Abstract

A total of 42 Escherichia coli strains isolated from broilers and the halls of growth were examined between the years 2010 and 2011, in order to assess the prevalence of avian pathogenic E. coli (APEC) strains in the West of Romania, where the majority broiler is represented by the imported ones. Multiplex PCR technique was used in order to detect three genes governing the synthesis of some virulence factors associated with APEC strains. It was observed that OmpA gene encodes an outer membrane protein that is responsible for bacterial attachment in 18 strains tested, the iss gene encodes an outer membrane protein that induces resistance to complement and thus promotes the APEC strains colonization and this was present in 17 strains tested. FimH gene encoding the synthesis of type 1 fimbria was noted in 19 of the strains tested. All isolates had common biochemical characteristics of E. coli strains and were multiple resistant to lincomycin, spectinomycin, neomycine, tetracycline, erythromycin, doxycyclin, enrofloxacin.Fixation of Congo red correlated with the presence of three genes is a phenotypic characteristic of E. coli strains of avian origin. Presence of these genes is useful in defining the APEC pathotype.

Key words: Avian pathogenic E. coli, colibacillosis, multiplex PCR.