WorldWideScience

Sample records for aspergillus flavus clinical

  1. Microsatellite typing of Aspergillus flavus from clinical and environmental avian isolates

    OpenAIRE

    2013-01-01

    Aspergillosis is one of the most common causes of death in captive birds. Aspergillus fumigatus accounts for approximately 95 % of aspergillosis cases and Aspergillus flavus is the second most frequent organism associated with avian infections. In the present study, the fungi were grown from avian clinical samples (post-mortem lung material) and environmental samples (eggs, food and litter). Microsatellite markers were used to type seven clinical avian isolates and 22 environmental isolates o...

  2. Microsatellite typing of Aspergillus flavus from clinical and environmental avian isolates.

    Science.gov (United States)

    Hadrich, Inès; Drira, Inès; Neji, Sourour; Mahfoud, Nedia; Ranque, Stéphane; Makni, Fattouma; Ayadi, Ali

    2013-01-01

    Aspergillosis is one of the most common causes of death in captive birds. Aspergillus fumigatus accounts for approximately 95 % of aspergillosis cases and Aspergillus flavus is the second most frequent organism associated with avian infections. In the present study, the fungi were grown from avian clinical samples (post-mortem lung material) and environmental samples (eggs, food and litter). Microsatellite markers were used to type seven clinical avian isolates and 22 environmental isolates of A. flavus. A. flavus was the only species (28 % prevalence) detected in the avian clinical isolates, whereas this species ranked third (19 %) after members of the genera Penicillium (39 %) and Cladosporium (21 %) in the environmental samples. Upon microsatellite analysis, five to eight distinct alleles were detected for each marker. The marker with the highest discriminatory power had eight alleles and a 0.852 D value. The combination of all six markers yielded a 0.991 D value with 25 distinct genotypes. One clinical avian isolate (lung biopsy) and one environmental isolate (egg) shared the same genotype. Microsatellite typing of A. flavus grown from avian and environmental samples displayed an excellent discriminatory power and 100 % reproducibility. This study showed a clustering of clinical and environmental isolates, which were clearly separated. Based upon these results, aspergillosis in birds may be induced by a great diversity of isolates.

  3. High resolution genotyping of clinical Aspergillus flavus isolates from India using microsatellites.

    Directory of Open Access Journals (Sweden)

    Shivaprakash M Rudramurthy

    Full Text Available BACKGROUND: Worldwide, Aspergillus flavus is the second leading cause of allergic, invasive and colonizing fungal diseases in humans. However, it is the most common species causing fungal rhinosinusitis and eye infections in tropical countries. Despite the growing challenges due to A. flavus, the molecular epidemiology of this fungus has not been well studied. We evaluated the use of microsatellites for high resolution genotyping of A. flavus from India and a possible connection between clinical presentation and genotype of the involved isolate. METHODOLOGY/PRINCIPAL FINDINGS: A panel of nine microsatellite markers were selected from the genome of A. flavus NRRL 3357. These markers were used to type 162 clinical isolates of A. flavus. All nine markers proved to be polymorphic displaying up to 33 alleles per marker. Thirteen isolates proved to be a mixture of different genotypes. Among the 149 pure isolates, 124 different genotypes could be recognized. The discriminatory power (D for the individual markers ranged from 0.657 to 0.954. The D value of the panel of nine markers combined was 0.997. The multiplex multicolor approach was instrumental in rapid typing of a large number of isolates. There was no correlation between genotype and the clinical presentation of the infection. CONCLUSIONS/SIGNIFICANCE: There is a large genotypic diversity in clinical A. flavus isolates from India. The presence of more than one genotype in clinical samples illustrates the possibility that persons may be colonized by multiple genotypes and that any isolate from a clinical specimen is not necessarily the one actually causing infection. Microsatellites are excellent typing targets for discriminating between A. flavus isolates from various origins.

  4. 76 FR 16297 - Aspergillus flavus

    Science.gov (United States)

    2011-03-23

    ..., lawns, or buildings (residential and other indoor uses). A. Dietary Exposure 1. Food. Current uses of... emergence). Once applied to corn and after exposure to moisture, Aspergillus flavus AF36 germinates,...

  5. High resolution genotyping of clinical Aspergillus flavus isolates from India using microsatellites.

    NARCIS (Netherlands)

    Rudramurthy, S.M.; Valk, H.A. de; Chakrabarti, A.; Meis, J.F.G.M.; Klaassen, C.H.

    2011-01-01

    BACKGROUND: Worldwide, Aspergillus flavus is the second leading cause of allergic, invasive and colonizing fungal diseases in humans. However, it is the most common species causing fungal rhinosinusitis and eye infections in tropical countries. Despite the growing challenges due to A. flavus, the mo

  6. Interaction between maize seed and Aspergillus flavus

    Science.gov (United States)

    Aspergillus flavus is an opportunistic fungal pathogen that colonizes maize seeds and contaminates them with aflatoxin. The fungus is localized in the endosperm and aleurone. To investigate the plant microbe interaction, we conducted histological and molecular studies to characterize the internal co...

  7. Clinical efficacy and tolerability of caspofungin in a renal transplant patient with Aspergillus flavus lung infection: case report.

    Science.gov (United States)

    Pasticci, M B; Barchiesi, F; Fallani, S; Palladino, N; Lapalorcia, L M; Gubbiotti, M; Cozzari, M; Novelli, A; Baldelli, F

    2006-10-01

    Organ transplant recipients are at increased risk for severe invasive aspergillosis, and amphotericin deoxycholate has been the standard treatment for many years. Currently, however, lipid formulations are preferred due to their few side effects. Also, a number of new antifungal drugs have been developed including new azoles and echinocandins. Caspofungin is the first of the echinocandin derivatives patented to treat patients with invasive aspergillosis who are refractory or intolerant to other therapies. A renal transplant patient on immunosuppressive treatment with chronic hepatitis B virus infection was admitted with fever, hemophthisis and lung consolidation, diagnosed to be probably caused by Aspergillus flavus. The patient developed cholestatic hepatitis most likely related to itraconazole. Clinical failure and in vitro itraconazole resistance of the isolate was also documented while the patient was receiving itraconazole at a reduced dosage. Caspofungin was administered once a day as ambulatory treatment and was well tolerated. Clinical improvement was observed after 6 weeks of treatment and no hepatic toxicity was documented. Caspofungin seems to be a potentially useful antifungal agent in renal transplant patients with invasive aspergillosis. Further evaluation of the efficacy of caspofungin is needed.

  8. In vitro susceptibility of 188 clinical and environmental isolates of Aspergillus flavus for the new triazole isavuconazole and seven other antifungal drugs

    NARCIS (Netherlands)

    Shivaprakash, M.R.; Geertsen, E.; Chakrabarti, A.; Mouton, J.W.; Meis, J.F.G.M.

    2011-01-01

    Recently isavuconazole, an experimental triazole agent, was found to be active against Aspergillus species. As Aspergillus flavus is the second-most common Aspergillus species isolated from human infection and the fungus has not been widely tested against the drug, we studied a large collection of c

  9. Scleral buckle infection with aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Bouhaimed Manal

    2008-01-01

    Full Text Available Purpose: To present a case of scleral buckle infection with Aspergillus flavus in a tertiary eye center in Saudi Arabia. Methods: A retrospective case report of a 28-year-old Saudi male who presented with a six-month history of conjunctival injection and discharge from the left eye which had undergone uncomplicated conventional retinal detachment surgery, at the King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia, in the form of cryopexy, subretinal fluid drainage and scleral buckle (grooved segmental sponge and circumferential band with sleeve for a macula on retinal detachment four years earlier. A diagnosis of infected extruded scleral buckle was made and the buckle was removed. Results: The infected scleral buckle was removed under local anesthesia with administration of sub-conjunctival irrigation of 50 mg solution of Vancomycin, and sub-conjunctival injection of 25mg of Vancomycin. Post operative microbiological studies revealed infection with silver staining of moderate Aspergillus flavus hyphae. Visual acuity of the left eye improved from 20/200 before surgery to 20/60 in the two years follow-up visit. Conclusion: This case report indicates the importance of considering infection with multiple organisms - including fungal ones - in cases of scleral buckle infections in our population.

  10. Aspergillus flavus myositis in a patient after liver transplantation.

    NARCIS (Netherlands)

    Li, D.M.; Xiu, D.R.; Li, R.Y.; Samson, R.A.; de Hoog, G.S.; Wang, D.L.

    2008-01-01

    We describe the first case of Aspergillus myositis caused by Aspergillus flavus in a liver transplant patient. The patient was a 43-year-old man who underwent liver transplantation because of end-stage hepatic cirrhosis. He experienced pain in his left calf two months after the operation. Nodules wi

  11. 40 CFR 180.1206 - Aspergillus flavus AF36; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Aspergillus flavus AF36; exemption... FOOD Exemptions From Tolerances § 180.1206 Aspergillus flavus AF36; exemption from the requirement of a... pesticide Aspergillus flavus AF36 in or on cotton, gin byproducts; cotton, hulls; cotton, meal;...

  12. 40 CFR 180.1254 - Aspergillus flavus NRRL 21882; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Aspergillus flavus NRRL 21882... RESIDUES IN FOOD Exemptions From Tolerances § 180.1254 Aspergillus flavus NRRL 21882; exemption from the... of Aspergillus flavus NRRL 21882 on peanut; peanut, hay; peanut, meal; and peanut, refined oil....

  13. Molecular mechanisms of Aspergillus flavus secondary metabolism and development.

    Science.gov (United States)

    Amare, Meareg G; Keller, Nancy P

    2014-05-01

    The plant and human opportunistic fungus Aspergillus flavus is recognized for the production of the carcinogen aflatoxin. Although many reviews focus on the wealth of information known about aflatoxin biosynthesis, few articles describe other genes and molecules important for A. flavus development or secondary metabolism. Here we compile the most recent work on A. flavus secondary metabolite clusters, environmental response mechanisms (stress response pathways, quorum sensing and G protein signaling pathways) and the function of the transcriptional regulatory unit known as the Velvet Complex. A comparison to other Aspergilli reveals conservation in several pathways affecting fungal development and metabolism.

  14. RNA interference-mediated control of Aspergillus flavus in maize

    Science.gov (United States)

    Introduction: Aflatoxigenic Aspergillus flavus is a frequent contaminant of agricultural commodities such as corn, peanut, tree nuts and cottonseed. Ingestion of foods, especially corn, contaminated with aflatoxins has been implicated in acute toxicoses while chronic, low-level exposure can lead to...

  15. Occurrence of toxigenic Aspergillus flavus in commercial Bulgur wheat

    Directory of Open Access Journals (Sweden)

    Carla Bertechini FARIA

    Full Text Available Abstract Aflatoxins are mutagenic, carcinogenic, and teratogenic mycotoxins. The objective of this work was to study the presence of aflatoxigenic Aspergillus in commercial Bulgur wheat in the city of Maringá, Paraná, Brazil. Thirty samples of commercial Bulgur wheat, acquired in the period of August 2011 to January 2012, were evaluated. The enumeration analysis showed that samples had up to 273.3 CFU of molds and 133.3 CFU of aflatoxigenic Aspergillus per gram of wheat. Forty-two monosporic isolates were obtained and identified as Aspergillus flavus. The isolates were analyzed regarding their aflatoxigenic potential by culture in coconut milk agar; hydroxide vapor exposure; chromatography; and polymerase chain reaction (PCR targeting genes that code enzymes of the aflatoxins synthesis pathway. Some of the isolates were confirmed to be aflatoxin producers and several of them presented a genetic profile of aflatoxin synthesis. The obtained results demonstrated that Bulgur wheat A. flavus contamination is concerning.

  16. CONTROL OF AFLATOXIGENIC Aspergillus flavus IN PEANUTS USING NONAFLATOXIGENIC A. flavus, A. niger and Trichoderma harzianum

    Directory of Open Access Journals (Sweden)

    OKKY SETYAWATI DHARMAPUTRA

    2003-01-01

    Full Text Available The effects of nontoxigenic Aspergillus flavus, A. niger and Trichoderma harzianum inoculated into planting media on toxigenic A. flavus infection and its aflatoxin production in peanut kernels at harvest were investigated together with (1 the moisture content of planting media before peanut planting, at the time of inflorescence, and at harvest, (2 the population of aflatoxigenic and nonaflatoxigenic A. flavus, A. niger and T. harzianum in peanut planting media before peanut planting, at the time of inflorescence, and at harvest, (3 the moisture content of peanut kernels at harvest, and (4 toxigenic A. flavus invasion in peanut plant parts (r oots, stems, petioles, leaves and flowers at the time of inflorescence. The fungal isolates were inoculated into planting media at the same time with the planting of peanut seeds. Peanut plants were grown under glasshouse conditions. Treated planting media were inoculated with the combined use of (1 toxigenic and nontoxigenic A. flavus, (2 toxigenic A. flavus and A. niger, and (3 toxigenic A. flavus and T. harzianum. Planting media inoculated only with each fungal isolat e and uninoculated planting media were used as controls. Two watering treatments of peanut plants were carried out, i.e. watering un til harvest and not watering for 15 days before harvest. The populations of the fungal isolates in the planting media and peanut kernels were determined using dilution method followed by pour plate method; the percentages of toxigenic A. flavus and test fungal colonizations in peanut plant parts were de termined using plating method; the moisture content of planting media and peanut kernels were determined using oven method; the aflatoxin content of peanut kernels was determined using Thin Layer Chromatography method. The results indicated that at the time of harvest the decr ease in moisture contents of planting media not watered for 15 days before harvest was higher than those watered until harvest. The

  17. Lipids in Aspergillus flavus-maize interaction

    Directory of Open Access Journals (Sweden)

    Massimo eReverberi

    2014-02-01

    Full Text Available In sSome filamentous fungi, the pathways related to the oxidative stress and oxylipins production are involved both in the process of host-recognition of the host that and in the pathogenic phase. In fact, recent studies have shown that the production of oxylipins in filamentous fungi, yeasts and chromists is also related to the development of the organism itself and to mechanisms of communication with the host at the cellular level. The oxylipins, also involved produced in by the host during defense reactions, are able to induce sporulation and to modulate regulate the biosynthesis of mycotoxins in numerous several pathogenic fungi, apparently replacing the endogenous ones. In A. flavus, the oxylipins play a crucial role as signals for the regulation regulatingof the biosynthesis of aflatoxins, the conidiogenesis and the formation of sclerotia.To investigate the involvement of the an oxylipins based cross-talk into Z. mays and A. flavus interaction, we analyzed the oxylipins profile of the wild type strain and of three mutants of A. flavus that are deleted at the Aflox1 gene level also during maize kernel invasion; Aflox1 encodes for a manganese lipoxygenase.A lipidomic approach has been addressed through the use of LC-ToF-MS, followed by a statistical analysis of the principal components (PCA. The results showed the existence of a difference between the oxylipins profile generated by the WT and the mutants onto challenged maize. In relation to this, aflatoxin synthesis which is largely hampered in vitro, is intriguingly restored. These results highlight the important role of maize oxylipin in driving secondary metabolism in A. flavus.

  18. Primary cutaneous aspergillosis due to Aspergillus flavus: a case report

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qiang-qiang; LI Li; ZHU Min; ZHANG Chao-ying; WANG Jia-jun

    2005-01-01

    @@ Infections caused by opportunistic organisms which have been known as etiologic agents of disease become more and more frequent.Aspergillus spp. is one of the agents. Fungi of aspergillus genus are widely distributed in nature, particularly in the soil and in the decomposed vegetation. They are frequent opportunist pathogens in immunocompromised patients. The most frequent causative organisms that cause cutaneous aspergillosis are A.fumigatus and A.flavus.1-3 In this report, we present a case of primary cutaneous aspergillosis manifested by ulceration of the shank due to A. flavus. The patient had no deficiency of immunological status and severe disease associated with fungal infection. Excellent response was shown to anti-fungal therapy.

  19. Atoxigenic Aspergillus flavus endemic to Italy for biocontrol of aflatoxins in maize

    Science.gov (United States)

    Effective biological control of aflatoxin­producing Aspergillus flavus with atoxigenic members of that species requires suitable A. flavus well adapted to and resident in target agroecosystems. Eighteen atoxigenic isolates of A. flavus endemic in Italy were compared for ability to reduce aflatoxin c...

  20. Effect of gamma radiation on Aspergillus flavus and Aspergillus ochraceus ultrastructure and mycotoxin production

    Science.gov (United States)

    Ribeiro, J.; Cavaglieri, L.; Vital, H.; Cristofolini, A.; Merkis, C.; Astoreca, A.; Orlando, J.; Carú, M.; Dalcero, A.; Rosa, C. A. R.

    2011-05-01

    The aim of this work was to study the effect of gamma radiation (2 kGy) on Aspergillus flavus and Aspergillus ochraceus ultrastructure. Moreover, the influence on aflatoxin B 1 and ochratoxin A production was also observed. Irradiated A. flavus strain showed a dull orangish colony while control strain showed the typical green color. Minor differences were observed on stipes, metulae and conidia size between control and irradiated A. flavus and A. ochraceus strains. Irradiated fungi showed ultrastructural changes on cell wall, plasmalema and cytoplasm levels. The levels of mycotoxins produced by irradiated strains were two times greater than those produced by control strains. Successive transferences of irradiated strains on malt extract agar allowed the fungus to recuperate morphological characteristics. Although minor changes in the fungal morphology were observed, ultrastructural changes at cell wall level and the increase of mycotoxin production ability were observed. Inappropriate storage of irradiated food and feed would allow the development of potentially more toxicogenic fungal propagules.

  1. Cladal relatedness among Aspergillus oryzae isolates and Aspergillus flavus S and L morphotype isolates.

    Science.gov (United States)

    Chang, Perng-Kuang; Ehrlich, Kenneth C; Hua, Sui-Sheng T

    2006-04-25

    Aspergillus flavus is the main etiological agent for aflatoxin contamination of crops. Its close relative, A. oryzae, does not produce aflatoxins and has been widely used to produce fermented foods. We compared the phylogeny of A. oryzae isolates and L- and S-type sclerotial isolates of A. flavus using single nucleotide polymorphisms in the omtA gene in the aflatoxin biosynthesis gene cluster and deletions in and distal to the norB-cypA intergenic region as phylogenetic signals. Aflatoxin-producing ability and sclerotial size also were weighted in the analysis. Like A. flavus, the A. oryzae isolates form a polyphyletic assemblage. A. oryzae isolates in one clade strikingly resemble an A. flavus subgroup of atoxigenic L-type isolates. All toxigenic S-type isolates closely resemble another subgroup of atoxigenic L-type isolates. Because atoxigenic S-type isolates are extremely rare, we hypothesize that loss of aflatoxin production in S-type isolates may occur concomitantly with a change to L-type sclerotia. All toxigenic L-type isolates, unlike A. oryzae, have a 1.0 kb deletion in the norB-cypA region. Although A. oryzae isolates, like S-type, have a 1.5 kb deletion in the norB-cypA region, none were cladally related to S-type A. flavus isolates. Our results show that A. flavus populations are genetically diverse. A. oryzae isolates may descend from certain atoxigenic L-type A. flavus isolates.

  2. Trailing or paradoxical growth of Aspergillus flavus exposed to caspofungin is independent of genotype.

    Science.gov (United States)

    Hadrich, Inès; Neji, Sourour; Makni, Fattouma; Ayadi, Ali; Elloumi, Moez; Ranque, Stéphane

    2014-12-01

    There are limited data on in vitro susceptibility testing of echinocandins against Aspergillus species. The objective of this study was to describe the phenotypes of Aspergillus flavus observed on exposure to caspofungin in vitro and to test whether these phenotypes were associated with A. flavus genotypes. The caspofungin MICs of 37 A. flavus clinical isolates collected from 14 patients with invasive aspergillosis were determined using Etest assays. Caspofungin MICs ranged from 0.012 to 0.064 mg l(-1); the modal MIC was 0.023 mg l(-1) and the MIC₅₀ and MIC₉₀ were 0.032 and 0.064 mg l(-1), respectively. A clear end point was noted in 24 (65 %) isolates, whereas seven (19 %) displayed a trailing effect and six (16 %) showed paradoxical growth when exposed to caspofungin. In these A. flavus isolates, the absence of a significant population structure or genetic differentiation indicated that trailing or paradoxical growth phenotypes were independent of microsatellite genotype.

  3. Aflatoxigenic Aspergillus flavus and Aspergillus parasiticus strains in Hungarian maize fields.

    Science.gov (United States)

    Sebők, Flóra; Dobolyi, Csaba; Zágoni, Dóra; Risa, Anita; Krifaton, Csilla; Hartman, Mátyás; Cserháti, Mátyás; Szoboszlay, Sándor; Kriszt, Balázs

    2016-12-01

    Due to the climate change, aflatoxigenic Aspergillus species and strains have appeared in several European countries, contaminating different agricultural commodities with aflatoxin. Our aim was to screen the presence of aflatoxigenic fungi in maize fields throughout the seven geographic regions of Hungary. Fungi belonging to Aspergillus section Flavi were isolated in the ratio of 26.9% and 42.3% from soil and maize samples in 2013, and these ratios decreased to 16.1% and 34.7% in 2014. Based on morphological characteristics and the sequence analysis of the partial calmodulin gene, all isolates proved to be Aspergillus flavus, except four strains, which were identified as Aspergillus parasiticus. About half of the A. flavus strains and all the A. parasiticus strains were able to synthesize aflatoxins. Aflatoxigenic Aspergillus strains were isolated from all the seven regions of Hungary. A. parasiticus strains were found in the soil of the regions Southern Great Plain and Southern Transdanubia and in a maize sample of the region Western Transdanubia. In spite of the fact that aflatoxins have rarely been detected in feeds and foods in Hungary, aflatoxigenic A. flavus and A. parasiticus strains are present in the maize culture throughout Hungary posing a potential threat to food safety.

  4. Potential of essential oils for protection of grains contaminated by aflatoxin produced by Aspergillus flavus

    OpenAIRE

    Renata Hadad Esper; Edlayne eGonçalez; Marcia Ortiz Mayo Marques; Roberto Carlos Felicio; Joana D'arc Felicio

    2014-01-01

    Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Inhibitory effects of essential oils of Ageratum conyzoides (mentrasto) and Origanum vulgare (oregano) on the mycelial growth and aflatoxin B1 production by Aspergillus flavus have been studied previously in culture medium. The aim of this study was to evaluate aflatoxin B1 production by Aspergillus flavus in real food systems (corn and soybean) treated with ...

  5. Reduction of aflatoxin production by Aspergillus flavus and Aspergillus parasiticus in interaction with Streptomyces.

    Science.gov (United States)

    Verheecke, C; Liboz, T; Anson, P; Diaz, R; Mathieu, F

    2015-05-01

    The aim of this study is to investigate aflatoxin gene expression during Streptomyces-Aspergillus interaction. Aflatoxins are carcinogenic compounds produced mainly by Aspergillus flavus and Aspergillus parasiticus. A previous study has shown that Streptomyces-A. flavus interaction can reduce aflatoxin content in vitro. Here, we first validated this same effect in the interaction with A. parasiticus. Moreover, we showed that growth reduction and aflatoxin content were correlated in A. parasiticus but not in A. flavus. Secondly, we investigated the mechanisms of action by reverse-transcriptase quantitative PCR. As microbial interaction can lead to variations in expression of household genes, the most stable [act1, βtub (and cox5 for A. parasiticus)] were chosen using geNorm software. To shed light on the mechanisms involved, we studied during the interaction the expression of five genes (aflD, aflM, aflP, aflR and aflS). Overall, the results of aflatoxin gene expression showed that Streptomyces repressed gene expression to a greater level in A. parasiticus than in A. flavus. Expression of aflR and aflS was generally repressed in both Aspergillus species. Expression of aflM was repressed and was correlated with aflatoxin B1 content. The results suggest that aflM expression could be a potential aflatoxin indicator in Streptomyces species interactions. Therefore, we demonstrate that Streptomyces can reduce aflatoxin production by both Aspergillus species and that this effect can be correlated with the repression of aflM expression.

  6. Spinal osteomyelitis due to Aspergillus flavus in a child: a rare complication after haematopoietic stem cell transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Beluffi, Giampiero [Fondazione IRCCS Policlinico ' S.Matteo' , Section of Paediatric Radiology, Department of Radiodiagnosis, Pavia PV (Italy); Bernardo, Maria E.; Locatelli, Franco [University of Pavia, Fondazione IRCCS Policlinico ' S.Matteo' , Department of Paediatric Haematology/Oncology, Pavia (Italy); Meloni, Giulia [University of Pavia, Fondazione IRCCS Policlinico ' S.Matteo' , Institute of Radiology, Pavia (Italy); Spinazzola, Angelo [Fondazione IRCCS Policlinico ' S.Matteo' , Section of Paediatric Radiology, Department of Radiodiagnosis, Pavia PV (Italy); Ospedale Maggiore, Crema CR (Italy)

    2008-06-15

    We report the case of a child affected by acute myeloid leukaemia who was treated with allogeneic haematopoietic stem cell transplantation and developed cervicothoracic spinal osteomyelitis due to Aspergillus flavus. The diagnosis was difficult on a clinical basis, but made possible by conventional radiography and MRI. (orig.)

  7. Characterization of the Far Transcription Factor Family in Aspergillus flavus

    Science.gov (United States)

    Luo, Xingyu; Affeldt, Katharyn J.; Keller, Nancy P.

    2016-01-01

    Metabolism of fatty acids is a critical requirement for the pathogenesis of oil seed pathogens including the fungus Aspergillus flavus. Previous studies have correlated decreased ability to grow on fatty acids with reduced virulence of this fungus on host seed. Two fatty acid metabolism regulatory transcription factors, FarA and FarB, have been described in other filamentous fungi. Unexpectedly, we find A. flavus possesses three Far homologs, FarA, FarB, and FarC, with FarA and FarC showing a greater protein similarity to each other than FarB. farA and farB are located in regions of colinearity in all Aspergillus spp. sequenced to date, whereas farC is limited to a subset of species where it is inserted in an otherwise colinear region in Aspergillus genomes. Deletion and overexpression (OE) of farA and farB, but not farC, yielded mutants with aberrant growth patterns on specific fatty acids as well as altered expression of genes involved in fatty acid metabolism. Marked differences included significant growth defects of both ∆farA and ∆farB on medium-chain fatty acids and decreased growth of OE::farA on unsaturated fatty acids. Loss of farA diminished expression of mitochondrial β-oxidation genes whereas OE::farA inhibited expression of genes involved in unsaturated fatty acid catabolism. FarA also positively regulated the desaturase genes required to generate polyunsaturated fatty acids. Aflatoxin production on toxin-inducing media was significantly decreased in the ∆farB mutant and increased in the OE::farB mutant, with gene expression data supporting a role for FarB in tying β-oxidation processes with aflatoxin accumulation. PMID:27534569

  8. Enhanced diversity and aflatoxigenicity in interspecific hybrids of Aspergillus flavus and Aspergillus parasiticus.

    Science.gov (United States)

    Olarte, Rodrigo A; Worthington, Carolyn J; Horn, Bruce W; Moore, Geromy G; Singh, Rakhi; Monacell, James T; Dorner, Joe W; Stone, Eric A; Xie, De-Yu; Carbone, Ignazio

    2015-04-01

    Aspergillus flavus and A. parasiticus are the two most important aflatoxin-producing fungi responsible for the contamination of agricultural commodities worldwide. Both species are heterothallic and undergo sexual reproduction in laboratory crosses. Here we examine the possibility of interspecific matings between A. flavus and A. parasiticus. These species can be distinguished morphologically and genetically, as well as by their mycotoxin profiles. Aspergillus flavus produces both B aflatoxins and cyclopiazonic acid (CPA), B aflatoxins or CPA alone, or neither mycotoxin; Aspergillus parasiticus produces B and G aflatoxins or the aflatoxin precursor O-methylsterigmatocystin, but not CPA. Only four of forty-five attempted interspecific crosses between opposite mating types of A. flavus and A. parasiticus were fertile and produced viable ascospores. Single ascospore strains from each cross were shown to be recombinant hybrids using multilocus genotyping and array comparative genome hybridization. Conidia of parents and their hybrid progeny were haploid and predominantly monokaryons and dikaryons based on flow cytometry. Multilocus phylogenetic inference showed that experimental hybrid progeny were grouped with naturally occurring A. flavus L strain and A. parasiticus. Higher total aflatoxin concentrations in some F1 progeny strains compared to midpoint parent aflatoxin levels indicate synergism in aflatoxin production; moreover, three progeny strains synthesized G aflatoxins that were not produced by the parents, and there was evidence of allopolyploidization in one strain. These results suggest that hybridization is an important diversifying force resulting in the genesis of novel toxin profiles in these agriculturally important fungi.

  9. Antibiotic Extraction as a Recent Biocontrol Method for Aspergillus Niger andAspergillus Flavus Fungi in Ancient Egyptian mural paintings

    Science.gov (United States)

    Hemdan, R. Elmitwalli; Fatma, Helmi M.; Rizk, Mohammed A.; Hagrassy, Abeer F.

    Biodeterioration of mural paintings by Aspergillus niger and Aspergillus flavus Fungi has been proved in different mural paintings in Egypt nowadays. Several researches have studied the effect of fungi on mural paintings, the mechanism of interaction and methods of control. But none of these researches gives us the solution without causing a side effect. In this paper, for the first time, a recent treatment by antibiotic "6 penthyl α pyrone phenol" was applied as a successful technique for elimination of Aspergillus niger and Aspergillus flavus. On the other hand, it is favorable for cleaning Surfaces of Murals executed by tembera technique from the fungi metabolism which caused a black pigments on surfaces.

  10. In Vitro Susceptibility of Aflatoxigenic and Non-aflatoxigenic Aspergillus flavus Strains to Conventional Antifungal Agents

    Directory of Open Access Journals (Sweden)

    Mahmoud Mahmoudi

    2012-12-01

    Full Text Available Presently appearance of resistance to antifungal agents among Aspergillus species is dramatically increasing. The objective of this study was to look at the in vitro activities of antifungal drugs against Iranian clinical (from nail, bronchoalveolar lavage, paranasal sinus isolated A. flavus strains. The susceptibility of 45 aflatoxigenic and non-aflatoxigenic Aspergillus flavus strains were evaluated to six antifungal agents (caspofungin, itraconazole, amphotericin B, ketoconazole, fluconazole, nystatin using CLSI M38-A2 broth microdilution method. The results indicated that 57.1%, 28.6% of aflatoxigenic and 25.8%, 6.5% of non-aflatoxigenic isolates were susceptible to caspofungin, amphotericin B respectively. All isolates but one aflatoxigenic strain were sensitive to ketoconazole. All 45 strains showed to be resistant to nystatin. Also 64.28%, 92.9% of aflatoxigenic and 64.51%, 100% of non-aflatoxigenic isolates were resistant to fluconazole and itraconazole in ranking order. There was no statistically significant difference between the susceptibilities of aflatoxigenic and non-aflatoxigenic strains of A. flavus to tested antifungal agents

  11. Flocculation behavior and mechanism of bioflocculant produced by Aspergillus flavus.

    Science.gov (United States)

    Aljuboori, Ahmad H Rajab; Idris, Azni; Al-joubory, Hamid Hussain Rijab; Uemura, Yoshimitsu; Ibn Abubakar, B S U

    2015-03-01

    In this study, the flocculation behavior and mechanism of a cation-independent bioflocculant IH-7 produced by Aspergillus flavus were investigated. Results showed 91.6% was the lowest flocculating rate recorded by IH-7 (0.5 mg L(-1)) at pH range 4-8. Moreover, IH-7 showed better flocculation performance than polyaluminum chloride (PAC) at a wide range of flocculant concentration (0.06-25 mg L(-1)), temperature (5-45 °C) and salinity (10-60% w/w). The current study found that cation addition did not significantly enhance the flocculating rate and IH-7 is a positively charged bioflocculant. These findings suggest that charge neutralization is the main flocculation mechanism of IH-7 bioflocculant. IH-7 was significantly used to flocculate different types of suspended solids such as activated carbons, kaolin clays, soil solids and yeast cells.

  12. Keratitis by Aspergillus flavus infection after cataract surgery

    Directory of Open Access Journals (Sweden)

    João Luiz Pacini Costa

    Full Text Available ABSTRACT We report a case of keratis infection after cataract phacoemulsification with intraocular lens implantation in a 65-year-old female patient. The patient initially underwent cataract surgery on the right eye. Intraocular inflammation appeared on the second post-operative day and was initially treated as Toxic Anterior Segment Syndrome (TASS. The inflammation was reduced and vision improved initially but very aggressive and progressive keratitis destroyed the cornea due to the delay in correct diagnosis. Aspergillus flavus was isolated from a biopsy.The infection was treated with antifungal agents and loss of the eye was avoided by total corneal transplantation associated with Gundersen conjunctiva cover. To restore the lost vision, a second penetrating corneal graft with removal of the conjunctiva cover was performed 17 months later. The final best-corrected vision was 20/40 but prognosis for long-term graft survival is poor.

  13. Proteomic profile of Aspergillus flavus in response to water activity.

    Science.gov (United States)

    Zhang, Feng; Zhong, Hong; Han, Xiaoyun; Guo, Zhenni; Yang, Weiqiang; Liu, Yongfeng; Yang, Kunlong; Zhuang, Zhenhong; Wang, Shihua

    2015-03-01

    Aspergillus flavus, a common contaminant of crops and stored grains, can produce aflatoxins that are harmful to humans and other animals. Water activity (aw) is one of the key factors influencing both fungal growth and mycotoxin production. In this study, we used the isobaric tagging for relative and absolute quantitation (iTRAQ) technique to investigate the effect of aw on the proteomic profile of A. flavus. A total of 3566 proteins were identified, of which 837 were differentially expressed in response to variations in aw. Among these 837 proteins, 403 were over-expressed at 0.99 aw, whereas 434 proteins were over-expressed at 0.93 aw. According to Gene Ontology (GO) analysis, the secretion of extracellular hydrolases increased as aw was raised, suggesting that extracellular hydrolases may play a critical role in induction of aflatoxin biosynthesis. On the basis of Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) categorizations, we identified an exportin protein, KapK, that may down-regulate aflatoxin biosynthesis by changing the location of NirA. Finally, we considered the role of two osmotic stress-related proteins (Sln1 and Glo1) in the Hog1 pathway and investigated the expression patterns of proteins related to aflatoxin biosynthesis. The data uncovered in this study are critical for understanding the effect of water stress on toxin production and for the development of strategies to control toxin contamination of agricultural products.

  14. Degeneration of aflatoxin gene cluster in Aspergillus flavus from Africa and North America

    Science.gov (United States)

    Aspergillus flavus is the primary causal agent of food and feed contamination with the toxic fungal metabolites aflatoxins. Aflatoxin-producing potential of A. flavus is known to vary among isolates. The genes involved in aflatoxin biosynthesis are clustered together and the order of genes within th...

  15. Aspergillus flavus Blast2GO gene ontology database: elevated growth temperature alters amino acid metabolism

    Science.gov (United States)

    The availability of a representative gene ontology (GO) database is a prerequisite for a successful functional genomics study. Using online Blast2GO resources we constructed a GO database of Aspergillus flavus. Of the predicted total 13,485 A. flavus genes 8,987 were annotated with GO terms. The mea...

  16. Aspergillus flavus Genomic Data Mining Provides Clues for Its Use in Producing Biobased Products

    Science.gov (United States)

    Aspergillus flavus is notorious for its ability to produce aflatoxins. It is also an opportunistic pathogen that infects plants, animals and human beings. The ability to survive in the natural environment, living on plant tissues (leaves or stalks), live or dead insects make A. flavus a ubiquitous...

  17. Effect of gamma radiation on Aspergillus flavus and Aspergillus ochraceus ultrastructure and mycotoxin production

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, J. [Departamento de Microbiologia e Inmunologia Veterinaria, Universidad Federal Rural de Rio de Janeiro (UFRRJ) (Brazil); Cavaglieri, L., E-mail: lcavaglieri@arnet.com.a [Departamento de Microbiologia e Inmunologia, Universidad Nacional de Rio Cuarto (UNRC), Rio Cuarto, Cordoba (Argentina); Member of Consejo Nacional de Investigaciones Cientificas y Tecnologicas (CIC-CONICET) (Argentina); Vital, H. [Centro Tecnologico do Exercito (CTEx), Secao de Defesa Nuclear, Rio de Janeiro (Brazil); Cristofolini, A.; Merkis, C. [Departamento de Microscopia Electronica, Universidad Nacional de Rio Cuarto. Ruta 36 km 601 (5800) Rio Cuarto (Argentina); Astoreca, A. [Departamento de Microbiologia e Inmunologia, Universidad Nacional de Rio Cuarto (UNRC), Rio Cuarto, Cordoba (Argentina); Member of Consejo Nacional de Investigaciones Cientificas y Tecnologicas (CIC-CONICET) (Argentina); Orlando, J.; Caru, M. [Departamento de Ciencias Ecologicas, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Dalcero, A. [Departamento de Microbiologia e Inmunologia, Universidad Nacional de Rio Cuarto (UNRC), Rio Cuarto, Cordoba (Argentina); Member of Consejo Nacional de Investigaciones Cientificas y Tecnologicas (CIC-CONICET) (Argentina); Rosa, C.A.R. [Departamento de Microbiologia e Inmunologia Veterinaria, Universidad Federal Rural de Rio de Janeiro (UFRRJ) (Brazil); Member of Consejo Nacional de Pesquisas (CNPq) (Brazil)

    2011-05-15

    The aim of this work was to study the effect of gamma radiation (2 kGy) on Aspergillus flavus and Aspergillus ochraceus ultrastructure. Moreover, the influence on aflatoxin B{sub 1} and ochratoxin A production was also observed. Irradiated A. flavus strain showed a dull orangish colony while control strain showed the typical green color. Minor differences were observed on stipes, metulae and conidia size between control and irradiated A. flavus and A. ochraceus strains. Irradiated fungi showed ultrastructural changes on cell wall, plasmalema and cytoplasm levels. The levels of mycotoxins produced by irradiated strains were two times greater than those produced by control strains. Successive transferences of irradiated strains on malt extract agar allowed the fungus to recuperate morphological characteristics. Although minor changes in the fungal morphology were observed, ultrastructural changes at cell wall level and the increase of mycotoxin production ability were observed. Inappropriate storage of irradiated food and feed would allow the development of potentially more toxicogenic fungal propagules.

  18. Ageratum conyzoides essential oil as aflatoxin suppressor of Aspergillus flavus.

    Science.gov (United States)

    Nogueira, Juliana H C; Gonçalez, Edlayne; Galleti, Silvia R; Facanali, Roseane; Marques, Márcia O M; Felício, Joana D

    2010-01-31

    Aflatoxin B(1) (AFB(1)) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Inhibitory effects of essential oil of Ageratum conyzoides, on the mycelial growth and aflatoxin B(1) production by Aspergillus flavus were studied. Cultures were incubated in yeast extract-sucrose (YES) broth for days at 25 degrees C at the following different concentrations of the essential oil (from 0.0 to 30mug/mL). The essential oil inhibited fungal growth to different extents depending on the concentration, and completely inhibited aflatoxin production at concentrations above 0.10microg/mL. The analysis of the oil by GC/MS showed that its main components are precocene II (46.35%), precocene I (42.78%), cumarine (5.01%) and Trans-caryophyllene (3.02%). Comparison by transmission electron microscopy of the fungal cells, control and those incubated with different concentrations of essential oil, showed ultra-structural changes which were concentration dependent of the essential oil of A. conyzoides. Such ultra-structural changes were more evident in the endomembrane system, affecting mainly the mitochondria. Degradation was also observed in both surrounding fibrils. The ability to inhibit aflatoxin production as a new biological activity of A.conyzoides L. indicates that it may be considered as a useful tool for a better understanding of the complex pathway of aflatoxin biosynthesis.

  19. Modelling Aspergillus flavus growth and aflatoxins production in pistachio nuts.

    Science.gov (United States)

    Marín, Sonia; Ramos, Antonio J; Sanchis, V

    2012-12-01

    Aflatoxins (AFs) are the main contaminants in pistachio nuts. AFs production in pistachio has been attributed to Aspergillus flavus. The aim of this study was to apply existing models to predict growth and AFs production by an A. flavus isolated from pistachios as a function of moisture content and storage temperature of pistachios in order to test their usefulness and complementarities. A full factorial design was used: the moisture content levels assayed were 10, 15, 20, 25 and 30% and incubation temperatures were 10, 15, 20, 25, 30, 37 and 42 °C. Both kinetic and probability models were built to predict growth of the strain under the assayed conditions. Among the assayed models, cardinal ones gave a good quality fit for radial growth rate data. Moreover, the progressive approach, which was developed based on a reduced number of experimental points led to an improved prediction in the validation step. This is quite significant as may allow for improved experimental designs, less costly than full factorial ones. Probability model proved to be concordant in 91% of the calibration set observations. Even though the validation set included conditions around the growth/no-growth interface, there was a 100% agreement in the predictions from the data set (n = 16, cut off = 0.5) after 60 days. Similarly, the probability for AF presence was rightly predicted in 89% of the cases. According to our results EC maximum aflatoxin levels would be surpassed in a period as short as 1 month if pistachio nuts reach 20 °C, unless %mc is ≤10%.

  20. rmtA, encoding a putative anginine methyltransferase, regulates secondary metabolism and development in Aspergillus flavus

    Science.gov (United States)

    Aspergillus flavus is found colonizing numerous oil seed crops such as corn, peanuts, sorghum, treenuts and cotton worldwide, contaminating them with aflatoxin and other harmful potent toxins. In the phylogenetically related model fungus Aspergillus nidulans, the methyltransferase, RmtA, has been de...

  1. RNA interference reduces aflatoxin accumulation by Aspergillus flavus in peanut seeds

    Science.gov (United States)

    Aflatoxins are among the most powerful carcinogens in nature. They are produced by the fungal pathogen Aspergillus flavus Link and other Aspergillus species. Aflatoxins accumulate in many crops, including rice, wheat, oats, pecans, pistachios, soybean, cassava, almonds, peanuts, beans, corn and cot...

  2. Effect of irradiation on aflatoxin production by Aspergillus flavus

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hitoshi; Jintana Bunnak; Guzman, Z.M. de; Ishigaki, Isao (Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment)

    1991-10-01

    The effects of repeated exposure to gamma irradiation on Aspergillus flavus var. columnaris S46 was studied in terms of the development of increased radioresistance and mutations. Original D{sub 10} value was obtained as 0.22 kGy and increased a little after 6 times exposure at a dose of 0.8 kGy. Mutation ratios such as morphological changes and aflatoxin production were not remarkably changed even after 6 times exposure. A little stimulation of production of aflatoxin B{sub 1} occurred by irradiation of spores of strains S46, E11 and E14 at 0.4 and 0.6 kGy in Synthetic Low Salts broth after incubation for 10 days at 25degC. The levels of aflatoxin B{sub 1} was also increased 13 to 40% by incubation of irradiated spores of S46 strain at 1 kGy on autoclaved polished rice, black pepper and red pepper. However, these stimulation effects were not Observed after infection of these cultivates of irradiated sores to fresh media. (author).

  3. Decontamination of Aspergillus flavus and Aspergillus parasiticus spores on hazelnuts via atmospheric pressure fluidized bed plasma reactor.

    Science.gov (United States)

    Dasan, Beyhan Gunaydin; Mutlu, Mehmet; Boyaci, Ismail Hakki

    2016-01-04

    In this study, an atmospheric pressure fluidized bed plasma (APFBP) system was designed and its decontamination effect on aflatoxigenic fungi (Aspergillus flavus and Aspergillus parasiticus) on the surface of hazelnuts was investigated. Hazelnuts were artificially contaminated with A. flavus and A. parasiticus and then were treated with dry air plasma for up to 5min in the APFBP system at various plasma parameters. Significant reductions of 4.50 log (cfu/g) in A. flavus and 4.19 log (cfu/g) in A. parasiticus were achieved after 5min treatments at 100% V - 25kHz (655W) by using dry air as the plasma forming gas. The decontamination effect of APFBP on A. flavus and A. parasiticus spores inoculated on hazelnuts was increased with the applied reference voltage and the frequency. No change or slight reductions were observed in A. flavus and A. parasiticus load during the storage of plasma treated hazelnuts whereas on the control samples fungi continued to grow under storage conditions (30days at 25°C). Temperature change on hazelnut surfaces in the range between 35 and 90°C was monitored with a thermal camera, and it was demonstrated that the temperature increase taking place during plasma treatment did not have a lethal effect on A. flavus and A. parasiticus spores. The damage caused by APFBP treatment on Aspergillus spp. spores was also observed by scanning electron microscopy.

  4. Misidentification of Aspergillus nomius and Aspergillus tamarii as Aspergillus flavus: characterization by internal transcribed spacer, β-Tubulin, and calmodulin gene sequencing, metabolic fingerprinting, and matrix-assisted laser desorption ionization-time of flight mass spectrometry.

    Science.gov (United States)

    Tam, Emily W T; Chen, Jonathan H K; Lau, Eunice C L; Ngan, Antonio H Y; Fung, Kitty S C; Lee, Kim-Chung; Lam, Ching-Wan; Yuen, Kwok-Yung; Lau, Susanna K P; Woo, Patrick C Y

    2014-04-01

    Aspergillus nomius and Aspergillus tamarii are Aspergillus species that phenotypically resemble Aspergillus flavus. In the last decade, a number of case reports have identified A. nomius and A. tamarii as causes of human infections. In this study, using an internal transcribed spacer, β-tubulin, and calmodulin gene sequencing, only 8 of 11 clinical isolates reported as A. flavus in our clinical microbiology laboratory by phenotypic methods were identified as A. flavus. The other three isolates were A. nomius (n = 2) or A. tamarii (n = 1). The results corresponded with those of metabolic fingerprinting, in which the A. flavus, A. nomius, and A. tamarii strains were separated into three clusters based on ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC MS) analysis. The first two patients with A. nomius infections had invasive aspergillosis and chronic cavitary and fibrosing pulmonary and pleural aspergillosis, respectively, whereas the third patient had A. tamarii colonization of the airway. Identification of the 11 clinical isolates and three reference strains by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) showed that only six of the nine strains of A. flavus were identified correctly. None of the strains of A. nomius and A. tamarii was correctly identified. β-Tubulin or the calmodulin gene should be the gene target of choice for identifying A. flavus, A. nomius, and A. tamarii. To improve the usefulness of MALDI-TOF MS, the number of strains for each species in MALDI-TOF MS databases should be expanded to cover intraspecies variability.

  5. The chemical heritage of Aspergillus flavus in A. oryzae RIB 40

    DEFF Research Database (Denmark)

    Rank, Christian; Klejnstrup, Marie Louise; Petersen, Lene Maj

    Aspergillus oryzae is a very important species in biotechnology and has been used for centuries in traditional Asian fermentation. The RIB40 strain is particularly interesting as it was one of the first genome sequenced Aspergilli together with A. flavus, a prominent food and feed contaminant...... with indications to specific genetic changes. Several new metabolites and changes in biosynthetic routes have been found in A. oryzae, indicating subtle changes in the genomic heritage from A. flavus....

  6. Evaluation of antifungal activity of Pittosporum undulatum L. essential oil against Aspergillus flavus and aflatoxin production

    OpenAIRE

    Medeiros,Rosane Tamara da Silva; Gonçalez, Edlayne; Felicio,Roberto Carlos; Felicio,Joana D'Arc

    2011-01-01

    The presence of mycotoxins as a result of fungal attack can occur before, after and during the harvest and storage operations on agricultural crops and food commodities. Considering the inhibitory property of essential plant oils on the mycelial development of fungi and the importance of Aspergillus flavus, the main producer of aflatoxins, this research was designed to evaluate the toxicity of essential oil from Pittosporum undulatum against A. flavus. The essential oils were obtained from P....

  7. Inactivation of Aspergillus flavus in drinking water after treatment with UV irradiation followed by chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Al-Gabr, Hamid Mohammad [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); State Key Laboratory of Environmental Sciences, and Key Laboratory of Ministry of Education for Coast and Wetland Ecosystems, School of Life Sciences, Xiamen University, Xiamen 361005 (China); Zheng, Tianling [State Key Laboratory of Environmental Sciences, and Key Laboratory of Ministry of Education for Coast and Wetland Ecosystems, School of Life Sciences, Xiamen University, Xiamen 361005 (China); Yu, Xin, E-mail: xyu@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China)

    2013-10-01

    The disinfection process for inactivating microorganisms at drinking water treatment plants is aimed for safety of drinking water for humans from a microorganism, such as bacteria, viruses, algae, fungi by using chlorination, ozonation, UV irradiation, etc. In the present study, a combination of two disinfectants, UV irradiation followed by chlorination, was evaluated for inactivating Aspergillus flavus under low contact time and low dosage of UV irradiation. The results indicated an inverse correlation between the inactivation of A. flavus by using UV irradiation only or chlorination alone. By using UV radiation, the 2 log{sub 10} control of A. flavus was achieved after 30 s of irradiation, while chlorination was observed to be more effective than UV, where the 2 log was achieved at chlorine concentration of 0.5, 1, 2 and 3 mg/l, in contact time of 60, 5, 1 and 1 min, respectively. However, combined use (UV irradiation followed by chlorination) was more effective than using either UV or chlorination alone; 5 s UV irradiation followed by chlorination produced 4 log{sub 10} reduction of A. flavus at chlorine concentrations of 2 and 3 mg/l under a contact time of 15 min. The results indicated that efficiency of UV irradiation improves when followed by chlorination at low concentrations. - Highlights: • As a disinfectant, chlorine is more effective than UV in inactivating Aspergillus flavus. • As a combined method, UV irradiation followed by chlorination shows high efficiency. • UV irradiation can improve effectiveness of chlorination in reducing Aspergillus flavus.

  8. Polyamines as modulators of microcycle conidiation in Aspergillus flavus.

    Science.gov (United States)

    Khurana, N; Saxena, R K; Gupta, R; Rajam, M V

    1996-03-01

    Since polyamines (PAs) play a potential role in the regulation of growth and developmental processes in a wide variety of organisms, we have examined the influence of the PAs putrescine (Put) and spermidine (Spd) and the PA biosynthetic inhibitors alpha-difluoromethylornithine (DFMO), alpha-difluoromethylarginine (DFMA), methylglyoxal bis-(guanylhydrazone) (MGBG) and cyclohexylamine (CHA), singly and in combinations on microcycle conidiation (MC) in Aspergillus flavus. The exogenous application of the diamine Put (concentrations ranging from 0.1 to 5 mM) caused a sharp decline of MC in a dose-dependent fashion, but induced vegetative growth. However, the triamine Spd (0.1-5 mM) had a minimal effect on MC and induced a shift from MC to normal condition. PA inhibitors, especially DFMO, MGBG and CHA, produced greater inhibition of MC and complete inhibition of MC was observed at 5 mM of these inhibitors. DFMA even at 5 mM had only a weak inhibitory effect on MC. DFMO also inhibited conidial germination and germ tube growth. MGBG and CHA, while having an inhibitory effect on MC, induced vegetative growth. The inhibitory effect of PA inhibitors was partially reversed by exogenous Put or Spd, with Spd being more effective than Put. The analysis of free PA levels during various phases of MC revealed that undifferentiated spores contained a high Put/Spd ratio and there was a dramatic decrease in Put/Spd ratio before and during microcycle conidiophore maturity. The change in spermine titres could not be detected. These observations imply that Put is essential for vegetative growth, while Spd is involved in MC, and that a low Put/Spd ratio seems to be important for spore differentiation to MC.

  9. Evaluation of antifungal activity of essential oils against potentially mycotoxigenic Aspergillus flavus and Aspergillus parasiticus

    Directory of Open Access Journals (Sweden)

    Fernanda C. da Silva

    2012-10-01

    Full Text Available The antifungal activity of essential oils of fennel (Foeniculum vulgare Mill., Apiaceae, ginger (Zingiber officinale Roscoe, Zingiberaceae, mint (Mentha piperita L., Lamiaceae and thyme (Thymus vulgaris L., Lamiaceae was evaluated against mycotoxin producers Aspergillus flavus and A. parasiticus. High Resolution Gas Chromatography was applied to analyze chemical constituents of essential oils. The effect of different concentrations of essential oils was determined by solid medium diffusion assay. Mycelial growth and sporulation were determined for each essential oil at the concentrations established by solid medium diffusion assay. At the fifth, seventh and ninth days the mycelial diameter (Ø mm and spore production were also determined. FUN-1 staining was performed to assess cell viability after broth macrodilution assay. Trans-anethole, zingiberene, menthol and thymol are the major component of essential oils of fennel, ginger, mint and thyme, respectively. The effective concentrations for fennel, ginger, mint and thyme were 50, 80, 50 and 50% (oil/DMSO; v/v, respectively. The four essential oils analysed in this study showed antifungal effect. Additionally, FUN-1 staining showed to be a suitable method to evaluate cell viability of potential mycotoxigenic fungi A. flavus and A. parasiticus after treatment with essential oils.

  10. Local isolate of Saccharomyces cerevisiae as biocompetitive agent of Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Eni Kusumaningtyas

    2006-12-01

    Full Text Available Aspergillus flavus is a toxigenic fungus that contaminates feed and influences the animal health. Saccharomyces cerevisiae can be used as a biocompetitive agent to control the contamination. The ability of local isolate of S. cerevisiae as a biocompetitive agent for A. flavus was evaluated. A. flavus (30ml was swept on Sabouraud dextrose agar (SDA, while S. cerevisiae was swept on its left and right. Plates were incubated at 28oC for nine days. Lytic activity of S. cerevisiae was detected by pouring its suspension on the centre of the cross streaks of A. flavus. Plates were incubated at 28oC for five days. Growth inhibition of A. flavus by S. cerevisiae was determined by mixing the two fungi on Potato dextrose broth and incubated at 28oC for 24 hours. Total colony of A. flavus were then observed at incubation time of 2, 4, 6 and 24 hours by pour plates method on the SDA plates and incubated on 28oC for two days. Growth of hyphae of A. flavus sweep were inhibited with the swept of S. cerevisiae. The width of A. flavus colony treated with S. cerevisiae is narrower (3,02 cm than that of control ( 4,60 cm. The growth of A. flavus was also inhibited on the centre of cross streak where the S. cerevisiae poured. S. cerevisiae gradually reduced the colony number of A. flavus in the mixed culture of broth fungi ie. 14 x 103 CFU/ml while colony number of control is 80 x 103 CFU/ml. Results showed that S. cerevisiae could be used as biocompetitive agent of A. flavus.

  11. Genetic isolation among sympatric vegetative compatibility groups of the aflatoxin-producing fungus Aspergillus flavus.

    Science.gov (United States)

    Grubisha, L C; Cotty, P J

    2010-01-01

    Aspergillus flavus, a fungal pathogen of animals and both wild and economically important plants, is most recognized for producing aflatoxin, a cancer-causing secondary metabolite that contaminates food and animal feed globally. Aspergillus flavus has two self/nonself recognition systems, a sexual compatibility system and a vegetative incompatibility system, and both play a role in directing gene flow in populations. Aspergillus flavus reproduces clonally in wild and agricultural settings, but whether a cryptic sexual stage exists in nature is currently unknown. We investigated the distribution of genetic variation in 243 samples collected over 4 years from three common vegetative compatibility groups (VCGs) in Arizona and Texas from cotton using 24 microsatellite loci and the mating type locus (MAT) to assess population structure and potential gene flow among A. flavus VCGs in sympatric populations. All isolates within a VCG had the same mating type with OD02 having MAT1-2 and both CG136 and MR17 having MAT1-1. Our results support the hypothesis that these three A. flavus VCGs are genetically isolated. We found high levels of genetic differentiation and no evidence of gene flow between VCGs, including VCGs of opposite mating-type. Our results suggest that these VCGs diverged before domestication of agricultural hosts (>10,000 yr bp).

  12. Functional Analysis of the Nitrogen Metabolite Repression Regulator Gene nmrA in Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Xiaoyun Han

    2016-11-01

    Full Text Available In Aspergillus nidulans, the nitrogen metabolite repression regulator NmrA plays a major role in regulating the activity of the GATA transcription factor AreA during nitrogen metabolism. However, the function of nmrA in Aspergillus flavus has notbeen previously studied. Here, we report the identification and functional analysis of nmrA in A. flavus. Our work showed that the amino acid sequences of NmrA are highly conserved among Aspergillus species and that A. flavus NmrA protein contains a canonical Rossmann fold motif. Deletion of nmrA slowed the growth of A. flavus but significantly increased conidiation and sclerotia production. Moreover, seed infection experiments indicated that nmrA is required for the invasive virulence of A. flavus. In addition, the ΔnmrA mutant showed increased sensitivity to rapamycin and methyl methanesulfonate, suggesting that nmrA could be responsive to target of rapamycin signaling and DNA damage. Furthermore, quantitative real-time reverse transcription polymerase chain reaction analysis suggested that nmrA might interact with other nitrogen regulatory and catabolic genes. Our study provides a better understanding of nitrogen metabolite repression and the nitrogen metabolism network in fungi.

  13. Bisulfite sequencing reveals that Aspergillus flavus holds a hollow in DNA methylation.

    Directory of Open Access Journals (Sweden)

    Si-Yang Liu

    Full Text Available Aspergillus flavus first gained scientific attention for its production of aflatoxin. The underlying regulation of aflatoxin biosynthesis has been serving as a theoretical model for biosynthesis of other microbial secondary metabolites. Nevertheless, for several decades, the DNA methylation status, one of the important epigenomic modifications involved in gene regulation, in A. flavus remains to be controversial. Here, we applied bisulfite sequencing in conjunction with a biological replicate strategy to investigate the DNA methylation profiling of A. flavus genome. Both the bisulfite sequencing data and the methylome comparisons with other fungi confirm that the DNA methylation level of this fungus is negligible. Further investigation into the DNA methyltransferase of Aspergillus uncovers its close relationship with RID-like enzymes as well as its divergence with the methyltransferase of species with validated DNA methylation. The lack of repeat contents of the A. flavus' genome and the high RIP-index of the small amount of remanent repeat potentially support our speculation that DNA methylation may be absent in A. flavus or that it may possess de novo DNA methylation which occurs very transiently during the obscure sexual stage of this fungal species. This work contributes to our understanding on the DNA methylation status of A. flavus, as well as reinforces our views on the DNA methylation in fungal species. In addition, our strategy of applying bisulfite sequencing to DNA methylation detection in species with low DNA methylation may serve as a reference for later scientific investigations in other hypomethylated species.

  14. Efficacy of water dispersible formulations of biocontrol strains of Aspergillus flavus for aflatoxin management in corn

    Science.gov (United States)

    Field experiments were conducted in 2011 and 2012 to evaluate the efficacy of water dispersible granule (WDG) formulations of biocontrol strains of Aspergillus flavus in controlling aflatoxin contamination of corn. In 2011, when aflatoxin was present at very high levels, no WDG treatment provided s...

  15. Use of functional genomics to assess the climate change impact on Aspergillus flavus and aflatoxin production

    Science.gov (United States)

    Aspergillus flavus is an opportunistic pathogenic fungus that infects several crops of agricultural importance, among them, corn, cotton, and peanuts. Once established as a pathogen the fungus may secrete secondary metabolites commonly known as mycotoxins, that if consumed by humans or animals may r...

  16. Comparative transcriptome analysis of Aspergillus flavus isolates under different oxidative stresses and culture media

    Science.gov (United States)

    Aspergillus flavus and aflatoxin contamination in the field are known to be influenced by numerous stress factors, particularly drought and heat stress. However, the purpose of aflatoxin production is unknown. Here, we report transcriptome analyses comprised of 282.6 Gb of sequencing data describing...

  17. Evaluation of the atoxigenic Aspergillus flavus strain AF36 in pistachio orchards

    Science.gov (United States)

    The atoxigenic strain Aspergillus flavus AF36, which has been extensively used as a biocontrol agent in commercial corn and cotton fields to reduce aflatoxin contamination, was applied in research pistachio orchards from 2002 to 2005 and in commercial pistachio orchards from 2008 to 2011. AF36 was a...

  18. Managing and Monitoring of Aspergillus flavus in Corn Using Bioplastic-based Formulation

    Science.gov (United States)

    In this study, we evaluated the feasibility of bioplastic-based formulations for delivering a non-aflatoxigenic strain of Aspergillus flavus and for monitoring Aspergilli with the final objective of controlling aflatoxin contamination in corn. Field application of inoculated bioplastic granules show...

  19. Resistance to Aspergillus flavus in maize and peanut: Molecular biology, breeding, environmental stress and future perspectives

    Science.gov (United States)

    The colonization of maize (Zea mays L.) and peanut (Arachis hypogaea L.) by the fungal pathogen Aspergillus flavus and A. parasiticus results in the contamination with carcinogenic mycotoxins known as aflatoxins leading to economic losses as well as a potential health threat to human. The interactio...

  20. Seventeen years of subcutaneous infection by Aspergillus flavus; eumycetoma confirmed by immunohistochemistry

    NARCIS (Netherlands)

    Ahmed, Sarah A; Abbas, Manal A; Jouvion, Gregory; Al-Hatmi, Abdullah M S; de Hoog, G Sybren; Kolecka, Anna; Mahgoub, El Sheikh

    2015-01-01

    Chronic subcutaneous infections caused by Aspergillus species are considered to be extremely rare. Because these fungi are among the most common laboratory contaminants, their role as eumycetoma causative agents is difficult to ascertain. Here, we report the first case of A. flavus eumycetoma confir

  1. Comparative chemistry of Aspergillus oryzae (RIB40) and A. flavus (NRRL 3357)

    DEFF Research Database (Denmark)

    Rank, Christian; Klejnstrup, Marie Louise; Petersen, Lene Maj

    2012-01-01

    Aspergillus oryzae and A. flavus are important species in industrial biotechnology and food safety and have been some of the first aspergilli to be fully genome sequenced. Bioinformatic analysis has revealed 99.5% gene homology between the two species pointing towards a large coherence...... in the secondary metabolite production. In this study we report on the first comparison of secondary metabolite production between the full genome sequenced strains of A. oryzae (RIB40) and A. flavus (NRRL 3357). Surprisingly, the overall chemical profiles of the two strains were mostly very different across 15...... alkaloids related to the A. flavus metabolites ditryptophenalines and miyakamides. Generally the secondary metabolite capability of A. oryzae presents several novel end products likely to result from the domestication process from A. flavus....

  2. Seed-Derived Ethylene Facilitates Colonization but Not Aflatoxin Production by Aspergillus flavus in Maize

    Science.gov (United States)

    Wang, Shi; Park, Yong-Soon; Yang, Yang; Borrego, Eli J.; Isakeit, Tom; Gao, Xiquan; Kolomiets, Michael V.

    2017-01-01

    Ethylene (ET) emitted by plant tissues has been broadly reported to play important roles in plant development, response to environmental stresses and defense against certain pathogens. Recent evidence obtained from using in vitro fungal cultures exposed to ET suggested that exogenous ET may regulate the production of aflatoxin by Aspergilli. However, the function of endogenous, seed-derived ET has not been explored. In this study, we found that the maize lipoxygenase lox3 mutant, previously reported to be susceptible to Aspergillus spp., emitted greater levels of ET upon A. flavus infection, suggesting the potential involvement of endogenous ET in the susceptibility of maize to A. flavus. Supporting this idea, both colonization and conidiation of A. flavus were reduced in wild-type (WT) kernels treated with AgNO3, an ET synthesis inhibitor. There was no ET emission from non-viable kernels colonized by A. flavus, suggesting that living seed but not the fungus itself was the primary source of ET released upon infection with A. flavus. The kernels of acs2 and acs6, two ET biosynthetic mutants carrying Mutator transposons in the ACC synthase genes, ACS2 and ACS6, respectively, displayed enhanced seed colonization and conidiation, but not the levels of aflatoxin, upon infection with A. flavus. Surprisingly, both acs2 and acs6 mutant kernels emitted greater levels of ET in response to infection by A. flavus as compared with WT seed. The increased ET in single mutants was found to be due to overexpression of functional ACS genes in response to A. flavus infection. Collectively, these findings suggested that ET emitted by infected seed facilitates colonization by A. flavus but not aflatoxin production.

  3. Unravelling the diversity of the cyclopiazonic acid family of mycotoxins in Aspergillus flavus by UHPLC Triple-TOF HRMS

    Science.gov (United States)

    Cyclopiazonic acid (a-cyclopiazonic acid, a-CPA) is an indole-hydrindane-tetramic acid neurotoxin produced by various fungal species, including the notorious food and feed contaminant Aspergillus flavus. Despite its discovery in A. flavus cultures, approximately 40 years ago, its contribution to the...

  4. The master transcription factor mtfA governs aflatoxin production, morphological development, and pathogenicity in the fungus Aspergillus flavus

    Science.gov (United States)

    Aspergillus flavus produces a variety of toxic secondary metabolites, among them the aflatoxins (AFs) are the most well-known. These compounds are highly mutagenic and carcinogenic, particularly AFB1. A. flavus is capable of colonizing economically important crops contaminating them with AFs. Molecu...

  5. Enhanced aflatoxin production by aspergillus parasiticus and aspergillus flavus after low dose gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hitoshi (Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment)

    1992-09-01

    Spores of Aspergillus parasiticus IFO 30179 and A. flavus var. columnaris S46 were irradiated at 0.05, 0.2 and 0.4 kGy in the synthetic low salts (SL) broth, and the effect on aflatoxin production was examined after 10 days incubation at 30 or 25degC. In these two strains, irradiation of spores at 0.05 kGy resulted in higher B1 or G1 production than the non-irradiated controles. However, spores of the both strains irradiated at 0.2 or 0.4 kGy produced less aflatoxins than non-irradiated controles. In the SL broth, apparent stimulation by low dose irradiation was slight, and these enhanced effects were not observed after reinfection to fresh SL broth. In the case of food samples, the levels of aflatoxin B[sub 1] and G[sub 1] with A. parasiticus were increased from 15 to 90% by incubation of irradiated spores at 1 kGy in autoclaved polished rice, black pepper, white pepper and red pepper. These enhancement would be induced by change of composition in each substrates. Mutations of fungi induced by irradiation is not effective for enhancement of aflatoxin production. (author).

  6. Antifungal activity of extracts of Rosmarinus officinalis and Thymus vulgaris against Aspergillus flavus and A. ochraceus.

