Al-Mahmeed Ali, Senok Abiola C, Ismaeel Abdulrahman Y, Bindayna Khalid M, Tabbara Khaled S, Botta Giuseppe A
Department of Microbiology, Immunology and Infectious Diseases, College of Medicine and Medical Sciences, Arabian Gulf University, PO Box 22979, Manama, Kingdom of Bahrain.
J Med Microbiol. 2006 Jul;55(Pt 7):839-843. doi: 10.1099/jmm.0.46500-0.
There are no data describing the genetic make-up of Campylobacter strains (an important aetiological agent of diarrhoea) circulating in the Arabian Gulf region. Here, the molecular characterization of two virulence genes in Campylobacter jejuni from Bahrain and the relationship with clinical infection are reported. Molecular screening for cytolethal distending toxin (cdtB) and invasion-associated marker (iam) genes was carried out on C. jejuni stool isolates collected from January 2002 to January 2004 in Bahrain. The molecular characterization was correlated with the patients' socio-demographic and clinical parameters. Of the 96 C. jejuni strains tested, 50 (52 %) were cdtB+/iam+, 30 (31 %) were cdtB+/iam- and 16 (17 %) were cdtB-/iam-. Sixty-nine per cent (66/96) of patients were less than 3 years old, with significantly higher detection of cdtB+/iam+ and cdtB+/iam- strains (P < 0.001 and P < 0.01, respectively) in this age group. Seventy patients (73 %) were symptomatic. In the group that were less than 3 years old, 62 and 85 % of those with cdtB+/iam+ and cdtB+/iam- strains, respectively, were symptomatic compared with 100 % for those over 3 years of age. However, the presence of cdtB-/iam- strains still resulted in clinical infection in the children under 3 years but not in the older patients. This is the first report describing the molecular characterization of virulence genes in Campylobacter isolates from this region. The findings indicate that strains of different virulence genetic make-up are circulating in the population, with children under the age of 3 years being most vulnerable. Further work on the molecular characterization, gene expression and determination of the invasive phenotypes of C. jejuni strains circulating in different regions is needed.
目前尚无关于在阿拉伯湾地区传播的弯曲杆菌菌株（腹泻的一种重要病原体）基因组成的数据。在此，报告了来自巴林的空肠弯曲杆菌中两个毒力基因的分子特征及其与临床感染的关系。对2002年1月至2004年1月在巴林收集的空肠弯曲杆菌粪便分离株进行了细胞致死性膨胀毒素（cdtB）和侵袭相关标志物（iam）基因的分子筛查。分子特征与患者的社会人口统计学和临床参数相关。在检测的96株空肠弯曲杆菌菌株中，50株（52%）为cdtB+/iam+，30株（31%）为cdtB+/iam-，16株（17%）为cdtB-/iam-。69%（66/96）的患者年龄小于3岁，该年龄组中cdtB+/iam+和cdtB+/iam-菌株的检出率显著更高（分别为P < 0.001和P < 0.01）。70名患者（73%）有症状。在年龄小于3岁的组中，cdtB+/iam+和cdtB+/iam-菌株的患者分别有62%和85%出现症状，而3岁以上患者的这一比例为100%。然而，cdtB-/iam-菌株的存在仍导致3岁以下儿童发生临床感染，但在年龄较大的患者中未出现这种情况。这是第一份描述该地区弯曲杆菌分离株毒力基因分子特征的报告。研究结果表明，不同毒力基因组成的菌株在人群中传播，3岁以下儿童最为易感。需要进一步开展关于不同地区传播的空肠弯曲杆菌菌株的分子特征、基因表达和侵袭表型测定的研究。
