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

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 is relatively limited compared to isolates from food and animals. The current study illustrated the prevalence and antimicrobial resistance profiles of and 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 strains (761 and 130 ) isolates collected, high portions above 90% of resistance to ciprofloxacin, nalidixic acid, and tetracycline were observed for both and . The most common MDR profiles represented by and 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 (59.23%) is higher than (2.50%). A total of 76 erythromycin resistant isolates (16 and 60 ) 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 and , respectively. Among the 76 erythromycin-resistant isolates, mutation A2075G in 23S rRNA and (B) gene were detected in 53.95 and 39.47%, respectively. The (B) gene was identified exclusively in 30 isolates. All these (B) positive isolates were multi-drug resistant. Furthermore, comparison of the (B)-carrying isolates of multiple sources worldwide demonstrated the possibility of zoonotic transmission of (B) in . These findings highlight the importance of continuous surveillance of erythromycin resistance dissemination in which may compromise the effectiveness of antimicrobial therapy.