铜绿假单胞菌产 AmpC β-内酰胺酶及外膜孔蛋白 OprD2基因缺失分析

摘要

Objective to understand ampC beta-lactamase(ampC)and outer membrane porin OprD2 gene deletion in Pseudomonas aeruginosa. Methods the three-dimensional test was used to determine ampC . Polymerase chain reaction(PCr)was used to determine outer membrane porin OprD2 gene and ampC gene. the data were analyzed statistically. Results the 63 isolates of Pseudomonas aeruginosa were collected,of which 14 isolates(22.22%)produced ampC,OprD2 gene was positive in 22 isolates(OprD2 gene deletion rate 65.08%), and ampC gene was positive in 62 isolates(93.94%). the resistance rates to ampicillin,ampicillin / sulbactam, cefotetan and ceftriaxone and cefazolin were 100.00%. the resistance rates of ampC-producing isolates to imipenem, gentamicin and cefepime were 42.85%,64.29% and 57.14%,respectively. the resistance rates of non-ampC-producing isolates were 30.61%,6.12% and 14.29%,respectively. the resistance rates of Pseudomonas aeruginosa to gentamicin and cefepime had statistical significance between ampC-producing and non-ampC-producing isolates (P<0.01),but there was no statistical significance for imipenem(P>0.05). a total of 6 isolates of Pseudomonas aeruginosa had OprD2 gene deletion,and the resistance rates to imipenem,ceftazidime and cefepime were 100.00%, 66.67% and 55.56%. the resistance rates of 8 isolates of Pseudomonas aeruginosa with normal OprD2 gene expression and ampC-producing isolates were 0.00%,25.00% and 37.50%. Conclusions Multi-drug resistant Pseudomonas aeruginosa might be caused by a variety of mechanisms. Enzyme production and molecular epidemiological studies for Pseudomonas aeruginosa should be strengthened.%目的：了解临床分离的铜绿假单胞菌中产 ampC β-内酰胺酶（简称 ampC 酶）及外膜孔蛋白 OprD2基因缺失的情况。方法采用三维试验检测 ampC 酶，聚合酶链反应（PCr）检测外膜孔蛋白 OprD2基因和 ampC 酶结构基因 ampC，进行统计学分析。结果63株铜绿假单胞菌中 ampC 酶阳性14株（22.22%）；OprD2基因阳性22株（OprD2基因缺失率65.08%）；ampC 基因阳性62株（93.94%）。铜绿假单胞菌对氨苄西林、氨苄西林-舒巴坦、头孢替坦、头孢曲松和头孢唑啉的耐药率达100.00％。产 ampC 酶的菌株对亚胺培南、庆大霉素、头孢吡肟的耐药率分别为42.85%、64.29％和57.14％，不产 ampC 酶的菌株分别为30.61%、6.12%和14.29%，二者对庆大霉素和头孢吡肟的耐药率差异均有统计学意义（P<0.01），对亚胺培南的耐药率差异无统计学意义（P>0.05）。6株 OprD2缺失合并产 ampC 酶的铜绿假单胞菌对亚胺培南、头孢他啶、头孢吡肟的耐药率分别为100.00%、66.67%和55.56%，8株 OprD2正常表达合并产 ampC 酶的菌株分别为0.00%、25.00%和37.50%，二者差异有统计学意义（P<0.05）。结论铜绿假单胞菌多重耐药可能是由多种机制共同控制的，应加强铜绿假单胞菌产酶的监测及耐药基因的分子流行病学研究。