液态奶中阪崎肠杆菌污染状况的调查

Investigation on Enterobacter Sakazakii Pollution Situation in Liquid Milk

[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:6μl10×PCR buffer,4μl dNTPs混合物,2.5 Mg^(2+)μl(25 mM),2μl10μmol正向引物,2μl10μmol反向引物,0.25μl(5 U/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5 min;变性95℃1 min,退火61℃0.5 min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。

[ 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,6 μl 10 × PCR buffer,4μl mixture of dNTPs,2.5 μl Mg^2＋ （25 mM） ,2μl of 10 μmol forward primer,2 μl of 10 μmol reverse primer,0.25 μl （5UI/μ1） Taq,H2O 23.25μl ,total reaction system is 50μl; The suitable PCR amplification program is：PCR reaction used cold start, DNA predegeneration 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 eleetrophoresis 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.