Abstract

Following the intraperitoneal inoculation of 200 Wistar rats (96 males, 96 females and 8 controls) aged 2 to4 months with graded-doses of saline and peptone water broth cultures of Staphylococcus aureus, Staphylococcus xylosus and Staphylococcus lentus isolates obtained from urinary tract infection (UTI) in Enugu, Nigeria and typed down to species using API® Staph typing kit, the rats were observed for 72 h and were euthanized. The liver, kidney and bladder were harvested and processed histologically. Out of the 96 rats (48 males and 48 females) inoculated with peptone water broth cultures of S. aureus 834, S. xylosus 837, S. aureus 856 and S. lentus 853 strains, 12 (12.5%) died, with 8 (66.7%) from S. xylosus 837 and 4 (33.3%) from S. aureus 856 but no death from S. aureus 834 and S. lentus 853. More males 6(75%) died from S. xylosus 837 than females 2 (25%) while more females 4 (100%) died from S. aureus 856 than males 0 (0%). No death occurred from inoculation of another 96 rats with saline broth culture of the test strains. Evidence of necrosis of the liver parenchyma with infiltration of the inflammatory cells around the pericentral areas upon S. aureus inoculation was observed. S. xylosus and S. lentus showed no histological damage to the liver. In the kidney, S. aureus produced tubular casts, erosions and glomerular oedema. S. xylosus and S. lentus produced tubular casts, glomerular distortions and oedema. The bladder showed mild effect on the musculature with S. aureus and none for S. xylosus and S. lentus, respectively.

Key words: Staphylococcus species, liver, kidney, bladder, intraperitoneal inoculation, mortality rate and damage.