Contamination by Aspergillus flavus and aflatoxin B1 of 20 samples of lotus seed collected at Ha Noi was investigated. The results showed that 100% of samples were contaminated with Aspergillus flavus, the mean contamination rate with Aspergillus flavus was 40%. 4/20 samples was contaminated with aflatoxin B1, the mean contamination amount was 165 ppb, ranged from 17,5 ppb to 434 ppb. The samples were contaminated with aflatoxin B1 as high as A.flavus. The samples of lotus seed collected from traditional medicine shops had the contamination by A.flavus and aflatoxin B1 higher than that taken from the markets
Seeds ; Aspergillus flavus ; Aflatoxins ; epidemiology

Aims: To evaluate the antibacterial efficacy of ethyl acetate extract of Aspergillus flavus IBRL-C8 against Gram-positive and Gram-negative bacteria. Methodology and results: In this experiment, an endophytic fungus which identified as A. flavus IBRL-C8 was extracted using ethyl acetate and methanol, from Senna siamea, prior to in vitro antibacterial test on eight Gram-bacteria. The results were significantly more enunciated to the ethyl acetate extract since the Gram-bacteria signified 9.0 to 20.0 mm of inhibition zones on Muller Hinton Agar (MHA) during disc diffusion assay. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the extract were ranged from 125-1000 µg/mL and 125-2000 µg/mL, respectively. Time-kill assay depicted the ethyl acetate extract of A. flavus IBRL-C8 exceptionally retarded methicillin-resistant Staphylococcus aureus (MRSA) and also manifested extended antibacterial activity. The maximum reduction in cell numbers occurred at 2MIC concentration (250 µg/mL) during the interval time of 16 h. The malformations noticed from microscopic observations where the transformation of structural annihilation from regular spherical morphology to non-spherical shape with an irregular surface and also disruption around the cell membrane when the MRSA treated with ethyl acetate extract of A. flavus IBRL-C8. Conclusion, significance and impact of study This study proposed the ethyl acetate extract of A. flavus IBRL-C8 as a potential antibacterial agent against MRSA infection, which can be useful in pharmaceutical application.
Aspergillus flavus ; Anti-Bacterial Agents

Bioactive natural compounds, isolated from fungal endophytes, play a promising role in the search for novel drugs. They are an inspiring source for researchers due to their enormous structural diversity and complexity. During the present study fungal endophytes were isolated from a well-known medicinal shrub, Berberis aristata DC. and were explored for their antagonistic and antioxidant potential. B. aristata, an important medicinal shrub with remarkable pharmacological properties, is native to Northern Himalayan region. A total of 131 endophytic fungal isolates belonging to eighteen species and nine genera were obtained from three hundred and thirty surface sterilized segments of different tissues of B. aristata. The isolated fungi were classified on the basis of morphological and molecular analysis. Diversity and species richness was found to be higher in leaf tissues as compared to root and stem. Antibacterial activity demonstrated that the crude ethyl acetate extract of 80% isolates exhibited significant results against one or more bacterial pathogens. Ethyl acetate extract of Alternaria macrospora was found to have potential antibacterial activity. Significant antioxidant activity was also found in crude ethyl acetate extracts of Alternaria alternata and Aspergillus flavus. Similarly, antagonistic activity of the fungal endophytes revealed that all antagonists possessed inhibition potential against more than one fungal pathogen. This study is an important step towards tapping endophytic fungal diversity for bioactive metabolites which could be a step forward towards development of novel therapeutic agents.
Alternaria ; Aspergillus flavus ; Berberis* ; Endophytes* ; Fungi

Rice contaminated with fungal species during storage is not only of poor quality and low economic value, but may also have harmful effects on human and animal health. The predominant fungal species isolated from rice grains during storage belong to the genera Aspergillus and Penicillium. Some of these fungal species produce mycotoxins; they are responsible for adverse health effects in humans and animals, particularly Aspergillus flavus, which produces the extremely carcinogenic aflatoxins. Not surprisingly, there have been numerous attempts to devise safety procedure for the control of such harmful fungi and production of mycotoxins, including aflatoxins. This review provides information about fungal and mycotoxin contamination of stored rice grains, and microbe-based (biological) strategies to control grain fungi and mycotoxins. The latter will include information regarding attempts undertaken for mycotoxin (especially aflatoxin) bio-detoxification and microbial interference with the aflatoxin-biosynthetic pathway in the toxin-producing fungi.
Aflatoxins* ; Animals ; Aspergillus ; Aspergillus flavus ; Fungi* ; Humans ; Mycotoxins ; Penicillium

