Antifungal step-down therapy based on hospital intravenous to oral switch policy and susceptibility testing in adult patients with candidaemia: a single centre experience.

AIMS: Echinocandins are recommended for the treatment of candidaemia in moderately severe to severely ill patients. Step-down or de-escalation from echinocandin to fluconazole is advised in patients who are clinically stable but data in relation to step-down therapy are sparse. Using our hospital intravenous to oral switch therapy (IVOST) policy to guide antifungal de-escalation in patients with candidaemia, we aimed to determine what proportion of patients are de-escalated to fluconazole, the timescale to step-down, associated reduction in consumption of echinocandins and antifungal cost savings. METHODOLOGY: Patients with candidaemia were followed from April 2011 to March 2013. RESULTS: A total of 37 episodes of candidaemia were documented during the study period. Twenty-seven patients were commenced on an echinocandin or voriconazole and 19 (70.3%) were de-escalated to fluconazole based on the IVOST policy. The mean and median number of days to de-escalation of therapy was 4.6 and 5 days, respectively. One patient whose therapy was de-escalated relapsed. The overall 30 day crude mortality was 37.1%. The step-down approach led to significant saving in antifungal drug cost of £1133.88 per candidaemic episode and £2208.08 per de-escalation. CONCLUSION: Implementation of IVOST policy led to streamlining of antifungal therapy.

Introduction of a dermatophyte polymerase chain reaction assay to the diagnostic mycology service in Scotland.

BACKGROUND: Dermatophytes are the major cause of superficial mycoses in samples submitted to Clinical Mycology, Glasgow. The most prevalent species is Trichophyton rubrum as identified classically by microscopy and culture. Recent advances in polymerase chain reaction (PCR) technology were examined for the feasibility of introducing a T. rubrum real-time PCR assay into a routine diagnostic service. OBJECTIVE: To improve the diagnostic mycology service by the introduction of a real-time PCR test for T. rubrum. METHODS: The DNA from 4972 nail and skin samples was obtained using the Qiagen QIAsymphony automated extractor. This DNA was subjected to real-time PCR using T. rubrum-specific primers and a probe. RESULTS: During phase 1 of the study, 862 samples were analysed; 446 of 470 specimens that grew T. rubrum were detected by PCR. Out of 4110 samples analysed during phase 2, 753 T. rubrum infections were diagnosed and reported within 72 h. A total of 3357 samples were negative for a fungal infection by PCR and microscopy; these were also reported within 72 h. CONCLUSIONS: A vast reduction in the turnaround times can be achieved using this technique as opposed to classical methods. Samples which are PCR negative but microscopy positive are still subjected to culture. Screening samples for their suitability for PCR prior to processing eliminates the application of PCR for T. rubrum on inappropriate samples such those from the scalp or pityriasis versicolor.

Penicillium marneffei infection presenting as an immune reconstitution inflammatory syndrome in an HIV patient.

We describe a case of Penicillium marneffei infection acquired in Thailand, manifesting as an immune reconstitution inflammatory syndrome (IRIS) in a Caucasian man with advanced HIV-related immunosuppression (CD4 72 cells/mm³). Initial presentation was consistent with Pneumocystis jirovecii pneumonia, and empirical co-trimoxazole resulted in clinical improvement. One month after initiating antiretroviral therapy (ART), an enlarging scaly lesion on his forehead and erythematous nodules on his face, trunk and limbs developed. P. marneffei was isolated from a skin aspirate. Response to antifungal therapy was complicated by drug interactions but cure was complete after four months of treatment. Few cases of IRIS associated with P. marneffei have been reported.

Epidemiology of fungal scalp infections in the West of Scotland 2000-2006.

BACKGROUND: Fungal infections of the scalp commonly affect the paediatric population and are caused by dermatophytes which have the ability to invade the keratinised structures of skin, hair and nails. This study analyses the changes in the epidemiology of fungal scalp infections in the West of Scotland during the period 2000-2006. METHODS: Skin and hair from scalp specimens sent by General Practitioners and Dermatologists throughout the West of Scotland were examined microscopically for the presence of fungal hyphae and/or spores and cultured to determine the identity of the fungi. RESULTS: The most common dermatophyte to be isolated from scalps during 2000-2006 was Trichophyton violaceum with 29 reported cases followed by 23 cases of Trichophyton tonsurans infection. During 2000-2002, over 90% of patients were British but during 2003-2006, greater than 50% of patients were of non-UK origin. The majority of T. violaceum and T. tonsurans infections during this study were from patients originating in either Africa or Pakistan and were from people known to be seeking asylum in the UK. CONCLUSIONS: The overall increase and the change in pattern of reported fungal scalp infections in the West of Scotland may be explained by the migration of people to Scotland from Africa or Pakistan where T. violaceum and T. tonsurans are endemic. The increase in numbers of infections in the later period of this study reflects an increase in the awareness of General Practitioners and Dermatologists to send samples to Clinical Mycology.

Successful treatment of Candida krusei fungemia with amphotericin B and caspofungin.

