Antibiotic resistance and resistance mechanism of Corynebacterium kroppenstedtii isolated from patients with mastadenitis
AbstractTo investigate the antibiotic resistance and resistance mechanism ofCorynebacterium kroppenstedtii (C. kroppenstedtii) isolated from patients with mastadenitis. NinetyC. kroppenstedtii clinical isolates were obtained from clinical specimens in 2018 –2019. Species identification was performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antimicrobial susceptibility testing was performed by the broth microdilution method. The resistance genes were detected using PCR and DNA sequencing. The results of anti microbial susceptibility testing indicated that the resistance rates ofC. kroppenstedtii to erythromycin and clindamycin, ciprofloxacin, tetracycline, and trimethoprim-sulfamethoxazole were 88.9%, 88.9%, 67.8%, 62.2%, and 46.6%, respectively. None of theC. kroppenstedtii isolates was resistant to rifampicin, linezolid, vancomycin, or gentamicin. The gene oferm(X) was detected in all clindamycin and erythromycin-resistant strains. The gene ofsul(1) andtet(W) were detected among all trimethoprim sulfamethoxazole-resistant strains and tetracycline-resistant strains, respectively. Furthermore, 1 or 2 amino acid mutations (mainly single mutation) were observed in thegyrA gene among ciprofloxacin-resistant strains.