[Study on the role of alternaria alternata in the etiology of allergic asthma in patients admitted to loghman hospital by using the skin prick test and solid-phase immunoassay]

The prevalence of respiratory allergies, especially those induced by fungi such as Alternaria alternata, has dramatically increased over the past decade. This increase has caused major health problems worldwide. This study aimed to investigate the role of A.alternata in the etiology of allergic asthma, by using the skin prick test and assessment of IgE specific to the fungus in the patient's sera. This study enrolled 202 patients with allergic asthma, aged 12 to 83 years. Participants included 40.1% males and 59.9% females who were enrolled after recording demographic information. A skin prick test with the whole cell extract of A. alternata was performed on the epidermis of the patients' forearms. Histamine and normal saline were used as positive and negative controls, respectively. Serum levels of IgE specific for A.alternata were measured for all patients using the ImmunoCAP Phadiatop method in which the specific A. alternata allergen cocktail that connected to the solid phase reacted to IgE antibodies in each patient's sera. Data were analyzed by analysis of variance and chi-square tests. Among 202 patients with allergic asthma, 14 [6.93%] had mild asthma, 73 [36.10%] were moderate asthmatics and 115 [56.90%] had severe asthma. In total, 14 [6.93%] patients were positive for both the skin test and IgE specific to A. alternata, 35 [17.33%] had negative specific IgE and positive skin test results, and 36 [17.82%] had a positive specific IgE and negative skin test. A total of 117 [57.92%] patients were negative for both tests. The results of this study showed the presence of IgE specific for A. alternate in 50 of 202 [24.75%] patients diagnosed with allergic asthma. The skin prick test was successfully used as a screening test. The results were further confirmed

[Isolation and identification of fusarium species from maize and wheat and assessment of their ability to produce fumonisin B[1]]

Fusarium species are prevalent contaminants of foodstuffs and agricultural crops. They produce fumonisins, which are carcinogenic mycotoxins. The present study has evaluated maize and wheat samples from ten provinces in Iran that were contaminated with Fusarium species. Special attention was paid to the ability of the isolates to produce fumonisin B[1] [FB[1]] as a public health hazard. We collected 32 maize and 15 wheat samples from ten provinces that were major cultivation areas. Samples surface disinfected with a 1% sodium hypochlorite solution for 2 minutes. Fusarium species were isolated by the flotation method on malachite green agar. Pure cultures on potato dextrose agar [PDA] were identified using a combination of macroscopic and microscopic morphological criteria. The ability of the isolates to produce FB[1] was evaluated by thin layer chromatography [TLC] and the amounts of fumonisin B[1] produced were assessed by high performance liquid chromatography [HPLC]. A total of 55 Fusarium isolates that belonged to five species were isolated. There were 27 of the 32 maize samples [84.4%] and 11 of 15 wheat samples [73.3%] that were contaminated with Fusarium species. Species consisted of F. verticillioides [23 isolates], F. proliferatum [22 isolates], F. subglutinans [5 isolates], F. nygamai [4 isolates] and F. redolens [1 isolate] based on morphological criteria. Twenty-two of the 55 [40%] Fusarium isolates produced FB[1] in a total range from 230.4 to 9565 microg/ml. The highest amounts of FB[1] production were related to toxigenic isolates of F. verticillioides and F. proliferatum. Results of the present work indicates a high degree of contamination of maize and wheat with Fusarium strains that belong to the Gibberella fujikuroi species complex, particularly F. verticillioides and F. proliferatum. This contamination is a potential public health threat due to food spoilage and subsequent production of high levels of carcinogenic FB[1]

Comparative study of the major Iranian cereal cultivars and some selected spices in relation to support Aspergillus parasiticus growth and aflatoxin production

Aflatoxins are toxic fungal metabolites enable to contaminate a wide range of natural substrates. This contamination can be host-specific for different plant species. In this study, the ability of a toxigenic Aspergillus parasiticus to produce various aflatoxins on major Iranian cereals was evaluated with special focus on plant susceptibility to toxin production at cultivar level. Aspergillus parasiticus cultured on major Iranian cereal cultivars and some selected spices was incubated in shaking condition at 28?C for 6 days. The concentration of aflatoxins B1 and total [B1, B2, G1 and G2] was measured by thin layer chromatography. The amounts of aflatoxin B1 produced on maize, wheat and rice cultivars were in the ranges of 1.0-33.9, 41.9-193.7, and 39.1-82.3 micro g/g fungal weight, respectively. Interestingly, genetically modified Bacillus thuringiensis rice [GM rice] of Tarom Molaii cultivar examined for the first time in this study showed less susceptibility to aflatoxin production in comparison with its normal counterpart [P < 0.05]. The mean of aflatoxin production on maize cultivars was less than both wheat and rice cultivars that indicates considerable resistance of maize to aflatoxin compared with two other cereals. Unlike to Cuminum cyminum, both Helianthus annuus and Carum carvi seeds were highly resistant to aflatoxin production. These results indicate that inter- and intra-species differences exist in susceptibility of the major Iranian cereals as well as spices tested to A. parasiticus growth and aflatoxin production. Further studies are recommended to determine resistance markers of selected cultivars of Iranian cereals

Biological activities of chamomile (Matricaria chamomile) flowers' extract against the survival and egg laying of the cattle fever tick (Acari Ixodidae) / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

