Identification of new flagellin-encoding fliC genes in Escherichia coli isolated from domestic animals using RFLP-PCR and sequencing methods

Abstract

Identification of Escherichia coli requires knowledge regarding the prevalent serotypes and virulence factors profiles allows the classification in pathogenic/non-pathogenic. However, some of these bacteria do not express flagellar antigen in vitro. In this case the PCR--restriction fragment length polymorphism (RFLP-PCR) and sequencing of the fliC may be suitable for the identification of antigens by replacing the traditional serology. We studied 17 samples of E. coli isolated from animals and presenting antigen H nontypeable (HNT). The H antigens were characterized by PCR-RFLP and sequencing of fliC gene. Three new flagellin genes were identified, for which specific antisera were obtained. The PCR-RFLP was shown to be faster than the serotyping H antigen in E. coli, provided information on some characteristics of these antigens and indicated the presence of new genes fliC.INDEX TERMS: Escherichia coli, H antigen, PCR-RFLP, sequencing, serotyping. Os antígenos H foram caracterizados por PCR-RFLP e sequenciamento do gene fliC. Três novos genes da flagelina foram identificados, para os quais anti-soros específicos foram obtidos. A técnica PCR-RFLP mostrou-se mais rápida que a sorotipagem do antígeno H em E. coli, fornecendo informações sobre algumas características desses antígenos e indicou a presença de novos genes fliC.