Antimicrobial Resistance of Helicobacter pylori in Gastric Biopsy Samples from Lima/Peru.

Background: Helicobacter pylori prevalence and gastric cancer rates are remarkably high in Peru. Effective antimicrobial regimens are essential for successful H. pylori eradication. We aimed at assessing antimicrobial resistance rates to first- and second-line therapeutic agents in H. pylori strains detected in gastric biopsy samples. Materials and Methods: Gastric biopsy samples (antrum and corpus) were collected from therapy-naive patients (n = 154). H. pylori presence in the samples was confirmed by histopathology. Genotypic resistance to clarithromycin and quinolones was determined by real-time PCR. Results: Histology results were 100% concordant with PCR results (97/154; 63% H. pylori-positive in both). In 6% (6/97) of the patients, we found discordant results of H. pylori infection in antrum and corpus samples from the same patient. Resistance rates to clarithromycin and quinolone were 34% (33/97) and 68% (56/82), respectively. Antimicrobial resistance to both antimicrobials was 30% (25/82). Conclusion: Antimicrobial resistance rates of H. pylori to clarithromycin and quinolones are very high in Lima, Peru. Many first- and second-line, empiric eradication regimens may not be recommended for Peruvian patients.

An assessment of drinking water contamination with Helicobacter pylori in Lima, Peru.

BACKGROUND: Helicobacter pylori is a gut bacterium that is the primary cause of gastric cancer. H. pylori infection has been consistently associated with lack of access to sanitation and clean drinking water. In this study, we conducted time-series sampling of drinking water in Lima, Peru, to examine trends of H. pylori contamination and other water characteristics. MATERIALS AND METHODS: Drinking water samples were collected from a single faucet in Lima's Lince district 5 days per week from June 2015 to May 2016, and pH, temperature, free available chlorine, and conductivity were measured. Quantities of H. pylori in all water samples were measured using quantitative polymerase chain reaction. Relationships between the presence/absence and quantity of H. pylori and water characteristics in the 2015-2016 period were examined using regression methods accounting for the time-series design. RESULTS: Forty-nine of 241 (20.3%) of drinking water samples were contaminated with H. pylori. Statistical analyses identified no associations between sampling date and the likelihood of contamination with H. pylori. Statistically significant relationships were found between lower temperatures and a lower likelihood of the presence of H. pylori (P < .05), as well as between higher pH and higher quantities of H. pylori (P < .05). CONCLUSIONS: This study has provided evidence of the presence of H. pylori DNA in the drinking water of a single drinking water faucet in the Lince district of Lima. However, no seasonal trends were observed. Further studies are needed to determine the presence of H. pylori in other drinking water sources in other districts in Lima, as well as to determine the viability of H. pylori in these water sources. Such studies would potentially allow for better understanding and estimates of the risk of infection due to exposure to H. pylori in drinking water.

Antibiotic resistance among Helicobacter pylori clinical isolates in Lima, Peru.

OBJECTIVES: Gastric carcinoma is the most common cancer and cause of cancer mortality in Peru. Helicobacter pylori, a bacterium that colonizes the human stomach, is a Group 1 carcinogen due to its causal relationship to gastric carcinoma. While eradication of H. pylori can help prevent gastric cancer, characterizing regional antibiotic resistance patterns is necessary to determine targeted treatment for each region. Thus, we examined primary antibiotic resistance in clinical isolates of H. pylori in Lima, Peru. MATERIALS AND METHODS: H. pylori strains were isolated from gastric biopsies of patients with histologically proven H. pylori infection. Primary antibiotic resistance among isolates was examined using E-test strips. Isolates were examined for the presence of the cagA pathogenicity island and the vacA m1/m2 alleles via polymerase chain reaction. RESULTS: Seventy-six isolates were recovered from gastric biopsies. Clinical isolates showed evidence of antibiotic resistance to 1 (27.6%, n=21/76), 2 (28.9%, n=22/76), or ≥3 antibiotics (40.8%). Of 76 isolates, eight (10.5%) were resistant to amoxicillin and clarithromycin, which are part of the standard triple therapy for H. pylori infection. No trends were seen between the presence of cagA, vacA m1, or vacA m2 and antibiotic resistance. CONCLUSION: The rate of antibiotic resistance among H. pylori isolates in Lima, Peru, is higher than expected and presents cause for concern. To develop more targeted eradication therapies for H. pylori in Peru, more research is needed to better characterize antibiotic resistance among a larger number of clinical isolates prospectively.