amoxicillin (57.1%). Two isolates were resistant to aztreonam (7.1%) and tigecycline (7.1%), used only for the treatment of humans. Thus, pork meat may play a role in the transmission of antibiotic-resistant S. enterica subsp. arizonae to human consumers. This is the first report of S. enterica subsp. arizonae isolation from pigs. PMID:24335956

Pork meat as a potential source of Salmonella enterica subsp. arizonae infection in humans.

PubMed

Evangelopoulou, Grammato; Kritas, Spyridon; Govaris, Alexander; Burriel, Angeliki R

2014-03-01

Salmonella enterica subsp. arizonae was isolated from 13 of 123 slaughtered pigs in central Greece. The samples cultured were feces, ileum tissue, mesenteric lymph nodes, and gallbladder swabs. A total of 74 isolates from 492 samples were identified as Salmonella spp. by use of standard laboratory culture media and two commercial micromethods and by use of a polyvalent slide agglutination test for the detection of O and H antigens. Among them were 19 (25.68%) suspected to be S. enterica subsp. arizonae according to analysis with standard laboratory culture media. Of those, 14 were identified as S. enterica subsp. arizonae by the API 20E (bioMérieux, France) and the Microgen GnA+B-ID (Microgen Bioproducts, Ltd., United Kingdom) identification systems. All the isolates were tested for resistance to 23 antimicrobials. Strains identified as S. enterica subsp. arizonae were resistant to 17 (70.8%) antibiotics. The highest proportions of resistance were observed for sulfamethoxazole-trimethoprim (71.4%), tetracycline (71.4%), ampicillin (64.3%), and amoxicillin (57.1%). Two isolates were resistant to aztreonam (7.1%) and tigecycline (7.1%), used only for the treatment of humans. Thus, pork meat may play a role in the transmission of antibiotic-resistant S. enterica subsp. arizonae to human consumers. This is the first report of S. enterica subsp. arizonae isolation from pigs.

Isolation of Bartonella vinsonii subsp. berkhoffii Genotype II from a Boy with Epithelioid Hemangioendothelioma and a Dog with Hemangiopericytoma▿

PubMed Central

Breitschwerdt, Edward B.; Maggi, Ricardo G.; Varanat, Mrudula; Linder, Keith E.; Weinberg, Guy

2009-01-01

In this report, we describe isolation of Bartonella vinsonii subsp. berkhoffii genotype II from a boy with epithelioid hemangioendothelioma and a dog with hemangiopericytoma. These results suggest that B. vinsonii subsp. berkhoffii may cause vasoproliferative lesions in both humans and dogs. PMID:19369441

Isolation of Bartonella vinsonii subsp. berkhoffii genotype II from a boy with epithelioid hemangioendothelioma and a dog with hemangiopericytoma.

PubMed

Breitschwerdt, Edward B; Maggi, Ricardo G; Varanat, Mrudula; Linder, Keith E; Weinberg, Guy

2009-06-01

In this report, we describe isolation of Bartonella vinsonii subsp. berkhoffii genotype II from a boy with epithelioid hemangioendothelioma and a dog with hemangiopericytoma. These results suggest that B. vinsonii subsp. berkhoffii may cause vasoproliferative lesions in both humans and dogs.

Molecular Characterization of Multiresistant d-Tartrate-Positive Salmonella enterica Serovar Paratyphi B Isolates

PubMed Central

Miko, Angelika; Guerra, Beatriz; Schroeter, Andreas; Dorn, Christina; Helmuth, Reiner

2002-01-01

Since 1996, the National Salmonella Reference Laboratory of Germany has received an increasing number of Salmonella enterica subsp. enterica serovar Paratyphi B isolates. Nearly all of these belonged to the dextrorotatory tartrate-positive variant (S. enterica subsp. enterica serovar Paratyphi B dT+), formerly called S. enterica subsp. enterica serovar Java. A total of 55 selected contemporary and older S. enterica subsp. enterica serovar Paratyphi B dT+ isolates were analyzed by plasmid profiling, antimicrobial resistance testing, pulsed-field gel electrophoresis, IS200 profiling, and PCR-based detection of integrons. The results showed a high genetic heterogeneity among 10 old strains obtained from 1960 to 1993. In the following years, however, new distinct multiresistant S. enterica subsp. enterica serovar Paratyphi B dT+ clones emerged, and one clonal lineage successfully displaced the older ones. Since 1994, 88% of the isolates investigated were multiple drug resistant. Today, a particular clone predominates in some German poultry production lines, poultry products, and various other sources. It was also detected in contemporary isolates from two neighboring countries as well. PMID:12202551

Francisella tularensis Susceptibility to Antibiotics: A Comprehensive Review of the Data Obtained In vitro and in Animal Models

PubMed Central

Caspar, Yvan; Maurin, Max

2017-01-01

The antibiotic classes that are recommended for tularaemia treatment are the aminoglycosides, the fluoroquinolones and the tetracyclines. However, cure rates vary between 60 and 100% depending on the antibiotic used, the time to appropriate antibiotic therapy setup and its duration, and the presence of complications, such as lymph node suppuration. Thus, antibiotic susceptibility testing (AST) of F. tularensis strains remains of primary importance for detection of the emergence of antibiotic resistances to first-line drugs, and to test new therapeutic alternatives. However, the AST methods reported in the literature were poorly standardized between studies and AST data have not been previously evaluated in a comprehensive and comparative way. The aim of the present review was to summarize experimental data on antibiotic susceptibilities of F. tularensis obtained in acellular media, cell models and animal models since the introduction of fluoroquinolones in the treatment of tularaemia in 1989. We compiled MIC data of 33 antibiotics (including aminoglycosides, fluoroquinolones, tetracyclines, macrolides, β-lactams, chloramphenicol, rifampicin, and linezolid) against 900 F. tularensis strains (504 human strains), including 107 subsp. tularensis (type A), 789 subsp. holarctica (type B) and four subsp. mediasiatica strains, using various AST methods. Specific culture media were identified or confirmed as unsuitable for AST of F. tularensis. Overall, MICs were the lowest for ciprofloxacin (≤ 0.002–0.125 mg/L) and levofloxacin, and ranged from ≤ 0.016 to 2 mg/L for gentamicin, and 0.064 to 4 mg/L for doxycycline. No resistant strain to any of these antibiotics was reported. Fluoroquinolones also exhibited a bactericidal activity against intracellular F. tularensis and lower relapse rates in animal models when compared with the bacteriostatic compound doxycycline. As expected, lower MIC values were found for macrolides against type A and biovar I type B strains, compared to biovar II type B strains. The macrolides were more effective against F. tularensis grown in phagocytic cells than in acellular media. PMID:28443249

Isolation of Bartonella henselae, Bartonella koehlerae subsp. koehlerae, Bartonella koehlerae subsp. bothieri and a new subspecies of B. koehlerae from free-ranging lions (Panthera leo) from South Africa, cheetahs (Acinonyx jubatus) from Namibia and captive cheetahs from California.

PubMed

Molia, S; Kasten, R W; Stuckey, M J; Boulouis, H J; Allen, J; Borgo, G M; Koehler, J E; Chang, C C; Chomel, B B

2016-11-01

Bartonellae are blood- and vector-borne Gram-negative bacteria, recognized as emerging pathogens. Whole-blood samples were collected from 58 free-ranging lions (Panthera leo) in South Africa and 17 cheetahs (Acinonyx jubatus) from Namibia. Blood samples were also collected from 11 cheetahs (more than once for some of them) at the San Diego Wildlife Safari Park. Bacteria were isolated from the blood of three (5%) lions, one (6%) Namibian cheetah and eight (73%) cheetahs from California. The lion Bartonella isolates were identified as B. henselae (two isolates) and B. koehlerae subsp. koehlerae. The Namibian cheetah strain was close but distinct from isolates from North American wild felids and clustered between B. henselae and B. koehlerae. It should be considered as a new subspecies of B. koehlerae. All the Californian semi-captive cheetah isolates were different from B. henselae or B. koehlerae subsp. koehlerae and from the Namibian cheetah isolate. They were also distinct from the strains isolated from Californian mountain lions (Felis concolor) and clustered with strains of B. koehlerae subsp. bothieri isolated from free-ranging bobcats (Lynx rufus) in California. Therefore, it is likely that these captive cheetahs became infected by an indigenous strain for which bobcats are the natural reservoir.

Complete Genome Sequence of Campylobacter fetus subsp. venerealis Biovar Intermedius, Isolated from the Prepuce of a Bull

PubMed Central

Iraola, Gregorio; Pérez, Ruben; Naya, Hugo; Paolicchi, Fernando; Harris, David; Lawley, Trevor D.; Rego, Natalia; Hernández, Martín; Calleros, Lucía; Carretto, Luis; Velilla, Alejandra; Morsella, Claudia; Méndez, Alejandra

2013-01-01

Campylobacter fetus subsp. venerealis is the causative agent of bovine genital campylobacteriosis, a sexually transmitted disease distributed worldwide. Campylobacter fetus subsp. venerealis biovar Intermedius strains differ in their biochemical behavior and are prevalent in some countries. We report the first genome sequence for this biovar, isolated from bull prepuce. PMID:23908278

Complete Genome Sequence of the Yogurt Isolate Lactobacillus delbrueckii subsp. bulgaricus ACA-DC 87.

PubMed

Alexandraki, Voula; Kazou, Maria; Pot, Bruno; Tsakalidou, Effie; Papadimitriou, Konstantinos

2017-08-24

Lactobacillus delbrueckii subsp. bulgaricus is widely used in the production of yogurt and cheese. In this study, we present the complete genome sequence of L. delbrueckii subsp. bulgaricus ACA-DC 87 isolated from traditional Greek yogurt. Whole-genome analysis may reveal desirable technological traits of the strain for dairy fermentations. Copyright © 2017 Alexandraki et al.

Genome sequences of Salmonella enterica subsp. Kentucky ST152 isolated from dairy cows in the United States

USDA-ARS?s Scientific Manuscript database

Salmonella enterica subsp. enterica serovar Kentucky is frequently isolated from dairy cows in the United States, but is an infrequent cause of human salmonellosis. To investigate the genomic features of S. Kentucky strains isolated from these animals, genomes of eight isolates were sequenced and ad...

Isolation of Vibrio tapetis from two native fish species (Genypterus chilensis and Paralichthys adspersus) reared in Chile and description of Vibrio tapetis subsp. quintayensis subsp. nov.

PubMed

Levican, Arturo; Lasa, Aide; Irgang, Rute; Romalde, Jesús L; Poblete-Morales, Matías; Avendaño-Herrera, Ruben

2017-04-01

A group of seven Chilean isolates presumptively belonging to Vibrio tapetis was isolated from diseased fine flounders (Paralichthys adspersus) and red conger eel (Genypterus chilensis) experimentally reared in Quintay (Chile). All isolates were confirmed as members of V. tapetis on the basis of matrix-assisted laser desorption ionization time-of-flight MS, 16S rRNA gene sequencing, DNA-DNA hybridization values and G+C content. The ERIC-PCR and REP-PCR patterns were homogeneous among those isolates recovered from the same host (red conger or fine flounders), but distinct from the type strains V. tapetis subsp. tapetis CECT 4600T and V. tapetis subsp. britannicus CECT 8161T. On the basis of atpA, rpoA, rpoD, recA and pyrH gene sequence similarities (99.7-100 %) and clustering in the phylogenetic trees, the red conger isolates (Q20, Q047, Q48 and Q50) were confirmed as representing V. tapetis subsp. tapetis. However, they differed from V. tapetis subsp. tapetis CECT 4600T in their lipase, alpha quimiotripsin and non-acid phosphatase production. On the other hand, the fine flounder isolates (QL-9T, QL-35 and QL-41) showed rpoD, recA and pyrH gene sequence similarities ranging from 91.6 to 97.7 % with the type strains of the two V. tapetis subspecies (CECT 4600T and CECT 8161T) and consistently clustered together as an independent phylogenetic line within V. tapetis. Moreover, they could be differentiated phenotypically from strains CECT 4600T and CECT 8161T by nine and three different biochemical tests, respectively. In conclusion, the presence of V. tapetis in diseased red conger eel and fine flounder was demonstrated, extending the known host range and geographical location for this pathogen. Furthermore, this study demonstrates that the three isolates from fine flounder represent a novel subdivision within V. tapetis, for which the name V. tapetis subsp. quintayensis subsp. nov. is proposed and with QL-9T (=CECT 8851T=LMG 28759T) as the type strain. Although QL-9T was isolated from kidney of diseased fine flounder specimens, the challenge assays showed that it was non-pathogenic for this species.

Outer membrane vesicles displaying engineered glycotopes elicit protective antibodies

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

Chen, Linxiao; Valentine, Jenny L.; Huang, Chung-Jr

The O-antigen polysaccharide (O-PS) component of lipopolysaccharides on the surface of gram-negative bacteria is both a virulence factor and a B-cell antigen. Antibodies elicited by O-PS often confer protection against infection; therefore, O-PS glycoconjugate vaccines have proven useful against a number of different pathogenic bacteria. However, conventional methods for natural extraction or chemical synthesis of O-PS are technically demanding, inefficient, and expensive. In this paper, we describe an alternative methodology for producing glycoconjugate vaccines whereby recombinant O-PS biosynthesis is coordinated with vesiculation in laboratory strains of Escherichia coli to yield glycosylated outer membrane vesicles (glycOMVs) decorated with pathogen-mimetic glycotopes. Usingmore » this approach, glycOMVs corresponding to eight different pathogenic bacteria were generated. For example, expression of a 17-kb O-PS gene cluster from the highly virulent Francisella tularensis subsp. tularensis (type A) strain Schu S4 in hypervesiculating E. coli cells yielded glycOMVs that displayed F. tularensis O-PS. Immunization of BALB/c mice with glycOMVs elicited significant titers of O-PS–specific serum IgG antibodies as well as vaginal and bronchoalveolar IgA antibodies. Importantly, glycOMVs significantly prolonged survival upon subsequent challenge with F. tularensis Schu S4 and provided complete protection against challenge with two different F. tularensis subsp. holarctica (type B) live vaccine strains, thereby demonstrating the vaccine potential of glycOMVs. Finally, given the ease with which recombinant glycotopes can be expressed on OMVs, the strategy described here could be readily adapted for developing vaccines against many other bacterial pathogens.« less

Outer membrane vesicles displaying engineered glycotopes elicit protective antibodies

DOE PAGES

Chen, Linxiao; Valentine, Jenny L.; Huang, Chung-Jr; ...

2016-06-06

The O-antigen polysaccharide (O-PS) component of lipopolysaccharides on the surface of gram-negative bacteria is both a virulence factor and a B-cell antigen. Antibodies elicited by O-PS often confer protection against infection; therefore, O-PS glycoconjugate vaccines have proven useful against a number of different pathogenic bacteria. However, conventional methods for natural extraction or chemical synthesis of O-PS are technically demanding, inefficient, and expensive. In this paper, we describe an alternative methodology for producing glycoconjugate vaccines whereby recombinant O-PS biosynthesis is coordinated with vesiculation in laboratory strains of Escherichia coli to yield glycosylated outer membrane vesicles (glycOMVs) decorated with pathogen-mimetic glycotopes. Usingmore » this approach, glycOMVs corresponding to eight different pathogenic bacteria were generated. For example, expression of a 17-kb O-PS gene cluster from the highly virulent Francisella tularensis subsp. tularensis (type A) strain Schu S4 in hypervesiculating E. coli cells yielded glycOMVs that displayed F. tularensis O-PS. Immunization of BALB/c mice with glycOMVs elicited significant titers of O-PS–specific serum IgG antibodies as well as vaginal and bronchoalveolar IgA antibodies. Importantly, glycOMVs significantly prolonged survival upon subsequent challenge with F. tularensis Schu S4 and provided complete protection against challenge with two different F. tularensis subsp. holarctica (type B) live vaccine strains, thereby demonstrating the vaccine potential of glycOMVs. Finally, given the ease with which recombinant glycotopes can be expressed on OMVs, the strategy described here could be readily adapted for developing vaccines against many other bacterial pathogens.« less

Whole-genome sequencing of Salmonella enterica subsp. enterica serovar Cubana strains isolated from agricultural sources

USDA-ARS?s Scientific Manuscript database

We report draft genomes of Salmonella enterica subsp. enterica Serovar Cubana strain CVM42234 isolated from chick feed in 2012 and Salmonella Cubana strain 76814 isolated from swine in 2004. The genome sizes are 4,975,046 and 4,936,251 base pairs, respectively....

Description of Campylobacter fetus subsp. testudinum subsp. nov., isolated from humans and reptiles

USDA-ARS?s Scientific Manuscript database

A polyphasic study was undertaken to determine the taxonomic position of 13 Campylobacter fetus-like isolates from humans (n=8) and reptiles (n=5). Phenotypic characterization, Genusgenus-specific and sap insertion-PCR initially identified all human isolates as type A Campylobacter fetus. Phylogenet...

Culture Phenotypes of Genomically and Geographically Diverse Mycobacterium avium subsp. paratuberculosis Isolates from Different Hosts▿

PubMed Central

Whittington, Richard J.; Marsh, Ian B.; Saunders, Vanessa; Grant, Irene R.; Juste, Ramon; Sevilla, Iker A.; Manning, Elizabeth J. B.; Whitlock, Robert H.

2011-01-01

Mycobacterium avium subsp. paratuberculosis causes paratuberculosis (Johne's disease) in ruminants in most countries. Historical data suggest substantial differences in culturability of M. avium subsp. paratuberculosis isolates from small ruminants and cattle; however, a systematic comparison of culture media and isolates from different countries and hosts has not been undertaken. Here, 35 field isolates from the United States, Spain, Northern Ireland, and Australia were propagated in Bactec 12B medium and Middlebrook 7H10 agar, genomically characterized, and subcultured to Lowenstein-Jensen (LJ), Herrold's egg yolk (HEY), modified Middlebrook 7H10, Middlebrook 7H11, and Watson-Reid (WR) agars, all with and without mycobactin J and some with sodium pyruvate. Fourteen genotypes of M. avium subsp. paratuberculosis were represented as determined by BstEII IS900 and IS1311 restriction fragment length polymorphism analysis. There was no correlation between genotype and overall culturability, although most S strains tended to grow poorly on HEY agar. Pyruvate was inhibitory to some isolates. All strains grew on modified Middlebrook 7H10 agar but more slowly and less prolifically on LJ agar. Mycobactin J was required for growth on all media except 7H11 agar, but growth was improved by the addition of mycobactin J to 7H11 agar. WR agar supported the growth of few isolates. The differences in growth of M. avium subsp. paratuberculosis that have historically been reported in diverse settings have been strongly influenced by the type of culture medium used. When an optimal culture medium, such as modified Middlebrook 7H10 agar, is used, very little difference between the growth phenotypes of diverse strains of M. avium subsp. paratuberculosis was observed. This optimal medium is recommended to remove bias in the isolation and cultivation of M. avium subsp. paratuberculosis. PMID:21430104

Co-isolation of Bartonella henselae and Bartonella vinsonii subsp. berkhoffii from blood, joint and subcutaneous seroma fluids from two naturally infected dogs.

PubMed

Diniz, Pedro Paulo Vissotto de Paiva; Wood, Michael; Maggi, Ricardo G; Sontakke, Sushama; Stepnik, Matt; Breitschwerdt, Edward B

2009-09-18

This report describes the clinical presentation, isolation and treatment of two dogs naturally infected with Bartonella henselae and Bartonella vinsonii subsp. berkhoffii. Chronic and progressive polyarthritis was the primary complaint for dog #1, from which B. henselae and B. vinsonii subsp. berkhoffii were cultured on three independent occasions from blood and joint fluid samples, despite administration of nearly 4 months of non-consecutive antibiotic therapy. A clinically atypical and progressively severe trauma-associated seroma was the primary complaint for dog #2, from which B. henselae and B. vinsonii subsp. berkhoffii were isolated from serum, blood and seroma fluid. Dogs can be co-infected with two Bartonella spp. and infection with these organisms should not be ruled out if specific antibodies are not detected. Specialized culture techniques should be used for isolation and to assess antibiotic efficacy.

Aeromonas hydrophila subsp. dhakensis Isolated from Feces, Water and Fish in Mediterranean Spain

PubMed Central

Esteve, Consuelo; Alcaide, Elena; Blasco, María Dolores

2012-01-01

Eight Aeromonas hydrophila-like arabinose-negative isolates from diverse sources (i.e., river freshwater, cooling-system water pond, diseased wild European eels, and human stools) sampled in Valencia (Spain) during 2004–2005, were characterized by 16S rRNA gene sequencing and extensive biochemical testing along with reference strains of most Aeromonas species. These isolates and all reference strains of A. hydrophila subsp. dhakensis and A. aquariorum showed a 16S rRNA sequence similarity of 99.8–100%, and they all shared an identical phenotype. This matched exactly with that of A. hydrophila subsp. dhakensis since all strains displayed positive responses to the Voges-Prokauer test and to the use of dl-lactate. This is the first report of A. hydrophila subsp. dhakensis recovered from environmental samples, and further, from its original isolation in India during 1993–1994. This was accurately identified and segregated from other clinical aeromonads (A. hydrophila subsp. hydrophila, A. caviae, A. veronii biovars veronii and sobria, A. trota, A. schubertii and A. jandaei) by using biochemical key tests. The API 20 E profile for all strains included in A. hydrophila subsp. dhakensis was 7047125. The prevalence of this species in Spanish sources was higher for water (9.4%) than for feces (6%) or eels (1.3%). Isolates recovered as pure cultures from diseased eels were moderately virulent (LD50 of 3.3×106 CFU fish−1) to challenged eels in experimental trials. They were all resistant to ticarcillin, amoxicillin-clavuranic acid, cefoxitin, and imipenem, regardless of its source. Our data point to A. hydrophila subsp. dhakensis as an emerging pathogen for humans and fish in temperate countries. PMID:22472298

[Chalcones from Bauhinia glauca subsp. pernervosa].

PubMed

Wu, Zengbao; Wang, Bin; Zhao, Yuying; Yang, Xiuwei; Liang, Hong

2009-07-01

To study the chemical constituents of Bauhinia glauca subsp. pernervosa. The coulis of B. glauca subsp. pernervosa were extracted with 95% EtOH at room temperature. The compounds were isolated and separated by chromatographic techniques, and structures were identified by spectroscopic methods. Seven chalcones were isolated and identified: butein-4-methyl ether (1), isoliquiritigenin (2), butein (3), isoliquiritigenin-2'-methyl ether (4), 2',4'-dihydroxychalcone (5), isoliquiritigenin-4-methyl ether (6), 4-hydroxy-2',4'-dimethoxychalcone (7). Compounds 1, 3, and 7 were isolated from the genus Bauhinia for the first time, the other compounds were obtained from this plant for the first time.

Infection of sea lamprey with an unusual strain of Aeromonas salmonicida

USGS Publications Warehouse

Diamanka, Arfang; Loch, Thomas P.; Cipriano, Rocco C.; Winters, Andrew D.; Faisal, Mohamed

2014-01-01

The invasion of the Laurentian Great Lakes by the fish-parasitic sea lamprey has led to catastrophic consequences, including the potential introduction of fish pathogens. Aeromonas salmonicida is a bacterial fish pathogen that causes devastating losses worldwide. Currently, there are five accepted subspecies of Aeromonas salmonicida: A. salmonicida subsp. salmonicida, masoucida, smithia, achromogenes, and pectinolytica. We discuss the discovery of an isolate of A. salmonicida that is pathogenic to rainbow trout (Oncorhynchus mykiss) and exhibits unique phenotypic and molecular characteristics. We examined 181 adult sea lamprey (Petromyzon marinus) from the Humber River (Lake Ontario watershed) and 162 adult sea lamprey from Duffins Creek (Lake Ontario watershed) during the spring seasons of 2005–11. Among those, 4/343 (1.2%) sea lamprey were culture positive for A. salmonicida, whereby biochemical and molecular studies identified three of the isolates as A. salmonicida subsp. salmonicida. The remaining isolate (As-SL1) recovered from Humber River sea lamprey was phenotypically more similar to A. salmonicida subsp. salmonicida than to the four other A. salmonicida subspecies. However, unlike A. salmonicida subsp. salmonicida, As-SL1 was sucrose positive, produced an acid-over-acid reaction on triple-sugar iron medium and did not amplify with A. salmonicida subsp. salmonicida specific primers. Phylogenetic analysis based on partial stretches of the 16S rRNA and DNA gyrase subunit B genes further confirmed that the As-SL1 isolate was not A. salmonicida subsp. masoucida, smithia, achromogenes, or pectinolytica. Based on our analyses, the As-SL1 isolate is either an unusual strain of A. salmonicida subsp. salmonicida or a novel A. salmonicida subspecies. The four A. salmonicida isolates that were recovered from sea lamprey were pathogenic to rainbow trout in experimental challenge studies. Our study also underscores the potential role of sea lamprey in the ecology of infectious fish diseases.

Infection of sea lamprey with an unusual strain of Aeromonas salmonicida.

PubMed

Diamanka, Arfang; Loch, Thomas P; Cipriano, Rocco C; Winters, Andrew D; Faisal, Mohamed

2014-04-01

The invasion of the Laurentian Great Lakes by the fish-parasitic sea lamprey has led to catastrophic consequences, including the potential introduction of fish pathogens. Aeromonas salmonicida is a bacterial fish pathogen that causes devastating losses worldwide. Currently, there are five accepted subspecies of Aeromonas salmonicida: A. salmonicida subsp. salmonicida, masoucida, smithia, achromogenes, and pectinolytica. We discuss the discovery of an isolate of A. salmonicida that is pathogenic to rainbow trout (Oncorhynchus mykiss) and exhibits unique phenotypic and molecular characteristics. We examined 181 adult sea lamprey (Petromyzon marinus) from the Humber River (Lake Ontario watershed) and 162 adult sea lamprey from Duffins Creek (Lake Ontario watershed) during the spring seasons of 2005-11. Among those, 4/343 (1.2%) sea lamprey were culture positive for A. salmonicida, whereby biochemical and molecular studies identified three of the isolates as A. salmonicida subsp. salmonicida. The remaining isolate (As-SL1) recovered from Humber River sea lamprey was phenotypically more similar to A. salmonicida subsp. salmonicida than to the four other A. salmonicida subspecies. However, unlike A. salmonicida subsp. salmonicida, As-SL1 was sucrose positive, produced an acid-over-acid reaction on triple-sugar iron medium and did not amplify with A. salmonicida subsp. salmonicida specific primers. Phylogenetic analysis based on partial stretches of the 16S rRNA and DNA gyrase subunit B genes further confirmed that the As-SL1 isolate was not A. salmonicida subsp. masoucida, smithia, achromogenes, or pectinolytica. Based on our analyses, the As-SL1 isolate is either an unusual strain of A. salmonicida subsp. salmonicida or a novel A. salmonicida subspecies. The four A. salmonicida isolates that were recovered from sea lamprey were pathogenic to rainbow trout in experimental challenge studies. Our study also underscores the potential role of sea lamprey in the ecology of infectious fish diseases.

Unusual Outbreak of Clinical Mastitis in Dairy Sheep Caused by Streptococcus equi subsp. zooepidemicus

PubMed Central

Las Heras, Alfonso; Vela, Ana I.; Fernández, Elena; Legaz, Emilio; Domínguez, Lucas; Fernández-Garayzábal, Jose F.

2002-01-01

This work describes an outbreak of clinical mastitis affecting 13 of 58 lactating ewes due to Streptococcus equi subsp. zooepidemicus. S. equi subsp. zooepidemicus was isolated in pure culture from all milk samples. All the clinical isolates had identical biochemical profiles and antimicrobial susceptibility patterns and also exhibited indistinguishable macrorestriction patterns by pulsed-field gel electrophoresis, indicating that all cases of mastitis were produced by a single strain. PMID:11880454

First isolation of Mycoplasma capricolum subsp. capricolum, one of the causal agents of caprine contagious agalactia, on the island of Lanzarote (Spain).

PubMed

De la Fe, C; Gutiérrez, A; Poveda, J B; Assunção, P; Ramírez, A S; Fabelo, F

2007-03-01

During an unusually long period of bad weather, several outbreaks of caprine contagious agalactia (CCA) were reported in a number of flocks on the island of Lanzarote (Canary Islands, Spain). Clinical and subclinical mastitis in lactating goats and some cases of arthritis and pneumonia in kids were observed in the affected flocks. Mycoplasma capricolum subsp. capricolum was isolated as the main causal agent of the outbreaks, associated with M. mycoides subsp. mycoides "large colony type" (Mmm LC) in two flocks. This is the first report of an isolation of M. capricolum subsp. capricolum on the island of Lanzarote. The finding is of epidemiological importance and could complicate plans to control the disease. The significance of this mycoplasma species in association with CCA must now be studied in detail.

Human Treponema pallidum 11q/j isolate belongs to subsp. endemicum but contains two loci with a sequence in TP0548 and TP0488 similar to subsp. pertenue and subsp. pallidum, respectively

PubMed Central

Mikalová, Lenka; Strouhal, Michal; Oppelt, Jan; Grange, Philippe Alain; Janier, Michel; Benhaddou, Nadjet; Dupin, Nicolas; Šmajs, David

2017-01-01

Background Treponema pallidum subsp. endemicum (TEN) is the causative agent of endemic syphilis (bejel). An unusual human TEN 11q/j isolate was obtained from a syphilis-like primary genital lesion from a patient that returned to France from Pakistan. Methodology/Principal findings The TEN 11q/j isolate was characterized using nested PCR followed by Sanger sequencing and/or direct Illumina sequencing. Altogether, 44 chromosomal regions were analyzed. Overall, the 11q/j isolate clustered with TEN strains Bosnia A and Iraq B as expected from previous TEN classification of the 11q/j isolate. However, the 11q/j sequence in a 505 bp-long region at the TP0488 locus was similar to Treponema pallidum subsp. pallidum (TPA) strains, but not to TEN Bosnia A and Iraq B sequences, suggesting a recombination event at this locus. Similarly, the 11q/j sequence in a 613 bp-long region at the TP0548 locus was similar to Treponema pallidum subsp. pertenue (TPE) strains, but not to TEN sequences. Conclusions/Significance A detailed analysis of two recombinant loci found in the 11q/j clinical isolate revealed that the recombination event occurred just once, in the TP0488, with the donor sequence originating from a TPA strain. Since TEN Bosnia A and Iraq B were found to contain TPA-like sequences at the TP0548 locus, the recombination at TP0548 took place in a treponeme that was an ancestor to both TEN Bosnia A and Iraq B. The sequence of 11q/j isolate in TP0548 represents an ancestral TEN sequence that is similar to yaws-causing treponemes. In addition to the importance of the 11q/j isolate for reconstruction of the TEN phylogeny, this case emphasizes the possible role of TEN strains in development of syphilis-like lesions. PMID:28263990

Genetic diversity of clinical Mycobacterium avium subsp. hominissuis and Mycobacterium intracellulare isolates causing pulmonary diseases recovered from different geographical regions.

PubMed

Ichikawa, Kazuya; van Ingen, Jakko; Koh, Won-Jung; Wagner, Dirk; Salfinger, Max; Inagaki, Takayuki; Uchiya, Kei-Ichi; Nakagawa, Taku; Ogawa, Kenji; Yamada, Kiyofumi; Yagi, Tetsuya

2015-12-01

Mycobacterium avium complex (MAC) infections are increasing annually in many countries. MAC strains are the most common nontuberculous mycobacterial pathogens isolated from respiratory samples and predominantly consist of two species, Mycobacterium avium and Mycobacterium intracellulare. The aim of this study was to analyze the molecular epidemiology and genetic backgrounds of clinical MAC isolates collected from The Netherlands, Germany, United States, Korea and Japan. Variable numbers of tandem repeats (VNTR) analysis was used to examine the genetic relatedness of clinical isolates of M. avium subsp. hominissuis (n=261) and M. intracellulare (n=116). Minimum spanning tree and unweighted pair group method using arithmetic averages analyses based on the VNTR data indicated that M. avium subsp. hominissuis isolates from Japan shared a high degree of genetic relatedness with Korean isolates, but not with isolates from Europe or the United States, whereas M. intracellulare isolates did not show any specific clustering by geographic origin. The findings from the present study indicate that strains of M. avium subsp. hominissuis, but not M. intracellulare, exhibit geographical differences in genetic diversity and imply that MAC strains may have different sources, routes of transmission and perhaps clinical manifestations. Copyright © 2015 Elsevier B.V. All rights reserved.

Draft Genome Sequence of Staphylococcus cohnii subsp. urealyticus Isolated from a Healthy Dog

PubMed Central

Wigmore, Sarah M.; Wareham, David W.

2017-01-01

ABSTRACT   Staphylococcus cohnii subsp. urealyticus strain SW120 was isolated from the ear swab of a healthy dog. The isolate is resistant to methicillin and fusidic acid. The SW120 draft genome is 2,805,064 bp and contains 2,667 coding sequences, including 58 tRNAs and nine complete rRNA coding regions. PMID:28209829

Genotypic Characterization of Streptococcus infantarius subsp. coli Isolates from Sea Otters with Infective Endocarditis and/or Septicemia and from Environmental Mussel Samples

PubMed Central

Counihan-Edgar, Katrina L.; Gill, Verena A.; Doroff, Angela M.; Burek, Kathleen A.; Miller, Woutrina A.; Shewmaker, Patricia L.; Jang, Spencer; Goertz, Caroline E. C.; Tuomi, Pamela A.; Miller, Melissa A.; Jessup, David A.

2012-01-01

Pulsed-field gel electrophoresis (PFGE) was used to type 128 Streptococcus infantarius subsp. coli isolates from sea otters and mussels. Six SmaI PFGE groups were detected, with one predominant group representing 57% of the isolates collected over a wide geographic region. Several sea otter and mussel isolates were highly related, suggesting that an environmental infection source is possible. PMID:23052307

Towards Development of Improved Serodiagnostics for Tularemia by Use of Francisella tularensis Proteome Microarrays.

PubMed

Nakajima, Rie; Escudero, Raquel; Molina, Douglas M; Rodríguez-Vargas, Manuela; Randall, Arlo; Jasinskas, Algis; Pablo, Jozelyn; Felgner, Philip L; AuCoin, David P; Anda, Pedro; Davies, D Huw

2016-07-01

Tularemia in humans is caused mainly by two subspecies of the Gram-negative facultative anaerobe Francisella tularensis: F. tularensis subsp. tularensis (type A) and F. tularensis subsp. holarctica (type B). The current serological test for tularemia is based on agglutination of whole organisms, and the reactive antigens are not well understood. Previously, we profiled the antibody responses in type A and B tularemia cases in the United States using a proteome microarray of 1,741 different proteins derived from the type A strain Schu S4. Fifteen dominant antigens able to detect antibodies to both types of infection were identified, although these were not validated in a different immunoassay format. Since type A and B subspecies are closely related, we hypothesized that Schu S4 antigens would also have utility for diagnosing type B tularemia caused by strains from other geographic locations. To test this, we probed the Schu S4 array with sera from 241 type B tularemia cases in Spain. Despite there being no type A strains in Spain, we confirmed the responses against some of the same potential serodiagnostic antigens reported previously, as well as determined the responses against additional potential serodiagnostic antigens. Five potential serodiagnostic antigens were evaluated on immunostrips, and two of these (FTT1696/GroEL and FTT0975/conserved hypothetical protein) discriminated between the Spanish tularemia cases and healthy controls. We conclude that antigens from the type A strain Schu S4 are suitable for detection of antibodies from patients with type B F. tularensis infections and that these can be used for the diagnosis of tularemia in a deployable format, such as the immunostrip. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Towards Development of Improved Serodiagnostics for Tularemia by Use of Francisella tularensis Proteome Microarrays

PubMed Central

Nakajima, Rie; Escudero, Raquel; Molina, Douglas M.; Rodríguez-Vargas, Manuela; Randall, Arlo; Jasinskas, Algis; Pablo, Jozelyn; Felgner, Philip L.; AuCoin, David P.; Anda, Pedro

2016-01-01

Tularemia in humans is caused mainly by two subspecies of the Gram-negative facultative anaerobe Francisella tularensis: F. tularensis subsp. tularensis (type A) and F. tularensis subsp. holarctica (type B). The current serological test for tularemia is based on agglutination of whole organisms, and the reactive antigens are not well understood. Previously, we profiled the antibody responses in type A and B tularemia cases in the United States using a proteome microarray of 1,741 different proteins derived from the type A strain Schu S4. Fifteen dominant antigens able to detect antibodies to both types of infection were identified, although these were not validated in a different immunoassay format. Since type A and B subspecies are closely related, we hypothesized that Schu S4 antigens would also have utility for diagnosing type B tularemia caused by strains from other geographic locations. To test this, we probed the Schu S4 array with sera from 241 type B tularemia cases in Spain. Despite there being no type A strains in Spain, we confirmed the responses against some of the same potential serodiagnostic antigens reported previously, as well as determined the responses against additional potential serodiagnostic antigens. Five potential serodiagnostic antigens were evaluated on immunostrips, and two of these (FTT1696/GroEL and FTT0975/conserved hypothetical protein) discriminated between the Spanish tularemia cases and healthy controls. We conclude that antigens from the type A strain Schu S4 are suitable for detection of antibodies from patients with type B F. tularensis infections and that these can be used for the diagnosis of tularemia in a deployable format, such as the immunostrip. PMID:27098957

Draft Genome Sequences of 18 Salmonella enterica subsp. enterica Serovar Oranienburg Strains Isolated from Rivers in Northwestern Mexico

PubMed Central

Casteñeda-Ruelas, Gloria M.; Carreón-Gaxiola, César; Castelán-Sánchez, Hugo G.; Acatzi-Silva, Abraham; Romero-Martínez, Salvador; García-Molina, Alejandra

2017-01-01

ABSTRACT Salmonella enterica subsp. enterica serovar Oranienburg is recognized as a foodborne pathogen widely distributed in the environment. Here, we report 18 draft genomes of S. Oranienburg strains isolated from rivers in the northwestern region of Mexico. PMID:28280020

Complete Genome Sequences of 17 Canadian Isolates of Salmonella enterica subsp. enterica Serovar Heidelberg from Human, Animal, and Food Sources

PubMed Central

Labbé, Geneviève; Ziebell, Kim; Bekal, Sadjia; Parmley, E. Jane; Agunos, Agnes; Desruisseau, Andrea; Daignault, Danielle; Slavic, Durda; Hoang, Linda; Ramsay, Danielle; Pollari, Frank; Robertson, James; Nash, John H. E.

2016-01-01

Salmonella enterica subsp. enterica serovar Heidelberg is a highly clonal serovar frequently associated with foodborne illness. To facilitate subtyping efforts, we report fully assembled genome sequences of 17 Canadian S. Heidelberg isolates including six pairs of epidemiologically related strains. The plasmid sequences of eight isolates contain several drug resistance genes. PMID:27635008

Complete Genome Sequences of 17 Canadian Isolates of Salmonella enterica subsp. enterica Serovar Heidelberg from Human, Animal, and Food Sources.

PubMed

Labbé, Geneviève; Ziebell, Kim; Bekal, Sadjia; Macdonald, Kimberley A; Parmley, E Jane; Agunos, Agnes; Desruisseau, Andrea; Daignault, Danielle; Slavic, Durda; Hoang, Linda; Ramsay, Danielle; Pollari, Frank; Robertson, James; Nash, John H E; Johnson, Roger P

2016-09-15

Salmonella enterica subsp. enterica serovar Heidelberg is a highly clonal serovar frequently associated with foodborne illness. To facilitate subtyping efforts, we report fully assembled genome sequences of 17 Canadian S Heidelberg isolates including six pairs of epidemiologically related strains. The plasmid sequences of eight isolates contain several drug resistance genes. © Crown copyright 2016.

Clonal relationship and differentiation among Mycobacterium abscessus isolates as determined using the semiautomated repetitive extragenic palindromic sequence PCR-based DiversiLab system.

PubMed

Mougari, Faiza; Raskine, Laurent; Ferroni, Agnes; Marcon, Estelle; Sermet-Gaudelus, Isabelle; Veziris, Nicolas; Heym, Beate; Gaillard, Jean-Louis; Nassif, Xavier; Cambau, Emmanuelle

2014-06-01

Mycobacterium abscessus is a rapidly growing mycobacterium that causes respiratory tract infections in predisposed patients, such as those with cystic fibrosis and nosocomial skin and soft tissue infections. In order to investigate the clonal relationships between the strains causing epidemic episodes, we evaluated the discriminatory power of the semiautomated DiversiLab (DL) repetitive extragenic palindromic sequence PCR (REP-PCR) test for M. abscessus genotyping. Since M. abscessus was shown to be composed of subspecies (M. abscessus subsp. massiliense, M. abscessus subsp. bolletii, and M. abscessus subsp. abscessus), we also evaluated the ability of this technique to differentiate subspecies. The technique was applied to two collections of clinical isolates, (i) 83 M. abscessus original isolates (43 M. abscessus subsp. abscessus, 12 M. abscessus subsp. bolletii, and 28 M. abscessus subsp. massiliense) from infected patients and (ii) 35 repeated isolates obtained over 1 year from four cystic fibrosis patients. The DL REP-PCR test was standardized for DNA extraction, DNA amplification, and electrophoresis pattern comparisons. Among the isolates from distinct patients, 53/83 (62%) isolates showed a specific pattern, and 30 were distributed in 11 clusters and 6 patterns, with 2 to 4 isolates per pattern. The clusters and patterns did not fully correlate with multilocus sequence typing (MLST) analysis results. This revealed a high genomic diversity between patients, with a discriminatory power of 98% (Simpson's diversity index). However, since some isolates shared identical patterns, this raises the question of whether it is due to transmission between patients or a common reservoir. Multiple isolates from the same patient showed identical patterns, except for one patient infected by two strains. Between the M. abscessus subspecies, the indexes were <70%, indicating that the DL REP-PCR test is not an accurate tool for identifying organisms to the subspecies level. REP-PCR appears to be a rapid genotyping method that is useful for investigating epidemics of M. abscessus infections. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Phenotypic, Genotypic, and Antimicrobial Characteristics of Streptococcus halichoeri Isolates from Humans, Proposal To Rename Streptococcus halichoeri as Streptococcus halichoeri subsp. halichoeri, and Description of Streptococcus halichoeri subsp. hominis subsp. nov., a Bacterium Associated with Human Clinical Infections.

PubMed

Shewmaker, P L; Whitney, A M; Humrighouse, B W

2016-03-01

Phenotypic, genotypic, and antimicrobial characteristics of six phenotypically distinct human clinical isolates that most closely resembled the type strain of Streptococcus halichoeri isolated from a seal are presented. Sequencing of the 16S rRNA, rpoB, sodA, and recN genes; comparative whole-genome analysis; conventional biochemical and Rapid ID 32 Strep identification methods; and antimicrobial susceptibility testing were performed on the human isolates, the type strain of S. halichoeri, and type strains of closely related species. The six human clinical isolates were biochemically indistinguishable from each other and showed 100% 16S rRNA, rpoB, sodA, and recN gene sequence similarity. Comparative 16S rRNA gene sequencing analysis revealed 98.6% similarity to S. halichoeri CCUG 48324(T), 97.9% similarity to S. canis ATCC 43496(T), and 97.8% similarity to S. ictaluri ATCC BAA-1300(T). A 3,530-bp fragment of the rpoB gene was 98.8% similar to the S. halichoeri type strain, 84.6% to the S. canis type strain, and 83.8% to the S. ictaluri type strain. The S. halichoeri type strain and the human clinical isolates were susceptible to the antimicrobials tested based on CLSI guidelines for Streptococcus species viridans group with the exception of tetracycline and erythromycin. The human isolates were phenotypically distinct from the type strain isolated from a seal; comparative whole-genome sequence analysis confirmed that the human isolates were S. halichoeri. On the basis of these results, a novel subspecies, Streptococcus halichoeri subsp. hominis, is proposed for the human isolates and Streptococcus halichoeri subsp. halichoeri is proposed for the gray seal isolates. The type strain of the novel subspecies is SS1844(T) = CCUG 67100(T) = LMG 28801(T). Copyright © 2016, American Society for Microbiology. All Rights Reserved.

An Ecological Study of Lactococci Isolated from Raw Milk in the Camembert Cheese Registered Designation of Origin Area

PubMed Central

Corroler, D.; Mangin, I.; Desmasures, N.; Gueguen, M.

1998-01-01

The genetic diversity of lactococci isolated from raw milk in the Camembert cheese Registered Designation of Origin area was studied. Two seasonal samples (winter and summer) of raw milk were obtained from six farms in two areas (Bessin and Bocage Falaisien) of Normandy. All of the strains analyzed had a Lactococcus lactis subsp. lactis phenotype, whereas the randomly amplified polymorphic DNA (RAPD) technique genotypically identified the strains as members of L. lactis subsp. lactis or L. lactis subsp. cremoris. The genotypes were confirmed by performing standard PCR with primers corresponding to a region of the histidine biosynthesis operon. The geographic distribution of each subspecies of L. lactis was determined; 80% of the Bocage Falaisien strains were members of L. lactis subsp. lactis, and 30.5% of the Bessin strains were members of L. lactis subsp. lactis. A dendrogram was produced from a computer analysis of the RAPD profiles in order to evaluate the diversity of the lactococci below the subspecies level. The coefficient of similarity for 117 of the 139 strains identified as members of L. lactis subsp. cremoris was as high as 66%. The L. lactis subsp. lactis strains were more heterogeneous and formed 10 separate clusters (the level of similarity among the clusters was 18%). Reference strains of L. lactis subsp. lactis fell into 2 of these 10 clusters, demonstrating that lactococcal isolates are clearly different. As determined by the RAPD profiles, some L. lactis subsp. lactis strains were specific to the farms from which they originated and were recovered throughout the year (in both summer and winter). Therefore, the typicality of L. lactis subsp. lactis strains was linked to the farm of origin rather than the area. These findings emphasize the significance of designation of origin and the specificity of “Camembert de Normandie” cheese. PMID:9835555

An ecological study of lactococci isolated from raw milk in the camembert cheese registered designation of origin area.

PubMed

Corroler, D; Mangin, I; Desmasures, N; Gueguen, M

1998-12-01

The genetic diversity of lactococci isolated from raw milk in the Camembert cheese Registered Designation of Origin area was studied. Two seasonal samples (winter and summer) of raw milk were obtained from six farms in two areas (Bessin and Bocage Falaisien) of Normandy. All of the strains analyzed had a Lactococcus lactis subsp. lactis phenotype, whereas the randomly amplified polymorphic DNA (RAPD) technique genotypically identified the strains as members of L. lactis subsp. lactis or L. lactis subsp. cremoris. The genotypes were confirmed by performing standard PCR with primers corresponding to a region of the histidine biosynthesis operon. The geographic distribution of each subspecies of L. lactis was determined; 80% of the Bocage Falaisien strains were members of L. lactis subsp. lactis, and 30.5% of the Bessin strains were members of L. lactis subsp. lactis. A dendrogram was produced from a computer analysis of the RAPD profiles in order to evaluate the diversity of the lactococci below the subspecies level. The coefficient of similarity for 117 of the 139 strains identified as members of L. lactis subsp. cremoris was as high as 66%. The L. lactis subsp. lactis strains were more heterogeneous and formed 10 separate clusters (the level of similarity among the clusters was 18%). Reference strains of L. lactis subsp. lactis fell into 2 of these 10 clusters, demonstrating that lactococcal isolates are clearly different. As determined by the RAPD profiles, some L. lactis subsp. lactis strains were specific to the farms from which they originated and were recovered throughout the year (in both summer and winter). Therefore, the typicality of L. lactis subsp. lactis strains was linked to the farm of origin rather than the area. These findings emphasize the significance of designation of origin and the specificity of "Camembert de Normandie" cheese.

Proposal to rename Carnobacterium inhibens as Carnobacterium inhibens subsp. inhibens subsp. nov. and description of Carnobacterium inhibens subsp. gilichinskyi subsp. nov., a psychrotolerant bacterium isolated from Siberian permafrost.

PubMed

Nicholson, Wayne L; Zhalnina, Kateryna; de Oliveira, Rafael R; Triplett, Eric W

2015-02-01

A novel, psychrotolerant facultative anaerobe, strain WN1359(T), was isolated from a permafrost borehole sample collected at the right bank of the Kolyma River in Siberia, Russia. Gram-positive-staining, non-motile, rod-shaped cells were observed with sizes of 1-2 µm long and 0.4-0.5 µm wide. Growth occurred in the range of pH 5.8-9.0 with optimal growth at pH 7.8-8.6 (pH optimum 8.2). The novel isolate grew at temperatures from 0-37 °C and optimal growth occurred at 25 °C. The novel isolate does not require NaCl; growth was observed between 0 and 8.8 % (1.5 M) NaCl with optimal growth at 0.5 % (w/v) NaCl. The isolate was a catalase-negative, facultatively anaerobic chemo-organoheterotroph that used sugars but not several single amino acids or dipeptides as substrates. The major metabolic end-product was lactic acid in the ratio of 86 % l-lactate : 14 % d-lactate. Strain WN1359(T) was sensitive to ampicillin, chloramphenicol, fusidic acid, lincomycin, monocycline, rifampicin, rifamycin SV, spectinomycin, streptomycin, troleandomycin and vancomycin, and resistant to nalidixic acid and aztreonam. The fatty acid content was predominantly unsaturated (70.2 %), branched-chain unsaturated (11.7 %) and saturated (12.5 %). The DNA G+C content was 35.3 mol% by whole genome sequence analysis. 16S rRNA gene sequence analysis showed 98.7 % sequence identity between strain WN1359(T) and Carnobacterium inhibens. Genome relatedness was computed using both Genome-to-Genome Distance Analysis (GGDA) and Average Nucleotide Identity (ANI), which both strongly supported strain WN1359(T) belonging to the species C. inhibens. On the basis of these results, the permafrost isolate WN1359(T) represents a novel subspecies of C. inhibens, for which the name Carnobacterium inhibens subsp. gilichinskyi subsp. nov. is proposed. The type strain is WN1359(T) ( = ATCC BAA-2557(T) = DSM 27470(T)). The subspecies Carnobacterium inhibens subsp. inhibens subsp. nov. is created automatically. An emended description of C. inhibens is also provided. © 2015 IUMS.

Improvement of DNA transfer frequency and transposon mutagenesis of Erwinia carotovora subsp. betavasculorum.

PubMed Central

Rella, M; Axelrood, P E; Weinhold, A R; Schroth, M N

1989-01-01

The production of antibiotics and their role in microbial competition under natural conditions can be readily studied by the use of transposon mutants. Several antibiotic-producing strains of Erwinia carotovora subsp. betavasculorum were unable to accept foreign DNA. A plasmid delivery system was developed, using ethyl methanesulfonate mutagenesis, which entailed isolating E. carotovora subsp. betavasculorum mutants able to accept foreign DNA and transfer it to other strains. This enabled transposon mutagenesis of a wild-type antibiotic-producing strain of E. carotovora subsp. betavasculorum. Twelve antibiotic-negative mutants were isolated, and one of these showed a reduction in antibiotic production in vitro. Many of these mutants also showed a reduction in their ability to macerate potato tissue. The mutants were classified into four genetic groups on the basis of their genetic and phenotypic characteristics, indicating that several genes are involved in antibiotic biosynthesis by E. carotovora subsp. betavasculorum. PMID:2543291

Detection of Goss's Wilt Pathogen Clavibacter michiganensis subsp. nebraskensis in Maize by Loop-Mediated Amplification.

PubMed

Yasuhara-Bell, Jarred; de Silva, Asoka; Heuchelin, Scott A; Chaky, Jennifer L; Alvarez, Anne M

2016-03-01

The Goss's wilt pathogen, Clavibacter michiganensis subsp. nebraskensis, can cause considerable losses in maize (Zea mays) production. Diagnosis of Goss's wilt currently is based on symptomology and identification of C. michiganensis subsp. nebraskensis, following isolation on a semiselective medium and/or serological testing. In an effort to provide a more efficient identification method, a loop-mediated amplification (LAMP) assay was developed to detect the tripartite ATP-independent periplasmic (TRAP)-type C4-dicarboxylate transport system large permease component and tested using strains of C. michiganensis subsp. nebraskensis, all other C. michiganensis subspecies and several genera of nontarget bacteria. Only strains of C. michiganensis subsp. nebraskensis reacted positively with the LAMP assay. The LAMP assay was then used to identify bacterial isolates from diseased maize. 16S rDNA and dnaA sequence analyses were used to confirm the identity of the maize isolates and validate assay specificity. The Cmm ImmunoStrip assay was included as a presumptive identification test of C. michiganensis subsp. nebraskensis at the species level. The Cmn-LAMP assay was further tested using symptomatic leaf tissue. The Cmn-LAMP assay was run in a hand-held real-time monitoring device (SMART-DART) and performed equally to in-lab quantitative polymerase chain reaction equipment. The Cmn-LAMP assay accurately identified C. michiganensis subsp. nebraskensis and has potential as a field test. The targeted sequence also has potential application in other molecular detection platforms.

Campylobacter fetus subsp. jejuni in poultry reared under different management systems in Nigeria.

PubMed

Adekeye, J O; Abdu, P A; Bawa, E K

1989-01-01

Cloacal swabs from 487 live birds in 36 flocks and 70 poultry carcasses were cultured for Campylobacter fetus subsp. jejuni. It was isolated from 12.3% of the birds in 19 flocks. Chickens, turkeys, and guinea fowl differed from one another in isolation rates of the organism. Management system affected its occurrence, and only 7.1% of eviscerated carcasses yielded it. It was concluded that bird species, management system, and immersing slaughtered poultry in boiling water before dressing affect recovery of C. fetus subsp. jejuni from live birds and carcasses.

Lactobacillus plantarum subsp. argentoratensis subsp. nov., isolated from vegetable matrices.

PubMed

Bringel, Françoise; Castioni, Anna; Olukoya, Daniel K; Felis, Giovanna E; Torriani, Sandra; Dellaglio, Franco

2005-07-01

Fourteen strains isolated from vegetable sources and identified as belonging to Lactobacillus plantarum presented an atypical pattern of amplification with a species-specific multiplex-PCR assay. Phylogenetic analysis of two protein-encoding genes, recA (encoding the recombinase A protein) and cpn60 (encoding the GroEL chaperonin), as well as phenotypic and genomic traits revealed a homogeneous group of very closely related strains for which subspecies status is proposed, with the name Lactobacillus plantarum subsp. argentoratensis. The type strain is DKO 22(T) (=CIP 108320(T)=DSM 16365(T)).

[The occurrence of campylobacter fetus subsp. jejuni and Salmonella bacteria in some wild birds (author's transl)].

PubMed

Rosef, O

1981-12-01

An investigation was carried out into the occurrence of Campylobacter fetus subsp. jejuni and Salmonella species in some wild birds. A total of 129 birds was examined, consisting of 71 pigeons, 54 seagulls, three crows and one raven. Campylobacter bacteria were isolated from 32 birds (24.8%), of which three were pigeons, 27 seagulls and two were crows. Of the 27 Campylobacter strains isolated from seagulls, four had the biochemical characteristics of the NARTC biotype described by Skirrow and Benjamin, seven were grouped as Campylobacter coli biotype and 16 as the biotype of Campylobacter jejuni. All the strains isolated from crows and pigeons had the biochemical characteristics of Campylobacter jejuni biotypes. Salmonella bacteria were isolated from the intestinal contents of two of the 54 seagulls (3.7%), and were identified serologically as Salmonella indiana and Salmonella typhimurium. One seagull was found to be a carrier of both Campylobacter fetus subsp. jejuni and Salmonella typhimurium. A correlation could not be demonstrated between the occurrence of Salmonella bacteria and Campylobacter fetus subsp. jejuni.

Lactobacillus delbrueckii subsp. jakobsenii subsp. nov., isolated from dolo wort, an alcoholic fermented beverage in Burkina Faso.

PubMed

Adimpong, David B; Nielsen, Dennis S; Sørensen, Kim I; Vogensen, Finn K; Sawadogo-Lingani, Hagrétou; Derkx, Patrick M F; Jespersen, Lene

2013-10-01

Lactobacillus delbrueckii is divided into five subspecies based on phenotypic and genotypic differences. A novel isolate, designated ZN7a-9(T), was isolated from malted sorghum wort used for making an alcoholic beverage (dolo) in Burkina Faso. The results of 16S rRNA gene sequencing, DNA-DNA hybridization and peptidoglycan cell-wall structure type analyses indicated that it belongs to the species L. delbrueckii. The genome sequence of isolate ZN7a-9(T) was determined by Illumina-based sequencing. Multilocus sequence typing (MLST) and split-decomposition analyses were performed on seven concatenated housekeeping genes obtained from the genome sequence of strain ZN7a-9(T) together with 41 additional L. delbrueckii strains. The results of the MLST and split-decomposition analyses could not establish the exact subspecies of L. delbrueckii represented by strain ZN7a-9(T) as it clustered with L. delbrueckii strains unassigned to any of the recognized subspecies of L. delbrueckii. Strain ZN7a-9(T) additionally differed from the recognized type strains of the subspecies of L. delbrueckii with respect to its carbohydrate fermentation profile. In conclusion, the cumulative results indicate that strain ZN7a-9(T) represents a novel subspecies of L. delbrueckii closely related to Lactobacillus delbrueckii subsp. lactis and Lactobacillus delbrueckii subsp. delbrueckii for which the name Lactobacillus delbrueckii subsp. jakobsenii subsp. nov. is proposed. The type strain is ZN7a-9(T) = DSM 26046(T) = LMG 27067(T).

First description of atypical furunculosis in freshwater farmed Atlantic salmon, Salmo salar L., in Chile.

PubMed

Godoy, M; Gherardelli, V; Heisinger, A; Fernández, J; Olmos, P; Ovalle, L; Ilardi, P; Avendaño-Herrera, R

2010-05-01

We report the first isolation, identification and characterization of a group of Chilean strains of atypical Aeromonas salmonicida isolated from freshwater farmed Atlantic salmon, Salmo salar. Affected fish showed superficial ulcers and pale liver with or without petechial haemorrhages. Outbreaks of the disease occurred in two farms in the south of Chile about 2200 km apart. Five strains were isolated in pure culture and identified by serological assays and immunofluorescence tests as belonging to Aeromonas salmonicida. Although the bacterial isolates were phenotypically homogeneous, minor differences with the reference strain A. salmonicida subsp. salmonicida ATCC 33658 were noted. Three specific primer sets and partial 16S rRNA gene sequencing allowed the identification of the Chilean isolates as atypical A. salmonicida, with A. salmonicida subsp. achromogenes and A. salmonicida subsp. masoucida as their closest relatives (100% sequence similarity). Molecular typing indicated that the atypical isolates belong to two genetic groups that were associated with the geographical origin.

Multilocus sequence typing scheme versus pulsed-field gel electrophoresis for typing Mycobacterium abscessus isolates.

PubMed

Machado, Gabriel Esquitini; Matsumoto, Cristianne Kayoko; Chimara, Erica; Duarte, Rafael da Silva; de Freitas, Denise; Palaci, Moises; Hadad, David Jamil; Lima, Karla Valéria Batista; Lopes, Maria Luiza; Ramos, Jesus Pais; Campos, Carlos Eduardo; Caldas, Paulo César; Heym, Beate; Leão, Sylvia Cardoso

2014-08-01

Outbreaks of infections by rapidly growing mycobacteria following invasive procedures, such as ophthalmological, laparoscopic, arthroscopic, plastic, and cardiac surgeries, mesotherapy, and vaccination, have been detected in Brazil since 1998. Members of the Mycobacterium chelonae-Mycobacterium abscessus group have caused most of these outbreaks. As part of an epidemiological investigation, the isolates were typed by pulsed-field gel electrophoresis (PFGE). In this project, we performed a large-scale comparison of PFGE profiles with the results of a recently developed multilocus sequence typing (MLST) scheme for M. abscessus. Ninety-three isolates were analyzed, with 40 M. abscessus subsp. abscessus isolates, 47 M. abscessus subsp. bolletii isolates, and six isolates with no assigned subspecies. Forty-five isolates were obtained during five outbreaks, and 48 were sporadic isolates that were not associated with outbreaks. For MLST, seven housekeeping genes (argH, cya, glpK, gnd, murC, pta, and purH) were sequenced, and each isolate was assigned a sequence type (ST) from the combination of obtained alleles. The PFGE patterns of DraI-digested DNA were compared with the MLST results. All isolates were analyzable by both methods. Isolates from monoclonal outbreaks showed unique STs and indistinguishable or very similar PFGE patterns. Thirty-three STs and 49 unique PFGE patterns were identified among the 93 isolates. The Simpson's index of diversity values for MLST and PFGE were 0.69 and 0.93, respectively, for M. abscessus subsp. abscessus and 0.96 and 0.97, respectively, for M. abscessus subsp. bolletii. In conclusion, the MLST scheme showed 100% typeability and grouped monoclonal outbreak isolates in agreement with PFGE, but it was less discriminative than PFGE for M. abscessus. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Draft Genome Sequences of 18 Salmonella enterica subsp. enterica Serovar Oranienburg Strains Isolated from Rivers in Northwestern Mexico.

PubMed

Casteñeda-Ruelas, Gloria M; Carreón-Gaxiola, César; Castelán-Sánchez, Hugo G; Acatzi-Silva, Abraham; Romero-Martínez, Salvador; García-Molina, Alejandra; Jiménez-Edeza, Maribel

2017-03-09

Salmonella enterica subsp. enterica serovar Oranienburg is recognized as a foodborne pathogen widely distributed in the environment. Here, we report 18 draft genomes of S  Oranienburg strains isolated from rivers in the northwestern region of Mexico. Copyright © 2017 Casteñeda-Ruelas et al.

Thermophilic bacteria in Moroccan hot springs, salt marshes and desert soils.

PubMed

Aanniz, Tarik; Ouadghiri, Mouna; Melloul, Marouane; Swings, Jean; Elfahime, Elmostafa; Ibijbijen, Jamal; Ismaili, Mohamed; Amar, Mohamed

2015-06-01

The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240) thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5%) represented by B. licheniformis (119), B. aerius (44), B. sonorensis (33), B. subtilis (subsp. spizizenii (2) and subsp. inaquosurum (6)), B. amyloliquefaciens (subsp. amyloliquefaciens (4) and subsp. plantarum (4)), B. tequilensis (3), B. pumilus (3) and Bacillus sp. (19). Only six isolates (2.5%) belonged to the genus Aeribacillus represented by A. pallidus (4) and Aeribacillus sp. (2). In this study, B. aerius and B. tequilensis are described for the first time as thermophilic bacteria. Moreover, 71.25%, 50.41% and 5.41% of total strains exhibited high amylolytic, proteolytic or cellulolytic activity respectively.

Thermophilic bacteria in Moroccan hot springs, salt marshes and desert soils

PubMed Central

Aanniz, Tarik; Ouadghiri, Mouna; Melloul, Marouane; Swings, Jean; Elfahime, Elmostafa; Ibijbijen, Jamal; Ismaili, Mohamed; Amar, Mohamed

2015-01-01

The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240) thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5%) represented by B. licheniformis (119), B. aerius (44), B. sonorensis (33), B. subtilis (subsp. spizizenii (2) and subsp. inaquosurum (6)), B. amyloliquefaciens (subsp. amyloliquefaciens (4) and subsp. plantarum (4)), B. tequilensis (3), B. pumilus (3) and Bacillus sp. (19). Only six isolates (2.5%) belonged to the genus Aeribacillus represented by A. pallidus (4) and Aeribacillus sp. (2). In this study, B. aerius and B. tequilensis are described for the first time as thermophilic bacteria. Moreover, 71.25%, 50.41% and 5.41% of total strains exhibited high amylolytic, proteolytic or cellulolytic activity respectively. PMID:26273259

Comparative Genomics of Campylobacter fetus from Reptiles and Mammals Reveals Divergent Evolution in Host-Associated Lineages

PubMed Central

Gilbert, Maarten J.; Miller, William G.; Yee, Emma; Zomer, Aldert L.; van der Graaf-van Bloois, Linda; Fitzgerald, Collette; Forbes, Ken J.; Méric, Guillaume; Sheppard, Samuel K.; Wagenaar, Jaap A.; Duim, Birgitta

2016-01-01

Campylobacter fetus currently comprises three recognized subspecies, which display distinct host association. Campylobacter fetus subsp. fetus and C. fetus subsp. venerealis are both associated with endothermic mammals, primarily ruminants, whereas C. fetus subsp. testudinum is primarily associated with ectothermic reptiles. Both C. fetus subsp. testudinum and C. fetus subsp. fetus have been associated with severe infections, often with a systemic component, in immunocompromised humans. To study the genetic factors associated with the distinct host dichotomy in C. fetus, whole-genome sequencing and comparison of mammal- and reptile-associated C. fetus was performed. The genomes of C. fetus subsp. testudinum isolated from either reptiles or humans were compared with elucidate the genetic factors associated with pathogenicity in humans. Genomic comparisons showed conservation of gene content and organization among C. fetus subspecies, but a clear distinction between mammal- and reptile-associated C. fetus was observed. Several genomic regions appeared to be subspecies specific, including a putative tricarballylate catabolism pathway, exclusively present in C. fetus subsp. testudinum strains. Within C. fetus subsp. testudinum, sapA, sapB, and sapAB type strains were observed. The recombinant locus iamABC (mlaFED) was exclusively associated with invasive C. fetus subsp. testudinum strains isolated from humans. A phylogenetic reconstruction was consistent with divergent evolution in host-associated strains and the existence of a barrier to lateral gene transfer between mammal- and reptile-associated C. fetus. Overall, this study shows that reptile-associated C. fetus subsp. testudinum is genetically divergent from mammal-associated C. fetus subspecies. PMID:27333878

Homologous Recombination and Xylella fastidiosa Host-Pathogen Associations in South America.

PubMed

Coletta-Filho, Helvécio D; Francisco, Carolina S; Lopes, João R S; Muller, Christiane; Almeida, Rodrigo P P

2017-03-01

Homologous recombination affects the evolution of bacteria such as Xylella fastidiosa, a naturally competent plant pathogen that requires insect vectors for dispersal. This bacterial species is taxonomically divided into subspecies, with phylogenetic clusters within subspecies that are host specific. One subspecies, pauca, is primarily limited to South America, with the exception of recently reported strains in Europe and Costa Rica. Despite the economic importance of X. fastidiosa subsp. pauca in South America, little is known about its genetic diversity. Multilocus sequence typing (MLST) has previously identified six sequence types (ST) among plant samples collected in Brazil (both subsp. pauca and multiplex). Here, we report on a survey of X. fastidiosa genetic diversity (MLST based) performed in six regions in Brazil and two in Argentina, by sampling five different plant species. In addition to the six previously reported ST, seven new subsp. pauca and two new subsp. multiplex ST were identified. The presence of subsp. multiplex in South America is considered to be the consequence of a single introduction from its native range in North America more than 80 years ago. Different phylogenetic approaches clustered the South American ST into four groups, with strains infecting citrus (subsp. pauca); coffee and olive (subsp. pauca); coffee, hibiscus, and plum (subsp. pauca); and plum (subsp. multiplex). In areas where these different genetic clusters occurred sympatrically, we found evidence of homologous recombination in the form of bidirectional allelic exchange between subspp. pauca and multiplex. In fact, the only strain of subsp. pauca isolated from a plum host had an allele that originated from subsp. multiplex. These signatures of bidirectional homologous recombination between endemic and introduced ST indicate that gene flow occurs in short evolutionary time frames in X. fastidiosa, despite the ecological isolation (i.e., host plant species) of genotypes.

Multilocus sequence typing of Xylella fastidiosa causing Pierce's disease and oleander leaf scorch in the United States.

PubMed

Yuan, Xiaoli; Morano, Lisa; Bromley, Robin; Spring-Pearson, Senanu; Stouthamer, Richard; Nunney, Leonard

2010-06-01

Using a modified multilocus sequence typing (MLST) scheme for the bacterial plant pathogen Xylella fastidiosa based on the same seven housekeeping genes employed in a previously published MLST, we studied the genetic diversity of two subspecies, X. fastidiosa subsp. fastidiosa and X. fastidiosa subsp. sandyi, which cause Pierce's disease and oleander leaf scorch, respectively. Typing of 85 U.S. isolates (plus one from northern Mexico) of X. fastidiosa subsp. fastidiosa from 15 different plant hosts and 21 isolates of X. fastidiosa subsp. sandyi from 4 different hosts in California and Texas supported their subspecific status. Analysis using the MLST genes plus one cell-surface gene showed no significant genetic differentiation based on geography or host plant within either subspecies. Two cases of homologous recombination (with X. fastidiosa subsp. multiplex, the third U.S. subspecies) were detected in X. fastidiosa subsp. fastidiosa. Excluding recombination, MLST site polymorphism in X. fastidiosa subsp. fastidiosa (0.048%) and X. fastidiosa subsp. sandyi (0.000%) was substantially lower than in X. fastidiosa subsp. multiplex (0.240%), consistent with the hypothesis that X. fastidiosa subspp. fastidiosa and sandyi were introduced into the United States (probably just prior to 1880 and 1980, respectively). Using whole-genome analysis, we showed that MLST is more effective at genetic discrimination at the specific and subspecific level than other typing methods applied to X. fastidiosa. Moreover, MLST is the only technique effective in detecting recombination.

Comparative Genomic Analysis of a Clinical Isolate of Klebsiella quasipneumoniae subsp. similipneumoniae, a KPC-2 and OKP-B-6 Beta-Lactamases Producer Harboring Two Drug-Resistance Plasmids from Southeast Brazil

PubMed Central

Nicolás, Marisa F.; Ramos, Pablo Ivan Pereira; Marques de Carvalho, Fabíola; Camargo, Dhian R. A.; de Fátima Morais Alves, Carlene; Loss de Morais, Guilherme; Almeida, Luiz G. P.; Souza, Rangel C.; Ciapina, Luciane P.; Vicente, Ana C. P.; Coimbra, Roney S.; Ribeiro de Vasconcelos, Ana T.

2018-01-01

The aim of this study was to unravel the genetic determinants responsible for multidrug (including carbapenems) resistance and virulence in a clinical isolate of Klebsiella quasipneumoniae subsp. similipneumoniae by whole-genome sequencing and comparative analyses. Eighty-three clinical isolates initially identified as carbapenem-resistant K. pneumoniae were collected from nosocomial infections in southeast Brazil. After RAPD screening, the KPC-142 isolate, showing the most divergent DNA pattern, was selected for complete genome sequencing in an Illumina HiSeq 2500 instrument. Reads were assembled into scaffolds, gaps between scaffolds were resolved by in silico gap filling and extensive bioinformatics analyses were performed, using multiple comparative analysis tools and databases. Genome sequencing allowed to correct the classification of the KPC-142 isolate as K. quasipneumoniae subsp. similipneumoniae. To the best of our knowledge this is the first complete genome reported to date of a clinical isolate of this subspecies harboring both class A beta-lactamases KPC-2 and OKP-B-6 from South America. KPC-142 has one 5.2 Mbp chromosome (57.8% G+C) and two plasmids: 190 Kbp pKQPS142a (50.7% G+C) and 11 Kbp pKQPS142b (57.3% G+C). The 3 Kbp region in pKQPS142b containing the blaKPC−2 was found highly similar to that of pKp13d of K. pneumoniae Kp13 isolated in Southern Brazil in 2009, suggesting the horizontal transfer of this resistance gene between different species of Klebsiella. KPC-142 additionally harbors an integrative conjugative element ICEPm1 that could be involved in the mobilization of pKQPS142b and determinants of resistance to other classes of antimicrobials, including aminoglycoside and silver. We present the completely assembled genome sequence of a clinical isolate of K. quasipneumoniae subsp. similipneumoniae, a KPC-2 and OKP-B-6 beta-lactamases producer and discuss the most relevant genomic features of this important resistant pathogen in comparison to several strains belonging to K. quasipneumoniae subsp. similipneumoniae (phylogroup II-B), K. quasipneumoniae subsp. quasipneumoniae (phylogroup II-A), K. pneumoniae (phylogroup I), and K. variicola (phylogroup III). Our study contributes to the description of the characteristics of a novel K. quasipneumoniae subsp. similipneumoniae strain circulating in South America that currently represent a serious potential risk for nosocomial settings. PMID:29503635

Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Infantis Strain SPE101, Isolated from a Chronic Human Infection

PubMed Central

Iriarte, Andrés; Giner-Lamia, Joaquín; Betancor, Laura; Astocondor, Lizeth; Cestero, Juan J.; Ochoa, Theresa; García, Coralith; Puente, José L.; Chabalgoity, José A.

2017-01-01

ABSTRACT We report a 4.99-Mb draft genome sequence of Salmonella enterica subsp. enterica serovar Infantis strain SPE101, isolated from feces of a 5-month-old breast-fed female showing diarrhea associated with severe dehydration and malnutrition. The infection prolonged for 6 months despite antibiotic treatment. PMID:28729277

Complete genomic sequence of Campylobacter jejuni subsp. jejuni HS:19 strain RM1285 that was isolated from packaged chicken

USDA-ARS?s Scientific Manuscript database

Poultry products serve as the main source of Campylobacter jejuni subsp. jejuni (Cjj) infections in humans. Cjj infections are a leading cause of foodborne gastroenteritis and are a prevalent antecedent to Guillain-Barré syndrome (GBS). This study describes the genome of Cjj HS:19 strain RM1285 isol...

Genome Sequence of Streptococcus phocae subsp. salmonis Strain C-4T, Isolated from Atlantic Salmon (Salmo salar)

PubMed Central

Suarez, Rudy; Lazo, Eduardo; Bravo, Diego; Llegues, Katerina O.; Romalde, Jesús L.; Godoy, Marcos G.

2014-01-01

Streptococcus phocae subsp. salmonis is a fish pathogen that has an important impact on the Chilean salmon industry. Here, we report the genome sequence of the type strain C-4T isolated from Atlantic salmon (Salmo salar), showing a number of interesting features and genes related to its possible virulence factors. PMID:25502668

Draft Genome Sequence of Lactobacillus delbrueckii subsp. bulgaricus CRL871, a Folate-Producing Strain Isolated from a Northwestern Argentinian Yogurt.

PubMed

Laiño, Jonathan Emiliano; Hebert, Elvira María; Savoy de Giori, Graciela; LeBlanc, Jean Guy

2015-06-25

Lactobacillus delbrueckii subsp. bulgaricus CRL871 is the first strain of L. delbrueckii subsp. bulgaricus reported as a folate-producing strain. We report the draft genome sequence of L. delbrueckii subsp. bulgaricus CRL871 (2,063,981 bp, G+C content of 49.1%). This strain is of great biotechnological importance to the dairy industry because it constitutes an alternative to folic acid fortification. Copyright © 2015 Laiño et al.

Escherichia coli, Salmonella, and Mycobacterium avium subsp. paratuberculosis in wild European starlings at a Kansas cattle feedlot.

PubMed

Gaukler, Shannon M; Linz, George M; Sherwood, Julie S; Dyer, Neil W; Bleier, William J; Wannemuehler, Yvonne M; Nolan, Lisa K; Logue, Catherine M

2009-12-01

The prevalence of Escherichia coli, Salmonella spp., and Mycobacterium avium subsp. paratuberculosis isolated from the feces of wild European starlings (Sturnus vulgaris) humanely trapped at a feedlot in central Kansas was assessed. All E. coli and Salmonella isolates recovered were tested for antimicrobial susceptibility using National Antimicrobial Resistance Monitoring System panels and the E. coli isolates were classified as to their content of genes associated with pathogenic E. coli of birds and cattle, including cvaC, iroN2, ompTp, hlyF2, eitC, iss, iutA, ireA, papC, stxI, stxII, sta, K99, F41, and eae. Escherichia coli O157:H7 and Mycobacterium avium subsp. paratuberculosis were not detected and Salmonella was isolated from only three samples, two of which displayed antimicrobial resistance. Approximately half of the E. coli isolates were resistant to antimicrobial agents with 96% showing resistance to tetracycline. Only one isolate was positive for a single gene associated with bovine pathogenic E. coli. An interesting finding of this study was that 5% of the E. coli isolates tested met the criteria established for identification as avian pathogenic E. coli (APEC). Thus these findings suggest that starlings are not a significant source of Salmonella spp., Mycobacterium avium subsp. paratuberculosis, E. coli O157, or other shiga toxin-producing E. coli in this feedlot. However, they may have the potential to spread APEC, an important pathogen of poultry and a potential pathogen to human beings.

Comparative Genomics of Campylobacter fetus from Reptiles and Mammals Reveals Divergent Evolution in Host-Associated Lineages.

PubMed

Gilbert, Maarten J; Miller, William G; Yee, Emma; Zomer, Aldert L; van der Graaf-van Bloois, Linda; Fitzgerald, Collette; Forbes, Ken J; Méric, Guillaume; Sheppard, Samuel K; Wagenaar, Jaap A; Duim, Birgitta

2016-07-02

Campylobacter fetus currently comprises three recognized subspecies, which display distinct host association. Campylobacter fetus subsp. fetus and C fetus subsp. venerealis are both associated with endothermic mammals, primarily ruminants, whereas C fetus subsp. testudinum is primarily associated with ectothermic reptiles. Both C. fetus subsp. testudinum and C. fetus subsp. fetus have been associated with severe infections, often with a systemic component, in immunocompromised humans. To study the genetic factors associated with the distinct host dichotomy in C. fetus, whole-genome sequencing and comparison of mammal- and reptile-associated C fetus was performed. The genomes of C fetus subsp. testudinum isolated from either reptiles or humans were compared with elucidate the genetic factors associated with pathogenicity in humans. Genomic comparisons showed conservation of gene content and organization among C fetus subspecies, but a clear distinction between mammal- and reptile-associated C fetus was observed. Several genomic regions appeared to be subspecies specific, including a putative tricarballylate catabolism pathway, exclusively present in C fetus subsp. testudinum strains. Within C fetus subsp. testudinum, sapA, sapB, and sapAB type strains were observed. The recombinant locus iamABC (mlaFED) was exclusively associated with invasive C fetus subsp. testudinum strains isolated from humans. A phylogenetic reconstruction was consistent with divergent evolution in host-associated strains and the existence of a barrier to lateral gene transfer between mammal- and reptile-associated C fetus Overall, this study shows that reptile-associated C fetus subsp. testudinum is genetically divergent from mammal-associated C fetus subspecies. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Lactobacillus delbrueckii subsp. sunkii subsp. nov., isolated from sunki, a traditional Japanese pickle.

PubMed

Kudo, Yuko; Oki, Kaihei; Watanabe, Koichi

2012-11-01

Although four strains of bacteria isolated from sunki, a traditional Japanese, non-salted pickle, were initially identified as Lactobacillus delbrueckii, the molecular and phenotypic characteristics of the strains did not match those of any of the four recognized subspecies of L. delbrueckii. Together, the results of phenotypic characterization, DNA-DNA hybridizations (in which the relatedness values between the novel strains and type strains of the recognized subspecies of L. delbrueckii were all >88.7%) and 16S rRNA gene sequence, amplified fragment length polymorphism (AFLP) and whole-cell MALDI-TOF/MS spectral pattern analyses indicated that the four novel strains represented a single, novel subspecies, for which the name Lactobacillus delbrueckii subsp. sunkii subsp. nov. is proposed. The type strain is YIT 11221(T) (=JCM 17838(T) =DSM 24966(T)).

Local genetic diversity of Xanthomonas citri subsp. citri in citrus orchards in northwest Paraná state, Brazil

USDA-ARS?s Scientific Manuscript database

Xanthomonas citri subsp. citri, causal agent of Asiatic citrus canker, is an important pathogen of citrus in Brazil and elsewhere. The genetic diversity of X. citri subsp. citri pathtype ‘A’ has not been studied in Brazil at a local scale (up to 300 km). A total of 40 isolates were collected from le...

Quick detection of Leifsonia xyli subsp. xyli by PCR and necleotide sequence analysis of PCR amplicons from Chinese Leifsonia xyli subsp. xyli isolates

USDA-ARS?s Scientific Manuscript database

A quick polymerase chain reaction (PCR) assay was developed for the detection of Leifsonia xyli subsp. xyli (Lxx), the bacterial causal agent of ratoon stunting disease (RSD) of sugarcane, in crude juice samples from stalks. After removal of abiotic impurities and large molecular weight microorgani...

Phylogenetic Analysis and Polyphasic Characterization of Clavibacter michiganensis Strains Isolated from Tomato Seeds Reveal that Nonpathogenic Strains Are Distinct from C. michiganensis subsp. michiganensis

PubMed Central

Durand, Karine; Orgeur, Geoffrey; Balidas, Samuel; Fricot, Céline; Bonneau, Sophie; Quillévéré, Anne; Audusseau, Corinne; Olivier, Valérie; Grimault, Valérie; Mathis, René

2012-01-01

The genus Clavibacter comprises one species and five subspecies of plant-pathogenic bacteria, four of which are classified as quarantine organisms due to the high economic threat they pose. Clavibacter michiganensis subsp. michiganensis is one of the most important pathogens of tomato, but the recommended diagnostic tools are not satisfactory due to false-negative and/or -positive results. To provide a robust analysis of the genetic relatedness among a worldwide collection of C. michiganensis subsp. michiganensis strains, relatives (strains from the four other C. michiganensis subspecies), and nonpathogenic Clavibacter-like strains isolated from tomato, we performed multilocus sequence-based analysis and typing (MLSA and MLST) based on six housekeeping genes (atpD, dnaK, gyrB, ppK, recA, and rpoB). We compared this “framework” with phenotypic and genotypic characteristics such as pathogenicity on tomato, reaction to two antisera by immunofluorescence and to five PCR identification tests, and the presence of four genes encoding the main C. michiganensis subsp. michiganensis pathogenicity determinants. We showed that C. michiganensis subsp. michiganensis is monophyletic and is distinct from its closest taxonomic neighbors. The nonpathogenic Clavibacter-like strains were identified as C. michiganensis using 16S rRNA gene sequencing. These strains, while cross-reacting with C. michiganensis subsp. michiganensis identification tools, are phylogenetically distinct from the pathogenic strains but belong to the C. michiganensis clade. C. michiganensis subsp. michiganensis clonal complexes linked strains from highly diverse geographical origins and also strains isolated over long periods of time in the same location. This illustrates the importance of seed transmission in the worldwide dispersion of this pathogen and its survival and adaptation abilities in a new environment once introduced. PMID:23001675

Phylogenetic analysis and polyphasic characterization of Clavibacter michiganensis strains isolated from tomato seeds reveal that nonpathogenic strains are distinct from C. michiganensis subsp. michiganensis.

PubMed

Jacques, Marie-Agnès; Durand, Karine; Orgeur, Geoffrey; Balidas, Samuel; Fricot, Céline; Bonneau, Sophie; Quillévéré, Anne; Audusseau, Corinne; Olivier, Valérie; Grimault, Valérie; Mathis, René

2012-12-01

The genus Clavibacter comprises one species and five subspecies of plant-pathogenic bacteria, four of which are classified as quarantine organisms due to the high economic threat they pose. Clavibacter michiganensis subsp. michiganensis is one of the most important pathogens of tomato, but the recommended diagnostic tools are not satisfactory due to false-negative and/or -positive results. To provide a robust analysis of the genetic relatedness among a worldwide collection of C. michiganensis subsp. michiganensis strains, relatives (strains from the four other C. michiganensis subspecies), and nonpathogenic Clavibacter-like strains isolated from tomato, we performed multilocus sequence-based analysis and typing (MLSA and MLST) based on six housekeeping genes (atpD, dnaK, gyrB, ppK, recA, and rpoB). We compared this "framework" with phenotypic and genotypic characteristics such as pathogenicity on tomato, reaction to two antisera by immunofluorescence and to five PCR identification tests, and the presence of four genes encoding the main C. michiganensis subsp. michiganensis pathogenicity determinants. We showed that C. michiganensis subsp. michiganensis is monophyletic and is distinct from its closest taxonomic neighbors. The nonpathogenic Clavibacter-like strains were identified as C. michiganensis using 16S rRNA gene sequencing. These strains, while cross-reacting with C. michiganensis subsp. michiganensis identification tools, are phylogenetically distinct from the pathogenic strains but belong to the C. michiganensis clade. C. michiganensis subsp. michiganensis clonal complexes linked strains from highly diverse geographical origins and also strains isolated over long periods of time in the same location. This illustrates the importance of seed transmission in the worldwide dispersion of this pathogen and its survival and adaptation abilities in a new environment once introduced.

Specific Detection of Clavibacter michiganensis subsp. sepedonicus by Amplification of Three Unique DNA Sequences Isolated by Subtraction Hybridization.

PubMed

Mills, D; Russell, B W; Hanus, J W

1997-08-01

ABSTRACT Three single-copy, unique DNA fragments, designated Cms50, Cms72, and Cms85, were isolated from strain CS3 of Clavibacter michiganensis subsp. sepedonicus by subtraction hybridization using driver DNA from C. michiganensis subsp. insidiosus, C. michiganensis subsp. michiganensis, and Rhodococcus facians. Radio-labeled probes made of these fragments and used in Southern blot analysis revealed each to be absolutely specific to all North American C. michiganensis subsp. sepedonicus strains tested, including plasmidless and nonmucoid strains. The probes have no homology with genomic DNA from related C. michiganensis subspecies insidiosus, michiganensis, and tessellarius, nor with DNA from 11 additional bacterial species and three unidentified strains, some of which have been previously reported to display cross-reactivity with C. michiganensis subsp. sepedonicus-specific antisera. The three fragments shared no homology, and they appeared to be separated from each other by at least 20 kbp in the CS3 genome. Internal primer sets permitted amplification of each fragment by the polymerase chain reaction (PCR) only from C. michiganensis subsp. sepedonicus DNA. In a PCR-based sensitivity assay using a primer set that amplifies Cms85, the lowest level of detection of C. michiganensis subsp. sepedonicus was 100 CFU per milliliter when cells were added to potato core fluid. Erroneous results that may arise from PCR artifacts and mutational events are, therefore, minimized by the redundancy of the primer sets, and the products should be verifiable with unique capture probes in sequence-based detection systems.

Draft Genome Sequences of 20 Salmonella enterica subsp. enterica Serovar Typhimurium Strains Isolated from Swine in Santa Catarina, Brazil.

PubMed

Seribelli, Amanda Aparecida; Frazão, Miliane Rodrigues; Gonzales, Júlia Cunha; Cao, Guojie; Leon, Maria Sanchez; Kich, Jalusa Deon; Allard, Marc William; Falcão, Juliana Pfrimer

2018-04-19

Salmonellosis is a disease with a high incidence worldwide, and Salmonella enterica subsp. enterica serovar Typhimurium is one of the most clinically important serovars. We report here the draft genome sequences of 20 S. Typhimurium strains isolated from swine in Santa Catarina, Brazil. These draft genomes will improve our understanding of S. Typhimurium in Brazil.

Draft Genome Sequence of Staphylococcus carnosus subsp. utilis LTH 7013, Isolated from South Tyrolean Ham.

PubMed

Müller, Anne; Huptas, Christopher; Wenning, Mareike; Schmidt, Herbert; Weiss, Agnes

2015-05-14

Staphylococcus carnosus is used as a starter culture in meat fermentation, where it contributes to color formation and produces aromatic compounds. Here, we report the first draft genome sequence of an S. carnosus subsp. utilis strain, LTH 7013, isolated from South Tyrolean ham, with potential application as a starter culture. Copyright © 2015 Müller et al.

Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Infantis Strain SPE101, Isolated from a Chronic Human Infection.

PubMed

Iriarte, Andrés; Giner-Lamia, Joaquín; Silva, Claudia; Betancor, Laura; Astocondor, Lizeth; Cestero, Juan J; Ochoa, Theresa; García, Coralith; Puente, José L; Chabalgoity, José A; García-Del Portillo, Francisco

2017-07-20

We report a 4.99-Mb draft genome sequence of Salmonella enterica subsp. enterica serovar Infantis strain SPE101, isolated from feces of a 5-month-old breast-fed female showing diarrhea associated with severe dehydration and malnutrition. The infection prolonged for 6 months despite antibiotic treatment. Copyright © 2017 Iriarte et al.

Comparison of the acidifying activity of Lactococcus lactis subsp. lactis strains isolated from goat's milk and Valdeteja cheese.

PubMed

Alonso-Calleja, C; Carballo, J; Capita, R; Bernardo, A; García-López, M L

2002-01-01

This work was carried out to study the acid production by Lactococcus lactis subsp. lactis strains isolated from goat's milk and goat cheese (Valdeteja variety) in order to select a suitable starter culture for industrial goat cheese manufacturing. The titrable acidity of 45 Lactococcus lactis subsp. lactis strains isolated from a home-made batch of Valdeteja cheese with excellent sensory characteristics was measured over a period of 18 h. The strains were divided into two groups depending on the acid production rate: 20 fast acid producer (F) strains and 25 slow acid producer (S) strains. The kinetic parameters (lag phase, maximum acid production rate and value of upper asymptote curve) of the acid production curves for F and S strains were significantly (P < 0.001) different. Significant (P < 0.001) differences between titrable acidity of F and S strains were observed after the second hour of incubation. An F strain acetoin producer (Lactococcus lactis subsp. lactis 470Ch2) was selected as autochthonous starter culture for industrial Valdeteja goat cheese manufacturing.

Virulence Gene Pool Detected in Bovine Group C Streptococcus dysgalactiae subsp. dysgalactiae Isolates by Use of a Group A S. pyogenes Virulence Microarray ▿

PubMed Central

Rato, Márcia G.; Nerlich, Andreas; Bergmann, René; Bexiga, Ricardo; Nunes, Sandro F.; Vilela, Cristina L.; Santos-Sanches, Ilda; Chhatwal, Gursharan S.

2011-01-01

A custom-designed microarray containing 220 virulence genes of Streptococcus pyogenes (group A Streptococcus [GAS]) was used to test group C Streptococcus dysgalactiae subsp. dysgalactiae (GCS) field strains causing bovine mastitis and group C or group G Streptococcus dysgalactiae subsp. equisimilis (GCS/GGS) isolates from human infections, with the latter being used for comparative purposes, for the presence of virulence genes. All bovine and all human isolates carried a fraction of the 220 genes (23% and 39%, respectively). The virulence genes encoding streptolysin S, glyceraldehyde-3-phosphate dehydrogenase, the plasminogen-binding M-like protein PAM, and the collagen-like protein SclB were detected in the majority of both bovine and human isolates (94 to 100%). Virulence factors, usually carried by human beta-hemolytic streptococcal pathogens, such as streptokinase, laminin-binding protein, and the C5a peptidase precursor, were detected in all human isolates but not in bovine isolates. Additionally, GAS bacteriophage-associated virulence genes encoding superantigens, DNase, and/or streptodornase were detected in bovine isolates (72%) but not in the human isolates. Determinants located in non-bacteriophage-related mobile elements, such as the gene encoding R28, were detected in all bovine and human isolates. Several virulence genes, including genes of bacteriophage origin, were shown to be expressed by reverse transcriptase PCR (RT-PCR). Phylogenetic analysis of superantigen gene sequences revealed a high level (>98%) of identity among genes of bovine GCS, of the horse pathogen Streptococcus equi subsp. equi, and of the human pathogen GAS. Our findings indicate that alpha-hemolytic bovine GCS, an important mastitis pathogen and considered to be a nonhuman pathogen, carries important virulence factors responsible for virulence and pathogenesis in humans. PMID:21525223

Characterization of two nisin-producing Lactococcus lactis subsp. lactis strains isolated from a commercial sauerkraut fermentation.

PubMed Central

Harris, L J; Fleming, H P; Klaenhammer, T R

1992-01-01

Two Lactococcus lactis subsp. lactis strains, NCK400 and LJH80, isolated from a commercial sauerkraut fermentation were shown to produce nisin. LJH80 was morphologically unstable and gave rise to two stable, nisin-producing (Nip+) derivatives, NCK318-2 and NCK318-3. NCK400 and derivatives of LJH80 exhibited identical morphological and metabolic characteristics, but could be distinguished on the basis of plasmid profiles and genomic hybridization patterns to a DNA probe specific for the iso-ISS1 element, IS946. NCK318-2 and NCK318-3 harbored two and three plasmids, respectively, which hybridized with IS946. Plasmid DNA was not detected in NCK400, and DNA from this strain failed to hybridize with IS946. Despite the absence of detectable plasmid DNA in NCK400, nisin-negative derivatives (NCK402 and NCK403) were isolated after repeated transfer in broth at 37 degrees C. Nisin-negative derivatives concurrently lost the ability to ferment sucrose and became sensitive to nisin. A 4-kbp HindIII fragment containing the structural gene for nisin (spaN), cloned from L. lactis subsp. lactis ATCC 11454, was used to probe genomic DNA of NCK318-2, NCK318-3, NCK400, and NCK402 digested with EcoRI or HindIII. The spaN probe hybridized to an 8.8-kbp EcoRI fragment and a 10-kbp HindIII fragment in the Nip+ sauerkraut isolates, but did not hybridize to the Nip- derivative, NCK402. A different hybridization pattern was observed when the same probe was used against Nip+ L. lactis subsp. lactis ATCC 11454 and ATCC 7962. These phenotypic and genetic data confirmed that unique Nip+ L. lactis subsp. lactis strains were isolated from fermenting sauerkraut. Images PMID:1622214

The prevalence of bovine venereal campylobacteriosis in cattle herds in the Lake Chad basin of Nigeria.

PubMed

Mshelia, Gideon Dauda; Amin, Jibrilla Dahiru; Egwu, Godwin Onyeamaechi; Woldehiwet, Zerai; Murray, Richard Donald

2012-10-01

The prevalence of bovine venereal campylobacteriosis (BVC) was investigated in the Lake Chad basin of Nigeria. Preputial washings and cervico-vaginal mucus samples were obtained from 270 cattle presenting a history of abortion and lowered fertility, kept in traditional and institutional farms. All the samples investigated were cultured using standard bacteriological technique. Campylobacter fetus was isolated from six bulls and four cows. In all cattle sampled, the isolation rates were 2.2% for C. fetus subsp. venerealis and 1.5% for C. fetus subsp. fetus; the herd and within-herd prevalence rates for C. fetus were 22.2% and 3.4%, respectively, while the overall active infectivity rate was 3.7%. BVC probably contributes to lowered fertility and abortions found in cattle in the Lake Chad basin of Nigeria, associated more with C. fetus subsp. venerealis than C. fetus subsp. fetus.

Mycoplasma detection and isolation from one-humped camels (Camelus dromedarius).

PubMed

Mederos-Iriarte, Lidia E; Poveda, José B; Poveda, Carlos G; Vega-Orellana, Orestes M; Gutiérrez, Carlos; Corbera, Juan A; Ramírez, Ana S

2014-10-01

In scientific literature, a small amount of information is found concerning mycoplasmosis in camel species. Mycoplasma (M.) arginini, Acholeplasma (A.) laidlawii, and Acholeplasma oculi have been reported to be isolated from these host species. Serologically positive results have been reported for Mycoplasma mycoides subsp. mycoides SC type, Mycoplasma capricolum subsp. capripneumoniae, and M. mycoides subsp. capri. The aims of this study were to detect, isolate, and identify mycoplasmas from camels (Camelus dromedarius). Initially, saliva and ear smears plus conjunctival and vaginal secretions were taken from five female animals, but only conjunctival secretions in three male animals, all belonging to the same farm. An unknown mycoplasma was isolated from one of the vagina samples. Additionally, another unknown and uncultured mycoplasma was detected with molecular biology in the same sample. In the second stage, 23 vaginal secretions were taken from the same farm plus another secretion from a different one. Ten isolates of the same unknown and previously isolated mycoplasma were detected, nine of them recovered from the vagina of female camels. Some mycoplasmas have been related to reproductive disorders; however, there is no evidence that the isolated mycoplasmas are related to such disorders.

Lactococcus lactis subsp. cremoris strain JFR1 attenuates Salmonella adhesion to human intestinal cells in vitro.

PubMed

Zhang, Justina Su; Guri, Anilda; Corredig, Milena; Morales-Rayas, Rocio; Hassan, Ashraf; Griffiths, Mansel; LaPointe, Gisèle

2016-12-01

Lactococcus lactis subsp. cremoris JFR1 has been studied in reduced fat cheese due to its ability to produce exopolysaccharides (EPS) in situ, contributing to improved textural and organoleptic properties. In this study, the effect of strain JFR1 on virulence gene expression and attachment of Salmonella to HT-29 human colon carcinoma cells was investigated. Overnight cultures of L. lactis subsp. cremoris JFR1 containing EPS, grown in M17 media with 0.5% glucose supplementation, decreased attachment as well as down regulated virulence gene expression in Salmonella enterica subsp. enterica when tested on HT-29 cells. However, EPS isolated from milk fermented with L. lactis subsp. cremoris JFR1 did not affect Salmonella virulence gene expression or attachment to HT-29 cells. These results suggest that EPS does not contribute to the attachment of Salmonella to human intestinal cells. However, the possibility that the isolation process may have affected the structural features of EPS cannot be ruled out. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessing the In Vitro Effectiveness of Antimicrobials against Mycoplasma mycoides subsp. mycoides Small-Colony Type To Reduce Contagious Bovine Pleuropneumonia Infection

PubMed Central

Ayling, R. D.; Bisgaard-Frantzen, S.; March, J. B.; Godinho, K.; Nicholas, R. A. J.

2005-01-01

In vitro minimum inhibitory concentrations were determined for 21 antimicrobials against 41 isolates of Mycoplasma mycoides subsp. mycoides small-colony type, the cause of contagious bovine pleuropneumonia. Of the antimicrobials used most widely in Africa, oxytetracycline and tilmicosin were effective, while the isolates were resistant to tylosin. These results provide a baseline for monitoring antimicrobial resistance. PMID:16304194

Complete genome sequence of a ciprofloxacin resistant Salmonella enterica subsp. enterica serovar Kentucky sequence of a ciprofloxacin strain, PU131, isolated from a human patient in Washington State.

USDA-ARS?s Scientific Manuscript database

A ciprofloxacin resistant (CipR) Salmonella enterica subsp. enterica serovar Kentucky ST198 has rapidly and extensively disseminated globally to become a major food-safety and public health concern. Here, we report a complete genome sequence of a CipR S. Kentucky ST198 strain PU131 isolated from a ...

Genome Sequence of Streptococcus phocae subsp. salmonis Strain C-4T, Isolated from Atlantic Salmon (Salmo salar).

PubMed

Avendaño-Herrera, Ruben; Suarez, Rudy; Lazo, Eduardo; Bravo, Diego; Llegues, Katerina O; Romalde, Jesús L; Godoy, Marcos G

2014-12-11

Streptococcus phocae subsp. salmonis is a fish pathogen that has an important impact on the Chilean salmon industry. Here, we report the genome sequence of the type strain C-4(T) isolated from Atlantic salmon (Salmo salar), showing a number of interesting features and genes related to its possible virulence factors. Copyright © 2014 Avendaño-Herrera et al.

Clavibacter michiganensis subsp. capsici subsp. nov., causing bacterial canker disease in pepper.

PubMed

Oh, Eom-Ji; Bae, Chungyun; Lee, Han-Beoyl; Hwang, In Sun; Lee, Hyok-In; Yea, Mi Chi; Yim, Kyu-Ock; Lee, Seungdon; Heu, Sunggi; Cha, Jae-Soon; Oh, Chang-Sik

2016-10-01

Clavibacter michiganensis is a Gram-stain-positive bacterium with eight subspecies. One of these subspecies is C. michiganensis subsp. michiganensis, which causes bacterial canker disease in tomato. Bacterial strains showing very similar canker disease symptoms to those of a strain originally classified as C. michiganensis have been isolated from pepper. In this paper, we reclassified strains isolated from pepper. On the basis of phylogenetic analysis with 16S rRNA gene sequences, the strains isolated from pepper were grouped in a separate clade from other subspecies of C. michiganensis. Biochemical, physiological and genetic characteristics of strain PF008T, which is the representative strain of the isolates from pepper, were examined in this study. Based on multi-locus sequence typing and other biochemical and physiological features including colony color, utilization of carbon sources and enzyme activities, strain PF008T was categorically differentiated from eight subspecies of C. michiganensis. Moreover, genome analysis showed that the DNA G+C content of strain PF008T is 73.2 %. These results indicate that PF008T is distinct from other known subspecies of C. michiganensis. Therefore, we propose a novel subspecies, C. michiganensis subsp. capsici, causing bacterial canker disease in pepper, with a type strain of PF008T (=KACC 18448T=LMG 29047T).

Antibacterial activities of naturally occurring compounds against Mycobacterium avium subsp. paratuberculosis.

PubMed

Wong, Stella Y Y; Grant, Irene R; Friedman, Mendel; Elliott, Christopher T; Situ, Chen

2008-10-01

The antibacterial activities of 18 naturally occurring compounds (including essential oils and some of their isolated constituents, apple and green tea polyphenols, and other plant extracts) against three strains of Mycobacterium avium subsp. paratuberculosis (a bovine isolate [NCTC 8578], a raw-milk isolate [806R], and a human isolate [ATCC 43015]) were evaluated using a macrobroth susceptibility testing method. M. avium subsp. paratuberculosis was grown in 4 ml Middlebrook 7H9 broth containing 10% oleic acid-albumin-dextrose-catalase, 0.05% Tween 80 (or 0.2% glycerol), and 2 microg/ml mycobactin J supplemented with five concentrations of each test compound. The changes in the optical densities of the cultures at 600 nm as a measure of CFU were recorded at intervals over an incubation period of 42 days at 37 degrees C. Six of the compounds were found to inhibit the growth of M. avium subsp. paratuberculosis. The most effective compound was trans-cinnamaldehyde, with a MIC of 25.9 microg/ml, followed by cinnamon oil (26.2 microg/ml), oregano oil (68.2 microg/ml), carvacrol (72.2 microg/ml), 2,5-dihydroxybenzaldehyde (74 microg/ml), and 2-hydroxy-5-methoxybenzaldehyde (90.4 microg/ml). With the exception of carvacrol, a phenolic compound, three of the four most active compounds are aldehydes, suggesting that the structure of the phenolic group or the aldehyde group may be important to the antibacterial activity. No difference in compound activity was observed between the three M. avium subsp. paratuberculosis strains studied. Possible mechanisms of the antimicrobial effects are discussed.

Antibacterial Activities of Naturally Occurring Compounds against Mycobacterium avium subsp. paratuberculosis▿

PubMed Central

Wong, Stella Y. Y.; Grant, Irene R.; Friedman, Mendel; Elliott, Christopher T.; Situ, Chen

2008-01-01

The antibacterial activities of 18 naturally occurring compounds (including essential oils and some of their isolated constituents, apple and green tea polyphenols, and other plant extracts) against three strains of Mycobacterium avium subsp. paratuberculosis (a bovine isolate [NCTC 8578], a raw-milk isolate [806R], and a human isolate [ATCC 43015]) were evaluated using a macrobroth susceptibility testing method. M. avium subsp. paratuberculosis was grown in 4 ml Middlebrook 7H9 broth containing 10% oleic acid-albumin-dextrose-catalase, 0.05% Tween 80 (or 0.2% glycerol), and 2 μg/ml mycobactin J supplemented with five concentrations of each test compound. The changes in the optical densities of the cultures at 600 nm as a measure of CFU were recorded at intervals over an incubation period of 42 days at 37°C. Six of the compounds were found to inhibit the growth of M. avium subsp. paratuberculosis. The most effective compound was trans-cinnamaldehyde, with a MIC of 25.9 μg/ml, followed by cinnamon oil (26.2 μg/ml), oregano oil (68.2 μg/ml), carvacrol (72.2 μg/ml), 2,5-dihydroxybenzaldehyde (74 μg/ml), and 2-hydroxy-5-methoxybenzaldehyde (90.4 μg/ml). With the exception of carvacrol, a phenolic compound, three of the four most active compounds are aldehydes, suggesting that the structure of the phenolic group or the aldehyde group may be important to the antibacterial activity. No difference in compound activity was observed between the three M. avium subsp. paratuberculosis strains studied. Possible mechanisms of the antimicrobial effects are discussed. PMID:18676709

Phenotypic variation in Lactococcus lactis subsp. lactis isolates derived from intestinal tracts of marine and freshwater fish.

PubMed

Itoi, S; Yuasa, K; Washio, S; Abe, T; Ikuno, E; Sugita, H

2009-09-01

We compared phenotypic characteristics of Lactococcus lactis subsp. lactis derived from different sources including the intestinal tract of marine fish and freshwater fish, and cheese starter culture. In the phylogenetic analysis based on partial 16S rRNA gene nucleotide sequences (1371 bp), freshwater fish-, marine fish- and cheese starter culture-derived strains were identical to that of L. lactis subsp. lactis previously reported. Fermentation profiles determined using the API 50 CH system were similar except for fermentation of several sugars including l-arabinose, mannitol, amygdalin, saccharose, trehalose, inulin and gluconate. The strains did have distinct levels of halotolerance: marine fish-derived strains > cheese starter-derived strain > freshwater fish-derived isolate. Lactococcus lactis subsp. lactis showed extensive diversity in phenotypic adaptation to various environments. The phenotypic properties of these strains suggested that L. lactis subsp. lactis strains from fish intestine have additional functions compared with the cheese starter-derived strain that has previously described. The unique phenotypic traits of the fish intestinal tract-derived L. lactis subsp. lactis might make them useful as a probiotics in aquaculture, and contribute to the development of functional foods and novel food additives, since the strains derived from fish intestines might have additional functions such as antibacterial activity.

Distribution of IS900 restriction fragment length polymorphism types among animal Mycobacterium avium subsp. paratuberculosis isolates from Argentina and Europe.

PubMed

Moreira, A R; Paolicchi, F; Morsella, C; Zumarraga, M; Cataldi, A; Fabiana, B; Alicia, A; Piet, O; van Soolingen, D; Isabel, R M

1999-12-01

Sixty-one Mycobacterium avium subsp. paratuberculosis isolates from cattle and deer from the Buenos Aires province, an important livestock region in Argentina, were typed by restriction fragment length polymorphisms (RFLP) analysis based on IS900. Four different RFLP patterns (designated 'A', 'B', 'C' and 'E') were identified in BstEII digests of genomic DNA. The most frequently observed type, pattern 'A', was found in 46 isolates (75%). The second, pattern 'E', included 8 isolates (13%), while the third, pattern 'B', included 6 isolates (10%). Pattern 'C' was found for only one isolate. All of the deer isolates were classified as pattern 'A', while cattle isolates represented all four RFLP patterns. Twenty-one isolates representing the four different BstEII-RFLP patterns were digested with PstI. Twenty isolates showed identical PstI-RFLP pattern. BstEII-RFLP patterns from Argentine cattle and deer were compared with patterns found in cattle, goat, deer, rabbit, and human isolates from Europe. The most common pattern in Argentina, pattern 'A', was identical to a less frequently occurring pattern R9 (C17) from Europe. The other Argentine patterns 'B', 'C' and 'E', were not found in the Europe. These results indicate that the distribution of M. avium subsp. paratuberculosis genotypes in the Buenos Aires province of Argentina is different from that found in Europe.

Complete genome sequence of Campylobacter fetus subsp. testudinum type strain 03-427T

USDA-ARS?s Scientific Manuscript database

Campylobacter fetus subsp. testudinum has been isolated from reptiles and humans. This Campylobacter subspecies is genetically distinct from other C. fetus subspecies. Here we present the first whole genome sequence for this C. fetus subspecies....

Draft Genome Sequences of Two Novel Salmonella enterica subsp. enterica Strains Isolated from Low-Moisture Foods with Applications in Food Safety Research.

PubMed

Radford, Devon R; Leon-Velarde, Carlos G; Chen, Shu; Hamidi Oskouei, Amir M; Balamurugan, Sampathkumar

2018-03-29

The genomes of two strains of Salmonella enterica subsp. enterica serovar Cubana and serovar Muenchen, isolated from dry hazelnuts and chia seeds, respectively, were sequenced using the Illumina MiSeq platform, assembled de novo using the overlap-layout-consensus method, and aligned to their respective most identical sequence genome scaffolds using MUMMER and BLAST searches. Copyright © 2018 Radford et al.

Chemical decontamination with N-acetyl-L-cysteine-sodium hydroxide improves recovery of viable Mycobacterium avium subsp. paratuberculosis organisms from cultured milk.

PubMed

Bradner, L; Robbe-Austerman, S; Beitz, D C; Stabel, J R

2013-07-01

Mycobacterium avium subsp. paratuberculosis is shed into the milk and feces of cows with advanced Johne's disease, allowing the transmission of M. avium subsp. paratuberculosis between animals. The objective of this study was to formulate an optimized protocol for the isolation of M. avium subsp. paratuberculosis in milk. The parameters investigated included chemical decontamination with N-acetyl-l-cysteine-sodium hydroxide (NALC-NaOH), alone and in combination with antibiotics (vancomycin, amphotericin B, and nalidixic acid), and the efficacy of solid (Herrold's egg yolk medium [HEY]) and liquid (Bactec 12B and para-JEM) culture media. For each experiment, raw milk samples from a known noninfected cow were inoculated with 10(2) to 10(8) CFU/ml of live M. avium subsp. paratuberculosis organisms. The results indicate that an increased length of exposure to NALC-NaOH from 5 to 30 min and an increased concentration of NaOH from 0.5 to 2.0% did not affect the viability of M. avium subsp. paratuberculosis. Additional treatment of milk samples with the antibiotics following NALC-NaOH treatment decreased the recovery of viable M. avium subsp. paratuberculosis cells more than treatment with NALC-NaOH alone. The Bactec 12B medium was the superior medium of the three evaluated for the isolation of M. avium subsp. paratuberculosis from milk, as it achieved the lowest threshold of detection. The optimal conditions for NALC-NaOH decontamination were determined to be exposure to 1.50% NaOH for 15 min followed by culture in Bactec 12B medium. This study demonstrates that chemical decontamination with NALC-NaOH resulted in a greater recovery of viable M. avium subsp. paratuberculosis cells from milk than from samples treated with hexadecylpyridinium chloride (HPC). Therefore, it is important to optimize milk decontamination protocols to ensure that low concentrations of M. avium subsp. paratuberculosis can be detected.

Characterization of a novel bacteriophage, Phda1, infecting the histamine-producing Photobacterium damselae subsp. damselae.

PubMed

Yamaki, S; Kawai, Y; Yamazaki, K

2015-06-01

Photobacterium damselae subsp. damselae is a potent histamine-producing micro-organism. The aim of this study was to isolate and characterize a bacteriophage Phda1 that infected P. damselae subsp. damselae to inhibit its growth and histamine accumulation. Phda1 was isolated from a raw oyster, and the host range, morphology and the bacteriophage genome size were analysed. Phda1 formed a clear plaque only against P. damselae subsp. damselae JCM8969 among five Gram-positive and 32 Gram-negative bacterial strains tested. Phda1 belongs to the family Myoviridae, and its genome size was estimated as 35·2-39·5 kb. According to the one-step growth curve analysis, the latent period, rise period and burst size of Phda1 were 60 min, 50 min and 19 plaque-forming units per infected cell, respectively. Divalent cations, especially Ca(2+) and Mg(2+) , strongly improved Phda1 adsorption to the host cells and its propagation. Phda1 treatment delayed the growth and histamine production of P. damselae subsp. damselae in an in vitro challenge test. The bacteriophage Phda1 might serve as a potential antimicrobial agent to inhibit the histamine poisoning caused by P. damselae subsp. damselae. This is the first description of a bacteriophage specifically infecting P. damselae subsp. damselae and its potential applications. Bacteriophage therapy could prove useful in the prevention of histamine poisoning. © 2015 The Society for Applied Microbiology.

Genome-Wide Analysis Provides Evidence on the Genetic Relatedness of the Emergent Xylella fastidiosa Genotype in Italy to Isolates from Central America.

PubMed

Giampetruzzi, Annalisa; Saponari, Maria; Loconsole, Giuliana; Boscia, Donato; Savino, Vito Nicola; Almeida, Rodrigo P P; Zicca, Stefania; Landa, Blanca B; Chacón-Diaz, Carlos; Saldarelli, Pasquale

2017-07-01

Xylella fastidiosa is a plant-pathogenic bacterium recently introduced in Europe that is causing decline in olive trees in the South of Italy. Genetic studies have consistently shown that the bacterial genotype recovered from infected olive trees belongs to the sequence type ST53 within subspecies pauca. This genotype, ST53, has also been reported to occur in Costa Rica. The ancestry of ST53 was recently clarified, showing it contains alleles that are monophyletic with those of subsp. pauca in South America. To more robustly determine the phylogenetic placement of ST53 within X. fastidiosa, we performed a comparative analysis based on single nucleotide polymorphisms (SNPs) and the study of the pan-genome of the 27 currently public available whole genome sequences of X. fastidiosa. The resulting maximum-parsimony and maximum likelihood trees constructed using the SNPs and the pan-genome analysis are consistent with previously described X. fastidiosa taxonomy, distinguishing the subsp. fastidiosa, multiplex, pauca, sandyi, and morus. Within the subsp. pauca, the Italian and three Costa Rican isolates, all belonging to ST53, formed a compact phylotype in a clade divergent from the South American pauca isolates, also distinct from the recently described coffee isolate CFBP8072 imported into Europe from Ecuador. These findings were also supported by the gene characterization of a conjugative plasmid shared by all the four ST53 isolates. Furthermore, isolates of the ST53 clade possess an exclusive locus encoding a putative ATP-binding protein belonging to the family of histidine kinase-like ATPase gene, which is not present in isolates from the subspecies multiplex, sandyi, and pauca, but was detected in ST21 isolates of the subspecies fastidiosa from Costa Rica. The clustering and distinctiveness of the ST53 isolates supports the hypothesis of their common origin, and the limited genetic diversity among these isolates suggests this is an emerging clade within subsp. pauca.

Diversity of pulsed-field gel electrophoresis pulsotypes, serovars, and antibiotic resistance among Salmonella isolates from wild amphibians and reptiles in the California Central Coast.

PubMed

Gorski, Lisa; Jay-Russell, Michele T; Liang, Anita S; Walker, Samarpita; Bengson, Yingjia; Govoni, Jessica; Mandrell, Robert E

2013-06-01

A survey of cold-blooded vertebrates and associated surface waters in a produce-growing region on the Central California Coast was done between May and September 2011 to determine the diversity of Salmonella. Samples from 460 amphibians and reptiles and 119 water samples were collected and cultured for Salmonella. Animals sampled were frogs (n=331), lizards (n=59), newts (n=5), salamanders (n=6), snakes (n=39), and toads (n=20). Salmonella was isolated from 37 individual animals, including frogs, lizards, snakes, and toads. Snakes were the most likely to contain Salmonella, with 59% testing positive followed by 15.3% of lizards, 5% of toads, and 1.2% of frogs. Fifteen water samples (12.6%) were positive. Twenty-two different serovars were identified, and the majority of isolates were S. enterica subsp. IIIb, with subsp. I, II, and IIIa also found. The serovar isolated most frequently was S. enterica subsp. IIIb 16:z₁₀:e,n,x,z₁₅, from snakes and frogs in five different locations. S. enterica subsp. I serovar Typhimurium and the monophasic I 6,8:d:- were isolated from water, and subspecies I Duisburg and its variants were found in animals and water. Some samples contained more than one type of Salmonella. Analysis of pulsed-field gel electrophoresis pulsotypes indicated that some strains persisted in animals and water collected from the same location. Sixty-six isolates displayed antibiotic resistance, with 27 isolates resistant to more than one antibiotic, including a subspecies IIIb isolate from snake having resistance to five different antibiotics. Twenty-three isolates were resistant to more than one class of antibiotic, and six isolates were resistant to three classes. While these subspecies of IIIa and IIIb cause fewer instances of human illness, they may serve as reservoirs of antibiotic resistance, determinants in the environment, and be sources of contamination of leafy greens associated with product recalls.

Isolation of Mycobacterium avium subsp. paratuberculosis from Free-Ranging Birds and Mammals on Livestock Premises

PubMed Central

Corn, Joseph L.; Manning, Elizabeth J. B.; Sreevatsan, Srinand; Fischer, John R.

2005-01-01

Surveys for Mycobacterium avium subsp. paratuberculosis infection in free-ranging mammals and birds were conducted on nine dairy and beef cattle farms in Wisconsin and Georgia. Specimens were collected from 774 animals representing 25 mammalian and 22 avian species. Specimens of ileum, liver, intestinal lymph nodes, and feces were harvested from the larger mammals; a liver specimen and the gastrointestinal tract were harvested from birds and small mammals. Cultures were performed by using radiometric culture and acid-fast isolates were identified by 16S/IS900/IS1311 PCR and mycobactin dependency characteristics. M. avium subsp. paratuberculosis was cultured from tissues and feces from 39 samples from 30 animals representing nine mammalian and three avian species. The prevalence of infected wild animals by premises ranged from 2.7 to 8.3% in Wisconsin and from 0 to 6.0% in Georgia. Shedding was documented in seven (0.9%) animals: three raccoons, two armadillos, one opossum, and one feral cat. The use of two highly polymorphic short sequence repeat loci for analysis of 29 of the 39 strains identified 10 alleles. One allelic pattern broadly shared in domestic ruminants (“7,5”) appeared in approximately one-third of the wildlife M. avium subsp. paratuberculosis isolates studied. Given the few cases of shedding by free-ranging animals compared to the volume of contaminated manure produced by infected domestic ruminant livestock, contamination of the farm environment by infected wildlife was negligible. Wildlife may, however, have epidemiological significance for farms where M. avium subsp. paratuberculosis recently has been eliminated or on farms free of M. avium subsp. paratuberculosis but located in the geographic vicinity of farms with infected livestock. PMID:16269731

Large-Scale Intersubspecific Recombination in the Plant-Pathogenic Bacterium Xylella fastidiosa Is Associated with the Host Shift to Mulberry

PubMed Central

Schuenzel, Erin L.; Scally, Mark; Bromley, Robin E.; Stouthamer, Richard

2014-01-01

Homologous recombination plays an important role in the structuring of genetic variation of many bacteria; however, its importance in adaptive evolution is not well established. We investigated the association of intersubspecific homologous recombination (IHR) with the shift to a novel host (mulberry) by the plant-pathogenic bacterium Xylella fastidiosa. Mulberry leaf scorch was identified about 25 years ago in native red mulberry in the eastern United States and has spread to introduced white mulberry in California. Comparing a sequence of 8 genes (4,706 bp) from 21 mulberry-type isolates to published data (352 isolates representing all subspecies), we confirmed previous indications that the mulberry isolates define a group distinct from the 4 subspecies, and we propose naming the taxon X. fastidiosa subsp. morus. The ancestry of its gene sequences was mixed, with 4 derived from X. fastidiosa subsp. fastidiosa (introduced from Central America), 3 from X. fastidiosa subsp. multiplex (considered native to the United States), and 1 chimeric, demonstrating that this group originated by large-scale IHR. The very low within-type genetic variation (0.08% site polymorphism), plus the apparent inability of native X. fastidiosa subsp. multiplex to infect mulberry, suggests that this host shift was achieved after strong selection acted on genetic variants created by IHR. Sequence data indicate that a single ancestral IHR event gave rise not only to X. fastidiosa subsp. morus but also to the X. fastidiosa subsp. multiplex recombinant group which infects several hosts but is the only type naturally infecting blueberry, thus implicating this IHR in the invasion of at least two novel native hosts, mulberry and blueberry. PMID:24610840

Large-scale intersubspecific recombination in the plant-pathogenic bacterium Xylella fastidiosa is associated with the host shift to mulberry.

PubMed

Nunney, Leonard; Schuenzel, Erin L; Scally, Mark; Bromley, Robin E; Stouthamer, Richard

2014-05-01

Homologous recombination plays an important role in the structuring of genetic variation of many bacteria; however, its importance in adaptive evolution is not well established. We investigated the association of intersubspecific homologous recombination (IHR) with the shift to a novel host (mulberry) by the plant-pathogenic bacterium Xylella fastidiosa. Mulberry leaf scorch was identified about 25 years ago in native red mulberry in the eastern United States and has spread to introduced white mulberry in California. Comparing a sequence of 8 genes (4,706 bp) from 21 mulberry-type isolates to published data (352 isolates representing all subspecies), we confirmed previous indications that the mulberry isolates define a group distinct from the 4 subspecies, and we propose naming the taxon X. fastidiosa subsp. morus. The ancestry of its gene sequences was mixed, with 4 derived from X. fastidiosa subsp. fastidiosa (introduced from Central America), 3 from X. fastidiosa subsp. multiplex (considered native to the United States), and 1 chimeric, demonstrating that this group originated by large-scale IHR. The very low within-type genetic variation (0.08% site polymorphism), plus the apparent inability of native X. fastidiosa subsp. multiplex to infect mulberry, suggests that this host shift was achieved after strong selection acted on genetic variants created by IHR. Sequence data indicate that a single ancestral IHR event gave rise not only to X. fastidiosa subsp. morus but also to the X. fastidiosa subsp. multiplex recombinant group which infects several hosts but is the only type naturally infecting blueberry, thus implicating this IHR in the invasion of at least two novel native hosts, mulberry and blueberry.

Factors affecting isolation and identification of Mycobacterium avium subsp. paratuberculosis from fecal and tissue samples in a liquid culture system.

PubMed

Whittington, Richard J

2009-03-01

Culture of Mycobacterium avium subsp. paratuberculosis is the definitive diagnostic test for Johne's disease, a chronic granulomatous enteropathy of animals. Compared to solid media, the identification of all strains of the organism in liquid media can be more difficult because the appearance of colonies and mycobactin dependence are not observable, and the growth of other organisms needs to be distinguished, commonly by PCR. Factors affecting the isolation rate of S strains and the contamination rate in modified Middlebrook 7H9 broth (Bactec 12B) and 7H10 agar were studied using 11,598 fecal samples and 2,577 tissue samples from sheep from 1,421 farms over 10 years. Minimization of contamination in Bactec cultures required the avoidance of the carryover of fecal particles from the first sedimentation step in the double-incubation centrifugation method, and contamination was reduced significantly by incubating the sample in a solution containing vancomycin, amphotericin B, and nalidixic acid for 3 days compared to 2 days. The growth of irrelevant microorganisms confounded the identification of M. avium subsp. paratuberculosis in liquid culture by inhibiting IS900 PCR and in solid medium culture by inhibiting the growth of M. avium subsp. paratuberculosis or obscuring colonies. The contamination of samples was clustered in certain laboratory submissions and was reduced by including ampicillin in Bactec medium without affecting the odds of isolation of M. avium subsp. paratuberculosis. The long-term contamination rate for fecal cultures was about 7%, and that for tissue cultures was <0.2%. Liquid medium was more sensitive than solid medium culture for M. avium subsp. paratuberculosis. The applicability of these findings for C strains is discussed.

Detection and molecular characterization of Escherichia coli CTX-M-15 and Klebsiella pneumoniae SHV-12 β-lactamases from bovine mastitis isolates in the United Kingdom.

PubMed

Timofte, Dorina; Maciuca, Iuliana E; Evans, Nicholas J; Williams, Helen; Wattret, Andrew; Fick, Jenny C; Williams, Nicola J

2014-01-01

Recent reports raised concerns about the role that farm stock may play in the dissemination of extended-spectrum β-lactamase (ESBL)-producing bacteria. This study characterized the ESBLs in two Escherichia coli and three Klebsiella pneumoniae subsp. pneumoniae isolates from cases of clinical bovine mastitis in the United Kingdom. Bacterial culture and sensitivity testing of bovine mastitic milk samples identified Gram-negative cefpodoxime-resistant isolates, which were assessed for their ESBL phenotypes. Conjugation experiments and PCR-based replicon typing (PBRT) were used for characterization of transferable plasmids. E. coli isolates belonged to sequence type 88 (ST88; determined by multilocus sequence typing) and carried blaCTX-M-15 and blaTEM-1, while K. pneumoniae subsp. pneumoniae isolates carried blaSHV-12 and blaTEM-1. Conjugation experiments demonstrated that blaCTX-M-15 and blaTEM-1 were carried on a conjugative plasmid in E. coli, and PBRT identified this to be an IncI1 plasmid. The resistance genes were nontransferable in K. pneumoniae subsp. pneumoniae isolates. Moreover, in the E. coli isolates, an association of ISEcp1 and IS26 with blaCTX-M-15 was found where the IS26 element was inserted upstream of both ISEcp1 and the blaCTX-M promoter, a genetic arrangement highly similar to that described in some United Kingdom human isolates. We report the first cases in Europe of bovine mastitis due to E. coli CTX-M-15 and also of bovine mastitis due to K. pneumoniae subsp. pneumoniae SHV-12 β-lactamases in the United Kingdom. We also describe the genetic environment of blaCTX-M-15 and highlight the role that IncI1 plasmids may play in the spread and dissemination of ESBL genes, which have been described in both human and cattle isolates.

Detection and Molecular Characterization of Escherichia coli CTX-M-15 and Klebsiella pneumoniae SHV-12 β-Lactamases from Bovine Mastitis Isolates in the United Kingdom

PubMed Central

Maciuca, Iuliana E.; Evans, Nicholas J.; Williams, Helen; Wattret, Andrew; Fick, Jenny C.; Williams, Nicola J.

2014-01-01

Recent reports raised concerns about the role that farm stock may play in the dissemination of extended-spectrum β-lactamase (ESBL)-producing bacteria. This study characterized the ESBLs in two Escherichia coli and three Klebsiella pneumoniae subsp. pneumoniae isolates from cases of clinical bovine mastitis in the United Kingdom. Bacterial culture and sensitivity testing of bovine mastitic milk samples identified Gram-negative cefpodoxime-resistant isolates, which were assessed for their ESBL phenotypes. Conjugation experiments and PCR-based replicon typing (PBRT) were used for characterization of transferable plasmids. E. coli isolates belonged to sequence type 88 (ST88; determined by multilocus sequence typing) and carried blaCTX-M-15 and blaTEM-1, while K. pneumoniae subsp. pneumoniae isolates carried blaSHV-12 and blaTEM-1. Conjugation experiments demonstrated that blaCTX-M-15 and blaTEM-1 were carried on a conjugative plasmid in E. coli, and PBRT identified this to be an IncI1 plasmid. The resistance genes were nontransferable in K. pneumoniae subsp. pneumoniae isolates. Moreover, in the E. coli isolates, an association of ISEcp1 and IS26 with blaCTX-M-15 was found where the IS26 element was inserted upstream of both ISEcp1 and the blaCTX-M promoter, a genetic arrangement highly similar to that described in some United Kingdom human isolates. We report the first cases in Europe of bovine mastitis due to E. coli CTX-M-15 and also of bovine mastitis due to K. pneumoniae subsp. pneumoniae SHV-12 β-lactamases in the United Kingdom. We also describe the genetic environment of blaCTX-M-15 and highlight the role that IncI1 plasmids may play in the spread and dissemination of ESBL genes, which have been described in both human and cattle isolates. PMID:24247146

Campylobacter fetus subsp. testudinum subsp. nov., isolated from humans and reptiles.

PubMed

Fitzgerald, Collette; Tu, Zheng Chao; Patrick, Mary; Stiles, Tracy; Lawson, Andy J; Santovenia, Monica; Gilbert, Maarten J; van Bergen, Marcel; Joyce, Kevin; Pruckler, Janet; Stroika, Steven; Duim, Birgitta; Miller, William G; Loparev, Vladimir; Sinnige, Jan C; Fields, Patricia I; Tauxe, Robert V; Blaser, Martin J; Wagenaar, Jaap A

2014-09-01

A polyphasic study was undertaken to determine the taxonomic position of 13 Campylobacter fetus-like strains from humans (n = 8) and reptiles (n = 5). The results of matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) MS and genomic data from sap analysis, 16S rRNA gene and hsp60 sequence comparison, pulsed-field gel electrophoresis, amplified fragment length polymorphism analysis, DNA-DNA hybridization and whole genome sequencing demonstrated that these strains are closely related to C. fetus but clearly differentiated from recognized subspecies of C. fetus. Therefore, this unique cluster of 13 strains represents a novel subspecies within the species C. fetus, for which the name Campylobacter fetus subsp. testudinum subsp. nov. is proposed, with strain 03-427(T) ( = ATCC BAA-2539(T) = LMG 27499(T)) as the type strain. Although this novel taxon could not be differentiated from C. fetus subsp. fetus and C. fetus subsp. venerealis using conventional phenotypic tests, MALDI-TOF MS revealed the presence of multiple phenotypic biomarkers which distinguish Campylobacter fetus subsp. testudinum subsp. nov. from recognized subspecies of C. fetus.

Six-Month Multicenter Study on Invasive Infections Due to Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis in Argentina

PubMed Central

Lopardo, Horacio A.; Vidal, Patricia; Sparo, Monica; Jeric, Paola; Centron, Daniela; Facklam, Richard R.; Paganini, Hugo; Pagniez, N. Gaston; Lovgren, Marguerite; Beall, Bernard

2005-01-01

During a 6-month period, 95 invasive infections due to Streptococcus pyogenes and group C or group G Streptococcus dysgalactiae subsp. equisimilis were recorded from 40 centers of 16 cities in Argentina. We describe here epidemiologic data available for 55 and 19 patients, respectively, associated with invasive infections due to S. pyogenes and S. dysgalactiae subsp. equisimilis. The associated isolates and 58 additional pharyngeal isolates were genotyped and subjected to serologic and/or antibiotic susceptibility testing. Group A streptococcal emm type distribution and strain association with toxic shock appeared to differ somewhat from results found within the United States; however, serologic characterization and sof sequence typing suggested that emm types found in both countries are reflective of shared clonal types. PMID:15695683

Detection of Mycobacterium avium subsp. paratuberculosis in Drinking Water and Biofilms Using Quantitative PCR

EPA Science Inventory

Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne’s disease in domestic animals and has been implicated in Crohn’s disease in humans. Cows infected with Johne’s disease shed large quantities of MAP into soil. Further, MAP has been isolated from surface water, is resi...

Genetic analysis and antimicrobial susceptibility of Francisella noatunensis subsp. orientalis (sun. F. asiatica) isolates from fish

USDA-ARS?s Scientific Manuscript database

Francisella noatunensis subsp. orientalis (syn. F. asiatica) (Fno) is an emergent fish pathogen that causes acute to chronic disease in a wide variety of freshwater, brackish and marine fish. Due to the emergent nature of this bacterium, established protocols to measure antimicrobial susceptibility ...

Draft Genome Sequence of the Putrescine-Producing Strain Lactococcus lactis subsp. lactis 1AA59

PubMed Central

del Rio, Beatriz; Linares, Daniel M.; Fernandez, María; Mayo, Baltasar; Martín, M. Cruz

2015-01-01

We report here the 2,576,542-bp genome annotated draft assembly sequence of Lactococcus lactis subsp. lactis 1AA59. This strain—isolated from a traditional cheese—produces putrescine, one of the most frequently biogenic amines found in dairy products. PMID:26089428

Genetic diversity and population structure of Lactobacillus delbrueckii subspecies bulgaricus isolated from naturally fermented dairy foods.

PubMed

Song, Yuqin; Sun, Zhihong; Guo, Chenyi; Wu, Yarong; Liu, Wenjun; Yu, Jie; Menghe, Bilige; Yang, Ruifu; Zhang, Heping

2016-03-04

Lactobacillus delbrueckii subsp. bulgaricus is one of the most widely used starter culture strains in industrial fermented dairy manufacture. It is also common in naturally fermented dairy foods made using traditional methods. The subsp. bulgaricus strains found in naturally fermented foods may be useful for improving current industrial starter cultures; however, little is known regarding its genetic diversity and population structure. Here, a collection of 298 L. delbrueckii strains from naturally fermented products in Mongolia, Russia, and West China was analyzed by multi-locus sequence typing based on eight conserved genes. The 251 confirmed subsp. bulgaricus strains produced 106 unique sequence types, the majority of which were assigned to five clonal complexes (CCs). The geographical distribution of CCs was uneven, with CC1 dominated by Mongolian and Russian isolates, and CC2-CC5 isolates exclusively from Xinjiang, China. Population structure analysis suggested six lineages, L1-L6, with various homologous recombination rates. Although L2-L5 were mainly restricted within specific regions, strains belonging to L1 and L6 were observed in diverse regions, suggesting historical transmission events. These results greatly enhance our knowledge of the population diversity of subsp. bulgaricus strains, and suggest that strains from CC1 and L4 may be useful as starter strains in industrial fermentation.

[A comparison of the properties of bacteriocins formed by Lactococcus lactis subsp. lactis strains of diverse origin].

PubMed

Stoianova, L G; Egorov, N S; Fedorova, G B; Katrukha, G S; Netrusov, A I

2007-01-01

Bacteriocins formed by four strains of Lactococcus lactis subsp. lactis have been studied and compared: 729 (a natural strain isolated from milk), 1605 (a mutant of strain 729), F-116 (a recombinant obtained by fusing of protoplasts of the two related strain 729 and 1605), and a nisin-forming strain obtained by adaptive selection at Moscow State University. Antimicrobial activity studies revealed differences between the strains in the effects on individual groups of microorganisms; the activities of the strains were also distinct from that of Nisaplin (a commercial preparation of the bacteriocin nisin). Methods for isolation and purification of bacteriocins have been developed, making it possible to obtain individual components of antibiotic complexes as chromatographically pure preparations. Bacteriocins formed by the strains of Lactococcus lactis subsp. lactis have been identified and differences in their biological and physicochemical properties, established. A novel potent broad-spectrum antibiotic substance distinct from nisin has been isolated from the recombinant strain F-116.

Diversity and dynamics of lactobacilli populations during ripening of RDO Camembert cheese.

PubMed

Henri-Dubernet, Ségolène; Desmasures, Nathalie; Guéguen, Micheline

2008-03-01

The diversity and dynamics of Lactobacillus populations in traditional raw milk Camembert cheese were monitored throughout the manufacturing process in 3 dairies. Culture-dependent analysis was carried out on isolates grown on acidified de Man - Rogosa - Sharpe agar and Lactobacillus anaerobic de Man Rogosa Sharpe agar supplemented with vancomycin and bromocresol green media. The isolates were identified by polymerase chain reaction - temperature gradient gel electrophoresis (PCR-TGGE) and (or) species-specific PCR and (or) sequencing, and Lactobacillus paracasei and Lactobacillus plantarum isolates were characterized by pulsed field gel electrophoresis (PFGE). Milk and cheese were subjected to culture-independent analysis by PCR-TGGE. Presumed lactobacilli were detected by plate counts throughout the ripening process. However, molecular analysis of total DNA and DNA of isolates failed to detect Lactobacillus spp. in certain cases. The dominant species in the 3 dairies was L. paracasei. PFGE analysis revealed 21 different profiles among 39 L. paracasei isolates. Lactobacillus plantarum was the second most isolated species, but it occurred nearly exclusively in one dairy. The other species isolated were Lactobacillus parabuchneri, Lactobacillus fermentum, Lactobacillus acidophilus, Lactobacillus helveticus, a Lactobacillus psittaci/delbrueckii subsp. bulgaricus/gallinarum/crispatus group, Lactobacillus rhamnosus, Lactobacillus delbrueckii subsp. bulgaricus, L. delbrueckii subsp. lactis, Lactobacillus brevis, Lactobacillus kefiri, and Lactobacillus perolens. Lactobacilli diversity at the strain level was high. Dynamics varied among dairies, and each cheese exhibited a specific picture of species and strains.

Aeromonas salmonicida subsp. salmonicida strains isolated from Chinese freshwater fish contain a novel genomic island and possible regional-specific mobile genetic elements profiles.

PubMed

Long, Meng; Nielsen, Tue K; Leisner, Jørgen J; Hansen, Lars H; Shen, Zhi X; Zhang, Qian Q; Li, Aihua

2016-09-01

Two strains of Aeromonas salmonicida, YK and BG, were isolated from largemouth bronze gudgeon and northern whitefish in China, and identified as A. salmonicida subsp. salmonicida based on phylogenetic analysis of vapA and 16S rRNA gene sequences. YK and BG originated from freshwater fish, one of which belonged to the cyprinid family, and the strains showed a difference in virulence. Subsequently, we performed whole genome sequencing of the strains, and comparison of their genomic sequences to the genome of the A449 reference strain revealed various genomic rearrangements, including a new variant of the genomic island AsaGEI in BG, designated as AsaGEI2c This is the first report on a GEI of A. salmonicida strain from China. Furthermore, both YK and BG strains contained a Tn7 transposon inserted at the same position in the chromosome. Finally, IS-dependent rearrangements on pAsa5 are deemed likely to have occurred, with omission of the resD gene in both strains as well as omission of genes related to the IncF conjugal transfer system in the YK isolate. This study demonstrates that A. salmonicida subsp. salmonicida can infect non-salmonids (cyprinids) in addition to salmonids, and that AsaGEI2c might be useful as a geographical indicator of Chinese A. salmonicida subsp. salmonicida isolates. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The Complex Biogeography of the Plant Pathogen Xylella fastidiosa: Genetic Evidence of Introductions and Subspecific Introgression in Central America

PubMed Central

Nunney, Leonard; Ortiz, Beatriz; Russell, Stephanie A.; Ruiz Sánchez, Rebeca; Stouthamer, Richard

2014-01-01

The bacterium Xylella fastidiosa is a plant pathogen with a history of economically damaging introductions of subspecies to regions where its other subspecies are native. Genetic evidence is presented demonstrating the introduction of two new taxa into Central America and their introgression into the native subspecies, X. fastidiosa subsp. fastidiosa. The data are from 10 genetic outliers detected by multilocus sequence typing (MLST) of isolates from Costa Rica. Six (five from oleander, one from coffee) defined a new sequence type (ST53) that carried alleles at six of the eight loci sequenced (five of the seven MLST loci) diagnostic of the South American subspecies Xylella fastidiosa subsp. pauca which causes two economically damaging plant diseases, citrus variegated chlorosis and coffee leaf scorch. The two remaining loci of ST53 carried alleles from what appears to be a new South American form of X. fastidiosa. Four isolates, classified as X. fastidiosa subsp. fastidiosa, showed a low level of introgression of non-native DNA. One grapevine isolate showed introgression of an allele from X. fastidiosa subsp. pauca while the other three (from citrus and coffee) showed introgression of an allele with similar ancestry to the alleles of unknown origin in ST53. The presence of X. fastidiosa subsp. pauca in Central America is troubling given its disease potential, and establishes another route for the introduction of this economically damaging subspecies into the US or elsewhere, a threat potentially compounded by the presence of a previously unknown form of X. fastidiosa. PMID:25379725

The complex biogeography of the plant pathogen Xylella fastidiosa: genetic evidence of introductions and Subspecific introgression in Central America.

PubMed

Nunney, Leonard; Ortiz, Beatriz; Russell, Stephanie A; Ruiz Sánchez, Rebeca; Stouthamer, Richard

2014-01-01

The bacterium Xylella fastidiosa is a plant pathogen with a history of economically damaging introductions of subspecies to regions where its other subspecies are native. Genetic evidence is presented demonstrating the introduction of two new taxa into Central America and their introgression into the native subspecies, X. fastidiosa subsp. fastidiosa. The data are from 10 genetic outliers detected by multilocus sequence typing (MLST) of isolates from Costa Rica. Six (five from oleander, one from coffee) defined a new sequence type (ST53) that carried alleles at six of the eight loci sequenced (five of the seven MLST loci) diagnostic of the South American subspecies Xylella fastidiosa subsp. pauca which causes two economically damaging plant diseases, citrus variegated chlorosis and coffee leaf scorch. The two remaining loci of ST53 carried alleles from what appears to be a new South American form of X. fastidiosa. Four isolates, classified as X. fastidiosa subsp. fastidiosa, showed a low level of introgression of non-native DNA. One grapevine isolate showed introgression of an allele from X. fastidiosa subsp. pauca while the other three (from citrus and coffee) showed introgression of an allele with similar ancestry to the alleles of unknown origin in ST53. The presence of X. fastidiosa subsp. pauca in Central America is troubling given its disease potential, and establishes another route for the introduction of this economically damaging subspecies into the US or elsewhere, a threat potentially compounded by the presence of a previously unknown form of X. fastidiosa.

[Resistance of Lactobacillus casei subsp. casei SY13 and Lactobacillus delbrueckii subsp. bulgaricus LJJ to reactive oxygen species].

PubMed

Zhang, Shuwen; Lv, Jiaping; Menghe, Bilige; Zhang, Heping; Zhang, Liyu; Song, Jinhui; Wang, Zhifei

2009-02-01

We evaluated antioxidative effect of two antioxidative strains, isolated from the traditional fermented dairy products. Both intact cells and cell-free extract of Lactobacillus casei subsp. casei SY13 and Lactobacillus delbrueckii subsp. bulgaricus LJJ were used to study the inhibited effect of linoleic acid peroxidation, the ability of scavenging 1,1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, superoxide anion radical,the ability of tolerancing hydrogen peroxide and the chelating capacity of ferrous ion and reducting activity. Lactobacillus casei subsp. casei SY13 and Lactobacillus delbrueckii subsp. bulgaricus LJJ demonstrated highest inhibition on linoleic acid peroxidation by 62.95% and 66.16%, respectively. The cell-free extract showed excellent scavenging superoxide anion and hydroxyl radicals activity. However, the intact cells of Lactobacillus delbrueckii subsp. bulgaricus LJJ scavenging superoxide and hydroxyl radicals capacity were not detected. The intact cells of Lactobacillus casei subsp. casei SY13 and Lactobacillus delbrueckii subsp. bulgaricus LJJ on 1,1-diphenyl-2-picrylhydrazyl radical scavenging ability and chelating ferrous ion capacity were superior to cell-free extract. The highest reduced activety was equivalent to 305 micromol/L and 294 micromol/L L-cysteine. Two latobacilli strains had good antioxidant capacity. As potential probiotics, it can be used in future.

Five cases of vector-borne Francisella tularensis holarctica infections in south-western Germany and genetic diversity.

PubMed

Borde, Johannes P; Zange, Sabine; Antwerpen, Markus H; Georgi, Enrico; von Buttlar, Heiner; Kern, Winfried V; Rieg, Siegbert

2017-08-01

Tularemia is a rare zoonotic disease in Germany. Francisella tularensis has been isolated previously from ticks in southern Germany underscoring the importance of ticks (Ixodes ricinus) in tularemia transmission, but there have been only few reports from this region with single cases or small case series of tick-borne transmissions of tularemia. We report five cases of non-game animal associated tularemia diagnosed from 2010 to 2016 in southwestern Germany - Baden-Wuerttemberg. Our case series and molecular typing (MLVA) results add published clinical experience to this underdiagnosed disease and consolidate previous findings regarding tick-borne transmission of tularemia and phylogenetic diversity in Germany. Copyright © 2017 Elsevier GmbH. All rights reserved.

Complete genome sequence of Clavibacter michiganensis subsp. insidiosus R1-1 using PacBio single-molecule real-time technology

USDA-ARS?s Scientific Manuscript database

We report the complete genome sequence of Clavibacter michiganensis subsp. insidiosus R1-1 isolated in Minnesota, USA. The R1-1 genome, generated by de novo assembly of PacBio sequencing data, is the first complete genome sequence available for this subspecies....

Stawamycin analog, JBIR-11 from Streptomyces viridochromogenes subsp. sulfomycini NBRC 13830.

PubMed

Izumikawa, Miho; Komaki, Hisayuki; Hashimoto, Junko; Takagi, Motoki; Shin-ya, Kazuo

2008-05-01

A stawamycin analog, JBIR-11 (1) was isolated from mycelium of Streptomyces viridochromogenes subsp. sulfomycini NBRC 13830. The structure was determined on the basis of the spectroscopic data. Compound 1 exhibited growth inhibitory effect against human fibrosarcoma HT1080 cells with an IC50 value of 25 microM.

Genome Sequence of the Cheese-Starter Strain Lactobacillus delbrueckii subsp. lactis CRL 581.

PubMed

Hebert, Elvira María; Raya, Raúl R; Brown, Lucía; Font de Valdez, Graciela; Savoy de Giori, Graciela; Taranto, María Pía

2013-08-08

We report the genome sequence of Lactobacillus delbrueckii subsp. lactis CRL 581 (1,911,137 bp, GC 49.7%), a proteolytic strain isolated from a homemade Argentinian hard cheese which has a key role in bacterial nutrition and releases bioactive health-beneficial peptides from milk proteins.

Complete genome sequence of salmonella enterica subsp. enterica Serovar Thompson Strain RM6836

USDA-ARS?s Scientific Manuscript database

Salmonella enterica subsp. enterica serovar Thompson (S. Thompson) strain RM6836 was isolated from lettuce in 2002. We report the complete sequence and annotation of the genome of S. Thompson strain RM6836. This is the first reported complete genome sequence for S. Thompson and will provide a point ...

An introgressed wing pattern acts as a mating cue.

PubMed

Sánchez, Angela P; Pardo-Diaz, Carolina; Enciso-Romero, Juan; Muñoz, Astrid; Jiggins, Chris D; Salazar, Camilo; Linares, Mauricio

2015-06-01

Heliconius butterflies provide good examples of both homoploid hybrid speciation and ecological speciation. In particular, examples of adaptive introgression have been detected among the subspecies of Heliconius timareta, which acquired red color pattern elements from H. melpomene. We tested whether the introgression of red wing pattern elements into H. timareta florencia might also be associated with incipient reproductive isolation (RI) from its close relative, H. timareta subsp. nov., found in the eastern Andes. No choice experiments show a 50% reduction in mating between females of H. t. subsp. nov. and males of H .t. florencia, but not in the reciprocal direction. In choice experiments using wing models, males of H. timareta subsp. nov. approach and court red phenotypes less than their own, whereas males of H. t. florencia prefer models with a red phenotype. Intrinsic postzygotic isolation was not detected in crosses between these H. timareta races. These results suggest that a color pattern trait gained by introgression is triggering RI between H. timareta subsp. nov. and H. t. florencia. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Characterization of Fusobacterium necrophorum isolated from llama and alpaca.

PubMed

Kumar, Amit; Anderson, David; Amachawadi, Raghavendra G; Nagaraja, Tiruvoor G; Narayanan, Sanjeev K

2013-07-01

Fusobacterium necrophorum, a Gram-negative, anaerobic bacterium, is an opportunistic animal and human pathogen that causes a variety of infections termed necrobacillosis. There are 2 subspecies of F. necrophorum (subsp. necrophorum and subsp. funduliforme) that differ morphologically and biochemically and in virulence. Leukotoxin, a secreted protein, is considered to be the major virulence factor. In camelids, F. necrophorum causes a variety of infections, generally involving the lips, tongue, pharynx, interdigital spaces, foot pad, larynx, mandible, or maxillary bones. The objective of the current study was to characterize the presumptive Fusobacterium isolates from a variety of necrotic infections in llama (Lama glama) and alpaca (Vicugna pacos) and determine whether the strains possess leukotoxin activities. A total of 7 isolates from alpaca and 2 isolates from llama were characterized. Based on growth characteristics in broth culture, and biochemical and polymerase chain reaction analyses, all 9 isolates belonged to subsp. necrophorum and possessed the putative hemagglutinin gene. Western blot analysis with antileukotoxin antibodies raised in rabbit showed the presence of leukotoxin protein in the culture supernatant of all isolates. Furthermore, flow cytometry of the culture supernatants demonstrated cytotoxicity to bovine and alpaca polymorphonuclear leukocytes (PMNs). The extent of cytotoxicity to either alpaca or bovine PMNs differed among camelid strains. The cytotoxicity of many of the camelid strains was higher (P < 0.05) toward alpaca PMNs compared to bovine PMNs. Fusobacterium necrophorum isolates from llama and alpaca are similar to bovine isolates, and leukotoxin may be a major virulence factor.

Biochemical responses and oxidative stress in Francisella tularensis infection: a European brown hare model

PubMed Central

2011-01-01

Background The aim of the present study was to investigate biochemical and oxidative stress responses to experimental F. tularensis infection in European brown hares, an important source of human tularemia infections. Methods For these purposes we compared the development of an array of biochemical parameters measured in blood plasma using standard procedures of dry chemistry as well as electrochemical devices following a subcutaneous infection with a wild Francisella tularensis subsp. holarctica strain (a single dose of 2.6 × 109 CFU pro toto). Results Subcutaneous inoculation of a single dose with 2.6 × 109 colony forming units of a wild F. tularensis strain pro toto resulted in the death of two out of five hares. Plasma chemistry profiles were examined on days 2 to 35 post-infection. When compared to controls, the total protein, urea, lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase were increased, while albumin, glucose and amylase were decreased. Both uric and ascorbic acids and glutathione dropped on day 2 and then increased significantly on days 6 to 12 and 6 to 14 post-inoculation, respectively. There was a two-fold increase in lipid peroxidation on days 4 to 8 post-inoculation. Conclusions Contrary to all expectations, the present study demonstrates that the European brown hare shows relatively low susceptibility to tularemia. Therefore, the circumstances of tularemia in hares under natural conditions should be further studied. PMID:21232117

Dynamics of a Tularemia Outbreak in a Closely Monitored Free-Roaming Population of Wild House Mice.

PubMed

Dobay, Akos; Pilo, Paola; Lindholm, Anna K; Origgi, Francesco; Bagheri, Homayoun C; König, Barbara

2015-01-01

Infectious disease outbreaks can be devastating because of their sudden occurrence, as well as the complexity of monitoring and controlling them. Outbreaks in wildlife are even more challenging to observe and describe, especially when small animals or secretive species are involved. Modeling such infectious disease events is relevant to investigating their dynamics and is critical for decision makers to accomplish outbreak management. Tularemia, caused by the bacterium Francisella tularensis, is a potentially lethal zoonosis. Of the few animal outbreaks that have been reported in the literature, only those affecting zoo animals have been closely monitored. Here, we report the first estimation of the basic reproduction number R0 of an outbreak in wildlife caused by F. tularensis using quantitative modeling based on a susceptible-infected-recovered framework. We applied that model to data collected during an extensive investigation of an outbreak of tularemia caused by F. tularensis subsp. holarctica (also designated as type B) in a closely monitored, free-roaming house mouse (Mus musculus domesticus) population in Switzerland. Based on our model and assumptions, the best estimated basic reproduction number R0 of the current outbreak is 1.33. Our results suggest that tularemia can cause severe outbreaks in small rodents. We also concluded that the outbreak self-exhausted in approximately three months without administrating antibiotics.

Dynamics of a Tularemia Outbreak in a Closely Monitored Free-Roaming Population of Wild House Mice

PubMed Central

Dobay, Akos; Pilo, Paola; Lindholm, Anna K.; Origgi, Francesco; Bagheri, Homayoun C.; König, Barbara

2015-01-01

Infectious disease outbreaks can be devastating because of their sudden occurrence, as well as the complexity of monitoring and controlling them. Outbreaks in wildlife are even more challenging to observe and describe, especially when small animals or secretive species are involved. Modeling such infectious disease events is relevant to investigating their dynamics and is critical for decision makers to accomplish outbreak management. Tularemia, caused by the bacterium Francisella tularensis, is a potentially lethal zoonosis. Of the few animal outbreaks that have been reported in the literature, only those affecting zoo animals have been closely monitored. Here, we report the first estimation of the basic reproduction number R 0 of an outbreak in wildlife caused by F. tularensis using quantitative modeling based on a susceptible-infected-recovered framework. We applied that model to data collected during an extensive investigation of an outbreak of tularemia caused by F. tularensis subsp. holarctica (also designated as type B) in a closely monitored, free-roaming house mouse (Mus musculus domesticus) population in Switzerland. Based on our model and assumptions, the best estimated basic reproduction number R 0 of the current outbreak is 1.33. Our results suggest that tularemia can cause severe outbreaks in small rodents. We also concluded that the outbreak self-exhausted in approximately three months without administrating antibiotics. PMID:26536232

Bacteriocinogenic Lactococcus lactis subsp. lactis DF04Mi isolated from goat milk: Characterization of the bacteriocin

PubMed Central

Furtado, Danielle N.; Todorov, Svetoslav D.; Landgraf, Mariza; Destro, Maria T.; Franco, Bernadette D.G.M.

2014-01-01

Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its antimicrobial activity. The bacteriocin presented a broad spectrum of activity, was sensitive to proteolytic enzymes, resistant to heat and pH extremes, and not affected by the presence of SDS, Tween 20, Tween 80, EDTA or NaCl. Bacteriocin production was dependent on the components of the culture media, especially nitrogen source and salts. When tested by PCR, the bacteriocin gene presented 100% homology to nisin Z gene. These properties indicate that this L. lactis subsp. lactis DF4Mi can be used for enhancement of dairy foods safety and quality. PMID:25763065

Chemical composition and antimicrobial activity of the essential oils of some species of Anthemis sect. Anthemis (Asteraceae) from Sicily.

PubMed

Riccobono, Luana; Maggio, Antonella; Bruno, Maurizio; Spadaro, Vivienne; Raimondo, Francesco Maria

2017-12-01

The chemical composition of the essential oils isolated from the aerial parts of Anthemis arvensis L. subsp. arvensis, Anthemis cretica subsp. messanensis (Brullo) Giardina & Raimondo and from flowers and leaves of Anthemis cretica subsp. columnae (Ten.) Frezén were determinated by GC-FID and GC-MS analyses. Torreyol (85.4%) was recognised as the main constituent of the Anthemis arvensis subsp. arvensis essential oil, while in the essential oils of Anthemis cretica subsp. messanensis, collected on the rock and cultivated in Hortus Botanicus Panormitanus, (E)-chrysanthenyl acetate (28.8 and 24.2% resp.), 14-hydroxy-α-humulene (8.1 and 5.3% resp.), santolina triene (8 and 5.8% resp.) and α-pinene (6.7 and 5.4% resp.) prevailed. 18-cineole (13.3 and 12.2% resp.), was the main component of both flower and leaf oils of Anthemis cretica subsp. columnae together with δ-cadinene (9.0 and 8.2% resp.) and (E)-caryophyllene (8.3 and 5.6% resp.).

Prevalence and Characteristics of Salmonella and Campylobacter in Retail Poultry Meat in Japan.

PubMed

Furukawa, Ichiro; Ishihara, Tomoe; Teranishi, Hiroshi; Saito, Shioko; Yatsuyanagi, Jun; Wada, Eriko; Kumagai, Yuko; Takahashi, Shiho; Konno, Takayuki; Kashio, Hiroko; Kobayashi, Akihiko; Kato, Naoki; Hayashi, Ken-Ichi; Fukushima, Keisuke; Ishikawa, Kazuhiko; Horikawa, Kazumi; Oishi, Akira; Izumiya, Hidemasa; Ohnishi, Takahiro; Konishi, Yoshiko; Kuroki, Toshiro

2017-05-24

This study was performed to determine the prevalence, antimicrobial susceptibility, and genetic relatedness of Salmonella enterica subsp. enterica and Campylobacter spp. in poultry meat, and to analyze the association of genetic types of these bacteria with their geographical distribution and antimicrobial resistance profiles. Salmonella and Campylobacter isolates have been detected, respectively, in 54 and 71 samples out of 100 samples tested. Nine Salmonella serotypes were found, including S. enterica subsp. enterica serovar Infantis (33%), Schwarzengrund (12%), Manhattan (9%), and others. Campylobacter jejuni and C. coli were detected in 64 (64%) and 14 (14%) samples, respectively. S. enterica subsp. enterica isolates were very frequently resistant to tetracycline (78.3%) and streptomycin (68.3%). Many C. jejuni and C. coli isolates were resistant to sulfamethoxazole/trimethoprim (90.5%), nalidixic acid (47.3%), ampicillin (45.9%), and ciprofloxacin (40.5%). Cluster analysis was performed for the Salmonella isolates using pulsed-field gel electrophoresis (PFGE) data. For Campylobacter isolates, the cluster analysis was based on both PFGE and comparative genomic fingerprinting. The molecular typing results were compared with the information about antimicrobial resistance and geographical locations in which the poultry meat was produced. This analysis revealed that C. jejuni strains with a particular genotype and antimicrobial resistance profile are spreading in specific areas of Japan.

Use of biochemical kinetic data to determine strain relatedness among Salmonella enterica subsp. enterica isolates.

PubMed

de la Torre, E; Tello, M; Mateu, E M; Torre, E

2005-11-01

Classical biotyping characterizes strains by creating biotype profiles that consider only positive and negative results for a predefined set of biochemical tests. This method allows Salmonella subspecies to be distinguished but does not allow serotypes and phage types to be distinguished. The objective of this study was to determine the relatedness of isolates belonging to distinct Salmonella enterica subsp. enterica serotypes by using a refined biotyping process that considers the kinetics at which biochemical reactions take place. Using a Vitek GNI+ card for the identification of gram-negative organisms, we determined the biochemical kinetic reactions (28 biochemical tests) of 135 Salmonella enterica subsp. enterica strains of pig origin collected in Spain from 1997 to 2002 (59 Salmonella serotype Typhimurium strains, 25 Salmonella serotype Typhimurium monophasic variant strains, 25 Salmonella serotype Anatum strains, 12 Salmonella serotype Tilburg strains, 7 Salmonella serotype Virchow strains, 6 Salmonella serotype Choleraesuis strains, and 1 Salmonella enterica serotype 4,5,12:-:- strain). The results were expressed as the colorimetric and turbidimetric changes (in percent) and were used to enhance the classical biotype profile by adding kinetic categories. A hierarchical cluster analysis was performed by using the enhanced profiles and resulted in 14 clusters. Six major clusters grouped 94% of all isolates with a similarity of > or =95% within any given cluster, and eight clusters contained a single isolate. The six major clusters grouped not only serotypes of the same type but also phenotypic serotype variations into individual clusters. This suggests that metabolic kinetic reaction data from the biochemical tests commonly used for classic Salmonella enterica subsp. enterica biotyping can possibly be used to determine the relatedness between isolates in an easy and timely manner.

Development of a Multilocus Sequence Typing (MLST) scheme for Treponema pallidum subsp. pertenue: Application to yaws in Lihir Island, Papua New Guinea

PubMed Central

Godornes, Charmie; Giacani, Lorenzo; Barry, Alyssa E.; Mitja, Oriol

2017-01-01

Background Yaws is a neglected tropical disease, caused by Treponema pallidum subsp. pertenue. The disease causes chronic lesions, primarily in young children living in remote villages in tropical climates. As part of a global yaws eradication campaign initiated by the World Health Organization, we sought to develop and evaluate a molecular typing method to distinguish different strains of T. pallidum subsp. pertenue for disease control and epidemiological purposes. Methods and principal findings Published genome sequences of strains of T. pallidum subsp. pertenue and pallidum were compared to identify polymorphic genetic loci among the strains. DNA from a number of existing historical Treponema isolates, as well as a subset of samples from yaws patients collected in Lihir Island, Papua New Guinea, were analyzed using these targets. From these data, three genes (tp0548, tp0136 and tp0326) were ultimately selected to give a high discriminating capability among the T. pallidum subsp. pertenue samples tested. Intragenic regions of these three target genes were then selected to enhance the discriminating capability of the typing scheme using short readily amplifiable loci. This 3-gene multilocus sequence typing (MLST) method was applied to existing historical human yaws strains, the Fribourg-Blanc simian isolate, and DNA from 194 lesion swabs from yaws patients on Lihir Island, Papua New Guinea. Among all samples tested, fourteen molecular types were identified, seven of which were found in patient samples and seven among historical isolates or DNA. Three types (JG8, TD6, and SE7) were predominant on Lihir Island. Conclusions This MLST approach allows molecular typing and differentiation of yaws strains. This method could be a useful tool to complement epidemiological studies in regions where T. pallidum subsp. pertenue is prevalent with the overall goals of improving our understanding of yaws transmission dynamics and helping the yaws eradication campaign to succeed. PMID:29281641

Description of Mycobacterium chelonae subsp. bovis subsp. nov., isolated from cattle (Bos taurus coreanae), emended description of Mycobacterium chelonae and creation of Mycobacterium chelonae subsp. chelonae subsp. nov.

PubMed

Kim, Byoung-Jun; Kim, Ga-Na; Kim, Bo-Ram; Jeon, Che Ok; Jeong, Joseph; Lee, Seon Ho; Lim, Ji-Hun; Lee, Seung-Heon; Kim, Chang Ki; Kook, Yoon-Hoh; Kim, Bum-Joon

2017-10-01

Three rapidly growing mycobacterial strains, QIA-37 T , QIA-40 and QIA-41, were isolated from the lymph nodes of three separate Korean native cattle, Hanwoo (Bos taurus coreanae). These strains were previously shown to be phylogenetically distinct but closely related to Mycobacterium chelonae ATCC 35752 T by taxonomic approaches targeting three genes (16S rRNA, hsp6 and rpoB) and were further characterized using a polyphasic approach in this study. The 16S rRNA gene sequences of all three strains showed 99.7 % sequence similarity with that of the M. chelonae type strain. A multilocus sequence typing analysis targeting 10 housekeeping genes, including hsp65 and rpoB, revealed a phylogenetic cluster of these strains with M. chelonae. DNA-DNA hybridization values of 78.2 % between QIA-37 T and M. chelonae indicated that it belongs to M. chelonae but is a novel subspecies distinct from M. chelonae. Phylogenetic analysis based on whole-genome sequences revealed a 95.44±0.06 % average nucleotide identity (ANI) value with M. chelonae, slightly higher than the 95.0 % ANI criterion for determining a novel species. In addition, distinct phenotypic characteristics such as positive growth at 37 °C, at which temperature M. chelonae does not grow, further support the taxonomic status of these strains as representatives of a novel subspecies of M. chelonae. Therefore, we propose an emended description of Mycobacterium chelonae, and descriptions of M. chelonae subsp. chelonae subsp. nov. and M. chelonae subsp. bovis subsp. nov. are presented; strains ATCC 35752 T (=CCUG 47445 T =CIP 104535 T =DSM 43804 T =JCM 6388 T =NCTC 946 T ) and QIA-37 T (=KCTC 39630 T =JCM 30986 T ) are the type strains of the two novel subspecies.

Isolation of Campylobacter fetus subsp. jejuni from migratory waterfowl.

PubMed Central

Luechtefeld, N A; Blaser, M J; Reller, L B; Wang, W L

1980-01-01

Since the sources from which humans acquire Campylobacter enteritis are only partially known, we studied the frequency of carriage of Campylobacter fetus subsp. jejuni in migratory waterfowl. Cecal contents of various species of wild ducks were cultured on selective media that contained antibiotics to inhibit normal flora. Thirty-five percent of the 445 ducks cultured harbored C. fetus subsp. jejuni. Migratory waterfowl are yet another reservoir for this enteric pathogen and may be of public health importance for humans in the contamination of water or when used as food. PMID:7217334

Development and use of a selective medium for isolation of Leuconostoc spp. from vegetables and dairy products.

PubMed Central

Benkerroum, N; Misbah, M; Sandine, W E; Elaraki, A T

1993-01-01

A selective medium (LUSM medium) for the isolation of Leuconostoc spp. was developed. This medium contained 1.0% glucose, 1.0% Bacto Peptone (Difco), 0.5% yeast extract (BBL), 0.5% meat extract (Difco), 0.25% gelatin (Difco), 0.5% calcium lactate, 0.05% sorbic acid, 75 ppm of sodium azide (Sigma), 0.25% sodium acetate, 0.1% (vol/vol) Tween 80, 15% tomato juice, 30 micrograms of vancomycin (Sigma) per ml, 0.20 microgram of tetracycline (Serva) per ml, 0.5 mg of cysteine hydrochloride per ml, and 1.5% agar (Difco). LUSM medium was used successfully for isolation and enumeration of Leuconostoc spp. in dairy products and vegetables. Of 116 colony isolates obtained from fresh raw milk, curdled milk, or various vegetables, 115 were identified as members of the genus Leuconostoc. A total of 89 of these isolates were identified to species; 13.5% of the isolates were Leuconostoc cremoris, 7.9% were Leuconostoc mesenteroides subsp. mesenteroides, 11.2% were Leuconostoc mesenteroides subsp. dextranicum, 16.9% were Leuconostoc mesenteroides subsp. paramesenteroides, 10.1% were leuconostoc lactis, and 40.4% were Leuconostoc oenos. When we compared the counts obtained for two Leuconostoc strains, Leuconostoc dextranicum 181 and L. cremoris JLL8, on MRS agar and LUSM medium, we found no significant difference between the values obtained on the two media. PMID:8434926

First time isolation of Photobacterium damselae subsp. damselae from Caranx sexfasciatus in Persian Gulf, Iran

PubMed Central

Hassanzadeh, Yashgin; Bahador, Nima; Baseri-Salehi, Majid

2015-01-01

Background and Objective: Photobacterium damselae subsp. damselae is a marine pathogenic bacterium which causes disease in marine animals and human. This bacterium mostly found in coastal shallow seawater. So, the aim of this study was isolation and characterization of Photobacterium damselae subsp. damselae from edible fish of Persian Gulf, Bandar Abbas. Material and Methods: Totally 100 fish from different species were evaluated and out of that 5 different types of fish with external symptoms including: Caranx sexfasciatus, Lethrinus olivaceus, Scomberoid tol, Auxis thazard and Liza macrolepis, were collected from Bandar Abbas local fish market in September 2013. The samples were cultured on Marin Agar 2216 and Thiosulfate Citrate Bile salts Sucrose Agar media and incubated at 25°C for 48 hrs. Then the isolates were characterized using biochemical (API 20 NE system) and molecular techniques. In addition, antibiotic susceptibility, presence of poly β hydroxy butyrate and hemolysis activity of isolates were evaluated. Results and Conclusion: Entirely, 30 Gram negative bacterial colonies were isolated from the selected fish. Among the isolates, two suspected colonies were identified as Photobacterium damselae from Caranx sexfasciatus with API 20NE biochemical test. This results confirmed by 16s rRNA sequencing method. Both isolates showed α hemolytic with existence of β hydroxyl butyrate. Furthermore, the isolates were susceptible to ciprofloxacin, chloramphenicol and nalidixic acid. Conclusion: Overall, the study indicated first time isolation of this bacterium from one type of fish caught from Persian Gulf, which warns us to pay more attention to fishery in this geographical area. PMID:26668707

Dominant lactic acid bacteria and their technological properties isolated from the Himalayan ethnic fermented milk products.

PubMed

Dewan, Sailendra; Tamang, Jyoti Prakash

2007-10-01

Ethnic people of the Himalayan regions of India, Nepal, Bhutan and China consume a variety of indigenous fermented milk products made from cows milk as well as yaks milk. These lesser-known ethnic fermented foods are dahi, mohi, chhurpi, somar, philu and shyow. The population of lactic acid bacteria (LAB) ranged from 10(7) to 10(8) cfu/g in these Himalayan milk products. A total of 128 isolates of LAB were isolated from 58 samples of ethnic fermented milk products collected from different places of India, Nepal and Bhutan. Based on phenotypic characterization including API sugar test, the dominant lactic acid bacteria were identified as Lactobacillus bifermentans, Lactobacillus paracasei subsp. pseudoplantarum, Lactobacillus kefir, Lactobacillus hilgardii, Lactobacillus alimentarius, Lactobacillus paracasei subsp. paracasei, Lactobacillus plantarum, Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris and Enterococcus faecium. LAB produced a wide spectrum of enzymes and showed high galactosidase, leucine-arylamidase and phosphatase activities. They showed antagonistic properties against selected Gram-negative bacteria. None of the strains produced bacteriocin and biogenic amines under the test conditions used. Most strains of LAB coagulated skim milk with a moderate drop in pH. Some strains of LAB showed a high degree of hydrophobicity, suggesting these strains may have useful adhesive potential. This paper is the first report on functional lactic acid bacterial composition in some lesser-known ethnic fermented milk products of the Himalayas.

Genetic diversity and population structure of Lactobacillus delbrueckii subspecies bulgaricus isolated from naturally fermented dairy foods

PubMed Central

Song, Yuqin; Sun, Zhihong; Guo, Chenyi; Wu, Yarong; Liu, Wenjun; Yu, Jie; Menghe, Bilige; Yang, Ruifu; Zhang, Heping

2016-01-01

Lactobacillus delbrueckii subsp. bulgaricus is one of the most widely used starter culture strains in industrial fermented dairy manufacture. It is also common in naturally fermented dairy foods made using traditional methods. The subsp. bulgaricus strains found in naturally fermented foods may be useful for improving current industrial starter cultures; however, little is known regarding its genetic diversity and population structure. Here, a collection of 298 L. delbrueckii strains from naturally fermented products in Mongolia, Russia, and West China was analyzed by multi-locus sequence typing based on eight conserved genes. The 251 confirmed subsp. bulgaricus strains produced 106 unique sequence types, the majority of which were assigned to five clonal complexes (CCs). The geographical distribution of CCs was uneven, with CC1 dominated by Mongolian and Russian isolates, and CC2–CC5 isolates exclusively from Xinjiang, China. Population structure analysis suggested six lineages, L1–L6, with various homologous recombination rates. Although L2–L5 were mainly restricted within specific regions, strains belonging to L1 and L6 were observed in diverse regions, suggesting historical transmission events. These results greatly enhance our knowledge of the population diversity of subsp. bulgaricus strains, and suggest that strains from CC1 and L4 may be useful as starter strains in industrial fermentation. PMID:26940047

Fluoroquinolone Resistance in Streptococcus dysgalactiae subsp. equisimilis and Evidence for a Shared Global Gene Pool with Streptococcus pyogenes▿

PubMed Central

Pinho, M. D.; Melo-Cristino, J.; Ramirez, M.

2010-01-01

Quinolone resistance is an emerging problem in Streptococcus pyogenes, and recombination with Streptococcus dysgalactiae DNA has been implicated as a frequent mechanism leading to resistance. We have characterized a collection of S. dysgalactiae subsp. equisimilis isolates responsible for infections in humans (n = 314) and found a high proportion of levofloxacin-resistant isolates (12%). Resistance was associated with multiple emm types and genetic lineages, as determined by pulsed-field gel electrophoretic profiling. Since we could not find evidence for a role of efflux pumps in resistance, we sequenced the quinolone resistance-determining regions of the gyrA and parC genes of representative resistant and susceptible isolates. We found much greater diversity among the parC genes (19 alleles) than among the gyrA genes (5 alleles). While single mutations in either GyrA or ParC were sufficient to raise the MIC so that the strains were classified as intermediately resistant, higher-level resistance was associated with mutations in both GyrA and ParC. Evidence for recombination with S. pyogenes DNA was found in some parC alleles, but this was not exclusively associated with resistance. Our data support the existence of a common reservoir of genes conferring quinolone resistance shared between S. dysgalactiae subsp. equisimilis and S. pyogenes, while no recombination with the animal pathogen S. dysgalactiae subsp. dysgalactiae could be found. PMID:20145082

Protein shift and antigenic variation in the S-layer of Campylobacter fetus subsp. venerealis during bovine infection accompanied by genomic rearrangement of sapA homologs.

PubMed Central

Garcia, M M; Lutze-Wallace, C L; Denes, A S; Eaglesome, M D; Holst, E; Blaser, M J

1995-01-01

Campylobacter fetus subsp. venerealis isolated from a case of human vaginosis was inoculated into the uterus of a C. fetus-negative heifer. Isolates obtained weekly from the vaginal mucus exhibited variations in high-molecular-mass-protein profiles from that of the original inoculum, which had a dominant 110-kDa S-layer protein. Immunoblots of the weekly isolates with monoclonal antibody probes against the 110-kDa S-layer protein and other C. fetus S-layer proteins demonstrated antigenic shifts. Genomic digests of the isolates probed with a 75-mer oligonucleotide of the conserved sapA region also indicated that antigenic variation of the S-layer is accompanied by DNA rearrangement. PMID:7721688

First report of bacterial blight of crucifers caused by Pseudomonas cannabina pv. alisalensis in Minnesota on arugula (Eruca vesicaria subsp. sativa)

USDA-ARS?s Scientific Manuscript database

In 2011, bacterial blight of arugula (Eruca vesicaria subsp. sativa; cv. Roquette) was observed in organically grown plants under overhead irrigation near Delano, MN. Approximately 80 to 100% of each planting was affected. Blue-green fluorescent pseudomonads were isolated consistently on King’s Medi...

