Navegando por Palavras-chave "virulence markers"
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- ItemSomente MetadadadosDistribution of virulence profiles related to new toxins and putative adhesins in Shiga toxin-producing Escherichia coli isolated from diverse sources in Brazil(Blackwell Publishing, 2007-09-01) Cergole-Novella, Maria Cecilia [UNIFESP]; Nishimura, Lucilia S. [UNIFESP]; Santos, Luis Fernando dos [UNIFESP]; Irino, Kinue; Vaz, Tania Mara I. [UNIFESP]; Bergamini, Alzira M. M.; Guth, Beatriz Ernestina C. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Inst Adolfo Lutz RegistroThe distribution of virulence markers related to cytolethal distending toxin-V (CDT-V), subtilase cytotoxin (SubAB), the enterohemorrhagic Escherichia coli factor for adherence (Efa1), the adhesin similar to IrgA (Iha), the long polar fimbriae (LpfO113), the autoagglutinating adhesin (Saa), and the protein required for full expression of adherence of O157:H7 Sakai strain (ToxB) was investigated in 121 Shiga toxin-producing E. coli (STEC) strains isolated in Brazil. STEC strains were isolated from human infections (n=49), cattle (n=68) and ground meat samples (n=4). Overall, the lpfA(O113), iha, efa1, saa, and toxB sequences were observed in 89.2%, 87.6%, 47.1%, 43%, and 13.2% of the strains, respectively. the genes efa1 (96.6%) and toxB (27%) were only identified among eae-positive strains, while saa (83.8%), cdt-V (12.9%), and subAB (48.4%) just occurred in eae-negative STEC strains. STEC strains harboring cdt-V and subAB were for the first time described in the South American subcontinent. in addition, the simultaneous presence of cdt-V and subAB has not been previously reported, nor the presence of subAB in STEC O77, O79, O105, O174, and O178 serogroups. A diversity of virulence profiles was observed among the STEC strains studied. the most prevalent profile observed among eae-positive STEC strains mainly isolated from humans was eae efa1 iha lpfA(O113), whereas iha lpfA(O113) saa ehxA subAB prevailed among eae-negative STEC strains, mostly isolated from cattle and foods.
- ItemSomente MetadadadosDiversity of virulence profiles of Shiga toxin-producing Escherichia coli serotypes in food-producing animals in Brazil(Elsevier B.V., 2008-09-30) Oliveira, Murilo Gomes; Feitosa Brito, Jose Renaldi; Tardelli Gomes, Tania Aparecida [UNIFESP]; Cabilio Guth, Beatriz Ernestina [UNIFESP]; Midolli Vieira, Monica Aparecida [UNIFESP]; Furtado Naves, Zita Valeria; Ibelli Vaz, Tania Mara; Irino, Kinue; Inst Adolfo Lutz Registro; Univ Fed Juiz de Fora; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA); Universidade Federal de São Paulo (UNIFESP)The prevalence, serotypes and virulence profiles of Shiga toxin-producing Escherichia coli (STEC) were investigated in 205 healthy beef and dairy cattle. and 106 goats reared in the southeastern region of Minas Gerais State, Brazil. the prevalence of STEC was 57.5% (61/106) in goats, 39.2%, (40/102) in beef cattle and 17.5% (18/103) in dairy cattle. Among the 514 STEC isolates, 40 different serotypes were found and some of them were identified in a specific host. STEC isolates harboring stx(1) corresponded to 15.6% (28/180), 26.7% (16/60) and 24.1% (661274) in beef cattle, dairy cattle and goats. respectively. Stx(2) was found in 30% (54/180), 53.3% (32/60) and 34.7% (95/274) of beef and dairy cattle, and goats. stx(1) Plus Stx(2) sequences were harbored by 54.4% (98/180), 20% (12/60) and 41.2% (113/274) of beef cattle, dairy cattle and goats. respectively. the eae sequence was found in 15% (9/60) and 0.6% (1/180) of STEC isolates from dairy and beef cattle, respectively, and the toxB gene was found only in one O157:H7 strain isolated from beef cattle. Strains with the genetic profiles stx(2) ehxA iha saa and stx(1) stx(2) ehxA iha saa were the most prevalent among STEC isolates from cattle. Profiles stx, Stx(2) ehxA ilia, stx2, and stx, iha accounted for 75.5% (207 /274) of the STEC isolates from goats. While STEC strains carrying either Stx(2) alone or associated with stx(1) were found more frequently in cattle, those harboring sequences stx(1), and Stx(2d) alone or associated with stx(1c) predominated in goats. Our data show a diversity of STEC strains in food-producing animals, most of them carrying genes linked to severe forms of human diseases. (C) 2008 Elsevier B.V. All rights reserved.
