Experimental intraabdominal candidiasis in rabbits: therapy with low-total-dose intravenous amphotericin B

By using a recently developed rabbit model, we examined the efficacy of relatively low-total-dose intravenous amphotericin B (Am-B; 7 to 14 mg/kg) in the treatment of intraabdominal candidiasis due to Candida albicans. Forty-eight percent of the rabbits developed evidence of hematogenously disseminated infection (Candida endophthalmitis) before therapy. By day 7 of therapy, there was a significant decrease in the mean log10 colony-forming units per gram of peritoneal abscess in comparison with both pretherapy cultures and concomitantly sacrificed controls (no Am-B treatment; P less than 0.25). By day 11 of therapy, peritoneal abscesses were sterilized by Am-B, whereas control rabbit cultures remained positive. In contrast, low-dose Am-B therapy produced no significant decrease in colony-forming units per gram of renal or chorioretinal abscess in rabbits which developed hematogenously disseminated candidiasis. Serum Am-B levels approached or exceeded the minimal fungistatic concentrations for this C. albicans strain in most animals tested. Low-dose Am-B was effective in eradicating intraabdominal candidiasis, but was not curative when extraperitoneal dissemination occurred.