TY - JOUR

T1 - Pseudomonas aeruginosa mutations in lasI and rhlI quorum sensing systems result in milder chronic lung infection

AU - Wu, H

AU - Song, Z

AU - Givskov, Michael

AU - Doring, G

AU - Worlitzsch, D

AU - Mathee, K

AU - Rygaard, J

AU - Høiby, N

PY - 2001

Y1 - 2001

N2 - To understand the importance of quorum sensing in chronic Pseudomonas aeruginosa lung infection, the in vivo pathogenic effects of the wild-type P. aeruginosa PAO1 and its double mutant, PAO1 lasI rhlI, in which the signal-generating parts of the quorum sensing systems are defective were compared. The rat model of P. aeruginosa lung infection was used in the present study. The rats were killed on days 3, 7, 14 and 28 after infection with the P. aeruginosa strains. The results showed that during the early stages of infection, the PAO1 double mutant induced a stronger serum antibody response, higher production of pulmonary interferon gamma, and more powerful blood polymorphonuclear leukocyte (PMN) chemiluminescence compared to its wild-type counterpart. On days 14 and 28 post-infection, significantly milder lung pathology, a reduction in the number of mast cells present in the lung foci, a reduced number of lung bacteria, and minor serum IgG and IgG1 responses but increased lung interferon gamma production were detected in the group infected with the PAO1 double mutant when compared with the PAO1-infected group. Delayed immune responses were observed in the PAO1-infected group and they might be associated with the production of virulence factors that are controlled by the quorum sensing systems. The conclusion of this study is that functional lasI and rhlI genes of P. aeruginosa PAO1 play a significant role during lung infection.

AB - To understand the importance of quorum sensing in chronic Pseudomonas aeruginosa lung infection, the in vivo pathogenic effects of the wild-type P. aeruginosa PAO1 and its double mutant, PAO1 lasI rhlI, in which the signal-generating parts of the quorum sensing systems are defective were compared. The rat model of P. aeruginosa lung infection was used in the present study. The rats were killed on days 3, 7, 14 and 28 after infection with the P. aeruginosa strains. The results showed that during the early stages of infection, the PAO1 double mutant induced a stronger serum antibody response, higher production of pulmonary interferon gamma, and more powerful blood polymorphonuclear leukocyte (PMN) chemiluminescence compared to its wild-type counterpart. On days 14 and 28 post-infection, significantly milder lung pathology, a reduction in the number of mast cells present in the lung foci, a reduced number of lung bacteria, and minor serum IgG and IgG1 responses but increased lung interferon gamma production were detected in the group infected with the PAO1 double mutant when compared with the PAO1-infected group. Delayed immune responses were observed in the PAO1-infected group and they might be associated with the production of virulence factors that are controlled by the quorum sensing systems. The conclusion of this study is that functional lasI and rhlI genes of P. aeruginosa PAO1 play a significant role during lung infection.

KW - Animals

KW - Bacterial Proteins

KW - Chronic Disease

KW - Cytokines

KW - Enzyme-Linked Immunosorbent Assay

KW - Female

KW - Ligases

KW - Luminescent Measurements

KW - Lung

KW - Lung Diseases

KW - Mutation

KW - Pseudomonas Infections

KW - Pseudomonas aeruginosa

KW - Rats

KW - Rats, Inbred Lew

KW - Transcription Factors

KW - Virulence

M3 - Journal article

C2 - 11320114

VL - 147

SP - 1105

EP - 1113

JO - Microbiology

JF - Microbiology

SN - 1350-0872

IS - Pt 5

ER -