Navegando por Palavras-chave "Shiga toxin-producing Escherichia coli"
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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.
- ItemAcesso aberto (Open Access)Phenotypic and genotypic characteristics of shiga toxin-producing Escherichia coli strains isolated from children in São Paulo, Brazil(Instituto Oswaldo Cruz, Ministério da Saúde, 2002-12-01) Guth, Beatriz Ernestina Cabilio [UNIFESP]; Ramos, Sônia Rts; Cerqueira, Aloysio Mf; Andrade, João Ramos da Costa; Gomes, Tania Aparecida Tardelli [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP); Universidade Estadual do Rio de Janeiro; Universidade Federal Fluminense Departamento de Microbiologia e ParasitologiaThe biochemical and serological characteristics, virulence properties, and genetic relatedness of Shiga toxin-producing Escherichia coli (STEC) strains isolated in São Paulo, from April 1989 through March 1990, were determined. This is also the first report on clinic findings of human STEC infections in Brazil. The only three STEC strains identified in that period were lysine decarboxylase negative, belonged to serotype O111ac: non-motile, were Stx1 producers, carried the eae and astA genes, and 2 of them also presented the EHEC-hly sequence. The children carrying STEC were all boys, with less than two years old, and had no previous history of hospitalization. None of them presented blood in stools. Vomiting, cough and coryza were the most common clinical manifestations observed. Although the STEC strains were isolated during summer months, and presented similar phenotypic and genotypic characteristics, carbohydrate fermentation patterns and PFGE analysis suggested that these diarrheal episodes were not caused by a single clone.
- ItemSomente MetadadadosSerotypes, virulence markers and cell invasion ability of Shiga toxin-producing Escherichia coli strains isolated from healthy dairy cattle(Wiley-Blackwell, 2016) Gonzalez, Alice Gonçalves Martins; Cerqueira, Aloysio de Mello Figueiredo; Guth, Beatriz Ernestina Cabilio [UNIFESP]; Coutinho, Cesar Augusto de Souza; Liberal, Maira Halfen Teixeira; Souza, Rossiane de Moura; Andrade, João Ramos da Costa; Universidade Federal de São Paulo (UNIFESP)AimThe occurrence of virulence markers, serotypes and invasive ability were investigated in Shiga toxin-producing Escherichia coli (STEC) isolated from faecal samples of healthy dairy cattle at Rio de Janeiro State, Brazil. Methods and ResultsFrom 1562 stx-positive faecal samples, 105 STEC strains were isolated by immuno-magnetic separation (IMS) or plating onto MacConkey agar (MC) followed by colony hybridisation. Fifty (476%) strains belonged to nine serotypes (O8:H19, O22:H8, O22:H16, O74:H42, O113:H21, O141:H21, O157:H7, O171:H2 and ONT:H21). The prevalent serotypes were O157:H7 (124%), O113:H21 (67%) and O8:H19 (57%). Virulence genes were identified by polymerase chain reaction (PCR). E-hlyA (771%) was the more prevalent virulence marker, followed by espP (648%), saa (39%), eae (248%) and astA (219%). All O157:H7 strains carried the (gamma) variant of the locus of enterocyte effacement (LEE) genes and the stx2c gene, while the stx1/stx2 genotype prevailed among the eae-negative strains. None of the eae-positive STEC produced the localized adherence (LA) phenotype in HEp-2 or Caco-2 cells. However, intimate attachment (judged by the fluorescent actin staining test) was detected in some eae-positive strains, both in HEp-2 (231%) and in Caco-2 cells (115%). Most strains (875%) showed peripheral association' (PA) adherence phenotype to undifferentiated Caco-2 cells. Twenty-five (926%) of 27 strains invaded Caco-2 cells. The highest average value of invasion (96%) was observed among the eae-negative bovine strains from serotypes described in human disease. ConclusionHealthy dairy cattle is a reservoir of STEC carrying virulence genes and properties associated with human disease. Significance and Impact of the StudyAlthough reports of human disease associated with STEC are scarce in Brazil, the colonization of the animal reservoir by potentially pathogenic strains offers a significant risk to our population.
