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D W Denning

Publications and source records attributed to D W Denning.

At least 19 recordsLinked to original sources
PubMed1995

Resistance to fluconazole in Candida albicans from AIDS patients correlated with reduced intracellular accumulation of drug.

Mucosal candidosis is an almost inevitable consequence of AIDS. Resistance to fluconazole therapy associated with enhanced tolerance, detectable in microbiological estimation of sensitivity, occurs in up to 10% of cases with late-stage AIDS. We report here our biochemical analysis of the basis of resistance in a study of two susceptible and two resistant isolates. Resistance was not associated with a change in the target enzyme sterol 14 alpha-demethylase, as indicated by equivalent levels of fluconazole inhibition of activity in extracts from all four isolates, or by mutations in sterol delta desaturase as previously observed in Saccharomyces cerevisiae and Ustilago maydis. Reduced cellular content of fluconazole in the resistant isolates of between six to ten-fold was observed which could account for their resistant phenotype.

AIDS-Related Opportunistic Infections↗
PubMed1995

Liposomal amphotericin B (AmBisome) therapy in invasive fungal infections. Evaluation of United Kingdom compassionate use data.

BACKGROUND: Invasive fungal infections in the immunocompromised patient are associated with substantial mortality. The use of conventional amphotericin B, the main-stay of treatment, has often been limited by its adverse effects. The incorporation of amphotericin B into liposomes enables more drug to be given without an increase in adverse reactions. We examined the efficacy of AmBisome (Vestar Inc, San Diego, Calif), a small unilamellar liposomal formulation of amphotericin B, in the treatment of mycologically proven systemic fungal diseases. METHODS: A retrospective analysis of the "Compassionate Use of AmBisome" in 58 patients who were treated in 34 centers throughout the United Kingdom between July 1990 and August 1992, before licensure of the drug. RESULTS: Thirty patients had a definite or probable mycologic diagnosis, including 17 who had invasive aspergillosis, nine with Candida infections (three with mucosal disease only), three with zygomycosis, and one with cryptococcal meningitis. The overall response rate was 59% for patients with aspergillosis (80% for those who had had no prior therapy with amphotericin B) and 56% for those with candidosis. More than 40% of those in whom AmBisome was used as "salvage therapy" responded. A daily dose of up to 5 mg/kg was tolerated with minimal side effects. CONCLUSIONS: AmBisome is efficacious in the treatment of invasive fungal infections and provides an alternative therapy for those who fail to respond or become intolerant to conventional amphotericin B therapy.

Adolescent↗
PubMed1995

When to use fluconazole.

Explore the source record for details and available documents.

AIDS-Related Opportunistic Infections↗
PubMed1995

Molecular typing of Aspergillus species.

In the last four years, several molecular typing methods have been applied to various Aspergillus species, primarily A. fumigatus and A. niger. Many 'clones' or DNA types exist in the environment and in patients. The most discriminatory methods appear to be restriction fragment length polymorphism analysis with or without specific probes and random amplification of polymorphic DNA analysis. Insufficient work on interlaboratory reproducibility has been done. Most patients are infected by single DNA types, although occasionally multiple isolates are detected. Little work has been done with regard to detailed hospital epidemiology using molecular typing methods.

Aspergillus↗
PubMed1995

Scedosporium prolificans, a multi-resistant fungus, from a U.K. AIDS patient.

We report the first isolation of Scedosporium prolificans (inflatum) in the U.K. The patient, with advanced AIDS and neutropenia, had respiratory tract colonisation over many months without invasive disease despite neutropenia, while on itraconazole therapy. The organism was resistant in vitro to all licensed systemic antifungal agents tested.

AIDS-Related Opportunistic Infections↗
PubMed1995

Aspergillus fungemia: report of two cases and review.

We present two cases of aspergillus infection confirmed by blood culture and review 30 other cases of genuine aspergillus fungemia and 34 cases of aspergillus pseudofungemia. Multiple different media and blood culture systems were used to isolated Aspergillus. The median time to positive blood culture was 8.5 days (range, 1-27 days) in the genuine cases. Genuine aspergillus fungemia was observed more often after cardiac surgery (n = 11 [34%]) or during neutropenia (n = 9 [28%]) than in other settings. In a recent series of fungemia during neutropenia, 7.6% of all episodes were due to Aspergillus. Other patients at risk for aspergillus fungemia were similar to those at risk for invasive aspergillosis, including patients with AIDS. Seven (44%) of 19 patients who were treated survived. In the group of patients with aspergillus pseudofungemia, there were no deaths, and cultures of additional specimens from the same patient were not positive. Criteria that may be applied to ascertain whether the isolation of Aspergillus from blood cultures is clinically significant are put forward.

Aged↗
PubMed1995

In vitro activity of D0870 compared with those of other azoles against fluconazole-resistant Candida spp.

