Contribution of quorum-sensing systems to virulence of Pseudomonas aeruginosa in an experimental pyelonephritis model
Rahul Mittal, Saroj Sharma, Sanjay Chhibber, Kusum Harjai
Department of Microbiology, Panjab University, Chandigarh, India
Received: November 11, 2005 Revised: December 1, 2005 Accepted: December 26, 2005
Background and purpose:
Pseudomonas aeruginosa has been reported to monitor its cell density as well as expression of virulence determinants by quorum-sensing signal mechanisms operative through autoinducers. In the present investigation, we studied the contribution of quorum-sensing signals during the course of P. aeruginosa-induced pyelonephritis in mice.
The standard parent strain of P. aeruginosa (PAO1), possessing functional las and rhl quorum-sensing systems and its isogenic mutant strains, PAO-JP1 (single mutant), harboring a mutated lasI gene and PAO-JP3 (double mutant), harboring mutated lasI and rhlR genes were employed. One uroisolate of P. aeruginosa belonging to serotype O8 and deficient in production of quorum-sensing signals was also used.
The parent strain of P. aeruginosa was significantly more virulent compared to its isogenic mutant strains and quorum-sensing negative clinical strain, as assessed by neutrophil influx, malondialdehyde production, renal bacterial load and pathology induced in experimental animals.
Quorum-sensing systems play an important role in the pathogenicity of P. aeruginosa in pyelonephritis. Both the las and rhl quorum-sensing systems are important for the virulence of P. aeruginosa in the development of pyelonephritis.
Animal disease model, Pseudomonas aeruginosa , quorum sensing, virulence
J Microbiol Immunol Infect 2006;39:302-309.