Differential Gene Expression of Heat Shock Protein 90 (Hsp90) of Candida albicans obtained from Malaysian and Iranian Patients

Background: Candida albicans (C. albicans) has several virulence factors, in particular heat shock protein 90 (Hsp90), which is expressed by Hsp90 gene. The purposes of this study were to assess the expression of Hsp90 gene in clinical and control isolates of C. albicans obtained from different geographical regions (Malaysia and Iran), different temperatures (25ºC, 37ºC and 42ºC) and mice with candidiasis. Methods: C. albicans isolates were cultured onto sabouraud dextrose agar (SDA). The assessment of the expression of Hsp90 gene was performed using real time-polymerase chain reaction (RT-PCR). Results: The results showed a significant increase in the expression of C. albicans Hsp90 gene under high thermal shock (42ºC) when compared to other temperatures tested (P-value = 0.001). The mean differences in the expression of Hsp90 gene at 37ºC were 0.20 (95% confidence interval (CI) 0.13-0.29) between Malaysian and Iranian controls (P-value = 0.040) and 0.47 (95% CI 0.27-0.60) between Malaysian and Iranian patients (P-value = 0.040). Conclusion: The results demonstrated that the expression of C. albicans Hsp90 gene varied between Malaysian and Iranian subjects, representing the efficacy of geographical and thermal conditions on virulence gene expression.

Sequences type analysis of Candida albicans isolates from Iranian human immunodeficiency virus infected patients with oral candidiasis

The growing number of immunocompromised individuals has increased the incidence of infections caused by Candida species during the recent decades. Typing of C. albicans on the basis of DNA sequences at multiple loci has greatly advanced our knowledge about the epidemiology and phylogeny of candidiasis. The aim of this study was to evaluate the diversity, and genetic relationships among C. albicans isolates obtained from HIV patients in Iran using multilocus sequence typing [MLST] method. We analyzed 25 C. albicans isolates obtained from HIV positive patients referred to Iranian Research Center for HIV/AIDS. After diagnostic test and DNA extraction C. albicans isolates were typed using the original MLST scheme explained previously include of six loci: ACC1, VPS13, GLN4, ADP1, RPN2, and SYA1. Fifty one [2.17%] nucleotide sites were found to be polymorphic; all were found to be heterozygous in at least one isolate. For the 25 clinical isolates, 22 diploid sequence types were defined by the genotypes identified from the six loci. The MLST data suggest a relatively high level of divergence in the population structure of C. albicans isolated from HIV infected patients. These findings indicate that in these patients there is a favorable context for the growth of potential pathogenic C. albicans. We found no association between fluconazole resistance, highly active antiretroviral therapy [HAART] receiving and either sequence type or group

Fungal flora of the combs and wattles of Iranian native chickens

Poultry are more susceptible to receiving and spreading of fungal infections in exact conditions. The goal of this study was to identify the normal fungal flora and dermatophytes agent of the combs and wattles of adult native chickens in Tehran, Iran. A total of 150 combs and wattles samples were collected by skin scraping or brushing of the margin of the suspected lesion and skin of organ. The mycological analyses were performed by direct microscopy and culture media. One hundred and ninety fungi were isolated from the combs of 150 native chickens' samples that including non-dermatophytes isolates 165 [86.8%], dermatophytes 6 [3.2%] and yeast 19 [10%]. Among different fungal isolates, Aspergillus was the predominant species. Our results showed that human in contact with poultry, both at the household and the industrial level, have a clear risk factor for exposure to fungal pathogens, especially dermatophytes

[In vitro antifungal susceptibility of oral candida species from Iranian HIV infected patients]

Oropharyngeal candidiasis and antifungal drug resistance are major problems in HIV positive patients. The increased reports of antifungal resistance and expanding therapeutic options prompted the determination of antifungal susceptibility profile of Candida species isolates in Iranian patients living with HIV/AIDS [PLWHA] in the present study. One hundred fifty oral samples from Iranian HIV positive patients were obtained and cultured on CHROMagar and Sabouraud's dextrose agar. All isolates were identified according to assimilation profile, germ tube, colony color and other conventional methods. Disk diffusion testing and Broth Microdilution of six antifungal agents were performed according to the methods described in CLSI. Candida albicans [50.2%] was the most frequent isolated yeast, followed by C. glabrata [22%]. Non-Candida albicans species were isolated from 71 [61%] positive cultures. 25.7% of Candida albicans isolates were resistant to fluconazole [MIC >/= 64 micro g/ml] as were 21.9% and 16.4% to ketoconazole and clotrimazole [MIC>0.125 micro g/ml], respectively. Resistance to polyene antifungals including amphotericin B and nystatin, and caspofungin were scarce. 57.7% of candida glabrata isolates were resistant to fluconazole, 31% to ketoconazole and 35% to clotrimazole. Screening for antifungal resistant candida isolates by disk diffusion or broth dilution methods in clinical laboratories is an ideal surveillance measure in the management of oral thrush in patients with HIV/AIDS. Although nystatin is widely used in clinical practice for HIV positive patients, there was no evidence of enhanced resistance to it. Regarding no resistance to caspofungin, its administration is suggested

