Survival of Salmonella Enteritidis on Four Types of Stainless Steel Surface under a Dry Condition and Recovery by Swabbing

摘要

組成と表面仕上げの異なる4種類のステンレス表面に添加したSalmonella Enteritidisの生残性と菌の回収について調査した.バイオフィルム産生能の異なる2株のS. Enteritidisをトリプトソイブロス(TSB)と卵黄液(EY)で培養し，ステンレスの表面に添加した.乾燥状態 (22℃)で保管した後，綿棒を用いたふき取り法により生残菌を回収し.回収菌数とステンレス表面に残った菌数を測定した.バイオフィルム産生能の高い菌の生残率は，産生能の低い菌の生残率より高かった.TSBで培養添加された菌の生残率は.EYで培養添加された菌の生残率より高い傾向が見られた.ステンレス組成と表面仕上げの違いに基づく菌の生残率と回収率には有意の差は見られなかつた.一例を除いて.添加されたS.Enteritidisの98％以上が綿棒を使用したふき取り法により回収された.%The survival and recovery of Salmonella Enteritiais inoculated on stainless steel surfaces with different metal contents and surface finishes were examined. Two S. Enteritidis strains possessing different levels of biofilm productivity were inoculated with tryptone soya broth (TSB) and egg yolk emulsion (EY) on the surface of stainless steel squares (1cm ×1cm) and stored at 22℃ under a dry condition. After storage, cells were recovered from the stainless steel surfaces by swabbing with a cotton swab. The numbers of cells recovered by swabbing and the cells remaining on the stainless steel squares were counted. The survival ratio of the strain possessing high biofilm productivity was greater than that of the strain possessing low biofilm productivity. The survival ratio of S. Enteritidis suspended in TSB was often higher than that in EY. There were no significant differences in the survival and recovery ratios of S. Enteritidis based on stainless steel composition or surface finish. From all except one sample, more than 98％ of viable cells of S. Enteritidis were recovered by swabbing with a cotton swab.