- Email: [email protected]
72. Longitudinal changes of the antibiotic susceptibility of Pseudomonas aeruginosa in CF-patients
S42
Supplement / The Netherlands Journal of Medicine 54 (1999) S3 –S84
71. Longterm follow up of first pseudomonas aeruginosa (PSA) detection: Risk factors for conversion to chronical PSA infection in patients with CF. P. Rabsch, M. Ballmann, H. von der Hardt. Medical School Hannover Paediatric Dept., Hannover, Germany. In CF colonization with Pseudomonas aeruginosa (PSA) is a multistep process. It starts with first detection of PSA and finish in most patients after a variable time with chronic mucoid colonization. Clinical relevant changes in pulmonary function are related to chronic and mucoid colonization not just to the first detection of PSA. Aim of this study was to identify risk factors for an early conversion to the chronic states of PSA colonization. N 5 82 patients from a single CF-center were followed for at least three years after first PSA detection. Time till conversion to the chronic states of PSA colonization was registrated and the relative risk to convert to chronic PSA colonization was calculated depending on genotype, age, pulmonary function and Crispin Norman score at first PSA detection. The chronic states of colonization were earlier achieved from patients who were DF508 homozygous, . 8 years, FEV1 , 70% and CNS . 7 at first PSA detection. The relative risk factors were 4.6 for FEV1 , 70%, 3.6 for DF508 homozygosis and 3.2 for CNS . 7. The results may help with indication for early treatment of PSA and should be regarded with respect to randomisation of patients in studies of early treatment of PSA detection.
72. Longitudinal changes of the antibiotic susceptibility of Pseudomonas aeruginosa in CF-patients. B. Przyklenk 1 , A. Bauernfeind 2 . 1 Dr von Haunersches Kinderspital, Lindwurmstr. ¨ 4, 80337 Munchen , Germany, 2 Max von Pettenkofer-Institut, ¨ Pettenkofer Str. 9 a, 80336 Munchen , Germany. The main bacterial pathogen in CF is P. aeruginosa. The changes of the antibiotic susceptibility after the initial infection with P. aeruginosa was investigated in a retrospective study. Patients with the first culture positive for P. aeruginosa between 1985 and 1995 and at least three positive cultures over a period $ 24 months were included (mean age at the time of initial infection with P. aeruginosa 11.3614.4 years; 34 males, 38 females). We compared the antibiotic susceptibility of the initial (n 5 88) and the final (n 5 170) strains of P. aeruginosa. The frequency of susceptible strains was as follows: for ciprofloxacin 92% initially versus 77% finally (p 5 0.004), ceftazidime 81% vs. 51% (p , 0.001), tobramycin 73% vs. 42% (p , 0.001), and for imipenem 47% vs. 35% (p 5 0.104). The prevalence of patients with at least one strain moderately sensitive or resistant to ceftazidime increased from 25% initially to 67% finally (p , 0.001), to imipenem from 54% to 85% (p , 0.001), to tobramycin from 32% to 75% (p , 0.001) and to ciprofloxacin from 8% to 29% (p 5 0.104). Therefore, significant changes of the antibiotic susceptibility occur in the individual CF-patient. A combination therapy is strictly recommended to reduce the risk of selection of resistant mutants.
73.* The N-acyl-bomoserine lactones from Pseudomonas aeruginosa can be monitored by green fluorescent protein in vivo. Hong Wu 1 , Zhijun Song 1 , Peter W. Lindum 2 , Claus Moser 1 , Michael Givskov 2 , Niels Høiby 1 . 1 Department of Clinical
Microbiology, University Hospital of Copenhagen, Rigshospitalet, 2 Denmark, Institute of Microbiology, the Technical University of Denmark. Chronic Pseudomonas aeruginosa (PA) lung infection is a main factor responsible for the morbidity and mortality in cystic fibrosis (CF) patients. The infection is impossible to eradicate with antibiotic treatment, because PA grows in biofilm and develops resistance to anti-biotics. The pathogenicity of PA is associated with the virulent factors from the bacteria, which are controlled by a N-acyl homoserine lactone (AHL) based quorum sensing system. Some bacteria containing green fluorescent protein (GFP) can monitor the AHLs from PA in vitro. In the present study we report a method to detect the production of AHLs from PA in vivo. Three E. coli (EC) monitor strains with different GFP in half-life and copy numbers were used as AHL monitors (indicators). The PA and monitors were embedded in alginate and made into alginate beads separately. Mice were challenged intratracheally with PA 1 EC alginate beads or PA beads or EC beads separately, and sacrificed on different days after challenge. Frozen lung sections were prepared for normal fluorescent microscopy and confocal scanning laser microscopy. On day 3, GFP could be detected in the lung tissues challenged with all the 3 different GFP monitors in the mixed beads respectively. From day 5 on, GFP could not be detected in the lungs. In PA or EC control groups, no GFP was found. These results demonstrated that the production of AHLs from PA could be confirmed in vivo by the expression of GFP in the monitoring EC bacteria.
