四川省部分地区2010-2011年猪肉生产链中沙门菌耐药特征及分子分型研究

Characterization of antimicrobial resistances and molecular characteristics of Salmonella isolates from the pork production chain in Sichuan province,2010-2011

目的：分析2010-2011年四川省部分地区猪肉生产链中沙门菌耐药特性及分子分型特征。方法对分离的112株沙门菌采用肉汤微量稀释法进行10种抗生素（组合）药敏试验，参考CLSI标准（2010）判定结果。选取不同菌株来源、血清型和耐药谱的74株沙门菌，按照美国PulseNet标准进行脉冲场凝胶电泳（PFGE）分型。结果猪肉生产链中沙门菌对四环素耐药率最高（89.29%），其次为大观霉素（36.61%）、甲氧苄啶/磺胺甲噁唑（35.71%）、萘啶酸（33.93%）和氨苄西林（24.11%），多重耐药率为33.93%，对头孢噻呋敏感，共有19种耐药谱。来自猪肉生产链的74株沙门菌可分为34个PFGE谱型，其相似性为40%～100%。结论四川省猪肉生产链中沙门菌耐药较为严重，其血清型及耐药谱与PFGE分型有一定相关性；生产链中沙门菌可能存在自上游生产链向下游生产链水平传播的情况。

Objective To investigate the antimicrobial resistance and resistance profiles of Salmonella isolates,from the pork production chain in several districts of Sichuan province and to determine the correlation between serotype and the pulse field gel electrophoresis（PFGE）patterns. Methods From 2010 to 2011,a total of 112 Salmonella isolates from pork production chain were examined for their antimicrobial susceptibility,using the micro-dilution method against 10 antimicrobial agents. Results were assessed by the standard by the Clinical and Laboratory Standards Institute （CLSI,2010）. In addition,PFGE patterns were investigated among the Salmonella strains from different sources,under different serovars and antimicrobial profiles. Results For Salmonella isolated from the pork production chain,resistance to tetracycline（89.29%）was frequently observed. Many isolates were resistant to spectinomycin（36.61%）,trimethoprim/sulfamethoxazole（35.71%）, nalidixic acid（33.93%）and ampicillin（24.11%）,but all of the isolates were susceptible to ceftiofur. 33.93% of the isolates were multi-drug resistant. Salmonella isolates from the pork production chain had 19 antibiotic resistance profiles. Totally,34 PFGE patterns were detected among 74 Salmonella isolates from the pork production chain,with the PFGE patterns of the 74 Salmonella isolates sharing 40%to 100%similarities. Conclusion The antimicrobial resistances of the Salmonella isolates were commonly detected from the pork production chain in Sichuan province suggesting that Salmonella might horizontally spread from food animals to retail meat products.