储存环境对鸡蛋壳表面3种沙门氏菌存活与迁移的影响

Effects of Storage Conditions on Survival and Migration of Three Kinds of Salmonellaon Eggshell

为探明不同储存环境对蛋壳表面沙门氏菌存活和向蛋内迁移的影响,在鸡蛋壳表面人工接种肠炎沙门氏菌、鼠伤寒沙门氏菌和鸡白痢沙门氏菌,试验环境设定温度4、25和37℃,环境相对湿度(RH)设定为50%和90%,在不同的储存环境下,各个时间点检测蛋壳表面沙门氏菌数量与蛋内容物中沙门氏菌污染情况。结果显示,4℃环境下可显著减少蛋壳表面3种沙门氏菌的数量;50%RH、25和37℃环境下蛋壳表面3种沙门氏菌的数量均逐渐下降;90%RH、25℃环境下蛋壳表面肠炎沙门氏菌、鼠伤寒沙门氏菌在个别时间点出现数量反弹,其总体数量呈现下降趋势,37℃环境下鸡白痢沙门氏菌的数量快速下降,而肠炎沙门氏菌和鼠伤寒沙门氏菌的数量先下降后上升,并保持在接种的数量级水平。鸡蛋内容物的检测结果显示,肠炎沙门氏菌和鼠伤寒沙门氏菌在高温、高湿环境下更易被检出,而鸡白痢沙门氏菌始终未被检出。综上所述,低温、低湿可减少蛋壳表面沙门氏菌存活,并阻止其菌体向蛋内迁移,高温、高湿环境促进蛋壳表面沙门氏菌的增殖,增加了其向蛋内迁移的几率,不同血清型沙门氏菌在鸡蛋壳表面的存活和向蛋内迁移的侵袭力存在一定差异。

In order to study the effects of storage conditions on survival and migration of three kinds of Salmonella,S.enteritidis,S.typhimuriumand S.pullorum were artificially contaminated on eggshell.Different environment temperatures（4,25 and 37℃）and relative humidity（50%and 90%）were seted,and the number of Salmonellas on the surface of eggshell and egg contents were counted and detected on various time points.The results showed that 4℃ obviously reduced the number of three kinds of Salmonellas.At 50% RH,the number of three kinds of Salmonellas were reduced on eggshell surface at 25 and 37℃environment.At 90% RH,despite the individual time points,the number of S.enteritidis and S.typhimuriumpresented downward trend at 25℃.And at the 37℃,the number of S.pullorumrapidly reduced,and the number of S.enteritidis and S.typhimuriumfirstly decreased and then increased,and finally maintained at the level of inoculated magnitude.The results of egg content detection showed that S.enteritidis and S.typhimuri-um were more likely to be detected in high temperature and high humidity environment,while S.pullorum was not detected in all kinds of experimental environment.The results suggested that low temperature and low humidity reduced Salmonellas survival on eggshell and inhibited it migration into the egg,and high temperature and high humidity could promote Salmonellas proliferation,increase the risk of its penetration into egg.There were some differences in the survival on eggshell and invasion between the different serotypes Salmonellas.