title: Contribution of efflux pumps in fluroquinolone resistance in multi-drug resistant nosocomial isolates of Pseudomanas aeruginosa from a tertiary referral hospital in north east India.
abstract: BACKGROUND
  Pseudomonas aeruginosa is one of the leading opportunistic pathogen and its ability to acquire resistance against series of antimicrobial agents confine treatment option for nosocomial infections. Increasing resistance to fluroquinolone (FQ) agents has further worsened the scenario. The major mechanism of resistance to FQs includes mutation in FQs target genes in bacteria (DNA gyrase and/or topoisomerases) and overexpression of antibiotic efflux pumps.
  
  
  OBJECTIVE
  We have investigated the role of efflux pump mediated FQ resistance in nosocomial isolates of P. aeruginosa from a tertiary referral hospital in north eastern part of India.
  
  
  METHODS
  A total of 234 non-duplicate, consecutive clinical isolates of P. aeruginosa were obtained from a tertiary referral hospital of north-east India. An efflux pump inhibitor (EPI), carbonyl cyanide m-chlorophenylhydrazone (CCCP) based method was used for determination of efflux pump activity and multiplex polymerase chain reaction (PCR) was performed for molecular characterisation of efflux pump. Minimum inhibitory concentration (MIC) reduction assay was also performed for all the isolates.
  
  
  CONCLUSIONS
  A total number of 56 (23%) have shown efflux mediated FQ resistance. MexAB-OprM efflux system was predominant type. This is the first report of efflux pump mediated FQ resistance from this part of the world and the continued emergence of these mutants with such high MIC range from this part of the world demands serious awareness, diagnostic intervention, and proper therapeutic option.
authors.forename: D
authors.initials: D
authors.lastname: Choudhury
authors.forename: A Das
authors.initials: AD
authors.lastname: Talukdar
authors.forename: A P
authors.initials: AP
authors.lastname: Maurya
authors.forename: M Dutta
authors.initials: MD
authors.lastname: Choudhury
authors.forename: D
authors.initials: D
authors.lastname: Dhar Chanda
authors.forename: A
authors.initials: A
authors.lastname: Chakravarty
authors.affiliation: Department of Microbiology, Assam University, Silchar, India.
authors.forename: A
authors.initials: A
authors.lastname: Bhattacharjee
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism*; D001693:Biological Transport, Active; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000378:metabolism; D003428:Cross Infection / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial; D024841:Fluoroquinolones / Q000378:metabolism*; D006801:Humans; D007194:India; D008826:Microbial Sensitivity Tests; D060885:Multiplex Polymerase Chain Reaction; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D062606:Tertiary Care Centers; D014475:Uncoupling Agents / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D014475:Uncoupling Agents; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone