cefotaxime and Rodent-Diseases

Focal extraintestinal infections from nontyphoid salmonellae have increased in incidence during the past decade. Typically, they are manifested as either osteomyelitis or meningitis as a complication of either bacteremia or enteric fever. Isolated salmonellal soft tissue infections, however, are rare and occur mostly in adults with chronic underlying conditions such as human immunodeficiency virus (HIV) infection, diabetes mellitus, and cell-mediated immunity defects. We report a case of an otherwise healthy adolescent who was exposed to a guinea pig with a skin mass. She subsequently had an isolated soft tissue infection with cartilaginous involvement of the anterior chest wall due to Salmonella enterica serogroup C1 (bioserotype oranienburg).

Topics: Amoxicillin; Animals; Biopsy; Cartilage Diseases; Cefotaxime; Ceftriaxone; Cephalosporins; Child; Female; Guinea Pigs; Humans; Microbial Sensitivity Tests; Penicillins; Rodent Diseases; Salmonella enterica; Salmonella Infections; Serotyping; Soft Tissue Infections; Tomography, X-Ray Computed

The purpose of this study was to develop a model of bacterial meningitis in young adult rats for assessing the efficacy of antimicrobial agents. Sixty 200- to 300-g male Sprague Dawley CD rats were inoculated intracisternally with 5.78 log10 CFU of a clinical isolate of Streptococcus pneumoniae in 5% hog gastric mucin. Inoculated rats were assigned to six groups containing 10 animals each. Group-1 rats served as controls and did not receive antibiotics. Rats of groups 2 to 4 received (subcutaneously every 12 h) cefotaxime (25, 6.25, and 1.56 mg/kg of body weight respectively). Rats of groups 5 and 6 received ampicillin (50 and 12.5 mg/kg respectively) and gentamicin (2.0 and 0.5 mg/kg respectively). Five additional Sprague Dawley CD rats were inoculated with only gastric hog mucin and were assigned to group 7. At postinoculation day 4 all animals were euthanized. Cerebral spinal fluid was collected for culturing. Brains were harvested for histologic examination and culturing. Untreated, infected control (group-1) animals were culture-positive for S. pneumoniae in the brain and cerebral spinal fluid. Of the antibiotic regimens evaluated, only cefotaxime (25 mg/kg) eradicated bacteria from the cerebral spinal fluid and brain. Cefotaxime at 25 or 6.25 mg/kg significantly (P < or = 0.05) decreased the bacterial burden of S. pneumoniae, whereas cefotaxime at 1.56 mg/kg and ampicillin/gentamicin combinations did not. There was histopathological evidence of subacute meningitis in infected rats. No meningitis was observed in rats receiving 25 mg of cefotaxime/kg. This model demonstrates the ability to induce bacterial meningitis with S. pneumoniae in adult rats and the ability to clear infection in 90 to 100% of the animals by administration of cefotaxime at dosages of 6.25 and 25 mg/kg given subcutaneously every 12 h.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Brain; Cefotaxime; Cerebrospinal Fluid; Disease Models, Animal; Gentamicins; Male; Meninges; Meningitis; Rats; Rats, Sprague-Dawley; Rodent Diseases; Rodentia; Streptococcus pneumoniae