ABSTRACT
Enteroaggregative Escherichia coli (EAEC) is characterized by the expression of the aggregative adherence pattern to cultured epithelial cells. In this study, we determined the phenotypic and genotypic relationships among 86 EAEC strains of human and animal (calves, piglets and horses) feces. Serotypes and the presence of EAEC virulence markers were determined, and these results were associated with ribotyping. Strains harboring aggR (typical EAEC) of human origin were found carrying several of the searched markers, while atypical EAEC harbored none or a few markers. The strains of animal origin were classified as atypical EAEC (strains lacking aggR) and harbored only irp2 or shf. Strains from humans and animals belonged to several different serotypes, although none of them prevailed. Sixteen ribotypes were determined, and there was no association with virulence genes profiles or serotypes. Relationship was not found among the strains of this study, and the assessed animals may not represent a reservoir of human pathogenic typical EAEC.
Subject(s)
Escherichia coli Infections/microbiology , Escherichia coli Infections/veterinary , Escherichia coli/genetics , Escherichia coli/physiology , Virulence/genetics , Animals , Cattle , Cattle Diseases/microbiology , DNA Fingerprinting , DNA, Bacterial/genetics , DNA, Bacterial/metabolism , Escherichia coli/classification , Escherichia coli/isolation & purification , Escherichia coli Proteins/genetics , Horse Diseases/microbiology , Horses/microbiology , Humans , Iron Regulatory Protein 2/genetics , Molecular Epidemiology , Nucleic Acid Hybridization , Phylogeny , Ribotyping , Serotyping , Swine/microbiology , Swine Diseases/microbiology , Trans-Activators/genetics , Virulence Factors/geneticsABSTRACT
Forty-nine avian Escherichia coli isolates isolated from different outbreak cases of septicemia (24 isolates), swollen head syndrome (14 isolates) and omphalitis (11 isolates), and 30 commensal isolates isolated from poultry with no signs of illness were characterized by enterobacterial repetitive intergenic consensus (ERIC)-PCR technique and their serotypes were determined. The ERIC-PCR profile allowed the typing of the 79 isolates into 68 ERIC-types and grouped the isolates into four main clusters (A-D), with the omphalitis isolates being grouped with the commensals and separated from the septicaemia and swollen head syndrome. These results indicate that ERIC-PCR is a technique that could replace other molecular characterization techniques such as random amplification of polymorphic DNA (RAPD)-PCR and restriction fragment length polymorphism (RFLP), reinforce previous observations that omphalitis isolates are just opportunistic agents, and are consistent with many reports that specific genotypes are responsible for causing specific diseases. Most of the isolates were either nontypable or rough, supporting the need for alternative methods for typing these isolates.