We report a leukemic patient with C. krusei fungemia who failed to respond to liposomal amphotericin B therapy alone. The addition of caspofungin eradicated infection and was well tolerated. Our report is the first to describe successful treatment of a patient with invasive C. krusei infection using this combination of antifungals. Combination therapy could be a useful treatment option for invasive candidosis, particularly when caused by more resistant species such as C. krusei.

Fluconazole and itraconazole susceptibilities of Candida spp. isolated from oropharyngeal specimens and blood cultures of paediatric haematology/oncology patients.

This study examined the in vitro susceptibilities to fluconazole and itraconazole of isolates of Candida spp. from surveillance oropharyngeal specimens and blood cultures from paediatric patients with malignancy. The species distribution of 100 isolates from oropharyngeal specimens was C. albicans 86%, C. glabrata 7%, C. lusitaniae 4%, C. parapsilosis 2% and C. tropicalis 1%. From a total of nine isolates from blood cultures the species distribution was C. albicans 33.3%, C. parapsilosis 33.3 % and C. guilliermondii 33.3%. Only three of the oropharyngeal isolates were resistant to fluconazole (MIC > or = 64 mg l(-1)) and only two were resistant to itraconazole (MIC > or = 1 mg l(-1)). None of the blood culture isolates was resistant to either agent. At this centre, C. albicans is the predominant species from oropharyngeal specimens, but non-albicans Candida species predominate in blood cultures. Although resistance to fluconazole and itraconazole is rare at present, continued surveillance is warranted to monitor trends in species distribution and antifungal susceptibility.

Cryptococcus neoformans var. gattii meningitis in an HIV-positive patient: first observation in the United Kingdom.

We present a case of meningitis due to Cryptococcus neoformans var. gattii in an HIV-infected man recently returned from South Africa. We believe this is the first imported case of meningitis secondary to Cryptococcus neoformans var. gattii in an HIV-infected patient to be reported in the UK.

Development of an indirect ELISA for the detection of serum antibodies to Aspergillus fumigatus in captive penguins.

Aspergillosis is a significant cause of mortality in captive penguins (Sphenisciformes). An indirect ELISA for the detection of Aspergillus fumigatus-specific immunoglobulin in penguins was developed and standardised by making use of a family-specific antiserum (anti-Aptenodyptes patagonica patagonicus). The results were calculated quantitatively as ELISA units, derived by polynomial regression analysis, and semi-quantitatively as end titres. Serum samples from 61 captive penguins were tested with the assay, and the results were compared with those obtained by counterimmunoelectrophoresis (CIE). The ELISA results correlated with the CIE results only when end titres were reported (R(s) = -0.676, P < 0.002). Fifty-seven of the penguins (93 per cent) were seropositive, but the detection of immunoglobulin did not correlate with clinical disease. At Whipsnade Wild Animal Park, Humboldt's penguins (Spheniscus humboldti) demonstrated higher seropositivity than king penguins (Aptenodyptes patagonicapatagonicus) (P = 0.022), but Humboldt's penguins at Fota Wildlife Park had a significantly higher seropositivity than Humboldt's penguins at Whipsnade (P = 0.035).

Fungal surveillance of an open haematology ward.

Air sampling and surveillance cultures for fungi were performed in a Scottish general haematology ward over a five-month period in 1997. The mean total fungal count from the air sampling appeared to be correlated with the number of patients colonized by Aspergillus. The most commonly isolated species were Aspergillus versicolor, A. fumigatus and A. niger. Rooms with portable air filtration units had significantly lower total fungal counts than the others. Swabs were taken from 70 patients (mean age 62 years); 114 of the 563 cultures (20.2%) were positive. The most commonly isolated species were A. fumigatus, Candida albicans, C. glabrata and C. parapsilosis. Samples taken from the tongue and perineum showed colonization more often than those taken from the nostrils. Almost half the patients (48.6%) were colonized on, or within seven days of, admission; 11.4% became colonized whilst on the unit. One patient developed fatal aspergillosis. We conclude that colonization or high air-borne spore concentrations are not necessarily predictive of fungal infection but may prompt early treatment or more aggressive prophylaxis of potentially fatal invasive infections.

Cerebral candidiasis in a child 1 year after leukaemia.

We describe an unusual case of a late presentation of a fungal brain abscess in a non-neutropenic child 1 year after completing chemotherapy for M5 acute myeloid leukaemia (AML). Biopsy of the mass identified candidal hyphae and the patient was treated with 5 mg/kg of liposomal amphotericin B for 6 weeks. The lesion resolved completely and the child remains well 2 years later. Invasive fungal infection should be included in the differential diagnosis of unexplained symptoms in patients who have previously received intensive chemotherapy.

Multicenter evaluation of proposed standardized procedure for antifungal susceptibility testing of filamentous fungi.