[Effects of fumonisin B1 on the stomach and colon cell lines in vitro]

Fumonisins, a family of mycotoxins, are mainly found in wheat, corn and their products. Previous studies have shown that fumonisin B1 [FB1], the most abundant and toxic of known fumonisins, has been associated with many animal and human diseases including cancer. In the present study, the effects of FB1 were examined on the production of inflammatory cytokines in intestine and stomach cell lines. This study was performed in the Cancer Research Center of Tehran University of Medical Sciences in 2010. The cell lines of colon adenocarcinoma [SW742] and gastric epithelium [AGS] were purchased from the Pasteur Institute of Iran. The cells were pretreated with different concentrations of FB1 [0 to 100 micro M] for 3 days. The cells were later stimulated by lipopolysaccharides. Twenty-four hours after cell induction, the cytokines including tumor necrosis factor-alpha [TNF- alpha], interlukin-1 beta [IL-1 beta] and interlukin-8 [IL-8] were measured by ELISA. Treatment with FB1 induced a dose-dependent decrease in IL-8 production [P<0.05]. This decrease was seen in both SW742 and AGS cell lines. Moreover, FB1 induced a dose-dependent increase in the production of TNF- alpha and IL-1 beta in both cell lines [P<0.05]. The results of this study indicated that FB1 could increase the inflammatory cytokines including TNF- alpha and IL-1 beta in gastric and intestinal cell lines. These effects might result in the development of inflammatory responses and subsequent mucosal atrophy in in-vivo conditions

Effect of invasive aspergillosis infection on the immune responses of Cancer mice

Using a cancer murine model of invasive aspergillosis [IA], we investigated the expression of TLR-2, Dectin-1 and the level of cytokine production by CD4+ T helper cells in different groups of mice [with or without cancer], also, the effect of invasive aspergillosis on the immune response pattern of cancer mice. Patterns of susceptibility and resistance to infection obtained with different groups of mice injected with Aspergillus fumigatus conidia. TLR-2 and Dectin-1 analyzed applying flowcytometry and cytokine production of cultured splenocytes by ELISA method. Cancer mice that challenged with A. fumigatus conidia showed significant increase in TLR-2 and Dectin-1 levels compared with the two other control groups [normal mice challenged with A. fumigatus and non-infected cancer mice]. Moreover, it showed insignificant decrease in IFN-gamma and IL-10 levels and insignificant increase in TNF-alpha level. The data demonstrated remarkable rise in IL-4 level and the mortality of cancer mice that intravenously infected with A. fumigatus. Probably IA causes stimulation in innate immunity and Th2 cells, also some disorganization in cytokine production in CD4+ T helper cells. We hypothesize that concomitance of IA and cancer may change the microenvironment for local or systemic immune responses. Other complementary studies could help supporting our hypothesis

role of Zataria multiflora essence [Iranian herb] on innate immunity of animal model

Herbal medicines have been used since ancient times for treatment of a range of diseases and have represented stimulatory effects on the function of innate immunity. To evaluate the effects of Zataria multiflora [Z. multiflora] on the function of innate immunity including phagocytic activity and TNF-alpha secretion in animal model. Eight BALB/c mice were divided into two equal groups. In group A, Z. multiflora essence was injected intraperitoneally to the mice, in group B, distilled water was injected. Blood was obtained from 4 mice in each group, 4 and 7 days following injection. The amounts of phagocytosis [respiratory burst] and TNF-alpha secretion were assessed by chemiluminescence and ELISA method, respectively. Significant increase in phagocytosis and TNF-alpha secretion was observed in group A compared with the control group at days 4 and 7. Z. multiflora essence can remarkably stimulate innate immunity function and it may be used to immunize individuals alone or in combination with other immunostimulatory agents