- ItemSomente MetadadadosShiga toxin-producing Escherichia coli and atypical enteropathogenic Escherichia coli strains isolated from healthy sheep of different populations in São Paulo, Brazil(Wiley-Blackwell, 2009-07-01) Vettorato, M. P.; Castro, A. F. P. de; Cergole-Novella, Maria Cecilia [UNIFESP]; Camargo, F. L. L. [UNIFESP]; Irino, K.; Guth, Beatriz Ernestina Cabilio [UNIFESP]; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); Inst Adolfo Lutz RegistroAims: Sheep are important carriers of Shiga toxin-producing Escherichia coli (STEC) in several countries. However, there are a few reports about ovine STEC in American continent.Methods and Results: About 86 E. coli strains previously isolated from 172 healthy sheep from different farms were studied. PCR was used for detection of stx(1), stx(2), eae, ehxA and saa genes and for the identification of intimin subtypes. Restriction fragment length polymorphism (RFLP)-PCR was performed to investigate the variants of stx(1) and stx(2), and the flagellar antigen (fliC) genes in nonmotile isolates. Five isolates were eae(+) and stx(-), and belonged to serotypes O128:H2/beta-intimin (2), O145:H2/gamma, O153:H7/beta and O178:H7/epsilon. Eighty-one STEC isolates were recovered, and the stx genotypes identified were stx(1c)stx(2d-O118) (46.9%), stx(1c) (27.2%), stx(2d-O118) (23.4%), and stx(1c)stx(2dOX3a) (2.5%). Pulsed-field gel electrophoresis (PFGE) revealed 27 profiles among 53 STEC and atypical enteropathogenic Escherichia coli (EPEC) isolates.Conclusions: This study demonstrated that healthy sheep in São Paulo, Brazil, can be carriers of potential human pathogenic STEC and atypical EPEC.Significance and Impact of the Study: As some of the STEC serotypes presently found have been involved with haemolytic uraemic syndrome (HUS) in other countries, the important role of sheep as sources of STEC infection in our settings should not be disregarded.
- 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 MetadadadosStx genotypes and antimicrobial resistance profiles of Shiga toxin-producing Escherichia coli strains isolated from human infections, cattle and foods in Brazil(Wiley-Blackwell, 2006-06-01) Cergole-Novella, Maria Cecilia [UNIFESP]; Nishimura, Lucilia S. [UNIFESP]; Irino, Kinue; Vaz, Tania Mara I. [UNIFESP]; Castro, Antonio Fernando Pestana de; Leomil, Luciana; Guth, Beatriz Ernestina Cabilio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Adolfo Lutz Inst; Universidade de São Paulo (USP)A total of 107 Shiga toxin-producing Escherichia coli strains (STEC) isolated from different origins in São Paulo, Brazil, and belonging to different serotypes were characterized regarding stx subtypes and susceptibility to antimicrobial agents. Most of the human STEC strains harbored stx(1) (85.7%), while stx(2), associated or not to stx(1), was identified preferentially in the animal and food strains. None of the STEC strains carried stx(1c). Some genotypes occurred exclusively among strains of bovine origin as stx(2c), stx(1+2+2c) (16.5% each), and stx(2d) (0.9%), whereas stx(2+2c(2vha)) was only identified among the O157:H7 human strains. Moreover, the stx(2c(2vhb)) subtype was found more frequently among bovine than human strains (39% vs. 4.8%). the highest frequencies of susceptibility to antimicrobial agents were observed among bovine (87%) and food (100%) STEC strains, while 47.6% of the human isolates were resistant to at least one drug. Multiresistance occurred among O111 STEC strains from human and bovine origin. the antimicrobials to which resistance was most frequently observed were tetracycline (90%) and streptomycin (75%) among human strains, and also sulphazotrin (88%) in animal strains. A few serotypes were commonly identified among STEC strains isolated from diverse sources in Brazil, but in general the strains presented distinct stx subtypes and/or antimicrobial resistance profiles.
- 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.