    Science.gov (United States)

    Centeno, S; Calvo, M A; Adelantado, C; Figueroa, S

    2010-05-01

    The antifungal activity of ethanolic extracts of Rosmarinus officinalis and Thymus vulgaris were tested against strains of Aspergillus flavus and A. ochraceus, since these two species are common contaminants of cereals and grains and are able to produce and accumulate mycotoxins. The methodology used is based on measuring the inhibition halos produced by discs impregnated with the extracts and establishing their Minimum Inhibitory Concentration (MIC) as well as the Minimum Fungicide Concentration (MFC). The results obtained suggest that the assayed extracts affect the proper development of A. flavus and A. ochraceus; leading to a lower MIC (1200 ppm) and MFC (2400 ppm) for T. vulgaris extract against A. ochraceus than against A. flavus. The results show, that the extracts of Rosmarinus officinalis and Thymus vulgaris used at low concentrations could have significant potential for the biological control of fungi in foodstuffs.

  7. Use of aflatoxin-producing ability medium to distinguish aflatoxin-producing strains of Aspergillus flavus.

    OpenAIRE

    1981-01-01

    Aflatoxin-producing ability medium was tested for its ability to distinguish aflatoxin-positive from aflatoxin-negative strains of Aspergillus flavus in naturally occurring populations from corn at harvest. All of the aflatoxin-positive strains and some of the aflatoxin-negative strains produced aflatoxins when cultured on cracked corn. Although the data indicate that aflatoxin-producing ability medium is not entirely reliable in distinguishing potential aflatoxin-producing strains of A. flav...

  8. Effects of Citral on Aspergillus flavus Spores by Quasi-elastic Light Scattering and Multiplex Microanalysis Techniques

    Institute of Scientific and Technical Information of China (English)

    Man LUO; Li-Ke JIANG; Yao-Xiong HUANG; Ming XIAO; Bo LI; Guo-Lin ZOU

    2004-01-01

    Citral refined from Litsea cubeba oil has been found to have a strong influence on fungi,especially Aspergillus flavus. Multiplex microanalysis and quasi-elastic light scattering techniques were applied to study the effects of citral on Aspergillus flavus spores from the levels of membrane, organelle and intracellular macromolecule. It was found that citral injured the wall and the membrane of A. flavus spore,resulting in decrease of its elasticity. After entering the cell, citral not only influenced the genetic expression of mitochondrion reduplication and its morphology, but also changed the aggregation of protein-like macromolecules. As a result, cells, organelles and macromolecules lost their normal structures and functions,eventually leading to the loss of germination ability of A. flavus spores. Since Litsea cubeba oil as food additive and antifungal agent is safe and less poisonous, it is important to elucidate the inhibitory mechanisms of Litsea cubeba oil on the germination ability ofA. flavus spore.

  9. Characterization of Iranian nonaflatoxigenic strains of Aspergillus flavus based on microsatellite-primed PCR.

    Science.gov (United States)

    Houshyarfard, Mahmoud; Rouhani, Hamid; Falahati-Rastegar, Mahrokh; Malekzadeh-Shafaroudi, Saeid; Mahdikhani-Moghaddam, Esmat

    2015-01-01

    Out of fifty-two Iranian nonaflatoxigenic strains of Aspergillus flavus,collected from various substrates (soil and kernel) and sources (peanut, corn and pistachio), fifteen representatives were selected according to their different geographical origins (six provinces: Guilan and Golestan, Ardebil, Fars, Kerman and Semnan) and vegetative compatibility groups (VCGs, IR1 to IR15) for microsatellite-primed PCR analysis. Two inter-simple sequence repeat (ISSR) primers AFMPP and AFM13 were used to determine polymorphism and the relationship among strain isolates. A. flavus isolates were identified by their morphologies and their identities were confirmed by PCR amplification using the specific primer pair ITS1 and ITS4. The results revealed variations in the percentages of polymorphisms. In the ISSR analysis, primers AFMPP and AFM13 generated a total of 18 and 23 amplicons among the fungal strains, out of which 12 (66.7%) and 22 (95.7%) were polymorphic, respectively. Cluster analysis of the ISSR data was carried out using 1 D DNA gel image analysis. The two dendrograms obtained through these markers showed six different clusterings of testing nonaflatoxigenic A. flavus L strains, but we noticed that some clusters were different in some cases. The microsatellite-primed PCR data revealed that the Iranian nonaflatoxigenic isolates of A. flavus were not clustered according to their origins and sources. This study is the first to characterize Iranian nonaflatoxigenic isolates of A. flavus using ISSR markers.

  10. Isolation of maize soil and rhizosphere bacteria with antagonistic activity against Aspergillus flavus and Fusarium verticillioides.

    Science.gov (United States)

    Palumbo, Jeffrey D; O'Keeffe, Teresa L; Abbas, Hamed K

    2007-07-01

    Bacterial isolates from Mississippi maize field soil and maize rhizosphere samples were evaluated for their potential as biological control agents against Aspergillus flavus and Fusarium verticillioides. Isolated strains were screened for antagonistic activities in liquid coculture against A. flavus and on agar media against A. flavus and F. verticillioides. We identified 221 strains that inhibited growth of both fungi. These bacteria were further differentiated by their production of extracellular enzymes that hydrolyzed chitin and yeast cell walls and by production of antifungal metabolites. Based on molecular and nutritional identification of the bacterial strains, the most prevalent genera isolated from rhizosphere samples were Burkholderia and Pseudomonas, and the most prevalent genera isolated from nonrhizosphere soil were Pseudomonas and Bacillus. Less prevalent genera included Stenotrophomonas, Agrobacterium, Variovorax, Wautersia, and several genera of coryneform and enteric bacteria. In quantitative coculture assays, strains of P. chlororaphis and P. fluorescens consistently inhibited growth of A. flavus and F. verticillioides in different media. These results demonstrate the potential for developing individual biocontrol agents for simultaneous control of the mycotoxigenic A. flavus and F. verticillioides.

  11. Characterization of Iranian Nonaflatoxigenic Strains of Aspergillus flavus Based on Microsatellite-primed PCR

    Directory of Open Access Journals (Sweden)

    Mahmoud Houshyarfard

    2015-03-01

    Full Text Available Out of fifty-two Iranian nonaflatoxigenic strains of Aspergillus flavus, which were collected from various substrates (soil and kernel and sources (peanut, corn and pistachio, fifteen representatives were selected according to their different geographical origins (six provinces: Guilan and Golestan, Ardebil, Fars, Kerman and Semnan and vegetative compatibility groups (VCGs, IR1 to IR15 for microsatellite-primed PCR analysis. Two inter-simple sequence repeat (ISSR primers AFMPP and AFM13 were used to determine the polymorphism and the relationship among strain isolates. The A. flavus isolates were identified by their morphologies and their identities were confirmed by PCR amplification using the specific primer pair ITS1 and ITS4. The results revealed variations in the percentages of polymorphisms. In ISSR analysis, primers AFMPP and AFM13 generated a total of 18 and 23 amplicons among the fungal strains, which 12 (66.7% and 22 (95.7% were polymorphic, respectively. Cluster analysis of ISSR data was carried out by using 1 D DNA gel image analysis. The two dendrograms obtained through these markers showed six different clustering of testing nonaflatoxigenic A. flavus L strains, but we noted that some clusters were different in some cases. The microsatellite-primed PCR data revealed that the Iranian nonaflatoxigenic isolates of A. flavus were not clustered based on their origins and sources. This study is the first to characterize Iranian nonaflatoxigenic isolates of A. flavus using ISSR markers.

  12. Inhibitory activity of compounds isolated from Polymnia sonchifolia on aflatoxin production by Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Pak Adriana

    2006-01-01

    Full Text Available Polymnia sonchifolia, commonly known as ";yacon";, was originally cultivated at Andes moutains in South America. Recently, the specie attracted worldwide attention because of its wide range of uses, for example in the control of diabetes melitus, besides the antifungal and pesticidal compounds were found in the leaves. This study describes the identification of two flavonoids: 3', 5, 7 trihydroxy-3, 4'-dimethoxyflavone (compound 1 and 3', 4', 5- trihydroxy-7-methoxy flavanone (compound 2 and two sesquiterpenes lactones: enhydrin (compound 3 and a mixture of enhydrin and uvedalin (compound 4 isolated from Polymnia sonchifolia leaves and their effects on the aflatoxin production by Aspergillus flavus. The identification of the compounds were achieved by ¹H and 13C NMR. All compounds were tested in different concentration, to evaluate the growth of Aspergillus flavus culture and the production of aflatoxin. The compound 1, at the concentration 15 mug/mL, inhibited 25% of the aflatoxin B1 production (p<0.01. The compound 4 inhibited 34% and 76% of the fungal growth and AFB1 production respectively. These results show that Polymnia sonchifolia can be used for the development of agents to control aflatoxin B1 production by Aspergillus flavus.

  13. Genome Sequences of Eight Aspergillus flavus spp. and One A. parasiticus sp., Isolated From Peanut Seeds in Georgia

    Science.gov (United States)

    Aspergillus flavus and A. parasiticus fungi, carcinogen-mycotoxins producers, infect peanut seeds, causing considerable impact on both human health and the economy. Here we report 9 genome sequences of Aspergillus spp. isolated from peanut seeds. The information obtained will allow conducting biodiv...

  14. Cryptic Sexuality Influences Aflatoxigenicity in Aspergillus parasiticus and A. flavus

    Science.gov (United States)

    Ascomycetous fungi of the genus Aspergillus comprise a wide variety of species of biotechnological importance as well as pathogens and toxin producers. Recent studies report A. fumigatus to be heterothallic and possibly undergoing sexual reproduction. We therefore investigated whether compatible mat...

  15. Rapid detection of Aspergillus flavus in rice using biofunctionalized carbon nanotube field effect transistors.

    Science.gov (United States)

    Villamizar, Raquel A; Maroto, Alicia; Rius, F Xavier

    2011-01-01

    In the present study, we have used carbon nanotube field effect transistors (FET) that have been functionalized with protein G and IgG to detect Aspergillus flavus in contaminated milled rice. The adsorbed protein G on the carbon nanotubes walls enables the IgG anti-Aspergillus antibodies to be well oriented and therefore to display full antigen binding capacity for fungal antigens. A solution of Tween 20 and gelatine was used as an effective blocking agent to prevent the non-specific binding of the antibodies and other moulds and also to protect the transducer against the interferences present in the rice samples. Our FET devices were able to detect at least 10 μg/g of A. flavus in only 30 min. To evaluate the selectivity of our biosensors, Fusarium oxysporum and Penicillium chrysogenum were tested as potential competing moulds for A. flavus. We have proved that our devices are highly selective tools for detecting mycotoxigenic moulds at low concentrations in real samples.

  16. Molecular characterisation of Aspergillus flavus isolates from peanut fields in India using AFLP

    Directory of Open Access Journals (Sweden)

    Diwakar Singh

    2015-09-01

    Full Text Available Aflatoxin contamination of peanut, due to infection by Aspergillus flavus, is a major problem of rain-fed agriculture in India. In the present study, molecular characterisation of 187 Aspergillus flavus isolates, which were sampled from the peanut fields of Gujarat state in India, was performed using AFLP markers. On a pooled cluster analysis, the markers could successfully discriminate among the ‘A’, ‘B’ and ‘G’ group A. flavus isolates. PCoA analysis also showed equivalent results to the cluster analysis. Most of the isolates from one district could be clustered together, which indicated genetic similarity among the isolates. Further, a lot of genetic variability was observed within a district and within a group. The results of AMOVA test revealed that the variance within a population (84% was more than that between two populations (16%. The isolates, when tested by indirect competitive ELISA, showed about 68.5% of them to be atoxigenic. Composite analysis between the aflatoxin production and AFLP data was found to be ineffective in separating the isolate types by aflatoxigenicity. Certain unique fragments, with respect to individual isolates, were also identified that may be used for development of SCAR marker to aid in rapid and precise identification of isolates.

  17. Effects of Nutrients in Substrates of Different Grains on Aflatoxin B1 Production by Aspergillus flavus

    Science.gov (United States)

    Liu, Jie; Sun, Lvhui; Zhang, Niya; Zhang, Jiacai; Guo, Jiao; Li, Chong; Rajput, Shahid Ali; Qi, Desheng

    2016-01-01

    The current study was to better understand the potential factors affecting aflatoxin B1 (AFB1) accumulation varies between different grains. The nutrient composition and contents of defatted substrates were determined; additionally, according to the nutrient content of the substrates, the effects of starch, soluble sugars, amino acids, and trace elements on AFB1 production and mycelial growth in Czapek-Dox medium were examined. These results verified that removal of lipids from ground substrates significantly reduced the substrate's potential for AFB1 production by Aspergillus flavus. Maltose, glucose, sucrose, arginine, glutamic acid, aspartic acid, and zinc significantly induced AFB1 production up to 1.7- to 26.6-fold. And stachyose more significantly promoted A. flavus growth than the other nutrients. Thus, this study demonstrated that, combined with the nutrients content of grains, in addition to lipids, sucrose, stachyose, glutamic acid, and zinc might play key roles in various grains that are differentially infected by A. flavus. Particularly, two new nutrients (arginine and stachyose) of the grains we found significantly stimulate AFB1 production and A. flavus growth, respectively. The results provide new concepts for antifungal methods to protect food and animal feed from AFB1 contamination. PMID:27294129

  18. The Aspergillus flavus Histone Acetyltransferase AflGcnE Regulates Morphogenesis, Aflatoxin Biosynthesis, and Pathogenicity

    Science.gov (United States)

    Lan, Huahui; Sun, Ruilin; Fan, Kun; Yang, Kunlong; Zhang, Feng; Nie, Xin Y.; Wang, Xiunai; Zhuang, Zhenhong; Wang, Shihua

    2016-01-01

    Histone acetyltransferases (HATs) help regulate fungal development and the production of secondary metabolites. In this study, we determined that the HAT AflGcnE influenced morphogenesis and aflatoxin biosynthesis in Aspergillus flavus. We observed that AflGcnE localized to the nucleus and cytoplasm during the conidial production and germination stages, while it was located mainly in the nucleus during the hyphal development stage. Deletion of AflgcnE inhibited the growth of A. flavus and decreased the hydrophobicity of the cell surface. The ΔAflgcnE mutant exhibited a lack of asexual sporulation and was unable to generate sclerotia. Additionally, AflgcnE was required to maintain cell wall integrity and genotoxic stress responses. Importantly, the ΔAflgcnE mutant did not produce aflatoxins, which was consistent with a significant down-regulation of aflatoxin gene expression levels. Furthermore, our data revealed that AflgcnE is a pathogenicity factor required for colonizing maize seeds. In summary, we revealed that A. flavus AflGcnE is crucial for morphological development, aflatoxin biosynthesis, stress responses, and pathogenicity. Our findings help clarify the functional divergence of GcnE orthologs, and may provide a possible target for controlling A. flavus infections of agriculturally important crops. PMID:27625637

  19. Sequence breakpoints in the aflatoxin biosynthesis gene cluster and flanking regions in nonaflatoxigenic Aspergillus flavus isolates.

    Science.gov (United States)

    Chang, Perng-Kuang; Horn, Bruce W; Dorner, Joe W

    2005-11-01

    Aspergillus flavus populations are genetically diverse. Isolates that produce either, neither, or both aflatoxins and cyclopiazonic acid (CPA) are present in the field. We investigated defects in the aflatoxin gene cluster in 38 nonaflatoxigenic A. flavus isolates collected from southern United States. PCR assays using aflatoxin-gene-specific primers grouped these isolates into eight (A-H) deletion patterns. Patterns C, E, G, and H, which contain 40 kb deletions, were examined for their sequence breakpoints. Pattern C has one breakpoint in the cypA 3' untranslated region (UTR) and another in the verA coding region. Pattern E has a breakpoint in the amdA coding region and another in the ver1 5'UTR. Pattern G contains a deletion identical to the one found in pattern C and has another deletion that extends from the cypA coding region to one end of the chromosome as suggested by the presence of telomeric sequence repeats, CCCTAATGTTGA. Pattern H has a deletion of the entire aflatoxin gene cluster from the hexA coding region in the sugar utilization gene cluster to the telomeric region. Thus, deletions in the aflatoxin gene cluster among A. flavus isolates are not rare, and the patterns appear to be diverse. Genetic drift may be a driving force that is responsible for the loss of the entire aflatoxin gene cluster in nonaflatoxigenic A. flavus isolates when aflatoxins have lost their adaptive value in nature.

  20. Effects of Nutrients in Substrates of Different Grains on Aflatoxin B1 Production by Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Jie Liu

    2016-01-01

    Full Text Available The current study was to better understand the potential factors affecting aflatoxin B1 (AFB1 accumulation varies between different grains. The nutrient composition and contents of defatted substrates were determined; additionally, according to the nutrient content of the substrates, the effects of starch, soluble sugars, amino acids, and trace elements on AFB1 production and mycelial growth in Czapek-Dox medium were examined. These results verified that removal of lipids from ground substrates significantly reduced the substrate’s potential for AFB1 production by Aspergillus flavus. Maltose, glucose, sucrose, arginine, glutamic acid, aspartic acid, and zinc significantly induced AFB1 production up to 1.7- to 26.6-fold. And stachyose more significantly promoted A. flavus growth than the other nutrients. Thus, this study demonstrated that, combined with the nutrients content of grains, in addition to lipids, sucrose, stachyose, glutamic acid, and zinc might play key roles in various grains that are differentially infected by A. flavus. Particularly, two new nutrients (arginine and stachyose of the grains we found significantly stimulate AFB1 production and A. flavus growth, respectively. The results provide new concepts for antifungal methods to protect food and animal feed from AFB1 contamination.

  1. Aspergillus flavus: A potential Bioremediator for oil contaminated soils

    Directory of Open Access Journals (Sweden)

    Y.Avasn Maruthi

    2013-02-01

    Full Text Available Biodegradation is cost-effective, environmentally friendly treatment for oily contaminated sites by the use of microorganisms. In this study, laboratory experiments were conducted to establish the performance of fungal isolates in degradation of organic compounds contained in soils contaminated with petrol and diesel. As a result of the laboratory screening, two natural fungal strains capable of degrading total organic carbons (TOC were prepared from isolates enriched from the oil contaminated sites. Experiments were conducted in Erlenmeyer flasks under aerobic conditions, with TOC removal percentage varied from 0.7 to 32% depending on strains type and concentration. Strains Phanerocheate chrysosporium and Aspergillus niger exhibited the highest TOC removal percentage of 32 and 21%, respectively, before nutrient addition. TOC removal rate was enhanced after addition of nutrients to incubated flasks. The highest TOC reduction (45% was estimated after addition of combination of nitrogen, phosphorus and sulphur to Phanerocheate chrysosporium strains. Results of experimental work carried out elucidate that the fungi like Phanerocheate chrysosporium and Aspergillus niger were capabled of producing enzymes at a faster rate to decompose the substrate hydrocarbon and released more CO2 and hence these potential fungi can be utilized effectively as agents of biodegradation in waste recycling process and Bioremediation of oil contaminated sites.

  2. 植酸对黄曲霉菌(Aspergillus flavus)糖化力的影响%Effects of Phytic Acid on Saccharification of Aspergillus flavus

    Institute of Scientific and Technical Information of China (English)

    汪志君; 夏艳秋; 方维明; 朱强

    2003-01-01

    该文通过添加不同浓度的植酸于黄曲霉菌(Aspergillus flavus)培养基中,用不同添加方式,于不同生长时刻测定黄曲霉菌糖化力,研究植酸对黄曲霉菌糖化力的影响.结果表明加入植酸后黄曲霉菌糖化力均有很大提高,可为工业生产带来可观的经济效益.植酸最佳作用浓度范围是0.20%~0.25%,发酵24h糖化力最大可提高44.32%.

  3. Proteomic analysis of rutin-induced secreted proteins from Aspergillus flavus.

    Science.gov (United States)

    Medina, Martha L; Kiernan, Urban A; Francisco, Wilson A

    2004-03-01

    Few studies have been conducted to identify the extracellular proteins and enzymes secreted by filamentous fungi, particularly with respect to dispensable metabolic pathways. Proteomic analysis has proven to be the most powerful method for identification of proteins in complex mixtures and is suitable for the study of the alteration of protein expression under different environmental conditions. The filamentous fungus Aspergillus flavus can degrade the flavonoid rutin as the only source of carbon via an extracellular enzyme system. In this study, a proteomic analysis was used to differentiate and identify the extracellular rutin-induced and non-induced proteins secreted by A. flavus. The secreted proteins were analyzed by two-dimensional electrophoresis and MALDI-TOF mass spectrometry. While 15 rutin-induced proteins and 7 non-induced proteins were identified, more than 90 protein spots remain unidentified, indicating that these proteins are either novel proteins or proteins that have not yet been sequenced.

  4. Degradation of polyurethane by Aspergillus flavus (ITCC 6051) isolated from soil.

    Science.gov (United States)

    Mathur, Garima; Prasad, Ramasare

    2012-07-01

    The present study deals with the isolation of fungi from soil with the ability to degrade polyurethane (PU). A pure fungal isolate was analyzed for its ability to utilize PU as a sole carbon source in shaking culture for 30 days. Incubation of PU with Aspergillus flavus resulted in 60.6% reduction in weight of PU. The scanning electron microscopy and Fourier transform infrared spectroscopy (FTIR) results showed certain changes on the surface of PU film and formation of some new intermediate products after polymer breakdown. Thermogravimetric curves showed changes between the thermal behavior of the samples that were inoculated with A. flavus and control. FTIR spectra showed detectable changes in control and incubated samples, suggesting that degradation occurs, with the decreased intensity of band at 1,715 cm(-1), corresponding to ester linkages. We have identified an extracellular esterase activity which might be responsible for the polyurethanolytic activity.

  5. 75 FR 9596 - Notice of Filing of a Pesticide Petition for Residues of a Aspergillus flavus AF36 on Corn Food...

    Science.gov (United States)

    2010-03-03

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY Notice of Filing of a Pesticide Petition for Residues of a Aspergillus flavus AF36 on Corn Food... residues of the antifungal ] agent, Aspergillus flavus AF36, in or on corn food and feed commodities....

  6. Controlling Aspergillus flavus and Aspergillus parasiticus growth and aflatoxin production in poultry feed using carvacrol and trans-cinnamaldehyde.

    Science.gov (United States)

    Yin, Hsin-Bai; Chen, Chi-Hung; Kollanoor-Johny, Anup; Darre, Michael J; Venkitanarayanan, Kumar

    2015-09-01

    Aflatoxins (AF) are toxic metabolites primarily produced by molds, Aspergillus flavus and Aspergillus parasiticus. Contamination of poultry feed with AF is a major concern to the poultry industry due to severe economic losses stemming from poor performance, reduced egg production, and diminished egg hatchability. This study investigated the inhibitory effect of 2 generally regarded as safe (GRAS), natural plant compounds, namely carvacrol (CR) and trans-cinnamaldehyde (TC), on A. flavus and A. parasiticus growth and AF production in potato dextrose broth (PDB) and in poultry feed. In broth culture, PDB supplemented with CR (0%, 0.02%, 0.04% and 0.08%) or TC (0%, 0.005%, 0.01% and 0.02%) was inoculated with A. flavus or A. parasiticus (6 log CFU/mL), and mold counts and AF production were determined on days 0, 1, 3, and 5. Similarly, 200 g portions of poultry feed supplemented with CR or TC (0%, 0.4%, 0.8%, and 1.0%) were inoculated with each mold, and their counts and AF concentrations in the feed were determined at 0, 1, 2, 3, 4, 8, and 12 weeks of storage. Moreover, the effect of CR and TC on the expression of AF synthesis genes in A. flavus and A. parasiticus (aflC, nor1, norA, and ver1) was determined using real-time quantitative PCR (RT-qPCR). All experiments had duplicate samples and were replicated 3 times. Results indicated that CR and TC reduced A. flavus and A. parasiticus growth and AF production in broth culture and chicken feed (P<0.05). All tested concentrations of CR and TC decreased AF production in broth culture and chicken feed by at least 60% when compared to controls (P<0.05). In addition, CR and TC down-regulated the expression of major genes associated with AF synthesis in the molds (P<0.05). Results suggest the potential use of CR and TC as feed additives to control AF contamination in poultry feed.

  7. Non-aflatoxigenic Aspergillus flavus to prevent aflatoxin contamination in crops: advantages and limitations

    Science.gov (United States)

    Ehrlich, Kenneth C.

    2014-01-01

    Aspergillus flavus is a diverse assemblage of strains that include aflatoxin-producing and non-toxigenic strains with cosmopolitan distribution. The most promising strategy currently being used to reduce preharvest contamination of crops with aflatoxin is to introduce non-aflatoxin (biocontrol) A. flavus into the crop environment. Whether or not introduction of biocontrol strains into agricultural fields is enough to reduce aflatoxin contamination to levels required for acceptance of the contaminated food as fit for consumption is still unknown. There is no question that biocontrol strains are able to reduce the size of the populations of aflatoxin-producing strains but the available data suggests that at most only a four- to five-fold reduction in aflatoxin contamination is achieved. There are many challenges facing this strategy that are both short term and long term. First, the population biology of A. flavus is not well understood due in part to A. flavus’s diversity, its ability to form heterokaryotic reproductive forms, and its unknown ability to survive for prolonged periods after application. Second, biocontrol strains must be selected that are suitable for the environment, the type of crop, and the soil into which they will be introduced. Third, there is a need to guard against inadvertent introduction of A. flavus strains that could impose an additional burden on food safety and food quality, and fourth, with global warming and resultant changes in the soil nutrients and concomitant microbiome populations, the biocontrol strategy must be sufficiently flexible to adapt to such changes. Understanding genetic variation within strains of A. flavus is important for developing a robust biocontrol strategy and it is unlikely that a “one size fits all” strategy will work for preharvest aflatoxin reduction. PMID:24575088

  8. Toxicity, analgesic and sedative potential of crude extract of soil-borne phytopathogenic fungi Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Bashir Ahmad

    2016-11-01

    Full Text Available Background: Aspergillus flavus is one of the most abundant mold present around the world. The present study was conducted to investigate the acute toxicity, analgesic and sedative effect of the crude extract obtained from soil borne fungi A. flavus. Methods: The fungi was isolated from soil samples and identified morphologically and microscopically. The growth condition i.e. media, temperature, pH, and incubation period were optimized. In these optimized growth condition, A. flavus was grown in batch culture in shaking incubator. Crude contents were extracted by using ethyl acetate solvent. Crude secondary metabolites were screened for acute toxicity, analgesic and sedative effect. Results: Upon completion of the experiment, blood was collected from the tail vein of albino mice, and different haematological tests were conducted. White blood cells counts displayed a slight increase (10.6× 109/L above their normal range (0.8–6.8 × 109/L, which may be due to the increment in the number of lymphocytes or granulocytes. However, the percentage of lymphocytes was much lower (17.7%, while the percentage of the granulocytes was higher (61.4% than its normal range (8.6–38.9%. A reduction in the mean number of writhing in the different test groups was caused by the application of the crude ethyl acetate extract through the i.p. route at different doses (50, 100, and 150 mg/kg body weight. The results of our investigation showed the EtOAc extract of A. flavus can cause a significant sedative effect in open field. Conclusion: It was concluded from the present study that the A. flavus has the potential to produce bioactive metabolites which have analgesic and sedative effect.

  9. Identification of novel metabolites from Aspergillus flavus by high resolution and multiple stage mass spectrometry.

    Science.gov (United States)

    Malysheva, Svetlana V; Arroyo-Manzanares, Natalia; Cary, Jeffrey W; Ehrlich, Kenneth C; Vanden Bussche, Julie; Vanhaecke, Lynn; Bhatnagar, Deepak; Di Mavungu, José Diana; De Saeger, Sarah

    2014-01-01

    The filamentous fungus Aspergillus flavus is one of the most important species in the Aspergillus genus and is distributed worldwide as a prevalent aflatoxin-producing food and feed contaminant. A. flavus contains more than 55 gene clusters that are predicted to encode proteins involved in secondary metabolite production. One of these, cluster 27, contains a polyketide synthase (pks27) gene that encodes a protein that is highly homologous to the aflatoxin cluster PKS. Comparative metabolomics, using ultra-high performance liquid chromatography (UHPLC) coupled to high resolution Orbitrap mass spectrometry (MS) was used to detect metabolites differentially expressed in the A. flavus wild-type and ∆pks27 mutant strains. Metabolite profiling was aided by a statistical differential analysis of MS data using SIEVE software. This differential analysis combined with accurate mass data from the Orbitrap and ion trap multiple stage MS allowed four metabolites to be identified that were produced only by the wild-type culture. These included asparasone A (358 Da), an anthraquinone pigment, and related anthraquinones with masses of 316, 340 and 374 Da. These latter three compounds had similar fragmentation patterns to that of asparasone A. The 316 Da anthraquinone is particularly interesting because it is most likely formed by incorporation of seven malonyl-CoA units rather than the eight units required for the formation of asparasone A. The 340 and 374 Da metabolites are the dehydration and an oxy-derivative of asparasone A, respectively. Asparasone A was also identified in extracts from several other Aspergillus species.

  10. ZnS semiconductor quantum dots production by an endophytic fungus Aspergillus flavus

    Energy Technology Data Exchange (ETDEWEB)

    Uddandarao, Priyanka, E-mail: uddandaraopriyanka@gmail.com; B, Raj Mohan, E-mail: rajmohanbala@gmail.com

    2016-05-15

    Graphical abstract: - Highlights: • Endophytic fungus Aspergillus flavus isolated from a medicinal plant Nothapodytes foetida was used for the synthesis of quantum dots. • Morris-Weber kinetic model and Lagergren's pseudo-first-order rate equation were used to study the biosorption kinetics. • Polycrystalline ZnS quantum dots of 18 nm and 58.9 nm from TEM and DLS, respectively. - Abstract: The development of reliable and eco-friendly processes for the synthesis of metal sulphide quantum dots has been considered as a major challenge in the field of nanotechnology. In the present study, polycrystalline ZnS quantum dots were synthesized from an endophytic fungus Aspergillus flavus. It is noteworthy that apart from being rich sources of bioactive compounds, endophytic fungus also has the ability to mediate the synthesis of nanoparticles. TEM and DLS revealed the formation of spherical particles with an average diameter of about 18 nm and 58.9 nm, respectively. The ZnS quantum dots were further characterized using SEM, EDAX, XRD, UV–visible spectroscopy and FTIR. The obtained results confirmed the synthesis of polycrystalline ZnS quantum dots and these quantum dots are used for studying ROS activity. In addition this paper explains kinetics of metal sorption to study the role of biosorption in synthesis of quantum dots by applying Morris-Weber kinetic model. Since Aspergillus flavus is isolated from a medicinal plant Nothapodytes foetida, quantum dots synthesized from this fungus may have great potential in broad environmental and medical applications.

  11. Potential of essential oils for protection of grains contaminated by aflatoxin produced by Aspergillus flavus.

    Science.gov (United States)

    Esper, Renata H; Gonçalez, Edlayne; Marques, Marcia O M; Felicio, Roberto C; Felicio, Joana D

    2014-01-01

    Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Inhibitory effects of essential oils of Ageratum conyzoides (mentrasto) and Origanum vulgare (oregano) on the mycelial growth and aflatoxin B1 production by Aspergillus flavus have been studied previously in culture medium. The aim of this study was to evaluate aflatoxin B1 production by Aspergillus flavus in real food systems (corn and soybean) treated with Ageratum conyzoides (mentrasto) and Origanum vulgare (oregano) essential oils. Samples with 60 g of the grains were treated with different volumes of essential oils, 200, 100, 50, and 10 μL for oregano and 50, 30, 15, and 10 μL for mentrasto. Fungal growth was evaluated by disk diffusion method. Aflatoxin B1 production was evaluated inoculating suspensions of A. flavus containing 1.3 × 10(5) spores/mL in 60 g of grains (corn and soybeans) after adjusting the water activity at 0.94. Aflatoxin was quantified by photodensitometry. Fungal growth and aflatoxin production were inhibited by essential oils, but the mentrasto oil was more effective in soybeans than that of oregano. On the other hand, in corn samples, the oregano essential oil was more effective than that of mentrasto. Chemical compositions of the essential oils were also investigated. The GC/MS oils analysis showed that the main component of mentrasto essential oil is precocene I and of the main component of oregano essential oil is 4-terpineol. The results indicate that both essential oils can become an alternative for the control of aflatoxins in corn and soybeans.

  12. Hydrophobic Effect of Amphiphilic Derivatives of Chitosan on the Antifungal Activity against Aspergillus flavus and Aspergillus parasiticus

    Directory of Open Access Journals (Sweden)

    Vera Ap. de Oliveira Tiera

    2013-04-01

    Full Text Available Low molecular weight amphiphilic derivatives of chitosan were synthesized, characterized and their antifungal activities against Aspergillus flavus and Aspergillus parasiticus were tested. The derivatives were synthesized using as starting material a deacetylated chitosan sample in a two step process: the reaction with propyltrimethyl-ammonium bromide (Pr, followed by reductive amination with dodecyl aldehyde. Aiming to evaluate the effect of the hydrophobic modification of the derivatives on the antifungal activity against the pathogens, the degree of substitution (DS1 by Pr groups was kept constant and the proportion of dodecyl (Dod groups was varied from 7 to 29% (DS2. The derivatives were characterized by 1H-NMR and FTIR and their antifungal activities against the pathogens were tested by the radial growth of the colony and minimum inhibitory concentration (MIC methods. The derivatives substituted with only Pr groups exhibited modest inhibition against A. flavus and A. parasiticus, like that obtained with deacetylated chitosan. Results revealed that the amphiphilic derivatives grafted with Dod groups exhibited increasing inhibition indexes, depending on polymer concentration and hydrophobic content. At 0.6 g/L, all amphiphilic derivatives having from 7.0 to 29% of Dod groups completely inhibited fungal growth and the MIC values were found to decrease from 4.0 g/L for deacetylated chitosan to 0.25–0.50 g/L for the derivatives. These new derivatives open up the possibility of new applications and avenues to develop effective biofungicides based on chitosan.

  13. Biotransformation of chalcones by the endophytic fungus Aspergillus flavus isolated from Paspalum maritimum trin

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Marivaldo J.C.; Nunes, Fatima M.; Bitencourt, Heriberto R.; Borges, Fabio C.; Guilhon, Giselle M.S.P.; Arruda, Mara S.P.; Marinho, Andrey M. R.; Santos, Alberdan S.; Alves, Claudio N.; Santos, Lourivaldo S., E-mail: lss@ufpa.b [Universidade Federal do Para (IQ/FEQ/UFPA), Belem, PA (Brazil). Inst. de Tecnologia. Faculdade de Engenharia Quimica; Brasil, Davi S.B. [Universidade Federal do Para (PPGQ/IQ/UFPA), Belem, PA (Brazil). Inst. de Quimica. Programa de Pos-Graduacao em Quimica

    2011-07-01

    The fungus Aspergillus flavus isolated as endophytic of the plant Paspalum maritimum Trin. was evaluated for its potential application in biotransformation reactions. The compounds chalcone (1), 3,4,5-trimethoxychalcone (2) and 2,3,4,4'-tetramethoxy chalcone (3) were biotransformed, respectively, in dihydrochalcone (4), 3,4,5-trimethoxydihydrochalcone (5) and 2,3,4,4'-tetramethoxydihydrochalcone (6). The structures were elucidated by spectroscopic methods including 1D and 2D NMR techniques, and MS analysis. The dihydrochalcones 5 and 6 are new compounds. (author)

  14. 医院空气中黄曲霉菌含量分析研究%Analysis of Air Concentration of Aspergillus Flavus in Hospital

    Institute of Scientific and Technical Information of China (English)

    索继江; 邢玉斌; 谢丽君; 杜明梅; 贾宁; 高岩; 邓春燕; 陈孟莉; 刘运喜

    2009-01-01

    目的 了解医院空气中黄曲霉菌污染程度和规律.方法 采用离心式空气微生物采样器和真菌培养的方法,在1年中不同季节分别选择1 d中不同的5个时段,对医院不同环境空气中黄曲霉菌进行采集、培养、计数和分析.结果 所有采样点在4个季度均采集到了黄曲霉菌株;6个环境区空气中黄曲霉菌含量不同,以门诊楼最高,平均达1238.9 CFU/m~3;其中内科楼各科室空气中黄曲霉菌含量各季节间差异有统计学意义(P0.05);同时内科与外环境空气中黄曲霉菌含量在冬、夏季差异有统计学意义(均P0.05).结论 医院环境中黄曲霉菌污染较严重,加强环境控制,预防曲霉菌属感染非常必要.%OBJECTIVE To study the degree and regular of Aspergillus flavus air contamination in hospital.METHODS Some ambient air of different environment in our hospital was taken 5 times in one day of four seasons one year by using centrifugal air sampler, and then cultivated (using eumycete cultural methods), counted and analyzed. RESULTS A. flavus strain was collected in all sampling points in four seasons. The concentration of Aspergillus flavus in six standort was diverse from each other, and the highest was the out-patient clinic with 1238. 9 CFU/m~2. The concentration of Aspergillus flavus in each division of Medical Department was significant difference during four seasons (P 0.05). The difference between internal medicine and external enviroment was significant between the first and the third season( P=0.022, P=0.039),but that of the second and the fouth season was not significant (P=0.022, P=0.624). CONCLUSIONS The contamination of Aspergillus flavus in hospital was severe. So it's necessary to prevent the Aspergillus flavus infection and enhance the environmental control of susceptible population.

  15. The Inhibitory Effects of Curcuma longa L. Essential Oil and Curcumin on Aspergillus flavus Link Growth and Morphology

    OpenAIRE

    Flávio Dias Ferreira; Simone Aparecida Galerani Mossini; Francine Maery Dias Ferreira; Carla Cristina Arrotéia; Christiane Luciana da Costa; Celso Vataru Nakamura; Miguel Machinski Junior

    2013-01-01

    The essential oil from Curcuma longa L. was analysed by GC/MS. The major components of the oil were ar-turmerone (33.2%), α -turmerone (23.5%) and β -turmerone (22.7%). The antifungal activities of the oil were studied with regard to Aspergillus flavus growth inhibition and altered morphology, as preliminary studies indicated that the essential oil from C. longa inhibited Aspergillus flavus Link aflatoxin production. The concentration of essential oil in the culture media ranged from 0.01% to...

  16. Unravelling the Diversity of the Cyclopiazonic Acid Family of Mycotoxins in Aspergillus flavus by UHPLC Triple-TOF HRMS

    Science.gov (United States)

    Uka, Valdet; Moore, Geromy G.; Arroyo-Manzanares, Natalia; Nebija, Dashnor; De Saeger, Sarah; Diana Di Mavungu, José

    2017-01-01

    Cyclopiazonic acid (α-cyclopiazonic acid, α-CPA) is an indole-hydrindane-tetramic acid neurotoxin produced by various fungal species, including the notorious food and feed contaminant Aspergillus flavus. Despite its discovery in A. flavus cultures approximately 40 years ago, its contribution to the A. flavus mycotoxin burden is consistently minimized by our focus on the more potent carcinogenic aflatoxins also produced by this fungus. Here, we report the screening and identification of several CPA-type alkaloids not previously found in A. flavus cultures. Our identifications of these CPA-type alkaloids are based on a dereplication strategy involving accurate mass high resolution mass spectrometry data and a careful study of the α-CPA fragmentation pattern. In total, 22 CPA-type alkaloids were identified in extracts from the A. flavus strains examined. Of these metabolites, 13 have been previously reported in other fungi, though this is the first report of their existence in A. flavus. Two of our metabolite discoveries, 11,12-dehydro α-CPA and 3-hydroxy-2-oxo CPA, have never been reported for any organism. The conspicuous presence of CPA and its numerous derivatives in A. flavus cultures raises concerns about the long-term and cumulative toxicological effects of these fungal secondary metabolites and their contributions to the entire A. flavus mycotoxin problem. PMID:28098779

  17. Adenylate Cyclase AcyA Regulates Development, Aflatoxin Biosynthesis and Fungal Virulence in Aspergillus flavus

    Science.gov (United States)

    Yang, Kunlong; Qin, Qiuping; Liu, Yinghang; Zhang, Limei; Liang, Linlin; Lan, Huahui; Chen, Chihao; You, Yunchao; Zhang, Feng; Wang, Shihua

    2016-01-01

    Aspergillus flavus is one of the most important opportunistic pathogens of crops and animals. The carcinogenic mycotoxin, aflatoxins produced by this pathogen cause a health problem to human and animals. Since cyclic AMP signaling controls a range of physiological processes, like fungal development and infection when responding to extracellular stimuli in fungal pathogens, in this study, we investigated the function of adenylate cyclase, a core component of cAMP signaling, in aflatoxins biosynthesis and virulence on plant seeds in A. flavus. A gene replacement strategy was used to generate the deletion mutant of acyA that encodes the adenylate cyclase. Severe defects in fungal growth, sporulation and sclerotia formation were observed in the acyA deletion mutant. The defect in radical growth could be partially rescued by exogenous cAMP analog. The acyA mutant was also significantly reduced in aflatoxins production and virulence. Similar to the former studies in other fungi, The acyA mutant showed enhancing tolerance to oxidative stress, but more sensitive to heat stress. Overall, the pleiotropic defects of the acyA deletion mutant indicates that the cAMP-PKA pathway is involved in fungal development, aflatoxins biosynthesis and plant seed invasion in A. flavus. PMID:28066725

  18. Using Predictions Based on Geostatistics to Monitor Trends in Aspergillus flavus Strain Composition.

    Science.gov (United States)

    Orum, T V; Bigelow, D M; Cotty, P J; Nelson, M R

    1999-09-01

    ABSTRACT Aspergillus flavus is a soil-inhabiting fungus that frequently produces aflatoxins, potent carcinogens, in cottonseed and other seed crops. A. flavus S strain isolates, characterized on the basis of sclerotial morphology, are highly toxigenic. Spatial and temporal characteristics of the percentage of the A. flavus isolates that are S strain (S strain incidence) were used to predict patterns across areas of more than 30 km(2). Spatial autocorrelation in S strain incidence in Yuma County, AZ, was shown to extend beyond field boundaries to adjacent fields. Variograms revealed both short-range (2 to 6 km) and long-range (20 to 30 km) spatial structure in S strain incidence. S strain incidence at 36 locations sampled in July 1997 was predicted with a high correlation between expected and observed values (R = 0.85, P = 0.0001) by kriging data from July 1995 and July 1996. S strain incidence at locations sampled in October 1997 and March 1998 was markedly less than predicted by kriging data from the same months in prior years. Temporal analysis of four locations repeatedly sampled from April 1995 through July 1998 also indicated a major reduction in S strain incidence in the Texas Hill area after July 1997. Surface maps generated by kriging point data indicated a similarity in the spatial pattern of S strain incidence among all sampling dates despite temporal changes in the overall S strain incidence. Geostatistics provided useful descriptions of variability in S strain incidence over space and time.

  19. Lactobacillus casei CRL 431 and Lactobacillus rhamnosus CRL 1224 as biological controls for Aspergillus flavus strains.

    Science.gov (United States)

    Bueno, Dante J; Silva, Julio O; Oliver, Guillermo; González, Silvia N

    2006-10-01

    The effect of two species of lactobacilli, Lactobacillus casei CRL 431 and Lactobacillus rhamnosus CRL 1224, on growth of different Aspergillus flavus strains was determined. A. flavus strains (Ap, TR2, or CF80) were grown in LAPTg broth at 37 degrees C for 7 days as a single culture and in association with L. casei CRL 431 or L. rhamnosus CRL 1224 at initial inoculum ratios of 1:1, 1:10, and 1:100. In most cases, the mixed cultures had a lower fungal growth and a lower pH than the control cultures. Mycelial dry weight was reduced to 73 and 85% using L. casei CRL 431 and L. rhamnosus CRL 1224, respectively. The pH decrease in mixed cultures when the fungal mycelial dry weight is reduced may play an important role in inhibition. The number of viable bacteria was variably affected by fungal growth. These results indicate that L. casei CRL 431 and L. rhamnosus CRL 1224 may be useful as potential biocontrol agent against A. flavus.

  20. Antifungal properties and inhibitory effects upon aflatoxin production of Thymus vulgaris L. by Aspergillus flavus Link.

    Science.gov (United States)

    Kohiyama, Cássia Yumie; Yamamoto Ribeiro, Milene Mayumi; Mossini, Simone Aparecida Galerani; Bando, Erika; Bomfim, Natália da Silva; Nerilo, Samuel Botião; Rocha, Gustavo Henrique Oliveira; Grespan, Renata; Mikcha, Jane Martha Graton; Machinski, Miguel

    2015-04-15

    The antifungal and antiaflatoxigenic properties of Thymus vulgaris essential oil (TEO) were evaluated upon Aspergillus flavus "in vitro". Suspension containing 10(6) of A. flavus were cultivated with TEO in concentrations ranging from 50 to 500 μg/mL. TEO reached minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) at 250 μg/mL. Inhibition of ergosterol biosynthesis was detected at a concentration of 100 μg/mL of TEO. Morphological evaluation performed by both light microscopy and scanning electron microscopy showed that antifungal activity of TEO could be detected starting at a concentration of 50 μg/mL and the fungicide effect at a concentration of 250 μg/mL. TEO completely inhibited production of both B1 and B2 aflatoxins (AFB1 and AFB2) at a concentration of 150 μg/mL. This way, fungal biomass development and aflatoxin production were dependent on TEO concentration. Therefore, TEO was capable of controlling the growth of A. flavus and its production of aflatoxins.

  1. INFLUENCE OF ENVIRONMENTAL FACTORS ON THE GROWTH OF BUILDING DETERIORATING FUNGI: ASPERGILLUS FLAVUS AND PENICILLIUM CHRYSOGENUM

    Directory of Open Access Journals (Sweden)

    Padma Singh* and Mamta Chauhan

    2013-01-01

    Full Text Available The performance of whole building depends on many factors: structure, coating, environment, climate, type of use, service etc. Fungi are essential for the survival of our global ecology but they may pose a significant threat to the health of occupants when they grow in our buildings. The most important factor that affect microbial growth on buildings materials are temperature, moisture and nutrients. The moisture conditions connected with temperature and exposure time are the most important factor for the development of biological problems and damage in buildings. In vitro studies were conducted on the effect of temperature, pH levels and moisture on the growth of Aspergillus flavus and Penicillium chrysogenum. Maximum growth was observed on pH level 6 and 7 against A. flavus and P. chrysogenum respectively after 12 days. The most suitable temperature for the growth of A. flavus and P. chrysogenum was observed on 25°C and 30°C respectively. The fungus showed maximum growth at 90% relative humidity.

  2. Aspergillus flavus induces granulomatous cerebral aspergillosis in mice with display of distinct cytokine profile.

    Science.gov (United States)

    Anand, R; Shankar, J; Tiwary, B N; Singh, A P

    2015-04-01

    Aspergillus flavus is one of the leading Aspergillus spp. resulting in invasive aspergillosis of central nervous system (CNS) in human beings. Immunological status in aspergillosis of central nervous system remains elusive in case of both immunocompetent and immunocompromised patients. Since cytokines are the major mediators of host response, evaluation of disease pathology along with cytokine profile in brain may provide snapshots of neuro-immunological response. An intravenous model of A. flavus infection was utilized to determine the pathogenicity of infection and cytokine profile in the brain of male BALB/c mice. Enumeration of colony forming units and histopathological analyses were performed on the brain tissue at distinct time periods. The kinetics of cytokines (TNF-α, IFN-γ, IL-12/IL-23p40, IL-6, IL-23, IL-17A and IL-4) was evaluated at 6, 12, 24, 48, 72 and 96h post infection (hPI) in brain homogenates using murine cytokine specific enzyme linked immunosorbent assay. Histological analysis exhibited the hyphae with leukocyte infiltrations leading to formation of granulomata along with ischemia and pyknosis of neurons in the brain of infected mice. Diseased mice displayed increased secretion of IFN-γ, IL-12p40 and IL-6 with a concomitant reduction in the secretion of Th2 cytokine IL-4, and Th17 promoting cytokine, IL-23 during the late phase of infection. A.flavus induced inflammatory granulomatous cerebral aspergillosis in mice, characterized by a marked increase in the Th1 cytokines and neurons undergoing necrosis. A marked increase in necrosis of neurons with concurrent inflammatory responses might have led to the host mortality during late phase of infection.

  3. Morphological and molecular identification of filamentous Aspergillus flavus and Aspergillus parasiticus isolated from compound feeds in South Africa.

    Science.gov (United States)

    Iheanacho, Henry E; Njobeh, Patrick B; Dutton, Francis M; Steenkamp, Paul A; Steenkamp, Lucia; Mthombeni, Julian Q; Daru, Barnabas H; Makun, Anthony H

    2014-12-01

    Isolation of filamentous species of two Aspergillum genera from compound feeds produced in South Africa, and subsequent extraction of their individual DNA in this study, presents a simple but rapid molecular procedure for high through-put analysis of the individual morphological forms. DNA was successfully isolated from the Aspergillus spp. from agar cultures by use of a commercial kit. Agarose gel electrophoresis fractionation of the fungi DNA, showed distinct bands. The DNA extracted by this procedure appears to be relatively pure with a ratio absorbance at 260 and 280 nm. However, the overall morphological and molecular data indicated that 67.5 and 51.1% of feed samples were found to be contaminated with Aspergillus flavus and Aspergillus parasiticus, respectively, with poultry feed having the highest contamination mean level of 5.7 × 105 CFU/g when compared to cattle (mean: 4.0 × 106 CFU/g), pig (mean: 2.7 × 104 CFU/g) and horse (1.0 × 102 CFU) feed. This technique presents a readily achievable, easy to use method in the extraction of filamentous fungal DNA and it's identification. Hence serves as an important tool towards molecular study of these organisms for routine analysis check in monitoring and improving compound feed quality against fungal contamination.

  4. Buckwheat achenes antioxidant profile modulates Aspergillus flavus growth and aflatoxin production.

    Science.gov (United States)

    Chitarrini, G; Nobili, C; Pinzari, F; Antonini, A; De Rossi, P; Del Fiore, A; Procacci, S; Tolaini, V; Scala, V; Scarpari, M; Reverberi, M

    2014-10-17

    Buckwheat (Fagopyrum spp.) is a "pseudo-cereal" of great interest in the production of healthy foods since its flour, derived from achenes, is enriched with bioactive compounds and, due to the absence of gluten, may be used in composition of celiac diets. Amongst buckwheat species, F. tataricum achenes possess a larger amount of the antioxidant flavenol rutin than the common buckwheat F. esculentum. Ongoing climate change may favor plant susceptibility to the attack by pathogenic, often mycotoxigenic, fungi with consequent increase of mycotoxins in previously unexploited feeds and foodstuffs. In particular, Aspergillus flavus, under suitable environmental conditions such as those currently occurring in Italy, may produce aflatoxin B1 (AFB1), the most carcinogenic compound of fungal origin which is classified by IARC as Category 1. In this study, the viable achenes of two buckwheat species, F. tataricum (var. Golden) and F. esculentum (var. Aelita) were inoculated with an AFB1-producing A. flavus NRRL 3357 to analyze their relative performances against fungal invasion and toxin contamination. Notably, we sought the existence of a correlation between the amount of tocols/flavonols in the achenes of buckwheat, infected and non-infected with A. flavus, and to analyze the ability of the pathogen to grow and produce toxin during achene infection. Results suggest that achenes of F. tataricum, the best producer of antioxidant compounds in this study, are less susceptible to A. flavus infection and consequently, but not proportionally, to mycotoxin contamination compared with F. esculentum. Moreover, rutin-derived quercetin appears to be more efficient in inhibiting aflatoxin biosynthesis than the parent compound.

  5. Toxicidade de óleos essenciais de alho e casca de canela contra fungos do grupo Aspergillus flavus Evaluation of essential oils from Allium sativum and Cinnamomum zeilanicum and their toxicity against fungi of the Aspergillus flavus group

    Directory of Open Access Journals (Sweden)

    Elson de C. Viegas

    2005-12-01

    Full Text Available Diante da propriedade inibitória de óleos essenciais vegetais sobre o desenvolvimento micelial de fungos e da importância das espécies do grupo Aspergillus flavus, que apresentam potencial para síntese de aflatoxina, este trabalho teve como objetivo avaliar in vitro a toxicidade de óleos essenciais vegetais contra fungos do grupo A. flavus, isolados a partir da cultura do amendoim. Inicialmente, foi avaliada a toxicidade de oito óleos essenciais vegetais no desenvolvimento micelial de dois isolados do grupo A. flavus, em comparação ao fungicida sintético benomyl. Em seguida, foi avaliada a toxicidade dos óleos de casca de canela (Cinnamomum zeilanicum Breym. e de bulbilho de alho (Allium sativum L. contra 37 isolados do grupo A. flavus, durante 12 meses. A maior inibição do desenvolvimento micelial de A. flavus foi obtida com o emprego dos óleos essenciais de casca de canela e de bulbilho de alho, e o efeito inibitório variou com o isolado testado.Considering the inhibitory property of essential plant oils on the mycelial development of fungi, and the importance of Aspergillus flavus-like fungi which may produce aflatoxins, this research was designed to evaluate the toxicity of essential oils against fungi belonging to the group A. flavus isolated from peanut crops. The toxicity of eight essential oils against two isolates of A. Flavuslike fungi was evaluated in comparison to the synthetic fungicide benomyl. The toxicity of Cinnamomum zeilanicum Breym. and Allium sativum L. essential oils was also evaluated against 37 fungal isolates for a period of 12 months. The highest inhibition of the mycelial development of A. flavus was obtained with cinnamon and garlic essential oils. The inhibitory effect on growth was variable according to the fungal isolate.

  6. Aspergillus flavus growth and aflatoxin production as influenced by total lipid content during growth and development of cottonseed

    Science.gov (United States)

    Aspergillus flavus infects several food and feed crops such as corn, cotton, peanuts and tree nut crops and contaminates the seed with carcinogenic aflatoxins. These susceptible crops contain rich reserves of lipids and fatty acids. The nature of relationship between lipids and the ability of the f...

  7. Evaluation of recycled bioplastic pellets and a sprayable formulation for application of an Aspergillus flavus biocontrol strain

    Science.gov (United States)

    Biocontrol of Aspergillus flavus using inoculated bioplastic granules has been proven to be effective under laboratory and field conditions. In the present study, the use of low-density pellets from recycled bioplastic as a biocontrol strain carrier was evaluated. Applying recycled bioplastic pell...

  8. Inhibition of Aspergillus flavus on agar media and brown rice cereal bars using cold atmospheric plasma treatment.

    Science.gov (United States)

    Suhem, Kitiya; Matan, Narumol; Nisoa, Mudtorlep; Matan, Nirundorn

    2013-02-01

    This study aimed to optimize the operating parameters of cold atmospheric plasma treatment to inhibit the growth of Aspergillus flavus on agar media and brown rice cereal bars. The effects of argon plasma jet treatment on the growth of A. flavus on malt extract agar (MEA) at powers of 20 W and 40 W with exposure times at 5, 15 and 25 min were studied using response surface methodology (RSM) with a central composite face-centered (CCF) design. Multiple regression analysis indicated that plasma treatment at 40 W for 25 min is most effective for inhibiting growth of A. flavus on the agar medium. On brown rice cereal bars, plasma powered at 40 W for 20 min was capable of giving protection against A. flavus growth for up to 20 days under storage conditions of 25°C and 100% RH. These results demonstrated the potential of cold atmospheric plasma jet treatment to control mold growth on various food products.

  9. Menadione-Induced Oxidative Stress Re-Shapes the Oxylipin Profile of Aspergillus flavus and Its Lifestyle

    Directory of Open Access Journals (Sweden)

    Marco Zaccaria

    2015-10-01

    Full Text Available Aspergillus flavus is an efficient producer of mycotoxins, particularly aflatoxin B1, probably the most hepatocarcinogenic naturally-occurring compound. Although the inducing agents of toxin synthesis are not unanimously identified, there is evidence that oxidative stress is one of the main actors in play. In our study, we use menadione, a quinone extensively implemented in studies on ROS response in animal cells, for causing stress to A. flavus. For uncovering the molecular determinants that drive A. flavus in challenging oxidative stress conditions, we have evaluated a wide spectrum of several different parameters, ranging from metabolic (ROS and oxylipin profile to transcriptional analysis (RNA-seq. There emerges a scenario in which A. flavus activates several metabolic processes under oxidative stress conditions for limiting the ROS-associated detrimental effects, as well as for triggering adaptive and escape strategies.

  10. Larval Preference and Performance of Amyelois transitella (Navel Orangeworm, Lepidoptera: Pyralidae) in Relation to the Fungus Aspergillus flavus.

    Science.gov (United States)

    Ampt, Eline A; Bush, Daniel S; Siegel, Joel P; Berenbaum, May R

    2016-02-01

    The navel orangeworm, Amyelois transitella (Walker), is a polyphagous pest of California nut crops and is responsible for extensive losses in the United States. It directly damages crops by feeding and contaminating nuts with frass and webbing and vectors saprophytic fungi that infect crops. The navel orangeworm is commonly associated with Aspergillus species, including the toxigenic Aspergillus flavus, which causes crop loss by producing carcinogens, including aflatoxin B1. This lepidopteran-fungus association is the most economically serious pest complex in Central Valley orchards, and evidence indicates that this relationship is mutualistic. We assessed preference and performance of navel orangeworm larvae associated with A. flavus in behavioral bioassays in which neonates were allowed to orient within arenas to media with or without fungal tissue, and performance bioassays in which larvae were reared with and without A. flavus on potato dextrose agar (PDA) and a semidefined almond PDA diet to evaluate effects on development and pupal weight. Navel orangeworm larvae were attracted to A. flavus and developed faster in its presence, indicating a nutritional benefit to the caterpillars. Larvae reached pupation ∼33% faster on diet containing A. flavus, and pupal weights were ∼18% higher for males and ∼13% higher for females on this diet. Our findings indicate that A. flavus plays an important role in larval orientation and development on infected hosts. The preference-performance relationship between navel orangeworms and Aspergillus flavus is consistent with a facultative mutualism that has broad implications for pest management efforts and basic understanding of Lepidoptera-plant interactions.

  11. Effect of dietary intervention on the performance and biochemical indices of broilers challenged with Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    S. A. Bolu,

    2011-05-01

    Full Text Available A study was conducted to determine the effects of dietary interventions of vitamins A, C, methionine and lysine singly and their combination on broilers challenged with Aspergillus flavus. The interventions were Vitamins A and C (A+C, methionine and lysine (METH+LYS and their combination (A+C+METH+LYS. The experiment which was conducted for 8 weeks employed a completely randomized design. Feed intake, weight gain, nutrient retention and feed conversion efficiency were significantly influenced (P<0.05 by dietary supplementation of the Aspergillus challenged birds. Highest feed intake (42.81 g/bird/day was observe for Aspergillus challenged birds supplemented with A+C+METH+LYS which compared favourably with the positive control birds (42.48 g/bird/day. The lowest feed intake was observed for the negative control birds (Aspergillus challenged without dietary intervention. Weight gain was highest for the positive control bird (20.14 g/bird/day. This value was similar to the value obtained for Aspergillus challenged birds supplemented with A+C+METH+LYS. Lowest weight gain was observed in the negative control birds (12.44 g/bird/day. These birds also recorded significantly (P<0.05 lowest feed conversion efficiency (3.09. Haematological and serum indices showed no significant differences, however, higher lymphocytes values were observed in challenged birds with dietary intervention. As a general immune modulator, vitamins A and C with lysine and methionine may be an attractive alternative to the on-farm use of vaccines in poultry in the management of aspergillosis.

  12. Susceptibility breakpoints for amphotericin B and Aspergillus species in an in vitro pharmacokinetic-pharmacodynamic model simulating free-drug concentrations in human serum

    NARCIS (Netherlands)

    Elefanti, A.; Mouton, J.W.; Verweij, P.E.; Zerva, L.; Meletiadis, J.

    2014-01-01

    Although conventional amphotericin B was for many years the drug of choice and remains an important agent against invasive aspergillosis, reliable susceptibility breakpoints are lacking. Three clinical Aspergillus isolates (Aspergillus fumigatus, Aspergillus flavus, and Aspergillus terreus) were tes

  13. The inhibitory effects of Curcuma longa L. essential oil and curcumin on Aspergillus flavus link growth and morphology.

    Science.gov (United States)

    Dias Ferreira, Flávio; Mossini, Simone Aparecida Galerani; Dias Ferreira, Francine Maery; Arrotéia, Carla Cristina; da Costa, Christiane Luciana; Nakamura, Celso Vataru; Machinski, Miguel

    2013-01-01

    The essential oil from Curcuma longa L. was analysed by GC/MS. The major components of the oil were ar-turmerone (33.2%), α -turmerone (23.5%) and β -turmerone (22.7%). The antifungal activities of the oil were studied with regard to Aspergillus flavus growth inhibition and altered morphology, as preliminary studies indicated that the essential oil from C. longa inhibited Aspergillus flavus Link aflatoxin production. The concentration of essential oil in the culture media ranged from 0.01% to 5.0% v/v, and the concentration of curcumin was 0.01-0.5% v/v. The effects on sporulation, spore viability, and fungal morphology were determined. The essential oil exhibited stronger antifungal activity than curcumin on A. flavus. The essential oil reduced the fungal growth in a concentration-dependent manner. A. flavus growth rate was reduced by C. longa essential oil at 0.10%, and this inhibition effect was more efficient in concentrations above 0.50%. Germination and sporulation were 100% inhibited in 0.5% oil. Scanning electron microscopy (SEM) of A. flavus exposed to oil showed damage to hyphae membranes and conidiophores. Because the fungus is a plant pathogen and aflatoxin producer, C. longa essential oil may be used in the management of host plants.

  14. The Inhibitory Effects of Curcuma longa L. Essential Oil and Curcumin on Aspergillus flavus Link Growth and Morphology

    Directory of Open Access Journals (Sweden)

    Flávio Dias Ferreira

    2013-01-01

    Full Text Available The essential oil from Curcuma longa L. was analysed by GC/MS. The major components of the oil were ar-turmerone (33.2%, α-turmerone (23.5% and β-turmerone (22.7%. The antifungal activities of the oil were studied with regard to Aspergillus flavus growth inhibition and altered morphology, as preliminary studies indicated that the essential oil from C. longa inhibited Aspergillus flavus Link aflatoxin production. The concentration of essential oil in the culture media ranged from 0.01% to 5.0% v/v, and the concentration of curcumin was 0.01–0.5% v/v. The effects on sporulation, spore viability, and fungal morphology were determined. The essential oil exhibited stronger antifungal activity than curcumin on A. flavus. The essential oil reduced the fungal growth in a concentration-dependent manner. A. flavus growth rate was reduced by C. longa essential oil at 0.10%, and this inhibition effect was more efficient in concentrations above 0.50%. Germination and sporulation were 100% inhibited in 0.5% oil. Scanning electron microscopy (SEM of A. flavus exposed to oil showed damage to hyphae membranes and conidiophores. Because the fungus is a plant pathogen and aflatoxin producer, C. longa essential oil may be used in the management of host plants.

  15. Biosynthesis of fat in surface culture of a local strain of Aspergillus flavus.

    Science.gov (United States)

    Selim, M S; Attah, N K

    1979-01-01

    An Aspergillus flavus strain isolated from Egyptian soil produced fat in appreciable amounts. General evidence for the operation of the tricarboxylic acid cycle in this organism has been ascertained by the detection of citric, malic and fumaric acids in the metabolized culture solution. Maximum fat yield was attained after seven days of incubation. The lower intial pH value of the media favoured the fat obtained from the felts and raised its acid value. When the felts were sterilized in their acidic metabolism solutions increased the acid values of the fats over those of fats extracted from felts sterilized in distilled water. The felts autoclaved for the longest time produced the highest yields of fat with the highest free acidity. The employment of calcium carbonate in the nutrient solutions raised appreciably the acid values of the fats and suppressed the other metabolic activities.

  16. Control of Aspergillus flavus in maize with plant essential oils and their components.

    Science.gov (United States)

    Montes-Belmont, R; Carvajal, M

    1998-05-01

    The effects of 11 plant essential oils for maize kernel protection against Aspergillus flavus were studied. Tests were conducted to determine optimal levels of dosages for maize protection, effects of combinations of essential oils, and residual effects and toxicity of essential oils to maize plants. Principal constituents of eight essential oils were tested for ability to protect maize kernels. Essential oils of Cinnamomum zeylanicum (cinnamon), Mentha piperita (peppermint), Ocimum basilicum (basil), Origanum vulgare (origanum), Teloxys ambrosioides (the flavoring herb epazote), Syzygium aromaticum (clove), and Thymus vulgaris (thyme) caused a total inhibition of fungal development on maize kernels. Thymol and o-methoxycinnamaldehyde significantly reduced maize grain contamination. The optimal dosage for protection of maize varied from 3 to 8%. Combinations of C. zeylanicum with the remaining oils gave efficient control. A residual effect of C. zeylanicum was detected after 4 weeks of kernel treatment. No phytotoxic effect on germination and corn growth was detected with any of these oils.

  17. Optimization of L-malic acid production by Aspergillus flavus in a stirred fermentor.

    Science.gov (United States)

    Battat, E; Peleg, Y; Bercovitz, A; Rokem, J S; Goldberg, I

    1991-05-01

    Effects of various nutritional and environmental factors on the accumulation of organic acids (mainly L-malic acid) by the filamentous fungus Aspergillus flavus were studied in a 16-L stirred fermentor. Improvement of the molar yield (moles acid produced per moles glucose consumed) of L-malic acid was obtained mainly by increasing the agitation rate (to 350 rpm) and the Fe(z+) ion concentration (to 12 mg/L) and by lowering the nitrogen (to 271 mg/L) and phosphate concentrations (to 1.5 mM) in the medium. These changes resulted in molar yields for L-malic acid and total C(4) acids (L-malic, succinic, and fumaric acids) of 128 and 155%, respectively. The high molar yields obtained (above 100%) are additional evidence for the operation of part of the reductive branch of the tricarboxylic acid cycle in L-malic acid accumulation by A. flavus. The fermentation conditions developed using the above mentioned factors and 9% CaCO(3) in the medium resulted in a high concentration (113 g/L L-malic acid from 120 g/L glucose utilized) and a high overall productivity (0.59 g/L h) of L-malic acid. These changes in acid accumulation coincide with increases in the activities of NAD(+)-malate dehydrogenase, fumarase, and citrate synthase.

  18. Inactivation of Aspergillus flavus spores in a sealed package by cold plasma streamers

    Science.gov (United States)

    Sohbatzadeh, F.; Mirzanejhad, S.; Shokri, H.; Nikpour, M.

    2016-06-01

    The main objective of this study is to investigate the inactivation efficacy of cold streamers in a sealed package on pathogenic fungi Aspergillus flavus ( A. flavus) spores that artificially contaminated pistachio surface. To produce penetrating cold streamers, electric power supply was adapted to deposit adequate power into the package. The plasma streamers were generated by an alternating high voltage with carrier frequency of 12.5 kHz which was suppressed by a modulated pulsed signal at frequency of 110 Hz. The plasma exposition time was varied from 8 to 18 min to show the effect of the plasma treatment on fungal clearance while the electrode and sample remained at room temperature. This proved a positive effect of the cold streamers treatment on fungal clearance. Benefits of deactivation of fungal spores by streamers inside the package include no heating, short treatment time and adaptability to existing processes. Given its ability to ensure the safety and longevity of food products, this technology has great potential for utilization in food packaging and processing industry. In this study, moisture and pH changes of pistachio samples after plasma streamers treatment were also investigated.

