Occurrence of Virulent Strains of Helicobacter Pylori and Its association with Endoscopic findings in a Tertiary Centre Teaching Hospital in Chennai

Anand, V (2014) Occurrence of Virulent Strains of Helicobacter Pylori and Its association with Endoscopic findings in a Tertiary Centre Teaching Hospital in Chennai. Masters thesis, Kilpauk Medical College, Chennai.

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Abstract

INTRODUCTION: Helicobacter pylori is a Gram-negative organism which ismicroaerophilic, It is slow-growing, processing flagella and is spiral-shaped.It can survive in an acid environment of the human gastric mucosa. It is the most common cause of gastritis caused by bacterial infection. Its incidence rate is as high as 50% worldwide. In World Health Organization classification, it comes under type 1 carcinogen. It causes acid peptic disease, carcinoma of stomach, and mucosa-associated lymphoid tissue lymphomas(MALT). AIM OF THE STUDY: 1. To identify the mucosal patterns of H. pylori associated gastritis using video upper G.I endoscopy. 2. To determine the association of virulence genes of H. pylori to that of the mucosal changes on endoscopy and histopathology. MATERIALS AND METHODS: This is a hospital based cross-sectional study conducted in the Department of Digestive Health and Diseases (DDHD), Government peripheral hospital, Chennai from December 2012 to January 2014. Patients with Active peptic ulcer disease, Confirmed history of peptic ulcer, Gastric MALT-lymphoma, Following endoscopic resection of early gastric cancer, Uninvestigated dyspepsia were included. Functional dyspepsia, GERD, Persons using NSAIDs, Current or recent use of medications such as antibiotics, bismuth-containing compounds, or acid inhibitors, especially PPIs were excluded. Helicobacter pylori testing by rapid urease test and histological examination by antral biopsy done using gastroscopy. Patients with positive or negative rapid urease test were subjected for molecular characterisation by PCR targeting glmm for presence of H.Pylori. glmm positive specimen were analysed for presence of cag and vac genes by PCR. RESULTS: In the study population of 147, 59 patients were positive for H. pylori diagnosed by the presence of genetic studies. Out of the 59 patients Type 1 and 2 gastritis were seen in 5 patients, while Type 3 and 4 gastritis were seen in 27 patients thus indicating a more severe gastritis seen in individuals infected with H. pylori. Ulcers were seen in 9 patients out of which duodenal ulcer was seen in 7 patients while there were 2 patients with gastric ulcer. There were no mucosal abnormalities as observed on conventional endoscope in 18 patients. PCR positivity of glm gene of H. pylori was seen in 59(40%) patients of the study population, meanwhile the incidence of the virulence genes by the way of Cag positivity was seen in 6 patients, Vac positivity in 22 patients and both virulence genes were seen in 31 .Among patients with Vac positivity the subtype s1m2 constituted 50% while s1m1 was seen in 37.7%, both were seen in 11.3% of individuals. In the VacA positive group precancerous lesions i.e., atrophic gastritis and intestinal metaplasia were seen in 7 patients on subtyping 6 patients in s1m2and only one had both s1m1 and s1m2. In the Cag subgroup only one person had a precancerous lesion.In the subgroup who had both Cag and VacA genes, 22 had gastritis and 9 patients had precancerous lesion.There was significant correlation s1/m2 virulent gene of H. pylori to that of intestinal metaplasia and atrophic gastritis. In this study there was an insignificant difference in between PCR and RUT, thus confirming that RUT even though a cheap test is valuable in establishing the diagnosis of H. pylori in an office setting. CONCLUSION: Our study identified predominant type 3 and 4 mucosal pattern followed by type 1 and type 2. Also PCR correlates well with type 3 and type 4 pattern. Among the prevalence of virulent genes, Vac gene is most common than Cag, with the predominant subtype being s1m2. There was significant correlation of H. pylori virulent genes s1m2 to that of intestinal metaplasia and atrophic gastritis. In this study disease positivity of RUT is more or less equal with PCR, confirming that RUT is valuable in establishing the diagnosis of H. pylori.

Item Type: Thesis (Masters)
Additional Information: Reg.No.16112651
Uncontrolled Keywords: Mucosal patterns of H. pylori, Virulence genes of H. pylori, Endoscopy in H. pylori.
Subjects: MEDICAL > Gastroenterology
Depositing User: Subramani R
Date Deposited: 07 Mar 2020 05:20
Last Modified: 07 Mar 2020 05:20
URI: http://repository-tnmgrmu.ac.in/id/eprint/12164

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