鸡肉源沙门氏菌对喹诺酮和氟喹诺酮类抗生素耐药状况及相关基因

Drug resistance and related genes of chickenborne Salmonella to quinolone and fluoroquinolones

摘要:

摘要:【目的】研究分离于陕西、河南、四川和北京四省( 市) 鸡肉源沙门氏菌对喹诺酮和部分氟喹诺酮类抗生素的药敏性及相关耐药基因，更好地了解耐药性的产生和传播途径，确保食品安全。【方法】用琼脂稀释法测定沙门氏菌的药敏性，用PCR 和基因序列测定法确定耐药沙门氏菌中与(氟) 喹诺酮类抗生素耐药相关的喹诺酮类抗性决定区基因突变及质粒携带的耐药基因。【结果】390 株沙门氏菌中，63. 59% 的菌株对萘啶酮酸产生抗性，21. 28%、16. 67% 和14. 62% 的菌株分别对环丙沙星、左氧氟沙星和加替沙星产生抗性。248 株萘啶酮酸抗性菌中，aac(6’)-Ib-cr、qnrA、qnrB 和qnrS 基因的检出率分别为20. 16%、10. 89%、10. 08% 和1. 61%。83 株耐环丙沙星的菌株中，gyrA 和parC 基因的点突变共199 个;其中gyrA 基因中以Ser83Phe 和Asp87Gly 双突变最为常见，其次分别为Ser83Phe 和Asp87Asn 双突变、Ser83Tyr、Ser83Phe、Asp87Gly;parC 基因的65 个点突变均为Ser80Arg 突变。【结论】四省市中鸡肉源沙门氏菌耐药状况严重，其解旋酶和拓扑异构酶基因突变及质粒携带的耐药基因是导致沙门氏菌耐药的重要机制。

Abstract:

Abstract: ［Objective］ Antimicrobial susceptibility to quinolone and fluoroquinolones and the related genes of chickenborne Salmonella in Shaanxi，Henan， Sichuan and Beijing provinces were studied to better understand the development of antimicrobial resistance and routes of transmission to ensure food safety． ［Methods］ Antimicrobial susceptibility was tested according to agar dilution method． GyrA and parC gene mutations of quinolone resistance determination region (QRDR) of fluoroquinolone resistant Samonella and the resistant genes of qnrA，qnrB，qnrS and aac (6’) -Ib-cr were determined using PCR and DNA sequencing analysis． ［Result］ Among the 390 Salmonellae isolates，63. 59% were resistant to nalidixic acid，followed by ciprofloxacin (21. 28% ) ，levofloxacin (16. 67% ) ，and gatifloxacin(14. 62% ) ． Among 248 nalidixic acid resistant Salmonella， antimicrobial resistant genes carried by plasmid weredetected as aac(6’) -Ib-cr (20. 16% ) ，qnrA (10. 89% ) ，qnrB (10. 08% ) and qnrS (1. 61% ) ，respectively． In total 199 point mutations were detected in gyrA and parC of 83 fluoroquinolone-resistant Salmonella isolates． The most common mutations in gyrA gene was Ser83Phe and Asp87Gly double mutation，followed by Ser83Phe and Asp87Asn double mutation，Ser83Tyr，Ser83Phe，Asp87Gly． Sixty-five point mutations detected in parC was Ser80Arg ． ［Conclusion］Antimicrobial resistance of Salmonella recovered from chicken in the four provinces was common． Genetic elements including mutations of unwindase， topoisomerase， and plasmid with antimicrobial， played important roles in the antimicrobial resistance of Salmonella．