Alternative sigma factor σB is not essential for Listeria monocytogenes surface attachment
Alternative sigma factor σB is not essential for Listeria monocytogenes surface attachment
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DOI：
10.4315/0362-028x-68.2.311
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发表时间：
2005-02-01
影响因子：
2
通讯作者：
Boor, KJ
中科院分区：
文献类型：
--
作者：
Schwab, U;Hu, Y;Boor, KJ
单核细胞增生李斯特菌是一种食源性致病菌，经常从食品加工环境中分离出来。多方面的证据表明，L。单核细胞增生交替转录因子σ B（σ（B））在表面附着和生物膜形成中的作用。因此，通过平板计数和显微技术，L。测试单核细胞增多症10403 S菌株和其它等基因DeltasigB菌株对不锈钢的附着。显微图像分析显示，在24 ℃静态条件下72小时后，受试L.单核细胞增生菌株作为单细胞均匀地附着在表面上。两种菌株都能够快速附着（即，孵育5分钟或24小时后，附着细胞的数量基本相同）。在24 ℃下孵育48和72 h后，附着的DeltasigB细胞的数量显著低于野生型菌株（P = 0.001）。无论温度如何（24或37 ℃），附着在不锈钢上的DeltasigB菌株数量相似;然而，在6%NaCl存在下，48和72 h后，DeltasigB细胞以较高的相对数量附着。此外，在荧光假单胞菌的存在下，类似地大量的野生型和DeltasigB细胞附着于表面，形成混合的生物膜。我们的数据表明，σ（B）是不需要的初始表面附着的L。单核细胞增多症。
Listeria monocytogenes is a foodborne pathogen frequently isolated from the food processing environment. Multiple lines of evidence suggested a possible role for the L. monocytogenes alternative transcription factor sigma B (sigma(B)) in surface attachment and biofilm formation. Therefore, through plate count and microscopic techniques, the L. monocytogenes 10403S strain and an otherwise isogenic DeltasigB strain were tested for attachment to stainless steel. Analysis of microscopic images revealed that after 72 h at 24 degreesC under static conditions the tested L. monocytogenes strains attached uniformly to surfaces as single cells. Both strains were capable of rapid attachment (i.e., numbers of attached cells were essentially the same after either 5 min or 24 h of incubation). Numbers of attached DeltasigB cells were significantly lower than those of the wild-type strain after 48 and 72 h of incubation at 24 degreesC (P = 0.001). Similar numbers of the DeltasigB strain attached to stainless steel regardless of temperature (24 or 37 degreesC); however, DeltasigB cells attached at higher relative numbers in the presence of 6% NaCl after 48 and 72 h. Furthermore, in the presence of Pseudomonas fluorescens, similarly high numbers of wild-type and DeltasigB cells attached to the surfaces, forming mixed biofilms. Our data suggest that sigma(B) is not required for initial surface attachment of L. monocytogenes.