In our previous studies, Bacillus megaterium KU143, Microbacterium testaceum KU313, and Pseudomonas protegens AS15 have been shown to be antagonistic to Aspergillus flavus in stored rice grains. In this study, the biocontrol activities of these strains were evaluated against Aspergillus candidus, Aspergillus fumigatus, Penicillium fellutanum, and Penicillium islandicum, which are predominant in stored rice grains. In vitro and in vivo antifungal activities of the bacterial strains were evaluated against the fungi on media and rice grains, respectively. The antifungal activities of the volatiles produced by the strains against fungal development and population were also tested using I-plates. In in vitro tests, the strains produced secondary metabolites capable of reducing conidial germination, germ-tube elongation, and mycelial growth of all the tested fungi. In in vivo tests, the strains significantly inhibited the fungal growth in rice grains. Additionally, in I-plate tests, strains KU143 and AS15 produced volatiles that significantly inhibited not only mycelial growth, sporulation, and conidial germination of the fungi on media but also fungal populations on rice grains. GC-MS analysis of the volatiles by strains KU143 and AS15 identified 12 and 17 compounds, respectively. Among these, the antifungal compound, 5-methyl-2-phenyl-1H-indole, was produced by strain KU143 and the antimicrobial compounds, 2-butyl 1-octanal, dimethyl disulfide, 2-isopropyl-5-methyl-1-heptanol, and 4-trifluoroacetoxyhexadecane, were produced by strain AS15. These results suggest that the tested strains producing extracellular metabolites and/or volatiles may have a broad spectrum of antifungal activities against the grain fungi. In particular, B. megaterium KU143 and P. protegens AS15 may be potential biocontrol agents against Aspergillus and Penicillium spp. during rice grain storage.
Aspergillus flavus ; Aspergillus fumigatus ; Aspergillus* ; Bacillus megaterium* ; Bacillus* ; Fungi ; Germination ; In Vitro Techniques ; Penicillium* ; Pseudomonas*

In this study, we evaluated the effect of different temperatures (10, 20, 30, and 40 °C) and relative humidities (RHs; 12, 44, 76, and 98%) on populations of predominant grain fungi (Aspergillus candidus, Aspergillus flavus, Aspergillus fumigatus, Penicillium fellutanum, and Penicillium islandicum) and the biocontrol activity of Pseudomonas protegens AS15 against aflatoxigenic A. flavus KCCM 60330 in stored rice. Populations of all the tested fungi in inoculated rice grains were significantly enhanced by both increased temperature and RH. Multiple linear regression analysis revealed that one unit increase of temperature resulted in greater effects than that of RH on fungal populations. When rice grains were treated with P. protegens AS15 prior to inoculation with A. flavus KCCM 60330, fungal populations and aflatoxin production in the inoculated grains were significantly reduced compared with the grains untreated with strain AS15 regardless of temperature and RH (except 12% RH for fungal population). In addition, bacterial populations in grains were significantly enhanced with increasing temperature and RH, regardless of bacterial treatment. Higher bacterial populations were detected in biocontrol strain-treated grains than in untreated control grains. To our knowledge, this is the first report showing consistent biocontrol activity of P. protegens against A. flavus population and aflatoxin production in stored rice grains under various environmental conditions of temperature and RH.
Aflatoxins ; Aspergillus flavus* ; Aspergillus fumigatus ; Aspergillus* ; Fungi ; Humidity* ; Linear Models ; Penicillium* ; Pseudomonas*