- ItemAcesso aberto (Open Access)Escherichia coli produtora de toxina Shiga ( STEC): marcadores de Virulência e análise clonal(Universidade Federal de São Paulo (UNIFESP), 2006-12-31) Vaz, Tânia Mara Ibelli [UNIFESP]; Guth, Beatriz Ernestina Cabilio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Forty eigth Shiga toxin-producing Escherichia coli (STEC) strains, the majority from human origin, and thirty non-STEC strains carrying eae and belonging to the same serogroups of STEC strains, and isolated between 1976 and 2003 were studied. Phenotypical traits, virulence characteristics and genetic diversity were evaluated. The majority of STEC strains was isolated in two distinct periods: some strains were recovered from a retrospective study (1976-99), and other strains from a prospective study (2000-03). STEC and non-STEC strains from human origin were from sporadic and unrelated cases of infection, except for two strains isolated from one patient. STEC strains belonging to serotypes O111:H8(H-), O26:H11 e O157:H7 prevailed. Differences on the prevalence of serotypes during the two periods were observed; while O111:H8(H-) e O26:H11 STEC strains prevailed during the period 1976-99, only one O111:H- STEC strain was identified during the period 2000-03. The inability to ferment rhamnose and dulcitol was mostly associated with O26 and O118 strains, whereas O111 STEC strains failed to decarboxylate lysine. The majority of the STEC strains was susceptible to all drugs; however, multi-resistant strains were detected mainly among O111:H- and O111:H8 STEC strains. All O157:H7 STEC strains carried stx2. Strains belonging to O93:H19 and O77:H18 harbored stx1 and stx2 sequences, and the remaining STEC strains carried only stx1. Except for O93:H19, O77:H18 e O55:H19 serotypes, all STEC strains carried eae. A close relationship was seen between intimin types, serotypes and diarrheagenic groups of E. coli. The presence of ehxA gene varied according to the serotypes. Multiple PFGE patterns were found among STEC strains of distinct serotypes. Moreover, PFGE restriction patterns of STEC strains differed substantially from those observed among non-STEC strains of the same serogroup except for O26 strains. Based on the indistinguishable PFGE pattern seen in two O157:H7 STEC strains, it can be suggested the first probable occurrence of an O157:H7 outbreak in Brazil. Human infections caused by STEC strains of distinct phenotypical and genotypical features occurred in our setting since the late 1970.
- ItemAcesso aberto (Open Access)Genetic analysis of Escherichia coli strains carrying enteropathogenic Escherichia coli (EPEC) markers, isolated from children in Rio de Janeiro city, Brazil(Sociedade Brasileira de Microbiologia, 2003-11-01) Regua-Mangia, Adriana Hamond; Gomes, Tania Aparecida Tardelli [UNIFESP]; Andrade, João Ramos da Costa; Vieira, Mônica Aparecida Midolli [UNIFESP]; Gonzalez, Alice Gonçalves Martins; Zahner, Viviane; Irino, Kinue; Teixeira, Lúcia Martins; Fundação Oswaldo Cruz; Universidade Federal de São Paulo (UNIFESP); Universidade Estadual do Rio de Janeiro; Universidade Federal Fluminense; Instituto Adolfo Lutz; Universidade Federal do Rio de JaneiroIn the present study, 47 enteropathogenic Escherichia coli strains identified according to serotyping, presence of eae, bfp and EAF sequences, adherence phenotype and ability to induce attaching-effacing lesions were analyzed by pulsed-field gel electrophoresis (PFGE), multilocus enzyme electrophoresis (MLEE), and the presence of LEE genes (eae, espA, espB, tir) as well as the respective alleles. Amplification of LEE genes subtypes revealed 18 different pathotypes. Typing of the eae gene showed that most strains contained nontypable intimin (42%) followed by beta (35%), gamma and alpha genes (12% each). PFGE analysis revealed a variable degree of polymorphism among isolates and, in general, no clear correlation was observed among PFGE profiles and the virulence markers identified. Otherwise, grouping based on MLEE analysis showed a close association between eae allele and clonal cluster distribution leading us to indicate the eae profile as a promising marker to establish relatedness among such microorganisms.
