AUTHOR=Zhang Yongxiong , Gu Haiying , Shi Zhouhong , Chen Weiqin , Li Airu , Ye Weiwei , Zhang Cheng , Yuan Huikun , Zhao Mingming 

TITLE=High prevalence of Helicobacter pylori mixed infections identified by multilocus sequence typing in Ningbo, China

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1207878

DOI=10.3389/fmicb.2023.1207878

ISSN=1664-302X

ABSTRACT=<p>This study used multilocus sequence typing (MLST) to investigate the prevalence of <italic>Helicobacter pylori</italic> (<italic>H. pylori</italic>) mixed infections and <italic>H. pylori</italic> mixed infections involving unrelated strains; and determined the phylogeographic groups of <italic>H. pylori</italic> recovered from patients in Ningbo, China. A total of 156 <italic>H. pylori</italic> isolates were obtained from a convenience sample of 33 patients with culture-positive <italic>H. pylori</italic> infection. MLST was used to classify 150 <italic>H. pylori</italic> clinical isolates and 12 methodological control strains (6 clinical isolates and 6 strains of American Type Culture Collection <italic>H. pylori</italic>) into 43 and 12 sequence types (STs), respectively. In this study, 246 new alleles and 53 new STs were identified by MLST. The prevalence of mixed infections was 41% (11/27). The prevalence of <italic>H. pylori</italic> mixed infections involving unrelated strains was 46% (5/11) and the prevalence of <italic>H. pylori</italic> mixed infections involving completely unrelated strains (strains with all 7 housekeeping genes different) was 36% (4/11). A phylogenetic tree was created to determine the evolutionary relationships between different strains. The STs in this study were clustered within the hspEAsia subgroup (98%) and hpEurope group (2%). <italic>H. pylori</italic> mixed infections were common in Ningbo, China. The <italic>H. pylori</italic> isolates belonging to the hpEurope group were recovered from three different biopsy samples in a native Chinese patient. Most of <italic>H. pylori</italic> strains colonizing the antrum, corpus, and duodenum bulb were homologous.</p>