中华医学杂志（英文版）Issue(19)：1615-1622,8.
The action of Pseudomonas aeruginosa biofilms in intrinsic drug resistance
The action of Pseudomonas aeruginosa biofilms in intrinsic drug resistance
摘要
Abstract
Background There is a growing interest in studying the relationship between intrinsic resistance and biofilms resistance to drugs. However, the relationship still remains unclear in the macroscopic bacterial growth. Our study is to illuminate the change of bacterial drug resistance of gyrA mutant and active efflux pump during the development of Pseudomonas aeruginosa (P. aeruginosa) biofilms. Methods The strains of type Ⅱ topoisomerase gene mutant (gyrA mutant) and multidrug resistance (MDR) efflux pump were clinical isolates and detected by polymerase chain reaction (PCR). The process of bacterial biofilms development was observed by scanning electron microscope. Triparental mating experiments were performed to transfer report gene of green fluorescent protein (GFP) into P. aeruginosa biofilms strains and followed by analysis of bacterial survival rate between intrinsic resistance and biofilms resistance.Results The fluorescent strains with pGFPuv could develop mature biofilms on Teflon surface. Before a period of 72 hours, the survival rate of biofilms bacteria and intrinsic resistance strains in ciprofloxacin solution was significantly different (P<0.05). The survival number of intrinsic resistance strains (gyrA mutation and active efflux pump) was illustriously higher than biofilm strain in the initial stage of biofilms development. After 72 hours incubation, there was no clearly difference between mutants and biofilms strains in the survival rate (P>0.05). The carbonyl cyanide m-chlorophenylhydrazone and azithromycin could significantly reduce the drug resistance of biofilm strains and efflux pump strains.Conclusions In the development of P. aeruginosa biofilms, the strains of gyrA mutation and MDR efflux could be conferred with new level of drug resistance. When co-cultured mutated strains with biofilm strains, biofilms may play a major role in bacterial resistance. But after 72 hours incubation (a mature biofilms had been developed), there was no clearly difference between the number of mutant strains and biofilm strains.关键词
Pseudomonas aeruginosa/drug resistance/bacteria/biofilmsKey words
Pseudomonas aeruginosa/drug resistance/bacteria/biofilms分类
医药卫生引用本文复制引用
XIE Yi,JIA Wen-xiang,ZENG Wei,YANG Wei-qing,CHENG Xi,LI Xue-ru,WANG Lan-lan,KANG Mei,ZHANG Zai-rong..The action of Pseudomonas aeruginosa biofilms in intrinsic drug resistance[J].中华医学杂志（英文版）,2005,(19):1615-1622,8.基金项目
This work was supported by grants from the National Science Foundation of China (No. 30370079) and Chinese Medical Board (CMB) of New York (CMB NO.82-412). （No. 30370079）