74. Azithromycin reduces epithelial adhesion of P. aeruginosa in patients with cystic fibrosis. J.J. Fischer, U. Baumann, P. ¨ Gudowius, B. Tummler, H. von der Hardt. Dept. of Paediatric Pulmology, Hanover Medical School, Germany. Long term treatment with macrolides was proven beneficial for patients with diffuse panbronchiolitis (DPB), that are chronically infected with Pseudomonas aeruginosa (PA). The mechanisms, however, are still unclear. We assessed the effect of long term treatment ( $ 12 weeks) with azithromycin (AZM) on adhesion of PA on buccal epithelial cells in patients with CF in an open prospective study. 11 children (mean age 14.6 yrs) chronically infected with PA participated. Adhesion was reduced in all patients (p 5 0.0069) by 70% from 8.0 (SD 4.8) to 2.4 (SD 1.1) bacteria per cell, reaching near normal levels (1–2). After termination of treatment with AZM, adhesion started to increase in 3 of 4 patients as yet tested, apparently in a time dependent manner. Since macrolides do not necessarily eradicate PA in DPB, modifying host defence may be responsible for the improved prognosis in this disease. Here, we show that AZM reduces the increased adherence of PA to epithelial cells of CF patients in viva. Our findings provide a new model for a beneficial effect of macrolides that may be of therapeutic relevance.
75. Colonisation Of Pseudomonas aeruginosa in patients with CF at Stockholm CF center. L. Hjelte 1 , A. Geborek 1 , B.-M. Jakobsson 1 , A Samuelson 2 . Departments of 1 Paediatrics, 2 Clinical Bacteriology, Karolinska Institutet, Huddinge Hospital, Huddinge, Sweden.
Supplement / The Netherlands Journal of Medicine 54 (1999) S3 –S84
71. Longterm follow up of first pseudomonas aeruginosa (PSA) detection: Risk factors for conversion to chronical PSA infection in patients with CF. P. Rabsch, M. Ballmann, H. von der Hardt. Medical School Hannover Paediatric Dept., Hannover, Germany. In CF colonization with Pseudomonas aeruginosa (PSA) is a multistep process. It starts with first detection of PSA and finish in most patients after a variable time with chronic mucoid colonization. Clinical relevant changes in pulmonary function are related to chronic and mucoid colonization not just to the first detection of PSA. Aim of this study was to identify risk factors for an early conversion to the chronic states of PSA colonization. N 5 82 patients from a single CF-center were followed for at least three years after first PSA detection. Time till conversion to the chronic states of PSA colonization was registrated and the relative risk to convert to chronic PSA colonization was calculated depending on genotype, age, pulmonary function and Crispin Norman score at first PSA detection. The chronic states of colonization were earlier achieved from patients who were DF508 homozygous, . 8 years, FEV1 , 70% and CNS . 7 at first PSA detection. The relative risk factors were 4.6 for FEV1 , 70%, 3.6 for DF508 homozygosis and 3.2 for CNS . 7. The results may help with indication for early treatment of PSA and should be regarded with respect to randomisation of patients in studies of early treatment of PSA detection.
