Maintenance of antimicrobial susceptibility of Acinetobacter baumannii in modeled microgravity.

Abstract

OBJECTIVE: The purpose of this study was to evaluate the effect of a modeled microgravity environment on the antimicrobial resistance of Acinetobacter baumannii. DESIGN: Clinical isolates of A. baumannii (n=10) in Mueller Hinton broth were grown in high aspect ratio vessels using a rotary cell culture system oriented to achieve either normal earth gravity (1 x G) or low sheer modeled microgravity (LSMMG) conditions. After culture MICs were determined by Etest. Antimicrobials included in the study were amikacin, ampicillin/sulbactam, azithromycin, ceftazidime, gatifloxacin, gentamicin, imipenem, meropenem, minocycline, ticarcillin/clavulanic acid, tigecycline, and trimethoprim/sulfamethoxazole. Results were compared for MIC value and category interpretation (S, I, R). RESULTS: Overall category agreement was 100% (360/360). 100% of MIC values compared were within one twofold dilution of each other. CONCLUSION: Under these test conditions LSMMG had no apparent effect on the resistance pattern of A. baumannii.