配方奶粉加工过程阪崎克罗诺杆菌PFGE分子分型研究

PFGE molecular typing research on Enterobacter Sakazakii isolates during the process of formula milk powder manufacture

目的对配方奶粉加工控制过程中分离的阪崎克罗诺杆菌开展PFGE图谱研究。方法用XbaⅠ酶切割,脉冲场凝胶电泳技术建立PFGE指纹图谱,Bio Numerics V 6.6软件进行聚类分析。结果 46株阪崎克罗诺杆菌共形成了29种PFGE基因指纹图谱。除图谱PTP29外,其余菌株的同源性>60%。1件半成品、3件不同批次的产品分离的菌株图谱一致(图谱PTP3)。图谱PTP7、PTP8的菌株分别分离自原料奶粉和浓缩乳清蛋白粉。图谱PTP18菌株分离自成品、筛粉、墙壁、设备传送带样品。图谱PTP27菌株分离自成品、混料(半成品)和α-乳白蛋白。结论 PFGE技术对阪崎克罗诺杆菌具有很好的分型效果。阪崎克罗诺杆菌存在局部流行现象,原料带菌、加工环境是婴儿配方粉阪崎克罗诺杆菌污染的主要途径。

Objective To analyze pulse-field gel electrophoresis（PFGE） type of Enterobacter Sakazakii isolated during the process of formula milk powder production and monitoring.Methods Enterobacter Sakazakii isolates were digested with enzyme Xba I,fingerprintings were established with PFGE,and clustered and analyzed with Bio Numerics V 6.6 software.Results Total 29 types of genome fingerprintings were detected from 46 Enterobacter Sakazakii isolates.The homology of other strains were above 60% except type PTP29.Type PTP3 were observed among strains isolated from 1 batch semi-manufactured product and3 batches of product.Strains from Type PTP7 and PTP8 were isolated from raw milk powder and concentrated whey protein powder respectively.Strains from Type PTP18 were isolated from milk powder,powder particles,the wall of producing department,and conveyor.Strains from Type PTP27 were isolated from milk powder,semi-manufactured products and α-whey protein.Conclusion PFGE was demonstrated to be efficient for E.Sakazakii molecular typing.Meanwhile,E.Sakazakii is prevalent regionally.Raw material and produce environments were illuminated to be main sources of contamination.