TY - JOUR
T1 - Antibodies against beta-lactamase can improve ceftazidime treatment of lung infection with beta-lactam-resistant Pseudomonas aeruginosa in a rat model of chronic lung infection
AU - Ciofu, Oana
AU - Bagge, Niels
AU - Høiby, Niels
PY - 2002/12
Y1 - 2002/12
N2 - To test the hypothesis that antibodies against the chromosomal beta-lactamase of Pseudomonas aeruginosa (a beta ab) might act as beta-lactamase inhibitors in patients with cystic fibrosis and chronic lung infection with P. aeruginosa, we compared in a rat model of chronic lung infection the efficacy of treatment with ceftazidime in beta-lactamase-immunized (group I) and non-immunized (group II) rats. Chronic lung infection was established with alginate-embedded P. aeruginosa producing high amounts of beta-lactamase in 133 Lewis rats. Prior to infection, group I (66 rats) was immunized three times at 2-week intervals with purified beta-lactamase in incomplete Freund's adjuvant (IFA) and group II (67 rats) received IFA. Ceftazidime treatment was initiated after challenge and continued for 10 days, after which the rats were sacrificed and the lung bacteriology and pathology were analysed. Rat serum was analysed for the beta-lactamase inhibitory activity and a beta ab-specific IgG and IgG subclasses titres. Beta-lactamase inhibitory activity was found only in sera of rats belonging to group I and it was used to divide these rats into two subgroups: rats whose sera inhibited > or = 75% of beta-lactamase activity (responders) and rats whose sera inhibited < or = 25% of beta-lactamase activity (non-responders). The responder subgroup had significantly smaller pathological areas in the lungs and lower cfu/ml lung homogenate compared to the non-immunized group (p=0.02 and p=0.01, respectively) and compared to the non-responder subgroup (p=0.008 and p=0.0001, respectively). On the day of challenge, significantly higher titres of a beta ab-specific IgG and IgG subclasses antibodies were found in the responders compared to the non-responders (p<0.0001). In the responder subgroup the avidity of IgG a beta ab was significantly higher than in the non-responder subgroup (p=0.0003). Our study showed that a beta ab with beta-lactamase inhibitory activity raised by immunization with beta-lactamase can improve the outcome of treatment with ceftazidime of resistant P. aeruginosa in a rat model of chronic lung infection.
AB - To test the hypothesis that antibodies against the chromosomal beta-lactamase of Pseudomonas aeruginosa (a beta ab) might act as beta-lactamase inhibitors in patients with cystic fibrosis and chronic lung infection with P. aeruginosa, we compared in a rat model of chronic lung infection the efficacy of treatment with ceftazidime in beta-lactamase-immunized (group I) and non-immunized (group II) rats. Chronic lung infection was established with alginate-embedded P. aeruginosa producing high amounts of beta-lactamase in 133 Lewis rats. Prior to infection, group I (66 rats) was immunized three times at 2-week intervals with purified beta-lactamase in incomplete Freund's adjuvant (IFA) and group II (67 rats) received IFA. Ceftazidime treatment was initiated after challenge and continued for 10 days, after which the rats were sacrificed and the lung bacteriology and pathology were analysed. Rat serum was analysed for the beta-lactamase inhibitory activity and a beta ab-specific IgG and IgG subclasses titres. Beta-lactamase inhibitory activity was found only in sera of rats belonging to group I and it was used to divide these rats into two subgroups: rats whose sera inhibited > or = 75% of beta-lactamase activity (responders) and rats whose sera inhibited < or = 25% of beta-lactamase activity (non-responders). The responder subgroup had significantly smaller pathological areas in the lungs and lower cfu/ml lung homogenate compared to the non-immunized group (p=0.02 and p=0.01, respectively) and compared to the non-responder subgroup (p=0.008 and p=0.0001, respectively). On the day of challenge, significantly higher titres of a beta ab-specific IgG and IgG subclasses antibodies were found in the responders compared to the non-responders (p<0.0001). In the responder subgroup the avidity of IgG a beta ab was significantly higher than in the non-responder subgroup (p=0.0003). Our study showed that a beta ab with beta-lactamase inhibitory activity raised by immunization with beta-lactamase can improve the outcome of treatment with ceftazidime of resistant P. aeruginosa in a rat model of chronic lung infection.
KW - Animals
KW - Antibodies, Bacterial/biosynthesis
KW - Antibody Affinity
KW - Antibody Specificity
KW - Bacterial Proteins/immunology
KW - Biofilms
KW - Ceftazidime/therapeutic use
KW - Chronic Disease
KW - Enzyme-Linked Immunosorbent Assay
KW - Female
KW - Immunization
KW - Immunization, Secondary
KW - Immunoglobulin G/biosynthesis
KW - Microspheres
KW - Models, Animal
KW - Neutralization Tests
KW - Pneumonia, Bacterial/drug therapy
KW - Pseudomonas Infections/drug therapy
KW - Pseudomonas aeruginosa/drug effects
KW - Rats
KW - Rats, Inbred Lew
KW - beta-Lactam Resistance
KW - beta-Lactamases/immunology
U2 - 10.1034/j.1600-0463.2002.1101207.x
DO - 10.1034/j.1600-0463.2002.1101207.x
M3 - Journal article
C2 - 12645667
SN - 0903-4641
VL - 110
SP - 881
EP - 891
JO - APMIS - Journal of Pathology, Microbiology and Immunology
JF - APMIS - Journal of Pathology, Microbiology and Immunology
IS - 12
ER -