- ItemAcesso aberto (Open Access)Production of cytolethal distending toxin and other virulence characteristics of Escherichia coli strains of serogroup O86(Instituto Oswaldo Cruz, Ministério da Saúde, 2001-07-01) Ghilardi, Ângela Cristina Rodrigues; Gomes, Tania Aparecida Tardelli [UNIFESP]; Trabulsi, Luiz Rachid; Instituto Adolfo Lutz Seção de Bacteriologia; Universidade Federal de São Paulo (UNIFESP); Instituto Butantã Laboratório Especial de MicrobiologiaGenetic and phenotypic virulence markers of different categories of diarrhoeagenic Escherichia coli were investigated in 106 strains of enteropathogenic E. coli (EPEC) serogroup O86. The most frequent serotype found was O86:H34 (86%). Strains of this serotype and the non motile ones behaved as EPEC i.e., carried eae, bfpA and EAF DNA sequences and presented localised adherence to HeLa cells. Serotypes O86:H2, O86:H6, O86:H10, O86:H18, O86:H27 and O86:H non determined, belonged to other categories. The majority of the strains of serotype O86:H34 and non motile strains produced cytolethal-distending toxin (CDT). The ribotyping analysis showed a correlation among ribotypes, virulence markers and serotypes, thus suggesting that CDT production might be a property associated with a universal clone represented by the O86:H34 serotype.
- ItemSomente MetadadadosShiga toxin-producing Escherichia coli in drinking water supplies of north Parana State, Brazil(Wiley-Blackwell, 2013-04-01) Lascowski, K. M. S. [UNIFESP]; Guth, B. E. C. [UNIFESP]; Martins, F. H.; Rocha, S. P. D.; Irino, K.; Pelayo, J. S.; Universidade Federal de São Paulo (UNIFESP); Universidade Estadual de Londrina (UEL); Adolfo Lutz InstAim To determine the occurrence and characteristics of Shiga toxin-producing Escherichia coli (STEC) in drinking water supplies treated and untreated. Methods and Results Drinking water samples (n=1850) were collected from 41 municipalities in the north of Parana State between February 2005 and January 2006. Escherichia coli isolates (n=300) were recovered from water and investigated for the presence of virulence markers related to STEC by PCR. STEC isolates recovered were then characterized for both phenotypic and genotypic traits. A total of 12 isolates (11 from untreated water and one from treated water) were positive for stx, including five positive for both stx1 and stx2, two positive for stx1 and five positive for stx2. None of the STEC isolates contained eae, but other virulence genes were observed such as ehxA (100%), saa (100%), lpfAO113 (75%), iha (42%), subAB (25%) and cdtV (8%). Multidrug resistance was identified in 25% of the STEC isolates. the 12 STEC isolates belonged to seven distinct serotypes and pulsed-field gel electrophoresis typing revealed the presence of two clusters and two clones in this region. Conclusion Drinking water, especially from untreated water supplies, can be source of STEC strains potentially pathogenic for humans. Significance and Impact of the Study the investigation of the drinking water supplies for pathogenic E.coli, as STEC, may be useful to prevent waterborne outbreaks.
- ItemSomente MetadadadosVirulence markers and serotypes of Shiga toxin-producing Escherichia coli, isolated from cattle in Rio Grande do Sul, Brazil(Blackwell Publishing, 2007-04-01) Timm, C. D.; Irino, K.; Gomes, Tania Aparecida Tardelli [UNIFESP]; Vieira, Monica Aparecida Midolli [UNIFESP]; Guth, Beatriz Ernestina Cabilio [UNIFESP]; Vaz, T. M. I.; Moreira, C. N.; Aleixo, J. A. G.; Univ Fed Pelotas; Universidade Federal de São Paulo (UNIFESP); Inst Adolfo Lutz RegistroAims: To determine the prevalence of Shiga toxin-producing Escherichia coli (STEC) and serotypes and virulence markers of the STEC isolates from beef and dairy cattle in Rio Grande do Sul, Brazil.Methods and Results: Faecal samples from beef cattle were collected at slaughterhouses. the isolates were submitted to colony hybridization assay with specific DNA probes for stx1, stx2 and eae genes, and serotyped for the identification of O and H antigens. Thirty-nine per cent of beef cattle surveyed harboured at least one STEC strain. Among the distinct serotypes identified, 10 were shared by both beef and dairy cattle. Most of the strains isolated harboured stx2. Genotypic and phenotypic profiles allowed the identification of 34 and 31 STEC strains, isolated from beef and dairy cattle, respectively. Serotypes O10:H14, O15:H21, O96:H21, O119:H4, O124:H11, O128:H21, O137:H-, O141:H19, O159:H42, O160:H2 and O177:H11, identified in this study, have not been previously reported as STEC isolated from cattle.Conclusions: Cattle are an important reservoir of STEC strains associated with human diseases in South America.Significance and Impact of the Study: Determining the prevalence, genotypic profile and serotypes of STEC strains isolated from cattle enables the prediction of possible risk for public health.