Aureobasidin A (AbA) is a cyclic depsipeptide antifungal compound that inhibits a wide range of pathogenic fungi. In this study, the in vitro susceptibility of 92 clinical isolates of various Candida species against AbA was assessed by determining the planktonic and biofilm MICs of the isolates. The MIC(50) and MIC(90) of the planktonic Candida yeast were 1 and 1 μg ml(-1), respectively, whereas the biofilm MIC(50) and MIC(90) of the isolates were 8 and ≥64 μg ml(-1) respectively. This study demonstrates AbA inhibition on filamentation and biofilm development of C. albicans. The production of short hyphae and a lack of filamentation might have impaired biofilm development of AbA-treated cells. The AbA resistance of mature Candidia biofilms (24 h adherent population) was demonstrated in this study.
This study describes the isolation of Cryptococcus neoformans and Cryptococcus gattii from patients with chronic meningitis who were admitted to 16 Malaysian hospitals, from 2003 to 2004. Of the 96 cryptococcal cases reported over the 2-year period, 74 (77.1%) patients were male and 45 (46.9%) patients were between 30 and 39 years old. Cryptococcosis was uncommon in children. A total of 57 (59.4%) and 23 (24.0%) patients were Malay and Chinese respectively. Human immunodeficiency virus infection was the major underlying disease reported in 36 (37.5%) patients. C. neoformans var. grubii (serotype A and molecular type VNI) was the predominant Cryptococcus species isolated from 88.5% of cryptococcal cases in this country. Cryptococcal cases due to C. neoformans var. grubii were reported from all the five regions in Malaysia, with the most number of cases reported from the central and northern regions. Cryptococcus gattii (all were serotype B and molecular types VGI/II) was isolated from all regions except the southern region. Compared with a study conducted prior to the AIDS era, our findings show substantial changes in the demographical characteristics of patients.
This study compared the enzymatic activity of clinical isolates of Cryptococcus neoformans, Cryptococcus gattii, environmental isolates of C. neoformans and non-neoformans Cryptococcus. Most of the cryptococcal isolates investigated in this study exhibited proteinase and phospholipase activities. Laccase activity was detected from all the C. neoformans and C. gattii isolates, but not from the non-neoformans Cryptococcus isolates. There was no significant difference in the proteinase, phospholipase and laccase activities of C. neoformans and C. gattii. However, significant difference in the enzymatic activities of beta-glucuronidase, alpha-glucosidase, beta-glucosidase and N-acetyl-beta-glucosaminidase between C. neoformans and C. gattii isolates was observed in this study. Environmental isolates of C. neoformans exhibited similar enzymatic profiles as the clinical isolates of C. neoformans, except for lower proteinase and laccase activities.
The in vitro susceptibilities of Malaysian clinical isolates of Cryptococcus neoformans var. grubii and C . gattii to five antifungal drugs (amphotericin B, flucytosine, fluconazole, itraconazole and ketoconazole) were determined using the Etest method. None of the Malaysian isolates was resistant to amphotericin B and ketoconazole. Isolates resistant to flucytosine, fluconazole and itraconazole were observed in this study. Minimum inhibition concentrations (MICs) of > or = 32 microg ml(-1) against flucytosine, > or = 64 microg ml(-1) against fluconazole and > or = 1 microg ml(-1) against itraconazole were noted in four (8.3%), two (4.2%) and one (2.1%) isolates respectively. There was no significant difference in the MICs for both Cryptococcus species (P > 0.05), indicating that C. gattii was as susceptible as var. grubii to all the antifungal drugs tested. No significant difference in the MICs for both Cryptococcus species collected from 1980 to 1990 and 2002 to 2004 were observed (P > 0.05).
The serological responses to Cryptococcus neoformans proteins of blood donors and HIV patients with active cryptococcosis from a tropical region were investigated in this study. Exposure to C. neoformans, an organism ubiquitous in the environment, contributes to the antibody responses observed in the blood donors. IgG responses to cryptococcal proteins were stronger than IgM responses in most sera tested in this study. A 53-kDa cryptococcal protein fragment was identified as the most immunoreactive protein on the IgM immunoblots of both blood donors and patients. Overall, there was no obvious difference in IgG responses of patients when compared with blood donors. Some immunogenic protein fragments (27.5, 76, 78 and 91.5 kDa) were detected at least two times more frequently on IgM immunoblots of patients compared with those of blood donors. It is yet to be investigated whether the proteins identified in this study may have any potential to be used as biomarker for cryptococcosis.
Cryptococcus albidus and C. laurentii were the predominant non-neoformans cryptococci isolated during an environmental sampling study for C. gattii at Klang Valley, Malaysia. Cryptococcus gattii was not isolated from any of the environmental samples. Cryptococcus albidus and C. laurentii were isolated mainly from vegetative samples of Eucalyptus trees and bird droppings. Upon testing on canavanine-glycine-bromothymol blue (CGB) agar, all the C. albidus isolates remained unchanged. Interestingly, a total of 29 (76.3%) C. laurentii isolates formed blue colours on the CGB agar. Sequence analysis of ITS1-5.8rDNA-ITS2 gene sequences (468 bp) of four CGB-blue C. laurentii isolates demonstrated the closest match (99%) with that of C. laurentii CBS 7140. This study demonstrated the diverse environmental niche of C. albidus and C. laurentii in Malaysia.
