title: [Laboratory and clinical study on combined effects of fosfomycin plus sulbactam/cefoperazone for mixed infections of MRSA and Pseudomonas aeruginosa].
abstract: Pseudomonas aeruginosa has been a major bacterial partner when MRSA (Methicillin-resistant Staphylococcus aureus) is isolated clinically. Hence, we studied the in vitro combined effect of fosfomycin (FOM) plus sulbactam/cefoperazone (SBT/CPZ) against mixed infections of MRSA and P. aeruginosa. The combined effect of FOM plus SBT/CPZ was observed through an FIC index using the checkerboard method, log reduction of colony counts on the time killing curve, and morphological changes observed using scanning electron micrography. Under serum concentration at 3 hours after administration in consider of pharmacokinetics, the combination effect was also evaluated. Furthermore, we evaluated a time-lag combination therapy in which FOM is administered 60 minutes before SBT/CPZ administration for mixed infections. Synergistic effects of FOM plus SBT/CPZ were clearly observed against mixed infections of MRSA and P. aeruginosa. Log reduction of colony counts on the time killing curve seemed to be an appropriate indicator in the evaluation of synergistic effects.
authors.affiliation: Department of Internal Medicine, Cancer Institute Hospital.
authors.forename: I
authors.initials: I
authors.lastname: Hayashi
authors.forename: M
authors.initials: M
authors.lastname: Sakurai
authors.forename: M
authors.initials: M
authors.lastname: Ichiki
authors.forename: I
authors.initials: I
authors.lastname: Sekine
authors.forename: K
authors.initials: K
authors.lastname: Nakayama
authors.forename: J
authors.initials: J
authors.lastname: Shiotani
authors.forename: T
authors.initials: T
authors.lastname: Yoshida
authors.forename: M
authors.initials: M
authors.lastname: Niida
authors.forename: M
authors.initials: M
authors.lastname: Ogawa
authors.forename: A
authors.initials: A
authors.lastname: Koumoto
mesh_terms: D000368:Aged; D002438:Cefoperazone / Q000494:pharmacology / Q000627:therapeutic use; D004359:Drug Therapy, Combination / Q000494:pharmacology / Q000627:therapeutic use*; D005578:Fosfomycin / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D008297:Male; D016106:Methicillin Resistance; D011552:Pseudomonas Infections / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification; D013203:Staphylococcal Infections / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D013407:Sulbactam / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D005578:Fosfomycin; D002438:Cefoperazone; D013407:Sulbactam