Serotypes and virulence genes (vt1, vt2, eae ehxA, saa) of VTEC isolated from cattle, food and humans in Argentina

BLANCO, JESÚS E.; BLANCO, MIGUEL; SANZ, MARCELO E.; KRÜGER, ALEJANDRA; MORA, AZUCENA; DAHBI, GHIZLANE; LUCCHESI, PAULA M. A.; PADOLA, NORA L.; ALONSO, M.P.; PARMA, ALBERTO E.; BLANCO, JORGE

Edinburgo, Escocia

Simposio; 5th International Symposium on Shiga toxin (Verocytotoxin)-producing escherichia coli infections (VTEC 2003); 2003

Comité Internacional

We have characterized 134 VTEC strains isolated from cattle (108), food (24) and human infections (2) in Argentina. PCR demonstrated that 22 (16%) strains carried vt1 genes , 96 (72%) possessed vt2 genes and 16 (12%) carried both vt1 and vt2 genes. VTEC strains belonged to 47 O:H serotypes, including 20 serotypes associated with HUS (O2:H5, O5:H-, O8:H19, O20:H19, O22:H8, O26:H11, O91:H21, O103:H-, O111:H-, O113:H21, O118:H16, O145:H-, O157:H7, O165:H-, O171:H-, O174:H21, ONT:H7, ONT:H16 and ONT:H-). The saa (STEC autoagglitinating adhesin), ehxA (enterohemolysin or EHEC-HlyA) and eae virulence genes were detected in 106 (79%), 63 (47%) and in 36 (26%) strains respectively. Fourteen strains of serotypes O5:H- (4), O26:H11 (7), O38:H39 (1), O118:H16 (1) and O177:H- (1) had intimin b1, 12 strains of serotypes O145:H- (7), and O157:H7 (5) possessed intimin g1, 5 strains of serotypes O103:H2 (2), O103:H- (2) and O165:H- (1) had intimin type e, and one strain of serotype O111:H- had intimin g2. The saa gene was detected in eae-positive strains of serotypes O145:H- (7/7) but not in eae.positive strains of serotypes O5:H- (0/4), O26:H11 (0/7) O103:H2 (0/4) and O157:H7 (0/5).