PCR-based genotyping of Helicobacter pylori of Gambian children and adults directly from biopsy specimens and bacterial cultures
نویسندگان
چکیده
BACKGROUND Helicobacter pylori is an important agent of gastroduodenal disease in Africa and throughout the world. We sought to determine an optimum method for genotyping H. pylori strains from children and adults in The Gambia, West Africa. RESULTS Virulence genes were amplified in 127 of 190 cases tested (121 adults and 6 children); each of 60 bacterial cultures, and 116 from DNA extracted directly from biopsies. The proportion of biopsies that were cagA+, the ratio of vacAs1/s2, and vacAm1/m2, and the proportion of mixed strain populations in individual subjects changed with age. Strains lacking virulence cagA and vacA genes and with apparently homogeneous (one predominant strain) infections were more common among infants than adults. CONCLUSIONS In order to detect the range of bacterial genotypes harbored by individual patients, direct PCR proved slightly superior to isolation of H. pylori by biopsy culture, but the techniques were complementary, and the combination of both culture and direct PCR produced the most complete picture. The seemingly higher virulence of strains from adult than infant infections in The Gambia merits further analysis.
منابع مشابه
PCR and RFLP Analysis for Identification and Typing of Helicobacter pylori Strains from Gastric Biopsy Specimens
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PCR and RFLP Analysis for Identification and Typing of Helicobacter pylori Strains from Gastric Biopsy Specimens
Helicobacter pylori is the causative agent of chronic gastritis and peptic ulcer diseases and is also a risk factor for gastric cancer. Since culture of Helicobacter pylori is relatively insensitive and cumbersome, PCR-based molecular detection and typing of this organism is gaining importance for strain differentiation. The aim of present study was to apply molecular methods for detection and ...
متن کاملMultiplex PCR assay for rapid detection and genotyping of Helicobacter pylori directly from biopsy specimens.
We developed and evaluated a simple, novel multiplex PCR assay for rapid detection of Helicobacter pylori infection and for the determination of vacA and cagA genotypes directly from gastric biopsy specimens. This assay did not require culturing of strains or extraction of DNA from biopsy samples. This multiplex PCR assay would be of particularly great value for laboratories in developing count...
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بررسی وجود ژن cagE در ایزوله های هلیکوباکترپیلوری جدا شده از بیماران مبتلا به زخمهای پپتیک، سرطان معده سو هاضمه های بدون زخم
Background and Purpose: Helicobacter pylori are a bacterial pathogen evolved to chronically colonize the gastric epithelium and causes gastritis, peptic ulcers, and even gastric malignancies in few infected humans. More recently, a pathogenicity island has been identified within the H. pylori genome that contains a cluster of genes, including cagE. The aim of the current study was to investig...
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عنوان ژورنال:
دوره 3 شماره
صفحات -
تاریخ انتشار 2011