Revista do Instituto de Medicina Tropical de São Paulo
On-line version ISSN 1678-9946
TIBA, Monique Ribeiro; YANO, Tomomasa and LEITE, Domingos da Silva. Genotypic characterization of virulence factors in Escherichia coli strains from patients with cystitis. Rev. Inst. Med. trop. S. Paulo [online]. 2008, vol.50, n.5, pp.255-260. ISSN 1678-9946. http://dx.doi.org/10.1590/S0036-46652008000500001.
Adhesins (P-fimbriae, S-fimbriae, type 1 fimbriae and afimbrial adhesin), toxins (α-hemolysin and cytotoxic necrotizing factor type 1), iron acquisition systems (aerobactin) and host defense avoidance mechanisms (capsule or lipopolysaccharide) have been shown to be prevalent in Escherichia coli strains associated with urinary tract infections. In this work, 162 Uropathogenic Escherichia coli (UPEC) strains from patients with cystitis were genotypically characterized by polymerase chain reaction (PCR) assay. We developed three multiplex PCR assays for virulence-related genes papC, papE/F, papG alleles, fimH, sfa/foc, afaE, hly, cnf-1, usp, cdtB, iucD, and kpsMTII, all of them previously identified in UPEC strains. The PCR assay results identified 158 fimH (97.5%), 86 kpsMTII (53.1%), 53 papC/papEF/papG (32.7%), 45 sfa (27.8%), 42 iucD (25.9%), 41 hly (25.3%), 36 usp (22.2%), 30 cnf-1(18.5%) and 10 afa (6.2%) strains. No strain was positive for cdtB. In this work, we also demonstrated that adhesins may be multiple within a single strain and that several virulence genes can occur combined in association.
Keywords : Uropathogenic Escherichia coli (UPEC); Polymerase chain reaction (PCR); Virulence factor (VF).