Jeyamani Lavanya, Jayarajan Jayalakshmi, Leelakrishnan Venkatakrishnan, Swaminathan Mukundan
Department of Microbiology, Karpagam Faculty of Medical Sciences and Research, Coimbatore, Tamil Nadu, India.
Department of Microbiology and Gastroenterology, PSG Institute of Medical Science and Research, Coimbatore, Tamil Nadu, India.
Indian J Pathol Microbiol. 2018 Jan-Mar;61(1):66-69. doi: 10.4103/IJPM.IJPM_234_17.
: Helicobacter pylori is associated with the development of a variety of gastroduodenal diseases which varies with ethnicity and the type of strains that infect the population.
This study aims to evaluate the prevalence of H. pylori cagA and vacA genotypes in our region and to determine their relationship to the severity of the lesions that they cause.
: This study was an observational cross-sectional study.
DNA was extracted from 165 gastric biopsies from patients evaluated for dyspepsia. PCR was used to detect cagA and vacA (s1, s2, m1, m2) genes of H. pylori. Statistical analysis of associations was performed between endoscopy findings and virulence genes.
Pearson Chi-square test and Fischer's exact test.
The prevalence of H. pylori infection was 37% and the dominant genotypes was vacA s1 cagA-positive strain (54.1%) in this study. The vacAs1 subtype was found in all patients with peptic ulcer disease (PUD). The entire normal study group had VacA s2 variant only. This clearly shows that vacA s1 is a significant virulence marker and patients harboring s1 strains are more prone to develop ulcers (P = 0.007). There was a significant association of cagA with s1 strain rather than s2. Variation in VacA m genotype did not seem to have any association with disease status. There was a statistically significant association between the presence of cagA gene and PUD rather than the nonulcer dyspepsia (P = 0.027).
The predominant genotype in our population was cagA positive vacA s1, which was found to be significantly associated with patients with gastric diseases, especially PUD. VacA s1 can serve as a single best virulence marker of the disease manifestation.
幽门螺杆菌与多种胃十二指肠疾病的发生有关,其相关性因种族以及感染人群的菌株类型而异。
本研究旨在评估本地区幽门螺杆菌cagA和vacA基因型的流行情况,并确定它们与所引发病变严重程度的关系。
本研究为观察性横断面研究。
从165例因消化不良接受评估的患者的胃活检组织中提取DNA。采用聚合酶链反应(PCR)检测幽门螺杆菌的cagA和vacA(s1、s2、m1、m2)基因。对内镜检查结果与毒力基因之间的关联进行统计学分析。
Pearson卡方检验和Fisher精确检验。
本研究中幽门螺杆菌感染率为37%,优势基因型为vacA s1 cagA阳性菌株(54.1%)。在所有消化性溃疡病(PUD)患者中均发现了vacA s1亚型。整个正常研究组仅存在VacA s2变异型。这清楚地表明vacA s1是一个重要的毒力标志物,携带s1菌株的患者更容易发生溃疡(P = 0.007)。cagA与s1菌株而非s2菌株存在显著关联。VacA m基因型的变异似乎与疾病状态无任何关联。cagA基因的存在与PUD而非非溃疡性消化不良之间存在统计学显著关联(P = 0.027)。
我们研究人群中的主要基因型为cagA阳性vacA s1,发现其与胃部疾病患者,尤其是PUD患者显著相关。VacA s1可作为疾病表现的单一最佳毒力标志物。