Listeria monocytogenes is a foodborne pathogen whose biofilm formation and desiccation tolerance may contribute to its survival in the food industry. L. monocytogenes possesses three cold-shock domain family proteins (CspA, CspB and CspD) known to be essential for adaptation against various food-relevant stress conditions including cold growth. The role of Csps in desiccation tolerance and biofilm formation was investigated in csp mutants as well as twenty-one other wild-type (WT) strains. Mutants with a single (ΔcspA) or multiple (ΔcspAB, ΔcspAD and ΔcspABD) deletions of csp genes, in a desiccation sensitive WT background (L. monocytogenes EGD-e) were immotile and exhibited an elevated desiccation tolerance compared to the parent strain. However, deletion of cspA in the more desiccation resistant food and outbreak related L. monocytogenes strains 568 and 08-5578 had no impact on desiccation tolerance although compared to the parent strains the mutants were also immotile. A correlation between lower motility and higher desiccation tolerance was observed among the 20 WT strains (Spearman rank correlation, r_s = −0.56, p = 0.01), although exceptions occurred indicating that multiple factors influence the diverse desiccation tolerance among L. monocytogenes strains. Expression of cspA was upregulated in WT EGD-e, 568 and 08-5578 strains after desiccation for seven days, while the 568 and 08-5578 ΔcspA mutants expressed elevated levels of cspD and cspB (>30 fold higher) compared to their WTs. This indicates that upregulation of the other csps compensates for the deleted cspA gene. Although biofilm formation was improved in all EGDe csp mutants relative to the WT strain, the opposite was observed for 568 and 08-5578 WT strains and their cspA deletion mutants. Only motile strains formed biofilm in the peg lid assay but a significant negative correlation (r_s = −0.60, p = 0.01) was seen between higher motility and higher biofilm formation of WT strains. In conclusion, the survival of L. monocytogenes strains in the food processing environment may depend on the control of motility, which is a necessity for biofilm formation but disadvantageous for desiccation survival.

单核细胞增生李斯特菌是一种食源性病原体，其生物膜形成和耐干燥性可能有助于其在食品工业中的生存。单核细胞增生李斯特菌具有三种冷休克结构域家族蛋白（CspA，CspB和CspD），已知这些蛋白对于适应各种与食物相关的应激条件（包括寒冷生长）至关重要。在csp突变体以及其他21种野生型（WT）菌株中研究了Csps在干燥耐性和生物膜形成中的作用。与单个（Δ突变体的CspA）或多个（Δ cspAB，Δ cspAD和Δ cspABD）的缺失CSP基因，在干燥敏感的WT背景中（单核细胞增生李斯特菌EGD-e）不易动，并且与亲本菌株相比显示出提高的干燥耐受性。然而，尽管与亲本菌株相比，突变体也不能移动，但在更具抗干燥性的食品中和与暴发相关的单核细胞增生李斯特菌菌株568和08-5578的cspA缺失对脱水耐受性没有影响。在20株WT菌株中观察到了较低的运动力和较高的脱水耐受性之间的相关性（Spearman等级相关性，r _s  = -0.56，p  = 0.01），尽管发生了例外，表明多种因素影响单核细胞增生李斯特氏菌的多样化脱水耐受性株。的表达的CspA被上调在WT EGD-E，干燥7天之后568个08-5578菌株，而568和08-5578Δ的CspA突变体表达升高水平的CSPD和的cspB（倍高> 30）相比，它们的WT 。这表明其他csps的上调补偿了缺失的cspA基因。尽管相对于WT菌株，在所有EGDe csp突变体中生物膜形成均得到改善，但是对于568和08-5578 WT菌株及其cspA缺失突变体却观察到相反的情况。钉盖测定中仅运动菌株形成生物膜，但显着负相关（r _s ＝ -0.60，p  ＝ 0.01）在WT菌株的较高运动性和较高生物膜形成之间被观察到。总之，在食品加工环境中单核细胞增生李斯特氏菌菌株的存活可能取决于运动性的控制，这对于生物膜的形成是必要的，但对干燥的存活是不利的。