副溶血性弧菌在动态体外人胃仿生原位消化系统中的存活情况研究

Survival of Vibrio parahaemolyticus in Dynamic Human Stomach System in vitro

副溶血性弧菌(Vibrio parahaemolyticus)是一种经口摄入感染的食源性致病菌,广泛存在于水产品中,然而其进入人胃后的存活情况尚属研究空白。本研究将浓度为107 cfu/g的副溶血性弧菌接种于三文鱼和南美白对虾中,运用体外人胃仿生原位消化系统进行消化模拟,经过120 min后,测定食物排空率、胃部pH值变化及幽门排出食糜中副溶血性弧菌的存活情况。结果显示三文鱼的胃排空滞后时间为60 min,南美白对虾为90 min,模拟消化120 min时,两种食糜均未完全排空。胃部pH值为(1.6±0.1),在食物摄入10 min后大幅上升,随着胃酸的不断分泌及食物的消化分解,其pH值开始下降,并保持在5.41左右。在食品消化120 min进入肠道后,副溶血性弧菌并没有完全被胃酸杀灭,对虾中该菌的存活率为(0.119±0.025)%,而三文鱼中存活率为(0.007±0.005)%。综上所述,副溶血性弧菌可随食物基质的消化分解通过胃排空进入肠道,从而躲避胃酸的杀灭并导致人体患病。

Vibrio parahaemolyticus is a food-borne pathogen ingested orally,and is widely found in aquatic products.However,its survival after entering the human stomach remains a research gap.In this study,V.parahaemolyticus with a concentration of 107 cfu/g was inoculated into salmon and S.American white shrimp(Panaeus vannamei),and the digestion was simulated by in vitro dynamic human stomach bionic in situ intestine system.After 120 min,the food emptying rate and the changes of gastric pH were measured,as well as the survival conditions of V.parahaemolyticus in the chyme discharged from pylorus.The results showed that the gastric lag time of salmon was 60 min,and that of white shrimp was 90 min.When the simulated digestion was 120 min,both chymes were not completely empty.The pH value of the stomach was(1.6±0.1),which increased sharply after 10 minutes of food intake.As the gastric acid was continuously secreted and the food was digested and decomposed,the pH began to decrease and remained at around 5.41.After the food was digested for 120 min into the intestine,V.parahaemolyticus was not completely killed by gastric acid.The survival rate of the bacteria in the shrimp was(0.119±0.025)%,and the survival rate in the salmon was(0.007±0.005)%.In summary,V.parahaemolyticus can be separated into the intestine through gastric emptying as the food matrix is digested,thereby avoiding the killing of gastric acid and causing illness in the human body.