Detection of Salmonella in river in urban area of Yuyao after flood

Objective To understand the contamination, serotyping and antibiotic susceptibility of Salmonella in the rivers in urban area of Yuyao, Zhejiang province. Methods The samples were collected from 12 monitoring sites in Yuyao, and then enrichment, isolation, biochemical identification,serotyping and drug susceptibility test of the isolates were carried out. Results Salmonella was detected in 58 of 110 river water samples (52.73%), and 84 strains of Salmonella were detected (76.36%). The 84 strains were divided into 17 serotypes,the predominant serotype was Salmonella typhimurium,accounting for 34.52%, and Salmonella derby accounted for 16.67%.The contamination was most serious and complex in Sanguantang of Yaojiang river and in poultry hospital of Houqingjiang river.These strains had high sensitivities to cephalosporins and monobactams, beta lactam/beta lactamase inhibitors, quinolones and aminoglycosides, and the resistant rate to ampicillin, cotrimoxazole, piperacillin, tobramycin and gentamicin were 67.86%,53.57%,51.19%,20.24%and 17.86% respectively. It was found that 65 strains were drug resistant,accounting for 77.38%, and 18 strains were multidrug resistant, accounting for 21.43%,in which 3 strains were resistant to more than 10 antibiotics. Conclusion Salmonella contamination in the rivers in urban area of Yuyao was serious. The isolated strains had various serotypes and high drug resistant rate. The predominant serotype of Salmonella were Salmonella typhimurium and Salmonella derby which shared the same serotypes with those of Salmonella etected in human infections.