Chemical decontamination with n-acetyl-l-cysteine-sodium hydroxide improves recovery of viable Mycobacterium avium subsp. paratuberculosis organisms from cultured milk

USDA-ARS?s Scientific Manuscript database

Mycobacterium avium subsp. paratuberculosis (MAP) is shed into milk and feces of cows with advanced Johne’s disease, allowing transmission of MAP among animals. The objective of this study was to formulate an optimized protocol for the isolation of MAP from milk. Parameters investigated included che...

Sensitivity of mycobacterium avium subsp paratuberculosis, escherichia coli and salmonella enterica serotype typhimurium to low pH, high organic acids and ensiling

USDA-ARS?s Scientific Manuscript database

The ability of Mycobacterium avium subsp paratuberculosis (M. paratuberculosis), Salmonella enterica serotype Typhimurium (S. Typhimurium) and a commensal Escherichia coli (E. coli) isolate to persist under low pH and high organic acid conditions was determined. Die-off rates were calculated followi...

Genome Sequence of the Rice-Pathogenic Bacterium Acidovorax avenae subsp. avenae RS-1 ▿

PubMed Central

Xie, Guan-Lin; Zhang, Guo-Qing; Liu, He; Lou, Miao-Miao; Tian, Wen-Xiao; Li, Bin; Zhou, Xue-Ping; Zhu, Bo; Jin, Gu-Lei

2011-01-01

Acidovorax avenae subsp. avenae is a phytobacterium which is the causative agent of several plant diseases with economic significance. Here, we present the draft genome sequence of strain RS-1, which was isolated from rice shoots in a rice field in China. This strain can cause bacterial stripe of rice. PMID:21742879

Complete Genome Sequence of Clavibacter michiganensis subsp. insidiosus R1-1 Using PacBio Single-Molecule Real-Time Technology

PubMed Central

Lu, You; Samac, Deborah A.; Glazebrook, Jane

2015-01-01

We report here the complete genome sequence of Clavibacter michiganensis subsp. insidiosus R1-1, isolated in Minnesota, USA. The R1-1 genome, generated by a de novo assembly of PacBio sequencing data, is the first complete genome sequence available for this subspecies. PMID:25953184

PCR-Mediated Detection and Quantification of the Goss's Wilt Pathogen Clavibacter michiganensis subsp. nebraskensis Via a Novel Gene Target.

PubMed

McNally, R Ryan; Ishimaru, Carol A; Malvick, Dean K

2016-12-01

Goss's leaf blight and wilt of maize (corn) is a significant and reemerging disease caused by the bacterium Clavibacter michiganensis subsp. nebraskensis. Despite its importance, molecular tools for diagnosing and studying this disease remain limited. We report the identification of CMN_01184 as a novel gene target and its use in conventional PCR (cPCR) and SYBR green-based quantitative PCR (qPCR) assays for specific detection and quantification of C. michiganensis subsp. nebraskensis. The cPCR and qPCR assays based on primers targeting CMN_01184 specifically amplified only C. michiganensis subsp. nebraskensis among a diverse collection of 129 bacterial and fungal isolates, including multiple maize bacterial and fungal pathogens, environmental organisms from agricultural fields, and all known subspecies of C. michiganensis. Specificity of the assays for detection of only C. michiganensis subsp. nebraskensis was also validated with field samples of C. michiganensis subsp. nebraskensis-infected and uninfected maize leaves and C. michiganensis subsp. nebraskensis-infested and uninfested soil. Detection limits were determined at 30 and 3 ng of pure C. michiganensis subsp. nebraskensis DNA, and 100 and 10 CFU of C. michiganensis subsp. nebraskensis for the cPCR and qPCR assays, respectively. Infection of maize leaves by C. michiganensis subsp. nebraskensis was quantified from infected field samples and was standardized using an internal maize DNA control. These novel, specific, and sensitive PCR assays based on CMN_01184 are effective for diagnosis of Goss's wilt and for studies of the epidemiology and host-pathogen interactions of C. michiganensis subsp. nebraskensis.

Experimental infection of dogs with Bartonella henselae and Bartonella vinsonii subsp. berkhoffii.

PubMed

Balakrishnan, Nandhakumar; Cherry, Natalie A; Linder, Keith E; Pierce, Eric; Sontakke, Neal; Hegarty, Barbara C; Bradley, Julie M; Maggi, Ricardo G; Breitschwerdt, Edward B

2013-11-15

The lack of a suitable infection model remains an important obstacle for the pathophysiological understanding of Bartonella spp. The following pilot study was designed to determine whether cell culture-grown Bartonella henselae SA2 and Bartonella vinsonii subsp. berkhoffii genotype III would cause persistent bacteremia in dogs. Pre-inoculation screening established that two laboratory-raised Golden retrievers were naturally-infected with Bartonella koehlerae. Despite prior infection, one dog each was inoculated subcutaneously with 5 × 10(4)B. henselae (SA2 strain) or 3 × 10(4)B. vinsonii subsp. berkhoffii genotype III. Dogs were bled weekly for serological testing and culture using Bartonella alpha proteobacteria growth medium (BAPGM) diagnostic platform. Dog 1 seroconverted to B. henselae and Dog 2 seroconverted to B. vinsonii subsp. berkhoffii genotype III. Throughout the study period, Bartonella spp. DNA was neither amplified nor isolated in ante-mortem BAPGM enrichment blood cultures. B. henselae SA2 was isolated from a postmortem bone marrow from Dog 1 and B. koehlerae DNA was amplified from postmortem lung from Dog 2 following BAPGM enrichment culture. Limitations include lack of uninfected controls, a potentially suboptimal B. vinsonii subsp. berkhoffii inoculum and a relatively short duration of study. We conclude that following intradermal infection, sequestration of Bartonella spp. in tissues may limit diagnostic detection of these bacteria in dog blood samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Characterization of Salmonella Occurring at High Prevalence in a Population of the Land Iguana Conolophus subcristatus in Galápagos Islands, Ecuador

PubMed Central

Franco, Alessia; Hendriksen, Rene S.; Lorenzetti, Serena; Onorati, Roberta; Gentile, Gabriele; Dell'Omo, Giacomo; Aarestrup, Frank M.; Battisti, Antonio

2011-01-01

The aim of the study was to elucidate the association between the zoonotic pathogen Salmonella and a population of land iguana, Colonophus subcristatus, endemic to Galápagos Islands in Ecuador. We assessed the presence of Salmonella subspecies and serovars and estimated the prevalence of the pathogen in that population. Additionally, we investigated the genetic relatedness among isolates and serovars utilising pulsed field gel electrophoresis (PFGE) on XbaI-digested DNA and determined the antimicrobial susceptibility to a panel of antimicrobials. The study was carried out by sampling cloacal swabs from animals (n = 63) in their natural environment on in the island of Santa Cruz. A high prevalence (62/63, 98.4%) was observed with heterogeneity of Salmonella subspecies and serovars, all known to be associated with reptiles and with reptile-associated salomonellosis in humans. Serotyping revealed 14 different serovars among four Salmonella enterica subspecies: S. enterica subsp. enterica (n = 48), S. enterica subsp. salamae (n = 2), S. enterica subsp. diarizonae (n = 1), and S. enterica subsp. houtenae (n = 7). Four serovars were predominant: S. Poona (n = 18), S. Pomona (n = 10), S. Abaetetuba (n = 8), and S.Newport (n = 5). The S. Poona isolates revealed nine unique XbaI PFGE patterns, with 15 isolates showing a similarity of 70%. Nine S. Pomona isolates had a similarity of 84%. One main cluster with seven (88%) indistinguishable isolates of S. Abaetetuba was observed. All the Salmonella isolates were pan-susceptible to antimicrobials representative of the most relevant therapeutic classes. The high prevalence and absence of clinical signs suggest a natural interaction of the different Salmonella serovars with the host species. The interaction may have been established before any possible exposure of the iguanas and the biocenosis to direct or indirect environmental factors influenced by the use of antimicrobials in agriculture, in human medicine or in veterinary medicine. PMID:21853080

Characterization of Salmonella occurring at high prevalence in a population of the land iguana Conolophus subcristatus in Galápagos Islands, Ecuador.

PubMed

Franco, Alessia; Hendriksen, Rene S; Lorenzetti, Serena; Onorati, Roberta; Gentile, Gabriele; Dell'Omo, Giacomo; Aarestrup, Frank M; Battisti, Antonio

2011-01-01

The aim of the study was to elucidate the association between the zoonotic pathogen Salmonella and a population of land iguana, Colonophus subcristatus, endemic to Galápagos Islands in Ecuador. We assessed the presence of Salmonella subspecies and serovars and estimated the prevalence of the pathogen in that population. Additionally, we investigated the genetic relatedness among isolates and serovars utilising pulsed field gel electrophoresis (PFGE) on XbaI-digested DNA and determined the antimicrobial susceptibility to a panel of antimicrobials. The study was carried out by sampling cloacal swabs from animals (n = 63) in their natural environment on in the island of Santa Cruz. A high prevalence (62/63, 98.4%) was observed with heterogeneity of Salmonella subspecies and serovars, all known to be associated with reptiles and with reptile-associated salomonellosis in humans. Serotyping revealed 14 different serovars among four Salmonella enterica subspecies: S. enterica subsp. enterica (n = 48), S. enterica subsp. salamae (n = 2), S. enterica subsp. diarizonae (n = 1), and S. enterica subsp. houtenae (n = 7). Four serovars were predominant: S. Poona (n = 18), S. Pomona (n = 10), S. Abaetetuba (n = 8), and S. Newport (n = 5). The S. Poona isolates revealed nine unique XbaI PFGE patterns, with 15 isolates showing a similarity of 70%. Nine S. Pomona isolates had a similarity of 84%. One main cluster with seven (88%) indistinguishable isolates of S. Abaetetuba was observed. All the Salmonella isolates were pan-susceptible to antimicrobials representative of the most relevant therapeutic classes. The high prevalence and absence of clinical signs suggest a natural interaction of the different Salmonella serovars with the host species. The interaction may have been established before any possible exposure of the iguanas and the biocenosis to direct or indirect environmental factors influenced by the use of antimicrobials in agriculture, in human medicine or in veterinary medicine.

Tomato fruit and seed colonization by Clavibacter michiganensis subsp. michiganensis through external and internal routes.

PubMed

Tancos, Matthew A; Chalupowicz, Laura; Barash, Isaac; Manulis-Sasson, Shulamit; Smart, Christine D

2013-11-01

The Gram-positive bacterium Clavibacter michiganensis subsp. michiganensis, causal agent of bacterial wilt and canker of tomato, is an economically devastating pathogen that inflicts considerable damage throughout all major tomato-producing regions. Annual outbreaks continue to occur in New York, where C. michiganensis subsp. michiganensis spreads via infected transplants, trellising stakes, tools, and/or soil. Globally, new outbreaks can be accompanied by the introduction of contaminated seed stock; however, the route of seed infection, especially the role of fruit lesions, remains undefined. In order to investigate the modes of seed infection, New York C. michiganensis subsp. michiganensis field strains were stably transformed with a gene encoding enhanced green fluorescent protein (eGFP). A constitutively eGFP-expressing virulent C. michiganensis subsp. michiganensis isolate, GCMM-22, was used to demonstrate that C. michiganensis subsp. michiganensis could not only access seeds systemically through the xylem but also externally through tomato fruit lesions, which harbored high intra- and intercellular populations. Active movement and expansion of bacteria into the fruit mesocarp and nearby xylem vessels followed, once the fruits began to ripen. These results highlight the ability of C. michiganensis subsp. michiganensis to invade tomato fruits and seeds through multiple entry routes.

Tomato Fruit and Seed Colonization by Clavibacter michiganensis subsp. michiganensis through External and Internal Routes

PubMed Central

Tancos, Matthew A.; Chalupowicz, Laura; Barash, Isaac; Manulis-Sasson, Shulamit

2013-01-01

The Gram-positive bacterium Clavibacter michiganensis subsp. michiganensis, causal agent of bacterial wilt and canker of tomato, is an economically devastating pathogen that inflicts considerable damage throughout all major tomato-producing regions. Annual outbreaks continue to occur in New York, where C. michiganensis subsp. michiganensis spreads via infected transplants, trellising stakes, tools, and/or soil. Globally, new outbreaks can be accompanied by the introduction of contaminated seed stock; however, the route of seed infection, especially the role of fruit lesions, remains undefined. In order to investigate the modes of seed infection, New York C. michiganensis subsp. michiganensis field strains were stably transformed with a gene encoding enhanced green fluorescent protein (eGFP). A constitutively eGFP-expressing virulent C. michiganensis subsp. michiganensis isolate, GCMM-22, was used to demonstrate that C. michiganensis subsp. michiganensis could not only access seeds systemically through the xylem but also externally through tomato fruit lesions, which harbored high intra- and intercellular populations. Active movement and expansion of bacteria into the fruit mesocarp and nearby xylem vessels followed, once the fruits began to ripen. These results highlight the ability of C. michiganensis subsp. michiganensis to invade tomato fruits and seeds through multiple entry routes. PMID:24014525

Molecular typing of Mycobacterium Abscessus isolated from cystic fibrosis patients.

PubMed

Trovato, Alberto; Baldan, Rossella; Costa, Danila; Simonetti, Tullia M; Cirillo, Daniela M; Tortoli, Enrico

2017-01-01

The possibility of inter-human transmission of Mycobacterium abscessus in cystic fibrosis centres has been recently hypothesized suggesting the need for the molecular characterization of strains isolated from such patients. One hundred and forty one isolates of M. abscessus grown from sputum samples of 29 patients with cystic fibrosis were genotyped resorting to variable number of tandem repeats (VNTR) determination and whole genome sequencing (WGS). Out of 29 VNTR profiles, 15 were unique to the same number of patients while seven were shared by multiple patients. WGS showed that only two of the patients sharing common VNTR patterns were indeed infected by the same strain. The shared VNTR patterns were mostly present among the isolates of M. abscessus subsp. abscessus. As expected WGS showed a clearly higher discriminatory power in comparison with VNTR and appeared the only molecular epidemiology tool suitable to effectively discriminate the isolates of M. abscessus subsp. abscessus.

Draft Genome Sequence of Lactococcus lactis subsp. lactis bv. diacetylactis CRL264, a Citrate-Fermenting Strain

PubMed Central

Zuljan, Federico; Espariz, Martín; Blancato, Victor S.; Esteban, Luis; Alarcón, Sergio

2016-01-01

We report the draft genome sequence of Lactococcus lactis subsp. lactis bv. diacetylactis CRL264, a natural strain isolated from artisanal cheese from northwest Argentina. L. lactis subsp. lactis bv. diacetylactis is one of the most important microorganisms used as starter culture around the world. The CRL264 strain constitutes a model microorganism in the studies on the generation of aroma compounds (diacetyl, acetoin, and 2,3-butanediol) by lactic acid bacteria. Our genome analysis shows similar genetic organization to other available genomes of L. lactis bv. diacetylactis strains. PMID:26847906

Complete genomic sequences of two salmonella enterica subsp. enterica serogroup C2 (O:6,8) strains from central California

USDA-ARS?s Scientific Manuscript database

Salmonella enteric subsp. enterica strains RM11060, serotype 6,8:d:-, and RM11065, serotype 6,8:-:e,n,z15, were isolated from environmental sampling in Central California in 2009. We report the complete genome sequences and annotation of these two strains. These genomic sequences are distinct and wi...

Complete Genome Sequence of Clavibacter michiganensis subsp. insidiosus R1-1 Using PacBio Single-Molecule Real-Time Technology.

PubMed

Lu, You; Samac, Deborah A; Glazebrook, Jane; Ishimaru, Carol A

2015-05-07

We report here the complete genome sequence of Clavibacter michiganensis subsp. insidiosus R1-1, isolated in Minnesota, USA. The R1-1 genome, generated by a de novo assembly of PacBio sequencing data, is the first complete genome sequence available for this subspecies. Copyright © 2015 Lu et al.

Bacillus velezensis is not a later heterotypic synonym of Bacillus amyloliquefaciens; Bacillus methylotrophicus, Bacillus amyloliquefaciens subsp plantarum and ‘Bacillus oryzicola’ are later heterotypic synonyms of Bacillus

USDA-ARS?s Scientific Manuscript database

The rhizosphere isolated bacteria belonging to the Bacillus amyloliquefaciens subsp. plantarum and Bacillus methylotrophicus clades are an important group of strains that are used as plant growth promoters and antagonists of plant pathogens. These properties have made these strains the focus of comm...

Complete Whole-Genome Sequence of Salmonella enterica subsp. enterica Serovar Java NCTC5706.

PubMed

Fazal, Mohammed-Abbas; Alexander, Sarah; Burnett, Edward; Deheer-Graham, Ana; Oliver, Karen; Holroyd, Nancy; Parkhill, Julian; Russell, Julie E

2016-11-03

Salmonellae are a significant cause of morbidity and mortality globally. Here, we report the first complete genome sequence for Salmonella enterica subsp. enterica serovar Java strain NCTC5706. This strain is of historical significance, having been isolated in the pre-antibiotic era and was deposited into the National Collection of Type Cultures in 1939. © Crown copyright 2016.

Anoxybacillus kamchatkensis subsp. asaccharedens subsp. nov., a thermophilic bacterium isolated from a hot spring in Batman.

PubMed

Gul-Guven, Reyhan; Guven, Kemal; Poli, Annarita; Nicolaus, Barbara

2008-12-01

A new thermophilic spore-forming strain KG8(T) was isolated from the mud of Taslidere hot spring in Batman. Strain KG8(T) was aerobe, Gram-positive, rod-shaped, motile, occurring in pairs or filamentous. Growth was observed from 35-65 degrees C (optimum 55 degrees C) and at pH 5.5-9.5 (optimum pH 7.5). It was capable of utilizing starch, growth was observed until 3% NaCl (w/v) and it was positive for nitrate reduction. On the basis of 16S rRNA gene sequence similarity, strain KG8(T) was shown to be related most closely to Anoxybacillus species. Chemotaxonomic data (major isoprenoid quinone-menaquinone-7; major fatty acid-iso-C15:0 and iso-C17:0) supported the affiliation of strain KG8(T) to the genus Anoxybacillus. The results of DNA-DNA hybridization, physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain KG8(T). Based on these results we propose assigning a novel subspecies of Anoxybacillus kamchatkensis, to be named Anoxybacillus kamchatkensis subsp. asaccharedens subsp. nov. with the type strain KG8(T) (DSM 18475(T)=CIP 109280(T)).

Proteolysis in goat "coalho" cheese supplemented with probiotic lactic acid bacteria.

PubMed

Bezerra, Taliana Kênia Alves; de Araujo, Ana Rita Ribeiro; do Nascimento, Edilza Santos; de Matos Paz, José Eduardo; Gadelha, Carlos Alberto; Gadelha, Tatiane Santi; Pacheco, Maria Teresa Bertoldo; do Egypto Queiroga, Rita de Cássia Ramos; de Oliveira, Maria Elieidy Gomes; Madruga, Marta Suely

2016-04-01

This study aimed to analyse the proteolytic effects of adding isolated and combined probiotic strains to goat "coalho" cheese. The cheeses were: QS - with culture Start, composed by Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris (R704); QLA - with Lactobacillus acidophilus (LA-5); QLP - with Lactobacillus paracasei subsp. paracasei (L. casei 01); QB - with Bifidobacterium animalis subsp. lactis (BB 12); and QC, co-culture with the three probiotic microorganisms. The cheeses were analysed during 28 days of storage at 10°C. The probiotic cell count was higher than 6.5 and 7 log colony-forming units (CFU) g(-1) of cheese at the 1st and 28th days of storage, respectively. The addition of co-culture influenced (p<0.01) proteolysis in the cheese and resulted in a higher content of soluble protein and release of amino acids at the 1st day after processing. However, over all 28 days, the cheese supplemented with Bifidobacterium lactis in its isolated form showed the highest proteolytic activity, particularly in the hydrolysis of the alpha-s2 and kappa-casein fractions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Drug susceptibility testing of Mycobacterium Avium subsp. Avium isolates from naturally infected domestic pigeons to avian tuberculosis.

PubMed

Parvandar, Kaveh; Mayahi, Mansour; Mosavari, Nader; Pajoohi, Reza Aref

2016-12-01

Avian tuberculosis is one of the most important infections affecting most species of birds. Several mycobacterial species have been identified causing avian tuberculosis, and the organisms confirmed most frequently are Mycobacterium avium and Mycobacterium genavense. Any species of birds can be infected with M. avium. Generally, domesticated fowl or captive wild birds are affected more frequently than those living in the wild. M. avium can not only infect all species of birds, but can also infect some domesticated mammals to cause disease, usually with localized lesion. In immunocompetent individuals, M. avium complex isolates produce localized soft tissue infections, including chronic pulmonary infections in the elderly and cervical lymphadenitis in children, but rarely any disseminated disease. In patients infected with HIV and AIDS or in other immunocompromised individuals, M. avium complex isolates frequently cause severe systemic infections. The importance of avian tuberculosis and the risk of its zoonotic spread motivated our interest to determine the drug susceptibility testing of M. avium subsp. avium isolates from naturally infected domestic pigeons to avian tuberculosis. Based on their clinical signs, 80 pigeons suspected with avian tuberculosis were subjected to the study. Out of the 51 identified isolates, 20 M. avium subsp. avium were subjected to the test. Drug susceptibly testing was performed according to the guidelines by Centers for Disease Control and Prevention and using proportional method. In the drug susceptibility testing, all isolates were resistant to streptomycin, kanamycin, ethionamide, and thiophene carboxylic acid hydrazide. Additionally, 3, 2, and 1 isolates were susceptible to isoniazid, rifampin, and ethambutol, respectively. To date, no study has documented the drug susceptibility testing of M. avium isolates from infected birds to avian tuberculosis. Pigeons are extensively kept in urban and rural areas for homing and racing purposes; thus, they can infect people and farm animals exposed to their droppings containing pathogenic M. avium, and the severity of drug resistance of these isolates indicate lethality in immunocompromised individuals and incurable lymphadenitis in immunocompetent individuals. We suggest drug susceptibility testing for more nontuberculous mycobateria, particularly M. avium complex isolated from infected birds and humans, as well as molecular basics of drug sensitivity in order to detect resistance genes of pathogenic M. avium subsp. avium. Copyright © 2016.

Isolation of Mycobacterium avium subsp paratuberculosis (Map) from feral cats on a dairy farm with Map-infected cattle.

PubMed

Palmer, Mitchell V; Stoffregen, William C; Carpenter, Jeremy G; Stabel, Judith R

2005-07-01

Paratuberculosis is an economically important disease of dairy cattle caused by Mycobacterium avium subsp. paratuberculosis (Map). The role of nonruminant, nondomestic animals in the epidemiology of paratuberculosis in cattle is unclear. To examine nonruminant, nondomestic animals for the presence of Map, 25 feral cats, nine mice (species unknown), eight rabbits (Sylvilagus floridanus), six raccoons (Procyon lotor), and three opossums (Didelphis virginiana) were collected from a mid-western dairy with known Map-infected cattle. Mycobacterium avium subsp. paratuberculosis was isolated from the mesenteric lymph node from seven of 25 (28%) feral cats. Ileum was culture-positive for three of these seven cats, and an isolation of Map was also made from the ileum of one of nine (11%) mice. Tissue samples from other species were negative as determined by Map culture; microscopic lesions consistent with paratuberculosis were not seen in any animal. Restriction fragment polymorphism analysis of isolates from cats and dairy cattle suggest interspecies transmission. The means by which interspecies transmission occurred may be through ingestion of Map-contaminated feces or waste milk or through ingestion of Map-infected prey. Shedding of Map from infected cats was not evaluated. The epidemiologic role of Map-infected feral cats on dairy farms requires further investigation.

Isolation of Campylobacter spp. from Three Species of Antarctic Penguins in Different Geographic Locations.

PubMed

García-Peña, F J; Llorente, M T; Serrano, T; Ruano, M J; Belliure, J; Benzal, J; Herrera-León, S; Vidal, V; D'Amico, V; Pérez-Boto, D; Barbosa, A

2017-03-01

The presence of Campylobacter species was studied in three Antarctic penguin species, Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua). A total of 390 penguins were captured in 12 different rookeries along the Antarctic Peninsula with differences in the amount of human visitation: six colonies were highly visited [Stranger Point, King George Island (P. papua and P. adeliae); Hannah Point, Livingston Island (P. papua and P. antarctica); Deception Island (P. antarctica); and Paradise Bay, Antarctic Peninsula (P. papua)], and six colonies were rarely visited [Devil's Point, Byers Peninsula, Livingston Island (P. papua); Cierva Cove, Antarctic Peninsula (P. papua); Rongé Island (P. papua and P. antarctica); Yalour Island (P. adeliae); and Avian Island (P. adeliae)]. A total of 23 strains were isolated from penguins from nine different rookeries. Campylobacter lari subsp. lari was isolated from eight samples (seven from P. papua and one from P. adeliae); C. lari subsp. concheus from 13 (ten from P. adeliae and three from P. antarctica) and C. volucris from two samples (both from P. papua). We did not find any significant differences in the prevalence of Campylobacter spp. between the populations in highly and rarely visited areas. This is the first report of C. lari subsp. concheus and C. volucris isolation from penguins in the Antarctic region.

Detecting Genetic Introgression: High Levels of Intersubspecific Recombination Found in Xylella fastidiosa in Brazil

PubMed Central

Yuan, Xiaoli; Bromley, Robin E.; Stouthamer, Richard

2012-01-01

Documenting the role of novel mutation versus homologous recombination in bacterial evolution, and especially in the invasion of new hosts, is central to understanding the long-term dynamics of pathogenic bacteria. We used multilocus sequence typing (MLST) to study this issue in Xylella fastidiosa subsp. pauca from Brazil, a bacterium causing citrus variegated chlorosis (CVC) and coffee leaf scorch (CLS). All 55 citrus isolates typed (plus one coffee isolate) defined three similar sequence types (STs) dominated by ST11 (85%), while the remaining 22 coffee isolates defined two STs, mainly ST16 (74%). This low level of variation masked unusually large allelic differences (>1% divergence with no intermediates) at five loci (leuA, petC, malF, cysG, and holC). We developed an introgression test to detect whether these large differences were due to introgression via homologous recombination from another X. fastidiosa subspecies. Using additional sequencing around these loci, we established that the seven randomly chosen MLST targets contained seven regions of introgression totaling 2,172 bp of 4,161 bp (52%), only 409 bp (10%) of which were detected by other recombination tests. This high level of introgression suggests the hypothesis that X. fastidiosa subsp. pauca became pathogenic on citrus and coffee (crops cultivated in Brazil for several hundred years) only recently after it gained genetic variation via intersubspecific recombination, facilitating a switch from native hosts. A candidate donor is the subspecies infecting plum in the region since 1935 (possibly X. fastidiosa subsp. multiplex). This hypothesis predicts that nonrecombinant native X. fastidiosa subsp. pauca (not yet isolated) does not cause disease in citrus or coffee. PMID:22544234

Detecting genetic introgression: high levels of intersubspecific recombination found in Xylella fastidiosa in Brazil.

PubMed

Nunney, Leonard; Yuan, Xiaoli; Bromley, Robin E; Stouthamer, Richard

2012-07-01

Documenting the role of novel mutation versus homologous recombination in bacterial evolution, and especially in the invasion of new hosts, is central to understanding the long-term dynamics of pathogenic bacteria. We used multilocus sequence typing (MLST) to study this issue in Xylella fastidiosa subsp. pauca from Brazil, a bacterium causing citrus variegated chlorosis (CVC) and coffee leaf scorch (CLS). All 55 citrus isolates typed (plus one coffee isolate) defined three similar sequence types (STs) dominated by ST11 (85%), while the remaining 22 coffee isolates defined two STs, mainly ST16 (74%). This low level of variation masked unusually large allelic differences (>1% divergence with no intermediates) at five loci (leuA, petC, malF, cysG, and holC). We developed an introgression test to detect whether these large differences were due to introgression via homologous recombination from another X. fastidiosa subspecies. Using additional sequencing around these loci, we established that the seven randomly chosen MLST targets contained seven regions of introgression totaling 2,172 bp of 4,161 bp (52%), only 409 bp (10%) of which were detected by other recombination tests. This high level of introgression suggests the hypothesis that X. fastidiosa subsp. pauca became pathogenic on citrus and coffee (crops cultivated in Brazil for several hundred years) only recently after it gained genetic variation via intersubspecific recombination, facilitating a switch from native hosts. A candidate donor is the subspecies infecting plum in the region since 1935 (possibly X. fastidiosa subsp. multiplex). This hypothesis predicts that nonrecombinant native X. fastidiosa subsp. pauca (not yet isolated) does not cause disease in citrus or coffee.

H(+) -ATPase-defective variants of Lactobacillus delbrueckii subsp. bulgaricus contribute to inhibition of postacidification of yogurt during chilled storage.

PubMed

Wang, Xinhui; Ren, Hongyang; Liu, Dayu; Wang, Bing; Zhu, Wenyou; Wang, Wei

2013-02-01

Continued acid production by Lactobacillus delbrueckii subsp. bulgaricus during the chilled storage of yogurt is the major cause of postacidification, resulting in a short shelf life. Two H(+) -ATPase defective variants of L. delbrueckii subsp. bulgaricus were successfully isolated and their H(+) -ATPase activities were reduced by 51.3% and 34.3%, respectively. It was shown that growth and acid production of variants were remarkably inhibited. The variants were more sensitive to acidic condition and had a significant rate for inactivation of H(+) -ATPase by N, N-dicyclohexylcarbodiimide (DCCD), along with a low H(+) -extrusion, suggesting that H(+) -ATPase is direct response for H(+) -extrusion. In addition, the variants were also more sensitive to NaCl, while H(+) -ATPase activities of variants and parent strain were significantly enhanced by NaCl stress. Obviously, H(+) -ATPase might be involved in Na(+) transportation. Furthermore, variants were inoculated in fermented milk to ferment yogurt. There was no significant difference in flavor, whereas the postacidification of yogurt during chilled storage was remarkably inhibited. It is suggested that application of L. delbrueckii subsp. bulgaricus with reduced H(+) -ATPase activity in yogurt fermentation is one of effect, economic and simple avenues of inhibiting postacidification of yogurt during refrigerated storage, giving a longer shelf life. During yogurt fermentation, continued acid production by Lactobacillus delbrueckii subsp. bulgaricus during the chilled storage of yogurt leads to milk fermentation with high postacidification, resulting in a short shelf life. In this work, 2 acid-sensitive variant strains of L. delbrueckii subsp. bulgaricus were isolated. The characteristics related to H(+) -ATPase were compared and it was observed that milk fermented by the variants had lower postacidification, giving a longer shelf life. Application of L. delbrueckii subsp. bulgaricus with reduced H(+) -ATPase activity in yogurt fermentation might be one of effect, economic and simple avenues of inhibiting yogurt postacidification during chilled storage, giving a longer shelf life. © 2013 Institute of Food Technologists®

Intersubspecific Recombination in Xylella fastidiosa Strains Native to the United States: Infection of Novel Hosts Associated with an Unsuccessful Invasion

PubMed Central

Hopkins, Donald L.; Morano, Lisa D.; Russell, Stephanie E.; Stouthamer, Richard

2014-01-01

The bacterial pathogen Xylella fastidiosa infects xylem and causes disease in many plant species in the Americas. Different subspecies of this bacterium and different genotypes within subspecies infect different plant hosts, but the genetics of host adaptation are unknown. Here we examined the hypothesis that the introduction of novel genetic variation via intersubspecific homologous recombination (IHR) facilitates host shifts. We investigated IHR in 33 X. fastidiosa subsp. multiplex isolates previously identified as recombinant based on 8 loci (7 multilocus sequence typing [MLST] loci plus 1 locus). We found significant evidence of introgression from X. fastidiosa subsp. fastidiosa in 4 of the loci and, using published data, evidence of IHR in 6 of 9 additional loci. Our data showed that IHR regions in 2 of the 4 loci were inconsistent (12 mismatches) with X. fastidiosa subsp. fastidiosa alleles found in the United States but consistent with alleles from Central America. The other two loci were consistent with alleles from both regions. We propose that the recombinant forms all originated via genomewide recombination of one X. fastidiosa subsp. multiplex ancestor with one X. fastidiosa subsp. fastidiosa donor from Central America that was introduced into the United States but subsequently disappeared. Using all of the available data, 5 plant hosts of the recombinant types were identified, 3 of which also supported non-IHR X. fastidiosa subsp. multiplex, but 2 were unique to recombinant types from blueberry (7 isolates from Georgia, 3 from Florida); and blackberry (1 each from Florida and North Carolina), strongly supporting the hypothesis that IHR facilitated a host shift to blueberry and possibly blackberry. PMID:24296499

Intersubspecific recombination in Xylella fastidiosa Strains native to the United States: infection of novel hosts associated with an unsuccessful invasion.

PubMed

Nunney, Leonard; Hopkins, Donald L; Morano, Lisa D; Russell, Stephanie E; Stouthamer, Richard

2014-02-01

The bacterial pathogen Xylella fastidiosa infects xylem and causes disease in many plant species in the Americas. Different subspecies of this bacterium and different genotypes within subspecies infect different plant hosts, but the genetics of host adaptation are unknown. Here we examined the hypothesis that the introduction of novel genetic variation via intersubspecific homologous recombination (IHR) facilitates host shifts. We investigated IHR in 33 X. fastidiosa subsp. multiplex isolates previously identified as recombinant based on 8 loci (7 multilocus sequence typing [MLST] loci plus 1 locus). We found significant evidence of introgression from X. fastidiosa subsp. fastidiosa in 4 of the loci and, using published data, evidence of IHR in 6 of 9 additional loci. Our data showed that IHR regions in 2 of the 4 loci were inconsistent (12 mismatches) with X. fastidiosa subsp. fastidiosa alleles found in the United States but consistent with alleles from Central America. The other two loci were consistent with alleles from both regions. We propose that the recombinant forms all originated via genomewide recombination of one X. fastidiosa subsp. multiplex ancestor with one X. fastidiosa subsp. fastidiosa donor from Central America that was introduced into the United States but subsequently disappeared. Using all of the available data, 5 plant hosts of the recombinant types were identified, 3 of which also supported non-IHR X. fastidiosa subsp. multiplex, but 2 were unique to recombinant types from blueberry (7 isolates from Georgia, 3 from Florida); and blackberry (1 each from Florida and North Carolina), strongly supporting the hypothesis that IHR facilitated a host shift to blueberry and possibly blackberry.

Draft Genome Sequence of Lactobacillus delbrueckii subsp. bulgaricus CFL1, a Lactic Acid Bacterium Isolated from French Handcrafted Fermented Milk.

PubMed

Meneghel, Julie; Dugat-Bony, Eric; Irlinger, Françoise; Loux, Valentin; Vidal, Marie; Passot, Stéphanie; Béal, Catherine; Layec, Séverine; Fonseca, Fernanda

2016-03-03

Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus) is a lactic acid bacterium widely used for the production of yogurt and cheeses. Here, we report the genome sequence of L. bulgaricus CFL1 to improve our knowledge on its stress-induced damages following production and end-use processes. Copyright © 2016 Meneghel et al.

Bacillus amyloliquefaciens subsp. plantarum GR53, a potent biocontrol agent resists Rhizoctonia disease on Chinese cabbage through hormonal and antioxidants regulation.

PubMed

Kang, Sang-Mo; Radhakrishnan, Ramalingam; Lee, In-Jung

2015-10-01

The fungus Rhizoctonia solani is one of the causal agents of numerous diseases that affect crop growth and yield. The aim of this present investigation was to identify a biocontrol agent that acts against R. solani and to determine the agent's protective effect through phytohormones and antioxidant regulation in experimentally infected Chinese cabbage plants. Four rhizospheric soil bacterial isolates GR53, GR169, GR786, and GR320 were tested for their antagonistic activity against R. solani. Among these isolates, GR53 significantly suppressed fungal growth. GR53 was identified as Bacillus amyloliquefaciens subsp. plantarum by phylogenetic analysis of the 16S rDNA sequence. The biocontrol activity of B. amyloliquefaciens subsp. plantarum GR53 was tested in Chinese cabbage plants under controlled conditions. Results showed that R. solani inhibited plant growth (length, width, fresh and dry weight of leaves) by reducing chlorophyll and total phenolic content, as well as by increasing the levels of salicylic acid, jasmonic acid, abscisic acid, and DPPH scavenging activity. By regulating the levels of these compounds, the co-inoculation of B. amyloliquefaciens subsp. plantarum GR53 heightened induced systemic resistance in infected Chinese cabbage, effectively mitigating R. solani-induced damaging effects and improving plant growth. The results obtained from this study suggest that B. amyloliquefaciens subsp. plantarum GR53 is an effective biocontrol agent to prevent the damage caused by R. solani in Chinese cabbage plants.

Mycobacterium avium subsp. hominissuis infection in swine associated with peat used for bedding.

PubMed

Johansen, Tone Bjordal; Agdestein, Angelika; Lium, Bjørn; Jørgensen, Anne; Djønne, Berit

2014-01-01

Mycobacterium avium subsp. hominissuis is an environmental bacterium causing opportunistic infections in swine, resulting in economic losses. Additionally, the zoonotic aspect of such infections is of concern. In the southeastern region of Norway in 2009 and 2010, an increase in condemnation of pig carcasses with tuberculous lesions was seen at the meat inspection. The use of peat as bedding in the herds was suspected to be a common factor, and a project examining pigs and environmental samples from the herds was initiated. Lesions detected at meat inspection in pigs originating from 15 herds were sampled. Environmental samples including peat from six of the herds and from three peat production facilities were additionally collected. Samples were analysed by culture and isolates genotyped by MLVA analysis. Mycobacterium avium subsp. hominissuis was detected in 35 out of 46 pigs, in 16 out of 20 samples of peat, and in one sample of sawdust. MLVA analysis demonstrated identical isolates from peat and pigs within the same farms. Polyclonal infection was demonstrated by analysis of multiple isolates from the same pig. To conclude, the increase in condemnation of porcine carcasses at slaughter due to mycobacteriosis seemed to be related to untreated peat used as bedding.

Mycobacterium avium subsp. hominissuis Infection in Swine Associated with Peat Used for Bedding

PubMed Central

Johansen, Tone Bjordal; Lium, Bjørn; Jørgensen, Anne; Djønne, Berit

2014-01-01

Mycobacterium avium subsp. hominissuis is an environmental bacterium causing opportunistic infections in swine, resulting in economic losses. Additionally, the zoonotic aspect of such infections is of concern. In the southeastern region of Norway in 2009 and 2010, an increase in condemnation of pig carcasses with tuberculous lesions was seen at the meat inspection. The use of peat as bedding in the herds was suspected to be a common factor, and a project examining pigs and environmental samples from the herds was initiated. Lesions detected at meat inspection in pigs originating from 15 herds were sampled. Environmental samples including peat from six of the herds and from three peat production facilities were additionally collected. Samples were analysed by culture and isolates genotyped by MLVA analysis. Mycobacterium avium subsp. hominissuis was detected in 35 out of 46 pigs, in 16 out of 20 samples of peat, and in one sample of sawdust. MLVA analysis demonstrated identical isolates from peat and pigs within the same farms. Polyclonal infection was demonstrated by analysis of multiple isolates from the same pig. To conclude, the increase in condemnation of porcine carcasses at slaughter due to mycobacteriosis seemed to be related to untreated peat used as bedding. PMID:25431762

Antimicrobial susceptibility and multilocus sequence typing of Mycoplasma capricolum subsp. capricolum

PubMed Central

Tatay-Dualde, Juan; Prats-van der Ham, Miranda; Paterna, Ana; Sánchez, Antonio; Corrales, Juan Carlos; Contreras, Antonio; Tola, Sebastiana; Gómez-Martin, Ángel

2017-01-01

Mycoplasma capricolum subsp. capricolum is one of the causative agents of contagious agalactia (CA). Nevertheless, there is still a lack of information about its antimicrobial susceptibility and genetic characteristics. Therefore, the aim of this work was to study the antimicrobial and genetic variability of different Mycoplasma capricolum subsp. capricolum field isolates. For this purpose, the growth inhibition effect of 18 antimicrobials and a multilocus sequence typing (MLST) scheme based on five housekeeping genes (fusA, glpQ, gyrB, lepA and rpoB) were performed on 32 selected field isolates from Italy and Spain.The results showed a wide range of growth inhibitory effects for almost all the antimicrobials studied. Macrolides presented lower efficacy inhibiting Mcc growth than in previous works performed on other CA-causative mycoplasmas. Erythromycin was not able to inhibit the growth of any of the studied strains, contrary to doxycycline, which inhibited the growth of all of them from low concentrations. On the other hand, the study of the concatenated genes revealed a high genetic variability among the different Mcc isolates. Hence, these genetic variations were greater than the ones reported in prior works on other mycoplasma species. PMID:28346546

Draft Genome Sequence of Lactococcus lactis subsp. lactis bv. diacetylactis CRL264, a Citrate-Fermenting Strain.

PubMed

Zuljan, Federico; Espariz, Martín; Blancato, Victor S; Esteban, Luis; Alarcón, Sergio; Magni, Christian

2016-02-04

We report the draft genome sequence of Lactococcus lactis subsp. lactis bv. diacetylactis CRL264, a natural strain isolated from artisanal cheese from northwest Argentina. L. lactis subsp. lactis bv. diacetylactis is one of the most important microorganisms used as starter culture around the world. The CRL264 strain constitutes a model microorganism in the studies on the generation of aroma compounds (diacetyl, acetoin, and 2,3-butanediol) by lactic acid bacteria. Our genome analysis shows similar genetic organization to other available genomes of L. lactis bv. diacetylactis strains. Copyright © 2016 Zuljan et al.

Bioluminescence imaging of Clavibacter michiganensis subsp. michiganensis infection of tomato seeds and plants.

PubMed

Xu, Xiulan; Miller, Sally A; Baysal-Gurel, Fulya; Gartemann, Karl-Heinz; Eichenlaub, Rudolf; Rajashekara, Gireesh

2010-06-01

Clavibacter michiganensis subsp. michiganensis is a Gram-positive bacterium that causes wilting and cankers, leading to severe economic losses in commercial tomato production worldwide. The disease is transmitted from infected seeds to seedlings and mechanically from plant to plant during seedling production, grafting, pruning, and harvesting. Because of the lack of tools for genetic manipulation, very little is known regarding the mechanisms of seed and seedling infection and movement of C. michiganensis subsp. michiganensis in grafted plants, two focal points for application of bacterial canker control measures in tomato. To facilitate studies on the C. michiganensis subsp. michiganensis movement in tomato seed and grafted plants, we isolated a bioluminescent C. michiganensis subsp. michiganensis strain using the modified Tn1409 containing a promoterless lux reporter. A total of 19 bioluminescent C. michiganensis subsp. michiganensis mutants were obtained. All mutants tested induced a hypersensitive response in Mirabilis jalapa and caused wilting of tomato plants. Real-time colonization studies of germinating seeds using a virulent, stable, constitutively bioluminescent strain, BL-Cmm17, showed that C. michiganensis subsp. michiganensis aggregated on hypocotyls and cotyledons at an early stage of germination. In grafted seedlings in which either the rootstock or scion was exposed to BL-Cmm17 via a contaminated grafting knife, bacteria were translocated in both directions from the graft union at higher inoculum doses. These results emphasize the use of bioluminescent C. michiganensis subsp. michiganensis to help better elucidate the C. michiganensis subsp. michiganensis-tomato plant interactions. Further, we demonstrated the broader applicability of this tool by successful transformation of C. michiganensis subsp. nebraskensis with Tn1409::lux. Thus, our approach would be highly useful to understand the pathogenesis of diseases caused by other subspecies of the agriculturally important C. michiganensis.

Bioluminescence Imaging of Clavibacter michiganensis subsp. michiganensis Infection of Tomato Seeds and Plants ▿

PubMed Central

Xu, Xiulan; Miller, Sally A.; Baysal-Gurel, Fulya; Gartemann, Karl-Heinz; Eichenlaub, Rudolf; Rajashekara, Gireesh

2010-01-01

Clavibacter michiganensis subsp. michiganensis is a Gram-positive bacterium that causes wilting and cankers, leading to severe economic losses in commercial tomato production worldwide. The disease is transmitted from infected seeds to seedlings and mechanically from plant to plant during seedling production, grafting, pruning, and harvesting. Because of the lack of tools for genetic manipulation, very little is known regarding the mechanisms of seed and seedling infection and movement of C. michiganensis subsp. michiganensis in grafted plants, two focal points for application of bacterial canker control measures in tomato. To facilitate studies on the C. michiganensis subsp. michiganensis movement in tomato seed and grafted plants, we isolated a bioluminescent C. michiganensis subsp. michiganensis strain using the modified Tn1409 containing a promoterless lux reporter. A total of 19 bioluminescent C. michiganensis subsp. michiganensis mutants were obtained. All mutants tested induced a hypersensitive response in Mirabilis jalapa and caused wilting of tomato plants. Real-time colonization studies of germinating seeds using a virulent, stable, constitutively bioluminescent strain, BL-Cmm17, showed that C. michiganensis subsp. michiganensis aggregated on hypocotyls and cotyledons at an early stage of germination. In grafted seedlings in which either the rootstock or scion was exposed to BL-Cmm17 via a contaminated grafting knife, bacteria were translocated in both directions from the graft union at higher inoculum doses. These results emphasize the use of bioluminescent C. michiganensis subsp. michiganensis to help better elucidate the C. michiganensis subsp. michiganensis-tomato plant interactions. Further, we demonstrated the broader applicability of this tool by successful transformation of C. michiganensis subsp. nebraskensis with Tn1409::lux. Thus, our approach would be highly useful to understand the pathogenesis of diseases caused by other subspecies of the agriculturally important C. michiganensis. PMID:20400561

An outbreak of fatal hemorrhagic pneumonia caused by Streptococcus equi subsp. zooepidemicus in shelter dogs.

PubMed

Byun, Jae Won; Yoon, Soon Seek; Woo, Gye-Hyeong; Jung, Byeong Yeal; Joo, Yi-Seok

2009-09-01

An outbreak of fatal hemorrhagic pneumonia with 70-90% morbidity and 50% mortality occurred in an animal shelter in Yangju, Gyeonggi Province, Korea. Clinically, the affected dogs showed severe respiratory distress within 48 h after arriving in the shelter. The dead were found mainly with nasal bleeding and hematemesis. At necropsy, hemothorax and hemorrhagic pneumonia along with severe pulmonary consolidation was observed, though histopathological analysis showed mainly hemorrhagic bronchopneumonia. Lymphoid depletion was inconsistently seen in the spleen, tonsil and bronchial lymph node. Gram-positive colonies were shown in blood vessels or parenchyma of cerebrum, lung, liver, spleen, and kidney. Also, Streptococcus (S.) equi subsp. zooepidemicus was isolated from the various organs in which the bacterium was microscopically and histologically detected. In addition, approximately 0.9 Kb specific amplicon, antiphagocytic factor H binding protein, was amplified in the bacterial isolates. In this study, we reported an outbreak of canine hemorrhagic bronchopneumonia caused by S. equi subsp. zooepidemicus in an animal shelter in Yangju, Korea.

An outbreak of fatal hemorrhagic pneumonia caused by Streptococcus equi subsp. zooepidemicus in shelter dogs

PubMed Central

Yoon, Soon-Seek; Woo, Gye-Hyeong; Jung, Byeong Yeal; Joo, Yi-Seok

2009-01-01

An outbreak of fatal hemorrhagic pneumonia with 70~90% morbidity and 50% mortality occurred in an animal shelter in Yangju, Gyeonggi Province, Korea. Clinically, the affected dogs showed severe respiratory distress within 48 h after arriving in the shelter. The dead were found mainly with nasal bleeding and hematemesis. At necropsy, hemothorax and hemorrhagic pneumonia along with severe pulmonary consolidation was observed, though histopathological analysis showed mainly hemorrhagic bronchopneumonia. Lymphoid depletion was inconsistently seen in the spleen, tonsil and bronchial lymph node. Gram-positive colonies were shown in blood vessels or parenchyma of cerebrum, lung, liver, spleen, and kidney. Also, Streptococcus (S.) equi subsp. zooepidemicus was isolated from the various organs in which the bacterium was microscopically and histologically detected. In addition, approximately 0.9 Kb specific amplicon, antiphagocytic factor H binding protein, was amplified in the bacterial isolates. In this study, we reported an outbreak of canine hemorrhagic bronchopneumonia caused by S. equi subsp. zooepidemicus in an animal shelter in Yangju, Korea. PMID:19687630

Four new diterpenoid alkaloids from Aconitum japonicum subsp. subcuneatum.

PubMed

Yamashita, Hiroshi; Takeda, Keiko; Haraguchi, Machiko; Abe, Yuki; Kuwahara, Natsumi; Suzuki, Shota; Terui, Ayaka; Masaka, Takumi; Munakata, Naoko; Uchida, Mariko; Nunokawa, Masashi; Kaneda, Kyousuke; Goto, Masuo; Lee, Kuo-Hsiung; Wada, Koji

2018-01-01

Diterpenoid alkaloids with remarkable chemical properties and biological activities are frequently found in plants of the genera Aconitum, Delphinium, and Garrya. Accordingly, several diterpenoid alkaloid constituents of Aconitum and Delphinium plants as well as their derivatives exhibited cytotoxic activity against lung, prostate, nasopharyngeal, and vincristine-resistant nasopharyngeal cancer cell lines. Four new C 19 -diterpenoid alkaloids, 14-anisoyllasianine (1), 14-anisoyl-N-deethylaconine (2), N-deethylaljesaconitine A (3), and N-deethylnevadensine (4), together with 17 known C 19 - and C 20 -diterpenoid alkaloids, were isolated in a phytochemical investigation of rhizoma of Aconitum japonicum THUNB. subsp. subcuneatum (NAKAI) KADOTA. Their structures were elucidated by extensive spectroscopic methods including NMR (1D and 2D), IR, and MS (HRMS). Eight known diterpenoid alkaloids, lipoaconitine, lipomesaconitine, aconine, nevadenine, talatisamine, nevadensine, ryosenamine, and dehydrolucidusculine, were isolated the first time from A. japonicum subsp. subcuneatum. Three of the new C 19 -diterpenoid alkaloids (1, 3, 4) and six of the known diterpenoid alkaloids were evaluated for cytotoxic activity against five human tumor cell lines.

Probiotic Properties of Leuconostoc mesenteroides Isolated from Aguamiel of Agave salmiana.

PubMed

Diana, Castro-Rodríguez; Humberto, Hernández-Sánchez; Jorge, Yáñez Fernández

2015-06-01

Four lactic acid bacteria, Leuconostoc mesenteroides subsp. mesenteroides, were isolated from aguamiel the sap obtained from Agave salmiana from México and identified by 16S rRNA gene sequence analysis. The probiotic potential of these strains was evaluated and compared with a commercial probiotic (Lactobacillus plantarum 299v) from human origin. All the strains survived the in vitro gastrointestinal simulation conditions: the stomach simulation (3 h, pH 2, 37 °C) and the intestinal simulation (4 h, bile salts 0.5%, 37 °C). All the strains showed a strong hydrophilic character with n-hexadecane and chloroform assays, and all the strains showed a mucin adhesion rate similar to that of L. plantarum 299v. The strains of L. mesenteroides subsp. mesenteroides exhibited similar antimicrobial activity against some pathogens in comparison with L. plantarum 299v. Some antibiotics inhibited the growth of the strains. L. mesenteroides subsp. mesenteroides exhibited in vitro probiotic potential, and it could be better characterized through future in vivo tests.

Francisella tularensis: No Evidence for Transovarial Transmission in the Tularemia Tick Vectors Dermacentor reticulatus and Ixodes ricinus.

PubMed

Genchi, Marco; Prati, Paola; Vicari, Nadia; Manfredini, Andrea; Sacchi, Luciano; Clementi, Emanuela; Bandi, Claudio; Epis, Sara; Fabbi, Massimo

2015-01-01

Tularemia is a zoonosis caused by the Francisella tularensis, a highly infectious Gram-negative coccobacillus. Due to easy dissemination, multiple routes of infection, high environmental contamination and morbidity and mortality rates, Francisella is considered a potential bioterrorism threat and classified as a category A select agent by the CDC. Tick bites are among the most prevalent modes of transmission, and ticks have been indicated as a possible reservoir, although their reservoir competence has yet to be defined. Tick-borne transmission of F. tularensis was recognized in 1923, and transstadial transmission has been demonstrated in several tick species. Studies on transovarial transmission, however, have reported conflicting results. The aim of this study was to evaluate the role of ticks as reservoirs for Francisella, assessing the transovarial transmission of F. tularensis subsp. holarctica in ticks, using experimentally-infected females of Dermacentor reticulatus and Ixodes ricinus. Transmission electron microscopy and fluorescence in situ hybridization showed F. tularensis within oocytes. However, cultures and bioassays of eggs and larvae were negative; in addition, microscopy techniques revealed bacterial degeneration/death in the oocytes. These results suggest that bacterial death might occur in oocytes, preventing the transovarial transmission of Francisella. We can speculate that Francisella does not have a defined reservoir, but that rather various biological niches (e.g. ticks, rodents), that allow the bacterium to persist in the environment. Our results, suggesting that ticks are not competent for the bacterium vertical transmission, are congruent with this view.

Draft Genome Sequence of a Multidrug-Resistant Klebsiella quasipneumoniae subsp. similipneumoniae Isolate from a Clinical Source

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

Ozer, Egon A.; Morris, Andrew R.; Krapp, Fiorella

We report here the draft genome sequence of a multidrug-resistant clinical isolate ofKlebsiella quasipneumoniaesubsp.similipneumoniae, KP_Z4175. This strain, isolated as part of a hospital infection-control screening program, is resistant to multiple β-lactam antibiotics, aminoglycosides, and trimethoprim-sulfamethoxazole.

Taxonomic Subgroups of Pasteurella multocida Correlate with Clinical Presentation

PubMed Central

Chen, Henry I.; Hulten, Kristina; Clarridge III, Jill E.

2002-01-01

Pasteurella multocida is a small nonmotile gram-negative coccobacillus that is found in the nasopharynx and gastrointestinal tract of many wild and domesticated animals. In humans it most commonly causes cellulitis and localized superficial skin abscesses following an animal bite or scratch. The respiratory tract is the second most common site of infection for Pasteurella. Of the more than 17 species of Pasteurella known, Pasteurella multocida subsp. multocida and Pasteurella multocida subsp. septica are among the most common pathogens in humans. With the use of molecular techniques, distinction between different subspecies of P. multocida can be made more easily and accurately. We used the sequence of the 16S ribosomal DNA (rDNA) and repetitive extragenic palindromic sequence-PCR (REP-PCR) to characterize 20 strains (14 of P. multocida subsp. multocida and 6 of P. multocida subsp. septica; the 16S rDNA is identical for P. multocida subsp. multocida and Pasteurella multocida subsp. gallicida but differs from that of P. multocida subsp. septica) isolated from various anatomic sites. We found excellent correlation between the 16S rDNA sequence (a marker for a small conserved region of the genome), REP-PCR (a marker for a large portion of the genome), and biochemical tests (trehalose and sorbitol). We also found a correlation between the clinical presentation and the taxonomic group, with P. multocida subsp. septica more often associated with wounds than with respiratory infections (67 versus 17%, respectively) (P < 0.05, Z test) and P. multocida subsp. multocida more often associated with respiratory infections than with wounds (71 versus 14%, respectively) (P < 0.05, Z test). PMID:12202590

Common genomic features of Campylobacter jejuni subsp. doylei strains distinguish them from C. jejuni subsp. jejuni

PubMed Central

Parker, Craig T; Miller, William G; Horn, Sharon T; Lastovica, Albert J

2007-01-01

Background Campylobacter jejuni has been divided into two subspecies: C. jejuni subsp. jejuni (Cjj) and C. jejuni subsp. doylei (Cjd). Nearly all of the C. jejuni strains isolated are Cjj; nevertheless, although Cjd strains are isolated infrequently, they differ from Cjj in two key aspects: they are obtained primarily from human clinical samples and are associated often with bacteremia, in addition to gastroenteritis. In this study, we utilized multilocus sequence typing (MLST) and a DNA microarray-based comparative genomic indexing (CGI) approach to examine the genomic diversity and gene content of Cjd strains. Results A geographically diverse collection of eight Cjd strains was examined by MLST and determined to be phylogenetically distinct from Cjj strains. Microarray-based CGI approach also supported this. We were able to demonstrate that Cjd strains exhibited divergence from Cjj strains NCTC 11168 and RM1221 in many of the intraspecies hypervariable regions. Moreover, multiple metabolic, transport and virulence functions (e.g. cytolethal distending toxin) were shown to be absent in the Cjd strains examined. Conclusion Our data demonstrate that Cjd are phylogenetically distinct from Cjj strains. Using the CGI approach, we identified subsets of absent genes from amongst the C. jejuni genes that provide clues as to the potential evolutionary origin and unusual pathogenicity of Cjd. PMID:17535437

Whole Genome Shotgun Analysis: the Resolving Power to Distinguish 2009 and 2010 Clinical Isolates of Salmonella Typhimurium Possessing the Same PFGE Type

USDA-ARS?s Scientific Manuscript database

Between 2009 and 2011, Salmonella enterica subsp. enterica serovar Typhimurium with the JPXX01.0014 pulse field gel electrophoresis (PFGE) type was isolated across the United States. The 2009 isolates were associated with an outbreak from an unidentified food source, while later isolates were linked...

DNA methylase activity as a marker for the presence of a family of phage-like elements conferring efflux-mediated macrolide resistance in streptococci.

PubMed

Figueiredo, T A; Aguiar, S I; Melo-Cristino, J; Ramirez, M

2006-11-01

Recently, two related chimeric genetic elements (Tn1207.3 and Phi10394.4) were shown to carry the macrolide efflux gene mef in Streptococcus pyogenes (group A streptococci [GAS]). The dissemination of elements belonging to the Tn1207.3/Phi10394.4 family in recent isolates of GAS, Streptococcus dysgalactiae subsp. equisimilis, Streptococcus pneumoniae, and Streptococcus agalactiae recovered in Portugal was surveyed. In total, 149 GAS, 18 S. pneumoniae, 4 S. dysgalactiae subsp. equisimilis, and 5 S. agalactiae isolates from infections, presenting the M phenotype of macrolide resistance and containing the mef gene, were screened for the presence of Tn1207.3/Phi10394.4 by PCR targeting open reading frames (ORFs) specific for these related elements. All the GAS isolates tested and one of the S. dysgalactiae subsp. equisimilis isolates carried Tn1207.3. However, neither of these elements was found in the isolates of the other streptococcal species. It was also noted that the DNAs of the isolates carrying Tn1207.3 were resistant to cleavage by the endonuclease SmaI. Cloning and expression of ORF12 of Tn1207.3 in Escherichia coli showed that it encoded a methyltransferase that rendered DNA refractory to cleavage by SmaI (M.Spy10394I). Using this characteristic as a marker for the presence of the Tn1207.3/Phi10394.4 family, we reviewed the literature and concluded that these genetic elements are widely distributed among tetracycline-susceptible GAS isolates presenting the M phenotype from diverse geographic origins and may have played an important role in the dissemination of macrolide resistance in this species.

Multilocus Sequence Analysis of Streptococcus canis Confirms the Zoonotic Origin of Human Infections and Reveals Genetic Exchange with Streptococcus dysgalactiae subsp. equisimilis

PubMed Central

Pinho, M. D.; Matos, S. C.; Pomba, C.; Lübke-Becker, A.; Wieler, L. H.; Preziuso, S.; Melo-Cristino, J.

2013-01-01

Streptococcus canis is an animal pathogen that occasionally causes human infections. Isolates recovered from infections of animals (n = 78, recovered from 2000 to 2010 in three European countries, mainly from house pets) and humans (n = 7, recovered from 2006 to 2010 in Portugal) were identified by phenotypic and genotypic methods and characterized by antimicrobial susceptibility testing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and emm typing. S. canis isolates presented considerable variability in biochemical profiles and 16S rRNA. Resistance to antimicrobial agents was low, with the most significant being tet(M)- and tet(O)-mediated tetracycline resistance. MLST analysis revealed a polyclonal structure of the S. canis population causing infections, where the same genetic lineages were found infecting house pets and humans and were disseminated in distinct geographic locations. Phylogenetic analysis indicated that S. canis was a divergent taxon of the sister species Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis and found evidence of acquisition of genetic material by S. canis from S. dysgalactiae subsp. equisimilis. PFGE confirmed the MLST findings, further strengthening the similarity between animal and human isolates. The presence of emm-like genes was restricted to a few isolates and correlated with some MLST-based genetic lineages, but none of the human isolates could be emm typed. Our data show that S. canis isolates recovered from house pets and humans constitute a single population and demonstrate that isolates belonging to the main genetic lineages identified have the ability to infect the human host, providing strong evidence for the zoonotic nature of S. canis infection. PMID:23345291

Multilocus sequence analysis of Streptococcus canis confirms the zoonotic origin of human infections and reveals genetic exchange with Streptococcus dysgalactiae subsp. equisimilis.

PubMed

Pinho, M D; Matos, S C; Pomba, C; Lübke-Becker, A; Wieler, L H; Preziuso, S; Melo-Cristino, J; Ramirez, M

2013-04-01

Streptococcus canis is an animal pathogen that occasionally causes human infections. Isolates recovered from infections of animals (n = 78, recovered from 2000 to 2010 in three European countries, mainly from house pets) and humans (n = 7, recovered from 2006 to 2010 in Portugal) were identified by phenotypic and genotypic methods and characterized by antimicrobial susceptibility testing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and emm typing. S. canis isolates presented considerable variability in biochemical profiles and 16S rRNA. Resistance to antimicrobial agents was low, with the most significant being tet(M)- and tet(O)-mediated tetracycline resistance. MLST analysis revealed a polyclonal structure of the S. canis population causing infections, where the same genetic lineages were found infecting house pets and humans and were disseminated in distinct geographic locations. Phylogenetic analysis indicated that S. canis was a divergent taxon of the sister species Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis and found evidence of acquisition of genetic material by S. canis from S. dysgalactiae subsp. equisimilis. PFGE confirmed the MLST findings, further strengthening the similarity between animal and human isolates. The presence of emm-like genes was restricted to a few isolates and correlated with some MLST-based genetic lineages, but none of the human isolates could be emm typed. Our data show that S. canis isolates recovered from house pets and humans constitute a single population and demonstrate that isolates belonging to the main genetic lineages identified have the ability to infect the human host, providing strong evidence for the zoonotic nature of S. canis infection.

Molecular and biochemical characterizations of human oral lactobacilli as putative probiotic candidates.

PubMed

Strahinic, I; Busarcevic, M; Pavlica, D; Milasin, J; Golic, N; Topisirovic, L

2007-04-01

The objective of this study was to characterize the lactobacilli from the human oral cavity as a potential source of probiotic strains. Samples were collected from four different locations within the oral cavity: surface of healthy tooth, oral mucous membrane, surface of tooth decay and deep tooth decay. On the basis of morphological and biochemical properties eight categories were formed and 26 isolates were selected for further characterization. The isolates were determined as Lactobacillus sp. using primers specific for 16S rDNA. Sequencing of 16S rDNA genes and repetitive sequence-based polymerase chain reactions were used for determination to species and subspecies levels. Predominant species were Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus salivarius and Lactobacillus paracasei subsp. paracasei, while Lactobacillus acidophilus, Lactobacillus cellobiosus, Lactobacillus delbrueckii subsp. lactis and Lactobacillus gasseri were also present. The isolates Lactobacillus salivarius BGHO1, Lactobacillus fermentum BGHO36 and BGHO64, Lactobacillus gasseri BGHO89 and Lactobacillus delbrueckii subsp. lactis BGHO99 exhibited antagonistic action on the growth of Staphylococcus aureus, Enterococcus faecalis, Micrococcus flavus, Salmonella enteritidis, Streptococcus pneumoniae and Streptococcus mutans, but not on growth of Candida albicans. Moreover, the isolates L. salivarius BGHO1 and L. gasseri BGHO89 were tolerant to low pH and high concentration of bile salts. Taken together, these findings imply that L. salivarius BGHO1 and L. gasseri BGHO89 might be subjects for additional investigation as potential probiotic strains.

Clavibacter michiganensis subsp. phaseoli subsp. nov., pathogenic in bean.

PubMed

González, Ana J; Trapiello, Estefanía

2014-05-01

A yellow Gram-reaction-positive bacterium isolated from bean seeds (Phaseolus vulgaris L.) was identified as Clavibacter michiganensis by 16S rRNA gene sequencing. Molecular methods were employed in order to identify the subspecies. Such methods included the amplification of specific sequences by PCR, 16S amplified rDNA restriction analysis (ARDRA), RFLP and multilocus sequence analysis as well as the analysis of biochemical and phenotypic traits including API 50CH and API ZYM results. The results showed that strain LPPA 982T did not represent any known subspecies of C. michiganensis. Pathogenicity tests revealed that the strain is a bean pathogen causing a newly identified bacterial disease that we name bacterial bean leaf yellowing. On the basis of these results, strain LPPA 982T is regarded as representing a novel subspecies for which the name Clavibacter michiganensis subsp. phaseoli subsp. nov. is proposed. The type strain is LPPA 982T (=CECT 8144T=LMG 27667T).

Evolution of Salmonella Cerro on a dairy farm over an eight-year period

USDA-ARS?s Scientific Manuscript database

Salmonella enterica subsp. enterica serovar Cerro, frequently isolated from dairy cattle and an occasional pathogen of humans, was recurrently isolated over an eight-year period on a dairy farm in south-central Pennsylvania. The genomes of 18 S. Cerro isolates recovered directly from the feces of in...

Comparison of the antimicrobial activities of gallium nitrate and gallium maltolate against Mycobacterium avium subsp. paratuberculosis in vitro.

PubMed

Fecteau, Marie-Eve; Aceto, Helen W; Bernstein, Lawrence R; Sweeney, Raymond W

2014-10-01

Johne's disease (JD) is an enteric infection of cattle and other ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). This study compared the antimicrobial activities of gallium nitrate (GaN) and gallium maltolate (GaM) against two field MAP isolates by use of broth culture. The concentrations that resulted in 99% growth inhibition of isolates 1 and 2 were, respectively, 636 µM and 183 µM for GaN, and 251 µM and 142 µM for GaM. For both isolates, time to detection was significantly higher for GaM than GaN. These results suggest that GaM is more efficient than GaN in inhibiting MAP growth in vitro. Copyright © 2014 Elsevier Ltd. All rights reserved.

Bacteriocinogenic Lactococcus lactis subsp. lactis DF04Mi isolated from goat milk: evaluation of the probiotic potential.

PubMed

Furtado, Danielle N; Todorov, Svetoslav D; Landgraf, Mariza; Destro, Maria T; Franco, Bernadette D G M

2014-01-01

Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its probiotic potential. Lc. lactis DF4Mi was resistant to acidic pH and oxbile, presented co-aggregation with Listeria monocytogenes, and was not affected by several drugs from different generic groups, being sensitive to most tested antibiotics. These properties indicate that this Lc. lactis strain can be used for enhancement of dairy foods safety and quality, in combination with potential probiotic properties.

Biological suppression of potato ring rot by fluorescent pseudomonads.

PubMed Central

de la Cruz, A R; Poplawsky, A R; Wiese, M V

1992-01-01

Three strains of fluorescent pseudomonads (IS-1, IS-2, and IS-3) isolated from potato underground stems with roots showed in vitro antibiosis against 30 strains of the ring rot bacterium Clavibacter michiganensis subsp. sepedonicus. On the basis of morphological and biochemical tests and fatty acid analysis, IS-1 and IS-2 were identified as Pseudomonas aureofaciens and IS-3 was identified as P. fluorescens biovar III. IS-1 was the most inhibitory to C. michiganensis subsp. sepedonicus strains in vitro, followed by IS-3 and IS-2. Suppression of ring rot by these antagonists was demonstrated in greenhouse trials with stem-cultured potato (cv. Russet Burbank) seedlings. Although each antagonist significantly reduced C. michiganensis subsp. sepedonicus populations, only IS-1 reduced infection by C. michiganensis subsp. sepedonicus. In a second experiment, treatment with IS-1 (10(9) CFU/ml) significantly reduced ring rot infection by 23.4 to 26.7% after 5 to 8 weeks. The average C. michiganensis subsp. sepedonicus population was also significantly reduced by 50 to 52%. Application of different combinations of antagonist strains was not more effective than single-strain treatment. Images PMID:1622275

Understanding the ontogeny and succession of Bacillus velezensis and B. subtilis subsp. subtilis by focusing on kimchi fermentation.

PubMed

Cho, Min Seok; Jin, Yong Ju; Kang, Bo Kyoung; Park, Yu Kyoung; Kim, ChangKug; Park, Dong Suk

2018-05-04

Bacillus subtilis and B. velezensis are frequently isolated from various niches, including fermented foods, water, and soil. Within the Bacillus subtilis group, B. velezensis and B. subtilis subsp. subtilis have received significant attention as biological resources for biotechnology-associated industries. Nevertheless, radical solutions are urgently needed to identify microbes during their ecological succession to accurately confirm their action at the species or subspecies level in diverse environments, such as fermented materials. Thus, in this study, previously published genome data of the B. subtilis group were compared to exploit species- or subspecies-specific genes for use as improved qPCR targets to detect B. velezensis and B. subtilis subsp. subtilis in kimchi samples. In silico analyses of the selected genes and designed primer sequences, in conjunction with SYBR Green real-time PCR, confirmed the robustness of this newly developed assay. Consequently, this study will allow for new insights into the ontogeny and succession of B. velezensis and B. subtilis subsp. subtilis in various niches. Interestingly, in white kimchi without red pepper powder, neither B. subtilis subsp. subtilis nor B. velezensis was detected.

Seed-associated subspecies of the genus Clavibacter are clearly distinguishable from Clavibacter michiganensis subsp. michiganensis.

PubMed

Yasuhara-Bell, Jarred; Alvarez, Anne M

2015-03-01

The genus Clavibacter contains one recognized species, Clavibacter michiganensis. Clavibacter michiganensis is subdivided into subspecies based on host specificity and bacteriological characteristics, with Clavibacter michiganensis subsp. michiganensis causing bacterial canker of tomato. Clavibacter michiganensis subsp. michiganensis is often spread through contaminated seed leading to outbreaks of bacterial canker in tomato production areas worldwide. The frequent occurrence of non-pathogenic Clavibacter michiganensis subsp. michiganensis-like bacteria (CMB) is a concern for seed producers because Clavibacter michiganensis subsp. michiganensis is a quarantine organism and detection of a non-pathogenic variant may result in destruction of an otherwise healthy seed lot. A thorough biological and genetic characterization of these seed-associated CMB strains was performed using standard biochemical tests, cell wall analyses, metabolic profiling using Biolog, and single-gene and multilocus sequence analyses. Combined, these tests revealed two distinct populations of seed-associated members of the genus Clavibacter that differed from each other, as well as from all other described subspecies of Clavibacter michiganensis. DNA-DNA hybridization values are 70 % or higher, justifying placement into the single recognized species, C. michiganensis, but other analyses justify separate subspecies designations. Additionally, strains belonging to the genus Clavibacter isolated from pepper also represent a distinct population and warrant separate subspecies designation. On the basis of these data we propose subspecies designations for separate non-pathogenic subpopulations of Clavibacter michiganensis: Clavibacter michiganensis subsp. californiensis subsp. nov. and Clavibacter michiganensis subsp. chilensis subsp. nov. for seed-associated strains represented by C55(T) ( = ATCC BAA-2691(T) = CFBP 8216(T)) and ZUM3936(T) ( = ATCC BAA-2690(T) = CFBP 8217(T)), respectively. Recognition of separate subspecies is essential for improved international seed testing operations. © 2015 IUMS.

In vivo wound-healing activity of Euphorbia characias subsp. wulfenii: Isolation and quantification of quercetin glycosides as bioactive compounds.

PubMed

Özbilgin, Serkan; Acıkara, Özlem Bahadır; Akkol, Esra Küpeli; Süntar, Ipek; Keleş, Hikmet; İşcan, Gülçin Saltan

2018-06-16

The latex and the aerial parts of Euphorbia characias L. (Euphorbiaceae) have been used as medicinal plant to treat wounds and warts in traditional medicine. The effect of the plant extract was tested in vivo and in vitro with experimental models to find scientific evidence for traditional use in wound healing. Potentially active wound-healer compounds were isolated from the active fraction using fractionation procedures under the guidance of biological assay and the possible role of the compounds in the wound healing process was also determined. N-hexane, ethyl acetate, and methanol extracts were successively prepared from the aerial parts of E. characias subsp. wulfenii. The extracts were tested with linear incision, circular excision wound models and the hydroxyproline assay method to assess the wound-healing activity. The inhibition of the increase in capillary permeability induced by acetic acid, an acute inflammation model, was used to assay the anti-inflammatory activity. Different chromatographic separation techniques on sephadex and silica gel columns, and bioassay guided assay techniques have been used to isolate the active compounds of the plant. Moreover, hyaluronidase, collagenase and elastase enzymes inhibitory effect of active principle were investigated in vitro to find out the mechanism of action. The methanol (MeOH-ex) extract of the aerial parts of E. characias subsp. wulfenii showed significant wound healing activity (linear incision wound model: 43.04%; circular excision wound model 65.24%) and anti-inflammatory activity (34.74%). The methanol extract was separated into its fractions by column chromatography for isolation of efficient compounds. Biological activity of the fractions were assessed and further isolation and purification processes have been carried out in the active fraction. Isolation studies were carried out from the MeOH-ex fraction to obtain active constituents and their structures were elucidated to be quercetin-3-O-rhamnoside (quercitrin), quercetin-3-O-galactoside (hyperoside), and quercetin-3-O-arabinoside (guaijaverin). Further in vitro and in vivo assays showed that quercetin derivatives were responsible for the wound-healing eactivity of the plant, and also found to be significant anti-elastase and anti-collagenase activities. The amounts of three compounds, isolated from active fraction, were determined by using high performance liquid chromatography. Calibration equation was calculated with dilutions, prepared from pure substances, and assay was performed in total extract, prepared from E. characias subsp. wulfenii. It was detected that the plant had 1.22% quercitrin, 0.35% hyperoside, and 0.11% guaijaverin. The validation of the analytical method was performed by linearity, precision, limit of detection, and limit of quantification parameters. Present study supported the traditional use of the aerial parts E. characias subsp. wulfenii as wound healer and quercetin derivatives were isolated as active components from the active fraction by using bioassay-guided fractionation technique. Copyright © 2018. Published by Elsevier B.V.

Secondary Metabolites, Glandular Trichomes and Biological Activity of Sideritis montana L. subsp. montana from Central Italy.

PubMed

Venditti, Alessandro; Bianco, Armandodoriano; Frezza, Claudio; Serafini, Mauro; Giacomello, Ginevra; Giuliani, Claudia; Bramucci, Massimo; Quassinti, Luana; Lupidi, Giulio; Lucarini, Domenico; Papa, Fabrizio; Maggi, Filippo

2016-10-01

Sideritis montana subsp. montana is a small annual herb occurring in countries bordering the Mediterranean and Balkan regions. The secondary metabolism of this plant has not been fully explored so far. The aim of the present study was to understand the complex mixture of secondary metabolites and the type of secretory structures. The polar constituents were isolated by column chromatography from the ethanolic extract, and their structure was elucidated by NMR and MS. The essential oil was isolated by hydrodistillation and analysed by GC/MS. The plant indumentum was studied by light and scanning electron microscopy. To complete the work, the essential oil antioxidant activity and cytotoxicity on tumor cells were evaluated by DPPH, ABTS, FRAP, and MTT methods. Four different classes of secondary metabolites were isolated, namely flavonoids, caffeoylquinic derivatives, glycosidic hydroquinones and iridoids. The essential oil was mainly characterized by sesquiterpenene hydrocarbons. Peltate and long-capitate hairs were the main sites where terpenes and polar constituents are produced. The secondary metabolites found in S. montana subsp. montana are of chemotaxonomic interest, some of them being typical of the genus Sideritis. The trichomes types observed partially differ from those described in other members of the genus Sideritis. The essential oil showed noteworthy inhibition on tumor cells. © 2016 Wiley-VHCA AG, Zürich.

Characterization and purification of a bacteriocin from Lactobacillus paracasei subsp. paracasei BMK2005, an intestinal isolate active against multidrug-resistant pathogens.

PubMed

Bendjeddou, Kamel; Fons, Michel; Strocker, Pierre; Sadoun, Djamila

2012-04-01

A strain of Lactobacillus paracasei subsp. paracasei BMK2005 isolated from healthy infant faeces has shown a remarkable antibacterial activity against 32 bacterial pathogenic strains of human clinical isolates. Among them, 13 strains belonging to species of Escherichia coli, Citrobacter freundii, Citrobacter diversus, Klebsiella oxytoca, Enterobacter cloacae and Pseudomonas aeruginosa were resistant to Cefotaxime (CTX) and Ceftazidime (CAZ), and 4 strains of Staphylococcus aureus were resistant to Methicillin (MRSA). This antibacterial activity was attributed to a bacteriocin designated as Paracaseicin A. It was heat-stable up to 120°C for 5 min and active within the pH range of 2-5. Its activity was lost when treated with proteases, which reveals its proteinaceous nature. This bacteriocin was successfully purified only by two steps of reversed phase chromatography. Its molecular mass, determined by mass spectrometry analysis, was 2,462.5 Da. To our knowledge, the present study is the first report on characterization and purification of a bacteriocin, produced by a L. paracasei subsp. paracasei strain exhibiting an antibacterial activity against various multidrug-resistant species of Gram-positive and Gram-negative bacteria, which reveals its potential for use in prevention or treatment of infections caused by multidrug-resistant species especially in cases of antibiotics-associated diarrhea (AAD).

Oceanobacillus neutriphilus sp. nov., isolated from activated sludge in a bioreactor.

PubMed

Yang, Jun-Yi; Huo, Ying-Yi; Xu, Xue-Wei; Meng, Fan-Xu; Wu, Min; Wang, Chun-Sheng

2010-10-01

A Gram-stain-positive, neutrophilic, rod-shaped bacterium, strain A1g(T), was isolated from activated sludge of a bioreactor and was subjected to a polyphasic taxonomic characterization. The isolate grew in the presence of 0-17.0 % (w/v) NaCl and at pH 6.0-9.0; optimum growth was observed in the presence of 3.0-5.0 % (w/v) NaCl and at pH 7.0. Strain A1g(T) was motile, formed cream-coloured colonies, was catalase- and oxidase-positive and was able to hydrolyse aesculin, Tween 40 and Tween 60. Chemotaxonomic analysis revealed menaquinone-7 as the predominant respiratory quinone and anteiso-C₁₅:₀, anteiso-C₁₇:₀, iso-C₁₆:₀ and iso-C₁₅:₀ as major fatty acids. The genomic DNA G+C content of strain A1g(T) was 36.3 mol%. Comparative 16S rRNA gene sequence analysis revealed that the new isolate belonged to the genus Oceanobacillus and exhibited closest phylogenetic affinity to the type strains of Oceanobacillus oncorhynchi subsp. incaldanensis (97.9 % similarity) and O. oncorhynchi subsp. oncorhynchi (97.5 %), but less than 97 % sequence similarity with respect to the type strains of other recognized Oceanobacillus species. Levels of DNA-DNA relatedness between strain A1g(T) and reference strains O. oncorhynchi subsp. incaldanensis DSM 16557(T), O. oncorhynchi subsp. oncorhynchi JCM 12661(T) and Oceanobacillus iheyensis DSM 14371(T) were 29, 45 and 38 %, respectively. On the basis of phenotypic and genotypic data, strain A1g(T) is considered to represent a novel species of the genus Oceanobacillus, for which the name Oceanobacillus neutriphilus sp. nov. is proposed. The type strain is A1g(T) (=CGMCC 1.7693(T) =JCM 15776(T)).

Characterization of lactic acid bacteria isolated from a Thai low-salt fermented fish product and the role of garlic as substrate for fermentation.

PubMed

Paludan-Müller, C; Huss, H H; Gram, L

1999-02-18

Lactic acid bacteria (LAB) isolated from raw materials (fish, rice, garlic and banana leaves) and processed som-fak (a Thai low-salt fermented fish product) were characterized by API 50-CH and other phenotypic criteria. Lactococcus lactis subsp. lactis and Leuconostoc citreum were specifically associated with fish fillet and minced fish, Lactobacillus paracasei subsp. paracasei with boiled rice and Weisella confusa with garlic mix and banana leaves. In addition, Lactobacillus plantarum, Lactobacillus pentosus and Pediococcus pentosaceus were isolated from raw materials. A succession of aciduric, homofermentative lactobacillus species, dominated by Lb. plantarum/pentosus, was found during fermentation. In total, 9% of the strains fermented starch and 19% fermented garlic, the two main carbohydrate components in som-fak. The ability to ferment garlic was paralleled by a capacity to ferment inulin. An increased percentage of garlic fermenting strains was found during fermentation of som-fak, from 8% at day 1 to 40% at day 5. No starch fermenting strains were isolated during fermentation. Three mixed LAB cultures, composed of either starch fermenting Lc. lactis subsp. lactis and Lb. paracasei subsp. paracasei, or garlic fermenting Lb. plantarum and Pd. pentosaceus, or a combination of these strains were inoculated into laboratory prepared som-fak with or without garlic. In som-fak without garlic, pH was above 4.8 after three days, irrespective of addition of mixed LAB cultures. The starch fermenting LAB were unable to ferment som-fak and sensory spoilage occurred after three days. Fermentation with the combined mix of starch and garlic fermenting strains led to production of 2.5% acid and a decrease in pH to 4.5 in two days. The fermentation was slightly slower with the garlic fermenting strains alone. This is the first report describing the role of garlic as carbohydrate source for LAB in fermented fish products.

Terrestrial and marine Antarctic fungi extracts active against Xanthomonas citri subsp. citri.

PubMed

Vieira, G; Purić, J; Morão, L G; Dos Santos, J A; Inforsato, F J; Sette, L D; Ferreira, H; Sass, D C

2018-07-01

This study aims to obtain secondary metabolites extracts from filamentous fungi isolated from soil and marine sediments from Antarctica and assess its potential antibacterial activity on Xanthomonas citri subsp. citri, the agent of citrus canker. Metabolites production was conducted in Malt 2% broth at 15°C for 20 days after which intracellular and extracellular extracts were obtained. The extracts were evaluated by cell viability assays through Resazurin Microtitre Assay. From 158 fungal extracts, 33 hampered bacterial growth in vitro. The average inhibition of the extracts obtained from terrestrial (soil) and marine (sediments) fungi was 94 and 97% respectively. These inhibition values were close to the average of 90% cell death for the positive control. MIC90 and MBC for the bioactive extracts were established. Isolates that produced active metabolites against the phytopathogen were identified using molecular taxonomy (ITS-rRNA sequencing) as: Pseudogymnoascus, Penicillium, Cadophora, Paraconiothyrium and Toxicocladosporium. Antarctic fungal strains isolated from terrestrial and marine sediments were able to produce secondary metabolites with antimicrobial activity against X. citri subsp. citri, highlighting the importance of these microbial genetic resources. These metabolites have potential to be used as alternatives for the control of this plant pathogen. This manuscript makes an impact on the study of micro-organisms from extreme habitats and their possible contribution in discovering new active molecules against pathogens of agricultural interest. Studies on the Antarctic continent and its communities have attracted the scientific community due to the long period of isolation and low levels of disturbance that surrounds the region. Knowing the potential of fungi in this region to produce active secondary metabolites, we aim to contribute to the discovery of compounds with antibacterial action in Xanthomonas citri subsp. citri, a plant pathogen present in several regions around the globe. © 2018 The Society for Applied Microbiology.

Hippophins C-F, four new flavonoids, acylated with one monoterpenic acid from the seed residue of Hippophae rhamnoides subsp. sinensis.

PubMed

Gao, Wen; Chen, Chao; Kong, De-Yun

2013-01-01

Four new flavonol glycosides (1-4), hippophins C-F, together with one known flavonoid (5), were isolated from the seed residue of Hippophae rhamnoides subsp. sinensis. The chemical structures of these compounds were characterized by 1D and 2D NMR, and HR-ESI-MS data. This report is a continuous research work on the systematic chemical investigation of plants of the genus Hippophae in our laboratory.

DNA probe for lactobacillus delbrueckii

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

Delley, M.; Mollet, B.; Hottinger, H.

1990-06-01

From a genomic DNA library of Lactobacillus delbrueckii subsp. bulgaricus, a clone was isolated which complements a leucine auxotrophy of an Escherichia coli strain (GE891). Subsequent analysis of the clone indicated that it could serve as a specific DNA probe. Dot-blot hybridizations with over 40 different Lactobacillus strains showed that this clone specifically recognized L. delbrueckii subsp. delbrueckii, bulgaricus, and lactis. The sensitivity of the method was tested by using an {alpha}-{sup 32}P-labeled probe.

DNA Probe for Lactobacillus delbrueckii

PubMed Central

Delley, Michèle; Mollet, Beat; Hottinger, Herbert

1990-01-01

From a genomic DNA library of Lactobacillus delbrueckii subsp. bulgaricus, a clone was isolated which complements a leucine auxotrophy of an Escherichia coli strain (GE891). Subsequent analysis of the clone indicated that it could serve as a specific DNA probe. Dot-blot hybridizations with over 40 different Lactobacillus strains showed that this clone specifically recognizes L. delbrueckii subsp. delbrueckii, bulgaricus, and lactis. The sensitivity of the method was tested by using an α-32P-labeled DNA probe. Images PMID:16348233

Salmonella enterica serovar Kentucky isolates from dairy cows and poultry demonstrate different evolutionary histories and host-specific polymorphisms

USDA-ARS?s Scientific Manuscript database

Salmonella enterica subsp. enterica serovar Kentucky is commonly isolated from dairy cows and poultry in the United States. Although it is not among the most frequently isolated serovars from cases of human salmonellosis, its high prevalence in livestock and poultry indicate it is a potential public...

