Dataset Information

Current status of Helicobacter pylori resistance to Clarithromycin and Levofloxacin in Malaysia-findings from a molecular based study.

ABSTRACT:

Background

Resistance to clarithromycin and levofloxacin in Helicobacter pylori which resulted in treatment failures has become a major challenge for physicians worldwide. The resistance is mainly mediated by mutations in a specific domain of the 23S rRNA, gyrA and gyrB genes for clarithromycin and levofloxacin respectively. Hence in this study, we aimed to investigate the current status of H. pylori resistance in our hospital to these two antibiotics based on the molecular approach.

Materials and methods

Gastric biopsy samples were obtained from treatment-naïve patients. Bacterial genomic DNA was extracted using a commercial kit and continued with DNA amplification using polymerase chain reaction (PCR) with specific primers. The PCR amplicons were subjected to sequencing on 23S rRNA gene targeting nucleotide positions at 2,146, 2,147, 2,186 and amino acids at gyrA positions 87 and 91 and gyrB positions 436, 438, 481, 484 to investigate the possible mutations or polymorphisms of genes that lead to clarithromycin and levofloxacin resistance respectively.

Results

Sixty-one urease-positive gastric biopsy samples were studied. The findings revealed the primary resistance rates to clarithromycin was 14.8% and to levofloxacin was 3.3% in our current scenario based on detection of reported resistance-related mutations of A2147G and D91N in 23S rRNA and gyrA genes, respectively. Interestingly, we found a high rate of silent mutations of the gyrA codon 87Asn (32.8%, 20/61) and two polymorphisms of the gyrB D481E (16.4%, 10/61) and R484K (21.3%, 13/61). The role of these polymorphisms in gyrB remained to be elucidated whether the levels of levofloxacin resistance are related to the position/amino acid.

Conclusion

The primary resistance rate of H. pylori to clarithromycin has increased compared to the previous report in Malaysia. Therefore, molecular screening could aid and is important for the selection of antibiotics for H. pylori eradication therapies.

SUBMITTER: Puah SM

PROVIDER: S-EPMC8197033 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:IntroductionUnderstanding drug resistance is important in drug selection for Helicobacter pylori (H. pylori) eradication, and drug resistance data are lacking in Beijing.PurposeThis cross-sectional study aimed to isolate H. pylori from patients with gastroduodenal diseases and to analyze drug resistance to clarithromycin (CLA) and levofloxacin (LEV), which are used frequently in China.Patients and methodsOne hundred and seventy-six patients with gastroduodenal diseases undergoing gastroduodenoscopy were selected by convenient sampling. Gastric mucosa samples were cultured and sub-cultured using a new medium broth. Active H. pylori strains were confirmed by microscopy observation as Gram-negative curved bacilli with positive test results for urease, oxidase, and catalase, and H. pylori 16S rRNA amplification by polymerase chain reaction (PCR). CLA and LEV resistance was identified by minimum inhibitory concentration (MIC) tests and sequencing of 23S rRNA, gyrA, and gyrB genes.ResultsFrom the 176 clinical samples, 112 (112/176, 63.6%) were confirmed with H. pylori infection and 65 (65/176, 36.9%) active H. pylori strains were obtained and further confirmed by MIC assay. Overall, the rates of CLA-resistant and LEV-resistant mutations in the 112 samples were 50.9% and 33.0%, respectively. Mutation related to CLA resistance was A2143G in the 23S rRNA gene and mutations associated with LEV resistance were N87K, D91G, and D91Y in the gyrA gene. Of 112 samples, 22 (19.6%) presented dual resistance to CLA and LEV. Resistance of the H. pylori strains to CLA (r=0.846, P<0.001) and LEV (r=0.936, P<0.001) had a strong correlation in phenotypic and genotypic level.ConclusionThe results indicated that resistance of CLA and LEV is severe among patients with gastroduodenitis. A good consistency could be found as to drug resistance between genotypic or phenotypic assay, suggested extending the detection of H. pylori drug resistance from the MIC method to a genotypic assay.

