College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan 430070, China.
Int J Mol Sci. 2021 Nov 11;22(22):12218. doi: 10.3390/ijms222212218.
The evolution of resistance in to fluoroquinolones (FQs) under a broad range of sub-inhibitory concentrations (sub-MICs) has not been systematically studied. This study investigated the mechanism of resistance development in serovar Enteritidis (. Enteritidis) under sub-MICs of 1/128×MIC to 1/2×MIC of enrofloxacin (ENR), a widely used veterinary FQ. It was shown that the resistance rate and resistance level of . Enteritidis varied with the increase in ENR concentration and duration of selection. qRT-PCR results demonstrated that the expression of outer membrane porin (OMP) genes, , and , were down-regulated first to rapidly adapt and develop the resistance of 4×MIC, and as the resistance level increased (≥8×MIC), the up-regulated expression of efflux pump genes, , amd , along with mutations in quinolone resistance-determining region (QRDR) gradually played a decisive role. Cytohubba analysis based on transcriptomic profiles demonstrated that , , , , , , , , and were the hub genes for the FQs resistance. The 'de novo' IMP biosynthetic process, purine ribonucleoside monophosphate biosynthetic process and purine ribonucleotide biosynthetic process were the top three biological processes screened by MCODE. This study first described the dynamics of FQ resistance evolution in under a long-term selection of sub-MICs of ENR in vitro. In addition, this work offers greater insight into the transcriptome changes of . Enteritidis under the selection of ENR and provides a framework for FQs resistance of for further studies.
氟喹诺酮类药物（FQs）在广泛的亚抑制浓度（sub-MICs）下的耐药性演变尚未得到系统研究。本研究在恩诺沙星（ENR）的 1/128×MIC 至 1/2×MIC 等亚 MIC 浓度下，研究了肠炎沙门氏菌（. Enteritidis）耐药性发展的机制，ENR 是一种广泛应用于兽医的 FQ。结果表明，肠炎沙门氏菌的耐药率和耐药水平随 ENR 浓度的增加和选择时间的延长而变化。qRT-PCR 结果表明，外膜孔蛋白（OMP）基因 、 、 和 的表达首先下调，以快速适应和发展 4×MIC 的耐药性，随着耐药水平的增加（≥8×MIC），外排泵基因 、 、 和 的上调表达以及喹诺酮耐药决定区（QRDR）的突变逐渐起决定性作用。基于转录组谱的 Cytohubba 分析表明， 、 、 、 、 、 、 和 是 FQs 耐药的枢纽基因。“从头”IMP 生物合成过程、嘌呤核糖核苷酸单磷酸生物合成过程和嘌呤核糖核苷酸生物合成过程是 MCODE 筛选的前三个生物学过程。本研究首次描述了肠炎沙门氏菌在体外长期选择恩诺沙星亚 MIC 下 FQ 耐药性的演变动态。此外，这项工作深入了解了恩诺沙星选择下肠炎沙门氏菌的转录组变化，并为进一步研究肠炎沙门氏菌的 FQs 耐药性提供了框架。
