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|Title||Determination of cagA and vacA Genotypes and Evaluation of Clarithromycin Resistance of Helicobacter pylori Infections in Gaza Strip, Palestine|
|Title in Arabic||تحديد الطرز الجينية للبكتريا الملوية البوابية وتحديد مدى مقاومتها للكلاريثرومايسين للمرضى المصابين في قطاع غزة - فلسطين|
Helicobacter pylori is the most widely spread bacteria world wide, it infects more than half of the world population. It is associated with many different gastric and extra-gastric diseases. The bacterium was classified by the international agency for cancer research and the WHO as a definite class I carcinogen in 1994. The wide range of its pathogenicity may be due to host, environmental, and bacterial virulence factors. Some genes like the cagA and vacA are responsible for the pathogenicity of the organism. The vacA gene exhibits a highly mosaic and recombination between two different regions, the signal and the mid region which may be associated with the highly difference in associated disease in association with the host and environmental factors. Clarithromycin is the key component of treatment where the resistance to this antibiotic results in treatment failure. Therefore, the aim of this study was to determine the genotypes of vacA and cagA, and to evaluate clarithromycin resistance in H. pylori infected patients in Gaza strip. In order to achieve this goal, two different biopsy samples from different sites of the antrum were collected from 94 patients where just one biopsy sample was collected from seven patients. The first biopsy sample was extracted for PCR to determine the vacA and cagA genotypes. (The second biopsy was formalin-fixed and paraffin-embedded, five - 4 µ thick slides were used for FISH for clarithromycin resistance evaluation, the other two slides were used for Giemsa stain and Haematoxyline & Eosin stain for identification of H. pylori and histopathological assessment). Clinical diagnosis and clinical information were recorded from the index for every patient. The results of the study showed that the most predominant vacA was s2m2 (43.2%), and the gene cagA was present in 30.8% of infected cases. The frequency of mutations were found (3.9%: A2143G), (3.9%: A2144G), (0.0%: A2143C) and 19.6% were not typed by the most common three mutations (A2143G, A2144G and A2143C ) or the wild type. There is no statistically significant relationship between the H. pylori infection or genotypes of H. pylori and the clinical diagnosis of gastroscope. The results revealed that there was statistically significant correlation between H. pylori infection, and the degree of mucosal inflammation (P = 0.004). There is also statistically significant correlation between H. pylori infected patients and Whitehead degree of gastritis index (P = 0.032). Moreover there is statistically significant correlation between the genotype s1m1 and atrophy (P = 0.006), and almost close to Intestinal metaplasia (P = 0.052). In conclusion the genotypes of H. pylori cagA and vacA in Gaza strip are similar to that in our region (Egypt, Jordan, "Israel"). There was no statistically significant relationship between the genotypes of H. pylori and the clinical diagnosis of gastroscope and this may be due to other environmental or dietary factors.
|Publisher||the islamic university|
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