Antimicrobial resistance and molecular characterization of Salmonella Enterica serovar kedougou isolates from clinical specimens and environmental samples in Thailand, 2006-2009

Abstract

Salmonella enterica serovar Kedougou was among the top 10 serovars causing salmonellosis in humans and animals during 2006-2009 in Thailand. Two hundred and twenty-four S. Kedougou isolates from human, food and environmental samples were collected from 2006 to 2009. Antimicrobial susceptibility of all isolates, presence or absence of antimicrobial resistance genes and pulsedfield gel electrophoresis (PFGE) profiles were determined. Multidrug resistance (resistance to at least three different classes of antimicrobials) was observed in 126/185 (68.1%) and 31/39 (79.5%) of S. Kedougou isolates from human and environmental origins, respectively. Nine (4%) S. Kedougou isolates were positive for extended spectrum β-lactamase (ESBL), including 8 isolates from humans and 1 isolate from raw food. Seven of 8 ESBL-producing isolates from humans harbored blaCTX-M-63 and blaTEM-1b, and the remaining isolate blaCMY-2 and blaCTX-M-63. Additionally, one ESBL-producing isolate from fresh pork harbored only blaCMY-2. All ESBL-producing isolates positive for blaCTX-M-63 were resistant to cefotaxime. The PFGE clonal characteristics among the isolates from human and environmental sources may indicate a recent spread of this serovar. The presence of multidrug resistance and β-lactamase genes in S. Kedougou isolated from humans and raw food poses a potential public health problem in Thailand. © 2017, SEAMEO TROPMED Network. All rights reserved.