Correlation of susceptibility of Cryptococcus neoformans to amphotericin B with clinical outcome.

Testing of Cryptococcus neoformans for susceptibility to antifungal drugs by standard microtiter methods has not been shown to correlate with clinical outcomes. This report describes a modified quantitative broth macrodilution susceptibility method showing a correlation with both the patient's quantitative biological response in the cerebrospinal fluid (CSF) and the survival of 85 patients treated with amphotericin B (AMB). The Spearman rank correlation between the quantitative in vitro measure of susceptibility and the quantitative measure of the number of organisms in the patient's CSF was 0.37 (P < 0.01; 95% confidence interval [95% CI], 0.20, 0.60) for the first susceptibility test replicate and 0.46 (P < 0.001; 95% CI, 0.21, 0.62) for the second susceptibility test replicate. The median in vitro estimated response (defined as the fungal burden after AMB treatment) at 1.5 mg/liter AMB for patients alive at day 14 was 5 CFU (95% CI, 3, 8), compared to 57 CFU (95% CI, 4, 832) for those who died before day 14. These exploratory results suggest that patients whose isolates show a quantitative in vitro susceptibility response below 10 CFU/ml were more likely to survive beyond day 14.

Activity of antibiotics against Fusarium and Aspergillus.

BACKGROUND/AIMS: To study the susceptibility of Fusarium and Aspergillus isolated from keratitis to amoxicillin, cefazolin, chloramphenicol, moxifloxacin, tobramycin and benzalkonium chloride (BAK). METHODS: 10 isolates of Fusarium and 10 isolates of Aspergillus from cases of fungal keratitis at Aravind Eye Hospital in South India were tested using microbroth dilution for susceptibility to amoxicillin, cefazolin, chloramphenicol, moxifloxacin, tobramycin and BAK. The minimum inhibitory concentration (MIC) median and 90th percentile were determined. RESULTS: BAK had the lowest MIC for both Fusarium and Aspergillus. Chloramphenicol had activity against both Fusarium and Aspergillus, while moxifloxacin and tobramycin had activity against Fusarium but not Aspergillus. CONCLUSIONS: The susceptibility of Fusarium to tobramycin, moxifloxacin, chloramphenicol and BAK and of Aspergillus to chloramphenicol and BAK may explain anecdotal reports of fungal ulcers that improved with antibiotic treatment alone. While some of the MICs of antibiotics and BAK are lower than the typically prescribed concentrations, they are not in the range of antifungal agents such as voriconazole, natamycin and amphotericin B. Antibiotics may, however, have a modest effect on Fusarium and Aspergillus when used as initial treatment prior to identification of the pathological organism.

Efficacy of SCH56592 in a rabbit model of invasive aspergillosis.

SCH56592 (SCH) was evaluated in an immunosuppressed rabbit model of invasive aspergillosis. SCH was more effective than similar doses of itraconazole and as effective as amphotericin B in the clearance of Aspergillus spp. from tissues. Compared with controls, SCH regimens reduced mortality, improved survival, and significantly reduced tissue colony counts.

Pradimicin therapy of disseminated Candida tropicalis infection in the mouse.

BMS 181184 (BMS), an analogue of pradimicin, was administered intravenously to neutropenic mice infected with either a fluconazole-susceptible or a fluconazole-resistant clinical isolate of Candida tropicalis. BMS prolonged survival at doses >3 mg kg -1 day-1, and at higher doses reduced tissue counts in mice. BMS was less potent mg for mg than amphotericin B. Combined BMS and amphotericin B were no more effective than either of the individual drugs.

Clinical evaluation and microbiology of oropharyngeal infection due to fluconazole-resistant Candida in human immunodeficiency virus-infected patients.

