Molecular Subtyping and Antimicrobial Susceptibilities of Campylobacter coli Isolates from Diarrheal Patients and Food-Producing Animals in China

The aim of this study was to determine the molecular subtyping and antimicrobial susceptibility characteristics of Campylobacter coli isolates from different sources in China. One hundred thirteen C. coli isolates were subtyped by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and porA and flaA short variable region (SVR) nucleotide sequences. Cluster analysis was performed based on the PFGE and sequence types (ST). Eighty-four PFGE patterns (SmaI) were observed in 113 isolates. Fifty-four STs (28 novel) and three clonal complexes (CC), 86% of which were clustered to CC828, were observed, as well as 52 porA and 37 flaA-SVR sequence alleles. MLST, porA, and flaA-SVR analysis demonstrated that many isolates from diarrheal patients shared identical genotypes with chicken isolates. Minimum inhibitory concentration values of 10 antibiotics were analyzed for 109 isolates isolated in 2011 using the E-test method. The most frequently observed resistance agents were nalidixic acid (100%) and ciprofloxacin (100%), followed by levofloxacin (99%), tetracycline (94%), metronidazole (93%), erythromycin (61%), streptomycin (72%), gentamicin (59%), ampicillin (50%), and chloramphenicol (29%). Multidrug resistance was detected in 108 of 109 C. coli isolates (99%).