Development of a Streptococcus pneumoniae keratitis model in mice.
BACKGROUND
Streptococcus pneumoniae is a common cause of bacterial keratitis, and models to examine the ocular pathogenesis of this bacterium would aid in efforts to treat pneumococcal keratitis. The aim of this study was to establish a murine model of pneumococcal keratitis.


METHODS
The corneas of A/J, BALB/c or C57BL/6 mice were scratched and topically infected with a clinical strain of S. pneumoniae. Slitlamp examination (SLE), enumeration of bacteria in the corneas and histology were performed.


RESULTS
Bacteria were recovered from the eyes of A/J mice on postinfection (PI) days 1 [1.96 +/- 0.61 log(10) colony-forming units (CFU)] and 3 (1.41 +/- 0.71 log(10) CFU). SLE scores were significantly higher in the infected A/J mice as compared to the BALB/c or C57BL/6 mice on PI day 3 (p < 0.0001) and steadily increased over time, reaching a maximal value of 3.00 +/- 0.35 on PI day 10. Histopathology revealed stromal edema and the influx of polymorphonuclear leukocytes on PI days 7 and 10, and corneal disruption on PI day 7.


CONCLUSIONS
S. pneumoniae keratitis was established in A/J mice, but not BALB/c or C57BL/6 mice.
Moore
Quincy C
QC
Department of Microbiology, University of Mississippi Medical Center, Jackson, Miss. 39216, USA.
McCormick
Clare C
CC
Norcross
Erin W
EW
Onwubiko
Chinwendu
C
Sanders
Melissa E
ME
Fratkin
Jonathan
J
McDaniel
Larry S
LS
O'Callaghan
Richard J
RJ
Marquart
Mary E
ME
D000818:Animals; D003315:Cornea / Q000382:microbiology / Q000473:pathology; D015715:Corneal Edema / Q000209:etiology / Q000473:pathology; D004195:Disease Models, Animal; D015818:Eye Infections, Bacterial / Q000150:complications / Q000382:microbiology* / Q000473:pathology; D054884:Host-Pathogen Interactions; D006801:Humans; D007634:Keratitis / Q000209:etiology* / Q000473:pathology; D051379:Mice; D008815:Mice, Inbred Strains; D009504:Neutrophils / Q000473:pathology; D011008:Pneumococcal Infections / Q000150:complications / Q000382:microbiology* / Q000473:pathology; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*