  19. Aspergillus flavus infection induces transcriptional and physical changes in developing maize kernels

    Directory of Open Access Journals (Sweden)

    Andrea L Dolezal

    2014-07-01

    Full Text Available Maize kernels are susceptible to infection by the opportunistic pathogen Aspergillus flavus. Infection results in reduction of grain quality and contamination of kernels with the highly carcinogenic mycotoxin, aflatoxin. To understanding host response to infection by the fungus, transcription of approximately 9,000 maize genes were monitored during the host-pathogen interaction with a custom designed Affymetrix GeneChip® DNA array. More than 1,000 maize genes were found differentially expressed at a fold change of 2 or greater. This included the up regulation of defense related genes and signaling pathways. Transcriptional changes also were observed in primary metabolism genes. Starch biosynthetic genes were down regulated during infection, while genes encoding maize hydrolytic enzymes, presumably involved in the degradation of host reserves, were up regulated. These data indicate that infection of the maize kernel by A. flavus induced metabolic changes in the kernel, including the production of a defense response, as well as a disruption in kernel development.

  20. The Metabolic Responses of Aspergillus flavus to N-Acetylcysteine, Ascorbate, and H2O2

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Aflatoxin, the secondary metabolite of Aspergillus flavus and A. Parasiticus, is the most toxic product in nature. In this study, N-acetylcysteine (NAC), ascorbate, and H2O2 were used to ascertain their effects on fungal metabolic esponse of A. Flavus. The results demonstrated that NAC did not affect fungal growth, but inhibited the aflatoxin B1 production, with the concomitant sporulation reduction. NAC increased the ratio of reduced glutathione (GSH) and oxidized glutathione (GSSG), hut decreased the activity of glutathione reductase (GR). Ascorbate had similar effect on fungal growth, sporulation,and GR activity, but GSH/GSSG and total glutathione (tGSH, including GSH and GSSG) were significantly increased. H2O2 at high concentration (5 mM) inhibited fungal growth, but the aflatoxin production was increased. At the same time, it reduced GR activity and enhanced tGSH. Though reductive agents had different effects on GSH metabolism, reductive conditions inhibited aflatoxin production and sporulation without any effect on fungal growth. The results in this report confirmed that the relationship between oxidative stress and aflatoxin production is theoretically important in controlling aflatoxin contamination.

  1. INHIBITION OF AFLATOXIN PRODUTION BY ASPERGILLUS FLAVUS USING LOW LEVEL Y - IRRADIATION

    Directory of Open Access Journals (Sweden)

    F

    1981-05-01

    Full Text Available Effects o f s e l ected l ow l evel doses of y - Rad iation (100-400 K rad on t he abi l ity o f toxin strain o f Asperg i l l us flavus t o survive and pr oduce a f latox in in c ul t ure med ium and p is tachio nuts hav e been s tudied . A reduction of 60 per c e nt in growth and spore production by Asperg i l l us flavus in c u l ture me di um was observed after treatment wi th 100 K rad of y - Radiation ."nIn spore inoculated pistachio nuts , 100 K rad o f y Radi a tion reduced the a f la toxin B l and G l nroduction by 75% aft er e i ght week s s t orage per iod . The afla toxin prod~ ction ability by Aspergillus f lavus on pistachio nuts was affectively eliminated by t he treatment o f spore inoculated pist achio nuts wi th 200 K rad of y-Radiation , although very l itt le growth coul d be detected after eight weeks ' storage of 40 0 K rad y-irradiated pistachio nuts.  

  2. Survey of Thymus migricus essential oil on aflatoxin inhibition in Aspergillus flavus.

    Science.gov (United States)

    Alizadeh, Alireza; Sharaifi, Rohollah; Javan-Nikkhah, Mohammad; Sedaghat, Narges

    2010-01-01

    Essential oil components as result of non host disease resistance of plants have high capability to introduce as alternative of chemical pesticides. Thymus migricus essential oil was selected to investigation of its antifungal activity on survival and growth of Aspergillus flavus. For obtain essential oil first Leaves and flowers of Th. migricus collected then dried. The Essential oil was extracted by means of hydro-distillation and afterwards GC-MS analysis was performed to identify their components. The main constituents that resulted were Thymol (44.9%), Geraniol (10.8%), gamma-Terpinene (10.3%), Citronellol (8.5%) and p-Cymene (7.2%). EC50 and MIC (Minimum Inhibitory Concentration) of Th. migricus oil against A. flavus was 324.42 microl/l and 451.62 microl/l, respectively. Whereas EC50 and MIC for chemical thiabendazol was 650 microl/l and 1635 microl/l, respectively. The EC50 and MIC concentrations of Th. migricus oil in antifungal activity examination were used in aflatoxin inhibition test. Result of HPTLC measurement showed that both of concentrations inhibit aflatoxin production completely compares to control with 7.63 ppm aflatoxin production. In other word, Th. migricus oil can suppress aflatoxin production in concentrations lower than EC50 for mycelium growth.

  3. Enterococcus raffinosus sinusitis post-Aspergillus flavus paranasal infection, in a patient with myelodysplastic syndrome: report of a case and concise review of pertinent literature.

    Science.gov (United States)

    Savini, Vincenzo; Catavitello, Chiara; Favaro, Marco; Masciarelli, Gioviana; Astolfi, Daniela; Balbinot, Andrea; Bianco, Azaira; Mauti, Alessandro; Dianetti, Janet; Fontana, Carla; D'Amario, Claudio; D'Antonio, Domenico

    2010-03-01

    A case of Enterococcus raffinosus nosocomial sinusitis which appeared to complicate a previous Aspergillus flavus paranasal infection is presented. This uncommon enterococcal species is rarely responsible for human diseases, and has never previously been associated with sinusitis.

  4. Studies on the control of fungal contamination and aflatoxin production by Aspergillus flavus Link in a cereal grain by comb. treatment of heat and irradiation.

    NARCIS (Netherlands)

    Odamtten, G.T.

    1986-01-01

    Traditional storage of maize in tropical countries such as Ghana results in the rapid development of numerous fungi, including potential mycotoxin producers such as Aspergillus flavus (aflatoxins), A. ochraceus (ochratoxins, penicillic acid), Fusarium moniliforme (moniliformin), Paecilomyces varioti

  5. Environmental distribution and genetic diversity of vegetative compatibility groups determine biocontrol strategies to mitigate aflatoxin contamination of maize by Aspergillus flavus

    Science.gov (United States)

    Maize infected by aflatoxin-producing Aspergillus flavus may become contaminated with aflatoxins and as a result, threaten human health, food security, and farmers’ income in developing countries where maize is a staple. Environmental distribution and genetic diversity of A. flavus can influence the...

  6. rtfA, a putative RNA-Pol II transcription elongation factor, is necessary for normal morphological and chemical development in Aspergillus flavus

    Science.gov (United States)

    The filamentous fungus Aspergillus flavus is an agriculturally important opportunistic plant pathogen that produces potent carcinogenic compounds called aflatoxins. We identified the A. flavus rtfA gene, the ortholog of rtf1 in S. cerevisiae and rtfA in A. nidulans. Interestingly, rtfA has multiple ...

  7. Aspergillus flavus genetic diversity of corn fields treated with non-toxigenic strain afla-guard in the southern U.S

    Science.gov (United States)

    Aspergillus flavus genetic diversity of corn fields treated with the non-toxigenic strain Afla-Guard (NRRL 21882) was determined for 384 A. flavus isolates from 14 locations within 6 states in the southern U.S. ELISA test has determined low levels of toxigenic strains (only 91 positive). Nearly hal...

  8. APPLICATION OF ULTRASOUND TO CONTROL OF ASPERGILLUS FLAVUS IN COSMETICS = APLICAÇÃO DE ULTRASSOM NO CONTROLE DE ASPERGILLUS FLAVUS EM COSMÉTICOS

    Directory of Open Access Journals (Sweden)

    Kassima Timoni Góes-Campanha

    2011-01-01

    Full Text Available The effect of ultrasound on organic compounds in living tissue and are often related to the cavitation’ phenomenon, a term used to describe the formation of cavities or bubbles in a liquid medium containing varying amounts of gas or vapor that are dissolved in the middle. In medicine it is suggested that ultrasound of high intensity is able to cause some reduction in certain infectious agents and microbiology, mechanisms of inactivation of cells appear to be associated with cavitation. Due to the high power of fungal contamination of cosmetics, it is important to develop new techniques to preserve it to rapid fungi deterioration and subsequent consumer health hazard. On the present work it was probed the efficiency of ultrasound in decreasing the growth of Aspergillus flavus in cosmetic.Thus contaminated samples with the above mentioned fungus, were irradiated at constant temperature (25 oC and power (600W/cm2, for a variety of time exposure: 0 (control, 12, 16, and 20 minutes. The ultrasound generator model VCX- 600 was utilized.It was possible to show that the use of ultrasound is efficient in decreasing the growth of microrganisms and thus preserve cosmetic which went from 35,000 CFU/mL to 50 CFU/mL. Ultrasound is a excellent biocide agent in preparation and preservation of emulsion-type cosmetics. Twenty minutes of continuous irradiation yelded an almost complete depletion of microrganisms. = Devido ao alto poder de contaminação dos cosméticos por fungos, é de grande importância o desenvolvimento de novas técnicas para preservação desses, uma vez que a contaminação microbiológica pode, além de causar a deterioração do produto, apresentar danos à saúde do consumidor. Procurou-se, então, nesse trabalho, determinar a eficácia do ultrassom na diminuição do crescimento do fungo Aspergillus flavus em cosméticos. Para isso, amostras de cosméticos contaminados com o fungo foram irradiadas em equipamento gerador de ultrassom

  9. Polymerase chain reaction-mediated characterization of molds belonging to the Aspergillus flavus group and detection of Aspergillus parasiticus in peanut kernels by a multiplex polymerase chain reaction.

    Science.gov (United States)

    Chen, Ruey-Shyang; Tsay, Jwu-Guh; Huang, Yu-Fen; Chiou, Robin Y Y

    2002-05-01

    The Aspergillus flavus group covers species of A. flavus and Aspergillus parasiticus as aflatoxin producers and Aspergillus oryzae and Aspergillus sojae as koji molds. Genetic similarity among these species is high, and aflatoxin production of a culture may be affected by cultivation conditions and substrate composition. Therefore, a polymerase chain reaction (PCR)-mediated method of detecting the aflatoxin-synthesizing genes to indicate the degree of risk a genotype has of being a phenotypic producer was demonstrated. In this study, 19 strains of the A. flavus group, including A. flavus, A. parasiticus, A. oryzae, A. sojae, and one Aspergillus niger, were subjected to PCR testing in an attempt to detect four genes, encoding for norsolorinic acid reductase (nor-1), versicolorin A dehydrogenase (ver-1), sterigmatocystin O-methyltransferase (omt-1), and a regulatory protein (apa-2), involved in aflatoxin biosynthesis. Concurrently, the strains were cultivated in yeast-malt (YM) broth for aflatoxin detection. Fifteen strains were shown to possess the four target DNA fragments. With regard to aflatoxigenicity, all seven aflatoxigenic strains possessed the four DNA fragments, and five strains bearing less than the four DNA fragments did not produce aflatoxin. When peanut kernels were artificially contaminated with A. parasiticus and A. niger for 7 days, the contaminant DNA was extractable from a piece of cotyledon (ca. 100 mg), and when subjected to multiplex PCR testing using the four pairs of primers coding for the above genes, they were successfully detected. The target DNA fragments were detected in the kernels infected with A. parasiticus, and none was detected in the sound (uninoculated) kernels or in the kernels infected with A. niger.

  10. Effect of sexual recombination on population diversity in aflatoxin production by Aspergillus flavus and evidence for cryptic heterokaryosis.

    Science.gov (United States)

    Olarte, Rodrigo A; Horn, Bruce W; Dorner, Joe W; Monacell, James T; Singh, Rakhi; Stone, Eric A; Carbone, Ignazio

    2012-03-01

    Aspergillus flavus is the major producer of carcinogenic aflatoxins (AFs) in crops worldwide. Natural populations of A. flavus show tremendous variation in AF production, some of which can be attributed to environmental conditions, differential regulation of the AF biosynthetic pathway and deletions or loss-of-function mutations in the AF gene cluster. Understanding the evolutionary processes that generate genetic diversity in A. flavus may also explain quantitative differences in aflatoxigenicity. Several population studies using multilocus genealogical approaches provide indirect evidence of recombination in the genome and specifically in the AF gene cluster. More recently, A. flavus has been shown to be functionally heterothallic and capable of sexual reproduction in laboratory crosses. In the present study, we characterize the progeny from nine A. flavus crosses using toxin phenotype assays, DNA sequence-based markers and array comparative genome hybridization. We show high AF heritability linked to genetic variation in the AF gene cluster, as well as recombination through the independent assortment of chromosomes and through crossing over within the AF cluster that coincides with inferred recombination blocks and hotspots in natural populations. Moreover, the vertical transmission of cryptic alleles indicates that while an A. flavus deletion strain is predominantly homokaryotic, it may harbour AF cluster genes at a low copy number. Results from experimental matings indicate that sexual recombination is driving genetic and functional hyperdiversity in A. flavus. The results of this study have significant implications for managing AF contamination of crops and for improving biocontrol strategies using nonaflatoxigenic strains of A. flavus.

  11. Biosynthesis of extracellular and intracellular gold nanoparticles by Aspergillus fumigatus and A. flavus.

    Science.gov (United States)

    Gupta, Saurabh; Bector, Shruti

    2013-05-01

    Green chemistry is a boon for the development of safe, stable and ecofriendly nanostructures using biological tools. The present study was carried out to explore the potential of selected fungal strains for biosynthesis of intra- and extracellular gold nanostructures. Out of the seven cultures, two fungal strains (SBS-3 and SBS-7) were selected on the basis of development of dark pink colour in cell free supernatant and fungal beads, respectively indicative of extra- and intracellular gold nanoparticles production. Both biomass associated and cell free gold nanoparticles were characterized using X-ray diffractogram (XRD) analysis and transmission electron microscopy (TEM). XRD analysis confirmed crystalline, face-centered cubic lattice of metallic gold nanoparticles along with average crystallite size. A marginal difference in average crystallite size of extracellular (17.76 nm) and intracellular (26 and 22 nm) Au-nanostructures was observed using Scherrer equation. In TEM, a variety of shapes (triangles, spherical, hexagonal) were observed in both extra- and intracellular nanoparticles. 18S rRNA gene sequence analysis by multiple sequence alignment (BLAST) indicated 99 % homology of SBS-3 to Aspergillus fumigatus with 99 % alignment coverage and 98 % homology of SBS-7 to Aspergillus flavus with 98 % alignment coverage respectively. Native-PAGE and activity staining further confirmed enzyme linked synthesis of gold nanoparticles.

  12. Assessment of the antifungal activity of Spirulina platensis phenolic extract against Aspergillus flavus Avaliação da atividade antifúngica de extrato fenólico de Spirulina platensis contra Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Michele Moraes de Souza

    2011-12-01

    Full Text Available The production of safe food has stimulated the search for natural substances that possess antifungal activity. The indirect methods of estimating fungal biomass are based on the measurement of glucosamine, ergosterol and protein - typical compounds produced during the development of biomass. The aim of the study was to assess the effect of the phenolic extract from Spirulina platensis on the production of structural compounds in Aspergillus flavus, in order to identify its action on fungal inhibition. The Spirulina platensis methanolic extracts presented 1.15 mg phenolic compound/g Spirulina platensis, which showed an antifungal effect against Aspergillus flavus, inhibiting the glucosamine production up to 56%. Therefore, it may be employed as natural defense when food protection is necessary.A produção de alimentos seguros tem estimulado a busca por substâncias naturais que possuem atividade antifúngica. Os métodos indiretos de estimativa de biomassa fúngica são baseados na medição de glucosamina, ergosterol e proteína - compostos típicos produzidos durante o desenvolvimento da biomassa. Neste estudo, objetivou-se avaliar o efeito do extrato fenólico de Spirulina platensis na produção de componentes estruturais em Aspergillus flavus, a fim de identificar seu mecanismo de ação dos fenóis na inibição fúngica. O extrato metanólico de Spirulina platensis apresentou 1,15 mg de compostos fenólicos/g Spirulina platensis, apresentando um efeito antifúngico contra Aspergillus flavus, inibindo a produção de glucosamina em até 56%. Portanto, pode ser empregado como antifúngico natural quando for necessária a proteção de alimentos.

  13. Comparison of Expression of Secondary Metabolite Biosynthesis Cluster Genes in Aspergillus flavus, A. parasiticus, and A. oryzae

    Directory of Open Access Journals (Sweden)

    Kenneth C. Ehrlich

    2014-06-01

    Full Text Available Fifty six secondary metabolite biosynthesis gene clusters are predicted to be in the Aspergillus flavus genome. In spite of this, the biosyntheses of only seven metabolites, including the aflatoxins, kojic acid, cyclopiazonic acid and aflatrem, have been assigned to a particular gene cluster. We used RNA-seq to compare expression of secondary metabolite genes in gene clusters for the closely related fungi A. parasiticus, A. oryzae, and A. flavus S and L sclerotial morphotypes. The data help to refine the identification of probable functional gene clusters within these species. Our results suggest that A. flavus, a prevalent contaminant of maize, cottonseed, peanuts and tree nuts, is capable of producing metabolites which, besides aflatoxin, could be an underappreciated contributor to its toxicity.

  14. Comparison of expression of secondary metabolite biosynthesis cluster genes in Aspergillus flavus, A. parasiticus, and A. oryzae.

    Science.gov (United States)

    Ehrlich, Kenneth C; Mack, Brian M

    2014-06-23

    Fifty six secondary metabolite biosynthesis gene clusters are predicted to be in the Aspergillus flavus genome. In spite of this, the biosyntheses of only seven metabolites, including the aflatoxins, kojic acid, cyclopiazonic acid and aflatrem, have been assigned to a particular gene cluster. We used RNA-seq to compare expression of secondary metabolite genes in gene clusters for the closely related fungi A. parasiticus, A. oryzae, and A. flavus S and L sclerotial morphotypes. The data help to refine the identification of probable functional gene clusters within these species. Our results suggest that A. flavus, a prevalent contaminant of maize, cottonseed, peanuts and tree nuts, is capable of producing metabolites which, besides aflatoxin, could be an underappreciated contributor to its toxicity.

  15. POTENTIAL OF ESSENTIAL OILS FOR PROTECTION OF GRAINS CONTAMINATED BY AFLATOXIN PRODUCED BY Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Renata Hadad Esper

    2014-06-01

    Full Text Available Aflatoxin B1 (AFB1 is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Inhibitory effects of essential oils of Ageratum conyzoides (mentrasto and Origanum vulgare (oregano on the mycelial growth and aflatoxin B1 production by Aspergillus flavus have been studied previously in culture medium. The aim of this study was to evaluate aflatoxin B1 production by Aspergillus flavus in real food systems (corn and soybean treated with Ageratum conyzoides (mentrasto and Origanum vulgare (oregano essential oils. Samples with 60 g of the grains were treated with different volumes of essential oils, 200, 100, 50, and 10 μL for oregano and 50, 30, 15, and 10μL for mentrasto. Fungal growth was evaluated by disk diffusion method. Aflatoxin B1 production was evaluated inoculating suspensions of A. flavus containing 1.3×105 spores/ mL in 60 g of grains (corn and soybeans after adjusting the water activity at 0.94. Aflatoxin was quantified by photodensitometry. Fungal growth and aflatoxin production were inhibited by essential oils, but the mentrasto oil was more effective in soybeans than that of oregano. On the other hand, in corn samples, the oregano essential oil was more effective than that of mentrasto. Chemical compositions of the essential oils were also investigated. The GC/MS oils analysis showed that the main component of mentrasto essential oil is precocene I and of the main component of oregano essential oil is 4-terpineol. The results indicate that both essential oils can become an alternative for the control of aflatoxins in corn and soybeans.

  16. Identification of Aspergillus (A. flavus and A. niger) Allergens and Heterogeneity of Allergic Patients' IgE Response.

    Science.gov (United States)

    Vermani, Maansi; Vijayan, Vannan Kandi; Agarwal, Mahendra Kumar

    2015-08-01

    Aspergillus species (A. flavus and A. niger) are important sources of inhalant allergens. Current diagnostic modalities employ crude Aspergillus extracts which only indicate the source to which the patient has been sensitized, without identifying the number and type of allergens in crude extracts. We report a study on the identification of major and minor allergens of the two common airborne Aspergillus species and heterogeneity of patients' IgE response to them. Skin prick tests were performed on 300 patients of bronchial asthma and/or allergic rhinitis and 20 healthy volunteers. Allergen specific IgE in patients' sera was estimated by enzyme allergosorbent test (EAST). Immunoblots were performed to identify major/minor allergens of Aspergillus extracts and to study heterogeneity of patients'IgE response to them. Positive cutaneous responses were observed in 17% and 14.7% of patients with A. flavus and A. niger extracts, respectively. Corresponding EAST positivity was 69.2% and 68.7%. In immunoblots, 5 allergenic proteins were identified in A. niger extract, major allergens being 49, 55.4 and 81.5 kDa. Twelve proteins bound patients' IgE in A. flavus extract, three being major allergens (13.3, 34 and 37 kDa). The position and slopes of EAST binding and inhibition curves obtained with individual sera varied from patient to patient. The number and molecular weight of IgE-binding proteins in both the Aspergillus extracts varied among patients. These results gave evidence of heterogeneity of patients' IgE response to major/minor Aspergillus allergens. This approach will be helpful to identify disease eliciting molecules in the individual patients (component resolved diagnosis) and may improve allergen-specific immunotherapy.

  17. Resistance to Aspergillus flavus in maize and peanut:Molecular biology, breeding, environmental stress, and future perspectives

    Institute of Scientific and Technical Information of China (English)

    Jake C. Fountain; Baozhu Guo; Pawan Khera; Liming Yang; Spurthi N. Nayak; Brian T. Scully; Robert D. Lee; Zhi-Yuan Chen; Robert C. Kemerait; Rajeev K. Varshney

    2015-01-01

    The colonization of maize (Zea mays L.) and peanut (Arachis hypogaea L.) by the fungal pathogen Aspergillus flavus results in the contamination of kernels with carcinogenic mycotoxins known as aflatoxins leading to economic losses and potential health threats to humans. The regulation of aflatoxin biosynthesis in various Aspergillus spp. has been extensively studied, and has been shown to be related to oxidative stress responses. Given that environmental stresses such as drought and heat stress result in the accumulation of reactive oxygen species (ROS) within host plant tissues, host-derived ROS may play an important role in cross-kingdom communication between host plants and A. flavus. Recent technological advances in plant breeding have provided the tools necessary to study and apply knowledge derived from metabolomic, proteomic, and transcriptomic studies in the context of productive breeding populations. Here, we review the current understanding of the potential roles of environmental stress, ROS, and aflatoxin in the interaction between A. flavus and its host plants, and the current status in molecular breeding and marker discovery for resistance to A. flavus colonization and aflatoxin contamination in maize and peanut. We will also propose future directions and a working model for continuing research efforts linking environmental stress tolerance and aflatoxin contamination resistance in maize and peanut.

  18. Resistance to Aspergillus flavus in maize and peanut:Molecular biology, breeding, environmental stress,and future perspectives

    Institute of Scientific and Technical Information of China (English)

    Jake; C.Fountain; Pawan; Khera; Liming; Yang; Spurthi; N.Nayak; Brian; T.Scully; Robert; D.Lee; Zhi-Yuan; Chen; Robert; C.Kemerait; Rajeev; K.Varshney; Baozhu; Guo

    2015-01-01

    The colonization of maize(Zea mays L.) and peanut(Arachis hypogaea L.) by the fungal pathogen Aspergillus flavus results in the contamination of kernels with carcinogenic mycotoxins known as aflatoxins leading to economic losses and potential health threats to humans. The regulation of aflatoxin biosynthesis in various Aspergillus spp. has been extensively studied, and has been shown to be related to oxidative stress responses. Given that environmental stresses such as drought and heat stress result in the accumulation of reactive oxygen species(ROS) within host plant tissues, host-derived ROS may play an important role in cross-kingdom communication between host plants and A. flavus. Recent technological advances in plant breeding have provided the tools necessary to study and apply knowledge derived from metabolomic, proteomic, and transcriptomic studies in the context of productive breeding populations. Here, we review the current understanding of the potential roles of environmental stress, ROS, and aflatoxin in the interaction between A.flavus and its host plants, and the current status in molecular breeding and marker discovery for resistance to A. flavus colonization and aflatoxin contamination in maize and peanut. We will also propose future directions and a working model for continuing research efforts linking environmental stress tolerance and aflatoxin contamination resistance in maize and peanut.

  19. THE EFFECT OF PHYTIC ACID, ZINC AND SOYBEAN EXTRACT ON THE GROWTH AND AFLATOXIN B1 PRODUCTION BY Aspergillus flavus

    OpenAIRE

    Sardjono, Sardjono

    2012-01-01

    It has been reported that aflatoxin contamination in soybean was relatively low, but it was not guaranteed that soybean products is free from aflatoxin contamination. Naturally, soybean containing phytic acid and it bound zinc and protein. Zinc (Zn) is an important mineral for aflatoxin biosynthesis. Previous research indicated that some soybean products such as kecap was contaminated by aflatoxin. It might be Aspergillus flavus involved during kecap fermentation and it produced phytase for p...

  20. Aplicação de biofungicidas no controle do fungo Aspergillus flavus L. em amendoim (Arachis hypogaea)

    OpenAIRE

    Gorayeb, Teresa Cristina Castilho [UNESP

    2015-01-01

    This study aims to evaluate the technical feasibility of the application of biofungicides extracted from plants in the processing of peanut (Arachis hypogaea L.), with the objective of reducing infestation by fungus Aspergillus flavus L., and consequent contamination by aflatoxin, a chemical hazard. Firstly, we studied the fungal and aflatoxin contamination for the 2011/12, 2012/13, and 2013/14 crops, during the Runner IAC 886 peanut pods' harvesting and post-harvesting stages, in the region ...

  1. Septic arthritis of the temporomandibular joint caused by Aspergillus flavus infection as a complication of otitis externa.

    Science.gov (United States)

    Varghese, Lalee; Chacko, Rabin; Varghese, George M; Job, Anand

    2015-03-01

    Septic arthritis of the temporomandibular joint (TMJ) is a very rare complication of otitis externa that can lead to ankylosis and destruction of the joint. We report the case of a 74-year-old man who developed aspergillosis of the TMJ following otitis externa. To the best of our knowledge, this is the first reported case of TMJ septic arthritis secondary to otitis externa caused by Aspergillus flavus. The patient was successfully managed with condylectomy, debridement, and drug treatment with voriconazole.

  2. Tissue-specific gene expression in maize seeds during colonization by Aspergillus flavus and Fusarium verticillioides.

    Science.gov (United States)

    Shu, Xiaomei; Livingston, David P; Franks, Robert G; Boston, Rebecca S; Woloshuk, Charles P; Payne, Gary A

    2015-09-01

    Aspergillus flavus and Fusarium verticillioides are fungal pathogens that colonize maize kernels and produce the harmful mycotoxins aflatoxin and fumonisin, respectively. Management practice based on potential host resistance to reduce contamination by these mycotoxins has proven difficult, resulting in the need for a better understanding of the infection process by these fungi and the response of maize seeds to infection. In this study, we followed the colonization of seeds by histological methods and the transcriptional changes of two maize defence-related genes in specific seed tissues by RNA in situ hybridization. Maize kernels were inoculated with either A. flavus or F. verticillioides 21-22 days after pollination, and harvested at 4, 12, 24, 48, 72, 96 and 120 h post-inoculation. The fungi colonized all tissues of maize seed, but differed in their interactions with aleurone and germ tissues. RNA in situ hybridization showed the induction of the maize pathogenesis-related protein, maize seed (PRms) gene in the aleurone and scutellum on infection by either fungus. Transcripts of the maize sucrose synthase-encoding gene, shrunken-1 (Sh1), were observed in the embryo of non-infected kernels, but were induced on infection by each fungus in the aleurone and scutellum. By comparing histological and RNA in situ hybridization results from adjacent serial sections, we found that the transcripts of these two genes accumulated in tissue prior to the arrival of the advancing pathogens in the seeds. A knowledge of the patterns of colonization and tissue-specific gene expression in response to these fungi will be helpful in the development of resistance.

  3. Pharmacodynamics of voriconazole against wild-type and azole-resistant aspergillus flavus isolates in a nonneutropenic murine model of disseminated aspergillosis

    NARCIS (Netherlands)

    S.M. Rudramurthy; S. Seyedmousavi (Seyedmojtaba); Dhaliwal, M. (Manpreet); A. Chakrabarti; J.F. Meis (Jacques F.); J.W. Mouton (Johan)

    2016-01-01

    textabstractInvasive aspergillosis (IA) due to Aspergillus flavus is associated with high mortality. Although voriconazole (VRC) is widely recommended as the first-line treatment for IA, emergence of azole resistance in Aspergillus spp. is translating to treatment failure. We evaluated the efficacy

  4. Biosynthesis of silver nanoparticles synthesized by Aspergillus flavus and their antioxidant, antimicrobial and cytotoxicity properties

    Indian Academy of Sciences (India)

    Ghassan M Sulaiman; Hiba T Hussien; Maysoon M N M Saleem

    2015-06-01

    In the present study, biosynthesis of silver nanoparticles and its antioxidant, antimicrobial and cytotoxic activities were investigated. Silver nanoparticles were extracellularly synthesized using Aspergillus flavus and the formation of nanoparticles was observed after 72 h of incubation. The results recorded from colour changes, UV–vis spectrum and X-ray diffraction (XRD) support the biosynthesis and characterization of silver nanoparticles. UV–vis spectral analysis showed silver surface plasmon resonance band at 420 nm. X-ray diffraction showed that the particles were crystalline with face-centred cubic structure at 45.05°, 65.45° and 78.65° and the size of the silver nanoparticles was 33.5 nm. The synthesized silver nanoparticles showed potent antimicrobial activity against various pathogens, including bacteria and fungi. Biosynthesized silver nanoparticles exhibited strong antioxidant activity as well as cytotoxicity against HL-60 cells in a dose–response relationship. The powerful bioactivity demonstrated by the synthesized silver nanoparticles leads towards the biomedical use as antioxidant, antibacterial and cytotoxic agents.

  5. Autoxidated linolenic acid inhibits aflatoxin biosynthesis in Aspergillus flavus via oxylipin species.

    Science.gov (United States)

    Yan, Shijuan; Liang, Yating; Zhang, Jindan; Chen, Zhuang; Liu, Chun-Ming

    2015-08-01

    Aflatoxins produced by Aspergillus species are among the most toxic and carcinogenic compounds in nature. Although it has been known for a long time that seeds with high oil content are more susceptible to aflatoxin contamination, the role of fatty acids in aflatoxin biosynthesis remains controversial. Here we demonstrate in A. flavus that both the saturated stearic acid (C18:0) and the polyunsaturated linolenic acid (C18:3) promoted aflatoxin production, while C18:3, but not C18:0, inhibited aflatoxin biosynthesis after exposure to air for several hours. Further experiments showed that autoxidated C18:3 promoted mycelial growth, sporulation, and kojic acid production, but inhibited the expression of genes in the AF biosynthetic gene cluster. Mass spectrometry analyses of autoxidated C18:3 fractions that were able to inhibit aflatoxin biosynthesis led to the identification of multiple oxylipin species. These results may help to clarify the role of fatty acids in aflatoxin biosynthesis, and may explain why controversial results have been obtained for fatty acids in the past.

  6. Black gill disease of Pacific white leg shrimp (Litopenaeus vannamei by Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Naresh Kumar Dewangan

    2015-10-01

    Full Text Available Objective: To study the epidemiology of black gill disease in white leg shrimp which is a major problem being faced by the commercial shrimp farmers who are culturing Litopenaeus vannamei (L. vannamei in India. Methods: The normal and infected shrimps were collected from shrimp pond and the gill was preserved in appropriate preservative for histopathological examination and scanning electron microscope analysis. Pathogenic fungus was isolated from black gill of L. vannamei in potato dextrose agar medium. Morphological study and fungal strain identification were done by using light microscopy and scanning electron microscope. Fungal DNA was amplified by ITS4 and ITS5 primers and gene sequencing was done by Macrogen Inc., Korea. Phylogenetic tree was prepared by using MEGA 6 software. Results: Fungal spores and hyphae were observed both in internal and external gill surface of infected shrimps. Fungal spores were round in shape and mature sporangium was observed. The histopathology study showed clearly that infected gill was damaged by the fungi. Scanning electron microscopic study showed adherence of fungi in infected gill. Internal transcribed spacer gene sequencing revealed that it was caused by Aspergillus flavus. Conclusions: The outcome of the present study would help to know the cause of black gill disease and to understand the effect of pathogenic fungi in shrimp culture. This study will initiate researchers for work in field of treatment or prevention of black gill disease in commercial L. vannamei culture.

  7. Nutritional changes in powdered red pepper upon in vitro infection of Aspergillus flavus

    Science.gov (United States)

    Tripathi, Smita; Mishra, H.N.

    2009-01-01

    Quantitative losses in various biochemical constituents like capsaicin, carotenes, ascorbic acid, polyphenols, mineral matter, sugars (soluble and insoluble), protein and fat were estimated after the successful growth of Aspergillus flavus for 30 days on powdered red pepper. The fungal biomass was measured by ergosterol content and Aflatoxin B1 by HPLC. Amongst the various nutritional constituents evaluated for nutritional losses and changes the highest nutritional loss was reported in total carotenoids (88.55%) followed by total sugars (85.5%). The protein content of the infected sample increased from 18.01% to 23%. The nutritional profile of chilli powder (Capsicum annum var. sannam L.) shows highest share of total soluble sugars (32.89%) and fiber content (21.05%), followed by protein (18.01%) and fat (13.32%) making it an ideal solid- substrate for mould growth. At the end of incubation the fungal biomass was 192. 25 mg / 100 gram powder, total plate count 17.5 X 10 4 CFU/g and Aflatoxin B1 content was 30.06 μg / kg. PMID:24031333

  8. Effect of climate change on Aspergillus flavus and aflatoxin B1 production

    Directory of Open Access Journals (Sweden)

    Angel eMedina

    2014-07-01

    Full Text Available This review considers the available information on the potential impact of key environmental factors and their interactions on the molecular ecology, growth and aflatoxin production by Aspergillus flavus in vitro and in maize grain. The recent studies which have been carried out to examine the impact of water activity x temperature on aflatoxin biosynthesis and phenotypic aflatoxin production are examined. These have shown that there is a direct relationship between the relative expression of key regulatory and structural genes under different environmental conditions which correlate directly with aflatoxin B1 production. A model has been developed to integrate the relative expression of 10 biosynthetic genes in the pathway, growth and aflatoxin B1 (AFB1 production which was validated under elevated temperature and water stress conditions. The effect of interacting conditions of aw x temperature x elevated CO2 (2x and 3x existing levels are detailed for the first time. This suggests that while such interacting environmental conditions have little effect on growth they do have a significant impact on aflatoxin biosynthetic gene expression (structural aflD and regulatory aflR genes and can significantly stimulate the production of AFB1. While the individual factors alone have an impact, it is the combined effect of these three abiotic factors which have an impact on mycotoxin production. This approach provides data which is necessary to help predict the real impacts of climate change on mycotoxigenic fungi.

  9. Molecular Detection of Aflatoxin Producing Strains of Aspergillus Flavus from Peanut (Arachis Hypogaea

    Directory of Open Access Journals (Sweden)

    Adeela Hussain

    2015-02-01

    Full Text Available Aflatoxins are the potential carcinogens produced as secondary metabolites by Aspergillus flavus. They have the ability to contaminate large number of food which ultimately affect the human population. Malt extract agar was selected for the growth of control stains of fungus. The aim of the study was to develop a reliable and quick method for the detection of aflatoxin producing strains in peanuts by using molecular approaches. Total 80 samples of infected peanuts were collected from four different cities of Punjab and checked for their aflatoxin contamination. For aflatoxin detection, three target genes nor1, ver1 and aflR were selected which was involved in the aflatoxin biosynthesis. In all examined cases, 24 out of 80 (30% samples successfully amplified all three genes indicating aflatoxigenic activity. Discrimination between aflatoxigenic and non-aflatoxigenic strains were also determined on the basis of amplification of these three target DNA fragments. In this study, it was also demonstrated that only specific strains were able to produce the aflatoxin contamination in peanuts.

  10. Effect of Zataria multiflora Boiss. essential oil on colony morphology and ultrastructure of Aspergillus flavus.

    Science.gov (United States)

    Gandomi, Hassan; Misaghi, Ali; Basti, Afshin Akhondzadeh; Hamedi, Hassan; Shirvani, Zahra Ramezani

    2011-09-01

    The mode of inhibitory action of Zataria multiflora Boiss. essential oil (EO) on the fungus, Aspergillus flavus, was studied by colony morphology examination, light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The EO at concentrations used in this study suppressed the size of the colony as well as sporulation. SEM of mycelia treated with given concentrations of EO showed morphological alterations ranging from loss of turgidity and uniformity of mycelia at low concentrations of EO to evident destruction of the hyphae at higher concentration of EO. Semi-thin sections of mycelia exposed to different concentrations of EO were analysed by light microscopy and revealed that the major change at level as low as 50 ppm of EO was limited to vacuolisation of cytoplasm resulting in cell swelling, while at higher concentrations, detachment of the cell membrane from the cell wall, deformation of mycelia and shedding the cytoplasm from the cell were the main alterations. These damages were well documented by TEM, which showed that the main sites of action of EO were the plasma membrane and cell wall. In conclusion, morphological and structural changes observed in this study may be one of the mechanisms involved in growth inhibition of the fungi and reducing aflatoxin production.

  11. Sexual Reproduction in Aspergillus flavus Sclerotia: Acquisition of Novel Alleles from Soil Populations and Uniparental Mitochondrial Inheritance.

    Directory of Open Access Journals (Sweden)

    Bruce W Horn

    Full Text Available Aspergillus flavus colonizes agricultural commodities worldwide and contaminates them with carcinogenic aflatoxins. The high genetic diversity of A. flavus populations is largely due to sexual reproduction characterized by the formation of ascospore-bearing ascocarps embedded within sclerotia. A. flavus is heterothallic and laboratory crosses between strains of the opposite mating type produce progeny showing genetic recombination. Sclerotia formed in crops are dispersed onto the soil surface at harvest and are predominantly produced by single strains of one mating type. Less commonly, sclerotia may be fertilized during co-infection of crops with sexually compatible strains. In this study, laboratory and field experiments were performed to examine sexual reproduction in single-strain and fertilized sclerotia following exposure of sclerotia to natural fungal populations in soil. Female and male roles and mitochondrial inheritance in A. flavus were also examined through reciprocal crosses between sclerotia and conidia. Single-strain sclerotia produced ascospores on soil and progeny showed biparental inheritance that included novel alleles originating from fertilization by native soil strains. Sclerotia fertilized in the laboratory and applied to soil before ascocarp formation also produced ascospores with evidence of recombination in progeny, but only known parental alleles were detected. In reciprocal crosses, sclerotia and conidia from both strains functioned as female and male, respectively, indicating A. flavus is hermaphroditic, although the degree of fertility depended upon the parental sources of sclerotia and conidia. All progeny showed maternal inheritance of mitochondria from the sclerotia. Compared to A. flavus populations in crops, soil populations would provide a higher likelihood of exposure of sclerotia to sexually compatible strains and a more diverse source of genetic material for outcrossing.

  12. Sexual Reproduction in Aspergillus flavus Sclerotia: Acquisition of Novel Alleles from Soil Populations and Uniparental Mitochondrial Inheritance.

    Science.gov (United States)

    Horn, Bruce W; Gell, Richard M; Singh, Rakhi; Sorensen, Ronald B; Carbone, Ignazio

    2016-01-01

    Aspergillus flavus colonizes agricultural commodities worldwide and contaminates them with carcinogenic aflatoxins. The high genetic diversity of A. flavus populations is largely due to sexual reproduction characterized by the formation of ascospore-bearing ascocarps embedded within sclerotia. A. flavus is heterothallic and laboratory crosses between strains of the opposite mating type produce progeny showing genetic recombination. Sclerotia formed in crops are dispersed onto the soil surface at harvest and are predominantly produced by single strains of one mating type. Less commonly, sclerotia may be fertilized during co-infection of crops with sexually compatible strains. In this study, laboratory and field experiments were performed to examine sexual reproduction in single-strain and fertilized sclerotia following exposure of sclerotia to natural fungal populations in soil. Female and male roles and mitochondrial inheritance in A. flavus were also examined through reciprocal crosses between sclerotia and conidia. Single-strain sclerotia produced ascospores on soil and progeny showed biparental inheritance that included novel alleles originating from fertilization by native soil strains. Sclerotia fertilized in the laboratory and applied to soil before ascocarp formation also produced ascospores with evidence of recombination in progeny, but only known parental alleles were detected. In reciprocal crosses, sclerotia and conidia from both strains functioned as female and male, respectively, indicating A. flavus is hermaphroditic, although the degree of fertility depended upon the parental sources of sclerotia and conidia. All progeny showed maternal inheritance of mitochondria from the sclerotia. Compared to A. flavus populations in crops, soil populations would provide a higher likelihood of exposure of sclerotia to sexually compatible strains and a more diverse source of genetic material for outcrossing.

  13. Identification of Aspergillus (A flavus and A niger Allergens and Heterogeneity of Allergic Patients’ IgE Response

    Directory of Open Access Journals (Sweden)

    Maansi Vermani

    2015-10-01

    Full Text Available Aspergillus species (A flavus and A niger are important sources of inhalant allergens. Current  diagnostic  modalities  employ  crude  Aspergillus  extracts  which  only  indicate  the source to which the patient has been sensitized, without identifying the number and type of allergens in crude extracts. We report a study on the identification of major and minor allergens of the two common airborne Aspergillus species and heterogeneity of patients’ IgE response to them.Skin prick tests were performed on 300 patients of bronchial asthma and/or allergicrhinitis and 20 healthy volunteers. Allergen specific IgE in patients’ sera was estimated by enzyme allergosorbent test (EAST. Immunoblots were performed to identify major/minor allergens of Aspergillus extracts and to study heterogeneity of patients’ IgE response to them.Positive cutaneous responses were observed in 17% and 14.7% of patients with A flavusand A niger extracts, respectively. Corresponding EAST positivity was 69.2% and 68.7%. In immunoblots, 5 allergenic proteins were identified in A niger extract, major allergens being49, 55.4 and 81.5 kDa. Twelve proteins bound patients’ IgE in A flavus extract, three being major allergens (13.3, 34 and 37 kDa. The position and slopes of EAST binding and inhibition curves obtained with individual sera varied from patient to patient. The number and molecular weight of IgE-binding proteins in both the Aspergillus extracts varied among patients.These results gave evidence of heterogeneity of patients’ IgE response to major/minorAspergillus allergens. This approach will be helpful to identify disease eliciting molecules in the individual patients (component resolved diagnosis and may improve allergen-specific immunotherapy.

  14. Toward elucidation of genetic and functional genetic mechanisms in corn host resistance to Aspergillus flavus infection and aflatoxin contamination

    Directory of Open Access Journals (Sweden)

    Xueyan eShan

    2014-07-01

    Full Text Available Aflatoxins are carcinogenic mycotoxins produced by some species in the Aspergillus genus, such as A. flavus and A. parasiticus. Contamination of aflatoxins in corn profusely happens at pre-harvest stage when heat and drought field conditions favor A. flavus colonization. Commercial corn hybrids are generally susceptible to A. flavus infection. An ideal strategy for preventing aflatoxin contamination is through the enhancement of corn host resistance to Aspergillus infection and aflatoxin production. Constant efforts have been made by corn breeders to develop resistant corn genotypes. Significantly low levels of aflatoxin accumulation have been determined in certain resistant corn inbred lines. A number of reports of quantitative trait loci (QTLs have provided compelling evidence supporting the quantitative trait genetic basis of corn host resistance to aflatoxin accumulation. Important findings have also been obtained from the investigation on candidate resistance genes through transcriptomics approach. Elucidation of molecular mechanisms will provide in-depth understanding of the host-pathogen interactions and hence facilitate the breeding of corn with resistance to A. falvus infection and aflatoxin accumulation.

  15. Efficacy of two chemical coagulants and three different filtration media on removal of Aspergillus flavus from surface water.

    Science.gov (United States)

    Al-Gabr, Hamid Mohammad; Zheng, Tianling; Yu, Xin

    2014-02-01

    Aquatic fungi are common in various aqueous environments and play potentially crucial roles in nutrient and carbon cycling as well as interacting with other organisms. Species of Aspergillus are the most common fungi that occur in water. The present study was undertaken to elucidate the efficacy of two coagulants, aluminum sulfate and ferric chloride, used at different concentrations to treat drinking water, in removing Aspergillus flavus, as well as testing three different filtration media: sand, activated carbon, and ceramic granules, for their removal of fungi from water. The results revealed that both coagulants were effective in removing fungi and decreasing the turbidity of drinking water, and turbidity decreased with increasing coagulant concentration. Also, at the highest concentration of the coagulants, A. flavus was decreased by 99.6% in the treated water. Among ceramic granules, activated carbon, and sand used as media for water filtration, the sand and activated carbon filters were more effective in removing A. flavus than ceramic granules while simultaneously decreasing the turbidity levels in the test water samples. Post-treatment total organic carbon (TOC) and total nitrogen (TN) concentrations in the experimental water did not decrease; on the contrary, TN concentrations increased with the increasing dosage of coagulants. The filtration process had no effect in reducing TOC and TN in tested water.

  16. Effect of Plectranthus glandulosus and Ocimum gratissimum Essential Oils on Growth of Aspergillus flavus and Aflatoxin B1 Production

    Directory of Open Access Journals (Sweden)

    Mbofung, CMF.

    2008-01-01

    Full Text Available Essential oils of Ocimum gratissimum and Plectranthus glandulosus leaves were extracted by steam distillation and analysed by GC-MS, and their effects on growth and aflatoxin B1 production by Aspergillus flavus were tested at five levels (i.e 200, 400, 600, 800 and 1000 mg/l using SMKY agar medium. The main components of O. gratissimum were thymol (47.7% and -terpinene (14.3% whereas those of P. glandulosus were represented by -terpinene (30.8% and terpinolene (25.2%. After 8 days of incubation on essential oil-supplemented medium, growth of A. flavus was totally inhibited by 800 mg/l of O. gratissimum essential oil and by 1000 mg/l of P. glandulosus essential oil. The effect of essential oils on aflatoxin B1 synthesis was evaluated in SMKY broth. The medium supplemented with different essential oil concentrations, was inoculated with A. flavus mycelium and incubated at 25 °C. At 2, 4, 6 and 8 days, aflatoxin B1 concentrations in the supernatant were estimated using Enzyme Linked Immuno-Sorbent Assay (ELISA. Results showed that aflatoxin B1 synthesis was inhibited by 1000 mg/l of both essential oils of O. gratissimum and P. glandulosus after 8 days of incubation. Results obtained in the present study indicate the possibility of exploiting O. gratissimum and P. glandulosus essential oils in the fight against strains of A. flavus responsible for biodeterioration of stored food products.

  17. Characterization of a fungistatic substance produced by Aspergillus flavus isolated from soil and its significance in nature.

    Science.gov (United States)

    Chen, Yen-Ting; Lin, Mei-Ju; Yang, Ching-Hui; Ko, Wen-Hsiung

    2011-10-01

    A fungus capable of using vegetable tissues for multiplication in soil was isolated and identified as Aspergillus flavus based on morphological characteristics and sequence similarity of ITS and 28S. When grown in liquid medium prepared from the same vegetable tissues used in soil amendment, the isolate of A. flavus produced a substance capable of preventing disease development of black leaf spot of mustard cabbage caused by Alternaria brassicicola and inhibiting the germination of A. brassicicola conidia. The inhibitory substance was fungistatic, and was very stable under high temperature and high or low pH value. It was soluble in ethanol or methanol, moderately soluble in water, and insoluble in acetone, ethyl acetate or ether. The inhibitor is not a protein and has no charges on its molecule. This is the first discovery of the production of a fungistatic substance by this deleterious fungus. Results from this study suggest the possession of a strong competitive saprophytic ability by A. flavus, which in turn may explain the widespread occurrence of this fungus in soils. Production of a fungistatic substance when A. flavus was grown in medium prepared from vegetable tissues suggests the importance of antibiotic production in its competitive saprophytic colonization of organic matters in soils.

  18. In vitro activity of isavuconazole against 208 Aspergillus flavus isolates in comparison with 7 other antifungal agents: assessment according to the methodology of the European Committee on Antimicrobial Susceptibility Testing

    NARCIS (Netherlands)

    Rudramurthy, S.M.; Chakrabarti, A.; Geertsen, E.; Mouton, J.W.; Meis, J.F.G.M.

    2011-01-01

    Aspergillus flavus is the second most common species causing invasive aspergillosis after A. fumigatus. In certain countries like India, Sudan, and Saudi Arabia, A. flavus is most frequently isolated from patients with fungal rhinosinusitis and endophthalmitis. A. flavus exhibit an increased resista

  19. Production of aflatoxins by Aspergillus flavus and of fumonisins by Fusarium species isolated from Brazilian sorghum Avaliação da toxigenidade das cepas de Aspergillus flavus e Fusarium spp. isoladas de amostras de sorgo

    Directory of Open Access Journals (Sweden)

    Josefa B. da Silva

    2004-09-01

    Full Text Available Fifty-nine Aspergillus flavus and 35 Fusarium verticillioides strains, isolated from freshly harvested (10 and stored (130 Brazilian sorghum samples, were tested regarding their ability to produce aflatoxins (coconut milk agar and fumonisins (rice culture, respectively. Aflatoxins B1 and B2 were detected by TLC, and fumonisins B1 and B2 were analyzed by HPLC. Thirty-eight (64.4% A. flavus strains produced detectable levels of aflatoxins at concentrations ranging from 12.00 to 3282.50 µg/kg (AFB1 + AFB2, while thirty two (91% F. verticillioides strains produced FB1 at concentrations ranging from 0.12 to 5.38 µg/g. Two F. proliferatum strains produced low fumonisin levels. The toxigenic potential of A. flavus (64.4% and F. verticillioides (91.5% strains observed in sorghum samples indicates that rigorous control should be directed at the storage conditions of these products to minimize contamination with toxigenic deteriorating fungi, preventing further hazard to human and animal health.A produção de aflatoxinas por 59 cepas de Aspergillus flavus e fumonisinas por 35 cepas de Fusarium verticillioides isoladas de amostras de grãos de sorgo recém colhido (10 amostras e armazenado (130 amostras, foram avaliadas. A detecção de aflatoxinas (AFB1 e AFB2 foi efetuada por Cromatografia em Camada Delgada (CCD e fumonisinas (FB1 e FB2 foram analisadas por Cromatografia Líquida de Alta Eficiência (CLAE. Os resultados demonstram a produção de AFB1 e AFB2 em 38 cepas (64,4% de A. flavus cujos níveis variaram de 12,00 a 3282,50 µg/kg. Referente às cepas de F. verticillioides, 32 (91% produziram FB1, nas concentrações de 0,12 a 5,38 µg/g. Baixos níveis de fumonisinas foram detectados em 2 cepas de F. proliferatum. A constatação da potencialidade toxígena das cepas de A. flavus (64,4% e de F. verticillioides (91,5% nesta investigação, revelam a importância da pesquisa de aflatoxinas e fumonisinas nas amostras de sorgo. Diante disto

  20. Effect of water activity and temperature on growth of three Penicillium species and Aspergillus flavus on a sponge cake analogue.

    Science.gov (United States)

    Abellana, M; Sanchis, V; Ramos, A J

    2001-12-30

    This study compared the effect of temperature and water activity and their interactions on the rate of mycelial growth of Penicillium aurantiogriseum, P. chrysogenum, P. corylophilum and Aspergillus flavus on a sponge cake analogue. As expected, growth rates showed dependence on a(w), and temperature. However, no significant differences were observed in the growth rates of different isolates. The minimum a(w) values for growth of the Penicillium spp. was 0.85-0.90. A. flavus was able to grow at 0.90 a(w) when the temperature was above 15 degrees C. This study has shown that fungal growth by these species on a sponge cake analogue, with a composition similar to usual bakery products, is prevented if the a(w) is kept at < 0.85.

  1. Identification of maize genes associated with host plant resistance or susceptibility to Aspergillus flavus infection and aflatoxin accumulation.

    Directory of Open Access Journals (Sweden)

    Rowena Y Kelley

    Full Text Available BACKGROUND: Aspergillus flavus infection and aflatoxin contamination of maize pose negative impacts in agriculture and health. Commercial maize hybrids are generally susceptible to this fungus. Significant levels of host plant resistance have been observed in certain maize inbred lines. This study was conducted to identify maize genes associated with host plant resistance or susceptibility to A. flavus infection and aflatoxin accumulation. RESULTS: Genome wide gene expression levels with or without A. flavus inoculation were compared in two resistant maize inbred lines (Mp313E and Mp04:86 in contrast to two susceptible maize inbred lines (Va35 and B73 by microarray analysis. Principal component analysis (PCA was used to find genes contributing to the larger variances associated with the resistant or susceptible maize inbred lines. The significance levels of gene expression were determined by using SAS and LIMMA programs. Fifty candidate genes were selected and further investigated by quantitative RT-PCR (qRT-PCR in a time-course study on Mp313E and Va35. Sixteen of the candidate genes were found to be highly expressed in Mp313E and fifteen in Va35. Out of the 31 highly expressed genes, eight were mapped to seven previously identified quantitative trait locus (QTL regions. A gene encoding glycine-rich RNA binding protein 2 was found to be associated with the host hypersensitivity and susceptibility in Va35. A nuclear pore complex protein YUP85-like gene was found to be involved in the host resistance in Mp313E. CONCLUSION: Maize genes associated with host plant resistance or susceptibility were identified by a combination of microarray analysis, qRT-PCR analysis, and QTL mapping methods. Our findings suggest that multiple mechanisms are involved in maize host plant defense systems in response to Aspergillus flavus infection and aflatoxin accumulation. These findings will be important in identification of DNA markers for breeding maize lines

  2. Toxigenic potentiality of Aspergillus flavus and Aspergillus parasiticus strains isolated from black pepper assessed by an LC-MS/MS based multi-mycotoxin method.

    Science.gov (United States)

    Yogendrarajah, Pratheeba; Devlieghere, Frank; Njumbe Ediage, Emmanuel; Jacxsens, Liesbeth; De Meulenaer, Bruno; De Saeger, Sarah

    2015-12-01

    A liquid chromatography triple quadrupole tandem mass spectrometry method was developed and validated to determine mycotoxins, produced by fungal isolates grown on malt extract agar (MEA). All twenty metabolites produced by different fungal species were extracted using acetonitrile/1% formic acid. The developed method was applied to assess the toxigenic potentiality of Aspergillus flavus (n = 11) and Aspergillus parasiticus (n = 6) strains isolated from black peppers (Piper nigrum L.) following their growth at 22, 30 and 37 °C. Highest mean radial colony growth rates were observed at 30 °C for A. flavus (5.21 ± 0.68 mm/day) and A. parasiticus (4.97 ± 0.33 mm/day). All of the A. flavus isolates produced aflatoxin B1 and O-methyl sterigmatocystin (OMST) while 91% produced aflatoxin B2 (AFB2) and 82% of them produced sterigmatocystin (STERIG) at 30 °C. Except one, all the A. parasiticus isolates produced all the four aflatoxins, STERIG and OMST at 30 °C. Remarkably high AFB1 was produced by some A. flavus isolates at 22 °C (max 16-40 mg/kg). Production of mycotoxins followed a different trend than that of growth rate of both species. Notable correlations were found between different secondary metabolites of both species; R(2) 0.87 between AFB1 and AFB2 production. Occurrence of OMST could be used as a predictor for AFB1 production.

  3. Corn-Soybean Rotation Systems in the Mississippi Delta: Implications on Mycotoxin Contamination and Soil Populations of Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Hamed K. Abbas

    2012-01-01

    Full Text Available The effect of corn-soybean rotation on mycotoxin contamination in corn (Zea mays L. and soybean (Glycine max L. Merrill. grains has not been fully evaluated. Therefore, this research investigated the effect of corn-soybean rotation on aflatoxin and fumonisin contamination in respective grains. The results showed that aflatoxin levels in soybean averaged 2.3, <0.5, 0.6, and 6.8 ng/g in 2005, 2006, 2007, and 2008, while corn aflatoxin levels were 16.7, 37.1, 2.4, and 54.8 ng/g, respectively. Aspergillus flavus colonization was significantly greater (P≤0.05 in corn (log 1.9, 2.9, and 4.0 cfu/g compared to soybean (<1.3, 2.6, and 2.7 cfu/g in 2005, 2007, and 2008, respectively. Aflatoxigenic A. flavus isolates were more frequent in corn than in soybean in all four years. Higher fumonisin levels were found in corn (0.2 to 3.6 μg/g than in soybean (<0.2 μg/g. Rotating soybean with corn reduces the potential for aflatoxin contamination in corn by reducing A. flavus propagules in soil and grain and reducing aflatoxigenic A. flavus colonization. These results demonstrated that soybean grain is less susceptible to aflatoxin contamination compared to corn due to a lower level of colonization by A. flavus with a greater occurrence of non-aflatoxigenic isolates.

  4. Control of Aspergillus flavus Growth in Tomato Paste by Cinnamomum zeylanicum and Origanum vulgare L. Essential Oils

    Directory of Open Access Journals (Sweden)

    F Kalantary

    2014-05-01

    Full Text Available This study was conducted to evaluate the antifungal activities of cinnamon (Cinnamomum zeylanicum and oregano (Origanum vulgare L. essential oils against Aspergillus flavus in culture media and tomato paste. The chemical compositions of the essential oils were determined by Gas Chromatography-Mass Spectroscopy (GC-MS. Trans- cinnamaldehyde was found to be the main constituent of Cinnamomum zeylanicum essential oil (CZEO, followed by methyl eugenol, δ- cadinene and γ- cadinene. The major components of Origanum vulgare L. essential oil (OVEO were limonene, caryophyllene oxide, α-ionone, germacrene– D, γ- terpinene, β- pinene and terpinene-4-ol. For evaluating antifungal activities of CZEO and OVEO, A. flavus PTCC: 5006, was inoculated in Sabouraud Dextrose Broth (SDB and tomato paste, then 0, 50, 100, 200, 300, 400, 500 and 600 ppm of essential oils were added to each sample and incubated at 25±0.5oC for 30 and 60 days, respectively. The antifungal activity was measured by Agar Dilution method. The EOs at all tested concentrations had inhibitory effect against A. flavus growth. 200 ppm of CZEO and 500 ppm of OVEO completely inhibited A. flavus growth in culture media, while in tomato paste 300 ppm of CZEO and 200 ppm of OVEO had the same effect. Test panel evaluations were carried out in tomato ketchup base and samples with 100 and 200 ppm CZEO were accepted by panelists. The results may suggest the potential replacement of antifungal chemicals by CZEO as natural inhibitor to control A. flavus growth in tomato paste.

  5. Characterization of aflatoxigenic and non-aflatoxigenic Aspergillus flavus isolates from pistachio.

    Science.gov (United States)

    Hua, Sui Sheng T; McAlpin, Cesaria E; Chang, Perng-Kuang; Sarreal, Siov Bouy L

    2012-02-01

    Pistachio is a popular snack food. Aflatoxin contamination of pistachio nuts is a serious problem for many producing countries. The development of biological control methods based on ecological parameters is an environmentally friendly approach. Thirty-eight Aspergillus flavus isolates collected from a pistachio orchard in California (CA) were analyzed for production of aflatoxin (AF), cyclopiazonic acid (CPA), vegetative compatibility groups (VCGs), and mating types. All aflatoxigenic isolates produced both AFB1 and CPA. The most toxigenic one was CA28 which produced 164 μg AFB1 per 5 ml PDA fungal culture and small sclerotia (S strain, sclertoium size less than 400 μm). The other aflatoxigenic strains produce AFB1 ranging from 1.2 μg to 80 μg per 5 ml fungal culture. Twenty-one percent of the CA isolates produced AFB1, 84% produced CPA and half formed sclerotia on at least one of three tested media. The 38 CA isolates formed 26 VCGs, 6 of which had two or more isolates and 20 contained single isolates. The S strain isolates belong to 4 different VCGs. Genomic profiling by a retrotransposon DNA probe revealed fingerprint patterns that were highly polymorphic. The predicted VCGs (Pred-VCGs) based on a similarity coefficient >80% matched the VCGs of multiple isolates determined by complementation. All isolates within a VCG had the same mating-type gene of either MAT1-1 or MAT1-2. Uncorrected and VCG-corrected MAT1-1 and MAT1-2 among the isolates were equally distributed.

  6. Effect of Plectranthus glandulosus and Ocimum gratissimum Essential Oils on Growth of Aspergillus flavus and Aflatoxin B1 Production

    OpenAIRE

    Mbofung, CMF.; Etoa, FX.; Tadsadjieu, NL.; Ngassoum, MB.

    2008-01-01

    Essential oils of Ocimum gratissimum and Plectranthus glandulosus leaves were extracted by steam distillation and analysed by GC-MS, and their effects on growth and aflatoxin B1 production by Aspergillus flavus were tested at five levels (i.e 200, 400, 600, 800 and 1000 mg/l) using SMKY agar medium. The main components of O. gratissimum were thymol (47.7%) and -terpinene (14.3%) whereas those of P. glandulosus were represented by -terpinene (30.8%) and terpinolene (25.2%). After 8 days of inc...

  7. Efeito de óleos essenciais sobre o crescimento e produção de aflatoxinas por Aspergillus flavus

    OpenAIRE

    Alessandra Marcon Gasperini

    2014-01-01

    Resumo: O fungo Aspergillus flavus é responsável pela degradação de alimentos, além de produzir aflatoxinas que são reconhecidas como potentes carcinógenos. Atualmente, frente ao aumento acelerado de cepas resistentes aos antifúngicos sintéticos e à pressão dos consumidores pela substituição destes por produtos naturais, a busca de novos antimicrobianos a partir de óleos essenciais (OE) tem se tornado uma opção promissora. Neste contexto, o objetivo deste trabalho foi avaliar a capacidade de ...

  8. Evaluation of viability of Aspergillus flavus and aflatoxins degradation in irradiated samples of maize Avaliação da viabilidade de Aspergillus flavus e degradação de aflatoxinas em amostras de milho irradiadas

    Directory of Open Access Journals (Sweden)

    Simone Aquino

    2005-12-01

    Full Text Available One of the currently most important fungi in stored grains is Aspergillus flavus, which produce aflatoxins. This fungus can grow on diverse substrates and represents a serious public health and animal nutritional problem. Therefore, the study of techniques that can be applied to the control of aflatoxins is of great importance. The objective of the present study was to determine the effects of gamma radiation on the growth of Aspergillus flavus Link and on degradation of aflatoxin B1 and B2 (AFB1 and AFB2 at a relative humidity of 97 99% and a water activity (Aw of 0.88-0.94. Samples of corn grains were irradiated using a cobalt 60 source emitting gamma rays at doses of 2, 5 and 10 kGy. Irradiation was found to be effective in reducing the number colony-forming units of A. flavus, per gram, in the corn samples analyzed. In addition, the fluorescent viability test (fluorescein diacetate and ethidium bromide revealed a decrease in the number of viable cells with increasing irradiation doses and three different fluorescence patterns. Furthermore, irradiation induced a partial reduction in AFB1 and AFB2 levels at the doses of 2 and 5 kGy, whereas complete degradation of aflatoxins was observed in the assay employing 10 kGy.Um dos fungos mais importantes atualmente em grãos armazenados é o Aspergillus flavus, o qual produz aflatoxinas. Este fungo pode crescer em diversos substratos e representa uma séria preocupação em saúde pública e nutrição animal. Portanto, o estudo de técnicas que possam ser aplicadas no controle das aflatoxinas é de grande importância. Assim sendo, o objetivo do presente trabalho foi estudar os efeitos da radiação gama no crescimento de Aspergillus flavus Link e na degradação das aflatoxinas B1 e B2, (AFB1 e AFB2 em umidade relativa (UR de 97-99% e atividade de água (Aa de 0,88-0,94. Amostras de grãos de milho foram irradiadas, utilizando-se uma fonte de Cobalto 60, emissora de raios gama, com as doses de 2; 5

  9. Treatment of two postoperative endophthalmitis cases due to Aspergillus flavus and Scopulariopsis spp. with local and systemic antifungal therapy

    Directory of Open Access Journals (Sweden)

    Uyar Guliz

    2007-07-01

    Full Text Available Abstract Background Endophthalmitis is the inflammatory response to invasion of the eye with bacteria or fungi. The incidence of endophthalmitis after cataract surgery varies between 0.072–0.13 percent. Treatment of endophthalmitis with fungal etiology is difficult. Case Presentation Case 1: A 71-year old male diabetic patient developed postoperative endophthalmitis due to Aspergillus flavus. The patient was treated with topical amphotericin B ophthalmic solution, intravenous (IV liposomal amphotericin-B and caspofungin following vitrectomy. Case 2: A 72-year old male cachectic patient developed postoperative endophthalmitis due to Scopulariopsis spp. The patient was treated with topical and IV voriconazole and caspofungin. Conclusion Aspergillus spp. are responsible of postoperative fungal endophthalmitis. Endophthalmitis caused by Scopulariopsis spp. is a very rare condition. The two cases were successfully treated with local and systemic antifungal therapy.

  10. Aspergillus flavus F52菌株鉴定及不同碳源对曲酸产量的影响%Identification of a kojic-acid producing Aspergillus flavus F52

    Institute of Scientific and Technical Information of China (English)

    魏少鹏; 徐楠; 姬志勤

    2014-01-01

    [目的]探明豇豆内生真菌F52的分类地位及不同碳源对曲酸产量的影响.[方法]采用形态观察及ITS序列分析对豇豆内生真菌F52进行分类鉴定;通过重结晶获得曲酸高纯度产物,采用核磁共振波谱、高分辨质谱及红外光谱对其进行结构鉴定;采用高效液相色谱检测不同碳源对曲酸产量的影响.[结果]该曲酸产生菌为黄曲霉Aspergillus flavus F52;葡萄糖与蔗糖组成的复合碳源曲酸产量最高,乳糖的存在不利于曲酸的生成;该菌株发酵液中曲酸含量可达24.44 g/L.[结论]Aspergillus flavus F52是一株具有产业化开发价值的曲酸高产菌株.