We compared the in vitro activity of a new triazole, D0870, with those of fluconazole, itraconazole, and ketoconazole against 41 clinical isolates of fluconazole-resistant Candida belonging to nine different species. The 50% inhibitory concentrations (IC50s) were determined by a microdilution method with morpholinopropanesulfonic acid (MOPS)-buffered RPMI medium and an inoculum of approximately 10(4) yeasts per ml. After incubation for 48 h at 37 degrees C the optical density at 550 nm was measured. The IC50 was the lowest drug concentration which reduced the optical density at 550 nm by > or = 50% compared with that for a drug-free control. D0870 had significant activity against many of the isolates. Its activity was comparable to that of ketoconazole, slightly superior to that of itraconazole, and markedly superior to that of fluconazole against Candida albicans. Against Candida glabrata, Candida krusei, and Candida inconspicua, it had activity similar to those of itraconazole and ketoconazole but had activity superior to that of fluconazole. D0870 IC50s for some isolates were increased. This may be due to cross-resistance mechanisms because the IC50s of both itraconazole and ketoconazole for these isolates were often high. When IC50s and IC80s were compared there was a marked organism and drug variation. With C. glabrata much higher endpoints for itraconazole were observed when an IC80 endpoint was used. For C. albicans there was also a significant shift upward in endpoints for itraconazole and ketoconazole. Values were changed little when IC50 and IC80 endpoints of D0870 were compared. For 35 of 41 isolates tested the D0870 IC50 was less than the 2.5-mg/liter breakpoint threshold proposed previously. Therefore, D0870 may be a useful agent for the therapy of infections caused by fluconazole-resistant Candida spp.

Antifungal Agents↗
PubMed1995

Efficacy of D0870 compared with those of itraconazole and amphotericin B in two murine models of invasive aspergillosis.

D0870 is a novel azole antifungal compound. It was compared with conventional amphotericin B and itraconazole therapy in two murine models of invasive aspergillosis, one a systemic nonimmunocompromised mouse model and the other a temporarily neutropenic mouse respiratory model. D0870 was given orally and achieved measurable concentrations in serum approximately proportional to the daily dose with accumulation over time if it was given twice daily. Amphotericin B at 3.3 mg/kg of body weight was given intraperitoneally for four to six doses, and itraconazole was given orally in a cyclodextrin suspension at 5 to 50 mg/kg daily or twice daily (BID). The duration of therapy varied from 7 to 14 days. In the nonimmunocompromised mouse model, D0870 at 25 mg/kg BID was slightly inferior to amphotericin B and itraconazole with regard to mortality, with a median survival of 20 days for the three groups (P = 0.03 compared with amphotericin B). However, D0870 at 25 mg/kg BID was inferior to amphotericin B (but not itraconazole) with respect to renal culture (P = 0.01) and brain culture (P = 0.0001) results. Only amphotericin B was statistically superior to controls with regard to mortality. In the neutropenic mouse respiratory model, D0870 at 50 mg/kg/day was superior to amphotericin B, itraconazole, and controls with regard to mortality. D0870 at both 25 and 50 mg/kg/day was statistically superior to controls with regard to lung culture results (P = 0.004 to 0.04). A second experiment with a higher inoculum showed that no drug regimen was effective in that model. In all models low doses and concentrations of D0870 in serum were ineffective. D0870 has some efficacy for the treatment of invasive aspergillosis when it is given at modest doses.

Amphotericin B↗
PubMed1994

High prevalence of antifungal resistance in Candida spp. from patients with AIDS.

Three hundred and forty-eight isolates of Candida spp. from patients treated at a regional infectious diseases unit for AIDS, immunocompromised patients admitted to the Hope Hospital and isolates referred from around the North West of England were tested for their in-vitro susceptibility to amphotericin B, fluconazole and flucytosine using standardized methods. Candida albicans comprised 73% of isolates, Candida glabrata 10% and Candida parapsilosis 7%. Ninety-six percent of isolates were susceptible to amphotericin B and resistance to > or = 12.5 mg/L fluconazole was found in 61 (17.5%) of the 348 isolates tested. Among isolates from patients with AIDS the incidence of fluconazole resistance was 33% whereas in other patients the incidence was only 11%. Flucytosine resistance was seen in only 12 (3.4%) isolates, 11 of which were C. albicans and in 6.5% of isolates from patients with AIDS. Resistance to fluconazole and flucytosine is now sufficiently prevalent among Candida spp. isolated from patients with AIDS to warrant routine susceptibility testing of yeast isolates.

AIDS-Related Opportunistic Infections↗
PubMed1992

Control of invasive pulmonary aspergillosis with oral itraconazole in a bone marrow transplant patient.

Pulmonary aspergillosis following bone marrow transplantation carries a mortality of 94%, irrespective of current treatment. We treated a patient who had acquired aspergillosis some 80 days after allogeneic bone marrow transplantation, with oral itraconazole, 600 mg daily. After initial deterioration, clinical and radiographic resolution occurred during 3 months of therapy despite severe graft-vs.-host and cytomegalovirus disease. Itraconazole should be considered for therapy of pulmonary aspergillosis in this and other immunocompromised settings.

Administration, Oral↗