Distribution of bacterial proteins in biofilms formed by non-typeable Haemophilus influenzae.
The ability to preserve the fragile ultrastructural organization of bacterial biofilms using cryo-preparation methods for electron microscopy has enabled us to probe sections through non-typeable Haemophilus influenzae (NTHi) biofilms and determine the localization of NTHi-specific lipooligosaccharide (LOS) and proteins within these structures. Some of the proteins we examined are currently being considered as candidates for vaccine development, so it is important that their distribution and accessibility within the biofilms formed by NTHi be determined. We have localized LOS to the extracellular matrix (ECM) of the biofilm and the P6 outer membrane protein to the membrane of what appear to be viable bacteria within the biofilm. The Hap and HWM1/HMW2 adhesive proteins were associated with bacteria within the biofilm and were present in the biofilm ECM. The IgA1 protease is a secreted protein that was also associated with NTHi in the biofilm and was in the ECM, but was more concentrated in the top region of the biofilm, suggesting a role in protecting biofilm bacteria from antibody attack.
Ahmanson Advanced Electron Microscopy and Imaging Center, House Ear Institute, Los Angeles, CA 90057, USA. pwebster@hei.org
Paul
P
Webster
Siva
S
Wu
Gerardo
G
Gomez
Michael
M
Apicella
Andrew G
AG
Plaut
Joseph W
JW
St Geme
D018829:Adhesins, Bacterial / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D001431:Bacteriological Techniques; D018441:Biofilms; D004396:Coloring Agents; D015925:Cryopreservation; D005840:Gentian Violet; D018073:Haemophilus Vaccines / Q000378:metabolism; D006193:Haemophilus influenzae / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry; D008070:Lipopolysaccharides / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D010033:Otitis Media / Q000382:microbiology; D012697:Serine Endopeptidases / Q000378:metabolism
D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004396:Coloring Agents; C117431:HMW1 protein, bacteria; C117432:HMW2 protein, bacteria; D018073:Haemophilus Vaccines; C091552:Hap protein, Hemophilus influenzae; D008070:Lipopolysaccharides; C069990:P6 outer membrane protein, Haemophilus; D012697:Serine Endopeptidases; C021433:IgA-specific serine endopeptidase; D005840:Gentian Violet