Characterization of certain bacterial strains for potential use as starter or probiotic cultures in dairy products.

PubMed

Monteagudo-Mera, A; Caro, I; Rodríguez-Aparicio, L B; Rúa, J; Ferrero, M A; García-Armesto, M R

2011-08-01

The present work was aimed at characterizing 12 strains of lactic acid bacteria (LAB) to obtain improved potential starter or probiotic cultures that could be used for making dairy products from ewe's milk and cow's milk. Eight strains with antimicrobial properties, isolated from ewe's milk and from cheese made from ewe's and/or cow's milk, were studied. They were identified as Enterococcus faecalis (five strains), Lactococcus lactis subsp. cremoris, Leuconostoc mesenteroides, and Lactobacillus paracasei subsp. paracasei (one strain of each species). Additionally, four strains were obtained from the American Type Culture Collection: Lactobacillus casei 393 (isolated from cheese), L. lactis subsp. lactis 11454 (origin nonspecified and a producer of nisin), and two strains isolated from human feces (L. paracasei subsp. paracasei 27092 and Lactobacillus rhamnosus 53103, antibacterial agent producer). All E. faecalis strains showed at least one virulence factor (either hemolysin or gelatinase), which emphasizes the importance of these studies in this species. Both L. lactis strains and most Lactobacillus spp. were good acidifiers in ewe's milk and cow's milk at 30°C. High β-galactosidase activity, as well as aminopeptidase activities that favor the development of desirable flavors in cheese, were detected in all Lactobacillus spp. strains. Furthermore, L. rhamnosus ATCC 53103 showed α-fucosidase activity (thought to help colonization of the intestine) and lack of α-glucosidase activity (a trait considered positive for diabetic and obese humans). This last enzymatic activity was also lacking in L. lactis ATCC 11454. L. mesenteroides was the only strain D(2)-lactic acid producer. The selection of any particular strain for probiotic or dairy cultures should be performed according to the technological and/or functional abilities needed.

Screening of the Antimicrobial Activity against Drug Resistant Bacteria of Photorhabdus and Xenorhabdus Associated with Entomopathogenic Nematodes from Mae Wong National Park, Thailand

PubMed Central

Muangpat, Paramaporn; Yooyangket, Temsiri; Fukruksa, Chamaiporn; Suwannaroj, Manawat; Yimthin, Thatcha; Sitthisak, Sutthirat; Chantratita, Narisara; Vitta, Apichat; Tobias, Nicholas J.; Bode, Helge B.; Thanwisai, Aunchalee

2017-01-01

Photorhabdus and Xenorhabdus are symbiotic with entomopathogenic nematodes (EPNs) of the genera Heterorhabditis and Steinernema, respectively. These bacteria produce several secondary metabolites including antimicrobial compounds. The objectives of this study were to isolate and identify EPNs and their symbiotic bacteria from Mae Wong National Park, Thailand and to evaluate the antibacterial activities of symbiont extracts against drug resistant bacteria. A total of 550 soil samples from 110 sites were collected between August 2014 and July 2015. A total of EPN isolates were obtained through baiting and White trap methods, which yielded 21 Heterorhabditis and 3 Steinernema isolates. Based on molecular identification and phylogenetic analysis, the most common species found in the present study was P. luminescens subsp. akhurstii associated with H. indica. Notably, two species of EPNs, H. zealandica and S. kushidai, and two species of symbiotic bacteria, X. japonica and P. temperata subsp. temperata represented new recorded organisms in Thailand. Furthermore, the association between P. temperata subsp. temperata and H. zealandica has not previously been reported worldwide. Disk diffusion, minimal inhibitory concentration, and minimal bactericidal concentration analyses demonstrated that the crude compound extracted by ethyl acetate from P. temperata subsp. temperata could inhibit the growth of up to 10 strains of drug resistant bacteria. Based on HPLC-MS analysis, compound classes in bacterial extracts were identified as GameXPeptide, xenoamicin, xenocoumacin, mevalagmapeptide phurealipids derivatives, and isopropylstilbene. Together, the results of this study provide evidence for the diversity of EPNs and their symbiotic bacteria in Mae Wong National Park, Thailand and demonstrate their novel associations. These findings also provide an important foundation for further research regarding the antimicrobial activity of Photorhabdus bacteria. PMID:28702004

Assessment of probiotic properties of lactic acid bacteria isolated from Indonesian naturally fermented milk

NASA Astrophysics Data System (ADS)

Jatmiko, Yoga Dwi; Howarth, Gordon S.; Barton, Mary D.

2017-11-01

This study aimed to characterize the probiotic properties of lactic acid bacteria from the naturally fermented milk of Indonesia, namely dangke and dadih. Fifty-one representative lactic acid bacteria belonging to the species Lactobacillus Plantarum, Lactococcus lactis subsp. lactis and Enterococcus faecium were evaluated in vitro for potential probiotic properties based on their bile salt resistance, low pH tolerance, antimicrobial activity, antibiotic susceptibility and adherence to Caco-2 colon cancer cells. In addition, bacteriocin related gene (plantaricin A), bile salt hydrolase (bsh) and mannose-specific adhesin (msa) genes in the genome of lactobacilli were also examined. None of the dangke isolates, which belonged to the species L. lactis subsp. lactis tolerated low pH. However, eight of the isolates were able to grow in the presence of bile salts. It was observed that L. plantarum strain S1.30 and SL2.7 from dadih tolerated low pH, survived bile salt concentrations and were resistant to vancomycin. Furthermore, these strains also contained bacteriocin regulating gene (plantaricin A) and msa and bsh genes in their genome. However, only the strain S1.30 exhibited optimal antimicrobial activity against the selected pathogens and was able to adhere to Caco-2 cells by up to 82.24±0.14%. Antagonistic activity of L. lactis subsp. lactis from dadih and dangke was not detected. However, 73.94±1.26% adherence to Caco-2 cells was demonstrated by L. lactis subsp. lactis strain SL3.34 sourced from dangke. These results suggest that Lactobacillus plantarum strain S1.30 associated with dadih fulfilled the in vitro probiotic criteria and could be exploited for further in vivo evaluation. In addition, dadih was an effective probiotic carrier compared to dangke.

Antimicrobial Resistance, Biofilm Formation and mecA Characterization of Methicillin-Susceptible S. aureus and Non-S. aureus of Beef Meat Origin in Egypt

PubMed Central

Osman, Kamelia M.; Amer, Aziza M.; Badr, Jihan M.; Helmy, Nashwa M.; Elhelw, Rehab A.; Orabi, Ahmed; Bakry, Magdy; Saad, Aalaa S. A.

2016-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) have been found in various farm animal species throughout the world. Yet, methicillin-susceptible S. aureus (MSSA), methicillin-susceptible non-S. aureus (MS-NSA), and methicillin-resistant non-S. aureus (MR-NSA) were not investigated. Therefore, we persued to determine the diversity in their phenotypic virulence assay, phenotypic antimicrobial resistance profile and molecular characterization in one of the food chains in Egypt. Samples were collected during 2013 from beef meat at retail. Twenty seven isolates comprising five species (S. hyicus, S. aureus, S. schleiferi subsp. coagulans, S. intermedius, and S. lentus) were characterized for their antibiotic resistance phenotypic profile and antibiotic resistance genes (mecA, cfr, gyrA, gyrB, and grlA). Out of the 27 Staphylococcus isolates only one isolate was resistant to the 12 antibiotics representing nine classes. Raw beef meat sold across the Great Cairo zone, contains 66.7% of MRS, with highest prevalence was reported in S. aureus (66.7%), while the MRS non-S. aureus strains constituted 66.7% from which S. hyicus (60%), S. intermedius (33.3%), S. schleiferi subsp. coagulans (100%), and S. lentus (100%) were MRS. Seven S. aureus, six S. hyicus, four S. schleiferi subsp. coagulans, three S. intermedius, and one S. lentus isolates although being resistant to oxacillin yet, 11/27 (40.7%) carried the mecA gene. At the same time, the cfr gene was present in 2 of the nine S. aureus isolates, and totally undetectable in S. hyicus, S. schleiferi subsp. coagulans, S. intermedius, and S. lentus. Although, global researches largely focused into MRSA and MR-NSA in animals on pigs, the analysis of our results stipulates, that buffaloes and cattle could be MRSA dispersers and that this theme is not specific to pigs. Detection of MSSA virulence determinants is a must, as although oxacillin resistance may be absent yet, the MSSA may carry the virulence determinants which could be a source of perilous S. aureus for the human community. PMID:26973606

Identification of entomopathogenic nematodes and symbiotic bacteria from Nam Nao National Park in Thailand and larvicidal activity of symbiotic bacteria against Aedes aegypti and Aedes albopictus

PubMed Central

Yooyangket, Temsiri; Muangpat, Paramaporn; Polseela, Raxsina; Tandhavanant, Sarunporn; Thanwisai, Aunchalee

2018-01-01

Entomopathogenic nematodes (EPNs) that are symbiotically associated with Xenorhabdus and Photorhabdus bacteria can kill target insects via direct infection and toxin action. There are limited reports identifying such organisms in the National Park of Thailand. Therefore, the objectives of this study were to identify EPNs and symbiotic bacteria from Nam Nao National Park, Phetchabun Province, Thailand and to evaluate the larvicidal activity of bacteria against Aedes aegypti and Ae. albopictus. A total of 12 EPN isolates belonging to Steinernema and Heterorhabditis were obtained form 940 soil samples between February 2014 and July 2016. EPNs were molecularly identified as S. websteri (10 isolates) and H. baujardi (2 isolates). Symbiotic bacteria were isolated from EPNs and molecularly identified as P. luminescens subsp. akhurstii (13 isolates), X. stockiae (11 isolates), X. vietnamensis (2 isolates) and X. japonica (1 isolate). For the bioassay, bacterial suspensions were evaluated for toxicity against third to early fourth instar larvae of Aedes spp. The larvae of both Aedes species were orally susceptible to symbiotic bacteria. The highest larval mortality of Ae. aegypti was 99% after exposure to X. stockiae (bNN112.3_TH) at 96 h, and the highest mortality of Ae. albopictus was 98% after exposure to P. luminescens subsp. akhurstii (bNN121.4_TH) at 96 h. In contrast to the control groups (Escherichia coli and distilled water), the mortality rate of both mosquito larvae ranged between 0 and 7% at 72 h. Here, we report the first observation of X. vietnamensis in Thailand. Additionally, we report the first observation of P. luminescens subsp. akhurstii associated with H. baujardi in Thailand. X. stockiae has potential to be a biocontrol agent for mosquitoes. This investigation provides a survey of the basic diversity of EPNs and symbiotic bacteria in the National Park of Thailand, and it is a bacterial resource for further studies of bioactive compounds. PMID:29641570

Identification of entomopathogenic nematodes and symbiotic bacteria from Nam Nao National Park in Thailand and larvicidal activity of symbiotic bacteria against Aedes aegypti and Aedes albopictus.

PubMed

Yooyangket, Temsiri; Muangpat, Paramaporn; Polseela, Raxsina; Tandhavanant, Sarunporn; Thanwisai, Aunchalee; Vitta, Apichat

2018-01-01

Entomopathogenic nematodes (EPNs) that are symbiotically associated with Xenorhabdus and Photorhabdus bacteria can kill target insects via direct infection and toxin action. There are limited reports identifying such organisms in the National Park of Thailand. Therefore, the objectives of this study were to identify EPNs and symbiotic bacteria from Nam Nao National Park, Phetchabun Province, Thailand and to evaluate the larvicidal activity of bacteria against Aedes aegypti and Ae. albopictus. A total of 12 EPN isolates belonging to Steinernema and Heterorhabditis were obtained form 940 soil samples between February 2014 and July 2016. EPNs were molecularly identified as S. websteri (10 isolates) and H. baujardi (2 isolates). Symbiotic bacteria were isolated from EPNs and molecularly identified as P. luminescens subsp. akhurstii (13 isolates), X. stockiae (11 isolates), X. vietnamensis (2 isolates) and X. japonica (1 isolate). For the bioassay, bacterial suspensions were evaluated for toxicity against third to early fourth instar larvae of Aedes spp. The larvae of both Aedes species were orally susceptible to symbiotic bacteria. The highest larval mortality of Ae. aegypti was 99% after exposure to X. stockiae (bNN112.3_TH) at 96 h, and the highest mortality of Ae. albopictus was 98% after exposure to P. luminescens subsp. akhurstii (bNN121.4_TH) at 96 h. In contrast to the control groups (Escherichia coli and distilled water), the mortality rate of both mosquito larvae ranged between 0 and 7% at 72 h. Here, we report the first observation of X. vietnamensis in Thailand. Additionally, we report the first observation of P. luminescens subsp. akhurstii associated with H. baujardi in Thailand. X. stockiae has potential to be a biocontrol agent for mosquitoes. This investigation provides a survey of the basic diversity of EPNs and symbiotic bacteria in the National Park of Thailand, and it is a bacterial resource for further studies of bioactive compounds.

Characterization of Lactobacillus fermentum PL9988 Isolated from Healthy Elderly Korean in a Longevity Village.

PubMed

Park, Jong-Su; Shin, Eunju; Hong, Hyunjin; Shin, Hyun-Jung; Cho, Young-Hoon; Ahn, Ki-Hyun; Paek, Kyungsoo; Lee, Yeonhee

2015-09-01

In this work, we wanted to develop a probiotic from famous longevity villages in Korea. We visited eight longevity villages in Korea to collect fecal samples from healthy adults who were aged above 80 years and had regular bowel movements, and isolated lactic-acid-producing bacteria from the samples. Isolated colonies that appeared on MRS agar containing bromophenol blue were identified by means of 16S rRNA sequencing, and 102 of the isolates were identified as lactic-acid-producing bacteria (18 species). Lactobacillus fermentum was the most frequently found species. Eight isolates were selected on the basis of their ability to inhibit the growth of six intestinal pathogens (Escherichia coli O157:H7, Salmonella enterica subsp. enterica Typhimurium, Salmonella enterica subsp. enterica Enteritidis, Enterococcus faecalis, Staphylococcus aureus, and Listeria monocytogenes) and their susceptibility to 15 antimicrobial agents. Among these eight isolates, four Lactobacillus fermentum isolates were found not to produce any harmful enzymes or metabolites. Among them, Lactobacillus fermentum isolate no. 24 showed the strongest binding to intestinal epithelial cells, the highest immune-enhancing activity, anti-inflammation activity, and anti-oxidation activity as well as the highest survival rates in the presence of artificial gastric juice and bile solution. This isolate, designated Lactobacillus fermentum PL9988, has all the characteristics for a good probiotic.

A quantitative and direct PCR assay for the subspecies-specific detection of Clavibacter michiganensis subsp. michiganensis based on a ferredoxin reductase gene.

PubMed

Cho, Min Seok; Lee, Jang Ha; Her, Nam Han; Kim, Changkug; Seol, Young-Joo; Hahn, Jang Ho; Baeg, Ji Hyoun; Kim, Hong Gi; Park, Dong Suk

2012-06-01

The Gram-positive bacterium Clavibacter michiganensis subsp. michiganensis is the causal agent of canker disease in tomato. Because it is very important to control newly introduced inoculum sources from commercial materials, the specific detection of this pathogen in seeds and seedlings is essential for effective disease control. In this study, a novel and efficient assay for the detection and quantitation of C. michiganensis subsp. michiganensis in symptomless tomato and red pepper seeds was developed. A pair of polymerase chain reaction (PCR) primers (Cmm141F/R) was designed to amplify a specific 141 bp fragment on the basis of a ferredoxin reductase gene of C. michiganensis subsp. michiganensis NCPPB 382. The specificity of the primer set was evaluated using purified DNA from 16 isolates of five C. michiganensis subspecies, one other Clavibacter species, and 17 other reference bacteria. The primer set amplified a single band of expected size from the genomic DNA obtained from the C. michiganensis subsp. michiganensis strains but not from the other C. michiganensis subspecies or from other Clavibacter species. The detection limit was a single cloned copy of the ferredoxin reductase gene of C. michiganensis subsp. michiganensis. In conclusion, this quantitative direct PCR assay can be applied as a practical diagnostic method for epidemiological research and the sanitary management of seeds and seedlings with a low level or latent infection of C. michiganensis subsp. michiganensis.

Genomic Diversity of Erwinia carotovora subsp. carotovora and Its Correlation with Virulence

PubMed Central

Yap, Mee-Ngan; Barak, Jeri D.; Charkowski, Amy O.

2004-01-01

We used genetic and biochemical methods to examine the genomic diversity of the enterobacterial plant pathogen Erwinia carotovora subsp. carotovora. The results obtained with each method showed that E. carotovora subsp. carotovora strains isolated from one ecological niche, potato plants, are surprisingly diverse compared to related pathogens. A comparison of 23 partial mdh sequences revealed a maximum pairwise difference of 10.49% and an average pairwise difference of 2.13%, values which are much greater than the maximum variation (1.81%) and average variation (0.75%) previously reported for Escherichia coli. Pulsed-field gel electrophoresis analysis of I-CeuI-digested genomic DNA revealed seven rrn operons in all E. carotovora subsp. carotovora strains examined except strain WPP17, which had only six copies. We identified 26 I-CeuI restriction fragment length polymorphism patterns and observed significant polymorphism in fragment sizes ranging from 100 to 450 kb for all strains. We detected large plasmids in two strains, including the model strain E. carotovora subsp. carotovora 71. The two least virulent strains had an unusual chromosomal structure, suggesting that a particular pulsotype is correlated with virulence. To compare chromosomal organization of multiple enterobacterial genomes, several genes were mapped onto I-CeuI fragments. We identified portions of the genome that appear to be conserved across enterobacteria and portions that have undergone genome rearrangements. We found that the least virulent strain, WPP17, failed to oxidize cellobiose and was missing several hrp and hrc genes. The unexpected variability among isolates obtained from clonal hosts in one region and in one season suggests that factors other than the host plant, potato, drive the evolution of this common environmental bacterium and key plant pathogen. PMID:15128563

Three new flavonoids, hippophins K-M, from the seed residue of Hippophae rhamnoides subsp. sinensis.

PubMed

Chen, Chao; Gao, Wen; Ou-Yang, Dan-Wei; Zhang, Jing; Kong, De-Yun

2014-01-01

Three new flavonol glycosides (1-3), hippophins K-M, were isolated from the seed residue of Hippophae rhamnoides subsp. sinensis. The chemical structures of these three new compounds were identified by 1D, 2D NMR, mass spectroscopy and high resolution electrospray ionization mass spectrometry spectroscopic data and by comparison with the literature data. This report is a continuous research work on the systematic chemical investigation of plants of the genus Hippophae in our laboratory.

An outbreak of Streptococcus equi subspecies zooepidemicus associated with consumption of fresh goat cheese

PubMed Central

Kuusi, Markku; Lahti, Elina; Virolainen, Anni; Hatakka, Maija; Vuento, Risto; Rantala, Leila; Vuopio-Varkila, Jaana; Seuna, Eija; Karppelin, Matti; Hakkinen, Marjaana; Takkinen, Johanna; Gindonis, Veera; Siponen, Kyosti; Huotari, Kaisa

2006-01-01

Background Streptococcus equi subspecies zooepidemicus is a rare infection in humans associated with contact with horses or consumption of unpasteurized milk products. On October 23, 2003, the National Public Health Institute was alerted that within one week three persons had been admitted to Tampere University Central Hospital (TaYS) because of S. equi subsp. zooepidemicus septicaemia. All had consumed fresh goat cheese produced in a small-scale dairy located on a farm. We conducted an investigation to determine the source and the extent of the outbreak. Methods Cases were identified from the National Infectious Disease Register. Cases were persons with S. equi subsp. zooepidemicus isolated from a normally sterile site who had illness onset 15.9-31.10.2003. All cases were telephone interviewed by using a standard questionnaire and clinical information was extracted from patient charts. Environmental and food specimens included throat swabs from two persons working in the dairy, milk from goats and raw milk tank, cheeses made of unpasteurized milk, vaginal samples of goats, and borehole well water. The isolates were characterized by ribotyping and pulsed-field gel electrophoresis (PFGE). Results Seven persons met the case definition; six had septicaemia and one had purulent arthritis. Five were women; the median age was 70 years (range 54–93). None of the cases were immunocompromized and none died. Six cases were identified in TaYS, and one in another university hospital in southern Finland. All had eaten goat cheese produced on the implicated farm. S. equi subsp. zooepidemicus was isolated from throat swabs, fresh goat cheese, milk tank, and vaginal samples of one goat. All human and environmental strains were indistinguishable by ribotyping and PFGE. Conclusion The outbreak was caused by goat cheese produced from unpasteurized milk. Outbreaks caused by S. equi subsp. zooepidemicus may not be detected if streptococcal strains are only typed to the group level. S. equi subsp. zooepidemicus may be a re-emerging disease if unpasteurized milk is increasingly used for food production. Facilities using unpasteurized milk should be carefully monitored to prevent this type of outbreaks. PMID:16504158

Genetic Variability and Population Structure of Disanthus cercidifolius subsp. longipes (Hamamelidaceae) Based on AFLP Analysis

PubMed Central

Yu, Yi; Fan, Qiang; Shen, Rujiang; Guo, Wei; Jin, Jianhua; Cui, Dafang; Liao, Wenbo

2014-01-01

Disanthus cercidifolius subsp. longipes is an endangered species in China. Genetic diversity and structure analysis of this species was investigated using amplified fragments length polymorphism (AFLP) fingerprinting. Nei's gene diversity ranged from 0.1290 to 0.1394. The AMOVA indicated that 75.06% of variation was distributed within populations, while the between-group component 5.04% was smaller than the between populations-within-group component 19.90%. Significant genetic differentiation was detected between populations. Genetic and geographical distances were not correlated. PCA and genetic structure analysis showed that populations from East China were together with those of the Nanling Range. These patterns of genetic diversity and levels of genetic variation may be the result of D. c. subsp. longipes restricted to several isolated habitats and “excess flowers production, but little fruit set”. It is necessary to protect all existing populations of D. c. subsp. longipes in order to preserve as much genetic variation as possible. PMID:25250583

Reclassification of Lactobacillus kefirgranum Takizawa et al. 1994 as Lactobacillus kefiranofaciens subsp. kefirgranum subsp. nov. and emended description of L. kefiranofaciens Fujisawa et al. 1988.

PubMed

Vancanneyt, M; Mengaud, J; Cleenwerck, I; Vanhonacker, K; Hoste, B; Dawyndt, P; Degivry, M C; Ringuet, D; Janssens, D; Swings, J

2004-03-01

Fourteen homofermentative lactic acid bacteria that were isolated from kefir grains and kefir fermented milks were assigned to either Lactobacillus kefiranofaciens or Lactobacillus kefirgranum, based on their characteristic morphotypes, phenotypic features and SDS-PAGE profiles of whole-cell proteins. Further genotypic analyses on representative strains from both taxa demonstrated that L. kefiranofaciens and L. kefirgranum share 100 % 16S rDNA sequence similarity and belong phylogenetically to the Lactobacillus acidophilus species group. DNA-DNA binding values of >79 % and analogous DNA G+C contents of 37-38 mol% showed that the strains studied belonged to one species: L. kefirgranum is a later synonym of L. kefiranofaciens. An emended description is proposed for L. kefiranofaciens. Due to the specific morphological and biochemical characteristics of these taxa in kefir grain formation, it is proposed that L. kefirgranum should be reclassified as L. kefiranofaciens subsp. kefirgranum subsp. nov.

Genetic analysis of a novel Xylella fastidiosa subspecies found in the southwestern United States.

PubMed

Randall, Jennifer J; Goldberg, Natalie P; Kemp, John D; Radionenko, Maxim; French, Jason M; Olsen, Mary W; Hanson, Stephen F

2009-09-01

Xylella fastidiosa, the causal agent of several scorch diseases, is associated with leaf scorch symptoms in Chitalpa tashkentensis, a common ornamental landscape plant used throughout the southwestern United States. For a number of years, many chitalpa trees in southern New Mexico and Arizona exhibited leaf scorch symptoms, and the results from a regional survey show that chitalpa trees from New Mexico, Arizona, and California are frequently infected with X. fastidiosa. Phylogenetic analysis of multiple loci was used to compare the X. fastidiosa infecting chitalpa strains from New Mexico, Arizona, and trees imported into New Mexico nurseries with previously reported X. fastidiosa strains. Loci analyzed included the 16S ribosome, 16S-23S ribosomal intergenic spacer region, gyrase-B, simple sequence repeat sequences, X. fastidiosa-specific sequences, and the virulence-associated protein (VapD). This analysis indicates that the X. fastidiosa isolates associated with infected chitalpa trees in the Southwest are a highly related group that is distinct from the four previously defined taxons X. fastidiosa subsp. fastidiosa (piercei), X. fastidiosa subsp. multiplex, X. fastidiosa subsp. sandyi, and X. fastidiosa subsp. pauca. Therefore, the classification proposed for this new subspecies is X. fastidiosa subsp. tashke.

Francisella tularensis: No Evidence for Transovarial Transmission in the Tularemia Tick Vectors Dermacentor reticulatus and Ixodes ricinus

PubMed Central

Genchi, Marco; Prati, Paola; Vicari, Nadia; Manfredini, Andrea; Sacchi, Luciano; Clementi, Emanuela; Bandi, Claudio; Epis, Sara; Fabbi, Massimo

2015-01-01

Background Tularemia is a zoonosis caused by the Francisella tularensis, a highly infectious Gram-negative coccobacillus. Due to easy dissemination, multiple routes of infection, high environmental contamination and morbidity and mortality rates, Francisella is considered a potential bioterrorism threat and classified as a category A select agent by the CDC. Tick bites are among the most prevalent modes of transmission, and ticks have been indicated as a possible reservoir, although their reservoir competence has yet to be defined. Tick-borne transmission of F. tularensis was recognized in 1923, and transstadial transmission has been demonstrated in several tick species. Studies on transovarial transmission, however, have reported conflicting results. Objective The aim of this study was to evaluate the role of ticks as reservoirs for Francisella, assessing the transovarial transmission of F. tularensis subsp. holarctica in ticks, using experimentally-infected females of Dermacentor reticulatus and Ixodes ricinus. Results Transmission electron microscopy and fluorescence in situ hybridization showed F. tularensis within oocytes. However, cultures and bioassays of eggs and larvae were negative; in addition, microscopy techniques revealed bacterial degeneration/death in the oocytes. Conclusions These results suggest that bacterial death might occur in oocytes, preventing the transovarial transmission of Francisella. We can speculate that Francisella does not have a defined reservoir, but that rather various biological niches (e.g. ticks, rodents), that allow the bacterium to persist in the environment. Our results, suggesting that ticks are not competent for the bacterium vertical transmission, are congruent with this view. PMID:26244842

Assessing the intra-species genetic variability in the clonal pathogen Campylobacter fetus: CRISPRs are highly polymorphic DNA markers.

PubMed

Calleros, Lucía; Betancor, Laura; Iraola, Gregorio; Méndez, Alejandra; Morsella, Claudia; Paolicchi, Fernando; Silveyra, Silvia; Velilla, Alejandra; Pérez, Ruben

2017-01-01

Campylobacter fetus is a Gram-negative, microaerophilic bacterium that infects animals and humans. The subspecies Campylobacter fetus subsp. fetus (Cff) affects a broad range of vertebrate hosts and induces abortion in cows and sheep. Campylobacter fetus subsp. venerealis (Cfv) is restricted to cattle and causes the endemic disease bovine genital campylobacteriosis, which triggers reproductive problems and is responsible for major economic losses. Campylobacter fetus subsp. testudinum (Cft) has been isolated mostly from apparently healthy reptiles belonging to different species but also from ill snakes and humans. Genotypic differentiation of Cff and Cfv is difficult, and epidemiological information is scarce because there are few methods to study the genetic diversity of the strains. We analyze the efficacy of MLST, ribosomal sequences (23S gene and internal spacer region), and CRISPRs to assess the genetic variability of C. fetus in bovine and human isolates. Sequences retrieved from complete genomes were included in the analysis for comparative purposes. MLST and ribosomal sequences had scarce or null variability, while the CRISPR-cas system structure and the sequence of CRISPR1 locus showed remarkable diversity. None of the sequences here analyzed provided evidence of a genetic differentiation of Cff and Cfv in bovine isolates. Comparison of bovine and human isolates with Cft strains showed a striking divergence. Inter-host differences raise the possibility of determining the original host of human infections using CRISPR sequences. CRISPRs are the most variable sequences analyzed in C. fetus so far, and constitute excellent representatives of a dynamic fraction of the genome. CRISPR typing is a promising tool to characterize isolates and to track the source and transmission route of C. fetus infections. Copyright © 2016 Elsevier B.V. All rights reserved.

Recent Evolutionary Radiation and Host Plant Specialization in the Xylella fastidiosa Subspecies Native to the United States

PubMed Central

Vickerman, Danel B.; Bromley, Robin E.; Russell, Stephanie A.; Hartman, John R.; Morano, Lisa D.; Stouthamer, Richard

2013-01-01

The bacterial pathogen, Xylella fastidiosa, infects many plant species in the Americas, making it a good model for investigating the genetics of host adaptation. We used multilocus sequence typing (MLST) to identify isolates of the native U.S. subsp. multiplex that were largely unaffected by intersubspecific homologous recombination (IHR) and to investigate how their evolutionary history influences plant host specialization. We identified 110 “non-IHR” isolates, 2 minimally recombinant “intermediate” ones (including the subspecific type), and 31 with extensive IHR. The non-IHR and intermediate isolates defined 23 sequence types (STs) which we used to identify 22 plant hosts (73% trees) characteristic of the subspecies. Except for almond, subsp. multiplex showed no host overlap with the introduced subspecies (subspecies fastidiosa and sandyi). MLST sequences revealed that subsp. multiplex underwent recent radiation (<25% of subspecies age) which included only limited intrasubspecific recombination (ρ/θ = 0.02); only one isolated lineage (ST50 from ash) was older. A total of 20 of the STs grouped into three loose phylogenetic clusters distinguished by nonoverlapping hosts (excepting purple leaf plum): “almond,” “peach,” and “oak” types. These host differences were not geographical, since all three types also occurred in California. ST designation was a good indicator of host specialization. ST09, widespread in the southeastern United States, only infected oak species, and all peach isolates were ST10 (from California, Florida, and Georgia). Only ST23 had a broad host range. Hosts of related genotypes were sometimes related, but often host groupings crossed plant family or even order, suggesting that phylogenetically plastic features of hosts affect bacterial pathogenicity. PMID:23354698

Recent evolutionary radiation and host plant specialization in the Xylella fastidiosa subspecies native to the United States.

PubMed

Nunney, Leonard; Vickerman, Danel B; Bromley, Robin E; Russell, Stephanie A; Hartman, John R; Morano, Lisa D; Stouthamer, Richard

2013-04-01

The bacterial pathogen, Xylella fastidiosa, infects many plant species in the Americas, making it a good model for investigating the genetics of host adaptation. We used multilocus sequence typing (MLST) to identify isolates of the native U.S. subsp. multiplex that were largely unaffected by intersubspecific homologous recombination (IHR) and to investigate how their evolutionary history influences plant host specialization. We identified 110 "non-IHR" isolates, 2 minimally recombinant "intermediate" ones (including the subspecific type), and 31 with extensive IHR. The non-IHR and intermediate isolates defined 23 sequence types (STs) which we used to identify 22 plant hosts (73% trees) characteristic of the subspecies. Except for almond, subsp. multiplex showed no host overlap with the introduced subspecies (subspecies fastidiosa and sandyi). MLST sequences revealed that subsp. multiplex underwent recent radiation (<25% of subspecies age) which included only limited intrasubspecific recombination (ρ/θ = 0.02); only one isolated lineage (ST50 from ash) was older. A total of 20 of the STs grouped into three loose phylogenetic clusters distinguished by nonoverlapping hosts (excepting purple leaf plum): "almond," "peach," and "oak" types. These host differences were not geographical, since all three types also occurred in California. ST designation was a good indicator of host specialization. ST09, widespread in the southeastern United States, only infected oak species, and all peach isolates were ST10 (from California, Florida, and Georgia). Only ST23 had a broad host range. Hosts of related genotypes were sometimes related, but often host groupings crossed plant family or even order, suggesting that phylogenetically plastic features of hosts affect bacterial pathogenicity.

An Outbreak of Respiratory Tularemia Caused by Diverse Clones of Francisella tularensis

PubMed Central

Johansson, Anders; Lärkeryd, Adrian; Widerström, Micael; Mörtberg, Sara; Myrtännäs, Kerstin; Öhrman, Caroline; Birdsell, Dawn; Keim, Paul; Wagner, David M.; Forsman, Mats; Larsson, Pär

2014-01-01

Background. The bacterium Francisella tularensis is recognized for its virulence, infectivity, genetic homogeneity, and potential as a bioterrorism agent. Outbreaks of respiratory tularemia, caused by inhalation of this bacterium, are poorly understood. Such outbreaks are exceedingly rare, and F. tularensis is seldom recovered from clinical specimens. Methods. A localized outbreak of tularemia in Sweden was investigated. Sixty-seven humans contracted laboratory-verified respiratory tularemia. F. tularensis subspecies holarctica was isolated from the blood or pleural fluid of 10 individuals from July to September 2010. Using whole-genome sequencing and analysis of single-nucleotide polymorphisms (SNPs), outbreak isolates were compared with 110 archived global isolates. Results. There were 757 SNPs among the genomes of the 10 outbreak isolates and the 25 most closely related archival isolates (all from Sweden/Finland). Whole genomes of outbreak isolates were >99.9% similar at the nucleotide level and clustered into 3 distinct genetic clades. Unexpectedly, high-sequence similarity grouped some outbreak and archival isolates that originated from patients from different geographic regions and up to 10 years apart. Outbreak and archival genomes frequently differed by only 1–3 of 1 585 229 examined nucleotides. Conclusions. The outbreak was caused by diverse clones of F. tularensis that occurred concomitantly, were widespread, and apparently persisted in the environment. Multiple independent acquisitions of F. tularensis from the environment over a short time period suggest that natural outbreaks of respiratory tularemia are triggered by environmental cues. The findings additionally caution against interpreting genome sequence identity for this pathogen as proof of a direct epidemiological link. PMID:25097081

Discrimination and divergence among Lactobacillus plantarum-group (LPG) isolates with reference to their probiotic functionalities from vegetable origin.

PubMed

Devi, Sundru Manjulata; Aishwarya, Subramanian; Halami, Prakash M

2016-12-01

The present study was aimed to evaluate the diversity and probiotic properties of Lactobacillus plantarum-group cultures from vegetable origin. First, genotypic diversity of L. plantarum (n=34) was achieved by PCR of Random Amplified Polymorphic DNA and recA gene-specific multiplex PCR. The isolates were segregated into five groups namely, Lactobacillus pentosus, Lactobacillus paraplantarum, Lactobacillus arizonensis, Lactobacillus plantarum subsp. plantarum and argentoratensis. Further discrimination was achieved by restriction fragment length polymorphism of probiotic adhesion genes viz.fbp, mub and msa gene. As determined by nucleotide sequence analysis and bioinformatics Pfam database, the putative Fbp protein had only one FBP domain, whereas Mub protein had 8-10 MUB domain repeats. However, L. pentosus (except CFR MFT9), L. plantarum subsp. argentoratensis (except CFR MFT5) and L. arizonensis (except CFR MFT2) isolates gave no amplicon for the tested marker genes. Selected cultures (n=15) showed tolerance to simulated digestive fluids (20-85%), exhibited auto-aggregation (10-77%), cellular hydrophobicity (12-78%), and broad spectrum of anti-microbial activity. Concurrently, high adherence capacity to mucin was achieved for L. plantarum subsp. plantarum (MCC 2974 and CFR MFT1) and L. paraplantarum (MTCC 9483, MCC 2977, MCC 2978), which had an additional MUB domain repeat. Copyright © 2016 Elsevier GmbH. All rights reserved.

Rapid Real-Time PCR Assay for Detection and Quantitation of Mycobacterium avium subsp. paratuberculosis DNA in Artificially Contaminated Milk

PubMed Central

O'Mahony, Jim; Hill, Colin

2004-01-01

Using fluorescence resonance energy transfer technology and Lightcycler analysis, we developed a real-time PCR assay with primers and probes designed by using IS900 which allowed rapid detection of Mycobacterium avium subsp. paratuberculosis DNA in artificially contaminated milk. Initially, the PCR parameters (including primer and probe levels, assay volume, Mg2+ concentration, and annealing temperature) were optimized. Subsequently, the quantitative ability of the assay was tested and was found to be accurate over a broad linear range (3 × 106 to 3 × 101 copies). The assay sensitivity when purified DNA was used was determined to be as low as five copies, with excellent reproducibility. A range of DNA isolation strategies was developed for isolating M. avium subsp. paratuberculosis DNA from spiked milk, the most effective of which involved the use of 50 mM Tris HCl, 10 mM EDTA, 2% Triton X-100, 4 M guanidinium isothiocyante, and 0.3 M sodium acetate combined with boiling, physical grinding, and nucleic acid spin columns. When this technique was used in conjunction with the real-time PCR assay, it was possible to consistently detect <100 organisms per ml of milk (equivalent to 2,000 organisms per 25 ml). Furthermore, the entire procedure (extraction and PCR) was performed in less than 3 h and was successfully adapted to quantify M. avium subsp. paratuberculosis in spiked milk from heavily and mildly contaminated samples. PMID:15294786

Evaluation of Lactococcus lactis Isolates from Nondairy Sources with Potential Dairy Applications Reveals Extensive Phenotype-Genotype Disparity and Implications for a Revised Species

PubMed Central

Cavanagh, Daniel; Casey, Aidan; Altermann, Eric; Cotter, Paul D.; Fitzgerald, Gerald F.

2015-01-01

Lactococcus lactis is predominantly associated with dairy fermentations, but evidence suggests that the domesticated organism originated from a plant niche. L. lactis possesses an unusual taxonomic structure whereby strain phenotypes and genotypes often do not correlate, which in turn has led to confusion in L. lactis classification. A bank of L. lactis strains was isolated from various nondairy niches (grass, vegetables, and bovine rumen) and was further characterized on the basis of key technological traits, including growth in milk and key enzyme activities. Phenotypic analysis revealed all strains from nondairy sources to possess an L. lactis subsp. lactis phenotype (lactis phenotype); however, seven of these strains possessed an L. lactis subsp. cremoris genotype (cremoris genotype), determined by two separate PCR assays. Multilocus sequence typing (MLST) showed that strains with lactis and cremoris genotypes clustered together regardless of habitat, but it highlighted the increased diversity that exists among “wild” strains. Calculation of average nucleotide identity (ANI) and tetranucleotide frequency correlation coefficients (TETRA), using the JSpecies software tool, revealed that L. lactis subsp. cremoris and L. lactis subsp. lactis differ in ANI values by ∼14%, below the threshold set for species circumscription. Further analysis of strain TIFN3 and strains from nonindustrial backgrounds revealed TETRA values of <0.99 in addition to ANI values of <95%, implicating that these two groups are separate species. These findings suggest the requirement for a revision of L. lactis taxonomy. PMID:25841018

Identification and characterization of a NBS–LRR class resistance gene analog in Pistacia atlantica subsp. Kurdica

PubMed Central

Bahramnejad, Bahman

2014-01-01

P. atlantica subsp. Kurdica, with the local name of Baneh, is a wild medicinal plant which grows in Kurdistan, Iran. The identification of resistance gene analogs holds great promise for the development of resistant cultivars. A PCR approach with degenerate primers designed according to conserved NBS-LRR (nucleotide binding site-leucine rich repeat) regions of known disease-resistance (R) genes was used to amplify and clone homologous sequences from P. atlantica subsp. Kurdica. A DNA fragment of the expected 500-bp size was amplified. The nucleotide sequence of this amplicon was obtained through sequencing and the predicted amino acid sequence compared to the amino acid sequences of known R-genes revealed significant sequence similarity. Alignment of the deduced amino acid sequence of P. atlantica subsp. Kurdica resistance gene analog (RGA) showed strong identity, ranging from 68% to 77%, to the non-toll interleukin receptor (non-TIR) R-gene subfamily from other plants. A P-loop motif (GMMGGEGKTT), a conserved and hydrophobic motif GLPLAL, a kinase-2a motif (LLVLDDV), when replaced by IAVFDDI in PAKRGA1 and a kinase-3a (FGPGSRIII) were presented in all RGA. A phylogenetic tree, based on the deduced amino-acid sequences of PAKRGA1 and RGAs from different species indicated that they were separated in two clusters, PAKRGA1 being on cluster II. The isolated NBS analogs can be eventually used as guidelines to isolate numerous R-genes in Pistachio. PMID:27843981

Biofilm Formation and Morphotypes of Salmonella enterica subsp.arizonae Differs from Those of Other Salmonella enterica Subspecies in Isolates from Poultry Houses.

PubMed

Lamas, A; Fernandez-No, I C; Miranda, J M; Vázquez, B; Cepeda, A; Franco, C M

2016-07-01

Salmonella serovars are responsible for foodborne diseases around the world. The ability to form biofilms allows microorganisms to survive in the environment. In this study, 73 Salmonella strains, belonging to four different subspecies, were isolated from poultry houses and foodstuffs and tested. Biofilm formation was measured at four different temperatures and two nutrient concentrations. Morphotypes and cellulose production were evaluated at three different temperatures. The presence of several genes related to biofilm production was also examined. All strains and subspecies of Salmonella had the ability to form biofilms, and 46.57% of strains produced biofilms under all conditions tested. Biofilm formation was strain dependent and varied according to the conditions. This is the first study to analyze biofilm formation in a wide number of Salmonella enterica subsp. arizonae strains, and no direct relationship between the high prevalence of Salmonella enterica subsp. arizonae strains and their ability to form biofilm was established. Morphotypes and cellulose production varied as the temperature changed, with 20°C being the optimum temperature for expression of the red, dry, and rough morphotype and cellulose. Salmonella enterica subsp. arizonae, whose morphotype is poorly studied, only showed a smooth and white morphotype and lacked the csgD and gcpA genes that are implicated in biofilm production. Thus, Salmonella biofilm formation under different environmental conditions is a public health problem because it can survive and advance through the food chain to reach the consumer.

New Coffee Plant-Infecting Xylella fastidiosa Variants Derived via Homologous Recombination

PubMed Central

Denancé, Nicolas; Legendre, Bruno; Morel, Emmanuelle; Briand, Martial; Mississipi, Stelly; Durand, Karine; Olivier, Valérie; Portier, Perrine; Poliakoff, Françoise; Crouzillat, Dominique

2015-01-01

Xylella fastidiosa is a xylem-limited phytopathogenic bacterium endemic to the Americas that has recently emerged in Asia and Europe. Although this bacterium is classified as a quarantine organism in the European Union, importation of plant material from contaminated areas and latent infection in asymptomatic plants have engendered its inevitable introduction. In 2012, four coffee plants (Coffea arabica and Coffea canephora) with leaf scorch symptoms growing in a confined greenhouse were detected and intercepted in France. After identification of the causal agent, this outbreak was eradicated. Three X. fastidiosa strains were isolated from these plants, confirming a preliminary identification based on immunology. The strains were characterized by multiplex PCR and by multilocus sequence analysis/typing (MLSA-MLST) based on seven housekeeping genes. One strain, CFBP 8073, isolated from C. canephora imported from Mexico, was assigned to X. fastidiosa subsp. fastidiosa/X. fastidiosa subsp. sandyi. This strain harbors a novel sequence type (ST) with novel alleles at two loci. The two other strains, CFBP 8072 and CFBP 8074, isolated from Coffea arabica imported from Ecuador, were allocated to X. fastidiosa subsp. pauca. These two strains shared a novel ST with novel alleles at two loci. These MLST profiles showed evidence of recombination events. We provide genome sequences for CFBP 8072 and CFBP 8073 strains. Comparative genomic analyses of these two genome sequences with publicly available X. fastidiosa genomes, including the Italian strain CoDiRO, confirmed these phylogenetic positions and provided candidate alleles for coffee plant adaptation. This study demonstrates the global diversity of X. fastidiosa and highlights the diversity of strains isolated from coffee plants. PMID:26712553

Structural characterization of the lipid A region of Aeromonas salmonicida subsp. salmonicida lipopolysaccharide.

PubMed

Wang, Zhan; Li, Jianjun; Altman, Eleonora

2006-12-11

The lipid A components of Aeromonas salmonicida subsp. salmonicida from strains A449, 80204-1 and an in vivo rough isolate were isolated by mild acid hydrolysis of the lipopolysaccharide. Structural studies carried out by a combination of fatty acid, electrospray ionization-mass spectrometry and nuclear magnetic resonance analyses confirmed that the structure of lipid A was conserved among different isolates of A. salmonicida subsp. salmonicida. All analyzed strains contained three major lipid A molecules differing in acylation patterns corresponding to tetra-, penta- and hexaacylated lipid A species and comprising 4'-monophosphorylated beta-2-amino-2-deoxy-d-glucopyranose-(1-->6)-2-amino-2-deoxy-d-glucopyranose disaccharide, where the reducing end 2-amino-2-deoxy-d-glucose was present primarily in the alpha-pyranose form. Electrospray ionization-tandem mass spectrometry fragment pattern analysis, including investigation of the inner-ring fragmentation, allowed the localization of fatty acyl residues on the disaccharide backbone of lipid A. The tetraacylated lipid A structure containing 3-(dodecanoyloxy)tetradecanoic acid at N-2',3-hydroxytetradecanoic acid at N-2 and 3-hydroxytetradecanoic acid at O-3, respectively, was found. The pentaacyl lipid A molecule had a similar fatty acid distribution pattern and, additionally, carried 3-hydroxytetradecanoic acid at O-3'. In the hexaacylated lipid A structure, 3-hydroxytetradecanoic acid at O-3' was esterified with a secondary 9-hexadecenoic acid. Interestingly, lipid A of the in vivo rough isolate contained predominantly tetra- and pentaacylated lipid A species suggesting that the presence of the hexaacyl lipid A was associated with the smooth-form lipopolysaccharide.

Effect of oligosaccharides on the growth of Lactobacillus delbrueckii subsp. bulgaricus strains isolated from dairy products.

PubMed

Ignatova, Tseteslava; Iliev, Ilia; Kirilov, Nikolai; Vassileva, Tonka; Dalgalarrondo, Michèle; Haertlé, Thomas; Chobert, Jean-Marc; Ivanova, Iskra

2009-10-28

Eighteen lactic acid bacteria (LAB) strains isolated from dairy products, all identified as Lactobacillus delbrueckii subsp. bulgaricus, were tested for their ability to grow on three different oligosaccharides: fructo-oligosaccharides (FOS), gluco-oligosaccharides (GOS) and galacto-oligosaccharides (GalOS). The growth of LAB on different oligosaccharides was very different. Study of the antimicrobial activities of these LAB indicated that the system of uptake of unusual sugars influenced in a specific way the production of antimicrobial substances (bacteriocins) specific against gram-negative bacteria. The added oligosaccharides induced LAB to form end-products of a typical mixed acid fermentation. The utilization of different types of oligosaccharides may help to explain the ability of Lactobacillus strains to compete with other bacteria in the ecosystem of the human gastro-intestinal tract.

Antimicrobial phenolics and unusual glycerides from Helichrysum italicum subsp. microphyllum.

PubMed

Taglialatela-Scafati, Orazio; Pollastro, Federica; Chianese, Giuseppina; Minassi, Alberto; Gibbons, Simon; Arunotayanun, Warunya; Mabebie, Blessing; Ballero, Mauro; Appendino, Giovanni

2013-03-22

During a large-scale isolation campaign for the heterodimeric phloroglucinyl pyrone arzanol (1a) from Helichrysum italicum subsp. microphyllum, several new phenolics as well as an unusual class of lipids named santinols (5a-c, 6-8) have been characterized. Santinols are angeloylated glycerides characterized by the presence of branched acyl- or keto-acyl chains and represent a hitherto unreported class of plant lipids. The antibacterial activity of arzanol and of a selection of Helichrysum phenolics that includes coumarates, benzofurans, pyrones, and heterodimeric phloroglucinols was evaluated, showing that only the heterodimers showed potent antibacterial action against multidrug-resistant Staphylococcus aureus isolates. These observations validate the topical use of Helichrysum extracts to prevent wound infections, a practice firmly established in the traditional medicine of the Mediterranean area.

Virulence of Photobacterium damselae subsp. piscicida in cultured cobia Rachycentron canadum.

PubMed

Liu, Ping-Chung; Lin, Ji-Yang; Lee, Kuo-Kau

2003-01-01

An outbreak of serious mortality among the cultured cobia Rachycentron canadum (weighing 3 kg) characterized by the presence of whitish granulomatous deposits on the kidney, liver and spleen occurred in July of 2000 in Taiwan. A non-motile strain CP1 was isolated from kidney and/or liver on tryptic soy agar and/or brain heart infusion agar plates (both supplemented with 1% NaCl, w/v). This strain was characterized and identified as Photobacterium damselae subsp. piscicida using biochemical characteristics and Bionor mono-Pp tests. The bacterium and its extracellular products (ECP) were lethal to the cobia (weighing 10 g) with LD50 values of 1.03 x 10(4) colony forming units and 1.26 microg protein/g fish body weight, respectively. All the moribund/dead fish exhibited darkness in color with no gross or internal leasions. However, the bacteria could be reisolated from kidney and liver after bacterial challenge. The present results reveal that Ph. damselae subsp. piscicida is the causative agent of fish photobacteriosis in the cobia and the bacterium isolated from sub-adult cobia (chronic form) is virulent to young cobia causing acute form of the disease.

Complete closed genome sequences of Salmonella enterica subsp. enterica serotypes Anatum, Montevideo, Typhimurium and Newport, isolated from beef, cattle, and humans

USDA-ARS?s Scientific Manuscript database

Salmonella enterica are a versatile group of bacteria with a wide range in virulence potential. To facilitate genome comparisons across this virulence spectrum, we present eight complete closed genome sequences of four S. enterica serotypes (Anatum, Montevideo, Typhimurium, and Newport) isolated fro...

Three new insertion sequence elements ISLdl2, ISLdl3, and ISLdl4 in Lactobacillus delbrueckii: isolation, molecular characterization, and potential use for strain identification.

PubMed

Ravin, Victor; Alatossava, Tapani

2003-05-01

A group of new insertion sequence (IS) elements, ISLdl2, ISLdl3, and ISLdl4, from Lactobacillus delbrueckii subsp. lactis ATCC 15808 was isolated, characterized, and used for strain identification together with ISLdl1, recently characterized as an L. delbrueckii IS element belonging to the ISL3 family. ISLdl2 was 1367 bp in size and had a 24 bp IR and an 8 bp DR. The single ORF of ISLdl2 encoded a protein of 392 aa similar to transposases of the IS256 family. ISLdl3 had a single ORF encoding a protein of 343 aa similar to transposases of the IS30 family. Finally, ISLdl4 had a single ORF encoding a protein of 406 aa and displayed homology to the transposases of the IS110 family. ISLdl4 was only slight different from ISL4 (Accession No. AY040213). ISLdl1, ISLdl2, and ISLdl4 were present in all of the 10 L. delbrueckii subsp. lactis and subsp. delbrueckii strains tested, as well as in three of the 11 L. delbrueckii subsp. bulgaricus strains tested. ISLdl3 was present only in four closely related strains of L. delbrueckii subsp. lactis. These IS elements were not observed in Lactobacillus rhamnosus, Lactobacillus acidophilus, Lactobacillus helveticus, or Lactobacillus plantarum. A cluster of IS elements, ISLdl1, ISLdl2, ISLdl3, ISLdl4, and ISL6, was observed in L. delbrueckii subsp. lactis strain ATCC 15808. Within this cluster, ISLdl4 was inserted into ISLdl1 between the left IR and the start codon of ORF455, encoding a putative transposase. Most of the integration sites of the IS elements were strain-specific. We have observed that IS elements can migrate from one strain to another as integral parts of bacterial DNA by using phage LL-H as a vehicle. We demonstrate for the first time that inverse PCR and vectorette PCR methods with primers based on sequences of the IS elements could be used for identification of L. delbrueckii strains.

Desulfovibrio oceani subsp. oceani sp. nov., subsp. nov. and Desulfovibrio oceani subsp. galateae subsp. nov., novel sulfate-reducing bacteria isolated from the oxygen minimum zone off the coast of Peru.

PubMed

Finster, Kai W; Kjeldsen, Kasper U

2010-03-01

Two deltaproteobacterial sulfate reducers, designated strain I.8.1(T) and I.9.1(T), were isolated from the oxygen minimum zone water column off the coast of Peru at 400 and 500 m water depth. The strains were Gram-negative, vibrio-shaped and motile. Both strains were psychrotolerant, grew optimally at 20 degrees C at pH 7.0-8.0 and at 2.5-3.5% NaCl (w/v). The strains grew by utilizing hydrogen/acetate, C(3-4) fatty acids, amino acids and glycerol as electron acceptors for sulfate reduction. Fumarate, lactate and pyruvate supported fermentative growth. Sulfate, sulfite, thiosulfate and taurin supported growth as electron acceptors. Both strains were catalase-positive and highly oxygen-tolerant, surviving 24 days of exposure to atmospheric concentrations. MK6 was the only respiratory quinone. The most prominent cellular fatty acid was iso-17:1-omega9c (18%) for strain I.8.1(T) and iso-17:0-omega9c (14%) for strain I.9.1(T). The G+C contents of their genomic DNA were 45-46 mol%. Phylogenetic analysis of 16S rRNA and dsrAB gene sequences showed that both strains belong to the genus Desulfovibrio. Desulfovibrio acrylicus DSM 10141(T) and Desulfovibrio marinisediminis JCM 14577(T) represented their closest validly described relatives with pairwise 16S rRNA gene sequence identities of 98-99%. The level of DNA-DNA hybridization between strains I.8.1(T) and I.9.1(T) was 30-38%. The two strains shared 10-26% DNA-DNA relatedness with D. acrylicus. Based on a polyphasic investigation it is proposed that strains I.8.1(T) and I.9.1(T) represent a novel species for which the name Desulfovibrio oceani sp. nov. is proposed with the two subspecies D. oceani subsp. oceani (type strain, I.8.1(T) = DSM 21390(T) = JCM 15970(T)) and D. oceani subsp. galateae (type strain, I.9.1(T) = DSM 21391(T) = JCM 15971(T)).

Phenotypic and genotypic diversity of dominant lactic acid bacteria isolated from traditional yoghurts produced by tribes of Iran

PubMed Central

RoushanZadeh, S; Eskandari, M. H.; Shekarforoush, S. S.; Hosseini, A

2014-01-01

Morphological, biochemical and molecular characteristics were studied to identify dominant lactic acid bacteria (LAB), isolated from traditional yoghurts produced by tribes of Iran. From 60 yoghurt samples, a total of 137 LAB isolates were determined, in which 66 and 71 were identified as lactic acid cocci and bacilli, respectively. Biochemical tests showed the occurrence of 9.76% mesophilic homofermentative, 10.98% mesophilic hetrofermentative, 26.83% thermophilic homofermentative and 47.56% mesophilic homofermentative cocci. As for lactic acid bacilli, mesophilic facultative hetrofermentative (26%); thermophilic obligate homofermentative (56%); mesophilic obligate hetrofermentative (18%) were found. Genetically the presence of the following species were verified: E. faecium; E. faecalis; E. durans; L. lactis subsp. lactis; St. thermophilus; Lb. delbruecki subsp. bulgaricus; Lb. brevis; Lb. diolivorans; Lb. helveticus; Lb. jensenii; Lb. plantarum. 9% of the Lactobacillus isolates showed incompatible results between phenotypic and genotypic characteristics. From the cocci isolates, 38.46% showed identical results between phylogenetic characteristics. The current study constitutes the first step in the designing process of LAB starter cultures, to protect the typical organoleptic characteristics of traditional yoghurt. The results could also be used to introduce new starter cultures for commercial use. PMID:27175129

Genetic diversity of Streptococcus equi subsp. zooepidemicus and doxycycline resistance in kennelled dogs.

PubMed

Chalker, Victoria J; Waller, Andrew; Webb, Katy; Spearing, Emma; Crosse, Patricia; Brownlie, Joe; Erles, Kerstin

2012-06-01

The genetic diversity and antibiotic resistance profiles of 38 Streptococcus equi subsp. zooepidemicus isolates were determined from a kennelled canine population during two outbreaks of hemorrhagic pneumonia (1999 to 2002 and 2007 to 2010). Analysis of the szp gene hypervariable region and the 16S-23S rRNA intergenic spacer region and multilocus sequence typing (MLST) indicated a predominant tetO-positive, doxycycline-resistant ST-10 strain during 1999 to 2002 and a predominant tetM-positive doxycycline-resistant ST-62 strain during 2007 to 2010.

Genetic Diversity of Streptococcus equi subsp. zooepidemicus and Doxycycline Resistance in Kennelled Dogs

PubMed Central

Chalker, Victoria J.; Waller, Andrew; Webb, Katy; Spearing, Emma; Crosse, Patricia; Brownlie, Joe

2012-01-01

The genetic diversity and antibiotic resistance profiles of 38 Streptococcus equi subsp. zooepidemicus isolates were determined from a kennelled canine population during two outbreaks of hemorrhagic pneumonia (1999 to 2002 and 2007 to 2010). Analysis of the szp gene hypervariable region and the 16S-23S rRNA intergenic spacer region and multilocus sequence typing (MLST) indicated a predominant tetO-positive, doxycycline-resistant ST-10 strain during 1999 to 2002 and a predominant tetM-positive doxycycline-resistant ST-62 strain during 2007 to 2010. PMID:22495558

Factors Affecting Exocellular Polysaccharide Production by Lactobacillus delbrueckii subsp. bulgaricus Grown in a Chemically Defined Medium†

PubMed Central

Petry, Sandrine; Furlan, Sylviane; Crepeau, Marie-Jeanne; Cerning, Jutta; Desmazeaud, Michel

2000-01-01

We developed a chemically defined medium (CDM) containing lactose or glucose as the carbon source that supports growth and exopolysaccharide (EPS) production of two strains of Lactobacillus delbrueckii subsp. bulgaricus. The factors found to affect EPS production in this medium were oxygen, pH, temperature, and medium constituents, such as orotic acid and the carbon source. EPS production was greatest during the stationary phase. Composition analysis of EPS isolated at different growth phases and produced under different fermentation conditions (varying carbon source or pH) revealed that the component sugars were the same. The EPS from strain L. delbrueckii subsp. bulgaricus CNRZ 1187 contained galactose and glucose, and that of strain L. delbrueckii subsp. bulgaricus CNRZ 416 contained galactose, glucose, and rhamnose. However, the relative proportions of the individual monosaccharides differed, suggesting that repeating unit structures can vary according to specific medium alterations. Under pH-controlled fermentation conditions, L. delbrueckii subsp. bulgaricus strains produced as much EPS in the CDM as in milk. Furthermore, the relative proportions of individual monosaccharides of EPS produced in pH-controlled CDM or in milk were very similar. The CDM we developed may be a useful model and an alternative to milk in studies of EPS production. PMID:10919802

A 38-Kilobase Pathogenicity Island Specific for Mycobacterium avium subsp. paratuberculosis Encodes Cell Surface Proteins Expressed in the Host

PubMed Central

Stratmann, Janin; Strommenger, Birgit; Goethe, Ralph; Dohmann, Karen; Gerlach, Gerald-F.; Stevenson, Karen; Li, Ling-ling; Zhang, Qing; Kapur, Vivek; Bull, Tim J.

2004-01-01

We have used representational difference analysis to identify a novel Mycobacterium avium subsp. paratuberculosis-specific ABC transporter operon (mpt), which comprises six open reading frames designated mptA to -F and is immediately preceded by two putative Fur boxes. Functional genomics revealed that the mpt operon is flanked on one end by a fep cluster encoding proteins involved in the uptake of Fe3+ and on the other end by a sid cluster encoding non-ribosome-dependent heterocyclic siderophore synthases. Together these genes form a 38-kb M. avium subsp. paratuberculosis-specific locus flanked by an insertion sequence similar to IS1110. Expression studies using Western blot analyses showed that MptC is present in the envelope fraction of M. avium subsp. paratuberculosis. The MptD protein was shown to be surface exposed, using a specific phage (fMptD) isolated from a phage-peptide library, by differential screening of Mycobacterium smegmatis transformants. The phage fMptD-derived peptide could be used in a peptide-mediated capture PCR with milk from infected dairy herds, thereby showing surface-exposed expression of the MptD protein in the host. Together, these data suggest that the 38-kb locus constitutes an M. avium subsp. paratuberculosis pathogenicity island. PMID:14977927

Characterization and Comparison of Clavibacter michiganensis subsp. nebraskensis Strains Recovered from Epiphytic and Symptomatic Infections of Maize in Iowa

PubMed Central

Robertson, Alison E.

2015-01-01

Clavibacter michiganensis subsp. nebraskensis (Cmn), the causal organism of Goss’s wilt and leaf blight of maize, can be detected in the phyllosphere of its host prior to disease development. We compared the morphology and pathogenicity of 37 putative isolates of Cmn recovered from asymptomatic and symptomatic maize leaves. Thirty-three of the isolates produced mucoid orange colonies, irrespective of the source of isolation and all but four of these isolates were pathogenic on maize. The remaining 4 isolates recovered from asymptomatic leaves had large fluidal yellow colonies, and were non-pathogenic on maize. Isolates varied in their aggressiveness on a susceptible hybrid of maize but no significant differences in aggressiveness were detected between epiphytic isolates and those recovered from diseased maize tissues. The genomics of Cmn is poorly understood; therefore as a first step to determining what genes may play a role in virulence, we compared 33 putative virulence gene sequences from 6 pathogenic and a non-pathogenic isolate recovered from the phyllosphere. Sequence polymorphisms were detected in 5 genes, cellulase A, two endoglucanases, xylanase B and a pectate lyase but there was no relationship with pathogenicity. Further research is needed to determine what genes play a role in virulence of Cmn. Our data show however, that the virulence factors in Cmn likely differ from those reported for the closely related subspecies michiganensis and sepedonicus. PMID:26599211

Characterization and Comparison of Clavibacter michiganensis subsp. nebraskensis Strains Recovered from Epiphytic and Symptomatic Infections of Maize in Iowa.

PubMed

Ahmad, Azeem; Mbofung, Gladys Y; Acharya, Jyotsna; Schmidt, Clarice L; Robertson, Alison E

2015-01-01

Clavibacter michiganensis subsp. nebraskensis (Cmn), the causal organism of Goss's wilt and leaf blight of maize, can be detected in the phyllosphere of its host prior to disease development. We compared the morphology and pathogenicity of 37 putative isolates of Cmn recovered from asymptomatic and symptomatic maize leaves. Thirty-three of the isolates produced mucoid orange colonies, irrespective of the source of isolation and all but four of these isolates were pathogenic on maize. The remaining 4 isolates recovered from asymptomatic leaves had large fluidal yellow colonies, and were non-pathogenic on maize. Isolates varied in their aggressiveness on a susceptible hybrid of maize but no significant differences in aggressiveness were detected between epiphytic isolates and those recovered from diseased maize tissues. The genomics of Cmn is poorly understood; therefore as a first step to determining what genes may play a role in virulence, we compared 33 putative virulence gene sequences from 6 pathogenic and a non-pathogenic isolate recovered from the phyllosphere. Sequence polymorphisms were detected in 5 genes, cellulase A, two endoglucanases, xylanase B and a pectate lyase but there was no relationship with pathogenicity. Further research is needed to determine what genes play a role in virulence of Cmn. Our data show however, that the virulence factors in Cmn likely differ from those reported for the closely related subspecies michiganensis and sepedonicus.

Prevalence and comparison of Streptococcus infantarius subsp. infantarius and Streptococcus gallolyticus subsp. macedonicus in raw and fermented dairy products from East and West Africa.

PubMed

Jans, Christoph; Kaindi, Dasel Wambua Mulwa; Böck, Désirée; Njage, Patrick Murigu Kamau; Kouamé-Sina, Sylvie Mireille; Bonfoh, Bassirou; Lacroix, Christophe; Meile, Leo

2013-10-15

Streptococcus infantarius subsp. infantarius (Sii) and Streptococcus gallolyticus subsp. macedonicus are members of the Streptococcus bovis/Streptococcus equinus complex (SBSEC) associated with human infections. SBSEC-related endocarditis was furthermore associated with rural residency in Southern Europe. SBSEC members are increasingly isolated as predominant species from fermented dairy products in Europe, Asia and Africa. African variants of Sii displayed dairy adaptations to lactose metabolism paralleling those of Streptococcus thermophilus including genome decay. In this study, the aim was to assess the prevalence of Sii and possibly other SBSEC members in dairy products of East and West Africa in order to identify their habitat, estimate their importance in dairy fermentation processes and determine geographic areas affected by this potential health risk. Presumptive SBSEC members were isolated on semi-selective M17 and SM agar media. Subsequent genotypic identification of isolates was based on rep-PCR fingerprinting and SBSEC-specific16S rRNA gene PCR assay. Detailed identification was achieved through application of novel primers enhancing the binding stringency in partial groES/groEL gene amplification and subsequent DNA sequencing. The presence of S. thermophilus-like lacS and lacZ genes in the SBSEC isolates was determined to elucidate the prevalence of this dairy adaptation. Isolates (n = 754) were obtained from 72 raw and 95 fermented milk samples from Côte d'Ivoire and Kenya on semi-selective agar media. Colonies of Sii were not detected from raw milk despite high microbial titers of approximately 10(6)CFU/mL on M17 agar medium. However, after spontaneous milk fermentation Sii was genotypically identified in 94.1% of Kenyan samples and 60.8% of Kenyan isolates. Sii prevalence in Côte d'Ivoire displayed seasonal variations in samples from 32.3% (June) to 40.0% (Dec/Jan) and isolates from 20.5% (June) to 27.7% (Dec/Jan) present at titers of 10(6)-10(8)CFU/mL. lacS and lacZ genes were detected in all Kenyan and 25.8% (June) to 65.4% (Dec/Jan) of Ivorian Sii isolates. Regional differences in prevalence of Sii and dairy adaptations were observed, but no clear effect of dairy animal, fermentation procedure and climate was revealed. Conclusively, the high prevalence of Sii in Kenya, Côte d'Ivoire in addition to Somalia, Sudan and Mali strongly indicates a pivotal role of Sii in traditional African dairy fermentations potentially paralleling that of typical western dairy species S. thermophilus. Putative health risks associated with the consumption of high amounts of live Sii and potential different degrees of evolutionary adaptation or ecological colonization require further epidemiologic and genomic investigations, particularly in Africa. © 2013.

Prevalence and comparison of Streptococcus infantarius subsp. infantarius and Streptococcus gallolyticus subsp. macedonicus in raw and fermented dairy products from East and West Africa

PubMed Central

Jans, Christoph; Kaindi, Dasel Wambua Mulwa; Böck, Désirée; Njage, Patrick Murigu Kamau; Kouamé-Sina, Sylvie Mireille; Bonfoh, Bassirou; Lacroix, Christophe; Meile, Leo

2016-01-01

Streptococcus infantarius subsp. infantarius (Sii) and Streptococcus gallolyticus subsp. macedonicus are members of the Streptococcus bovis/Streptococcus equinus complex (SBSEC) associated with human infections. SBSEC-related endocarditis was furthermore associated with rural residency in Southern Europe. SBSEC members are increasingly isolated as predominant species from fermented dairy products in Europe, Asia and Africa. African variants of Sii displayed dairy adaptations to lactose metabolism paralleling those of Streptococcus thermophilus including genome decay. In this study, the aim was to assess the prevalence of Sii and possibly other SBSEC members in dairy products of East and West Africa in order to identify their habitat, estimate their importance in dairy fermentation processes and determine geographic areas affected by this potential health risk. Presumptive SBSEC members were isolated on semi-selective M17 and SM agar media. Subsequent genotypic identification of isolates was based on rep-PCR fingerprinting and SBSEC-specific16S rRNA gene PCR assay. Detailed identification was achieved through application of novel primers enhancing the binding stringency in partial groES/groEL gene amplification and subsequent DNA sequencing. The presence of S. thermophilus-like lacS and lacZ genes in the SBSEC isolates was determined to elucidate the prevalence of this dairy adaptation. Isolates (n = 754) were obtained from 72 raw and 95 fermented milk samples from Côte d'Ivoire and Kenya on semi-selective agar media. Colonies of Sii were not detected from raw milk despite high microbial titers of approximately 106 CFU/mL on M17 agar medium. However, after spontaneous milk fermentation Sii was genotypically identified in 94.1% of Kenyan samples and 60.8% of Kenyan isolates. Sii prevalence in Côte d'Ivoire displayed seasonal variations in samples from 32.3% (June) to 40.0% (Dec/Jan) and isolates from 20.5% (June) to 27.7% (Dec/Jan) present at titers of 106–108 CFU/mL. lacS and lacZ genes were detected in all Kenyan and 25.8% (June) to 65.4% (Dec/Jan) of Ivorian Sii isolates. Regional differences in prevalence of Sii and dairy adaptations were observed, but no clear effect of dairy animal, fermentation procedure and climate was revealed. Conclusively, the high prevalence of Sii in Kenya, Côte d'Ivoire in addition to Somalia, Sudan and Mali strongly indicates a pivotal role of Sii in traditional African dairy fermentations potentially paralleling that of typical western dairy species S. thermophilus. Putative health risks associated with the consumption of high amounts of live Sii and potential different degrees of evolutionary adaptation or ecological colonization require further epidemiologic and genomic investigations, particularly in Africa. PMID:24131584

Profiles of Volatile Flavor Compounds in Milk Fermented with Different Proportional Combinations of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus.

PubMed

Dan, Tong; Wang, Dan; Wu, Shimei; Jin, Rulin; Ren, Weiyi; Sun, Tiansong

2017-09-29

Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus are key factors in the fermentation process and the final quality of dairy products worldwide. This study was performed to investigate the effects of the proportions of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus isolated from traditionally fermented dairy products in China and Mongolia on the profile of volatile compounds produced in samples. Six proportional combinations (1:1, 1:10, 1:50, 1:100, 1:1000, and 1:10,000) of L. delbrueckii subsp. bulgaricus IMAU20401 to S. thermophilus ND03 were considered, and the volatiles were identified and quantified by solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS) against an internal standard. In total, 89 volatile flavor compounds, consisting of aldehydes, ketones, acids, alcohols, esters, and aromatic hydrocarbons, were identified. Among these, some key flavor volatile compounds were identified, including acetaldehyde, 3-methylbutanal, acetoin, 2-heptanone, acetic acid, butanoic acid, and 3-methyl-1-butanol. The of L. delbrueckii subsp. bulgaricus IMAU20401 to S. thermophilus ND03 influenced the type and concentration of volatiles produced. In particular, aldehydes and ketones were present at higher concentrations in the 1:1000 treatment combination than in the other combinations. Our findings emphasize the importance of selecting the appropriate proportions of L. delbrueckii subsp. bulgaricus and S. thermophilus for the starter culture in determining the final profile of volatiles and the overall flavor of dairy products.

Cell-Wall-Bound Proteinase of Lactobacillus delbrueckii subsp. lactis ACA-DC 178: Characterization and Specificity for β-Casein

PubMed Central

Tsakalidou, E.; Anastasiou, R.; Vandenberghe, I.; van Beeumen, J.; Kalantzopoulos, G.

1999-01-01

Lactobacillus delbrueckii subsp. lactis ACA-DC 178, which was isolated from Greek Kasseri cheese, produces a cell-wall-bound proteinase. The proteinase was removed from the cell envelope by washing the cells with a Ca2+-free buffer. The crude proteinase extract shows its highest activity at pH 6.0 and 40°C. It is inhibited by phenylmethylsulfonyl fluoride, showing that the enzyme is a serine-type proteinase. Considering the substrate specificity, the enzyme is similar to the lactococcal PI-type proteinases, since it hydrolyzes β-casein mainly and α- and κ-caseins to a much lesser extent. The cell-wall-bound proteinase from L. delbrueckii subsp. lactis ACA-DC 178 liberates four main peptides from β-casein, which have been identified. PMID:10223997

Ecology, Epidemiology and Disease Management of Ralstonia syzygii in Indonesia.

PubMed

Safni, Irda; Subandiyah, Siti; Fegan, Mark

2018-01-01

Ralstonia solanacearum species complex phylotype IV strains, which have been primarily isolated from Indonesia, Australia, Japan, Korea, and Malaysia, have undergone recent taxonomic and nomenclatural changes to be placed in the species Ralstonia syzygii . This species contains three subspecies; Ralstonia syzygii subsp. syzygii , a pathogen causing Sumatra disease of clove trees in Indonesia, Ralstonia syzygii subsp. indonesiensis , the causal pathogen of bacterial wilt disease on a wide range of host plants, and Ralstonia syzygii subsp. celebesensis , the causal pathogen of blood disease on Musa spp. In Indonesia, these three subspecies have devastated the cultivation of susceptible host plants which have high economic value. Limited knowledge on the ecology and epidemiology of the diseases has hindered the development of effective control strategies. In this review, we provide insights into the ecology, epidemiology and disease control of these three subspecies of Ralstonia syzygii .

Screening of lactic acid bacteria from vacuum packaged beef for antimicrobial activity

PubMed Central

Oliveira, Roseane B. P.; de L. Oliveira, Afonso; Glória, M. Beatriz A.

2008-01-01

The objective of this study was to isolate lactic acid bacteria (LAB) from vacuum packaged beef and to investigate their antagonist activity. LAB mean counts of 5.19 log cfu/cm2 were obtained from five samples of vacuum packaged beef. Two hundred isolates were selected and screened for the inhibitory effect on five ATCC reference Lactobacillus strains. Thirty six isolates showed activity in the agar spot test against at least two of the indicator strains. However, only six cell free supernatants (CFS) from these isolates exhibited activity against the indicator strains using the well-diffusion test and conditions that eliminated the effects of organic acids and hydrogen peroxide. L. acidophilus was the most sensitive indicator tested, whereas L. plantarum and L. fermentum were the most resistant ones. Identification by MIDI system indicated that these LAB isolates were Lactococcus lactis subsp. cremoris, Pediococcus acidilactici, Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus casei GC subgroup A. The antagonistic factors produced by most of these LAB against L. acidophilus were resistant to heat treatment (100°C for 10 min) and stable over a wide pH range (4.0 to 9.0). These data suggest that these isolates could be used as promising hurdles aiming increased safety and extended shelf life of meat products. PMID:24031232

In vitro evaluation of the probiotic and functional potential of Lactobacillus strains isolated from fermented food and human intestine.

PubMed

Ren, Dayong; Li, Chang; Qin, Yanqing; Yin, Ronglan; Du, Shouwen; Ye, Fei; Liu, Cunxia; Liu, Hongfeng; Wang, Maopeng; Li, Yi; Sun, Yang; Li, Xiao; Tian, Mingyao; Jin, Ningyi

2014-12-01

This study aims to evaluate the functional and probiotic characteristics of eight indigenous Lactobacillus strains in vitro. The selected lactobacilli include strains of Lactobacillus casei subsp. casei, Lactobacillus salivarius subsp. salicinius, Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus delbrueckii subsp. lactis, Lactobacillus delbrueckii subsp. bulgaricus, and Lactobacillus rhamnosus. All strains tolerated both pH 2 for 3 h and 1% bile salt for 24 h. The strains CICC 23174 and CGMCC 1.557 were the most adhesive strains producing the highest quantity of EPS. Although a wide variation in the ability of the eight strains to deplete cholesterol and nitrite, antagonize pathogens, scavenge free radical, and stimulate innate immune response were observed, the strains CICC 23174 and CGMCC 1.557 showed the widest range of these useful traits. Taken together, the strains CICC 23174 and CGMCC 1.557 exhibited the best probiotic properties with the potential for use in the production of probiotic fermented foods. Copyright © 2014 Elsevier Ltd. All rights reserved.

Photobacterium damselae subsp. damselae, an Emerging Fish Pathogen in the Black Sea: Evidence of a Multiclonal Origin

PubMed Central

Terceti, Mateus S.; Ogut, Hamdi

2016-01-01

ABSTRACT Photobacterium damselae subsp. damselae is considered to be an emerging pathogen of marine fish of importance in aquaculture, with a notable increase in its geographical distribution during the last several years. In this study, we carried out for the first time to our knowledge a genetic and pathobiological characterization of 14 strains isolated from sea bass (Dicentrarchus labrax) reared in the Southeastern Black Sea, where high mortalities were observed at two aquaculture farms during the summer and autumn of 2011. Heterogeneity was evidenced among strains in phenotypical traits, such as sucrose fermentation, motility, and hemolysis. Although 11 of 14 isolates were hemolytic, we found that all of the isolates lacked the pPHDD1 virulence plasmid that encodes the phospholipase-D damselysin (Dly) and the pore-forming toxin PhlyP, two hemolysins previously reported to constitute major virulence factors for turbot. Subsequent PCR and sequencing analyses demonstrated that the 11 hemolytic isolates harbored a complete hlyAch gene, a chromosome I-borne gene that encodes HlyAch hemolysin, whereas the three nonhemolytic isolates contained hlyAch pseudogenes caused by insertion sequence elements. Virulence challenges with two representative strains revealed that, albeit less virulent than the pPHDD1-harboring strain RM-71, the plasmidless hlyAch-positive and hlyAch-negative Black Sea isolates were pathogenic for sea bass. A phylogenetic analysis based on the toxR gene sequence uncovered a greater diversity in the isolates, indicating that the presence of this pathogen in the Black Sea was not caused by the introduction and spread of a single virulent clone but by the proliferation of different clones. IMPORTANCE The geographical distribution of marine bacterial pathogens is undergoing a worldwide increase. In particular, bacteria of the group vibrios are increasingly being isolated as the causative agents of disease in novel species of cultivated fish in areas where they had not been previously reported. Here we characterize for the first time to our knowledge a collection of isolates of the fish and human pathogen Photobacterium damselae subsp. damselae from diseased sea bass reared in the Black Sea. We uncovered great genetic diversity in the Black Sea isolates of this pathogen, suggesting a multiclonal origin. We also demonstrate for the first time that these isolates bear pathogenic potential for sea bass cultures by virulence challenges. PMID:27084008

Antibiotic resistance of lactic acid bacteria and Bifidobacterium spp. isolated from dairy and pharmaceutical products.

PubMed

D'Aimmo, Maria Rosaria; Modesto, Monica; Biavati, Bruno

2007-04-01

The outlines of antibiotic resistance of some probiotic microorganisms were studied. This study was conducted with the double purpose of verifying their ability to survive if they are taken simultaneously with an antibiotic therapy and to increase the selective properties of suitable media for the isolation of samples containing mixed bacterial populations. We isolated from commercial dairy and pharmaceutical products, 34 strains declared as probiotics, belonging to the genera Bifidobacterium and Lactobacillus, and 21 strains of starter culture bacteria. All the microorganisms have been compared by electrophoresis of the soluble proteins for the purpose of identifying them. A Multiplex-PCR with genus- and species-specific primers was used to detect for Bifidobacterium animalis subsp. lactis presence. All bifidobacteria were B. animalis subsp. lactis except one Bifidobacterium longum. Sometimes the identification showed that the used strain was not the one indicated on the label. The lactobacilli were Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus delbrueckii subsp. bulgaricus. The streptococci were all Streptococcus thermophilus. The minimal inhibitory concentration (MIC) of 24 common antibiotic substances has been valued by the broth microdilution method. All tested strains were susceptible to ampicillin, bacitracin, clindamycin, dicloxacillin, erytromycin, novobiocin, penicillin G, rifampicin (MIC(90) ranging from 0.01 to 4 microg/ml); resistant to aztreonam, cycloserin, kanamycin, nalidixic acid, polymyxin B and spectinomycin (MIC(90) ranging from 64 to >1000 microg/ml). The susceptibility to cephalothin, chloramphenicol, gentamicin, lincomycin, metronidazole, neomycin, paromomycin, streptomycin, tetracycline and vancomycin was variable and depending on the species.

Streptococcus dysgalactiae subsp. equisimilis Isolated From Infections in Dogs and Humans: Are Current Subspecies Identification Criteria accurate?

PubMed

Ciszewski, Marcin; Zegarski, Kamil; Szewczyk, Eligia M

2016-11-01

Streptococcus dysgalactiae is a pyogenic species pathogenic both for humans and animals. Until recently, it has been considered an exclusive animal pathogen causing infections in wild as well as domestic animals. Currently, human infections are being reported with increasing frequency, and their clinical picture is often similar to the ones caused by Streptococcus pyogenes. Due to the fact that S. dysgalactiae is a heterogeneous species, it was divided into two subspecies: S. dysgalactiae subsp. equisimilis (SDSE) and S. dysgalactiae subsp. dysgalactiae (SDSD). The first differentiation criterion, described in 1996, was based on strain isolation source. Currently applied criteria, published in 1998, are based on hemolysis type and Lancefield group classification. In this study, we compared subspecies identification results for 36 strains isolated from clinical cases both in humans and animals. Species differentiation was based on two previously described criteria as well as MALDI-TOF and genetic analyses: RISA and 16S rRNA genes sequencing. Antimicrobial susceptibility profiles were also determined according to CLSI guidelines. The results presented in our study suggest that the subspecies differentiation criteria previously described in the above two literature positions seem to be inaccurate in analyzed group of strains, the hemolysis type on blood agar, and Lancefield classification should not be here longer considered as criteria in subspecies identification. The antimicrobial susceptibility tests indicate emerging of multiresistant human SDSE strains resistant also to vancomycin, linezolid and tigecycline, which might pose a substantial problem in treatment.

Demonstration that a Klebsiella pneumoniae subsp. pneumoniae isolated from an insect (Nezara viridula) harbors a functional plasmid-borne type IV secretion system

USDA-ARS?s Scientific Manuscript database

Previously, we reported the isolation of Klebsiella pneumoniae subspecies pneumoniae strain Kp 5-1 from a southern green stink bug (Nezara viridula) that is a significant pest of numerous economically important crops. We subsequently sequenced the strains whole genome. Here, we report the presence...

Genome sequence of the thermotolerant foodborne pathogen Salmonella enterica serovar Senftenberg ATCC 43845 and phylogenetic analysis of Loci encoding increased protein quality control mechanisms

USDA-ARS?s Scientific Manuscript database

Salmonella enterica subsp. enterica bacteria are important foodborne pathogens with major economic impact. Some isolates exhibit increased heat tolerance, a concern for food safety. Analysis of a finished-quality genome sequence of an isolate commonly used in heat resistance studies, S. enterica sub...

DrsG from Streptococcus dysgalactiae subsp. equisimilis Inhibits the Antimicrobial Peptide LL-37

PubMed Central

Smyth, Danielle; Cameron, Ainslie; Davies, Mark R.; McNeilly, Celia; Hafner, Louise; Sriprakash, Kadaba S.

2014-01-01

SIC and DRS are related proteins present in only 4 of the >200 Streptococcus pyogenes emm types. These proteins inhibit complement-mediated lysis and/or the activity of certain antimicrobial peptides (AMPs). A gene encoding a homologue of these proteins, herein called DrsG, has been identified in the related bacterium Streptococcus dysgalactiae subsp. equisimilis. Here we show that geographically dispersed isolates representing 14 of 50 emm types examined possess variants of drsG. However, not all isolates within the drsG-positive emm types possess the gene. Sequence comparisons also revealed a high degree of conservation in different S. dysgalactiae subsp. equisimilis emm types. To examine the biological activity of DrsG, recombinant versions of two major DrsG variants, DrsGS and DrsGL, were expressed and purified. Western blot analysis using antisera raised to these proteins demonstrated both variants to be expressed and secreted into culture supernatants. Unlike SIC, but similar to DRS, DrsG does not inhibit complement-mediated lysis. However, like both SIC and DRS, DrsG is a ligand of the cathelicidin LL-37 and is inhibitory to its bactericidal activity in in vitro assays. Conservation of prolines in the C-terminal region also suggests that these residues are important in the biology of this family of proteins. This is the first report demonstrating the activity of an AMP-inhibitory protein in S. dysgalactiae subsp. equisimilis and suggests that inhibition of AMP activity is the primary function of this family of proteins. The acquisition of the complement-inhibitory activity of SIC may reflect its continuing evolution. PMID:24664506

Serratia nematodiphila sp. nov., associated symbiotically with the entomopathogenic nematode Heterorhabditidoides chongmingensis (Rhabditida: Rhabditidae).

PubMed

Zhang, Chong-Xing; Yang, Shou-Yun; Xu, Ming-Xu; Sun, Jie; Liu, Huan; Liu, Jing-Rui; Liu, Hui; Kan, Fei; Sun, Jing; Lai, Ren; Zhang, Ke-Yun

2009-07-01

A novel red-pigmented, Gram-negative, motile, fluorescent, rod-shaped strain, DZ0503SBS1(T), with a single lateral flagellum, was isolated from the intestine of the nematode Heterorhabditidoides chongmingensis. Comparative 16S rRNA gene sequence analysis indicated that the strain is a member of the genus Serratia, sharing highest sequence similarities with Serratia marcescens subsp. sakuensis JCM 11315(T) (99.8 %), S. marcescens subsp. marcescens DSM 30121(T) (99.5 %) and Serratia ureilytica LMG 22860(T) (98.3 %). Similarities between the rpoB gene sequence of strain DZ0503SBS1(T) and those of S. marcescens subsp. sakuensis JCM 11315(T), S. marcescens subsp. marcescens DSM 30121(T) and S. ureilytica LMG 22860(T) were 98.0, 97.4 and 98.3 %, respectively. DNA-DNA hybridization values of strain DZ0503SBS1(T) with S. marcescens subsp. sakuensis JCM 11315(T), S. marcescens subsp. marcescens DSM 30121(T) and S. ureilytica LMG 22860(T) were 68.2, 65.1 and 53.0 %, respectively. The major isoprenoid quinone of strain DZ0503SBS1(T) was Q-8 and the predominant fatty acids were C(16 : 0) (34.76 %), cyclo-C(17 : 0) (20.03 %) and cyclo-C(19 : 0)omega8c (17.24 %). The cyclo-C(19 : 0)omega8c content (17.24 %) was significantly different from those found in S. marcescens subsp. sakuensis JCM 11315(T) and S. marcescens subsp. marcescens DSM 30121(T). Some characteristics of strain DZ0503SBS1(T), i.e. fluorescence and its symbiotic association with nematodes, have not been reported previously in any species of the genus Serratia. Phenotypic and biochemical characteristics and molecular data show that strain DZ0503SBS1(T) represents a novel species, for which the name Serratia nematodiphila sp. nov. is proposed; the type strain is DZ0503SBS1(T) (=KCTC 22130(T) =CGMCC 1.6853(T)).

