Ripio M T, Geoffroy C, Domínguez G, Alouf J E, Vázquez-Boland J A
Unidad de Microbiología e Inmunología, Facultad de Veterinaria, Universidad Complutense, Madrid.
Res Microbiol. 1995 May;146(4):303-13. doi: 10.1016/0923-2508(96)81053-9.
The negative mutant approach was used in this study to identify listerial cytolytic factors involved in cooperative haemolysis (CAMP-like phenomenon) with Staphylococcus aureus and Rhodococcus equi. A Listeria monocytogenes non-haemolytic mutant specifically impaired in listeriolysin O (LLO) production gave no CAMP reaction with S. aureus, and was virtually CAMP-negative with R. equi, indicating that the listerial sulphydryl-activated toxin played a major role in cooperative haemolysis. This was confirmed by direct evidence using purified LLO and alveolysin (from Bacillus alvei) in diffusion CAMP assays. To our knowledge, this is the first evidence of involvement of a sulphydryl-activated toxin in cooperative lytic processes. Phosphatidylcholine- and phosphatidylinositol-specific phospholipases C from L. monocytogenes did not seem to significantly contribute to cooperative haemolysis, as the corresponding mutants displayed wild-type CAMP reactions. In contrast, the sphingomyelinase C from Listeria iva-novii was the cytolytic factor responsible for the characteristic shovel-shaped CAMP reaction shown by this listerial species with R. equi. Possible mechanisms of lytic cooperation are discussed.
本研究采用负突变体方法来鉴定与金黄色葡萄球菌和马红球菌协同溶血（类CAMP现象）相关的李斯特菌溶细胞因子。一株产单核细胞李斯特菌非溶血突变体，其溶菌酶O（LLO）产生受到特异性损害，与金黄色葡萄球菌无CAMP反应，与马红球菌几乎呈CAMP阴性，表明李斯特菌巯基激活毒素在协同溶血症中起主要作用。在扩散CAMP试验中使用纯化的LLO和肺泡溶血素（来自肺泡芽孢杆菌）的直接证据证实了这一点。据我们所知，这是巯基激活毒素参与协同溶解过程的首个证据。产单核细胞李斯特菌的磷脂酰胆碱和磷脂酰肌醇特异性磷脂酶C似乎对协同溶血没有显著贡献，因为相应的突变体表现出野生型CAMP反应。相比之下，伊氏李斯特菌的鞘磷脂酶C是导致该李斯特菌种与马红球菌出现特征性铲形CAMP反应的溶细胞因子。文中讨论了溶解协同作用的可能机制。
