Oral Candida colonization in HIV-infected patients: Species and antifungal susceptibility in Tripoli/Libya

Introduction: Candidiasis is more frequent in human immunodeficiency virus (HIV)-infected patients and knowledge about the distribution and antifungal susceptibility of oral Candida species is important for effective management of candidiasis. Material and Methods: An oral rinses sample collected from hundred HIV-infected patients with and without clinical evidence of oral candidiasis in this study at the Infectious Department/Tripoli Medical Center, Libya. Species identified by standard phenotypic and conventional methods and in vitro susceptibility testing of the yeast isolates to antifungals were performed using the Disc diffusion method protocol as recommended by the Clinical Laboratory Scientific Institute. Results: Oral Candida colonization is detected in all patients with and without clinical syndromes, and Candida albicans were accounted for (74%), C. dubliniensis (11%) and C. glabrata (6%). A high proportion of Candida species (42%) showed decreased susceptibility to fluconazole. Among C., albicans more than 30% of isolate were resistant to most new azole antifungal including fluconazole, itraconazole, posoconazole and voriconazole. Conclusions: A significant number of oral Candida species particular Candida albicans exhibiting decreased susceptibility to fluconazole were isolated from colonized HIV-infected individual, given the high incidence and severity of fungal infections in HIV-infected individuals. The results of this study reinforce the importance of antifungal susceptibility testing, which contributes to the therapeutic strategies and highlights the need for continuous surveillance of Candida colonization in this population

Evaluation of novel culture media prepared from plant substrates for isolation and identification of Cryptococcus Neoformans Species Complex

Background: Melanin production due to phenoloxidase activity is a distinctive property of Cryptococcus neoformans and Cryptococcus gattii species complex yeasts. Therefore, an agar medium containing a precursor of melanin pigment is potentially useful to identify and differentiate cryptococcal colonies from other yeasts. Background: This study aimed to evaluate and compare the ability of Cryptococcus neoformans species complex isolates to produce brown-pigmented colonies when grown on media prepared from various plant leaves or seeds extracts. Material and Methods: Forty-six C. neoformans species complex isolates which were obtained from various environmental and clinical samples were inoculated on different media containing coriander, cumin, soybean, lupine, flax, pumpkin, basil, peppermint, and marjoram, were observed for the rate of growth and pigment production during a five-day period. Results: All isolates were pigmented on all media within 24-48 hours, and brown or dark brown colonies were observed in less than five days, while C. albicans grew but did not produce any pigment. Conclusion: The differential media tested in the present study are simple and inexpensive, and represent alternative valid tools for presumptive identification of C. neoformans species complex from clinical and environmental sample

The Effect of Aspergillus fumigatus Infection on Vitamin D Receptor Expression in Cystic Fibrosis

Rationale: Aspergillus fumigatus (A. fumigatus) in cystic fibrosis (CF) is increasingly recognized. Although allergic bronchopulmonary aspergillosis (ABPA) leads to deterioration of pulmonary function, the effect of A. fumigatus colonization in the absence of ABPA remains unclear. Objectives: To address this, we examined individuals with CF with A. fumigatus who were ABPA negative to identify the effects of itraconazole therapy on Aspergillus-induced lung inflammation. Methods: The effect of A. fumigatus on nuclear vitamin D receptor (VDR) expression was investigated using qRT-PCR and Western blotting. IL-5 and IL-13 levels were quantified by ELISA. The effect of itraconazole was assessed by a combination of high-resolution computed tomography, lung function test, and microbiological analysis. Measurements and Main Results: We demonstrate that A. fumigatus down-regulates VDR in macrophages and airway epithelial cells and that the fungal metabolite gliotoxin (Gt) is the main causative agent. Gt overcame the positive effect of 1,25-OH vitamin D3 on VDR expression in vitro, resulting in increased IL-5 and IL-13 production. In vivo, A. fumigatus positivity was associated with increased Gt in CF bronchoalveolar lavage fluid and increased bronchoalveolar lavage fluid levels of IL-5 and IL-13. After airway eradication of A. fumigatus with itraconazole, we observed decreased Gt, IL-5 and IL-13, improved respiratory symptoms, and diminished high-resolution computed tomography mosaic pattern consistent with sustained pulmonary function. Conclusions: This study provides a rationale for the therapeutic effect of itraconazole and implied that the therapeutic potential of vitamin D supplementation in preventing ABPA is only feasible with concurrent elimination of A. fumigatus to permit VDR expression and its positive functional consequences