JS25噬菌体生物特性及对食品中致病菌的生物防治  

Biological properties of bacteriophages and biocontrol of staphylococcus aureus in foods

作　　者：龙门[1,2,3] 詹歌[3] 金双潮 周卉[3] 杜庆飞[3] 王冉[1,2] 

机构地区：[1]江苏省农业科学院食品质量安全与检测研究所农业部农产品质量安全控制技术与标准重点实验室省部共建国家重点实验室培育基地江苏省食品质量安全重点实验室 [2]南京农业大学协同创新中心,南京210014 [3]滁州学院生物与食品工程学院,滁州239000

出　　处：《农业工程学报》2016年第22期303-308,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：江苏省农业科技自主创新引导资金项目(CX(15)1049);安徽省高校自然科学研究一般项目(KJ2015B04);滁州学院生物与食品学院实验室开放课题(SWSP201513KF)

摘　　要：该试验以JS25噬菌体为研究对象,在分析稳定性的基础上,确定其对宿主细胞的侵染时间及最佳感染复数,最后通过在即食食品中的抑菌效应确定对即食食品的生物防治效果。结果表明,JS25噬菌体最佳感染复数为0.1、侵染时间为20 min、最适温度及p H值分别为4~60℃和6~9;另外,JS25噬菌体的潜伏期为20 min,60 min后平均裂解量为24.55 PFU/cell;试验结果表明,JS25噬菌体在即食食品中有较高的稳定性,且随噬菌体初始效价的增加,对即食食品中金黄色葡萄球菌的抑制作用也逐渐增加;但是在不同即食食品中的生物防治效果存在差异,主要表现为当效价为108及1010 PFU/g时,能分别有效的抑制鲜牛奶和圆白菜在贮藏过程中的金黄色葡萄球菌数量,当效价大于109 PFU/g时,对肉干及火腿中的致病菌有良好的防治效果。Staphylococcus aureus, as one of the most common food-borne pathogens, is related to the health, safety in the food industry and fields of medicine and it can be transmitted to humans and animals through the food. Although many foods can serve as vehicles,Staphylococcus aureus is often isolated from ready-to-eat （RTE） foods, such as milk ,ham and cabbage. RTE foods have been implicated in most of the major listeriosis outbreaks in the last 30 years. Of particular concern is the fact that they are consumed directly, without a final bactericidal processing step. Since the preservation methods applicable to minimally processed RTE foods often seem to be insufficient to preventStaphylococcus aureus contamination and growth, new strategies to combat this opportunistic pathogen in foods are needed. Bacteriophages are natural enemies of bacterias and are suitable candidates for the environmentally friendly biocontrol of these pathogens. Using bacteriophages as a tool to the control of pathogens is a complementary to antibiotic therapy. We have isolated a lytic bacteriophage, broad-host-range phages, designated JS25 （Morphologic analysis of JS25 revealed that it was closely related to other Myoviridae phages infecting Staphylococcus species.）, from sewage effluent on a dairy farm in Jiangsu, using as a biocontrol agent againstStaphylococcus aureus infections. In a comprehensive set of experiments, we evaluated thermal and pH stability,studied phage adsorption and determined the optimal multiplicity of infection. Then, we determined the latent period and burst size of JS25 bacteriophages by one-step growth. Last, we evaluated the virulent, broad-host-range phages JS25 bacteriophages for control of Staphylococcus aureus in different RTE foods （ham, dried meat, fresh milk, cabbage） known to frequently carry the pathogens and analyzed its stablity during storage. Food samples were spiked with bacteria （1×103CFU/g） respectively, with phage added thereafter （1×108 PFU/g）, and then samples were stored at 4

关 键 词：噬菌体 稳定性 生物防治 效价 即食食品 

分 类 号：TS205[轻工技术与工程—食品科学]