Estudo da frequência e caracterização genotípica e fenotípica de amostras de Escherichia coli produtoras da Toxina Shiga (STEC) isoladas de ovinos no Estado de São Paulo.

Vettorato, Maria Paula

doi:10.11606/T.42.2008.tde-30032009-153111

Home

Facilities

Doctoral Thesis

DOI

https://doi.org/10.11606/T.42.2008.tde-30032009-153111

Document

Doctoral Thesis

Author

Vettorato, Maria Paula (Catálogo USP)

Full name

Maria Paula Vettorato

Institute/School/College

Instituto de Ciências Biomédicas

Knowledge Area

Microbiology

Date of Defense

2008-12-11

Published

São Paulo, 2008

Supervisor

Castro, Antonio Fernando Pestana de (Catálogo USP)
Guth, Beatriz Ernestina Cabilio - (Co-supervisor) (Catálogo USP)

Committee

Castro, Antonio Fernando Pestana de (President)
Brocchi, Marcelo
Ferreira, Rita de Cassia Cafe
Moreno, Andrea Micke
Piazza, Roxane Maria Fontes

Title in Portuguese

Estudo da frequência e caracterização genotípica e fenotípica de amostras de Escherichia coli produtoras da Toxina Shiga (STEC) isoladas de ovinos no Estado de São Paulo.

Keywords in Portuguese

EPEC atípica
Fatores de virulência
Ovinos
PFGE
Sorotipos
STEC

Abstract in Portuguese

Ovinos são considerados reservatórios de Escherichia coli produtora da toxina Shiga (STEC). Este estudo pesquisou amostras de 100 carneiros no Estado de São Paulo. PCR foi empregada para detecção de stx₁, stx₂, eae, ehx, e intiminas. RFLP-PCR foi realizado para identificação das variantes de stx₁/stx₂ e fliC. Cinco isolados eae⁺stx^- de sorotipos O128:H2, O145:H2, O153:H7 e O178:H7 apresentaram intiminas b, g e e. Cinqüenta e seis STEC foram obtidos e os genótipos foram stx_1cstx_2d-_O118 (56,1%), stx_1c (33,3%), stx_2d-O118 (7,6%), e stx_1cstx_2dOX3a (3%). Os sorotipos mais freqüentes foram ONT:H8, ONT:H-, O75:H-, O174:H8 e O5:H-. Gene fliC codificando para H2, H8, H14, H16, H19, H21 ou H28 foi identificado em 25/33 isolados. ehx foi detectado em três/cinco EPEC Atípicas e em 38 (57,6%) STEC. Sensibilidade aos antimicrobianos foi observada em 77,2% dos isolados STEC. A análise da similaridade genética por PFGE revelou 24 perfis entre 40 isolados STEC e EPEC atípicas. O estudo demonstrou que ovinos saudáveis podem se comportar como reservatórios de STEC e EPEC atípica.

Title in English
A comparative study of Shiga toxin-producing Escherichia coli and atypical Enteropathogenic Escherichia coli strains isolated from healthy ovine of different populations in São Paulo, Brazil.

Keywords in English
Atypical EPEC
PFGE
Serotypes
Sheep
STEC
Virulence markers

Abstract in English

Lambs are reported as carriers of Shiga toxin-producing Escherichia coli (STEC) worldwide. This study surveyed 100 sheep in São Paulo, Brazil. PCR was used for detection of stx₁, stx₂, eae, ehx, and intimins. RFLP-PCR investigated the stx₁/stx₂ variants and flagellar antigen (fliC). Five isolates were eae⁺/stx^-, belonging to serotypes O128:H2, O145:H2, O153:H7 and O178:H7, harboring b, g and e intimins. Fifty-six STEC isolates were recovered, and stx genotypes were stx_1cstx_2d-O118 (56.1%), stx_1c(33.3%), stx_2d-O118 (7.6%), and stx_1cstx_2dOX3a (3%). A diversity of STEC serotypes was observed, but most frequent were ONT:H8, ONT:H-, O75:H-, O174:H8 and O5:H-. fliC gene coding for H2, H8, H14, H16, H19, H21 or H28 was identified in 25/33 isolates. ehx gene was detected in three Atypical EPEC and in 38 (57,6%) STEC. Fifty-one (77.2%) STEC were susceptible to antimicrobials tested. Pulsed field gel electrophoresis (PFGE) revealed 24/40 profiles. The study showed that healthy ovine can be carrier of STEC and atypical EPEC in Brazil.

WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.

MariaPaulaVettorato_Doutorado.pdf (218.37 Kbytes)

Publishing Date
2009-04-06

Derived works

WARNING: Learn what derived works are clicking here.