猪链球菌2型对氟喹诺酮类抗菌药耐药机制的初步研究  

Preliminary study on drug resistance mechanism of Streptococcus suis serotype 2 against fluoroquinolones

作　　者：李军[1] 何彩美[2,3] 陈泽祥[1] 禤雄标[1] 杨威[1] 胡庭俊[2] 胡帅[1] 马春霞[1] 许力干[1] 

机构地区：[1]广西兽医研究所广西畜禽疫苗新技术重点实验室,广西南宁530001 [2]广西大学动物科学技术学院,广西南宁530005 [3]来宾市动物疫病预防控制中心,广西来宾546100

出　　处：《中国预防兽医学报》2013年第4期280-284,共5页Chinese Journal of Preventive Veterinary Medicine

基　　金：广西自然科学基金(桂科自0991221);广西科技攻关项目(桂科攻0537008-3B;10100014-4)

摘　　要：为研究猪链球菌2型(S.suis 2)对氟喹诺酮类药物的耐药机制,本研究采用PCR和基因测序的方法分析氟喹诺酮类药物耐药诱导菌株的gyrA和parC喹诺酮耐药决定区(QRDR)。与亲本药物敏感菌株和自然耐药菌株相应的氨基酸序列对比,所有耐药诱导菌株GyrA QRDR均无特征性的氨基酸变异;而有62.5%耐药诱导菌株(5/8)的ParC QRDR在第83位氨基酸突变为赖氨酸。应用质子能驱动型外排泵抑制剂氰氯苯腙(CCCP)与氟喹诺酮类药物联合用药后,CCCP可以使耐药诱导菌株对药物的敏感性提高8倍～32倍。交叉耐药性结果显示,耐药诱导菌株获得了氟喹诺酮类药物交叉耐药。To investigate the mechanism of drug resistance of Streptococcus suis serotype 2 against fluoroquinolones, quinolone resistant determining region （QRDR） of gyrA and parC, which were fluoroquinolones target genes of S.suis 2, were amplified by PCR and sequenced. Comparisons of amino acid sequences of QRDR among induced drug resistant strains and their parental strains as well as natural drug resistant strains indicated that none of characteristic variation was occurred in the amino acid sequences of QRDR of GyrA in all induced drug resistant strains. However, Lys mutation at position 83 of ParC QRDR was detected in 62.5% of induced drug resistant strain （5/8）. Furthermore, the drug resistant S.suis 2 was able to increase fluoroquinolones sensitivity from 8 to 32 folds when treated with the effiux pump inhibitor of Carbonyl cyanidem-chlorophenyl hydrazone. Drug cross-resistance test showed that drug resistant strains acquired fluoroquinolones cross-resistance.

关 键 词：猪链球菌2型 氟喹诺酮类药物 耐药 喹诺酮耐药决定区 外排泵 

分 类 号：S852.61[农业科学—基础兽医学]