Tu1341 Molecular Detection of Primary H. pylori Resistance to Clarithromycin and Fluoroquinolones in Brazil: A National Survey

Sanches, Bruno Squárcio Fernandes; Martins, Gustavo Luís Mamoré; Lima, Kauana Santos de; Cota, Bianca Della Croce Vieira; Moretzsohn, Luciana Dias; Ribeiro, Laércio Tenório; Breyer, Helenice Pankowski; Maguilnik, Ismael; Bessa, Alinne; Rezende-Filho, Joffre; Meira, Ana Carolina G.; Pinto, Henrique; Alves, Edson J.; Mascarenhas, Ramiro; Passos, Raissa I.; Souza, Julia Duarte de; Trindade, Osmar Reni; Coelho, Luiz G.

doi:10.1016/s0016-5085(16)32966-3

Cited by 12 publications

(19 citation statements)

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“…With the extensive implementation of eradication therapy, the resistance of H. pylori to antibiotics has been increasing year by year. 5 Other new mutation sites including T2115G, G2141A, T2190C, C2195T, A2223G, C2694A, 6 and A2144G 7 have also been mentioned in other areas. Some changes of H. pylori genes could result in the loss of antibiotics targets and thus induce bacterial resistance.…”

Section: Introductionmentioning

confidence: 99%

Molecular detection of H. pylori antibiotic‐resistant genes and molecular docking analysis

et al. 2019

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To explore the mutation characteristics of H. pylori resistance-related genes to antibiotics of clarithromycin (CAM), levofloxacin (LVX) and metronidazole, 23SrRNA, gyrA, gyrB, rdxA, and frxA genes were amplified and sequenced, respectively. Molecular docking study was performed to explore molecular interactions between chemotherapeutic agents and target proteins. In the CAM-resistant strains, the mutation rate in site A2143G was 74.2% (n = 23). The interactions in sites of G1949A, C1953T, and G2211T with CAM were weaker after mutation. In the LVX-resistant strains, the mutation rates in 87 (N to K/I) and 91 (D to N/Y/G) of gyrA were 28.6% (n = 16) and 12.5% (n = 7), respectively. We could infer by docking studies that N87 K/I, D91Y/G/N, D99N, and D143E mutations in GyrA protein all had weakened interaction with LVX. The mutation types of RdxA protein consisted of protein truncation caused by premature stop codons (n = 26, 33.3%), frameshift mutations (n = 8, 10.3%), FMN-binding sites (n = 16, 20.5%), and the others (n = 11, 14.1%).Docking analysis showed that some mutations in those four types of RdxA protein could reduce interaction with MNZ, and play a significant role in antibiotic resistance. What's more, we performed natural transformation with some of these mutated DNA fragments to see if they really impact susceptibility to antibiotics. Our study suggested that in addition to the reported mutation sites, H. pylori antibiotic resistance in this region may also be associated with changes in some new sites. Our study provides novel ideas and methods for the identification of H. pylori resistancerelated mutations, and also clues and basis for further investigation on specific molecular mechanism.

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Section: Introductionmentioning

confidence: 99%

Molecular detection of H. pylori antibiotic‐resistant genes and molecular docking analysis

et al. 2019

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“…However, several other mutations have been detected in A2144G, A2143C, and T2182C positions. Given the heterogeneous distribution of antibiotic resistance across different geographical areas, determining regional patterns of antibiotic resistance can help the physicians choose a valuable and specific treatment [11,12].…”

Section: Introductionmentioning

confidence: 99%

Molecular Assessment of Resistance to Clarithromycin in Helicobacter pylori Strains Isolated from Patients with Dyspepsia by Fluorescent In Situ Hybridization in the Center of Iran

Vazirzadeh

Falahi

Moghim

et al. 2020

BioMed Research International

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Background and Aims. Helicobacter pylori is a common infectious bacterium mostly found in gastroduodenal diseases. The increased prevalence of clarithromycin-resistant H. pylori strains is a major challenge in the successful treatment of infections caused by this organism. The present study is aimed at detecting the clarithromycin resistance pattern of H. pylori strains isolated from gastric biopsies and evaluating point mutations of the 23S rRNA gene. Patients and methods. In the present descriptive cross-sectional study, 165 patients with gastrointestinal disorders, who were referred to the Endoscopy Center of Dr. Shariati Hospital of Isfahan, Iran, were enrolled from April to July 2018. H. pylori infection was diagnosed by culture, and susceptibility of the isolates to clarithromycin was assessed by the E-test. Minimum inhibitory concentration (MIC) values were obtained based on EUCAST recommendations. Also, fluorescence in situ hybridization (FISH) was used to determine point mutations associated with clarithromycin resistance. Results. By using culturing, H. pylori was isolated from 50.3% (83/165) gastric biopsy specimens. The overall frequency of resistance to clarithromycin was 25.3% (21/83) by the E-test. In the resistance genotypic analysis, 19 isolates had mutations. The prevalence of A2143G and A2144G mutations was 68.4% (13/19) and 31.5% (6/19), respectively. A2143C mutation was not tracked in any isolate. Two isolates with MIC > 0:5 μg/mL had no mutations that could be related to other mechanisms of resistance. Conclusion. As presented in the study, the high prevalence of clarithromycin-resistant H. pylori due to point mutations of the 23S rRNA gene indicates the necessity of revising the standard treatment regimen based on antibiotic susceptibility pattern of each region.

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“…The Genotype HelicoDR (Hain Lifescience GmbH, Nehren, Germany), i.e. a multiplex PCR followed by reverse hybridization, was used with success in a large multicenter survey of antimicrobial resistance in Brazil, while a number of mutations associated with fluoroquinolone resistance were not specified . In contrast the results obtained from DNA extracted from stools for clarithromycin and fluoroquinolones in Ireland were not concordant with those from biopsy specimens …”

Section: Molecular Methodsmentioning

confidence: 99%

Diagnosis of Helicobacter pylori infection

et al. 2017

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Important progress is being made in endoscopic methods which allow clinicians to predict the presence of Helicobacter pylori based on characteristics of gastric mucosa and to obtain targeted biopsies. There are also important developments in molecular methods with various techniques derived from standard PCR, applied both on gastric biopsies and stool specimens. Progress is being made in microfluidic systems to get a reliable diagnosis in a very short time. The interest of the C urea breath test has been confirmed as well as stool antigen tests. Attempts are being made to find biological markers of premalignant conditions by serology, other than pepsinogens.

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Tu1341 Molecular Detection of Primary H. pylori Resistance to Clarithromycin and Fluoroquinolones in Brazil: A National Survey

Cited by 12 publications

References 0 publications

Molecular detection of H. pylori antibiotic‐resistant genes and molecular docking analysis

Molecular detection of H. pylori antibiotic‐resistant genes and molecular docking analysis

Molecular Assessment of Resistance to Clarithromycin in Helicobacter pylori Strains Isolated from Patients with Dyspepsia by Fluorescent In Situ Hybridization in the Center of Iran

Diagnosis of Helicobacter pylori infection

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