Role of novel multidrug efflux pump involved in drug resistance in Klebsiella pneumoniae.
BACKGROUND
Multidrug resistant Klebsiella pneumoniae have caused major therapeutic problems worldwide due to the emergence of the extended-spectrum β-lactamase producing strains. Although there are >10 major facilitator super family (MFS) efflux pumps annotated in the genome sequence of the K. pneumoniae bacillus, apparently less is known about their physiological relevance.


RESULTS
Insertional inactivation of kpnGH resulting in increased susceptibility to antibiotics such as azithromycin, ceftazidime, ciprofloxacin, ertapenem, erythromycin, gentamicin, imipenem, ticarcillin, norfloxacin, polymyxin-B, piperacillin, spectinomycin, tobramycin and streptomycin, including dyes and detergents such as ethidium bromide, acriflavine, deoxycholate, sodium dodecyl sulphate, and disinfectants benzalkonium chloride, chlorhexidine and triclosan signifies the wide substrate specificity of the transporter in K. pneumoniae. Growth inactivation and direct fluorimetric efflux assays provide evidence that kpnGH mediates antimicrobial resistance by active extrusion in K. pneumoniae. The kpnGH isogenic mutant displayed decreased tolerance to cell envelope stressors emphasizing its added role in K. pneumoniae physiology.


CONCLUSIONS
The MFS efflux pump KpnGH involves in crucial physiological functions besides being an intrinsic resistance determinant in K. pneumoniae.
Bacterial signaling and Drug Resistance Laboratory, Council of Scientific Industrial Research- Institute of Microbial Technology, Chandigarh, India.
Vijaya Bharathi
VB
Srinivasan
Bacterial signaling and Drug Resistance Laboratory, Council of Scientific Industrial Research- Institute of Microbial Technology, Chandigarh, India.
Bharat Bhushan
BB
Singh
Bacterial signaling and Drug Resistance Laboratory, Council of Scientific Industrial Research- Institute of Microbial Technology, Chandigarh, India.
Nitesh
N
Priyadarshi
Bacterial signaling and Drug Resistance Laboratory, Council of Scientific Industrial Research- Institute of Microbial Technology, Chandigarh, India.
Neeraj Kumar
NK
Chauhan
Bacterial signaling and Drug Resistance Laboratory, Council of Scientific Industrial Research- Institute of Microbial Technology, Chandigarh, India.
Govindan
G
Rajamohan
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D019450:Genes, MDR / Q000502:physiology*; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000235:genetics*; D026901:Membrane Transport Proteins / Q000235:genetics*; D008826:Microbial Sensitivity Tests
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D026901:Membrane Transport Proteins