Virulence Gene Profiling and Antibiotic Resistance Analysis of <i>Clostridium perfringens</i> from Farmed Sika Deer in Northern China

<i>Clostridium perfringens</i> is an important zoonotic pathogen that can be carried by both humans and small ruminants. This study aimed to investigate the virulence gene profiles and antibiotic resistance characteristics of <i>C. perfringens</i> isolates from farmed sika deer. A total of 10 isolates were obtained from fecal samples, with an overall isolation rate of 2.59%. All strains were identified as type A. Antimicrobial susceptibility testing revealed varying degrees of resistance to tetracycline (10%), tigecycline (50%), penicillin (50%), clindamycin (50%), and metronidazole (50%). Whole-genome sequencing identified 12 virulence-associated genes (including <i>nagK</i>, <i>nagH</i>, <i>colA</i>, <i>cloSI</i>, <i>plc</i>, and <i>pfoA</i>) and 8 resistance genes (<i>tetA</i>(P), <i>tetB</i>(P), <i>ermQ</i>, <i>mprF</i>, etc.). Molecular typing by multilocus sequence typing and core genome multilocus sequence typing uncovered limited clonal spread and substantial genetic diversity, with the majority of isolates (7/10) representing novel sequence types. These findings provide new insights into the genomic characteristics of <i>C. perfringens</i> in farmed sika deer and underscore the potential public health and animal health risks associated with antimicrobial-resistant strains.