Al-Shaikh Sana A, Senok Abiola C, Ismaeel Abdulrahman Y, Botta G A
Department of Microbiology, Immunology & Infectious Diseases, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain.
Acta Microbiol Immunol Hung. 2007 Jun;54(2):139-50. doi: 10.1556/AMicr.54.2007.2.4.
The association between putative virulence genes in Campylobacter jejuni clinical isolates, in vitro invasive capability and severity of infection is yet to be clearly described. We have characterized three virulence genes and correlated their presence with the severity of infection and in vitro invasiveness. We studied eight C. jejuni strains isolated from patients whose clinical data were scored to determine severity of infection. Cytolethal distending toxin (cdtB), invasion associated marker (iam) and Campylobacter invasion antigen (ciaB) genes were detected by PCR and INT407 cells used for invasion assays. Two strains positive for all three genes were the most invasive and isolated from patients with the most severe infection. Four strains positive for two genes and two strains negative for all the three genes were identified. The two cdtB(+ve)/ciaB(+ve) strains were more invasive than the cdtB(+ve)/iam(+ve) strains. One of the cdtB(-ve)/ciaB(-ve) strains showed invasion levels similar to cdtB(+ve)/ciaB(+ve) strains, but the second strain had a non-invasive phenotype. The findings indicate a correlation between in vitro invasive capability, and the presence of all three genes. The pattern of association between invasiveness and molecular characterization suggests that the ciaB gene confers a more invasive capability.
空肠弯曲菌临床分离株中假定的毒力基因、体外侵袭能力与感染严重程度之间的关联尚未得到清晰描述。我们已对三个毒力基因进行了特征分析，并将它们的存在情况与感染严重程度及体外侵袭性相关联。我们研究了从患者体内分离出的八株空肠弯曲菌菌株，这些患者的临床数据经过评分以确定感染的严重程度。通过聚合酶链反应（PCR）检测细胞致死扩张毒素（cdtB）、侵袭相关标志物（iam）和弯曲菌侵袭抗原（ciaB）基因，并使用INT407细胞进行侵袭试验。所有三个基因均呈阳性的两株菌株侵袭性最强，且是从感染最严重的患者体内分离得到的。鉴定出四株两个基因呈阳性的菌株和两株所有三个基因均呈阴性的菌株。两株cdtB（阳性）/ciaB（阳性）菌株比cdtB（阳性）/iam（阳性）菌株更具侵袭性。一株cdtB（阴性）/ciaB（阴性）菌株的侵袭水平与cdtB（阳性）/ciaB（阳性）菌株相似，但另一株菌株具有非侵袭表型。这些发现表明体外侵袭能力与所有三个基因的存在之间存在相关性。侵袭性与分子特征之间的关联模式表明ciaB基因赋予了更强的侵袭能力。