  11. Use of a granular bioplastic formulation for carrying conidia of a non-aflatoxigenic strain of Aspergillus flavus.

    Science.gov (United States)

    Accinelli, Cesare; Saccà, M Ludovica; Abbas, Hamed K; Zablotowicz, Robert M; Wilkinson, Jeffery R

    2009-09-01

    Previous research demonstrated that aflatoxin contamination in corn is reduced by field application of wheat grains pre-inoculated with the non-aflatoxigenic Aspergillus flavus strain NRRL 30797. To facilitate field applications of this biocontrol isolate, a series of laboratory studies were conducted on the reliability and efficiency of replacing wheat grains with the novel bioplastic formulation Mater-Bi to serve as a carrier matrix to formulate this fungus. Mater-Bi granules were inoculated with a conidial suspension of NRRL 30797 to achieve a final cell density of approximately log 7 conidia/granule. Incubation of 20-g soil samples receiving a single Mater-Bi granule for 60-days resulted in log 4.2-5.3 propagules of A. flavus/g soil in microbiologically active and sterilized soil, respectively. Increasing the number of granules had no effect on the degree of soil colonization by the biocontrol fungus. In addition to the maintenance of rapid vegetative growth and colonization of soil samples, the bioplastic formulation was highly stable, indicating that Mater-Bi is a suitable substitute for biocontrol applications of A. flavus NRRL 30797.

  12. Effects of Cymbopogon citratus L. essential oil on the growth, morphogenesis and aflatoxin production of Aspergillus flavus ML2-strain.

    Science.gov (United States)

    Helal, G A; Sarhan, M M; Abu Shahla, A N K; Abou El-Khair, E K

    2007-02-01

    The mycelial growth of Aspergillus flavus Link was completely inhibited using 1.5 (microl/ml or 2.0 (microl/ml of Cymbopogon citratus essential oil applied by fumigation or contact method in Czapek's liquid medium, respectively. This oil was found also to be fungicidal at the same concentrations. The sublethal doses 1.0 and 1.5 (microl/ml inhibited about 65% of fungal growth after five days of incubation and delayed conidiation as compared with the control. Microscopic observations using Light Microscope (LM), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) were carried out to determine the ultra structural modifications of A. flavus hyphae after treatment with C. citratus essential oil. The hyphal diameter decreased and hyphal wall appeared as precipitates and disappeared in some regions. This oil also caused plasma membrane disruption and mitochondrial structure disorganization. Moreover, Ca(+2), K(+) and Mg(+2) leakages increased from the fumigated mycelium and its total lipid content decreased, while the saturated and unsaturated fatty acids increased. One of the most important results obtained during this study was the ability of C. citratus essential oil at its sublethal dose to completely inhibit aflatoxin B(1) production from A. flavus. These findings increase the possibility of exploiting C. citratus essential oil as an effective inhibitor of biodegradation and storage contaminating fungi and also in fruit juice preservation.

  13. PCR-RFLP on β-tubulin gene for rapid identification of the most clinically important species of Aspergillus.

    Science.gov (United States)

    Nasri, Tuba; Hedayati, Mohammad Taghi; Abastabar, Mahdi; Pasqualotto, Alessandro C; Armaki, Mojtaba Taghizadeh; Hoseinnejad, Akbar; Nabili, Mojtaba

    2015-10-01

    Aspergillus species are important agents of life-threatening infections in immunosuppressed patients. Proper speciation in the Aspergilli has been justified based on varied fungal virulence, clinical presentations, and antifungal resistance. Accurate identification of Aspergillus species usually relies on fungal DNA sequencing but this requires expensive equipment that is not available in most clinical laboratories. We developed and validated a discriminative low-cost PCR-based test to discriminate Aspergillus isolates at the species level. The Beta tubulin gene of various reference strains of Aspergillus species was amplified using the universal fungal primers Bt2a and Bt2b. The PCR products were subjected to digestion with a single restriction enzyme AlwI. All Aspergillus isolates were subjected to DNA sequencing for final species characterization. The PCR-RFLP test generated unique patterns for six clinically important Aspergillus species, including Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus terreus, Aspergillus clavatus and Aspergillus nidulans. The one-enzyme PCR-RFLP on Beta tubulin gene designed in this study is a low-cost tool for the reliable and rapid differentiation of the clinically important Aspergillus species.

  14. Aspergillus pragensis sp. nov. discovered during molecular reidentification of clinical isolates belonging to Aspergillus section Candidi.

    Science.gov (United States)

    Hubka, Vit; Lyskova, Pavlina; Frisvad, Jens C; Peterson, Stephen W; Skorepova, Magdalena; Kolarik, Miroslav

    2014-08-01

    The identity of nine clinical isolates recovered from Czech patients and presumptively identified as Aspergillus sp. section Candidi based on colony morphology was revised using sequences of β-tubulin, calmodulin gene sequence, and internal transcribed spacer rDNA. Six isolates were from suspected and proven onychomycosis, one from otitis externa, and two associated with probable invasive aspergillosis. The results showed that one Aspergillus candidus isolate was the cause of otitis externa, and both isolates obtained from sputa of patients with probable invasive aspergillosis were reidentified as A. carneus (sect. Terrei) and A. flavus (sect. Flavi). Three isolates from nail scrapings were identified as A. tritici, a verified agent of nondermatophyte onychomycosis. One isolate from toenail was determined to be A. candidus and the two isolates belonged to a hitherto undescribed species, Aspergillus pragensis sp. nov. This species is well supported by phylogenetic analysis based on β-tubulin and calmodulin gene and is distinguishable from other members of sect. Candidi by red-brown reverse on malt extract agar, slow growth on Czapek-Dox agar and inability to grow at 37°C. A secondary metabolite analysis was also provided with comparison of metabolite spectrum to other species. Section Candidi now encompasses five species for which a dichotomous key based on colony characteristics is provided. All clinical isolates were tested for susceptibilities to selected antifungal agents using the Etest and disc diffusion method. Overall sect. Candidi members are highly susceptible to common antifungals.

  15. Optimization of process parameters influencing the submerged fermentation of extracellular lipases from Pseudomonas aeruginosa, candida albicans and Aspergillus flavus.

    Science.gov (United States)

    Padhiar, Jigita; Das, Arijit; Bhattacharya, Sourav

    2011-11-15

    The present study was aimed at optimization, production and partial purification of lipases from Pseudomonas aeruginosa, Candida albicans and Aspergillus flavus. Various nutritional and physical parameters affecting lipase production such as carbon and nitrogen supplements, pH, temperature, agitation speed and incubation time were studied. Refined sunflower oil (1% v/v) and tryptone at a pH of 6.2 favored maximum lipase production in Pseudomonas at 30 degrees C and 150 rpm, when incubated for 5 days. In C. albicans refined sunflower oil (3% v/v) and peptone resulted in maximum lipase production at pH 5.2, 30 degrees C and 150 rpm, when incubated for 5 days. In A. flavus coconut oil (3% v/v) and peptone yielded maximum lipase at pH 6.2, 37 degrees C, 200 rpm after an incubation period of 5 days. The lipases were partially purified by ammonium sulphate precipitation and dialysis. In P. aeruginosa enzyme activity of the dialyzed fraction was found to be 400 U mL-' and for C. albicans 410 U mL(-1). The dialysed lipase fraction from A. flavus demonstrated an activity of 460 U mL(-1). The apparent molecular weights of the dialyzed lipases were determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The dialyzed lipase fraction obtained from P. aeruginosa revealed molecular weights of 47, 49 and 51 kDa, whereas, lipases from C. albicans and A. flavus demonstrated 3 bands (16.5, 27 and 51 kDa) and one band (47 kDa), respectively. These extracellular lipases may find wide industrial applications.

  16. 杜仲抗真菌肽对黄曲霉的抑制作用%Effect of Eucommia Antifungal Peptide Against Aspergillus flavus

    Institute of Scientific and Technical Information of China (English)

    刘世会; 赵德刚

    2008-01-01

    Using paper-disc agar-diffusion method,the activity of Eucommia antifungal peptide 3(EAFP3) against Aspergillus flavus were investigated.The results indicated that EAFP3 could effectively inhibit A.flavus.The minimum inhibition concentration (MIC) was 125 μg/mL.%用纸片琼脂扩散法,研究了杜仲抗真菌肽EAFP3对黄曲霉(Aspergillus flavus)的抗真菌活性.研究结果表明,EAFP3对黄曲霉有明显抑制作用,最小抑菌浓度为125 μg/mL.

  17. Effect of inoculum concentrations of Aspergillus flavus and A. parasiticus on aflatoxin accumulation and kernel infection in resistant and susceptible maize hybrids

    Science.gov (United States)

    Over a three year period, we compared aflatoxin accumulation and kernel infection in maize hybrids inoculated with six inoculum concentrations of Aspergillus flavus isolate NRRL 3357 or A. parasiticus isolate NRRL 6111 which is a norsolorinic acid producer. Aflatoxin resistant and susceptible mai...

  18. Identification and quantification of a toxigenic and non-toxigenic Aspergillus flavus strain in contaminated maize using quantitative real-time PCR

    Science.gov (United States)

    Aflatoxins, which are produced by the fungus Aspergillus flavus, are toxic to humans, livestock, and pets. The value of maize (Zea mays) grain is markedly reduced when contaminated with aflatoxin. Plant resistance and biological control using non-toxin producing strains are considered effective st...

  19. Nanocapsular Dispersion of Cinnamaldehyde for Enhanced Inhibitory Activity against Aflatoxin Production by Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Hongbo Li

    2015-04-01

    Full Text Available Cinnamaldehyde (CA is marginally soluble in water, making it challenging to evenly disperse it in foods, and resulting in lowered anti-A. flavus efficacy. In the present study, nano-dispersed CA (nano-CA was prepared to increase its aqueous solubility. Free and nano-dispersed CA were compared in terms of their inhibitory activity against fungal growth and aflatoxin production of A. flavus both in Sabouraud Dextrose (SD culture and in peanut butter. Our results indicated that free CA inhibited the mycelia growth and aflatoxin production of A. flavus with a minimal inhibitory concentration (MIC value of 1.0 mM, but promoted the aflatoxin production at some concentrations lower than the MIC. Nano-CA had a lower MIC value of 0.8 mM against A. flavus, and also showed improved activity against aflatoxin production without the promotion at lower dose. The solidity of peanut butter had an adverse impact on the antifungal activity of free CA, whereas nano-dispersed CA showed more than 2-fold improved activity against the growth of A. flavus. Free CA still promoted AFB1 production at the concentration of 0.25 mM, whereas nano-CA showed more efficient inhibition of AFB1 production in the butter.

  20. The potential inhibitory effect of cuminum cyminum, ziziphora clinopodioides and nigella sativa essential oils on the growth of Aspergillus fumigatus and Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    A.R Khosravi

    2011-03-01

    Full Text Available The goals of this study were to evaluate the effectiveness of Cuminum cyminum, Ziziphora clinopodioides and Nigella sativa essential oils to inhibit the growth of Aspergillus fumigatus and A. flavus and to evoke ultrastructural changes. The fungi were cultured into RPMI 1640 media in the presence of oils at concentrations of 8, 6, 5, 4, 3, 2, 1.5, 1.25, 1, 0.75 and 0.5 mg/ml in broth microdilution and 2, 1.5, 1 and 0.5 mg/ml in broth macrodilution methods with shaking for 48 h at 28ºC. Conidial and mycelial samples exposed to 0.25, 0.5, 1, 1.5 and 2 mg essential oils/ml for 5 days in 2% yeast extract granulated plus 15% Saccharose media were processed for transmission electron microscopy (TEM. Based on broth dilution methods, C. cyminum and to a lesser extent Z. clinopodioides oils exhibited the strongest activity against A. fumigatus and A. flavus with MIC90 ranging from 0.25 to 1.5 mg/ml, while the oil from N. sativa exhibited relatively moderate activity against two above fungi with MIC90 ranging from 1.5 to 2 mg/ml. The main changes observed by TEM were in the cell wall, plasma membrane and membranous organelles; in particular, in the nuclei and mitochondria. These modifications in fungal structure were associated with the interference of the essential oils with the enzymes responsible for cell wall synthesis, which disturbed normal growth. Moreover, the essential oils caused high vacuolation of the cytoplasm, detachment of fibrillar layer of cell wall, plasma membrane disruption and disorganization of the nuclear and mitochondrial structures. Aspergillus fumigatus and A. flavus growth inhibition induced by these oils were found to be well-correlated with subsequent morphological changes of the fungi exposed to different fungistatic concentrations of the oils. Our results show the anti-Aspergillus activities of C. cyminum, Z. clinopodioides and N. sativa essential oils, which strengthens the potential use of these substances as anti

  1. Transcriptomic profiles of Aspergillus flavus CA42, a strain that produces small sclerotia, by decanal treatment and after recovery.

    Science.gov (United States)

    Chang, Perng-Kuang; Scharfenstein, Leslie L; Mack, Brian; Yu, Jiujiang; Ehrlich, Kenneth C

    2014-07-01

    Aspergillus flavus is a ubiquitous saprophyte and is capable of producing many secondary metabolites including the carcinogenic aflatoxins. The A. flavus population that produces small sclerotia (S strain) has been implicated as the culprit for persistent aflatoxin contamination in field crops. We investigated how the plant volatile decanal, a C10 fatty aldehyde, affected the growth and development of the S strain A. flavus. Decanal treatment yielded fluffy variants lacking sclerotia and conidia and exhibiting a dosage-dependent radial colony growth. We used RNA-Seq analysis to examine transcriptomic changes caused by decanal and after removal of decanal. Mature sclerotia contained only 80% of the total transcripts detected in all samples in comparison to 94% for the decanal treated culture. Gene ontology (GO) analysis showed that decanal treatment increased expression of genes involved in oxidoreductase activity, cellular carbohydrate metabolism, alcohol metabolism and aflatoxin biosynthesis. The treatment affected cellular components associated with cell wall, and gene expression of glucanases, α-amylases, pectinesterase and peptidase required for its biosynthesis was increased. After decanal was removed, the culture resumed sclerotial production. Moreover, its GO terms significantly overlapped with those of the untreated culture; five of the enriched molecular functions, oxidoreductase activity, monooxygenase activity, electron carrier activity, heme binding, and iron binding were found in the untreated culture. The GO term of cellular component enriched was mainly integral protein constituents of the membrane. The results suggested that decanal halted development at the vegetative state rendering the fungus unable to produce conidia and sclerotia. The induced fluffy phenotype could be related to lower transcript abundance of flbB, flbD, and flbE but not to veA expression. Increased abundance of the laeA transcript in the treated culture correlated with early

  2. Secondary metabolite production in Hypericum perforatum L. cell suspensions upon elicitation with fungal mycelia from Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Gadzovska-Simic Sonja

    2012-01-01

    Full Text Available We investigated the production of phenylpropanoids (phenolic compounds, flavanols, flavonols and anthocyanins and naphtodianthrones (hypericins in elicited Hypericum perforatum L. cell suspensions. To determine whether secondary metabolite production could be enhanced, Hypericum cell suspensions were exposed to mycelia extract from the fungus Aspergillus flavus. Elicited Hypericum cell suspension cultures displayed reduced growth and viability and a modification of secondary metabolites production. Anthocyanins were only stimulated in fungal-elicited cell suspensions. Secondary metabolite production in elicited Hypericum cells revealed an antagonism between the flavonoid/naphtodianthrone and anthocyanin pathways. The data suggest a modification of the channeling of the phenylpropanoid compounds. Together, these results represent useful data for monitoring the channeling in different secondary metabolite pathways during the scaled-up production of naphtodianthrones for medicinal uses.

  3. Mechanisms of antifungal and anti-aflatoxigenic properties of essential oil derived from turmeric (Curcuma longa L.) on Aspergillus flavus.

    Science.gov (United States)

    Hu, Yichen; Zhang, Jinming; Kong, Weijun; Zhao, Gang; Yang, Meihua

    2017-04-01

    The antifungal activity and potential mechanisms in vitro as well as anti-aflatoxigenic efficiency in vivo of natural essential oil (EO) derived from turmeric (Curcuma longa L.) against Aspergillus flavus was intensively investigated. Based on the previous chemical characterization of turmeric EO by gas chromatography-mass spectrometry, the substantially antifungal activities of turmeric EO on the mycelial growth, spore germination and aflatoxin production were observed in a dose-dependent manner. Furthermore, these antifungal effects were related to the disruption of fungal cell endomembrane system including the plasma membrane and mitochondria, specifically i.e. the inhibition of ergosterol synthesis, mitochondrial ATPase, malate dehydrogenase, and succinate dehydrogenase activities. Moreover, the down-regulation profiles of turmeric EO on the relative expression of mycotoxin genes in aflatoxin biosynthetic pathway revealed its anti-aflatoxigenic mechanism. Finally, the suppression effect of fungal contamination in maize indicated that turmeric EO has potential as an eco-friendly antifungal agent.

  4. Non-aflatoxigenic Aspergillus flavus as potential biocontrol agents to reduce aflatoxin contamination in peanuts harvested in Northern Argentina.

    Science.gov (United States)

    Alaniz Zanon, María Silvina; Barros, Germán Gustavo; Chulze, Sofía Noemí

    2016-08-16

    Biological control is one of the most promising strategies for preventing aflatoxin contamination in peanuts at field stage. A population of 46 native Aspergillus flavus nonaflatoxin producers were analysed based on phenotypic, physiological and genetic characteristics. Thirty-three isolates were characterized as L strain morphotype, 3 isolates as S strain morphotype, and 10 isolates did not produce sclerotia. Only 11 of 46 non-aflatoxigenic isolates did not produce cyclopiazonic acid. The vegetative compatibility group (VCG) diversity index for the population was 0.37. For field trials we selected the non-aflatoxigenic A. flavus AR27, AR100G and AFCHG2 strains. The efficacy of single and mixed inocula as potential biocontrol agents in Northern Argentina was evaluated through a 2-year study (2014-2015). During the 2014 peanut growing season, most of the treatments reduced the incidence of aflatoxigenic strains in both soil and peanut kernel samples, and no aflatoxin was detected in kernels. During the 2015 growing season, there was a reduction of aflatoxigenic strains in kernel samples from the plots treated with the potential biocontrol agents. Reductions of aflatoxin contamination between 78.36% and 89.55% were observed in treated plots in comparison with the un-inoculated control plots. This study provides the first data on aflatoxin biocontrol based on competitive exclusion in the peanut growing region of Northern Argentina, and proposes bioproducts with potential use as biocontrol agents.

  5. Utilization of waste fruit-peels to inhibit aflatoxins synthesis by Aspergillus flavus: a biotreatment of rice for safer storage.

    Science.gov (United States)

    Naseer, R; Sultana, Bushra; Khan, M Z; Naseer, D; Nigam, Poonam

    2014-11-01

    Antifungal activity in lemon and pomegranate peels was considerable against Aspergillus flavus, higher in pomegranate (DIZ 37mm; MIC 135μg/mL). Powdered peels (5, 10, 20% w/w) were mixed in inoculated rice. The inhibitory effect on fungal-growth and production of aflatoxins by A. flavus was investigated at storage conditions - temperature (25, 30°C) and moisture (18%, 21%) for 9months. The maximum total aflatoxins accumulated at 30°C, 21% moisture and at 25°C, 18% moisture were 265.09 and 163.45ng/g, respectively in control. Addition of pomegranate-peels inhibited aflatoxins production to 100% during four month-storage of rice at 25°C and 18% moisture, while lemon-peels showed similar inhibitory effect for 3months at same conditions. However a linear correlation was observed in aflatoxins level with temperature and moisture. Studies showed that both fruit-wastes are potent preventer of aflatoxin production in rice, useful for a safer and longer storage of rice.

  6. Comparison of temperature and moisture requirements for sporulation of Aspergillus flavus sclerotia on natural and artificial substrates.

    Science.gov (United States)

    Giorni, Paola; Camardo Leggieri, Marco; Magan, Naresh; Battilani, Paola

    2012-06-01

    A key step in the infection cycle by Aspergillus flavus in maize is sporulation of sclerotia present in soil or in crop debris. However, little information is available on this critical and important phase. This study included experiments on artificial (Czapek Dox Agar (CZ)) and natural (maize stalks) substrates under different conditions of temperature (T; from 5 to 45 °C) and water activity (a(w); from 0.50 to 0.99) levels to quantify sporulation from sclerotia. The mean numbers of spores were higher on defined nutritional medium in vitro on CZ agar than on maize stalks (4.5×10(6) spores/sclerotium versus 4.2×10(4) spores/sclerotium) with production initiated after 6 and 24h, respectively. Surprisingly, the optimal temperature was found at 30-35 °C for CZ agar (9.23×10(6) spores/sclerotium) and to be 20-25 °C for maize stalks (6.26×10(4) spores/sclerotium). Water stress imposition only reduced sporulation at ≤0.90 a(w.) With more available water no significant differences were found between 0.90 and 0.99 a(w). This type of data is critical in the development of a mechanistic model to predict the infection cycle of A. flavus in maize in relation to meteorological conditions.

  7. Evaluation of antifungal activity of aqueous extracts of some medicinal plants against Aspergillus flavus, pistachio aflatoxin producing fungus in vitro

    Directory of Open Access Journals (Sweden)

    Sahar Omidpanah

    2015-01-01

    Full Text Available Background: Contamination with aflatoxin, by Aspergillus flavus, is one the major challenges in agriculture and food industry. Preparation of organic products using natural components is widely considered these days. Aims: In this study, effects of aqueous extracts of five medicinal herbs, including thyme, senna, mentha, basil, and safflower on the growth of the A. flavus were investigated. Mterials and Methods: The extracts with different concentrations (200-800 µg/mL and polyethylene glycol with the equal osmotic potential of plant extracts were added to the potato dextrose agar medium to evaluate fungus growth after 7 days using agar dilution method. Benomyl, a fungicide, was used as a positive standard. The tests were performed in triplicate, and the mean diameters of fungus growth were calculated as well. Results and Conclusion: All concentrations of the plants extracts significantly inhibited the fungus growth in comparison with each other and control treatments, while the extracts of thyme and safflower manifested the most effective prohibition compared to benomyl with minimum inhibitory concentration of 200 and 400 µg/mL, respectively.

  8. In silico analysis of β-mannanases and β-mannosidase from Aspergillus flavus and Trichoderma virens UKM1

    Science.gov (United States)

    Yee, Chai Sin; Murad, Abdul Munir Abdul; Bakar, Farah Diba Abu

    2013-11-01

    A gene encoding an endo-β-1,4-mannanase from Trichoderma virens UKM1 (manTV) and Aspergillus flavus UKM1 (manAF) was analysed with bioinformatic tools. In addition, A. flavus NRRL 3357 genome database was screened for a β-mannosidase gene and analysed (mndA-AF). These three genes were analysed to understand their gene properties. manTV and manAF both consists of 1,332-bp and 1,386-bp nucleotides encoding 443 and 461 amino acid residues, respectively. Both the endo-β-1,4-mannanases belong to the glycosyl hydrolase family 5 and contain a carbohydrate-binding module family 1 (CBM1). On the other hand, mndA-AF which is a 2,745-bp gene encodes a protein sequence of 914 amino acid residues. This β-mannosidase belongs to the glycosyl hydrolase family 2. Predicted molecular weight of manTV, manAF and mndA-AF are 47.74 kDa, 49.71 kDa and 103 kDa, respectively. All three predicted protein sequences possessed signal peptide sequence and are highly conserved among other fungal β-mannanases and β-mannosidases.

  9. Chemoprevention by essential oil of turmeric leaves (Curcuma longa L.) on the growth of Aspergillus flavus and aflatoxin production.

    Science.gov (United States)

    Sindhu, S; Chempakam, B; Leela, N K; Suseela Bhai, R

    2011-05-01

    Turmeric is well known for a wide range of medicinal properties. Essential oil of turmeric leaves (Curcuma longa L.) were evaluated at varying concentrations of 0.01, 0.05, 0.1, 0.5, 0.75, 1.0 and 1.5% (v/v) in Yeast Extract Sucrose (YES) broth inoculated with spore suspension of Aspergillus flavus of 10(6)conidia/ml. These were evaluated for their potential in the control of aflatoxigenic fungus A. flavus and aflatoxin production. Turmeric leaf oil exhibited 95.3% and 100% inhibition of toxin production respectively at 1.0% and 1.5%. The extent of inhibition of fungal growth and aflatoxin production was dependent on the concentration of essential oil used. The oil exhibited significant inhibition of fungal growth as well as aflatoxins B(1) and G(1) production. The LD(50) and LD(90) were also determined. GC-MS analysis of the oil showed α-phellandrene, p-cymene and terpinolene as the major components in turmeric leaf oil. The possibility of using these phytochemical components as bio-preservatives for storage of spices is discussed.

  10. Effect of Zataria multiflora Boiss. essential oil on growth and aflatoxin formation by Aspergillus flavus in culture media and cheese.

    Science.gov (United States)

    Gandomi, Hassan; Misaghi, Ali; Basti, Afshin Akhondzadeh; Bokaei, Saeed; Khosravi, Alireza; Abbasifar, Arash; Javan, Ashkan Jebelli

    2009-10-01

    The effect of Zataria multiflora Boiss. essential oil (EO) against growth, spore production and aflatoxin formation by Aspergillus flavus ATCC 15546 was investigated in synthetic media as well as Iranian ultra-filtered white cheese in brine. EO effectively inhibited radial growth and spore production on potato dextrose agar (PDA) in a dose-dependent manner. At 200 ppm, the radial growth and sporulation reduced by 79.4% and 92.5%, respectively. The growth was completely prevented at EO400 ppm on PDA, and minimum fungicidal concentration (MFC) of the oil was estimated at 1000 ppm. The oil also significantly suppressed mycelial growth and aflatoxin synthesis in broth medium at all concentrations tested (Paflatoxin accumulation reduced by 90% and 99.4%, respectively. The EO at all concentrations tested, had an inhibitory effect against radial fungal growth and aflatoxin production by A. flavus in cheese. However, no concentration of EO examined was able to completely inhibit the growth and aflatoxin production in cheese. The results suggested the potential substitution of the antifungal chemicals by this EO as a natural inhibitor to control the growth of molds in foods such as cheese.

  11. Effect of Citrus reticulata and Cymbopogon citratus essential oils on Aspergillus flavus growth and aflatoxin production on Asparagus racemosus.

    Science.gov (United States)

    Singh, Priyanka; Shukla, Ravindra; Kumar, Ashok; Prakash, Bhanu; Singh, Shubhra; Dubey, Nawal Kishore

    2010-09-01

    Essential oils extracted from Citrus reticulata and Cymbopogon citratus were tested in vitro against the toxigenic strain of Aspergillus flavus, isolated from the tuberous roots of Asparagus racemosus, used in preparation of herbal drugs. The essential oils completely inhibited the growth of A. flavus at 750 ppm and also exhibited a broad fungitoxic spectrum against nine additional fungi isolated from the roots. Citrus reticulata and Cymbopogon citratus essential oils completely inhibited aflatoxin B(1) production at 750 and 500 ppm, respectively. During in vivo investigation, the incidence of fungi and aflatoxin B(1) production decreased considerably in essential oil-treated root samples. The findings thus indicate possible exploitation of the essential oils as effective inhibitor of aflatoxin B(1) production and as post-harvest fungitoxicant of traditionally used plant origin for the control of storage fungi. These essential oils may be recommended as plant-based antifungals as well as aflatoxin B(1) suppressors in post-harvest processing of herbal samples.

  12. The inhibitory effect of Bacillus megaterium on aflatoxin and cyclopiazonic acid biosynthetic pathway gene expression in Aspergillus flavus.

    Science.gov (United States)

    Kong, Qing; Chi, Chen; Yu, Jiujiang; Shan, Shihua; Li, Qiyu; Li, Qianting; Guan, Bin; Nierman, William C; Bennett, Joan W

    2014-06-01

    Aspergillus flavus is one of the major moulds that colonize peanut in the field and during storage. The impact to human and animal health, and to the economy in agriculture and commerce, is significant since this mold produces the most potent known natural toxins, aflatoxins, which are carcinogenic, mutagenic, immunosuppressive, and teratogenic. A strain of marine Bacillus megaterium isolated from the Yellow Sea of East China was evaluated for its effect in inhibiting aflatoxin formation in A. flavus through down-regulating aflatoxin pathway gene expression as demonstrated by gene chip analysis. Aflatoxin accumulation in potato dextrose broth liquid medium and liquid minimal medium was almost totally (more than 98 %) inhibited by co-cultivation with B. megaterium. Growth was also reduced. Using expression studies, we identified the fungal genes down-regulated by co-cultivation with B. megaterium across the entire fungal genome and specifically within the aflatoxin pathway gene cluster (aflF, aflT, aflS, aflJ, aflL, aflX). Modulating the expression of these genes could be used for controlling aflatoxin contamination in crops such as corn, cotton, and peanut. Importantly, the expression of the regulatory gene aflS was significantly down-regulated during co-cultivation. We present a model showing a hypothesis of the regulatory mechanism of aflatoxin production suppression by AflS and AflR through B. megaterium co-cultivation.

  13. Variabilidade de produção de aflatoxinas por linhagens de Aspergillus flavus em diferentes tempos de manutenção Aflatoxin production variability by Aspergillus flavus strains after different storage times

    Directory of Open Access Journals (Sweden)

    M.H. Taniwaki

    1993-05-01

    Full Text Available O presente trabalho fui realizado com a finalidade de se estudar a produção de aflatoxinas por linhagens de A. flavus, recém isoladas, em diferentes tempos de manutenção, a fim de contribuir para um melhor entendimento do mecanismo de variação na produção de aflatoxinas. Para isso, foram utilizadas três linhagens de A. flavus produtoras de aflatoxinas, classificadas como: a grande produtora; b média produtora e c baixa produtora. Neste experimento, que se estendeu por 280 dias, os fungos foram estudados em dois métodos de preservação: mantido em óleo mineral, no meio Czapeck, e repicado periodicamente em meio Czapeck modificado. A análise da produção de aflatoxinas foi efetuada de 30 em 30 dias. A quantificação da toxina foi feita por cromatografía em camada delgada, pela técnica de avaliação visual, de diluição até extinção. Foi constatada uma variação na produção de toxina em todas as linhagens, contudo elas não perderam suas características originais.Aflatoxin production by strains recently isolated of Aspergillus flavus was studied, after different storage times understand the mechanisms of possible variations in aflatoxin production. Three A. flavus aflatoxin producing strains were utilized, classified as: a high producer; b medium producer and c low producer. The experiment lasted 280 days and the moulds were studied by two preservation methods: oil covered slants on Czapeck's medium and periodic transfer on Czapeck's modified medium. Quantification of the aflatoxin produced was made at 30 day intervals, on thin-layer chromatography and visual determination by the dilution-to-extinction technique. The production of aflatoxin by all strains varied but they did not lose their initial characteristics. Microscopic examinations revealed thickened zones and hifal enlargements over some globous structures that may be related to aflatoxin production sites.

  14. Effects of gamma radiation and electron beam on samples of the Brazil nuts artificially inoculated with Aspergillus flavus; Efeitos da radiacao gama e feixe de eletrons sobre amostras de castanhas-do-Brasil inoculadas artificialmente com Aspergillus flavus

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, Ednei Assuncao Antunes

    2012-07-01

    The high level of contamination by aflatoxin produced by fungi in lots of Brazil nuts and the strict control by importing countries in relation to the levels of toxins in food, European Union countries decided in 2003 by the return of these lots products from Brazil. Despite the economic loss represented by contamination by toxigenic fungi in Brazil nuts, a major product of extractive Northern of Brazil, studies are still preliminary as the control of contamination aflatoxigenic fungal using methods such as gamma radiation (G.R) and mainly, electron beam (E.B). These facts motivated this research, which aimed to evaluate the effects of gamma radiation and application of electron beam in samples of Brazil nut artificially inoculated with Aspergillus flavus. This goal, we were studied 50 samples of the Brazil nut previously inoculated with spores of A. flavus and subsequently incubated at 30 °C in relative humidity controlled at 93%. After incubation, period of 15 days, the average water activity of the samples was 0.80, the samples were divided into 5 groups that received the following doses of radiation: control (0 kGy), 5 and 10 kGy 5 E.B and G.R. The mycobiota was performed by serial dilution, plated on surface using potato dextrose agar. The results demonstrated that treatment with E.B using a dose of 5 kGy and 10 kGy resulted in reduced growth of A. flavus in 74% (37/50) and 94% (47/50) of samples. The samples treated with G.R at the dose of 5 kGy and 10 kGy no fungal growth occurred in 92% (46/50) 100% (50/50) of. The study of aflatoxins showed that doses of E.B of 5 kGy and 10 kGy reduced levels of AFB1 at 53.32% and 65.66% respectively. The application of gamma rays at doses of 5 and 10 kGy reduced levels of toxins in 70.61% and 84.15% respectively. This result may be attributed to higher penetrability of gamma radiation. Sensory analysis showed greater acceptance of the judges for the samples irradiated with E.B and G.R at the dose of 10 kGy. We concluded

  15. NO对黄曲霉产毒的影响研究%Effect of NO on aftatoxin production of Aspergillus flavus

    Institute of Scientific and Technical Information of China (English)

    张永帅; 王淼焱; 孙俊良; 梁新红; 张婷

    2014-01-01

    The effects of different concentrations of NO donor SNP and NO scavenger cPTIO on aflatoxin production of Aspergillus flavus was weinvestigated in this study.The results showed that:SNP is added in the process of A. flavus training can lead to NO increase in the number of quantity,reduce the amount of aflatoxin toxin-producing,A. flavus NO amount reduced and leading to A. flavus toxin-producing quantity increase when adding NO scavenger cPTIO,Aspergillus flavus producing aflatoxin is 0.87 μg/mL,lower than when no added (including 16.35μg/mL) and add the SNP A. flavus NO fluorescence value is significantly increased when the amount of addition of SNP is 0.200 mmol.NO to A. flavus toxin-producing has certain inhibitory effect.%研究了不同浓度NO供体SNP和NO清除剂cPTIO对黄曲霉菌产毒的影响.结果表明:在黄曲霉培养过程中添加SNP能导致黄曲霉菌体内NO量增多,产毒量减少;当添加NO清除剂cPTIO时黄曲霉菌体内NO量降低,产毒量增加.SNP浓度为0.200 mmol/L时,黄曲霉产黄曲霉毒素的量为0.87μg/mL,比不添加时降低了16.35μg/mL,而且添加SNP的黄曲霉菌体NO荧光值明显增高.说明NO对黄曲霉产毒有一定的抑制作用.

  16. A Network Approach of Gene Co-expression in the Zea mays/Aspergillus flavus Pathosystem to Map Host/Pathogen Interaction Pathways.

    Science.gov (United States)

    Musungu, Bryan M; Bhatnagar, Deepak; Brown, Robert L; Payne, Gary A; OBrian, Greg; Fakhoury, Ahmad M; Geisler, Matt

    2016-01-01

    A gene co-expression network (GEN) was generated using a dual RNA-seq study with the fungal pathogen Aspergillus flavus and its plant host Zea mays during the initial 3 days of infection. The analysis deciphered novel pathways and mapped genes of interest in both organisms during the infection. This network revealed a high degree of connectivity in many of the previously recognized pathways in Z. mays such as jasmonic acid, ethylene, and reactive oxygen species (ROS). For the pathogen A. flavus, a link between aflatoxin production and vesicular transport was identified within the network. There was significant interspecies correlation of expression between Z. mays and A. flavus for a subset of 104 Z. mays, and 1942 A. flavus genes. This resulted in an interspecies subnetwork enriched in multiple Z. mays genes involved in the production of ROS. In addition to the ROS from Z. mays, there was enrichment in the vesicular transport pathways and the aflatoxin pathway for A. flavus. Included in these genes, a key aflatoxin cluster regulator, AflS, was found to be co-regulated with multiple Z. mays ROS producing genes within the network, suggesting AflS may be monitoring host ROS levels. The entire GEN for both host and pathogen, and the subset of interspecies correlations, is presented as a tool for hypothesis generation and discovery for events in the early stages of fungal infection of Z. mays by A. flavus.

  17. Inhibition of the Aspergillus flavus Growth and Aflatoxin B1 Contamination on Pistachio Nut by Fengycin and Surfactin-Producing Bacillus subtilis UTBSP1

    Science.gov (United States)

    Farzaneh, Mohsen; Shi, Zhi-Qi; Ahmadzadeh, Masoud; Hu, Liang-Bin; Ghassempour, Alireza

    2016-01-01

    In this study, the treatment of pistachio nuts by Bacillus subtilis UTBSP1, a promising isolate to degrade aflatoxin B1 (AFB1), caused to reduce the growth of Aspergillus flavus R5 and AFB1 content on pistachio nuts. Fluorescence probes revealed that the cell free supernatant fluid from UTBSP1 affects spore viability considerably. Using high-performance liquid chromatographic (HPLC) method, 10 fractions were separated and collected from methanol extract of cell free supernatant fluid. Two fractions showed inhibition zones against A. flavus. Mass spectrometric analysis of the both antifungal fractions revealed a high similarity between these anti-A. flavus compounds and cyclic-lipopeptides of surfactin, and fengycin families. Coproduction of surfactin and fengycin acted in a synergistic manner and consequently caused a strong antifungal activity against A. flavus R5. There was a positive significant correlation between the reduction of A. flavus growth and the reduction of AFB1 contamination on pistachio nut by UTBSP1. The results indicated that fengycin and surfactin-producing B. subtilis UTBSP1 can potentially reduce A. flavus growth and AFB1 content in pistachio nut. PMID:27298596

  18. Inhibition of the Aspergillus flavus Growth and Aflatoxin B1 Contamination on Pistachio Nut by Fengycin and Surfactin-Producing Bacillus subtilis UTBSP1

    Directory of Open Access Journals (Sweden)

    Mohsen Farzaneh

    2016-06-01

    Full Text Available In this study, the treatment of pistachio nuts by Bacillus subtilis UTBSP1, a promising isolate to degrade aflatoxin B1 (AFB1, caused to reduce the growth of Aspergillus flavus R5 and AFB1 content on pistachio nuts. Fluorescence probes revealed that the cell free supernatant fluid from UTBSP1 affects spore viability considerably. Using high-performance liquid chromatographic (HPLC method, 10 fractions were separated and collected from methanol extract of cell free supernatant fluid. Two fractions showed inhibition zones against A. flavus. Mass spectrometric analysis of the both antifungal fractions revealed a high similarity between these anti-A. flavus compounds and cyclic-lipopeptides of surfactin, and fengycin families. Coproduction of surfactin and fengycin acted in a synergistic manner and consequently caused a strong antifungal activity against A. flavus R5. There was a positive significant correlation between the reduction of A. flavus growth and the reduction of AFB1 contamination on pistachio nut by UTBSP1. The results indicated that fengycin and surfactin-producing B. subtilis UTBSP1 can potentially reduce A. flavus growth and AFB1 content in pistachio nut.

  19. 大米中黄曲霉的微波杀菌工艺优化%Optimization of microwave sterilization process on Aspergillus flavus from rice

    Institute of Scientific and Technical Information of China (English)

    李科静; 徐艳阳; 关欢欢

    2015-01-01

    目的:探索微波处理对大米中黄曲霉的杀菌工艺条件。方法以黄曲霉孢子减少对数周期为检测指标,考察微波功率、微波时间和装载量对黄曲霉孢子减少对数周期的影响,在单因素试验的基础上,采用3因素3水平响应面法设计并优化微波杀菌工艺,建立相应的回归方程。结果微波杀菌最佳工艺条件为:微波功率231 W,微波时间32 s,装载量34 g,在此条件下黄曲霉孢子减少对数周期为3.496±0.069,实际值与理论值的相对误差为-9.97%。结论本研究获得了微波杀灭大米中黄曲霉的最佳工艺条件,应用微波技术可以作为粮食杀菌的一种有效手段。%Objective To explore effects of microwave sterilization on Aspergillus flavus from rice. Methods Effects of microwave power, microwave time, and loads of rice on log-periodic reduction of Aspergillus flavus spores were investigated and the log-periodic reduction of Aspergillus flavus spores was determined as an indicator. Based on the single-factor experiments, optimal microwave sterilization process was studied by response surface methodology and corresponding regression equation was established. Results Optimum sterilization conditions were as follows: microwave power of 231 W, microwave time of 32 s, and loads of rice of 34 g. Under these conditions, log-periodic reduction of Aspergillus flavus spores was 3.496±0.069, and relative error between determined and predicted value of log-periodic reduction of Aspergillus flavus spores was -9.97%. Conclusion The optimal sterilization conditions of microwave for Aspergillus flavus spores from rice were obtained, and the microwave technique can be an effective method for grains’ sterilization.

  20. Mycotoxin production and predictive modelling kinetics on the growth of Aspergillus flavus and Aspergillus parasiticus isolates in whole black peppercorns (Piper nigrum L).

    Science.gov (United States)

    Yogendrarajah, Pratheeba; Vermeulen, An; Jacxsens, Liesbeth; Mavromichali, Evangelia; De Saeger, Sarah; De Meulenaer, Bruno; Devlieghere, Frank

    2016-07-02

    The growth and mycotoxin production of three Aspergillus flavus isolates and an Aspergillus parasiticus isolate were studied in whole black peppercorns (Piper nigrum L.) using a full factorial design with seven water activity (aw) (0.826-0.984) levels and three temperatures (22, 30 and 37°C). Growth rates and lag phases were estimated using linear regression. Diverse secondary models were assessed for their ability to describe the radial growth rate as a function of individual and combined effect of aw and temperature. Optimum radial growth rate ranged from 0.75±0.04 to 2.65±0.02mm/day for A. flavus and 1.77±0.10 to 2.50±0.10mm/day for A. parasiticus based on the Rosso cardinal estimations. Despite the growth failure of some isolates at marginal conditions, all the studied models showed good performance to predict the growth rates. Validation of the models was performed on independently derived data. The bias factors (0.73-1.03), accuracy factors (0.97-1.36) and root mean square error (0.050-0.278) show that the examined models are conservative predictors of the colony growth rate of both fungal species in black peppers. The Rosso cardinal model can be recommended to describe the individual aw effect while the extended Gibson model was the best model for describing the combined effect of aw and temperature on the growth rate of both fungal species in peppercorns. Temperature optimum ranged from 30 to 33°C, while aw optimum was 0.87-0.92 as estimated by multi-factorial cardinal model for both species. The estimated minimum temperature and aw for A. flavus and A. parasiticus for growth were 11-16°C and 0.73-0.76, respectively, hence, achieving these conditions should be considered during storage to prevent the growth of these mycotoxigenic fungal species in black peppercorns. Following the growth study, production of mycotoxins (aflatoxins B1, B2, G1, G2, sterigmatocystin and O-methyl sterigmatocystin (OMST)) was quantified using LC-MS/MS. Very small

  1. [Effect of alcoholic extracts of wild plants on the inhibition of growth of Aspergillus flavus, Aspergillus niger, Penicillium chrysogenum, Penicillium expansum, Fusarium moniliforme and Fusarium poae moulds].

    Science.gov (United States)

    Tequida-Meneses, Martín; Cortez-Rocha, Mario; Rosas-Burgos, Ema Carina; López-Sandoval, Susana; Corrales-Maldonado, Consuelo

    2002-06-01

    Fungicidal activity of wild plants Larrea tridentata, Karwinskia humboldtiana, Ricinus communis, Eucalyptus globulus, Ambrosia ambrosioides, Nicotiana glauca, Ambrosia confertiflora, Datura discolor, Baccharis glutinosa, Proboscidea parviflora, Solanum rostratum, Jatropha cinerea, Salpianthus macrodonthus y Sarcostemma cynanchoides was evaluated against the moulds species Aspergillus flavus, Aspergillus niger, Penicillium chrysogenum, Penicillium expansum, Fusarium poae y Fusarium moniliforme moulds species. Alcoholic extracts 6% (w/v) were prepared using six grams of dried plant powders (leaves and stems) and alcohol (70% ethanol or 70% methanol). A spore suspension (1x10(6); ufc/ml) of each mould was prepared by adding saline solution (0.85%) and 0.1% tween 80. The extracts were mixed with Czapeck yeast agar (CYA) at 45-50 degrees C in 1:10 relation on Petri dishes. Triplicate Petri dishes of each treatment and for each mould were centrally inoculated and three Petri dishes were used without treatment as controls. The inoculated dishes and controls were incubated at 25 +/- 2 degrees C for eight days. The incubated dishes were examined each 48 h and after the colony diameter (radial growth) was measured. Two mould species were controlled by L. tridentata, B. glutinosa and P. parviflora. Extracts of L. tridentata in methanol or ethanol at 41.5-100% inhibited all six species of moulds.

  2. rtfA, a putative RNA-Pol II transcription elongation factor gene, is necessary for normal morphological and chemical development in Aspergillus flavus.

    Science.gov (United States)

    Lohmar, Jessica M; Harris-Coward, Pamela Y; Cary, Jeffrey W; Dhingra, Sourabh; Calvo, Ana M

    2016-06-01

    The filamentous fungus Aspergillus flavus is an agriculturally important opportunistic plant pathogen that produces potent carcinogenic compounds called aflatoxins. We identified the A. flavus rtfA gene, the ortholog of rtf1 in Saccharomyces cerevisiae and rtfA in Aspergillus nidulans. Interestingly, rtfA has multiple cellular roles in this mycotoxin-producing fungus. In this study, we show that rtfA regulates conidiation. The rtfA deletion mutant presented smaller conidiophores with significantly reduced conidial production compared to the wild-type strain. The absence of rtfA also resulted in a significant decrease or lack of sclerotial production under conditions that allowed abundant production of these resistance structures in the wild type. Importantly, the deletion of rtfA notably reduced the production of aflatoxin B1, indicating that rtfA is a regulator of mycotoxin biosynthesis in A. flavus. In addition, the deletion rtfA also altered the production of several unknown secondary metabolites indicating a broader regulatory scope. Furthermore, our study revealed that rtfA controls the expression of the global regulators veA and laeA, which further influence morphogenesis and secondary metabolism in A. flavus.

  3. Nutritional changes in powdered red pepper upon in vitro infection of Aspergillus flavus Alterações nutricionais em pimenta vermelha em pó após infecção in vitro com Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Smita Tripathi

    2009-03-01

    Full Text Available Quantitative losses in various biochemical constituents like capsaicin, carotenes, ascorbic acid, polyphenols, mineral matter, sugars (soluble and insoluble, protein and fat were estimated after the successful growth of Aspergillus flavus for 30 days on powdered red pepper. The fungal biomass was measured by ergosterol content and Aflatoxin B1 by HPLC. Amongst the various nutritional constituents evaluated for nutritional losses and changes the highest nutritional loss was reported in total carotenoids (88.55% followed by total sugars (85.5%. The protein content of the infected sample increased from 18.01% to 23%. The nutritional profile of chilli powder (Capsicum annum var. sannam L. shows highest share of total soluble sugars (32.89% and fiber content (21.05%, followed by protein (18.01% and fat (13.32% making it an ideal solid - substrate for mould growth. At the end of incubation the fungal biomass was 192. 25 mg / 100 gram powder, total plate count 17.5 X 10 4 CFU/g and Aflatoxin B1 content was 30.06 µg / kg.Foram avaliadas as perdas de vários constituintes bioquímicos como capsaicina, carotenos, acido ascórbico, polifenóis, matéria orgânica, açucares (solúveis e insolúveis, proteína e gordura em pimenta vermelha em pó após a multiplicação de Aspergillus flavus por 30 dias. A biomassa fúngica foi mensurada pelo conteúdo de ergosterol e aflatoxina por HPLC. Entre os vários constituintes avaliados, a maior perda foi a de carotenóides totais (88,55%, seguido de açucares totais (85,5%. O conteúdo protéico da amostra infectada aumentou de 18,01% para 23%. O perfil nutricional da pimenta em pó (Capsicum annum var. sannam L. indica alto teor de açucares totais (32,89% e fibras (21,05%, seguido de proteína (18,01% e gordura (13,32%, tornando-a um substrato ideal para crescimento de fungos. Ao final dos 30 dias, a biomassa fúngica foi 192,25 mg/100g, a contagem total em placas foi 17,5 x 10(4 CFU/g e o conteúdo de

  4. Perillaldehyde, a Promising Antifungal Agent Used in Food Preservation, Triggers Apoptosis through a Metacaspase-Dependent Pathway in Aspergillus flavus.

    Science.gov (United States)

    Tian, Jun; Wang, Yanzhen; Lu, Zhaoqun; Sun, Chunhui; Zhang, Man; Zhu, Aihua; Peng, Xue

    2016-10-05

    In the present study, we provide detailed insights into perillaldehyde (PAE)'s mechanisms of action on Aspergillus flavus and offer evidence in favor of the induction of an apoptosis-like phenotype. Specifically, PAE's antifungal mode of action was investigated through the detection of mitochondrial membrane potential (MtΔψ) and phosphatidylserine (PS) exposure, as well as intracellular Ca(2+) level, reactive oxygen species accumulation, and metacaspase activation. This was done by way of fluorometry, measuring DNA fragmentation, and condensation by fluorescent microscopy. Furthermore, we searched for phenotypic changes characteristic of apoptosis by transmission electron microscopy and flow cytometry, determining the amount of cytochrome c released using Western blotting. Results indicated that cultivation of A. flavus in the presence of PAE caused depolarization of MtΔψ, rapid DNA condensation, large-scale DNA fragmentation, and an elevation of intracellular Ca(2+) level. The percentage of early apoptotic cells with exposure of PS were 27.4% and 48.7%, respectively, after 9 h incubations with 0.25 and 0.5 μL/mL of PAE. The percentage of stained cells with activated intracellular metacaspases exposed to PAE at concentrations of 0.25 and 0.5 μL/mL compared with control subjects were increased by 28.4 ± 3.25% and 37.9 ± 4.24%, respectively. The above results has revealed that PAE induces fungal apoptosis through a caspase-dependent mitochondrial pathway. In all, our findings provide a novel mechanism for exploring a possible antifungal agent used in food preservation.

  5. Transcriptional Profiles Uncover Aspergillus flavus-Induced Resistance in Maize Kernels

    Directory of Open Access Journals (Sweden)

    Zhi-Yuan Chen

    2011-06-01

    Full Text Available Aflatoxin contamination caused by the opportunistic pathogen A. flavus is a major concern in maize production prior to harvest and through storage. Previous studies have highlighted the constitutive production of proteins involved in maize kernel resistance against A. flavus’ infection. However, little is known about induced resistance nor about defense gene expression and regulation in kernels. In this study, maize oligonucleotide arrays and a pair of closely-related maize lines varying in aflatoxin accumulation were used to reveal the gene expression network in imbibed mature kernels in response to A. flavus’ challenge. Inoculated kernels were incubated 72 h via the laboratory-based Kernel Screening Assay (KSA, which highlights kernel responses to fungal challenge. Gene expression profiling detected 6955 genes in resistant and 6565 genes in susceptible controls; 214 genes induced in resistant and 2159 genes induced in susceptible inoculated kernels. Defense related and regulation related genes were identified in both treatments. Comparisons between the resistant and susceptible lines indicate differences in the gene expression network which may enhance our understanding of the maize-A. flavus interaction.

  6. Identification of lipoxygenase (LOX) genes from legumes and their responses in wild type and cultivated peanut upon Aspergillus flavus infection

    Science.gov (United States)

    Song, Hui; Wang, Pengfei; Li, Changsheng; Han, Suoyi; Lopez-Baltazar, Javier; Zhang, Xinyou; Wang, Xingjun

    2016-01-01

    Lipoxygenase (LOX) genes are widely distributed in plants and play crucial roles in resistance to biotic and abiotic stress. Although they have been characterized in various plants, little is known about the evolution of legume LOX genes. In this study, we identified 122 full-length LOX genes in Arachis duranensis, Arachis ipaënsis, Cajanus cajan, Cicer arietinum, Glycine max, Lotus japonicus and Medicago truncatula. In total, 64 orthologous and 36 paralogous genes were identified. The full-length, polycystin-1, lipoxygenase, alpha-toxin (PLAT) and lipoxygenase domain sequences from orthologous and paralogous genes exhibited a signature of purifying selection. However, purifying selection influenced orthologues more than paralogues, indicating greater functional conservation of orthologues than paralogues. Neutrality and effective number of codons plot results showed that natural selection primarily shapes codon usage, except for C. arietinum, L. japonicas and M. truncatula LOX genes. GCG, ACG, UCG, CGG and CCG codons exhibited low relative synonymous codon usage (RSCU) values, while CCA, GGA, GCU, CUU and GUU had high RSCU values, indicating that the latter codons are strongly preferred. LOX expression patterns differed significantly between wild-type peanut and cultivated peanut infected with Aspergillus flavus, which could explain the divergent disease resistance of wild progenitor and cultivars. PMID:27731413

  7. The Breeding of a Pigment Mutant Strain of Steroid Hydroxylation Aspergillus Flavus by Low Energy Ion Implantation

    Institute of Scientific and Technical Information of China (English)

    YE Hui; MA Jingming; FENG Chun; CHENG Ying; ZHU Suwen; CHENG Beijiu

    2009-01-01

    In the process of the fermentation of steroid C11α-hydroxylgenation strain Aspergillus flavus AF-ANo208.a red pigment is derived.which will affect the isolation and purification of the target product.Low energy ion beam implantation is a new tool for breeding excellent mutant strains.In this study,the ion beam implantation experiments were performed by infusing two different ions:argon ion(Ar+)and nitrogen ion(N+).The results showed that the optimal ion implantation was N+ with an optimum dose of 2.08×1015 ions/cm2.with which the mutant strain AF-ANml6 that produced no red pigment was obtained.The strain had high genetic stability and kept the strong capacity of C11α-hydroxylgenation,which could be utilized in industrial fermentation.The difierences between the original strain and the mutant strain at a molecular level were analyzed by randomly amplified polymorphic DNA(RAPD).The results indicated that the frequency of variation Was 7.00%,which would establish the basis of application investigation into the breeding of pigment mutant strains by low energy ion implantation.

  8. Construction and preliminary evaluation of an Aspergillus flavus reporter gene construct as a potential tool for screening aflatoxin resistance.

    Science.gov (United States)

    Brown, Robert L; Brown-Jenco, Carmen S; Bhatnagar, Deepak; Payne, Gary A

    2003-10-01

    Effective preharvest strategies to eliminate aflatoxin accumulation in crops are not presently available. The molecular biology of aflatoxin biosynthesis has been extensively studied, and genetic and molecular tools such as reporter gene systems for the measurement of fungal growth have been developed. A reporter construct containing the Aspergillus flavus beta-tubulin gene promoter fused to Escherichia coli beta-glucuronidase (GUS) has been shown to be a reliable tool for the indirect measurement of fungal growth in maize kernels. Since cost-saving alternative methods for the direct measurement of aflatoxin levels are needed to facilitate more widespread field and laboratory screening of maize lines, a new reporter gene construct involving the promoter region of the omtA gene of the aflatoxin biosynthetic pathway was constructed and tested. Expression of GUS activity by this construct (omtA::GUS) was correlated with aflatoxin accumulation in culture. In the fungal transformant GAP26-1, which harbors this construct, aflatoxin production and GUS expression on sucrose-containing medium showed the same temporal pattern of toxin induction. Furthermore, GUS expression by GAP26-1 was shown to be associated with aflatoxin accumulation in maize kernels inoculated with this strain. Our results suggest that this and other reporter gene pathway promoter constructs may provide superior alternatives to direct aflatoxin quantification with respect to time, labor, and materials for the screening of maize lines for resistance to aflatoxin accumulation.

  9. Efficacy of a coating composed of chitosan from Mucor circinelloides and carvacrol to control Aspergillus flavus and the quality of cherry tomato fruits.

    Science.gov (United States)

    de Souza, Evandro L; Sales, Camila V; de Oliveira, Carlos E V; Lopes, Laênia A A; da Conceição, Maria L; Berger, Lúcia R R; Stamford, Thayza C M

    2015-01-01

    Cherry tomato (Lycopersicon esculentum Mill) fruits are susceptible to contamination by Aspergillus flavus, which may cause the development of fruit rot and significant postharvest losses. Currently there are significant drawbacks for the use of synthetic fungicides to control pathogenic fungi in tomato fruits, and it has increased the interest in exploring new alternatives to control the occurrence of fungal infections in these fruits. This study evaluated the efficacy of chitosan (CHI) from Mucor circinelloides in combination with carvacrol (CAR) in inhibiting A. flavus in laboratory media and as a coating on cherry tomato fruits (25°C, 12 days and 12°C, 24 days). During a period of storage, the effect of coatings composed of CHI and CAR on autochthonous microflora, as well as on some quality characteristics of the fruits such as weight loss, color, firmness, soluble solids, and titratable acidity was evaluated. CHI and CAR displayed MIC valuesof 7.5 mg/mL and 10 μL/mL, respectively, against A. flavus. The combined application of CHI (7.5 or 3.75 mg/mL) and CAR (5 or 2.5 μL/mL) strongly inhibited the mycelial growth and spore germination of A. flavus. The coating composed of CHI (3.75 mg/mL) and CAR (2.5 or 1.25 μL/mL) inhibited the growth of A. flavus in artificially contaminated fruits, as well as the native fungal microflora of the fruits stored at room or low temperature. The application of the tested coatings preserved the quality of cherry tomato fruits as measured by some physicochemical attributes. From this, composite coatings containing CHI and CAR offer a promising alternative to control postharvest infection caused by A. flavus or native fungal microflora in fresh cherry tomato fruits without negatively affecting their quality over storage.

  10. Efficacy of a coating composed of chitosan from Mucor circinelloides and carvacrol to control Aspergillus flavus and the quality of cherry tomato fruits

    Science.gov (United States)

    de Souza, Evandro L.; Sales, Camila V.; de Oliveira, Carlos E. V.; Lopes, Laênia A. A.; da Conceição, Maria L.; Berger, Lúcia R. R.; Stamford, Thayza C. M.

    2015-01-01

    Cherry tomato (Lycopersicon esculentum Mill) fruits are susceptible to contamination by Aspergillus flavus, which may cause the development of fruit rot and significant postharvest losses. Currently there are significant drawbacks for the use of synthetic fungicides to control pathogenic fungi in tomato fruits, and it has increased the interest in exploring new alternatives to control the occurrence of fungal infections in these fruits. This study evaluated the efficacy of chitosan (CHI) from Mucor circinelloides in combination with carvacrol (CAR) in inhibiting A. flavus in laboratory media and as a coating on cherry tomato fruits (25°C, 12 days and 12°C, 24 days). During a period of storage, the effect of coatings composed of CHI and CAR on autochthonous microflora, as well as on some quality characteristics of the fruits such as weight loss, color, firmness, soluble solids, and titratable acidity was evaluated. CHI and CAR displayed MIC valuesof 7.5 mg/mL and 10 μL/mL, respectively, against A. flavus. The combined application of CHI (7.5 or 3.75 mg/mL) and CAR (5 or 2.5 μL/mL) strongly inhibited the mycelial growth and spore germination of A. flavus. The coating composed of CHI (3.75 mg/mL) and CAR (2.5 or 1.25 μL/mL) inhibited the growth of A. flavus in artificially contaminated fruits, as well as the native fungal microflora of the fruits stored at room or low temperature. The application of the tested coatings preserved the quality of cherry tomato fruits as measured by some physicochemical attributes. From this, composite coatings containing CHI and CAR offer a promising alternative to control postharvest infection caused by A. flavus or native fungal microflora in fresh cherry tomato fruits without negatively affecting their quality over storage. PMID:26257717

  11. Isolation and Identification of Aspergillus Flavus Strains and Analysis of Toxin - Producing Ability%黄曲霉菌株的分离、鉴定及产毒能力分析

    Institute of Scientific and Technical Information of China (English)

    杨生瑞; 屈凌波; 孙长坡; 沈晗; 沈瑾; 伍松陵

    2012-01-01

    Several Aspergillus flavus strains were isolated from moldy grain, then were identified by spore morphological and Molecular Biological Identification. The toxin - producing ability of strains were detected and analyzed by HPL?after fermentation. The results showed that experimental isolated strain were Aspergillus flavus and contains toxigenic key gene of afl; the toxin - producing ability was very different between these Aspergillus flavus strains. Aspergillus flavus 3. 4408 produce the hightest aflatoxin while Aspergillus flavus HDWS only produces a little. Even more, Aspergillus flavus 3.2572 could not produce aflatoxin under the same condition; Among aflatoxin -producing strains, some of the strains produce aflatoxin AFB1, AFB2, AFG1, AFG2 ,Aspergilius flavus HDWH only produces aflatoxin AFB1, AFB2.%对几株从发霉粮食中分离出的黄曲霉菌菌株进行形态学和分子生物学鉴定,并进行发酵培养和产毒能力的HPLC测定.结果表明:试验分离菌株均为黄曲霉菌株且含有黄曲霉毒素产生的关键基因aflR;黄曲霉菌株之间产毒能力差异巨大:黄曲霉菌株3.4408产毒量最高,黄曲霉菌株HDWS产毒量最低,黄曲霉菌株3.2572甚至不产生黄曲霉毒素;产生黄曲霉毒素菌株中部分黄曲霉菌株产生4种黄曲霉毒素AFB1、AFB2、AFG1、AFG2,黄曲霉菌株HDWH只产生黄曲霉毒素AFB1、AFB2.

  12. α--AMYLASES OF Aspergillus flavus var. oryzae AND Bacillus subtilis: THE SUBSTRATE SPECIFICITY AND RESISTANCE TO A NUMBER OF CHEMICALLY ACTIVE SUBSTANCES

    Directory of Open Access Journals (Sweden)

    K. V. Avdiyuk

    2013-06-01

    Full Text Available The ability of Aspergillus flavus var. oryzae 80428 and Bacillus subtilis 147 α-amylases to split different carbohydrate-containing substrates, such as maltose, sucrose, trehalose, dextrin, α- and β-cyclodextrin, amylose, amylopectin, glycogen, pullulan, soluble starch, insoluble starch, corn starch, wheat starch, dextran 500 has been studied. It was shown that investigated enzymes differ by substrate specificity. α-Amylase of A. flavus var. oryzae 80428 rapidly hydrolysed soluble potato and wheat starch, while the α-amylase of B. subtilis 147 — only wheat starch. Both enzymes don’t cleave maltose, α-cyclodextrin and dextran 500. A. flavus var. oryzae 80428 α-amylase display very small ability to hydrolyze pullulan, while α-amylase of B. subtilis 147 it does not act in general. The lowest values of Michaelis constant for both enzymes at splitting of glycogen have been obtained, indicating that enzymes have the greatest affinity to this substrate. The studies of influence of chemically active substances on activity of A. flavus var. oryzae 80428 and B. subtilis 147 ?-amylases show there are resistant to urea, deoxycholic acid, Tween-80, Triton X-100 and hydrogen peroxide. It’s indicate the enzymes tested may be competitive in compare with earlier described in literature enzymes. The obtained results give a possibility to propose in future usage these enzymes in different fields of industry, foremost in detergent industry.

  13. Genetic diversity of environmental Aspergillus flavus strains in the state of São Paulo, Brazil by random amplified polymorphic DNA

    Directory of Open Access Journals (Sweden)

    Alexandre Lourenço

    2007-09-01

    Full Text Available Aspergillus flavus is a very important toxigenic fungus that produces aflatoxins, a group of extremely toxic substances to man and animals. Toxigenic fungi can grow in feed crops, such as maize, peanuts, and soybeans, being thus of high concern for public health. There are toxigenic and non-toxigenic A. flavus variants, but the necessary conditions for expressing the toxigenic potential are not fully understood. Therefore, we have studied total-DNA polymorphism from toxigenic and non toxigenic A. flavus strains isolated from maize crops and soil at two geographic locations, 300 km apart, in the Southeast region of Brazil. Total DNA from each A. flavus isolate was extracted and subjected to polymerase chain reaction amplification with five randomic primers through the RAPD (random amplified polymorphic DNA technique. Phenetic and cladistic analyses of the data, based on bootstrap analyses, led us to conclude that RAPD was not suitable to discriminate toxigenic from non toxigenic strains. But the present results support the use of RAPD for strain characterization, especially for preliminary evaluation over extensive collections.

  14. Biotechnological advances for combating Aspergillus flavus and aflatoxin contamination in crops.

    Science.gov (United States)

    Bhatnagar-Mathur, Pooja; Sunkara, Sowmini; Bhatnagar-Panwar, Madhurima; Waliyar, Farid; Sharma, Kiran Kumar

    2015-05-01

    Aflatoxins are toxic, carcinogenic, mutagenic, teratogenic and immunosuppressive byproducts of Aspergillus spp. that contaminate a wide range of crops such as maize, peanut, and cotton. Aflatoxin not only affects crop production but renders the produce unfit for consumption and harmful to human and livestock health, with stringent threshold limits of acceptability. In many crops, breeding for resistance is not a reliable option because of the limited availability of genotypes with durable resistance to Aspergillus. Understanding the fungal/crop/environment interactions involved in aflatoxin contamination is therefore essential in designing measures for its prevention and control. For a sustainable solution to aflatoxin contamination, research must be focused on identifying and improving knowledge of host-plant resistance factors to aflatoxin accumulation. Current advances in genetic transformation, proteomics, RNAi technology, and marker-assisted selection offer great potential in minimizing pre-harvest aflatoxin contamination in cultivated crop species. Moreover, developing effective phenotyping strategies for transgenic as well as precision breeding of resistance genes into commercial varieties is critical. While appropriate storage practices can generally minimize post-harvest aflatoxin contamination in crops, the use of biotechnology to interrupt the probability of pre-harvest infection and contamination has the potential to provide sustainable solution.

  15. Activity of the aqueous extract from Polymnia sonchifolia leaves on growth and production of aflatoxin B1 by Aspergillus flavus Atividade do extrato aquoso de folhas de Polymnia sonchifolia no crescimento e produção de aflatoxina B1 por Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Marina M. Pinto

    2001-06-01

    Full Text Available The aqueous extract from Polymnia sonchifolia leaves (AE was tested for inhibitory activity on aflatoxin B1(AFB1 production and growth of Aspergillus flavus. The cytotoxicity of AE on Vero cells was also performed. Suspensions of A. flavus spores were inoculated into 50 mL of YES medium together with different concentrations of the AE. The aflatoxin B1 was extracted, analyzed by thin layer chromatography and quantified by photodensitometry. All the concentrations of AE induced inhibition of AFB1 production. The aqueous extract showed in vitro cytotoxicity to Vero cells only at concentrations above 500 µg/mL.Neste trabalho verificou-se a atividade do extrato aquoso de folhas de Polymnia sonchifolia no crescimento e na produção de aflatoxinas B1 por Aspergillus flavus. Suspensões de esporos de A. flavus foram inoculadas em 50 mL de meio de YES com diferentes concentrações do extrato aquoso. A aflatoxina B1 foi extraída e analisada por cromatografia de camada delgada e quantificada por fotodensitometria. Todas as concentrações testadas inibiram a produção de aflatoxina B1. O extrato aquoso apresentou citotoxicidade em células Vero somente em concentrações acima de 500 µg/mL.