A multicenter study was conducted to expand the generation and analysis of data that supports the proposal of a reference method for the antifungal susceptibility testing of filamentous fungi. Broth microdilution MICs of amphotericin B and itraconazole were determined in 11 centers against 30 coded duplicate pairs of Aspergillus spp., Fusarium spp., Pseudallescheria boydii, and Rhizopus arrhizus. The effect of inoculum density (approximately 10(3) and 10(4) CFU/ml), incubation time (24, 48, and 72 h), and procedure of MIC determination (conventional and colorimetric [Alamar Blue] evaluation of growth inhibition) on intra- and interlaboratory agreement was analyzed. Based on intra- (97 to 100%) and interlaboratory (94 to 95%) agreement for both drugs, the overall optimal testing conditions identified were determination of colorimetric MICs after 48 to 72 h of incubation with an inoculum density of approximately 10(4) CFU/ml. These testing conditions are proposed as guidelines for a reference broth microdilution method.

DNA typing of epidemiologically-related isolates of Aspergillus fumigatus.

Invasive aspergillosis is often nosocomially acquired and carries a high mortality. Molecular typing methods to discriminate isolates have now been developed. Using simple restriction endonuclease (Sal1 and Xho1) digestion of total genomic DNA, we have typed 25 epidemiologically-related isolates of A. fumigatus from six hospital episodes of invasive aspergillosis. Eight DNA types were found and in each case the DNA type matched precisely the epidemiological data. Thus DNA typing of A. fumigatus can provide the means to match isolates from linked sources and distinguish isolates from diverse origins.

Adherence of arthroconidia and germlings of anthropophilic and zoophilic varieties of Trichophyton mentagrophytes to human corneocytes as an early event in the pathogenesis of dermatophytosis.

The association (adherence) between human corneocytes and arthroconidia of Trichophyton mentagrophytes strains 121 and 126, and T. interdigitale strain 4 was studied in vitro. Adherence of arthroconidia to corneocytes from either the palm and sole occurred and increased with time up to 6 h, by which time germination of arthroconidia had started. Significant differences were seen between the T. mentagrophytes strains and T. interdigitale in their adherence to corneocytes from the palm. When adherence values for plantar corneocytes were compared, significant differences were found between T. mentagrophytes and T. interdigitale. Not all corneocytes from either site had adherent arthroconidia, although there was a time-dependent increase in the numbers of corneocytes with adherent fungal cells. By scanning and transmission electron microscopy it was seen that there was a loose association between arthroconidia and corneocytes with no apparent damage to the corneocyte membrane. Adherence of germlings of T. interdigitale to corneocytes from the palm appeared to be mediated by germling outer cell wall fibrils. Hyphal branches and secondary germlings were observed to enhance the attachment of the parent hypha to adjacent corneocytes.

Differential binding of acapsulate and encapsulated strains of Cryptococcus neoformans to human neutrophils.

Investigations into mechanisms of binding of encapsulated and acapsulate strains of Cryptococcus neoformans by human neutrophils were performed, using a monolayer assay. The two strains bound to neutrophils by different mechanisms although both had an absolute requirement for opsonization with complement components in normal human serum for binding to occur. Neutrophil binding of encapsulated yeasts required conformational changes in actin yet did not appear to lead to phagocytosis of the organism. A maximum of 12 acapsulate cells bound per neutrophil compared with only four encapsulated yeasts. Cytochalasin D treatment reduced the maximum numbers able to bind per neutrophil by 50%. The encapsulated cryptococci appeared to compete with each other for binding to neutrophils whereas the acapsulate yeast cells bound to neutrophils in an approximately Poisson distribution, suggesting independent binding. Binding of acapsulate cryptococci did not require actin filaments and appeared to trigger phagocytosis. Thus, the capsule of C. neoformans appeared to inhibit binding and internalization by neutrophils.

Activity of topically applied leukotriene B4 in experimental dermatophytosis.

In a pilot study to assess the antimycotic potential of the chemoattractant leukotriene B4 (LTB4), guinea pigs were infected with Trichophyton mentagrophytes var. mentagrophytes and divided into groups of untreated control animals or treated daily with LTB4, isoconazole nitrate or vehicle alone. The animals were assessed clinically, mycologically and histopathologically. Treatment with isoconazole nitrate was the most effective. The LTB4-treated group were clinically worse than the non-treated group and the mycological results remained positive throughout the assessment period.

Effect of cilofungin on phagocytosis and intracellular killing of Candida albicans by human neutrophils.

The effect of a beta glucan synthase inhibitor, cilofungin, amphotericin B and 5-fluorocytosine on opsonization, phagocytosis and intracellular killing of Candida albicans blastospores by glass-adherent human neutrophils was determined by microscopy and dye exclusion staining. Pretreatment of blastospores for 2, 4, 6 and 18 h with 1.25 mg/l cilofungin resulted in 24-28% of neutrophils ingesting compared to 24% with no drug present. There was no significant difference in the phagocytic index with increased incubation time. Percentage ingestion and phagocytic index values were not significantly different when blastospores were pretreated for 2 h in the presence of 3, 7, 15, 31 and 62 mg/l cilofungin. Comparable concentrations of amphotericin B and 5-fluorocytosine gave similar results. In the absence of cilofungin, intracellular killing after 2 h was 54%. In the presence of 1 and 10 mg/l cilofungin, 85-90% of intracellular blastospores were killed. Therapeutic levels of amphotericin B or 5-fluorocytosine did not enhance intracellular killing. These data demonstrate the potentiation of intracellular killing of Candida albicans by neutrophils in the presence of cilofungin.