Virulence profile comparison between LEE-negative Shiga toxin-producing Escherichia coli (STEC) strains isolated from cattle and humans.
For comparison purposes, the prevalence of 8 virulence markers was investigated, by PCR, in 153 cattle and 47 human Locus for Enterocyte Effacement (LEE)-negative Shiga toxin-producing Escherichia coli (STEC) strains isolated in Argentina. Also, their correlation with severe disease was established. The virulence markers studied comprises 5 fimbrial and nonfimbrial adhesin-encoding genes (fimA, iha, efa1, lpfA(O113), and saa) and 3 toxin genes (cdt-V, subAB and astA) in addition to the Shiga toxins. The most prevalent virulence marker found was that encoded by the lpfA(O113) gene (199/200, 99%). Comparatively, the lpfA(O113), fimA, iha, saa, subAB, cdt-V and astA genes were detected in 100%, 92.8%, 85%, 52.9%, 36%, 11.8% and 9.8% of the cattle strains and in 97.9%, 95.7%, 89.4%, 40.4%, 32%, 17% and 10.6% of the human strains, respectively. All STEC strains were efa1 negative. The most prevalent profile observed among cattle and human STEC strains was lpfA(O113)iha fimA. These results show that bovine LEE-negative STEC strains possessed genes encoding virulence factors present in human LEE-negative STEC strains that are associated with disease. Despite a great diversity of virulence profiles observed, further studies comparing wild type strains and their allelic mutants are needed to evaluate the role of each factor in the pathogenesis of LEE-negative STEC strains during human infections.
Galli
Lucía
L
Servicio Fisiopatogenia, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS Dr. Carlos G. Malbrán, Av. Vélez Sarsfield 563, 1281 Buenos Aires, Argentina. lgalli@anlis.gov.ar
Miliwebsky
Elizabeth
E
Irino
Kinue
K
Leotta
Gerardo
G
Rivas
Marta
M
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D005838:Genotype; D006801:Humans; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D054323:Shiga-Toxigenic Escherichia coli / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D014774:Virulence
D029968:Escherichia coli Proteins; C457340:LEE protein, E coli; D010750:Phosphoproteins