Production and Properties of Bacteriocin-Like Inhibitory Substances from the Swine Pathogen Streptococcus suis Serotype 2

PubMed Central

Mélançon, D.; Grenier, D.

2003-01-01

Streptococcus suis serotype 2 is a major pathogen found in the upper respiratory tract of swine. In this study, isolates of this bacterial species were tested for the production of bacteriocin-like inhibitory substances (BLIS). Of the 38 strains tested, four inhibited the growth of other S. suis isolates according to a deferred-antagonism plate assay. Interestingly, three of the strains were originally isolated from healthy carrier pigs and were considered nonvirulent. Three isolates (94-623, 90-1330, and AAH4) that produced BLIS in liquid broth were selected for further characterization. None of the inhibitory activities was related to the production of either organic acids or hydrogen peroxide. The BLIS produced by these strains were heat stable and proteinase K, pronase, and elastase sensitive but were trypsin and chymotrypsin resistant. They were stable at pH 2 and 12 and had molecular masses in the range of 14 to 30 kDa. Maximum production was observed during the mid-log phase. Following a curing procedure with novobiocin, only 90-1330 lost the ability to produce BLIS, suggesting that the BLIS might be plasmid encoded. Analysis of the inhibitory spectra revealed that the BLIS-producing strains also inhibited the growth of Actinobacillus minor, Actinobacillus porcinus, Enterococcus durans, Micrococcus luteus, Streptococcus agalactiae, Streptococcus dysgalactiae subsp. dysgalactiae, Streptococcus equi subsp. zooepidemicus, and S. dysgalactiae subsp. equisimilis. This study reports for the first time the ability of the swine pathogen S. suis serotype 2 to produce BLIS with the characteristics of classic bacteriocins. Further studies are required to investigate the possibility of using bacteriocin-producing strains to prevent swine infections caused by virulent strains of S. suis serotype 2. PMID:12902232

New Coffee Plant-Infecting Xylella fastidiosa Variants Derived via Homologous Recombination.

PubMed

Jacques, Marie-Agnès; Denancé, Nicolas; Legendre, Bruno; Morel, Emmanuelle; Briand, Martial; Mississipi, Stelly; Durand, Karine; Olivier, Valérie; Portier, Perrine; Poliakoff, Françoise; Crouzillat, Dominique

2015-12-28

Xylella fastidiosa is a xylem-limited phytopathogenic bacterium endemic to the Americas that has recently emerged in Asia and Europe. Although this bacterium is classified as a quarantine organism in the European Union, importation of plant material from contaminated areas and latent infection in asymptomatic plants have engendered its inevitable introduction. In 2012, four coffee plants (Coffea arabica and Coffea canephora) with leaf scorch symptoms growing in a confined greenhouse were detected and intercepted in France. After identification of the causal agent, this outbreak was eradicated. Three X. fastidiosa strains were isolated from these plants, confirming a preliminary identification based on immunology. The strains were characterized by multiplex PCR and by multilocus sequence analysis/typing (MLSA-MLST) based on seven housekeeping genes. One strain, CFBP 8073, isolated from C. canephora imported from Mexico, was assigned to X. fastidiosa subsp. fastidiosa/X. fastidiosa subsp. sandyi. This strain harbors a novel sequence type (ST) with novel alleles at two loci. The two other strains, CFBP 8072 and CFBP 8074, isolated from Coffea arabica imported from Ecuador, were allocated to X. fastidiosa subsp. pauca. These two strains shared a novel ST with novel alleles at two loci. These MLST profiles showed evidence of recombination events. We provide genome sequences for CFBP 8072 and CFBP 8073 strains. Comparative genomic analyses of these two genome sequences with publicly available X. fastidiosa genomes, including the Italian strain CoDiRO, confirmed these phylogenetic positions and provided candidate alleles for coffee plant adaptation. This study demonstrates the global diversity of X. fastidiosa and highlights the diversity of strains isolated from coffee plants. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Phylogenomics of Brazilian epidemic isolates of Mycobacterium abscessus subsp. bolletii reveals relationships of global outbreak strains

PubMed Central

Davidson, Rebecca M.; Hasan, Nabeeh A.; de Moura, Vinicius Calado Nogueira; Duarte, Rafael Silva; Jackson, Mary; Strong, Michael

2013-01-01

Rapidly growing, non-tuberculous mycobacteria (NTM) in the Mycobacterium abscessus (MAB) species are emerging pathogens that cause various diseases including skin and respiratory infections. The species has undergone recent taxonomic nomenclature refinement, and is currently recognized as two subspecies, M. abscessus subsp. abscessus (MAB-A) and M. abscessus subsp. bolletii (MAB-B). The recently reported outbreaks of MAB-B in surgical patients in Brazil from 2004 to 2009 and in cystic fibrosis patients in the United Kingdom (UK) in 2006 to 2012 underscore the need to investigate the genetic diversity of clinical MAB strains. To this end, we sequenced the genomes of two Brazilian MAB-B epidemic isolates (CRM-0019 and CRM-0020) derived from an outbreak of skin infections in Rio de Janeiro, two unrelated MAB strains from patients with pulmonary infections in the United States (US) (NJH8 and NJH11) and one type MAB-B strain (CCUG 48898) and compared them to 25 publically available genomes of globally diverse MAB strains. Genome-wide analyses of 27,598 core genome single nucleotide polymorphisms (SNPs) revealed that the two Brazilian derived CRM strains are nearly indistinguishable from one another and are more closely related to UK outbreak isolates infecting CF patients than to strains from the US, Malaysia or France. Comparative genomic analyses of six closely related outbreak strains revealed geographic-specific large-scale insertion/deletion variation that corresponds to bacteriophage insertions and recombination hotspots. Our study integrates new genome sequence data with existing genomic information to explore the global diversity of infectious M. abscessus isolates and to compare clinically relevant outbreak strains from different continents. PMID:24055961

Streptosporangium minutum sp. nov., isolated from garden soil exposed to microwave radiation.

PubMed

Le Roes-Hill, Marilize; Durrell, Kim; Prins, Alaric; Meyers, Paul R

2018-06-01

The actinobacterium, strain M26 T , was isolated from garden soil that was pre-treated with microwave radiation. The soil sample was collected in Roodepoort, Gauteng Province, South Africa as part of an antibiotic-screening programme. The isolate produced branched vegetative mycelium with sporangiophores bearing small sporangia ranging from 3 to 6 μm in diameter. Rapid genus identification revealed that the isolate belongs to the genus Streptosporangium. To confirm this result, the strain was subjected to polyphasic taxonomic characterisation. Chemotaxonomic characteristics were as follows: meso-DAP in the peptidoglycan, the whole-cell hydrolysate yielded madurose, predominant menaquinones were MK9 (21%), MK9(H 2 ) (40%), MK9(H 4 ) (31%) and MK9(H 6 ) (3%); the polar lipid profile included an aminolipid, phosphoglycolipids, phosphatidylethanolamine, and phosphatidylmonomethylethanolamine. In addition, the fatty acid profile showed the presence of C 16:0 (12.8%), C 17:1 ω8c (14.2%), and 10-methyl-C 17:0 (15.8%). Furthermore, 16S rRNA gene sequence phylogenetic analysis showed that the strain is closely related to members of the genus Streptosporangium, which supports its classification within the family Streptosporangiaceae. Strain M26 T exhibited antibiosis against a range of pathogenic bacteria, including, but not limited to Acinetobacter baumannii ATCC 19606 T , Enterobacter cloacae subsp. cloacae ATCC BAA-1143, Enterococcus faecalis ATCC 51299 (vancomycin resistant), Escherichia coli ATCC 25922, Listeria monocytogenes ATCC 19111, Mycobacterium tuberculosis H37Rv T , Pseudomonas aeruginosa ATCC 27853, Salmonella enterica subsp. arizonae ATCC 13314 T , and the methicillin-resistant Staphylococcus aureus subsp. aureus ATCC 33591 (MRSA). The name Streptosporangium minutum is proposed with the type strain M26 T (=LMG 28850 T =NRRL B-65295 T ).

An outbreak of respiratory tularemia caused by diverse clones of Francisella tularensis.

PubMed

Johansson, Anders; Lärkeryd, Adrian; Widerström, Micael; Mörtberg, Sara; Myrtännäs, Kerstin; Ohrman, Caroline; Birdsell, Dawn; Keim, Paul; Wagner, David M; Forsman, Mats; Larsson, Pär

2014-12-01

The bacterium Francisella tularensis is recognized for its virulence, infectivity, genetic homogeneity, and potential as a bioterrorism agent. Outbreaks of respiratory tularemia, caused by inhalation of this bacterium, are poorly understood. Such outbreaks are exceedingly rare, and F. tularensis is seldom recovered from clinical specimens. A localized outbreak of tularemia in Sweden was investigated. Sixty-seven humans contracted laboratory-verified respiratory tularemia. F. tularensis subspecies holarctica was isolated from the blood or pleural fluid of 10 individuals from July to September 2010. Using whole-genome sequencing and analysis of single-nucleotide polymorphisms (SNPs), outbreak isolates were compared with 110 archived global isolates. There were 757 SNPs among the genomes of the 10 outbreak isolates and the 25 most closely related archival isolates (all from Sweden/Finland). Whole genomes of outbreak isolates were >99.9% similar at the nucleotide level and clustered into 3 distinct genetic clades. Unexpectedly, high-sequence similarity grouped some outbreak and archival isolates that originated from patients from different geographic regions and up to 10 years apart. Outbreak and archival genomes frequently differed by only 1-3 of 1 585 229 examined nucleotides. The outbreak was caused by diverse clones of F. tularensis that occurred concomitantly, were widespread, and apparently persisted in the environment. Multiple independent acquisitions of F. tularensis from the environment over a short time period suggest that natural outbreaks of respiratory tularemia are triggered by environmental cues. The findings additionally caution against interpreting genome sequence identity for this pathogen as proof of a direct epidemiological link. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Presence of an emerging subclone of Francisella tularensis holarctica in Ixodes ricinus ticks from south-western Germany.

PubMed

Gehringer, Heike; Schacht, Erik; Maylaender, Nicole; Zeman, Ella; Kaysser, Philipp; Oehme, Rainer; Pluta, Silvia; Splettstoesser, Wolf D

2013-02-01

The zoonotic disease tularaemia is caused by the bacterial pathogen Francisella tularensis. Although the causative agent is known for 100 years, knowledge of its enzootic cycles is still rudimentary. Apart from tabanids and mosquitoes, hard ticks have been described as important vectors and potential reservoirs for F. tularensis. Available data on the incidence of human tularaemia indicate an increase in cases in the federal state of Baden-Wuerttemberg. To determine whether ticks are involved in the reported increase in F. tularensis infections in humans and wildlife in this south-western part of Germany, 916 Ixodes ricinus and 211 adult Dermacentor marginatus and D. reticulatus ticks were collected in two different locations. Screening for the presence of F. tularensis was performed by real-time PCR of the 16S rRNA gene. Of the 95 pools of I. ricinus ticks (representing 916 individual ticks), 8 tick pools (8.4%) were positive in this PCR. 30-bp deletion PCR confirmed that the F. tularensis subspecies holarctica was present. FtM24 VNTR analysis revealed that they belong to the emerging Franco-Iberian subclone group of F. tularensis holarctica. Of the 211 ticks of the genus Dermacentor, 35 randomly chosen DNAs were subjected to 16S rRNA gene screening PCR; 20 of these (57%) gave positive signals. For cluster analysis, the lpnA gene region of all Francisella-positive I. ricinus pools and 6 Dermacentor ticks with a positive reaction in the screening PCR was amplified and sequenced. In the resulting neighbour-joining tree, all Francisella-positive I. ricinus samples clustered with sequences of F. tularensis, whilst all Dermacentor tick samples clustered with FLE (Francisella-like endosymbiont) sequences. This study shows that I. ricinus ticks may serve as vectors and/or reservoirs of F. tularensis in Germany and supports the hypothesis that the state of Baden-Wuerttemberg represents an emerging endemic focus of tularaemia. Copyright © 2012 Elsevier GmbH. All rights reserved.

Identification of Coccoidal Bacteria in Traditional Fermented Milk Products from Mongolia, and the Fermentation Properties of the Predominant Species, Streptococcus thermophilus

PubMed Central

2015-01-01

The objective of this study was to identify the coccoidal bacteria present in 188 samples of fermented yaks’, mares’ and cows’ milk products collected from 12 different regions in Mongolia. Furthermore, we evaluated the fermentation properties of ten selected isolates of the predominant species, Streptococcus (S.) thermophiles, during the process of milk fermentation and subsequent storage of the resulting yoghurt at 4℃. Overall, 159 isolates were obtained from 188 samples using M17 agar. These isolates were presumed to be lactic acid bacteria based on their gram-positive and catalase-negative properties, and were identified to species level using 16S rRNA gene sequence analysis. These coccoid isolates were distributed in four genera and six species: Enterococcus (E.) durans, Enterococcus (E.) faecalis, Lactococcus (Lac.) subsp. lactis, Leuconostoc (Leuc.) lactis, Leuconostoc (Leuc.) mesenteroides. subsp. mesenteroides and S. thermophilus. Among these S. thermophilus was the most common species in most samples. From evaluation of the fermentation characteristics (viable counts, pH, titratable acidity [TA]) of ten selected S. thermophilus isolates we could identify four isolates (IMAU 20246, IMAU20764, IMAU20729 and IMAU20738) that were fast acid producers. IMAU20246 produced the highest concentrations of lactic acid and formic acid. These isolates have potential as starter cultures for yoghurt production. PMID:26761898

Enterobacter mori sp. nov., associated with bacterial wilt on Morus alba L.

PubMed

Zhu, Bo; Lou, Miao-Miao; Xie, Guan-Lin; Wang, Guo-Fen; Zhou, Qin; Wang, Fang; Fang, Yuan; Su, Ting; Li, Bin; Duan, Yong-Pin

2011-11-01

Two isolates of mulberry-pathogenic bacteria isolated from diseased mulberry roots were investigated in a polyphasic taxonomic study. Comparative 16S rRNA gene sequence analysis combined with rpoB gene sequence analysis allocated strains R18-2(T) and R3-3 to the genus Enterobacter, with Enterobacter asburiae, E. amnigenus, E. cancerogenus, E. cloacae subsp. cloacae, E. cloacae subsp. dissolvens and E. nimipressuralis as their closest relatives. Cells of the isolates were Gram-negative, facultatively anaerobic rods, 0.3-1.0 µm wide and 0.8-2.0 µm long, with peritrichous flagella, showing a DNA G+C content of 55.1 ± 0.5 mol%. Calculation of a similarity index based on phenotypic features and fatty acid methyl ester (FAME) analysis suggested that these isolates are members of E. cancerogenus or E. asburiae or a closely related species. Biochemical data revealed that the isolates could be differentiated from their nearest neighbours by the presence of lysine decarboxylase activity and their ability to utilize d-arabitol. DNA-DNA relatedness also distinguished the two isolates from phylogenetically closely related Enterobacter strains. Based on these data, it is proposed that the isolates represent a novel species of the genus Enterobacter, named Enterobacter mori sp. nov. The type strain is R18-2(T) ( = CGMCC 1.10322(T) = LMG 25706(T)).

Ecology, Epidemiology and Disease Management of Ralstonia syzygii in Indonesia

PubMed Central

Safni, Irda; Subandiyah, Siti; Fegan, Mark

2018-01-01

Ralstonia solanacearum species complex phylotype IV strains, which have been primarily isolated from Indonesia, Australia, Japan, Korea, and Malaysia, have undergone recent taxonomic and nomenclatural changes to be placed in the species Ralstonia syzygii. This species contains three subspecies; Ralstonia syzygii subsp. syzygii, a pathogen causing Sumatra disease of clove trees in Indonesia, Ralstonia syzygii subsp. indonesiensis, the causal pathogen of bacterial wilt disease on a wide range of host plants, and Ralstonia syzygii subsp. celebesensis, the causal pathogen of blood disease on Musa spp. In Indonesia, these three subspecies have devastated the cultivation of susceptible host plants which have high economic value. Limited knowledge on the ecology and epidemiology of the diseases has hindered the development of effective control strategies. In this review, we provide insights into the ecology, epidemiology and disease control of these three subspecies of Ralstonia syzygii. PMID:29662468

Molecular identification and cluster analysis of homofermentative thermophilic lactobacilli isolated from dairy products.

PubMed

Andrighetto, C; De Dea, P; Lombardi, A; Neviani, E; Rossetti, L; Giraffa, G

1998-10-01

Twenty-five strains of thermophilic lactobacilli isolated from yoghurt and from semi-hard and hard cheeses (in parallel with nine type or reference strains) were identified and grouped according to their genetic relatedness. Strains were identified by sugar fermentation patterns using the "API 50 CHL" galleries, by species-specific DNA probes in dot-blot hybridization experiments, by amplification and restriction analysis of the 16S rRNA gene (ARDRA) and by polymerase chain reaction (PCR) using species-specific oligonucleotide primers. Strains were classified as Lactobacillus delbrueckii subsp. lactis and subsp. bulgaricus, L. helveticus, and L. acidophilus. Strains which were atypical by sugar fermentation patterns were also identified. Most of the strains could not be grouped using carbohydrate fermentation profiles. PCR fingerprinting was used to identify DNA profiles for the 25 lactobacilli. Experimentally obtained PCR profiles enabled discrimination of all strains, which were grouped according to the similarities in their combined patterns. In general, the clustering of the strains corresponded well with species delineation obtained by molecular identification. The dendrogram of genetic relatedness enabled the unambiguous identification of most of the strains which were shown to be atypical by the sugar fermentation profile, except for a discrepancy in one L. delbrueckii subsp. lactis strain and one atypical Lactobacillus sp. strain.

The xeric side of the Brazilian Atlantic Forest: The forces shaping phylogeographic structure of cacti.

PubMed

Franco, Fernando Faria; Jojima, Cecília Leiko; Perez, Manolo Fernandez; Zappi, Daniela Cristina; Taylor, Nigel; Moraes, Evandro Marsola

2017-11-01

In order to investigate biogeographic influences on xeric biota in the Brazilian Atlantic Forest (BAF), a biodiversity hotspot, we used a monophyletic group including three cactus taxa as a model to perform a phylogeographic study: Cereus fernambucensis subsp. fernambucensis , C. fernambucensis subsp. sericifer , and C. insularis . These cacti are allopatric and grow in xeric habitats along BAF, including isolated granite and gneiss rock outcrops (Inselbergs), sand dune vegetation (Restinga forest), and the rocky shore of an oceanic archipelago (islands of Fernando de Noronha). The nucleotide information from nuclear gene phytochrome C and plastid intergenic spacer trnS-trnG was used to perform different approaches and statistical analyses, comprising population structure, demographic changes, phylogenetic relationships, and biogeographic reconstruction in both spatial and temporal scales. We recovered four allopatric population groups with highly supported branches in the phylogenetic tree with divergence initiated in the middle Pleistocene: southern distribution of C. fernambucensis subsp. fernambucensis , northern distribution of C. fernambucensis subsp. fernambucensis together with C. insularis , southern distribution of C. fernambucensis subsp. sericifer , and northern distribution of C. fernambucensis subsp. sericifer . Further, the results suggest that genetic diversity of population groups was strongly shaped by an initial colonization event from south to north followed by fragmentation. The phylogenetic pattern found for C. insularis is plausible with peripatric speciation in the archipelago of Fernando de Noronha. To explain the phylogeographic patterns, the putative effects of both climatic and sea level changes as well as neotectonic activity during the Pleistocene are discussed.

Characterization of a Wild, Novel Nisin A-Producing Lactococcus Strain with an L. lactis subsp. cremoris Genotype and an L. lactis subsp. lactis Phenotype, Isolated from Greek Raw Milk

PubMed Central

Parapouli, Maria; Delbès-Paus, Céline; Kakouri, Athanasia; Koukkou, Anna-Irini; Montel, Marie-Christine

2013-01-01

Several molecular taxonomic studies have revealed that many natural (wild) Lactococcus lactis strains of dairy origin which are phenotypically representative of the L. lactis subspecies lactis cluster genotypically within subspecies cremoris and vice versa. Recently, we isolated two wild nisin-producing (Nis+) L. lactis strains, M78 and M104, of the lactis phenotype from Greek raw milk (J. Samelis, A. Lianou, A. Kakouri, C. Delbès, I. Rogelj, B. B. Matijašic, and M. C. Montel, J. Food Prot. 72:783–790, 2009); strain M78 possess a novel nisin A sequence (GenBank accession number HM219853). In this study, the actual subspecies identity of M78 and M104 isolates was elucidated, using 16S rRNA and acmA (encoding lactococcal N-acetylmuramidase) gene and histidine biosynthesis operon polymorphisms and 16S rRNA and ldh (encoding lactate dehydrogenase) gene phylogenies. Except the acmA gene analysis, molecular tools revealed that isolates M78 and M104 clustered with strains of the cremoris genotype, including the LMG 6897T strain, while they were distant from strains of the lactis genotype, including the LMG 6890T strain. The two wild isolates had identical repetitive sequence-based PCR (rep-PCR), randomly amplified polymorphic DNA (RAPD), plasmid, and whole-cell protein profiles and shared high 16S rRNA (99.9%) and ldh (100%) gene sequence homologies. In contrast, they exhibited identical sugar fermentation and enzymatic patterns which were similar to those of the subspecies lactis LMG 6890T strain. To our knowledge, this is the first complete identification report on a wild L. lactis subsp. cremoris genotype of the lactis phenotype which is capable of nisin A production and, thus, has strong potential for use as a novel dairy starter and/or protective culture. PMID:23542625

Detection of antifungal properties in Lactobacillus paracasei subsp. paracasei SM20, SM29, and SM63 and molecular typing of the strains.

PubMed

Schwenninger, Susanne Miescher; von Ah, Ueli; Niederer, Brigitte; Teuber, Michael; Meile, Leo

2005-01-01

Lactobacilli isolated from different food and feed samples such as raw milk, cheese, yoghurt, olives, sour dough, as well as corn and grass silage, were screened for their antifungal activities. Out of 1,424 isolates tested, 82 were shown to be inhibitory to different yeasts (Candida spp. and Zygosaccharomyces bailii) and a Penicillium sp., which were previously isolated from spoiled yoghurt and fruits. Carbohydrate fermentation patterns suggested that a substantial portion, 25%, belonged to the Lactobacillus casei group, including L. casei, L. paracasei, and L. rhamnosus. The isolates SM20 (DSM14514), SM29 (DSM14515), and SM63 (DSM14516) were classified by PCR using species-specific primers to target the corresponding type strains (L. casei, L. paracasei, and L. rhamnosus) as controls. Further molecular typing methods such as randomly amplified polymorphic DNA, pulsed-field gel electrophoresis, and sequencing analysis of the 16S rRNA gene allowed classifying strains SM20, SM29, and SM63 as L. paracasei subsp. paracasei in accordance with the new reclassification of the L. casei group proposed by Collins et al.

Phage-resistance linked to cell heterogeneity in the commercial strain Lactobacillus delbrueckii subsp. lactis Ab1.

PubMed

Suárez, Viviana B; Maciel, Natalia; Guglielmotti, Daniela; Zago, Miriam; Giraffa, Giorgio; Reinheimer, Jorge

2008-12-10

The aim of this work was to study the relationship between the cell morphological heterogeneity and the phage-resistance in the commercial strain Lactobacillus delbrueckii subsp. lactis Ab1. Two morphological variants (named C and T) were isolated from this strain. Phage-resistant derivatives were isolated from them and the percentage of occurrence of confirmed phage-resistant cells was 0.001% of the total cellular population. Within these phage-resistant cell derivatives there were T (3 out of 4 total isolates) and C (1 out of 4 total isolates) variants. The study of some technological properties (e.g. proteolytic and acidifying activities) demonstrated that most of phage-resistant derivatives were not as good as the parental strain. However, for one derivative (a T variant), the technological properties were better than those of the parental strain. On the other hand, it was possible to determinate that the system of phage-resistance in the T variants was interference in adsorption step, with adsorption rates <15%. For the C variant derivative it was possible to demonstrate the presence of a restriction/modification system and, moreover, to determinate that this system could be Type I R/M.

Molecular Characterization of Mycobacterium avium subsp. hominissuis of Two Groups of Lymph Nodes, Being Intradermal Tuberculin or Interferon-Gamma Test Positive and Negative, Isolated from Swiss Cattle at Slaughter.

PubMed

Scherrer, Simone; Landolt, Patricia; Carroli, Natasha; Stephan, Roger

2018-01-01

Mycobacterium avium subsp. hominissuis (MAH) is an important zoonotic pathogen with raising global health concerns. In humans, MAH is one of the most widespread non-tuberculous mycobacterial species responsible for lung disease. In animals, MAH is frequently isolated from pigs; however, it is also an opportunistic pathogen for other mammals including cattle. To elucidate the genetic diversity of MAH in cattle, a molecular characterization of isolates ( n  = 26) derived from lymph nodes was performed. Fourteen isolates originated from slaughtered cattle with visible altered lymph nodes at meat inspection, whereas 12 isolates were from lymph nodes without any gross pathological changes of healthy slaughtered cattle. Variable number of tandem repeat (VNTR) analysis was performed at 20 loci to examine genetic differences of isolates and to compare to previously reported VNTR data of human isolates from different countries. Genetic elements IS901, IS1245, IS1311, LSPA17, ITS1 sequevar, and hsp65 code were determined. Interestingly, two bovine MAH isolates harbored ISMav6 and hsp65 code 15, which so far has only been observed in human isolates. We supposed that VNTR data of Swiss samples would show clustering with European samples. Minimum spanning tree and unweighted pair group method using arithmetic averages analyses based on the VNTR data indicated a specific cluster of MAH isolates obtained from lymph nodes without any gross pathological changes of healthy slaughtered cattle. Comparing Swiss isolates with isolates from different other countries, no geographical clustering was observed; however, four Swiss isolates had an identical VNTR profile as human isolates from the Netherlands, the United States, and Japan. These findings indicate a possible public health issue.

Laminaria japonica Extract, an Inhibitor of Clavibater michiganense Subsp. Sepedonicum

PubMed Central

Cai, Jin; Feng, Jia; Xie, Shulian; Wang, Feipeng; Xu, Qiufeng

2014-01-01

Bacterial ring rot of potato is one of the most serious potato plant and tuber diseases. Laminaria japonica extract was investigated for its antimicrobial activity against Clavibater michiganense subsp. sepedonicum (Spieckermann & Kotthoff) Davis et al., the causative agent of bacterial ring rot of potato. The results showed that the optimum extraction conditions of antimicrobial substances from L. japonica were an extraction temperature of 80°C, an extraction time of 12 h, and a solid to liquid ratio of 1∶25. Active compounds of L. japonica were isolated by solvent partition, thin layer chromatography (TLC) and column chromatography. All nineteen fractionations had antimicrobial activities against C. michiganense subsp. sepedonicum, while Fractionation three (Fr.3) had the highest (P<0.05) antimicrobial activity. Chemical composition analysis identified a total of 26 components in Fr.3. The main constituents of Fr.3 were alkanes (80.97%), esters (5.24%), acids (4.87%) and alcohols (2.21%). Antimicrobial activity of Fr.3 against C. michiganense subsp. sepedonicum could be attributed to its ability to damage the cell wall and cell membrane, induce the production of reactive oxygen species (ROS), increase cytosolic Ca2+ concentration, inhibit the glycolytic pathway (EMP) and tricarboxylic acid (TCA) cycle, inhibit protein and nucleic acid synthesis, and disrupt the normal cycle of DNA replication. These findings indicate that L. japonica extracts have potential for inhibiting C. michiganense subsp. sepedonicum. PMID:24714388

Comparative Genome Analysis of Campylobacter fetus Subspecies Revealed Horizontally Acquired Genetic Elements Important for Virulence and Niche Specificity

PubMed Central

Kienesberger, Sabine; Sprenger, Hanna; Wolfgruber, Stella; Halwachs, Bettina; Thallinger, Gerhard G.; Perez-Perez, Guillermo I.; Blaser, Martin J.; Zechner, Ellen L.; Gorkiewicz, Gregor

2014-01-01

Campylobacter fetus are important animal and human pathogens and the two major subspecies differ strikingly in pathogenicity. C. fetus subsp. venerealis is highly niche-adapted, mainly infecting the genital tract of cattle. C. fetus subsp. fetus has a wider host-range, colonizing the genital- and intestinal-tract of animals and humans. We report the complete genomic sequence of C. fetus subsp. venerealis 84-112 and comparisons to the genome of C. fetus subsp. fetus 82-40. Functional analysis of genes predicted to be involved in C. fetus virulence was performed. The two subspecies are highly syntenic with 92% sequence identity but C. fetus subsp. venerealis has a larger genome and an extra-chromosomal element. Aside from apparent gene transfer agents and hypothetical proteins, the unique genes in both subspecies comprise two known functional groups: lipopolysaccharide production, and type IV secretion machineries. Analyses of lipopolysaccharide-biosynthesis genes in C. fetus isolates showed linkage to particular pathotypes, and mutational inactivation demonstrated their roles in regulating virulence and host range. The comparative analysis presented here broadens knowledge of the genomic basis of C. fetus pathogenesis and host specificity. It further highlights the importance of surface-exposed structures to C. fetus pathogenicity and demonstrates how evolutionary forces optimize the fitness and host-adaptation of these pathogens. PMID:24416416

Allergenicity reduction of bovine milk β-lactoglobulin by proteolytic activity of lactococcus lactis BMC12C and BMC19H isolated from Iranian dairy products.

PubMed

Kazemi, Rezvan; Taheri-Kafrani, Asghar; Motahari, Ahmad; Kordesedehi, Reihane

2018-06-01

Nowadays health benefits of bioactive food constituents, known as probiotic microorganisms, are a growing awareness. Cow's milk is a nutritious food containing probiotic bacteria. However, milk allergenicity is one of the most common food allergies. The milk protein, β-lactoglobulin (BLG), is in about 80% of all main cases of milk allergies for children and infants. With the aim of screening proteolytic strains of lactic acid bacteria to evaluate their potential for the reduction of allergenicity of the major bovine milk proteins, we isolated new proteolytic strains of cocci lactic acid bacteria from traditional Iranian dairy products. The proteases produced by these strains had strong proteolytic activity against BLG. Proteolysis of BLG, observed after sodium dodecyl sulfate-PAGE, was confirmed by the analysis of the peptide profiles by reversed-phase HPLC. The two isolates were submitted to 16S rDNA sequencing and identified as Lactcoccus lactis subsp. cremoris and Lactcoccus lactis subsp. hordniea. The competitive ELISA experiments confirmed that these isolates, with high proteolytic activity, reduce significantly the allergenicity of BLG. Accordingly, these isolates can reduce the immunoreactivity of bovine milk proteins, which can be helpful for the production of low-allergic dairy products. Copyright © 2018 Elsevier B.V. All rights reserved.

Helichrysum arenarium subsp. arenarium: phenolic composition and antibacterial activity against lower respiratory tract pathogens.

PubMed

Gradinaru, Adina C; Silion, Mihaela; Trifan, Adriana; Miron, Anca; Aprotosoaie, Ana C

2014-01-01

The aim of this study was to investigate the phenolic content and antibacterial activity of the methanol extract from Helichrysum arenarium (L.) Moench subsp. arenarium inflorescences against lower respiratory tract pathogens (standard strains and clinical isolates). The extract was characterised by a total phenolic content of 160.17 mg/g. Several caffeic acid conjugates (chlorogenic acid and dicaffeoylquinic acids) and flavonoids (apigenin, naringenin, apigenin-7-O-glucoside and naringenin-O-hexosides) were identified as major constituents by HPLC-DAD-ESI-MS. Staphylococcus aureus ATCC 25923 was more susceptible to Helichrysum extract than Streptococcus pneumoniae ATCC 49619 (minimum inhibitory concentration [MIC] = 0.62  and 1.25 mg/mL, respectively). The extract exhibited similar antibacterial effects against methicillin-resistant S. aureus and penicillin-resistant S. pneumoniae clinical isolates (MIC = 2.5 mg/mL) displaying a higher activity against ampicillin-resistant Moraxella catarrhalis isolate (MIC = 0.15 mg/mL). The combination with ciprofloxacin exhibited additivity against both standard strains (fractional inhibitory concentration [FIC] index = 0.75 and 0.73) and S. aureus isolates (FIC index = 0.62) and synergy against S. pneumoniae isolates (FIC index = 0.5).

[Chemical constituents from the aerial part of Stauntonia obovatifoliola Hayata subsp. urophylla].

PubMed

Peng, Xiao-bing; Gao, Wei-lue; Hu, Dong-qun; Ma, Fang-fang; Fu, Li-gang; Deng, Qian; Wei, Ying

2013-11-01

To study the chemical constituents of the aerial part of Stauntonia obovatifoliola. The chemical constituents of ethyl acetate fraction were isolated and purified by several chromatography. Their structures were elucidated by their physiochemical properties and spectral methods. Six known compounds were isolated and identified as lupeone(1), lupeol(2), stigmasterol(3),3beta-O-acetyloleanolic acid(4), resinone(5) and daucosterol(6). Compounds 1-6 are isolated from this plant for the first time.

Geobacter sulfurreducens subsp. ethanolicus, subsp. nov., an ethanol-utilizing dissimilatory Fe(III)-reducing bacterium from a lotus field.

PubMed

Viulu, Samson; Nakamura, Kohei; Kojima, Akihiro; Yoshiyasu, Yuki; Saitou, Sakiko; Takamizawa, Kazuhiro

2013-01-01

An ethanol-utilizing Fe(III)-reducing bacterial strain, OSK2A(T), was isolated from a lotus field in Aichi, Japan. Phylogenetic analysis of the 16S rRNA gene sequences of OSK2A(T) and related strains placed it within Geobacter sulfurreducens PCA(T). Strain OSK2A(T) was shown to be a Gram-negative, motile, rod-shaped bacterium, strictly anaerobic, 0.76-1.65 µm long and 0.28-0.45 μm wide. Its growth occurred at 20-40℃, pH 6.0-8.1, and it tolerated up to 1% NaCl. The G+C content of the genomic DNA was 61.2 mol% and DNA-DNA hybridization value with Geobacter sulfurreducens PCA(T) was 60.7%. The major respiratory quinone was MK-8. The major fatty acids were 16：1 ω7c, 16：0, 14：0, 15：0 iso, 16：1 ω5c, and 18：1 ω7c. Strain OSK2A(T) could utilize H2, ethanol, acetate, lactate, pyruvate, and formate as substrates with Fe(III)-citrate as electron acceptor. Amorphous Fe(III) hydroxide, Fe(III)-NTA, fumarate, malate, and elemental sulfur were utilized as electron acceptors with either acetate or ethanol as substrates. Results obtained from physiological, DNA-DNA hybridization, and chemotaxonomic tests support genotypic and phenotypic differentiation of strain OSK2A(T) from its closest relative. The isolate is assigned as a novel subspecies with the name Geobacter sulfurreducens subsp. ethanolicus, subsp. nov. (type strain OSK2A(T)=DSMZ 26126(T)=JCM 18752(T)).

Effect of Turbulent-Flow Pasteurization on Survival of Mycobacterium avium subsp. paratuberculosis Added to Raw Milk

PubMed Central

Pearce, Lindsay E.; Truong, H. Tuan; Crawford, Robert A.; Yates, Gary F.; Cavaignac, Sonia; de Lisle, Geoffrey W.

2001-01-01

A pilot-scale pasteurizer operating under validated turbulent flow (Reynolds number, 11,050) was used to study the heat sensitivity of Mycobacterium avium subsp. paratuberculosis added to raw milk. The ATCC 19698 type strain, ATCC 43015 (Linda, human isolate), and three bovine isolates were heated in raw whole milk for 15 s at 63, 66, 69, and 72°C in duplicate trials. No strains survived at 72°C for 15 s; and only one strain survived at 69°C. Means of pooled D values (decimal reduction times) at 63 and 66°C were 15.0 ± 2.8 s (95% confidence interval) and 5.9 ± 0.7 s (95% confidence interval), respectively. The mean extrapolated D72°C was <2.03 s. This was equivalent to a >7 log10 kill at 72°C for 15 s (95% confidence interval). The mean Z value (degrees required for the decimal reduction time to traverse one log cycle) was 8.6°C. These five strains showed similar survival whether recovery was on Herrold's egg yolk medium containing mycobactin or by a radiometric culture method (BACTEC). Milk was inoculated with fresh fecal material from a high-level fecal shedder with clinical Johne's disease. After heating at 72°C for 15 s, the minimum M. avium subsp. paratuberculosis kill was >4 log10. Properly maintained and operated equipment should ensure the absence of viable M. avium subsp. paratuberculosis in retail milk and other pasteurized dairy products. An additional safeguard is the widespread commercial practice of pasteurizing 1.5 to 2° above 72°C. PMID:11525992

Purification of a toxic metalloprotease produced by the pathogenic Photobacterium damselae subsp. piscicida isolated from cobia (Rachycentron canadum).

PubMed

Liu, Ping-Chung; Chuang, Wen-Hsiao; Lee, Kuo-Kau

2011-01-01

The aim of the present study was to purify and characterize a toxic protease secreted by the pathogenic Photobacterium damselae subsp. piscicida strain CP1 originally isolated from diseased cobia (Rachycentron canadum). The toxin isolated by anion exchange chromatography, was a metalloprotease, inhibited by L-cysteine, ethylenediaminetetraacetic acid (EDTA), ethylene glycol-bis(beta-aminoethyl ether)N,N,N',N'-tetraacetic acid (EGTA), 1,10-phenanthroline, N-tosyl-L-phenylalanine-chloromethyl ketone (TPCK), and N-alpha-p-tosyl-L-lysine-chloromethyl ketone (TLCK), and showed maximal activity at pH 6.0-8.0 and an apparent molecular mass of about 34.3 kDa. The toxin was also completely inhibited by HgCl2, and partially by sodium dodecyl sulfate (SDS) and CuCl2. The extracellular products and the partially purified protease were lethal to cobia with LD50 values of 1.26 and 6.8 microg protein/g body weight, respectively. The addition of EDTA completely inhibited the lethal toxicity of the purified protease, indicating that this metalloprotease was a lethal toxin produced by the bacterium.

Identification by 16S rRNA Gene Sequencing of Lactobacillus salivarius Bacteremic Cholecystitis

PubMed Central

Woo, Patrick C. Y.; Fung, Ami M. Y.; Lau, Susanna K. P.; Yuen, Kwok-Yung

2002-01-01

An anaerobic, nonsporulating, gram-positive bacterium was isolated from blood and bile pus cultures of a 70-year-old man with bacteremic acute cholecystitis. The API 20A system showed that it was 70% Actinomyces naeslundii and 30% Bifidobacterium species, whereas the Vitek ANI system and the ATB ID32A Expression system showed that it was “unidentified.” The 16S rRNA gene of the strain was amplified and sequenced. There were 3 base differences between the nucleotide sequence of the isolate and that of Lactobacillus salivarius subsp. salivarius or L. salivarius subsp. salicinius, indicating that the isolate was a strain of L. salivarius. The patient responded to cholecystectomy and a 2-week course of antibiotic treatment. Identification of the organism in the present study was important because the duration of antibiotic therapy would have been entirely different depending on the organism. If the bacterium had been identified as Actinomyces, penicillin for 6 months would have been the regimen of choice. However, it was Lactobacillus, and a 2-week course of antibiotic was sufficient. PMID:11773128

Complete Genome Sequence of the Streptomyces Phage Nanodon.

PubMed

Erill, Ivan; Caruso, Steven M

2016-10-06

Streptomyces phage Nanodon is a temperate double-stranded DNA Siphoviridae belonging to cluster BD1. It was isolated from soil collected in Kilauea, HI, using Streptomyces griseus subsp. griseus as a host. Copyright © 2016 Erill et al.

Geographic Differentiation of Francisella Tularensis using Molecular Methods

DTIC Science & Technology

2006-05-01

most often through direct exposure to infected animals or by bites from infected arthropod vectors. Recently, terrestrial and aquatic life cycles have...virulent in humans. F. tularensis species have been isolated throughout the Northern Hemisphere, but subsp. tularensis isolates appear restricted to North...John Wise for administering Pathogene-server access. From Northern Airzona University, I am grateful to Dr. Paul Keim, Miles Stanley, Julia Rhodes, Dr

Comparative analysis of twenty-four complete aenome aequences of Salmonella enterica Serotypes Anatum, Montevideo, Typhimurium and Newport isolated from ground beef or asymptomatic cattle on farm or at harvest

USDA-ARS?s Scientific Manuscript database

Salmonella enterica subsp. enterica are a versatile group of bacteria with a wide range of variation in virulence potential. Complete S. enterica genome sequences available to date are primarily of strains isolated from humans or of serotypes that commonly cause human disease. To facilitate genomic ...

Variable-Number Tandem Repeats That Are Useful in Genotyping Isolates of Salmonella enterica subsp. enterica Serovars Typhimurium and Newport▿

PubMed Central

Witonski, D. ; Stefanova, R.; Ranganathan, A.; Schutze, G. E.; Eisenach, K. D.; Cave, M. D.

2006-01-01

The genome of Salmonella enterica subsp. enterica serovar Typhimurium strain LT2 was analyzed for direct repeats, and 54 sequences containing variable-number tandem repeat loci were identified. Ten primer pairs that anneal upstream and downstream of each selected locus were designed and used to amplify PCR targets in isolates of S. enterica serovars Typhimurium and Newport. Four of the 10 loci did not show polymorphism in the length of products. Six loci were selected for analysis. Isolates of S. enterica serovars Typhimurium and Newport that were related to specific outbreaks and showed identical pulsed-field gel electrophoresis patterns were indistinguishable by the length of the six variable-number tandem repeats. Isolates that differed in their pulsed-field gel electrophoresis patterns showed polymorphism in variable-number tandem repeat profiles. Length of the products was confirmed by DNA sequence analysis. Only 2 of the 10 loci contained exact integers of the direct repeat. Eight loci contained partial copies. The partial copies were maintained at the ends of the variable-number tandem repeat loci in all isolates. In spite of having partial copies that were maintained in all isolates, the number of direct repeats at a locus was polymorphic. Six variable-number tandem repeat loci were useful in distinguishing isolates of S. enterica serovars Typhimurium and Newport that had different pulsed-field gel electrophoresis patterns and in identifying outbreak-associated cases that shared a common pulsed-field gel pattern. PMID:16943354

Non-tuberculous Mycobacteria in South African Wildlife: Neglected Pathogens and Potential Impediments for Bovine Tuberculosis Diagnosis.

PubMed

Gcebe, Nomakorinte; Hlokwe, Tiny M

2017-01-01

Non-tuberculous mycobacteria (NTM) are not only emerging and opportunistic pathogens of both humans and animals, but from a veterinary point of view some species induce cross-reactive immune responses that hamper the diagnosis of bovine tuberculosis (bTB) in both livestock and wildlife. Little information is available about NTM species circulating in wildlife species of South Africa. In this study, we determined the diversity of NTM isolated from wildlife species from South Africa as well as Botswana. Thirty known NTM species and subspecies, as well as unidentified NTM, and NTM closely related to Mycobacterium goodii/Mycobacterium smegmatis were identified from 102 isolates cultured between the years 1998 and 2010, using a combination of molecular assays viz PCR and sequencing of different Mycobacterial house-keeping genes as well as single nucleotide polymorphism (SNP) analysis. The NTM identified in this study include the following species which were isolated from tissue with tuberculosis- like lesions in the absence of Mycobacterium tuberculosis complex (MTBC) implying their potential role as pathogens of animals: Mycobacterium abscessus subsp. bolletii, Mycobacterium gastri, Mycobacterium species closely related to Mycobacterium goodii/Mycobacterium smegmatis, Mycobacterium brasiliensis, Mycobacterium sinense JMD 601, Mycobacterium avium subsp. avium, Mycobacterium sp. GR-2007, Mycobacterium bouchedurhonense , and Mycobacterium septicum / M. peregrinum. Mycobaterium brasiliensis, Mycobacterium gastri, Mycobacterium sp. GR-2007, and a potential novel Mycobacterium species closely related to Mycobacterium goodii were found for the first time in this study to be potential pathogens of animals. Mycobacterium simiae was isolated from a sample originating from a tuberculin skin test positive reactor, demonstrating its potential to elicit inappropriate immune responses in animals that may interfere with diagnosis of tuberculosis by immunology. Mycobacterium abscessus subsp. bolletti was the most frequently detected NTM identified in 37 of the 102 isolates. Other NTM species were also isolated from animals not showing any pathological changes. Knowledge gained in this study contribute to the understanding of NTM species circulating in wild animals in South Africa and the pathogenic potential of certain species, whose role in disease causation need to be examined, as well as to a certain extent the potential of M. simiae to hamper the diagnosis of bTB.

Non-tuberculous Mycobacteria in South African Wildlife: Neglected Pathogens and Potential Impediments for Bovine Tuberculosis Diagnosis

PubMed Central

Gcebe, Nomakorinte; Hlokwe, Tiny M.

2017-01-01

Non-tuberculous mycobacteria (NTM) are not only emerging and opportunistic pathogens of both humans and animals, but from a veterinary point of view some species induce cross-reactive immune responses that hamper the diagnosis of bovine tuberculosis (bTB) in both livestock and wildlife. Little information is available about NTM species circulating in wildlife species of South Africa. In this study, we determined the diversity of NTM isolated from wildlife species from South Africa as well as Botswana. Thirty known NTM species and subspecies, as well as unidentified NTM, and NTM closely related to Mycobacterium goodii/Mycobacterium smegmatis were identified from 102 isolates cultured between the years 1998 and 2010, using a combination of molecular assays viz PCR and sequencing of different Mycobacterial house-keeping genes as well as single nucleotide polymorphism (SNP) analysis. The NTM identified in this study include the following species which were isolated from tissue with tuberculosis- like lesions in the absence of Mycobacterium tuberculosis complex (MTBC) implying their potential role as pathogens of animals: Mycobacterium abscessus subsp. bolletii, Mycobacterium gastri, Mycobacterium species closely related to Mycobacterium goodii/Mycobacterium smegmatis, Mycobacterium brasiliensis, Mycobacterium sinense JMD 601, Mycobacterium avium subsp. avium, Mycobacterium sp. GR-2007, Mycobacterium bouchedurhonense, and Mycobacterium septicum/M. peregrinum. Mycobaterium brasiliensis, Mycobacterium gastri, Mycobacterium sp. GR-2007, and a potential novel Mycobacterium species closely related to Mycobacterium goodii were found for the first time in this study to be potential pathogens of animals. Mycobacterium simiae was isolated from a sample originating from a tuberculin skin test positive reactor, demonstrating its potential to elicit inappropriate immune responses in animals that may interfere with diagnosis of tuberculosis by immunology. Mycobacterium abscessus subsp. bolletti was the most frequently detected NTM identified in 37 of the 102 isolates. Other NTM species were also isolated from animals not showing any pathological changes. Knowledge gained in this study contribute to the understanding of NTM species circulating in wild animals in South Africa and the pathogenic potential of certain species, whose role in disease causation need to be examined, as well as to a certain extent the potential of M. simiae to hamper the diagnosis of bTB. PMID:28194371

Complete Genome Sequence of a Multidrug-Resistant Salmonella enterica Serovar Typhimurium var. 5- Strain Isolated from Chicken Breast.

PubMed

Hoffmann, Maria; Muruvanda, Tim; Allard, Marc W; Korlach, Jonas; Roberts, Richard J; Timme, Ruth; Payne, Justin; McDermott, Patrick F; Evans, Peter; Meng, Jianghong; Brown, Eric W; Zhao, Shaohua

2013-12-19

Salmonella enterica subsp. enterica serovar Typhimurium is a leading cause of salmonellosis. Here, we report a closed genome sequence, including sequences of 3 plasmids, of Salmonella serovar Typhimurium var. 5- CFSAN001921 (National Antimicrobial Resistance Monitoring System [NARMS] strain ID N30688), which was isolated from chicken breast meat and shows resistance to 10 different antimicrobials. Whole-genome and plasmid sequence analyses of this isolate will help enhance our understanding of this pathogenic multidrug-resistant serovar.

Oligogalacturonide-mediated induction of a gene involved in jasmonic acid synthesis in response to the cell-wall-degrading enzymes of the plant pathogen Erwinia carotovora.

PubMed

Norman, C; Vidal, S; Palva, E T

1999-07-01

Identification of Arabidopsis thaliana genes responsive to plant cell-wall-degrading enzymes of Erwinia carotovora subsp. carotovora led to the isolation of a cDNA clone with high sequence homology to the gene for allene oxide synthase, an enzyme involved in the biosynthesis of jasmonates. Expression of the corresponding gene was induced by the extracellular enzymes from this pathogen as well as by treatment with methyl jasmonate and short oligogalacturonides (OGAs). This suggests that OGAs are involved in the induction of the jasmonate pathway during plant defense response to E. carotovora subsp. carotovora attack.

tuf Gene Sequence Variation in Bifidobacterium longum subsp. infantis Detected in the Fecal Microbiota of Chinese Infants.

PubMed

Lawley, Blair; Centanni, Manuela; Watanabe, Jun; Sims, Ian; Carnachan, Susan; Broadbent, Roland; Lee, Pheng Soon; Wong, Khai Hong; Tannock, Gerald W

2018-07-01

Members of the bacterial genus Bifidobacterium generally dominate the fecal microbiota of infants. The species Bifidobacterium longum is prevalent, but the B. longum subsp. longum and B. longum subsp. infantis strains that are known to colonize the infant bowel are not usually differentiated in microbiota investigations. These subspecies differ in their capacities to metabolize human milk oligosaccharides (HMO) and may have different ecological and symbiotic roles in humans. Quantitative PCR provides a quick analytical method by which to accurately ascertain the abundances of target species in microbiotas and microcosms. However, amplification targets in DNA extracted from samples need to be dependably differential. We evaluated the tuf gene sequence as a molecular target for quantitative PCR measurements of the abundances of B. longum subsp. infantis and B. longum subsp. longum in fecal microbiotas. This approach resulted in the detection of a tuf gene variant (operational taxonomic unit 49 [OTU49]) in Chinese infants that has sequence similarities to both B. longum subsp. infantis and B. longum subsp. longum We compared the genome sequence and growth and transcriptional characteristics of an OTU49 isolate cultured in HMO medium to those of other B. longum subsp. infantis cultures. We concluded from these studies that OTU49 belongs to B. longum subsp. infantis , that dependable quantitative PCR (qPCR) differentiation between the B. longum subspecies cannot be achieved by targeting tuf gene sequences, and that functional genes involved in carbohydrate metabolism might be better targets because they delineate ecological functions. IMPORTANCE High-throughput DNA sequencing methods and advanced bioinformatics analysis have revealed the composition and biochemical capacities of microbial communities (microbiota and microbiome), including those that inhabit the gut of human infants. However, the microbiology and function of natural ecosystems have received little attention in recent decades, so an appreciation of the dynamics of gut microbiota interactions is lacking. With respect to infants, rapid methodologies, such as quantitative PCR, are needed to determine the prevalences and proportions of different bifidobacterial species in observational and microcosm studies in order to obtain a better understanding of the dynamics of bifidobacterial nutrition and syntrophy, knowledge that might be used to manipulate the microbiota and perhaps ensure the better health of infants. Copyright © 2018 American Society for Microbiology.

High-Throughput Direct Fecal PCR Assay for Detection of Mycobacterium avium subsp. paratuberculosis in Sheep and Cattle

PubMed Central

Waldron, Anna M.; Galea, Francesca; Whittington, Ann-Michele; Saunders, Vanessa F.; Begg, Douglas J.; de Silva, Kumudika; Purdie, Auriol C.; Whittington, Richard J.

2014-01-01

Johne's disease (JD) is a chronic enteric disease caused by Mycobacterium avium subsp. paratuberculosis that affects ruminants. Transmission occurs by the fecal-oral route. A commonly used antemortem diagnostic test for the detection of M. avium subsp. paratuberculosis in feces is liquid culture; however, a major constraint is the 2- to 3-month incubation period needed for this method. Rapid methods for the detection of M. avium subsp. paratuberculosis based on PCR have been reported, but comprehensive validation data are lacking. We describe here a new test, the high-throughput-Johnes (HT-J), to detect M. avium subsp. paratuberculosis in feces. Its diagnostic accuracy was compared with that of liquid radiometric (Bactec) fecal culture using samples from cattle (1,330 samples from 23 herds) and sheep (596 samples from 16 flocks). The multistage protocol involves the recovery of M. avium subsp. paratuberculosis cells from a fecal suspension, cell rupture by bead beating, extraction of DNA using magnetic beads, and IS900 quantitative PCR. The limit of detection of the assay was 0.0005 pg, and the limit of quantification was 0.005 pg M. avium subsp. paratuberculosis genomic DNA. Only M. avium subsp. paratuberculosis was detected from a panel of 51 mycobacterial isolates, including 10 with IS900-like sequences. Of the 549 culture-negative fecal samples from unexposed herds and flocks, 99% were negative in the HT-J test, while 60% of the bovine- and 84% of the ovine-culture-positive samples were positive in the HT-J test. As similar total numbers of samples from M. avium subsp. paratuberculosis-exposed animals were positive in culture and HT-J tests in both species, and as the results of a McNemar's test were not significant, these methods probably have similar sensitivities, but the true diagnostic sensitivities of these tests are unknown. These validation data meet the consensus-based reporting standards for diagnostic test accuracy studies for paratuberculosis and the Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines (S. A. Bustin et al., Clin. Chem. 55:611–622, 2009, doi:10.1373/clinchem.2008.112797). The HT-J assay has been approved for use in JD control programs in Australia and New Zealand. PMID:24352996

Comparative genome analysis of two Streptococcus phocae subspecies provides novel insights into pathogenicity.

PubMed

Bethke, J; Avendaño-Herrera, R

2017-02-01

Streptococcus phocae is a beta-hemolytic, Gram-positive bacterium that was first isolated in Norway from clinical specimens of harbor seal (Phoca vitulina) affected by pneumonia or respiratory infection, and in 2005, this bacterium was identified from disease outbreaks at an Atlantic salmon farm. A recent comparative polyphasic study reclassified Streptococcus phocae as subsp. phocae and subsp. salmonis, and there are currently two S. phocae NCBI sequencing projects for the type strains ATCC 51973 T and C-4 T . The present study compared these genome sequences to determine shared properties between the pathogenic mammalian and fish S. phocae subspecies. Both subspecies presented genomic islands, prophages, CRISPRs, and multiple gene activator and RofA regulator regions that could play key roles in the pathogenesis of streptococcal species. Likewise, proteins possibly influencing immune system evasion and virulence strategies were identified in both genomes, including Streptokinases, Streptolysin S, IgG endopeptidase, Fibronectin binding proteins, Daunorubicin, and Penicillin resistance proteins. Comparative differences in phage, non-phage, and genomic island sequences may form the genetic basis for the virulence, pathogenicity, and ability of S. phocae subsp. salmonis to infect and cause disease in Atlantic salmon, in contrast to S. phocae subsp. phocae. This comparative genomic study between two S. phocae subsp. provides novel insights into virulence factors and pathogenicity, offering important information that will facilitate the development of preventive and treatment measures against this pathogen. Copyright © 2016 Elsevier B.V. All rights reserved.

Bioprocessing of some agro-industrial residues for endoglucanase production by the new subsp.; Streptomyces albogriseolus subsp. cellulolyticus strain NEAE-J

PubMed Central

El-Naggar, Noura El-Ahmady; Abdelwahed, Nayera A.M.; Saber, Wesam I.A.; Mohamed, Asem A.

2014-01-01

The use of low cost agro-industrial residues for the production of industrial enzymes is one of the ways to reduce significantly production costs. Cellulase producing actinomycetes were isolated from soil and decayed agricultural wastes. Among them, a potential culture, strain NEAE-J, was selected and identified on the basis of morphological, cultural, physiological and chemotaxonomic properties, together with 16S rDNA sequence. It is proposed that strain NEAE-J should be included in the species Streptomyces albogriseolus as a representative of a novel sub-species, Streptomyces albogriseolus subsp. cellulolyticus strain NEAE-J and sequencing product was deposited in the GenBank database under accession number JN229412. This organism was tested for its ability to produce endoglucanase and release reducing sugars from agro-industrial residues as substrates. Sugarcane bagasse was the most suitable substrate for endoglucanase production. Effects of process variables, namely incubation time, temperature, initial pH and nitrogen source on production of endoglucanase by submerged fermentation using Streptomyces albogriseolus subsp. cellulolyticus have been studied. Accordingly optimum conditions have been determined. Incubation temperature of 30 °C after 6 days, pH of 6.5, 1% sugarcane bagasse as carbon source and peptone as nitrogen source were found to be the optimum for endoglucanase production. Optimization of the process parameters resulted in about 2.6 fold increase in the endoglucanase activity. Therefore, Streptomyces albogriseolus subsp. cellulolyticus coud be potential microorganism for the intended application. PMID:25242966

Culture phenotypes and molecular characterization of Mycobacterium avium subsp. paratuberculosis isolates from small ruminants.

PubMed

Dimareli-Malli, Z; Mazaraki, K; Stevenson, K; Tsakos, P; Zdragas, A; Giantzi, V; Petridou, E; Heron, I; Vafeas, G

2013-08-01

In this study the suitability of different solid media was investigated for the isolation of Mycobacterium avium subsp. paratuberculosis (Map) in order to identify the optimum single or combination of media to permit the isolation of all strain types from small ruminants. A subset of these Map strains was then further characterized by molecular typing methods to assess the genetic diversity of Map strains in the study area (Northern Greece). Map strains were isolated from tissues and faeces of infected goats (n=52) and sheep (n=8) and were analysed for polymorphisms in IS1311 to classify the strain type as Type C or S. The study found that M7H11 supplemented with mycobactin j, OADC and new born calf serum (M7H11+Mj) is the best single choice of medium for the primary isolation of Map of both Type C and S from small ruminants. The combination of M7H11+Mj and Herrolds egg yolk medium supplemented with mycobactin j and sodium pyruvate allowed the detection of all Map isolates in this study. Nineteen Map isolates were characterised by pulsed-field gel electrophoresis and the isolates demonstrated significant genetic diversity. Twelve different SnaBI and 16 distinct SpeI profiles were detected of which 25 have not been described previously and are new profiles. The combination of both enzyme profiles gave 13 different multiplex profiles. Ten different multiplex profiles were detected in goats and three in sheep. One ovine isolate gave the same multiplex profile as a caprine isolate and two different profiles were found within a single goat herd. Copyright © 2013 Elsevier Ltd. All rights reserved.

Regulation of the production of extracellular pectinase, cellulase, and protease in the soft rot bacterium Erwinia carotovora subsp. carotovora: evidence that aepH of E. carotovora subsp. carotovora 71 activates gene expression in E. carotovora subsp. carotovora, E. carotovora subsp. atroseptica, and Escherichia coli.

PubMed Central

Murata, H; Chatterjee, A; Liu, Y; Chatterjee, A K

1994-01-01

The production of pectolytic enzymes (pectate lyase [Pel] and polygalacturonase [Peh]), cellulase (Cel), and protease (Prt) is activated in the soft rot bacterium Erwinia carotovora subsp. carotovora by aepA (activator of extracellular protein production) and celery extract (Y. Liu, H. Murata, A. Chatterjee, and A. K. Chatterjee, Mol. Plant-Microbe Interact. 6:299-308, 1993). We recently isolated a new class of mutants of strain E. carotovora subsp. carotovora 71 which overproduces Pel, Peh, Cel, and Prt. From the overproducing strain AC5034, we identified an activator locus, designated aepH*, which stimulated Pel, Peh, Cel, and Prt production in E. carotovora subsp. carotovora 71 or its derivatives. The nucleotide sequence of the aepH* DNA segment revealed an open reading frame of 141 bp that could encode a small (5.45-kDa) highly basic (pI 11.7) protein of 47 amino acid residues. Analyses of deletions and MudI insertions indicated that the activator function required the 508-bp DNA segment which contains this open reading frame. The wild-type locus, aepH+, is localized within a DNA segment upstream of aepA. An AepH- strain constructed by exchanging aepH+ with aepH*::MudI was deficient in Pel, Peh, Cel, and Prt production; exoenzyme production was restored upon the introduction of a plasmid carrying aepH+ or aepH*. Plasmids carrying either aepH+ or aepH* activated the production of Pel-1, Peh-1, and Cel in Escherichia coli HB101 carrying the cognate genes. The aepH effect in E. coli was due to the activation of transcription, as indicated by assays of pel-1 and peh-1 mRNAs. The aepH+ and aepH* plasmids also stimulated Pel, Peh, Cel, and Prt production in other wild-type E. carotovora subsp. carotovora strains as well as in E. carotovora subsp. atroseptica. Although the stimulatory effect was generally more pronounced with aepH* than with aepH+, the extent of activation in the wild-type strains depended upon the bacterial strain and the growth medium. Southern blot hybridization revealed the presence of aepH homologs in E. carotovora subsp. carotovora and E. carotovora subsp. atroseptica, and provided physical evidence for linkage between aepA and aepH homologs in genomes of these bacteria. We conclude that aepH-mediated activation of exoprotein gene expression is a feature common to most strains of E. carotovora. Images PMID:7944360

Occurrence of Natural Bacillus thuringiensis Contaminants and Residues of Bacillus thuringiensis-Based Insecticides on Fresh Fruits and Vegetables

PubMed Central

Frederiksen, Kristine; Rosenquist, Hanne; Jørgensen, Kirsten; Wilcks, Andrea

2006-01-01

A total of 128 Bacillus cereus-like strains isolated from fresh fruits and vegetables for sale in retail shops in Denmark were characterized. Of these strains, 39% (50/128) were classified as Bacillus thuringiensis on the basis of their content of cry genes determined by PCR or crystal proteins visualized by microscopy. Random amplified polymorphic DNA analysis and plasmid profiling indicated that 23 of the 50 B. thuringiensis strains were of the same subtype as B. thuringiensis strains used as commercial bioinsecticides. Fourteen isolates were indistinguishable from B. thuringiensis subsp. kurstaki HD1 present in the products Dipel, Biobit, and Foray, and nine isolates grouped with B. thuringiensis subsp. aizawai present in Turex. The commercial strains were primarily isolated from samples of tomatoes, cucumbers, and peppers. A multiplex PCR method was developed to simultaneously detect all three genes in the enterotoxin hemolysin BL (HBL) and the nonhemolytic enterotoxin (NHE), respectively. This revealed that the frequency of these enterotoxin genes was higher among the strains indistinguishable from the commercial strains than among the other B. thuringiensis and B. cereus-like strains isolated from fruits and vegetables. The same was seen for a third enterotoxin, CytK. In conclusion, the present study strongly indicates that residues of B. thuringiensis-based insecticides can be found on fresh fruits and vegetables and that these are potentially enterotoxigenic. PMID:16672488

Occurrence, Persistence, and Virulence Potential of Listeria ivanovii in Foods and Food Processing Environments in the Republic of Ireland

PubMed Central

Morgan, Ciara A.; Hill, Colin; Gahan, Cormac G. M.; Jordan, Kieran

2015-01-01

The aim of this study was to assess the occurrence of L. ivanovii in foods and food processing environments in Ireland, to track persistence, and to characterize the disease causing potential of the isolated strains. A total of 2,006 samples (432 food samples and 1,574 environmental swabs) were collected between March 2013 and March 2014 from 48 food business operators (FBOs) belonging to different production sectors (dairy, fish, meat, and fresh-cut vegetable). Six of the forty-eight FBOs had samples positive for L. ivanovii on at least one sampling occasion. L. ivanovii was present in fifteen samples (fourteen environmental samples and one food sample). All but one of those positive samples derived from the dairy sector, where L. ivanovii prevalence was 1.7%. Six distinguishable pulsotypes were obtained by PFGE analysis, with one pulsotype being persistent in the environment of a dairy food business. Sequence analysis of the sigB gene showed that fourteen isolates belonged to L. ivanovii subsp. londoniensis, while only one isolate was L. ivanovii subsp. ivanovii. Cell invasion assays demonstrated that the majority of L. ivanovii strains were comparable to L. monocytogenes EGDe in their ability to invade CACO-2 epithelial cells whilst four isolates had significantly higher invasion efficiencies. PMID:26543856

A rural worker infected with a bovine-prevalent genotype of Campylobacter fetus subsp. fetus supports zoonotic transmission and inconsistency of MLST and whole-genome typing.

PubMed

Iraola, G; Betancor, L; Calleros, L; Gadea, P; Algorta, G; Galeano, S; Muxi, P; Greif, G; Pérez, R

2015-08-01

Whole-genome characterisation in clinical microbiology enables to detect trends in infection dynamics and disease transmission. Here, we report a case of bacteraemia due to Campylobacter fetus subsp. fetus in a rural worker under cancer treatment that was diagnosed with cellulitis; the patient was treated with antibiotics and recovered. The routine typing methods were not able to identify the microorganism causing the infection, so it was further analysed by molecular methods and whole-genome sequencing. The multi-locus sequence typing (MLST) revealed the presence of the bovine-associated ST-4 genotype. Whole-genome comparisons with other C. fetus strains revealed an inconsistent phylogenetic position based on the core genome, discordant with previous ST-4 strains. To the best of our knowledge, this is the first C. fetus subsp. fetus carrying the ST-4 isolated from humans and represents a probable case of zoonotic transmission from cattle.

The molecular identification of Streptococcus equi subsp. equi strains isolated within New Zealand.

PubMed

Patty, O A; Cursons, R T M

2014-03-01

To identify Streptococcus equi subsp. equi (S. equi) by PCR analysis and obtain isolates by culture, in order to investigate the strains of S. equi infecting horses within New Zealand. A diagnostic PCR, based on the amplification of the seeI gene for S. equi, was used on 168 samples submitted from horses with and without clinical signs of strangles. Samples were also processed and cultured on selective media for the isolation of β-haemolytic colonies. In addition, the hypervariable region of the seM gene of S. equi was amplified and then sequenced for strain typing purposes. Of the 168 samples, 35 tested positive for S. equi using PCR. Thirty-two confirmed samples were from horses with a clinical diagnosis of strangles and three were from horses where clinical information was unavailable. Only 22/35 (63%) confirmed S. equi samples were successfully isolated following culture. Strain typing demonstrated that two novel seM alleles of S. equi were found in New Zealand with SeM-99 strains being restricted to the North Island while SeM-100 strains were found in both North and South Islands. The application of PCR for the laboratory confirmation of strangles allowed for a rapid and sensitive identification of S. equi. Moreover, seM typing revealed that within the samples examined two strains of S. equi co-circulated within the North Island of New Zealand but only one strain in the South Island. PCR reduces the time required to obtain laboratory confirmation of strangles compared with culture methods. It also has greater sensitivity in detecting S. equi infections, which is of particular importance in the detection of carrier animals which normally shed low numbers of bacteria. Additionally, seM molecular typing can differentiate between bacterial strains, assisting in the monitoring of local strains of S. equi subsp. equi causing disease.

Antibiotic resistance due to an unusual ColE1-type replicon plasmid in Aeromonas salmonicida.

PubMed

Vincent, Antony T; Emond-Rheault, Jean-Guillaume; Barbeau, Xavier; Attéré, Sabrina A; Frenette, Michel; Lagüe, Patrick; Charette, Steve J

2016-06-01

Aeromonas salmonicida subsp. salmonicida is a fish pathogen known to have a rich plasmidome. In the present study, we discovered an isolate of this bacterium bearing an additional unidentified small plasmid. After having sequenced the DNA of that isolate by next-generation sequencing, it appeared that the new small plasmid is a ColE1-type replicon plasmid, named here pAsa7. This plasmid bears a functional chloramphenicol-acetyltransferase-encoding gene (cat-pAsa7) previously unknown in A. salmonicida and responsible for resistance to chloramphenicol. A comparison of pAsa7 with pAsa2, the only known ColE1-type replicon plasmid usually found in A. salmonicida subsp. salmonicida, revealed that even if both plasmids share a high structural similarity, it is still unclear if pAsa7 is a derivative of pAsa2 since they showed several mutations at the nucleotide level. Transcriptomic analysis revealed that the cat-pAsa4 gene, another chloramphenicol-acetyltransferase-encoding gene, found on the large plasmid pAsa4, was significantly more transcribed than cat-pAsa7. This was correlated with a higher chloramphenicol resistance for isolates bearing pAsa4 compared with the one having pAsa7. Finally, a phylogenetic analysis showed that both CAT-pAsa4 and CAT-pAsa7 proteins were in different clusters. The clustering was supported by the identity of residues involved in the catalytic site. In addition, to give a better understanding of the large drug-resistance panel of A. salmonicida, this study reinforces the hypothesis that A. salmonicida subsp. salmonicida is a considerable reservoir for mobile genetic elements such as plasmids.

Comprehensive Insights in the Mycobacterium avium subsp. paratuberculosis Genome Using New WGS Data of Sheep Strain JIII-386 from Germany

PubMed Central

Möbius, Petra; Hölzer, Martin; Felder, Marius; Nordsiek, Gabriele; Groth, Marco; Köhler, Heike; Reichwald, Kathrin; Platzer, Matthias; Marz, Manja

2015-01-01

Mycobacterium avium (M. a.) subsp. paratuberculosis (MAP)—the etiologic agent of Johne’s disease—affects cattle, sheep, and other ruminants worldwide. To decipher phenotypic differences among sheep and cattle strains (belonging to MAP-S [Type-I/III], respectively, MAP-C [Type-II]), comparative genome analysis needs data from diverse isolates originating from different geographic regions of the world. This study presents the so far best assembled genome of a MAP-S-strain: Sheep isolate JIII-386 from Germany. One newly sequenced cattle isolate (JII-1961, Germany), four published MAP strains of MAP-C and MAP-S from the United States and Australia, and M. a. subsp. hominissuis (MAH) strain 104 were used for assembly improvement and comparisons. All genomes were annotated by BacProt and results compared with NCBI (National Center for Biotechnology Information) annotation. Corresponding protein-coding sequences (CDSs) were detected, but also CDSs that were exclusively determined by either NCBI or BacProt. A new Shine–Dalgarno sequence motif (5′-AGCTGG-3′) was extracted. Novel CDSs including PE-PGRS family protein genes and about 80 noncoding RNAs exhibiting high sequence conservation are presented. Previously found genetic differences between MAP-types are partially revised. Four of ten assumed MAP-S-specific large sequence polymorphism regions (LSPSs) are still present in MAP-C strains; new LSPSs were identified. Independently of the regional origin of the strains, the number of individual CDSs and single nucleotide variants confirms the strong similarity of MAP-C strains and shows higher diversity among MAP-S strains. This study gives ambiguous results regarding the hypothesis that MAP-S is the evolutionary intermediate between MAH and MAP-C, but it clearly shows a higher similarity of MAP to MAH than to Mycobacterium intracellulare. PMID:26384038

Preparation of low galactose yogurt using cultures of Gal(+) Streptococcus thermophilus in combination with Lactobacillus delbrueckii ssp. bulgaricus.

PubMed

Anbukkarasi, Kaliyaperumal; UmaMaheswari, Thiyagamoorthy; Hemalatha, Thiagarajan; Nanda, Dhiraj Kumar; Singh, Prashant; Singh, Rameshwar

2014-09-01

Streptococcus thermophilus is an important lactic starter used in the production of yogurt. Most strains of S. thermophilus are galactose negative (Gal(-)) and are able to metabolize only glucose portion of lactose and expel galactose into the medium. This metabolic defect leads to the accumulation of free galactose in yogurt, resulting in galactosemia among consumers. Hence there is an absolute need to develop low galactose yogurt. Therefore, in this study, three galactose positive (Gal(+)) S. thermophilus strains from National Collection of Dairy Cultures (NCDC) viz. NCDC 659 (AJM), NCDC 660 (JM1), NCDC 661 (KM3) and a reference galactose negative (Gal(-)) S. thermophilus NCDC 218 were used for preparation of low galactose yogurt. In milk fermented using S. thermophilus isolates alone, NCDC 659 released less galactose (0.27 %) followed by NCDC 661 (0.3 %) and NCDC 660 (0.45 %) after 10 h at 42 °C. Milk was fermented in combination with Gal(-) L. delbrueckii subsp. bulgaricus NCDC 04, in which NCDC 659 released least galactose upto 0.49 % followed by NCDC 661 (0.51 %) and NCDC 660 (0.60 %) than reference Gal(-) NCDC 218(0.79 %). Low galactose yogurt was prepared following standard procedure using Gal(+) S. thermophilus isolates and Gal(-) L. delbrueckii subsp. bulgaricus NCDC 04 in 1:1 ratio. Among which low galactose yogurt by NCDC 659 combination contained less galactose 0.37 % followed by NCDC 661 (0.51 %), NCDC 660 (0.65 %) and reference Gal(-) NCDC 218 (0.98 %) after 4 h of fermentation. This study clearly reveals that Gal(+) S. thermophilus isolates can be paired with Gal(-) L. delbrueckii subsp. bulgaricus for developing low galactose yogurt.

Streptococcus dysgalactiae subsp. dysgalactiae isolated from milk of the bovine udder as emerging pathogens: In vitro and in vivo infection of human cells and zebrafish as biological models.

PubMed

Alves-Barroco, Cinthia; Roma-Rodrigues, Catarina; Raposo, Luís R; Brás, Catarina; Diniz, Mário; Caço, João; Costa, Pedro M; Santos-Sanches, Ilda; Fernandes, Alexandra R

2018-03-25

Streptococcus dysgalactiae subsp. dysgalactiae (SDSD) is a major cause of bovine mastitis and has been regarded as an animal-restricted pathogen, although rare infections have been described in humans. Previous studies revealed the presence of virulence genes encoded by phages of the human pathogen Group A Streptococcus pyogenes (GAS) in SDSD isolated from the milk of bovine udder with mastitis. The isolates SDSD VSD5 and VSD13 could adhere and internalize human primary keratinocyte cells, suggesting a possible human infection potential of bovine isolates. In this work, the in vitro and in vivo potential of SDSD to internalize/adhere human cells of the respiratory track and zebrafish as biological models was evaluated. Our results showed that, in vitro, bovine SDSD strains could interact and internalize human respiratory cell lines and that this internalization was dependent on an active transport mechanism and that, in vivo, SDSD are able to cause invasive infections producing zebrafish morbidity and mortality. The infectious potential of these isolates showed to be isolate-specific and appeared to be independent of the presence or absence of GAS phage-encoded virulence genes. Although the infection ability of the bovine SDSD strains was not as strong as the human pathogenic S. pyogenes in the zebrafish model, results suggested that these SDSD isolates are able to interact with human cells and infect zebrafish, a vertebrate infectious model, emerging as pathogens with zoonotic capability. © 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Lactobacillus Species Identification, H2O2 Production, and Antibiotic Resistance and Correlation with Human Clinical Status

PubMed Central

Felten, Annie; Barreau, Claude; Bizet, Chantal; Lagrange, Philippe Henri; Philippon, Alain

1999-01-01

Lactobacilli recovered from the blood, cerebrospinal fluid, respiratory tract, and gut of 20 hospitalized immunocompromised septic patients were analyzed. Biochemical carbohydrate fermentation and total soluble cell protein profiles were used to identify the species. Hydrogen peroxide production was measured. Susceptibility to 19 antibiotics was tested by a diffusion method, and the MICs of benzylpenicillin, amoxicillin, imipenem, erythromycin, vancomycin, gentamicin, and levofloxacin were determined. A small number of species produced H2O2, and antibiotic susceptibilities were species related. Eighteen (90%) of the isolates were L. rhamnosus, one was L. paracasei subsp. paracasei, and one was L. crispatus. L. rhamnosus, L. paracasei subsp. paracasei isolates, and the type strains were neither H2O2 producers nor vancomycin susceptible (MICs, ≥256 μg/ml). L. crispatus, as well as most of the type strains of lactobacilli which belong to the L. acidophilus group, was an H2O2 producer and vancomycin susceptible (MICs, <4 μg/ml). PMID:9986841

Characterization of lactococci isolated from milk produced in the Camembert region of Normandy.

PubMed

Desmasures, N; Mangin, I; Corroler, D; Guéguen, M

1998-12-01

Thirty-eight Lactococcus strains, isolated from raw milk produced in two dairy areas in Normandy, were identified at the phenotypic level. Only Lactococcus lactis strains with the lactis phenotype were found in the milk samples. Most strains fermented lactose (97%) and showed proteinase activity (76%). Isolates were characterized by RAPD technique and rRNA gene restriction analysis. More L. lactis strains with the lactis genotype were found in the first area, while L. lactis strains with the cremoris genotype predominated in the second area. RAPD was more efficient than rRNA gene restriction analysis in differentiating between strains with the subsp. lactis genotype. For L. lactis with the subsp. cremoris genotype, the second method gave a better result but there was poor discrimination between strains. Plasmid profiles were determined. Patterns ranged in size from 1.3 to 16.5 kbp, and 29 different profiles were found. Six groups of strains were determined, five of which were specific for the area of origin. It is suggested that the region of manufacture could influence organoleptic properties of cheeses because of different Lactococcus strains in the raw milk used for cheese making.

Identification and characterization of tetracycline resistance in Lactococcus lactis isolated from Polish raw milk and fermented artisanal products.

PubMed

Zycka-Krzesinska, Joanna; Boguslawska, Joanna; Aleksandrzak-Piekarczyk, Tamara; Jopek, Jakub; Bardowski, Jacek K

2015-10-15

To assess the occurrence of antibiotic-resistant Lactic Acid Bacteria (LAB) in Polish raw milk and fermented artisanal products, a collection comprising 500 isolates from these products was screened. Among these isolates, six strains (IBB28, IBB160, IBB161, IBB224, IBB477 and IBB487) resistant to tetracycline were identified. The strains showing atypical tetracycline resistance were classified as Lactococcus lactis: three of them were identified as L. lactis subsp. cremoris (IBB224, IBB477 and IBB487) and the other three (IBB28, IBB160, IBB161) were identified as L. lactis subsp. lactis. The mechanism involving Ribosomal Protection Proteins (RPP) was identified as responsible for tetracycline resistance. Three of the tested strains (IBB28, IBB160 and IBB224) had genes encoding the TetS protein, whereas the remaining three (IBB161, IBB477 and IBB487) expressed TetM. The results also demonstrated that the genes encoding these proteins were located on genetic mobile elements. The tet(S) gene was found to be located on plasmids, whereas tet(M) was found within the Tn916 transposon. Copyright © 2015 Elsevier B.V. All rights reserved.

[Phenolic acid derivatives from Bauhinia glauca subsp. pernervosa].

PubMed

Zhao, Qiao-Li; Wu, Zeng-Bao; Zheng, Zhi-Hui; Lu, Xin-Hua; Liang, Hong; Cheng, Wei; Zhang, Qing-Ying; Zhao, Yu-Ying

2011-08-01

To study the chemical constituents of Bauhinia glauca subsp. pernervosa, eleven phenolic acids were isolated from a 95% ethanol extract by using a combination of various chromatographic techniques including column chromatography over silica gel, ODS, MCI, Sephadex LH-20, and semi-preparative HPLC. By spectroscopic techniques including 1H NMR, 13C NMR, 2D NMR, and HR-ESI-MS, these compounds were identified as isopropyl O-beta-(6'-O-galloyl)-glucopyranoside (1), ethyl O-beta-(6'-O-galloyl)-glucopyranoside (2), 3, 4, 5-trimethoxyphenyl-(6'-O-galloyl)-O-beta-D-glucopyranoside (3), 3, 4, 5-trimethoxyphenyl-beta-D-glucopyranoside (4), gallic acid (5), methyl gallate (6), ethyl gallate (7), protocatechuic acid (8), 3, 5-dimethoxy-4-hydroxybenzoic acid (9), erigeside C (10) and glucosyringic acid (11). Among them, compound 1 is a new polyhydroxyl compound; compounds 2, 10, and 11 were isolated from the genus Bauhinia for the first time, and the other compounds were isolated from the plant for the first time. Compounds 6 and 8 showed significant protein tyrosine phosphatase1B (PTP1B) inhibitory activity in vitro with the IC50 values of 72.3 and 54.1 micromol x L(-1), respectively.

Campylobacter fetus meningitis associated with eating habits of raw meat and raw liver in a healthy patient: A case report and literature review.

PubMed

Ishihara, Ayaka; Hashimoto, Etaro; Ishioka, Haruhiko; Kobayashi, Hiroyuki; Gomi, Harumi

2018-01-01

Meningitis caused by the zoonotic pathogen Campylobacter fetus in immunocompetent adults is rare. We report a 48-year-old Japanese woman with no underlying disease who was found to have meningitis caused by C. fetus . Both C. fetus subsp. fetus and C. fetus subsp. venerealis were isolated from the cerebrospinal fluid culture. The mode of infection in our patient was considered to be associated with the consumption of raw beef and raw cattle liver on a regular basis. Public awareness and education to avoid the consumption of raw or undercooked meat might help prevent C. fetus meningitis.

RNA polymerase activity is associated with viral particles isolated from Leishmania braziliensis subsp. guyanensis.

PubMed Central

Widmer, G; Keenan, M C; Patterson, J L

1990-01-01

Viral particles purified from species of the protozoan parasite Leishmania braziliensis subsp. guyanensis by centrifugation in CsCl gradients were examined for the presence of viral polymerase. We demonstrated that RNA-dependent RNA polymerase is associated with viral particles. Viral transcription was studied in vitro with pulse-chase experiments and by assaying the RNase sensitivity of the viral transcripts. Viral polymerase synthesized full-length transcripts within 1 h. Double-strained, genome-length, and single-stranded RNAs were produced in this system. The nature of the RNA extracted from virions was also tested by RNase protection assays; both single-stranded and double-stranded RNAs were found. Images PMID:2370680

A Closed-tube Loop-Mediated Isothermal Amplification Assay for the Visual Endpoint Detection of Brucella spp. and Mycobacterium avium subsp. paratuberculosis.

PubMed

Trangoni, Marcos D; Gioffré, Andrea K; Cravero, Silvio L

2017-01-01

LAMP (loop-mediated isothermal amplification) is an isothermal nucleic acid amplification technique that is characterized by its efficiency, rapidity, high yield of final product, robustness, sensitivity, and specificity, with the blueprint that it can be implemented in laboratories of low technological complexity. Despite the conceptual complexity underlying the mechanistic basis for the nucleic acid amplification, the technique is simple to use and the amplification and detection can be carried out in just one step. In this chapter, we present a protocol based on LAMP for the rapid identification of isolates of Brucella spp. and Mycobacterium avium subsp. paratuberculosis, two major bacterial pathogens in veterinary medicine.

Complete Genome Sequence of a Multidrug-Resistant Salmonella enterica Serovar Typhimurium var. 5− Strain Isolated from Chicken Breast

PubMed Central

Muruvanda, Tim; Allard, Marc W.; Korlach, Jonas; Roberts, Richard J.; Timme, Ruth; Payne, Justin; McDermott, Patrick F.; Evans, Peter; Meng, Jianghong; Brown, Eric W.; Zhao, Shaohua

2013-01-01

Salmonella enterica subsp. enterica serovar Typhimurium is a leading cause of salmonellosis. Here, we report a closed genome sequence, including sequences of 3 plasmids, of Salmonella serovar Typhimurium var. 5− CFSAN001921 (National Antimicrobial Resistance Monitoring System [NARMS] strain ID N30688), which was isolated from chicken breast meat and shows resistance to 10 different antimicrobials. Whole-genome and plasmid sequence analyses of this isolate will help enhance our understanding of this pathogenic multidrug-resistant serovar. PMID:24356834

Free-Living Turtles Are a Reservoir for Salmonella but Not for Campylobacter

PubMed Central

Marin, Clara; Ingresa-Capaccioni, Sofia; González-Bodi, Sara; Marco-Jiménez, Francisco; Vega, Santiago

2013-01-01

Different studies have reported the prevalence of Salmonella in turtles and its role in reptile-associated salmonellosis in humans, but there is a lack of scientific literature related with the epidemiology of Campylobacter in turtles. The aim of this study was to evaluate the prevalence of Campylobacter and Salmonella in free-living native (Emys orbicularis, n=83) and exotic ( Trachemys scripta elegans, n=117) turtles from 11 natural ponds in Eastern Spain. In addition, different types of samples (cloacal swabs, intestinal content and water from Turtle containers) were compared. Regardless of the turtle species, natural ponds where individuals were captured and the type of sample taken, Campylobacter was not detected. Salmonella was isolated in similar proportions in native (8.0±3.1%) and exotic (15.0±3.3%) turtles (p=0.189). The prevalence of Salmonella positive turtles was associated with the natural ponds where animals were captured. Captured turtles from 8 of the 11 natural ponds were positive, ranged between 3.0±3.1% and 60.0±11.0%. Serotyping revealed 8 different serovars among four Salmonella enterica subspecies: S. enterica subsp. enterica (n = 21), S. enterica subsp. salamae (n = 2), S. enterica subsp. diarizonae (n = 3), and S. enterica subsp. houtenae (n = 1). Two serovars were predominant: S. Thompson (n=16) and S . typhimurium (n=3). In addition, there was an effect of sample type on Salmonella detection. The highest isolation of Salmonella was obtained from intestinal content samples (12.0±3.0%), while lower percentages were found for water from the containers and cloacal swabs (8.0±2.5% and 3.0±1.5%, respectively). Our results imply that free-living turtles are a risk factor for Salmonella transmission, but do not seem to be a reservoir for Campylobacter . We therefore rule out turtles as a risk factor for human campylobacteriosis. Nevertheless, further studies should be undertaken in other countries to confirm these results. PMID:23951312

Screening in a Lactobacillus delbrueckii subsp. bulgaricus collection to select a strain able to survive to the human intestinal tract.

PubMed

Vázquez, Clotilde; Botella-Carretero, José I; García-Albiach, Raimundo; Pozuelo, María J; Rodríguez-Baños, Mercedes; Baquero, Fernando; Baltadjieva, María A; del Campo, Rosa

2013-01-01

Genetic diversity and resistance of Lactobacillus bulgaricus sbsp. delbrueckii collection with 100 isolates from different home-made yogurt in rural Bulgarian areas were determined. The strain K98 was the most resistant to bile salts and low pH. Survival and effects on short chain fatty acids production were tested in 20 healthy volunteers. High genetic diversity was observed in the L. bulgaricus collection by RAPD, whereas the ability of tolerate high deoxycholic acid concentrations, and different acid pHs was variable. The strain K98 was selected and used to prepare a homemade yogurt which was administered to 20 healthy volunteers (500 ml/day during 15d). A basal faecal sample and another after yogurt intake were recovered. DGGE experiments, using both universal and Lactic Acid Bacteria (LAB) primers, demonstrated no significant changes in the qualitative composition of gut microbiota. A band corresponding to L. bulgaricus was observed in all 20 samples. Viable L. bulgaricus K98 strain was only recovered in one volunteer. After yogurt intake we found an increase of LAB and Clostridium perfringens, and a decrease of Bacteroides- Prevotella-Porphyromonas. In addition, increases of acetic, butyric and 2-hydroxy-butyric acids in faeces were detected. Genetic diversity of L. delbrueckii subsp. bulgaricus especie is high We have isolated a probiotic resistant strain to bile and high acidity, L. delbrueckii subsp. bulgaricus-K98. Qualitative and quantitative changes in the intestinal microbiota are found after ingestion of a homemade yogurt containing this strain, with a concomitant increase in faecal SCFA. Our findings support the interest in developing further studies providing different amounts of L. delbrueckii subsp. bulgaricus-K98, and should evaluate its clinical effects in human disease. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

Identification of Group G Streptococcal Isolates from Companion Animals in Japan and Their Antimicrobial Resistance Patterns.

PubMed

Tsuyuki, Yuzo; Kurita, Goro; Murata, Yoshiteru; Goto, Mieko; Takahashi, Takashi

2017-07-24

In this study, we conducted a species-level identification of group G streptococcal (GGS) isolates from companion animals in Japan and analyzed antimicrobial resistance (AMR) patterns. Strains were isolated from sterile and non-sterile specimens collected from 72 animals with clinical signs or symptoms in April-May, 2015. We identified the strain by 16S rRNA sequencing, mass spectrometry (MS), and an automated method based on their biochemical properties. Antimicrobial susceptibility was determined using the broth microdilution method and E-test. AMR determinants (erm(A), erm(B), mef(A), tet(M), tet(O), tet(K), tet(L), and tet(S)) in corresponding resistant isolates were amplified by PCR. The 16S rRNA sequencing identified the GGS species as Streptococcus canis (n = 68), Streptococcus dysgalactiae subsp. equisimilis (n = 3), and S. dysgalactiae subsp. dysgalactiae (n = 1). However, there were discrepancies between the sequencing data and both the MS and automated identification data. MS and the automated biochemical technique identified 18 and 37 of the 68 sequencing-identified S. canis strains, respectively. The AMR rates were 20.8% for tetracycline and 5.6% for clarithromycin, with minimum inhibitory concentrations (MIC) 50 -MIC 90 of 2-64 and ≤ 0.12-0.25μg/mL, respectively. AMR genotyping showed single or combined genotypes: erm(B) or tet(M)-tet(O)-tet(S). Our findings show the unique characteristics of GGS isolates from companion animals in Japan in terms of species-level identification and AMR patterns.

Bacterial Secretome Analysis in Hunt for Novel Bacteriocins with Ability to Control Xanthomonas citri subsp. Citri

PubMed Central

Gholami, Dariush; Goodarzi, Tannaz; Aminzadeh, Saeed; Alavi, Seyed Mehdi; Kazemipour, Nasrin; Farrokhi, Naser

2015-01-01

Background Xanthomonas citri subsp. citri (Xcc), the causative agent of bacterial citrus canker, has affected citriculture worldwide. Varieties of means have been used to minimize its devastating effects, but no attention has been given to bacteriocins. Objectives Here and for the first time, we report the isolation and characterization of two novel bacteriocins. Materials and Methods Secretome containing bacteriocins of isolated bacteria was separated via SDS-PAGE. Each isolated protein band was characterized and checked for its efficacy in controlling two pathogenic isolates of Xcc via disk diffusion assay. The effects of varieties of carbon, nitrogen and phosphate sources were evaluated on both bacterial growth and bacteriocin production via Taguchi orthogonal method. Results The two bacteriocins showed an activity up to 55ºC that were sensitive to proteases suggesting being protein in nature. Analysis of SDS-PAGE purified protein bands of bacterial secretomes with demonstrated potency against Xcc revealed the presence of peptides with relative molecular masses of 16.9 and 17 kDa for Cronobacter and Enterobacter, respectively. Sequence analysis of peptides revealed an HCP1 family VI secretion system homologue for Cronobacter (YP_001439956) and pilin FimA homologue for Enterobacter (CBK85798.1). A Taguchi orthogonal array was also implemented to determine the effect of temperature and eight other chemical factors on bacteriocin production for each bacterium. Conclusions Two peptides with novel antibacterial activities effective against Xcc were isolated, characterized and conditions were optimized for their higher production. PMID:28959294

Aneurysm of the cranial mesenteric artery as a site of carriage of Salmonella enterica subsp. enterica serovar Abortusequi in the horse.

PubMed

Niwa, Hidekazu; Hobo, Seiji; Kinoshita, Yuta; Muranaka, Masanori; Ochi, Akihiro; Ueno, Takanori; Oku, Kazuomi; Hariu, Kazuhisa; Katayama, Yoshinari

2016-07-01

Salmonella enterica subsp. enterica serovar Abortusequi is a pathogen restricted to horses. Our investigation targeted 4 draft horses (9-10 months old) kept on a Japanese farm that had suffered an outbreak of S. Abortusequi abortion. The 4 horses were suspected to be carriers of the bacterium owing to their high agglutination titers (≥1:2,560) in tube agglutination testing. The owners' on-farm observations confirmed that the horses had no apparent abnormalities, and S. Abortusequi was not isolated from their blood, rectal swabs, or sternal bone marrow fluid at antemortem investigation. However, at autopsy, all horses displayed the following: suppurative aneurysm of the cranial mesenteric artery with heavy infection with Strongylus vulgaris larvae; heavy intestinal parasitic infection with Gasterophilus intestinalis, Parascaris equorum, Anoplocephala perfoliata, and S. vulgaris; and enlargement of the systemic lymph nodes. In each case, large numbers of S. Abortusequi were isolated from the anterior mesenteric artery thrombus. The thrombus isolates harbored a single virulence plasmid, and the pulsed-field gel electrophoresis profiles of the isolates were identical not only to each other but also to those of Japanese enzootic strains of S. Abortusequi. These results reveal that parasitic aneurysms of the cranial mesenteric artery should be considered an important possible site of carriage of S. Abortusequi in horses. The results also suggest high clonality of the isolated serovar in the horse population in Japan. © 2016 The Author(s).

Genome-Wide Diversity and Phylogeography of Mycobacterium avium subsp. paratuberculosis in Canadian Dairy Cattle

PubMed Central

Ahlstrom, Christina; Barkema, Herman W.; Stevenson, Karen; Zadoks, Ruth N.; Biek, Roman; Kao, Rowland; Trewby, Hannah; Haupstein, Deb; Kelton, David F.; Fecteau, Gilles; Labrecque, Olivia; Keefe, Greg P.; McKenna, Shawn L. B.; Tahlan, Kapil; De Buck, Jeroen

2016-01-01

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative bacterium of Johne’s disease (JD) in ruminants. The control of JD in the dairy industry is challenging, but can be improved with a better understanding of the diversity and distribution of MAP subtypes. Previously established molecular typing techniques used to differentiate MAP have not been sufficiently discriminatory and/or reliable to accurately assess the population structure. In this study, the genetic diversity of 182 MAP isolates representing all Canadian provinces was compared to the known global diversity, using single nucleotide polymorphisms identified through whole genome sequencing. MAP isolates from Canada represented a subset of the known global diversity, as there were global isolates intermingled with Canadian isolates, as well as multiple global subtypes that were not found in Canada. One Type III and six “Bison type” isolates were found in Canada as well as one Type II subtype that represented 86% of all Canadian isolates. Rarefaction estimated larger subtype richness in Québec than in other Canadian provinces using a strict definition of MAP subtypes and lower subtype richness in the Atlantic region using a relaxed definition. Significant phylogeographic clustering was observed at the inter-provincial but not at the intra-provincial level, although most major clades were found in all provinces. The large number of shared subtypes among provinces suggests that cattle movement is a major driver of MAP transmission at the herd level, which is further supported by the lack of spatial clustering on an intra-provincial scale. PMID:26871723

Metagenomic analysis of the bovine hindgut from Salmonella Kentucky and Cerro-shedding dairy cows

USDA-ARS?s Scientific Manuscript database

In the United States Salmonella enterica subsp. enterica serovars Kentucky and Cerro are frequently isolated from dairy cows that appear asymptomatic. Although they are not major contributors to the salmonellosis burden, these serovars have been implicated in human clinical cases in recent years. To...

Bacterial diskospondylitis in juvenile mink from 2 Ontario mink farms

PubMed Central

Martínez, Jorge; Vidaña, Beatriz; Cruz-Arambulo, Robert; Slavic, Durda; Tapscott, Brian; Brash, Marina L.

2013-01-01

Nine juvenile mink with hind-limb paresis/paralysis from 2 Ontario farms were submitted for necropsy. Diagnostic tests revealed spinal compression and severe thoracic diskospondylitis with intralesional Gram-positive coccoid bacterial colonies. Streptococcus canis, Streptococcus dysgalactiae subsp. equisimilis, and hemolytic Staphylococcus spp. were isolated from vertebral lesions. PMID:24155490

Bacterial diskospondylitis in juvenile mink from 2 Ontario mink farms.

PubMed

Martínez, Jorge; Vidaña, Beatriz; Cruz-Arambulo, Robert; Slavic, Durda; Tapscott, Brian; Brash, Marina L

2013-09-01

Nine juvenile mink with hind-limb paresis/paralysis from 2 Ontario farms were submitted for necropsy. Diagnostic tests revealed spinal compression and severe thoracic diskospondylitis with intralesional Gram-positive coccoid bacterial colonies. Streptococcus canis, Streptococcus dysgalactiae subsp. equisimilis, and hemolytic Staphylococcus spp. were isolated from vertebral lesions.

Col plasmids contribute to the fitness of Salmonella Heidelberg in poultry litter evolution experiment

USDA-ARS?s Scientific Manuscript database

Salmonella enterica subsp. enterica serovar Heidelberg (S. Heidelberg) is a clinically-important serovar, linked to food-borne illness, and commonly isolated from poultry. Investigations of a large, multistate outbreak in the USA in 2011 identified poultry litter (PL) as an important extra-intestina...

High-Quality Draft Genome Sequence of Desulfovibrio carbinoliphilus FW-101-2B, an Organic Acid-Oxidizing Sulfate-Reducing Bacterium Isolated from Uranium(VI)-Contaminated Groundwater

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

Ramsay, Bradley D.; Hwang, Chiachi; Woo, Hannah L.

2015-03-12

Desulfovibrio carbinoliphilus subsp. oakridgensis FW-101-2B is an anaerobic, organic acid/alcohol-oxidizing, sulfate-reducing δ-proteobacterium. FW-101-2B was isolated from contaminated groundwater at The Field Research Center at Oak Ridge National Lab after in situ stimulation for heavy metal-reducing conditions. The genome will help elucidate the metabolic potential of sulfate-reducing bacteria during uranium reduction.

Antibacterial activities of multi drug resistant Myroides odoratimimus bacteria isolated from adult flesh flies (Diptera: sarcophagidae) are independent of metallo beta-lactamase gene

PubMed Central

Dharne, M.S.; Gupta, A.K.; Rangrez, A.Y.; Ghate, H.V.; Patole, M.S.; Shouche, Y.S.

2008-01-01

Flesh flies (Diptera: Sarcophagidae) are well known cause of myiasis and their gut bacteria have never been studied for antimicrobial activity against bacteria. Antimicrobial studies of Myroides spp. are restricted to nosocomial strains. A Gram-negative bacterium, Myroides sp., was isolated from the gut of adult flesh flies (Sarcophaga sp.) and submitted to evaluation of nutritional parameters using Biolog GN, 16S rRNA gene sequencing, susceptibility to various antimicrobials by disc diffusion method and detection of metallo β-lactamase genes (TUS/MUS). The antagonistic effects were tested on Gram-negative and Gram-positive bacteria isolated from human clinical specimens, environmental samples and insect mid gut. Bacterial species included were Aeromonas hydrophila, A. culicicola, Morganella morganii subsp. sibonii, Ochrobactrum anthropi, Weissella confusa, Escherichia coli, Ochrobactrum sp., Serratia sp., Kestersia sp., Ignatzschineria sp., Bacillus sp. The Myroides sp. strain was resistant to penicillin-G, erythromycin, streptomycin, amikacin, kanamycin, gentamycin, ampicillin, trimethoprim and tobramycin. These strain showed antibacterial action against all bacterial strains except W. confusa, Ignatzschineria sp., A. hydrophila and M. morganii subsp. sibonii. The multidrug resistance of the strain was similar to the resistance of clinical isolates, inhibiting growth of bacteria from clinical, environmental and insect gut samples. The metallo β-lactamase (TUS/MUS) genes were absent, and resistance due to these genes was ruled out, indicating involvement of other secretion machinery. PMID:24031236

Natural coinfection by Streptococcus agalactiae and Francisella noatunensis subsp. orientalis in farmed Nile tilapia (Oreochromis niloticus L.).

PubMed

Assis, G B N; Tavares, G C; Pereira, F L; Figueiredo, H C P; Leal, C A G

2017-01-01

Streptococcus agalactiae and Francisella noatunensis subsp. orientalis (Fno) are important pathogens for farm-raised tilapia worldwide. There are no reports of coinfection caused by S. agalactiae and Fno in fish. This study aimed to determine the aetiology of atypical mortalities in a cage farm of Nile tilapia and to characterize the genetic diversity of the isolates. Fifty-two fish were sampled and subjected to parasitological and bacteriological examination. The S. agalactiae and Fno isolates were genotyped using MLST and REP-PCR, respectively. Whole-genome sequencing was performed to confirm the MLST results. Seven fish were shown coinfected by S. agalactiae and Fno. Chronic hypoxia and a reduction in the water temperature were determined as risk factors for coinfection. Fno isolates were shown clonally related in REP-PCR. The MLST analysis revealed that the S. agalactiae isolates from seven coinfected fish were negative for the glcK gene; however, these were determined to be members of clonal complex CC-552. This is the first description of coinfection by S. agalactiae and Fno in farm-raised Nile tilapia. The coinfection was predisposed by chronic hypoxia and was caused by the main genotypes of S. agalactiae and Fno reported in Brazil. Finally, a new S. agalactiae genotype with glcK gene partially deleted was described. © 2016 John Wiley & Sons Ltd.

In vitro assessment of the antimicrobial susceptibility of caprine isolates of Mycoplasma mycoides subsp. capri.

PubMed

Paterna, A; Tatay-Dualde, J; Amores, J; Prats-van der Ham, M; Sánchez, A; de la Fe, C; Contreras, A; Corrales, J C; Gómez-Martín, Á

2016-08-01

The minimum inhibitory concentration (MIC) and minimum mycoplasmacidal concentration (MMC) of 17 antimicrobials against 41 Spanish caprine isolates of Mycoplasma mycoides subsp. capri (Mmc) obtained from different specimens (milk, external auricular canal and semen) were determined using a liquid microdilution method. For half of the isolates, the MIC was also estimated for seven of the antimicrobials using an epsilometric test (ET), in order to compare both methods and assess the validity of ET. Mutations in genes gyrA, gyrB, parC and parE conferring fluoroquinolone resistance, which have been recently described in Mmc, were investigated using PCR. The anatomical origin of the isolate had no effect on its antimicrobial susceptibility. Moxifloxacin and doxycycline had the lowest MIC values. The rest of the fluoroquinolones studied (except norfloxacin), together with tylosin and clindamycin, also had low MIC values, although the MMC obtained for clindamycin was higher than for the other antimicrobials. For all the aminoglycosides, spiramycin and erythromycin, a notable level of resistance was observed. The ET was in close agreement with broth microdilution at low MICs, but not at intermediate or high MICs. The analysis of the genomic sequences revealed the presence of an amino acid substitution in codon 83 of the gene gyrA, which has not been described previously in Mmc. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of multiplex PCR assay for simultaneous detection of Salmonella genus, Salmonella subspecies I, Salm. Enteritidis, Salm. Heidelberg and Salm. Typhimurium.

PubMed

Park, S H; Ricke, S C

2015-01-01

The aim of this research was to develop multiplex PCR assay that could simultaneously detect Salmonella genus, Salmonella subsp. I, Salm. Enteritidis, Heidelberg and Typhimurium because these Salmonella serovars are the most common isolates associated with poultry products. Five primers were utilized to establish multiplex PCR and applied to Salmonella isolates from chickens and farm environments. These isolates were identified as Salmonella subsp. I and 16 of 66 isolates were classified as Salm. Enteritidis, while Heidelberg or Typhimurium was not detected. We also spiked three Salmonella strains on chicken breast meat to evaluate the specificity and sensitivity of multiplex PCR as well as qPCR to optimize quantification of Salmonella in these samples. The optimized multiplex PCR and qPCR could detect approx. 2·2 CFU of Salmonella per gram after 18 h enrichment. The multiplex PCR and qPCR would provide rapid and consistent results. Also, these techniques would be useful for the detection and quantification of Salmonella in contaminated poultry, foods and environmental samples. The strategy for the rapid detection of Salmonella serovars in poultry is needed to further reduce the incidence of salmonellosis in humans. The optimized multiplex PCR will be useful to detect prevalent Salmonella serovars in poultry products. © 2014 The Society for Applied Microbiology.

Foodborne Outbreak of Group G Streptococcal Pharyngitis in a School Dormitory in Osaka, Japan.

PubMed

Yamaguchi, Takahiro; Kawahara, Ryuji; Katsukawa, Chihiro; Kanki, Masashi; Harada, Tetsuya; Yonogi, Shinya; Iwasaki, Satomi; Uehara, Hirokazu; Okajima, Saori; Nishimura, Hiroshi; Motomura, Kazushi; Miyazono, Masaya; Kumeda, Yuko; Kawatsu, Kentaro

2018-05-01

In September 2016, 140 patients with primary symptoms of sore throat and fever were identified in a school dormitory in Osaka, Japan. Epidemiological and laboratory investigations determined that these symptomatic conditions were from a foodborne outbreak of group G streptococcus (GGS), with GGS being isolated from samples from patients, cooks, and foods. The strain of GGS was identified as Streptococcus dysgalactiae subsp. equisimilis of two emm types ( stG652.0 and stC36.0 ). The causative food, a broccoli salad, was contaminated with the two types of S. dysgalactiae subsp. equisimilis , totaling 1.3 × 10 4 CFU/g. Pulsed-field gel electrophoresis (PFGE) of samples from patients, cooks, and foods produced similar band patterns among samples with the same emm type. This result suggested the possibility of exposure from the contaminated food. The average onset time was 44.9 h and the prevalence rate was 62%. This is the first report to identify the causative food of a foodborne outbreak by Streptococcus dysgalactiae subsp. equisimilis . Copyright © 2018 American Society for Microbiology.

Novel phenanthrene and isocoumarin from the rhizomes of Dioscorea nipponica Makino subsp. rosthornii (Prain et Burkill) C. T. Ting (Dioscoreaceae).

PubMed

Li, Xuejiao; Zhao, Chengcheng; Jing, Songsong; Sun, Jiachen; Li, Xia; Man, Shuli; Wang, Ying; Gao, Wenyuan

2017-08-01

The investigation of the constituents in the rhizomes of Dioscorea nipponica Makino subsp. rosthornii (Prain et Burkill) C. T. Ting afforded one new phenanthrene 2,2',7,7'-tetramethoxy-[1,1'-biphenanthrene]-4,4',6,6'-tetrol (7) and one new isocoumarin diorosthornoumarin (8), together with 16 known compounds (1-6 and 9-18). Their structures were established on the basis of extensive spectroscopic evidences (IR, HR-ESI-MS, NMR and optical rotation), as well as comparison with literature values. All the compounds 1-18 were firstly isolated from Dioscorea nipponica Makino subsp. Rosthornii (Prain et Burkill) C. T. Ting, and compound 9 was firstly obtained as a natural product from plants, while the compounds 11 and 14 were obtained from both the genus Dioscorea and the family Dioscoreaceae for the first time. Moreover, the antitumor activities of the compounds were tested against lung carcinoma NCI-H460 cell line. Compound 12, 13, 15 and 16 showed significant cytotoxic activities, whereas 7 displayed moderate cytotoxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tularaemia in Berlin - two independent cases in travellers returning from central Anatolia, Turkey, February 2011.

PubMed

Schubert, A; Splettstoesser, W; Bätzing-Feigenbaum, J

2011-05-05

Tularaemia, though rare, has recently been increasingly reported in Germany. Most cases are indigenous infections. This report describes two epidemiologically independent infections with Francisella tularensis subspecies holarctica detected in Berlin in February 2011 that were acquired in central Anatolia, Turkey. In Turkey, there have been repeated tularaemia outbreaks since 2000 and the disease should therefore be considered as a differential diagnosis in travellers returning from that country.

Antibacterial activity of antagonistic bacterium Bacillus subtilis DJM-51 against phytopathogenic Clavibacter michiganense subsp. michiganense ATCC 7429 in vitro.

PubMed

Jung, W J; Mabood, F; Souleimanov, A; Whyte, L G; Niederberger, T D; Smith, D L

2014-12-01

To investigate antibacterial activity against the tomato pathogen Clavibacter michiganense subsp. michiganense ATCC 7429 (Cmm ATCC 7429), Bacillus subtilis DJM-51 was isolated from rhizosphere soil. For isolation of bacteria, samples were taken from rhizosphere soil. The isolate, DJA-51, had strong antagonistic ability against Tomato pathogen Cmm ATCC 7429 on nutrient-broth yeast extract agar (NBYA) as indicated by inhibition zones around colonies. On the basis of the nucleotide sequence of a conserved segment of the 16S rRNA gene, the bacterium has been identified as B. subtilis DJM-51. The growth of Cmm ATCC 7429 on NBYA plates was inhibited by culture broth of B. subtilis DJM-51 including cells, by the supernatant of culture broth of B. subtilis DJM-51, and by the liquid material resulting from butanol extract of bacterial cultures. The OD value in co-culture mixture was lower than the control throughout the entire incubation period. Antibiotics obtained from B. subtilis DJM-51 inhibited the growth of Tomato pathogen Cmm ATCC 7429. These results provide potentially information about the protection of tomato from pathogen Cmm ATCC 7429 under greenhouse conditions in Quebec. Copyright © 2014 Elsevier Ltd. All rights reserved.

Heterogeneity of Powdery Mildew Resistance Revealed in Accessions of the ICARDA Wild Barley Collection

PubMed Central

Dreiseitl, Antonin

2017-01-01

The primary genepool of barley comprises two subspecies – wild barley (Hordeum vulgare subsp. spontaneum) and cultivated barley H. vulgare. subsp. vulgare. The former originated 5.5 million years ago in southwest Asia and is the immediate ancestor of cultivated barley, which arose around 10,000 years ago. In this study, the specific resistance of a set of 146 wild barley accessions, maintained by the International Center for Agriculture Research in the Dry Areas (ICARDA), to 32 isolates of barley powdery mildew caused by Blumeria graminis f. sp. hordei was evaluated. The set comprised 146 heterogeneous accessions of a previously tested collection. Seed was obtained by single seed descent and each accession was usually represented by five single plant progenies. In total, 687 plant progenies were tested. There were 211 phenotypes of resistance among the accessions, 87 of which were found in single plants, while 202 plants contained the eight most common phenotypes. The most frequent phenotype was found in 56 plants that were susceptible to all pathogen isolates, whereas the second most frequent phenotype, which occurred in 46 plants, was resistant to all isolates. The broad resistance diversity that was revealed is of practical importance and is an aid to determining the extent and role of resistance in natural ecosystems. PMID:28261253

Screening for Salmonella in backyard chickens.

PubMed

Manning, Johanna; Gole, Vaibhav; Chousalkar, Kapil

2015-06-15

Salmonellosis is a significant zoonotic disease which has a considerable economic impact on the egg layer industry. There is limited information about the prevalence of Salmonella spp. in backyard chickens. The current study was conducted to determine the prevalence of Salmonella in backyard chickens, and the associated virulence of any serovars identified. Hundred and fifteen pooled samples from 30 backyard flocks in South Australia were screened. Four flocks tested positive for Salmonella spp. The overall Salmonella isolation rate in the current study was 10.4%. The estimated prevalence at individual bird level was 0.02% (95% CI 0.025-0.975). The serovars isolated were Salmonella Agona, Salmonella subsp 2 ser 21:z10:z6 (Wandsbek) and Salmonella Bovismorbificans. All Salmonella isolates tested positive for the prgH, orfL and spiC genes. The Salmonella subsp 2 ser 21:z10:z6 (Wandsbek) had the most antibiotic resistance, being resistant to ampicillin and cephalothin and having intermediate resistance to florphenicol. All of the Salmonella Agona had intermediate resistance to the ampicillin, while the Salmonella Bovismorbificans were susceptible to all antibiotics tested. With the increased interest of keeping backyard chickens, the current study highlights the zoonotic risk from Salmonella spp. associated with home flocks. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Mobilome differences between Salmonella enterica serovars Anatum and Typhimurium isolated from cattle and humans and potential impact on virulence

USDA-ARS?s Scientific Manuscript database

Salmonella enterica subsp. enterica is an important group of pathogens capable of inhabiting a range of niches and hosts with varying degrees of impact, from commensal colonization to invasive infection. Recent outbreaks of multi-drug resistant S. enterica, attributed to consumption of contaminated ...

Antibacterial activity of different honeys against pathogenic bacteria.

PubMed

Voidarou, C; Alexopoulos, A; Plessas, S; Karapanou, A; Mantzourani, I; Stavropoulou, E; Fotou, K; Tzora, A; Skoufos, I; Bezirtzoglou, E

2011-12-01

To study the antimicrobial activity of honey, 60 samples of various botanical origin were evaluated for their antimicrobial activities against 16 clinical pathogens and their respective reference strains. The microbiological quality of honeys and the antibiotic susceptibility of the various isolates were also examined. The bioassay applied for determining the antimicrobial effect employs the well-agar diffusion method and the estimation of minimum active dilution which produces a 1mm diameter inhibition zone. All honey samples, despite their origin (coniferous, citrus, thyme or polyfloral), showed antibacterial activity against the pathogenic and their respective reference strains at variable levels. Coniferous and thyme honeys showed the highest activity with an average minimum dilution of 17.4 and 19.2% (w/v) followed by citrus and polyfloral honeys with 20.8 and 23.8% respectively. Clinical isolates of Staphylococcus aureus subsp. aureus, Escherichia coli, Salmonella enterica subsp. Enterica, Streptococcus pyogenes, Bacillus cereus and Bacillus subtilis were proven to be up to 60% more resistant than their equal reference strains thus emphasizing the variability in the antibacterial effect of honey and the need for further research. Copyright © 2011 Elsevier Ltd. All rights reserved.

Mupirocin-mucin agar for selective enumeration of Bifidobacterium bifidum.

PubMed

Pechar, Radko; Rada, Vojtech; Parafati, Lucia; Musilova, Sarka; Bunesova, Vera; Vlkova, Eva; Killer, Jiri; Mrazek, Jakub; Kmet, Vladimir; Svejstil, Roman

2014-11-17

Bifidobacterium bifidum is a bacterial species exclusively found in the human intestinal tract. This species is becoming increasingly popular as a probiotic organism added to lyophilized products. In this study, porcine mucin was used as the sole carbon source for the selective enumeration of B. bifidum in probiotic food additives. Thirty-six bifidobacterial strains were cultivated in broth with mucin. Only 13 strains of B. bifidum utilized the mucin to produce acids. B. bifidum was selectively enumerated in eight probiotic food supplements using agar (MM agar) containing mupirocin (100 mg/L) and mucin (20 g/L) as the sole carbon source. MM agar was fully selective if the B. bifidum species was presented together with Bifidobacterium animalis subsp. lactis, Bifidobacterium breve, and Bifidobacterium longum subsp. longum species and with lactic acid bacteria (lactobacilli, streptococci). Isolated strains of B. bifidum were identified using biochemical, PCR, MALDI-TOF procedures and 16S rRNA gene sequencing. The novel selective medium was also suitable for the isolation of B. bifidum strains from human fecal samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Purification and characteristics of a novel bacteriocin produced by Enterococcus faecalis L11 isolated from Chinese traditional fermented cucumber.

PubMed

Gao, Yurong; Li, Benling; Li, Dapeng; Zhang, Liyuan

2016-05-01

To purify and characterize a novel bacteriocin with broad inhibitory spectrum produced by an isolate of Enterococcus faecalis from Chinese fermented cucumber. E. faecalis L11 produced a bacteriocin with antimicrobial activity against both Escherichia coli and Staphylococcus aureus. The amino acid sequence of the purified bacteriocin, enterocin L11, was assayed by Edman degradation method. It differs from other class II bacteriocins and exhibited a broad antimicrobial activity against not only Gram-positive bacteria, including Bacillus subtilis, S. aureus, Listeria monocytogenes, Sarcina flava, Lactobacillus acidophilus, L. plantarum, L. delbrueckii subsp. delbrueckii, L. delbrueckii subsp. bulgaricus and Streptococcus thermophilus, but also some Gram-negative bacteria including Salmonella typhimurium, E. coli and Shigella flexneri. Enterocin L11 retained 91 % of its activity after holding at 121 °C for 30 min. It was also resistant to acids and alkalis. Enterocin L11 is a novel broad-spectrum Class II bacteriocin produced by E. faecalis L11, and may have potential as a food biopreservative.

Antilisterial Activity of Nisin-Like Bacteriocin-Producing Lactococcus lactis subsp. lactis Isolated from Traditional Sardinian Dairy Products

PubMed Central

Cosentino, Sofia; Fadda, Maria Elisabetta; Deplano, Maura; Melis, Roberta; Pomata, Rita; Pisano, Maria Barbara

2012-01-01

With the aim of selecting LAB strains with antilisterial activity to be used as protective cultures to enhance the safety of dairy products, the antimicrobial properties of 117 Lactococcus lactis subsp. lactis isolated from artisanal Sardinian dairy products were evaluated, and six strains were found to produce bacteriocin-like substances. The capacity of these strains to antagonize Listeria monocytogenes during cocultivation in skimmed milk was evaluated, showing a reduction of L. monocytogenes counts of approximately 4 log units compared to the positive control after 24 h of incubation. In order for a strain to be used as bioprotective culture, it should be carefully evaluated for the presence of virulence factors, to determine what potential risks might be involved in its use. None of the strains tested was found to produce biogenic amines or to possess haemolytic activity. In addition, all strains were sensitive to clinically important antibiotics such as ampicillin, tetracycline, and vancomycin. Our results suggest that these bac+ strains could be potentially applied in cheese manufacturing to control the growth of L. monocytogenes. PMID:22536018

The generalist Inga subnuda subsp. luschnathiana (Fabaceae): negative effect of floral visitors on reproductive success?

PubMed

Avila, R; Pinheiro, M; Sazima, M

2015-05-01

Inga species are characterised by generalist or mixed pollination system. However, this feature does not enhance reproductive rates in species with very low fruit set under natural conditions. Some ecological and genetic factors are associated with this feature, and to test the effect of massive visits on pollination success in Inga subnuda subsp. luschnathiana, we studied the efficacy of polyads deposited on stigmas of flowers isolated from visitors and polyads exposed to visitors. The proportion of polyads fixed in stigmas decreased after exposure to visitors (24 h) in comparison to stigmas isolated from visitors (hummingbirds, bees, wasps, hawkmoths and bats), and fruit set was very low. Furthermore, nectar production, sugar composition and other floral biology traits were evaluated. Increased nectar production, sugar availability and sucrose dominance during the night indicates adaptation to nocturnal visitors and supports their role as main pollinators; although the brush-flower morphology, time of anthesis, nectar dynamics and chemical composition also allow daytime visitors. Thus the species is an important resource for a diverse group of floral visitors. We conclude that excess visits (diurnal and nocturnal) are responsible for the decrease in fixed polyads in stigmas of I. subnuda subsp. luschnathiana flowers, thus contributing, with others factors, to its low fruit set. Therefore, the generalist pollination system does not result in reproductive advantages because the low fruit set in natural conditions could be the result of a negative effect of visitors/pollinators. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

Accessory genetic content in Campylobacter jejuni ST21CC isolates from feces and blood.

PubMed

Skarp, C P A; Akinrinade, O; Kaden, R; Johansson, C; Rautelin, H

2017-06-01

Campylobacter jejuni is an important foodborne pathogen and the most commonly reported bacterial cause of gastroenteritis. C. jejuni is occasionally found in blood, although mechanisms important for invasiveness have remained unclear. C. jejuni is divided into many different lineages, of which the ST21 clonal complex (CC) is widely distributed. Here, we performed comparative genomic and in vitro analyses on 17C. jejuni ST21CC strains derived from human blood and feces in order to identify features associated with isolation site. The ST21CC lineage is divided into two large groups; centered around ST-21 and ST-50. Our clinical strains, typed as ST-50, showed further microevolution into two distinct clusters. These clusters were distinguished by major differences in their capsule loci and the distribution of accessory genetic content, including C. jejuni integrated elements (CJIEs) and plasmids. Accessory genetic content was more common among fecal than blood strains, whereas blood strains contained a hybrid capsule locus which partially consisted of C. jejuni subsp. doylei-like content. In vitro infection assays with human colon cell lines did not show significant differences in adherence and invasion between the blood and fecal strains. Our results showed that CJIEs and plasmid derived genetic material were less common among blood isolates than fecal isolates; in contrast, hybrid capsule loci, especially those containing C. jejuni subsp. doylei-like gene content, were found among many isolates derived from blood. The role of these findings requires more detailed investigation. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Efficacy of Daphne oleoides subsp. kurdica used for wound healing: identification of active compounds through bioassay guided isolation technique.

PubMed

Süntar, Ipek; Küpeli Akkol, Esra; Keles, Hikmet; Yesilada, Erdem; Sarker, Satyajit D; Arroo, Randolph; Baykal, Turhan

2012-06-14

In Turkish traditional medicine, the aerial parts of Daphne oleoides Schreber subsp. kurdica (DOK) have been used to treat malaria, rheumatism and for wound healing. The aim was to evaluate the ethnopharmacological usage of the plant using in vivo and in vitro pharmacological experimental models, and to perform bioassay-guided fractionation of the 85% methanolic extract of DOK for the isolation and identification of active wound-healing component(s) and to elucidate possible mechanism of the wound-healing activity. In vivo wound-healing activity was evaluated by the linear incision and the circular excision wound models. Anti-inflammatory and antioxidant activities, which are known to support the wound healing process, were also assessed by the Whittle method and the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging assays, respectively. The total phenolic content of the extract and subextracts was estimated to establish any correlation between the phenolic content and the antioxidant activity. The methanolic extract of DOK was subjected to various chromatographic separation techniques leading to the isolation and identification of the active component(s). Furthermore, in vitro hyaluronidase, collagenase and elastase enzymes inhibitory activity assays were conducted on the active components to explore the activity pathways of the remedy. After confirmation of the wound-healing activity, the methanolic extract was subjected to successive solvent partitioning using solvents of increasing polarity creating five subextracts. Each subextract was tested on the same biological activity model and the ethyl acetate (EtOAc) subextract had the highest activity. The EtOAc subextract was subjected to further chromatographic separation for the isolation of components 1, 2 and 3. The structures of these compounds were elucidated as daphnetin (1), demethyldaphnoretin 7-O-glucoside (2) and luteolin-7-O-glucoside (3). Further in vivo testing revealed that luteolin-7-O-glucoside was responsible for the wound-healing activity of the aerial parts. It was also found to exert significant anti-inflammatory, antioxidant, anti-hyaluronidase and anti-collagenase activities. The present study explored the wound-healing potential of Daphne oleoides subsp. kurdica. Through bioassay-guided fractionation and isolation techniques, luteolin-7-O-glucoside was determined as the main active component of the aerial parts. This compound exerts its activity through inhibition of hyaluronidase and collagenase enzymes activity as well as interfering with the inflammatory stage. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Complete genome sequences of two strains of Treponema pallidum subsp. pertenue from Ghana, Africa: Identical genome sequences in samples isolated more than 7 years apart.

PubMed

Strouhal, Michal; Mikalová, Lenka; Havlíčková, Pavla; Tenti, Paolo; Čejková, Darina; Rychlík, Ivan; Bruisten, Sylvia; Šmajs, David

2017-09-01

Treponema pallidum subsp. pertenue (TPE) is the causative agent of yaws, a multi-stage disease, endemic in tropical regions of Africa, Asia, Oceania, and South America. To date, four TPE strains have been completely sequenced including three TPE strains of human origin (Samoa D, CDC-2, and Gauthier) and one TPE strain (Fribourg-Blanc) isolated from a baboon. All TPE strains are highly similar to T. pallidum subsp. pallidum (TPA) strains. The mutation rate in syphilis and related treponemes has not been experimentally determined yet. Complete genomes of two TPE strains, CDC 2575 and Ghana-051, that infected patients in Ghana and were isolated in 1980 and 1988, respectively, were sequenced and analyzed. Both strains had identical consensus genome nucleotide sequences raising the question whether TPE CDC 2575 and Ghana-051 represent two different strains. Several lines of evidence support the fact that both strains represent independent samples including regions showing intrastrain heterogeneity (13 and 5 intrastrain heterogeneous sites in TPE Ghana-051 and TPE CDC 2575, respectively). Four of these heterogeneous sites were found in both genomes but the frequency of alternative alleles differed. The identical consensus genome sequences were used to estimate the upper limit of the yaws treponeme evolution rate, which was 4.1 x 10-10 nucleotide changes per site per generation. The estimated upper limit for the mutation rate of TPE was slightly lower than the mutation rate of E. coli, which was determined during a long-term experiment. Given the known diversity between TPA and TPE genomes and the assumption that both TPA and TPE have a similar mutation rate, the most recent common ancestor of syphilis and yaws treponemes appears to be more than ten thousand years old and likely even older.

Stability and Activities of Antibiotics Produced during Infection of the Insect Galleria mellonella by Two Isolates of Xenorhabdus nematophilus

PubMed Central

Maxwell, Philip W.; Chen, Genhui; Webster, John M.; Dunphy, Gary B.

1994-01-01

Xenorhabdus nematophilus subsp. dutki, an entomopathogenic bacterium, is vectored by steinernematid nematodes into insects, where it produces broad-spectrum antibiotics. The use of the nematode-bacterium complex against soil-dwelling pest insects could introduce antibiotics into the soil via the dead insect fragments during the emergence phase of the nematodes. Studies on the stability and activities of these antibiotics produced in the insect Galleria mellonella may contribute to assessing the possible impact of antibiotics on soil bacteria. Two isolates of X. nematophilus subsp. dutki (isolates GI and SFU) produced xenocoumacins 1 and 2 in cadavers of G. mellonella larvae in a 1:1 ratio. Total xenocoumacin 1 and 2 production was 800 ng/200 mg (wet weight) of insect tissue for the GI isolate. Antibiotic activity of water extracts from insects that had been infected with X. nematophilus was stable at 60°C for 1 h and after repeated freeze-thaw cycles. The antibiotic titer of extracts held at 27°C declined by day 10. The spectrum of bacterial species killed by antibiotics produced in insect cadavers varied with the isolate of X. nematophilus. Levels of antibiotic activity were greater in vivo than in tryptic soy broth, which may represent a nutrient effect. The bacterial isolate, culture condition, and presence of nematodes influenced the total antibiotic production in vivo. However, the levels of activity were not correlated with bacterial levels in the different growth environments. Insect cadavers with antibiotic activity transiently lowered the numbers of the bacteria in the soil, the extent of decline varying with the strain of X. nematophilus and the time of sampling. PMID:16349198

Licheniocin 50.2 and Bacteriocins from Lactococcus lactis subsp. lactis biovar. diacetylactis BGBU1-4 Inhibit Biofilms of Coagulase Negative Staphylococci and Listeria monocytogenes Clinical Isolates.

PubMed

Cirkovic, Ivana; Bozic, Dragana D; Draganic, Veselin; Lozo, Jelena; Beric, Tanja; Kojic, Milan; Arsic, Biljana; Garalejic, Eliana; Djukic, Slobodanka; Stankovic, Slavisa

2016-01-01

Coagulase negative staphylococci (CoNS) and Listeria monocytogenes have important roles in pathogenesis of various genital tract infections and fatal foetomaternal infections, respectively. The aim of our study was to investigate the inhibitory effects of two novel bacteriocins on biofilms of CoNS and L. monocytogenes genital isolates. The effects of licheniocin 50.2 from Bacillus licheniformis VPS50.2 and crude extract of bacteriocins produced by Lactococcus lactis subsp. lactis biovar. diacetylactis BGBU1-4 (BGBU1-4 crude extract) were evaluated on biofilm formation and formed biofilms of eight CoNS (four S. epidermidis, two S. hominis, one S. lugdunensis and one S. haemolyticus) and 12 L. monocytogenes genital isolates. Licheniocin 50.2 and BGBU1-4 crude extract inhibited the growth of both CoNS and L. monocytogenes isolates, with MIC values in the range between 200-400 AU/ml for licheniocin 50.2 and 400-3200 AU/ml for BGBU1-4 crude extract. Subinhibitory concentrations (1/2 × and 1/4 × MIC) of licheniocin 50.2 inhibited biofilm formation by all CoNS isolates (p < 0.05, respectively), while BGBU1-4 crude extract inhibited biofilm formation by all L. monocytogenes isolates (p < 0.01 and p < 0.05, respectively). Both bacteriocins in concentrations of 100 AU/mL and 200 AU/mL reduced the amount of 24 h old CoNS and L. monocytogenes biofilms (p < 0.05, p < 0.01, p < 0.001). This study suggests that novel bacteriocins have potential to be used for genital application, to prevent biofilm formation and/or to eradicate formed biofilms, and consequently reduce genital and neonatal infections by CoNS and L. monocytogenes.

Prevalence of Complement-Mediated Cell Lysis-like Gene (sicG) in Streptococcus dysgalactiae subsp. equisimilis Isolates From Japan (2014-2016).

PubMed

Takahashi, Takashi; Fujita, Tomohiro; Shibayama, Akiyoshi; Tsuyuki, Yuzo; Yoshida, Haruno

2017-07-01

Streptococcus dysgalactiae subsp. equisimilis (SDSE; a β-hemolytic streptococcus of human or animal origin) infections are emerging worldwide. We evaluated the clonal distribution of complement-mediated cell lysis-like gene (sicG) among SDSE isolates from three central prefectures of Japan. Group G/C β-hemolytic streptococci were collected from three institutions from April 2014 to March 2016. Fifty-five strains (52 from humans and three from animals) were identified as SDSE on the basis of 16S rRNA sequencing data.; they were obtained from 25 sterile (blood, joint fluid, and cerebrospinal fluid) and 30 non-sterile (skin-, respiratory tract-, and genitourinary tract-origin) samples. emm genotyping, multilocus sequence typing, sicG amplification/sequencing, and random amplified polymorphic DNA (RAPD) analysis of sicG-positive strains were performed. sicG was detected in 30.9% of the isolates (16 human and one canine) and the genes from the 16 human samples (blood, 10; open pus, 3; sputum, 2; throat swab, 1) and one canine sample (open pus) showed the same sequence pattern. All sicG-harboring isolates belonged to clonal complex (CC) 17, and the most prevalent emm type was stG6792 (82.4%). There was a significant association between sicG presence and the development of skin/soft tissue infections. CC17 isolates with sicG could be divided into three subtypes by RAPD analysis. CC17 SDSE harboring sicG might have spread into three closely-related prefectures in central Japan during 2014-2016. Clonal analysis of isolates from other areas might be needed to monitor potentially virulent strains in humans and animals. © The Korean Society for Laboratory Medicine

Tularaemia in European Brown Hares (Lepus europaeus) and Mountain Hares (Lepus timidus) Characterized by Histopathology and Immunohistochemistry: Organ Lesions and Suggestions of Routes of Infection and Shedding.

PubMed

Hestvik, G; Uhlhorn, H; Södersten, F; Åkerström, S; Karlsson, E; Westergren, E; Gavier-Widén, D

Tularaemia is an emerging zoonotic infectious disease caused by the bacterium Francisella tularensis. In Sweden, hares are considered to be key species in the epidemiology of tularaemia. The aim of this study was to characterize the pathology of natural tularaemia infection in European brown hares (EBHs) (Lepus europaeus) and mountain hares (MHs) (Lepus timidus) in Sweden, in order to better understand the presentation of disease and the routes of infection, body dissemination and shedding of F. tularensis. During 2000-2013, 49 EBHs and 37 MHs were diagnosed with tularaemia. Enlargement of the spleen was seen in 80% of EBHs and 62% of MHs. Necrosis was often obvious in the bone marrow, liver, lung and spleen, but 30% of the hares had no lesions or minimal gross lesions. On microscopical examination of tissues from 27 EBHs and three MHs, necrosis was seen in the majority of samples of liver, spleen, bone marrow, lymph node and adrenal glands and was common in the lungs and brain meninges. Immunohistochemistry for Francisella spp. detected bacteria in association with necrosis and inflammation. In several cases, Francisella spp. were also found inside blood vessels, in the renal pelvis, in lactating mammary glands, in bronchioles and in the skin, associated with tick bites. Using quantitative polymerase chain reaction, two genotypes of F. tularensis subsp. holarctica were found; canSNP group B.6, all belonging to subgroup B.7, and canSNP group B.12. There were no differences in pathology between the genotypes. Our results indicate that the urinary tract and mammary glands are important routes for the shedding of F. tularensis. Hunters may not be aware of the risks of contracting tularaemia while handling hares, since infected hares do not always show noticeable gross lesions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Resistance of Francisella Novicida to Fosmidomycin Associated with Mutations in the Glycerol-3-Phosphate Transporter

PubMed Central

Mackie, Ryan S.; McKenney, Elizabeth S.; van Hoek, Monique L.

2012-01-01

The methylerythritol phosphate (MEP) pathway is essential in most prokaryotes and some lower eukaryotes but absent from human cells, and is a validated target for antimicrobial drug development. The formation of MEP is catalyzed by 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR). MEP pathway genes have been identified in many category A and B biothreat agents, including Francisella tularensis, which causes the zoonosis tularemia. Fosmidomycin (Fos) inhibits purified Francisella DXR. This compound also inhibits the growth of F. tularensis NIH B38, F. novicida and F. tularensis subsp. holarctica LVS bacteria. Related compounds such as FR900098 and the lipophilic prodrug of FR900098 (compound 1) have been developed to improve the bioavailability of these DXR inhibitors. In performing disk-inhibition assays with these compounds, we observed breakthrough colonies of F. novicida in the presence of Fos, suggesting spontaneous development of Fos resistance (FosR). FosR bacteria had decreased sensitivity to both Fos and FR900098. The two most likely targets for the development of mutants would be the DXR enzyme itself or the glycerol-3-phosphate transporter (GlpT) that allows entry of Fos into the bacteria. Sensitivity of FosR F. novicida bacteria to compound 1 was not abated suggesting that spontaneous resistance is not due to mutation of DXR. We thus predicted that the glpT transporter may be mutated leading to this resistant phenotype. Supporting this, transposon insertion mutants at the glpT locus were also found to be resistant to Fos. DNA sequencing of four different spontaneous FosR colonies demonstrated a variety of deletions in the glpT coding region. The overall frequency of FosR mutations in F. novicida was determined to be 6.3 × 10−8. Thus we conclude that one mechanism of resistance of F. novicida to Fos is caused by mutations in GlpT. This is the first description of spontaneous mutations in Francisella leading to FosR. PMID:22905031

Molecular Characterization of Three Lactobacillus delbrueckii subsp. bulgaricus Phages

PubMed Central

Casey, Eoghan; Mahony, Jennifer; O'Connell-Motherway, Mary; Bottacini, Francesca; Cornelissen, Anneleen; Neve, Horst; Heller, Knut J.; Noben, Jean-Paul; Dal Bello, Fabio

2014-01-01

In this study, three phages infecting Lactobacillus delbrueckii subsp. bulgaricus, named Ld3, Ld17, and Ld25A, were isolated from whey samples obtained from various industrial fermentations. These phages were further characterized in a multifaceted approach: (i) biological and physical characterization through host range analysis and electron microscopy; (ii) genetic assessment through genome analysis; (iii) mass spectrometry analysis of the structural components of the phages; and (iv), for one phage, transcriptional analysis by Northern hybridization, reverse transcription-PCR, and primer extension. The three obtained phage genomes display high levels of sequence identity to each other and to genomes of the so-called group b L. delbrueckii phages c5, LL-Ku, and phiLdb, where some of the observed differences are believed to be responsible for host range variations. PMID:25002431

The genome sequence of Bifidobacterium longum subsp. infantis reveals adaptations for milk utilization within the infant microbiome

PubMed Central

Sela, D. A.; Chapman, J.; Adeuya, A.; Kim, J. H.; Chen, F.; Whitehead, T. R.; Lapidus, A.; Rokhsar, D. S.; Lebrilla, C. B.; German, J. B.; Price, N. P.; Richardson, P. M.; Mills, D. A.

2008-01-01

Following birth, the breast-fed infant gastrointestinal tract is rapidly colonized by a microbial consortium often dominated by bifidobacteria. Accordingly, the complete genome sequence of Bifidobacterium longum subsp. infantis ATCC15697 reflects a competitive nutrient-utilization strategy targeting milk-borne molecules which lack a nutritive value to the neonate. Several chromosomal loci reflect potential adaptation to the infant host including a 43 kbp cluster encoding catabolic genes, extracellular solute binding proteins and permeases predicted to be active on milk oligosaccharides. An examination of in vivo metabolism has detected the hallmarks of milk oligosaccharide utilization via the central fermentative pathway using metabolomic and proteomic approaches. Finally, conservation of gene clusters in multiple isolates corroborates the genomic mechanism underlying milk utilization for this infant-associated phylotype. PMID:19033196

Antimicrobial Resistance and Molecular Investigation of H2S-Negative Salmonella enterica subsp. enterica serovar Choleraesuis Isolates in China.

PubMed

Xie, Jing; Yi, Shengjie; Zhu, Jiangong; Li, Peng; Liang, Beibei; Li, Hao; Yang, Xiaoxia; Wang, Ligui; Hao, Rongzhang; Jia, Leili; Wu, Zhihao; Qiu, Shaofu; Song, Hongbin

2015-01-01

Salmonella enterica subsp. enterica serovar Choleraesuis is a highly invasive pathogen of swine that frequently causes serious outbreaks, in particular in Asia, and can also cause severe invasive disease in humans. In this study, 21 S. Choleraesuis isolates, detected from 21 patients with diarrhea in China between 2010 and 2011, were found to include 19 H2S-negative S. Choleraesuis isolates and two H2S-positive isolates. This is the first report of H2S-negative S. Choleraesuis isolated from humans. The majority of H2S-negative isolates exhibited high resistance to ampicillin, chloramphenicol, gentamicin, tetracycline, ticarcillin, and trimethoprim-sulfamethoxazole, but only six isolates were resistant to norfloxacin. In contrast, all of the isolates were sensitive to cephalosporins. Fifteen isolates were found to be multidrug resistant. In norfloxacin-resistant isolates, we detected mutations in the gyrA and parC genes and identified two new mutations in the parC gene. Pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and clustered regularly interspaced short palindromic repeat (CRISPR) analysis were employed to investigate the genetic relatedness of H2S-negative and H2S-positive S. Choleraesuis isolates. PFGE revealed two groups, with all 19 H2S-negative S. Choleraesuis isolates belonging to Group I and H2S-positive isolates belonging to Group II. By MLST analysis, the H2S-negative isolates were all found to belong to ST68 and H2S-positive isolates belong to ST145. By CRISPR analysis, no significant differences in CRISPR 1 were detected; however, one H2S-negative isolate was found to contain three new spacers in CRISPR 2. All 19 H2S-negative isolates also possessed a frame-shift mutation at position 760 of phsA gene compared with H2S-positive isolates, which may be responsible for the H2S-negative phenotype. Moreover, the 19 H2S-negative isolates have similar PFGE patterns and same mutation site in the phsA gene, these results indicated that these H2S-negative isolates may have been prevalent in China. These findings suggested that surveillance should be increased of H2S-negative S. Choleraesuis in China.

Antimicrobial Resistance and Molecular Investigation of H2S-Negative Salmonella enterica subsp. enterica serovar Choleraesuis Isolates in China

PubMed Central

Li, Peng; Liang, Beibei; Li, Hao; Yang, Xiaoxia; Wang, Ligui; Hao, Rongzhang; Jia, Leili; Wu, Zhihao; Qiu, Shaofu; Song, Hongbin

2015-01-01

Salmonella enterica subsp. enterica serovar Choleraesuis is a highly invasive pathogen of swine that frequently causes serious outbreaks, in particular in Asia, and can also cause severe invasive disease in humans. In this study, 21 S. Choleraesuis isolates, detected from 21 patients with diarrhea in China between 2010 and 2011, were found to include 19 H2S-negative S. Choleraesuis isolates and two H2S-positive isolates. This is the first report of H2S-negative S. Choleraesuis isolated from humans. The majority of H2S-negative isolates exhibited high resistance to ampicillin, chloramphenicol, gentamicin, tetracycline, ticarcillin, and trimethoprim-sulfamethoxazole, but only six isolates were resistant to norfloxacin. In contrast, all of the isolates were sensitive to cephalosporins. Fifteen isolates were found to be multidrug resistant. In norfloxacin-resistant isolates, we detected mutations in the gyrA and parC genes and identified two new mutations in the parC gene. Pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and clustered regularly interspaced short palindromic repeat (CRISPR) analysis were employed to investigate the genetic relatedness of H2S-negative and H2S-positive S. Choleraesuis isolates. PFGE revealed two groups, with all 19 H2S-negative S. Choleraesuis isolates belonging to Group I and H2S-positive isolates belonging to Group II. By MLST analysis, the H2S-negative isolates were all found to belong to ST68 and H2S-positive isolates belong to ST145. By CRISPR analysis, no significant differences in CRISPR 1 were detected; however, one H2S-negative isolate was found to contain three new spacers in CRISPR 2. All 19 H2S-negative isolates also possessed a frame-shift mutation at position 760 of phsA gene compared with H2S-positive isolates, which may be responsible for the H2S-negative phenotype. Moreover, the 19 H2S-negative isolates have similar PFGE patterns and same mutation site in the phsA gene, these results indicated that these H2S-negative isolates may have been prevalent in China. These findings suggested that surveillance should be increased of H2S-negative S. Choleraesuis in China. PMID:26431037

Continuous D-lactic acid production by a novel thermotolerant Lactobacillus delbrueckii subsp. lactis QU 41.

PubMed

Tashiro, Yukihiro; Kaneko, Wataru; Sun, Yanqi; Shibata, Keisuke; Inokuma, Kentaro; Zendo, Takeshi; Sonomoto, Kenji

2011-03-01

We isolated and characterized a D-lactic acid-producing lactic acid bacterium (D-LAB), identified as Lactobacillus delbrueckii subsp. lactis QU 41. When compared to Lactobacillus coryniformis subsp. torquens JCM 1166 (T) and L. delbrueckii subsp. lactis JCM 1248 (T), which are also known as D-LAB, the QU 41 strain exhibited a high thermotolerance and produced D-lactic acid at temperatures of 50 °C and higher. In order to optimize the culture conditions of the QU 41 strain, we examined the effects of pH control, temperature, neutralizing reagent, and initial glucose concentration on D-lactic acid production in batch cultures. It was found that the optimal production of 20.1 g/l D-lactic acid was acquired with high optical purity (>99.9% of D-lactic acid) in a pH 6.0-controlled batch culture, by adding ammonium hydroxide as a neutralizing reagent, at 43 °C in MRS medium containing 20 g/l glucose. As a result of product inhibition and low cell density, continuous cultures were investigated using a microfiltration membrane module to recycle flow-through cells in order to improve D-lactic acid productivity. At a dilution rate of 0.87 h(-1), the high cell density continuous culture exhibited the highest D-lactic acid productivity of 18.0 g/l/h with a high yield (ca. 1.0 g/g consumed glucose) and a low residual glucose (<0.1 g/l) in comparison with systems published to date.

Immune Regulatory Effect of Newly Isolated Lactobacillus delbrueckii from Indian Traditional Yogurt.

PubMed

Hong, Yi-Fan; Lee, Yoon-Doo; Park, Jae-Yeon; Jeon, Boram; Jagdish, Deepa; Jang, Soojin; Chung, Dae Kyun; Kim, Hangeun

2015-08-01

Lactic acid bacteria (LAB) are microorganisms that are believed to provide health benefits. Here, we isolated LAB from Indian fermented foods, such as traditional Yogurt and Dosa. LAB from Yogurt most significantly induced TNF-α and IL-1β production, whereas LAB from Dosa induced mild cytokine production. After 16S rRNA gene sequencing and phylogenetic analysis, a Yogurt-borne lactic acid bacterium was identified and classified as Lactobacillus delbrueckii subsp. bulgaricus, and it was renamed L. delbrueckii K552 for the further studies. Our data suggest that the newly isolated L. delbrueckii can be used for the treatment of immune deficiency disorders.

Use of Taiwanese ropy fermented milk (TRFM) and Lactococcus lactis subsp. cremoris isolated from TRFM in manufacturing of functional low-fat cheeses.

PubMed

Chiang, Ming-Lun; Chen, Hsi-Chia; Wang, Sheng-Yao; Hsieh, Yueh-Ling; Chen, Ming-Ju

2011-09-01

The purpose of this study was to manufacture new functional low-fat cheeses using Taiwanese ropy fermented milk (TRFM) and Lactococcus lactis subsp. cremoris strains isolated from TRFM. After 28 d of ripening and storage, the viable populations of lactic acid bacteria (LAB) in the low-fat cheeses made with L. lactis subsp. cremoris TL1 (TL1), L. lactis subsp. cremoris TL4 (TL4), and TRFM still maintained above 10(8) CFU/g. The low-fat cheeses made with TL1 and TRFM showed higher moisture contents than the cheeses made with TL4, full-fat, and low-fat cheese controls. The low-fat cheeses made with TL1 and TL4 had higher customer preferential scores similar to full-fat cheese control in the sensory evaluation. Additionally, the low-fat cheeses fermented with TL1, TL4, and TRFM for 4 h had higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging and ferrous ion-chelating abilities than the cheeses fermented with the starters for 8 h, full-fat, and low-fat cheese controls. A better angiotensin-converting enzyme (ACE) inhibition activity was also observed in the low-fat cheeses made with TL1, TL4, and TRFM than that in the full-fat and low-fat cheese controls during ripening and storage period. As health-conscious consumers continue to seek low-fat alternatives in their diets, there remain strong interests for the dairy industry to develop low-fat cheeses to meet the demands. This study clearly demonstrated that the low-fat cheeses fermented with TL1 for 4 h showed a better overall acceptability and possessed antioxidative abilities and ACE inhibitory activities than other cheeses tested in this study. By improving its flavor and investigating the possible mechanisms of its functionalities in the future, this low-fat cheese might possibly be commercialized and give a positive impact on cheese consumption in the future. © 2011 Institute of Food Technologists®

Avian cholera in Southern Great Petrel (Macronectes giganteus) from Antarctica

USGS Publications Warehouse

Leotta, G.A.; Rivas, M.; Chinen, I.; Vigo, G.B.; Moredo, F.A.; Coria, N.; Wolcott, M.J.

2003-01-01

A southern giant petrel (Macronectes giganteus) was found dead at Potter Peninsula, King George Island, South Shetland, Antarctica. The adult male was discovered approximately 48 hr after death. Macroscopic and microscopic lesions were compatible with avian cholera and the bacterium Pasteurella multocida subsp. gallicida, serotype A1 was isolated from lung, heart, liver, pericardial sac, and air sacs. In addition, Escherichia coli was isolated from pericardial sac and air sacs. This is the first known report of avian cholera in a southern giant petrel in Antarctica.

Limitations of variable number of tandem repeat typing identified through whole genome sequencing of Mycobacterium avium subsp. paratuberculosis on a national and herd level.

PubMed

Ahlstrom, Christina; Barkema, Herman W; Stevenson, Karen; Zadoks, Ruth N; Biek, Roman; Kao, Rowland; Trewby, Hannah; Haupstein, Deb; Kelton, David F; Fecteau, Gilles; Labrecque, Olivia; Keefe, Greg P; McKenna, Shawn L B; De Buck, Jeroen

2015-03-08

Mycobacterium avium subsp. paratuberculosis (MAP), the causative bacterium of Johne's disease in dairy cattle, is widespread in the Canadian dairy industry and has significant economic and animal welfare implications. An understanding of the population dynamics of MAP can be used to identify introduction events, improve control efforts and target transmission pathways, although this requires an adequate understanding of MAP diversity and distribution between herds and across the country. Whole genome sequencing (WGS) offers a detailed assessment of the SNP-level diversity and genetic relationship of isolates, whereas several molecular typing techniques used to investigate the molecular epidemiology of MAP, such as variable number of tandem repeat (VNTR) typing, target relatively unstable repetitive elements in the genome that may be too unpredictable to draw accurate conclusions. The objective of this study was to evaluate the diversity of bovine MAP isolates in Canadian dairy herds using WGS and then determine if VNTR typing can distinguish truly related and unrelated isolates. Phylogenetic analysis based on 3,039 SNPs identified through WGS of 124 MAP isolates identified eight genetically distinct subtypes in dairy herds from seven Canadian provinces, with the dominant type including over 80% of MAP isolates. VNTR typing of 527 MAP isolates identified 12 types, including "bison type" isolates, from seven different herds. At a national level, MAP isolates differed from each other by 1-2 to 239-240 SNPs, regardless of whether they belonged to the same or different VNTR types. A herd-level analysis of MAP isolates demonstrated that VNTR typing may both over-estimate and under-estimate the relatedness of MAP isolates found within a single herd. The presence of multiple MAP subtypes in Canada suggests multiple introductions into the country including what has now become one dominant type, an important finding for Johne's disease control. VNTR typing often failed to identify closely and distantly related isolates, limiting the applicability of using this typing scheme to study the molecular epidemiology of MAP at a national and herd-level.

Isolation and characterization of a new CO-utilizing strain, Thermoanaerobacter thermohydrosulfuricus subsp. carboxydovorans, isolated from a geothermal spring in Turkey.

PubMed

Balk, Melike; Heilig, Hans G H J; van Eekert, Miriam H A; Stams, Alfons J M; Rijpstra, Irene C; Sinninghe-Damsté, Jaap S; de Vos, Willem M; Kengen, Servé W M

2009-11-01

A novel anaerobic, thermophilic, Gram-positive, spore-forming, and sugar-fermenting bacterium (strain TLO) was isolated from a geothermal spring in Ayaş, Turkey. The cells were straight to curved rods, 0.4-0.6 microm in diameter and 3.5-10 microm in length. Spores were terminal and round. The temperature range for growth was 40-80 degrees C, with an optimum at 70 degrees C. The pH optimum was between 6.3 and 6.8. Strain TLO has the capability to ferment a wide variety of mono-, di-, and polysaccharides and proteinaceous substrates, producing mainly lactate, next to acetate, ethanol, alanine, H(2), and CO(2). Remarkably, the bacterium was able to grow in an atmosphere of up to 25% of CO as sole electron donor. CO oxidation was coupled to H(2) and CO(2) formation. The G + C content of the genomic DNA was 35.1 mol%. Based on 16S rRNA gene sequence analysis and the DNA-DNA hybridization data, this bacterium is most closely related to Thermoanaerobacter thermohydrosulfuricus and Thermoanaerobacter siderophilus (99% similarity for both). However, strain TLO differs from Thermoanaerobacter thermohydrosulfuricus in important aspects, such as CO-utilization and lipid composition. These differences led us to propose that strain TLO represents a subspecies of Thermoanaerobacter thermohydrosulfuricus, and we therefore name it Thermoanaerobacter thermohydrosulfuricus subsp. carboxydovorans.

Outbreak of reproductive disorders and mycobacteriosis in swine associated with a single strain of Mycobacterium avium subspecies hominissuis.

PubMed

Eisenberg, T; Volmer, R; Eskens, U; Moser, I; Nesseler, A; Sauerwald, C; Seeger, H; Klewer-Fromentin, K; Möbius, P

2012-09-14

In a breeding and fattening pig farm an increasing number of cases of abortion and generalized mycobacteriosis at slaughter occurred. Pathological findings compatible with mycobacteriosis, acid-fast organisms in tissues, and isolation of mycobacteria from tissue samples including fetuses, lungs and reproductive organs from sows, genital swabs, mesenteric lymph nodes, and from a sperm sample revealed the cause of the disease. Bacterial cultures were identified as Mycobacterium avium subsp. hominissuis using IS901-/IS1245-specific PCR. Genotyping of selected isolates from animals as well as from their environment by MIRU-VNTR analysis showed that the herd was infected with one single outbreak strain. The same genotype was also isolated from pigs of two other farms which showed comparable symptoms and were in direct contact with the index farm as well as from their environment. Immunological host responses detected by tuberculin skin test and ELISA gave positive results at herd level only. Despite the detection of other potential pathogens mycobacteria were regarded as the causative agent of the reproductive disorders. To our knowledge this is the first report of an epidemic mycobacterial infection in a pig holding associated with reproductive disorders, which could be attributed to one single virulent strain, and the first report of detection of M. avium subsp. hominissuis in pig sperm. Copyright © 2012 Elsevier B.V. All rights reserved.

Molecular characterization and antibiotic resistance of clinical Streptococcus dysgalactiae subsp. equisimilis in Beijing, China.

PubMed

Lu, Binghuai; Fang, Yujie; Huang, Lei; Diao, Baowei; Du, Xiaoli; Kan, Biao; Cui, Yanchao; Zhu, Fengxia; Li, Dong; Wang, Duochun

2016-06-01

Streptococcus dysgalactiae subsp. equisimilis (SDSE) is presently considered as a human pathogen associated with clinical infection. We characterized 56 SDSE isolates collected from two tertiary hospitals in Beijing, China. Sixteen distinct emm types/subtypes were detected, dominated by stG245.0 (32.1%), stG652.0 (10.7%), stG6.1 (10.7%) and stG485.0 (10.7%), and a novel stG840.0 variant type was identified. All isolates possessed virulence genes of sagA and scpA, and most carried slo (98.2%), ska (98.2%) and speG(dys) (35.7%). By multilocus sequence typing (MLST) analysis, 17 individual sequence types (STs) were distinguished, including 7 newly-identified STs (26.8% of isolates), of which ST127 (30.4%), ST7 (12.5%) and ST44 (10.7%) dominated. Meanwhile, pulsed-field gel electrophoresis (PFGE) analysis revealed 33 pattern types (PTs), which were further combined into 16 pattern clusters (PCs), and 59.3% of isolates were distributed into 2 dominant PCs. Notably, emm types had both close relationship and consistency with STs and PFGE PCs. Furthermore, of 56 SDSE isolates, the predominant antibiotic resistances were erythromycin (71.4%), clindamycin (71.4%) and tetracycline (60.7%). Correspondingly, the prevalent resistance genes of macrolide and tetracycline were erm(B) (78.6%) and tet(M) (73.2%). In addition, multiple point mutations of parC, one of fluoroquinolone resistance genes, were observed (accounting for 75%), and were divided into 12 types, with parC 07 as the predominant type. Our data suggested the wide molecular diversity and distinctive regional features of SDSE from clinical infection in Beijing, China. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantitative analyses of the bacterial microbiota of rearing environment, tilapia and common carp cultured in earthen ponds and inhibitory activity of its lactic acid bacteria on fish spoilage and pathogenic bacteria.

PubMed

Kaktcham, Pierre Marie; Temgoua, Jules-Bocamdé; Ngoufack Zambou, François; Diaz-Ruiz, Gloria; Wacher, Carmen; Pérez-Chabela, María de Lourdes

2017-02-01

The present study aimed to evaluate the bacterial load of water, Nile Tilapia and common Carp intestines from earthen ponds, isolate lactic acid bacteria (LAB) and assess their antimicrobial activity against fish spoilage and pathogenic bacteria. Following enumeration and isolation of microorganisms the antimicrobial activity of the LAB isolates was evaluated. Taxonomic identification of selected antagonistic LAB strains was assessed, followed by partial characterisation of their antimicrobial metabolites. Results showed that high counts (>4 log c.f.u ml -1 or 8 log c.f.u g -1 ) of total aerobic bacteria were recorded in pond waters and fish intestines. The microbiota were also found to be dominated by Salmonella spp., Vibrio spp., Staphylococcus spp. and Escherichia coli. LAB isolates (5.60%) exhibited potent direct and extracellular antimicrobial activity against the host-derived and non host-derived spoilage and pathogenic bacteria. These antagonistic isolates were identified and Lactococcus lactis subsp. lactis was found as the predominant (42.85%) specie. The strains displayed the ability to produce lactic, acetic, butyric, propionic and valeric acids. Bacteriocin-like inhibitory substances with activity against Gram-positive and Gram-negative (Vibrio spp. and Pseudomonas aeruginosa) bacteria were produced by three L. lactis subsp. lactis strains. In this study, the LAB from the microbiota of fish and pond water showed potent antimicrobial activity against fish spoilage or pathogenic bacteria from the same host or ecological niche. The studied Cameroonian aquatic niche is an ideal source of antagonistic LAB that could be appropriate as new fish biopreservatives or disease control agents in aquaculture under tropical conditions in particular or worldwide in general.

Molecular characterization of invasive Streptococcus dysgalactiae subsp. equisimilis. Multicenter study: Argentina 2011-2012.

PubMed

Traverso, Fernando; Blanco, Alejandra; Villalón, Pilar; Beratz, Noelia; Sáez Nieto, Juan Antonio; Lopardo, Horacio

Streptococcus dysgalactiae subsp. equisimilis (SDSE) has virulence factors similar to those of Streptococcus pyogenes. Therefore, it causes pharyngitis and severe infections indistinguishable from those caused by the classic pathogen. The objectives of this study were: to know the prevalence of SDSE invasive infections in Argentina, to study the genetic diversity, to determine the presence of virulence genes, to study antibiotic susceptibility and to detect antibiotic resistance genes. Conventional methods of identification were used. Antibiotic susceptibility was determined by the disk diffusion and the agar dilution methods and the E-test. Twenty eight centers from 16 Argentinean cities participated in the study. Twenty three isolates (16 group G and 7 group C) were obtained between July 1 2011 and June 30 2012. Two adult patients died (8.7%). Most of the isolates were recovered from blood (60.9%). All isolates carried speJ and ssa genes. stG62647, stG653 and stG840 were the most frequent emm types. Nineteen different PFGE patterns were detected. All isolates were susceptible to penicillin and levofloxacin, 6 (26.1%) showed resistance or reduced susceptibility to erythromycin [1 mef(A), 3 erm(TR), 1 mef(A)+erm(TR) and 1 erm(TR)+erm(B)] and 7 (30.4%) were resistant or exhibited reduced susceptibility to tetracycline [2 tet(M), 5 tet(M)+tet(O)]. The prevalence in Argentina was of at least 23 invasive infections by SDSE. A wide genetic diversity was observed. All isolates carried speJ and ssa genes. Similarly to other studies, macrolide resistance (26.1%) was mainly associated to the MLS B phenotype. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Variable Number of Tandem Repeats in Salmonella enterica subsp. enterica for Typing Purposes

PubMed Central

Ramisse, Vincent; Houssu, Perrine; Hernandez, Eric; Denoeud, France; Hilaire, Valérie; Lisanti, Olivier; Ramisse, Françoise; Cavallo, Jean-Didier; Vergnaud, Gilles

2004-01-01

The genomic sequences of Salmonella enterica subsp. enterica strains CT18, Ty2 (serovar Typhi), and LT2 (serovar Typhimurium) were analyzed for potential variable number tandem repeats (VNTRs). A multiple-locus VNTR analysis (MLVA) of 99 strains of S. enterica supsp. enterica based on 10 VNTRs distinguished 52 genotypes and placed them into four groups. All strains tested were independent human isolates from France and did not reflect isolates from outbreak episodes. Of these 10 VNTRs, 7 showed variability within serovar Typhi, whereas 1 showed variability within serovar Typhimurium. Four VNTRs showed high Nei's diversity indices (DIs) of 0.81 to 0.87 within serovar Typhi (n = 27). Additionally, three of these more variable VNTRs showed DIs of 0.18 to 0.58 within serovar Paratyphi A (n = 10). The VNTR polymorphic site within multidrug-resistant (MDR) serovar Typhimurium isolates (n = 39; resistance to ampicillin, chloramphenicol, spectinomycin, sulfonamides, and tetracycline) showed a DI of 0.81. Cluster analysis not only identified three genetically distinct groups consistent with the present serovar classification of salmonellae (serovars Typhi, Paratyphi A, and Typhimurium) but also discriminated 25 subtypes (93%) within serovar Typhi isolates. The analysis discriminated only eight subtypes within serovar Typhimurium isolates resistant to ampicillin, chloramphenicol, spectinomycin, sulfonamides, and tetracycline, possibly reflecting the emergence in the mid-1990s of the DT104 phage type, which often displays such an MDR spectrum. Coupled with the ongoing improvements in automated procedures offered by capillary electrophoresis, use of these markers is proposed in further investigations of the potential of MLVA in outbreaks of salmonellosis, especially outbreaks of typhoid fever. PMID:15583305

Fermentation performance of lactic acid bacteria in different lupin substrates-influence and degradation ability of antinutritives and secondary plant metabolites.

PubMed

Fritsch, C; Vogel, R F; Toelstede, S

2015-10-01

The main objectives were to determine the influence of secondary plant metabolites and antinutritives in lupin seeds on the fermentation performance of lactic acid bacteria and to study their ability to degrade these substances. The suitability of lupin raw materials as fermentation substrates was examined. To evaluate the fermentation performance, microbial growth, metabolite formation and substrate uptake in three different lupin substrates was monitored. On the one hand, a lupin protein isolate, which contained only trace amounts of phytochemicals was used in the study. On the other hand, the flour of Lupinus angustifolius cv. Boregine and the flour of the alkaloid rich lupin Lupinus angustifolius cv. Azuro were inoculated with Bifidobacterium animalis subsp. lactis, Pediococcus pentosaceus, Lactobacillus plantarum and Lactococcus lactis subsp. lactis. The micro-organisms showed no significant differences in the fermentation performance on the different lupin flours. Similarly, the growth of most strains on lupin protein isolate was comparable to that on the lupin flours. The fermentation with Bifidobacterium animalis subsp. lactis led to a significant decrease in flatulence causing oligosaccharides. During fermentation with Lactobacillus plantarum the phytic acid content was partially degraded. Neither the secondary plant metabolites nor the antinutritives of lupin flour inhibited the growth or metabolic activity of the tested micro-organisms. Therefore, lupin flour is suitable for lactic fermentation. Some strains showed the ability to degrade oligosaccharides or phytic acid. This work contributes to the fundamental knowledge of the metabolism of lactic acid bacteria during fermentation of lupin substrates. Fermentation of lupin raw materials could be used to improve the nutritional value of the substrates due to the reduction of antinutritives. © 2015 The Society for Applied Microbiology.

Manufacture of a beverage from cheese whey using a "tea fungus" fermentation.

PubMed

Belloso-Morales, Genette; Hernández-Sánchez, Humberto

2003-01-01

Kombucha is a sour beverage reported to have potential health effects prepared from the fermentation of black tea and sugar with a "tea fungus", a symbiotic culture of acetic acid bacteria and yeasts. Although black tea is the preferred substrate for Kombucha fermentation, other beverages have also been tested as substrates with fair results. Cheese whey is a by-product with a good amount of fermentable lactose that has been used before in the production of beverages, so the objective of this study was to test three types of whey (fresh sweet, fresh acid and reconstituted sweet) in the elaboration of a fermented beverage using a kombucha culture as inoculum. The isolation and identification of bacteria and yeasts from the fermented tea and wheys was done along with the study of the rates of change in sugar consumption, acid production and pH decrease. Several species of acetic acid bacteria (Acetobacter aceti subsp. aceti, Gluconobacter oxydans subsp. industrius, subsp. oxydans and Gluconoacetobacter xylinus) were isolated from the different kombuchas along with the yeasts Saccharomyces cerevisiae, Kluyveromyces marxianus, and Brettanomyces bruxelensis. The main metabolic products in the fermented wheys included ethanol, lactic and acetic acids. A good growth was obtained in both sweet wheys in which a pH of 3.3 and a total acid content (mainly lactic and acetic acids) of 0.07 mol/l was reached after 96 h. The sweet whey fermented beverages contained a relatively low lactose concentration (< 12 g/l). The final ethanol content was low (5 g/l) in all the fermented wheys. The whey products were strongly sour and salty non sparkling beverages.

Occurrence of Thermotolerant Campylobacter in Raw Poultry Meat, Environmental and Pigeon Stools Collected in Open-Air Markets.

PubMed

Bellio, Alberto; Traversa, Amaranta; Adriano, Daniela; Bianchi, Daniela Manila; Colzani, Alberto; Gili, Stefano; Dondo, Alessandro; Gallina, Silvia; Grattarola, Carla; Maurella, Cristiana; Zoppi, Simona; Zuccon, Fabio; Decastelli, Lucia

2014-08-28

Campylobacteriosis was the most commonly reported zoonosis for confirmed human cases in European Union during 2011. Poultry meat was very often implicated in Campylobacter infections in humans. In Italy commerce of raw poultry meat is common in open-air markets: these areas can be considered at high risk of bacterial contamination due to the high presence birds like pigeons. The aim of this study was to collect data about the contamination by thermotolerant Campylobacter of raw poultry meat commercialised in open-air markets, of work-surfaces in contact with poultry meat and of pigeon stools sampled in the market areas in Turin, Northern Italy. Between September 2011 and December 2012, 86 raw poultry meat samples, 86 environmental swabs and 108 animal samples were collected in 38 open-air markets. Analysis were carried out according to ISO10272-1:2006 standard. C.coli was detected in 2.3% (2/86) of raw poultry meat samples, whereas no swab (0/86) resulted positive. Of pigeon stool 28% (30/107) was positive for C.jejuni (83.3% C.jejuni subsp . jejuni and 16.7% C.jejuni subsp . doylei ). C.jejuni subsp. jejuni was isolated from 1 dead pigeon . Our results showed lower rates of contamination than those reported at retail in Europe. Although samples were collected in areas at high risk of contamination, raw poultry meat and work surfaces reported a low level of presence of thermotolerant Campylobacter . The high percentage of C.jejuni isolated from pigeon stools showed the importance of a continuous application of preventive measures by the food business operators and the surveillance activity by the Competent Authority.

Comparative analysis of innate immune responses to Streptococcus phocae strains in Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss).

PubMed

Salazar, Soraya; Oliver, Cristian; Yáñez, Alejandro J; Avendaño-Herrera, Ruben

2016-04-01

Streptococcus phocae subsp. salmonis is a Gram-positive bacterium that causes mortality only in Atlantic salmon (Salmo salar) farmed in Chile, even when this species is co-cultured with rainbow trout (Oncorhynchus mykiss). This susceptibility could be determined by innate immune response components and their responses to bacterial infection. This fish pathogen shares subspecies status with Streptococcus phocae subsp. phocae isolated from seals. The present study compared innate immune system mechanisms in Atlantic salmon and rainbow trout when challenged with different S. phocae, including two isolates from Atlantic salmon (LM-08-Sp and LM-13-Sp) and two from seal (ATCC 51973(T) and P23). Streptococcus phocae growth was evaluated in the mucus and serum of both species, with rainbow trout samples evidencing inhibitory effects. Lysozyme activity supported this observation, with significantly higher (p < 0.01) expression in rainbow trout serum and mucus as compared to Atlantic salmon. No differences were found in phagocytic capacity between fish species when stimulated with ATCC 51973(T) and P23. Against all S. phocae strains, rainbow trout and Atlantic salmon showed up to two-fold increased bactericidal activity, and rainbow trout demonstrated up to three-fold greater reactive oxygen species production in macrophages. In conclusion, the non-specific humoral and cellular barriers of Atlantic salmon were immunologically insufficient against S. phocae subsp. salmonis, thereby facilitating streptococcosis. Moreover, the more robust response of rainbow trout to S. phocae could not be attributed to any specific component of the innate immune system, but was rather the consequence of a combined response by the evaluated components. Copyright © 2016 Elsevier Ltd. All rights reserved.

Serological and genetic examination of some nontypical Streptococcus mutans strains.

PubMed

Coykendall, A L; Bratthall, D; O'Connor, K; Dvarskas, R A

1976-09-01

Thirty-four strains of Streptococcus mutans whose antigenic or genetic positions were unclear or unknown with respect to the serological scheme of Bratthall (1970) and Perch et al. (1974), or the genetic (deoxyribonucleic acid base sequence homology) scheme of Coykendall were analyzed to clarify their relationship to previously well-characterized strains. Strain OMZ175 of the "new" serotype f was genetically homologous with strains of S. mutans subsp. mutans. Strains of the "new" serotype g were homologous with serotype d strains (S. mutans subsp. sobrinus). Strains isolated from wild rats constituted a new genetic group but carried the c antigen. Thus, strains within a "genospecies" (subspecies) of S. mutans may not always carry a unique or characteristic antigen. We suggest that the existence of multiple serotypes within subspecies represents antigenic variation and adaptations to hosts.

Novel mutants of Erwinia carotovora subsp. carotovora defective in the production of plant cell wall degrading enzymes generated by Mu transpososome-mediated insertion mutagenesis.

PubMed

Laasik, Eve; Ojarand, Merli; Pajunen, Maria; Savilahti, Harri; Mäe, Andres

2005-02-01

As in Erwinia carotovora subsp. carotovora the regulation details of the main virulence factors, encoding extracellular enzymes that degrade the plant cell wall, is only rudimentally understood, we performed a genetic screen to identify novel candidate genes involved in the process. Initially, we used Mu transpososome-mediated mutagenesis approach to generate a comprehensive transposon insertion mutant library of ca. 10000 clones and screened the clones for the loss of extracellular enzyme production. Extracellular enzymes production was abolished by mutations in the chromosomal helEcc, trkAEcc yheLEcc, glsEcc, igaAEcc and cysQEcc genes. The findings reported here demonstrate that we have isolated six new representatives that belong to the pool of genes modulating the production of virulence factors in E. carotovora.

Molecular characterization of three Lactobacillus delbrueckii subsp. bulgaricus phages.

PubMed

Casey, Eoghan; Mahony, Jennifer; O'Connell-Motherway, Mary; Bottacini, Francesca; Cornelissen, Anneleen; Neve, Horst; Heller, Knut J; Noben, Jean-Paul; Dal Bello, Fabio; van Sinderen, Douwe

2014-09-01

In this study, three phages infecting Lactobacillus delbrueckii subsp. bulgaricus, named Ld3, Ld17, and Ld25A, were isolated from whey samples obtained from various industrial fermentations. These phages were further characterized in a multifaceted approach: (i) biological and physical characterization through host range analysis and electron microscopy; (ii) genetic assessment through genome analysis; (iii) mass spectrometry analysis of the structural components of the phages; and (iv), for one phage, transcriptional analysis by Northern hybridization, reverse transcription-PCR, and primer extension. The three obtained phage genomes display high levels of sequence identity to each other and to genomes of the so-called group b L. delbrueckii phages c5, LL-Ku, and phiLdb, where some of the observed differences are believed to be responsible for host range variations. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

A novel dimeric flavonol glycoside from Cynanchum acutum subsp. sibiricum.

PubMed

Yuan, Si-Wen; Dai, Wei; Pan, Xin-Hui; Lu, Yan; Chen, Dao-Feng; Wang, Qi

2018-06-11

A novel dimeric flavonol glycoside, Cynanflavoside A (1), together with six analogues, kaempferol-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (2), quercetin-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (3), kaempferol-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside (4), quercetin-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside (5), kaempferol-3-O-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside (6), and quercetin-3-O-galactoside (7) were isolated from the n-butyl alcohol extract of Cynanchum acutum subsp. sibiricum. Their structures were determined spectroscopically and compared with previously reported spectral data. All compounds were evaluated for their anti-complementary activity in vitro, and only compound 5 exhibited anti-complement effects with CH 50 value of 0.33 mM.

Investigation of bovine venereal campyloacteriosis in beef cow herds in New Zealand.

