Identifying Escherichia coli genes involved in intrinsic multidrug resistance

Miao Duo, Shuyu Hou, Dacheng Ren

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


Multidrug resistance is a major cause of clinical failure in treating bacterial infections. Increasing evidence suggests that bacteria can resist multiple antibiotics through intrinsic mechanisms that rely on gene products such as efflux pumps that expel antibiotics and special membrane proteins that block the penetration of drug molecules. In this study, Escherichia coli was used as a model system to explore the genetic basis of intrinsic multidrug resistance. A random mutant library was constructed in E. coli EC100 using transposon mutagenesis. The library was screened by growth measurement to identify the mutants with enhanced or reduced resistance to chloramphenicol (Cm). Out of the 4,000 mutants screened, six mutants were found to be more sensitive to Cm and seven were more resistant compared to the wild-type EC100. Mutations in 12 out of the 13 mutants were identified by inverse polymerase chain reaction. Mutants of the genes rob, garP, bipA, insK, and yhhX were more sensitive to Cm compared to the wild-type EC100, while the mutation of rhaB, yejM, dsdX, nagA, yccE, atpF, or htrB led to higher resistance. Overexpression of rob was found to increase the resistance of E. coli biofilms to tobramycin (Tob) by 2.7-fold, while overexpression of nagA, rhaB, and yccE significantly enhanced the susceptibility of biofilms by 2.2-, 2.5-, and 2.1-fold respectively.

Original languageEnglish (US)
Pages (from-to)731-741
Number of pages11
JournalApplied Microbiology and Biotechnology
Issue number4
StatePublished - Dec 2008


  • Escherichia coli
  • Multidrug resistance
  • Transposon mutagenesis

ASJC Scopus subject areas

  • Biotechnology
  • Applied Microbiology and Biotechnology


Dive into the research topics of 'Identifying Escherichia coli genes involved in intrinsic multidrug resistance'. Together they form a unique fingerprint.

Cite this