Extended-spectrum β-lactamase-producing Salmonella enterica serovar Oranienburg (CTX-M-2 group) in a pediatric hospital in Tucumán, Argentina Salmonella enterica serovar Oranienburg produtora de β-lactamase de espectro extendido (grupo CTX-M-2) em um hospital pediátrico de Tucumán, Argentina

Introduction: Salmonella sp infections have been reported over recent years in hospitals in Argentina and other countries due to multiresistant strains. The aim of this study was to characterize the extended-spectrum β-lactamases in third-generation cephalosporin-resistant strains of Salmonella enterica serovar Oranienburg. Methods: We studied 60 strains isolated from children with gastroenteritis and/or extraintestinal complications. The antibiotic susceptibility patterns of the isolates were analyzed and the β-lactamases were characterized using phenotyping and genotyping methods. Results: All the strains were resistant to ampicillin, cefotaxime, cefepime and aztreonam and partially susceptible to ceftazidime, thus corresponding well with the resistance phenotype conferred by CTX-M-type β-lactamases. An isoelectric point enzyme (pI = 7.9) was detected in all of the strains, and this was confirmed by PCR as a member of the CTX-M-2 group. Conclusions: This is the first report of Salmonella enterica serovar Oranienburg producing β-lactamases of the CTX-M-2 group in a pediatric hospital in Tucumán, Argentina. Key-words: Salmonella enterica serovar Oranienburg. Extended Spectrum β-lactamases.