PubMed

McFadden, A M; Heuer, C; Jackson, R; West, D M; Parkinson, T J

2005-02-01

To determine regional prevalences of beef cow herds in New Zealand positive for Campylobacter fetus subsp venerealis antibodies in samples of vaginal mucus tested using an immunoglobulin (Ig) A enzyme-linked immunosorbent assay (ELISA), and to examine the suitability of the IgA ELISA for detecting infection with C. fetus subsp venerealis under field conditions in New Zealand. Vaginal mucus samples (n=1,230) collected from beef cow herds (n=125) throughout New Zealand (approximately 10 samples/herd) were tested for antibodies to C. fetus subsp venerealis using an IgA ELISA. Test results were compared between herds classified as having low, medium and high fertility based on pregnancy test results interpreted in relation to the duration of the mating period used. In addition, a small number of samples were collected from dairy cows that were mated using artificial insemination (AI) and had no contact with breeding bulls. The influence of putative risk factors for the spread of venereal disease and the effect of sample quality on the status of herds according to test results was assessed using multivariate logistical regression. Preputial washings from 54 bulls from nine herds classified as low fertility in which mucus samples from > or =3 cows were IgA antibody-positive were cultured for the presence of Campylobacter spp, and isolates of C. fetus subspecies were characterised using a polymerase chain reaction (PCR) test. One or more mucus samples was positive to the IgA ELISA in 70% of all herds tested. The prevalence of IgA antibody- positive individuals was >20% in most regions of New Zealand and did not differ significantly for cows from herds classified as high, medium or low fertility (28%, 26% and 23%, respectively; p=0.39). No relationship was found between mucus antibody status and age of breeding group, herd size, herd fertility, number of herds that female replacements or breeding bulls were sourced from, whether a serving ability test (SAT) was used to assess bulls, or the quality of samples submitted to the laboratory. Campylobacter fetus subsp venerealis was not cultured from any of the 54 bulls sampled. Four other species of Campylobacter and related organisms were cultured, viz Arcobacter cryaerophilus, Campylobacter jejuni, Campylobacter fetus subsp fetus and Helicobacter cinaedi. The specificity of the IgA ELISA as a diagnostic test for C. fetus subsp venerealis was found to be unsatisfactory under New Zealand conditions. It is possible that an immunological response by cows to Campylobacter species other than C. fetus subsp venerealis caused cross-reactivity in the IgA ELISA. The results do not support the hypothesis that C. fetus subsp venerealis is widespread in New Zealand.

Bacterial infection of the lower respiratory tract in 34 horses.

PubMed

Racklyeft, D J; Love, D N

2000-08-01

To investigate associations between the bacteriology and aspects of history, clinical presentation, outcome and pathology of lower respiratory tract disease of 34 horses. Detailed aerobic and anaerobic bacteriological investigations were performed on clinical specimens from horses with pneumonia, lung abscessation and necrotic pneumonia with or without pleurisy in an attempt to identify those bacteria that might contribute to the initiation and progression of infection. Bacteria were cultured from 33 of the 34 horses. In ten cases, only aerobic/facultatively anaerobic isolates were cultured while aerobic/facultatively anaerobic bacteria and obligately anaerobic bacteria were isolated in the other 23 cases. Moderate to large numbers of anaerobic bacteria were isolated only when the estimated duration of illness was at least five days. Bacteria were not cultured from 12 of the pleural fluid samples but were always cultured from pulmonary samples (either transtracheal aspirates from live horses or pulmonary lesions at necropsy). Streptococcus equi subsp zooepidemicus was isolated in the three cases where only one bacterial species was cultured. In the other 30 cases, multiple species were isolated. These included most often and in greatest numbers, Streptococcus equi subsp zooepidemicus, Pasteurellaceae, Escherichia coli, anaerobic cocci, Eubacterium fossor, Bacteroides tectum, Prevotella heparinolytica, Fusobacterium spp, and pigmented members of the genera Prevotella and Porphyromonas. Aerobic/facultatively anaerobic organisms were isolated from 97% of horses, while obligately anaerobic organisms were cultured from 68% of horses. There was no association between the isolation of any specific bacterium and the outcome of disease. However, obligately anaerobic bacteria (such as anaerobic cocci, Bacteroides tectum, P heparinolytica and Fusobacterium spp) and the facultatively anaerobic species Escherichia coli, were recovered more commonly from horses that died or were euthanased than from those that survived. There was an association between failure of horses to recover from pleuropneumonia and delay in diagnosis and initiation of treatment.

Effects of Lactic Acid Bacteria on Residual Nitrite in a Summer Style Sausage.

DTIC Science & Technology

1984-01-01

faecalis and an atypical lactobacillus isolated from beef) showed abilities to reduce pH and residual nitrite to levels similar to L. plantarum and P...Leuconostoc mesenteroides reduced nitrite at a faster rate than either Lactobacillus plantarum or Lactobacillus viridescens, while Lactobacillus ... Lactobacillus plantarum 4008 Lactobacillus bulgaricus 11842 Lactobacillus fermentum 9338 Lactobacillus casei subsp. rhamnosus 7469 Pediococcus acidilactici

Enterobacter siamensis sp. nov., a transglutaminase-producing bacterium isolated from seafood processing wastewater in Thailand.

PubMed

Khunthongpan, Suwannee; Bourneow, Chaiwut; H-Kittikun, Aran; Tanasupawat, Somboon; Benjakul, Soottawat; Sumpavapol, Punnanee

2013-01-01

A novel strain of Enterobacter, C2361(T), a Gram-negative, non-spore-forming, rod-shaped and facultative anaerobic bacterium with the capability to produce transglutaminase, was isolated from seafood processing wastewater collected from a treatment pond of a seafood factory in Songkhla Province, Thailand. Phylogenetic analyses and phenotypic characteristics, including chemotaxonomic characteristics, showed that the strain was a member of the genus Enterobacter. The 16S rRNA gene sequence similarities between strain C2361(T) and Enterobacter cloacae subsp. cloacae ATCC 13047(T) and Enterobacter cloacae subsp. dissolvens LMG 2683(T) were 97.5 and 97.5%, respectively. Strain C2361(T) showed a low DNA-DNA relatedness with the above-mentioned species. The major fatty acids were C16:0, C17:0cyclo and C14:0. The DNA G+C content was 53.0 mol%. On the basis of the polyphasic evidence gathered in this study, it should be classified as a novel species of the genus Enterobacter for which the name Enterobacter siamensis sp. nov. is proposed. The type strain is C2361(T) (= KCTC 23282(T) = NBRC 107138(T)).

Inhibition of initial adhesion of uropathogenic Enterococcus faecalis by biosurfactants from Lactobacillus isolates.

PubMed

Velraeds, M M; van der Mei, H C; Reid, G; Busscher, H J

1996-06-01

In this study, 15 Lactobacillus isolates were found to produce biosurfactants in the mid-exponential and stationary growth phases. The stationary-phase biosurfactants from lactobacillus casei subsp. rhamnosus 36 and ATCC 7469, Lactobacillus fermentum B54, and Lactobacillus acidophilus RC14 were investigated further to determine their capacity to inhibit the initial adhesion of uropathogenic Enterococcus faecalis 1131 to glass in a parallel-plate flow chamber. The initial deposition rate of E. faecalis to glass with an adsorbed biosurfactant layer from L. acidophilus RC14 or L. fermentum B54 was significantly decreased by approximately 70%, while the number of adhering enterococci after 4 h of adhesion was reduced by an average of 77%. The surface activity of the biosurfactants and their activity inhibiting the initial adhesion of E. faecalis 1131 were retained after dialysis (molecular weight cutoff, 6,000 to 8,000) and freeze-drying. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy revealed that the freeze-dried biosurfactants from L. acidophilus RC14 and L. fermentum B54 were richest in protein, while those from L. casei subsp. rhamnosus 36 and ATCC 7469 had relatively high polysaccharide and phosphate contents.

Inhibition of initial adhesion of uropathogenic Enterococcus faecalis by biosurfactants from Lactobacillus isolates.

PubMed Central

Velraeds, M M; van der Mei, H C; Reid, G; Busscher, H J

1996-01-01

In this study, 15 Lactobacillus isolates were found to produce biosurfactants in the mid-exponential and stationary growth phases. The stationary-phase biosurfactants from lactobacillus casei subsp. rhamnosus 36 and ATCC 7469, Lactobacillus fermentum B54, and Lactobacillus acidophilus RC14 were investigated further to determine their capacity to inhibit the initial adhesion of uropathogenic Enterococcus faecalis 1131 to glass in a parallel-plate flow chamber. The initial deposition rate of E. faecalis to glass with an adsorbed biosurfactant layer from L. acidophilus RC14 or L. fermentum B54 was significantly decreased by approximately 70%, while the number of adhering enterococci after 4 h of adhesion was reduced by an average of 77%. The surface activity of the biosurfactants and their activity inhibiting the initial adhesion of E. faecalis 1131 were retained after dialysis (molecular weight cutoff, 6,000 to 8,000) and freeze-drying. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy revealed that the freeze-dried biosurfactants from L. acidophilus RC14 and L. fermentum B54 were richest in protein, while those from L. casei subsp. rhamnosus 36 and ATCC 7469 had relatively high polysaccharide and phosphate contents. PMID:8787394

Serratia ureilytica sp. nov., a novel urea-utilizing species.

PubMed

Bhadra, Bhaskar; Roy, Pradosh; Chakraborty, Ranadhir

2005-09-01

A Gram-negative, rod-shaped, urea-dissolving and non-spore-forming bacterium, designated strain NiVa 51(T), was isolated from water of the River Torsa in Hasimara, Jalpaiguri district, West Bengal, India. On the basis of 16S rRNA gene sequence similarity, strain NiVa 51(T) was shown to belong to the gamma-Proteobacteria and to be related to Serratia marcescens subsp. sakuensis (98.35%) and S. marcescens subsp. marcescens (98.30%); however, strain NiVa 51(T) exhibited only 43.7% similarity to S. marcescens by DNA-DNA hybridization. The G+C content of the genomic DNA of the isolate was 60 mol%. Both biochemical characteristics and fatty acid analysis data supported the affiliation of strain NiVa 51(T) to the genus Serratia. Furthermore, strain NiVa 51(T) was found to utilize urea as nitrogen source. The results of DNA-DNA hybridization as well as physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain NiVa 51(T) from recognized Serratia species. Strain NiVa 51(T) therefore represents a novel species, for which the name Serratia ureilytica sp. nov. is proposed, with type strain NiVa 51(T) (=LMG 22860(T)=CCUG 50595(T)).

An outbreak of multidrug-resistant Salmonella enterica subsp. enterica serotype Typhimurium, DT104L linked to dried anchovy in Singapore.

PubMed Central

Ling, M. L.; Goh, K. T.; Wang, G. C. Y.; Neo, K. S.; Chua, T.

2002-01-01

Multidrug-resistant Salmonella enterica subsp. enterica serotype Typhimurium DT104L was first reported in Singapore from mid-July to mid-October 2000. Salmonella strains isolated from clinical laboratories were submitted to a reference laboratory for serotyping, phage-typing and pulsed-field gel electrophoresis (PFGE) using XbaI restriction endonuclease. An epidemiological investigation was conducted to determine the source of infection and mode of transmission using a structured questionnaire. A total of 33 cases involving mainly infants and toddlers were detected in the 3-month long outbreak. The outbreak strain was of the R-type ACGSTSu, i.e. resistant to ampicillin, chloramphenicol, gentamicin, streptomycin, tetracycline and sulphonamide. PFGE showed all isolates had an indistinguishable pattern, indicating a common source of infection. Consumption of imported dried anchovy was found to be the vehicle of transmission after adjusting for all confounding variables in the case-control study using stepwise logistic regression (OR 25.6; 95% CI 3.9-167.9; P = 0.001). Imported dried seafood should be properly processed, packed, labelled, and thoroughly cooked to prevent transmission of multidrug-resistant S. Typhimurium. PMID:11895083

Mycobacterium avium subsp. paratuberculosis (Map) Fatty Acids Profile Is Strain-Dependent and Changes Upon Host Macrophages Infection

PubMed Central

Alonso-Hearn, Marta; Abendaño, Naiara; Ruvira, Maria A.; Aznar, Rosa; Landin, Mariana; Juste, Ramon A.

2017-01-01

Johne's disease is a chronic granulomatous enteritis of ruminants caused by the intracellular bacterium Mycobacterium avium subsp. paratuberculosis (Map). We previously demonstrated that Map isolates from sheep persisted within host macrophages in lower CFUs than cattle isolates after 7 days of infection. In the current study, we hypothesize that these phenotypic differences between Map isolates may be driven be the fatty acids (FAs) present on the phosphadidyl-1-myo-inositol mannosides of the Map cell wall that mediate recognition by the mannose receptors of host macrophages. FAs modifications may influence Map's envelope fluidity ultimately affecting pathogenicity. To test this hypothesis, we investigated the responses of two Map isolates from cattle (K10 isolate) and sheep (2349/06-1) to the bovine and ovine macrophage environment by measuring the FAs content of extracellular and intracellular bacteria. For this purpose, macrophages cell lines of bovine (BOMAC) and ovine (MOCL-4) origin were infected with the two isolates of Map for 4 days at 37°C. The relative FAs composition of the two isolates recovered from infected BOMAC and MOCL-4 cells was determined by gas chromatography and compared with that of extracellular bacteria and that of bacteria grown in Middlebrook 7H9 medium. Using this approach, we demonstrated that the FAs composition of extracellular and 7H9-grown bacteria was highly conserved within each Map isolate, and statistically different from that of intracellular bacteria. Analysis of FAs composition from extracellular bacteria enabled the distinction of the two Map strains based on the presence of the tuberculostearic acid (18:0 10Me) exclusively in the K10 strain of Map. In addition, significant differences in the content of Palmitic acid and cis-7 Palmitoleic acid between both isolates harvested from the extracellular environment were observed. Once the infection established itself in BOMAC and MOCL-4 cells, the FAs profiles of both Map isolates appeared conserved. Our results suggest that the FAs composition of Map might influence its recognition by macrophages and influence the survival of the bacillus within host macrophages. PMID:28377904

In Vitro Fermentation of caprine milk oligosaccharides by bifidobacteria isolated from breast-fed infants

PubMed Central

Thum, Caroline; Roy, Nicole C; McNabb, Warren C; Otter, Don E; Cookson, Adrian L

2015-01-01

This study was conducted to investigate the catabolism and fermentation of caprine milk oligosaccharides (CMO) by selected bifidobacteria isolated from 4 breast-fed infants. Seventeen bifidobacterial isolates consisting of 3 different species (Bifidobacterium breve, Bifidobacterium longum subsp. longum and Bifidobacterium bifidum) were investigated. A CMO-enriched fraction (CMOF) (50% oligosaccharides, 10% galacto-oligosaccharides (GOS), 20% lactose, 10% glucose and 10% galactose) from caprine cheese whey was added to a growth medium as a sole source of fermentable carbohydrate. The inclusion of the CMOF was associated with increased bifidobacterial growth for all strains compared to glucose, lactose, GOS, inulin, oligofructose, 3'-sialyl-lactose and 6'-sialyl-lactose. Only one B. bifidum strain (AGR2166) was able to utilize the sialyl-CMO, 3'-sialyl-lactose and 6'-sialyl-lactose, as carbohydrate sources. The inclusion of CMOF increased the production of acetic and lactic acid (P < 0.001) after 36 h of anaerobic fermentation at 37°C, when compared to other fermentable substrates. Two B. bifidum strains (AGR2166 and AGR2168) utilised CMO, contained in the CMOF, to a greater extent than B. breve or B. longum subsp longum isolates, and this increased CMO utilization was associated with enhanced sialidase activity. CMOF stimulated bifidobacterial growth when compared to other tested fermentable carbohydrates and also increased the consumption of mono- and disaccharides, such as galactose and lactose present in the CMOF. These findings indicate that the dietary consumption of CMO may stimulate the growth and metabolism of intestinal Bifidobacteria spp. including B. bifidum typically found in the large intestine of breast-fed infants. PMID:26587678

Classification of Culturable Bifidobacterial Population from Colonic Samples of Wild Pigs (Sus scrofa) Based on Three Molecular Genetic Methods.

PubMed

Pechar, Radko; Killer, Jiří; Mekadim, Chahrazed; Geigerová, Martina; Rada, Vojtěch

2017-11-01

Occurrence of bifidobacteria, known as health-promoting probiotic microorganisms, in the digestive tract of wild pigs (Sus scrofa) has not been examined yet. One hundred forty-nine fructose-6-phosphate phosphoketolase positive bacterial strains were isolated from colonic content of twenty-two individuals of wild pigs originated from four localities in the Czechia. Based on PCR-DGGE technique targeting the variable V3 region of the 16S rRNA genes, strains were initially differentiated into four groups represented by: (i) probably a new Bifidobacterium species (89 strains), (ii) B. boum/B. thermophilum/B. thermacidophilum subsp. porcinum/B. thermacidophilum subsp. thermacidophilum (sub)species (49 strains), (iii) Pseudoscardovia suis (7 strains), and (iv) B. pseudolongum subsp. globosum/B. pseudolongum subsp. pseudolongum (4 strains), respectively. Given the fact that DGGE technique did not allow to differentiate the representatives of thermophilic bifidobacteria and B. pseudolongum subspecies, strains were further classified by the 16S rRNA and thrS gene sequences. Primers targeting the variable regions of the latter gene were designed to be applicable in identification and phylogeny of Bifidobacteriaceae family. The 16S rRNA-derived phylogenetic study classified members of the first group into five subgroups in a separated cluster of thermophilic bifidobacteria. Comparable results were obtained by the thrS-derived phylogenetic analysis. Remarkably, variability among thrS sequences was higher compared with 16S rRNA gene sequences. Overall, molecular genetic techniques application allowed to identify a new Bifidobacterium phylotype which is predominant in the digestive tract of examined wild pigs.

A comparative study on the antinociceptive and anti-inflammatory activities of five Juniperus taxa.

PubMed

Akkol, Esra Küpeli; Güvenç, Ayşegül; Yesilada, Erdem

2009-09-07

Juniperus L. (Cupressaceae) species have been used to various inflammatory and infectious diseases such as bronchitis, colds, cough, fungal infections, hemorrhoids, gynecological diseases, and wounds in Turkish folk medicine. To evaluate this traditional information, anti-inflammatory and antinociceptive activities of the methanolic and aqueous extracts prepared from different parts (stem, fruit and leaves) of the five Turkish taxa under Juniperus section of the gender; J. drupacea, J. communis var. communis, J. communis var. saxatilis, J. oxycedrus subsp. oxycedrus, and J. oxycedrus subsp. macrocarpa growing were investigated. For the anti-inflammatory activity, carrageenan-induced and PGE(2)-induced hind paw edema models, and for the antinociceptive activity p-benzoquinone-induced writhing and hot plate tests in mice were employed. The methanolic extracts of fruit and leaves from J. oxycedrus subsp. oxycedrus and J. communis var. saxatilis exhibited notable inhibition in carrageenan-induced edema model at a dose of 100mg/kg. The same extracts also displayed significant activity against PGE(2)-induced edema model. While, the remaining extracts were found inactive against these edema models. A similar activity pattern was observed against p-benzoquinone-induced abdominal constriction test without inducing any gastric damage or apparent acute toxicity, whereas all extracts were inactive in hot plate test. The experimental data demonstrated that J. oxycedrus subsp. oxycedrus and J. communis var. saxatilis displayed remarkable anti-inflammatory and antinociceptive activities; however, further studies are warranted to define and isolate the active anti-inflammatory and antinociceptive components from these active species which may yield safe and effective agents to be used in the treatment of inflammatory disorders.

Analysis of the 16S–23S rRNA Gene Internal Transcribed Spacer Region in Klebsiella Species▿

PubMed Central

Wang, Min; Cao, Boyang; Yu, Qunfang; Liu, Lei; Gao, Qili; Wang, Lei; Feng, Lu

2008-01-01

The 16S-23S rRNA gene internal transcribed spacer (ITS) regions of Klebsiella spp., including Klebsiella pneumoniae subsp. pneumoniae, Klebsiella pneumoniae subsp. ozaenae, Klebsiella pneumoniae subsp. rhinoscleromatis, Klebsiella oxytoca, Klebsiella planticola, Klebsiella terrigena, and Klebsiella ornithinolytica, were characterized, and the feasibility of using ITS sequences to discriminate Klebsiella species and subspecies was explored. A total of 336 ITS sequences from 21 representative strains and 11 clinical isolates of Klebsiella were sequenced and analyzed. Three distinct ITS types—ITSnone (without tRNA genes), ITSglu [with a tRNAGlu (UUC) gene], and ITSile+ala [with tRNAIle (GAU) and tRNAAla (UGC) genes]—were detected in all species except for K. pneumoniae subsp. rhinoscleromatis, which has only ITSglu and ITSile+ala. The presence of ITSnone in Enterobacteriaceae had never been reported before. Both the length and the sequence of each ITS type are highly conserved within the species, with identity levels from 0.961 to 1.000 for ITSnone, from 0.967 to 1.000 for ITSglu, and from 0.968 to 1.000 for ITSile+ala. Interspecies sequence identities range from 0.775 to 0.989 for ITSnone, from 0.798 to 0.997 for ITSglu, and from 0.712 to 0.985 for ITSile+ala. Regions with significant interspecies variations but low intraspecies polymorphisms were identified; these may be targeted in the design of probes for the identification of Klebsiella to the species level. Phylogenetic analysis based on ITS regions reveals the relationships among Klebsiella species similarly to that based on 16S rRNA genes. PMID:18753345

Geographic distribution and taxonomic circumscription of populations within Coryphantha section Robustispina (Cactaceae).

PubMed

Baker, Marc A; Butterworth, Charles A

2013-05-01

Taxonomic circumscription of subspecific taxa within Coryphantha robustispina was evaluated with morphological data and microsatellites. This study was the first to compare adequately sampled morphological and DNA analyses at the population level in the Cactaceae. This comparison was important to test reliability of both methods and to gain a better understanding of phytogeography, evolution, and systematics of the species, knowledge that could prove useful for other taxa as well. Populations of C. robustispina subsp. robustispina are listed as endangered by the U. S. Fish and Wildlife Service. Our primary goal was to explore correlations among geographical distribution, morphology, and genetics of selected populations throughout the range of the species and the outgroup, C. poselgeriana. • Stem characters were measured for 638 individuals among 16 populations. Flower characters were measured for 180 individuals among 12 populations. Ten microsatellite DNA loci were isolated and characterized for 204 individuals among 13 populations. Data were analyzed using various multivariate analyses. • Our results indicated that, within Coryphantha robustispina, there were three morphologically, genetically, and geographically coherent groups represented by the names C. robustispina subsp. robustispina, C. robustispina subsp. uncinata, and C. robustispina subsp. scheeri. For most analyses, distinctions among the three groups were primarily not as great as those between any one of them and the outgroup. • Results suggested that the three subspecific taxa within Coryphantha robustispina are good subspecies but should not be elevated to species rank. The closely aligned results between morphology and microsatellite data support the design and utility of both methods.

The Host Genotype and Environment Affect Strain Types of Bifidobacterium longum subsp. longum Inhabiting the Intestinal Tracts of Twins.

PubMed

Zhang, Min; Hang, Xiaomin; Tan, Jing; Yang, Hong

2015-07-01

To investigate the influences of host genotype and environment on Bifidobacterium longum subsp. longum inhabiting human intestines at the strain level, six pairs of twins, divided into two groups (children and adults), were recruited. Each group consisted of two monozygotic (MZ) twin pairs and one dizygotic (DZ) twin pair. Child twins had been living together from birth, while adult twins had been living separately for 5 to 10 years. A total of 345 B. longum subsp. longum isolates obtained from 60 fecal samples from these twins were analyzed by multilocus sequence typing (MLST), and 35 sequence types (STs) were finally acquired. Comparison of strains within and between the twin pairs showed that no strains with identical STs were observed between unrelated individuals or within adult DZ twin pairs. Eight STs were found to be monophyletic, existing within MZ twins and child DZ twins. The similarity of strain types within child cotwins was significantly higher than that within adult cotwins, which indicated that environment was one of the important determinants in B. longum subsp. longum strain types inhabiting human intestines. However, although these differences between MZ and DZ twins were observed, it is still difficult to reach an exact conclusion about the impact of host genotype. This is mainly because of the limited number of subjects tested in the present study and the lack of strain types tracing in the same twin pairs from birth until adulthood. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Diagnostics for Yaws Eradication: Insights From Direct Next-Generation Sequencing of Cutaneous Strains of Treponema pallidum

PubMed Central

Marks, Michael; Fookes, Maria; Wagner, Josef; Butcher, Robert; Ghinai, Rosanna; Sokana, Oliver; Sarkodie, Yaw-Adu; Lukehart, Sheila A; Solomon, Anthony W; Mabey, David C W; Thomson, Nicholas

2018-01-01

Abstract Background Yaws-like chronic ulcers can be caused by Treponema pallidum subspecies pertenue, Haemophilus ducreyi, or other, still-undefined bacteria. To permit accurate evaluation of yaws elimination efforts, programmatic use of molecular diagnostics is required. The accuracy and sensitivity of current tools remain unclear because our understanding of T. pallidum diversity is limited by the low number of sequenced genomes. Methods We tested samples from patients with suspected yaws collected in the Solomon Islands and Ghana. All samples were from patients whose lesions had previously tested negative using the Centers for Disease Control and Prevention (CDC) diagnostic assay in widespread use. However, some of these patients had positive serological assays for yaws on blood. We used direct whole-genome sequencing to identify T. pallidum subsp pertenue strains missed by the current assay. Results From 45 Solomon Islands and 27 Ghanaian samples, 11 were positive for T. pallidum DNA using the species-wide quantitative polymerase chain reaction (PCR) assay, from which we obtained 6 previously undetected T. pallidum subsp pertenue whole-genome sequences. These show that Solomon Islands sequences represent distinct T. pallidum subsp pertenue clades. These isolates were invisible to the CDC diagnostic PCR assay, due to sequence variation in the primer binding site. Conclusions Our data double the number of published T. pallidum subsp pertenue genomes. We show that Solomon Islands strains are undetectable by the PCR used in many studies and by health ministries. This assay is therefore not adequate for the eradication program. Next-generation genome sequence data are essential for these efforts. PMID:29045605

Phytochemical composition and antinociceptive activity of Bauhinia glauca subsp. hupehana in rats.

PubMed

Xu, Jinlong; Zhao, Qizhi; Wei, Lei; Yang, Yu; Xu, Rui; Yu, Nengjiang; Zhao, Yimin

2015-01-01

In traditional medicine, Bauhinia glauca subsp. hupehana has long been used as an analgesic agent in China. The aim of this study was to evaluate the antinociceptive activity of the ethanol extract of the aerial parts of B. glauca subsp. hupehana (BHE) in rats and its chemical fingerprint. The antinociceptive activity of BHE was assessed in mice using chemically and heat-induced pain models, such as the acetic acid-induced writhing, hot plate, tail-flick and glutamate tests. Naltrexone hydrochloride, a non-selective opioid receptor antagonist, was utilized to determine the involvement of the opioid system. In addition to this, the involvements of the cGMP and ATP-sensitive K+ channel pathways were also detected using methylene blue and glibenclamide. The oral administration of BHE (at doses of 50, 100 and 200 mg/kg) produced significant and dose-related inhibitions in both the chemically and heat-induced pain models. Interestingly, in the abdominal constriction test, when the dose of BHE was increased to 800 mg/kg (p.o., n = 10), the inhibition rate was 100%. The antinociceptive mechanism may involve the cGMP pathway and ATP sensitive K+ channel pathway. The central antinociceptive effect was not antagonized by naltrexone. One phenolic acid, one lignin and five flavonoids were isolated from BHE. The antinociceptive activity of BHE was most likely due to the presence of the flavonoids. The acute toxicity results showed that BHE was safe at a high dose (2 g/kg, p.o.). The current investigation demonstrates that B. glauca subsp. hupehana is a potential candidate for the development of novel, non-opioid, analgesic phytomedicines.

Proposal to reclassify Roseivirga ehrenbergii (Nedashkovskaya et al., 2008) as Roseivirga seohaensis comb. nov., description of Roseivirga seohaensis subsp. aquiponti subsp. nov. and emendation of the genus Roseivirga.

PubMed

Selvaratnam, Chitra; Thevarajoo, Suganthi; Goh, Kian Mau; Chan, Kok-Gan; Chong, Chun Shiong

2016-12-01

The genus Roseivirga currently includes five species: Roseivirga ehrenbergii, R. echinicomitans, R. spongicola, R. marina and R. maritima. Marinicola seohaensis SW-152T was renamed as Roseivirgaseohaensis SW-152T and then reclassified again as a later heterotypic synonym of R. ehrenbergii KMM 6017T. In this study, based on average nucleotide identity and digital DNA-DNA hybridization values obtained from in silico methods, together with fatty acid analyses and biochemical tests, we propose to reclassify R. ehrenbergii SW-152 as Roseivirga seohaensis comb. nov. (type strain SW-152T=KCTC 1231T=JCM 12600T). In this work, a Gram-negative, rod-shaped, aerobic and pink-pigmented strain designated as D-25T was isolated from seawater (Desaru Beach, Johor, Malaysia). The 16S rRNA gene analysis revealed that strain D-25T was related to the genus Roseivirga. Strain D-25T was found most closely related to R. seohaensis SW-152T based on average nucleotide identity and digital DNA-DNA hybridization values, phenotypic and chemotaxonomic analyses, indicating that these strains belong to the same species. Thus, it is proposed to split the species R.oseivirga seohaensis into two novel subspecies, Roseivirga seohaensissubsp. seohaensis subsp. nov. (type strain SW-152T=KCTC 12312T=JCM 12600T) and Roseivirga seohaensissubsp. aquiponti subsp. nov. (type strain D-25T=KCTC 42709T=DSM 101709T) and to emend the description of the genus Roseivirga.

Comparative genome analysis of Streptococcus infantarius subsp. infantarius CJ18, an African fermented camel milk isolate with adaptations to dairy environment.

PubMed

Jans, Christoph; Follador, Rainer; Hochstrasser, Mira; Lacroix, Christophe; Meile, Leo; Stevens, Marc J A

2013-03-22

Streptococcus infantarius subsp. infantarius (Sii) belongs to the Streptococcus bovis/Streptococcus equinus complex associated with several human and animal infections. Sii is a predominant bacterium in spontaneously fermented milk products in Africa. The genome sequence of Sii strain CJ18 was compared with that of other Streptococcus species to identify dairy adaptations including genome decay such as in Streptococcus thermophilus, traits for its competitiveness in spontaneous milk fermentation and to assess potential health risks for consumers. The genome of Sii CJ18 harbors several unique regions in comparison to Sii ATCC BAA-102T, among others an enlarged exo- and capsular polysaccharide operon; Streptococcus thermophilus-associated genes; a region containing metabolic and hypothetical genes mostly unique to CJ18 and the dairy isolate Streptococcus gallolyticus subsp. macedonicus; and a second oligopeptide transport operon. Dairy adaptations in CJ18 are reflected by a high percentage of pseudogenes (4.9%) representing genome decay which includes the inactivation of the lactose phosphotransferase system (lacIIABC) by multiple transposases integration. The presence of lacS and lacZ genes is the major dairy adaptation affecting lactose metabolism pathways also due to the disruption of lacIIABC.We constructed mutant strains of lacS, lacZ and lacIIABC and analyzed the resulting strains of CJ18 to confirm the redirection of lactose metabolism via LacS and LacZ.Natural competence genes are conserved in both Sii strains, but CJ18 contains a lower number of CRISPR spacers which indicates a reduced defense capability against alien DNA. No classical streptococcal virulence factors were detected in both Sii strains apart from those involved in adhesion which should be considered niche factors. Sii-specific virulence factors are not described. Several Sii-specific regions encoding uncharacterized proteins provide new leads for virulence analyses and investigation of the unclear association of dairy and clinical Sii with human diseases. The genome of the African dairy isolate Sii CJ18 clearly differs from the human isolate ATCC BAA-102T. CJ18 possesses a high natural competence predisposition likely explaining the enlarged genome. Metabolic adaptations to the dairy environment are evident and especially lactose uptake corresponds to S. thermophilus. Genome decay is not as advanced as in S. thermophilus (10-19%) possibly due to a shorter history in dairy fermentations.

Comparative genome analysis of Streptococcus infantarius subsp. infantarius CJ18, an African fermented camel milk isolate with adaptations to dairy environment

PubMed Central

2013-01-01

Background Streptococcus infantarius subsp. infantarius (Sii) belongs to the Streptococcus bovis/Streptococcus equinus complex associated with several human and animal infections. Sii is a predominant bacterium in spontaneously fermented milk products in Africa. The genome sequence of Sii strain CJ18 was compared with that of other Streptococcus species to identify dairy adaptations including genome decay such as in Streptococcus thermophilus, traits for its competitiveness in spontaneous milk fermentation and to assess potential health risks for consumers. Results The genome of Sii CJ18 harbors several unique regions in comparison to Sii ATCC BAA-102T, among others an enlarged exo- and capsular polysaccharide operon; Streptococcus thermophilus-associated genes; a region containing metabolic and hypothetical genes mostly unique to CJ18 and the dairy isolate Streptococcus gallolyticus subsp. macedonicus; and a second oligopeptide transport operon. Dairy adaptations in CJ18 are reflected by a high percentage of pseudogenes (4.9%) representing genome decay which includes the inactivation of the lactose phosphotransferase system (lacIIABC) by multiple transposases integration. The presence of lacS and lacZ genes is the major dairy adaptation affecting lactose metabolism pathways also due to the disruption of lacIIABC. We constructed mutant strains of lacS, lacZ and lacIIABC and analyzed the resulting strains of CJ18 to confirm the redirection of lactose metabolism via LacS and LacZ. Natural competence genes are conserved in both Sii strains, but CJ18 contains a lower number of CRISPR spacers which indicates a reduced defense capability against alien DNA. No classical streptococcal virulence factors were detected in both Sii strains apart from those involved in adhesion which should be considered niche factors. Sii-specific virulence factors are not described. Several Sii-specific regions encoding uncharacterized proteins provide new leads for virulence analyses and investigation of the unclear association of dairy and clinical Sii with human diseases. Conclusions The genome of the African dairy isolate Sii CJ18 clearly differs from the human isolate ATCC BAA-102T. CJ18 possesses a high natural competence predisposition likely explaining the enlarged genome. Metabolic adaptations to the dairy environment are evident and especially lactose uptake corresponds to S. thermophilus. Genome decay is not as advanced as in S. thermophilus (10-19%) possibly due to a shorter history in dairy fermentations. PMID:23521820

Genome Sequences of Multidrug-Resistant Salmonella enterica subsp. enterica Serovar Infantis Strains from Broiler Chicks in Hungary

PubMed Central

Wilk, Tímea; Szabó, Móni; Szmolka, Ama; Kiss, János; Barta, Endre; Nagy, Tibor

2016-01-01

Three strains of Salmonella enterica serovar Infantis isolated from healthy broiler chickens from 2012 to 2013 have been sequenced. Comparison of these and previously published S. Infantis genome sequences of broiler origin in 1996 and 2004 will provide new insight into the genome evolution and recent spread of S. Infantis in poultry. PMID:27979950

Two new monoterpene glucosides from Xanthium strumarium subsp. sibiricum with their anti-inflammatory activity.

PubMed

Jiang, Hai; Xing, Xudong; Yan, Meiling; Guo, Xinyue; Yang, Lin; Yang, Liu

2018-06-01

Two new monoterpene glucosides: xanmonoter A (1) and xanmonoter B (2) were isolated from Xanthium strumarium. Their structures were elucidated on the basis of 1D and 2D NMR, MS and CD analysis. Compounds 1 and 2 were tested for their anti-inflammatory activity with IC 50 values of 17.4, 22.1 μM, respectively.

Draft genome sequence of Xylella fastidiosa supsp. multiplex strain Griffin-1 from Quercus rubra in Georgia

USDA-ARS?s Scientific Manuscript database

The draft genome sequence of Xylella fastidiosa subsp. multiplex Strain Griffin-1 isolated from a red oak tree (Quercus rubra) in Georgia, U.S.A. is reported. The bacterium has a genome size of 2,387,314 bp with 51.7% G+C content and comprises 2,903 predicted open reading frames (ORFs), and 50 RNA g...

Complete genomic sequences of Campylobacter jejuni strains RM3196 (233.94) and RM3197 (308.95) that were isolated from patients with Guillain-Barré Syndrome

USDA-ARS?s Scientific Manuscript database

An infection with Campylobacter jejuni subsp. jejuni (Cjj) is a leading cause of foodborne gastroenteritis in humans and also the most prevalent infection preceding Guillain-Barré syndrome (GBS). This study describes the complete genomic sequences of Cjj HS:41 strains RM3196 (233.94) and RM3197 (308...

Evidence for the presence of restriction/modification systems in Lactobacillus delbrueckii.

PubMed

Suárez, Viviana; Zago, Miriam; Giraffa, Giorgio; Reinheimer, Jorge; Quiberoni, Andrea

2009-11-01

The bacteriophages Cb1/204 and Cb1/342 were obtained by induction from the commercial strain Lactobacillus delbrueckii subsp. lactis Cb1, and propagated on Lactobacillus delbrueckii subsp. lactis 204 (Lb.l 204) and Lactobacillus delbrueckii subsp. bulgaricus 342 (Lb.b 342), respectively. By cross sensitivity, it was possible to detect a delay in the lysis of Lb.l 204 with Cb1/342 phage, while the adsorption rate was high (99.5%). Modified and unmodified phages were isolated using phage Cb1/342 and strain Lb.l 204. The EOP (Efficiency of Plaquing) values for the four phages (Cb1/204, Cb1/342, Cb1/342modified and Cb1/342unmodified) suggested that an R/M system modified the original temperate phage, and the BglII-DNA restriction patterns of these phages might point out the presence of a Type II R/M system. Also, the existence of a Type I R/M system was demonstrated by PCR and nucleotide sequence, being the percentages of alignment homology with Type I R/M systems reported previously higher than 95%. In this study it was possible to demonstrate that the native phage resistant mechanisms and the occurrence of prophages in commercial host strains, contribute strongly to diversify the phage population in a factory environment.

Optimization of Exopolysaccharide Production by Lactobacillus delbrueckii subsp. bulgaricus RR Grown in a Semidefined Medium

PubMed Central

Kimmel, Stacy A.; Roberts, Robert F.; Ziegler, Gregory R.

1998-01-01

The optimal fermentation temperature, pH, and Bacto-casitone (Difco Laboratories, Detroit, Mich.) concentration for production of exopolysaccharide by Lactobacillus delbrueckii subsp. bulgaricus RR in a semidefined medium were determined by using response surface methods. The design consisted of 20 experiments, 15 unique combinations, and five replications. All fermentations were conducted in a fermentor with a 2.5-liter working volume and were terminated when 90% of the glucose in the medium had been consumed. The population of L. delbrueckii subsp. bulgaricus RR and exopolysaccharide content were measured at the end of each fermentation. The optimum temperature, pH, and Bacto-casitone concentration for exopolysaccharide production were 38°C, 5, and 30 g/liter, respectively, with a predicted yield of 295 mg of exopolysaccharide/liter. The actual yield under these conditions was 354 mg of exopolysaccharide/liter, which was within the 95% confidence interval (217 to 374 mg of exopolysaccharide/liter). An additional experiment conducted under optimum conditions showed that exopolysaccharide production was growth associated, with a specific production at the endpoint of 101.4 mg/g of dry cells. Finally, to obtain material for further characterization, a 100-liter fermentation was conducted under optimum conditions. Twenty-nine grams of exopolysaccharide was isolated from centrifuged, ultrafiltered fermentation broth by ethanol precipitation. PMID:9464404

Antibodies Induced by Lipoarabinomannan in Bovines: Characterization and Effects on the Interaction between Mycobacterium Avium Subsp. Paratuberculosis and Macrophages In Vitro

PubMed Central

Jolly, Ana; Colavecchia, Silvia Beatriz; Fernández, Bárbara; Fernández, Eloy; Mundo, Silvia Leonor

2011-01-01

Lipoarabinomannan (LAM) is a major glycolipidic antigen on the mycobacterial envelope. The aim of this study was to characterize the humoral immune response induced by immunization with a LAM extract in bovines and to evaluate the role of the generated antibodies in the in vitro infection of macrophages with Mycobacterium avium subsp. paratuberculosis (MAP). Sera from fourteen calves immunized with LAM extract or PBS emulsified in Freund's Incomplete Adjuvant and from five paratuberculosis-infected bovines were studied. LAM-immunized calves developed specific antibodies with IgG1 as the predominant isotype. Serum immunoglobulins were isolated and their effect was examined in MAP ingestion and viability assays using a bovine macrophage cell line. Our results show that the antibodies generated by LAM immunization significantly increase MAP ingestion and reduce its intracellular viability, suggesting an active role in this model. PMID:21772964

Antibodies Induced by Lipoarabinomannan in Bovines: Characterization and Effects on the Interaction between Mycobacterium Avium Subsp. Paratuberculosis and Macrophages In Vitro.

PubMed

Jolly, Ana; Colavecchia, Silvia Beatriz; Fernández, Bárbara; Fernández, Eloy; Mundo, Silvia Leonor

2011-01-01

Lipoarabinomannan (LAM) is a major glycolipidic antigen on the mycobacterial envelope. The aim of this study was to characterize the humoral immune response induced by immunization with a LAM extract in bovines and to evaluate the role of the generated antibodies in the in vitro infection of macrophages with Mycobacterium avium subsp. paratuberculosis (MAP). Sera from fourteen calves immunized with LAM extract or PBS emulsified in Freund's Incomplete Adjuvant and from five paratuberculosis-infected bovines were studied. LAM-immunized calves developed specific antibodies with IgG1 as the predominant isotype. Serum immunoglobulins were isolated and their effect was examined in MAP ingestion and viability assays using a bovine macrophage cell line. Our results show that the antibodies generated by LAM immunization significantly increase MAP ingestion and reduce its intracellular viability, suggesting an active role in this model.

New compounds, nanaomycin F and G, discovered by physicochemical screening from a culture broth of Streptomyces rosa subsp. notoensis OS-3966.

PubMed

Nakashima, Takuji; Boonsnongcheep, Panitch; Kimura, Toru; Iwatsuki, Masato; Sato, Noriko; Nonaka, Kenichi; Prathanturarug, Sompop; Takahashi, Yōko; Ōmura, Satoshi

2015-11-01

Two new compounds, nanaomycin F and G, were isolated by physicochemical screening method from cultured broth of Streptomyces rosa subsp. notoensis OS-3966, which is known to produce nanaomycin A, B, C, D, and E. Nanaomycin F is a new nanaomycin analog, a 4a-hydroxyl analog of nanaomycin B. Nanaomycin G has a unique skeleton with 1-indanone infused with a tetrahydropyran ring. Nanaomycin A possesses broad antimicrobial activity but nanaomycin F and G demonstrated no bioactivity against all bacteria and fungi tested in this study. In addition, in both nanaomycin F and G, the production of superoxide radicals was majorly decreased in comparison to nanaomycin A. It was considered that the antimicrobial properties were lost as a result of the decrease in production of the superoxide radicals. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Antifungal activity and isomerization of octadecyl p-coumarates from Ipomoea carnea subsp. fistulosa.

PubMed

Nidiry, Eugene Sebastian J; Ganeshan, Girija; Lokesha, Ankanahalli N

2011-12-01

Bioassay monitored HPLC assisted isolation and purification of the chief antifungal fraction of the leaves of Ipomoea carnea subsp. fistulosa (Convulvulaceae) were achieved using Colletotrichum gloeosporioides and Cladosporium cucumerinum as test organisms. The activity of the purified fraction was further confirmed by the dose dependent inhibition of the spore germination of Alternaria alternata and A. porri. The active fraction was identified as a mixture of (E)-octadecyl p-coumarate and (Z)-octadecyl p-coumarate. The two isomers were detected on an HPLC column with substantially different retention times, but once eluted from the column, one form was partly converted to the other in daylight. Conclusive evidence for the structures and their isomerization were obtained from the HPLC behavior, IR, UV, HRESIMS, CIMS and and NMR spectral data. Important 1H NMR and 13C NMR signals could be separately assigned for the isomers using 2D NMR techniques.

Prevalence of emm types and antimicrobial susceptibility of Streptococcus dysgalactiae subsp. equisimilis in Austria.

PubMed

Leitner, Eva; Zollner-Schwetz, Ines; Zarfel, Gernot; Masoud-Landgraf, Lilian; Gehrer, Michael; Wagner-Eibel, Ute; Grisold, Andrea J; Feierl, Gebhard

2015-12-01

An increase of severe infections caused by Streptococcus dysgalactiae subsp. equisimilis (SDSE) similar to infections caused by Streptococcus pyogenes has been reported over the last years. Little is known about infections with SDSE in Austria. Therefore, we investigated a collection of 113 SDSE invasive and non-invasive isolates from different infection sites and type of infections as well as patients' characteristics. The isolates were phenotypically identified and emm typed using the enlarged emm database from the Centers for Disease Control and Prevention. Additionally, 13 antimicrobial agents were tested using EUCAST guidelines and virulence genes were investigated. Severe SDSE infections were most common in elderly men with underlying diseases especially diabetes mellitus. With VitekMS identification of SDSE isolates was successful to the species level only. Emm typing revealed 24 different emm types, one new type and one new subtype. StG485, stG6, stC74a, stG643, and stG480 were the predominant types in this study, stC74a and stG652 in invasive infections and stG643, stC74a and stG485 in non-invasive infections. Resistance was observed to tetracycline (62%), macrolides (13%) with one M phenotype, and clindamycin (12%) presenting 6 constitutive MLS(B) phenotypes and 8 inducible MLS(B) phenotypes. Levofloxacin resistance was detected only in one isolate. All isolates tested for virulence genes were positive for scpA, ska, saga and slo. Superantigenic genes were negative except speG(dys) (positive 17/34; 50%). This paper presents the first report of SDSE infections in Austria. Severe SDSE infections were found mainly in elderly men with underlying diseases. SDSE isolates demonstrated substantial emm type diversity without association with infections site or invasiveness. Analysis of virulence genes showed no significant difference between invasive and non-invasive infections. Copyright © 2015 Elsevier GmbH. All rights reserved.

Licheniocin 50.2 and Bacteriocins from Lactococcus lactis subsp. lactis biovar. diacetylactis BGBU1-4 Inhibit Biofilms of Coagulase Negative Staphylococci and Listeria monocytogenes Clinical Isolates

PubMed Central

Draganic, Veselin; Lozo, Jelena; Beric, Tanja; Kojic, Milan; Arsic, Biljana; Garalejic, Eliana; Djukic, Slobodanka; Stankovic, Slavisa

2016-01-01

Background Coagulase negative staphylococci (CoNS) and Listeria monocytogenes have important roles in pathogenesis of various genital tract infections and fatal foetomaternal infections, respectively. The aim of our study was to investigate the inhibitory effects of two novel bacteriocins on biofilms of CoNS and L. monocytogenes genital isolates. Methods The effects of licheniocin 50.2 from Bacillus licheniformis VPS50.2 and crude extract of bacteriocins produced by Lactococcus lactis subsp. lactis biovar. diacetylactis BGBU1-4 (BGBU1-4 crude extract) were evaluated on biofilm formation and formed biofilms of eight CoNS (four S. epidermidis, two S. hominis, one S. lugdunensis and one S. haemolyticus) and 12 L. monocytogenes genital isolates. Results Licheniocin 50.2 and BGBU1-4 crude extract inhibited the growth of both CoNS and L. monocytogenes isolates, with MIC values in the range between 200–400 AU/ml for licheniocin 50.2 and 400–3200 AU/ml for BGBU1-4 crude extract. Subinhibitory concentrations (1/2 × and 1/4 × MIC) of licheniocin 50.2 inhibited biofilm formation by all CoNS isolates (p < 0.05, respectively), while BGBU1-4 crude extract inhibited biofilm formation by all L. monocytogenes isolates (p < 0.01 and p < 0.05, respectively). Both bacteriocins in concentrations of 100 AU/mL and 200 AU/mL reduced the amount of 24 h old CoNS and L. monocytogenes biofilms (p < 0.05, p < 0.01, p < 0.001). Conclusions This study suggests that novel bacteriocins have potential to be used for genital application, to prevent biofilm formation and/or to eradicate formed biofilms, and consequently reduce genital and neonatal infections by CoNS and L. monocytogenes. PMID:27930711

Draft genome sequence of CTX-M-type β-lactamase-producing Klebsiella quasipneumoniae subsp. similipneumoniae isolated from a Box turtle.

PubMed

Li, Chien-Feng; Tang, Hui-Ling; Chiou, Chien-Shun; Tung, Kwong-Chung; Lu, Min-Chi; Lai, Yi-Chyi

2018-03-01

Klebsiella spp. are regarded as major pathogens causing infections in humans and various animals. Here we report the draft genome sequence of a CTX-M-type β-lactamase-producing Klebsiella quasipneumoniae subsp. similipneumoniae strain CHKP0062 isolated from a Yellow-margined Box turtle. An Illumina-Solexa platform was used to sequence the genome of CHKP0062. Qualified reads were assembled de novo using Velvet. The draft genome was annotated by the NCBI Prokaryotic Genome Annotation Pipeline (PGAP). The resistome and virulome of the strain were investigated. A total of 5423 protein-coding sequences, 87 tRNAs, 24 rRNAs and 12 ncRNAs were identified in the 5 699 275-bp genome. CHKP0062 was assigned to sequence type ST2131 with the K-loci type as KL67. No virulence-associated genes were identified. However, numerous antimicrobial resistance genes were present in this strain. Plasmid contigs were assembled and revealed homology to the multidrug resistance plasmids pC15-K, pCTX-M3 and pKF3-94, with the carriage of the class A β-lactamase genes bla TEM-1b and bla CTX-M-3 . The genome sequence reported in this study will be useful for comparative genomic analysis regarding the dissemination of clinically important antibiotic resistance genes among Klebsiella spp. isolated from humans and animals. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Utilization of galactooligosaccharides by Bifidobacterium longum subsp. infantis isolates

PubMed Central

Garrido, Daniel; Ruiz-Moyano, Santiago; Jimenez-Espinoza, Rogelio; Eom, Hyun-Ju; Block, David E.; Mills, David A.

2013-01-01

Prebiotics are non-digestible substrates that stimulate the growth of beneficial microbial populations in the intestine, especially Bifidobacterium species. Among them, fructo- and galacto-oligosaccharides are commonly used in the food industry, especially as a supplement for infant formulas. Mechanistic details on the enrichment of bifidobacteria by these prebiotics are important to understand the effects of these dietary interventions. In this study the consumption of galactooligosaccharides was studied for 22 isolates of Bifidobacterium longum subsp. infantis, one of the most representative species in the infant gut microbiota. In general all isolates showed a vigorous growth on these oligosaccharides, but consumption of larger galactooligosaccharides was variable. Bifidobacterium infantis ATCC 15697 has five genes encoding β-galactosidases, and three of them were induced during bacterial growth on commercial galactooligosaccharides. Recombinant β-galactosidases from B. infantis ATCC 15697 displayed different preferences for β-galactosides such as 4′ and 6′-galactobiose, and four β-galactosidases in this strain released monosaccharides from galactooligosaccharides. Finally, we determined the amounts of short chain fatty acids produced by strain ATCC 15697 after growth on different prebiotics. We observed that biomass and product yields of substrate were higher for lactose and galactooligosaccharides, but the amount of acids produced per cell was larger after growth on human milk oligosaccharides. These results provide a molecular basis for galactooligosaccharide consumption in B. infantis, and also represent evidence for physiological differences in the metabolism of prebiotics that might have a differential impact on the host. PMID:23200660

Clonal population structure of Legionella pneumophila inferred from allelic profiling.

PubMed

Edwards, Martin T; Fry, Norman K; Harrison, Timothy G

2008-03-01

The population structure of Legionella pneumophila was investigated by analysing nucleotide sequences from six loci (flaA, pilE, asd, mip, mompS and proA) of 335 globally distributed isolates from clinical and environmental sources over a 29-year period (1977-2006). Data were obtained from unrelated isolates from Europe (n=270), Japan (n=31), Canada (n=7), the USA (n=24) and Australia (n=1). The country of origin of two strains was unknown. Analysis of these isolates indicated significant linkage disequilibrium between the six loci. Application of six sequence-based recombination detection tests did not reveal evidence of recombination, but estimates of rates of recombination and mutation made by a seventh test suggested that recombination could have occurred at a rate similar to, but probably lower than, that of mutation. Genealogies inferred under models with and without recombination were congruent with each other, providing no definitive evidence regarding recombination, and were in agreement with sequence clusters identified by graph methods. Further evidence supporting the distinct nature of two of the three subspecies of L. pneumophila, subsp. fraseri and subsp. pascullei, was also found. The ratios of non-synonymous to synonymous nucleotide polymorphisms for each of the allele sets were examined and revealed that the putative virulence loci mompS and pilE are under diversifying pressure, while the allelic regions of three other loci linked to virulence (flaA, proA and mip) do not appear to be.

Detection of Streptococcus pyogenes virulence genes in Streptococcus dysgalactiae subsp. equisimilis from Vellore, India.

PubMed

Babbar, Anshu; Itzek, Andreas; Pieper, Dietmar H; Nitsche-Schmitz, D Patric

2018-03-12

Streptococcus dysgalactiae subsp. equisimilis (SDSE), belonging to the group C and G streptococci, are human pathogens reported to cause clinical manifestations similar to infections caused by Streptococcus pyogenes. To scrutinize the distribution of gene coding for S. pyogenes virulence factors in SDSE, 255 isolates were collected from humans infected with SDSE in Vellore, a region in southern India, with high incidence of SDSE infections. Initial evaluation indicated SDSE isolates comprising of 82.35% group G and 17.64% group C. A multiplex PCR system was used to detect 21 gene encoding virulence-associated factors of S. pyogenes, like superantigens, DNases, proteinases, and other immune modulatory toxins. As validated by DNA sequencing of the PCR products, sequences homologous to speC, speG, speH, speI, speL, ssa and smeZ of the family of superantigen coding genes and for DNases like sdaD and sdc were detected in the SDSE collection. Furthermore, there was high abundance (48.12% in group G and 86.6% in group C SDSE) of scpA, the gene coding for C5a peptidase in these isolates. Higher abundance of S. pyogenes virulence factor genes was observed in SDSE of Lancefield group C as compared to group G, even though the incidence rates in former were lower. This study not only substantiates detection of S. pyogenes virulence factor genes in whole genome sequenced SDSE but also makes significant contribution towards the understanding of SDSE and its increasing virulence potential.

Emended description of Salinivibrio proteolyticus, including Salinivibrio costicola subsp. vallismortis and five new isolates.

PubMed

López-Hermoso, Clara; de la Haba, Rafael R; Sánchez-Porro, Cristina; Ventosa, Antonio

2018-05-01

We carried out a comparative taxonomic study of Salinivibrio proteolyticus and Salinivibrio costicola subsp. vallismortis, as well as of five halophilic strains (IB574, IB872, PR5, PR919 and PR932), isolated from salterns in Spain and Puerto Rico that were closely related to these bacteria. Multilocus sequence analysis of concatenated gyrB, recA, rpoA and rpoD housekeeping genes showed that they constituted a single cluster separate from the other species and subspecies of Salinivibrio. Experimental and in silico DNA-DNA hybridization studies indicated that they are members of the same species, with relatedness of 100-74 % and 97.8-70.0 %, respectively. The average nucleotide identity (ANI) determined for these strains was 99.7-95.6 % for ANIb and 99.7-95.7 % for OrthoANI. However, the ANI values for S. costicolasubsp.vallismortis DSM 8285 T with respect to S. costicolasubsp.costicola DSM 11403 T and S. costicolasubsp.alcaliphilus DSM 16359 T were 78.7 and 78.9 % (ANIb) and 79.4 and 79.4 % (OrthoANI), respectively. The phylogenomic tree based on 1072 concatenated orthologous single-copy core genes confirmed that S. proteolyticus, S. costicolasubsp.vallismortis and the five new isolates constitute a coherent single phylogroup, separated from the other species and subspecies of Salinivibrio. All these data indicate that S. costicolasubsp.vallismortis is a heterotypic synonym of S. proteolyticus and we propose an emended description of this species.

Combined use of a new SNP-based assay and multilocus SSR markers to assess genetic diversity of Xylella fastidiosa subsp. pauca infecting citrus and coffee plants.

PubMed

Montes-Borrego, Miguel; Lopes, Joao R S; Jiménez-Díaz, Rafael M; Landa, Blanca B

2015-03-01

Two haplotypes of Xylella fastidiosa subsp. pauca (Xfp) that correlated with their host of origin were identified in a collection of 90 isolates infecting citrus and coffee plants in Brazil, based on a single-nucleotide polymorphism in the gyrB sequence. A new single-nucleotide primer extension (SNuPE) protocol was designed for rapid identification of Xfp according to the host source. The protocol proved to be robust for the prediction of the Xfp host source in blind tests using DNA from cultures of the bacterium, infected plants, and insect vectors allowed to feed on Xfp-infected citrus plants. AMOVA and STRUCTURE analyses of microsatellite data separated most Xfp populations on the basis of their host source, indicating that they were genetically distinct. The combined use of the SNaPshot protocol and three previously developed multilocus SSR markers showed that two haplotypes and distinct isolates of Xfp infect citrus and coffee in Brazil and that multiple, genetically different isolates can be present in a single orchard or infect a single tree. This combined approach will be very useful in studies of the epidemiology of Xfp-induced diseases, host specificity of bacterial genotypes, the occurrence of Xfp host jumping, vector feeding habits, etc., in economically important cultivated plants or weed host reservoirs of Xfp in Brazil and elsewhere. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

Starch Flocculation by the Sweet Potato Sour Liquid Is Mediated by the Adhesion of Lactic Acid Bacteria to Starch

PubMed Central

Zhang, Lili; Yu, Yang; Li, Xinhua; Li, Xiaona; Zhang, Huajiang; Zhang, Zhen; Xu, Yunhe

2017-01-01

In the current study, we focused on the mechanism underlying starch flocculation by the sweet potato sour liquid. The traditional microbial techniques and 16S rDNA sequencing revealed that Lactobacillus was dominant flocculating microorganism in sour liquid. In total, 86 bacteria, 20 yeasts, and 10 molds were isolated from the sour liquid and only eight Lactobacillus species exhibited flocculating activity. Lactobacillus paracasei subsp. paracasei L1 strain with a high flocculating activity was isolated and identified, and the mechanism of starch flocculation was examined. L. paracasei subsp. paracasei L1 cells formed chain-like structures on starch granules. Consequently, these cells connected the starch granules to one another, leading to formation of large flocs. The results of various treatments of L1 cells indicated that bacterial surface proteins play a role in flocculation and L1 cells adhered to the surface of starch granules via specific surface proteins. These surface starch-binding proteins were extracted using the guanidine hydrochloride method; 10 proteins were identified by mass spectrometry: three of these proteins were glycolytic enzymes; two were identified as the translation elongation factor Tu; one was a cell wall hydrolase; one was a surface antigen; one was lyzozyme M1; one was a glycoside hydrolase; and one was an uncharacterized proteins. This study will paves the way for future industrial application of the L1 isolate in starch processing and food manufacturing. PMID:28791000

Comparative genomics of Campylobacter fetus from reptiles and mammals reveals divergent evolution in host-associated lineages

USDA-ARS?s Scientific Manuscript database

Campylobacter fetus currently comprises three recognized subspecies: C. fetus subsp. fetus, C. fetus subsp. venerealis, and C. fetus subsp. testudinum, which display a distinct host association. Both C. fetus subsp. fetus and C. fetus subsp. venerealis are associated with endothermic mammals, primar...

Tularaemia in a brown hare (Lepus europaeus) in 2013: first case in the Netherlands in 60 years.

PubMed

Rijks, J M; Kik, M; Koene, M G; Engelsma, M Y; van Tulden, P; Montizaan, M G; Oomen, T; Spierenburg, M A; Ijzer, J; van der Giessen, J W; Gröne, A; Roest, H J

2013-12-05

Tularaemia has not been reported in Dutch wildlife since 1953. To enhance detection, as of July 2011, brown hares (Lepus europaeus) submitted for postmortem examination in the context of non-targeted wildlife disease surveillance, were routinely tested for tularaemia by polymerase chain reaction (PCR). Francisella tularensis subspecies holarctica infection was confirmed in a hare submitted in May 2013. The case occurred in Limburg, near the site of the 1953 case. Further surveillance should clarify the significance of this finding.

Whole genome sequencing of the fish pathogen Francisella noatunensis subsp. orientalis Toba04 gives novel insights into Francisella evolution and pathogenecity

PubMed Central

2012-01-01

Background Francisella is a genus of gram-negative bacterium highly virulent in fishes and human where F. tularensis is causing the serious disease tularaemia in human. Recently Francisella species have been reported to cause mortality in aquaculture species like Atlantic cod and tilapia. We have completed the sequencing and draft assembly of the Francisella noatunensis subsp. orientalisToba04 strain isolated from farmed Tilapia. Compared to other available Francisella genomes, it is most similar to the genome of Francisella philomiragia subsp. philomiragia, a free-living bacterium not virulent to human. Results The genome is rearranged compared to the available Francisella genomes even though we found no IS-elements in the genome. Nearly 16% percent of the predicted ORFs are pseudogenes. Computational pathway analysis indicates that a number of the metabolic pathways are disrupted due to pseudogenes. Comparing the novel genome with other available Francisella genomes, we found around 2.5% of unique genes present in Francisella noatunensis subsp. orientalis Toba04 and a list of genes uniquely present in the human-pathogenic Francisella subspecies. Most of these genes might have transferred from bacterial species through horizontal gene transfer. Comparative analysis between human and fish pathogen also provide insights into genes responsible for pathogenecity. Our analysis of pseudogenes indicates that the evolution of Francisella subspecies’s pseudogenes from Tilapia is old with large number of pseudogenes having more than one inactivating mutation. Conclusions The fish pathogen has lost non-essential genes some time ago. Evolutionary analysis of the Francisella genomes, strongly suggests that human and fish pathogenic Francisella species have evolved independently from free-living metabolically competent Francisella species. These findings will contribute to understanding the evolution of Francisella species and pathogenesis. PMID:23131096

Essential oil of Juniperus communis subsp. alpina (Suter) Čelak needles: chemical composition, antifungal activity and cytotoxicity.

PubMed

Cabral, C; Francisco, V; Cavaleiro, C; Gonçalves, M J; Cruz, M T; Sales, F; Batista, M T; Salgueiro, L

2012-09-01

Essential oils are known to possess antimicrobial activity against a wide spectrum of bacteria and fungi. In the present work the composition and the antifungal activity of the oils of Juniperus communis subsp. alpina (Suter) Čelak were evaluated. Moreover, the skin cytotoxicity, at concentrations showing significant antifungal activity, was also evaluated. The oils were isolated by hydrodistillation and analysed by gas chromatography and gas chromatography-mass spectrometry. Minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) were used to evaluate the antifungal activity of the oil against dermatophytes (Epidermophyton floccosum, Microsporum canis, M. gypseum, Trichophyton mentagrophytes, T. mentagrophytes var. interdigitale, T. rubrum, T. verrucosum), yeasts (Candida albicans, C. guillermondii, C. krusei, C. parapsilosis, C. tropicalis, Cryptococcus neoformans) and Aspergillus species (Aspergillus flavus, A. fumigatus, A. niger). Cytotoxicity was tested in HaCaT keratinocytes through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Essential oil of J. communis subsp. alpina needles was predominantly composed of monoterpene hydrocarbons (78.4%), with the main compounds being sabinene (26.2%), α-pinene (12-9%) and limonene (10.4%). Results concerning the antifungal activity demonstrated the potential of needle oil against dermatophytes, particularly for Microsporum canis and Trichophyton rubrum with MIC and MLC of 0.32 μL/mL. Furthermore, evaluation of cell viability showed no significant cytotoxicity in HaCaT keratinocytes at concentrations between 0.32 and 0.64 μL/mL. These results show that it is possible to find appropriate doses of J. communis subsp. alpina oil with both antifungal activity and a very low detrimental effect on keratinocytes. Copyright © 2012 John Wiley & Sons, Ltd.

Sensitive and specific enzyme-linked immunosorbent assay for detecting serum antibodies against Mycobacterium avium subsp. paratuberculosis in fallow deer.

PubMed

Prieto, José M; Balseiro, Ana; Casais, Rosa; Abendaño, Naiara; Fitzgerald, Liam E; Garrido, Joseba M; Juste, Ramon A; Alonso-Hearn, Marta

2014-08-01

The enzyme-linked immunosorbent assay (ELISA) is the diagnostic test most commonly used in efforts to control paratuberculosis in domestic ruminants. However, commercial ELISAs have not been validated for detecting antibodies against Mycobacterium avium subsp. paratuberculosis in wild animals. In this study, we compared the sensitivities and specificities of five ELISAs using individual serum samples collected from 41 fallow deer with or without histopathological lesions consistent with paratuberculosis. Two target antigenic preparations were selected, an ethanol-treated protoplasmic preparation obtained from a fallow deer M. avium subsp. paratuberculosis isolate (ELISAs A and B) and a paratuberculosis protoplasmic antigen (PPA3) (ELISAs C and D). Fallow deer antibodies bound to the immobilized antigens were detected by using a horseradish peroxidase (HRP)-conjugated anti-fallow deer IgG antibody (ELISAs A and C) or HRP-conjugated protein G (ELISAs B and D). A commercially available assay, ELISA-E, which was designed to detect M. avium subsp. paratuberculosis antibodies in cattle, sheep, and goats, was also tested. Although ELISAs A, C, and E had the same sensitivity (72%), ELISAs A and C were more specific (100%) for detecting fallow deer with lesions consistent with paratuberculosis at necropsy than was the ELISA-E (87.5%). In addition, the ELISA-A was particularly sensitive for detecting fallow deer in the latent stages of infection (62.5%). The antibody responses detected with the ELISA-A correlated with both the severity of enteric lesions and the presence of acid-fast bacteria in gut tissue samples. In summary, our study shows that the ELISA-A can be a cost-effective diagnostic tool for preventing the spread of paratuberculosis among fallow deer populations. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Sensitive and Specific Enzyme-Linked Immunosorbent Assay for Detecting Serum Antibodies against Mycobacterium avium subsp. paratuberculosis in Fallow Deer

PubMed Central

Prieto, José M.; Balseiro, Ana; Casais, Rosa; Abendaño, Naiara; Fitzgerald, Liam E.; Garrido, Joseba M.; Juste, Ramon A.

2014-01-01

The enzyme-linked immunosorbent assay (ELISA) is the diagnostic test most commonly used in efforts to control paratuberculosis in domestic ruminants. However, commercial ELISAs have not been validated for detecting antibodies against Mycobacterium avium subsp. paratuberculosis in wild animals. In this study, we compared the sensitivities and specificities of five ELISAs using individual serum samples collected from 41 fallow deer with or without histopathological lesions consistent with paratuberculosis. Two target antigenic preparations were selected, an ethanol-treated protoplasmic preparation obtained from a fallow deer M. avium subsp. paratuberculosis isolate (ELISAs A and B) and a paratuberculosis protoplasmic antigen (PPA3) (ELISAs C and D). Fallow deer antibodies bound to the immobilized antigens were detected by using a horseradish peroxidase (HRP)-conjugated anti-fallow deer IgG antibody (ELISAs A and C) or HRP-conjugated protein G (ELISAs B and D). A commercially available assay, ELISA-E, which was designed to detect M. avium subsp. paratuberculosis antibodies in cattle, sheep, and goats, was also tested. Although ELISAs A, C, and E had the same sensitivity (72%), ELISAs A and C were more specific (100%) for detecting fallow deer with lesions consistent with paratuberculosis at necropsy than was the ELISA-E (87.5%). In addition, the ELISA-A was particularly sensitive for detecting fallow deer in the latent stages of infection (62.5%). The antibody responses detected with the ELISA-A correlated with both the severity of enteric lesions and the presence of acid-fast bacteria in gut tissue samples. In summary, our study shows that the ELISA-A can be a cost-effective diagnostic tool for preventing the spread of paratuberculosis among fallow deer populations. PMID:24872517

In Vitro Inhibition of Klebsiella pneumoniae by Lactobacillus delbrueckii Subsp. delbrueckii LDD01 (DSM 22106): An Innovative Strategy to Possibly Counteract Such Infections in Humans?

PubMed

Mogna, Luca; Deidda, Francesca; Nicola, Stefania; Amoruso, Angela; Del Piano, Mario; Mogna, Giovanni

To determine the in vitro antimicrobial activity of selected Lactobacillus strains isolated from the feces of healthy humans against Klebsiella pneumoniae. Klebsiella is ubiquitous in nature and may colonize the skin, the pharynx, or the gastrointestinal tract of humans. Despite the widespread use of antibiotic molecules with a broad spectrum in hospitalized patients, an increased overall load of klebsiellae as well as the subsequent development of multidrug-resistant strains able to synthesize extended-spectrum beta-lactamase have been registered. These strains are particularly virulent, express capsular-type K55, and have a considerable ability to propagate. The 4 strains Lactobacillus paracasei LPC01 (CNCM I-1390), Lactobacillus rhamnosus LR04 (DSM 16605), Bifidobacterium longum B2274 (DSM 24707), and Lactobacillus delbrueckii subsp. delbrueckii LDD01 (DSM 22106) were tested. The analysis was performed using both a disc-diffusion assay and the broth-dilution procedure, also including an evaluation of the supernatants obtained from a fresh broth culture of each bacterium. L. delbrueckii subsp. delbrueckii LDD01 demonstrated the best inhibitory results among all the tested strains. The antibacterial activity of the supernatant was retained even after treatment with α-amylase and neutralization with NaOH 1N, thus suggesting the protein structure of the inhibitory molecule. In contrast, it was completely lost after treatment with proteinase K. Overall results suggest that the inhibitory effect of L. delbrueckii subsp. delbrueckii LDD01 should be attributed to the production of a bacteriocin. This strain may be prospectively useful for strengthening probiotic formulations and possibly counteract infections by K. pneumoniae in humans.

Diagnostics for Yaws Eradication: Insights From Direct Next-Generation Sequencing of Cutaneous Strains of Treponema pallidum.

PubMed

Marks, Michael; Fookes, Maria; Wagner, Josef; Butcher, Robert; Ghinai, Rosanna; Sokana, Oliver; Sarkodie, Yaw-Adu; Lukehart, Sheila A; Solomon, Anthony W; Mabey, David C W; Thomson, Nicholas

2018-03-05

Yaws-like chronic ulcers can be caused by Treponema pallidum subspecies pertenue, Haemophilus ducreyi, or other, still-undefined bacteria. To permit accurate evaluation of yaws elimination efforts, programmatic use of molecular diagnostics is required. The accuracy and sensitivity of current tools remain unclear because our understanding of T. pallidum diversity is limited by the low number of sequenced genomes. We tested samples from patients with suspected yaws collected in the Solomon Islands and Ghana. All samples were from patients whose lesions had previously tested negative using the Centers for Disease Control and Prevention (CDC) diagnostic assay in widespread use. However, some of these patients had positive serological assays for yaws on blood. We used direct whole-genome sequencing to identify T. pallidum subsp pertenue strains missed by the current assay. From 45 Solomon Islands and 27 Ghanaian samples, 11 were positive for T. pallidum DNA using the species-wide quantitative polymerase chain reaction (PCR) assay, from which we obtained 6 previously undetected T. pallidum subsp pertenue whole-genome sequences. These show that Solomon Islands sequences represent distinct T. pallidum subsp pertenue clades. These isolates were invisible to the CDC diagnostic PCR assay, due to sequence variation in the primer binding site. Our data double the number of published T. pallidum subsp pertenue genomes. We show that Solomon Islands strains are undetectable by the PCR used in many studies and by health ministries. This assay is therefore not adequate for the eradication program. Next-generation genome sequence data are essential for these efforts. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Phytochemical Composition and Antinociceptive Activity of Bauhinia glauca subsp. hupehana in Rats

PubMed Central

Xu, Jinlong; Zhao, Qizhi; Wei, Lei; Yang, Yu; Xu, Rui; Yu, Nengjiang; Zhao, Yimin

2015-01-01

In traditional medicine, Bauhinia glauca subsp. hupehana has long been used as an analgesic agent in China. The aim of this study was to evaluate the antinociceptive activity of the ethanol extract of the aerial parts of B. glauca subsp. hupehana (BHE) in rats and its chemical fingerprint. The antinociceptive activity of BHE was assessed in mice using chemically and heat–induced pain models, such as the acetic acid–induced writhing, hot plate, tail–flick and glutamate tests. Naltrexone hydrochloride, a non–selective opioid receptor antagonist, was utilized to determine the involvement of the opioid system. In addition to this, the involvements of the cGMP and ATP–sensitive K+ channel pathways were also detected using methylene blue and glibenclamide. The oral administration of BHE (at doses of 50, 100 and 200 mg/kg) produced significant and dose–related inhibitions in both the chemically and heat–induced pain models. Interestingly, in the abdominal constriction test, when the dose of BHE was increased to 800 mg/kg (p.o., n = 10), the inhibition rate was 100%. The antinociceptive mechanism may involve the cGMP pathway and ATP sensitive K+ channel pathway. The central antinociceptive effect was not antagonized by naltrexone. One phenolic acid, one lignin and five flavonoids were isolated from BHE. The antinociceptive activity of BHE was most likely due to the presence of the flavonoids. The acute toxicity results showed that BHE was safe at a high dose (2 g/kg, p.o.). The current investigation demonstrates that B. glauca subsp. hupehana is a potential candidate for the development of novel, non–opioid, analgesic phytomedicines. PMID:25658740

Non-tuberculous Mycobacteria isolated from lymph nodes and faecal samples of healthy slaughtered cattle and the abattoir environment.

PubMed

Ghielmetti, G; Friedel, U; Scherrer, S; Sarno, E; Landolt, P; Dietz, O; Hilbe, M; Zweifel, C; Stephan, R

2018-06-01

Infections caused by non-tuberculous mycobacteria (NTM) are reported as emerging disease in many countries worldwide. The occurrence of NTM in different hosts and their implication as obligate or opportunistic pathogen remain largely unclear. Lymph nodes and faecal samples of clinically healthy Swiss cattle at slaughter were analysed for the presence of NTM. Based on the examined lymph nodes, NTM were detected in 20% of 108 cattle originating from different premises. The 22 isolates belonged to five different species of Mycobacteria (M. avium subsp. hominissuis, M. kansasii, M. persicum, "M. lymphaticum" and M. europaeum). M. avium subsp. hominissuis (63%) and M. kansasii (18%) thereby predominated and were found in lymph nodes with and without macroscopic changes. Moreover, M. persicum found in two cattle has recently been described as a human pathogen and is closely related to M. kansasii. Amongst cattle with lymph nodes positive for mycobacteria, viable NTM were occasionally also detected in bovine faeces. However, the isolated NTM species from lymph nodes and respective faecal samples (M. hassiacum, M. phlei and M. vaccae) did not coincide. Moreover, NTM species identified amongst isolates from the slaughterhouse environment clearly differed from those from lymph nodes and faecal samples, excluding cross-contamination of the tissue specimens through the environment or laboratory processing. Assuming that some NTM interfere with the detection of bovine tuberculosis (bTB), the present findings in healthy animals emphasize the need of more specific diagnostic tools for bTB eradication programs. © 2017 The Authors. Transboundary and Emerging Diseases Published by Blackwell Verlag GmbH.

Antibacterial screening of Rumex species native to the Carpathian Basin and bioactivity-guided isolation of compounds from Rumex aquaticus.

PubMed

Orbán-Gyapai, Orsolya; Liktor-Busa, Erika; Kúsz, Norbert; Stefkó, Dóra; Urbán, Edit; Hohmann, Judit; Vasas, Andrea

2017-04-01

Plants belonging to the genus Rumex (family Polygonaceae) are used worldwide in traditional medicine for the treatment of various diseases caused by different microorganisms (e.g. bacteria-related dermatologic conditions, dysentery and enteritis). The present study focused on the antibacterial screening of Rumex species native to the Carpathian Basin, and isolation of compounds from one of the most efficient species, Rumex aquaticus. The antibacterial effects of n-hexane, chloroform and aqueous fractions of methanol extracts prepared from different parts of 14 Rumex species (R. acetosella, R. acetosa, R. alpinus, R. aquaticus, R. conglomeratus, R. crispus, R. hydrolapathum, R. obtusifolius subsp. obtusifolius, R. obtusifolius subsp. subalpinus, R. patientia, R. pulcher, R. scutatus, R. stenophyllus and R. thyrsiflorus) were investigated against Staphylococcus epidermidis, S. aureus, MRSA, Bacillus subtilis, Moraxella catarrhalis, Streptococcus pyogenes, S. pneumoniae, S. agalactiae, Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae using the disc diffusion method. Mainly the n-hexane and chloroform extracts prepared from the roots of the plants displayed high antibacterial activity (inhibition zones>15mm) against one or more bacterial strains. The highly active extracts of the aerial part and root of R. aquaticus were subjected to a multistep separation procedure. 19 Compounds, among them naphthalenes (musizin, and its glucoside, torachrysone-glucoside, 2-methoxystypandrone), anthraquinones (emodin, chrysophanol, physcion, citreorosein, chrysophanol-8-O-glucoside), flavonoids (quercetin, quercetin-3,3'-dimethylether, isokaempferide, quercetin 3-O-arabinoside, quercetin 3-O-galactoside, catechin), stilbenes (resveratrol, piceid), and 1-stearoylglycerol were isolated from the plant. The antibacterial activities of isolated compounds were determined, and it was observed that especially naphthalenes exerted remarkable antibacterial effects against several bacterial strains. Copyright © 2017 Elsevier B.V. All rights reserved.

Wild Griffon Vultures (Gyps fulvus) as a Source of Salmonella and Campylobacter in Eastern Spain

PubMed Central

Marin, Clara; Palomeque, Maria-Dolores; Marco-Jiménez, Francisco; Vega, Santiago

2014-01-01

The existence of Campylobacter and Salmonella reservoirs in wildlife is a potential hazard to animal and human health; however, the prevalence of these species is largely unknown. Until now, only a few studies have evaluated the presence of Campylobacter and Salmonella in wild griffon vultures and based on a small number of birds. The aim of this study was to evaluate the presence of Campylobacter and Salmonella in wild griffon vultures (n = 97) during the normal ringing programme at the Cinctorres Observatory in Eastern Spain. In addition, the effect of ages of individuals (juveniles, subadult and adult) on the presence were compared. Campylobacter was isolated from 1 of 97 (1.0%) griffon vultures and identified as C. jejuni. Salmonella was isolated from 51 of 97 (52.6%) griffon vultures. No significant differences were found between the ages of individuals for the presence of Salmonella. Serotyping revealed 6 different serovars among two Salmonella enterica subspecies; S. enterica subsp. enterica (n = 49, 96.1%) and S. enterica subsp. salamae (n = 2, 3.9%). No more than one serovar was isolated per individual. The serovars isolated were S. Typhimurium (n = 42, 82.3%), S. Rissen (n = 4, 7.8%), S. Senftenberg (n = 3, 5.9%) and S. 4,12:b[-] (n = 2, 3.9%). Our results imply that wild griffon vultures are a risk factor for Salmonella transmission, but do not seem to be a reservoir for Campylobacter. We therefore rule out vultures as a risk factor for human campylobacteriosis. Nevertheless, further studies should be undertaken in other countries to confirm these results. PMID:24710464

The evaluation and application of multilocus variable number tandem repeat analysis (MLVA) for the molecular epidemiological study of Salmonella enterica subsp. enterica serovar Enteritidis infection.

PubMed

Liu, Yao; Shi, Xiaolu; Li, Yinghui; Chen, Qiongcheng; Jiang, Min; Li, Wanli; Qiu, Yaqun; Lin, Yiman; Jiang, Yixiang; Kan, Biao; Sun, Qun; Hu, Qinghua

2016-01-29

Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) is one of the most prevalent Salmonella serotypes that cause gastroenteritis worldwide and the most prevalent serotype causing Salmonella infections in China. A rapid molecular typing method with high throughput and good epidemiological discrimination is urgently needed for detecting the outbreaks and finding the source for effective control of S. Enteritidis infections. In this study, 194 strains which included 47 from six outbreaks that were well-characterized epidemiologically were analyzed with pulse field gel electrophoresis (PFGE) and multilocus variable number tandem repeat analysis (MLVA). Seven VNTR loci published by the US Center for Disease Control and Prevention (CDC) were used to evaluate and develop MLVA scheme for S. Enteritidis molecular subtyping by comparing with PFGE, and then MLVA was applied to the suspected outbreaks detection. All S. Enteritidis isolates were analyzed with MLVA to establish a MLVA database in Shenzhen, Guangdong province, China to facilitate the detection of S. Enteritidis infection clusters. There were 33 MLVA types and 29 PFGE patterns among 147 sporadic isolates. These two measures had Simpson indices of 0.7701 and 0.8043, respectively, which did not differ significantly. Epidemiological concordance was evaluated by typing 47 isolates from six epidemiologically well-characterized outbreaks and it did not differ for PFGE and MLVA. We applied the well established MLVA method to detect two S. Enteritidis foodborne outbreaks and find their sources successfully in 2014. A MLVA database of 491 S. Enteritidis strains isolated from 2004 to 2014 was established for the surveillance of clusters in the future. MLVA typing of S. Enteritidis would be an effective tool for early warning and epidemiological surveillance of S. Enteritidis infections.

Characterization, identification and application of lactic Acid bacteria isolated from forage paddy rice silage.

PubMed

Ni, Kuikui; Wang, Yanping; Li, Dongxia; Cai, Yimin; Pang, Huili

2015-01-01

There has been growing interest to develop forage rice as a new feed resource for livestock. This study was to characterize the natural population of lactic acid bacteria (LAB) and select potentially excellent strains for paddy rice silage preparation in China. One hundred and twenty-six strains were isolated and screened from paddy rice silage prepared using a small-scale fermentation system, and ninety-nine of these isolates were considered to be LAB based on their Gram-positive and catalase-negative morphology and the production of most of their metabolic products as lactic acid. These isolates were divided into eight groups (A-H) on the basis of their morphological and biochemical characteristics. The Group A to H strains were identified as Lactobacillus (L.) plantarum subsp. plantarum (species ratio: 8.1%), L. casei (5.1%), Leuconostoc (Ln.) pseudomesenteroides (11.1%), Pediococcus (P.) pentosaceus (24.2%), Enterococcus (E.) mundtii (12.1%), Lactococcus (Lc.) garvieae (15.2%), E. faecium (9.1%) and Lc. lactis subsp. lactis (15.2%) based on sequence analyses of their 16S rRNA and recA genes. P. pentosaceus was the most abundant member of the LAB population in the paddy rice silage. A selected strain, namely L. casei R 465, was found to be able to grow under low pH conditions and to improve the silage quality with low pH and a relatively high content of lactic acid. This study demonstrated that forage paddy rice silage contains abundant LAB species and its silage can be well preserved by inoculation with LAB, and that strain R 465 can be a potentially excellent inoculant for paddy rice silage.

Characterization, Identification and Application of Lactic Acid Bacteria Isolated from Forage Paddy Rice Silage

PubMed Central

Ni, Kuikui; Wang, Yanping; Li, Dongxia; Cai, Yimin; Pang, Huili

2015-01-01

There has been growing interest to develop forage rice as a new feed resource for livestock. This study was to characterize the natural population of lactic acid bacteria (LAB) and select potentially excellent strains for paddy rice silage preparation in China. One hundred and twenty-six strains were isolated and screened from paddy rice silage prepared using a small-scale fermentation system, and ninety-nine of these isolates were considered to be LAB based on their Gram-positive and catalase-negative morphology and the production of most of their metabolic products as lactic acid. These isolates were divided into eight groups (A-H) on the basis of their morphological and biochemical characteristics. The Group A to H strains were identified as Lactobacillus (L.) plantarum subsp. plantarum (species ratio: 8.1%), L. casei (5.1%), Leuconostoc (Ln.) pseudomesenteroides (11.1%), Pediococcus (P.) pentosaceus (24.2%), Enterococcus (E.) mundtii (12.1%), Lactococcus (Lc.) garvieae (15.2%), E. faecium (9.1%) and Lc. lactis subsp. lactis (15.2%) based on sequence analyses of their 16S rRNA and recA genes. P. pentosaceus was the most abundant member of the LAB population in the paddy rice silage. A selected strain, namely L. casei R 465, was found to be able to grow under low pH conditions and to improve the silage quality with low pH and a relatively high content of lactic acid. This study demonstrated that forage paddy rice silage contains abundant LAB species and its silage can be well preserved by inoculation with LAB, and that strain R 465 can be a potentially excellent inoculant for paddy rice silage. PMID:25803578

Complete genome sequencing of a multidrug-resistant and human-invasive Salmonella enterica serovar Typhimurium strain of the emerging sequence type 213 genotype

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

Calva, Edmundo; Silva, Claudia; Zaidi, Mussaret B.

Salmonella enterica subsp. enterica serovar Typhimurium strain YU39 was isolated in 2005 in the state of Yucatán, Mexico, from a human systemic infection. The YU39 strain is representative of the multidrug-resistant emergent sequence type 213 (ST213) genotype. The YU39 complete genome is composed of a chromosome and seven plasmids.

Draft Genome Sequence of Photorhabdus luminescens Strain DSPV002N Isolated from Santa Fe, Argentina

PubMed Central

Del Valle, Eleodoro E.; Frizzo, Laureano; Berry, Colin; Caballero, Primitivo

2016-01-01

Here, we report the draft genome sequence of Photorhabdus luminescens strain DSPV002N, which consists of 177 contig sequences accounting for 5,518,143 bp, with a G+C content of 42.3% and 4,701 predicted protein-coding genes (CDSs). From these, 27 CDSs exhibited significant similarity with insecticidal toxin proteins from Photorhabdus luminescens subsp. laumondii TT01. PMID:27469965

Complete genome sequencing of a multidrug-resistant and human-invasive Salmonella enterica serovar Typhimurium strain of the emerging sequence type 213 genotype

DOE PAGES

Calva, Edmundo; Silva, Claudia; Zaidi, Mussaret B.; ...

