Effects on the ciliated epithelium of protein D-producing and -nonproducing nontypeable Haemophilus influenzae in nasopharyngeal tissue cultures.
A pair of isogenic, nontypeable Haemophilus influenzae strains, one expressing protein D and the other protein D-negative, was compared in their ability to cause damage in a human nasopharyngeal tissue culture model. Damage was assessed by measuring the ciliary beat frequency (CBF) of tissue specimens at 12 h intervals. Cultures inoculated with H. influenzae manifested a decrease in CBF beginning after 12 h, with a maximum decrease after 36 h. The impairment of ciliary function by the protein D-expressing strain was significantly greater than that caused by the protein D-negative mutant (P<.01). Tissue specimens examined by scanning and transmission electron microscopy after 24 h appeared normal. After 48 h of incubation, the protein D-expressing strain caused a significant loss of cilia. These findings suggest that protein D is involved in the pathogenesis of upper respiratory tract infections due to nontypeable H. influenzae, probably by enhancing functional and morphological damage to cilia.
Janson
H
H
Department of Medical Microbiology, Lund University, University Hospital, Malmö, Sweden.
Carl n
B
B
Cervin
A
A
Forsgren
A
A
Magnusdottir
A B
AB
Lindberg
S
S
Runer
T
T
D000234:Adenoids / Q000166:cytology / Q000382:microbiology / Q000502:physiology; D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology*; D002923:Cilia / Q000502:physiology* / Q000648:ultrastructure; D004847:Epithelial Cells / Q000382:microbiology / Q000502:physiology* / Q000648:ultrastructure; D006193:Haemophilus influenzae / Q000145:classification / Q000235:genetics / Q000502:physiology*; D006801:Humans; D007072:Immunoglobulin D; D008074:Lipoproteins / Q000235:genetics / Q000502:physiology*; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D009305:Nasopharynx / Q000166:cytology / Q000382:microbiology* / Q000502:physiology*; D009924:Organ Culture Techniques / Q000379:methods
D001426:Bacterial Proteins; D002352:Carrier Proteins; D007072:Immunoglobulin D; D008074:Lipoproteins; C067989:glpQ protein, Haemophilus influenzae