Mucormycosis in Iran: A six-year retrospective experience

Mucormycosis is a devastating infection caused by Mucoralean fungi (Mucormycotina, Mucorales). Data concerning the global epidemiology of mucormycosis are scarce and little is known about the characteristics of mucormycosis in Iran. In this study, we aimed to understand the distribution of this infection in Iran retrospectively and to ascertain whether the patterns of infection are associated with specific host factors or not. A total of 208 cases were included in this study occurring during 2008-2014 and were validated according to (EORTC/MSG) criteria. A rising trend as significant increase from 9.7% in 2008 to 23.7% in 2014 was observed. The majority of patients were female (51.4%) with median age of 50 and the infections were seen mostly in autumn season (39.4%). Diabetes mellitus (75.4%) was the most common underlying condition and sinus involvement (86%) was the mostly affected site of infection. Amphotericin B (AmB) was the drug of choice for the majority of cases. Sixty four isolates did not show any growth in the lab and only 21 cases were evaluated by ITS sequencing, among them; Rhizopus arrhizus var. arrhizus was the dominant species. Considering the high mortality rate of mucormycosis, early and accurate diagnosis, with the aid of molecular methods may provide accurate treatments and improve the survival rate. Therefore, increased monitoring and awareness of this life-threatening disease is critical.

Green synthesis of silver nanoparticles: Advantages of the yeast Saccharomyces cerevisiae model

Background and Purpose:

Microorganism-based synthesis of nanostructures has recently been noted as a green method for the sustainable development of nanotechnology. Nowadays, there have been numerous studies on the emerging resistant pathogenic bacteria and fungal isolates, the probable inability of bacteria and fungi to develop resistance against silver nanoparticles’ (SNPs) antibacterial, antifungal, antiviral and, particularly antibacterial activities. In this study, we aim to use the yeast Saccharomycescerevisiae model for synthesis of SNPs and to investigate its antifungal activity against some isolates of Candidaalbicans.

Materials and Methods:

A standard strain of S.cerevisiae was grown in liquid medium containing mineral salt; then, it was exposed to 2 mM AgNO₃. The reduction of Ag⁺ ions to metal nanoparticles was virtually investigated by tracing the color of the solution, which turned into reddish-brown after 72 hours. Further characterization of synthesized SNPs was performed afterwards. In addition, antifungal activity of synthesized SNPs was evaluated against fluconazole-susceptible and fluconazole-resistant isolates of Candidaalbicans.

Results:

The UV-vis spectra demonstrated a broad peak centering at 410 nm, which is associated with the particle sizes much less than 70 nm. The results of TEM demonstrated fairly uniform, spherical and small in size particles with almost 83.6% ranging between 5 and 20 nm. The zeta potential of SNPs was negative and equal to -25.0 (minus 25) mv suggesting that there was not much aggregation. Silver nanoparticles synthesized by S.cerevisiae, showed antifungal activity against fluconazole-susceptible and fluconazole-resistant Candida albicans isolates, and exhibited MIC₉₀ values of 2 and 4 μg/ml, respectively.

Conclusion:

The yeast S. cerevisiae model demonstrated the potential for extracellular synthesis of fairly monodisperse silver nanoparticles.

Candida parapsilosis as a Potent Biocontrol Agent against Growth and Aflatoxin Production by Aspergillus Species

BACKGROUND

Aflatoxin contamination of food and feed stuff is a serious health problem and significant economic concerns. In the present study, the inhibitory effect of Candida parapsilosis IP1698 on mycelial growth and aflatoxin production in aflatoxigenic strains of Aspergillus species was investigated.

METHODS

Mycelial growth inhibitions of nine strains of aflatoxigenic and non-aflatoxigenic Aspergillus species in the presence of C. parapsilosis investigated by pour plate technique at different pH, temperature and time of incubation. Reduction of aflatoxin was evaluated in co-cultured fungi in yeast extract sucrose broth after seven days of incubation using HPLC method. The data were analyzed by SPSS 11.5.

RESULTS

The presence of the C. parapsilosis at different pH did not affect significantly the growth rate of Aspergillus isolates. On the other hand, temperature and time of incubation showed to be significantly effective when compared to controls without C. parapsilosis (P≤0.05). In aflatoxigenic strains, minimum percentage of reductions in total aflatoxin and B1, B2, G1, G2 fractions were 92.98, 92.54, 77.48, 54.54 and 72.22 and maximum percentage of reductions were 99.59, not detectable, 94.42, and not detectable in both G1 and G2, respectively.

CONCLUSION

C. parapsilosis might employ as a good biocontrol agent against growth and aflatoxin production by aflatoxigenic Aspergillus species.