Signs and symptoms of oropharyngeal candidiasis (OPC) were correlated with microbiology and clinical response to fluconazole in a cohort of patients with advanced human immunodeficiency virus (HIV) infection and recurrent OPC. Sixty-four HIV-infected patients with a median CD4 cell count of < 50/mm3 (range, 3-318/mm3) who presented with OPC were enrolled in a longitudinal study. Specimens for cultures were taken weekly until clinical resolution. Therapy with fluconazole was increased weekly as required to a maximum daily dose of 800 mg until resolution of symptoms and oral lesions. Resistant or dose-dependent susceptible yeasts, defined as a minimum inhibitory concentration of > or = 16 micrograms/mL, were detected in 48 (31%) of 155 episodes. Clinical resolution with fluconazole therapy occurred in 107 (100%) of 107 episodes with susceptible yeasts vs. 44 (92%) of 48 episodes with resistant or dose-dependent susceptible strains (P = .008). Patients from whom fluconazole-resistant yeasts were isolated required longer courses of therapy and higher doses of fluconazole for response, but overall, excellent responses to fluconazole were seen in patients with advanced HIV infection.

Discrepancy between in vitro and in vivo antifungal activity of albendazole.

Albendazole has in vitro activity against Cryptococcus neoformans and reduced in vitro activity for albendazole when compared with Candida albicans. The major metabolite of albendazole, albendazole sulphoxide showed no in vitro activity against isolates of either fungus. Immunocompetent mice infected intravenously (i.v.) with C. albicans were treated with albendazole doses of 20-600 mg kg-1 per day in noble agar or sesame oil for per oral (PO) administration, or 80 mg kg-1 per day in DMSO for intraperitoneal (i.p.) and i.v. administration for 10 days, and were observed for survival. Mice infected with C. neoformans intracranially received albendazole in daily doses of 600 mg kg-1 prepared in DMSO (i.p.) or peanut butter/rat chow (PO) for 10 days and were observed for survival. Mortality was not different between the treated and control animals in any study. Plasma samples from uninfected mice dosed with similar formulations and doses of albendazole were analysed by HPLC for albendazole and albendazole sulphoxide. No albendazole could be detected in any sample, while concentrations of albendazole sulphoxide (286-8697 ng ml-1) were observed in all samples. These data suggest that the absence of in vivo activity for albendazole is due to rapid conversion to the inactive albendazole sulphoxide metabolite.

Detection and significance of fluconazole resistance in oropharyngeal candidiasis in human immunodeficiency virus-infected patients.

The epidemiology and clinical significance of fluconazole resistance were assessed in a cohort of advanced human immunodeficiency virus (HIV)-infected patients with recurrent oropharyngeal candidiasis. Fifty patients were prospectively evaluated using a novel method of detecting fluconazole resistance with chromogenic media containing fluconazole; results were confirmed with macrobroth testing. Resistant yeasts, defined as MICs > or = 8 micrograms/mL, were detected in 16 (32%) of 50 patients: 7 (14%) had resistant Candida albicans, 7 (14%) had resistant non-C. albicans yeast, and 2 (4%) had mixed resistant yeasts. MICs were > or = 32 in 11 of 16 isolates. Previous fluconazole use and severe immunosuppression were risk factors for resistance. However, 5 of 26 patients had resistant isolates with no prior fluconazole use, and all were severely immunosuppressed. Despite the high prevalence of resistance, 48 patients clinically responded to fluconazole. Fluconazole-resistant C. albicans and non-C. albicans yeast infections are common in patients with advanced immunodeficiency, but clinical efficacy of fluconazole remains high.

A comparison between fluconazole tablets and clotrimazole troches for the treatment of thrush in HIV infection.

Fluconazole, a newly available triazole, has been evaluated extensively as a treatment for thrush. It has been effective in the treatment of this condition in patients with HIV infection. Clotrimazole troches have been a common treatment for thrush in patients with HIV infection for several years. This study compared the efficacy and safety of fluconazole 100 mg tablets once per day versus clotrimazole 10 mg troches five times per day in the treatment of thrush in patients with HIV infection. Patients were evaluated at baseline, day 7, 14, 28, and 42. The following parameters were evaluated: clinical cure, colonization at the end of treatment, relapse at day 28, and relapse at day 42. Side effects including liver enzyme values were also monitored. Clinical cure was superior with fluconazole tablets than with clotrimazole troches. Also, rates of colonization at the end of therapy and relapse at days 28 and 42 were less with fluconazole tablets than with clotrimazole troches. However, these differences were not statistically significant. Patient compliance with fluconazole was superior to that of clotrimazole. This difference was statistically significant. Both fluconazole tablets and clotrimazole troches are effective in treating thrush in patients with HIV infection. The avoidance of multiple-per-day dosing would appear to favor fluconazole.