Project description:BackgroundDue to increased prevalence of H. pylori antimicrobial resistance worldwide and more importantly the resistance patterns vary between different geographical regions, it is important to survey local H. pylori antibiotic resistance profile to provide physicians with more informed drug choices to better treat H. pylori infection. To our knowledge, this is the first study to examine the prevalence of antimicrobial resistance of H. pylori in Karnataka state of South India.ResultsA total of 113 H. pylori strains were isolated from gastric biopsies and tested: 81.4% were resistant to metronidazole, 54.9% were resistant to levofloxacin, 20.4% were resistant to clarithromycin, 5.3% were resistant to tetracycline and 7.1% were resistant to amoxicillin. Multidrug resistance was detected in 59.3% of total isolated strains, among which 86.6% were resistant to at least both metronidazole and levofloxacin. In this study, 38 out of 113 H. pylori strains had been whole-genome sequenced. Based on the draft genomes, RdxA and/or FrxA inactivation mutations were found to present in 75% of metronidazole-resistant strains. Clarithromycin-resistant strains had mainly A2143G and G2224A mutations in the 23 rRNA gene. While 87.1% levofloxacin-resistant strains had amino acid substitution mutations occurring predominantly at N87 and D91 in GyrA, novel mutations in the same protein including an insertion of five amino acid residues (QDNSV), immediately after the start codon, and a substitution mutation at R295 were identified.ConclusionHigh primary resistance to metronidazole and levofloxacin, and a modest occurrence of clarithromycin resistance were revealed in H. pylori strains isolated from Karnataka patients. Therefore metronidazole-, levofloxacin- and clarithromycin-based triple therapies are not suitable as first-line treatment in Karnataka. Both amoxicillin and tetracycline can still be used to eradicate H. pylori infection in this region. We also revealed novel mutations in GyrA protein that possibly contribute to H. pylori resistance in levofloxacin, which merit further investigations.

Project description:Background. Helicobacter pylori (H. pylori) is one of the most frequent and persistent bacterial infections that affect nearly half of the world's population. Antibiotic resistance is a constantly evolving process and local surveillance of antibiotic resistance is warranted to guide clinicians in their choice of therapy. The aim of this study was to establish a microarray-based detection to identify H. pylori infection, clarithromycin and levofloxacin susceptibility, and CYP2C19 genetic polymorphism and guide to potential choice of proton pump inhibitor (PPI), antibiotic administration for tailored H. pylori eradication therapy. Methods. By analyzing the sequence of human genomic CYP2C19?2 and CYP2C19?3 and mutations within the 23S rRNA and gyrA gene regions conferring clarithromycin and levofloxacin resistance, respectively, we developed a microarray for individual therapy detection of H. pylori infection. Plasmids were established as positive or limit of detection (LOD) reference materials. The specificity and sensitivity of the microarray had been performed. And a total of 1083 gastric biopsy samples were tested and the Kappa value had been calculated between the array and Sanger sequencing. We also analyzed the resistance to clarithromycin and levofloxacin in China, as well as the CYP2C19 polymorphisms. Results. The LOD of detecting H. pylori was 103 CFU/mL and human genome DNA was 2?ng/?L. The detection results of 1083 gastric biopsy samples showed that 691 (63.80%) were H. pylori positive, of which 266 (38.49%) were resistant to clarithromycin, 192 (27.79%) were resistant to levofloxacin, and 61 (8.83%) were resistant to both of them. For the type of CYP2C19 polymorphism, 412 (38.04%) were homozygous fast type (HomEM), 574 (53%) were heterozygous EM (HetEM), and 97 (8.96%) were poor metabolizer (PM). Conclusions. The proposed microarray-based detection has high specificity, sensitivity, and reproducibility for detecting the resistance of clarithromycin or levofloxacin as well as CYP2C19 polymorphism, which may help to improve the clinical eradication rate of H. pylori.

Project description:BackgroundThe prevalence of Helicobacter pylori antibiotic susceptibility in the Nepalese strains is untracked. We determined the antibiotic susceptibility for H. pylori and analyzed the presence of genetic mutations associated with antibiotic resistance in Nepalese strains.ResultsThis study included 146 consecutive patients who underwent gastroduodenal endoscopy in Kathmandu, Nepal. Among 42 isolated H. pylori, there was no resistance to amoxicillin and tetracycline. In contrast, similar with typical South Asian patterns; metronidazole resistance rate in Nepalese strains were extremely high (88.1 %, 37/42). Clarithromycin resistance rate in Nepalese strains were modestly high (21.4 %, 9/42). Most of metronidazole resistant strains had highly distributed rdxA and frxA mutations, but were relative coincidence without a synergistic effect to increase the minimum inhibitory concentration (MIC). Among strains with the high MIC, 63.6 % (7/11) were associated with frameshift mutation at position 18 of frxA with or without rdxA involvement. However, based on next generation sequencing data we found that one strain with the highest MIC value had a novel mutation in the form of amino acid substituted at Ala-212, Gln-382, Ile-485 of dppA and Leu-145, Thr-168, Glu-117, Val-121, Arg-221 in dapF aside from missense mutations in full-length rdxA. Mutations at Asn-87 and/or Asp-91 of the gyrA were predominantly in levofloxacin-resistant strains. The gyrB mutation had steady relationship with the gyrA 87-91 mutations. Although three (44.4 %) and two (22.2 %) of clarithromycin resistant strains had point mutation on A2143G and A2146G, we confirmed the involvement of rpl22 and infB in high MIC strains without an 23SrRNA mutation.ConclusionsThe rates of resistance to clarithromycin, metronidazole and levofloxacin were high in Nepalese strains, indicating that these antibiotics-based triple therapies are not useful as first-line treatment in Nepal. Bismuth or non-bismuth-based quadruple regimens, furazolidone-based triple therapy or rifabutin-based triple therapy may become alternative strategy in Nepal.