某企业婴儿肉毒中毒乳粉相关样品中肉毒梭菌的分离与分型  

Isolation and typing of Clostridium botulinum from milk powder of an enterprise associated with a case of infant botulism

作　　者：骆海朋[1] 瞿洪仁 丁波 任秀[1] 赵琳娜 白继超 王亚萍 林兰[1] 崔生辉[1] LUO Haipeng;QU Hongren;DING Bo;REN Xiu;ZHAO Linna;BAI Jichao;WANG Yaping;LIN Lan;CUI Shenghui(China National Institute for Food and Drug Control,Beijing 100050,China;Yantai Food and Drug Inspection and Testing Center,Shandong Yantai 264003,China)

机构地区：[1]中国食品药品检定研究院,北京100050 [2]烟台市食品药品检验检测中心,山东烟台264003

出　　处：《中国食品卫生杂志》2023年第10期1475-1481,共7页Chinese Journal of Food Hygiene

基　　金：多重耐药食源性病原菌溯源及其耐药基因传播预警(2022YFC2303900)。

摘　　要：目的对从某企业获取的30批次婴儿配方乳粉样品进行肉毒毒素和肉毒梭菌检测,对分离到的1株B型肉毒梭菌进行全基因组测序分析。方法参照GB 4789.12—2016《食品安全国家标准食品微生物学检验肉毒梭菌及肉毒毒素检验》对样品进行肉毒梭菌分离及肉毒毒素分型实验;对分离到的菌株进行全基因组测序,并分析菌株的遗传特征。结果30批次样品中均未检出肉毒毒素;将增菌液进行小鼠腹腔注射后,4批次乳粉样品出现了典型小鼠肉毒中毒症状,但仅从1批次乳粉样品中分离到肉毒梭菌。基因组测序分析显示,该菌为Ⅰ群B型肉毒梭菌,毒素基因簇为Ha型,毒素基因为B2亚型。结论针对背景微生物复杂的婴儿配方乳粉中肉毒梭菌检测,不应以菌种分离作为金标准,而应以增菌液小鼠毒性实验结合肉毒抗血清保护实验作为确认方法。全基因组测序可对分离菌种进行精准鉴定和相关遗传特征分析,为中毒事件处理提供可靠的技术支撑。Objective The aim of this study was to detect botulinum toxin and Clostridium botulinum(C.botulinum)in 30 batches of infant formula milk powder obtained from an enterprise and to analyze the whole genome of the strain of C.botulinum type B isolated from the samples.Methods The samples were subjected to C.botulinum isolation and botulinum toxin typing experiments according to the“National standard for food safety microbiological examination of C.botulinum and botulinum toxin”(GB 4789.12—2016).The whole genomes of the isolated strains were sequenced and their genetic characteristics were analyzed.Results Botulinum toxin was not detected in any of the 30 batches of samples.After intraperitoneal injection of the enrichment solution into mice,four batches of milk powder samples induced symptoms of botulism,but C.botulinum was isolated from only one batch of milk powder samples.Genome sequencing revealed that the bacterium was C.botulinum groupⅠ,type B,the toxin gene cluster was type Ha,and the toxin gene was subtype B2.Conclusion The detection of C.botulinum in infant formula milk powder with a complex background of microorganisms should not be based on the isolation of bacteria as the gold standard but should be confirmed by a mouse toxicity test of the enrichment solution combined with a botulinum toxin antiserum protection test.Whole genome sequencing can accurately identify strains and analyze relevant genetic characteristics,providing reliable technical support for handling poisoning events.

关 键 词：肉毒梭菌 基因组 肉毒毒素分型 

分 类 号：R155[医药卫生—营养与食品卫生学]