Where to Biopsy to Detect and How Many Biopsies Are Needed to Detect Antibiotic Resistance in a Human Stomach.

This study aims to determine the gastric distribution, density, and diversity of infection. Subtotal resection of the stomachs of three -infected and asymptomatic obese patients were collected after a sleeve gastrectomy. Distribution and density of were determined using culture and RT-PCR on multiple gastric sites (88, 176, and 101 biopsies per patient). Diversity of strains was studied using antibiotic susceptibility testing, random amplified polymorphism DNA (RAPD) typing and gene detection on single-colony isolates (44, 96, and 49 isolates per patient). was detected in nearly all analyzed sites (354/365 biopsies, 97%). Antral density was higher in one patient only. The three stomachs were almost exclusively infected by an antibiotic-susceptible strain. One clarithromycin-resistant isolate in one biopsy was detected in two stomachs (1/44 and 1/49 isolates), while in the third one, eight (8/96 isolates) metronidazole-resistant isolates were detected. DNA typing showed infection with -negative strains for one patient, -positive strains for a second patient and the third patient was infected with two different strains of distinct genotypes. Infection with is shown to spread to the whole surface of the stomach, but a possibility of minor sub-population of antibiotic-resistant clones, undetectable in routine practice.