AUTHOR=Gao Fen , Tu Lihong , Chen Mingliang , Chen Hongyou , Zhang Xi , Zhuang Yuan , Luo Jiayuan , Chen Min 

TITLE=Erythromycin resistance of clinical Campylobacter jejuni and Campylobacter coli in Shanghai, China

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1145581

DOI=10.3389/fmicb.2023.1145581

ISSN=1664-302X

ABSTRACT=<p><italic>Campylobacter</italic> species are zoonotic pathogens, as well as the prevalent cause of foodborne bacterial gastroenteritis. The spread of antimicrobial-resistant strains poses a serious threat to global public health and attracts attention worldwide, but information about clinical <italic>Campylobacter</italic> is relatively limited compared to isolates from food and animals. The current study illustrated the prevalence and antimicrobial resistance profiles of <italic>Campylobacter jejuni</italic> and <italic>Campylobacter coli</italic> isolates collected from a consecutive surveillance program between 2012 and 2019 in Shanghai, China, using antimicrobial susceptibility testing and whole-genome sequencing. Among the 891 <italic>Campylobacter</italic> strains (761 <italic>C. jejuni</italic> and 130 <italic>C. coli</italic>) isolates collected, high portions above 90% of resistance to ciprofloxacin, nalidixic acid, and tetracycline were observed for both <italic>C. jejuni</italic> and <italic>C. coli</italic>. The most common MDR profiles represented by <italic>C. jejuni</italic> and <italic>C. coli</italic> were combination of ciprofloxacin, tetracycline, florfenicol and nalidixic acid (5.39%), and azithromycin, ciprofloxacin, erythromycin, gentamicin, tetracycline, clindamycin, nalidixic acid (28.46%), respectively. The erythromycin resistance of <italic>C. coli</italic> (59.23%) is higher than <italic>C. jejuni</italic> (2.50%). A total of 76 erythromycin resistant isolates (16 <italic>C. jejuni</italic> and 60 <italic>C. coli</italic>) were sequenced using Illumina platform for determining the genotypes, antimicrobial resistance patterns and phylogeny analysis. Multilocus sequence typing (MLST) analysis showed a high genetic diversity with 47 sequence types (STs), including 4 novel alleles and 12 new STs. The most abundant clonal complexes (CCs) were CC-403 (31.25%) and CC-828 (88.33%) for <italic>C. jejuni</italic> and <italic>C. coli</italic>, respectively. Among the 76 erythromycin-resistant isolates, mutation A2075G in 23S rRNA and <italic>erm</italic>(B) gene were detected in 53.95 and 39.47%, respectively. The <italic>erm</italic>(B) gene was identified exclusively in 30 <italic>C. coli</italic> isolates. All these <italic>erm</italic>(B) positive isolates were multi-drug resistant. Furthermore, comparison of the <italic>erm</italic>(B)-carrying isolates of multiple sources worldwide demonstrated the possibility of zoonotic transmission of <italic>erm</italic>(B) in <italic>Campylobacter</italic>. These findings highlight the importance of continuous surveillance of erythromycin resistance dissemination in <italic>Campylobacter</italic> which may compromise the effectiveness of antimicrobial therapy.</p>