目的 探究耐碳青霉烯粘质沙雷菌耐药表型和碳青霉烯酶基因,同时分析其分子流行病学特征.方法 收集临床分离非重复的67株碳青霉烯类耐药的粘质沙雷菌,以纸片扩散法和Vitek-2 Compact检测常见药物敏感性;采用改良碳青霉烯类灭活试验(m CIM)、Carba NP试验、改良Hodge试验(MHT)对碳青霉烯酶进行筛查;PCR检测碳青霉烯酶基因;PCR检测肠杆菌科细菌基因重复序列(ERIC)对耐药菌进行克隆型分析.结果 碳青霉烯耐药的粘质沙雷菌主要来自重症监护室(ICU),以痰液标本为主;药敏结果显示67株细菌对头孢噻肟、头孢曲松100％耐药,对亚胺培南、美罗培南、厄他培南、氨曲南耐药率均大于90％,对环丙沙星、庆大霉素、妥布霉素、哌拉西林/他唑巴坦、头孢他啶、头孢吡肟、左氧氟沙星耐药率较高,仅对阿米卡星和复方新诺明保持高度敏感;m CIM、Carba NP试验、MHT阳性率分别为92.54％、89.55％、91.04％;PCR显示67株粘质沙雷菌中,检出blaKPC基因32株、blaOXA-23组基因7株、blaOXA-51组基因7株、blaGES基因3株、blaOXA-58组基因1株,其中有8株细菌同时含有多种耐药基因;67株耐碳青霉烯的粘质沙雷菌可分为8个型别(以A～H表示),其中A型(50株)最多.结论 分离的耐碳青霉烯粘质沙雷菌呈现多重耐药性,主要携带blaKPC和blaOXA基因,且有多基因联合共存现象.同种克隆集中趋势明显,有引起院内感染爆发流行可能.%Objective To investigate the drug resistance phenotype and carbapenemase genes of carbapenem-resistant Serratia marcescens, and to analyze its molecular epidemiology. Methods Clinical isolates of 67 non-repeated carbapenem-resistant Serratia marcescens isolates were collected for common drug susceptibility by Kirby-Bauer method and Vitek-2 Compact.Carbapenemase was screened by modified carbapenem inactivation method (m CIM), Carba NP test and modified Hodge test (MHT).Carbapenemase genes was detected by PCR.The clone type of resistant bacteria was analyzed by PCR to detected the Enterobacterial repetitive intergenic consensus (ERIC).Results Carbapenem-resistant Serratia marcescens were mainly from intensive care unit (ICU) and mainly from sputum samples.The drug susceptibility results showed that 67 strains of bacteria were 100％resistant to cefotaxime and ceftriaxone.The resistance rates to imipenem, meropenem, ertapenem and aztreonam were all greater than90％.Ciprofloxacin, gentamicin, tobramycin, piperacillin/tazobactam, ceftazidime, cefepime, levofloxacin had higher resistance rates.Only highly sensitive to amikacin and cotrimoxazole.The positive rates of m CIM, Carba NP test and MHT were 92.54％, 89.55％and 91.04％, respectively.PCR showed that 32 strains of blaKPCgene and7 strains of blaOXA-23gene were detected in 67 strains of Serratia marcescens.There were 7 strains of blaOXA-51gene, 3 strains of blaGESgene, and 1 strain of blaOXA-58gene, among which 8 strains contained multiple drug resistance genes.67 strains of carbapenem-resistant Serratia marcescens can be divided into 8 types (represented by A to H), of which type A (50 strains) was the most. Conclusion The isolated carbapenem-resistant Serratia marcescens exhibits multi-drug resistance, mainly carrying blaKPCand blaOXAgenes, and has multiple genes coexisting.The trend of the same kind of cloning is obvious, and it may cause the outbreak of nosocomial infection.
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