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目的建立蜡样芽胞杆菌的分子分型方法,应用于蜡样芽胞杆菌食物中毒的溯源研究。方法从2000-2009年广东省深圳市食物中毒暴发和散发病例的临床分离株中挑选47株蜡样芽孢杆菌进行鉴定及生化分型,同时进行vrrA基因PCR扩增并对产物进行测序,用Bio-edit和MEGA软件对DNA序列进行同源性比较。结果传统生化分型:47株蜡样芽胞杆菌中有5株菌不能分型,其余42株菌可分为2型、10型和4型,其中2型16株,占34.04%,10型16株,占34.04%,4型10株,占21.28%;分子分型:47株菌可分为13个基因型MT1-MT13,其中MT13型19株,占40.43%,MT1型8株,占17.02%,MT10型4株,占8.51%。结论 vrrA基因作为蜡样芽胞杆菌分子分型的一个多态性遗传标记,可用于蜡样芽胞杆菌DNA分子分型研究,对食物中毒溯源有重要意义。
Objective To establish a molecular typing method of Bacillus cereus and apply it to the traceability of Bacillus cereus food poisoning. Methods From the clinical isolates of food poisoning outbreaks and sporadic cases from 2000 to 2009 in Shenzhen, Guangdong Province, 47 strains of Bacillus cereus were selected for identification and biochemical typing. At the same time, PCR products of vrrA gene were amplified and sequenced. DNA sequence homology comparison with -edit and MEGA software. Results The results of traditional biochemical typing showed that 5 of the 47 Bacillus cereus strains could not be typed, and the remaining 42 strains could be divided into 2 types, 10 types and 4 types, of which 16 strains were type 2 (34.04%) and 10 Strain accounted for 34.04%, 4 strains of 10, accounting for 21.28%; molecular typing: 47 strains can be divided into 13 genotypes MT1-MT13, of which 19 strains of MT13, accounting for 40.43%, MT1 8 strains accounted for 17.02 %, MT10 type 4, accounting for 8.51%. Conclusion The vrrA gene, as a polymorphic genetic marker of B. cereus, can be used to study the molecular typing of Bacillus cereus, which is of great importance to the traceability of food poisoning.