鸡肉空肠弯曲杆菌的分离鉴定及耐药性分析

Isolation,identification and antimicrobial resistance analysis of Campylobacter jejuniisolates originated from chicken

目的分离和收集食源性空肠弯曲杆菌的优势流行株,了解市场上鸡肉中空肠弯曲杆菌的污染和药物敏感性情况。方法根据GB/T4789.9-2003、SN0175-2010、ISO10272-1∶2006、FDA/BAM∶2001、USDA/FSIS∶1998等方法优化组合出一套对动物性食品源空肠弯曲杆菌有效的分离鉴定方法,从市场上鸡肉中分离疑似空肠弯曲杆菌,并进一步用生化试验及PCR方法进行准确鉴定。采用微量肉汤稀释法测定了所分离的空肠弯曲杆菌对22种常见抗菌药物(组合)的最低抑菌浓度值(MIC)。结果与结论根据培养特征、形态特征、生化试验和PCR结果准确鉴定出21株空肠弯曲杆菌,其污染率为11.5%。86%生化试验阳性的菌株经PCR鉴定为阳性。将空肠弯曲杆菌标准菌株和随机选出的分离株的16SrDNA扩增序列进行比对,二者同源率为100%。药敏试验表明,14.3%的分离菌株对氨苄西林具有耐药性;大多数菌株对头孢类抗生素MIC值相对较高;42.9%的菌株对萘啶酸具有耐药性;所有分离株对环丙沙星、四环素、红霉素、氯霉素、庆大霉素、链霉素不耐药。

According to the standards of GB/T4789.9-2003,SN0175-2010,ISO10272-1∶2006,FDA/BAM∶2001 and USDA/FSIS∶1998,a series of effective isolation and identification methods was developed for Campylobacter jejuni of chicken origin.By using these methods,suspected Campylobacter jejuni was firstly isolated from chicken in the market of Ya＇an City,Sichuan Province,and then biochemical test and PCR method were used to further confirm the isolation strains.Combining the results of cultural characteristics,morphologic characteristics,biochemical test and PCR results,21 isolates were accurately identified as Campylobacter jejuni,with which the contamination incidence was 11.5%（21/183）.The 86% of the strains identified by biochemical test were further confirmed by PCR.The 16S rDNA sequence comparison of the amplified region between the standard strain and the randomly selected isolated strain of Campylobacter jejuni indicated that the homology of the two strains was 100%.Screening of 21 Campylobacter jejuni isolates for determining their antimicrobial resistance using micro-broth dilution method showed that,14.3% of the strains were resistant to ampicillin;most of the strains had relatively high MIC to cephazoline,ceftriaxone sodium and ceftiofur sodium;the 42.9% of the strains were resistant to nalidixic acid;no strain was resistant to ciprofloxacin,tetracycline,erythromycin,chloramphenicol,gentamicin and streptomycin.