Coote J G, Stewart-Tull D E S, Owen R J, Bolton F J, Siemer Berit L, Candlish Denise, Thompson D H, Wardlaw A C, On S L W, Candlish A, Billcliffe Bronwen, Jordan Penelope J, Kristiansen K, Borman Pauline
Division of Infection and Immunity, Institute of Biomedical and Life Sciences, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow G12 8TA, UK.
Centre for Infections, Health Protection Agency Colindale, 61 Colindale Avenue, London NW9 5HT, UK.
J Med Microbiol. 2007 Jun;56(Pt 6):722-732. doi: 10.1099/jmm.0.47130-0.
Campylobacter jejuni is a major cause of human diarrhoeal disease, but specific virulence mechanisms have not been well defined. This blinded study was undertaken with 40 C. jejuni isolates from different sources to determine their haemolytic, cytotoxic and adhesion and invasion activities towards mammalian cells. The results were correlated with source of isolation and genetic makeup by amplified fragment length polymorphism (AFLP) typing. The isolates had variable degrees of haemolytic activity against rabbit erythrocytes and cytotoxicity towards CaCo-2, HeLa and Vero cells. The data indicated that the haemolytic and cytotoxic activities were due to separate factors. A range of cytotoxicity was exhibited, whereby some strains had no activity against the target cells and others had activity against all three cell lines. Certain strains had activity against CaCo-2 cells but little or no activity against the other cells, while others exhibited the opposite phenotype. The data suggested that the cytotoxicity assay with the different cell lines may have detected more than one cytotoxin. A wide variation between isolates was observed for both adherence and invasion with all three cell lines, yet, overall, the strains showed a significantly greater invasion capacity for CaCo-2. There was no clear relationship between source of isolation or disease manifestation and possession of statistically significantly higher levels of particular virulence-associated factors although, in some cases, a correlation between cytotoxicity and cell invasion was evident. Five AFLP clusters, each representing two to eleven isolates with similar profiles, were observed at the 90 % similarity level. Some AFLP groups contained isolates with a common serotype, but each group had C. jejuni isolates from more than one source with the exception of group IV, which contained only human isolates. Isolates with high cytotoxic activity against CaCo-2 cells were confined to groups I, III and IV and a group of unrelated strains (U). Group II isolates had uniformly low cytotoxicity. Isolates in groups I, V and U were more invasive for CaCo-2 cells than isolates in groups II, III and IV. The strain differences in cytotoxicity or invasion did not correlate with source of isolation.
空肠弯曲菌是人类腹泻疾病的主要病因，但具体的毒力机制尚未明确界定。本盲法研究采用来自不同来源的40株空肠弯曲菌分离株，以确定它们对哺乳动物细胞的溶血、细胞毒性以及黏附与侵袭活性。通过扩增片段长度多态性（AFLP）分型，将结果与分离来源和基因组成进行关联分析。这些分离株对兔红细胞具有不同程度的溶血活性，对CaCo-2、HeLa和Vero细胞具有细胞毒性。数据表明，溶血和细胞毒性活性是由不同因素导致的。呈现出一系列的细胞毒性，一些菌株对靶细胞无活性，而另一些菌株对所有三种细胞系均有活性。某些菌株对CaCo-2细胞有活性，但对其他细胞活性很小或无活性，而其他菌株则表现出相反的表型。数据提示，使用不同细胞系进行的细胞毒性测定可能检测到了不止一种细胞毒素。观察到所有三种细胞系的分离株在黏附与侵袭方面存在广泛差异，但总体而言，这些菌株对CaCo-2的侵袭能力明显更强。分离来源或疾病表现与具有统计学显著更高水平的特定毒力相关因子之间没有明确的关系，尽管在某些情况下，细胞毒性与细胞侵袭之间存在明显的相关性。在90%的相似性水平上观察到五个AFLP簇，每个簇代表两到十一个具有相似图谱的分离株。一些AFLP组包含具有共同血清型的分离株，但除了仅包含人类分离株的IV组外，每个组都有空肠弯曲菌分离株来自多个来源。对CaCo-2细胞具有高细胞毒性活性的分离株局限于I、III和IV组以及一组不相关的菌株（U）。II组分离株的细胞毒性一致较低。I、V和U组的分离株对CaCo-2细胞的侵袭性比II、III和IV组的分离株更强。细胞毒性或侵袭方面的菌株差异与分离来源无关。
