Antifungal activity of terrestrial Streptomyces rochei strain HF391 against clinical azole -resistant Aspergillus fumigatus.

BACKGROUND AND PURPOSE: Actinomycetes have been discovered as source of antifungal compounds that are currently in clinical use. Invasive aspergillosis (IA) due to Aspergillus fumigatus has been identified as individual drug-resistant Aspergillus spp. to be an emerging pathogen opportunities a global scale. This paper described the antifungal activity of one terrestrial actinomycete against the clinically isolated azole-resistant A. fumigatus. MATERIALS AND METHODS: Soil samples were collected from various locations of Kerman, Iran. Thereafter, the actinomycetes were isolated using starch-casein-nitrate-agar medium and the most efficient actinomycetes (capable of inhibiting A. fumigatus) were screened using agar block method. In the next step, the selected actinomycete was cultivated in starch-casein- broth medium and the inhibitory activity of the obtained culture broth was evaluated using agar well diffusion method. RESULTS: The selected actinomycete, identified as Streptomyces rochei strain HF391, could suppress the growth of A. fumigatus isolates which was isolated from the clinical samples of patients treated with azoles. This strain showed higher inhibition zones on agar diffusion assay which was more than 15 mm. CONCLUSION: The obtained results of the present study introduced Streptomyces rochei strain HF391 as terrestrial actinomycete that can inhibit the growth of clinically isolated A. fumigatus.

In vitro antifungal activities of Actinomyces species isolated from soil samples against Trichophyton mentagrophytes.

BACKGROUND AND PURPOSE: Cutaneous infections arise from a homogeneous group of keratinophilic fungi, known as dermatophytes. Since these pathogenic dermatophytes are eukaryotes in nature, use of chemical antifungal agents for treatment may affect the host tissue cells. In this study, we aimed to evaluate the antifungal activity of Actinomyces species against Trichophyton mentagrophytes (abbreviated as T. mentagrophytes). The isolates were obtained from soil samples and identified by polymerase chain reaction (PCR) technique. MATERIAL AND METHODS: In total, 100 strains of Actinomyces species were isolated from soil samples in order to determine their antagonistic activities against T. mentagrophytes in Kerman, Iran. The electron microscopic study of these isolates was performed, based on the physiological properties of these antagonists (e.g., lipase, amylase, protease and chitinase), using relevant protocols. The isolates were identified using gene 16S rDNA via PCR technique. RESULTS: Streptomyces flavogriseus, Streptomyces zaomyceticus strain xsd08149 and Streptomyces rochei were isolated and exhibited the most significant antagonistic activities against T. mentagrophytes. Images were obtained by an electron microscope and some spores, mycelia and morphology of spore chains were identified. Molecular, morphological and biochemical characteristics of these isolates were studied, using the internal 16S rDNA gene. Active isolates of Streptomyces sequence were compared to GenBank sequences. According to nucleotide analysis, isolate D5 had maximum similarity to Streptomyces flavogriseus (99%). CONCLUSION: The findings of this study showed that Streptomyces isolates from soil samples could exert antifungal effects on T. mentagrophytes.

Aspergillus colonization in patients with chronic obstructive pulmonary disease.

BACKGROUND AND PURPOSE: Chronic obstructive pulmonary disease (COPD) has been recognized as a risk factor for invasive aspergillosis. Airway colonization by Aspergillus species is a common feature of chronic pulmonary diseases. Nowadays, the incidence of COPD has increased in critically ill patients. The aim of the present study was to isolate and identify Aspergillus colonies in the respiratory tract of COPD patients. MATERIALS AND METHODS: This study was performed on 50 COPD patients, who were aged above 18 years, and were in intensive care units of three hospitals in Sari, Iran, for at least six days. All the samples obtained from sputum, bronchoalveolar lavage, and tracheal aspirates were cultured for fungi each week. According to the conventional techniques, Aspergillus isolates were initially based on growth and standard morphological characteristics. To confirm the identification of grown Aspergillus, the partial beta-tubulin gene was sequenced using specific primers. RESULTS: A total of 50 patients, who met our inclusion criteria, were enrolled in the study during 2012-14. The results showed that 27 (54%) and 23 (46%) of the participants were male and female, respectively. The majority of the patients developed dyspnea followed by hemoptysis, chest pain, and high fever. Corticosteroids and broad-spectrum antibacterial agents were administered to 75% and 80% of the patients, respectively. Based on the conventional and molecular approaches, A. fumigatus (seven cases; 43.7%), A. flavus (five cases; 31.2%), A. niger (one case; 6.2%), A. terreus (one case; 6.2%), A. orezea (one case; 6.2%), and A. tubingensis (one case; 6.2%) were recovered. CONCLUSION: Recovery of Aspergillus species from the respiratory tract of COPD patients with pneumonia indicates two possibilities: either colonization or invasive aspergillosis.