  16. Genome-Wide Transcriptome Analysis of Cotton (Gossypium hirsutum L.) Identifies Candidate Gene Signatures in Response to Aflatoxin Producing Fungus Aspergillus flavus.

    Science.gov (United States)

    Bedre, Renesh; Rajasekaran, Kanniah; Mangu, Venkata Ramanarao; Sanchez Timm, Luis Eduardo; Bhatnagar, Deepak; Baisakh, Niranjan

    2015-01-01

    Aflatoxins are toxic and potent carcinogenic metabolites produced from the fungi Aspergillus flavus and A. parasiticus. Aflatoxins can contaminate cottonseed under conducive preharvest and postharvest conditions. United States federal regulations restrict the use of aflatoxin contaminated cottonseed at >20 ppb for animal feed. Several strategies have been proposed for controlling aflatoxin contamination, and much success has been achieved by the application of an atoxigenic strain of A. flavus in cotton, peanut and maize fields. Development of cultivars resistant to aflatoxin through overexpression of resistance associated genes and/or knocking down aflatoxin biosynthesis of A. flavus will be an effective strategy for controlling aflatoxin contamination in cotton. In this study, genome-wide transcriptome profiling was performed to identify differentially expressed genes in response to infection with both toxigenic and atoxigenic strains of A. flavus on cotton (Gossypium hirsutum L.) pericarp and seed. The genes involved in antifungal response, oxidative burst, transcription factors, defense signaling pathways and stress response were highly differentially expressed in pericarp and seed tissues in response to A. flavus infection. The cell-wall modifying genes and genes involved in the production of antimicrobial substances were more active in pericarp as compared to seed. The genes involved in auxin and cytokinin signaling were also induced. Most of the genes involved in defense response in cotton were highly induced in pericarp than in seed. The global gene expression analysis in response to fungal invasion in cotton will serve as a source for identifying biomarkers for breeding, potential candidate genes for transgenic manipulation, and will help in understanding complex plant-fungal interaction for future downstream research.

  17. A study on trypsin, Aspergillus flavus and Bacillus sp. protease inhibitory activity in Cassia tora (L. syn Senna tora (L. Roxb. seed extract

    Directory of Open Access Journals (Sweden)

    Garg Satyendra K

    2011-07-01

    Full Text Available Abstract Background Proteases play an important role in virulence of many human, plant and insect pathogens. The proteinaceous protease inhibitors of plant origin have been reported widely from many plant species. The inhibitors may potentially be used for multiple therapeutic applications in viral, bacterial, fungal diseases and physiological disorders. In traditional Indian medicine system, Cassia tora (Senna tora is reportedly effective in treatment of skin and gastrointestinal disorders. The present study explores the protease inhibitory activity of the above plant seeds against trypsin, Aspergillus flavus and Bacillus sp. proteases. Methods The crushed seeds of Cassia tora were washed thoroughly with acetone and hexane for depigmentation and defatting. The proteins were fractionated by ammonium sulphate (0-30, 30-60, 60-90% followed by dialysis and size exclusion chromatography (SEC. The inhibitory potential of crude seed extract and most active dialyzed fraction against trypsin and proteases was established by spot test using unprocessed x-ray film and casein digestion methods, respectively. Electrophoretic analysis of most active fraction (30-60% and SEC elutes were carried employing Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE and Gelatin SDS-PAGE. Inhibition of fungal spore germination was studied in the presence of dialyzed active inhibitor fraction. Standard deviation (SD and ANOVA were employed as statistical tools. Results The crude seeds' extract displayed strong antitryptic, bacterial and fungal protease inhibitory activity on x-ray film. The seed protein fraction 30-60% was found most active for trypsin inhibition in caseinolytic assay (P Aspergillus flavus and Bacillus sp. proteases remained only 4, 7 and 3.1%, respectively when proteases were incubated with 3 mg ml-1 seed protein extract for 60 min. The inhibitory activity was evident in gelatin SDS-PAGE where a major band (~17-19 kD of protease

  18. Effects of temperature, water activity and incubation time on fungal growth and aflatoxin B1 production by toxinogenic Aspergillus flavus isolates on sorghum seeds.

    Science.gov (United States)

    Lahouar, Amani; Marin, Sonia; Crespo-Sempere, Ana; Saïd, Salem; Sanchis, Vicente

    2016-01-01

    Sorghum, which is consumed in Tunisia as human food, suffers from severe colonization by several toxigenic fungi and contamination by mycotoxins. The Tunisian climate is characterized by high temperature and humidity that stimulates mold proliferation and mycotoxin accumulation in foodstuffs. This study investigated the effects of temperature (15, 25 and 37°C), water activity (aw, between 0.85 and 0.99) and incubation time (7, 14, 21 and 28 d) on fungal growth and aflatoxin B1 (AFB1) production by three Aspergillus flavus isolates (8, 10 and 14) inoculated on sorghum grains. The Baranyi model was applied to identify the limits of growth and mycotoxin production. Maximum diameter growth rates were observed at 0.99 a(w) at 37°C for two of the isolates. The minimum aw needed for mycelial growth was 0.91 at 25 and 37°C. At 15°C, only isolate 8 grew at 0.99 a(w). Aflatoxin B1 accumulation could be avoided by storing sorghum at low water activity levels (≤0.91 a(w)). Aflatoxin production was not observed at 15°C. This is the first work on the effects of water activity and temperature on A. flavus growth and AFB1 production by A. flavus isolates on sorghum grains.

  19. An attempt to model the probability of growth and aflatoxin B1 production of Aspergillus flavus under non-isothermal conditions in pistachio nuts.

    Science.gov (United States)

    Aldars-García, Laila; Ramos, Antonio J; Sanchis, Vicente; Marín, Sonia

    2015-10-01

    Human exposure to aflatoxins in foods is of great concern. The aim of this work was to use predictive mycology as a strategy to mitigate the aflatoxin burden in pistachio nuts postharvest. The probability of growth and aflatoxin B1 (AFB1) production of aflatoxigenic Aspergillus flavus, isolated from pistachio nuts, under static and non-isothermal conditions was studied. Four theoretical temperature scenarios, including temperature levels observed in pistachio nuts during shipping and storage, were used. Two types of inoculum were included: a cocktail of 25 A. flavus isolates and a single isolate inoculum. Initial water activity was adjusted to 0.87. Logistic models, with temperature and time as explanatory variables, were fitted to the probability of growth and AFB1 production under a constant temperature. Subsequently, they were used to predict probabilities under non-isothermal scenarios, with levels of concordance from 90 to 100% in most of the cases. Furthermore, the presence of AFB1 in pistachio nuts could be correctly predicted in 70-81 % of the cases from a growth model developed in pistachio nuts, and in 67-81% of the cases from an AFB1 model developed in pistachio agar. The information obtained in the present work could be used by producers and processors to predict the time for AFB1 production by A. flavus on pistachio nuts during transport and storage.

  20. Efficacy of Mentha spicata essential oil in suppression of Aspergillus flavus and aflatoxin contamination in chickpea with particular emphasis to mode of antifungal action.

    Science.gov (United States)

    Kedia, Akash; Dwivedy, Abhishek Kumar; Jha, Dhruva Kumar; Dubey, Nawal Kishore

    2016-05-01

    The present study reports in vivo antifungal and antiaflatoxigenic efficacy of Mentha spicata essential oil (EO) against toxigenic Aspergillus flavus strain LHP(C)-D6 in chickpea food system up to 12 months of storage. In addition, the mode of antifungal action of EO was also determined to understand the mechanism of fungal growth inhibition. The in vivo study with different concentrations of M. spicata EO showed dose-dependent decrease in fungal colony count as well as aflatoxin B1 concentration. The EO caused >50% protection in inoculated sets and >70% protection in uninoculated sets of chickpea food system against A. flavus at 1.0 μL mL(-1) air concentration. However, at the same concentration, EO caused 100% inhibition to aflatoxin B1 production in both sets when analyzed through high-performance liquid chromatography (HPLC). The antifungal target of EO in fumigated cells of A. flavus was found to be the plasma membrane when analyzed through electron microscopic observations and ions leakage test. The EO fumigated chickpea seeds showed 100% seed germination and seedling growth after 12 months of storage. Based on these observations, M. spicata EO can be recommended as plant-based preservative for safe protection of food commodities during storage conditions against fungal and most importantly mycotoxin contaminations.

  1. Inorganic composition determination and evaluation of the biological activity of Peperomia pellucida in the Aspergillus flavus growth; Estudo da composicao inorganica e avaliacao da atividade biologica de Peperomia pellucida no crescimento de Aspergillus flavus

    Energy Technology Data Exchange (ETDEWEB)

    Sussa, Fabio Vitorio

    2011-07-01

    oil, ethanolic and hexane extracts of Peperomia pellucida were tested for antifungal activity against Aspergillus flavus in vitro on Petri plates. The antifungal activity was based on the inhibition zone and IC{sub 50} values against the pathogen on Petri plates assays. Also, the essential oil chemical composition was determined by GC-MS. (author)

  2. A study on Inhibitory Effects of Titanium Dioxide Nanoparticles and its Photocatalytic Type on Staphylococcus aureus, Escherichia coli and Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Elnaz Babaei

    2016-03-01

    Full Text Available Backgrounds and Objectives: Photocatalyst titanium dioxide nanoparticles can oxidize organic and inorganic compounds of microorganisms in aqueous solutions after exposure to UV light. In the present study, the inhibitory effect of titanium dioxide and its photocatalyst type on Aspergillus flavus, Escherichia coli and Staphylococcus aureus is investigated. Materials and Methods: Toxicogenic strains of Staphylococcus aureus, Escherichia coli and Aspergillus flavus were cultured in their selective media and two groups of samples both included three different concentrations of nanoparticles (0.1, 0.5 and 1 g l-1 and two control samples without any nanoparticles were considered. The first category of samples was placed on the shaker for 20 min, and the second category was irradiated by a UV lamp while shaking for 20, 40 and 60 min on a rotary shaker. Thereafter, they were cultured by using pour plate method in agar and after incubation the colonies were counted. Results and Conclusion: Based on obtained results the photocatalyst titanium dioxide had an inhibitory effect at concentration of 1 g l-1 at the highest timeframe (60 min. In addition, the test variables i.e. the type of bacteria, concentration of nanoparticles and time had a significant effect on the growth inhibition of microorganisms. Regarding the economic aspects of contamination control and its importance in dairy products, application of photocatalystic nanoparticles of titanium dioxide is recommended. 

  3. 一株黄曲霉拮抗细菌的分离筛选及鉴定%Isolation and identification of an antagonistic bacteria of Aspergillus flavus

    Institute of Scientific and Technical Information of China (English)

    涂彩虹; 秦文; 胡欣洁; 李素清

    2011-01-01

    Four bacteria which had obvious antagonistic effect on Aspergillus flavus were screened from soil. The secondary metabolite of bacterium could inhibit the growth of Aspergillus flavus effectively and the rate of inhibitory was 63%.It had fungi stasis on many different kinds of pathogenic fungi and had broad-spectrum antibacterial activity also. With regard to morphological features, physiological and biochemical test,and 16S rDNA sequences analysis,the strain was identified. The results showed that the strain belonged to Bacillus subtilis.%通过稀释分离法从土壤中分离纯化出一株具有黄曲霉拮杭活性的菌株.该菌株的次生代谢产物具有抑制黄曲霉生长的效果,抑菌率可达63%.该菌对多种病原真菌抑制效果明显,具有广谱抑菌效果.根据形态学观察、生理生化反应和16S rDNA鉴定,该菌株为枯草芽孢杆菌.

  4. Suppression of Aflatoxin Biosynthesis in Aspergillus flavus by 2-Phenylethanol Is Associated with Stimulated Growth and Decreased Degradation of Branched-Chain Amino Acids.

    Science.gov (United States)

    Chang, Perng-Kuang; Hua, Sui Sheng T; Sarreal, Siov Bouy L; Li, Robert W

    2015-09-24

    The saprophytic soil fungus Aspergillus flavus infects crops and produces aflatoxin. Pichia anomala, which is a biocontrol yeast and produces the major volatile 2-phenylethanol (2-PE), is able to reduce growth of A. flavus and aflatoxin production when applied onto pistachio trees. High levels of 2-PE are lethal to A. flavus and other fungi. However, at low levels, the underlying mechanism of 2-PE to inhibit aflatoxin production remains unclear. In this study, we characterized the temporal transcriptome response of A. flavus to 2-PE at a subinhibitory level (1 μL/mL) using RNA-Seq technology and bioinformatics tools. The treatment during the entire 72 h experimental period resulted in 131 of the total A. flavus 13,485 genes to be significantly impacted, of which 82 genes exhibited decreased expression. They included those encoding conidiation proteins and involved in cyclopiazonic acid biosynthesis. All genes in the aflatoxin gene cluster were also significantly decreased during the first 48 h treatment. Gene Ontology (GO) analyses showed that biological processes with GO terms related to catabolism of propionate and branched-chain amino acids (valine, leucine and isoleucine) were significantly enriched in the down-regulated gene group, while those associated with ribosome biogenesis, translation, and biosynthesis of α-amino acids OPEN ACCESS Toxins 2015, 7 3888 were over-represented among the up-regulated genes. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that metabolic pathways negatively impacted among the down-regulated genes parallel to those active at 30 °C, a condition conducive to aflatoxin biosynthesis. In contrast, metabolic pathways positively related to the up-regulated gene group resembled those at 37 °C, which favors rapid fungal growth and is inhibitory to aflatoxin biosynthesis. The results showed that 2-PE at a low level stimulated active growth of A. flavus but concomitantly rendered decreased activities in

  5. Suppression of Aflatoxin Biosynthesis in Aspergillus flavus by 2-Phenylethanol Is Associated with Stimulated Growth and Decreased Degradation of Branched-Chain Amino Acids

    Directory of Open Access Journals (Sweden)

    Perng-Kuang Chang

    2015-09-01

    Full Text Available The saprophytic soil fungus Aspergillus flavus infects crops and produces aflatoxin. Pichia anomala, which is a biocontrol yeast and produces the major volatile 2-phenylethanol (2-PE, is able to reduce growth of A. flavus and aflatoxin production when applied onto pistachio trees. High levels of 2-PE are lethal to A. flavus and other fungi. However, at low levels, the underlying mechanism of 2-PE to inhibit aflatoxin production remains unclear. In this study, we characterized the temporal transcriptome response of A. flavus to 2-PE at a subinhibitory level (1 μL/mL using RNA-Seq technology and bioinformatics tools. The treatment during the entire 72 h experimental period resulted in 131 of the total A. flavus 13,485 genes to be significantly impacted, of which 82 genes exhibited decreased expression. They included those encoding conidiation proteins and involved in cyclopiazonic acid biosynthesis. All genes in the aflatoxin gene cluster were also significantly decreased during the first 48 h treatment. Gene Ontology (GO analyses showed that biological processes with GO terms related to catabolism of propionate and branched-chain amino acids (valine, leucine and isoleucine were significantly enriched in the down-regulated gene group, while those associated with ribosome biogenesis, translation, and biosynthesis of α-amino acids were over-represented among the up-regulated genes. Kyoto Encyclopedia of Genes and Genomes (KEGG pathway analysis revealed that metabolic pathways negatively impacted among the down-regulated genes parallel to those active at 30 °C, a condition conducive to aflatoxin biosynthesis. In contrast, metabolic pathways positively related to the up-regulated gene group resembled those at 37 °C, which favors rapid fungal growth and is inhibitory to aflatoxin biosynthesis. The results showed that 2-PE at a low level stimulated active growth of A. flavus but concomitantly rendered decreased activities in branched-chain amino

  6. Inhibitory Effect of Cinnamaldehyde, Citral, and Eugenol on Aflatoxin Biosynthetic Gene Expression and Aflatoxin B1 Biosynthesis in Aspergillus flavus.

    Science.gov (United States)

    Liang, Dandan; Xing, Fuguo; Selvaraj, Jonathan Nimal; Liu, Xiao; Wang, Limin; Hua, Huijuan; Zhou, Lu; Zhao, Yueju; Wang, Yan; Liu, Yang

    2015-12-01

    In order to reveal the inhibitory effects of cinnamaldehyde, citral, and eugenol on aflatoxin biosynthesis, the expression levels of 5 key aflatoxin biosynthetic genes were evaluated by real-time PCR. Aspergillus flavus growth and AFB1 production were completely inhibited by 0.80 mmol/L of cinnamaldehyde and 2.80 mmol/L of citral. However, at lower concentration, cinnamaldehyde (0.40 mmol/L), eugenol (0.80 mmol/L), and citral (0.56 mmol/L) significantly reduced AFB1 production with inhibition rate of 68.9%, 95.4%, and 41.8%, respectively, while no effect on fungal growth. Real-time PCR showed that the expressions of aflR, aflT, aflD, aflM, and aflP were down-regulated by cinnamaldehyde (0.40 mmol/L), eugenol (0.80 mmol/L), and citral (0.56 mmol/L). In the presence of cinnamaldehyde, AflM was highly down-regulated (average of 5963 folds), followed by aflP, aflR, aflD, and aflT with the average folds of 55, 18, 6.5, and 5.8, respectively. With 0.80 mmol/L of eugenol, aflP was highly down-regulated (average of 2061-folds), followed by aflM, aflR, aflD, and aflT with average of 138-, 15-, 5.2-, and 4.8-folds reduction, respectively. With 0.56 mmol/L of citral, aflT was completely inhibited, followed by aflM, aflP, aflR, and aflD with average of 257-, 29-, 3.5-, and 2.5-folds reduction, respectively. These results suggest that the reduction in AFB1 production by cinnamaldehyde, eugenol, and citral at low concentration may be due to the down-regulations of the transcription level of aflatoxin biosynthetic genes. Cinnamaldehyde and eugenol may be employed successfully as a good candidate in controlling of toxigenic fungi and subsequently contamination with aflatoxins in practice.

  7. Bioprocess and biotecnology: effect of xylanase from Aspergillus niger and Aspergillus flavus on pulp biobleaching and enzyme production using agroindustrial residues as substract.

    Science.gov (United States)

    de Alencar Guimaraes, Nelciele Cavalieri; Sorgatto, Michele; Peixoto-Nogueira, Simone de Carvalho; Betini, Jorge Henrique Almeida; Zanoelo, Fabiana Fonseca; Marques, Maria Rita; de Moraes Polizeli, Maria de Lourdes Teixeira; Giannesi, Giovana C

    2013-01-01

    This study compares two xylanases produced by filamentous fungi such as A. niger and A. flavus using agroindustrial residues as substract and evaluated the effect of these enzymes on cellulose pulp biobleaching process. Wheat bran was the best carbon source for xylanase production by A. niger and A. flavus. The production of xylanase was 18 and 21% higher on wheat bran when we compare the xylanase production with xylan. At 50°C, the xylanase of A. niger retained over 85% activity with 2 h of incubation, and A. flavus had a half-life of more than 75 minutes. At 55°C, the xylanase produced by A. niger showed more stable than from A. flavus showing a half-life of more than 45 minutes. The xylanase activity of A. niger and A. flavus were somehow protected in the presence of glycerol 5% when compared to the control (without additives). On the biobleaching assay it was observed that the xylanase from A. flavus was more effective in comparison to A. niger. The kappa efficiency corresponded to 36.32 and 25.93, respectively. That is important to emphasize that the cellulase activity was either analyzed and significant levels were not detected, which explain why the viscosity was not significantly modified.

  8. 黑曲霉对黄曲霉生长、产毒及黄曲霉毒素B1的影响%Influence of Aspergillus niger on growth of Aspergillus flavus and aflatoxin B1

    Institute of Scientific and Technical Information of China (English)

    徐丹; 孙秀兰; 李永仙; 杨振东; 王洪新

    2011-01-01

    目的 研究黑曲霉对黄曲霉生长、产毒的抑制作用及对AFB1的降解作用.方法 将黑曲霉分别与黄曲霉、AFB1共同培养,定期测定培养液pH、菌丝体干重、黄曲霉孢子数、AFB1含量.结果 黑曲霉与黄曲霉混合培养时,黄曲霉孢子数、AFB1含量均比单独培养的低,2组之间差异有统计学意义 (P<0.05),抑制率达到68.06%~91.52%;加入黑曲霉后,AFB1含量降低,实验组与对照组之间差异有统计学意义 (P<0.05),降解率为46.19%.结论 黑曲霉既能抑制黄曲霉生长、产毒,又能降解AFB1.%Objective To study the influence of Aspergillus niger on the growth of Aspergillusflavus and degrada-tion of AFB1. Method Aspergillus niger was co-cultured with Aspergillus flavu s and AFB1, respectively; pH, dry weight of mycelium, spores of Aspergillus flavus and content of AFB1 were determined every 3 days. Result Compared with the control group, the number of Aspergillusflavus spores and content of AFB1 were much less in competitive situation. There was a significant difference between the two groups (P <0.05 ) and the rate of inhibition was 68.06% to 91.52%; more-over, AFB1 was reduced when Aspergillus niger was inoculated, with is a significant difference between the two groups (P < 0.05 ), and the rate of degradation was 46.19%. Conclusion Aspergillus niger not only can inhibit the growth of Aspergil-lus flavus and production of AFB1, but also degrade AFB1.

  9. Evaluation of antifungal activity of Pittosporum undulatum L. essential oil against Aspergillus flavus and aflatoxin production Avaliação da atividade antifúngica do óleo essencial de Pittosporum undulatum L. em Aspergillus flavus e produção de aflatoxina

    Directory of Open Access Journals (Sweden)

    Rosane Tamara da Silva Medeiros

    2011-02-01

    Full Text Available The presence of mycotoxins as a result of fungal attack can occur before, after and during the harvest and storage operations on agricultural crops and food commodities. Considering the inhibitory property of essential plant oils on the mycelial development of fungi and the importance of Aspergillus flavus, the main producer of aflatoxins, this research was designed to evaluate the toxicity of essential oil from Pittosporum undulatum against A. flavus. The essential oils were obtained from P. undulatum leaves, collected in different months and analyzed by GC/MS. The oils were rich in hydrocarbon, monoterpenes and sesquiterpenes and it was observed a significant variation on the chemical composition of the essential oil of leaves at different months. Besides, the essential oils were tested against fungal growth and the results showed different spectrum of inhibition on A. flavus. However, the essential oils inhibited the aflatoxin B1 production.A presença de micotoxinas como resultado do ataque fúngico pode ocorrer antes, após e durante a colheita e também no armazenamento de grãos e alimentos. Considerando as propriedades inibitórias dos óleos essenciais de plantas no desenvolvimento do micélio dos fungos e a importâncias do Aspergillus flavus, principal produtor de aflatoxinas, relatou-se neste trabalho, a atividade tóxica do óleo essencial do Pittosporum undulatum em cultura de A. flavus. Os óleos essenciais de P. undulatum foram obtidos a partir de folhas coletadas em diferentes meses e analisado por CG/EM. Os óleos se mostraram ricos em hidrocarbonetos, monoterpenos e sesquiterpenos e foi observada uma significante variação na composição química destes óleos nos diferentes meses de coleta. Os óleos essenciais mostraram diferentes espectros de inibição do crescimento de A. flavus, porém todos foram capazes de inibir a produção de aflatoxina B1.

  10. Bioprocess and biotecnology: effect of xylanase from Aspergillus niger and Aspergillus flavus on pulp biobleaching and enzyme production using agroindustrial residues as substract

    OpenAIRE

    de Alencar Guimaraes, Nelciele ; Sorgatto, Michele ; Nogueira, Simone de Peixoto; Betini, Jorge Henrique ; Zanoelo, Fabiana ; Marques, Maria ; Polizeli, Maria de Lourdes Teixeira de Moraes; Giannesi, Giovana C

    2013-01-01

    This study compares two xylanases produced by filamentous fungi such as A. niger and A. flavus using agroindustrial residues as substract and evaluated the effect of these enzymes on cellulose pulp biobleaching process. Wheat bran was the best carbon source for xylanase production by A. niger and A. flavus. The production of xylanase was 18 and 21% higher on wheat bran when we compare the xylanase production with xylan. At 50°C, the xylanase of A. niger retained over 85% activity with 2 h of ...

  11. Co-inoculation of aflatoxigenic and non-aflatoxigenic strains of Aspergillus flavus to study fungal invasion, colonization, and competition in maize kernels

    Directory of Open Access Journals (Sweden)

    Zuzana eHruska

    2014-03-01

    Full Text Available A currently utilized pre-harvest biocontrol method involves field inoculations with non-aflatoxigenic Aspergillus flavus strains, a tactic shown to strategically suppress native aflatoxin-producing strains and effectively decrease aflatoxin contamination in corn. The present in situ study focuses on tracking the invasion and colonization of an aflatoxigenic A. flavus strain (AF70, labeled with green fluorescent protein (GFP, in the presence of a non-aflatoxigenic A. flavus biocontrol strain (AF36 to better understand the competitive interaction between these two strains in seed tissue of corn (Zea mays. Corn kernels that had been co-inoculated with GFP-labeled AF70 and wild-type AF36 were cross-sectioned and observed under UV and blue light to determine the outcome of competition between these strains. After imaging, all kernels were analyzed for aflatoxin levels. There appeared to be a population difference between the co-inoculated AF70-GFP+AF36 and the individual AF70-GFP tests, both visually and with pixel count analysis. The GFP allowed us to observe that AF70-GFP inside the kernels was suppressed up to 82% when co-inoculated with AF36 indicating that AF36 inhibited progression of AF70-GFP. This was in agreement with images taken of whole kernels where AF36 exhibited a more robust external growth compared to AF70-GFP. The suppressed growth of AF70-GFP was reflected in a corresponding (up to 73% suppression in aflatoxin levels. Our results indicate that the decrease in aflatoxin production correlated with population depression of the aflatoxigenic fungus by the biocontrol strain supporting the theory of competitive exclusion through robust propagation and fast colonization by the non-aflatoxigenic fungus.

  12. Biomassa, proteína, colesterol e glicose extracelular de cinco isolados de Aspergillus flavus - doi: 10.5102/ucs.v3i2.557

    Directory of Open Access Journals (Sweden)

    Wencerly Ramos Rodrigues Jr.

    2008-04-01

    Full Text Available Fungos filamentosos são organismos importantes para a produção de enzimas, compostos químicos e farmacêuticos. O comportamento metabólico comparado dos fungos é importante para conhecer suas relações taxonômicas e seu potencial uso em microbiologia industrial. Cinco isolados de Aspergillus flavus foram analisados quanto à produção de biomassa, proteína total, colesterol e glicose em diferentes meios de cultura e temperatura. Poucas diferenças foram observadas. Alguns isolados foram capazes de produzir quantidades significativas de colesterol sob as condições utilizadas neste estudo.

  13. Genetic Control of the Resistance to Aspergillus flavus in Maize%玉米对黄曲霉菌抗性的遗传控制

    Institute of Scientific and Technical Information of China (English)

    邓德祥; 盖钧镒; 秦泰辰; 卞云龙; 印志同; 徐明良

    2000-01-01

    用7个玉米自交系进行完全双列杂交,对杂种F1进行自交,获得P1、P2、F1、F1、F2、F26个家系.对6个家系的种子用黄曲霉菌(Aspergillus flavus Link)接种.根据种子的感病程度,对抗性进行遗传分析.结果表明:玉米对黄曲霉菌的抗性遗传主要受2n核遗传体系控制,细胞质对抗性的遗传也有影响,但3n胚乳对抗性遗传影响甚微.

  14. A Public Platform for the Verification of the Phenotypic Effect of Candidate Genes for Resistance to Aflatoxin Accumulation and Aspergillus flavus Infection in Maize

    Directory of Open Access Journals (Sweden)

    Xueyan Shan

    2011-06-01

    Full Text Available A public candidate gene testing pipeline for resistance to aflatoxin accumulation or Aspergillus flavus infection in maize is presented here. The pipeline consists of steps for identifying, testing, and verifying the association of selected maize gene sequences with resistance under field conditions. Resources include a database of genetic and protein sequences associated with the reduction in aflatoxin contamination from previous studies; eight diverse inbred maize lines for polymorphism identification within any maize gene sequence; four Quantitative Trait Loci (QTL mapping populations and one association mapping panel, all phenotyped for aflatoxin accumulation resistance and associated phenotypes; and capacity for Insertion/Deletion (InDel and SNP genotyping in the population(s for mapping. To date, ten genes have been identified as possible candidate genes and put through the candidate gene testing pipeline, and results are presented here to demonstrate the utility of the pipeline.

  15. Occurrence of aflatoxins in mahua (Madhuca indica Gmel.) seeds: synergistic effect of plant extracts on inhibition of Aspergillus flavus growth and aflatoxin production.

    Science.gov (United States)

    Sidhu, O P; Chandra, Harish; Behl, H M

    2009-04-01

    Occurrence of aflatoxin in Madhuca indica Gmel. seeds was determined by competitive ELISA. Eighty percent of mahua seed samples were found to be contaminated with aflatoxin. Total aflatoxin content ranged from 115.35 to 400.54ppb whereas the concentration of AFB(1) was in the range of 86.43 to 382.45ppb. Mahua oil was extracted by cold press expeller and analysed for contamination of aflatoxin in both the oil and cake samples. Total aflatoxin and aflatoxin B(1) were 220.66 and 201.57ppb in oil as compared to that in cake samples where it was 87.55 and 74.35ppb, respectively. Various individual and combined plant extracts were evaluated for their efficacy against growth of Aspergillus flavus and aflatoxin production in vitro. Combination of botanicals were found to be more effective in controlling fungal growth and aflatoxin production than individual extracts. Results of the present study suggests that synergistic effect of plant extracts can be used for control of fungal growth and aflatoxin production. These natural plant products may successfully replace synthetic chemicals and provide an alternative method to protect mahua as well as other agricultural commodities of nutritional significance from toxigenic fungi such as A. flavus and aflatoxin production.

  16. Biosorption characteristics of Aspergillus flavus biomass for removal of Pb(II) and Cu(II) ions from an aqueous solution.

    Science.gov (United States)

    Akar, Tamer; Tunali, Sibel

    2006-10-01

    The Pb(II) and Cu(II) biosorption characteristics of Aspergillus flavus fungal biomass were examined as a function of initial pH, contact time and initial metal ion concentration. Heat inactivated (killed) biomass was used in the determination of optimum conditions before investigating the performance of pretreated biosorbent. The maximum biosorption values were found to be 13.46 +/- 0.99 mg/g for Pb(II) and 10.82 +/- 1.46 mg/g for Cu(II) at pH 5.0 +/- 0.1 with an equilibrium time of 2 h. Detergent, sodium hydroxide and dimethyl sulfoxide pretreatments enhanced the biosorption capacity of biomass in comparison with the heat inactivated biomass. The biosorption data obtained under the optimum conditions were well described by the Freundlich isotherm model. Competitive biosorption of Pb(II) and Cu(II) ions was also investigated to determine the selectivity of the biomass. The results indicated that A. flavus is a suitable biosorbent for the removal of Pb(II) and Cu(II) ions from aqueous solution.

  17. Efficacy of the combined application of chitosan and Locust Bean Gum with different citrus essential oils to control postharvest spoilage caused by Aspergillus flavus in dates.

    Science.gov (United States)

    Aloui, Hajer; Khwaldia, Khaoula; Licciardello, Fabio; Mazzaglia, Agata; Muratore, Giuseppe; Hamdi, Moktar; Restuccia, Cristina

    2014-01-17

    This study reports the efficacy of the combined application of chitosan (CH) and Locust Bean Gum (LBG) in combination with different citrus essential oils (EOs) to inhibit Aspergillus flavus in vitro and on artificially infected dates for a storage period of 12 days. The effect of these treatments on the fruits' sensory characteristics was evaluated to verify the complete absence of off-odours and off-flavours. Bergamot EO was the most effective in reducing mycelial growth, followed by bitter orange EO. Both bergamot and bitter orange oils significantly reduced conidial germination and a complete inhibition was obtained at concentrations higher than 2%. The mixtures based on CH-2% (v/v) bergamot EO or CH-2% (v/v) bitter orange EO proved to be the most effective coatings to reduce conidial germination resulting in an 87-90% inhibition compared with the control. In fruit decay assays coatings based on CH incorporating citrus oils were able to reduce fungal decay in the range of 52-62% at day 12. The study results and the complete absence of off-flavours and off-odours demonstrate the potential of CH coatings carrying citrus EOs at sub-inhibitory concentrations to control postharvest growth of A. flavus in dates.

  18. Genetic Analysis of the Aspergillus flavus Vegetative Compatibility Group to Which a Biological Control Agent That Limits Aflatoxin Contamination in U.S. Crops Belongs.

    Science.gov (United States)

    Grubisha, Lisa C; Cotty, Peter J

    2015-09-01

    Some filamentous fungi in Aspergillus section Flavi produce carcinogenic secondary compounds called aflatoxins. Aflatoxin contamination is routinely managed in commercial agriculture with strains of Aspergillus flavus that do not produce aflatoxins. These non-aflatoxin-producing strains competitively exclude aflatoxin producers and reshape fungal communities so that strains with the aflatoxin-producing phenotype are less frequent. This study evaluated the genetic variation within naturally occurring atoxigenic A. flavus strains from the endemic vegetative compatibility group (VCG) YV36. AF36 is a strain of VCG YV36 and was the first fungus used in agriculture for aflatoxin management. Genetic analyses based on mating-type loci, 21 microsatellite loci, and a single nucleotide polymorphism (SNP) in the aflC gene were applied to a set of 237 YV36 isolates collected from 1990 through 2005 from desert legumes and untreated fields and from fields previously treated with AF36 across the southern United States. One haplotype dominated across time and space. No recombination with strains belonging to VCGs other than YV36 was detected. All YV36 isolates carried the SNP in aflC that prevents aflatoxin biosynthesis and the mat1-2 idiomorph at the mating-type locus. These results suggest that VCG YV36 has a clonal population structure maintained across both time and space. These results demonstrate the genetic stability of atoxigenic strains belonging to a broadly distributed endemic VCG in both untreated populations and populations where the short-term frequency of VCG YV36 has increased due to applications of a strain used to competitively exclude aflatoxin producers. This work supports the hypothesis that strains of this VCG are not involved in routine genetic exchange with aflatoxin-producing strains.

  19. In vitro experimental environments lacking or containing soil disparately affect competition experiments of Aspergillus flavus and co-occurring fungi in maize grains.

    Science.gov (United States)

    Falade, Titilayo D O; Syed Mohdhamdan, Sharifah H; Sultanbawa, Yasmina; Fletcher, Mary T; Harvey, Jagger J W; Chaliha, Mridusmita; Fox, Glen P

    2016-07-01

    In vitro experimental environments are used to study interactions between microorganisms, and to predict dynamics in natural ecosystems. This study highlights that experimental in vitro environments should be selected to match closely the natural environment of interest during in vitro studies to strengthen extrapolations about aflatoxin production by Aspergillus and competing organisms. Fungal competition and aflatoxin accumulation were studied in soil, cotton wool or tube (water-only) environments, for Aspergillus flavus competition with Penicillium purpurogenum, Fusarium oxysporum or Sarocladium zeae within maize grains. Inoculated grains were incubated in each environment at two temperature regimes (25 and 30°C). Competition experiments showed interaction between the main effects of aflatoxin accumulation and the environment at 25°C, but not so at 30°C. However, competition experiments showed fungal populations were always interacting with their environments. Fungal survival differed after the 72-h incubation in different experimental environments. Whereas all fungi incubated within the soil environment survived, in the cotton wool environment none of the competitors of A. flavus survived at 30°C. With aflatoxin accumulation, F. oxysporum was the only fungus able to interdict aflatoxin production at both temperatures. This occurred only in the soil environment and fumonisins accumulated instead. Smallholder farmers in developing countries face serious mycotoxin contamination of their grains, and soil is a natural reservoir for the associated fungal propagules, and a drying and storage surface for grains on these farms. Studying fungal dynamics in the soil environment and other environments in vitro can provide insights into aflatoxin accumulation post-harvest.

  20. Vitality Stains and Real Time PCR Studies to Delineate the Interactions of Pichia anomala and Aspergillus flavus

    Science.gov (United States)

    The objectives of this study were to probe the effect of the yeast, P. anomala against A flavus by using real time RT-PCR technique and vitality fluorescent stains. Yeast and fungi were inoculated into a 250 ml-flask containing 50 ml potato dextrose broth (PDB) at yeast to fungus (Y : F) ratios of ...

  1. 不同萜类对黄曲霉菌抑制作用评价%Antifungal effect of seven terpenes against Aspergillus flavus

    Institute of Scientific and Technical Information of China (English)

    梁海燕; 王国昌

    2012-01-01

    目的 评价7种萜类对黄曲霉Aspergillus flavus的抑菌活性,获得抑菌性能优良的化合物,为研制和开发新型黄曲霉杀菌剂提供科学依据.方法 采用气体扩散法研究7种萜类挥发物在1、2、4、8μL4个浓度下对黄曲霉菌丝生长和孢子萌发率的影响.结果 除了1 μL的金合欢烯、β-罗勒烯、α-蒎烯以外,其余处理均对黄曲霉菌丝生长有明显抑制活性(P<0.05);1、2、4μL的香叶烯、1μL的β-罗勒烯和1μL的松油烯对黄曲霉孢子萌发率无明显影响,其余处理条件下萜类对孢子萌发均有抑制作用(P<0.05);芳樟醇的抑菌活性最明显,在8μL的浓度下对菌丝生长和孢子萌发的抑制率分别达到75.93%和86.32%.结论 7种萜类化合物对黄曲霉菌有不同程度的抑制活性,其中芳樟醇的活性最高.%Objective To evaluate antifungal effects of 7 terpenes against Aspergillus flavus(A. flavus) and to provide basis for development of antimicrobial against A. flavus. Methods The anti-A. flavus effects of the terpenes were investigated at the concentrations of 1 μL, 2 μL, 4 μL,and 8 μL with gaseous diffusion methods. Results All treatments had inhibitory effect on hyphal growth, with the exception of 1 μL farnesen,l μL β-ocimene, and 1 μL α-pinene. Myrcene at the concentrations of 1 μL,2 μL and 4 μL, p-ocimene at 1 μL, and terpinene at 1 μL were lack of inhibition on spore germination. The terpenes at other concentrations could inhibit spore germination significantly. The antifungal effect of linalool was the strongest with an inhibitory rates on hyphal growth and spore germination of 76. 53% and 86. 32% at the concentration of 8 μl/L. Conclusion The results indicate that the seven terpenes could inhibit A. flavus at different extent,and the effects of linalool is the best.

  2. Effects of essential oils on the growth and aflatoxin production of Aspergillus Flavus and Aspergillus Parasiticus%植物挥发油对黄曲霉毒素产生菌及其毒素合成的影响

    Institute of Scientific and Technical Information of China (English)

    李红玲; 高微微

    2012-01-01

    黄曲霉毒素(AFT)是由黄曲霉(Aspergillus flavus)和寄生曲霉(Aspergillus parasiticus)等曲霉属真菌产生的次生代谢产物,具有致畸、致癌、致突变等作用.AFT污染多种粮食作物及食品,其极强的毒性严重威胁到人体健康.寻找各种黄曲霉毒素抑制剂已成为国内外研究的热点.部分抗生素类药物及化学杀菌剂虽然具有较强的抗黄曲霉作用,但鉴于其毒副作用较明显,使用范围非常有限.近二十年来,人们开始从天然产物中寻找毒副作用低、易降解并且安全性高的黄曲霉抑制剂.本文对天然植物挥发油及其单体成分抑制黄曲霉和寄生曲霉生长并抑制AFT合成,以及在粮食、食品及其包装等方面的应用情况进行综述,为进一步研究植物挥发油类成分的抑菌机制和产品开发提供参考.%Aflatoxins (AFTs), a group of toxic secondary metabolites, are produced by species of Aspergilli, especially Aspergillus flavus and Aspergillus parasiticus. AFTs have been proved to be potent carcinogens, mutagens, and steratogens. The contamination of AFTs in cereal and foods brings a significant health problem due to their strong toxicity. Developing antiaflatoxigenic inhibitors has become a research hotspot. Some antibiotics and chemical fungicides were effective Aspergilli inhibitor, but were not widely used because of their obvious toxic and adverse effects. In recent two decades, some natural antiaflatoxigenic inhibitors with lower side effects and easy degradation have been discovered. This paper summarized reports about anti-aspergilli and antiaflatoxigenic activities of plant essential oils, their constituents and relevant application. This information may provide reference for further research on the antimicrobial mechanisms of plants volatile oils and product development.

  3. 普洱茶发酵过程中外源接种黄曲霉产毒研究%Research on Aspergillus flavus Toxin-producing in Pu′er Tea Fermentation

    Institute of Scientific and Technical Information of China (English)

    李亚莉; 康冠宏; 杨丽源; 祝红昆; 李治滢; 周红杰

    2014-01-01

    以云南大叶种晒青茶为原料,接种产毒黄曲霉进行模拟普洱茶发酵试验,并在发酵结束时通过LC-MS/MS 法对茶样进行黄曲霉毒素检测,研究普洱茶发酵过程中黄曲霉的生长及产毒情况。结果表明,在普洱茶发酵过程中,接种的黄曲霉能在茶叶中生长繁殖,初期生长较快,但随发酵时间的延长,黄曲霉在茶叶中的生长明显受到抑制,其数量逐渐下降。发酵终止时,未在茶样中检测出黄曲霉毒素。%For the purpose of studying the Aspergillus flavus growth and toxin production in Pu′er tea fermentation, the Yunnan large-leaves solar-drying green tea was used as the raw material to fermentate by inoculating toxigenic Aspergillus flavus fungus in Pu′er tea. Aflatoxin was tested by LC-MS/MS method at the end of tea samples fermentation. The results showed that during the tea fermentation, Aspergillus flavus growth was observed in the initial fermentation. However, with the extension of Pu′er tea fermentation time, Aspergillus flavus growth were inhibited in the late fermentation, the number decreased gradually, while the end of fermentation, the aflatoxin was not detected in tea samples.

  4. 花生黄曲霉抗性与糖原合成酶激酶-3的关系%Relationship between Peanut Aspergillus flavus Resistance and Glycogen Synthase Kinase-3

    Institute of Scientific and Technical Information of China (English)

    严海燕; 宗成志; 包文志; 单世华

    2011-01-01

    前期研究证明糖原合成酶激酶(GSK3β)在花生黄曲霉敏感品种中上调表达.本研究对花生黄曲霉抗性品种和易感品种发育种子表达的GSK3进行了生物信息学和定量PCR的分析验证.结果表明,在抗性品系中,GSK3β基因在小果时期上调表达.由于GSK3β是油菜类甾醇信号传导的负调控因子,在细胞延长中起着抑制作用.因此推测GSK3β在花生果实发育中是种子和果实大小的抑制因子,与黄曲霉抗性有间接或直接的关系.%It has been reported that Glycogen synthase kinase-3 was upregulated in peanut developing seed coat of Aspergillus flavus sensitive line. In this paper, we analyszed the expression differences of GSK3β gene in developing seeds between Aspergillus flavus resistant lines and susceptible lines with bioinformatic methods and QPCR-methods. The results indicated in early fruits stage, GSK3β gene was upregulated in Aspergillus flavus resistant lines. GSK3β is negative regulator for brassinosteroids,which inhibits cell elongation. Thus it's possible that GSK3β is a inhibitative factor in sizes of seeds and fruits in peanut development, direct or indirect related to the resistance to Aspergillus flavus.

  5. Detection of Expression Intensity of Aspergillus flavus Resistance Gene in Peanut Seed Capsule by Quantitative Real -Time PCR%荧光量PCR技术检测花生种皮抗黄曲霉基因表达强度

    Institute of Scientific and Technical Information of China (English)

    张廷婷; 李春娟; 闫彩霞; 孙兵; 郑奕雄; 单世华

    2012-01-01

    依据已获得的基因芯片和cDNA研究结果,筛选上调表达并且表达差异系数在5.0以上的花生种皮基因序列设计引物,采用SYBR Green Ⅰ实时荧光定量PCR法对上述基因进行相对定量分析,以验证基因芯片研究结果并为分离黄曲霉抗性相关基因奠定基础.结果表明:荧光定量PCR的结果与基因芯片的结果高度一致,目的基因在感病和抗病品种之间差异显著,其中BE87、AW03在抗病品种中相对表达量较高,可能在抵御黄曲霉侵染过程中发挥重要作用.%According to the research results of obtained gene chip and cDNA library, the primers were designed based on the gene sequences of peanut seed capsule which up - regulated expression and the differential expression coefficient more than 5.0. The relative quantitative analysis of these genes was carried out by SYBR Green I quantitative real - time PCR to identify the research results of gene chip and provide foundation for separating related genes resistant to Aspergillus flavus. The results showed that the quantitative real -time PCR results were consistent with the research results of gene chip on a high degree; there were significant differences between Aspergillus flavus resistant and susceptible varieties. Among which, BES1 and j4WD3 expressed more in Aspergillus flavus resistant varieties and maybe play an important role in defense from Aspergillus flavus infection.

  6. 几种多糖对黄曲霉菌生长及产毒的抑制作用%Inhibitory Effect of Several Polysaccharides on Growth and Toxin Production of Aspergillus flavus

    Institute of Scientific and Technical Information of China (English)

    李红波; 胡梁斌; 王淼焱; 孙俊良

    2011-01-01

    研究了香菇多糖、海带多糖、石耳素等10余种多糖对黄曲霉生长及产毒的抑制作用,发现海带多糖、香菇纤维素、马铃薯直链淀粉、A型大豆多糖能够明显降低黄曲霉菌丝产量;同时海带多粮、香菇纤维素、马铃薯直链淀粉、香菇多糖、绿豆多糖抑制了黄曲霉菌产毒,其中海带多糖、马铃薯直链淀粉、香菇纤维素、香菇多糖能够明显降低黄曲霉菌菌丝产毒能力.%The inhibitory effects of more than 10 polysaccharides on the growth and toxin production of Aspergillus flavus were studied.It was found that Laminaria polysaccharide, Lentinus edodes cellulose, potato amylose and A - type soybean polysaccharide could significantly reduce the mycelium yield of Aspergillus flavus, while Laminaria polysaccharide, Lentinus edodes cellulose, potato amylase, Lentinus edodes polysaccharide and mungbean polysaccharide could inhibit the aflatoxin production, of which Laminaria polysaccharide, Lentinus edodes cellulose, potato amylase and Lentinus edodes polysaccharide could obviously reduce the aflatoxin - producing capability of Aspergillus flavus.

  7. Perfil bioquímico do soro de frangos de corte alimentados com dieta suplementada com alfa-amilase de Cryptococcus flavus e Aspergillus niger HM2003 Biochemichal serum profile of broilers fed diets suplemented with alfa-amylase from Cryptococcus flavus and Aspergillus niger HM2003

    Directory of Open Access Journals (Sweden)

    Cibele Silva Minafra

    2010-12-01

    Full Text Available Avaliou-se o perfil bioquímico do soro de frangos de corte alimentados com a enzima α-amilase produzida por dois microrganismos. Produziram-se dois extratos, um com a-amilase obtida a partir de Cryptococcus flavus em meio de levedura comercial e outro com Aspergillus niger HM2003 em meio de proteína de soja e amido comercial, com atividade de 9,58 U/mL e 10,0 U/mL, respectivamente. Utilizaram-se 360 pintos de corte Cobb 500 de 1 dia de idade e com 49,72 ± 0,68 g de peso vivo inicial. As aves foram alojadas em baterias e foram criadas até os 21 dias de idade. Foram utilizados três dietas, cada uma com cinco repetições de 12 aves, em delineamento inteiramente casualizado. A primeira dieta (basal foi formulada sem adição de enzima e as outras duas receberam a suplementação de a-amilase produzida por cultivo de Cryptococcus flavus e Aspergillus niger HM2003. Dietas à base de milho e soja foram formuladas em duas fases: pré-inicial (1-7 dias e inicial (8-21 dias. Na fase pré-inicial, foram observados os seguintes valores médios para cálcio (6,90 e 5,99 mg/dL, proteína plasmática (2,0 e 2,50 g/dL e fosfatase alcalina (979,98 e 974,66 UI/L, respectivamente para Cryptococcus flavus e Aspergillus niger HM2003. A dieta acrescida de a-amilase obtida a partir de Aspergillus niger HM2003 determinou maior concentração sérica de fósforo. Na fase inicial, os resultados significativos relacionaram-se a potássio quando avaliadas dietas com adição de a-amilase pelas duas fontes. A incorporação das enzimas testadas não proporciona alterações metabólicas ou toxicidade nos animais.It was evaluated the biochemical serum profile of broilers fed rations supplemented with α-amylase produced by two microorganisms. Two extracts were produced, one was produced with a-amylase obtained from Cryptococcus flavus in a commercial yeast-based medium and the other with Aspergillus niger HM2003 produced in soybean protein and commercial starch medium

  8. Environmental distribution and genetic diversity of vegetative compatibility groups determine biocontrol strategies to mitigate aflatoxin contamination of maize by Aspergillus flavus.

    Science.gov (United States)

    Atehnkeng, Joseph; Donner, Matthias; Ojiambo, Peter S; Ikotun, Babatunde; Augusto, Joao; Cotty, Peter J; Bandyopadhyay, Ranajit

    2016-01-01

    Maize infected by aflatoxin-producing Aspergillus flavus may become contaminated with aflatoxins, and as a result, threaten human health, food security and farmers' income in developing countries where maize is a staple. Environmental distribution and genetic diversity of A. flavus can influence the effectiveness of atoxigenic isolates in mitigating aflatoxin contamination. However, such information has not been used to facilitate selection and deployment of atoxigenic isolates. A total of 35 isolates of A. flavus isolated from maize samples collected from three agro-ecological zones of Nigeria were used in this study. Ecophysiological characteristics, distribution and genetic diversity of the isolates were determined to identify vegetative compatibility groups (VCGs). The generated data were used to inform selection and deployment of native atoxigenic isolates to mitigate aflatoxin contamination in maize. In co-inoculation with toxigenic isolates, atoxigenic isolates reduced aflatoxin contamination in grain by > 96%. A total of 25 VCGs were inferred from the collected isolates based on complementation tests involving nitrate non-utilizing (nit(-)) mutants. To determine genetic diversity and distribution of VCGs across agro-ecological zones, 832 nit(-) mutants from 52 locations in 11 administrative districts were paired with one self-complementary nitrate auxotroph tester-pair for each VCG. Atoxigenic VCGs accounted for 81.1% of the 153 positive complementations recorded. Genetic diversity of VCGs was highest in the derived savannah agro-ecological zone (H = 2.61) compared with the southern Guinea savannah (H = 1.90) and northern Guinea savannah (H = 0.94) zones. Genetic richness (H = 2.60) and evenness (E5  = 0.96) of VCGs were high across all agro-ecological zones. Ten VCGs (40%) had members restricted to the original location of isolation, whereas 15 VCGs (60%) had members located between the original source of isolation and a distance

  9. Characterization of species of the Aspergillus section Nigri from corn field isolates co-infected with Aspergillus flavus/parasiticus species and the potential for ochratoxin A production.

    Science.gov (United States)

    Members of the Aspergillus section Nigri, known as black-spored aspergilli, can contaminate several substrates including maize. Although some species within the group can produce plant disease symptoms such as black mold in onions and maize ear rot, the main concern with A. niger aggregate contamina...

  10. Effect of gamma radiation on the growth of Aspergillus Flavus aflatoxins producer and on the use of polymerase chain reaction technique (PCR) in samples of maize grains artificially inoculated; Efeitos da radiacao gama no crescimento de Aspergillus flavus produtor de aflatoxinas e no emprego da tecnica da Reacao em Cadeia da Polimerase (RCP) em amostras de graos de milho inoculadas artificialmente

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Simone

    2003-07-01

    The aim of this present study was to verify the effects of gamma radiation on the growth of Aspergillus flavus Link aflatoxins producer; to demonstrate the application of Polymerase Chain Reaction (PCR) technique in the diagnostic of A. Flavus, as well to verify the effect of radiation in the profile of DNA bands. Twenty samples of grains maize with 200 g each were individually irradiated with 20 kGy, to eliminate the microbial contamination. In following, the samples were inoculated with an toxigenic A. flavus (1x10{sup 6} spores/ml), incubated for 15 days at 25 deg C with a relative humidity of around 97,5% and irradiated with 0, 2; 5 and 10 kGy. The samples, 5 to each dose of irradiation, were individually analyzed for the number of fungal cells, water activity, viability test (fluorescein diacetate and ethidium bromide), PCR and aflatoxins (AFB) detection. The results showed that the doses used were effective in reducing the number of Colony Forming Units (CFU/g) mainly the doses of 5 and 10 kGy. In addition, the viability test showed a decrease of viable cells with increase of irradiation doses. The reduction of AFB{sub 1} and AFB-2, was more efficient with the use of 2 kGy in comparison with the dose of 5 kGy, while the dose of 10 kGy, degraded the aflatoxins. Thereby, it was observed that AFB2 showed to be more radiosensitive. The use of PCR technique showed the presence of DNA bands, in all samples. (author)

  11. Metabolism of L-malic acid accumulation in Aspergillus flavus%黄曲霉积累L-苹果酸代谢机制初探

    Institute of Scientific and Technical Information of China (English)

    郝夕祥; 刘建军; 赵祥颖; 田延军; 张家祥

    2011-01-01

    L-malic acid is a member of tricarboxylic acid cycle (TCA cycle) in organism, which has widespread applications in food, medical, daily chemical industry, etc. The paper preliminary introduced the metabolic mechanism of L-malic acid in Aspergillus flavus from the aspects of limiting oxygen fermentation, the addition of calcium carbonate, the inhibitor of enzyme in the TCA cycle, glyoxylate cycle and so on. It was concluded that CO2 fixing pathway was the main route accumulating L-malic acid.%L-苹果酸是生物体内三羧酸循环的成员之一,在食品、医药、日用化工等部门具有广泛的用途.文中从限氧发酵、碳酸钙的添加量、乙醛酸循环和TCA循环相应酶的抑制剂几个方面初步探讨黄曲霉积累L-苹果酸的代谢机制,得出CO2固定途径是积累L-苹果酸的主要途径.

  12. The screening and identification of Lactic acid bacteria against Aspergillus flavus%抑黄曲霉乳酸菌的筛选及菌种鉴定

    Institute of Scientific and Technical Information of China (English)

    郭艳萍; 盛海圆; 陈晓琳; 张明

    2010-01-01

    目的 筛选具有抑制黄曲霉(Aspergillus flavus)生长的乳酸菌.方法 以各地泡菜、实验室自制泡菜、豆浆渣以及新鲜猪肠、鸡肠道内容物为材料,采用牛津杯法筛选所需菌株.对筛选出的菌株进行生理生化及16S rRNA基因序列同源性分析.结果 分离得到756株乳酸菌,其中有6株菌株对黄曲霉的生长有明显的抑制作用.结论 实验获得的6株产酸菌,3株为植物乳杆菌(Lactobacillus plantarum),2株为消化乳杆菌(L.alimentarius),1株为亚利桑那乳杆菌(L.arizonenensis).

  13. 玉米种质对黄曲霉菌抗性的鉴定%Identification of maize germplasm resistant to Aspergillus flavus

    Institute of Scientific and Technical Information of China (English)

    邓德祥; 盖钧镒; 卞云龙; 印志同; 王云翠; 王卫娟

    2002-01-01

    以145个玉米自交系作为试验材料,对其籽粒人工接种黄曲霉菌(Aspergillus flavus),根据籽粒的发病情况进行抗性鉴定.结果表明:(1)各玉米自交系对黄曲霉菌的抗性有极显著的差异,在145个自交系中,高抗的8份,中抗的72份,中感的57份,高感的8份;(2)对黄曲霉菌有较高抗性的自交系大多数来自于我国的南方地区;(3)通过辐射处理,对于提高抗性可能有较好的效果;(4)爆裂玉米具有较好的抗性;(5)不同致病菌株接种,抗性反应有差异.

  14. Aflatoxin production in six peanut (Arachis hypogaea L.) genotypes infected with Aspergillus flavus and Aspergillus parasiticus, isolated from peanut production areas of Cordoba, Argentina.

    Science.gov (United States)

    Asis, Ramon; Barrionuevo, Damian L; Giorda, Laura M; Nores, Maria L; Aldao, Mario A

    2005-11-16

    Aflatoxin contamination is one of the main factors affecting peanut seed quality. One of the strategies to decrease the risk of peanut aflatoxin contamination is the use of genotypes with resistance to Aspergillus infection. This laboratory study reports the resistance to Aspergillus infection and aflatoxin contamination of six peanut genotypes inoculated with 21 Aspergillus isolates obtained from the peanut production region of Cordoba, Argentina. The resistance was investigated in the seed coat and cotyledons of three resistant genotypes (J11, PI 337394, and PI 337409) and three breeding lines (Manfredi 68, Colorado Irradiado, and Florman INTA) developed at the Instituto Nacional de Tecnologia Agropecuaria (INTA), Manfredi Experimental Station, Cordoba, Argentina. Resistance to fungal colonization and aflatoxin contamination was found to be associated with seed coat integrity in the PI 337394, PI 337409, and J11 genotypes, whereas the INTA breeding lines such as Colorado Irradiado showed a moderate resistance and the Manfredi 68 and Florman INTA genotypes the least resistance. Furthermore, another type of resistance associated with cotyledons was found only in the PI 337394 genotype.

  15. Natural control of corn postharvest fungi Aspergillus flavus and Penicillium sp. using essential oils from plants grown in Argentina.

    Science.gov (United States)

    Camiletti, Boris X; Asensio, Claudia M; Pecci, María de la Paz Giménez; Lucini, Enrique I

    2014-12-01

    The objective in this study was to evaluate the antifungal activity of essential oils from native and commercial aromatic plants grown in Argentina against corn postharvest fungi and to link the essential oil bioactivity with lipid oxidation and morphological changes in fungus cell membrane. Essential oil (EO) of oregano variety Mendocino (OMen), Cordobes (OCor), and Compacto (OCom), mint variety Inglesa (Mi), and Pehaujo (Mp), Suico (Sui); rosemary (Ro), and Aguaribay (Ag) were tested in vitro against 4 corn fungi: A. flavus (CCC116-83 and BXC01), P. oxalicum (083296), and P. minioluteum (BXC03). The minimum fungicidal concentration (MFC) and the minimum inhibitory concentration (MIC) were determined. The chemical profiles of the EOs were analyzed by GC-MS. Lipid oxidation in cell membrane of fungi was determined by hydroperoxides and related with essential oil antifungal activity. The major compounds were Thymol in OCor (18.66%), Omen (12.18%), and OCom (9.44%); menthol in Mi and Mp; verbenone in Sui; dehydroxy-isocalamendiol in Ag; and eucaliptol in Ro. OCor, Omen, and OCom showed the best antifungal activity. No antifungal activity was observed in Ag and Ro EO. The hydroperoxide value depended on the fungi (P fungi that produce mycotoxin in maize.

  16. Production of thermostable glucoamylase by newly isolated Aspergillus flavus A 1.1 and Thermomyces lanuginosus A 13.37 Produção e glucoamilase por Aspergillus flavus A1.1 e Thermomyces lanuginosus A13.37

    Directory of Open Access Journals (Sweden)

    Eleni Gomes

    2005-03-01

    Full Text Available Thirteen thermophilic fungal strains were isolated from agricultural soil, tubers and compost samples in tropical Brazil. Two strains were selected based on of their ability to produce considerable glucoamylase activity while growing in liquid medium at 45ºC with starch as the only carbon source. They were identified as Aspergillus flavus A1.1 and Thermomyces lanuginosus A 13.37 Tsiklinsky. The experiment to evaluate the effect of carbon source, temperature and initial pH of the medium on enzyme production was developed in a full factorial design (2x2x3. Enzyme productivity was influenced by the type of starch used as carbon source. Cassava starch showed to be a better substrate than corn starch for glucoamylase production by A. flavus but for T. lanuginosus the difference was not significant. Enzyme activities were determined using as substrates 0.3% soluble starch, 0.3% maltose or 0.3% of starch plus 0.1% maltose. The enzymes from A. flavus A1.1 hydrolyzed soluble starch preferentially but also exhibited a significant maltase activity. Moreover higher quantities of glucose were released when the substrate used was a mixture of starch and maltose, suggesting that this fungus produced two types of enzyme. In the case T. lanuginosus A 13.37, the substrate specificity test indicated that the enzyme released also hydrolyzed starch more efficiently than maltose, but there was no increase in the liberation of glucose when a mixture of starch and maltose was used as substrate, suggesting that only one type of enzyme was secreted. Glucoamylases produced from A. flavus A1.1 and T. lanuginous A.13-37 have high optimum temperature (65ºC and 70ºC and good thermostability in the absence of substrate (maintaining 50% of activity for 5 and 8 hours, respectively, at 60ºC and are stable over in a wide pH range. These new strains offer an attractive alternative source of enzymes for industrial starch processing.Entre 13 linhagens de fungos filamentosos

  17. Determination of aspergillus flavus toxin M1 in milk by resonance light scattering%共振光散射法检测牛奶中黄曲霉毒素M1

    Institute of Scientific and Technical Information of China (English)

    黄明元; 刘倩楠; 李兰芳

    2013-01-01

    目的:建立一种基于大分子物质环糊精的共振散射光色谱差异测定牛奶中残余黄曲霉毒素M1的新型检测方法.方法:β-环糊精与黄曲霉毒素M1结合后,不同浓度黄曲霉毒素M1与环糊精形成的包合物存在不同强度的共振散射光光谱,用共振瑞利散射光对黄曲霉毒素M1进行检测.结果:在波长为335 nm处共振光散射增强强度与黄曲霉毒素M1的浓度呈线性关系.在pH =4.0~5.0时,包合物形成的最佳温度为60℃,静置时间为1h,方法的检出限为0.38 ng/ml;线性范围为0ng/nd~8.0 ng/ml,线性相关系数r=0.992回收率为85%~ 108%.结论:本方法可简便,快速地测定牛奶中的黄曲霉毒素M1,结果可靠.%objective:A new method for determination of residual aspergillus flavus toxin M1 in milk was established based on macromolecular material cyclodextrin and resonance light scattering spectrum difference.Methods:After combination of beta cyclodextrin and aspergillus flavus toxin M1,clathrate formed by different concentrations of aspergillus flavus toxin M1 and cyclodextrin showed resonance scattering light spectrum had various intensity,then resonance rayleigh scattering light was used to detect aspergillus flavus toxin M1.Results:At the wavelength of 335 nm,the intensity of resonance light scattering was linear with concentration of aspergillus flavus toxin M1.When the pH value was 4.0 ~ 5.0,the optimum temperature of inclusion formation was 60 ℃ and the standing time was 1 h.The detection limit of the method was 0.38 ng/ml,the linear range was 0 ng/ml ~ 8.0 ng/ml with correlation coefficient of r =0.992 and recovery of 85 % ~ 108%.Conclusion:The method is simple and fast in determining aspergillus flavus toxin M1 in milk,with reliable results.

  18. Improvement of the antifungal activity of Litsea cubeba vapor by using a helium-neon (He-Ne) laser against Aspergillus flavus on brown rice snack bars.

    Science.gov (United States)

    Suhem, Kitiya; Matan, Narumol; Matan, Nirundorn; Danworaphong, Sorasak; Aewsiri, Tanong

    2015-12-23

    The aim of this study was to improve the antifungal activity of the volatile Litsea cubeba essential oil and its main components (citral and limonene) on brown rice snack bars by applying He-Ne laser treatment. Different volumes (50-200 μL) of L. cubeba, citral or limonene were absorbed into a filter paper and placed inside an oven (18 L). Ten brown rice snack bars (2 cm wide × 4 cm long × 0.5 cm deep) were put in an oven and heated at 180 °C for 20 min. The shelf-life of the treated snack bars at 30 °C was assessed and sensory testing was carried out to investigate their consumer acceptability. A count of total phenolic content (TPC) and Fourier transform infrared spectroscopy (FTIR) on the properties of essential oil, citral, and limonene before and after the laser treatment was studied for possible modes of action. It was found that the laser treatment improved the antifungal activity of the examined volatile L. cubeba and citral with Aspergillus flavus inhibition by 80% in comparison with those of the control not treated with the laser. L. cubeba vapor at 100 μL with the laser treatment was found to completely inhibit the growth of natural molds on the snack bars for at least 25 days; however, without essential oil vapor and laser treatment, naturally contaminating mold was observed in 3 days. Results from the sensory tests showed that the panelists were unable to detect flavor and aroma differences between essential oil treatment and the control. Laser treatment caused an increase in TPC of citral oil whereas the TPC in limonene showed a decrease after the laser treatment. These situations could result from the changing peak of the aliphatic hydrocarbons that was revealed by the FTIR spectra.

