婴儿感染B族链球菌的喹诺酮耐药突变调查  

Investigation of quinolone resistance mutations in group B Streptococcus which infected the infants

作　　者：关小珊 唐倩 邓秋连 钟华敏 高坎坎 刘海英 GUAN Xiaoshan;TANG Qian;DENG Qiulian;ZHONG Huamin;GAO Kankan;LIU Haiying(Department of Clinical Laboratory,Guangzhou Women and Children′s Medical Center,Guangzhou,Guangdong 510120,China)

机构地区：[1]广东省广州市妇女儿童医疗中心儿童院区检验科,广东广州510120

出　　处：《检验医学与临床》2021年第24期3525-3527,3532,共4页Laboratory Medicine and Clinic

基　　金：广东省广州市科创委项目(201804010447)。

摘　　要：目的调查B族链球菌(GBS)的喹诺酮耐药情况,探讨耐药株的突变位点与血清学分型之间的关系。方法选取从2014年1月至2019年12月于该中心确诊为GBS感染的婴儿临床标本中分离出的非重复菌株共120株作为研究对象。对纳入研究的GBS进行药敏试验。PCR扩增喹诺酮耐药菌株的喹诺酮耐药决定区(QRDR)靶基因GyrA和ParC,乳胶凝集法检测上述菌株的血清学分型,分析不同位点突变与血清学分型之间的关系。结果2014-2019年共收集来自婴儿的GBS临床分离株120株,其中喹诺酮耐药株14株,喹诺酮耐药率为11.7%。将喹诺酮耐药株中的11株用于后续实验,这些耐药株100%存在GyrA的碱基突变,表现为81位丝氨酸变为亮氨酸,219位丙氨酸变为脯氨酸或缬氨酸。仅1株同时出现ParC和GyrA的有义突变。共检测出2种血清学分型,分别为Ⅲ型(90.9%)和Ⅰb型(9.1%)。结论2014-2019年,该中心喹诺酮耐药GBS临床分离株以GyrA基因耐药突变为主,表现为81位和(或)219位的氨基酸改变,血清学分型以Ⅲ型为主。Objective To investigate the quinolone resistance of group B Streptococcus(GBS),and the relationship between the mutation site of the resistant strains and the serological types.Methods A total of 120 non-repetitive strains isolated from clinical specimens of infants diagnosed with GBS infection in the center from January 2014 to December 2019 were selected as the research objects.A drug sensitivity test was conducted on the GBS included in the study.The quinolone resistance-determining regions(QRDRs)′target genes GyrA and ParC of quinolone-resistant strains were amplified by PCR,and the serological type of the above-mentioned strains was detected by latex agglutination,and the relationship between mutations at different sites and serological type was analyzed.Results From 2014 to 2019,a total of 120 GBS clinical isolates from infants were collected,of which 14 were quinolone-resistant strains,and the quinolone-resistant rate was 11.7%.Among them,100%of the 11 quinolone-resistant strains used in the follow-up experiment had GyrA mutations,which made the 81-position serine change to leucine,and the 219-position alanine change to proline or valine.Only one strain showed both ParC and GyrA sense mutations.A total of 2 serotypes were detected,typeⅢ(90.9%)and typeⅠb(9.1%).Conclusion From 2014 to 2019,quinolone-resistant GBS clinical isolates from the center were dominated by GyrA resistance mutations,which made changes in amino acids at positions 81 and(or)219,and the major serological type was typeⅢ.

关 键 词：B族链球菌 喹诺酮耐药 基因突变 婴儿 

分 类 号：R446.5[医药卫生—诊断学]