Serovar distribution and antimicrobial susceptibility of swine Salmonella isolates from clinically ill pigs in diagnostic submissions from Indiana in the United States

摘要

AIMS: To determine serovar distribution and levels of antimicrobial susceptibility of Salmonella isolated from clinically ill pigs in diagnostic submissions. METHODS AND RESULTS: A total of 197 Salmonella isolates were obtained by the Indiana Animal Disease Diagnostic Laboratory from 2003 to 2005. Minimal inhibitory concentrations (MICs) were determined using the standard microbroth dilution method. The top four serovars identified were Salm. enterica serovar Typhimurium variant Copenhagen, Salm. Derby, Salm. Choleraesuis var. Kunzendorf and Salm. Typhimurium. All isolates were susceptible to the fluoroquinolones tested except that eight isolates were intermediate to difloxacin. The isolates showed a low prevalence of resistance to trimethoprim/sulphadiazine (Sxt), gentamicin (G), ceftiofur (Cf) and cephalothin (Cp) with low MIC(50) value of