Effects of beta-toxin of Staphylococcus aureus on ciliary activity of nasal epithelial cells.
OBJECTIVE
To investigate the in vitro effects of staphylococcal beta-toxin on ciliary activity and the in vivo effects on sinusitis induction.


METHODS
The in vitro effects of staphylococcal beta-toxin on ciliary activity were investigated at different concentrations and exposure times. Experimental sinusitis was induced in rabbits with application of beta-toxin and confirmed 7 days later.


METHODS
Ciliated epithelial cells were taken from the maxillary sinus mucosa of 10 rabbits. Five culture dishes from each rabbit were used for the experimental group, and one culture dish from each rabbit was used for the control group. In the experimental group, ciliary beat frequency (CBF) was measured at concentrations of 0.1, 1, 2, 5 and 10 U/mL of beta-toxin using a video-computerized analysis technique, while in the control group, culture medium containing no toxin was used. CBF was measured 1, 2, 4, 6, 8, 12, 24, and 48 hours after administration of beta-toxin. To induce experimental sinusitis, 2 U/mL of beta-toxin was percutaneously applied to the maxillary sinus of 10 rabbits without occlusion of the natural ostium, while normal saline was percutaneously applied to the right-side maxillary sinus of 4 rabbits in the control group. At 7 days, mucosal membranes were taken from the inferomedial wall of the maxillary sinus for light microscopic study.


RESULTS
CBF dropped significantly after an 8-hour incubation at 2, 5, and 10 U/mL of beta-toxin. No ciliary activity was observed after a 24-hour incubation at 2 and 5 U/mL and a 12-hour incubation at 10 U/mL of beta-toxin. Mucoid, purulent discharge was observed in the maxillary sinuses of the beta-toxin-applied group. Prominent epithelial disruption and infiltration of inflammatory cells into the epithelium and lamina propria were observed in the beta-toxin-applied group.


CONCLUSIONS
Staphylococcal beta-toxin may reduce ciliary activity and induce sinusitis without occlusion of the natural ostium of the maxillary sinus in rabbits This study provides another animal model of sinusitis for understanding the pathogenesis of sinusitis induced by bacterial exotoxins.
Kim
C S
CS
Department of Otorhinolaryngology, Seoul Red Cross Hospital, Korea.
Jeon
S Y
SY
Min
Y G
YG
Rhyoo
C
C
Kim
J W
JW
Yun
J B
JB
Park
S W
SW
Kwon
T Y
TY
D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D002478:Cells, Cultured; D002923:Cilia / Q000187:drug effects* / Q000502:physiology; D004195:Disease Models, Animal; D004847:Epithelial Cells; D006460:Hemolysin Proteins; D015523:Maxillary Sinusitis / Q000382:microbiology*; D009297:Nasal Mucosa / Q000166:cytology*; D011817:Rabbits; D013108:Sphingomyelin Phosphodiesterase; D013211:Staphylococcus aureus
D001427:Bacterial Toxins; D006460:Hemolysin Proteins; D013108:Sphingomyelin Phosphodiesterase; C029878:hlb protein, Staphylococcus aureus