Clindamycin Protects Nonhuman Primates Against Inhalational Anthrax But Does Not Enhance Reduction of Circulating Toxin Levels When Combined With Ciprofloxacin.

BACKGROUND: Inhalational anthrax is rare and clinical experience limited. Expert guidelines recommend treatment with combination antibiotics including protein synthesis-inhibitors to decrease toxin production and increase survival, although evidence is lacking. METHODS: Rhesus macaques exposed to an aerosol of Bacillus anthracis spores were treated with ciprofloxacin, clindamycin, or ciprofloxacin + clindamycin after becoming bacteremic. Circulating anthrax lethal factor and protective antigen were quantitated pretreatment and 1.5 and 12 hours after beginning antibiotics. RESULTS: In the clindamycin group, 8 of 11 (73%) survived demonstrating its efficacy for the first time in inhalational anthrax, compared to 9 of 9 (100%) with ciprofloxacin, and 8 of 11 (73%) with ciprofloxacin + clindamycin. These differences were not statistically significant. There were no significant differences between groups in lethal factor or protective antigen levels from pretreatment to 12 hours after starting antibiotics. Animals that died after clindamycin had a greater incidence of meningitis compared to those given ciprofloxacin or ciprofloxacin + clindamycin, but numbers of animals were very low and no definitive conclusion could be reached. CONCLUSION: Treatment of inhalational anthrax with clindamycin was as effective as ciprofloxacin in the nonhuman primate. Addition of clindamycin to ciprofloxacin did not enhance reduction of circulating toxin levels.

Histology surrounding cystotomy healing in a Sprague-Dawley rat model.

INTRODUCTION AND HYPOTHESIS: The purpose of this study was to histologically chronicle wound healing following cystotomy repair using a small animal model. METHODS: Thirty female Sprague-Dawley rats were included in this study. Twenty-eight rats underwent a vertical cystotomy in the bladder dome, which was repaired in a single continuous fashion. Two rats served as histological controls. Following cystotomy repair, groups of three to four rats were studied at single day intervals for 4 days, then at 2-day intervals until 10 days post-repair. The animal bladders were harvested and examined for inflammation, scar formation, and bladder healing. RESULTS: Thirty rat bladders were histologically examined. An inflammatory wound phase was observed during the first 4 days after wounding. Transition from acute to chronic inflammation was observed at day 2 with chronic inflammation persisting through day 10. Inflammation severity peaked 4 days post-wounding without regression through day 10. Evidence of proliferative phase wound healing was first observed 4 days post-wounding. CONCLUSION: Early increases in wound healing are due to inflammatory events such as fibrin plugging of the wound. Later developments after day 4 are due to wound proliferation, collagen deposition, and re-epithelialization. Additionally, wound healing in the rat bladder is observed on a continuum and not necessarily in discrete stages observed on precisely the same postoperative day in each animal.