Helicobacter pylori strains from a Nigerian cohort show divergent antibiotic resistance rates and a uniform pathogenicity profile

Abstract

Antibiotic resistance in Helicobacter pylori is a factor preventing its successful eradication. Particularly in developing countries, resistance against commonly used antibiotics is widespread. Here, we present an epidemiological study from Nigeria with 111 isolates. We analyzed the associated disease outcome, and performed a detailed characterization of these isolated strains with respect to their antibiotic susceptibility and their virulence characteristics. Furthermore, statistical analysis was performed on microbiological data as well as patient information and the results of the gastroenterological examination. We found that the variability concerning the production of virulence factors between strains was minimal, with 96.4% of isolates being CagA-positive and 92.8% producing detectable VacA levels. In addition, high frequency of bacterial resistance was observed for metronidazole (99.1%), followed by amoxicillin (33.3%), clarithromycin (14.4%) and tetracycline (4.5%). In conclusion, this study indicated that the infection rate of H. pylori infection within the cohort in the present study was surprisingly low (36.6%). Furthermore, an average gastric pathology was observed by histological grading and bacterial isolates showed a uniform pathogenicity profile while indicating divergent antibiotic resistance rates.

Duodenal ulcer promoting gene (DupA), plasticity region genes and sigma factors in H. pyloristrains from Nigeria

“…(Serum plates) were incubated in a microaerophilic condition (85% N2, 10% CO2, 5% O2) at 37 °C for minimum of 3 days after which the serum plates were examined for possible growth of Helicobacter pylori strains. Rapid urease test was used for biochemical confirmation of the isolates [15]. Biopsies were also sent for histological examination for cancer, ulcer, erosion, dysplasia, metaplasia, atrophy and inflammation.…”

“…The cycling conditions of PCR for the sigma factors were as follows: 95 °C for 5 minutes, then 30 cycles at 95 °C for 30 seconds, 50°C for 30 seconds and extension at 72 °C for 1 minute. Amplicon were separated using Agarose gel electrophoresis and viewed under UV light [15].…”

“…pylori strain J99 has been reported to harbour the genes jhp0914 to jhp0961 in a plasticity region and that the open reading frames ORFs in the plasticity region display diversity [14]. The jhp0917 and 0918 are tagged duodenal ulcer promoting gene (dupA) and encode homologues of virB ATPase, which is thought to be involved in DNA uptake, transfer and protein transfer [13,[15][16]. Many genes have also been reported in H. pylori that are associated with virulence including cagA, vacA, urease, flagellin and dupA, but there is little knowledge about the genetic and regulatory function in H. pylori virulence [16][17][18].…”

Helicobacter pylori Prevalence by Urea Breath Test in a Southwestern Nigerian Population

“…It is believed that at least 50% of the world's population currently harbors the organism [6] . Nigeria is believed to have the highest infection rate globally [9] but the prevalence obtained from different studies varies widely from 35.7% to 94.5% depending on the diagnostic method utilized in conducting the study [7,[10][11][12][13][14][15][16][17][18][19][20][21] . This wide disparity could have resulted from the differences in the sampling methods and the diagnostic accuracies of the tests used in the conduct of the studies.…”

Preparation and biological evaluation of metronidazole derivatives with monoterpenes and eugenol

“…Metronidazole was and still is a reliable antibacterial with no evidence of serious bacterial resistance issues . However, bacterial resistance for some pathogens such as H. pylori may occur . Other unwanted side‐effects and safety issues may also occur, even though it is known to be highly tolerable …”