液态奶中阪崎肠杆菌污染状况的调查

目的]了解某地区液态奶中阪崎肠杆菌的污染情况，为政府加强对液态奶的管理提科学依据。方法]采用改进方法和PCR法检测液态奶。PCR适宜反应体系为：6μl 10×PCR buffer，4μl dNTPs混合物，2．5Mg^2＋ μl（25mM），2μl 10μmol正向引物，2山10μmol反向引物，0．25μl（5U／μl）Taq，23．25μl水，总反应体系为50μl；其适宜的PCR扩增程序为：PCR反应采用冷启动，95℃预变性5min；变性95℃ 1min，退火61℃0．5min进行35个循环。PCR反应产物在2％的琼脂糖凝胶中进行电泳，凝胶成像系统观察结果，检出率为2．4％，同时对阪崎肠杆菌的毒力进行了研究，所筛出的4株阪崎肠杆菌均导致受试昆明小鼠死亡。结果]从167份液态奶样品中检出4株阪崎肠杆菌。

Investigation on Enterobacter Sakazakii Pollution Situation in Liquid Milk

Objective]The paper aimed to understand the pollution situation of Enterobacter sakazakii in liquid milk of some area,in order to provide the scientific basis for the strengthening government management of the liquid milk.Method]Improved method and PCR method were used to determine the liquid milk.The suitable reaction system of PCR as follows,6μl 10×PCR buffer,4μl mixture of dNTPs,2.5μl Mg~(2+)(25 mM),2μl of 10μmol forward primer,2μl of 10μmol reverse primer,0.25μl(5Ul/μl) Taq,H_2O 23.25μl,total reaction system is 50μl;The suitable PCR amplification program is:PCR reaction used cold start,DNA pre- degeneration at 95℃for 5 min,DNA degeneration at 95℃for 1 min,primer annealing at 61℃,35 cycles.The PCR products were examined by 2%agarose gel electrophoresis detectionrate is 2.4%;and all of the four resulted in the death of the tested kunming mice.and toxicity of Enterobacter Sakazakii were studied.Observation results of gel imaging system.Result]Four strains of E.sakazakii were detected from 167 liquid milk samples.