In vitro activity of Sch 34343 and cefbuperazone against anaerobic bacteria

Abstract

The in vitro activities of Sch 34343, a new penem antibiotic, and cefbuperazone, a new cephamycin antibiotic, were determined against 459 clinical anaerobic bacterial isolates and compared with the activities of imipenem and cefoxitin, respectively, by an agar dilution method. Both penems showed potent and similar activity against all anaerobic bacteria tested, Two reference strains (Bacteroides fragilis ATCC 25285 and Clostridium perfringens ATCC 13124) were included on each agar plate to assess reproducibility. Plates were incubated for 48 h at 37°C in anaerobic jars with a gas mixture containing 80% nitrogen, 10% hydrogen, and 10% carbon dioxide. Anaerobic, microaerophilic (incubated in candle jars), and aerobic plates without antibiotics were used for controls. The MIC was the lowest concentration of antibiotic which permitted no visible growth. RESULTSThe reproducibility of the MIC determinations is indicated in Table 1. The MICs of Sch 34343, cefoxitin, and cefbuperazone against both control organisms were within one twofold dilution of the modal MIC for all 13 measurements.

In vitro Activity of SCH-34343, a New Penam, and Other Antimicrobial Agents against Clinical Isolates from Cancer Patients

“…The results of our study are in agreement with those of other investigators [4,6], SCH-34343 has also been shown to be ac tive against anaerobes including Bacteroides fragilis [9], Its lack of antipseudomonal activity makes it less attractive than imipenem, amifloxacin or ceftazidime, particularly for use in neutropenic pa tients in whom P. aeruginosa is a signifi cant pathogen. However, it could be use ful in combination with an agent that has antipseudomonal activity.…”

In vitro susceptibility of Clostridium difficile to new beta-lactam and quinolone antibiotics

“…The isolates were stored in 20% skim milk and frozen at -70°C until ready for susceptibility testing. The MICs for the organisms were determined by an agar dilution method with Wilkins-Chalgren medium and inocula of 105 CFU as previously described (14). Three reference strains (Bacteroides fragilis ATCC 25285, B. thetaiotaomicron ATCC 29741, and C. perfringens ATCC 13124) were included on each agar plate to assess reproducibility.…”