title: Differences in genetic diversity of nonecapsulated Haemophilus influenzae from various diseases.
abstract: Genetic relationships among 80 isolates of nonencapsulated Haemophilus influenzae recovered from different disease types were determined by multilocus enzyme electrophoresis (MEE) at 13 enzyme loci in an attempt to assess the association between multilocus genotype and disease. The isolates were obtained from 15 patients with meningitis, 10 with otitis media, 19 with chronic bronchitis, 20 with cystic fibrosis, and 16 were obtained from healthy carriers. The 80 isolates were assigned to 69 electrophoretic types (ETs) falling into 5 groups. Isolates from each disease entity were represented by a variety of genotypes; however, cluster analysis from a matrix of genetic distances between ETs revealed that the ETs of the otitis media and meningitis isolates were all clustered within a genetic distance of 0.55 (group I). In addition, no genotypes were shared between H. influenzae carrier isolates and isolates from cases of disease, H. influenzae isolates from healthy individuals were distributed significantly differently from those from chronic bronchitis meningitis and otitis media patients. The genetic diversity (H) of carrier strains was greatest, although not statistically different from that of isolates from patients with disease. It was concluded that the genetic distribution of acute disease isolates is not random over the five ET groups, although the genetic diversity within the groups is not different. The effect of bacterial persistence in the host on the genetic diversity of H. influenzae is discussed.
authors.affiliation: Academic Medical Center, Department of Medical Microbiology, Meibergdreef 15, NL-1105 AZ Amsterdam, The Netherlands.
authors.forename: Loek
authors.initials: L
authors.lastname: van Alphen
authors.affiliation: National Institute of Public Health, Department of Bacteriology, 0462 Oslo, Norway.
authors.forename: Dominique A
authors.initials: DA
authors.lastname: Caugant
authors.affiliation: Academic Medical Center, Department of Medical Microbiology, Meibergdreef 15, NL-1105 AZ Amsterdam, The Netherlands.
authors.forename: Birgitta
authors.initials: B
authors.lastname: Duim
authors.affiliation: Dept of Molecular Microbiology, School of Biological Sciences, University of Sussex, Brighton, UK.
authors.forename: Maria
authors.initials: M
authors.lastname: O'Rourke
authors.affiliation: Academic Medical Center, Department of Medical Microbiology, Meibergdreef 15, NL-1105 AZ Amsterdam, The Netherlands.
authors.forename: Lucas D
authors.initials: LD
authors.lastname: Bowler
mesh_terms: D015373:Bacterial Typing Techniques; D001991:Bronchitis / Q000382:microbiology; D002353:Carrier State; D003550:Cystic Fibrosis / Q000382:microbiology; D004586:Electrophoresis / Q000379:methods; D014644:Genetic Variation; D005838:Genotype; D006192:Haemophilus Infections / Q000145:classification / Q000382:microbiology*; D006193:Haemophilus influenzae / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D006801:Humans; D015810:Linkage Disequilibrium; D008581:Meningitis / Q000382:microbiology; D010033:Otitis Media / Q000382:microbiology