Dynamics of Long-Term Colonization of Respiratory Tract byHaemophilus influenzaein Cystic Fibrosis Patients Shows a Marked Increase in Hypermutable Strains
Open Access
- 1 April 2004
- journal article
- research article
- Published by American Society for Microbiology in Journal of Clinical Microbiology
- Vol. 42 (4), 1450-1459
- https://doi.org/10.1128/jcm.42.4.1450-1459.2004
Abstract
The persistence and variability of 188Haemophilus influenzaeisolates in respiratory tract of 30 cystic fibrosis (CF) patients over the course of 7 years was studied. Antibiotic susceptibility testing, DNA fingerprinting, and analysis of outer membrane protein profiles were performed on all isolates. A total of 115 distinct pulsed-field gel electrophoresis profiles were identified. Ninety percent of patients were cocolonized with two or more clones over the studied period. A third of the patients were cross-colonized with one or twoH. influenzaestrains; 11% of the clones persisted for 3 or more months. Biotype, outer membrane protein profiles, and resistance profiles showed variation along the studied period, even in persisting clones. Four isolates (2.1%) recovered from 3 patients were type f capsulate, with three of them belonging to the same clone. β-Lactamase production was detected in 23.9% of isolates while 7% of the β-lactamase-negative isolates presented diminished susceptibility to ampicillin (β-lactamase-negative ampicillin resistance phenotype). Remarkably, 21.3% of theH. influenzaeisolates presented decreased susceptibility to ciprofloxacin, which was mainly observed in persisting clones. Of theH. influenzaeisolates from CF patients, 18 (14.5%) were found to be hypermutable in comparison with 1 (1.4%) from non-CF patients (P< 0.0001). Ten patients (33.3%) were colonized by hypermutable strains over the study period. A multiresistance phenotype and long-term clonal persistence were significantly associated in some cases for up to 7 years. These results suggest thatH. influenzaebronchial colonization in CF patients is a dynamic process, but better-adapted clones can persist for long periods of time.Keywords
This publication has 32 references indexed in Scilit:
- Variable numbers of tandem repeat loci in genetically homogeneousHaemophilus influenzaestrains alter during persistent colonisation of cystic fibrosis patientsFEMS Microbiology Letters, 1999
- Comparative evaluation of an automated ribotyping system versus pulsed-field gel electrophoresis for epidemiological typing of clinical isolates of Escherichia coli and Pseudomonas aeruginosa from patients with recurrent gram-negative bacteremiaDiagnostic Microbiology and Infectious Disease, 1996
- Multiple Haemophilus influenzae Strains and Strain Variants Coexist in the Respiratory Tract of Patients with Cystic FibrosisThe Journal of Infectious Diseases, 1995
- Genomic DNA fingerprinting of clinical Haemophilus influenzae isolates by polymerase chain reaction amplification: comparison with major outer-membrane protein and restriction fragment length polymorphism analysisJournal of Medical Microbiology, 1994
- Epidemiology and Prevention of Respiratory Tract Infections Due to Nonencapsulated Haemophllus influenzaeThe Journal of Infectious Diseases, 1992
- Quality control limits for disk diffusion and broth microdilution susceptibility tests with Haemophilus test mediumDiagnostic Microbiology and Infectious Disease, 1991
- Temporal changes in biotypes of Haemophilus influenzae isolated from patients with cystic fibrosisJournal of Medical Microbiology, 1988
- Multivariate Analysis of Neisseria DNA Restriction Endonuclease PatternsMicrobiology, 1985
- A Taxonomic Study of the Genus Haemophilus, with the Proposal of a New SpeciesJournal of General Microbiology, 1976
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970