畜牧兽医学报2025，Vol.56Issue(4)：1934-1946,13.DOI:10.11843/j.issn.0366-6964.2025.04.040
生牛乳中金黄色葡萄球菌异质性耐药及机制研究
Investigation of Heteroresistance and Its Mechanism of Staphylococcus aureus in Raw Milk
摘要
Abstract
This experiment was conducted to study the drug resistances of Staphylococcus aureus isolated from raw milk,the prevalence of heteroresistance of Staphylococcus aureus and explore the mechanism of heteroresistance.Thirty-six Staphylococcus aureus isolates were isolated from 179 batches of raw milk collected from Northeast,North China,East China,South China,Northwest and Southwest.The sensitivity and resistance of Staphylococcus aureus were identi-fied using broth microdilution method.The combination of disk diffusion method and E-test method was used to screen suspected heteroresistant strains from strains with sensitive pheno-types,and then the suspected heteroresistant strains were confirmed by Population analysis profi-ling(PAP).The stability of the heteroresistant phenotype after serial passage was measured.Fi-nally,whole-genome sequencing and whole genome re-sequencing analysis were used to deter-mine the heteroresistant mechanisms.The results showed that 36 strains of Staphylococcus au-reus were resistant to β-lactam antibiotics,the resistant rate to ranges from 11.11％ to 61.11％,and had high sensitivity to tetracycline and aminoglycoside antibiotics.19 combinations of Staph-ylococcus aureus and antibiotics with heteroresistant were identified through initial screening,and it was confirmed that the 3 combinations exhibited heteroresistant phenotypes,of which only amoxicillin-clavulanate-J23 heteroresistant stabled after serial passage.This study demonstrates that S.aureus of raw milk origin is high resistant to β-lactam and quinolone antimicrobials.Het-eroresistant mechanisms to amoxicillin-clavulanic acid are associated with blaZ and metal β-lacta-mase expression.Heteroresistant mechanisms to tetracyclines is associated with tetracycline ef-flux pumps and resistance proteins.关键词
生牛乳/金黄色葡萄球菌/异质性耐药/耐药亚群/全基因组学Key words
raw milk/S.aureus/heteroresistant/resistant subpopulations/whole-genome se-quencing分类
农业科技引用本文复制引用
和晓兰,赵艳坤,孟璐,刘慧敏,高姣姣,郑楠..生牛乳中金黄色葡萄球菌异质性耐药及机制研究[J].畜牧兽医学报,2025,56(4):1934-1946,13.基金项目
国家重点研发计划(2022YFD1301000) （2022YFD1301000）
国家现代农业产业技术体系(CARS36) （CARS36）
农产品质量安全风险评估(GJFP20220304) （GJFP20220304）
中国农业科学院科技创新工程(ASTIP-IAS12) （ASTIP-IAS12）
天山创新团队(2022D14016) （2022D14016）
新疆奶产业技术体系专项经费资助(XJARS-11) （XJARS-11）