  19. Research of the inhibition activities effect of complex essential oil on Aspergillus flavus%复合精油对黄曲霉联合抑菌作用研究

    Institute of Scientific and Technical Information of China (English)

    曲春阳; 潘磊庆; 屠康; 杨立之

    2012-01-01

    The Diameter of Antibiotic Circle,Minimum Inhibition Concentration(MIC),Reduction Concentration(RC)and Fractional Inhibitory Concentration(FIC)of plant essential oils which used in single or combined were tested,and the fungicidal activities were evaluated by combined antiseptic evaluation method in order to find the best types and ratio of essential oils for inhibiting activities on Aspergillus flavus.The results indicated that garlic,cinnamon,clove and mint essential oils had strong inhibition activities on Aspergillus flavus.Combination of garlic and cinnamon essential oil showed surperimposed inhibition effects on Aspergillus flavus.The combined essential oil of garlic and cinnamon essential oil had the best inhibition effect on Aspergillus flavus when the volume ratio of them was 1:3.Therefore,this type of combined essential oil had a potential for the further applications as effective fungicidal components.%采用联合抑菌评价方法,通过测定植物精油抑菌圈直径、最低抑菌浓度(Minimum Inhibition Concentration,MIC)、最低生长下降浓度(Reduction Concentration,RC)、联合抑菌指数(Fractional Inhibitory Concentration,FIC),对植物精油单独及联合使用后的抑菌效果进行评价,筛选最佳抑制黄曲霉活性作用的复合精油种类及配比。结果表明:大蒜、肉桂、丁香、薄荷精油单独或复合使用均有较强抑制黄曲霉活性的作用。大蒜与肉桂精油联合抑菌评价为相加作用。当大蒜精油与肉桂精油复合体积比为1∶3时,复合精油具有最佳抑制黄曲霉活性的效果。因此,复合精油作为有效防霉保鲜成分具有良好的研发与应用前景。

  20. Inhibitory Effects of Seven Kinds of Green Leaf Volatiles on Aspergillus flavus%7种绿叶挥发物对黄曲霉的抑菌作用

    Institute of Scientific and Technical Information of China (English)

    梁海燕; 王国昌; 郎剑锋; 原庆霞; 孙玉凤

    2012-01-01

    Objective To understand the inhibitory effects of green leaf volatiles on Aspergillus flavus. Methods Among seven kinds of green leaf volatiles, their ability to inhibit A. flavus were compared at concentrations of 5 μl, 10 μl, 25 μl and 50 μl by the gaseous diffusion methods. Results The results showed that seven kinds of volatiles could inhibit hyphal growth at four concentrations. Except for 5 μl (Z)-3-hexene acetate, the tested volatiles inhibited spore germination rates significantly. It was noteworthy that the inhibition rates of (E)-2-hexenal on hyphal growth and spore germination were 100% at all tested concentrations. Conclusion The results suggest that seven kinds of tested green leaf volatiles can restrain A. flavus commonly. The inhibitory effect of (E)-2-hexenal is the best.%目的 研究7种绿叶挥发物对黄曲霉(Aspergillus flavus)的抑制作用,为开发黄曲霉杀菌剂提供科学依据.方法 比较(Z)-3-己烯醛、(Z)-3-己烯醇、(E)-2-己烯-1-醇、(E)-2-己烯乙酸酯、(Z)-3-己烯乙酸酯、(Z)-3-己烯丁酸酯7种挥发物在5、10、25、50μl加入量时对黄曲霉菌丝生长和孢子萌发率的影响.结果 在4种加入量时7种绿叶挥发物均对黄曲霉的菌丝生长有明显抑制作用(P<0.05).除5μl加入量的(Z)-3-已烯乙酸酯,其他试验条件下挥发物对孢子萌发率均有抑制作用(P<0.05).(E)-2-己烯醛在4个加入量时对菌丝生长和孢子萌发的抑制率均达到100%.结论 该7种绿叶挥发物均对黄曲霉菌丝生长和孢子萌发有抑制作用,抑制作用最强的为(E)-2-己烯醛.

  1. Atypical Aspergillus parasiticus isolates from pistachio with aflR gene nucleotide insertion identical to Aspergillus sojae

    Science.gov (United States)

    Aflatoxins are the most toxic and carcinogenic secondary metabolites produced primarily by the filamentous fungi Aspergillus flavus and Aspergillus parasiticus. The toxins cause devastating economic losses because of strict regulations on distribution of contaminated products. Aspergillus sojae are...

  2. Concentration-Dependent Effects of Caspofungin on the Metabolic Activity of Aspergillus Species▿

    OpenAIRE

    2006-01-01

    The minimum effective concentration (MEC) used to assess the in vitro antifungal activity of caspofungin against Aspergillus spp. is a qualitative endpoint requiring microscopic examination of hyphae. We therefore developed a tool for the quantitative assessment of caspofungin activity against Aspergillus spp. at clinically applicable concentrations. Susceptibility to caspofungin (0.008 to 8 μg/ml) was studied for 9 A. fumigatus, 8 A. flavus, and 12 A. terreus isolates based on the Clinical a...

  3. Study on Control Technology of Pollution Mulching Peanut by Aspergillus flavus%地膜覆盖花生黄曲霉污染的防治研究

    Institute of Scientific and Technical Information of China (English)

    周伟; 徐久飞; 杜献明

    2015-01-01

    采用单因素完全随机试验设计,通过地膜覆盖和裸露种植的方法,对不同试验地块土壤样本菌相、花生生长期土层温度等生长条件进行测定分析。结果表明,不同地块土壤中含黄曲霉菌数量不同,且不同地块菌株数量存在显著差异;不含产毒菌株的地块,覆膜种植对花生污染黄曲霉毒素的影响不显著;含产毒菌株的地块,覆膜种植对花生污染黄曲霉毒素的影响较大,且产毒菌株越多,受黄曲霉毒素污染越重。从果针下扎到收获期间,覆膜种植土层温度高于裸露种植是导致覆膜种植花生黄曲霉毒素污染加重的重要因素。实际生产中可采取综合防治技术以达到降低黄曲霉毒素污染的目的。%A single-factor completely randomized experimental design was used in this study. Through plastic film mulching and bare planting on different experimental plots, growth conditions such as soil sample bacterial phase, soil temperature in peanut growth period were determined and an-alyzed.The results showed that the number of Aspergillus flavus with different plots in soil was dif-ferent, and the number of strains showed significant difference.In the absence of toxigenic strain plots, effects of plastic film mulching cultivation on peanut aflatoxin contamination were not signifi-cant.On the contrary, in containing strains plots, effects of plastic film mulching cultivation on pea-nut aflatoxin contamination were significant.And the more the number of toxigenic strains, the more serious contamination conducted by aflatoxin.This study suggests that, the soil temperature under plastic film mulching cultivation was higher than under bare cultivation during the period from pegging to harvest.This is also the important factor leading to the more serious contamination by aflatoxin un-der plastic film mulching cultivation.In the actual production, we can adopt comprehensive prevention and control technology

  4. 姜黄挥发油脂质体制备及其抗黄曲霉菌评价研究%Preparation of Turmeric Essential Oil Liposome and Research on Its Anti-Aspergillus flavus Efficacy

    Institute of Scientific and Technical Information of China (English)

    胡一晨; 孔维军; 杨美华

    2015-01-01

    目的:研究及评价姜黄挥发油的纳米脂质体系,以用于抑制黄曲霉菌生长及产毒,为纳米抗菌剂研究和开发奠定基础。方法:以安全性好的卵磷脂、胆固醇为膜材,采用乙醇注入结合超声乳化法,采用单因素考察与正交设计结合的方法优选姜黄挥发油脂质体制备工艺,并对所得脂质体进行理化表征和抗黄曲霉菌作用的评价。结果:采用卵磷脂与胆固醇比例10∶1,加药量与脂质比例1∶5,乙醇滴加速度1 mL/min,超声5 min,制备所得姜黄挥发油脂质体包封率、粒径分布、稳定性均较好。采用2 mL 脂质体/25 mL 培养基浓度,与黄曲霉菌共培养10 d,可完全抑制霉菌生长和黄曲霉毒素的产生。结论:将姜黄挥发油制备成纳米脂质体,既增加其体系稳定性和均一性,又保证了其抗黄曲霉菌性效,具有极大开发前景。%Objective:To develop the nano-liposomal system of turmeric essential oil for inhibiting Aspergillus flavus growth and aflatoxin generation.Methods:The stabilized and bio-safe liposomes loading turmeric essential oil were prepared by the ethanol injection-ultrasonic emulsification method with lecithin and cholesterol as excipients.Based on the combination of single factor screening and orthogonal design,liposomes were obtained by means of the optimized technology.Subsequently,following with the physicochemical characterization,the anti-Aspergillus flavus activity of liposomes were evaluated.Results:With the ratio of leci-thin and cholesterol(1 0∶1 ,weight ratio),ratio of feeding drug and excipient(1 :5,weight ratio),1 mL/min of the ethyl alcohol adding speed and along with ultrasonic emulsification for 5 min,liposomes were prepared,exhibiting high encapsulation efficiency, suitable size distribution,and good storage stability.Particularly,after incubation with 2 mL essential oil liposome per 25 mL cul-ture medium for 1 0d,almost 1 00% of

  5. Establishment of Aspergillus flavus' growth predictive model in corn flour with different water contents%不同含水量玉米粉中黄曲霉的生长预测模型的构建

    Institute of Scientific and Technical Information of China (English)

    赵立; 赵希荣; 陈军; 周晓梅

    2010-01-01

    对玉米粉中黄曲霉(Aspergillus flavus,A.flavus)生长预测模型的构建进行了研究,建立了玉米粉中黄曲霉生长的一级和二级预测模型.结果表明:在20℃和28℃下黄曲霉的生长用Boltzmann和Logistic模型拟合效果都很好(R2达到0.9400).以Logistic一级模型拟合的参数(比生长速率)为基础建立二级平方根模型,R2值高于0.9200,可用于预测不同含水量玉米粉中黄曲霉的生长速率.此生长预测模型为玉米粉获得最佳贮藏条件以及玉米粉货架期的预测提供理论依据.

  6. Regulation of aflatoxin biosynthesis and branched-chain amino acids metabolism in Aspergillus flavus by 2-phenylethanol reveal biocontrol mechanism of Pichia anomala

    Science.gov (United States)

    Pichia anomala WRL-076 is a biocontrol yeast which has been shown to inhibit growth and aflatoxin production of A. flavus. Using the SPME-GC/MS analysis we identified that the volatile, 2-phenylethanol (2-PE) produced by this yeast and demonstrated that the compound inhibited aflatoxin production. W...

  7. POPULATION AND DYNAMIC ANALYSIS OF ASPERGILLUS FLAVUS AND OTHER FUNGI IN GROUNDNUT%花生黄曲霉与其他寄生真菌的种群及动态分析

    Institute of Scientific and Technical Information of China (English)

    杨文兰; 马桂珍

    2003-01-01

    对鲁花14,花育16,白沙,花37等四个花生品种不同生育时期籽仁、果壳、根部、果针等部位寄生真菌的种类进行了初步鉴定.共鉴定出8个真菌类型,其中黄曲霉菌(Aspergillus flavus Link)、镰刀菌(Fusarium spp.)、桑卷担菌(Helicobasidium mompa)、青霉菌(Penicillium spp.)、黑曲霉菌(Aspergillus niger)等为主要真菌.表现在不同品种各部位间分布广、带菌量高,持续时间长.其中,青霉菌在籽仁中的带菌率最高,镰刀菌在果针中的带菌率最高,桑卷担菌在根和果壳中的带菌率最高.不同品种的花生黄曲霉感染率有所差异.鲁花14的黄曲霉带菌率最低,花育16、白沙、花37的带菌率较高.

  8. Aspergillus pragensis sp nov discovered during molecular reidentification of clinical isolates belonging to Aspergillus section Candidi

    DEFF Research Database (Denmark)

    Lyskova, Pavlina; Hubka, Vit; Kolarik, Miroslav

    2014-01-01

    reidentified as A. carneus (sect. Terrei) and A. flavus (sect. Flavi). Three isolates from nail scrapings were identified as A. tritici, a verified agent of nondermatophyte onychomycosis. One isolate from toenail was determined to be A. candidus and the two isolates belonged to a hitherto undescribed species...

  9. 6种芳香族挥发性有机物对黄曲霉的抑菌作用%Inhibitory effects of six kinds of aromatic compounds on Aspergillus flavus

    Institute of Scientific and Technical Information of China (English)

    梁海燕; 王国昌; 秦雪峰; 吴利民

    2013-01-01

    Objective To understand the inhibitory effects of six kinds of aromatic compounds (benzyl alcohol,phenethyl alcohol,phenacetaldehyde,benzaldehyde,phenethyl butyrate, and phenyl acetate) on Aspergillus flavus. Methods The gaseous diffusion method was adopted. The A. flavus was exposed to 1,2,4 and 8 μl solution of six kinds of aromatic compounds respectively for 72 h at 28 ℃. Then, mycelial growth and spore production were measured. Results All treatments had inhibitory activities on mycelial growth significantly (P<0.05,P<0.01),with the exception of 1 μl benzaldehyde,l μl phenethyl butyrate, 1 μl and 2 μl phenyl acetate. Spore production did not reduce at 1 μl benzaldehyde, 1 Μl benzyl alcohol, 1 μl phenethyl alcohol, 1 μl and 2 μl phenethyl butyrate, 1 μl and 2 μl phenyl acetate,others were reduced significantly (P< 0.05,P<0.01). Conclusion These six kinds of aromatic compounds may inhibit A.flavus growth to some degree.%目的 研究6种芳香族挥发性有机物(苯甲醇、苯乙醇、苯乙醛、苯甲醛、丁酸苯乙酯、乙酸苯酯)对黄曲霉(Aspergillus flavus)的抑菌作用.方法 采用了气体扩散法,在28℃下把黄曲霉分别暴露于1、2、4、8μl的6种芳香族挥发性有机物原液72 h.测定黄曲霉菌丝生长和产孢量.结果 除了1μ1的苯甲醛、丁酸苯乙酯、乙酸苯酯和2μl乙酸苯酯外,其余处理对黄曲霉菌丝生长都有抑制作用,差异有统计学意义(P<0.05,P<0.01);1μl苯甲醛、苯甲醇、苯乙醇、丁酸苯乙酯、乙酸苯酯和2μl的丁酸苯乙酯、乙酸苯酯对产孢量无影响,其余处理条件对产孢量均有抑制作用,差异有统计学意义(P<0.05,P<0.01).结论 6种芳香族挥发性有机物对黄曲霉菌有不同程度的抑制作用.

  10. Simultaneous Detection and Identification of Aspergillus and Mucorales Species in Tissues Collected from Patients with Fungal Rhinosinusitis▿

    OpenAIRE

    2011-01-01

    Rapid detection and differentiation of Aspergillus and Mucorales species in fungal rhinosinusitis diagnosis are desirable, since the clinical management and prognosis associated with the two taxa are fundamentally different. We describe an assay based on a combination of broad-range PCR amplification and reverse line blot hybridization (PCR/RLB) to detect and differentiate the pathogens causing fungal rhinosinusitis, which include five Aspergillus species (A. fumigatus, A. flavus, A. niger, A...

  11. Movilidad de Aspergillus flavus link ex fries en mazorcas de cinco genotipos de maiz (Zea Mays L. empleando tres métodos de inoculación (ING

    Directory of Open Access Journals (Sweden)

    Néstor Villalobos

    2016-03-01

    Full Text Available Three inoculation techniques for evaluating reaction of corn to kernel infection by Aspergillus flavus were tested in the field of five different genotypes. Inoculations were made 20 days after midsilk stage, using 0.5 ml of 105 conidial suspensions. The methods were: a injection of small amounts of inoculum in each kernel of a vertical row (M1; b injection in the first well developed kernels around the top part of the ear (M2; c injection of inoculum in the kernels at the lower part of the ear, forming a semicircle (M3. Two weeks after inoculation ears were harvested, and kernels not wounded were separated according to its position to the inoculated kernels, then surface sterilized and planted on PDA, to determine the infection percentage. M1 and M2 were found very efficient because they produced higher infection levels. M1 is considered the best because it provided a larger number of kernels for assay and was easy to use. No statistical difference was found among genotypes.

  12. Efficacy of Some Essential Oils Against Aspergillus flavus with Special Reference to Lippia alba Oil an Inhibitor of Fungal Proliferation and Aflatoxin B1 Production in Green Gram Seeds during Storage.

    Science.gov (United States)

    Pandey, Abhay K; Sonker, Nivedita; Singh, Pooja

    2016-04-01

    During mycofloral analysis of green gram (Vigna radiata (L.) R. Wilczek) seed samples taken from different grocery stores by agar and standard blotter paper methods, 5 fungal species were identified, of which Aspergillus flavus exhibited higher relative frequency (75.20% to 80.60%) and was found to produce aflatoxin B1 . On screening of 11 plant essential oils against this mycotoxigenic fungi, Lippia alba essential oil was found to be most effective and showed absolute inhibition of mycelia growth at 0.28 μL/mL. The oil of L. alba was fungistatic and fungicidal at 0.14 and 0.28 μL/mL, respectively. Oil had broad range of fungitoxicity at its MIC value and was absolutely inhibited the AFB1 production level at 2.0 μL/mL. Chemical analysis of this oil revealed geranial (36.9%) and neral (29.3%) as major components followed by myrcene (18.6%). Application of a dose of 80 μL/0.25 L air of Lippia oil in the storage system significantly inhibited the fungal proliferation and aflatoxin production without affecting the seed germination rate. By the virtue of fungicidal, antiaflatoxigenic nature and potent efficacy in storage food system, L. alba oil can be commercialized as botanical fungicide for the protection of green gram seeds during storage.

  13. Clinical Performance of Aspergillus PCR for Testing Serum and Plasma: a Study by the European Aspergillus PCR Initiative.

    Science.gov (United States)

    White, P Lewis; Barnes, Rosemary A; Springer, Jan; Klingspor, Lena; Cuenca-Estrella, Manuel; Morton, C Oliver; Lagrou, Katrien; Bretagne, Stéphane; Melchers, Willem J G; Mengoli, Carlo; Donnelly, J Peter; Heinz, Werner J; Loeffler, Juergen

    2015-09-01

    Aspergillus PCR testing of serum provides technical simplicity but with potentially reduced sensitivity compared to whole-blood testing. With diseases for which screening to exclude disease represents an optimal strategy, sensitivity is paramount. The associated analytical study confirmed that DNA concentrations were greater in plasma than those in serum. The aim of the current investigation was to confirm analytical findings by comparing the performance of Aspergillus PCR testing of plasma and serum in the clinical setting. Standardized Aspergillus PCR was performed on plasma and serum samples concurrently obtained from hematology patients in a multicenter retrospective anonymous case-control study, with cases diagnosed according to European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) consensus definitions (19 proven/probable cases and 42 controls). Clinical performance and clinical utility (time to positivity) were calculated for both kinds of samples. The sensitivity and specificity for Aspergillus PCR when testing serum were 68.4% and 76.2%, respectively, and for plasma, they were 94.7% and 83.3%, respectively. Eighty-five percent of serum and plasma PCR results were concordant. On average, plasma PCR was positive 16.8 days before diagnosis and was the earliest indicator of infection in 13 cases, combined with other biomarkers in five cases. On average, serum PCR was positive 10.8 days before diagnosis and was the earliest indicator of infection in six cases, combined with other biomarkers in three cases. These results confirm the analytical finding that the sensitivity of Aspergillus PCR using plasma is superior to that using serum. PCR positivity occurs earlier when testing plasma and provides sufficient sensitivity for the screening of invasive aspergillosis while maintaining methodological simplicity.

  14. 曲霉临床和环境分离株基因型和药敏表型分析%Genotyping and susceptibility testing of Aspergillus species from clinical settings and environmental sources

    Institute of Scientific and Technical Information of China (English)

    敖俊红; 杨燕妮; 郝飞

    2010-01-01

    Objective To investigate the genotype and antifungal susceptibility of AspergiIlus species isolated from clinical settings and environmental sources. Methods Random amplification of polymorphic DNA (RAPD) analysis was performed to profile the genotypes of 48 Aspergillus fumigatus strains, 59 Aspergillus flavus strains and 30 Aspergillus niger strains isolated from clinical settings and environmental sources. NCCLS M38-A protocol was carried out for antifungal susceptibility testing of these Aspergillus isolates. Results As RAPD analysis showed, the 48 Aspergillus fumigatus strains were classified into 8 genotypes, 59 Aspergillus flavus strains into 12 genotypes, and 30 Aspergillus niger strains into 5 genotypes. A significant difference was observed in the susceptibility to terbinafine among the 8 genotypes of Aspergillus fumigatus (χ2 = 33.092, P <0.01 ) as well as in that to amphotericin B among the 5 genotypes of Aspergillus niger (χ2 = 15.185, P< 0.05).No statistical difference was found in the susceptibility to amphoteriein B, itraconazole, fluconazole or flucytosine among the 8 genotypes of Aspergillus fumigatus or in that to terbinafine, itraconazole, fluconazole or flucytosine among the 5 genotypes of Aspergillus niger. Conclusion There is some difference in the susceptibility to some antifungal agents between different genotypes of Aspergillus fumigatus and Aspergillus niger.%目的 探讨临床和环境来源曲霉的基因分型情况以及不同基因型曲霉的药敏结果.方法 采用随机扩增DNA多态性(RAPD)分型方法对45株烟曲霉、59株黄曲霉和30株黑曲霉进行基因分型,采用M38-A方案分析曲霉对抗真菌药物的敏感性.结果 45株烟曲霉产生8种基因型,59株黄曲霉产生12种基因型,30株黑曲霉产生5种基因型.8种基因型烟曲霉对特比萘芬敏感性差异有统计学意义(χ2=33.092,P<0.01),而对其他抗真菌药物敏感性差异无统计学意义.5种基因型黑曲霉对两性

  15. Impact of bacterial biocontrol agents on aflatoxin biosynthetic genes, aflD and aflR expression, and phenotypic aflatoxin B₁ production by Aspergillus flavus under different environmental and nutritional regimes.

    Science.gov (United States)

    Al-Saad, Labeed A; Al-Badran, Adnan I; Al-Jumayli, Sami A; Magan, Naresh; Rodríguez, Alicia

    2016-01-18

    The objectives of this study were to examine the efficacy of four bacterial antagonists against Aspergillus flavus using 50:50 ratio of bacterial cells/conidia for the control of aflatoxin B1 (AFB1) production on two different nutritional matrices, nutrient and maize-based media at different water availabilities (0.98, 0.94 water activity (aw) on nutrient medium; 0.995, 0.98 aw on maize meal agar medium) at 35°C. The indicators of efficacy used were the relative expression of one structural and regulatory gene in the biosynthetic pathway (aflD and aflR respectively) and the production of AFB1. These studies showed that some of the bacterial species could significantly inhibit the relative expression of the aflD and aflR genes at both 0.98 and 0.94 aw on nutrient agar. On maize-based media some of the bacterial antagonists reduced the activity of both genes at 0.94 aw and some at 0.995 aw. However, the results for AFB1 production were not consistent with the effects on gene expression. Some bacterial species stimulated AFB1 production on both nutrient and maize-based media regardless of aw. However, some bacterial treatments did inhibit AFB1 production significantly when compared to the control. Overall, this study suggests that temporal studies are required on the biosynthetic genes under different environmental and nutritional conditions to evaluate the potential of antagonists to control AFB1.

  16. Aspergillus thyroiditis: a review of the literature to highlight clinical challenges.

    Science.gov (United States)

    Nguyen, J; Manera, R; Minutti, C

    2012-12-01

    Aspergillus involvement of the thyroid is the most commonly reported fungal thyroiditis. Aspergillus thyroiditis (AT) has primarily been a postmortem diagnosis in immunocompromised patients with diagnosed disseminated invasive Aspergillus or high suspicion of fungal infection during life. With better treatment modalities for the comorbidities that place patients at high risk for fungal infections, as well as better antifungal therapies for Aspergillus infections specifically, the spectrum of disease and presentation of AT may be shifting from what was primarily a postmortem finding to an antemortem diagnosis, necessitating a high index of clinical suspicion and timely intervention. We present a review of the literature to better clarify clinical features, diagnostic modalities, and management considerations pertaining to this disease.

  17. Efficacy of corn silage inoculants on the fermentation quality under farm conditions and their influence on Aspergillus parasitucus, A. flavus and A. fumigatus determined by q-PCR.

    Science.gov (United States)

    Dogi, Cecilia A; Pellegrino, Matías; Poloni, Valeria; Poloni, Luis; Pereyra, Carina M; Sanabria, Analía; Pianzzola, María Julia; Dalcero, Ana; Cavaglieri, Lilia

    2015-01-01

    Laboratory-scale silos were prepared to evaluate the efficacy of two different lactic acid bacteria (LAB) on the fermentation quality and mycobiota of corn silage. Their influence on Aspergillus species' variability by using the q-PCR technique was studied. Silage inoculated with Lactobacillus rhamnosus RC007 or L. plantarum RC009 were compared with uninoculated silage. Silos were opened after 1, 7, 45, 90 and 120 days after ensiling. At the end of the ensiling period, silos were left open for 7 days to evaluate aerobic stability. Rapid lactic acid production and decline in pH values were seen in the early stages of fermentation in silage inoculated with L. rhamnosus RC007. After aerobic exposure, a significant decline in lactic acid content was observed in untreated and L. plantarum RC009-inoculated silages. Counts for yeasted and toxigenic fungus remained lower, after aerobic exposure, in L. rhamnosus RC007-inoculated silage, in comparison with L. plantarum RC009 and uninoculated silages. Comparing the influence exerted by both BAL, it was observed that L. rhamnosus RC007 was more efficient at inhibiting the three fungal species tested whose DNA concentrations, determined by q-PCR, oscillated near the initial value (pre-ensiling maize). The ability of L. rhamnosus RC007 to produce lactic acid rapidly and the decline in pH values in the early stages of the fermentation along with the reduction of yeast and mycotoxicogenic fungus after aerobic exposure shows its potential as a bio-control inoculant agent in animal feed.

  18. Density and molecular epidemiology of Aspergillus in air and relationship to outbreaks of Aspergillus infection

    NARCIS (Netherlands)

    A.C.A.P. Leenders (Alexander); A.F. van Belkum (Alex); M.D. Behrendt (Myra); A. Luijendijk (Ad); H.A. Verbrugh (Henri)

    1999-01-01

    textabstractAfter five patients were diagnosed with nosocomial invasive aspergillosis caused by Aspergillus fumigatus and A. flavus, a 14-month surveillance program for pathogenic and nonpathogenic fungal conidia in the air within and outside the University Hospital in

  19. 2-hydroxyisocaproic acid is fungicidal for Candida and Aspergillus species.

    Science.gov (United States)

    Sakko, M; Moore, C; Novak-Frazer, L; Rautemaa, V; Sorsa, T; Hietala, P; Järvinen, A; Bowyer, P; Tjäderhane, L; Rautemaa, R

    2014-04-01

    The amino acid derivative 2-hydroxyisocaproic acid (HICA) is a nutritional additive used to increase muscle mass. Low levels can be detected in human plasma as a result of leucine metabolism. It has broad antibacterial activity but its efficacy against pathogenic fungi is not known. The aim was to test the efficacy of HICA against Candida and Aspergillus species. Efficacy of HICA against 19 clinical and reference isolates representing five Candida and three Aspergillus species with variable azole antifungal sensitivity profiles was tested using a microdilution method. The concentrations were 18, 36 and 72 mg ml(-1) . Growth was determined spectrophotometrically for Candida isolates and by visual inspection for Aspergillus isolates, viability was tested by culture and impact on morphology by microscopy. HICA of 72 mg ml(-1) was fungicidal against all Candida and Aspergillus fumigatus and Aspergillus terreus isolates. Lower concentrations were fungistatic. Aspergillus flavus was not inhibited by HICA. HICA inhibited hyphal formation in susceptible Candida albicans and A. fumigatus isolates and affected cell wall integrity. In conclusion, HICA has broad antifungal activity against Candida and Aspergillus at concentrations relevant for topical therapy. As a fungicidal agent with broad-spectrum bactericidal activity, it may be useful in the topical treatment of multispecies superficial infections.

  20. Decolorization mechanism of molasses wastewater by Aspergillus flavus A5p1%黄曲霉A5p1脱色糖蜜酒精废水机理初探

    Institute of Scientific and Technical Information of China (English)

    贺锴; 何小慧; 李必金; 邹成; 覃益民; 李青云; 刘幽燕

    2014-01-01

    研究自行筛选的一株黄曲霉( Aspergillus flavus) A5p1(保藏号CGMCC.4292)对糖蜜酒精废水( MSW)的脱色机理.在外加蔗糖情况下菌株A5p1对MSW具有较好的脱色效果,脱色率由14%增高至58%;脱色进程与细胞生长基本同步.从培养液中检测出3种木质素过氧化物酶---漆酶( Lac)及两种胞外过氧化物酶即锰过氧化物酶( MnP )和不依赖锰的过氧化物酶( MiP )的酶活,但是水平不高,认为此3种酶不是主要的脱色机制.发现由各种代谢过程产生的总H2 O2生成速率与脱色率基本同步,同时在第4天达到最大值,随后下降;还原糖总消耗也在初期阶段较快.外加蔗糖后总H2 O2生成速率增加10倍,达到0.0027 mmol·min-1·mL-1.认为体系中脱色机制可能与产H2 O2的酶相关.紫外可见光谱分析和凝胶色谱分析表明脱色过程中有大分子物质降解.综上所述初步认为,黄曲霉A5p1脱色糖蜜酒精废水是一个受产H2 O2酶影响、复杂的生物降解过程.%The decolorization mechanism of molasses wastewater ( MSW) by Aspergillus flavus A5P1 ( CGMCC.4292) was studied in this article. With the addition of sucrose, strain A5P1 displayed a better decolorization activity, and the decolorization rate increased from 14% to 58%. The cell dry weight was synchronized with the change of decolorization rate. Three lignin peroxidases relevant to the biodecolorization were detected in the culture fluid, including laccase and two extracellular peroxidases, a manganese-independent peroxidase ( MiP ) and manganese peroxidase ( MnP ) , but, with low activity. It is deducted that these three enzymes did not play a leading role in the the MSW-decolorization by the strain. The total generation rate of H2 O2 from a variety of metabolic processes was found to be synchronous to the decolorization rate, both reaching maximum after 4 d and decreasing subsequently. The total

  1. Development of RFLP-PCR method for the identification of medically important Aspergillus species using single restriction enzyme MwoI

    Directory of Open Access Journals (Sweden)

    K. Diba

    2014-06-01

    Full Text Available In this study we attempted to modify the PCR-RFLP method using restriction enzyme MwoI for the identification of medically important Aspergillus species. Our subjects included nine standard Aspergillus species and 205 Aspergillus isolates of approved hospital acquired infections and hospital indoor sources. First of all, Aspergillus isolates were identified in the level of species by using morphologic method. A twenty four hours culture was performed for each isolates to harvest Aspergillus mycelia and then genomic DNA was extracted using Phenol-Chloroform method. PCR-RFLP using single restriction enzyme MwoI was performed in ITS regions of rDNA gene. The electrophoresis data were analyzed and compared with those of morphologic identifications. Total of 205 Aspergillus isolates included 153 (75% environmental and 52 (25% clinical isolates. A. flavus was the most frequently isolate in our study (55%, followed by A. niger 65(31.7%, A. fumigatus 18(8.7%, A. nidulans and A. parasiticus 2(1% each. MwoI enabled us to discriminate eight medically important Aspergillus species including A. fumigatus, A. niger, A. flavus as the most common isolated species. PCR-RFLP method using the restriction enzyme MwoI is a rapid and reliable test for identification of at least the most medically important Aspergillus species.

  2. Development of RFLP-PCR method for the identification of medically important Aspergillus species using single restriction enzyme MwoI.

    Science.gov (United States)

    Diba, K; Mirhendi, H; Kordbacheh, P; Rezaie, S

    2014-01-01

    In this study we attempted to modify the PCR-RFLP method using restriction enzyme MwoI for the identification of medically important Aspergillus species. Our subjects included nine standard Aspergillus species and 205 Aspergillus isolates of approved hospital acquired infections and hospital indoor sources. First of all, Aspergillus isolates were identified in the level of species by using morphologic method. A twenty four hours culture was performed for each isolates to harvest Aspergillus mycelia and then genomic DNA was extracted using Phenol-Chloroform method. PCR-RFLP using single restriction enzyme MwoI was performed in ITS regions of rDNA gene. The electrophoresis data were analyzed and compared with those of morphologic identifications. Total of 205 Aspergillus isolates included 153 (75%) environmental and 52 (25%) clinical isolates. A. flavus was the most frequently isolate in our study (55%), followed by A. niger 65(31.7%), A. fumigatus 18(8.7%), A. nidulans and A. parasiticus 2(1% each). MwoI enabled us to discriminate eight medically important Aspergillus species including A. fumigatus, A. niger, A. flavus as the most common isolated species. PCR-RFLP method using the restriction enzyme MwoI is a rapid and reliable test for identification of at least the most medically important Aspergillus species.

  3. 主要生态因子对贮藏玉米中黄曲霉生长影响的模拟%Simulation of effect of main ecological factors on radial growth of Aspergillus flavus during storage period of corn

    Institute of Scientific and Technical Information of China (English)

    岳晓禹; 李自刚; 郝修振; 徐军; 刘相东; 牛天贵

    2013-01-01

    为了模拟贮藏玉米中主要生态因子对黄曲霉生长的影响,利用Baranyi和Roberts函数拟合了玉米中黄曲霉的生长数据,得到了不同温度和水分活度下玉米中黄曲霉的生长动力学模型。应用一个二次多项式函数分别建立了描述水分活度(aw)和温度对菌落生长的组合影响的模型。对模型的有效性分别进行了验证,其偏离因子分别为0.896和0.963。精确因子都小于1.15。结果证明构建的二次多项式预测模型可以很好的预报aw和温度对黄曲霉生长的比生长速率和迟滞期的组合影响。得出的方程可以用于预测贮藏玉米中黄曲霉生长情况。%The safety of corn storage is related to food safety and human health. According to the predictive microbiology, the microorganism’s growth in stored corn can be quickly judged in advance by construction of a predictive microbiology model. It plays an important part in controlling the growth of pathogens and spoilage microorganisms in stored grain. It is of important theoretical and practical application value to realize the ecological storage of corn and ensure the security of corn storage. The radial growth of A. flavus on corn was studied in this article. The testing of four temperatures and four aw values was designed. A full factorial design of four temperatures (20, 25, 30, and 35℃) and four aw values (0.97, 0.91, 0.85, 0.81) was used to investigate the growth of A. flavus on corn. The colony growth curve of A. flavus on corn was determined. The objective of the present study was to develop validated models that describe the effect of the main ecological factors on the radial growth of Aspergillus flavus on corn. The growth data of A. flavus on corn under different temperatures and water activity were fitted by the Baranyi and Roberts functions. The corresponding growth kinetics models were built. The higher R2 (0.993-0.998) showed that these growth kinetics models can be a good

  4. 60Coγ射线对生理盐水和玉米中黄曲霉孢子的辐照效应研究%Irradiation effect of 60Co gamma ray on Aspergillus flavus spores in normal saline and maize

    Institute of Scientific and Technical Information of China (English)

    钟凯; 高翔; 计融

    2011-01-01

    目的 研究γ射线对黄曲霉孢子辐照效应.方法 两种介质中不同浓度黄曲霉孢子经不同剂量辐照后进行菌落计数,计算D值和理论最小杀灭剂量,并实验验证实际最小杀灭剂量.结果 生理盐水中高浓度孢子D值0.39kGy,最低杀灭剂量2.5kGy,低浓度孢子D值0.47kGy,最低杀灭剂量1.5kGy;玉米中高浓度孢子D值为0.67kGy,最低杀灭剂量3.0kGy,低浓度孢子D值为0.72kGy,最低杀灭剂量2.0kGy.结论 3.0kGy可用于粮食中黄曲霉的杀灭.%Objective To observe irradiation effect of gamma ray on Aspergillus flavus spores.Methods Aspergillus flavus spores of different concentration were prepared on two media and were exposed to gamma ray.D10 values and theoretical minimal sterilizing doses were calculated by colony counting results.Actual minimal sterilizing doses were verified according to theoretical dose.Results D10 value and minimal sterilizing dose of high concentration spore in normal saline were 0.39kGy and 2.5kGy.Those of low concentration spore in normal saline were 0.47kGy and 1.5kGy.D10 value and minimal sterilizing dose of high concentration spore in maize were 0.67kGy and 3.0kGy.Those of low concentration spore in maize were 0.72kGy and 2.0kGy.Conclusion 3.0kGy may be suitable for grain processing to sterilize Aspergillus flavus.

  5. In vitro interactions of antifungal agents and tacrolimus against Aspergillus biofilms.

    Science.gov (United States)

    Gao, Lujuan; Sun, Yi

    2015-11-01

    Aspergillus biofilms were prepared from Aspergillus fumigatus, Aspergillus flavus, and Aspergillus terreus via a 96-well plate-based method, and the combined antifungal activity of tacrolimus with azoles or amphotericin B against Aspergillus biofilms was investigated via a broth microdilution checkerboard technique system. Our results suggest that combinations of tacrolimus with voriconazole or amphotericin B have synergistic inhibitory activity against Aspergillus biofilms. However, combinations of tacrolimus with itraconazole or posaconazole exhibit no synergistic or antagonistic effects.

  6. Antifungal activity of ibuprofen against aspergillus species and its interaction with common antifungal drugs

    Institute of Scientific and Technical Information of China (English)

    LI Li-juan; CHEN Wei; XU Hui; WAN Zhe; LI Ruo-yu; LIU Wei

    2010-01-01

    Background The incidence of invasive aspergillosis (IA) has increased in frequency in immunocompromised patients with a variety of diseases. The poor prognosis might be due to limited treatment option. This study aimed to evaluate antifungal activity of ibuprofen against clinical isolates of aspergillus species, as well as its interaction with azoles or with amphotericin B or with micafungin.Methods Antifungal activity of ibuprofen against 10 strains of Aspergillus fumigatus, Aspergillus flavus, and Aspergillus terreus were tested with both disk diffusion assay and standard broth microdilution method. To determine whether ibuprofen combined with itraconazole, voriconazole, amphotericin B, or micafungin had interactive effects on aspergillus spp., we used both disk diffusion assay and Chequerboard method.Results As for disk diffusion method, ibuprofen produced a zone of growth inhibition with diameters of (20.1±3.9) mm at 48 hours of incubation. As for broth microdilution method, the minimal inhibitory concentration (MIC) ranges of ibuprofen against aspergillus spp. were 1000-2000 μg/ml, and the minimal fungicidal concentration (MFC) ranges of that was 2000-8000 μg/ml. For 2 of 5 isolates, when ibuprofen combined with itraconazole or voriconazole, the zones of growth inhibition were larger than those of the individual drug. The results of Chequerboard method showed that fractional inhibitory concentration index (FICI) ranges were 1.125-2.500.Conclusions Ibuprofen is active against aspergillus spp.. And ibuprofen does not affect the in vitro activity of itraconazole, voriconazole, amphotericin B or micafungin against aspergillus spp..

  7. Molecular screening of 246 Portuguese Aspergillus isolates among different clinical and environmental sources.

    Science.gov (United States)

    Sabino, Raquel; Veríssimo, Cristina; Parada, Helena; Brandão, João; Viegas, Carla; Carolino, Elisabete; Clemons, Karl V; Stevens, David A

    2014-07-01

    Clinical and environmental samples from Portugal were screened for the presence of Aspergillus and the distributions of the species complexes were determined in order to understand how their distributions differ based on their source. Fifty-seven Aspergillus isolates from clinical samples were collected from 10 health institutions. Six species complexes were detected by internal transcribed spacer sequencing; Fumigati, Flavi, and Nigri were found most frequently (50.9%, 21.0%, and 15.8%, respectively). β-tubulin and calmodulin sequencing resulted in seven cryptic species (A. awamorii, A. brasiliensis, A. fructus, A. lentulus, A. sydowii, A. tubingensis, Emericella echinulata) being identified among the 57 isolates. Thirty-nine isolates of Aspergillus were recovered from beach sand and poultry farms, 31 from swine farms, and 80 from hospital environments, for a total 189 isolates. Eleven species complexes were found in these 189 isolates, and those belonging to the Versicolores species complex were found most frequently (23.8%). There was a significant association between the different environmental sources and distribution of the species complexes; the hospital environment had greater variability of species complexes than other environmental locations. A high prevalence of cryptic species within the Circumdati complex was detected in several environments; from the isolates analyzed, at least four cryptic species were identified, most of them growing at 37ºC. Because Aspergillus species complexes have different susceptibilities to antifungals, knowing the species-complex epidemiology for each setting, as well as the identification of cryptic species among the collected clinical isolates, is important. This may allow preventive and corrective measures to be taken, which may result in decreased exposure to those organisms and a better prognosis.

  8. Microscopic Evaluation, Molecular Identification, Antifungal Susceptibility, and Clinical Outcomes in Fusarium, Aspergillus and, Dematiaceous Keratitis

    Directory of Open Access Journals (Sweden)

    Devarshi U. Gajjar

    2013-01-01

    Full Text Available Purpose. Fusarium, Aspergillus, and Dematiaceous are the most common fungal species causing keratitis in tropical countries. Herein we report a prospective study on fungal keratitis caused by these three fungal species. Methodology. A prospective investigation was undertaken to evaluate eyes with presumed fungal keratitis. All the fungal isolates (n=73 obtained from keratitis infections were identified using morphological and microscopic characters. Molecular identification using sequencing of the ITS region and antifungal susceptibility tests using microdilution method were done. The final clinical outcome was evaluated in terms of the time taken for resolution of keratitis and the final visual outcome. The results were analyzed after segregating the cases into three groups, namely, Fusarium, Aspergillus, and Dematiaceous keratitis. Results. Diagnosis of fungal keratitis was established in 73 (35.9% cases out of 208 cases. The spectra of fungi isolated were Fusarium spp. (26.6%, Aspergillus spp. (21.6%, and Dematiaceous fungi (11.6%. The sequence of the ITS region could identify the Fusarium and Aspergillus species at the species complex level, and the Dematiaceous isolates were accurately identified. Using antifungal agents such as fluconazole, natamycin, amphotericin B, and itraconazole, the minimum inhibitory concentrations (MICs for Fusarium spp. were >32 μg/mL, 4–8 μg/mL, 0.5–1 μg/mL, and >32 μg/mL, respectively. Antifungal susceptibility data showed that Curvularia spp. was highly resistant to all the antifungal agents. Overall, natamycin and amphotericin B were found to be the most effective antifungal agents. The comparative clinical outcomes in all cases showed that the healing response in terms of visual acuity of the Dematiaceous group was significantly good when compared with the Fusarium and Aspergillus groups (P<0.05. The time required for healing in the Fusarium group was statistically significantly less when

  9. Genetic diversity of Aspergillus species isolated from onychomycosis and Aspergillus hongkongensis sp. nov., with implications to antifungal susceptibility testing.

    Science.gov (United States)

    Tsang, Chi-Ching; Hui, Teresa W S; Lee, Kim-Chung; Chen, Jonathan H K; Ngan, Antonio H Y; Tam, Emily W T; Chan, Jasper F W; Wu, Andrea L; Cheung, Mei; Tse, Brian P H; Wu, Alan K L; Lai, Christopher K C; Tsang, Dominic N C; Que, Tak-Lun; Lam, Ching-Wan; Yuen, Kwok-Yung; Lau, Susanna K P; Woo, Patrick C Y

    2016-02-01

    Thirteen Aspergillus isolates recovered from nails of 13 patients (fingernails, n=2; toenails, n=11) with onychomycosis were characterized. Twelve strains were identified by multilocus sequencing as Aspergillus spp. (Aspergillus sydowii [n=4], Aspergillus welwitschiae [n=3], Aspergillus terreus [n=2], Aspergillus flavus [n=1], Aspergillus tubingensis [n=1], and Aspergillus unguis [n=1]). Isolates of A. terreus, A. flavus, and A. unguis were also identifiable by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The 13th isolate (HKU49(T)) possessed unique morphological characteristics different from other Aspergillus spp. Molecular characterization also unambiguously showed that HKU49(T) was distinct from other Aspergillus spp. We propose the novel species Aspergillus hongkongensis to describe this previously unknown fungus. Antifungal susceptibility testing showed most Aspergillus isolates had low MICs against itraconazole and voriconazole, but all Aspergillus isolates had high MICs against fluconazole. A diverse spectrum of Aspergillus species is associated with onychomycosis. Itraconazole and voriconazole are probably better drug options for Aspergillus onychomycosis.

  10. Aspergillus spp. invasive external otitis: favourable outcome with a medical approach.

    Science.gov (United States)

    Marchionni, E; Parize, P; Lefevre, A; Vironneau, P; Bougnoux, M E; Poiree, S; Coignard-Biehler, H; DeWolf, S E; Amazzough, K; Barchiesi, F; Jullien, V; Alanio, A; Garcia-Hermoso, D; Wassef, M; Kania, R; Lortholary, O; Lanternier, F

    2016-05-01

    Aspergillus spp. invasive external otitis (IEO) is a rare infection. We performed a seven-year, single-centre retrospective study from 2007 to 2014 including all patients with proven Aspergillus spp. IEO. Twelve patients were identified. All patients had a poorly controlled diabetes mellitus and one underwent solid organ transplant. The most frequently isolated species was Aspergillus flavus (n = 10) and voriconazole was the first-line therapy in all cases, with a median length of treatment of 338.5 days (158-804 days). None of the patients underwent extensive surgery. The clinical outcome was excellent. However, otological sequelae were reported, including hearing impairment (n = 7) and facial palsy (n = 3).

  11. Preparation and anti-Aspergillus flavus activity of chitosan-trypsin inhibitor blend edible film%壳聚糖-胰蛋白酶抑制剂复合可食性膜的制备及抗黄曲霉活性

    Institute of Scientific and Technical Information of China (English)

    张宾; 汪东风; 邓尚贵; 林慧敏; 唐艳

    2012-01-01

    In order to explore the preparation method of biological film and its activity of anti-Aspergillus flavus, the chitosan-based blend film was prepared from chitosan, soybean trypsin inhibitor extract (TI) and glycerol solution, and the properties of which were also investigated, including thickness, mechanical property, water vapor transmission, optical transmittance, solubility apparent structure and anti-A flavus activity. The results showed that the chitosan, TI and glycerol concentration got 18 mg/mL, 2 mg/mL and 12 mg/mL respectively, the blend films exhibited good physical and chemical properties, and the germination and growth of A. Flavus were strongly inhibited by blend films on peanuts.%为探索新型生物膜材料的制备方法及抗黄曲霉活性,以壳聚糖和大豆胰蛋白酶抑制剂(TI)提取物为原料,甘油为增埋剂,利用溶液共混流延法制备壳聚糖-TI-甘油复合可食性膜,测试其厚度、表观结构、力学性质、透光率、水蒸气透过率及抗黄曲霉侵染活性.结果表明,当壳聚糖浓度为18 mg/mL、TI浓度2 mg/mL、甘油浓度12 mg/mL和干燥温度45℃时,制备复合膜具有优良抗黄曲霉活性,且综合理化性能最佳.制备壳聚糖-TI-甘油复合膜液涂膜于花生上,接种黄曲霉培养后发现,复合膜对于黄曲霍侵染具有较强的抵抗和抑制作用.

  12. A colorimetric and spectrophotometric method for in vitro susceptibility testing of Aspergillus species against caspofungin.

    NARCIS (Netherlands)

    Dorsthorst, D.T.A. te; Zwaaftink, R.B.; Rijs, A.J.M.M.; Meletiadis, J.; Verweij, P.E.

    2007-01-01

    The in vitro susceptibility of 45 Aspergillus fumigatus, Aspergillus flavus and Aspergillus terreus isolates against caspofungin (CAS) was assessed by the CLSI reference method with spectrophotometric reading and by a colorimetric method that employed the dye MTT. Perfect agreement was found between

  13. Cryptic and rare Aspergillus species in Brazil: prevalence in clinical samples and in vitro susceptibility to triazoles.

    Science.gov (United States)

    Negri, C E; Gonçalves, S S; Xafranski, H; Bergamasco, M D; Aquino, V R; Castro, P T O; Colombo, A L

    2014-10-01

    Aspergillus spp. are among the most common causes of opportunistic invasive fungal infections in tertiary care hospitals. Little is known about the prevalence and in vitro susceptibility of Aspergillus species in Latin America, because there are few medical centers able to perform accurate identification at the species level. The purpose of this study was to analyze the distribution of cryptic and rare Aspergillus species among clinical samples from 133 patients with suspected aspergillosis admitted in 12 medical centers in Brazil and to analyze the in vitro activity of different antifungal drugs. The identification of Aspergillus species was performed based on a polyphasic approach, as well as sequencing analysis of the internal transcribed spacer (ITS) region, calmodulin, and β-tubulin genes and phylogenetic analysis when necessary. The in vitro susceptibility tests with voriconazole, posaconazole, and itraconazole were performed according to the CLSI M38-A2 document (2008). We demonstrated a high prevalence of cryptic species causing human infection. Only three isolates, representing the species Aspergillus thermomutatus, A. ochraceus, and A. calidoustus, showed less in vitro susceptibility to at least one of the triazoles tested. Accurate identifications of Aspergillus at the species level and with in vitro susceptibility tests are important because some species may present unique resistance patterns against specific antifungal drugs.

  14. 花生种子受黄曲霉菌侵染后若干生化成份的变化及其与抗性的关系%Changes of some biochemical substances in peanut seeds under infection of Aspergillus flavus and their role in resistance to seed invasion

    Institute of Scientific and Technical Information of China (English)

    梁炫强; 周桂元; 潘瑞炽

    2001-01-01

    花生种子人工接种黄曲霉菌(Aspergillus flavus Link)侵染的生化测试结果表明,接种前后花生种子的过氧化物酶(POX)、多酚氧化酶(PPO)和苯丙氨酸解氨酶(PAL)活性以及木质素含量等均发生显著变化。接种前POX活性与侵染率呈极显著负相关,接种后POX活性随感染天数增加而增加,感病品种比抗病品种POX活性增幅大。接种后1~3d抗病品种PPO和PAL活性达峰值,而感病品种3~6d达峰值。接种后第7d木质素含量与感染率呈显著负相关(r=-0.7406),木质素含量的变化与POX活性变化呈显著正相关。

  15. Phenotypic differentiation of species from Aspergillus section Flavi on neutral red desiccated coconut agar

    DEFF Research Database (Denmark)

    Atanda, O. O.; Adetunji, M. C.; Ezekiel, C. N.

    2014-01-01

    /intensity of fluorescence and aflatoxin production were assessed. The isolates included 10 Aspergillus minisclerotigenes strains, 11 non-aflatoxigenic Aspergillus flavus L strains, 29 aflatoxigenic A. flavus L strains and 20 strains each of Aspergillus parasiticus and Aspergillus parvisclerotigenus. The NRDCA medium......In order to facilitate easy and rapid identification of aflatoxin-producing Aspergillus species, the phenotypic traits of Aspergillus section Flavi isolates were examined on neutral red desiccated coconut agar (NRDCA). Phenotype variations in colony morphology and the relationship between colour...... isolates produced aflatoxins in the culture medium in varying quantities. Plates of aflatoxigenic A. flavus L strains fluoresced bluish purple/lavender around the colony on the obverse and pastel blue on the reverse side due to aflatoxin B production while those of A. minisclerotigenes, A. parasiticus...

  16. Involvement of the opportunistic pathogen Aspergillus tubingensis in osteomyelitis of the maxillary bone : a case report

    NARCIS (Netherlands)

    Bathoorn, Erik; Salazar, Natalia Escobar; Sepehrkhouy, Shahrzad; Meijer, Martin; de Cock, Hans; Haas, Pieter-Jan

    2013-01-01

    Background: Aspergillus tubingensis is a black Aspergillus belonging to the Aspergillus section Nigri, which includes species that morphologically resemble Aspergillus niger. Recent developments in species determination have resulted in clinical isolates presumed to be Aspergillus niger being reclas

  17. Environmental contamination by Aspergillus spp. in laying hen farms and associated health risks for farm workers.

    Science.gov (United States)

    Cafarchia, Claudia; Camarda, Antonio; Iatta, Roberta; Danesi, Patrizia; Favuzzi, Vincenza; Di Paola, Giancarlo; Pugliese, Nicola; Caroli, Anna; Montagna, Maria Teresa; Otranto, Domenico

    2014-03-01

    Data on the occurrence and epidemiology of Aspergillus spp. in laying hens farms are scant. With the aims of determining levels of airborne contamination in laying hen farms and evaluating the potential risk of infection for workers and animals, 57 air samples from 19 sheds (Group I), 69 from faeces (Group II), 19 from poultry feedstuffs (Group III) and 60 from three anatomical sites (i.e. nostrils, pharynx, ears) of 20 farm workers (Group IV) were cultured. The Aspergillus spp. prevalence in samples ranged from 31.6% (Group III) to 55.5% (Group IV), whereas the highest conidia concentration was retrieved in Group II (1.2 × 10(4) c.f.u. g(-1)) and in Group III (1.9 × 10(3) c.f.u. g(-1)). The mean concentration of airborne Aspergillus spp. conidia was 70 c.f.u. m(-3) with Aspergillus fumigatus (27.3%) being the most frequently detected species, followed by Aspergillus flavus (6.3%). These Aspergillus spp. were also isolated from human nostrils (40%) and ears (35%) (Phens. The results demonstrate a relationship between the environmental contamination in hen farms and presence of Aspergillus spp. on animals and humans. Even if the concentration of airborne Aspergillus spp. conidia (i.e. 70 c.f.u. m(-3)) herein detected does not trigger clinical disease in hens, it causes human colonization. Correct management of hen farms is necessary to control environmental contamination by Aspergillus spp., and could lead to a significant reduction of animal and human colonization.

  18. Multilocus phylogeny and antifungal susceptibility of Aspergillus section Circumdati from clinical samples and description of A. pseudosclerotiorum sp. nov.

    Science.gov (United States)

    A multilocus phylogenetic study was carried out to assess the species distribution in a set of 34 clinical isolates of Aspergillus section Circumdati from the USA and their in vitro antifungal susceptibility were determined against eight antifungal drugs. The genetic markers used were ITS, BenA, CaM...

  19. [Indoor fungal exposure: What impact on clinical and biological status regarding Aspergillus during cystic fibrosis].

    Science.gov (United States)

    Pricope, D; Deneuville, E; Frain, S; Chevrier, S; Belaz, S; Roussey, M; Gangneux, J-P

    2015-06-01

    The sources of exposure during diseases due to Aspergillus fungi in cystic fibrosis patients are still poorly explored. We assessed home fungal exposure in patients suffering from cystic fibrosis and analysed its impact on the presence of Aspergillus biological markers, the colonisation of airways, as well as the sensitization and Aspergillus serology. Between March 2012 and August 2012, 34 patients benefited from a visit performed by a home environment medical adviser including sampling for mycological analysis. The number of colonies of Aspergillus was not significantly different in the various sampling sites (P=0.251), but the number of non-Aspergillus colonies was much higher in the kitchen (P=0.0045). Subsequently, home fungal exposure was compared between the groups "absence of Aspergillus-related markers" and "presence of Aspergillus-related markers". Home exposure to Aspergillus (P=0.453) and non-Aspergillus (P=0.972) flora was not significant between the 2 groups. Within this series of 34 patients that should be expanded, we note an absence of clear relationship between home exposure and the Aspergillus-linked markers in patients suffering from cystic fibrosis. This result should be taken into account regarding too restrictive hygiene advices provided to families, given the fact that fungal exposure can also results from activities performed away from home.

  20. A study on Aspergillus species in houses of asthmatic patients from Sari City, Iran and a brief review of the health effects of exposure to indoor Aspergillus.

    Science.gov (United States)

    Hedayati, Mohammad T; Mayahi, Sabah; Denning, David W

    2010-09-01

    To study the distribution of Aspergillus spp. in outdoor and indoor air of asthmatic patients' houses, as well as a review on the health effects of exposure to indoor Aspergillus. Open plates containing malt extract agar media were used to isolate fungi from the indoor (n = 360) and outdoor (n = 180) air of 90 asthmatic patients' houses living in Sari City, Iran. Plates were incubated at room temperature for 7-14 days. Cultured Aspergillus spp. were identified by standard mycological techniques. All culture plates grew fungi, a testament to the ubiquitous nature of fungal exposure. Cladosporium spp. (29.2%), Aspergillus spp. (19.0%), and Penicillium spp. (18.3%) were most common inside the houses while Cladosporium spp. (44.5%), Aspergillus spp. (12.4%), and Alternaria spp. (11.1%) were most common outside the houses. Aspergillus flavus (30.1%) and A. fumigatus (23.1%) are the most commonly isolated species in indoor air. Aspergillus flavus (44.5%) and A. fumigatus (42.6%) were the most prevalent Aspergillus spp. outside. The most colony numbers of Aspergillus were isolated from kitchens (30.4%) and the least from bedrooms (21.1%). Aspergillus flavus was the most prevalent species in all sampled rooms except in the kitchen where A. fumigatus was the most common. Aspergillus flavus is the most prevalent species among the Aspergillus spp. in the indoor and outdoor of a warm climate area. In these areas, A. flavus can be a major source of allergen in the air. Therefore, minimizing indoor fungal exposure could play an important role in reducing allergic symptoms in susceptible persons.

  1. Clinical Effects of Gamma-Radiation-Resistant Aspergillus sydowii on Germ-Free Mice Immunologically Prone to Inflammatory Bowel Disease

    Science.gov (United States)

    Aladyshkina, Natalia; Retuerto, Mauricio; Hager, Christopher L.; Ghannoum, Mahmoud A.; Cominelli, Fabio

    2016-01-01

    We report and investigated a case of inadvertent contamination of 125 mice (housed in two germ-free positive-pressurized isolators) with emerging human and coral pathogen Aspergillus sydowii. The infected mice correspond to genetic line SAMP1/YitFc, which have 100% immune predisposition to develop Crohn's disease-like spontaneous pathologies, namely, inflammatory bowel disease (IBD). Pathogen update based on a scoping review of the literature and our clinical observations and experimentation are discussed. The unwanted infection of germ-free mice (immunologically prone to suffer chronic inflammation) with human pathogen A. sydowii resulted in no overt signs of clinical disease over 3-week exposure period, or during DSS-induced colitis experiments. Results and observations suggest that A. sydowii alone has limited clinical effect in immunocompromised germ-free mice or that other commensal microbial flora is required for Aspergillus-associated disease to occur. PMID:27630775

  2. Aspergillus alabamensis, a New Clinically Relevant Species in the Section Terrei

    DEFF Research Database (Denmark)

    Balajee, S. A.; Baddley, J. W.; Peterson, S. W.;

    2009-01-01

    , Aspergillus alabamensis. Most members of this new cryptic species were recovered as colonizing isolates from immunocompetent patient populations, had decreased in vitro susceptibilities to the antifungal drug amphotericin B, and were morphologically similar to but genetically distinct from Aspergillus terreus......Phylogenetic analyses of sequences generated from portions of three genes coding for the proteins enolase (enoA), beta-tubulin (benA), and calmodulin (calM) of a large number of isolates within the section Terrei, genus Aspergillus, revealed the presence of a new cryptic species within this section...

  3. Chronological aging in conidia of pathogenic Aspergillus: Comparison between species.

    Science.gov (United States)

    Oliveira, Manuela; Pereira, Clara; Bessa, Cláudia; Araujo, Ricardo; Saraiva, Lucília

    2015-11-01

    Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus and Aspergillus niger are common airborne fungi, and the most frequent causative agents of human fungal infections. However, the resistance and lifetime persistence of these fungi in the atmosphere, and the mechanism of aging of Aspergillus conidia are unknown.With this work, we intended to study the processes underlying conidial aging of these four relevant and pathogenic Aspergillus species. Chronological aging was therefore evaluated in A. fumigatus, A. flavus, A. terreus and A. niger conidia exposed to environmental and human body temperatures. The results showed that the aging process in Aspergillus conidia involves apoptosis,with metacaspase activation, DNA fragmentation, and reactive oxygen species production, associated with secondary necrosis. Distinct results were observed for the selected pathogenic species. At environmental conditions, A. niger was the species with the highest resistance to aging, indicating a higher adaption to environmental conditions, whereas A. flavus followed by A. terreus were the most sensitive species. At higher temperatures (37 °C), A. fumigatus presented the longest lifespan, in accordance with its good adaptation to the human body temperature. Altogether,with this work new insights regarding conidia aging are provided, which may be useful when designing treatments for aspergillosis.

  4. In vitro activities of amphotericin B and AmBisome against Aspergillus isolates recovered from Italian patients treated for haematological malignancies.

    Science.gov (United States)

    Colozza, Camilla; Posteraro, Brunella; Santilli, Stefania; De Carolis, Elena; Sanguinetti, Maurizio; Girmenia, Corrado

    2012-05-01

    Although there is evidence that liposomal amphotericin B (AmBisome) is non-inferior to amphotericin B (AmB) in terms of in vivo efficacy, in vitro data regarding the activity of AmBisome against clinical isolates of Aspergillus are rare. In this study, the susceptibilities to AmB and AmBisome of 103 Aspergillus complex isolates (48 Aspergillus flavus, 33 Aspergillus fumigatus, 13 Aspergillus terreus and 9 Aspergillus niger) recovered from haematological patients with invasive infection were compared. Minimum inhibitory concentrations (MICs) were determined by the broth microdilution (BMD) method according to the Clinical and Laboratory Standards Institute (CLSI), whilst AmB susceptibility was also determined by Etest. Using a susceptible/resistant MIC cut-off of 1mg/L, all A. fumigatus and A. niger complexes isolates were susceptible to both AmB and AmBisome. In contrast, 38.5% and 30.8% of the A. terreus complex isolates were resistant to AmB and AmBisome, respectively, with good agreement between BMD and Etest methods. With respect to A. flavus complex isolates, 43.7% and 16.7% were resistant by the BMD method to AmBisome and AmB, respectively. For isolates with discrepant results, AmB MICs obtained by Etest were higher than those obtained for AmB by the BMD method and they were closer to those obtained for AmBisome by BMD. Aspergillus flavus AmB MICs ranged from 0.5 mg/L to 2 mg/L by the BMD method and from 1 mg/L to >16 mg/L by the Etest method, and AmBisome MICs ranged from 0.06 mg/L to >16 mg/L by the BMD method. Etest appears to be superior to the CLSI BMD method using AmB in detecting AmB resistance of Aspergillus spp., although the CLSI BMD method might be a suitable procedure if AmBisome is used as the test drug.

  5. Pharmacokinetic/pharmacodynamic analysis of voriconazole against Candida spp. and Aspergillus spp. in children, adolescents and adults by Monte Carlo simulation.

    Science.gov (United States)

    Xu, Gaoqi; Zhu, Liqin; Ge, Tingyue; Liao, Shasha; Li, Na; Qi, Fang

    2016-06-01

    The objective of this study was to investigate the cumulative fraction of response of various voriconazole dosing regimens against six Candida and six Aspergillus spp. in immunocompromised children, immunocompromised adolescents, and adults. Using pharmacokinetic parameters and pharmacodynamic data, 5000-subject Monte Carlo simulations (MCSs) were conducted to evaluate the ability of simulated dosing strategies in terms of fAUC/MIC targets of voriconazole. According to the results of the MCSs, current voriconazole dosage regimens were all effective for children, adolescents and adults against Candida albicans, Candida parapsilosis and Candida orthopsilosis. For adults, dosing regimens of 4 mg/kg intravenous every 12 h (q12h) and 300 mg orally q12h were sufficient to treat fungal infections by six Candida spp. (C. albicans, C. parapsilosis, Candida tropicalis, Candida glabrata, Candida krusei and C. orthopsilosis) and five Aspergillus spp. (Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, Aspergillus niger and Aspergillus nidulans). However, high doses should be recommended for children and adolescents in order to achieve better clinical efficacy against A. fumigatus and A. nidulans. The current voriconazole dosage regimens were all ineffective against A. niger for children and adolescents. All voriconazole dosage regimens were not optimal against Aspergillus versicolor. This is the first study to evaluate clinical therapy of various voriconazole dosing regimens against Candida and Aspergillus spp. infections in children, adolescents and adults using MCS. The pharmacokinetic/pharmacodynamic-based dosing strategy provided a theoretical rationale for identifying optimal voriconazole dosage regimens in children, adolescents and adults in order to maximise clinical response and minimise the probability of exposure-related toxicity.

  6. Putative Aspergillus niger-induced oxalate nephrosis in sheep : clinical communication

    Directory of Open Access Journals (Sweden)

    C.J. Botha

    2009-05-01

    Full Text Available A sheep farmer provided a maize-based brewer's grain (mieliemaroek and bales of Eragrostis curvula hay to ewes and their lambs, kept on zero-grazing in pens. The 'mieliemaroek' was visibly mouldy. After 14 days in the feedlot, clinical signs, including generalised weakness, ataxia of the hind limbs, tremors and recumbency, were noticed. Six ewes died within a period of 7 days. A post mortem examination was performed on 1 ewe. The carcass appeared to be cachectic with mild effusions into the body cavities; mild lung congestion and pallor of the kidneys were observed. Microscopical evaluation revealed nephrosis and birefringent oxalate crystals in the renal tubules when viewed under polarised light. A provisional diagnosis of oxalate nephrosis with subsequent kidney failure was made. Amongst other fungi, Aspergillus niger was isolated from 'mieliemaroek' samples submitted for fungal culture and identification. As A. niger is known to synthesise oxalates, a qualitative screen to detect oxalic acid in the mieliemaroek and purified A. niger isolates was performed using high-performance liquid chromatography (HPLC. Oxalic acid was detected, which supported a diagnosis of soluble oxalate-induced nephropathy.

  7. Two novel aflatoxin-producing Aspergillus species from Argentinean peanuts

    DEFF Research Database (Denmark)

    Pildain, M.B.; Frisvad, Jens Christian; Vaamonde, G.

    2008-01-01

    Two novel species from Aspergillus section Flavi from different species of Arachis (peanuts) in Argentina are described as Aspergillus arachidicola sp. nov. and Aspergillus minisclerotigenes sp. nov. Their novel taxonomic status was determined using a polyphasic taxonomic approach with phenotypic...... (morphology and extrolite profiles) and molecular (beta-tubulin and calmodulin gene sequences) characters. A. minisclerotigenes resembles Aspergillus flavus and Aspergillus parvisclerotigenus in producing aflatoxins B-1 and B-2, cyclopiazonic acid, kojic acid and aspergillic acid, but in addition it produces...... and parasiticolide, and some strains produce aspergillic acid. The type strain of A. arachidicola is CBS 117610(T) =IBT 25020(T) and that of A. minisclerotigenes is CBS 117635(T) =IBT 27196(T). The Mycobank accession numbers for Aspergillus minisclerotigenes sp. nov. and Aspergillus arachidicola sp. nov...

  8. Screening a Strain of Aspergillus niger and Optimization of Fermentation Conditions for Degradation of Aflatoxin B1

    OpenAIRE

    Wei Zhang; Beibei Xue; Mengmeng Li; Yang Mu; Zhihui Chen; Jianping Li; Anshan Shan

    2014-01-01

    Aflatoxin B1, a type of highly toxic mycotoxin produced by some species belonging to the Aspergillus genus, such as Aspergillus flavus and Aspergillus parasiticus, is widely distributed in feed matrices. Here, coumarin was used as the sole carbon source to screen microorganism strains that were isolated from types of feed ingredients. Only one isolate (ND-1) was able to degrade aflatoxin B1 after screening. ND-1 isolate, identified as a strain of Aspergillus niger using phylogenetic analysis ...

