铜绿假单胞菌耐药基因分子流行病学调查

目的了解云南省昆明某医院临床铜绿假单胞菌分离株耐药特征及耐药基因分子流行病学特征,为临床治疗与控制院内感染提供依据。方法 2013年6 9月共收集全院不同病区感染患者28株铜绿假单胞菌。微生物自动分析仪鉴定菌株及耐药分析。PCR扩增及序列分析β-内酰胺酶bla基因、氟喹诺酮类及氨基糖苷类耐药基因及IS插入元件及整合子。脉冲场凝胶电泳(pulsed field gel electrophoresis,PFGE)分析菌株间遗传变异关系。结果全部菌株呈现多重耐药且存在有广泛耐药性(extensively drug-resistant,XDR)及泛耐药性(pendrug-resistant,PDR)菌。100%(28/28)菌株对一代/二代及大部分三代/四代头孢霉素、磺胺类及叶酸代谢途径抑制剂耐药。85.7%(24/28)菌株对碳青霉烯类抗生素美罗培南(MEM)、亚胺培南(IMP)耐药,50.0%(14/28)菌株对厄他培南(ETP)耐药。92.9%(26/28)菌株同时携带β-内酰胺酶基因、氟喹诺酮类及氨基糖苷类耐药基因,且菌株间基因谱存在较大不同。blaFOX/qnr B/aac A4为主要耐药基因谱(21.4%,6/28)。57.1%(16/28)菌株携带int1整合酶基因,21.4%(6/28)菌株携带ISCR1插入元件,35.7%(10/28)菌株携带ISEcp1插入元件。PFGE显示14株菌株分为8个克隆群。结论本研究铜绿假单胞菌分离株存在较高耐药率,多种耐药基因存在不同克隆菌株中,提示耐药基因在菌株间及不同菌种间存在快速传播风险。

Molecular epidemiological survey of drug resistance gene of Pseudomonas aeruginosa in a hospital in Yunnan,China

Objective To understand the characteristics of drug resistance and molecular epidemiological characteristics of drug resistant gene of Pseudomonas aeruginosa in Yunnan province, and provide useful information for clinical antibiotic use. Methods A total of 28 P. aeruginosa strains were isolated from the patients in our hospital from June to September 2013. The identification and drug susceptibility test were conducted by using bioMerieux VITEK-2 system. The drug-resistance determents were analyzed by PCR amplification and sequencing. Results According to the standardized international definitions for drug-resistance, 22 strains （78.6%） were confirmed as multidrug-resistant （MDR）, 4 （14. 3% ） were extensive drug resistant （XDR） and 2 （7. 1% ） were pan-drug resistant （PDR）. All the isolates were resistant to the 1st and 2nd generation cephalosporins and most 3rd and 4th generation cephalosporins, trimethoprim-sulfamethoxazole and furadantin. Moreover, most strains （85.7%） showed carbapenem-resistant. The analysis of the resistance determinant indicated that 26 strains （ 92. 9% ） carried both quinolone and aminoglycosides resistance-associated genes, and the blapox/qnrB/aacA4 was predominant （21.4%, 6/28）. The analysis of the gene- capturing elements showed that 16（57.1% ）strains carried the int 1 gene, 6 （21.4%） carried the 1S CR1 gene and 10 （35.7%） carried the ISEcpl respectively. Multi-clone groups were found by PFGE analysis. Conclusion High positive rates of multi-clone MDR P. aeruginosa carrying β-Lactamase, quinolone and aminoglycosides resistance-associated genes was observed in this study and effective control measures should be taken urgently.