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目的探讨多重耐药铜绿假单胞菌不同类型外排泵基因表达与耐药表型和耐药程度的关系。方法收集多重耐药铜绿假单胞菌100株,分析其耐药表型,采用实时荧光定量PCR检测不同类型外排泵基因的表达量,用外排泵抑制剂苯丙氨酸-精氨酸-β萘酰胺(phenyl-arginine-β-naphthylamide,PAβN)进行外排泵基因筛查,并比较其结果。结果 (1)100株多重耐药菌株中,79株(79%)检出外排泵基因,其中单表达MexA 40株(40%)、MexC15株(15%)和MexX 15株(15%),共表达MexA和MexC6株(6%)、MexA和MexX3株(3%),外排泵抑制剂筛查实验总阳性率71%;(2)MexA外排泵的表达主要增强对大环内酯类、三代头孢菌素、美罗培南及氟喹诺酮类的耐药性,MexC型外排泵的表达主要增强对氟喹诺酮类、三代头孢霉素、氨基糖苷类、他唑巴坦类的耐药性,MexX型外排泵的表达主要增强对大环内酯类、氟喹诺酮类、氨基糖苷类和氨曲南的耐药性,MexA和MexC菌株的耐药表型与MexA基本一致,还可增强对氟喹诺酮类的耐药;共表达MexA和MexX型菌株的耐药表型基本与MexA一致,但降低了对氟喹诺酮类的耐药性;(3)耐药程度随外排泵基因表达的增高而增高。结论铜绿假单胞菌外排泵基因的表达量与特定种类药物耐药程度有关,外排泵基因高表达可加重铜绿假单胞菌的耐药性。
Objective To investigate the relationship between the gene expression of multidrug-resistant Pseudomonas aeruginosa efflux pump and the drug resistance phenotype and drug resistance. Methods 100 strains of multidrug-resistant Pseudomonas aeruginosa were collected and the resistant phenotypes were analyzed. The expression of different types of efflux pump genes was detected by real-time fluorescence quantitative PCR. The efflux pump inhibitor phenylalanine-arginine β-naphthylamide (PAβN) for efflux pump gene screening, and compare the results. Results (1) Of the 100 multidrug-resistant strains, 79 (79%) detected efflux pump genes, among which MexA 40 (40%), MexC15 (15%) and MexX 15 , MexA and MexC6 strains (6%), MexA and MexX3 strains (3%) were coexpressed, and the total positive rate of efflux pump inhibitor screening test was 71%. (2) The expression of MexA efflux pump was mainly enhanced in macrocyclic Esters, third-generation cephalosporins, meropenem and fluoroquinolones, the expression of MexC efflux pump mainly increased the resistance to fluoroquinolones, cephalo- cins of third generation, aminoglycosides and tazobactam The expression of MexX efflux pump mainly increased the resistance to macrolides, fluoroquinolones, aminoglycosides and aztreonam, and the resistant phenotypes of MexA and MexC strains were basically the same as MexA. Enhances resistance to fluoroquinolones; the resistant phenotype of MexA and MexX strains coexpressed is basically the same as that of MexA but reduces the resistance to fluoroquinolones; (3) The drug resistance changes with the expression of efflux pump gene Increase and increase. Conclusion The expression level of Pseudomonas aeruginosa efflux pump gene is related to the drug resistance of certain types of drugs. The high expression of efflux pump gene may aggravate the resistance of Pseudomonas aeruginosa.