In the present work, the potential of acaricidal activity of chamomile flowers' extract was studied against engorged Rhipicephalus annulatus tick under laboratory condition. For this purpose, the engorged females of Rhipicephalus annulatus were exposed to two-fold serial dilutions of chamomile flowers' extract (0.5%, 1.0%, 2.0%, 4.0% and 8.0%) using "dipping method" in vitro. The engorged ticks were immersed in different plant dilutions (five ticks for each dilution) for 1 min and they were immediately incubated in separate Petri dishes for each replicate at 26 degrees C and 80% relative humidity. Mortality rate for each treatment was recorded 5 d after incubation. The mortality rate caused by different dilutions of chamomile flower' extract ranged from 6.67% to 26.7%, whereas no mortality was recorded for non-treated control group. The mass of produced eggs varied form 0.23 g (in 8.0% solutions) to 0.58 g (in control), with no statistical differences between the treatments and control (P>0.05). Also the chamomile flowers' extract in highest concentration used (8.0%) caused 46.67% failure in egg laying in engorged females while non failure was observed for non-treated control group. Macroscopic observations indicated that in effective concentrations of plant (4.0% and 8.0%), patchy hemorrhagic swelling appeared on the skin of treated ticks. The results presented for the first time in this study imply that chamomile may be considered as a promising plant for biocontrol of cattle fever tick disease in the field condition.

Cellobiose dehydrogenase production by the genus cladosporium

Cellobiose dehydrogenase [CDH; EC.1.1.5.1] is an extracellular enzyme that mainly produced by wood-degrading fungi. It oxidizes cellobiose to cellobionolactone using a wide spectrum of electron acceptors. The key roles of CDH in growth, metabolism, and some other important cellular processes such as cellulose degradation in fungi have been noted. Since the demands for finding new sources of CDH among different organisms have been dramatically increased, this study was focused on the presence of CDH in the genus Cladosporium as a well-known cellulolytic fungus. Twenty strains of Cladosporium isolated from soil samples from different geographical origin were evaluated for CDH-producing ability. The early screening of the fungus by zymogram method revealed the presence of CDH as an extracellular form in all of the examined isolates. Submerged cultivation of the best producer of CDH [selected from initial screening] on a specific medium showed the maximum amounts of enzyme produced in shaking cultures with pH 4.5 at 28°C for a 14-day period. The enzyme activity was determined in the range of 27.83 to 1284.84 unit/mg protein among the isolates. Our observations show that Cladosporium isolates with high CDH producing ability i.e. isolates No. 10 and No. 18 can be used as selective candidates for large-scale production of this industrially important enzyme in further research programs. This is the first documented report on the presence of CDH in the fungus Cladosporium

Screening of soil and sheep faecal samples for predacious fungi: Isolation and characterization of the nematode-trapping fungus arthrobotrys oligospora

Over one-year period, 150 pasture soil samples and 138 sheep faecal samples, collected from different parts of Iran were screened for the presence of nematophagous fungi. The samples were cultured at 25°C on chloramphenicol-2% water agar [CHF-WA] plates in the presence of Haemonchus contortus third stage larvae [L3] and checked over a two-month period for characteristic conidia, conidiophores and hyphal traps of nematophagous fungi. Suspected nematophagous fungi were isolated by periodic transfer of the fungi on CHF-WA plates using the agar block method. Overall, 11 soil samples were found to harbour the nematode-trapping fungus Arthrobotrys from which 3 pure isolates were made and consequently identified as Arthrobotrys oligospora IRAN 877 C, IRAN 878 C and IRAN 879 C. Nematophagous fungi were not found in any tested sheep faecal samples. The predatory capacity of the isolates was tested against H. contortus infective larvae and then compared to reference strains A. oligospora CBS 111.37, A. oligospora CBS 251.82 and Duddingtonia flagrans CBS 583.91. The local strains of A. oligospora reduced the development of H. contortus L3 by 75-85%, whereas, the predatory capacity of reference A. oligospora and D. flagrans strains was measured in the range of 51-85% compared to the fungus free controls. Study of the effect of temperature on predatory activity of A. oligospora strains IRAN 877 C and CBS 111.37 revealed a reduction of more than 95% in infective larvae of H. contortus at temperature levels between 15 to 25°C. This reduction was significantly decreased to 30% and 50% at 10°C and 30°C, respectively. The nematode-trapping fungus A. oligospora is reported from soil of Iran for the first time and its potential role in biocontrol of gastrointestinal nematodes of ruminants is discussed

Inhibitory effect of aqueous onion and garlic extracts on growth and keratinase activity in trichophyton mentagrophytes

The effect of onion and garlic extracts on fungal growth and keratinolytic activity was studied in Trichophyton mentagrophytes as one of the major etiologic agents of human and animal dermatophytosis in Iran and other parts of the world. In order to find out the best keratinase producer for further steps, culture conditions for 30 strains of T. mentagrophytes isolated from human dermatophytosis were optimized on specific solid and liquid media. All of the isolates produced the enzyme on both selective culture media. The maximum keratinolytic activity at submerged cultivation was reported for cultures of T. mentagrophytes isolate No. 1 grown for a 12-day period at 32°C. Extracellular keratinase activity was in the range of 0.28 to 2.18 u/mg protein in different isolates at predetermined optimal conditions. The growth of T. mentagrophytes isolate No. 1 was inhibited in the presence of various concentrations of onion and garlic extracts. This inhibition reached to a maximum of 100% for both extracts at 10% v/v concentrations. Keratinase synthesis was also inhibited by two extracts as a dose-dependent manner with maximums about 58.54 and 71.36% at 5% concentrations, accordingly. In contrast to the fungal growth, keratinolytic activity was inhibited more by garlic as compared with onion extract. This is the first report on keratinase inhibition by these two natural compounds. Since fungal growth and keratinolytic activity are important factors in pathogenesis of the dermatophytes, their inhibition by onion and garlic indicate that these substances may have potential values for treatment of human and animal dermatophytosis