Goldberg J, Connolly P, Schnizlein-Bick C, Durkin M, Kohler S, Smedema M, Brizendine E, Hector R, Wheat J. Comparison of nikkomycin Z with amphotericin B and itraconazole for treatment of histoplasmosis in a murine model.
Antimicrob Agents Chemother 2000;
44:1624-9. [PMID:
10817719 PMCID:
PMC89923 DOI:
10.1128/aac.44.6.1624-1629.2000]
[Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nikkomycin Z was tested both in vitro and in vivo for efficacy against Histoplasma capsulatum. Twenty clinical isolates were tested for susceptibility to nikkomycin Z in comparison to amphotericin B and itraconazole. The median MIC was 8 microg/ml with a range of 4 to 64 microg/ml for nikkomycin Z, 0.56 microg/ml with a range of 0.5 to 1.0 microg/ml for amphotericin B, and < or =0.019 microg/ml for itraconazole. Primary studies were carried out by using a clinical isolate of H. capsulatum for which the MIC of nikkomycin Z was greater than or equal to 64 microg/ml. In survival experiments, mice treated with amphotericin B at 2.0 mg/kg/dose every other day (QOD) itraconazole at 75 mg/kg/dose twice daily (BID), and nikkomycin Z at 100 mg/kg/dose BID survived to day 14, while 70% of mice receiving nikkomycin Z at 20 mg/kg/dose BID and none of the mice receiving nikkomycin Z at 5 mg/kg/dose BID survived to day 14. All vehicle control mice died by day 12. Fungal burden was assessed on survivors. Mice treated with nikkomycin Z at 20 and 100 mg/kg/dose BID had significantly higher CFUs per gram of organ weight in quantitative cultures and higher levels of Histoplasma antigen in lung and spleen homogenates than mice treated with amphotericin B at 2.0 mg/kg/dose QOD or itraconazole at 75 mg/kg/dose BID. Studies also were carried out with a clinical isolate for which the MIC of nikkomycin Z was 4 microg/ml. All mice treated with amphotericin B at 2.0 mg/kg/dose QOD; itraconazole at 75 mg/kg/dose BID; and nikkomycin Z at 100, 20, and 5 mg/kg/dose BID survived until the end of the study at day 17 postinfection, while 30% of the untreated vehicle control mice survived. Fungal burden assessed on survivors showed similar levels of Histoplasma antigen in lung and spleen homogenates of mice treated with amphotericin B at 2.0 mg/kg/dose QOD; itraconazole at 75 mg/kg/dose BID; and nikkomycin Z at 100, 20, and 5 mg/kg/dose BID. The three surviving vehicle control mice had significantly higher antigen levels in lung and spleen than other groups (P<0.05). The efficacy of nikkomycin Z at preventing mortality and reducing fungal burden correlates with in vitro susceptibility.
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