南京地区肺炎链球菌的耐药变迁及喹诺酮耐药机制研究  

Changing resistant pattern of Streptococcus pneumoniae in Nanjing and the mechanisms of its resistance to fluoroquinolones

作　　者：刘青[1,2] 苏欣[1,2] 张明[1,2] 邵海枫[1,3] 高卫卫[1,2] 樊有 施毅[1,2] 

机构地区：[1]南京大学医学院临床学院 [2]南京军区南京总医院呼吸与危重症医学科,南京210002 [3]南京军区南京总医院检验科,南京210002 [4]解放军454医院

出　　处：《中国感染与化疗杂志》2014年第1期1-6,共6页Chinese Journal of Infection and Chemotherapy

基　　金：中国呼吸道感染优化治疗协作组科研专项基金(2009037)

摘　　要：目的了解南京地区肺炎链球菌临床分离株的耐药性变迁及对喹诺酮类的耐药机制。方法收集2010—2012年南京7所教学医院共147株肺炎链球菌,琼脂稀释法测定9种抗菌药物的MIC,与南京2006—2007年分离的肺炎链球菌耐药情况进行比较。并对氟喹诺酮耐药株的gyrA、gyrB、parE和parC基因喹喏酮耐药决定区域(QRDR)进行PCR扩增及测序。结果 147株肺炎链球菌中,对红霉素的耐药率为89.1%;青霉素不敏感肺炎链球菌(MIC≥4 mg/L)占3.4%;对头孢呋辛、头孢曲松、美罗培南、左氧氟沙星、莫西沙星的耐药率分别为26.5%、1.4%、3.4%、1.4%、0.7%;所有分离株对万古霉素、利奈唑胺敏感。与2006—2007年分离株相比,2010—2012年临床分离株对青霉素、头孢呋辛耐药率下降,对红霉素、头孢曲松耐药率变化不大,出现了少数左氧氟沙星及莫西沙星耐药株。对喹诺酮耐药株进行基因测序发现1菌株有gyrA突变(Asn167—Ile)和ParE突变(Ile 460—Val);另1菌株则有ParC突变(Ser 81—Gly;Asn 94—Asp)。结论南京地区肺炎链球菌对红霉素耐药率居高不下,对青霉素仍较敏感,出现了少数莫西沙星、左氧氟沙星耐药株。喹诺酮耐药株有gyrA、parE和parC的QRDR突变。Objective To investigate the changing pattern of antimicrobial resistance of S. pneumoniae in Nanjing and the mech- anisms of its resistance to fluoroquinolones. Methods A total of 147 clinical isolates of S. pneumoniae were collected from 7 teaching hospitals in Nanjing from 2010 to 2012. The minimum inhibitory concentrations （MICs） of 9 antimicrobial agents were determined by agar dilution method. Statistical methods were used to compare the antibiotic resistance of the S. pneumoniae i-solates with those collected during 2006-2007. Quinolone resistance-determining regions （QRDR） in gyrA, gyrB, pare and parC genes of fluoroquinolone-resistant strains were analyzed by gene amplification and sequencing. Results Of the 147 S. pneumoniae strains, 89. 10% were resistant to erythromycin. The prevalence of penicillin non-susceptible S. pneumoniae was 3.4% （MIC % 4 rag/L）. About 26. 5%0, ceftriaxone, meropenem, levofloxacin and 1.4%, 3.4%, 1.4% and 0.7% of these isolates were resistant to cefuroxime, moxifloxacin, respectively. All strains were sensitive to vancomycin and linezolid.Compared to the isolates collected during 2006-2007, the isolates collected during 2010-2012 showed relatively lower resistance rate to penicillin and cefuroxime, similar resist ance rate to erythromycin and celtriaxone. But a few levo floxacin- or moxifloxacin-resistant strains emerged during 2010-2012. DNA sequencing revealed gyrA mutation （Asn-167 to Ile） and parE mutation （Ile-460 to Val） in one strain resistant to levofloxacin and moxifloxacing and parC mutation （Ser-81 to Gly, Asn-94 to Asp） in another fluoroquinolone-re-sistant strain. Conclusions The S. pneumoniae isolates collected in Nanjing during 2010-2012 are still highly resistant to erythro- mycin. Most of the isolates are sensitive to penicillin. Levofloxacin and moxifloxacin-resistant strains are identified in this study. Fluoroquinolone-resistant strains have gyrA, pare and parC mutations in QRDR.

关 键 词：肺炎链球菌 耐药 抗菌药物 氟喹诺酮 喹诺酮耐药决定区域 

分 类 号：R446.5[医药卫生—诊断学]