神农架林区食源性沙门氏菌血清型、耐药性和毒力特征分析

Serotyping antibiotic susceptibility and virulence characteristics of food-borne Salmonella in Shennongjia Forestry District

为了解神农架林区食源性沙门氏菌的流行性、耐药状况和毒力特征,本文对神农架林区2017年食品风险监测检出的18株沙门氏菌进行了血清型检测。结果表明布利丹沙门氏菌为主要血清型。采用K-B药敏纸片法检验沙门氏菌分离株对萘啶酸、磺胺异恶唑、氨苄西林、链霉素、四环素、氯霉素、呋喃妥因等15种抗生素的敏感性,结果表明沙门氏菌耐药普遍,对氨苄西林的耐药率最高(61.1%),对头孢他啶最敏感,耐药率仅为5.6%。三重及以上耐药菌达72.2%,耐药性最强的1株菌对11种测试药物均有耐药性。采用PCR检测沙门氏菌耐药基因blaTEM-Ⅰ、sul-Ⅱ、strB、tetA及floR,毒力基因sseL、hilA、mgtC、stn、invA,结果显示18株沙门氏菌5种毒力基因的检出率均为100%,耐药基因中blaTEM-Ⅰ携带率最高(61.1%)。本文研究结果表明神农架林区食源性沙门氏菌污染程度虽不高但耐药严重,应予以注意。

Serotype,antibiotic susceptibility and virulence characteristics of food-borne Salmonella strains isolated from Shennongjia Forestry District were investigated in this study.A total of 18 Salmonella strains were obtained from food risk surveillance in Shennongjia Forestry District in 2017.Among Salmonella serovars,Salmonella blegdam was the most prevalent.The antimicrobial susceptibility testing was performed using the Kirby-Bauer disc diffusion test and 15 antibiotics including nalidixic acid,sulfisoxazole,ampicillin,streptomycin,tetracycline,chloramphenicol,and macrodantin were evaluated.The Salmonella isolates had a high prevalence(88.9%)of resistance to test drugs,particularly to ampicillin(61.1%).However,low level of resistance was observed to ceftazidime(5.6%).Thirteen of the eighteen isolates(72.2%)displayed resistance to at least three antibiotics.Among multidrug-resistant isolates,one strain was resistant to 11 antibiotics.The drug resistance gene(blaTEM-Ⅰ,sul-Ⅱ,strB,tetA and floR)and virulence gene(sseL,hilA,mgtC,stn and invA)profiles of Salmonella isolates were determined by PCR.Five genes were detected in all isolates and the drug resistance gene blaTEM-Ⅰwas commonly present in the isolates(61.1%).The results of this study showed that though Salmonella isolates were seldom detected from retail foods in Shennongjia Forestry District,the isolates are commonly resistant to multiple antimicrobials.