A total of 2,153 high vaginal swabs were processed for the presence of yeasts. The specimens were obtained from pregnant and non-pregnant Malaysian women with and without vaginitis. The yeast species most commonly isolated were Candida albicans, C. glabrata, C. famata and C. parapsilosis. C. albicans was isolated from 27% of pregnant women with vaginitis, 14% of pregnant women with no overt vaginitis, 15% of non-pregnant women with vaginitis, and 3% of non-pregnant women with no vaginitis. The significant difference of the isolation rates from women with and without vaginitis indicates that C. albicans is likely to be a vaginal pathogen.
Epidemiological data on the aetiologic agents of feline sporotrichosis in Malaysia have not been reported, though human sporotrichosis in Malaysia is reported to be transmitted primarily via cat scratch. To the best of our knowledge, the present report is the first study of the molecular epidemiology of Sporothrix schenckii isolates from cats with sporotrichosis in Malaysia. In the present work, we characterised 18 clinical isolates from cats in Malaysia based on molecular properties, including sequence analyses of the calmodulin gene and the rDNA ITS region and selective PCR of mating type (MAT) loci. In this study, isolates from feline sporotrichosis were identified as a S. schenckii sensu stricto by sequence analyses of the calmodulin gene and the internal transcribed spacer (ITS) region. Notably, phylogenetic analysis of the ITS confirmed assignment to clinical clade D (and not C) of S. schenckii sensu stricto. Therefore, clinical clade D of S. schenckii sensu stricto appeared to be the prevailing source of feline sporotrichosis in Malaysia. The ratio of MAT1-1-1:MAT1-2-1 in these Malaysian isolates was found to be 1 : 0. This result suggested that a clonal strain of S. schenckii is the prevailing causative agent of feline sporotrichosis in Malaysia.
Vulvovaginal candidosis (VVC) is a common gynaecological disorder that is delineated by the inflammation of vaginal wall and it is caused by the opportunistic fungal pathogen Candida species. In fact, three out of every four women will experience at least one occasion of VVC during some point in their lives. Although uncomplicated VVC is relatively harmless, the complicated VVC such as recurrent attack often creates restlessness and depression in the patients, thus greatly affects their quality of life. Managements of VVC are usually associated with the use of antimycotic suppositories, topical cream or oral agents. These antimycotic agents are either available over-the-counter or prescribed by the clinicians. In recent decades, the rise of clinical challenges such as the increased prevalence of resistant Candida strains, recurrent VVC infection and adverse effects of multidrug interactions have necessitated the development of novel therapeutic or prophylactic options to combat the complicated VVC in the future. In this review, we discuss the current antimycotic treatments available for Candida vaginitis and the problems that exist in these seemingly effective treatments. Besides, we attempt to contemplate some of the future and prospective strategies surrounding the development of alternative therapeutic and prophylactic options in treating and preventing complicated VVC respectively.
Candida wangnamkhiaoensis is a species clustered under the Hyphopichia clade has not ever been isolated from any clinical specimens. To the best of our knowledge, this is the first report of C. wangnamkhiaoensis associated with fungaemia in immunocompromised paediatric patient. The isolate was assigned a strain name as UZ1679/14, in which the identification was confirmed by a polymerase chain reaction-sequencing of the internal transcribed spacer (ITS) and large subunit (LSU) regions of the rRNA gene. Antifungal susceptibility pattern showed that the isolate was sensitive to anidulafungin, caspofungin, fluconazole and voriconazole. The patient clinically improved after the antifungal treatment with caspofungin.
Anidulafungin has been shown to be non-inferior to, and possibly more efficacious, than fluconazole in treating patients with invasive candidiasis (IC). This study aimed to determine the cost-effectiveness of anidulafungin vs fluconazole for treatment of IC in the Turkish setting. A decision analytic model was constructed to depict downstream economic consequences of using anidulafungin or fluconazole for treatment of IC in the Turkish hospitals. Transition probabilities (ie treatment success, observed or indeterminate treatment failures) were obtained from a published randomised clinical trial. Cost inputs were from the latest Turkish resources. Data not available in the literature were estimated by expert panels. Sensitivity analyses were performed to assess the robustness of the model outcome. While anidulafungin [TL 17 171 (USD 4589)] incurred a higher total cost than fluconazole [TL 8233 (USD 2200) per treated patient, treatment with anidulafungin was estimated to save an additional 0.58 life-years, with an incremental cost-effectiveness ratio of TL 15 410 (USD 4118) per life-years saved. Drug acquisition cost and hospitalisation were the main cost drivers for anidulafungin and fluconazole arms respectively. The model findings were robust over a wide range of input variables except for anidulafungin drug cost. Anidulafungin appears to be a cost-effective therapy in treating IC from the Turkish hospital perspective.