  9. Septic arthritis due to tubercular and Aspergillus co-infection.

    Science.gov (United States)

    Kumar, Mukesh; Thilak, Jai; Zahoor, Adnan; Jyothi, Arun

    2016-01-01

    Aspergillus septic arthritis is a rare and serious medical and surgical problem. It occurs mainly in immunocompromised patients. Aspergillus fumigatus is the most common causative organism followed by Aspergillus flavus. The most common site affected is knee followed by shoulder, ankle, wrist, hip and sacroiliac joint. Debridement and voriconazole are primary treatment of articular aspergilosis. To the best of our knowledge, there are no reported cases of co-infection of tuberculosis (TB) and Aspergillus infecting joints. We report a case of co-infection of TB and A. flavus of hip and knee of a 60-year-old male, with type 2 diabetes mellitus. He was treated with debridement, intravenous voriconazole, and antitubercular drugs.

  10. Septic arthritis due to tubercular and Aspergillus co-infection

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar

    2016-01-01

    Full Text Available Aspergillus septic arthritis is a rare and serious medical and surgical problem. It occurs mainly in immunocompromised patients. Aspergillus fumigatus is the most common causative organism followed by Aspergillus flavus. The most common site affected is knee followed by shoulder, ankle, wrist, hip and sacroiliac joint. Debridement and voriconazole are primary treatment of articular aspergilosis. To the best of our knowledge, there are no reported cases of co-infection of tuberculosis (TB and Aspergillus infecting joints. We report a case of co-infection of TB and A. flavus of hip and knee of a 60-year-old male, with type 2 diabetes mellitus. He was treated with debridement, intravenous voriconazole, and antitubercular drugs.

  11. In vitro susceptibility testing of Aspergillus spp. against voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin

    Institute of Scientific and Technical Information of China (English)

    SHI Jun-yan; WANG He; GUO Li-na; XU Ying-chun; SHI Yi; L(U) Huo-xiang; LIU Yong; ZHAO Wang-sheng; CHEN Dong-mei; XI Li-yan; ZHOU Xin

    2010-01-01

    Background During recent years, the incidence of serious infections caused by opportunistic fungi has increased dramatically due to alterations of the immune status of patients with hematological diseases, malignant tumors,transplantations and so forth. Unfortunately, the wide use of triazole antifungal agents to treat these infections has lead to the emergence of Aspergillus spp. resistant to triazoles. The present study was to assess the in vitro activities of five antifungal agents (voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin) against different kinds of Aspergillus spp. that are commonly encountered in the clinical setting.Methods The agar-based Etest MIC method was employed. One hundred and seven strains of Aspergillus spp. (5 species) were collected and prepared according to Etest Technique Manuel. Etest MICs were determined with RPMI agar containing 2% glucose and were read after incubation for 48 hours at 35℃. MIC50, MIC90 and MIC range were acquired by Whonet 5.4 software.Results The MIC90 of caspofungin against A. fumigatus, A. flavus and A. nidulans was 0.094 μg/ml whereas the MIC90 against A. niger was 0.19 μg/ml. For these four species, the MlC90 of caspofungin was the lowest among the five antifungal agents. For A. terrus, the MIC90 of posaconazole was the lowest. For A. fumigatus and A. flavus, the MlC90in order of increasing was caspofungin, posaconazole, voriconazole, itraconazole, and amphotericin B. The MIC of amphotericin B against A. terrus was higher than 32 μg/ml in all 7 strains tested.Conclusions The in vitro antifungal susceptibility test shows the new drug caspofungin, which is a kind of echinocandins, has good activity against the five species of Aspergillus spp. and all the triazoles tested have better in vitro activity than traditional amphotericin B.

  12. The distribution of Aspergillus spp. opportunistic parasites in hives and their pathogenicity to honey bees.

    Science.gov (United States)

    Foley, Kirsten; Fazio, Géraldine; Jensen, Annette B; Hughes, William O H

    2014-03-14

    Stonebrood is a disease of honey bee larvae caused by fungi from the genus Aspergillus. As very few studies have focused on the epidemiological aspects of stonebrood and diseased brood may be rapidly discarded by worker bees, it is possible that a high number of cases go undetected. Aspergillus spp. fungi are ubiquitous and associated with disease in many insects, plants, animals and man. They are regarded as opportunistic pathogens that require immunocompromised hosts to establish infection. Microbiological studies have shown high prevalences of Aspergillus spp. in apiaries which occur saprophytically on hive substrates. However, the specific conditions required for pathogenicity to develop remain unknown. In this study, an apiary was screened to determine the prevalence and diversity of Aspergillus spp. fungi. A series of dose-response tests were then conducted using laboratory reared larvae to determine the pathogenicity and virulence of frequently occurring isolates. The susceptibility of adult worker bees to Aspergillus flavus was also tested. Three isolates (A. flavus, Aspergillus nomius and Aspergillus phoenicis) of the ten species identified were pathogenic to honey bee larvae. Moreover, adult honey bees were also confirmed to be highly susceptible to A. flavus infection when they ingested conidia. Neither of the two Aspergillus fumigatus strains used in dose-response tests induced mortality in larvae and were the least pathogenic of the isolates tested. These results confirm the ubiquity of Aspergillus spp. in the apiary environment and highlight their potential to infect both larvae and adult bees.

  13. In Vitro Susceptibility of Clinical Isolates of Aspergillus spp. to Anidulafungin, Caspofungin, and Micafungin: a Head-to-Head Comparison Using the CLSI M38-A2 Broth Microdilution Method▿

    Science.gov (United States)

    Pfaller, M. A.; Boyken, L.; Hollis, R. J.; Kroeger, J.; Messer, S. A.; Tendolkar, S.; Diekema, D. J.

    2009-01-01

    We determined the in vitro activities of anidulafungin, caspofungin, and micafungin against 526 isolates of Aspergillus spp. (64 A. flavus, 391 A. fumigatus, 46 A. niger, and 25 A. terreus isolates) collected from over 60 centers worldwide from 2001 through 2007. Susceptibility testing was performed according to the CLSI M38-A2 method. All three echinocandins—anidulafungin (50% minimum effective concentration [MEC50], 0.007 μg/ml; MEC90, 0.015 μg/ml), caspofungin (MEC50, 0.015 μg/ml; MEC90, 0.03 μg/ml), and micafungin (MEC50, 0.007 μg/ml; MEC90, 0.015 μg/ml)—were very active against Aspergillus spp. More than 99% of all isolates were inhibited by ≤0.06 μg/ml of all three agents. PMID:19710267

  14. Unilateral cutaneous emboli of Aspergillus.

    Science.gov (United States)

    Watsky, K L; Eisen, R N; Bolognia, J L

    1990-09-01

    A 40-year-old white woman with acute nonlymphocytic leukemia, which relapsed despite bone marrow transplantation and various chemotherapeutic regimens, developed fever and neutropenia. Her fever was unresponsive to broad-spectrum antibiotics, and on hospital day 53 she developed purpuric macules with necrotic centers on her left hand and forearm. Frozen sections of lesional skin were stained with Grocott's methenamine-silver and showed hyphae consistent with a species of Aspergillus; culture of the skin biopsy specimen yielded a pure culture of Aspergillus flavus. Localization of the emboli to the left upper extremity was subsequently explained by magnetic resonance imaging scan of the chest demonstrating invasion of the left subclavian artery by a pulmonary aspergilloma.

  15. Antifungal susceptibility testing of Aspergillus species complex in the Clinical Laboratory: how to do it, when to do it, and how to interpret it

    Directory of Open Access Journals (Sweden)

    Esther Manso

    2014-12-01

    Full Text Available The emergence of drug resistance in fungal pathogens has a profound impact on human health given limited number of antifungal drugs. Antifungal resistance in Aspergillus spp. infection can be encountered in the antifungal drug-exposed patient due to selection of intrinsically resistant species or isolates with acquired resistance belonging to species that are normally susceptible. Resistance to triazoles is not common in Aspergillus spp., however, triazole resistance in A. fumigatus appears to be increasing in several European countries in recent years and can be clinically relevant. The Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing have developed breakpoints and epidemiological cutoff values that are now established for Aspergillus spp. Clinical microbiology laboratories will be employed commercial susceptibility assays, rather than reference broth microdilution methods and comparative studies are particularly important.

  16. Aflatoxin-producing Aspergillus spp. and aflatoxin levels in stored cassava chips as affected by processing practices

    DEFF Research Database (Denmark)

    Essono, G.; Ayodele, M.; Akoa, A.

    2009-01-01

    two months and contaminated by a wide array of harmful microbes. In order to assess persistence of toxigenic fungi in cassava chips, aflatoxin-producing fungi (Aspergillus flavus, Aspergillus nomius, and Aspergillus parasiticus) and aflatoxins were contrasted at regular intervals in home......-stored cassava chips collected in two locations of southern Cameroon throughout a two-month monitoring period. Three hundred and forty-six isolates of aflatoxin-producing fungi were found to be associated with all samples. A. flavus contaminated more samples in both types of chips (267 isolates in 53 samples...

  17. Toxigenic Aspergillus and Penicillium isolates from weevil-damaged chestnuts.

    Science.gov (United States)

    Wells, J M; Payne, J A

    1975-10-01

    Aspergillus and Penicillium were among the most common genera of fungi isolated on malt-salt agar from weevil-damaged Chinese chestnut kernels (16.8 and 40.7% occurrence, respectively). Chloroform extracts of 21 of 50 Aspergillus isolates and 18 of 50 representative Penicillium isolates, grown for 4 weeks at 21.1 C on artificial medium, were toxic to day-old cockerels. Tweleve of the toxic Aspergillus isolates were identified as A. wentii, eight as A. flavus, and one as A. flavus var. columnaris. Nine of the toxic Penicillium isolates were identified as P. terrestre, three as P. steckii, two each as P. citrinum and P. funiculosum, and one each as P. herquei (Series) and P. roqueforti (Series). Acute diarrhea was associated with the toxicity of A. wentii and muscular tremors with the toxicity of P. terrestre, one isolate of P. steckii, and one of P. funiculosum.

  18. Genomic sequences of Aspergillus flavus accessions in Georgia USA

    Data.gov (United States)

    US Agency for International Development — The data was produced as part of the Feed the Future Innovation Lab for Collaborative Research on Peanut Productivity and Aflatoxin Control (the Peanut &...

  19. A case report of severe Aspergillus flavus penile infection

    Institute of Scientific and Technical Information of China (English)

    Bing-Kun Li; Xiang Wang; Qiang Ding

    2009-01-01

    @@ Dear Sir, My name is Xiang Wang, from the Department of Urology of Huashan Hospital at Fudan University in China. In this letter, we present our experience with the diagnosis and treatment of a patient with severe penile aspergillosis.

  20. The activity of galanga (Alpinia galanga rhizome extract against the growth of filamentous fungi Aspergillus spp. that produce aflatoxin and Fusarium moniliforme

    Directory of Open Access Journals (Sweden)

    NOOR SOESANTI HANDAJANI

    2008-07-01

    Full Text Available Galanga (Alpinia galanga L. rhizome was known to inhibit the growth of pathogenic fungi. The antifungal substances of galangal rhizome were found from their volatile oil. The objectives of this experiment were to study the ethanol extract of galangal rhizome against the growth of filamentous fungi Fusarium moniliforme, Aspergillus flavus, Aspergillus terreus, and Aspergillus niger that produce mycotoxin, especially aflatoxin, based on biomass and colony area and to determinate minimum growth inhibitory concentration the extract of galangal rhizome. The extract of galangal rhizome was significant (p<0.05 effective against biomass of F. moniliforme and A. flavus. The extract of galangal rhizome however was significant (p<0.05 effective against colony area of F. moniliforme, A. flavus and A. niger. The minimum growth inhibitory concentration of extracts galangal rhizome against the growth of A. flavus, F. moniliforme and A. niger were 816, 1,682, and 3,366 mg/L repectively.

  1. Distribution of aflatoxigenic Aspergillus section Flavi in commercial poultry feed in Nigeria.

    Science.gov (United States)

    Ezekiel, C N; Atehnkeng, J; Odebode, A C; Bandyopadhyay, R

    2014-10-17

    The distribution and aflatoxigenicity of Aspergillus section Flavi isolates in 58 commercial poultry feed samples obtained from 17 states in five agro-ecological zones (AEZs) in Nigeria were determined in order to assess the safety of the feeds with respect to aflatoxin-producing fungi. Correlation was also performed for incidence of species, aflatoxin-producing ability of isolates in vitro, and aflatoxin (AFB1) concentrations in the feed. A total of 1006 Aspergillus section Flavi isolates were obtained from 87.9% of the feed samples and identified as Aspergillus flavus, unnamed taxon SBG, Aspergillus parasiticus and Aspergillus tamarii. A. flavus was the most prevalent (91.8%) of the isolates obtained from the feed in the AEZs while A. parasiticus had the lowest incidence (0.1%) and was isolated only from a layer mash sample collected from the DS zone. About 29% of the Aspergillus isolates produced aflatoxins in maize grains at concentrations up to 440,500μg/kg B and 341,000μg/kgG aflatoxins. The incidence of toxigenic isolates was highest (44.4%) in chick mash and lowest (19.9%) in grower mash. The population of A. flavus in the feed had positive (r=0.50) but non significant (p>0.05) correlations with proportion of toxigenic isolates obtained from the feed while SBG had significant (pAspergillus species and consequently, aflatoxins. This is a potential threat to the poultry industry and requires urgent intervention.

  2. Does fungicide application in vineyards induce resistance to medical azoles in Aspergillus species?

    Science.gov (United States)

    Lago, Magali; Aguiar, Ana; Natário, André; Fernandes, Carla; Faria, Miguel; Pinto, Eugénia

    2014-09-01

    This study assessed if the use of sterol demethylase inhibitor fungicides in vineyard production can induce resistance to azoles in Aspergillus strains and if it can induce selection of resistant species. We also tried to identify the Aspergillus species most prevalent in the vineyards. Two vineyards from northern Portugal were selected from "Vinhos Verdes" and "Douro" regions. The vineyards were divided into plots that were treated or not with penconazole (PEN). In each vineyard, air, soil, and plant samples were collected at three different times. The strains of Aspergillus spp. were isolated and identified by morphological and molecular techniques. We identified 46 Aspergillus section Nigri, eight Aspergillus fumigatus, seven Aspergillus lentulus, four Aspergillus wentii, two Aspergillus flavus, two Aspergillus terreus, one Aspergillus calidoustus, one Aspergillus westerdijkiae, one Aspergillus tamarii, and one Eurotium amstelodami. Aspergillus strains were evaluated for their susceptibility to medical azoles used in human therapy (itraconazole, posaconazole, and voriconazole) and to agricultural azoles (PEN) used in the prevention and treatment of plant diseases. The isolates showed moderate susceptibility to voriconazole. We did not observe any decrease of susceptibility to the medical azoles tested throughout the testing period in any of the treated plots, although some of the resistant species were isolated from there.

  3. Estudio de la eficacia de cuatro métodos de inoculación artificial con aspergillus flavus link Ex fries en seis genotipos de maíz (Zea Mays L bajo condición de campo. (ING

    Directory of Open Access Journals (Sweden)

    Miguel Quesada

    2016-03-01

    Full Text Available Four different inoculation methods were tested on six corn genotypes, under field condition. In call cases 1ml. Of 5 x 105 conidial suspension was applied, as follows: injection with a hypodermic needle in the central part of the ear (M1, injection in the silk channel (M2,  inoculum deposition on a wonded section of the ear (M3, inoculum deposition on the ear silk (M4. According to the statistical analysis the most efficient method was M3, followed by M1, M4 and M2. Fusarium spp and A. flavus showed a significative negative correlation (p>0,01 among them. Methods where inoculum was placed on the upper part of the ear showed more Fusarium and other fungi competition with A. flavus, and less efficiency. No statistical differences was found among genotypes.

  4. Epidemiological and Genomic Landscape of Azole Resistance Mechanisms in Aspergillus Fungi

    Science.gov (United States)

    Hagiwara, Daisuke; Watanabe, Akira; Kamei, Katsuhiko; Goldman, Gustavo H.

    2016-01-01

    Invasive aspergillosis is a life-threatening mycosis caused by the pathogenic fungus Aspergillus. The predominant causal species is Aspergillus fumigatus, and azole drugs are the treatment of choice. Azole drugs approved for clinical use include itraconazole, voriconazole, posaconazole, and the recently added isavuconazole. However, epidemiological research has indicated that the prevalence of azole-resistant A. fumigatus isolates has increased significantly over the last decade. What is worse is that azole-resistant strains are likely to have emerged not only in response to long-term drug treatment but also because of exposure to azole fungicides in the environment. Resistance mechanisms include amino acid substitutions in the target Cyp51A protein, tandem repeat sequence insertions at the cyp51A promoter, and overexpression of the ABC transporter Cdr1B. Environmental azole-resistant strains harboring the association of a tandem repeat sequence and punctual mutation of the Cyp51A gene (TR34/L98H and TR46/Y121F/T289A) have become widely disseminated across the world within a short time period. The epidemiological data also suggests that the number of Aspergillus spp. other than A. fumigatus isolated has risen. Some non-fumigatus species intrinsically show low susceptibility to azole drugs, imposing the need for accurate identification, and drug susceptibility testing in most clinical cases. Currently, our knowledge of azole resistance mechanisms in non-fumigatus Aspergillus species such as A. flavus, A. niger, A. tubingensis, A. terreus, A. fischeri, A. lentulus, A. udagawae, and A. calidoustus is limited. In this review, we present recent advances in our understanding of azole resistance mechanisms particularly in A. fumigatus. We then provide an overview of the genome sequences of non-fumigatus species, focusing on the proteins related to azole resistance mechanisms. PMID:27708619

  5. Wild-Type MIC Distributions and Epidemiological Cutoff Values for Amphotericin B and Aspergillus spp. for the CLSI Broth Microdilution Method (M38-A2 Document)▿

    Science.gov (United States)

    Espinel-Ingroff, A.; Cuenca-Estrella, M.; Fothergill, A.; Fuller, J.; Ghannoum, M.; Johnson, E.; Pelaez, T.; Pfaller, M. A.; Turnidge, J.

    2011-01-01

    Although clinical breakpoints have not been established for mold testing, epidemiological cutoff values (ECVs) are available for Aspergillus spp. versus the triazoles and caspofungin. Wild-type (WT) MIC distributions (organisms in a species-drug combination with no acquired resistance mechanisms) were defined in order to establish ECVs for six Aspergillus spp. and amphotericin B. Two sets (CLSI/EUCAST broth microdilution) of available MICs were evaluated: those for A. fumigatus (3,988/833), A. flavus (793/194), A. nidulans (184/69), A. niger (673/140), A. terreus (545/266), and A. versicolor (135/22). Three sets of data were analyzed: (i) CLSI data gathered in eight independent laboratories in Canada, Europe, and the United States; (ii) EUCAST data from a single laboratory; and (iii) the combined CLSI and EUCAST data. ECVs, expressed in μg/ml, that captured 95%, 97.5%, and 99% of the modeled wild-type population (CLSI and combined data) were as follows: for A. fumigatus, 2, 2, and 4; for A. flavus, 2, 4, and 4; for A. nidulans, 4, 4, and 4; for A. niger, 2, 2, and 2; for A. terreus, 4, 4, and 8; and for A. versicolor, 2, 2, and 2. Similar to the case for the triazoles and caspofungin, amphotericin B ECVs may aid in the detection of strains with acquired mechanisms of resistance to this agent. PMID:21876047

  6. Wild-Type MIC Distributions and Epidemiological Cutoff Values for Caspofungin and Aspergillus spp. for the CLSI Broth Microdilution Method (M38-A2 Document)▿

    Science.gov (United States)

    Espinel-Ingroff, A.; Fothergill, A.; Fuller, J.; Johnson, E.; Pelaez, T.; Turnidge, J.

    2011-01-01

    Clinical breakpoints have not been established for mold testing. Epidemiologic cutoff values (ECVs) are available for six Aspergillus spp. and the triazoles, but not for caspofungin. Wild-type (WT) minimal effective concentration (MEC) distributions (organisms in a species-drug combination with no acquired resistance mechanisms) were defined in order to establish ECVs for six Aspergillus spp. and caspofungin. The number of available isolates was as follows: 1,691 A. fumigatus, 432 A. flavus, 192 A. nidulans, 440 A. niger, 385 A. terreus, and 75 A. versicolor isolates. CLSI broth microdilution MEC data gathered in five independent laboratories in Canada, Europe, and the United States were aggregated for the analyses. ECVs expressed in μg/ml that captured 95% and 99% of the modeled wild-type population were for A. fumigatus 0.5 and 1, A. flavus 0.25 and 0.5, A. nidulans 0.5 and 0.5, A. niger 0.25 and 0.25, A. terreus 0.25 and 0.5, and A. versicolor 0.25 and 0.5. Although caspofungin ECVs are not designed to predict the outcome of therapy, they may aid in the detection of strains with reduced antifungal susceptibility to this agent and acquired resistance mechanisms. PMID:21422219

  7. Wild-type MIC distributions and epidemiological cutoff values for amphotericin B and Aspergillus spp. for the CLSI broth microdilution method (M38-A2 document).

    Science.gov (United States)

    Espinel-Ingroff, A; Cuenca-Estrella, M; Fothergill, A; Fuller, J; Ghannoum, M; Johnson, E; Pelaez, T; Pfaller, M A; Turnidge, J

    2011-11-01

    Although clinical breakpoints have not been established for mold testing, epidemiological cutoff values (ECVs) are available for Aspergillus spp. versus the triazoles and caspofungin. Wild-type (WT) MIC distributions (organisms in a species-drug combination with no acquired resistance mechanisms) were defined in order to establish ECVs for six Aspergillus spp. and amphotericin B. Two sets (CLSI/EUCAST broth microdilution) of available MICs were evaluated: those for A. fumigatus (3,988/833), A. flavus (793/194), A. nidulans (184/69), A. niger (673/140), A. terreus (545/266), and A. versicolor (135/22). Three sets of data were analyzed: (i) CLSI data gathered in eight independent laboratories in Canada, Europe, and the United States; (ii) EUCAST data from a single laboratory; and (iii) the combined CLSI and EUCAST data. ECVs, expressed in μg/ml, that captured 95%, 97.5%, and 99% of the modeled wild-type population (CLSI and combined data) were as follows: for A. fumigatus, 2, 2, and 4; for A. flavus, 2, 4, and 4; for A. nidulans, 4, 4, and 4; for A. niger, 2, 2, and 2; for A. terreus, 4, 4, and 8; and for A. versicolor, 2, 2, and 2. Similar to the case for the triazoles and caspofungin, amphotericin B ECVs may aid in the detection of strains with acquired mechanisms of resistance to this agent.

  8. The activity of galanga (Alpinia galanga) rhizome extract against the growth of filamentous fungi Aspergillus spp. that produce aflatoxin and Fusarium moniliforme

    OpenAIRE

    NOOR SOESANTI HANDAJANI; TJAHJADI PURWOKO,

    2008-01-01

    Galanga (Alpinia galanga L.) rhizome was known to inhibit the growth of pathogenic fungi. The antifungal substances of galangal rhizome were found from their volatile oil. The objectives of this experiment were to study the ethanol extract of galangal rhizome against the growth of filamentous fungi Fusarium moniliforme, Aspergillus flavus, Aspergillus terreus, and Aspergillus niger that produce mycotoxin, especially aflatoxin, based on biomass and colony area and to determinate minimum growth...

  9. Biodiversity of Aspergillus species in some important agricultural products

    DEFF Research Database (Denmark)

    Perrone, Giancarlo; Susca, A.,; Cozzi, G.

    2007-01-01

    The genus Aspergillus is one of the most important filamentous fungal genera. Aspergillus species are used in the fermentation industry, but they are also responsible of various plant and food secondary rot, with the consequence of possible accumulation of mycotoxins. The aflatoxin producing A....... flavus and A. parasiticus, and ochratoxinogenic A. niger, A. ochraceus and A. carbonarius species are frequently encountered in agricultural products. Studies on the biodiversity of toxigenic Aspergillus species is useful to clarify molecular, ecological and biochemical characteristics of the different...... occurring in agricultural fields. Altogether nine different black Aspergillus species can be found on grapes which are often difficult to identify with classical methods. The polyphasic approach used in our studies led to the identification of three new species occurring on grapes: A. brasiliensis, A...

  10. Aspergillus triggers phenazine production in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib

    Aspergillus species. Methods: A suspension of fungal spores was streaked onto WATM agar plates. After 24 hours incubation at 37 °C, a P. aeruginosa overnight culture was streaked out perpendicular to the fungal streak. The plates were incubated at 37 °C for five days, examined and plugs were extracted...... for HPLC-DAD and HPLC-DAD-MS analysis. Results: P. aeruginosa PAO1 suppressed growth of A. fumigatus, A. niger, A. flavus, A. oryzae, A. terreus and Emericella nidulans. HPLC and HPLC-DAD-MS results showed an increase in phenazine-1-carboxylic acid and phenazine-1-carboxamide production by P. aeruginosa...

  11. Suppression of Aspergillus by Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib

    culture plates. After 24 hours incubation at 37 °C, a P. aeruginosa overnight culture diluted to 108 CFU/ml was streaked out perpendicular to the fungal streak. The plates were incubated at 37 °C for 5 days, examined and plugs were extracted for HPLC and LC-DAD-MS analysis. Results: P. aeruginosa PAO1...... suppressed growth of A. fumigatus, A. niger, A. flavus, A. oryzae, A. terreus and E. nidulans. HPLC and LC-DAD-MS results showed an increase in phenazine-1-carboxylic acid and phenazine-1-carboxamide production by P. aeruginosa in the contact area of Aspergillus. Different quinolones were also identified...

  12. Understanding Nonaflatoxigenicity of Aspergillus sojae: A Windfall of Aflatoxin Biosynthesis Research

    Science.gov (United States)

    Aspergillus section Flavi includes aflatoxin-producing and nonproducing fungi. A. sojae is unable to produce aflatoxins and is generally recognized as safe for food fermentation. However, because of its taxonomical relatedness to aflatoxin-producing A. parasiticus and A. flavus, it is necessary to...

  13. Comparison of the aflR gene sequences of strains in Aspergillus section Flavi.

    Science.gov (United States)

    Lee, Chao-Zong; Liou, Guey-Yuh; Yuan, Gwo-Fang

    2006-01-01

    Aflatoxins are polyketide-derived secondary metabolites produced by Aspergillus parasiticus, Aspergillus flavus, Aspergillus nomius and a few other species. The toxic effects of aflatoxins have adverse consequences for human health and agricultural economics. The aflR gene, a regulatory gene for aflatoxin biosynthesis, encodes a protein containing a zinc-finger DNA-binding motif. Although Aspergillus oryzae and Aspergillus sojae, which are used in fermented foods and in ingredient manufacture, have no record of producing aflatoxin, they have been shown to possess an aflR gene. This study examined 34 strains of Aspergillus section Flavi. The aflR gene of 23 of these strains was successfully amplified and sequenced. No aflR PCR products were found in five A. sojae strains or six strains of A. oryzae. These PCR results suggested that the aflR gene is absent or significantly different in some A. sojae and A. oryzae strains. The sequenced aflR genes from the 23 positive strains had greater than 96.6 % similarity, which was particularly conserved in the zinc-finger DNA-binding domain. The aflR gene of A. sojae has two obvious characteristics: an extra CTCATG sequence fragment and a C to T transition that causes premature termination of AFLR protein synthesis. Differences between A. parasiticus/A. sojae and A. flavus/A. oryzae aflR genes were also identified. Some strains of A. flavus as well as A. flavus var. viridis, A. oryzae var. viridis and A. oryzae var. effuses have an A. oryzae-type aflR gene. For all strains with the A. oryzae-type aflR gene, there was no evidence of aflatoxin production. It is suggested that for safety reasons, the aflR gene could be examined to assess possible aflatoxin production by Aspergillus section Flavi strains.

  14. Aspergillus-Related Lung Disease

    Directory of Open Access Journals (Sweden)

    Alia Al-Alawi

    2005-01-01

    Full Text Available Aspergillus is a ubiquitous dimorphic fungus that causes a variety of human diseases ranging in severity from trivial to life-threatening, depending on the host response. An intact host defence is important to prevent disease, but individuals with pre-existing structural lung disease, atopy, occupational exposure or impaired immunity are susceptible. Three distinctive patterns of aspergillus-related lung disease are recognized: saprophytic infestation of airways, cavities and necrotic tissue; allergic disease including extrinsic allergic alveolitis, asthma, allergic bronchopulmonary aspergillosis, bronchocentric granulomatosis and chronic eosinophilic pneumonia; and airway and tissue invasive disease -- pseudomembranous tracheobronchitis, acute bronchopneumonia, angioinvasive aspergillosis, chronic necrotizing aspergillosis and invasive pleural disease. A broad knowledge of these clinical presentations and a high index of suspicion are required to ensure timely diagnosis and treatment of the potentially lethal manifestations of aspergillus-related pulmonary disease. In the present report, the clinical, radiographic and pathological aspects of the various aspergillus-related lung diseases are briefly reviewed.

  15. The newly nonsporulated characterization of an Aspergillus fumigatus isolate from an immunocompetent patient and its clinic indication.

    Science.gov (United States)

    Zhang, Caiyun; Kong, Qingtao; Cai, Zhendong; Liu, Fang; Chen, Peiying; Song, Jinxing; Lu, Ling; Sang, Hong

    2015-08-01

    Aspergillus fumigatus (A. fumigatus) commonly produces abundant and heavily melanized infectious conidia, which are the primary agents that cause invasive aspergillosis (IA) in immunocompromised patients. We isolated a white nonsporulating A. fumigatus strain (A1j) from an immunocompetent patient. It was identified by histopathological examination and morphological observation, and subsequently confirmed by DNA sequencing of internal transcribed spacer (ITS) regions and partial β-tubulin genes. Neither a long waiting time nor passage on various medium types could stimulate the formation of spores and pigment. No significant relative difference was found in sensitivity to antifungal agents or cell wall destabilizing reagents, as compared to wild-type A. fumigatus Af293. Nevertheless, A1j was hypovirulent in the immunosuppressed mice model, consistent with the good result in our patient. RNA deep-sequencing analysis (RNA-seq) revealed that hundreds of transcripts were significantly dysregulated, including those related to pigmentation and sporulation. qRT-PCR confirmed the anergic state of key regulator brlA for sporulation under the induction of conidiation conditions, but without mutation. To the best of our knowledge, this is the first report of a white, nonsporulating A. fumigatus strain infection in an immunocompetent patient. In our opinion, A1j may represent a mutant of typical A. fumigatus, providing a new clue for identification of clinical A. fumigatus isolates. Furthermore, the good prognosis of our patient and the reduced virulence in the mice model infected with A1j highlight the potential of sporulation inhibitors as a new generation of antifungal agents.

  16. Microclimatic conditions of Lasius flavus ant mounds

    Science.gov (United States)

    Véle, Adam; Holuša, Jaroslav

    2016-11-01

    Like other organisms, ants require suitable microclimatic conditions for their development. Thus, ant species inhabiting colder climates build nest mounds that rise above the soil surface, presumably to obtain heating from solar radiation. Although some ant species construct mounds of organic materials, which generate substantial heat due to microbial metabolism, Lasius flavus mounds consists mostly of soil, not organic material. The use of artificial shading in the current study demonstrated that L. flavus depends on direct solar radiation to regulate the temperature in its mound-like nests. Temperatures were much lower in shaded mounds than in unshaded mounds and were likely low enough in shaded mounds to reduce ant development and reproduction. In areas where L. flavus and similar ants are undesirable, they might be managed by shading.

  17. Population structure and aflatoxin production by Aspergillus Sect. Flavi from maize in Nigeria and Ghana.

    Science.gov (United States)

    Perrone, Giancarlo; Haidukowski, Miriam; Stea, Gaetano; Epifani, Filomena; Bandyopadhyay, Ranajit; Leslie, John F; Logrieco, Antonio

    2014-08-01

    Aflatoxins are highly toxic carcinogens that contaminate crops worldwide. Previous studies conducted in Nigeria and Ghana found high concentrations of aflatoxins in pre- and post-harvest maize. However, little information is available on the population structure of Aspergillus Sect. Flavi in West Africa. We determined the incidence of Aspergillus Sect. Flavi and the level of aflatoxin contamination in 91 maize samples from farms and markets in Nigeria and Ghana. Aspergillus spp. were recovered from 61/91 maize samples and aflatoxins B1 and/or B2 occurred in 36/91 samples. Three samples from the farms also contained aflatoxin G1 and/or G2. Farm samples were more highly contaminated than were samples from the market, in terms of both the percentage of the samples contaminated and the level of mycotoxin contamination. One-hundred-and-thirty-five strains representative of the 1163 strains collected were identified by using a multilocus sequence analysis of portions of the genes encoding calmodulin, β-tubulin and actin, and evaluated for aflatoxin production. Of the 135 strains, there were 110 - Aspergillus flavus, 20 - Aspergillus tamarii, 2 - Aspergillus wentii, 2 - Aspergillus flavofurcatus, and 1 - Aspergillus parvisclerotigenus. Twenty-five of the A. flavus strains and the A. parvisclerotigenus strain were the only strains that produced aflatoxins. The higher contamination of the farm than the market samples suggests that the aflatoxin exposure of rural farmers is even higher than previously estimated based on reported contamination of market samples. The relative infrequency of the A. flavus SBG strains, producing small sclerotia and high levels of both aflatoxins (B and G), suggests that long-term chronic exposure to this mycotoxin are a much higher health risk in West Africa than is the acute toxicity due to very highly contaminated maize in east Africa.

  18. EFFECT OF TREATMENT WITH MOLD INHIBITORS ON PLANT GROWTH OF CORN AND SOME NUTRITIONAL COMPONENTS OF STORED GRAINS, INFECTED WITH A. FLAVUS AND F. VERTICILLOIDES

    Directory of Open Access Journals (Sweden)

    Mervat S. Youssef

    2012-12-01

    Full Text Available Planting sterilized corn grains in soil, treated with the mold inhibitors Fix-a-tox (FAT or Antitox Plus (AP resulted, in cases, in dwarfed and malformed corn plants and in the development of deformed, bone-shaped and grain-free corn cobs. Moreover, treating corn grains with the mold inhibitors before storage for one month caused significant changes in some nutritional components of corn grains, i.e. proteins, aminoacids, crude fibers, moisture, fats, ash and carbohydrates. Insignificant differences in protein percetage were detected between control inoculated with Aspergillus flavus and those treated with butyl hydroxyanisole (BHA antioxidant or FAT treatments, whereas ground clove significantly reduced protein content. In corn grains inoculated with Fusariumverticillioides, previous treatment with FAT resulted in significant reduction in the content of proline, aspartic acid, cysteine, valine, isoleucine and leucine, whereas treatment with BHA significantly reduced the content of threonine, serine, glutamic, glycine, alanine, phenylalanine and tyrosine. In Aspergillus flavus treatments, FAT significantly increased the content of methionine and threonine, whereas, aspartic acid showed 26 percentage decreases, compared to the control. Pronounced reductions in threonine, isoleucine and leucine were also detected in corn grains treated with BHA. Significant increases in fiber content were detected in inoculated corn grains treated with BHA, attaining 1.34 to 2.05-fold over that of control, respectively. Treatment with FAT and BHA led to pronounced reductions in moisture content in corn inoculated with both F. verticilloides and A. flavus trials. However, treatment with ground clove significantly increased the moisture content in A. flavus treatment. FAT treatment led to significant increase in ash and fat contents in both A. flavus and F. verticilloides treatments, whereas the other tested treatments of F. verticilloides significantly

  19. Simultaneous detection and identification of Aspergillus and mucorales species in tissues collected from patients with fungal rhinosinusitis.

    Science.gov (United States)

    Zhao, Zuotao; Li, Lili; Wan, Zhe; Chen, Wei; Liu, Honggang; Li, Ruoyu

    2011-04-01

    Rapid detection and differentiation of Aspergillus and Mucorales species in fungal rhinosinusitis diagnosis are desirable, since the clinical management and prognosis associated with the two taxa are fundamentally different. We describe an assay based on a combination of broad-range PCR amplification and reverse line blot hybridization (PCR/RLB) to detect and differentiate the pathogens causing fungal rhinosinusitis, which include five Aspergillus species (A. fumigatus, A. flavus, A. niger, A. terreus, and A. nidulans) and seven Mucorales species (Mucor heimalis, Mucor racemosus, Mucor cercinelloidea, Rhizopus arrhizus, Rhizopus microsporus, Rhizomucor pusillus, and Absidia corymbifera). The assay was validated with 98 well-characterized clinical isolates and 41 clinical tissue specimens. PCR/RLB showed high sensitivity and specificity, with 100% correct identifications of 98 clinical isolates and no cross-hybridization between the species-specific probes. Results for five control isolates, Candida albicans, Fusarium solani, Scedosporium apiospermum, Penicillium marneffei, and Exophiala verrucosa, were negative as judged by PCR/RLB. The analytical sensitivity of PCR/RLB was found to be 1.8 × 10(-3) ng/μl by 10-fold serial dilution of Aspergillus genomic DNA. The assay identified 35 of 41 (85.4%) clinical specimens, exhibiting a higher sensitivity than fungal culture (22 of 41; 53.7%) and direct sequencing (18 of 41; 43.9%). PCR/RLB similarly showed high specificity, with correct identification 16 of 18 specimens detected by internal transcribed spacer (ITS) sequencing and 16 of 22 detected by fungal culture, but it also has the additional advantage of being able to detect mixed infection in a single clinical specimen. The PCR/RLB assay thus provides a rapid and reliable option for laboratory diagnosis of fungal rhinosinusitis.

  20. Simultaneous Detection and Identification of Aspergillus and Mucorales Species in Tissues Collected from Patients with Fungal Rhinosinusitis▿

    Science.gov (United States)

    Zhao, Zuotao; Li, Lili; Wan, Zhe; Chen, Wei; Liu, Honggang; Li, Ruoyu

    2011-01-01

    Rapid detection and differentiation of Aspergillus and Mucorales species in fungal rhinosinusitis diagnosis are desirable, since the clinical management and prognosis associated with the two taxa are fundamentally different. We describe an assay based on a combination of broad-range PCR amplification and reverse line blot hybridization (PCR/RLB) to detect and differentiate the pathogens causing fungal rhinosinusitis, which include five Aspergillus species (A. fumigatus, A. flavus, A. niger, A. terreus, and A. nidulans) and seven Mucorales species (Mucor heimalis, Mucor racemosus, Mucor cercinelloidea, Rhizopus arrhizus, Rhizopus microsporus, Rhizomucor pusillus, and Absidia corymbifera). The assay was validated with 98 well-characterized clinical isolates and 41 clinical tissue specimens. PCR/RLB showed high sensitivity and specificity, with 100% correct identifications of 98 clinical isolates and no cross-hybridization between the species-specific probes. Results for five control isolates, Candida albicans, Fusarium solani, Scedosporium apiospermum, Penicillium marneffei, and Exophiala verrucosa, were negative as judged by PCR/RLB. The analytical sensitivity of PCR/RLB was found to be 1.8 × 10−3 ng/μl by 10-fold serial dilution of Aspergillus genomic DNA. The assay identified 35 of 41 (85.4%) clinical specimens, exhibiting a higher sensitivity than fungal culture (22 of 41; 53.7%) and direct sequencing (18 of 41; 43.9%). PCR/RLB similarly showed high specificity, with correct identification 16 of 18 specimens detected by internal transcribed spacer (ITS) sequencing and 16 of 22 detected by fungal culture, but it also has the additional advantage of being able to detect mixed infection in a single clinical specimen. The PCR/RLB assay thus provides a rapid and reliable option for laboratory diagnosis of fungal rhinosinusitis. PMID:21325541

  1. Identification and toxigenic potential of the industrially important fungi, Aspergillus oryzae and Aspergillus sojae

    DEFF Research Database (Denmark)

    Jørgensen, Thomas R

    2007-01-01

    Mold strains belonging to the species Aspergillus oryzae and Aspergillus sojae are highly valued as koji molds in the traditional preparation of fermented foods, such as miso, sake, and shoyu, and as protein production hosts in modern industrial processes. A. oryzae and A. sojae are relatives....... sojae strains. Separation of A. oryzae and A. sojae from A. flavus and A. parasiticus, respectively, is inconsistent, and both morphologic and molecular evidence support conspecificity. The high degree of identity is reflected by the divergent identification of reference cultures maintained in culture...... collections. As close relatives of aflatoxin-producing wild molds, koji molds possess an aflatoxin gene homolog cluster. Some strains identified as A. oryzae and A. sojae have been implicated in aflatoxin production. Identification of a strain as A. oryzae or A. sojae is no guarantee of its inability...

  2. Metabolomics Analysis Reveals Specific Novel Tetrapeptide and Potential Anti-Inflammatory Metabolites in Pathogenic Aspergillus species.

    Science.gov (United States)

    Lee, Kim-Chung; Tam, Emily W T; Lo, Ka-Ching; Tsang, Alan K L; Lau, Candy C Y; To, Kelvin K W; Chan, Jasper F W; Lam, Ching-Wan; Yuen, Kwok-Yung; Lau, Susanna K P; Woo, Patrick C Y

    2015-06-17

    Infections related to Aspergillus species have emerged to become an important focus in infectious diseases, as a result of the increasing use of immunosuppressive agents and high fatality associated with invasive aspergillosis. However, laboratory diagnosis of Aspergillus infections remains difficult. In this study, by comparing the metabolomic profiles of the culture supernatants of 30 strains of six pathogenic Aspergillus species (A. fumigatus, A. flavus, A. niger, A. terreus, A. nomius and A. tamarii) and 31 strains of 10 non-Aspergillus fungi, eight compounds present in all strains of the six Aspergillus species but not in any strain of the non-Aspergillus fungi were observed. One of the eight compounds, Leu-Glu-Leu-Glu, is a novel tetrapeptide and represents the first linear tetrapeptide observed in Aspergillus species, which we propose to be named aspergitide. Two other closely related Aspergillus-specific compounds, hydroxy-(sulfooxy)benzoic acid and (sulfooxy)benzoic acid, may possess anti-inflammatory properties, as 2-(sulfooxy)benzoic acid possesses a structure similar to those of aspirin [2-(acetoxy)benzoic acid] and salicylic acid (2-hydroxybenzoic acid). Further studies to examine the potentials of these Aspergillus-specific compounds for laboratory diagnosis of aspergillosis are warranted and further experiments will reveal whether Leu-Glu-Leu-Glu, hydroxy-(sulfooxy)benzoic acid and (sulfooxy)benzoic acid are virulent factors of the pathogenic Aspergillus species.

  3. Comparison of different inoculating methods to evaluate the pathogenicity and virulence of Aspergillus niger on two maize hybrids

    Science.gov (United States)

    A two-year field study was conducted to determine the effects of inoculation techniques on the aggressiveness of Aspergillus niger kernel infection in A. flavus resistant and susceptible maize hybrids. Ears were inoculated with the silk-channel, side-needle, and spray techniques 7 days after midsilk...

  4. Cowpeas as growth substrate do not support the production of aflatoxinby Aspergillus sp

    DEFF Research Database (Denmark)

    Houssou, P.A.; Schnidt-Heydt, M.; Geisen, R.

    2008-01-01

    A number of 21 Aspergillus sp. strains isolated from cowpeas from Benin (Africa) were characterizedby RAPD methodology. Seven of these strains grouped with A. flavus in the dendrogram generated with the RAPD data. Only three were able to produce aflatoxin in significant amounts. Twelve other...... isolates grouped with A. parasiticus. All of these strains except 3 produced aflatoxin. Two additional strains neither fit with the A. flavus group, nor the A. parasiticus group according to their RAPD pattern. Both did not produce aflatoxin in measurable amounts. Generally the aflatoxin positive strains...

  5. DOPA and DHN pathway orchestrate melanin synthesis in Aspergillus species.

    Science.gov (United States)

    Pal, Anuradha K; Gajjar, Devarshi U; Vasavada, Abhay R

    2014-01-01

    Melanins are high molecular weight hydrophobic pigments that have been studied for their role in the virulence of fungal pathogens. We investigated the amount and type of melanin in 20 isolates of Aspergillus spp.; A. niger (n = 3), A. flavus (n = 5), A. tamarii (n = 3), A. terreus (n = 3), A. tubingensis (n = 3), A. sydowii (n = 3). Aspergillus spp. were identified by sequencing the internal transcribed spacer (ITS) region. Extraction of melanin from culture filtrate and fungal biomass was done and followed by qualitative and quantitative analysis of melanin pigment. Ultraviolet (UV), Fourier transformed infrared (FT-IR), and electron paramagnetic resonance (EPR) spectra analyses confirmed the presence of melanin. The melanin pathway was studied by analyzing the effects of inhibitors; kojic acid, tropolone, phthalide, and tricyclazole. The results indicate that in A. niger and A. tubingensis melanin was found in both culture filtrate and fungal biomass. For A. tamarii and A. flavus melanin was extracted from biomass only, whereas melanin was found only in culture filtrate for A. terreus. A negligible amount of melanin was found in A. sydowii. The maximum amount of melanin from culture filtrate and fungal biomass was found in A. niger and A. tamarrii, respectively. The DOPA (3,4-dihydroxyphenylalanine) pathway produces melanin in A. niger, A. tamarii and A. flavus, whereas the DHN (1,8-dihydroxynaphthalene) pathway produces melanin in A. tubingensis and A. terreus. It can be concluded that the amount and type of melanin in aspergilli largely differ from species to species.

  6. Wild-Type MIC Distributions and Epidemiological Cutoff Values for the Triazoles and Six Aspergillus spp. for the CLSI Broth Microdilution Method (M38-A2 Document)▿

    Science.gov (United States)

    Espinel-Ingroff, A.; Diekema, D. J.; Fothergill, A.; Johnson, E.; Pelaez, T.; Pfaller, M. A.; Rinaldi, M. G.; Canton, E.; Turnidge, J.

    2010-01-01

    Clinical breakpoints have not been established for mold testing. Wild-type (WT) MIC distributions (organisms in a species/drug combination with no detectable acquired resistance mechanisms) were defined in order to establish epidemiologic cutoff values (ECVs) for five Aspergillus spp. and itraconazole, posaconazole, and voriconazole. Also, we have expanded prior ECV data for Aspergillus fumigatus. The number of available isolates varied according to the species/triazole combination as follows: 1,684 to 2,815 for A. fumigatus, 323 to 592 for A. flavus, 131 to 143 for A. nidulans, 366 to 520 for A. niger, 330 to 462 for A. terreus, and 45 to 84 for A. versicolor. CLSI broth microdilution MIC data gathered in five independent laboratories in Europe and the United States were aggregated for the analyses. ECVs expressed in μg/ml were as follows (percentages of isolates for which MICs were equal to or less than the ECV are in parentheses): A. fumigatus, itraconazole, 1 (98.8%); posaconazole, 0.5 (99.2%); voriconazole, 1 (97.7%); A. flavus, itraconazole, 1 (99.6%); posaconazole, 0.25 (95%); voriconazole, 1 (98.1%); A. nidulans, itraconazole, 1 (95%); posaconazole, 1 (97.7%); voriconazole, 2 (99.3%); A. niger, itraconazole, 2 (100%); posaconazole, 0.5 (96.9%); voriconazole, 2 (99.4%); A. terreus, itraconazole, 1 (100%); posaconazole, 0.5 (99.7%); voriconazole, 1 (99.1%); A. versicolor, itraconazole, 2 (100%); posaconazole, 1 (not applicable); voriconazole, 2 (97.5%). Although ECVs do not predict therapy outcome as clinical breakpoints do, they may aid in detection of azole resistance (non-WT MIC) due to cyp51A mutations, a resistance mechanism in some Aspergillus spp. These ECVs should be considered for inclusion in the future CLSI M38-A2 document revision. PMID:20592159

  7. Bioleaching of serpentine group mineral by fungus Talaromyces flavus: application for mineral carbonation

    Science.gov (United States)

    Li, Z.; Lianwen, L.; Zhao, L.; Teng, H.

    2011-12-01

    Many studies of serpentine group mineral dissolution for mineral carbonation have been published in recent years. However, most of them focus mainly on either physical and chemical processes or on bacterial function, rather than fungal involvement in the bioleaching of serpentine group mineral. Due to the excessive costs of the magnesium dissolution process, finding a lower energy consumption method will be meaningful. A fungal strain Talaromyces flavus was isolated from serpentinic rock of Donghai (China). No study of its bioleaching ability is currently available. It is thus of great significance to explore the impact of T. flavus on the dissolution of serpentine group mineral. Serpentine rock-inhabiting fungi belonging to Acremonium, Alternaria, Aspergillus, Botryotinia, Cladosporium, Clavicipitaceae, Cosmospora, Fusarium, Monascus, Paecilomyces, Penicillium, Talaromyces, Trichoderma were isolated. These strains were chosen on the basis of resistance to magnesium and nickel characterized in terms of minimum inhibiting concentration (MIC). Specifically, the strain Talaromyces flavus has a high tolerance to both magnesium (1 mol/L) and nickel (10 mM/L), and we examine its bioleaching ability on serpentine group mineral. Contact and separation experiments (cut-off 8 000-14 000 Da), as well as three control experiments, were set up for 30 days. At least three repeated tests were performed for each individual experiment. The results of our experiments demonstrate that the bioleaching ability of T. flavus towards serpentine group mineral is evident. 39.39 wt% of magnesium was extracted from lizardite during the bioleaching period in the contact experiment, which showed a dissolution rate at about a constant 0.126 mM/d before reaching equilibrium in 13 days. The amount of solubilized Mg from chrysotile and antigorite were respectively 37.79 wt% and 29.78 wt% in the contact experiment. These results make clear the influence of mineral structure on mineral bioleaching

  8. 七种培养基对黄曲霉分离效果的比较%Comparison of Seven Media for the Isolation of Aspergullus Flavus Group

    Institute of Scientific and Technical Information of China (English)

    张初署; 刘阳; 邢福国; 杨庆利; 杨勃扬

    2013-01-01

    为了筛选出适宜黄曲霉分离的培养基,比较了7种常用于霉菌分离的培养基对10个花生土壤样品的黄曲霉分离效果,这7种培养基为氯硝胺18%甘油培养基(DG18)、高盐察氏培养基(SCDA)、马铃薯琼脂培养基(PDA)、改良的孟加拉红培养基(M-RB)、YES培养基、孟加拉红培养基(RB)、氯硝胺孟加拉红琼脂(DRBC).研究发现7种培养基对黄曲霉菌培养效果差别很大,培养效果最好的是DG18,黄曲霉的培养数是PDA的7.3倍.同时DG18能很好的抑制毛霉的生长,与DRBC培养基相比,能抑制81%的毛霉菌生长.因此DG18培养基能最大限度的保证黄曲霉的生长分离,同时也能更好地抑制毛霉的生长,更适用于黄曲霉种群、遗传方面的研究应用.%Seven agar media used to isolate mould were compared for utility in isolating the Aspergillus flavus from peanut-cropped soils. The seven agar media were Dicloran 18% glycerol medium salt capek Dox agar、Patato dextrose agar medium、Modified Rose Bengal medium、YES medium、Rose Bengal medium、Dicloran Rose Bengal medium. The results showed that seven media have apparent difference on isolating Aspergillus flavus. DG18 was the most suitable medium for studying the population biology of this group because it permitted both identification of the greatest number of Aspergillus flavus group strains and growth of the fewest competing fungi. DG18 supported about 7. 3times more Aspergillus flavus colonies than the PDA while reducing the number of mucorales colonies by 81% than the DRBC. So DG18 should be the most useful for studies on the population biology of the Aspergillus flavus group.

  9. Dhakeri-Bange syndrome in goats due to Penicillium and Aspergillus spp, in Banke district of Nepal: a Clinical-Laboratory Investigation

    Directory of Open Access Journals (Sweden)

    Kedar Karki

    Full Text Available An outbreak of syndrome of unknown etiology associated with the feeding of moldy dry forage and green fodder to goats in Dhakeri village of Banke District. Goats suddenly became ill with symptoms of knuckling of the fetlocks of the pelvic limbs, with no apparent ataxia or flexor weakness. Weight bearing was possible while the digits were extended, but with knuckling, weight was supported on the dorsal surface of the foot .The more severely affected goats were paraplegic and recumbent. Anorexia, apathy, diarrhea and ruminal stasis, flaccid posterior paralysis,hindlegs stretched forward both side of abdomin,paralysis of all four legs, head bented to sides, aimlessly head and rear shaking .On clinical examination based on history these goats were provisionally diagnosed as Dhakeri-Bange as being called locally and Endemic Mycotic polyneuropathy syndrome as seen first time in Nepal due to moldy forage/fodder poisoning in natural pasture were treated with Antidegnala liquor(sr. On mycological and microbiological examination of tissue samples from post-mortem of dead goat and forage/fodder samples from pasture and goats feeding stalls on respective medium revealed the growth of fungal pathogens like Aspergillus and Penicillium spp with E.coli.These results provide circumstantial evidence that feeding of moldy forages and green fodder leaves infected by Penicillium and Aspergillus spp may cause outbreaks of a systemic Mycosis in these goats. [Vet. World 2008; 1(12.000: 357-359

  10. Aspergillus mediastinitis after cardiac surgery

    Directory of Open Access Journals (Sweden)

    Marie-Josée Caballero

    2016-03-01

    Conclusion: The clinical features of postoperative Aspergillus mediastinitis may be paucisymptomatic, emphasizing the need for a low index of suspicion in cases of culture-negative mediastinitis or in indolent wound infections. In addition to surgical debridement, the central component of antifungal therapy should include amphotericin B or voriconazole.

  11. Prevalence and mechanism of triazole resistance in Aspergillus fumigatus in a referral chest hospital in Delhi, India and an update of the situation in Asia

    Directory of Open Access Journals (Sweden)

    Anuradha eChowdhary

    2015-05-01

    Full Text Available Aspergillus fumigatus causes varied clinical syndromes ranging from colonization to deep infections. The mainstay of therapy of Aspergillus diseases is triazoles but several studies globally highlighted variable prevalence of triazole resistance, which hampers the management of aspergillosis. We studied the prevalence of resistance in clinical A. fumigatus isolates during 4 years in a referral Chest Hospital in Delhi, India and reviewed the scenario in Asia and the Middle East. Aspergillus species (n=2117 were screened with selective plates for azole resistance. The isolates included 45.4% A. flavus, followed by 32.4% A. fumigatus, 15.6% Aspergillus species and 6.6% A. terreus. Azole resistance was found in only 12 (1.7% A. fumigatus isolates.These triazole resistant A. fumigatus (TRAF isolates were subjected to (a calmodulin and β tubulin gene sequencing (b in vitro antifungal susceptibility testing against triazoles using CLSI M38-A2 (c sequencing of cyp51A gene and real-time PCR assay for detection of mutations and (d microsatellite typing of the resistant isolates. TRAF harbored TR34/L98H mutation in 10 (83.3% isolates with a pan-azole resistant phenotype. Among the remaining 2 TRAF isolates, one had G54E and the other had three non-synonymous point mutations. The majority of patients were diagnosed as invasive aspergillosis followed by allergic bronchopulmonary aspergillosis and chronic pulmonary aspergillosis. The Indian TR34/L98H isolates had a unique genotype and were distinct from the Chinese, Middle East and European TR34/L98H strains. This resistance mechanism has been linked to the use of fungicide azoles in agricultural practices in Europe as it has been mainly reported from azole naïve patients. Reports published from Asia demonstrate the same environmental resistance mechanism in A. fumigatus isolates from two highly populated countries in Asia i.e., China and India and also from the neighboring Middle East.

  12. In Vitro Activity of a Novel Broad-Spectrum Antifungal, E1210, Tested against Aspergillus spp. Determined by CLSI and EUCAST Broth Microdilution Methods ▿

    Science.gov (United States)

    Pfaller, Michael A.; Duncanson, Frederick; Messer, Shawn A.; Moet, Gary J.; Jones, Ronald N.; Castanheira, Mariana

    2011-01-01

    E1210 is a first-in-class broad-spectrum antifungal that suppresses hyphal growth by inhibiting fungal glycophosphatidylinositol (GPI) biosynthesis. In the present study, we extend these findings by examining the activity of E1210 and comparator antifungal agents against Aspergillus spp. by using the methods of the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST) to test wild-type (WT) as well as amphotericin B (AMB)-resistant (-R) and azole-R strains (as determined by CLSI methods). Seventy-eight clinical isolates of Aspergillus were tested including 20 isolates of Aspergillus flavus species complex (SC), 22 of A. fumigatus SC, 13 of A. niger SC, and 23 of A. terreus SC. The collection included 15 AMB-R (MIC, ≥2 μg/ml) isolates of A. terreus SC and 10 itraconazole-R (MIC, ≥4 μg/ml) isolates of A. fumigatus SC (7 isolates), A. niger SC (2 isolates), and A. terreus SC (1 isolate). Comparator antifungal agents included anidulafungin, caspofungin, amphotericin B, itraconazole, posaconzole, and voriconazole. Both CLSI and EUCAST methods were highly concordant for E1210 and all comparators. The essential agreement (EA; ±2 log2 dilution steps) was 100% for all comparisons with the exception of posaconazole versus A. terreus SC (EA = 91.3%). The minimum effective concentration (MEC)/MIC90 values (μg/ml) for E1210, anidulafungin, caspofungin, itraconazole, posaconazole, and voriconazole, respectively, were as follows for each species: for A. flavus SC, 0.03, ≤0.008, 0.12, 1, 1, and 1; for A. fumigatus SC, 0.06, 0.015, 0.12, >8, 1, and 4; for A. niger SC, 0.015, 0.03, 0.12, 4, 1, and 2; and for A. terreus SC, 0.06, 0.015, 0.12, 1, 0.5, and 1. E1210 was very active against AMB-R strains of A. terreus SC (MEC range, 0.015 to 0.06 μg/ml) and itraconazole-R strains of A. fumigatus SC (MEC range, 0.03 to 0.12 μg/ml), A. niger SC (MEC, 0.008 μg/ml), and A. terreus SC (MEC, 0.015

  13. Neopetromyces gen. nov and an overview of teleomorphs of Aspergillus subgenus Circumdati

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Samson, R. A.

    2000-01-01

    in Aspergillus subgenus Circumdati section Flavi. The ascostromata of P. alliaceus and its synonym P. albertensis resemble those of A. flavus and A. nomius. Another species from section Circumdati, A. lanosus, is reassigned to section Flavi. All these taxa grow well at 37 degrees C, and produce kojic acid......Species in the anamorph genus Aspergillus are associated with several teleomorphic genera in the Eurotiales and the most important mycotoxin producers are concentrated in Aspergillus subgenus Circumdati. A new genus, Neopetromyces, is proposed for the recently described Petromyces muricatus......, because this species differs distinctly from the two other species, P. alliaceus and P. albertensis. Neopetromyces muricatus has flesh-coloured ascostromata and an anamorph in Aspergillus subgenus Circumdati section Circumdati, whereas other Petromyces species have black ascostromata and anamorphs...

  14. [Aspergillus galactomannan assay for the management of histoplasmosis due to Histoplasma capsulatum var. duboisii in HIV-infected patients: education from a clinical case].

    Science.gov (United States)

    Therby, A; Polotzanu, O; Khau, D; Monnier, S; Greder Belan, A; Eloy, O

    2014-06-01

    The diagnosis of histoplasmosis due to Histoplasma capsulatum var capsulatum is based on a direct examination identifying encapsulated yeast with narrow-based budding. Galactomannan antigenemia facilitates diagnosis, as well as the monitoring of patients receiving treatment. The case of a HIV-positive patient from Congo-Brazzaville with a disseminated form of African histoplasmosis highlighted the positive galactomannan antigen in this disease due to Histoplasma capsulatum var duboisii. Galactomannan antigenemia remained high with a very slow decrease during antifungal therapy and slow regression of clinical lesions. African histoplasmosis is a rare disease that is difficult to diagnose and rarely described in immunocompromised patients, in whom differential diagnosis can be common. This observation underlines the importance of the galactomannan antigen assay in patients who have travelled to endemic areas. As in the case of Histoplasma capsulatum var capsulatum, the positivity of the Aspergillus galactomannan antigen is very useful in the diagnosis and monitoring of African histoplasmosis.

  15. Host-Induced Gene Silencing (HIGS) of aflatoxin synthesis genes in peanut and maize: use of RNA interference and genetic diversity of Aspergillus

    Science.gov (United States)

    Approximately 4.5 billion people are chronically exposed to aflatoxins, these are powerful carcinogens produced by Aspergillus flavus and A. parasiticus. High levels of aflatoxins in crops result in approximately 100 million metric tons of cereals, ¬nuts, root crops and other agricultural products ...

  16. What can comparative genomics tell us about species concepts in the genus Aspergillus?

    Energy Technology Data Exchange (ETDEWEB)

    Rokas, Antonis; payne, gary; Federova, Natalie D.; Baker, Scott E.; Machida, Masa; yu, Jiujiang; georgianna, D. R.; Dean, Ralph A.; Bhatnagar, Deepak; Cleveland, T. E.; Wortman, Jennifer R.; Maiti, R.; Joardar, V.; Amedeo, Paolo; Denning, David W.; Nierman, William C.

    2007-12-15

    Understanding the nature of species" boundaries is a fundamental question in evolutionary biology. The availability of genomes from several species of the genus Aspergillus allows us for the first time to examine the demarcation of fungal species at the whole-genome level. Here, we examine four case studies, two of which involve intraspecific comparisons, whereas the other two deal with interspecific genomic comparisons between closely related species. These four comparisons reveal significant variation in the nature of species boundaries across Aspergillus. For example, comparisons between A. fumigatus and Neosartorya fischeri (the teleomorph of A. fischerianus) and between A. oryzae and A. flavus suggest that measures of sequence similarity and species-specific genes are significantly higher for the A. fumigatus - N. fischeri pair. Importantly, the values obtained from the comparison between A. oryzae and A. flavus are remarkably similar to those obtained from an intra-specific comparison of A. fumigatus strains, giving support to the proposal that A. oryzae represents a distinct ecotype of A. flavus and not a distinct species. We argue that genomic data can aid Aspergillus taxonomy by serving as a source of novel and unprecedented amounts of comparative data, as a resource for the development of additional diagnostic tools, and finally as a knowledge database about the biological differences between strains and species.

  17. Detection of Aspergillus-specific antibodies by agar gel double immunodiffusion and IgG ELISA in feline upper respiratory tract aspergillosis.

    Science.gov (United States)

    Barrs, V R; Ujvari, B; Dhand, N K; Peters, I R; Talbot, J; Johnson, L R; Billen, F; Martin, P; Beatty, J A; Belov, K

    2015-03-01

    Feline upper respiratory tract aspergillosis (URTA) is an emerging infectious disease. The aims of this study were: (1) to assess the diagnostic value of detection of Aspergillus-specific antibodies using an agar gel double immunodiffusion (AGID) assay and an indirect immunoglobulin G (IgG) ELISA; and (2) to determine if an aspergillin derived from mycelia of Aspergillus fumigatus, Aspergillus niger and Aspergillus flavus can be used to detect serum antibodies against cryptic Aspergillus spp. in Aspergillus section Fumigati. Sera from cats with URTA (group 1: n = 21) and two control groups (group 2: cats with other upper respiratory tract diseases, n = 25; group 3: healthy cats and cats with non-respiratory, non-fungal illness, n = 84) were tested. Isolates from cats with URTA comprised A. fumigatus (n = 5), A. flavus (n = 1) and four cryptic species: Aspergillus felis (n = 12), Aspergillus thermomutatus (Neosartorya pseudofischeri, n = 1), Aspergillus lentulus (n = 1) and Aspergillus udagawae (n = 1). Brachycephalic purebred cats were significantly more likely to develop URTA than other breeds (P = 0.013). The sensitivity (Se) of the AGID was 43% and the specificity (Sp) was 100%. At a cut-off value of 6 ELISA units/mL, the Se of the IgG ELISA was 95.2% and the Sp was 92% and 92.9% for groups 2 and 3 cats, respectively. Aspergillus-specific antibodies against all four cryptic species were detected in one or both assays. Assay Se was not associated with species identity. Detection of Aspergillus-specific antibodies by IgG ELISA has high Se and Sp for diagnosis of feline URTA.

  18. Effect of gamma radiation in peanuts for inhibition of Aspergillus flavus and nutritional composition; Irradiacao gama em amendoim para controle de Aspergillus flavus

    Energy Technology Data Exchange (ETDEWEB)

    Costa, L.F.; Silva, E.B. da, E-mail: lauryfrancis@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Oliveira, I.S. [Universidade Federal de Pernambuco (CAV/UFPE), Vitoria de Santo Antao, PE (Brazil). Centro Academico de Vitoria

    2013-08-15

    Care in food storage, controlling humidity and temperature, prevents fungal diseases in peanuts and the development of filamentous fungi in food and feed, which can result in the production of toxins known as mycotoxins. Ionizing radiation is a preventive method of food security, promoting inhibition of buds, delayed maturation, reduction of microbial load, elimination of pathogenic microorganisms, sterilization and disinfection in grains, cereals, fruits and spices. This work aimed to evaluate the effects of gamma radiation on the growth inhibition of aflatoxigenic fungi and on nutritional composition in peanut. Samples were collected directly from the producer (Petrolandia) and Supply Central of Pernambuco (CEASA-PE), and then grains inside / outside pods were packed and subjected to irradiation at doses of 6, 9, 12 and 15 kGy. Fungal growth and nutritional composition of the samples before and after irradiation were analyzed and statistical analysis using the Mann-Whitney-Wilcoxon. The results showed that the samples originated from CEASA-PE had the highest rates of contamination. The radiation was effective in the inhibition of aflatoxigenic fungi, achieving to eliminate the action of fungi, regardless of dose. Only one non-irradiated sample, originated from CEASA-PE, showed positive production of aflatoxins in the middle LCA. No significant difference in the values of the nutritional composition, with increasing radiation dose. The irradiation was shown to be an effective process for preserving peanuts, because it prevents the growth of fungi, particularly aflatoxin producer, making it safer for consumption, without changing its nutritional composition. (author)

  19. Secondary metabolite profiles and antifungal drug susceptibility of Aspergillus fumigatus and closely related species, Aspergillus lentulus, Aspergillus udagawae, and Aspergillus viridinutans.

    Science.gov (United States)

    Tamiya, Hiroyuki; Ochiai, Eri; Kikuchi, Kazuyo; Yahiro, Maki; Toyotome, Takahito; Watanabe, Akira; Yaguchi, Takashi; Kamei, Katsuhiko

    2015-05-01

    The incidence of Aspergillus infection has been increasing in the past few years. Also, new Aspergillus fumigatus-related species, namely Aspergillus lentulus, Aspergillus udagawae, and Aspergillus viridinutans, were shown to infect humans. These fungi exhibit marked morphological similarities to A. fumigatus, albeit with different clinical courses and antifungal drug susceptibilities. The present study used liquid chromatography/time-of-flight mass spectrometry to identify the secondary metabolites secreted as virulence factors by these Aspergillus species and compared their antifungal susceptibility. The metabolite profiles varied widely among A. fumigatus, A. lentulus, A. udagawae, and A. viridinutans, producing 27, 13, 8, and 11 substances, respectively. Among the mycotoxins, fumifungin, fumiquinazoline A/B and D, fumitremorgin B, gliotoxin, sphingofungins, pseurotins, and verruculogen were only found in A. fumigatus, whereas auranthine was only found in A. lentulus. The amount of gliotoxin, one of the most abundant mycotoxins in A. fumigatus, was negligible in these related species. In addition, they had decreased susceptibility to antifungal agents such as itraconazole and voriconazole, even though metabolites that were shared in the isolates showing higher minimum inhibitory concentrations than epidemiological cutoff values were not detected. These strikingly different secondary metabolite profiles may lead to the development of more discriminative identification protocols for such closely related Aspergillus species as well as improved treatment outcomes.

