新生儿耐碳青霉烯类肺炎克雷伯菌耐药性及耐药基因研究

Study on drug resistance and drug resistance genes of carbapenemresistant Klebsiella pneumoniae isolated from neonates

目的研究临床分离自新生儿的耐碳青霉烯肺炎克雷伯菌的耐药性及碳青霉烯酶耐药基因类型。方法收集2013年12月至2015年12月南宁市2家妇幼保健院住院新生儿临床分离碳青霉烯类耐药肺炎克雷伯菌8株。使用生物梅里埃公司的VITEK-2Compact全自动细菌鉴定仪对细菌进行鉴定以及菌株最低抑菌浓度(MIC)检测。改良Hodge试验筛选碳青霉烯酶阳性菌株,乙二胺四乙酸(EDTA)纸片增效试验筛选产金属酶菌株。PCR扩增碳青霉烯酶基因(KPC、GES、SME、NMC、IMI、IMP、NDM-1、VIM、SIM),并对PCR阳性产物测序鉴定,测序结果与GenBank数据库进行比对。结果药敏结果显示,8株耐药菌株对大部分临床常用抗菌药物高度耐药,对氟喹诺酮类抗菌药物和氨基糖苷类抗菌药物有较高的敏感性。表型确认试验显示,6株改良Hodge试验阳性,7株EDTA协同试验阳性。8株碳青霉烯类耐药肺炎克雷伯菌均携带IMP-4碳青霉烯酶基因,未检出KPC、GES、SME、NMC、IMI、NDM-1、VIM、SIM型碳青霉烯酶基因。结论本地区新生儿碳青霉烯类耐药肺炎克雷伯菌对多种抗菌药物的耐药率较高,新生儿临床分离碳青霉烯类耐药肺炎克雷伯菌主要耐药机制是产B类碳青霉烯酶,IMP-4是其主要酶型。

Objective To investigate the antimicrobial resistance and genotypes of carbapenem‐resistant Klebsiella pneumoniae i‐solated from newborn patients .Methods A total of 8 strains of carbapenem‐resistant Klebsiella penemoniae clinically isolated from neonatal inpatients in two maternal and child health care hospitals of Nanning City from December 2013 to December 2015 were col‐lected and identified .The strain identification and minimal inhibitory concentration（MIC） were carried out by using the VITEK au‐tomatic microbiological analyzer .The carbapenemase positive strains were screened by the modified Hodge tests and metallo‐β‐lacta‐mase producing strains by imipenem‐EDTA synergy tests .The carbapenemase genes（KPC ,GES ,SME ,NMC ,IMI ,IMP ,NDM‐1 , VIM ,SIM ） were amplified by polymerase chain reaction （PCR） ,moreover the PCR positive productions were performed the se‐quencing identification .The detection results were performed the comparison with the GenBank database .Results The antibacterial susceptibility test results showed that 8 strains were highly resistant to commonly used antibacterial drugs ,but highly sensitive to fluoroquinolones and aminoglycosides antibacterial drugs .The phenotypic validation test showed that 6 strains were positive in the modified Hodge test and 7 strains were positive in the EDTA synergy test .Eight strains of carbapenem‐resistant Klebsiella peneu‐moniaes were all carried IMP‐4 carbapenemase genes .No KPC ,GES ,SME ,NMC ,IMI ,NDM‐1 ,VIM and SIM types of carbapene‐mase genes were detected .Conclusion Carbapenem‐resistant Klebsiella pneumoniae isolated from neonates in this area has the high resistance to multiple antibacterial drugs ,its main drug resistance mechanism is the production of B‐carbapenemase （B‐MBL） and IM P‐4 is the main enzyme type .