Occurrence of plasmidic AmpC β-lactamase in a Salmonella Typhimurium isolate of equine origin: first report of CMY-2 in animals in Argentina.

DOMÍNGUEZ JOHANA; GUTKIND GABRIEL; DI CONZA JOSÉ; MERCADO ELSA

Journal of Global Antimicrobial Resistance

ELSEVIER SCIENCE INC

Año: 2015 vol. 3 p. 315 - 316

2213-7165

Salmonella enterica serovar Typhimurium is a broad host range serovar, and one of the most common serovar isolated worldwide. In Argentina, S. Typhimurium is the second most common endemic serovar isolated from humans. The emergence of zoonotic Salmonella with resistance to the third generation cephalosporins (TGC) constitutes a serious public health concern since it confers resistance to ceftriaxone, one of the therapeutic options for treatment of humans with severe infections. Extended-spectrum cephalosporin- resistant S. Typhimurium isolate obtained from a diarrheal stool sample of a race horse in 2010 in Buenos Aires were characterized in order to determinate the genetic basis of resistance. TGC resistance was mediated by an AmpC β-lactamase encoded by the blaCMY-2 gene in a 130-kb self transmissible IncI1 plasmid. Analysis of the genetic context of blaCMY-2 revealed an ISEcp1-like transposon which was truncated with an IS1294 element (IS1294-DISEcp1-blaCMY-2-blc-sugE-ecnR). The isolate belonged to ST 19 according to MLST database. To the best of our knowledge, this is the first report describing Salmonella from animals capable of producing transferable AmpC β-lactamase in our country, and even in South America.