Bacitracin-resistant Staphylococcus aureus induced in chicken gut and in vitro under bacitracin exposure

Fan Zhang; Fangjia Liu; Xijing Sheng; Quan Liu; Luqing Cui; Zhengzheng Cao; Tianyu Hu; Donghua Li; Menghong Dai

doi:10.1016/j.micpath.2024.106666

Bacitracin-resistant Staphylococcus aureus induced in chicken gut and in vitro under bacitracin exposure

Microb Pathog. 2024 Apr 27:191:106666. doi: 10.1016/j.micpath.2024.106666. Online ahead of print.

Authors

Fan Zhang¹, Fangjia Liu¹, Xijing Sheng¹, Quan Liu¹, Luqing Cui¹, Zhengzheng Cao¹, Tianyu Hu¹, Donghua Li¹, Menghong Dai²

Affiliations

¹ The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China; MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan, 430070, China.
² The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China; MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan, 430070, China. Electronic address: daimenghong@mail.hzau.edu.cn.

PMID: 38685360
DOI: 10.1016/j.micpath.2024.106666

Abstract

It is common knowledge that prolonged and excessive use of antibiotics can lead to antimicrobial resistance. However, the characteristics and mechanism of resistant-bacteria induced by clinically recommended and prophylactic dose drugs remain largely unclear. This study aimed to observe the trends of drug resistance of the bacitracin-susceptible Staphylococcus aureus strain FS127 under exposure to bacitracin (BAC), which were induced in vitro and in chicken gut. Antimicrobial susceptibility testing was used to detect the susceptibility of S. aureus induced in vitro and in the chicken gut to gentamicin, chloramphenicol, tetracycline, doxycycline, penicillin and chloramphenicol. The research results showed that bacitracin could induce drug resistance in S. aureus both in vitro and in vivo. The bacitracin-resistance rate of S. aureus isolated from chicken gut was positively correlated with the dose and time of bacitracin administration. The findings revealed that bacitracin-resistant S. aureus induced in vivo had enhanced susceptibility to chloramphenicol but no such change in vitro. Meanwhile, RT-qPCR assay was used to detect the expression levels of vraD, braD, braR and bacA in typical strains with different bacitracin-resistance levels. It was found that BacA may play a key role in the bacitracin resistance of S. aureus. In conclusion, this work reveals the characteristics and mechanism of bacitracin-resistant S. aureus induced by bacitracin in vivo and in vitro respectively.

Keywords: Bacitracin; Chicken gut; Resistance characteristics; Resistance gene; Staphylococcus aureus.