VARIATION IN METABOLIC ENZYME-ACTIVITY OF PERSISTENT HAEMOPHILUS-INFLUENZAE IN RESPIRATORY TRACTS OF PATIENTS WITH CYSTIC-FIBROSIS

Haemophilus influenzae organisms were isolated from sputum specimens p rospectively collected from 40 patients with cystic fibrosis during 2 years to study variations in the metabolic enzyme activities of persis tent H. influenzae strains as determined by biotyping, In total, 97 di stinct H. influenzae strains without variations in their major outer m embrane protein (MOMP) patterns and 73 MOMP variants derived from 30 o f these distinct strains were obtained, Twelve distinct strains and 42 MOMP variant strains were isolated at multiple time points during the study period, indicating the persistence of these strains. Among the 54 persistent H. influenzae strains, 22 (41%) strains with stable MOMP compositions showed random variations in biotypes, In 39 of 103 (38%) H. influenzae strains, biotype changes coincided with MOMP variations , Biotype variations were the result of both the loss and the acquisit ion of enzyme activities, The results of the study indicate that chang es in metabolic enzyme activity occur randomly during the persistence of H. influenzae organisms in cystic fibrosis patients, irrespective o f MOMP variations.