MOLECULAR DETECTION OF CLARITHROMYCIN AND FLUOROQUINOLONES RESISTANCE IN HELICOBACTER PYLORI INFECTION, DIRECTLY APPLIED TO GASTRIC BIOPSIES, IN AN URBAN BRAZILIAN POPULATION.
BACKGROUND
- Antimicrobial resistance is the major factor leading to eradication failure in H. pylori treatment. Molecular tests are useful to detect genetic mutations predictive of clarithromycin and fluoroquinolones resistance. Knowledge of the local prevalence rate of resistance is important to define the best recommended treatment.


OBJECTIVE
- To assess the prevalence of primary resistance of H. pylori to clarithromycin and fluoroquinolones, using a molecular test, in a Southeastern urban Brazilian population.


METHODS
- A total of 72 H. pylori seropositive patients [65% female, mean age 39 (19-73) years] never treated before for this infection were studied. All patients underwent gastroscopy in addition to antrum and corpus biopsies and molecular test GenoType HelicoDR (Hain Life Science, Germany) to detect H. pylori and point mutations in genes responsible for clarithromycin and fluoroquinolone resistance. The molecular procedure was divided into three steps: DNA extraction from biopsy samples, a multiplex amplification with biotinylated primers and a reverse hybridization. The most frequent point mutations involved in resistance to the two antibiotics were evaluated.


RESULTS
- Resistance to clarithromycin was detected in nine (12.5%) patients and to fluoroquinolones in eight (11.1%) patients. The point mutation A2147G was the most common (77.8%) among resistant strains to clarithromycin. In 50% of the resistant strains to fluoroquinolones, the mutant codon couldn't be identified.


CONCLUSIONS
- The resistance rates to clarithromycin and fluorquinolones in a large urban population in the Southeast of Brazil were acceptable, suggesting that these drugs remain appropriate options to first and second-line of H. pylori treatment. The molecular test represents an adequate diagnostic tool for monitoring H. pylori resistance.
Universidade Federal de Minas Gerais, Instituto Alfa de Gastroenterologia, Belo Horizonte, MG, Brasil., Universidade Federal de Minas Gerais, Universidade Federal de Minas Gerais, Instituto Alfa de Gastroenterologia, Belo Horizonte MG , Brazil.
Gustavo Miranda
GM
Martins
Universidade Federal de Minas Gerais, Instituto Alfa de Gastroenterologia, Belo Horizonte, MG, Brasil., Universidade Federal de Minas Gerais, Universidade Federal de Minas Gerais, Instituto Alfa de Gastroenterologia, Belo Horizonte MG , Brazil.
Bruno Squárcio Fernandes
BS
Sanches
Universidade Federal de Minas Gerais, Instituto Alfa de Gastroenterologia, Belo Horizonte, MG, Brasil., Universidade Federal de Minas Gerais, Universidade Federal de Minas Gerais, Instituto Alfa de Gastroenterologia, Belo Horizonte MG , Brazil.
Luciana Dias
LD
Moretzsohn
Universidade Federal de Minas Gerais, Instituto Alfa de Gastroenterologia, Belo Horizonte, MG, Brasil., Universidade Federal de Minas Gerais, Universidade Federal de Minas Gerais, Instituto Alfa de Gastroenterologia, Belo Horizonte MG , Brazil.
Karine Sampaio
KS
Lima
Universidade Federal de Minas Gerais, Instituto Alfa de Gastroenterologia, Belo Horizonte, MG, Brasil., Universidade Federal de Minas Gerais, Universidade Federal de Minas Gerais, Instituto Alfa de Gastroenterologia, Belo Horizonte MG , Brazil.
Bianca Della Croce V
BD
Cota
Universidade Federal de Minas Gerais, Instituto Alfa de Gastroenterologia, Belo Horizonte, MG, Brasil., Universidade Federal de Minas Gerais, Universidade Federal de Minas Gerais, Instituto Alfa de Gastroenterologia, Belo Horizonte MG , Brazil.
Luiz Gonzaga Vaz
LG
Coelho
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001706:Biopsy; D017291:Clarithromycin / Q000494:pharmacology* / Q000627:therapeutic use; D024881:Drug Resistance, Bacterial; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology* / Q000627:therapeutic use; D016481:Helicobacter Infections / Q000188:drug therapy / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D012307:Risk Factors; D014505:Urban Population; D055815:Young Adult
D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D017291:Clarithromycin