title: Effect of nikkomycin Z and 50% human serum on the killing activity of high-concentration caspofungin against Candida species using time-kill methodology.
abstract: Caspofungin and nikkomycin Z (NIK) efficacy alone and in combination were tested against seven Candida species showing or not showing paradoxical growth (PG) against caspofungin in time-kill test in RPMI-1640. Selected isolates against caspofungin and NIK were also tested in 50% serum. PG was always eliminated by NIK as well as by serum. In the serum, 1 and 16 μg/ml caspofungin yielded 0.14-4.0 and 0.34-4.0 log CFU decreases from the starting inocula for C. albicans, C. glabrata, C. tropicalis, and C. dubliniensis, respectively. CFU decrease (0.10-2.08 log) at 16 μg/ml, but not at lower caspofungin concentration was noted against C. parapsilosis, C. orthopsilosis, and C. metapsilosis. One C. parapsilosis isolate was not inhibited even by 16 μg/ml caspofungin. Caspofungin against C. albicans, C. glabrata, C. tropicalis, and C. dubliniensis maintained its activity in serum at even 1 μg/ml concentration. PG seems to an in vitro phenomenon, without clinical relevance.
authors.affiliation: Department of Medical Microbiology, Medical and Health Science Center, University of Debrecen, Hungary.
authors.forename: Judit
authors.initials: J
authors.lastname: Szilágyi
authors.forename: Richárd
authors.initials: R
authors.lastname: Földi
authors.forename: Sedigh
authors.initials: S
authors.lastname: Bayegan
authors.forename: Gábor
authors.initials: G
authors.lastname: Kardos
authors.forename: László
authors.initials: L
authors.lastname: Majoros
mesh_terms: D000617:Aminoglycosides / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000145:classification / Q000187:drug effects* / Q000254:growth & development; D002177:Candidiasis / Q000188:drug therapy* / Q000382:microbiology*; D000077336:Caspofungin; D004359:Drug Therapy, Combination; D054714:Echinocandins / Q000494:pharmacology*; D006801:Humans; D055666:Lipopeptides; D008826:Microbial Sensitivity Tests; D044967:Serum / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000617:Aminoglycosides; D000935:Antifungal Agents; D054714:Echinocandins; D055666:Lipopeptides; C011952:nikkomycin; D000077336:Caspofungin