Methods: Utilizing our established murine model of clostridial myonecrosis, we investigated the efficacy of standard antibiotics for anaerobic Gram positive soft-tissue infections (penicillin, clindamycin, tetracycline, vancomycin) in treating C. septicum gas gangrene. Following intramuscular challenge with 1x106 colony forming units of C. septicum, antibiotics were administered by intraperitoneal injection every four hours for a total of four doses.
Results: At 30 hours, all animals in all treatment groups survived the C. septicum challenge, compared to no survivors in the untreated controls (100% mortality by 10 hours). By 60 hours, mice treated with vancomycin exhibited 40% mortality, with no mortality observed in any other antibiotic treatment group. Additionally, microbroth dilution MIC analysis for three strains of C. septicum collectively demonstrated high susceptibility to penicillin, clindamycin and tetracycline, but considerably lower susceptibility to vancomycin.
Conclusion: These studies corroborate that penicillin, clindamycin and tetracycline may be suitable alternatives for the treatment of C. septicum infection in humans.
S. Rice, None
A. Bryant, Merck & Co.: Grant Investigator , Research grant
D. Stevens, None