Effects of alpha-toxin-deficient Staphylococcus aureus on the production of peripheral corneal ulceration in an animal model.
OBJECTIVE
To examine the role of Staphylococcus aureus alpha-toxin in contact lens-induced peripheral ulceration (CLPU).


METHODS
Proteolytic enzyme, hyaluronidase, alpha-toxin, and beta-toxin production by S. aureus 8325-4 and its alpha-toxin-deficient mutant (S. aureus DU1090) were examined. Using a rabbit model of CLPU, animals were fitted with hydrogel contact lenses colonized by either S. aureus 8325-4 or the mutant strain. The clinical presentation, bacterial cultures, and histology of the ulceration were examined.


RESULTS
Both strains of S. aureus produced similar levels of caseinase, gelatinase, elastase, hyaluronidase, and beta-toxin. S. aureus DU1090 induced weaker haemolysis of rabbit blood cells than S. aureus 8325-4. Ulceration in the S. aureus DU1090 eye was less frequent and less severe than that caused by S. aureus 8325-4.


CONCLUSIONS
The enzyme production profile of S. aureus DU1090 was similar to the parent strain. S. aureus strains may produce CLPU-like lesions irrespective of alpha-toxin production, but severe infectious lesions are produced only in the presence of alpha-toxin.
Wu
Peter Z J
PZ
Vision Cooperative Research Centre and Cornea and Contact Lens Research Unit, School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia.
Zhu
Hua
H
Stapleton
Fiona
F
Hume
Emma
E
Aliwarga
Yulina
Y
Thakur
Archana
A
Willcox
Mark D P
MD
D000818:Animals; D001422:Bacterial Adhesion / Q000502:physiology; D001427:Bacterial Toxins; D015169:Colony Count, Microbial; D003261:Contact Lenses / Q000382:microbiology; D003320:Corneal Ulcer / Q000382:microbiology* / Q000473:pathology; D004195:Disease Models, Animal; D015818:Eye Infections, Bacterial / Q000382:microbiology* / Q000473:pathology; D018093:Gelatinases / Q000378:metabolism; D006460:Hemolysin Proteins / Q000502:physiology*; D006821:Hyaluronoglucosaminidase / Q000378:metabolism; D008666:Metalloendopeptidases / Q000378:metabolism; D009504:Neutrophils / Q000201:enzymology; D010196:Pancreatic Elastase / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D011817:Rabbits; D013203:Staphylococcal Infections / Q000382:microbiology* / Q000473:pathology; D013211:Staphylococcus aureus / Q000201:enzymology / Q000502:physiology*
D001427:Bacterial Toxins; D006460:Hemolysin Proteins; C021091:staphylococcal alpha-toxin; D009195:Peroxidase; D006821:Hyaluronoglucosaminidase; D010196:Pancreatic Elastase; D018093:Gelatinases; D008666:Metalloendopeptidases; C030895:caseinase