Primary antibiotic resistance and its relationship with cagA and vacA genes in Helicobacter pylori isolates from Algerian patients

Abstract

The epidemiology of Helicobacter pylori resistance to antibiotics is poorly documented in Africa and especially in Algeria. The aim of our study was to determine the antibiotic resistance rates, as well as its possible relationship with VacA and CagA virulence markers of isolates from Algerian patients. One hundred and fifty one H. pylori isolate were obtained between 2012 and 2015 from 200 patients with upper abdominal pain. Antimicrobial susceptibility testing was performed for amoxicillin, clarithromycin, metronidazole, ciprofloxacin, rifampicin and tetracycline. Molecular identification of H. pylori and the detection of vacA and cagA genes were performed using specific primers. We found that H. pylori was present in 83.5% of collected biopsies, 54.9% of the samples were cagA positive, 49.67% were vacA s1m1, 18.30% were vacA s1m2 and 25.49% were vacA s2m2. Isolates were characterized by no resistance to amoxicillin (0%), tetracycline (0%), rifampicin (0%), a high rate of resistance to metronidazole (61.1%) and a lower rate of resistance to clarithromycin (22.8%) and ciprofloxacin (16.8%). No statically significant relationship was found between vagA and cagA genotypes and antibiotic resistance results (p > 0.5) except for the metronidazole, which had relation with the presence of cagA genotype (p = 0.001).

Molecular diagnosis of Helicobacter pylori antibiotic resistance in the Taif region, Saudi Arabia

“…Unlike plasmids, point mutations are transmitted vertically because of selection pressure. Additionally, transformation may occur consequent to simultaneous infection by wild and mutant strains . Because they are fastidious organisms, it is difficult to assess phenotypic antibiotic susceptibility of H. Pylori in routine clinical practice.…”

“…The efficacy of H. pylori therapeutic eradication is declining globally because of the development of antibiotic resistance. 13,34 H. pylori has acquired resistance by point mutations to most of the antibiotics proposed for its eradication regimens. Unlike plasmids, point mutations are transmitted vertically because of selection pressure.…”

“…Additionally, transformation may occur consequent to simultaneous infection by wild and mutant strains. 34 Because they are fastidious organisms, it is difficult to assess phenotypic antibiotic susceptibility of H. Pylori in routine clinical practice. Hence, valid and accurate molecular methods for detecting its antimicrobial resistance have been developed.…”

The Importance of H. pylori Infection in Liver Diseases

“…This Gram-negative bacillus is resistant to the activity of gastric acid. Active, vegetative form of the bacteria is spiral, while the sporulation form is granular [1]. The bacterium contains stable DNA and a system of very effective DNA repair.…”

“…pylori is mainly present on the surface of epithelial cells of the mucosa, in the prepyloric part of the stomach. It has cilia allowing transport into intercellular spaces, and thanks to produced adhesins, it adheres to cell surface [1].…”