目的:产气克雷伯菌是一种未充分研究的机会性病原体,可引起败血症并导致高死亡率。在这项研究中,我们报道了中国猪产气克雷伯菌的碳青霉烯类耐药blaOXA-181的发生,并阐明了其基因组特征。
方法:总共126个样本,包括109个猪粪便拭子,14个环境样本,从中国的一个养猪场收集了3个饲料样品。用LB肉汤培养物富集样品,然后接种到MacConkey琼脂板中用于细菌分离。PCR检测碳青霉烯酶基因后,携带blaOXA-181的分离株接受了抗菌药物敏感性测试,和全基因组序列分析。
结果:从猪粪便样品中获得了4种携带blaOXA-181基因的产气克雷伯菌分离株。4个菌株均属于ST438。blaOXA-181基因位于IncX3-ColKP3杂合质粒中,其核心遗传结构为IS26-ΔIS3000-ΔISECp1-blaOXA-181-ΔlysR-ΔerA-ΔrepA-ISKpn19-tinR-qnrS1-ΔIS2-IS26,这表明该抗性基因在其他细菌来源和肠源之间的水平转移和
结论:这项研究代表了中国从猪粪便中鉴定出生产OXA-181的产气K.保持持续监测和持续关注猪中携带blaOXA-181和其他抗性基因的产气K.
OBJECTIVE: Klebsiella aerogenes is a largely understudied opportunistic pathogen that can cause sepsis and lead to high mortality rates. In this study, we reported the occurrence of carbapenem-resistant blaOXA-181-carrying Klebsiella aerogenes from swine in China and elucidate their genomic characteristics.
METHODS: A total of 126 samples, including 109 swine fecal swabs, 14 environmental samples, and three feed samples were collected from a pig farm in China. The samples were enriched with LB broth culture and then inoculated into MacConkey agar plates for bacterial isolation. After PCR detection of carbapenemases genes, the blaOXA-181-carrying isolates were subjected to antimicrobial susceptibility testing, and whole-genome sequence analysis.
RESULTS: Four Klebsiella aerogenes isolates carrying the blaOXA-181 gene were obtained from swine faecal samples. All the 4 strains were belonged to ST438. The blaOXA-181 genes were located in IncX3-ColKP3 hybrid plasmids with the core genetic structure of IS26-ΔIS3000-ΔISEcp1-blaOXA-181-ΔlysR-ΔereA-ΔrepA-ISKpn19-tinR-qnrS1-ΔIS2-IS26, which suggests the potential for horizontal transfer and further dissemination of this resistance gene among Enterobacteriaceae and other sources.
CONCLUSIONS: This study represents the first instance of OXA-181-producing K. aerogenes being identified from swine faeces in China. It is crucial to maintain continuous monitoring and ongoing attention to the detection of K. aerogenes carrying blaOXA-181 and other resistance genes in pigs.