Isolation of Multidrug Resistant Salmonella from Diseased Pigs

摘要

This study was targeted to isolate Salmonella from diseased pigs, identify the predominant serotypes and determine antimicrobial resistance. Conventional culture, biochemical test, serotyping, and Kirby-Bauer disk diffusion were used to isolate Salmonella from fecal samples of pigs clinically diagnosed with salmonellosis and determine antimicrobial resistance. As a result, 33 salmonellosis cases were identified in 903 diseased pig herds mainly from central China. Salmonella choleraesuis constituted 64% (21/33) of isolates. Whereas, Salmonella typhimurium accounted for 24% (8/33). The 21 antimicrobials were tested and 94.3% of the isolates were resistant to at least 10antimicrobials. However, most serotypes except S. typhimurium were sensitive to amikacin, fluoroquinolones,furazolidone, polymyxin B, cephalosporins (cephradine and cefazolin). S. typhimurium isolates were susceptible only to amikacin and cephalosporins (cephradine and cefazolin). In conclusion, this study confirmed that salmonellosis constituted 3.65% of the pig diseases in the investigated area. The most common serotype is S. choleraesuis, followed by S. typhimurium. Currently, fluoroquinolones, cephalosporins (cephradine and cefazolin), amikacin, furazolidone,polymyxin B would be effective agents to treat most swine salmonellosis of China. Considering the large population of pigs in China and Salmonella persistence, salmonellosis should continue to be considered as a biological hazard to human health.