RESUMO
The bacterial genus Yersinia belongs to the family Enterobacteriaceae and comprises 15 species. Species of the genus Yersinia are usually identified by their phenotypic characteristics. Thus, it is essential to establish a complete phenotypic classification for all species of the genus Yersinia. The species Yersinia massiliensis was proposed in 2008, based on 16S rRNA, gyrB, hsp60, rpoB and sodA gene sequences and some distinguishing phenotypic characteristics. In this study, four Yersinia strains classified as Y. massiliensis based on the sequencing of the loci mentioned above were subjected to a more detailed phenotypic characterization. This characterization revealed differences in the results of four tests previously reported as diagnostic for Y. massiliensis and the results of 18 additional tests provided new information about the biochemical diversity of this species. In the light of the results of the phenotypic characteristics of the four strains of Y. massiliensis, an emended description of Y. massiliensis is presented.
Assuntos
Lactuca/microbiologia , Leite/microbiologia , Microbiologia da Água , Yersinia/classificação , Yersinia/isolamento & purificação , Animais , Bovinos , DNA Bacteriano/genética , Ácidos Graxos/metabolismo , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Yersinia/genética , Yersinia/metabolismoRESUMO
In the last few decades, molecular typing has become an important tool in taxonomic, phylogenetic and identification studies of numerous groups of bacteria, including the yersiniae. In this study, Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR), Pulsed-Field Gel Electrophoresis (PFGE), 16S rRNA gene sequencing and Multilocus Sequence Analysis (MLSA) were performed to determine the ability of these techniques to be used in taxonomy and identification of Yersinia strains. A total of 60 Yersinia strains were genotyped by ERIC-PCR and PFGE. Moreover, an in silico analysis was carried out for 16S rRNA gene sequencing and MLSA, using 68 and 49 Yersinia strains, respectively. A phylogenetic tree constructed from the ERIC-PCR, 16S rRNA gene sequencing and MLSA data grouped most of the Yersinia species into distinct species-specific clusters. In the PFGE assay these clusters were not observed. On this basis, ERIC-PCR, 16S rRNA gene sequencing and MLSA seem to be valuable techniques for use in taxonomic and identification studies of the genus Yersinia, whereas PFGE does not. Furthermore, ERIC-PCR has the advantage of being a cheaper, easier and faster assay than 16S rRNA gene sequencing or MLSA, and for these reasons can be considerate an alternative tool in taxonomic studies of yersiniae.
Assuntos
Técnicas Bacteriológicas/métodos , Impressões Digitais de DNA/métodos , Yersinia/classificação , Yersinia/genética , Animais , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Eletroforese em Gel de Campo Pulsado , Microbiologia Ambiental , Microbiologia de Alimentos , Genótipo , Humanos , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Sensibilidade e Especificidade , Análise de Sequência de DNA , Yersinia/isolamento & purificação , Yersiniose/diagnóstico , Yersiniose/veterináriaRESUMO
Molecular typing and virulence markers were used to evaluate the genetic profiles and virulence potential of 106 Yersinia enterocolitica strains. Of these strains, 71 were bio-serotype 4/O : 3, isolated from human and animal clinical material, and 35 were of biotype 1A or 2 and of diverse serotypes, isolated from food in Brazil between 1968 and 2000. Drug resistance was also investigated. All the strains were resistant to three or more drugs. The isolates showed a virulence-related phenotype in the aesculin, pyrazinamidase and salicin tests, except for the food isolates, only two of which were positive for these tests. For the other phenotypic virulence determinants (autoagglutination, Ca(++) dependence and Congo red absorption), the strains showed a diverse behaviour. The inv, ail and ystA genes were detected in all human and animal strains, while all the food isolates were positive for inv, and 3 % of them positive for ail and ystA. The presence of virF was variable in the three groups of strains. The strains were better discriminated by PFGE than by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). A higher genomic similarity was observed among the 4/O : 3 strains, isolated from human and animal isolates, than among the food strains, with the exception of two food strains possessing the virulence genes and grouped close to the 4/O : 3 strains by ERIC-PCR. Unusually, the results revealed the virulence potential of a bio-serotype 1A/O : 10 strain, suggesting that food contaminated with Y. enterocolitica biotype 1A may cause infection. This also suggests that ERIC-PCR may be used as a tool to reveal clues about the virulence potential of Y. enterocolitica strains. Furthermore, the results also support the hypothesis that animals may act as reservoirs of Y. enterocolitica for human infections in Brazil, an epidemiological aspect that has not been investigated in this country, confirming data from other parts of the world.
