AUTHOR=Xiao Jia , Cheng Yiluo , Zhang Wenting , Lu Qin , Guo Yunqing , Hu Qiao , Wen Guoyuan , Shao Huabin , Luo Qingping , Zhang Tengfei 

TITLE=Genetic characteristics, antimicrobial susceptibility, and virulence genes distribution of Campylobacter isolated from local dual-purpose chickens in central China

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2023.1236777

DOI=10.3389/fcimb.2023.1236777

ISSN=2235-2988

ABSTRACT=<p>Food-borne antibiotic-resistant <italic>Campylobacter</italic> poses a serious threat to public health. To understand the prevalence and genetic characteristics of <italic>Campylobacter</italic> in Chinese local dual-purpose (meat and eggs) chickens, the genomes of 30 <italic>Campylobacter</italic> isolates, including 13 C<italic>. jejuni</italic> and 17 C<italic>. coli</italic> from Jianghan-chickens in central China, were sequenced and tested for antibiotic susceptibility. The results showed that CC-354 and CC-828 were the dominant clonal complexes of <italic>C. jejuni</italic> and <italic>C. coli</italic>, respectively, and a phylogenetic analysis showed that three unclassified multilocus sequence types of <italic>C. coli</italic> were more closely genetically related to <italic>C. jejuni</italic> than to other <italic>C. coli</italic> in this study. Of the six antibiotics tested, the highest resistance rates were to ciprofloxacin and tetracycline (100%), followed by lincomycin (63.3%), erythromycin (30.0%), amikacin (26.7%), and cefotaxime (20.0%). The antibiotic resistance rate of <italic>C. coli</italic> was higher than that of <italic>C. jejuni</italic>. The GyrA T86I mutation and 15 acquired resistance genes were detected with whole-genome sequencing (WGS). Among those, the GyrA T86I mutation and <italic>tet(O)</italic> were most prevalent (both 96.7%), followed by the <italic>blaOXA</italic>-type gene (90.0%), <italic>ant(6)-Ia</italic> (26.7%), <italic>aac(6’)-aph(3’’)</italic> (23.3%), <italic>erm</italic>(B) (13.3%), and other genes (3.3%). The ciprofloxacin and tetracycline resistance phenotypes correlated strongly with the GyrA T86I mutation and <italic>tet(O)</italic>/<italic>tet(L)</italic>, respectively, but for other antibiotics, the correlation between genes and resistance phenotypes were weak, indicating that there may be resistance mechanisms other than the resistance genes detected in this study. Virulence gene analysis showed that several genes related to adhesion, colonization, and invasion (including <italic>cadF</italic>, <italic>porA</italic>, <italic>ciaB</italic>, and <italic>jlpA</italic>) and cytolethal distending toxin (<italic>cdtABC</italic>) were only present in <italic>C. jejuni</italic>. Overall, this study extends our knowledge of the epidemiology and antibiotic resistance of <italic>Campylobacter</italic> in local Chinese dual-purpose chickens.</p>