奇异变形杆菌耐药性的4年监测及碳青霉烯类耐药株的耐药机制研究

目的了解本地区2007年到2010年奇异变形杆菌的临床分布与常用抗菌药物的耐药情况，了解碳青霉烯类耐药菌株可能存在的机制。方法回顾分析2007年到2010年临床分离奇异变形杆菌的资料及整体耐药情况；对保存的耐亚胺培南（IPM）、美罗培南（MEM）或厄他培南（ETP）的菌株进行复苏，并做Hoage试验进行产碳青霉烯酶的确认，同时对试验菌株进行耐药基因的PCR扩增检测。结果2007年到2010年，奇异变形杆菌在临床各送检样本中以痰液分离率最高：51．1％、34．4％、22．1％和35．4％，其次为尿液：14．3％、28．O％、34．9％和33．6％；耐药监测分析显示，4年间对喹诺酮类、青霉素类、头孢菌素类及氨基糖苷类耐药率相对较高且较为稳定；对碳青霉烯类耐药最低但增加明显，亚胺培南从2007年的1．8％升到2010年的16．1％，美罗培南从2007年的1．7％升到2010年的16．8％。15株耐碳青霉烯类菌株中，Hoage试验阳性7株，6fn。基因阳性11株，blaCTX-M基因阳性13株。结论本地区奇异变形杆菌对临床常用的抗菌药物均有较高的耐药性，对碳青霉烯类药物的耐药率最低，但增加明显。位于质粒上的blaKPc基因所产生的碳青霉烯酶和6如cTx-M基因所产生的超广谱β-内酰胺酶是本菌对β-内酰胺类抗菌药物耐药的主要原因，临床应引起高度重视。

Monitoring on the drug-resistance of Proteus mirabilis in 4 years and study on the resistance mechanisms of Carbapenems resistant isolates

Objective To investigate the clinical distribution and the drug resistance of Proteus mirabilis from 2007 to 2010,and study the drug-resistant mechanism of the resistant isolates(CRE).Method The drug resistance of Proteus mirabilis isolated clinically during 2007 to 2010 was analyzied retrospectively.The preservied strains resistant to imipenem,meropenem or ertapenem were resuscitated.The modifided Hodge test was used to detect the carbapenemase,and the drug resistance genes were detected by PCR method.Result The isolation rate of Proteus mirabilis from sputum was the highest,which was 51.1% in 2007,34.4% in 2008,22.1% in 2009,and 35.4% in 2010.The isolation rate from urine was the second,which was 14.3% in 2007,28.0% in 2008,34.9% in 2009,and 33.6% in 2010.The resistance rates to fluoroquinolones,penicillins,cephalosporins and aminoglycosides remained high and stable during the 4 years,while that to carbapenem was the lowest yet increased obviously.The resistance rate to imipenem increased from 1.8% in 2007 to 16.1% in 2010,while to meropenem from 1.7% in 2007 to 16.8% in 2010.Of the 15 cephalosporins-resistant strains,7 strains were Hodge test positive,11 strains were blaKPC positive,and 13 strains were blaCTX-M positive.Conclusion The Proteus mirabilis isolated in the region is resistant to many commonly used antibiotics in clinics.The resistance rate to carbapenem is the lowest which,however,has increased obviously.The carbapenemase produced by blaKPC gene and the β-Lactamase by blaCTX-M gene are the prominent causes of resistance,to which great attention should be paid.