Molecular typing of antimicrobial-resistant Shiga-toxin-producing Escherichia coli strains (STEC) in Brazil.
Antimicrobial resistance patterns and molecular characteristics were determined in thirty-two Shiga-toxin-producing Escherichia coli (STEC) strains previously identified in São Paulo State associated with human infections (n = 21) and in cattle feces (n = 11). The highest resistance rates were identified for tetracycline (100%), streptomycin (78%) and trimethoprim-sulfamethoxazole (56%). Eleven STEC strains showed resistance to ampicillin and carried bla(TEM) that was confirmed as bla(TEM-1) in one representative isolate. The class 1 integrase gene (intI1) was detected in seven (22%) strains, and most of them belonged to the O111:H8 serotype. The class 1 integron was located on plasmids in five of the seven STEC strains, and conjugation assays confirmed the plasmid support of those resistant determinants. STEC strains were genetically classified into the B1 group, and PFGE analysis showed that most of the strains in each serogroup were grouped into the same cluster (80-97% similarity). The presence of a class 1 integron and bla(TEM-1) genes is described for the first time among STEC isolates in Brazil and clearly represents a public health concern.
Infectious Disease Division, Universidade Federal de São Paulo, São Paulo, Brazil. cecilia.cergole@unifesp.br
Maria Cecilia
MC
Cergole-Novella
Antonio Carlos Campos
AC
Pignatari
Mariana
M
Castanheira
Beatriz Ernestina Cabilio
BE
Guth
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D001938:Brazil; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology; D003227:Conjugation, Genetic; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary; D029968:Escherichia coli Proteins / Q000235:genetics; D006801:Humans; D032023:Integrons / Q000235:genetics; D008826:Microbial Sensitivity Tests; D058889:Molecular Typing; D010802:Phylogeny; D010957:Plasmids; D012703:Serotyping; D054323:Shiga-Toxigenic Escherichia coli / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins