Characterization of mucosal biofilms on human adenoid tissues.
OBJECTIVE
To demonstrate the presence of mucosal biofilm in adenoid tissue using double staining for visualization of both the bacterial matrix and the bacterial cells. To identify bacterial species present on the surface of the studied adenoids.


METHODS
Prospective study.


METHODS
A total of 39 specimens of adenoidectomy were removed from children with chronic and/or recurrent otitis media. The specimens were prepared for light microscopy using Gram staining, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Double staining was performed with CLSM to visualize both the bacteria and the glycocalyx matrix. Nine adenoids on which bacterial biofilms were visualized with CLSM were used for identification of bacterial species by 16S-DNA polymerase chain reaction (PCR) amplification and homology analysis.


RESULTS
Of the 39 adenoids investigated, 22 (54%) showed evidence of mucosal biofilms. Gram staining, SEM and CLSM showed the presence of bacterial cells, organized in bacterial microcolonies. CLSM with double staining demonstrated mucosal biofilms by showing the presence of both bacteria and the glycocalyx. The use of 16S-DNA polymerase chain reaction (PCR) amplification and subsequent sequence analyses identified the presence of Corynebacterium argentoratense, Streptococcus salivarius, Micrococcus luteus, and Staphylococcus aureus.


CONCLUSIONS
This study demonstrates that adenoid tissue in children with chronic or/and recurrent otitis media contains mucosal biofilms in 54% of the cases. The existence of living bacteria has been demonstrated. Further studies are required to describe the panel of bacteria that can be harbored in the biofilms present in adenoids and the mechanisms involved in the physiopathology of otitis prone children.
Kania
Romain E
RE
Department of Oto-Rhino-Laryngology, Head & Neck Surgery, Leiden University Medical Center, Leiden, The Netherlands. romain.kania@lrb.aphp.fr
Lamers
Gerda E M
GE
Vonk
Marcel J
MJ
Dorpmans
Esmee
E
Struik
Joyce
J
Tran Ba Huy
Patrice
P
Hiemstra
Pieter
P
Bloemberg
Guido V
GV
Grote
Jan J
JJ
D000233:Adenoidectomy; D000234:Adenoids / Q000382:microbiology*; D018441:Biofilms / Q000145:classification*; D002648:Child; D002908:Chronic Disease; D004396:Coloring Agents; D003352:Corynebacterium / Q000145:classification / Q000502:physiology; D004269:DNA, Bacterial / Q000032:analysis; D019276:Glycocalyx / Q000382:microbiology / Q000648:ultrastructure; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016982:Micrococcus luteus / Q000502:physiology; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D010033:Otitis Media / Q000382:microbiology / Q000601:surgery; D011446:Prospective Studies; D012008:Recurrence; D013211:Staphylococcus aureus / Q000502:physiology; D013291:Streptococcus / Q000145:classification / Q000502:physiology
D004396:Coloring Agents; D004269:DNA, Bacterial