多重耐药铜绿假单胞菌的耐药性及耐药基因检测

目的:了解铜绿假单胞菌耐药性及β-内酰胺酶基因类型,指导临床合理用药。方法:琼脂稀释法测定12种抗生素对临床分离70株铜绿假单胞菌的最低抑菌浓度;筛选出20株多重耐药菌,三维试验检测产ESBLs和AmpC酶的情况;用聚合酶链反应(PCR)法检测β-内酰胺酶基因并进行测序分析。结果:铜绿假单胞菌对亚胺培南、阿米卡星和环丙沙星的敏感率较高;6株菌产AmpC酶,2株菌产ESBLs;PCR检测出4株菌产TEM酶,经测序2株产TEM-1型,一株产TEM-29型,另一株产酶与TEM-29比较有1处氨基酸的改变,命名为TEM-147;未检出SHV、OXA、PER和VEB型β-内酰胺酶基因。结论:必须重视铜绿假单胞菌ESBLs的检测,对于该菌引起的感染采用碳青霉烯类、阿米卡星或环丙沙星治疗是较好的选择。

Resistance and Detection of Resistant Genes of Multi-resistant Pseudomonas Aeruginosa

OBJECTIVE：To investigate the resistance and prevalence of β - lactamases in clinical isolates of P. aeruginosa and guide rational use of antibacterial agents. METHODS ： MICs of 12 kinds of antibiotics to 70 P. aeruginosa isolates were tested by agar dilution. AmpC β - lactamases and ESBLs were detected in 20 multi - drug P. aeruginosa strains by three - dimensional test. ESBLs genotypes were analyzed by PCR amplification and product sequencing. RESULTS： Imipenem, amikaein and ciprofloxacin had good activity against P. aeruginosa . Three - dimensional test showed that 2 strains possessed ESBLs, 6 strains hyperexpressed AmpCβ - lactamases in 20 srains. PCR amplification and DNA sequencing showed that 4 strains with blaTEM, 2 strains produced TEM - 1, 1 strain produced TEM - 29, 1 strain produced TEM β - lactamase named as TEM- 147 by GenBank with only one amino acid substitutionfrom TEM- 29. CONCLUSIONS： Attention must be paid to the detection of ESBLs in P. aeruginosa which may cause clinical infections. Carbapenems, amikacin or ciprofloxacin can provide effective therapy for such infections.