Fungal peritonitis in continuous ambulatory peritoneal dialysis (CAPD) patients is rare. But, it is a serious complication of CAPD because of high morbidity and mortality. It is very important to diagnose and treat such infections promptly, as otherwise it has a poor prognosis. We experienced a case of peritonitis in a CAPD patient that was caused by Aspergillus flavus detected by fungal balls in blood culture bottles and treated successfully by administering anti-fungal agents and removing the peritoneal dialysis catheter.
Aspergillus ; Aspergillus flavus ; Fungi ; Humans ; Peritoneal Dialysis ; Peritoneal Dialysis, Continuous Ambulatory ; Peritonitis ; Prognosis

Fungal corneal ulcer could lead to a devastating outcome. The relative scarcity of readily available, inexpensive but effective topical antifungal drug has left many ophthalmologists desperate and frustated in treating the condition. The use of oral itraconazole has long been proven to be of clinical value in a number of forms of mycoses. Its safety profile is extremely good with minimal reported adverse effects. We investigated an aqueous form of itraconazole which we prepared into a 0.1 mg/ml concnetration and compared its efficacy as a topical antifungal against the standard drug. Natamycin 5 percent in the treatment of fungal keratitis in rabbits. A randomized animal trial was done using 24 rabbit eyes divided into 2 treatment groups. All rabbit corneas were inoculated with Aspergillus flavus and treated after 48 hours with either Topical itraconazole or Natamycin 5 percent for a period of 2 weeks. Results showed inhibition of the disease with both treatment groups. We also found no significant difference between the severity, progression and remission of the keratitis between both treatment groups clinically and statistically. Topical itraconazole 0.1 mg/ml was shown to be comparable to our standard topical antifungal Natamycin 5 percent in treating fungal keratitis. (Author)
Animal ; ASPERGILLUS KERATITIS ; OPHTHALMOLOGY ; ASPERGILLUS FLAVUS ; NATAMYCIN ; ITRACONAZOLE ; FUNGAL CORNEAL ULCER ; FUNGAL KERATITIS

Extracellular keratinase isolated from Aspergillus flavus K-03 was immobilized on calcium alginate. The properties and reaction activities of free and immobilized keratinase with calcium alginate were characterized. The immobilized keratinase showed proteolytic activity against soluble azo-casein and azo-keratin, and insoluble feather keratin. Heat stability and pH tolerance of keratinase were greatly enhanced by immobilization. It also displayed a higher level of heat stability and an increased tolerance toward alkaline pHs compared with free keratinase. During the durability test at 40degrees C, 48% of the original enzyme activity of the immobilized keratinase was remained after 7 days of incubation. The immobilized keratinase exhibited better stability, thus increasing its potential for use in industrial application.
Animals ; Aspergillus flavus* ; Aspergillus* ; Calcium ; Feathers* ; Hot Temperature ; Hydrogen-Ion Concentration ; Immobilization*

Five types of agricultural wastes were used for the production of xylanolytic enzyme by Aspergillus flavus K-03. All wastes materials supported high levels of xylanase and beta-xylosidase production. A high level of proteolytic activity was observed in barley and rice bran cultures, while only a weak proteolytic activity was detected in corn cob, barley and rice straw cultures. Maximum production of xylanase was achieved in basal liquid medium containing rice barn as carbon source for 5 days of culture at pH 6.5 and 25degrees C. The xylanolytic enzyme of A. flavus K-03 showed low thermostability. The times required for 50% reduction of the initial enzyme activity were 90 min at 40degrees C, 13 min at 50degrees C, and 3 min at 60degrees C. Xylanolytic activity showed the highest level at pH 5.5~10.5 and more than 70% of the original activity was retained at pH 6.5 and 7.0. The higher stability of xylanolytic enzymes in the broad range of alkaline pH is useful for utilization of the enzymes in industrial process requiring in alkaline conditions. Moreover, the highest production of xylanolytic enzyme was obtained when 0.5% of rice bran was supplied in basal liquid medium. SDS-PAGE analysis revealed a single xylanase band of approximately 28.5 kDa from the culture filtrates.
Aspergillus flavus* ; Aspergillus* ; Carbon ; Electrophoresis, Polyacrylamide Gel ; Hordeum ; Hydrogen-Ion Concentration ; Zea mays