福建地区鼠伤寒沙门菌喹诺酮耐药基因特征及MLVA分子分型  

Genetic characteristics of quinolone resistance and MLVA molecular typing of Salmonella typhimurium in the Fujian region

作　　者：邱玉锋 陈建辉[1] 黄梦颖[1] 徐海滨[1] 杨劲松[1,2] 翁顺太 QIU Yu-feng;CHEN Jian-hui;HUNG Meng-yin;XU Hai-bin;YANG Jin-song;WENG Shun-tai(Fujian Center for Disease Control and Prenetition,Fuzhou 350001,China;Fujian Provincial Key Laboratory of Zoonsis Disease Research Fuzhou)

机构地区：[1]福建省疾病预防控制中心,福建福州350001 [2]福建省人兽共患病研究重点实验室

出　　处：《中国病原生物学杂志》2021年第8期893-896,901,共5页Journal of Pathogen Biology

基　　金：福建省科技创新平台建设项目(No.2019Y2001);福建省卫计委青年课题(No.2017/1/21);福建省卫计委中青年骨干人才培养项目(No.2017-ZQN-20)。

摘　　要：目的了解福建地区鼠伤寒沙门菌喹诺酮耐药状况及其分子分型机制。方法采用微量肉汤稀释法测定萘啶酸、环丙沙星和左氧氟沙星对83株鼠伤寒沙门菌的最小抑菌浓度(MIC);PCR扩增沙门菌的喹诺酮耐药区(QRDR)基因(gyrA,parC)和质粒介导的喹诺酮耐药基因(PMQR)(aac(6’)-Ib-cr,oqxA,oqxB);采用多位点可变数目串联重复序列分析(MLVA)比较菌株间的遗传相似性。结果 83株鼠伤寒沙门菌对萘啶酸、环丙沙星和左氧氟沙星的耐药率分别为27.7%(23/83),13.2%(11/83)和4.8%(4/83),QRDR基因突变率为25.3%(21/83)。21株基因突变株存在gyrA和parC两个突变类型,突变氨基酸类型分别为Ser83Tyr、Ser83Phe、Asp87Tyr和Asp87Asn,其中以第87位氨基酸突变为主,占总突变数的52.4%(11/21)。parC基因突变菌1株,为第80位氨基酸突变Ser80Arg,该菌株同时为gyrA:Ser83Phe突变。PMQR基因(aac(6’)-Ib-cr,oqxA,oqxB)在83株鼠伤寒沙门菌中的检出率分别为20.5%(17/83)、15.7%(13/83)和16.9%(14/83)。72株鼠伤寒沙门菌经MLVA分型后遗传关联度介于42.3%~100%之间,按照100%的相似度可分为18个型别,其中次优势型MT5菌株耐药基因与MLVA分型表现出一定的关联性。结论福建地区鼠伤寒沙门菌对喹诺酮类药物的耐药率不高,但环丙沙星和左氧氟沙星中度敏感菌中存在耐药基因突变,并具有一定的聚集性,需继续加强检测。Objective To investigate the characteristics and molecular typing of quinolone resistance of Salmonella typhimurium in the Fujian region. Methods The minimal inhibitory concentration(MIC) of 83 strains of S. typhimurium against nalidixic acid, ciprofloxacin, and levofloxacin was determined using broth dilution. The determination of the MIC using broth microdilution was in accordance with CLSI guidelines and interpretations. QRDR genes(gyrA and parC) and PMQR genes(aac(6’)-ib-cr, oqxA, and oqxB) in S. typhimurium strains were detected using PCR, and the sites of mutations in the gyrA and parC genes were confirmed using sequencing. Molecular homology among strains was analyzed using multiple site tandem repeats(MLVA). Results The resistance of the 83 strains of S. typhimurium to nalidixic acid was 27.7%(23/83), their resistance to ciprofloxacin was 13.2%(11/83), and their resistance to levofloxacin was 4.8%(4/83). The rate of mutations in the QRDR gene was 25.3%(21/83), and no mutations were detected in strains susceptive to nalidixic acid, ciprofloxacin, and levofloxacin. Two mutations were found in gyrA and 2 were found in parC in the 21 mutant strains. The amino acid mutations in gyrA were Ser83 Tyr and Ser83 Phe those in parC were Asp87 Tyr and Asp87 Asn. The dominant mutation site was amino acid 87, which accounted for 52.4%(11/21) of the mutations. Only one strain had a mutation in the parC gene, Ser80 Arg at amino acid 80. The strain also had a gyrA: Ser83 Phe mutation. In 83 strains, the PMQR gene aac(6’)-ib-cr was detected at a rate of 20.5%(17/83), oqxA was detected at a rate of 15.7%(13/83), and oqxB was detected at a rate of 16.9%(14/83). MLVA typing indicated that the degree of genetic correlation of 72 strains of S. typhimurium ranged from 42.3 to 100%, and the strains were divided into 18 types in accordance with a level of similarity of 100%. Thirty of the strains belonged to dominant type MT1, and the drug resistance genes of MT5 strains were correlated with MLVA typing to an extent. Conclusion

关 键 词：鼠伤寒沙门菌 QRDR基因突变 PMQR基因 MLVA分子分型 

分 类 号：R378.22[医药卫生—病原生物学]