Analysis of Moraxella catarrhalis by DNA typing: evidence for a distinct subpopulation associated with virulence traits.
Two DNA typing methods, probe-generated restriction fragment length polymorphism analysis and single-adapter amplified fragment length polymorphism analysis, were used to study the genetic relationships among 90 Moraxella catarrhalis strains. Both methods were found to be highly concordant, generating a dendrogram with 2 main branches. The division of the M. catarrhalis population into 2 subspecies was supported by analysis of the 16S rRNA sequences. Both beta-lactamase-positive and beta-lactamase-negative strains were found in all main branches, suggesting horizontal transfer of the beta-lactamase gene. In contrast, 2 virulence traits, complement resistance and adherence to epithelial cells, were strongly associated with 1 of the 2 subspecies. The branch depth suggested that complement-resistant adherent strains diverged from a common ancestor more recently than did complement-sensitive nonadherent strains. These findings suggest the existence of subpopulations of M. catarrhalis that differ in virulence, and they may have implications for vaccine development.
Bootsma
H J
HJ
Eijkman-Winkler Institute for Microbiology, Infectious Diseases, and Inflammation, Utrecht University, Utrecht, The Netherlands.
van der Heide
H G
HG
van de Pas
S
S
Schouls
L M
LM
Mooi
F R
FR
D000328:Adult; D000942:Antigens, Bacterial / Q000235:genetics; D000954:Antigens, Surface / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001483:Base Sequence; D002353:Carrier State; D002648:Child; D006801:Humans; D007827:Laryngitis / Q000382:microbiology; D008173:Lung Diseases, Obstructive / Q000235:genetics / Q000382:microbiology; D008969:Molecular Sequence Data; D001936:Moraxella catarrhalis / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity*; D016870:Neisseriaceae Infections / Q000235:genetics / Q000382:microbiology; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000737:chemistry; D012141:Respiratory Tract Infections / Q000382:microbiology
D000942:Antigens, Bacterial; D000954:Antigens, Surface; D001425:Bacterial Outer Membrane Proteins; D012336:RNA, Ribosomal, 16S; C089675:UspA protein, Moraxella catarrhalis