Genetic and Drug Resistance Characteristics of <i>Campylobacter</i> Isolated — China, 2020–2023

<abstract abstract-type="Abstract"> <sec> <b>Introduction</b> This study aimed to characterize the genetic diversity and antimicrobial resistance patterns of <i>Campylobacter</i> isolates collected throughout China from 2020 to 2023. </sec><sec> <b>Methods</b> <i>Campylobacter</i> isolates analyzed in this study were obtained from the National Pathogen Identification Network Center database, maintained by the National Institute for Infectious Disease Control and Prevention of the Chinese Center for Disease Control and Prevention. Antimicrobial susceptibility testing (AST) was performed against eleven antimicrobial agents. Genomic characteristics were analyzed through comprehensive genome sequence analysis. </sec><sec> <b>Results</b> Between 2020 and 2023, the National Pathogen Identification Network documented 1,077 <i>Campylobacter jejuni</i> (<i>C. jejuni</i>) and 221 <i>Campylobacter coli</i> (<i>C. coli</i>) isolates. Most isolates originated from patients presenting with diarrhea. Antimicrobial susceptibility testing was conducted on 634 <i>C. jejuni</i> and 165 <i>C. coli</i> isolates. The tested isolates demonstrated high resistance rates to nalidixic acid (78.22%), ciprofloxacin (78.07%), and tetracycline (71.96%). Longitudinal analysis of antimicrobial susceptibility testing results revealed a declining resistance trend from 2020 to 2023. Whole genome sequences were obtained for 540 <i>C. jejuni</i> and 125 <i>C. coli</i> isolates within the database. Virulence factors and antibiotic resistance determinants were identified using the VFDB and CARD databases, respectively. Phylogenetic relationships were established through Snippy 4.0 software analysis based on core genome comparisons. </sec><sec> <b>Conclusions</b> This comprehensive analysis describes the antibiotic resistance profiles and genetic characteristics of <i>Campylobacter</i> isolates collected through the Identification Network Database from 2020 to 2023, establishing a foundational framework for campylobacteriosis control and prevention strategies in China. </sec>