摘要
目的了解河南省市售婴幼儿配方食品中克罗诺杆菌污染情况、分子分型特征及耐药情况,分析不同菌株间的系统发育进化关系。方法采集婴幼儿配方食品227份,按照GB 4789.40—2016《食品安全国家标准食品微生物学检验克罗诺杆菌属(阪崎肠杆菌)检验》方法进行克罗诺杆菌的分离鉴定,并用微量肉汤稀释法和脉冲场凝胶电泳(PFGE)对分离株进行药敏实验和溯源分析,采用16S rRNA和多位点序列分型(MLST)方法进行种属鉴定和系统发育进化分析。结果227份婴幼儿配方食品中检出13株克罗诺杆菌,分别属于阪崎克罗诺杆菌、苏黎世克罗诺杆菌和都柏林克罗诺杆菌。13株克罗诺杆菌药敏结果显示头孢唑啉耐药率达到84.6%(11/13),PFGE分型得到7个带型,MLST共分为6个ST型,其中ST1为优势型别,相同PFGE型的菌株也有相同的MLST型。结论河南省市售婴幼儿配方食品中克罗诺杆菌污染以阪崎克罗诺杆菌为主,种属和基因型具有多样性,系统进化树分析结果显示MLST能够更好地说明种水平之间的亲缘关系。
Objective To investigate the contamination,molecular typing characteristics and antibiotic resistance of Cronobacter in infants formula food in He’nan.Methods A total of 227 commercially available infants formula food were collected,and Cronobacter was isolated and identified according to GB 4789.40—2016.Pulse field gel electrophoresis(PFGE)and the broth microdilution method were used to confirm the molecular type and antibiotic resistance.16 S rRNA and multilocus sequence typing(MLST)were used to identify the species and analyze the phylogenetic evolution of Cronobacter.Results 13 Cronobacter strains isolated from 227 infants formula food were identified as C.sakazakii,C.turicensis and C.dublinensis.The antibiotic susceptibility result of 13 Cronobacter strains showed that the resistance rate of cefazolin reached 84.6%(11/13).13 strains of Cronobacter were divided into 7 clusters and 6 ST types.Majority of the strains with the same PFGE type also had the same MLST type of which ST1 was the dominant type.Conclusion The main contamination of Cronobacter in infants formula food was caused by C.sakazakii with diverse biochemical phenotypes and genotypes.The molecular phylogenetic tree of MLST well interpreted the genetic relationship between different kind of species.
作者
吴玲玲
戚浩彧
任高翔
邱正勇
炊慧霞
李辉
廖兴广
WU Lingling;QI Haoyu;REN Gaoxiang;QIU Zhengyong;CHUI Huixia;LI Hui;LIAO Xingguang(He'nan Provincial Center for Disease Control and Prevention,He'nan Zhengzhou 450016,China)
出处
《中国食品卫生杂志》
CSCD
北大核心
2022年第1期23-28,共6页
Chinese Journal of Food Hygiene
基金
河南省医学科技攻关项目(LHGJ20190690)。
