Antimicrobial resistance profile in Helicobacter pylori isolates from Costa Rica

Helicobacter pylori infection relates to multiple gastric diseases, and its eradication is becoming more challenging due to antimicrobial resistance to commonly used antibiotics, especially clarithromycin. The aim of this study is to describe the antimicrobial susceptibility profiles of H. pylori isolates from Costa Rican patients.

Antimicrobial susceptibility was assessed for 14 H. pylori isolates using the E-test method for amoxicillin, clarithromycin, levofloxacin, metronidazole, tetracycline, and rifampicin. Due to its importance, the point mutations A2143G and A2144G related to clarithromycin resistance were also studied using PCR-RFLP.

Resistance to clarithromycin (29%), levofloxacin (29%), metronidazole (29%), and rifampicin (7%) was found in the studied isolates. These included three isolates with multidrug resistance. A2143G mutation was detected in one isolate and A2144G was detected in two isolates, and the presence of mutations correlated significantly with phenotypic resistance to clarithromycin (r=0.8321, p=0.0071).

Antibiotic resistance was high in the studied isolates from Costa Rica. The number of isolates is small, but the results highlight the need for further studies to assess the antibiotic resistance as a growing problem in the country. H. pylori culture and phenotypic tests are difficult, but molecular testing can be used as a quick and cheap option to monitor clarithromycin resistance.