摘要目的 了解烧伤感染患者肺炎克雷伯菌( KPN)的耐药表型及同源性. 方法 收集2007年1月-2011年6月由西南医院全军烧伤研究所(简称本研究所)住院患者创面、血液、痰液、静脉导管、大便、口腔等分离的KPN共54株,经鉴定后采用K-B纸片扩散法检测菌株对氨苄西林、替卡西林等18种临床常用抗生素的耐药性.根据菌株耐药性筛选出产超广谱β内酰胺酶(ESBL)的KPN,PCR法检测其耐药基因SHV、TEM、CTX-M阳性率,采用脉冲场凝胶电泳及聚类分析法分析菌株同源性,另对各年检出的产ESBL的KPN进行同源性分析. 结果 (1)54株KPN对亚胺培南、美罗培南和厄他培南的敏感率依次为96.30％、92.59％、81.48％,对头孢替坦、头孢西丁的敏感率为70.37％和64.81％,对头孢他啶的敏感率为57.41％,对其他抗生素的敏感率均低于40.00％.(2)共筛选出26株产ESBL的KPN,其SHV、TEM、CTX-M阳性率分别为96.15％( 25/26)、76.92％( 20/26)、57.69％ (15/26).同时携带前述3种基因的菌株检出率为42.31％ (11/26),SHV和TEM双阳性菌株检出率为34.62％( 9/26),仅携带单一基因的菌株检出率均小于10.00％.(3)产ESBL的KPN共分为9种基因型,A、B、C、D、E型分别占30.77％(8/26)、19.23％(5/26)、15.38％ (4/26)、11.54％(3/26)和7.69％( 2/26),F、G、H和Ⅰ型均分别占3.85％ (1/26).(4)2007、2010年产ESBL的KPN基因型均以A型为主,分别占2/3和1/2；2008年C、E、F型各l株；2009年以B型为主,占1/2；2011年A、D、H、Ⅰ型各l株. 结论 本研究所烧伤感染患者KPN对临床常用抗生素耐药性高,可选择碳青霉烯类药物治疗.产ESBL的KPN大部分同时携带2种或者3种耐药基因,基因型以A型为主.

abstractsObjective To study the resistance phenotype and homology of Klebsiella pneumoniae (KPN) in burn patients with infection. Methods Fifty-four strains of KPN were isolated from wound excretion,blood,sputum,venous catheter,feces,and oral cavity of patients hospitalized in Institute of Burn Research of Southwest Hospital (briefly called our institute) from January 2007 to June 2011.Drug resistance of the 54 strains of KPN to 18 antibiotics commonly used in clinic,including ampicillin,ticarcillin,etc,was tested by K-B paper disk diffusion method after being identified.Extended-spectrum β-lactamase ( ESBL)-producing KPN was screened based on the drug resistance result.The positive rates of drug-resistant genes SHV,TEM,and CTX-M of the ESBL-producing KPN were detected by polymerase chain reaction.The homology of the ESBL-producing KPN was analyzed by pulse field gel electrophoresis and clustering methodology.The homology of ESBL-producing KPN isolated in each year was analyzed too. Results ( 1 ) The sensitive rate of the 54 strains of KPN to imipenem,meropenem,and ertapenem was respectively 96.30％,92.59％,and 81.48％,that of these strains to cefotetan and cefoxitin was respectively 70.37％ and 64.81％,and that of these strains to cefiazidime was 57.41％.The sensitive rates of the 54 strains of KPN to the other antibiotics were all lower than 40.00％.(2) Twenty-six ESBL-producing KPN strains were screened and the positive rate of SHV,TEM,and CTX-M was 96.15％ (25/26),76.92％ (20/26),and 57.69％ (15/26),respectively.Detection rate of ESBL-producing KPN strains carrying three genes at the same time was 42.31％ (11/26),that of these strains carrying both SHV and TEM was 34.62％ (9/26),and those of these strains carrying only a single gene were all less than 10.00％.( 3 ) The twenty-six ESBL-producing KPN were classified into 9 gene types,with 30.77％ (8/26) in type A,19.23％ (5/26) in type B,15.38％ (4/26) in type C,11.54％ (3/26) in type D,7.69％ (2/26) in type E,and the rest four strains respectively in type F,G,H,I [3.85％ (1/26) ].(4) The major gene type of ESBL-producing KPN in the year of 2007 and 2010 was type A,respectively accounting for 2/3 and 1/2,while that in the year of 2009 was type B,accounting for 1/2.The three strains in 2008 was respectively in type C,E,and F.The four strains in 2011 was respectively in type A,D,H,I. Conclusions KPN in burn patients with infection in our institute are highly resistant to commonly used antibiotics in clinic,but carbapenems antibiotics can be used for the treatment.Most of the ESBL-producing KPN strains carry two or three drug-resistant genes,and the main gene type of them is type A.