Evaluation of antifungal activities of the essential oil and various extracts of Nigella sativa and its main component, thymoquinone against pathogenic dermatophyte strains.

OBJECTIVE: Plant extracts and plant-derived compounds are valuable sources as folk medicine for the treatment and prevention of a wide range of diseases including infectious diseases. In the present study, the antifungal activities of the essential oil and various extracts Nigella sativa and its active principle, thymoquinone against Trichophyton mentagrophytes, Microsporum canis and Microsporum gypseum as pathogenic dermatophyte strains have been evaluated. In addition, the cytotoxic effects of N. sativa against murine macrophage cells were determined. MATERIALS AND METHODS: In this study, the antifungal activity was studied by disk diffusion method and assessment of minimum inhibitory concentration (MIC) of extracts using broth macrodilution method. In addition, the cytotoxic activity of N. sativa was evaluated by colorimetric assay (MTT). The components of the N. sativa essential oil were also identified by gas chromatography/mass spectroscopy (GC/MS) analysis. RESULTS: The results showed that the essential oil and various extracts of N. sativa particularly thymoquinone have potent antifungal effects on T. mentagrophytes, M. canis and M. gypseum as pathogenic dermatophyte strains. In the assessment of the cytotoxicity activity, it could be observed that N. sativa had no significant cytotoxicity in the murine macrophages at low concentrations. While, thymoquinone in comparison with essential oil and various extracts of N. sativa showed higher cytotoxicity on murine macrophage cells. In the GC/MS analysis, thymoquinone (42.4%), p-cymene (14.1%), carvacrol (10.3%) and longifolene (6.1%) were found to be the major components of N. sativa essential oil. CONCLUSION: The findings of this study suggest a first step in the search of new antidermatophytic drugs and aid the use of N. sativa seeds in the traditional medicine for dermatophytic infections.

Nitric oxide induction as a novel immunoepidemiological target in malaria-infected patients from endemic areas of the Islamic Republic of Iran.

OBJECTIVE: Malaria has been prevalent for a long time in Iran and continues to be a health problem despite substantial control programs. In addition to numerous cytokines, nitric oxide (NO) is thought to be a key molecule and a novel target of malaria immunopathology. MATERIAL AND METHODS: The objective of this research was to measure reactive nitrogen intermediates (RNI) as stable metabolites of NO induction in plasma of malaria-infected patients in Iran. In this study, 235 blood samples from malaria patients and 80 blood samples from healthy controls were randomly collected from different malarial endemic provinces of Iran, located in southeastern (Sistan & Balouchestan, Hormozgan, Kerman) and northwestern (Ardabil) areas. The involvement of NO in malaria patients has been investigated by statistical analysis of RNI values. Griess micro assay (GMA) was used during Plasmodium vivax, P. falciparum and mixed infections, in order to evaluate whether RNI changes are related to the provincial areas, parasite strains, clinical symptoms and age and gender parameters. RESULTS: The results showed a significant increase of RNI level in malaria patients compared with the control groups of Ardabil (p<0.01), Sistan & Balouchestan, Hormozgan and Kerman (p<0.001) provinces. The level of RNI was higher in mixed plasmodial infection than in single infection. CONCLUSIONS: The high level of RNI was dependent on the type of infection, the plasmodia strain, the clinical symptoms, the age groups and the endemic provinces. Although, this study did not clarify the pathogenic and/or protective role of NO in malaria, our findings provide a novel immunoepidemiological aspect of basal NO production in patients with malaria in endemic areas in Iran.