Assuntos
Microbiologia de Alimentos , Yersiniose/microbiologia , Yersinia enterocolitica/classificação , Testes de Aglutinação , Amidoidrolases , Animais , Álcoois Benzílicos/metabolismo , Brasil/epidemiologia , Vermelho Congo/metabolismo , DNA Bacteriano/química , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Esculina/metabolismo , Glucosídeos , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Virulência , Fatores de Virulência/química , Fatores de Virulência/genética , Yersiniose/epidemiologia , Yersinia enterocolitica/genética , Yersinia enterocolitica/isolamento & purificação , Yersinia enterocolitica/patogenicidadeRESUMO
In a recent study of the microbiological quality of commercial ice, 50 Escherichia coli isolates belonging to different serotypes were found. The potential hazard from these isolates was examined by testing their adherence patterns in HeLa cells and searching for the presence of DNA sequences related to E. coli virulence properties. Twelve potentially diarrheagenic isolates were found and classified as enteroaggregative E. coli (EAEC) based on their ability to produce aggregative adherence to HeLa cells. The remaining isolates were devoid of the virulence properties searched for. The EAEC isolates belonged to 10 different serotypes, among which O128ab:H35 is often found in diarrheic feces. None of these isolates reacted with a specific EAEC DNA probe or carried any of the known EAEC virulence genes. These data indicate that ice may be an important vehicle for transmission of enteropathogens, especially of the EAEC group.
Assuntos
Infecções por Escherichia coli/prevenção & controle , Escherichia coli/isolamento & purificação , Microbiologia de Alimentos , Gelo , Aderência Bacteriana , Qualidade de Produtos para o Consumidor , DNA Bacteriano/análise , Diarreia/microbiologia , Escherichia coli/fisiologia , Infecções por Escherichia coli/transmissão , Fezes/microbiologia , Células HeLa , Humanos , Produtos da Carne/microbiologia , Alimentos Marinhos/microbiologia , VirulênciaAssuntos
Linfócitos B/imunologia , Ativação Linfocitária/imunologia , Yersiniose/imunologia , Yersinia enterocolitica/imunologia , Animais , Anticorpos Antibacterianos/sangue , Formação de Anticorpos/imunologia , Modelos Animais de Doenças , Mucosa Gástrica/microbiologia , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Camundongos , Fatores de TempoAssuntos
Artrite/microbiologia , Linfócitos B/imunologia , Ativação Linfocitária , Yersiniose/imunologia , Yersinia enterocolitica/patogenicidade , Animais , Anticorpos Antibacterianos/sangue , Formação de Anticorpos , Modelos Animais de Doenças , Humanos , Imunoglobulina G/sangue , Isotipos de Imunoglobulinas/sangue , Camundongos , Virulência , Yersinia enterocolitica/classificação , Yersinia enterocolitica/isolamento & purificaçãoAssuntos
Yersiniose/epidemiologia , Yersinia enterocolitica/patogenicidade , Animais , Brasil/epidemiologia , Humanos , Antígenos O/genética , Fenótipo , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/veterinária , Sorotipagem , Virulência , Yersiniose/veterinária , Yersinia enterocolitica/genética , Yersinia enterocolitica/isolamento & purificaçãoRESUMO
A partir de amostras de água doce isolaram-se 26 cepas de Salmonella sp. de sorotipos diversos. A presença de plasmídios foi verificada nessas amostras sendo que onze delas apresentavam plasmídios de diferentes pesos moleculares. Quatro amostras contendo plasmídios e duas sem plasmídios foram analisadas quanto à capacidade de invasäo em camundongos. Com respeito a S. typhimurium, é possível sugerir uma correlaçäo entre virulência e a presença de plasmídio.