A high-efficiency pretreatment method for elution of pathogenic bacteria in lettuce  

作　　者：Xiaoyan Liao Chunmin Pu Yan Cui Yalong Bai Xianming Shi Lili Chen 廖小艳;普春敏;崔妍;白亚龙;史贤明;陈丽丽(Department of Public Health Laboratory Sciences,College of Public Health,Hengyang Medical School,University of South China,Hengyang,Hunan,China;Institute for Agri-food Standards and Testing Technology,Shanghai Academy of Agricultural Sciences,Shanghai,China;MOST-USDA Joint Research Center for Food Safety&Bor Luh Food Safety Center,Department of Food Science and Engineering,School of Agriculture and Biology,Shanghai Jiao Tong University,Shanghai,China)

机构地区：[1]Department of Public Health Laboratory Sciences,College of Public Health,Hengyang Medical School,University of South China,Hengyang,Hunan,China [2]Institute for Agri-food Standards and Testing Technology,Shanghai Academy of Agricultural Sciences,Shanghai,China [3]MOST-USDA Joint Research Center for Food Safety&Bor Luh Food Safety Center,Department of Food Science and Engineering,School of Agriculture and Biology,Shanghai Jiao Tong University,Shanghai,China

出　　处：《Food Quality and Safety》2022年第4期588-596,共9页食品品质与安全研究（英文版）

基　　金：supported by Shanghai‘Science and Technology Innovation Action Plan’for Agriculture Project(19391902100,21N31901100);the Special Project on Agricultural Science and Technology Innovation—Applied Basic Research Project of Shanghai Academy of Agricultural Sciences(Agricultural Science Application Foundation 2022-09),China.

摘　　要：Many current studies on rapid detection of pathogenic bacteria in foods have focused on the construction of detection methods,neglecting pretreatment.It is also a key step to efficiently elute pathogenic bacteria from food samples for rapid detection and can even determine the success or failure of an assay.In this study,we used Escherichia coli(E.coli),Salmonella enteritidis(S.enteritidis),and Listeria monocytogenes(L.monocytogenes)as model bacteria to compare the elution efficiency of different eluants;explore the effect of surfactant,ionic strength,protein(or amino acid and peptide),and enzyme on the recovery rate of bacteria in lettuce;and compare the compound effect caused by multiple factors.Finally,we developed an efficient bacterial recovery method and confirmed the superiority of this method to analyze the bacterial diversity of eluants from lettuce.The results showed that the recovery efficiency of E.coli,S.enteritidis,and L.monocytogenes,which were artificially contaminated with approximately 10^(5)CFU/g in lettuces,could reach 94.4%,90.6%,and 93.7%by using 10 mmol/L Tris·HCl(pH 9.5)with 0.1%peptone and 300 U/100 mL of cellulase,and furthermore,the elution efficiency could reach 99.6%,98.6%,and 100%with the aid of a 2-min stomaching.For the lettuce samples with only native bacteria,the recovery rate reached 92.1%for viable aerobic bacteria by this method,which was approximately 10%higher than that of the modified previous method.The bacterial diversity of the eluted solution was analyzed,and the result was significantly improved.Considering these advantages,it is important to improve the elution efficiency to achieve rapid and accurate detection of pathogenic bacteria in lettuces.

关 键 词：LETTUCE foodborne pathogens ELUTION PRETREATMENT diversity analysis 

分 类 号：O62[理学—有机化学]