72. Longitudinal changes of the antibiotic susceptibility of Pseudomonas aeruginosa in CF-patients. B. Przyklenk 1 , A. Bauernfeind 2 . 1 Dr von Haunersches Kinderspital, Lindwurmstr. ¨ 4, 80337 Munchen , Germany, 2 Max von Pettenkofer-Institut, ¨ Pettenkofer Str. 9 a, 80336 Munchen , Germany. The main bacterial pathogen in CF is P. aeruginosa. The changes of the antibiotic susceptibility after the initial infection with P. aeruginosa was investigated in a retrospective study. Patients with the first culture positive for P. aeruginosa between 1985 and 1995 and at least three positive cultures over a period $ 24 months were included (mean age at the time of initial infection with P. aeruginosa 11.3614.4 years; 34 males, 38 females). We compared the antibiotic susceptibility of the initial (n 5 88) and the final (n 5 170) strains of P. aeruginosa. The frequency of susceptible strains was as follows: for ciprofloxacin 92% initially versus 77% finally (p 5 0.004), ceftazidime 81% vs. 51% (p , 0.001), tobramycin 73% vs. 42% (p , 0.001), and for imipenem 47% vs. 35% (p 5 0.104). The prevalence of patients with at least one strain moderately sensitive or resistant to ceftazidime increased from 25% initially to 67% finally (p , 0.001), to imipenem from 54% to 85% (p , 0.001), to tobramycin from 32% to 75% (p , 0.001) and to ciprofloxacin from 8% to 29% (p 5 0.104). Therefore, significant changes of the antibiotic susceptibility occur in the individual CF-patient. A combination therapy is strictly recommended to reduce the risk of selection of resistant mutants.
73.* The N-acyl-bomoserine lactones from Pseudomonas aeruginosa can be monitored by green fluorescent protein in vivo. Hong Wu 1 , Zhijun Song 1 , Peter W. Lindum 2 , Claus Moser 1 , Michael Givskov 2 , Niels Høiby 1 . 1 Department of Clinical
Microbiology, University Hospital of Copenhagen, Rigshospitalet, 2 Denmark, Institute of Microbiology, the Technical University of Denmark. Chronic Pseudomonas aeruginosa (PA) lung infection is a main factor responsible for the morbidity and mortality in cystic fibrosis (CF) patients. The infection is impossible to eradicate with antibiotic treatment, because PA grows in biofilm and develops resistance to anti-biotics. The pathogenicity of PA is associated with the virulent factors from the bacteria, which are controlled by a N-acyl homoserine lactone (AHL) based quorum sensing system. Some bacteria containing green fluorescent protein (GFP) can monitor the AHLs from PA in vitro. In the present study we report a method to detect the production of AHLs from PA in vivo. Three E. coli (EC) monitor strains with different GFP in half-life and copy numbers were used as AHL monitors (indicators). The PA and monitors were embedded in alginate and made into alginate beads separately. Mice were challenged intratracheally with PA 1 EC alginate beads or PA beads or EC beads separately, and sacrificed on different days after challenge. Frozen lung sections were prepared for normal fluorescent microscopy and confocal scanning laser microscopy. On day 3, GFP could be detected in the lung tissues challenged with all the 3 different GFP monitors in the mixed beads respectively. From day 5 on, GFP could not be detected in the lungs. In PA or EC control groups, no GFP was found. These results demonstrated that the production of AHLs from PA could be confirmed in vivo by the expression of GFP in the monitoring EC bacteria.
74. Azithromycin reduces epithelial adhesion of P. aeruginosa in patients with cystic fibrosis. J.J. Fischer, U. Baumann, P. ¨ Gudowius, B. Tummler, H. von der Hardt. Dept. of Paediatric Pulmology, Hanover Medical School, Germany. Long term treatment with macrolides was proven beneficial for patients with diffuse panbronchiolitis (DPB), that are chronically infected with Pseudomonas aeruginosa (PA). The mechanisms, however, are still unclear. We assessed the effect of long term treatment ( $ 12 weeks) with azithromycin (AZM) on adhesion of PA on buccal epithelial cells in patients with CF in an open prospective study. 11 children (mean age 14.6 yrs) chronically infected with PA participated. Adhesion was reduced in all patients (p 5 0.0069) by 70% from 8.0 (SD 4.8) to 2.4 (SD 1.1) bacteria per cell, reaching near normal levels (1–2). After termination of treatment with AZM, adhesion started to increase in 3 of 4 patients as yet tested, apparently in a time dependent manner. Since macrolides do not necessarily eradicate PA in DPB, modifying host defence may be responsible for the improved prognosis in this disease. Here, we show that AZM reduces the increased adherence of PA to epithelial cells of CF patients in viva. Our findings provide a new model for a beneficial effect of macrolides that may be of therapeutic relevance.
75. Colonisation Of Pseudomonas aeruginosa in patients with CF at Stockholm CF center. L. Hjelte 1 , A. Geborek 1 , B.-M. Jakobsson 1 , A Samuelson 2 . Departments of 1 Paediatrics, 2 Clinical Bacteriology, Karolinska Institutet, Huddinge Hospital, Huddinge, Sweden.