2015-06-18

Salmonella enterica subsp. enterica serovar Typhimurium strain YU39 was isolated in 2005 in the state of Yucatán, Mexico, from a human systemic infection. The YU39 strain is representative of the multidrug-resistant emergent sequence type 213 (ST213) genotype. The YU39 complete genome is composed of a chromosome and seven plasmids.

Characteristics of a pink-pigmented bacterium isolated from biofilm in a cooling tower in Tokyo, Japan.

PubMed

Furuhata, Katsunori; Goto, Keiichi; Kato, Yuko; Saitou, Keiko; Sugiyama, Jun-ichi; Hara, Motonobu; Yoshida, Shin-ichi; Fukuyama, Masafumi

2007-01-01

Strain K-20, a Gram-negative, non-motile, non-spore-forming and strictly aerobic rod, which produces a pale pink pigment, was isolated from biofilm in a cooling tower in Tokyo, Japan. The taxonomic feature of the strain was studied using phenotypic tests and phylogenetic analysis. Phylogenetic analysis of 16S rRNA gene sequences showed that the strain was related to Roseomonas gilardii subsp. rosea, Roseomonas gilardii subsp. gilardii, Roseomonas cervicalis and Roseomonas mucosa at 94.3-94.6 sequence similarities. Growth occurred at 25-40 C and pH 5.0-10.0, optimal at 35 C and pH 7.0. Growth did not occur in the presence of >or=2% NaCl. The API 20NE identification system gave a positive result for urease, L-arabinose, potassium gluconate, adipic acid, malic acid and trisodium citrate (API code number 0201465). The predominant fatty acids of strain K-20 were C18:1Delta11 (50.8%) and C16:1 (17.2%). Cells contained ubiquinone 10 (Q-10) as the major quinone and the G+C content was 72.0 mol%. Based on phenotypic, chemotaxonomic and phylogenetic data, it was assumed that strain K-20 (=JCM 14634) is a novel species of the genus Roseomonas.

A novel cry2Ab gene from the indigenous isolate Bacillus thuringiensis subsp. kurstaki.

PubMed

Sevim, Ali; Eryüzlü, Emine; Demirbağ, Zihni; Demir, Ismail

2012-01-01

A novel cry2Ab gene was cloned and sequenced from the indigenous isolate of Bacillus thuringiensis subsp. kurstaki. This gene was designated as cry2Ab25 and its sequence revealed an open reading frame of 1,902 bp encoding a 633 aa protein with calculated molecular mass of 70 kDa and pI value of 8.98. The amino acid sequence of the Cry2Ab25 protein was compared with previously known Cry2Ab toxins, and the phylogenetic relationships among them were determined. The deduced amino acid sequence of the Cry2Ab25 protein showed 99% homology to the known Cry2Ab proteins, except for Cry2Ab10 and Cry2Ab12 with 97% homology, and a variation in one amino acid residue in comparison with all known Cry2Ab proteins. The cry2Ab25 gene was expressed in Escherichia coli BL21(DE3) cells. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the Cry2Ab25 protein is about 70 kDa. The toxin expressed in BL21(DE3) exhibited high toxicity against Malacosoma neustria and Rhagoletis cerasi with 73% and 75% mortality after 5 days of treatment, respectively.

Chemical and microbiological characterisation of kefir grains.

PubMed

Garrote, G L; Abraham, A G; De Antoni, G L

2001-11-01

Chemical and microbiological composition of four Argentinean kefir grains from different sources as well as characteristics of the corresponding fermented milk were studied. Kefir grains CIDCA AGK1, AGK2 and AGK4 did not show significant differences in their chemical and microbiological composition. In contrast, protein and yeast content of AGK3 was higher than in the other grains. Although grain microflora comprised lactobacilli, lactococcus, acetic acid bacteria and yeast, we found an important difference regarding species. Lactococcus lactis subsp. lactis, Lactobacillus kefir, Lactobacillus plantarum, Acetobacter and Saccharomyces were present in all types of kefir grain. While Leuconostoc mesenteroides was only isolated from grains CIDCA AGK1 and Lactococcus lactis subsp. lactis biovar diacetylactis, Lactobacillus parakefir and Kluyveromyces marxianus were only isolated from CIDCA AGK2 grains. All grains produced acid products with pH between 3.5 and 4.0. The apparent viscosity of AGK1 fermented milk was greater than the product obtained with AGK4. All fermented milks had inhibitory power towards Escherichia coli but AGK1 and AGK2 supernatants were able to halt the bacterial growth for at least 25 h. Grain weight increment in AGK1, AGK2 and AGK3 during growth in milk did not show significant differences. Despite their fermenting activity, AGK4 grains did not increase their weight.

Mycobacterium avium subsp paratuberculosis--incidences in milk and milk products, their isolation, enumeration, characterization, and role in human health.

PubMed

Patel, Ami; Shah, Nihir

2011-12-01

Mycobacterium avium subsp paratuberculosis (MAP), excreted in the feces and milk, is reported to be not easily inactivated by pasteurization and thermal treatments as other bacteria infecting humans and animals do. The D values of all MAP strains tested were considerably higher than those published for other pathogens. Culturing techniques for this organism are labor intensive. Although an increasing amount of scientific evidence suggests that this organism can be responsible for at least some cases of Crohn's disease (CD), there is controversy about MAP being a cause of CD in humans. In general, although some studies have described an association between the presence of MAP and CD, the role of Mycobacterium species and MAP in the etiology of this human disease remains unestablished. Although published reports indicate that it may not be completely inactivated by pasteurization of milk, the effectiveness of increasing the time or temperature in the pasteurization process has not been established and hence any potential benefit to human health cannot be determined. This article summarizes the incidences of MAP in milk and milk products with respect to human health and brief discussion of various serological as well as molecular techniques used for their isolation, enumeration, and characterization. Copyright © 2011. Published by Elsevier B.V.

Characterization of the genetic locus responsible for the production of ABP-118, a novel bacteriocin produced by the probiotic bacterium Lactobacillus salivarius subsp. salivarius UCC118.

PubMed

Flynn, Sarah; van Sinderen, Douwe; Thornton, Gerardine M; Holo, Helge; Nes, Ingolf F; Collins, J Kevin

2002-04-01

ABP-118, a small heat-stable bacteriocin produced by Lactobacillus salivarius subsp. salivarius UCC118, a strain isolated from the ileal-caecal region of the human gastrointestinal tract, was purified to homogeneity. Using reverse genetics, a DNA fragment specifying part of ABP-118 was identified on a 10769 bp chromosomal region. Analysis of this region revealed that ABP-118 was a Class IIb two-peptide bacteriocin composed of Abp118alpha, which exhibited the antimicrobial activity, and Abp118beta, which enhanced the antimicrobial activity. The gene conferring strain UCC118 immunity to the action of ABP-118, abpIM, was identified downstream of the abp118beta gene. Located further downstream of abp118beta, several ORFs were identified whose deduced proteins resembled those of proteins involved in bacteriocin regulation and secretion. Heterologous expression of ABP-118 was achieved in Lactobacillus plantarum, Lactococcus lactis and Bacillus cereus. In addition, the abp118 locus encoded an inducing peptide, AbpIP, which was shown to play a role in the regulation of ABP-118 production. This novel bacteriocin is, to the authors' knowledge, the first to be isolated from a known human probiotic bacterium and to be characterized at the genetic level.

Thermal Inactivation of Mycobacterium avium subsp. paratuberculosis in Artificially Contaminated Milk by Direct Steam Injection

PubMed Central

Butot, Sophie; Jagadeesan, Balamurugan; Bakker, Douwe; Donaghy, John

2016-01-01

ABSTRACT The efficiency of direct steam injection (DSI) at 105°C for 3 s to inactivate Mycobacterium avium subsp. paratuberculosis in milk at a pilot-plant scale was investigated. Milk samples were artificially contaminated with M. avium subsp. paratuberculosis and also with cow fecal material naturally infected with M. avium subsp. paratuberculosis. We also tested milk artificially contaminated with Mycobacterium smegmatis as a candidate surrogate to compare thermal inactivation between M. smegmatis and M. avium subsp. paratuberculosis. Following the DSI process, no viable M. avium subsp. paratuberculosis or M. smegmatis was recovered using culture methods for both strains. For pure M. avium subsp. paratuberculosis cultures, a minimum reduction of 5.6 log10 was achieved with DSI, and a minimum reduction of 5.7 log10 was found with M. smegmatis. The minimum log10 reduction for wild-type M. avium subsp. paratuberculosis naturally present in feces was 3.3. In addition, 44 dairy and nondairy powdered infant formula (PIF) ingredients used during the manufacturing process of PIF were tested for an alternate source for M. avium subsp. paratuberculosis and were found to be negative by quantitative PCR (qPCR). In conclusion, the results obtained from this study indicate that a >7-fold-log10 reduction of M. avium subsp. paratuberculosis in milk can be achieved with the applied DSI process. IMPORTANCE M. avium subsp. paratuberculosis is widespread in dairy herds in many countries. M. avium subsp. paratuberculosis is the causative agent of Johne's disease in cattle, and infected animals can directly or indirectly (i.e., fecal contamination) contaminate milk. Despite much research and debate, there is no conclusive evidence that M. avium subsp. paratuberculosis is a zoonotic bacterium, i.e., one that causes disease in humans. The presence of M. avium subsp. paratuberculosis or its DNA has been reported in dairy products, including pasteurized milk, cheese, and infant formula. In light of this, it is appropriate to evaluate existing mitigation measures to inactivate M. avium subsp. paratuberculosis in dairy products. The work conducted in this study describes the efficacy of direct steam injection, a thermal process commonly used in the dairy industry, to eliminate M. avium subsp. paratuberculosis and a surrogate bacterium in milk, thus ensuring the absence of M. avium subsp. paratuberculosis in dairy products subject to these process conditions. PMID:26944840

Molecular Characterization of Copper Resistance Genes from Xanthomonas citri subsp. citri and Xanthomonas alfalfae subsp. citrumelonis▿

PubMed Central

Behlau, Franklin; Canteros, Blanca I.; Minsavage, Gerald V.; Jones, Jeffrey B.; Graham, James H.

2011-01-01

Copper sprays have been widely used for control of endemic citrus canker caused by Xanthomonas citri subsp. citri in citrus-growing areas for more than 2 decades. Xanthomonas alfalfae subsp. citrumelonis populations were also exposed to frequent sprays of copper for several years as a protective measure against citrus bacterial spot (CBS) in Florida citrus nurseries. Long-term use of these bactericides has led to the development of copper-resistant (Cur) strains in both X. citri subsp. citri and X. alfalfae subsp. citrumelonis, resulting in a reduction of disease control. The objectives of this study were to characterize for the first time the genetics of copper resistance in X. citri subsp. citri and X. alfalfae subsp. citrumelonis and to compare these organisms to other Cur bacteria. Copper resistance determinants from X. citri subsp. citri strain A44(pXccCu2) from Argentina and X. alfalfae subsp. citrumelonis strain 1381(pXacCu2) from Florida were cloned and sequenced. Open reading frames (ORFs) related to the genes copL, copA, copB, copM, copG, copC, copD, and copF were identified in X. citri subsp. citri A44. The same ORFs, except copC and copD, were also present in X. alfalfae subsp. citrumelonis 1381. Transposon mutagenesis of the cloned copper resistance determinants in pXccCu2 revealed that copper resistance in X. citri subsp. citri strain A44 is mostly due to copL, copA, and copB, which are the genes in the cloned cluster with the highest nucleotide homology (≥92%) among different Cur bacteria. PMID:21515725

Dissecting the taxonomic heterogeneity within Propionibacterium acnes: proposal for Propionibacterium acnes subsp. acnes subsp. nov. and Propionibacterium acnes subsp. elongatum subsp. nov.

PubMed

Dekio, Itaru; Culak, Renata; Misra, Raju; Gaulton, Tom; Fang, Min; Sakamoto, Mitsuo; Ohkuma, Moriya; Oshima, Kenshiro; Hattori, Masahira; Klenk, Hans-Peter; Rajendram, Dunstan; Gharbia, Saheer E; Shah, Haroun N

2015-12-01

Propionibacterium acnes subsp. acnes subsp. nov. and Propionibacterium acnes subsp. elongatum subsp. nov. are described. These emanate from the three known phylotypes of P. acnes, designated types I, II and III. Electron microscopy confirmed the filamentous cell shape of type III, showing a striking difference from types I/II, which were short rods. Biochemical tests indicated that, in types I/II, either the pyruvate, l-pyrrolidonyl arylamidase or d-ribose 2 test was positive, whereas all of these were negative among type III strains. Matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) spectra, which profile mainly their ribosomal proteins, were different between these two groups. Surface-enhanced laser-desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) spectra of all phylotypes revealed a specific protein biomarker that was overexpressed in type III strains compared with types I/II only when grown aerobically. Reference strains had high whole-genome similarity between types I (>91 %) and II (>75 %), but a considerably lower level of 72 % similarity with type III. recA and gyrB sequence dendrograms confirmed the distant relatedness of type III, indicating the presence of two distinct centres of variation within the species P. acnes. On the other hand, cellular fatty acid profiles and 16S rRNA gene sequence relatedness (>99.3 %) circumscribed the species. Thus, we propose two subspecies, Propionibacterium acnes subsp. acnes subsp. nov. for types I/II and Propionibacterium acnes subsp. elongatum subsp. nov. for type III. The type strain of Propionibacterium acnes subsp. acnes is NCTC 737T ( = ATCC 6919T = JCM 6425T = DSM 1897T = CCUG 1794T), while the type strain of Propionibacterium acnes subsp. elongatum is K124T ( = NCTC 13655T = JCM 18919T).

Role of Antibiosis in Competition of Erwinia Strains in Potato Infection Courts

PubMed Central

Axelrood, Paige E.; Rella, Manuela; Schroth, Milton N.

1988-01-01

Erwinia carotovora subsp. betavasculorum strains produced a bactericidal antibiotic in vitro that inhibited a wide spectrum of gram-negative and gram-positive bacteria. The optimum temperature for production was 24°C, and the addition of glycerol to culture media enhanced antibiotic production. Antibiotic production by these strains in the infection court of potato was the principal determinant enabling it to gain ascendancy over competing antibiotic-sensitive Erwinia carotovora subsp. carotovora strains. There was a complete correlation between antibiotic production by E. carotovora subsp. betavasculorum in vitro and inhibition of competing E. carotovora subsp. carotovora strains in planta. Inhibition of the latter by the former was apparent after 10 h of incubation in potato tuber wounds. Population densities of sensitive E. carotovora subsp. carotovora strains in mixed potato tuber infections with E. carotovora subsp. betavasculorum were approximately 106-fold lower after 48 h of incubation than in corresponding single sensitive strain infections. E. carotovora subsp. carotovora were not inhibited in tuber infections that were incubated anaerobically. This correlated with the absence of antibiotic production during anaerobic incubation in vitro. Antibiotic-resistant strains of E. carotovora subsp. carotovora were not inhibited in planta or in vitro by E. carotovora subsp. betavasculorum. Moreover, isogenic antibiotic-negative (Ant−) mutant E. carotovora subsp. betavasculorum strains were not inhibitory to sensitive E. carotovora subsp. carotovora strains in tuber infections. PMID:16347633

Enhancing the Sweetness of Yoghurt through Metabolic Remodeling of Carbohydrate Metabolism in Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus

PubMed Central

Sørensen, Kim I.; Curic-Bawden, Mirjana; Junge, Mette P.; Janzen, Thomas

2016-01-01

ABSTRACT Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus are used in the fermentation of milk to produce yoghurt. These species normally metabolize only the glucose moiety of lactose, secreting galactose and producing lactic acid as the main metabolic end product. We used multiple serial selection steps to isolate spontaneous mutants of industrial strains of S. thermophilus and L. delbrueckii subsp. bulgaricus that secreted glucose rather than galactose when utilizing lactose as a carbon source. Sequencing revealed that the S. thermophilus strains had mutations in the galKTEM promoter, the glucokinase gene, and genes encoding elements of the glucose/mannose phosphotransferase system (PTS). These strains metabolize galactose but are unable to phosphorylate glucose internally or via the PTS. The L. delbrueckii subsp. bulgaricus mutants had mutations in genes of the glucose/mannose PTS and in the pyruvate kinase gene. These strains cannot grow on exogenous glucose but are proficient at metabolizing internal glucose released from lactose by β-galactosidase. The resulting strains can be combined to ferment milk, producing yoghurt with no detectable lactose, moderate levels of galactose, and high levels of glucose. Since glucose tastes considerably sweeter than either lactose or galactose, the sweetness of the yoghurt is perceptibly enhanced. These strains were produced without the use of recombinant DNA technology and can be used for the industrial production of yoghurt with enhanced intrinsic sweetness and low residual levels of lactose. IMPORTANCE Based on a good understanding of the physiology of the lactic acid bacteria Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, we were able, by selecting spontaneously occurring mutants, to change dramatically the metabolic products secreted into the growth medium. These mutants consume substantially more of the lactose, metabolize some of the galactose, and secrete the remaining galactose and most of the glucose back into the milk. This allows production of yoghurt with very low lactose levels and enhanced natural sweetness, because humans perceive glucose as sweeter than either lactose or galactose. PMID:27107115

Effect of growth conditions on production of rhamnose-containing cell wall and capsular polysaccharides by strains of Lactobacillus casei subsp. rhamnosus.

PubMed

Wicken, A J; Ayres, A; Campbell, L K; Knox, K W

1983-01-01

Strains of Lactobacillus casei subsp. rhamnosus possessing two cell wall polysaccharides, a hexosamine-containing H-polysaccharide and a rhamnose-containing R-polysaccharide, were examined for the effect of growth conditions on the production of these two components. In strain NCTC 6375, R- and H-polysaccharides accounted for an estimated 44 and 20%, respectively, of the cell wall for organisms grown in batch culture with glucose as the carbohydrate source. Growth on fructose-containing media reduced the amount of R-polysaccharide by approximately 50% without affecting the amount of H-polysaccharide. Subculture of fructose-grown organisms in glucose restored the original proportions of the two polysaccharides. Galactose- and sucrose-grown cells behaved similarly to glucose-grown cells with respect to polysaccharide production, whereas growth in rhamnose or ribose showed values close to those for fructose-grown cells. Continuous culture of strain NCTC 6375 for more than 100 generations showed a gradual and irreversible reduction of the R-polysaccharide to less than 5% of the cell wall and an increase of the H-polysaccharide to 40% of the cell wall. Other type culture strains of L. casei subsp. rhamnosus, NCIB 7473 and ATCC 7469, behaved similarly in batch and continuous culture. In contrast, strains of L. casei subsp. rhamnosus isolated at the Institute of Dental Research showed phenotypic stability with respect to the relative proportions of R- and H-polysaccharides in both batch and continuous culture. Changes in polysaccharide composition of type culture strains were also mirrored in changes in the immunogenicity of the two components and resistance to the rate of enzymic lysis of whole organisms. For L. casei subsp. rhamnosus strain NCTC 10302 the R-polysaccharide is present entirely as capsular material. The amount of R-polysaccharide produced was also markedly dependent on the carbohydrate component of the medium in batch culture and both dilution rate and nature of the limiting carbohydrate in continuous culture, varying over a 10-fold range, whereas the cell wall H-polysaccharide remained constant.

Effect of growth conditions on production of rhamnose-containing cell wall and capsular polysaccharides by strains of Lactobacillus casei subsp. rhamnosus.

PubMed Central

Wicken, A J; Ayres, A; Campbell, L K; Knox, K W

1983-01-01

Strains of Lactobacillus casei subsp. rhamnosus possessing two cell wall polysaccharides, a hexosamine-containing H-polysaccharide and a rhamnose-containing R-polysaccharide, were examined for the effect of growth conditions on the production of these two components. In strain NCTC 6375, R- and H-polysaccharides accounted for an estimated 44 and 20%, respectively, of the cell wall for organisms grown in batch culture with glucose as the carbohydrate source. Growth on fructose-containing media reduced the amount of R-polysaccharide by approximately 50% without affecting the amount of H-polysaccharide. Subculture of fructose-grown organisms in glucose restored the original proportions of the two polysaccharides. Galactose- and sucrose-grown cells behaved similarly to glucose-grown cells with respect to polysaccharide production, whereas growth in rhamnose or ribose showed values close to those for fructose-grown cells. Continuous culture of strain NCTC 6375 for more than 100 generations showed a gradual and irreversible reduction of the R-polysaccharide to less than 5% of the cell wall and an increase of the H-polysaccharide to 40% of the cell wall. Other type culture strains of L. casei subsp. rhamnosus, NCIB 7473 and ATCC 7469, behaved similarly in batch and continuous culture. In contrast, strains of L. casei subsp. rhamnosus isolated at the Institute of Dental Research showed phenotypic stability with respect to the relative proportions of R- and H-polysaccharides in both batch and continuous culture. Changes in polysaccharide composition of type culture strains were also mirrored in changes in the immunogenicity of the two components and resistance to the rate of enzymic lysis of whole organisms. For L. casei subsp. rhamnosus strain NCTC 10302 the R-polysaccharide is present entirely as capsular material. The amount of R-polysaccharide produced was also markedly dependent on the carbohydrate component of the medium in batch culture and both dilution rate and nature of the limiting carbohydrate in continuous culture, varying over a 10-fold range, whereas the cell wall H-polysaccharide remained constant. PMID:6401290

Enhancing the Sweetness of Yoghurt through Metabolic Remodeling of Carbohydrate Metabolism in Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus.

PubMed

Sørensen, Kim I; Curic-Bawden, Mirjana; Junge, Mette P; Janzen, Thomas; Johansen, Eric

2016-06-15

Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus are used in the fermentation of milk to produce yoghurt. These species normally metabolize only the glucose moiety of lactose, secreting galactose and producing lactic acid as the main metabolic end product. We used multiple serial selection steps to isolate spontaneous mutants of industrial strains of S. thermophilus and L. delbrueckii subsp. bulgaricus that secreted glucose rather than galactose when utilizing lactose as a carbon source. Sequencing revealed that the S. thermophilus strains had mutations in the galKTEM promoter, the glucokinase gene, and genes encoding elements of the glucose/mannose phosphotransferase system (PTS). These strains metabolize galactose but are unable to phosphorylate glucose internally or via the PTS. The L. delbrueckii subsp. bulgaricus mutants had mutations in genes of the glucose/mannose PTS and in the pyruvate kinase gene. These strains cannot grow on exogenous glucose but are proficient at metabolizing internal glucose released from lactose by β-galactosidase. The resulting strains can be combined to ferment milk, producing yoghurt with no detectable lactose, moderate levels of galactose, and high levels of glucose. Since glucose tastes considerably sweeter than either lactose or galactose, the sweetness of the yoghurt is perceptibly enhanced. These strains were produced without the use of recombinant DNA technology and can be used for the industrial production of yoghurt with enhanced intrinsic sweetness and low residual levels of lactose. Based on a good understanding of the physiology of the lactic acid bacteria Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, we were able, by selecting spontaneously occurring mutants, to change dramatically the metabolic products secreted into the growth medium. These mutants consume substantially more of the lactose, metabolize some of the galactose, and secrete the remaining galactose and most of the glucose back into the milk. This allows production of yoghurt with very low lactose levels and enhanced natural sweetness, because humans perceive glucose as sweeter than either lactose or galactose. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Molecular Characterization of tet(M) Genes in Lactobacillus Isolates from Different Types of Fermented Dry Sausage

PubMed Central

Gevers, Dirk; Danielsen, Morten; Huys, Geert; Swings, Jean

2003-01-01

The likelihood that products prepared from raw meat and milk may act as vehicles for antibiotic-resistant bacteria is currently of great concern in food safety issues. In this study, a collection of 94 tetracycline-resistant (Tcr) lactic acid bacteria recovered from nine different fermented dry sausage types were subjected to a polyphasic molecular study with the aim of characterizing the host organisms and the tet genes, conferring tetracycline resistance, that they carry. With the (GTG)5-PCR DNA fingerprinting technique, the Tcr lactic acid bacterial isolates were identified as Lactobacillus plantarum, L. sakei subsp. carnosus, L. sakei subsp. sakei, L. curvatus, and L. alimentarius and typed to the intraspecies level. For a selection of 24 Tcr lactic acid bacterial isolates displaying unique (GTG)5-PCR fingerprints, tet genes were determined by means of PCR, and only tet(M) was detected. Restriction enzyme analysis with AccI and ScaI revealed two different tet(M) allele types. This grouping was confirmed by partial sequencing of the tet(M) open reading frame, which indicated that the two allele types displayed high sequence similarities (>99.6%) with tet(M) genes previously reported in Staphylococcus aureus MRSA 101 and in Neisseria meningitidis, respectively. Southern hybridization with plasmid profiles revealed that the isolates contained tet(M)-carrying plasmids. In addition to the tet(M) gene, one isolate also contained an erm(B) gene on a different plasmid from the one encoding the tetracycline resistance. Furthermore, it was also shown by PCR that the tet(M) genes were not located on transposons of the Tn916/Tn1545 family. To our knowledge, this is the first detailed molecular study demonstrating that taxonomically and genotypically diverse Lactobacillus strains from different types of fermented meat products can be a host for plasmid-borne tet genes. PMID:12571056

Grana Padano cheese whey starters: microbial composition and strain distribution.

PubMed

Rossetti, Lia; Fornasari, Maria Emanuela; Gatti, Monica; Lazzi, Camilla; Neviani, Erasmo; Giraffa, Giorgio

2008-09-30

The aim of this work was to evaluate the species composition and the genotypic strain heterogeneity of dominant lactic acid bacteria (LAB) isolated from whey starter cultures used to manufacture Grana Padano cheese. Twenty-four Grana Padano cheese whey starters collected from dairies located over a wide geographic production area in the north of Italy were analyzed. Total thermophilic LAB streptococci and lactobacilli were quantified by agar plate counting. Population structure of the dominant and metabolically active LAB species present in the starters was profiled by reverse transcriptase, length heterogeneity-PCR (RT-LH-PCR), a culture-independent technique successfully applied to study whey starter ecosystems. The dominant bacterial species were Lactobacillus helveticus, Lactobacillus delbrueckii subsp. lactis, Streptococcus thermophilus, and Lactobacillus fermentum. Diversity in the species composition allowed the whey cultures to be grouped into four main typologies, the one containing L. helveticus, L. delbrueckii subsp. lactis, and S. thermophilus being the most frequent one (45% of the cultures analyzed), followed by that containing only the two lactobacilli (40%). Only a minor fraction of the cultures contained L. helveticus alone (4%) or all the four LAB species (11%). Five hundred and twelve strains were isolated from the 24 cultures and identified by M13-PCR fingerprinting coupled with 16S rRNA gene sequencing. Most of the strains were L. helveticus (190 strains; 37% of the total), L delbrueckii subsp. lactis (90 strains; 18%) and S. thermophilus (215 strains; 42%). This result was in good agreement with the qualitative whey starter composition observed by RT-LH-PCR. M13-PCR fingerprinting indicated a markedly low infra-species diversity, i.e. the same biotypes were often found in more than one culture. The distribution of the biotypes into the different cultures was mainly dairy plant-specific rather than correlated with the different production areas.

Experimental infection of octopus vulgaris (Cuvier, 1797) with Photobacterium damsela subsp. piscicida. Immunohistochemical tracking of antigen and tissue responses.

PubMed

Bakopoulos, Vasileios; White, Daniella; Valsamidis, Michail-Aggelos; Vasilaki, Feli

2017-03-01

Adult common octopus individuals were intramuscularly infected with Photobacterium damsela subsp. piscicida in order to investigate if this species is sensitive to this common and important fish pathogen. The fate of the bacterial antigens and the tissue responses of Octopus vulgaris were studied employing immunohistochemical techniques. Strong reaction at the site of injection was evident from day 2 post-infection that continued until day 14. Great numbers of hemocytes that were attracted at the site of infection were involved in phagocytosis of bacteria. Very early in the infection, a transition of cells to fibroblasts and an effort to isolate the infection was observed. During the course of the study, very large necrotic cells were seen at the site of infection, whereas during the later stages hemocytes with phagocytosed bacteria were observed in well-defined pockets inside the muscle tissue. None of the internal organs tested for the presence of the bacterium were positive with the exception of the digestive gland where antigen staining was observed which was not associated with hemocyte infiltration. The high doses of bacterial cells used in this experimental infection and the lack of disease signs from Octopus vulgaris suggest that, under normal conditions, octopus is resistant to Photobacterium damsela subsp. piscicida. Copyright © 2017 Elsevier Inc. All rights reserved.

Global regulators ExpA (GacA) and KdgR modulate extracellular enzyme gene expression through the RsmA-rsmB system in Erwinia carotovora subsp. carotovora.

PubMed

Hyytiäinen, H; Montesano, M; Palva, E T

2001-08-01

The production of the main virulence determinants, the extracellular plant cell wall-degrading enzymes, and hence virulence of Erwinia carotovora subsp. carotovora is controlled by a complex regulatory network. One of the global regulators, the response regulator ExpA, a GacA homolog, is required for transcriptional activation of the extracellular enzyme genes of this soft-rot pathogen. To elucidate the mechanism of ExpA control as well as interactions with other regulatory systems, we isolated second-site transposon mutants that would suppress the enzyme-negative phenotype of an expA (gacA) mutant. Inactivation of kdgR resulted in partial restoration of extracellular enzyme production and virulence to the expA mutant, suggesting an interaction between the two regulatory pathways. This interaction was mediated by the RsmA-rsmB system. Northern analysis was used to show that the regulatory rsmB RNA was under positive control of ExpA. Conversely, the expression of rsmA encoding a global repressor was under negative control of ExpA and positive control of KdgR. This study indicates a central role for the RsmA-rsmB regulatory system during pathogenesis, integrating signals from the ExpA (GacA) and KdgR global regulators of extracellular enzyme production in E. carotovora subsp. carotovora.

Complete Genome Sequencing of a Multidrug-Resistant and Human-Invasive Salmonella enterica Serovar Typhimurium Strain of the Emerging Sequence Type 213 Genotype

PubMed Central

Calva, Edmundo; Zaidi, Mussaret B.; Sanchez-Flores, Alejandro; Estrada, Karel; Silva, Genivaldo G. Z.; Soto-Jiménez, Luz M.; Wiesner, Magdalena; Fernández-Mora, Marcos; Edwards, Robert A.

2015-01-01

Salmonella enterica subsp. enterica serovar Typhimurium strain YU39 was isolated in 2005 in the state of Yucatán, Mexico, from a human systemic infection. The YU39 strain is representative of the multidrug-resistant emergent sequence type 213 (ST213) genotype. The YU39 complete genome is composed of a chromosome and seven plasmids. PMID:26089426

Electrophoretic Analysis of Diversity and Phylogeny of Pinus brutia and Closely Related Taxa

Treesearch

M. T. Conkle; G. Schiller; C. Grunwald

1988-01-01

Rangewide samples from mature natural stands of Pinus brutia Ten. subsp. brutia, subsp. stankewiczii (Sukaczew) Nahal, subsp. pithyusa (Stevenson) Nahal, and subsp. eldarica (Medw.) Nahal from throughout the eastern Mediterranean display a continuum of allozyme variation for...

Combination of Metabolomic and Proteomic Analysis Revealed Different Features among Lactobacillus delbrueckii Subspecies bulgaricus and lactis Strains While In Vivo Testing in the Model Organism Caenorhabditis elegans Highlighted Probiotic Properties

PubMed Central

Zanni, Elena; Schifano, Emily; Motta, Sara; Sciubba, Fabio; Palleschi, Claudio; Mauri, Pierluigi; Perozzi, Giuditta; Uccelletti, Daniela; Devirgiliis, Chiara; Miccheli, Alfredo

2017-01-01

Lactobacillus delbrueckii represents a technologically relevant member of lactic acid bacteria, since the two subspecies bulgaricus and lactis are widely associated with fermented dairy products. In the present work, we report the characterization of two commercial strains belonging to L. delbrueckii subspecies bulgaricus, lactis and a novel strain previously isolated from a traditional fermented fresh cheese. A phenomic approach was performed by combining metabolomic and proteomic analysis of the three strains, which were subsequently supplemented as food source to the model organism Caenorhabditis elegans, with the final aim to evaluate their possible probiotic effects. Restriction analysis of 16S ribosomal DNA revealed that the novel foodborne strain belonged to L. delbrueckii subspecies lactis. Proteomic and metabolomic approaches showed differences in folate, aminoacid and sugar metabolic pathways among the three strains. Moreover, evaluation of C. elegans lifespan, larval development, brood size, and bacterial colonization capacity demonstrated that L. delbrueckii subsp. bulgaricus diet exerted beneficial effects on nematodes. On the other hand, both L. delbrueckii subsp. lactis strains affected lifespan and larval development. We have characterized three strains belonging to L. delbrueckii subspecies bulgaricus and lactis highlighting their divergent origin. In particular, the two closely related isolates L. delbrueckii subspecies lactis display different galactose metabolic capabilities. Moreover, the L. delbrueckii subspecies bulgaricus strain demonstrated potential probiotic features. Combination of omic platforms coupled with in vivo screening in the simple model organism C. elegans is a powerful tool to characterize industrially relevant bacterial isolates. PMID:28702021

Combination of Metabolomic and Proteomic Analysis Revealed Different Features among Lactobacillus delbrueckii Subspecies bulgaricus and lactis Strains While In Vivo Testing in the Model Organism Caenorhabditis elegans Highlighted Probiotic Properties.

PubMed

Zanni, Elena; Schifano, Emily; Motta, Sara; Sciubba, Fabio; Palleschi, Claudio; Mauri, Pierluigi; Perozzi, Giuditta; Uccelletti, Daniela; Devirgiliis, Chiara; Miccheli, Alfredo

2017-01-01

Lactobacillus delbrueckii represents a technologically relevant member of lactic acid bacteria, since the two subspecies bulgaricus and lactis are widely associated with fermented dairy products. In the present work, we report the characterization of two commercial strains belonging to L. delbrueckii subspecies bulgaricus , lactis and a novel strain previously isolated from a traditional fermented fresh cheese. A phenomic approach was performed by combining metabolomic and proteomic analysis of the three strains, which were subsequently supplemented as food source to the model organism Caenorhabditis elegans , with the final aim to evaluate their possible probiotic effects. Restriction analysis of 16S ribosomal DNA revealed that the novel foodborne strain belonged to L. delbrueckii subspecies lactis . Proteomic and metabolomic approaches showed differences in folate, aminoacid and sugar metabolic pathways among the three strains. Moreover, evaluation of C. elegans lifespan, larval development, brood size, and bacterial colonization capacity demonstrated that L. delbrueckii subsp. bulgaricus diet exerted beneficial effects on nematodes. On the other hand, both L. delbrueckii subsp. lactis strains affected lifespan and larval development. We have characterized three strains belonging to L. delbrueckii subspecies bulgaricus and lactis highlighting their divergent origin. In particular, the two closely related isolates L. delbrueckii subspecies lactis display different galactose metabolic capabilities. Moreover, the L. delbrueckii subspecies bulgaricus strain demonstrated potential probiotic features. Combination of omic platforms coupled with in vivo screening in the simple model organism C. elegans is a powerful tool to characterize industrially relevant bacterial isolates.

In Vitro Activity of Pexiganan and 10 Comparator Antimicrobials against 234 Isolates, Including 93 Pasteurella Species and 50 Anaerobic Bacterial Isolates Recovered from Animal Bite Wounds

PubMed Central

Citron, Diane M.; Tyrrell, Kerin L.; Leoncio, Eliza S.

2017-01-01

ABSTRACT Animal bite wounds affect more than 5 million Americans annually, resulting in 300,000 emergency department visits, 10,000 hospitalizations, and an untold number of physician office visits. Various forms of topical therapy are empirically self-employed by many patients prior to seeking medical attention. Pexiganan, a 22-amino-acid synthetic cationic analogue of the peptide magainin II, acts by selectively damaging bacterial cell membranes. We determined the MICs for pexiganan and other antimicrobial agents often used for treatment of bite wounds. Most isolates were from U.S. patients, and ∼10% were from European and Canadian patients. The comparator antimicrobials studied were penicillin, amoxicillin-clavulanate, piperacillin-tazobactam, meropenem, clindamycin, doxycycline, moxifloxacin, ceftriaxone, linezolid, and metronidazole. The MIC90s of pexiganan were 32 μg/ml (against Pasteurella multocida subsp. multocida), 16 μg/ml (P. multocida subsp. septica, Pasteurella canis, and Pasteurella dagmatis), 8 μg/ml (Pasteurella stomatis), 8 μg/ml (Eikenella corrodens), 2 μg/ml (Neisseria weaveri, Neisseria zoodegmatis, and Moraxella canis-Moraxella lacunata group), 16 μg/ml (Bergeyella zoohelcum), 64 μg/ml (Bacteroides pyogenes), 4 μg/ml (Fusobacterium russii), 32 μg/ml (Fusobacterium canifelinum), and 64 μg/ml (Prevotella heparinolytica). The concentration of pexiganan in the cream used was 8,000 μg/ml, more than 60 to 100 times the highest MIC obtained. Pexiganan exhibited a broad range of antimicrobial activity, showing potential for treating animal bite infections. A clinical trial seems warranted. PMID:28373186

Effect of Soil Slope on the Appearance of Mycobacterium avium subsp. paratuberculosis in Water Running off Grassland Soil after Application of Contaminated Slurry

PubMed Central

Alfaro, M.; Salazar, F.; Troncoso, E.; Mitchell, R. M.; Ramirez, L.; Naguil, A.; Zamorano, P.; Collins, M. T.

2013-01-01

The study assessed the effect of soil slope on Mycobacterium avium subsp. paratuberculosis transport into rainwater runoff from agricultural soil after application of M. avium subsp. paratuberculosis-contaminated slurry. Under field conditions, 24 plots of undisturbed loamy soil 1 by 2 m2 were placed on platforms. Twelve plots were used for water runoff: 6 plots at a 3% slope and 6 plots at a 15% slope. Half of the plots of each slope were treated with M. avium subsp. paratuberculosis-contaminated slurry, and half were not treated. Using the same experimental design, 12 plots were established for soil sampling on a monthly basis using the same spiked slurry application and soil slopes. Runoff following natural rainfall was collected and analyzed for M. avium subsp. paratuberculosis, coliforms, and turbidity. M. avium subsp. paratuberculosis was detected in runoff from all plots treated with contaminated slurry and one control plot. A higher slope (15%) increased the likelihood of M. avium subsp. paratuberculosis detection but did not affect the likelihood of finding coliforms. Daily rainfall increased the likelihood that runoff would have coliforms and the coliform concentration, but it decreased the M. avium subsp. paratuberculosis concentration in the runoff. When there was no runoff, rain was associated with increased M. avium subsp. paratuberculosis concentrations. Coliform counts in runoff were related to runoff turbidity. M. avium subsp. paratuberculosis presence/absence, however, was related to turbidity. Study duration decreased bacterial detection and concentration. These findings demonstrate the high likelihood that M. avium subsp. paratuberculosis in slurry spread on pastures will contaminate water runoff, particularly during seasons with high rainfall. M. avium subsp. paratuberculosis contamination of water has potential consequences for both animal and human health. PMID:23542616

The first closed genome sequence of Campylobacter fetus subsp. venerealis biovar intermedius

USDA-ARS?s Scientific Manuscript database

Campylobacter fetus venerealis biovar intermedius is a variant of Campylobacter fetus subsp. venerealis, the causative agent of Bovine Genital Campylobacteriosis. In contrast to Campylobacter fetus subsp. venerealis which is restricted to the genital tract of cattle, Campylobacter fetus subsp. vener...

Antibiotic susceptibilities, streptococcal pyrogenic exotoxin gene profiles among clinical isolates of group C or G Streptococcus dysgalactiae subsp. equisimilis & of group G S. anginosus group at a tertiary care centre.

PubMed

Behera, Bijayini; Mathur, Purva; Bhardwaj, Nidhi; Jain, Neetu; Misra, M C; Kapil, Arti; Singh, Sarman

2014-03-01

Group C and group G streptococci (together GCGS) are often regarded as commensal bacteria and their role in streptococcal disease burden is under-recognized. While reports of recovery of GCGS from normally sterile body sites are increasing, their resistance to macrolides, fluoroquinolone further warrants all invasive β haemolytic streptococci to be identified to the species level and accurately tested for antimicrobial susceptibility. This study was aimed to determine the prevalence, clinical profile, antimicrobial susceptibility and streptococcal pyrogenic exotoxin gene profile (speA, speB, speC, speF, smeZ, speI, speM, speG, speH and ssa) of GCGS obtained over a period of two years at a tertiary care centre from north India. The clinical samples were processed as per standard microbiological techniques. β-haemolytic streptococci (BHS) were characterized and grouped. Antimicrobial susceptibility of GCGS was performed using disk diffusion method. All GCGS were characterized for the presence of streptococcal pyrogenic exotoxins (spe) and spe genes were amplified by PCR method. GCGS (23 GGS, 2GCS) comprised 16 per cent of β haemolytic streptococci (25/142 βHS, 16%) isolated over the study period. Of the 25 GCGS, 22 (88%) were recovered from pus, two (8%) from respiratory tract, whereas one isolate was recovered from blood of a fatal case of septicaemia. Of the total 23 GGS isolates, 18 (78%) were identified as Streptococcus dysgalactiae subsp equisimilis (SDSE, large-colony phenotype), five (21%) were Streptococcus anginosus group (SAG, small-colony phenotype). The two GCS were identified as SDSE. All GCGS isolates were susceptible to penicillin, vancomycin, and linezolid. Tetracycline resistance was noted in 50 per cent of SDSE isolates. The rates of macrolide and fluoroquinolone resistance in SDSE were low. Twelve of the 20 SDSE isolates were positive for one or more spe genes, with five of the SDSE isolates simultaneously carrying speA+ speB+ smeZ+ speF or speB+ smeZ+speF, speI+speM+speG+speH or, speI+spe M+speH or speA+ speB+ speC+ smeZ+ speF. One notable finding was the presence of spe B in four of the five isolates of the Streptococcus anginosus group. No isolate was positive for ssa. Our study showed no association between GCGS isolates harbouring streptococcal pyrogenic exotoxins and disease severity. This might be attributed to the small sample size of spe-positive isolates.

Repeated isolation of Salmonella enterica Goverdhan, a very rare serovar, from Danish poultry surveillance samples.

PubMed

Pedersen, Karl; Sørensen, Gitte; Szabo, Istvan; Hächler, Herbert; Le Hello, Simon

2014-12-05

We report here the appearance of a very rare serovar of Salmonella, S. enterica subsp. enterica serovar Goverdhan, in routine Salmonella surveillance samples from Danish poultry production. S. Goverdhan was found on nine occasions: in one broiler breeder farm in October 2010, four broiler farms and one broiler breeder farm in June-September 2012, two broiler breeder flocks simultaneously in June 2013, and one layer flock in July 2013. The five isolates from 2012 and the three isolates from 2013 had identical pulsed-field gel electrophoresis profiles, whereas the profile of the isolate from 2010 deviated in a single band. It is the first time this serovar has been described in samples from poultry. The origin of the bacterium is still unknown, but it is suggested that it may have been a pseudo-outbreak caused by contaminated sampling material. Copyright © 2014 Elsevier B.V. All rights reserved.

rep-PCR-Mediated Genomic Fingerprinting: A Rapid and Effective Method to Identify Clavibacter michiganensis.

PubMed

Louws, F J; Bell, J; Medina-Mora, C M; Smart, C D; Opgenorth, D; Ishimaru, C A; Hausbeck, M K; de Bruijn, F J; Fulbright, D W

1998-08-01

ABSTRACT The genomic DNA fingerprinting technique known as repetitive-sequence-based polymerase chain reaction (rep-PCR) was evaluated as a tool to differentiate subspecies of Clavibacter michiganensis, with special emphasis on C. michiganensis subsp. michiganensis, the pathogen responsible for bacterial canker of tomato. DNA primers (REP, ERIC, and BOX), corresponding to conserved repetitive element motifs in the genomes of diverse bacterial species, were used to generate genomic fingerprints of C. michiganensis subsp. michiganensis, C. michiganensis subsp. sepedonicus, C. michiganensis subsp. nebraskensis, C. michiganensis subsp. tessellarius, and C. michiganensis subsp. insidiosum. The rep-PCR-generated patterns of DNA fragments observed after agarose gel electrophoresis support the current division of C. michiganensis into five subspecies. In addition, the rep-PCR fingerprints identified at least four types (A, B, C, and D) within C. michiganensis subsp. michiganensis based on limited DNA polymorphisms; the ability to differentiate individual strains may be of potential use in studies on the epidemiology and host-pathogen interactions of this organism. In addition, we have recovered from diseased tomato plants a relatively large number of naturally occurring avirulent C. michiganensis subsp. michiganensis strains with rep-PCR fingerprints identical to those of virulent C. michiganensis subsp. michiganensis strains.

Tulipa cinnabarina subsp. toprakii (Liliaceae), a new subspecies from southwestern Anatolia.

PubMed

Eker, İsmail; Yıldırım, Hasan; Altıoğlu, Yusuf

2016-01-01

A new subpecies, Tulipa cinnabarina subsp. toprakii subsp. nov. (Liliaceae) from Turkey is described. Diagnostic characters, descriptions, detailed illustrations, geographical distribution, conservation status and ecological observations on the new taxon are provided. It is also compared with the closely related Tulipa cinnabarina subsp. cinnabarina.

A novel chimeric prophage vB_LdeS-phiJB from commercial Lactobacillus delbrueckii subsp. bulgaricus.

PubMed

Guo, Tingting; Zhang, Chenchen; Xin, Yongping; Xin, Min; Kong, Jian

2016-05-01

Prophage vB_LdeS-phiJB (phiJB) was induced by mitomycin C and UV radiation from the Lactobacillus delbrueckii subsp. bulgaricus SDMCC050201 isolated from a Chinese yoghurt sample. It has an isometric head and a non-contractile tail with 36,969 bp linear double-stranded DNA genome, which is classified into the group a of Lb. delbrueckii phages. The genome of phiJB is highly modular with functionally related genes clustered together. Unexpectedly, there is no similarity of its DNA replication module to any phages that have been reported, while it consists of open-reading frames homologous to the proteins of Lactobacillus strains. Comparative genomic analysis indicated that its late gene clusters, integration/lysogeny modules and DNA replication module derived from different evolutionary ancestors and integrated into a chimera. Our results revealed a novel chimeric phage of commercial Lb. delbrueckii and will broaden the knowledge of phage diversity in the dairy industry.

Safety evaluation of Lactobacillus delbrueckii subsp. lactis UO 004, a probiotic bacterium.

PubMed

Fernández, M Fernanda; Boris, Soledad; Barbés, Covadonga

2005-03-01

Lactobacillus delbrueckii subsp. lactis UO 004 was evaluated for its use as a potential probiotic from a safety point of view. The strain did not exhibit mucinolytic or other enzymatic activities that might be detrimental, such as those involving glycosidases (beta-D-glucosaminidase or alpha-D-galactosidase) or arylamidases (factor Xa and quimotrypsin-like activities), frequently present in Lactobacillus strains isolated from patients with endocarditis, although it was able to express protein Ca and kallikrein-like activities. On the other hand, the presence of the strain did not interfere with the growth of certain species of normal intestinal microbiota, such as Enterococcus fecalis, Escherichia coli, Bifidobacterium bifidum or Bacteroides fragilis. Moreover, the potential probiotic strain UO 004 is sensitive to antibiotics with transmissible resistance mechanisms in Lactobacillus such as chloramphenicol, erythromycin, tetracycline and vancomycin. In addition, strain L. delbrueckii UO 004 was not able to translocate towards the intestinal barrier of mice or produce changes in their activity or general health status.

Tulipa cinnabarina subsp. toprakii (Liliaceae), a new subspecies from southwestern Anatolia

PubMed Central

Eker, İsmail; Yıldırım, Hasan; Altıoğlu, Yusuf

2016-01-01

Abstract A new subpecies, Tulipa cinnabarina subsp. toprakii subsp. nov. (Liliaceae) from Turkey is described. Diagnostic characters, descriptions, detailed illustrations, geographical distribution, conservation status and ecological observations on the new taxon are provided. It is also compared with the closely related Tulipa cinnabarina subsp. cinnabarina. PMID:27698585

Otariodibacter oris gen. nov., sp. nov., a member of the family Pasteurellaceae isolated from the oral cavity of pinnipeds.

PubMed

Hansen, Mie Johanne; Bertelsen, Mads Frost; Christensen, Henrik; Bojesen, Anders Miki; Bisgaard, Magne

2012-11-01

A total of 27 bacterial isolates from California sea lions and a walrus tentatively classified within the family Pasteurellaceae was further characterized by genotypic and phenotypic tests. Phylogenetic analysis of partial 16S rRNA and rpoB gene sequences showed that the isolates investigated formed a monophyletic group, tentatively designated Bisgaard taxon 57. According to 16S rRNA gene sequences, the most closely related species with a validly published name was Bisgaardia hudsonensis and the most closely related species based on rpoB sequence comparison was Pasteurella multocida subsp. multocida; highest similarities between the isolates and the type strains of B. hudsonensis and P. multocida subsp. multocida were 95.0 and 88.2%. respectively. All isolates of Bisgaard taxon 57 exhibit the phenotypic characters of the family Pasteurellaceae. Members of Bisgaard taxon 57 can be separated from existing genera of the Pasteurellaceae by the following tests: positive reactions for catalase, oxidase, Voges-Proskauer and indole; no X- or V-factor dependency; and acid production from L-arabinose (slow), L-fucose, maltose and trehalose, but not from dulcitol, D-mannitol, D-mannose or sucrose. The main fatty acids of Bisgaard taxon 57 (CCUG 59994(T)) are C(14:0), C(16:0), C(16:1)ω7c and the summed feature C(14:0) 3-OH/iso-C(16:1) I. This fatty acid profile is characteristic of members of the Pasteurellaceae. The quinone profile of Bisgaard taxon 57 (DSM 23800(T)) was similar to that of other genera in the Pasteurellaceae. The DNA G+C content of strain Baika1(T) is 36.2 mol%, which is at the lower end of the range for members of the family Pasteurellaceae. On the basis of both phylogenetic and phenotypic evidence, it is proposed that members of Bisgaard taxon 57 should be classified as representatives of a novel species in a new genus, Otariodibacter oris gen. nov., sp. nov. The type strain of Otariodibacter oris is Baika1(T) (=CCUG 59994(T)=DSM 23800(T)), which was isolated from the oral cavity of a healthy California sea lion in Copenhagen Zoo, Denmark, in 2007.

Use of PCR-Based Methods for Rapid Differentiation of Lactobacillus delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis

PubMed Central

Torriani, Sandra; Zapparoli, Giacomo; Dellaglio, Franco

1999-01-01

Two PCR-based methods, specific PCR and randomly amplified polymorphic DNA PCR (RAPD-PCR), were used for rapid and reliable differentiation of Lactobacillus delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis. PCR with a single combination of primers which targeted the proline iminopeptidase (pepIP) gene of L. delbrueckii subsp. bulgaricus allowed amplification of genomic fragments specific for the two subspecies when either DNA from a single colony or cells extracted from dairy products were used. A numerical analysis of the RAPD-PCR patterns obtained with primer M13 gave results that were consistent with the results of specific PCR for all strains except L. delbrueckii subsp. delbrueckii LMG 6412T, which clustered with L. delbrueckii subsp. lactis strains. In addition, RAPD-PCR performed with primer 1254 provided highly polymorphic profiles and thus was superior for distinguishing individual L. delbrueckii strains. PMID:10508059

Use of PCR-based methods for rapid differentiation of Lactobacillus delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis.

PubMed

Torriani, S; Zapparoli, G; Dellaglio, F

1999-10-01

Two PCR-based methods, specific PCR and randomly amplified polymorphic DNA PCR (RAPD-PCR), were used for rapid and reliable differentiation of Lactobacillus delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis. PCR with a single combination of primers which targeted the proline iminopeptidase (pepIP) gene of L. delbrueckii subsp. bulgaricus allowed amplification of genomic fragments specific for the two subspecies when either DNA from a single colony or cells extracted from dairy products were used. A numerical analysis of the RAPD-PCR patterns obtained with primer M13 gave results that were consistent with the results of specific PCR for all strains except L. delbrueckii subsp. delbrueckii LMG 6412(T), which clustered with L. delbrueckii subsp. lactis strains. In addition, RAPD-PCR performed with primer 1254 provided highly polymorphic profiles and thus was superior for distinguishing individual L. delbrueckii strains.

Complete Genome Sequence of Salmonella enterica Serovar Typhimurium Strain YU15 (Sequence Type 19) Harboring the Salmonella Genomic Island 1 and Virulence Plasmid pSTV

PubMed Central

Calva, Edmundo; Puente, José L.; Zaidi, Mussaret B.

2016-01-01

The complete genome of Salmonella enterica subsp. enterica serovar Typhimurium sequence type 19 (ST19) strain YU15, isolated in Yucatán, Mexico, from a human baby stool culture, was determined using PacBio technology. The chromosome contains five intact prophages and the Salmonella genomic island 1 (SGI1). This strain carries the Salmonella virulence plasmid pSTV. PMID:27081132

Production of Succinic Acid from Citric Acid and Related Acids by Lactobacillus Strains

PubMed Central

Kaneuchi, Choji; Seki, Masako; Komagata, Kazuo

1988-01-01

A number of Lactobacillus strains produced succinic acid in de Man-Rogosa-Sharpe broth to various extents. Among 86 fresh isolates from fermented cane molasses in Thailand, 30 strains (35%) produced succinic acid; namely, 23 of 39 Lactobacillus reuteri strains, 6 of 18 L. cellobiosus strains, and 1 of 6 unidentified strains. All of 10 L. casei subsp. casei strains, 5 L. casei subsp. rhamnosus strains, 6 L. mali strains, and 2 L. buchneri strains did not produce succinic acid. Among 58 known strains including 48 type strains of different Lactobacillus species, the strains of L. acidophilus, L. crispatus, L. jensenii, and L. parvus produced succinic acid to the same extent as the most active fresh isolates, and those of L. alimentarius, L. collinoides, L. farciminis, L. fructivorans (1 of 2 strains tested), L. malefermentans, and L. reuteri were also positive, to lesser extents. Diammonium citrate in de Man-Rogosa-Sharpe broth was determined as a precursor of the succinic acid produced. Production rates were about 70% on a molar basis with two fresh strains tested. Succinic acid was also produced from fumaric and malic acids but not from dl-isocitric, α-ketoglutaric, and pyruvic acids. The present study is considered to provide the first evidence on the production of succinic acid, an important flavoring substance in dairy products and fermented beverages, from citrate by lactobacilli. PMID:16347795

Tiny Turtles Purchased at Pet Stores are a Potential High Risk for Salmonella Human Infection in the Valencian Region, Eastern Spain.

PubMed

Marin, Clara; Vega, Santiago; Marco-Jiménez, Francisco

2016-07-01

Turtles may be considered unsafe pets, particularly in households with children. This study aimed to assess Salmonella carriage by turtles in pet stores and in private ownership to inform the public of the potential health risk, enabling informed choices around pet selection. During the period between September and October 2013, 24 pet stores and 96 private owners were sampled in the Valencian Region (Eastern Spain). Salmonella identification procedure was based on ISO 6579: 2002 recommendations (Annex D). Salmonella strains were serotyped in accordance with Kauffman-White-Le-Minor technique. The rate of isolation of Salmonella was very high from pet store samples (75.0% ± 8.8%) and moderate for private owners (29.0% ± 4.6%). Serotyping revealed 18 different serotypes among two Salmonella enterica subspecies: S. enterica subsp. enterica and S. enterica subsp. diarizonae. Most frequently isolated serotypes were Salmonella Typhimurium (39.5%, 17/43) and Salmonella Pomona (9.3%, 4/43). Serotypes identified have previously been reported in turtles, and child Salmonella infections associate with pet turtle exposure. The present study clearly demonstrates that turtles in pet stores, as well as in private owners, could be a direct or indirect source of a high risk of human Salmonella infections. In addition, pet stores should advise their customers of the potential risks associated with reptile ownership.

Internalisation potential of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica subsp. enterica serovar Typhimurium and Staphylococcus aureus in lettuce seedlings and mature plants.

PubMed

Standing, Taryn-Ann; du Plessis, Erika; Duvenage, Stacey; Korsten, Lise

2013-06-01

The internalisation potential of Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7 and Salmonella enterica subsp. enterica serovar Typhimurium in lettuce was evaluated using seedlings grown in vermiculite in seedling trays as well as hydroponically grown lettuce. Sterile distilled water was spiked with one of the four human pathogenic bacteria (10(5) CFU/mL) and used to irrigate the plants. The potential for pathogen internalisation was investigated over time using light microscopy, transmission electron microscopy and viable plate counts. Additionally, the identities of the pathogens isolated from internal lettuce plant tissues were confirmed using polymerase chain reaction with pathogen-specific oligonucleotides. Internalisation of each of the human pathogens was evident in both lettuce seedlings and hydroponically grown mature lettuce plants. To our knowledge, this is the first report of S. aureus internalisation in lettuce plants. In addition, the levels of background microflora in the lettuce plants were determined by plate counting and the isolates identified using matrix-assisted laser ionisation-time of flight (MALDI-TOF). Background microflora assessments confirmed the absence of the four pathogens evaluated in this study. A low titre of previously described endophytes and soil inhabitants, i.e., Enterobacter cloacae, Enterococcus faecalis, Lysinibacillus fusiformis, Rhodococcus rhodochrous, Staphylococcus epidermidis and Staphylococcus hominis were identified.

Genetic Variation of Lactobacillus delbrueckii subsp. lactis Bacteriophages Isolated from Cheese Processing Plants in Finland

PubMed Central

Forsman, Päivi; Alatossava, Tapani

1991-01-01

The genomes of four Lactobacillus delbrueckii subsp. lactis bacteriophages were characterized by restriction endonuclease mapping, Southern hybridization, and heteroduplex analysis. The phages were isolated from different cheese processing plants in Finland between 1950 and 1972. All four phages had a small isometric head and a long noncontractile tail. Two different types of genome (double-stranded DNA) organization existed among the different phages, the pac type and the cos type, corresponding to alternative types of phage DNA packaging. Three phages belonged to the pac type, and a fourth was a cos-type phage. The pac-type phages were genetically closely related. In the genomes of the pac-type phages, three putative insertion/deletions (0.7 to 0.8 kb, 1.0 kb, and 1.5 kb) and one other region (0.9 kb) containing clustered base substitutions were discovered and localized. At the phenotype level, three main differences were observed among the pac-type phages. These concerned two minor structural proteins and the efficiency of phage DNA packaging. The genomes of the pac-type phages showed only weak homology with that of the cos-type phage. Phage-related DNA, probably a defective prophage, was located in the chromosome of the host strain sensitive to the cos-type phage. This DNA exhibited homology under stringent conditions to the pac-type phages. Images PMID:16348513

Production of succinic Acid from citric Acid and related acids by lactobacillus strains.

PubMed

Kaneuchi, C; Seki, M; Komagata, K

1988-12-01

A number of Lactobacillus strains produced succinic acid in de Man-Rogosa-Sharpe broth to various extents. Among 86 fresh isolates from fermented cane molasses in Thailand, 30 strains (35%) produced succinic acid; namely, 23 of 39 Lactobacillus reuteri strains, 6 of 18 L. cellobiosus strains, and 1 of 6 unidentified strains. All of 10 L. casei subsp. casei strains, 5 L. casei subsp. rhamnosus strains, 6 L. mali strains, and 2 L. buchneri strains did not produce succinic acid. Among 58 known strains including 48 type strains of different Lactobacillus species, the strains of L. acidophilus, L. crispatus, L. jensenii, and L. parvus produced succinic acid to the same extent as the most active fresh isolates, and those of L. alimentarius, L. collinoides, L. farciminis, L. fructivorans (1 of 2 strains tested), L. malefermentans, and L. reuteri were also positive, to lesser extents. Diammonium citrate in de Man-Rogosa-Sharpe broth was determined as a precursor of the succinic acid produced. Production rates were about 70% on a molar basis with two fresh strains tested. Succinic acid was also produced from fumaric and malic acids but not from dl-isocitric, alpha-ketoglutaric, and pyruvic acids. The present study is considered to provide the first evidence on the production of succinic acid, an important flavoring substance in dairy products and fermented beverages, from citrate by lactobacilli.

[Advenella kashmirensis subsp. methylica PK1, a facultative methylotroph from carex rhizosphere].

PubMed

Poroshina, M N; Doronina, N V; Kaparullina, E N; Trotsenko, Iu A

2015-01-01

A strain (PK1) of facultative methylobacteria growing on methanol as a carbon and energy source was isolated from carex rhizosphere (Pamukkale National Park, Turkey). The cells were nonmotile gram-negative rods propagating by binary fission. The organism was a strict anaerobe, oxidase- and catalase-positive. Optimal growth occurred at 29°C, pH 8.0-8.5, and 0.5% NaCl; no growth occurred at 2% NaCl. The organism used the ribulose bisphosphate pathway of C1 assimilation. Predominant fatty acids were 11-octodecenoic (18:1ω7) and cis-hexadecenoic (16:1ω7c). Phosphatidylethanolamine and diphosphatidylglycerol were the dominant phospholipids. Q8 was the main ubiquinone. DNA G+C content was 55.4 mol % (mp). Sequencing of the 16S rRNA gene revealed that strain PK1 belonged to the genus Advenella with 98.8 and 99.2% similarity to the type strains A. incenata CCUG 45225T and A. kashmirensis WT001T, respectively. DNA-DNA homology of strain PK1 and A. kashmirensis WT001T was 70%. While MALDI analysis confirmed their close clusterization, RAPD analysis revealed the differences between strain PKI and other Advenella strains. Based on its geno- and phenotypic properties, the isolate PK1 was classified as A. kashmirensis subsp. methylica PK1 (VKM-B 2850 = DSM 27514), the first known methylotroph of the genus Advenella.

PCR and restriction fragment length polymorphism of a pel gene as a tool to identify Erwinia carotovora in relation to potato diseases.

PubMed Central

Darrasse, A; Priou, S; Kotoujansky, A; Bertheau, Y

1994-01-01

Using a sequenced pectate lyase-encoding gene (pel gene), we developed a PCR test for Erwinia carotovora. A set of primers allowed the amplification of a 434-bp fragment in E. carotovora strains. Among the 89 E. carotovora strains tested, only the Erwinia carotovora subsp. betavasculorum strains were not detected. A restriction fragment length polymorphism (RFLP) study was undertaken on the amplified fragment with seven endonucleases. The Sau3AI digestion pattern specifically identified the Erwinia carotovora subsp. atroseptica strains, and the whole set of data identified the Erwinia carotovora subsp. wasabiae strains. However, Erwinia carotovora subsp. carotovora and Erwinia carotovora subsp. odorifera could not be separated. Phenetic and phylogenic analyses of RFLP results showed E. carotovora subsp. atroseptica as a homogeneous group while E. carotovora subsp. carotovora and E. carotovora subsp. odorifera strains exhibited a genetic diversity that may result from a nonmonophyletic origin. The use of RFLP on amplified fragments in epidemiology and for diagnosis is discussed. Images PMID:7912502

Isolation and characterization of probiotics from dairies

PubMed Central

Haghshenas, Babak; Nami, Yousef; Almasi, Ali; Abdullah, Norhafizah; Radiah, Dayang; Rosli, Rozita; Barzegari, Abolfazl; Khosroushahi, Ahmad Yari

2017-01-01

Background and Objectives: Probiotics are live microorganisms, which show beneficial health effects on hosts once consumed in sufficient amounts. LAB group can be isolated and characterized from traditional dairy sources. This study aimed at isolating, identifying, and in vitro characterizing (low pH/high bile salt tolerance, antibacterial activity, and antibiotic susceptibility) LAB strains from traditional Iranian dairy products. Materials and Methods: Isolated strains were identified by Gram staining, catalase assay, and 3 molecular identification methods; namely, (GTG) 5-PCR fingerprinting, ARDRA, and 16S rDNA gene sequencing. Results: A total of 19 LAB strains belonging to 4 genera (Lactococcus, Leuconostoc, Lactobacillus and Enterococcus) were identified. Conclusion: The experiments revealed that L. plantarum 15HN, L. lactis subsp. cremoris 44L and E. mundtii 50H strains, which were isolated from shiraz, cheese and shiraz, respectively, displayed a desirable tolerance to low pH and high bile salts, favorable anti-pathogen activity, and acceptable antibiotic susceptibility; hence, they could be considered as novel probiotic candidates and applied in the food industry. PMID:29238459

In Vitro Comparison of Ertapenem, Meropenem, and Imipenem against Isolates of Rapidly Growing Mycobacteria and Nocardia by Use of Broth Microdilution and Etest

PubMed Central

Brown-Elliott, Barbara A.; Killingley, Jessica; Vasireddy, Sruthi; Bridge, Linda

2016-01-01

We compared the activities of the carbapenems ertapenem, meropenem, and imipenem against 180 isolates of rapidly growing mycobacteria (RGM) and 170 isolates of Nocardia using the Clinical and Laboratory Standards Institute (CLSI) guidelines. A subset of isolates was tested using the Etest. The rate of susceptibility to ertapenem and meropenem was limited and less than that to imipenem for the RGM. Analysis of major and minor discrepancies revealed that >90% of the isolates of Nocardia had higher MICs by the broth microdilution method than by Etest, in contrast to the lower broth microdilution MICs seen for >80% of the RGM. Imipenem remains the most active carbapenem against RGM, including Mycobacterium abscessus subsp. abscessus. For Nocardia, imipenem was significantly more active only against Nocardia farcinica. Although there may be utility in testing the activities of the newer carbapenems against Nocardia, their activities against the RGM should not be routinely tested. Testing by Etest is not recommended by the CLSI. PMID:27053677

Genetic variation in Mediterranean Helichrysum italicum (Asteraceae; Gnaphalieae): do disjunct populations of subsp. microphyllum have a common origin?

PubMed

Galbany-Casals, M; Blanco-Moreno, J M; Garcia-Jacas, N; Breitwieser, I; Smissen, R D

2011-07-01

The yellow-flowered everlasting daisy Helichrysum italicum (Asteraceae, Gnaphalieae) is widely distributed in the Mediterranean basin, where it grows in continuous and widespread populations in diverse open habitats. Helichrysum italicum subsp. microphyllum has a disjunct distribution in the Balearic Islands (Majorca and Dragonera), Corsica, Sardinia, Crete and Cyprus. Numerous morphological intermediates between subsp. italicum and subsp. microphyllum are known from Corsica, where the two subspecies co-occur. The aims of the study were to investigate if subsp. microphyllum has a common origin, constituting an independent gene pool from subsp. italicum, or if the morphological differences between subsp. microphyllum and subsp. italicum have arisen independently in different locations from a common wider gene pool. Our analyses of AFLP, cpDNA sequences and morphological characters show that there is geographic structure to the genetic variation within H. italicum, with eastern and western Mediterranean groups, which do not correspond with the division into subsp. microphyllum and subsp. italicum as currently circumscribed. Local selection on quantitative trait loci provides sufficient explanation for the morphological divergence observed and is consistent with genetic data. Within the western Mediterranean group of the species we found considerable polymorphism in chloroplast DNA sequences among and within some populations. Comparison with chloroplast DNA sequences from other Helichrysum species showed that some chloroplast haplotypes are shared across species. © 2010 German Botanical Society and The Royal Botanical Society of the Netherlands.

Relationship between presence of cows with milk positive for Mycobacterium avium subsp. paratuberculosis-specific antibody by enzyme-linked immunosorbent assay and viable M. avium subsp. paratuberculosis in dust in cattle barns.

PubMed

Eisenberg, Susanne W F; Chuchaisangrat, Ruj; Nielen, Mirjam; Koets, Ad P

2013-09-01

Paratuberculosis, or Johne's disease, in cattle is caused by Mycobacterium avium subsp. paratuberculosis, which has recently been suspected to be transmitted through dust. This longitudinal study on eight commercial M. avium subsp. paratuberculosis-positive dairy farms studied the relationship between the number of cows with M. avium subsp. paratuberculosis antibody-positive milk and the presence of viable M. avium subsp. paratuberculosis in settled-dust samples, including their temporal relationship. Milk and dust samples were collected in parallel monthly for 2 years. M. avium subsp. paratuberculosis antibodies in milk were measured by enzyme-linked immunosorbent assay (ELISA) and used as a proxy for M. avium subsp. paratuberculosis shedding. Settled-dust samples were collected by using electrostatic dust collectors (EDCs) at six locations in housing for dairy cattle and young stock. The presence of viable M. avium subsp. paratuberculosis was identified by liquid culture and PCR. The results showed a positive relationship (odds ratio [OR], 1.2) between the number of cows with ELISA-positive milk and the odds of having positive EDCs in the same airspace as the adult dairy cattle. Moreover, the total number of lactating cows also showed an OR slightly above 1. This relationship remained the same for settled-dust samples collected up to 2 months before or after the time of milk sampling. The results suggest that removal of adult cows with milk positive for M. avium subsp. paratuberculosis-specific antibody by ELISA might result in a decrease in the presence of viable M. avium subsp. paratuberculosis in dust and therefore in the environment. However, this decrease is likely delayed by several weeks at least. In addition, the data support the notion that M. avium subsp. paratuberculosis exposure of young stock is reduced by separate housing.

Relationship between Presence of Cows with Milk Positive for Mycobacterium avium subsp. paratuberculosis-Specific Antibody by Enzyme-Linked Immunosorbent Assay and Viable M. avium subsp. paratuberculosis in Dust in Cattle Barns

PubMed Central

Chuchaisangrat, Ruj; Nielen, Mirjam; Koets, Ad P.

2013-01-01

Paratuberculosis, or Johne's disease, in cattle is caused by Mycobacterium avium subsp. paratuberculosis, which has recently been suspected to be transmitted through dust. This longitudinal study on eight commercial M. avium subsp. paratuberculosis-positive dairy farms studied the relationship between the number of cows with M. avium subsp. paratuberculosis antibody-positive milk and the presence of viable M. avium subsp. paratuberculosis in settled-dust samples, including their temporal relationship. Milk and dust samples were collected in parallel monthly for 2 years. M. avium subsp. paratuberculosis antibodies in milk were measured by enzyme-linked immunosorbent assay (ELISA) and used as a proxy for M. avium subsp. paratuberculosis shedding. Settled-dust samples were collected by using electrostatic dust collectors (EDCs) at six locations in housing for dairy cattle and young stock. The presence of viable M. avium subsp. paratuberculosis was identified by liquid culture and PCR. The results showed a positive relationship (odds ratio [OR], 1.2) between the number of cows with ELISA-positive milk and the odds of having positive EDCs in the same airspace as the adult dairy cattle. Moreover, the total number of lactating cows also showed an OR slightly above 1. This relationship remained the same for settled-dust samples collected up to 2 months before or after the time of milk sampling. The results suggest that removal of adult cows with milk positive for M. avium subsp. paratuberculosis-specific antibody by ELISA might result in a decrease in the presence of viable M. avium subsp. paratuberculosis in dust and therefore in the environment. However, this decrease is likely delayed by several weeks at least. In addition, the data support the notion that M. avium subsp. paratuberculosis exposure of young stock is reduced by separate housing. PMID:23793639

Tularaemia in Norwegian dogs.

PubMed

Nordstoga, Anne; Handeland, Kjell; Johansen, Tone Bjordal; Iversen, Lena; Gavier-Widén, Dolores; Mattsson, Roland; Wik-Larssen, Kjersti; Afset, Jan Egil; Næverdal, Rune; Lund, Arve

2014-10-10

We describe tularaemia in a Norwegian dog caused by Francisella tularensis subspecies holarctica. A Hamilton Hound and his owner developed tulaeremia after hunting an infected mountain hare (Lepus timidus). The dog showed signs of lethargy, anorexia and fever during a period two to four days after hunting and thereafter fully recovered. Its antibody titers increased 32-fold from one to three weeks post exposure. Thereafter, the titer declined and leveled off at moderate positive values up to one year after exposure (end of study). This is believed to be the first case report of clinical F. tularensis subspecies holarctica infection in a European dog. In 2011, enormous numbers of Norway lemmings (Lemmus lemmus) occurred in Finnmark, the northernmost county of Norway and many dogs caught and swallowed lemmings. Some of these dogs developed non-specific signs of disease and the owners consulted a veterinary surgeon, who suspected tularaemia. In order to investigate this hypothesis, serum samples from 33 dogs were examined for antibodies to F. tularensis. The dogs were allocated into three groups: Dogs from Finnmark that became sick (Group 1) or remained healthy following contact with lemmings (Group 2), and healthy control dogs from Oslo without known contact with lemmings (Group 3). All the serum samples were analyzed with a tube agglutination assay. Among dogs exposed to lemmings, 10/11 and 3/12 were antibody positive in Group 1 and Group 2, respectively, whereas none of the control dogs (n=10) were positive for antibodies against F. tularensis. These results strongly indicate that the non-specific disease seen in the dogs in Finnmark was linked to F. tularensis infection acquired through contact with lemmings. Copyright © 2014 Elsevier B.V. All rights reserved.

Dynamics of polyploid formation and establishment in the allotetraploid rock fern Asplenium majoricum

PubMed Central

Hunt, Harriet V.; Ansell, Stephen W.; Russell, Stephen J.; Schneider, Harald; Vogel, Johannes C.

2011-01-01

Background and Aims Successful establishment of newly formed polyploid species depends on several interlinked genetic and ecological factors. These include genetic diversity within and among individuals, chromosome behaviour and fertility, novel phenotypes resulting from novel genomic make-up and expression, intercytotypic and interspecific competition, and adaptation to distinct habitats. The allotetraploid rock fern Asplenium majoricum is known from one small population in Valencia, Spain, and several larger populations on the Balearic island of Majorca. In Valencia, it occurs sympatrically with its diploid parents, A. fontanum subsp. fontanum and A. petrarchae subsp. bivalens, and their diploid hybrid A. × protomajoricum. This highly unusual situation allowed the study of polyploid genetic diversity and its relationship to the formation and establishment of nascent polyploid lineages. Methods Genetic variation for isozyme and chloroplast DNA markers was determined for A. majoricum and A. × protomajoricum sampled thoroughly from known sites in Majorca and Valencia. Results were compared with variation determined previously for the diploid parent taxa. Key Results A highly dynamic system with recurring diploid hybrid and allotetraploid formation was discovered. High diversity in the small Valencian A. majoricum population indicates multiple de novo origins from diverse parental genotypes, but most of these lineages become extinct without becoming established. The populations on Majorca most probably represent colonization(s) from Valencia rather than an in situ origin. Low genetic diversity suggests that this colonization may have occurred only once. Conclusions There is a striking contrast in success of establishment of the Majorcan and Valencian populations of A. majoricum. Chance founding of populations in a habitat where neither A. fontanum subsp. fontanum nor A. petrarchae subsp. bivalens occurs appears to have been a key factor enabling the establishment of A. majoricum on Majorca. Successful establishment of this polyploid is probably dependent on geographic isolation from diploid progenitor competition. PMID:21593062

In vitro inhibition of Eimeria tenella sporozoite invasion into host cells by probiotics.

PubMed

Hessenberger, S; Schatzmayr, G; Teichmann, K

2016-10-15

The aim was to study the effects of probiotics isolated from the intestinal tract of livestock animals on Eimeria tenella invasion into Madin-Darby bovine kidney (MDBK) cells in vitro. E. tenella sporozoites were purified and labeled with 5(6)-carboxyfluorescein diacetate N-succinimidyl ester before seeding on cell cultures, and invasion was evaluated by fluorescence microscopy. Two protocols (A and B) were used. In protocol A, Enterococcus faecium # 589 or Lactobacillus salivarius subsp. salivarius # 505 were added together with sporozoites to MDBK cell cultures and invasion was evaluated after incubation for approximately 20h. Viable, dead, or spent culture supernatants of probiotics were tested. In protocol B, viable probiotics were incubated with MDBK cells for one hour before sporozoites were added and invasion was evaluated after two more hours of incubation. Parasite invasion of viable, dead, or spent culture supernatant of E. faecium # 589 was assessed. Using protocol A, it was shown that parasite invasion was inhibited by viable (80%) or dead (75%) E. faecium # 589. While inhibition by viable L. salivarius subsp. salivarius # 505 was not valid at the highest concentration and not significant at the other test concentrations, dead cells inhibited parasite invasion up to 45%. Spent culture supernatants of both probiotics had no influence on parasite invasion. Using protocol B, it was shown that viable Bifidobacterium animalis subsp. animalis # 503, E. faecium # 497, E. faecium # 589, L. reuteri # 514, L. salivarius subsp. salivarius # 505, and Bacillus subtilis # 588 inhibited parasite invasion into MDBK cells up to 80%. Anticoccidial activity was strain-specific for E. faecium strains, and the strongest effect was shown by E. faecium # 589. Anticoccidial effects of some of the tested probiotics have already been shown in vivo, which makes them candidates to prevent coccidiosis. These findings have now been confirmed in vitro. The used parasite invasion assay is a fast and inexpensive tool to screen probiotics for prevention of coccidiosis. Copyright © 2016 Elsevier B.V. All rights reserved.

A Novel Enzyme-Linked Immunosorbent Assay for Diagnosis of Mycobacterium avium subsp. paratuberculosis Infections (Johne's Disease) in Cattle

PubMed Central

Speer, C. A.; Scott, M. Cathy; Bannantine, John P.; Waters, W. Ray; Mori, Yasuyuki; Whitlock, Robert H.; Eda, Shigetoshi

2006-01-01

Enzyme-linked immunosorbent assays (ELISAs) for the diagnosis of Johne's disease (JD), caused by Mycobacterium avium subsp. paratuberculosis, were developed using whole bacilli treated with formaldehyde (called WELISA) or surface antigens obtained by treatment of M. avium subsp. paratuberculosis bacilli with formaldehyde and then brief sonication (called SELISA). ELISA plates were coated with either whole bacilli or sonicated antigens and tested for reactivity against serum obtained from JD-positive and JD-negative cattle or from calves experimentally inoculated with M. avium subsp. paratuberculosis, Mycobacterium avium subsp. avium, or Mycobacterium bovis. Because the initial results obtained from the WELISA and SELISA were similar, most of the subsequent experiments reported herein were performed using the SELISA method. To optimize the SELISA test, various concentrations (3.7 to 37%) of formaldehyde and intervals of sonication (2 to 300 s) were tested. With an increase in formaldehyde concentration and a decreased interval of sonication, there was a concomitant decrease in nonspecific binding by the SELISA. SELISAs prepared by treating M. avium subsp. paratuberculosis with 37% formaldehyde and then a 2-s burst of sonication produced the greatest difference (7×) between M. avium subsp. paratuberculosis-negative and M. avium subsp. paratuberculosis-positive serum samples. The diagnostic sensitivity and specificity for JD by the SELISA were greater than 95%. The SELISA showed subspecies-specific detection of M. avium subsp. paratuberculosis infections in calves experimentally inoculated with M. avium subsp. paratuberculosis or other mycobacteria. Based on diagnostic sensitivity and specificity, the SELISA appears superior to the commercial ELISAs routinely used for the diagnosis of JD. PMID:16682472

The response regulator expM is essential for the virulence of Erwinia carotovora subsp. carotovora and acts negatively on the sigma factor RpoS (sigma s).

PubMed

Andersson, R A; Palva, E T; Pirhonen, M

1999-07-01

The main virulence factors of Erwinia carotovora subsp. carotovora, the secreted, extracellular cell-wall-degrading enzymes, are controlled by several regulatory mechanisms. We have isolated transposon mutants with reduced virulence on tobacco. One of these mutants, with a mutation in a gene designated expM, was characterized in this study. This mutant produces slightly reduced amounts of extracellular enzymes in vitro and the secretion of the enzymes is also affected. The expM wild-type allele was cloned together with an upstream gene, designated expL, that has an unknown function. The expM gene was sequenced and found to encode a protein with similarity to the RssB/SprE protein of Escherichia coli and the MviA protein of Salmonella typhimurium. These proteins belong to a new type of two-component response regulators that negatively regulate the stability of the Sigma factor RpoS (sigma s) at the protein level. The results of this study suggest that ExpM has a similar function in E. carotovora subsp. carotovora. We also provide evidence that the overproduction of RpoS in the expM mutant is an important factor for the reduced virulence phenotype and that it partly causes the observed phenotype seen in vitro. However, an expM/rpoS double mutant is still affected in secretion of extracellular enzymes, suggesting that ExpM in addition to RpoS also acts on other targets.

Salinivibrio siamensis sp. nov., from fermented fish (pla-ra) in Thailand.

PubMed

Chamroensaksri, Nitcha; Tanasupawat, Somboon; Akaracharanya, Ancharida; Visessanguan, Wonnop; Kudo, Takuji; Itoh, Takashi

2009-04-01

A Gram-negative, facultatively anaerobic, moderately halophilic bacterium, strain ND1-1(T), was isolated from fermented fish (pla-ra) in Thailand. The cells were curved rods, motile and non-endospore-forming. The novel strain grew optimally at 37 degrees C, at pH 8 and in the presence of 9-10 % (w/v) NaCl. The predominant respiratory lipoquinone was Q-8. The major cellular fatty acids were C(16 : 0) and C(12 : 0). Polar lipid analysis revealed the presence of phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content was 49.0 mol%. Comparative 16S rRNA gene sequence analyses indicated that strain ND1-1(T) was closely related to Salinivibrio costicola, which comprises three subspecies, and Salinivibrio proteolyticus with gene sequence similarities of 98.3-98.6 %. Strain ND1-1(T) showed low levels of DNA-DNA relatedness with S. costicola subsp. costicola JCM 15095(T) (33.2 %), S. costicola subsp. alcaliphilus DSM 16359(T) (38.4 %), S. costicola subsp. vallismortis JCM 15096(T) (59.7 %), and S. proteolyticus AF-2004(T) (42.1 %). On the basis of the physiological and biochemical characteristics and the molecular data presented, strain ND1-1(T) should be classified as a novel species of the genus Salinivibrio for which the name Salinivibrio siamensis sp. nov. is proposed. The type strain is ND1-1(T) (=JCM 14472(T)=PCU 301(T)=TISTR 1810(T)).

Inhibitory activity of surfactin, produced by different Bacillus subtilis subsp. subtilis strains, against Listeria monocytogenes sensitive and bacteriocin-resistant strains.

PubMed

Sabaté, Daniela C; Audisio, M Carina

2013-03-30

Three surfactin-producing Bacillus subtilis strains, C4, M1 and G2III, previously isolated from honey and intestines from the Apis mellifera L. bee, were phylogenetically characterized at sub-species level as B. subtilis subsp. subtilis using gyrA gene sequencing. The antagonistic effect of surfactin was studied against seven different Listeria monocytogenes strains, 6 of which were resistant to bacteriocins. Surfactin showed anti-Listeria activity against all 7 strains and a dose of 0.125 mg/mL of surfactin was enough to inhibit this pathogen. Surfactin sintetized by B. subtilis subsp. subtilis C4 inhibited the pathogen in lower concentrations, 0.125 mg/mL, followed by G2III and M1 with 0.25 and 1mg/mL, respectively. In particular, a dose of 0.125 mg/mL reduced the viability of L. monocytogenes 99/287 RB6, a bacteriocin-resistant strain, to 5 log orders. Surfactin assayed maintained anti-Listeria activity within a pH range of between 2 and 10, after heat treatment (boiling for 10 min and autoclaving at 121 °C for 15 min) and after treatment with proteolytic enzymes. These results suggest that surfactin can be used as a new tool for prevention and the control of L. monocytogenes in different environments, for example, in the food industry. Copyright © 2012 Elsevier GmbH. All rights reserved.

Eradication of Helicobacter pylori infection by the probiotic strains Lactobacillus johnsonii MH-68 and L. salivarius ssp. salicinius AP-32.

PubMed

Hsieh, Pei-Shan; Tsai, Yi-Chun; Chen, Yi-Chun; Teh, Su-Fen; Ou, Chung-Mou; King, V An-Erl

2012-12-01

The current therapy for Helicobacter pylori infection includes antimicrobial agents and proton pump inhibitors. We have examined the ability of Lactobacillus spp. to inhibit H. pylori infection. Probiotic strains isolated from samples of adult feces, infant feces, breast milk, and vaginal swab collected from healthy volunteers in Taiwan and commercially available strains were screened for antagonism toward H. pylori. Inhibition liquid culture assay was used to screen potential anti-H. pylori activity. Then, we performed agar plate inhibition assay, and assays to determine the capacity of probiotics for adhesion, and inhibition and killing of H. pylori, and measured the levels of IL-8 and IL-10. Using animal models, we studied regulation of gastric acid and histopathological changes accompanying anti-H. pylori activity. We found that six of the tested strains suppressed urease activity of H. pylori: Lactobacillus acidophilus TYCA08, L. acidophilus TYCA15, L. johnsonii MH-68, and L. salivarius subsp. salicinius AP-32 were more effective than the others. In vivo, L. johnsonii MH-68 and L. salivarius subsp. salicinius AP-32 alone or in combination, reduced the H. pylori load in the gastric mucosa, and also reduced inflammatory chemokine expression and lymphocyte infiltration. Lactobacillus johnsonii MH-68 and L. salivarius subsp. salicinius AP-32 effectively suppress H. pylori viability, and when used as probiotics, they may help decrease the occurrence of gastritis, and even reduce the risk of H. pylori infection. © 2012 Blackwell Publishing Ltd.

Disparate host immunity to Mycobacterium avium subsp. paratuberculosis antigens in calves inoculated with M. avium subsp. paratuberculosis, M. avium subsp. avium, M. kansasii and M. bovis

USDA-ARS?s Scientific Manuscript database

Cross-reactivity of mycobacterial antigens in immune-based diagnostic assays has been a major concern and criticism of current tests for the detection of paratuberculosis. In the present study, host immune responses to antigen preparations of Mycobacterium avium subsp. paratuberculosis (MAP), consis...