  20. The Prevalence of Aflatoxinogenic Aspergillus parasiticus in Jordan

    Directory of Open Access Journals (Sweden)

    Nisreen Al-Hmoud

    2012-01-01

    Full Text Available Aflatoxins are potent carcinogens and produced by almost all Aspergillus parasiticus isolates and about 35% of Aspergillus flavus isolates. Chemical methods are used for detection of aflatoxins in food and feed. These methods cannot detect aflatoxinogenic fungi in samples, which contain undetectable amounts of aflatoxins. The objective of this research work was to ascertain the importance of molecular and microbiological methods in detection of aflatoxinogenic fungus A. parasiticus in food and feed samples in Jordan. Specific media for the detection of aflatoxins showed the prevalence of A. parasiticus (6–22% in contaminated food and feed samples. HPLC method confirmed the presence of aflatoxins B1, B2, G1, and G2 in food sample contaminated with A. parasiticus. Primer set OmtBII-F and OmtBII-R amplified DNA fragment of 611 base pairs from genomic DNA of aflatoxinogenic A. parasiticus isolated from food and feed samples but could not amplify DNA fragment of nonaflatoxinogenic A. flavus. The results of this study showed the prevalence of aflatoxinogenic A. parasiticus in food and feed samples in Jordan and give further evidence of suitability of microbiological and molecular methods in detection of aflatoxins, which are reliable low-cost approach to determine food and feed biosafety.

  1. Screening a strain of Aspergillus niger and optimization of fermentation conditions for degradation of aflatoxin B₁.

    Science.gov (United States)

    Zhang, Wei; Xue, Beibei; Li, Mengmeng; Mu, Yang; Chen, Zhihui; Li, Jianping; Shan, Anshan

    2014-11-13

    Aflatoxin B₁, a type of highly toxic mycotoxin produced by some species belonging to the Aspergillus genus, such as Aspergillus flavus and Aspergillus parasiticus, is widely distributed in feed matrices. Here, coumarin was used as the sole carbon source to screen microorganism strains that were isolated from types of feed ingredients. Only one isolate (ND-1) was able to degrade aflatoxin B₁ after screening. ND-1 isolate, identified as a strain of Aspergillus niger using phylogenetic analysis on the basis of 18S rDNA, could remove 26.3% of aflatoxin B₁ after 48 h of fermentation in nutrient broth (NB). Optimization of fermentation conditions for aflatoxin B₁ degradation by selected Aspergillus niger was also performed. These results showed that 58.2% of aflatoxin B₁ was degraded after 24 h of culture under the optimal fermentation conditions. The aflatoxin B₁ degradation activity of Aspergillus niger supernatant was significantly stronger than cells and cell extracts. Furthermore, effects of temperature, heat treatment, pH, and metal ions on aflatoxin B₁ degradation by the supernatant were examined. Results indicated that aflatoxin B₁ degradation of Aspergillus niger is enzymatic and this process occurs in the extracellular environment.

  2. Characterization of Aspergillus section Flavi isolated from organic Brazil nuts using a polyphasic approach.

    Science.gov (United States)

    Reis, T A; Baquião, A C; Atayde, D D; Grabarz, F; Corrêa, B

    2014-09-01

    Brazil nut (Bertholletia excelsa), an important non-timber forest product from Amazonia, is commercialized in worldwide markets. The main importers of this nut are North America and European countries, where the demand for organic products has grown to meet consumers concerned about food safety. Thus, the precise identification of toxigenic fungi is important because the Brazil nut is susceptible to colonization by these microorganisms. The present study aimed to characterize by polyphasic approach strains of Aspergillus section Flavi from organic Brazil nuts. The results showed Aspergillus flavus as the main species found (74.4%), followed by Aspergillus nomius (12.7%). The potential mycotoxigenic revealed that 80.0% of A. flavus were toxin producers, 14.3% of which produced only aflatoxin B (AFB), 22.85% of which produced only cyclopiazonic acid (CPA), and 42.85% produced both them. All strains of A. nomius were AFB and AFG producers and did not produce CPA. There is no consensus about what Aspergillus species predominates on Brazil nuts. Apparently, the origin, processing, transport and storage conditions of this commodity influence the species that are found. The understanding about population of fungi is essential for the development of viable strategies to control aflatoxins in organic Brazil nuts.

  3. Opportunistic Aspergillus pathogens measured in home and hospital tap water by quantitative PCR (QPCR).

    Science.gov (United States)

    Vesper, S J; Haugland, R A; Rogers, M E; Neely, A N

    2007-09-01

    Opportunistic fungal pathogens are a concern because of the increasing number of immunocompromised patients. The goal of this research was to test a simple extraction method and rapid quantitative PCR (QPCR) measurement of the occurrence of potential pathogens, Aspergillus fumigatus, A. flavus, A. terreus and A. niger, in home tap water and a hospital water supply. Water samples were taken from the kitchen tap in the homes of 60 patients who were diagnosed with legionellosis. Water samples were also taken from three locations in a hospital that generated all of its hot water by flash heating. Opportunistic infectious agents Aspergillus fumigatus, A. flavus, A. terreus and A. niger were measured using QPCR. Aspergillus terreus DNA was found in 16.7% and A. fumigatus DNA in 1.7% of the samples taken from the kitchen tap. None of the Aspergillus species were found in any of the hospital water samples.The development of a simple DNA extraction method along with QPCR analysis is suitable for rapid screening of tap water for opportunistic fungal pathogens. This simple method can be used to obtain pathogen occurrence results in about 3 h, instead of waiting days to weeks for culture data. Obtaining pathogen occurrence data in a timely manner could promote the elimination of the pathogens from the water supply of immunocompromised patients.

  4. Aspergillus tubingensis and Aspergillus niger as the dominant black Aspergillus, use of simple PCR-RFLP for preliminary differentiation.

    Science.gov (United States)

    Mirhendi, H; Zarei, F; Motamedi, M; Nouripour-Sisakht, S

    2016-03-01

    This work aimed to identify the species distribution of common clinical and environmental isolates of black Aspergilli based on simple restriction fragment length polymorphism (RFLP) analysis of the β-tubulin gene. A total of 149 clinical and environmental strains of black Aspergilli were collected and subjected to preliminary morphological examination. Total genomic DNAs were extracted, and PCR was performed to amplify part of the β-tubulin gene. At first, 52 randomly selected samples were species-delineated by sequence analysis. In order to distinguish the most common species, PCR amplicons of 117 black Aspergillus strains were identified by simple PCR-RFLP analysis using the enzyme TasI. Among 52 sequenced isolates, 28 were Aspergillus tubingensis, 21 Aspergillus niger, and the three remaining isolates included Aspergillus uvarum, Aspergillus awamori, and Aspergillus acidus. All 100 environmental and 17 BAL samples subjected to TasI-RFLP analysis of the β-tubulin gene, fell into two groups, consisting of about 59% (n=69) A. tubingensis and 41% (n=48) A. niger. Therefore, the method successfully and rapidly distinguished A. tubingensis and A. niger as the most common species among the clinical and environmental isolates. Although tardy, the Ehrlich test was also able to differentiate A. tubingensis and A. niger according to the yellow color reaction specific to A. niger. A. tubingensis and A. niger are the most common black Aspergillus in both clinical and environmental isolates in Iran. PCR-RFLP using TasI digestion of β-tubulin DNA enables rapid screening for these common species.

  5. Aspergillus spinal epidural abscess

    Energy Technology Data Exchange (ETDEWEB)

    Byrd, B.F. III (Vanderbilt Univ. School of Medicine, Nashville, TN); Weiner, M.H.; McGee, Z.A.

    1982-12-17

    A spinal epidural abscess developed in a renal transplant recipient; results of a serum radioimmunoassay for Aspergillus antigen were positive. Laminectomy disclosed an abscess of the L4-5 interspace and L-5 vertebral body that contained hyphal forms and from which Aspergillus species was cultured. Serum Aspergillus antigen radioimmunoassay may be a valuable, specific early diagnostic test when systemic aspergillosis is a consideration in an immunosuppressed host.

  6. Isolation and identification of a formaldehyde-degrading fungus Aspergillus spp.H4 strain%一株甲醛降解真菌Aspergillus spp.H4的分离鉴定

    Institute of Scientific and Technical Information of China (English)

    黄赛花; 陈能场; 胡文锋; 周建民; 毕洪亮

    2007-01-01

    甲醛是一种广泛使用和很重要的化工原材料,但它同时也是对大多数生物有机体有高毒性的物质.通过添加甲醛的选择性培养基从淤泥里分离了一株甲醛耐受真菌,将其接种于加孟加拉红的PDA培养基、察氏培养基、麦芽汁培养基平板培养,观察它的培养特征和孢子结构,结合DNA提取、PCR扩增、产物测序、GenBank比对等分子鉴定手段,结果表明:其培养特征、显微特征和黄曲霉(Aspergillus flavus)相似,18S rDNA序列与黄曲霉(Aspergillus flavus)同源率达99.8%.我们把它命名为Aspergillus flavus H4.该真菌最适生长pH值为pH 5.5,在培养的144 h内ρ(甲醛)从1241 mg·L-1下降到4 mg·L-1.在培养的96 h内ρ(甲醛)下降迅速,A值上升缓慢,当ρ(甲醛)下降到10 mg·L-1时,也就是120 h时, A值迅速上升,ρ(甲醛)下降缓慢.结论是这株Aspergillus flavus H4是甲醛耐受(降解)真菌.

  7. Potent synergistic in vitro interaction between nonantimicrobial membrane-active compounds and itraconazole against clinical isolates of Aspergillus fumigatus resistant to itraconazole.

    NARCIS (Netherlands)

    Afeltra, J.; Vitale, R.G.; Mouton, J.W.; Verweij, P.E.

    2004-01-01

    To develop new approaches for the treatment of invasive infections caused by Aspergillus fumigatus, the in vitro interactions between itraconazole (ITZ) and seven different nonantimicrobial membrane-active compounds--amiodarone (AMD), amiloride, lidocaine, lansoprazole (LAN), nifedipine (NIF), verap

  8. Distribution of Aspergillus species among apparently healthy birds in poultry farms in Kaduna state, Nigeria

    Directory of Open Access Journals (Sweden)

    Clara N Kwanashie

    2013-03-01

    Full Text Available The study wasconducted to determine the prevalence and distribution of Aspergilllus species among apparently healthy birds in poultryfarms. Trachea swabs from 1500 birds in 52 commercial (10% of birds in eachpoultry farm visited poultry farms were collected for this study. Six speciesof Aspergillus were isolated wasisolated from 718 (47.87% of the birds viz: A. fumigatus made up 52.37% (376 of the Aspergillus isolates followed by A. flavus 21.87% (157, A.niger 11.42% (82, A. terreus8.64% (62, A. restrictus 2.79% (20and A. ochraceous 2.92% (21. Aspergillus species was found to occurthroughout the year in the farms though with a higher incidence during therainy season compared to the dry season.

  9. Cystic fibrous osteodystrophy of the jaw in two pet kinkajous (Potos flavus).

    Science.gov (United States)

    Garma-Aviña, A; Torres-Montoya, J

    1998-11-07

    Two kinkajous (Potos flavus), which were separately owned as pets and fed an inappropriate diet consisting almost exclusively of succulent fruits developed cystic fibrous osteodystrophy of the jaw. In both cases there was a prominent enlargement of the chin and lower jaw, decalcification of facial bones, softening of the gingiva, and severe malocclusion, but no other relevant changes. Clinical, radiographic and histological findings were consistent with cystic fibrous osteodystrophy. The findings suggest that kinkajous with this condition are particularly prone to developing a bulbous enlargement of the chin as the main clinical sign, and that this change is histologically similar to the cystic form of the disease observed in man and monkeys.

  10. Aspergillus species: An emerging pathogen in onychomycosis among diabetics

    Directory of Open Access Journals (Sweden)

    T M Wijesuriya

    2015-01-01

    Full Text Available Introduction: Approximately, 33% patients with diabetes are afflicted with onychomycosis. In the past, nondermatophyte molds have been regarded as opportunistic pathogens; recently, Aspergillus species are considered as emerging pathogens of toenail infections. In Sri Lanka, the prevalence of Aspergillus species in onychomycosis among diabetics is not well documented. Objective: To determine the proportion of Aspergillus onychomycosis, risk factors and knowledge among diabetics. Materials and Methods: This was descriptive cross-sectional study. Three hundred diabetic patients were included. Clinical examinations of patients' toenails were performed by a clinical microbiologist. Laboratory identification was done, and pathogens were identified to the species level by morpho-physiological methods. All inferential statistics were tested at P age group. In men, Aspergillus onycomycosis was seen in 82%. Among patients who had Aspergillus nail infection, 114 (63% had diabetes for a period of > years. Among patients who were engaged in agricultural activities, 77% were confirmed to have infected nails due to Aspergillus species. Conclusion: Aspergillus niger was the most common pathogen isolated from toenail infection. Aspergillus species should be considered as an important pathogen in toenail onychomycosis in diabetic patients. Risk factors associated with Aspergillus onychomycosis were age, gender, duration of diabetes, length of exposure to fungi, and occupation.

  11. Molecular characterization of drug-resistant and drug-sensitive Aspergillus isolates causing infectious keratitis

    Directory of Open Access Journals (Sweden)

    Niranjan Nayak

    2011-01-01

    Full Text Available Purpose: To study the susceptibilities of Aspergillus species against amphotericin B in infectious keratitis and to find out if drug resistance had any association with the molecular characteristics of the fungi. Materials and Methods: One hundred and sixty Aspergillus isolates from the corneal scrapings of patients with keratitis were tested for susceptibilities to amphotericin B by broth microdilution method. These included Aspergillus flavus (64 isolates, A. fumigatus (43 and A. niger (53. Fungal DNA was extracted by glass bead vertexing technique. Polymerase chain reaction (PCR assay was standardized and used to amplify the 28S rRNA gene. Single-stranded conformational polymorphism (SSCP of the PCR product was performed by the standard protocol. Results: Of the 160 isolates, 84 (52.5% showed low minimum inhibitory concentration (MIC values (≤ 1.56 μg/ml and were designated as amphotercin B-sensitive. Similarly, 76 (47.5% had high MICs (≥ 3.12 μg/ml and were categorized as amphotericin B-resistant. MIC 50 and MIC 90 values ranged between 3.12-6.25 μg/ml and 3.12-12.5 μg/ml respectively. A. flavus and A. niger showed higher MIC 50 and MIC 90 values than A. fumigatus. The SSCP pattern exhibited three extra bands (150 bp, 200 bp and 250 bp each in addition to the 260 bp amplicon. Strains (lanes 1 and 7 lacking the 150 bp band showed low MIC values (≤ 1.56 μg/ml. Conclusion: A. niger and A. flavus isolates had higher MICs compared to A. fumigatus, suggesting a high index of suspicion for amphotericin B resistance. PCR-SSCP was a good molecular tool to characterize Aspergillus phenotypes in fungal keratitis.

  12. Nationwide Surveillance of Azole Resistance in Aspergillus Diseases.

    Science.gov (United States)

    Vermeulen, Edith; Maertens, Johan; De Bel, Annelies; Nulens, Eric; Boelens, Jerina; Surmont, Ignace; Mertens, Anna; Boel, An; Lagrou, Katrien

    2015-08-01

    Aspergillus disease affects a broad patient population, from patients with asthma to immunocompromised patients. Azole resistance has been increasingly reported in both clinical and environmental Aspergillus strains. The prevalence and clinical impact of azole resistance in different patient populations are currently unclear. This 1-year prospective multicenter cohort study aimed to provide detailed epidemiological data on Aspergillus resistance among patients with Aspergillus disease in Belgium. Isolates were prospectively collected in 18 hospitals (April 2011 to April 2012) for susceptibility testing. Clinical and treatment data were collected with a questionnaire. The outcome was evaluated to 1 year after a patient's inclusion. A total of 220 Aspergillus isolates from 182 patients were included. The underlying conditions included invasive aspergillosis (n = 122 patients), allergic bronchopulmonary aspergillosis (APBA) (n = 39 patients), chronic pulmonary aspergillosis (n = 10 patients), Aspergillus bronchitis (n = 7 patients), and aspergilloma (n = 5 patients). The overall azole resistance prevalence was 5.5% (95% confidence interval [CI] 2.8 to 10.2%) and was 7.0% (4/57; 95% CI, 2.3 to 17.2%) in patients with APBA, bronchitis, aspergilloma, or chronic aspergillosis and 4.6% in patients with invasive aspergillosis (5/108; 95% CI, 1.7 to 10.7%). The 6-week survival in invasive aspergillosis was 52.5%, while susceptibility testing revealed azole resistance in only 2/58 of the deceased patients. The clinical impact of Aspergillus fumigatus resistance was limited in our patient population with Aspergillus diseases.

  13. In Vitro Activities of Amphotericin B, Terbinafine, and Azole Drugs against Clinical and Environmental Isolates of Aspergillus terreus Sensu Stricto

    Science.gov (United States)

    Fernández, Mariana S.; Rojas, Florencia D.; Cattana, María E.; Sosa, María de los Ángeles; Iovannitti, Cristina A.; Giusiano, Gustavo E.

    2015-01-01

    The antifungal susceptibilities of 40 clinical and environmental isolates of A. terreus sensu stricto to amphotericin B, terbinafine, itraconazole, and voriconazole were determined in accordance with CLSI document M38-A2. All isolates had itraconazole and voriconazole MICs lower than epidemiologic cutoff values, and 5% of the isolates had amphotericin B MICs higher than epidemiologic cutoff values. Terbinafine showed the lowest MICs. No significant differences were found when MICs of clinical and environmental isolates were compared. PMID:25824228

  14. Metabolomics of Aspergillus fumigatus

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Rank, Christian; Nielsen, Kristian Fog

    2009-01-01

    Aspergillus fumigatus is the most important species in Aspergillus causing infective lung diseases. This species has been reported to produce a large number of extrolites, including secondary metabolites, acids, and proteins such as hydrophobins and extracellular enzymes. At least 226 potentially...

  15. High prevalence of clinical and environmental triazole-resistant Aspergillus fumigatus in Iran: is it a challenging issue?

    Science.gov (United States)

    Nabili, Mojtaba; Shokohi, Tahereh; Moazeni, Maryam; Khodavaisy, Sadegh; Aliyali, Masoud; Badiee, Parisa; Zarrinfar, Hossein; Hagen, Ferry; Badali, Hamid

    2016-06-01

    Triazole antifungal agents are the mainstay of aspergillosis treatment. As highlighted in numerous studies, the global increase in the prevalence of triazole resistance could hamper the management of aspergillosis. In the present three-year study, 513 samples (213 clinical and 300 environmental samples) from 10 provinces of Iran were processed and screened in terms of azole resistance (4 and 1 mg l-1 of itraconazole and voriconazole, respectively), using selective plates. Overall, 150 A. fumigatus isolates (71 clinical and 79 environmental isolates) were detected. The isolates were confirmed by partial sequencing of the β-tubulin gene. Afterwards, in vitro antifungal susceptibility tests against triazole agents were performed, based on the Clinical and Laboratory Standards Institute (CLSI) M38-A2 document. The CYP51A gene was sequenced in order to detect mutations. The MIC of itraconazole against 10 (6.6 %) strains, including clinical (n=3, 4.2 %) and environmental (n=7, 8.8 %) strains, was higher than the breakpoint and epidemiological cut-off value. Based on the findings, the prevalence of azole-resistant A. fumigatus in Iran has increased remarkablyfrom 3.3 % to 6.6 % in comparison with earlier epidemiological research. Among resistant isolates, TR34/L98H mutations in the CYP51A gene were the most prevalent (n=8, 80 %), whereas other point mutations (F46Y, G54W, Y121F, G138C, M172V, F219C, M220I, D255E, T289F, G432C and G448S mutations) were not detected. Although the number of patients affected by azole-resistant A. fumigatus isolates was limited, strict supervision of clinical azole-resistant A. fumigatus isolates and persistent environmental screening of azole resistance are vital to the development of approaches for the management of azole resistance in human pathogenic fungi.

  16. 黄曲霉的快速分子检测%Rapid Molecular Detection of Aspergillus f lavus

    Institute of Scientific and Technical Information of China (English)

    李本金; 尹容美; 邹雪玉; 王贤达; 陈庆河; 翁启勇

    2013-01-01

    Aspergillus flavus is a ubiquitous fungal pathogen in the worldwide . Early and accurate detection of A . flavus is essential to reduce the damage of Aflatoxins produced by A . flavus . Based on the difference of rDNA ITS sequences among A . flavus and other Aspergillus spp .,a pair of specific primers ,S1/X2 ,was designed in this study . The primer amplified a single 334 bp product from all isolates of A . flavus and that were not from other four Aspergillus species and 17 other fungi and bacteria isolates tested . The detection sensitivity was 280fg of genomic DNA . The PCR-based detection method developed here could also be used to detect A . flavus from naturally infected peanut or corn tissues .%黄曲霉 Aspergillus f lavus 是一种广泛存在的致病真菌,早期准确检测黄曲霉并加以控制是减少黄曲霉毒素产生的有效措施。本研究利用真菌通用引物 ITS1/ITS4扩增黄曲霉转录间隔区并进行克隆测序,通过序列比对,设计1对黄曲霉特异性引物 S1/X2,由此建立的 PCR 检测体系对包括黄曲霉在内的5种曲霉菌及其他17种不同的真菌、细菌基因组 DNA 进行扩增,结果只有不同来源的黄曲霉菌株能扩增出334 bp 的特异性条带,而其余参试菌株均无扩增产物,其检测灵敏度在 DNA 水平上可达到280 fg 。该检测体系能从自然发病的花生或玉米组织中扩增到334 bp 的特异片段,实现对黄曲霉的快速可靠检测。

  17. In vitro cytotoxicity and antimicrobial activity of Talaromyces flavus SP5 inhabited in the marine sediment of Southern Coast of India.

    Science.gov (United States)

    Anand, Bibin G; Thomas, C K Navin; Prakash, S

    2016-12-01

    Marine sediment samples were collected from the coastal areas of Southern India, particularly in Kanyakumari District. Twenty-eight different fungal strains were isolated. The screening of fungi from marine sediment was done to isolate a potent fungus that can produce bioactive compounds for biomedical applications. Only three strains viz Trichoderma gamsii SP4, Talaromyces flavus SP5 and Aspergillus oryzae SP6 were screened for further studies. The intracellular bioactive compounds were extracted using solvent extraction method. The crude extracts were tested for its anti-microbial and anti-cancer properties and analytically characterized using Gas Chromatography Mass Spectrometry (GC-MS). All the three extracts were active, but the extract from T. flavus SP5 was found to be more active against various human pathogens, viz., Pseudomonas aeruginosa ATCC 27853 (17.8 ± 0.1), Escherichia coli ATCC 52922 (18.3 ± 0.3), and Candida tropicalis ATCC 750 (17.7 ± 0.4). It also exhibited cytotoxic activity against HEp2 carcinoma cell line with the LC50 value of 25.7 μg·L(-1). The GC-MS data revealed the presence of effective bioactive compounds. These results revealed that the extract from isolated fungus T. flavus SP5 acted as a potent antimicrobial, antifungal, and anticancer agent, providing basic information on the potency of marine fungi towards biomedical applications; further investigation may lead to the development of novel anticancer drugs.

  18. 甘肃省土壤曲霉属(Aspergillus Mich.ex Link:Fr.)的种%Aspergillus spp. in Soil of Gansu Province

    Institute of Scientific and Technical Information of China (English)

    刘艳梅; 朱建兰

    2005-01-01

    对140份来自甘肃各地的土样进行曲霉属(Aspergillus Mich.ex Link:Fr.)菌的分离,结合菌落形态及显微镜下孢子的形态将各菌鉴定到种.结果表明:甘肃省土壤中分布有7个种和3个变种.分别是烟曲霉原变种(Aspergillus fumigatus var.fumigatus)、烟曲霉椭孢变种(Aspergtllus fumigatus var.ellipticus)、烟束曲霉(Aspergillus fumisynnematus)、黄曲霉原变种(Aspergillus flflavus var.flavus)、寄生曲霉(Aspergillus parasiticus)、刺孢裸胞壳(Emericella echinulata)、构巢裸胞壳(Emericella nidulans var.nidulans)、褶皱裸胞壳(Emericella rugulosa)、四脊裸胞壳(Emericella quadrilineata)及皱折裸胞壳(Emericella corrugata).

  19. What is the importance of classifying Aspergillus disease in cystic fibrosis patients?

    Science.gov (United States)

    Jones, Andrew M; Horsley, Alex; Denning, David W

    2014-08-01

    Aspergillus species are commonly isolated from lower respiratory tract samples of patients with cystic fibrosis (CF) and markers of immunological sensation to Aspergillus are frequently encountered in this group of patients; however, the contribution of Aspergillus to CF lung disease outside of the typical complications of ABPA and aspergilloma formation remains largely unclear. Patients with CF show discretely different responses to Aspergillus, though the underlying reasons for this variation are unknown. Recent work has begun to allow us to categorize patient responses to Aspergillus based upon molecular markers of infection and immune sensitization. Aspergillus sensitization and/or airway infection is associated with worse FEV1, in CF and other patients (asthma, chronic obstructive pulmonary disease, bronchiectasis). Classification of different clinical phenotypes of Aspergillus will enable future studies to determine the natural history of different manifestations of Aspergillus disease and evaluate the effects of intervention with antifungal therapy.

  20. Determination of saccharifying enzyme activity of three Aspergillus oryzae and quality analysis of sweet potato shochu%三种米曲霉糖化酶活及其红薯酒质量指标分析

    Institute of Scientific and Technical Information of China (English)

    郝萍萍; 吴发萍; 张文学; 张楷正; 郑天力; 邹光友

    2012-01-01

    In this paper, the saccharifying power, liquefying power and fermentation activity of rice-koji from three molds Aspergillus flavus QJ, JP and Aspergillus candidus ZZH were measured and analyzed. Koji obtained from them were analyzed, and Aspergillus flavus QJ were finally selected.%该文对由3株曲霉(黄曲霉QJ、黄曲霉JP和白曲霉ZZH)制得的米曲的糖化力、液化力和发酵力等指标进行了测定,并对利用3种米曲制得的红薯酒质量进行了对比分析,综合筛选得出酿造红薯酒的最佳糖化菌种为黄曲霉QJ.

  1. Screening a Strain of Aspergillus niger and Optimization of Fermentation Conditions for Degradation of Aflatoxin B1

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2014-11-01

    Full Text Available Aflatoxin B1, a type of highly toxic mycotoxin produced by some species belonging to the Aspergillus genus, such as Aspergillus flavus and Aspergillus parasiticus, is widely distributed in feed matrices. Here, coumarin was used as the sole carbon source to screen microorganism strains that were isolated from types of feed ingredients. Only one isolate (ND-1 was able to degrade aflatoxin B1 after screening. ND-1 isolate, identified as a strain of Aspergillus niger using phylogenetic analysis on the basis of 18S rDNA, could remove 26.3% of aflatoxin B1 after 48 h of fermentation in nutrient broth (NB. Optimization of fermentation conditions for aflatoxin B1 degradation by selected Aspergillus niger was also performed. These results showed that 58.2% of aflatoxin B1 was degraded after 24 h of culture under the optimal fermentation conditions. The aflatoxin B1 degradation activity of Aspergillus niger supernatant was significantly stronger than cells and cell extracts. Furthermore, effects of temperature, heat treatment, pH, and metal ions on aflatoxin B1 degradation by the supernatant were examined. Results indicated that aflatoxin B1 degradation of Aspergillus niger is enzymatic and this process occurs in the extracellular environment.

  2. [Rabies in Potos flavus identified in Madre de Dios, Peru].

    Science.gov (United States)

    Vargas-Linares, Elena; Romaní-Romaní, Franco; López-Ingunza, Ricardo; Arrasco-Alegre, Juan; Yagui-Moscoso, Martín

    2014-01-01

    The Potos flavus is a nocturnal mammal that lives in neotropical forests from Central America to South America. A study of four cases of rabies in Potos flavus was conducted; these occurred in April 2012 in the Madre de Dios region in Peru and were collected as part of epidemiological surveillance. The analysis performed in the regional reference laboratory of Madre de Dios determined the presence of the rabies virus antigen in three of the brain tissue samples. Results were verified in the Laboratory of Viral Zoonoses of the Peruvian National Institute of Health by direct immunofluorescence. The typification did not identify any of the known variants in bats or dogs. The occurrence of four cases of rabies in Potos flavus adds evidence of the emergence of a new reservoir of the rabies virus previously reported in the same region in 2007.

  3. PRODUCTION OF α-AMYLASE FROM ASPERGILLUS FLAVUS UNDER SOLID STATE FERMENTATION WITH OPTIMUM CONDITIONS

    Directory of Open Access Journals (Sweden)

    Mamatha J

    2012-08-01

    Full Text Available α-amylases are ubiquitous enzymes produced by plants, animals and microbes, where they play a dominant role in carbohydrate metabolism. In spite of the wide distribution of amylases, microbial sources, namely fungal and bacterial amylases, are used for the industrial production due to advantages such as cost effectiveness, consistency, less time and space required for production and ease of process modification and optimization. Filamentous fungi are known to be prolific producers of extracellular proteins; they are widely exploited for the production of different enzymes including a-amylase. SSF is generally defined as the growth of microorganisms on moist solid substrates with negligible free water, which is preferred than SmF because of simple technique, low capital investment, lower levels of catabolite repression, end- product inhibition, low waste water output, better product recovery and high quality production. Different substrates such as wheat bran, mollasses bran, rice bran, maize meal and sugarcane bagasse were used; out of which sugarcane bagasse has been reported to produce promising results. Different carbon and nitrogen supplements were given which increased the yield of the enzyme and optimized the pH as 6.0 and temperature 300C. Thus the maximum production of amylase was observed at optimized conditions, which can be employed in large scale.

  4. Effects of hydrogen peroxide on different toxigenic and atoxigenic isolates of Aspergillus flavus

    Science.gov (United States)

    Drought stress in the field has been shown to exacerbate aflatoxin contamination of maize and peanut. Drought and heat stress also produce reactive oxygen species (ROS) in plant tissues. Given the potential correlation between ROS and exacerbated aflatoxin production under drought and heat stress, t...

  5. Hypersensitivity Pneumonitis in a Housewife Exposed to Aspergillus flavus in Poor Living Conditions: A Case Report

    Science.gov (United States)

    Estibeiro, Anita Sandhya Mendonca; Mesquita, Anthony Menezes

    2016-01-01

    Hypersensitivity Pneumonitis (HP) or Extrinsic Allergic Alveolitis (EAA) is a disease resulting from immunologically induced inflammation in response to inhalation of a wide variety of airborne allergens. The condition develops mainly in non atopic individuals sensitized to organic dust due to repeated exposures. It is a relatively rare disease constituting upto 2% of interstitial lung diseases. Knowledge of classical High Resolution Computed Tomography (HRCT) of lung findings aid in early diagnosis. We report a case of subacute hypersensitivity pneumonitis in a housewife who despite being symptomatic remained undiagnosed for two years. She showed a good response to therapy, but soon relapsed. Visit to her home revealed that she lived in a damp house full of moldy walls. PMID:26894116

  6. Functional analysis and structure determination of alkaline protease from Aspergillus flavus.

    Science.gov (United States)

    Syed, Rabbani; Rani, Roja; Sabeena; Masoodi, Tariq Ahmad; Shafi, Gowher; Alharbi, Khalid

    2012-01-01

    Proteases are one of the highest value commercial enzymes as they have broad applications in food, pharmaceutical, detergent, and dairy industries and serve as vital tools in determination of structure of proteins and polypeptides. Multiple application of these enzymes stimulated interest to discover them with novel properties and considerable advancement of basic research into these enzymes. A broad understanding of the active site of the enzyme and of the mechanism of its inactivation is essential for delineating its structure-function relationship. Primary structure analysis of alkaline protease showed 42% of its content to be alpha helix making it stable for three dimensional structure modeling. Homology model of alkaline protease has been constructed using the X-ray structure (3F7O) as a template and swiss model as the workspace. The model was validated by ProSA, SAVES, PROCHECK, PROSAII and RMSD. The results showed the final refined model is reliable. It has 53% amino acid sequence identity with the template, 0.24 Å as RMSD and has -7.53 as Z-score, the Ramachandran plot analysis showed that conformations for 83.4 % of amino acid residues are within the most favored regions and only 0.4% in the disallowed regions.

  7. Visualization of aflatoxigenic Aspergillus flavus contamination of coconut (Cocos nucifera) nutmeat (Copra) using ammonia treatment

    Science.gov (United States)

    For many crops government regulations define mycotoxin contamination levels that reflect the primary determinants of quality, value and possible uses of crops. Quality can be raised by lowering the mycotoxin level through a remediation process. In the case of copra, the dried nutmeat of the coconu...

  8. Detection of aflatoxigenic aspergillus flavus contamination of coconut (cocos nucifera) nutmeat (copra) using ammonia treatment

    Science.gov (United States)

    For many crops government regulations define mycotoxin contamination levels that represent the primary determinants of quality, value and possible uses of crops. Quality can be raised in some crops by lowering the mycotoxin level through removal of infected products. In the case of copra, the drie...

  9. New Perspectives for the Application of Bioplastic Materials in the Biocontrol of Aspergillus flavus in Corn

    Science.gov (United States)

    Mycotoxins are secondary metabolities produced by certain filamentous fungi that can contaminate a large variety of agricultural commodities before and after harvest. Among different mycotoxins, aflatoxins and especially aflatoxin B1 are of particular concern because they are potent natural carcino...

  10. Toxigenic Potential of Aspergillus Species Occurring on Maize Kernels from Two Agro-Ecological Zones in Kenya

    Directory of Open Access Journals (Sweden)

    Vesa Joutsjoki

    2012-10-01

    Full Text Available Two agro-ecological zones in Kenya were selected to compare the distribution in maize of Aspergillus spp. and their toxigenicity. These were Nandi County, which is the main maize growing region in the country but where no human aflatoxicoses have been reported, and Makueni County where most of the aflatoxicosis cases have occurred. Two hundred and fifty-five households were sampled in Nandi and 258 in Makueni, and Aspergillus was isolated from maize. Aspergillus flavus and A. parasiticus isolates were tested for the presence of aflD and aflQ genes. Positive strains were induced to produce aflatoxins on yeast extract sucrose and quantified using liquid chromatography-tandem mass spectrometry (LCMSMS. Aspergillus flavus was the most common contaminant, and the incidence of occurrence in Nandi and Makueni was not significantly different (82.33% and 73.26%, respectively. Toxigenic strains were more prevalent than non-toxigenic strains. All the toxigenic strains from Makueni were of the S-type while those from Nandi belonged to the l-type. Quantitative differences in aflatoxin production in vitro between isolates and between strains were detected with S strains producing relatively larger amounts of total aflatoxins, B toxins and lower values for G toxins. This was in accord with the frequent aflatoxicosis outbreaks in Makueni. However some L strains produced considerable amounts of B toxins. Given the widespread distribution of toxigenic strains in both regions, the risk of aflatoxin poisoning is high when favorable conditions for toxin production occur.

  11. Toxigenic potential of Aspergillus species occurring on maize kernels from two agro-ecological zones in Kenya.

    Science.gov (United States)

    Okoth, Sheila; Nyongesa, Beatrice; Ayugi, Vincent; Kang'ethe, Erastus; Korhonen, Hannu; Joutsjoki, Vesa

    2012-10-25

    Two agro-ecological zones in Kenya were selected to compare the distribution in maize of Aspergillus spp. and their toxigenicity. These were Nandi County, which is the main maize growing region in the country but where no human aflatoxicoses have been reported, and Makueni County where most of the aflatoxicosis cases have occurred. Two hundred and fifty-five households were sampled in Nandi and 258 in Makueni, and Aspergillus was isolated from maize. Aspergillus flavus and A. parasiticus isolates were tested for the presence of aflD and aflQ genes. Positive strains were induced to produce aflatoxins on yeast extract sucrose and quantified using liquid chromatography-tandem mass spectrometry (LCMSMS). Aspergillus flavus was the most common contaminant, and the incidence of occurrence in Nandi and Makueni was not significantly different (82.33% and 73.26%, respectively). Toxigenic strains were more prevalent than non-toxigenic strains. All the toxigenic strains from Makueni were of the S-type while those from Nandi belonged to the l-type. Quantitative differences in aflatoxin production in vitro between isolates and between strains were detected with S strains producing relatively larger amounts of total aflatoxins, B toxins and lower values for G toxins. This was in accord with the frequent aflatoxicosis outbreaks in Makueni. However some L strains produced considerable amounts of B toxins. Given the widespread distribution of toxigenic strains in both regions, the risk of aflatoxin poisoning is high when favorable conditions for toxin production occur.

  12. Aspergillus Osteomyelitis of the Skull.

    Science.gov (United States)

    Nicholson, Simon; King, Richard; Chumas, Paul; Russell, John; Liddington, Mark

    2016-07-01

    Osteomyelitis of the craniofacial skeleton is rare, with fungal pathogens least commonly implicated. The authors present 2 patients of osteomyelitis of the skull caused by Aspergillus spp. and discuss the diagnosis, clinicopathological course, and management strategies.Late recurrence seen in this type of infection warrants long-term follow-up and a high index of suspicion for the clinical signs associated with recurrence.Such patients would benefit from their surgical debridement being planned and managed via a specialist craniofacial unit, so as to utilize the most aesthetically sensitive approach and the experience of specialists from several surgical disciplines.

  13. Aspergillus PCR: one step closer to standardization.

    NARCIS (Netherlands)

    White, P.L.; Bretagne, S.; Klingspor, L.; Melchers, W.J.G.; McCulloch, E.; Schulz, B.; Finnstrom, N.; Mengoli, C.; Barnes, R.A.; Donnelly, J.P.; Loeffler, J.

    2010-01-01

    PCR has been used as an aid in the diagnosis of invasive aspergillosis for almost 2 decades. A lack of standardization has limited both its acceptance as a diagnostic tool and multicenter clinical evaluations, preventing its inclusion in disease-defining criteria. In 2006, the European Aspergillus P

  14. Research progress on quorum sensing of Aspergilus flavus%黄曲霉群体感应研究进展

    Institute of Scientific and Technical Information of China (English)

    李彩艳; 梁志宏; 黄昆仑

    2015-01-01

    曲霉属真菌(Aspergillus)如黄曲霉、寄生曲霉侵染玉米、花生等富含油脂的作物种子后产生的黄曲霉毒素(aflatoxin)具有强致癌作用,严重威胁食品安全和人类健康。群体感应(quorum sensing, QS)曾经认为只存在于细菌中,但是在真菌中也存在 QS系统,菌体的形态建成和次级代谢产物的产生都与细胞的群体密度有关。黄曲霉拥有类似群体感应的机制,菌核到分生孢子的转换受细胞密度和脂肪氧合酶调控。氧脂素作为信号分子通过密度依赖机制可抑制或促进黄曲霉的生长及黄曲霉毒素的生物合成,本文综述了黄曲霉群体感应及信号通路的研究进展,旨在从群体感应的角度抑制黄曲霉毒素的产生,为微生物与食品安全的研究提供指导。%Aspergillus spp such as A. flavus and A. parasiticus can infect oil-rich crop seeds and subsequently lead to aflatoxin contamination, which has an important impact on economic loss and health risk. Although once thought to exist only in bacteria, QS systems are now well established in fungi. Recently it has been shown that A. flavus possesses a quorum-sensing-like mechanism, where a sclerotia-to-conidia transition is governed by cell density and lipoxygenase activity. Oxylipins can inhibit or stimulate fungal development and aflatoxin production via a density-dependent mechanism as a kind of signal .This paper reviewed the research progress on quorum sensing and signaling pathways of A. flavus and was aimed to inhibit the generation of aflatoxin from the perspective of quorum sensing, providing a guidance for the research of microorganism and food safety.

  15. Aspergillus vertebral osteomyelitis in immunocompetent patients

    Directory of Open Access Journals (Sweden)

    Somika Sethi

    2012-01-01

    Full Text Available Fungal infections are one of the important cause of morbidity and mortality in immunocompromised patients. Aspergillus vertebral osteomyelitis is extremely rare. We report two cases of aspergillus vertebral osteomyelitis in immunocompetent men in the absence of an underlying disorder. The clinical and radiological findings were suggestive of Pott′s spine. The absolute CD4, CD8 counts and their ratio were normal. The HIV status was negative in both patients. Both patients underwent surgical decompression. The histopathology of tissue obtained were suggestive of aspergillus osteomyelitis. One patient had antifungal treatment for 3 months and was doing well at 1 year followup, whereas other patient did not turnup after 2 months.

  16. Diagnosis and treatment of congestive heart failure secondary to hypertrophic cardiomyopathy in a kinkajou (Potos flavus).

    Science.gov (United States)

    Eshar, David; Peddle, Gordon D; Briscoe, Jeleen A

    2010-06-01

    An adult castrated male pet kinkajou (Potos flavus) presented with dyspnea due to congestive heart failure and was diagnosed with hypertrophic cardiomyopathy (HCM) and suspected pulmonary arterial hypertension. Diagnosis was based on history, clinical signs, clinical pathology, radiographs, abdominal ultrasonography, abdominal fluid analysis, electrocardiography, and echocardiogram. An undetermined hepatopathy also was found at presentation and resolved after metronidazole antimicrobial treatment. Cardiopulmonary medical treatment, including a loop diuretic, an angiotensin-converting enzyme inhibitor, a beta-adrenergic receptor blocker, and a bronchodilator provided improvement of the clinical signs. To the best of our knowledge, this is the first reported case of antemortem diagnosis and treatment of congestive heart failure and cardiomyopathy in a member of the family Procyonidae, suggesting that HCM should be considered as a differential diagnosis in kinkajous displaying clinical signs of dyspnea and exercise intolerance.

  17. LAMP-PCR detection of ochratoxigenic Aspergillus species collected from peanut kernel.

    Science.gov (United States)

    Al-Sheikh, H M

    2015-01-30

    Over the last decade, ochratoxin A (OTA) has been widely described and is ubiquitous in several agricultural products. Ochratoxins represent the second-most important mycotoxin group after aflatoxins. A total of 34 samples were surveyed from 3 locations, including Mecca, Madina, and Riyadh, Saudi Arabia, during 2012. Fungal contamination frequency was determined for surface-sterilized peanut seeds, which were seeded onto malt extract agar media. Aspergillus niger (35%), Aspergillus ochraceus (30%), and Aspergillus carbonarius (25%) were the most frequently observed Aspergillius species, while Aspergillus flavus and Aspergillus phoenicis isolates were only infrequently recovered and in small numbers (10%). OTA production was evaluated on yeast extract sucrose medium, which revealed that 57% of the isolates were A. niger and 60% of A. carbonarius isolates were OTA producers; 100% belonged to A. ochraceus. Only one isolate, morphologically identified as A. carbonarius, and 3 A. niger isolates unstably produced OTA. A polymerase chain reaction (PCR)-based identification and detection assay was used to identify A. ochraceus isolates. Using the primer sets OCRA1/OCRA2, 400-base pair PCR fragments were produced only when genomic DNA from A. ochraceus isolates was used. Recently, the loop-mediated isothermal amplification assay using recombinase polymerase amplification chemistry was used for A. carbonarius and A. niger DNA identification. As a non-gel-based technique, the amplification product was directly visualized in the reaction tube after adding calcein for naked-eye examination.

  18. Influence of volatile constituents of fruit peels of Citrus reticulata Blanco on clinically isolated pathogenic microorganisms under In-vitro

    Institute of Scientific and Technical Information of China (English)

    Husain Shahnaz Sultana; Mohammed Ali; Bibhu Prasad Panda

    2012-01-01

    Objective: To investigate the antimicrobial activity of volatile constituents of fruit peels of Citrus reticulata Blanco on clinically isolated pathogenic microorganisms. Methods: Extraction of volatile oil was carried out by Clevenger’s apparatus. Volatile chemical components were measured by GC-MS. Antimicrobial activity was carried by Agar well diffusion assay with reference to standard fluconazole and tetracycline. Results: The chemical composition of volatile oil of the fruit peels of Citrus reticulata Blanco (Rutaceae) of Delhi Region was composed mainly monoterpenes (99.1 %) constituting l-limonene (92.4 %), γ-terpene (2.6 %) andβ-phellandrene (1.8 %). The volatile oil showed antibacterial and antifungal activities against the clinically isolated pathogenic microbial strains Escherichia coli, Staphylococcus aureus, Aspergillus flavus, Aspergillus niger, Aspergillus fumigatus and Candida albicans under in vitro condition. Conclusions: The potential antimicrobial activity of volatile oil present in fruit peels of C. reticulata can be useful for treatment of skin disorder and/or in aroma. Therapy, it can be incorporated into cosmetic formulations.

  19. A preliminary study on the occurrence of Aspergillus spp. and aflatoxin B1 in imported wheat and barley in Penang, Malaysia.

    Science.gov (United States)

    Reddy, K R N; Salleh, Baharuddin

    2010-11-01

    Thirty samples consisting of wheat (15) and barley (15) were collected from different markets in Penang, Malaysia, originating from India and Thailand, respectively. All samples were analyzed for occurrence of Aspergillus spp. and aflatoxin B1 (AFB1). Aspergillus flavus was dominant in all samples followed by A. niger. AFB1 could be detected in three wheat samples ranging from 0.42 to 1.89 μg/kg and one barley sample had 0.58 μg/kg of AFB1. The AFB1 levels in all the samples were below the Malaysian regulatory limits (Penang, Malaysia.

  20. Defective phagocyte Aspergillus killing associated with recurrent pulmonary Aspergillus infections.

    Science.gov (United States)

    Fietta, A; Sacchi, F; Mangiarotti, P; Manara, G; Gialdroni Grassi, G

    1984-01-01

    An apparently healthy boy was suffering from recurrent Aspergillus infections. No classical conditions of immunodeficiency were found. Studies on the patient's phagocytic system revealed neutrophils and monocytes to function normally except in Aspergillus killing (microbicidal activity for bacteria and Candida was normal). Aspergillus killing mechanisms may be complex and peculiarly selective, possibly involving both oxygen-dependent and independent mechanisms.

  1. 重症患者气道分泌物曲霉培养阳性的临床意义%The clinical significance of Aspergillus isolation from airway samples in critically ill patients

    Institute of Scientific and Technical Information of China (English)

    石岩; 刘宏忠; 王小亭; 刘晔; 芮曦; 汤铂; 柴文昭; 赵华

    2009-01-01

    患者合并严重疾病状态时,气道分泌物曲霉阳性对预测感染有较高的价值.%Objective To analyze the risk factors and clinical significance of Aspergillus isolaton from airway samples of critically ill patients. Methods The study was conducted in an ICU between January 2007 and December 2007. The data of patients receiving mechanical ventilation with suspected invasive pulmonary fungal infection were analyzed. Tracheal aspirates were collected and cultured 3 times weekly. The cases were classified into groups of Aspergillus spp, Candida spp, and non-fungns spp according to the microbiological results. Isolation of Aspergillus spp. was subgrouped to proved-IPA (invasive pulmonary aspergillosis) , probable-IPA or colonization. The risk factors for airway isolation of Aspergillus and infection were assessed. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) for Windows (version 12.0) and quantitative variables were expressed as mean ± standard deviation. The Student' s t-test or the Mann-Whitney U-test was used for the comparison of categorical and normally distributed and nonnormally distributed variables, respectively. The x2 test or the Fisher's exact test was used in the comparison of categorical variables. Logistic regression analysis was conducted to evaluate risk factors for the isolation of Aspergillus spp. Results The study population included 160 patients (82 men) with amean age of (64.5±17.2) years. Aspergillus spp was isolated in 45,Candida spp in 63, and non-fungus spp in 52. The ICU mortality in the 3 groups was 48.9% (22/45 cases) ,23.8% (15/63 cases), 7.7% (4/52 cases), respectively. The ICU mortality in patients with Aspergillus spp. isolation was higher than those with Candida spp and non-fungus spp. In 28 patients isolation of Aspergillus spp. was interpreted as invasive aspergillosis(2 patients were proven, 26 patients were probable). The predictive value of isolating Aspergillus

  2. Aspergillus in the lung: diverse and coincident forms

    Energy Technology Data Exchange (ETDEWEB)

    Buckingham, Susan J.; Hansell, David M. [Department of Radiology, Royal Brompton Hospital, Sydney Street, London SW3 6NP (United Kingdom)

    2003-08-01

    Pulmonary disease caused by the fungus Aspergillus has traditionally been regarded as belonging to one of the following, apparently distinct, entities: saprophytic aspergilloma; allergic bronchopulmonary aspergillosis (ABPA); and invasive aspergillosis (IPA); which may be further categorised as angioinvasive, acute or chronic airway invasive [1]. It is not always obvious that there is overlap between these entities, and that in any given patient more than one Aspergillus-related pathological process can co-exist [2]. The aim of this article is to review the clinical and imaging features of the main categories of Aspergillus-related pulmonary disease and, in particular, to highlight the overlap between them. (orig.)

  3. Antifungal susceptibility profile of cryptic species of Aspergillus.

    Science.gov (United States)

    Alastruey-Izquierdo, Ana; Alcazar-Fuoli, Laura; Cuenca-Estrella, Manuel

    2014-12-01

    The use of molecular tools has led to the description of new cryptic species among different Aspergillus species complexes. Their frequency in the clinical setting has been reported to be between 10 and 15%. The susceptibility to azoles and amphotericin B of many of these species is low, and some of them, such as Aspergillus calidoustus or Aspergillus lentulus, are considered multi-resistant. The changing epidemiology, the frequency of cryptic species, and the different susceptibility profiles make antifungal susceptibility testing an important tool to identify the optimal antifungal agent to treat the infections caused by these species.

  4. Antifungal activity of Oleoresins used in meat industry on some toxigenic Aspergillus spp.

    Directory of Open Access Journals (Sweden)

    Šošo Vladislava M.

    2013-01-01

    Full Text Available Different spice oleoresins are widely used in meat industry. They contribute to the specific aroma and flavor of the end products, but they have also been reported to have strong antimicrobial activity. These properties open a plenty of possibilities to be used for defining the specific sensory profile of the product but also as natural food preservatives. This paper focuses on the antifungal activity of four oleoresins against different foodborne toxigenic Aspergillus species. Oleoresins used in the experiments were cayenne pepper, black pepper, garlic and rosemary oleoresins, and they were tested against following Aspergillus species: A. clavatus, A. flavus, A. fumigatus, A. niger, A. ochraceus and A. versicolor. Antifungal activity was tested using microtitre-plate-based assay incorporating resazurin as an indicator of cell growth and broth microdilution-method. [Projekat Ministarstva nauke Republike Srbije, br. III46009

  5. Biodegradation of HDPE by Aspergillus spp. from marine ecosystem of Gulf of Mannar, India.

    Science.gov (United States)

    Sangeetha Devi, Rajendran; Rajesh Kannan, Velu; Nivas, Duraisamy; Kannan, Kanthaiah; Chandru, Sekar; Robert Antony, Arokiaswamy

    2015-07-15

    High density polyethylene (HDPE) is the most commonly found non-degradable solid waste among the polyethylene. In this present study, HDPE degrading various fungal strains were isolated from the polyethylene waste dumped marine coastal area and screened under in vitro condition. Based on weight loss and FT-IR Spectrophotometric analysis, two fungal strains designated as VRKPT1 and VRKPT2 were found to be efficient in HDPE degradation. Through the sequence analysis of ITS region homology, the isolated fungi were identified as Aspergillus tubingensis VRKPT1 and Aspergillus flavus VRKPT2. The biofilm formation observed under epifluorescent microscope had shown the viability of fungal strains even after one month of incubation. The biodegradation of HDPE film nature was further investigated through SEM analysis. HDPE poses severe environmental threats and hence the ability of fungal isolates was proved to utilize virgin polyethylene as the carbon source without any pre-treatment and pro-oxidant additives.

  6. Biocidal synthetic coatings based on high-molecular metaloorganic compounds. [Aspergillus flavus; Aspergillus niger; Aspergillus terreus; Penicillium funiculosum; penicillium cyclopium; Penicillium chrysogenum; Paecilomyces varioti; Chaetomium globosum; trichoderma viride

    Energy Technology Data Exchange (ETDEWEB)

    Mishchenko, V.F.; Zubov, V.A.; Eremenko, Yu.G.

    Long-term stays of man and animals in closed life-support systems lead to contamination of the space-craft by various microorganisms. Organotin compounds are considered promising biocidal agents for paints and varnishes with a broad spectrum of action against a variety of microorganisms. Several organotin polymers of the acrylate type were prepared and were found to be effective fungicides.

  7. (+)-Geodin from Aspergillus terreus

    DEFF Research Database (Denmark)

    Rønnest, Mads Holger; Nielsen, Morten Thrane; Leber, Blanka

    2011-01-01

    The fungal metabolite (+)-geodin [systematic name: (2R)-methyl 5,7-dichloro-4-hydroxy-6'-methoxy-6-methyl-3,4'-dioxospiro[benzofuran-2,1'-cyclohexa-2',5'-diene]-2'-carboxylate], C(17)H(12)Cl(2)O(7), was isolated from Aspergillus terreus. The crystal structure contains two independent molecules...

  8. Isolation of culturable mycobiota from agricultural soils and determination of tolerance to glyphosate of nontoxigenic Aspergillus section Flavi strains.

    Science.gov (United States)

    Carranza, Cecilia S; Barberis, Carla L; Chiacchiera, Stella M; Dalcero, Ana María; Magnoli, Carina E

    2016-01-01

    Glyphosate-based herbicides are extensively used in Argentina's agricultural system to control undesirable weeds. This study was conducted to evaluate the culturable mycobiota [colony forming units (CFU) g(-1) and frequency of fungal genera or species] from an agricultural field exposed to pesticides. In addition, we evaluated the tolerance of A. oryzae and nontoxigenic A. flavus strains to high concentrations (100 to 500 mM - 17,000 to 84,500 ppm) of a glyphosate commercial formulation. The analysis of the mycobiota showed that the frequency of the main fungal genera varied according to the analyzed sampling period. Aspergillus spp. or Aspergillus section Flavi strains were isolated from 20 to 100% of the soil samples. Sterilia spp. were also observed throughout the sampling (50 to 100%). Aspergillus section Flavi tolerance assays showed that all of the tested strains were able to develop at the highest glyphosate concentration tested regardless of the water availability conditions. In general, significant reductions in growth rates were observed with increasing concentrations of the herbicide. However, a complete inhibition of fungal growth was not observed with the concentrations assayed. This study contributes to the knowledge of culturable mycobiota from agricultural soils exposed to pesticides and provides evidence on the effective growth ability of A. oryzae and nontoxigenic A. flavus strains exposed to high glyphosate concentrations in vitro.

  9. Anti-Aspergillus activities of plant essential oils and their combination effects with ketoconazole or amphotericin B.

    Science.gov (United States)

    Shin, Seungwon

    2003-05-01

    The essential oils from Cedrus atlantica, Styrax tonkinensis, Juniperus communis, Lavandula angustifolia, Melaleuca alternifolia, Pelargonium graveolens, Pogesternon patchouli and Rosmarinus officinalis were analyzed by GC-MS. Antifungal activities of the oils were investigated by disk diffusion assay and the broth dilution method against Aspergillus niger and A. flavus. The effects of geraniol and the essential oil fraction from P. graveolens on the antifungal activity of amphotericin B and ketoconazole were examined using a checkerboard microtiter assay against both Aspergillus fungi. Most of the tested essential oils, with the exception of C. atlantica, J. communis, and P. patchouli, significantly inhibited growth of A. niger and to a lesser extent that of A. flavus, with MICs (minimal inhibitory concentrations) in the range 0.78-12.5 mg/mL. The essential oil fraction of P. graveolens and its main components, geraniol and citronellol, exhibited additive effects with amphotericin B and with ketoconazole against both Aspergillus species, resulting in fractional inhibitory concentration (FIC) indices ranging from 0.52 to 1.00.

  10. Radiosensitivity of toxigenic Aspergillus isolated from spices and destruction of aflatoxins by gamma-irradiation

    Science.gov (United States)

    Kume, Tamikazu; Ito, Hitoshi; Soedarman, Harsono; Ishigaki, Isao

    Radiosensitivities of Aspergillus flavus var columnaris isolated from spices were investigated. The D10 values and induction doses were 267-293 Gy and 75-165 Gy in wet conditions, respectively. In dry conditions, the survival curves were exponential and D10 values were 538-600 Gy. The survival curves of standard strain of A. parasiticus IFO 30179 were similar both in wet and dry conditions. The necessary dose of 8 kGy for the destruction of these toxigenic Aspergillus was calculated from these values. Two of 11 strains of A. flavus var columnaris produced aflatoxins and the content of B 1 was especially high. In the study of irradiation effect on aflatoxins produced on polished rice, aflatoxins G 1 and B 1 were more radiosensitive than G 2 and B 2. However, these aflatoxins were very stable to radiation and the dose required for destruction was found to be more than 500 kGy. It is therfore concluded that the decontamination of molds by irradiation is necessary prior to their production of aflatoxins.

  11. Fumigant antifungal activity of Myrtaceae essential oils and constituents from Leptospermum petersonii against three Aspergillus species.

    Science.gov (United States)

    Kim, Eunae; Park, Il-Kwon

    2012-09-03

    Commercial plant essential oils obtained from 11 Myrtaceae plant species were tested for their fumigant antifungal activity against Aspergillus ochraceus, A. flavus, and A. niger. Essential oils extracted from Leptospermum petersonii at air concentrations of 56 × 10(-3) mg/mL and 28 × 10(-3) mg/mL completely inhibited the growth of the three Aspergillus species. However, at an air concentration of 14 × 10(-3) mg/mL, inhibition rates of L. petersonii essential oils were reduced to 20.2% and 18.8% in the case of A. flavus and A. niger, respectively. The other Myrtaceae essential oils (56 × 10(-3) mg/mL) only weakly inhibited the fungi or had no detectable affect. Gas chromatography-mass spectrometry analysis identified 16 compounds in L. petersonii essential oil. The antifungal activity of the identified compounds was tested individually by using standard or synthesized compounds. Of these, neral and geranial inhibited growth by 100%, at an air concentration of 56 × 10(-3) mg/mL, whereas the activity of citronellol was somewhat lover (80%). The other compounds exhibited only moderate or weak antifungal activity. The antifungal activities of blends of constituents identified in L. petersonii oil indicated that neral and geranial were the major contributors to the fumigant and antifungal activities.

  12. Radiosensitivity of toxigenic Aspergillus isolated from spices and destruction of aflatoxins by gamma-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kume, Tamikazu; Ito, Hitoshi; Ishigaki, Isao (Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment); Soedarman, Harsono (National Atomic Energy Agency, Jakarta (Indonesia). Centre for the Application of Isotopes and Radiation)

    1989-01-01

    Radiosensitivities of Aspergillus flavus var columnaris isolated from spices were investigated. The D{sub 10} values and induction doses were 267-293 Gy and 75-165 Gy in wet conditions, respectively. In dry conditions, the survival curves were exponential and D{sub 10} values were 538-600 Gy. The survival curves of standard strain of A. parasiticus IFO 30179 were similar both in wet and dry conditions. The necessary dose of 8 kGy for the destruction of these toxigenic Aspergillus was calculated from these values. Two of 11 strains of A. flavus var columnaris produced aflatoxins and the content of B{sub 1} was especially high. In the study of irradiation effect on aflatoxins produced on polished rice, aflatoxins G{sub 1} and B{sub 1} were more radiosensitive than G{sub 2} and B{sub 2}. However, these aflatoxins were very stable to radiation and the dose required for destruction was found to be more than 500 kGy. It is therefore concluded that the decontamination of molds by irradiation is necessary prior to their production of aflatoxins.

  13. Chemical composition and antifungal activity of Hyptis suaveolens (L. poit leaves essential oil against Aspergillus species

    Directory of Open Access Journals (Sweden)

    Ana Carolina Pessoa Moreira

    2010-03-01

    Full Text Available This study aimed to identify the constituents of the essential oil from Hyptis suaveolens (L. leaves using a Gas Chromatograph -Mass Spectrometer and assess its inhibitory effect on some potentially pathogenic Aspergilli (A. flavus, A. parasiticus, A. ochraceus, A. fumigatus and A. niger. Eucaliptol (47.64 % was the most abundant component in the oil, followed for gama-ellemene (8.15 %, beta-pynene (6.55 %, (+3-carene (5.16 %, trans-beta-cariophyllene (4.69 % and germacrene (4.86 %. The essential oil revealed an interesting anti-Aspergillus property characterized by a Minimum Inhibitory Concentration and Minimum Fungicidal Concentration of 40 and 80 µL/mL, respectively. The oil at 80 and 40 µL/mL strongly inhibited the mycelial growth of A. fumigatus and A. parasiticus along 14 days. In addition, at 10 and 20 µL/mL the oil was able to cause morphological changes in A. flavus as decreased conidiation, leakage of cytoplasm, loss of pigmentation and disrupted cell structure suggesting fungal wall degeneration. These findings showed the interesting anti-Aspergillus property of H. suaveolens leaves essential oil supporting its possible rational use as alternative source of new antifungal compounds to be applied in the aspergillosis treatment.

  14. Effect of Carum copticum essential oil on growth and aflatoxin formation by Aspergillus strains.

    Science.gov (United States)

    Kazemi, M

    2015-01-01

    The objectives of this study were to determine the antiaflatoxin B1 activity in vitro of the essential oil (EO) extracted from the seeds of Carum copticum and to evaluate its antifungal activity in vivo as a potential food preservative. The C. copticum EO exhibited noticeable inhibition on dry mycelium and synthesis of aflatoxin B1 (AFB1) by Aspergillus flavus, completely inhibiting AFB1 production at 4 μL/mL. C. copticum EOs showed the lowest percentages of decayed cherry tomatoes for all fungi compared with the control at 100 μL/mL with values of 5.01 ± 67% for A. flavus and 5.98 ± 54% for Aspergillus niger. The results indicated that the percentage of infected fruits is significantly (p oil at 100 μL/mL concentration showed the highest inhibition of fungal infection with a value of 80.45% compared with the control. Thus, the EO of dill could be used to control food spoilage and as a potential source of food preservative.

  15. Aspergillus Galactomannan Enzyme-Linked Immunosorbent Assay Cross-Reactivity Caused by Invasive Geotrichum capitatum

    Science.gov (United States)

    Giacchino, Mareva; Chiapello, Nadia; Bezzio, Stefania; Fagioli, Franca; Saracco, Paola; Alfarano, Alda; Martini, Vincenza; Cimino, Giuseppe; Martino, Pietro; Girmenia, Corrado

    2006-01-01

    We report three cases of invasive Geotrichum capitatum infection in patients with acute leukemia for which an enzyme-linked immunosorbent assay (ELISA) for Aspergillus galactomannan was positive, with no evidence of aspergillosis. Supernatants obtained from suspensions of 17 G. capitatum strains gave positive reactions with the Aspergillus galactomannan ELISA. These clinical and laboratory data seem to suggest that G. capitatum produces a soluble antigen that is cross-reactive with Aspergillus galactomannan. PMID:16954294

  16. Contaminação endógena por Aspergillus spp. em milho pós-colheita no Estado do Paraná

    Directory of Open Access Journals (Sweden)

    FARIAS ANTONIO XAVIER DE

    2000-01-01

    Full Text Available Sessenta amostras de milho pós-colheita foram avaliadas quanto à contaminação fúngica endógena e o potencial toxígeno de espécies do gênero Aspergillus e seus teleomorfos. Quarenta grãos aparentemente sadios de cada amostra foram desinfestados em NaClO e incubados em câmara úmida a 25±1ºC para exteriorização dos fungos, que posteriormente foram isolados em ágar Czapek-Dox. Foram identificadas as espécies Aspergillus flavus, A. parasiticus, Eurotium amstelodami e E. chevalieri. O potencial toxígeno dos fungos A. flavus e A. parasiticus foi avaliado quanto à síntese de aflatoxinas em meio ágar-coco. Espécies do gênero Eurotium foram avaliadas quanto à síntese de esterigmatocistina, nos meios ágar-amendoim e trigo triturado. A porcentagem de grãos contaminados variou entre 0 e 100%, prevalecendo os gêneros Aspergillus, Penicillium e Fusarium. A espécie predominante foi a A. flavus (64%, seguida por E. amstelodami (19%, E. chevalieri (10% e A. parasiticus (7%. A partir de 109 isolados de A. flavus, evidenciou-se que 73 isolados sintetizaram aflatoxinas B1 e B2, 20 sintetizaram B1, sete sintetizaram B1 e G1, três sintetizaram B1, B2 e G1 e em seis não foi detectada a síntese de aflatoxina. A síntese de esterigmatocistina pelas espécies E. amstelodami e E. chevalieri não foi detectada.

  17. Multicenter study of isavuconazole MIC distributions and epidemiological cutoff values for Aspergillus spp. for the CLSI M38-A2 broth microdilution method.

    Science.gov (United States)

    Espinel-Ingroff, A; Chowdhary, A; Gonzalez, G M; Lass-Flörl, C; Martin-Mazuelos, E; Meis, J; Peláez, T; Pfaller, M A; Turnidge, J

    2013-08-01

    Epidemiological cutoff values (ECVs) were established for the new triazole isavuconazole and Aspergillus species wild-type (WT) MIC distributions (organisms in a species-drug combination with no detectable acquired resistance mechanisms) that were defined with 855 Aspergillus fumigatus, 444 A. flavus, 106 A. nidulans, 207 A. niger, 384 A. terreus, and 75 A. versicolor species complex isolates; 22 Aspergillus section Usti isolates were also included. CLSI broth microdilution MIC data gathered in Europe, India, Mexico, and the United States were aggregated to statistically define ECVs. ECVs were 1 μg/ml for the A. fumigatus species complex, 1 μg/ml for the A. flavus species complex, 0.25 μg/ml for the A. nidulans species complex, 4 μg/ml for the A. niger species complex, 1 μg/ml for the A. terreus species complex, and 1 μg/ml for the A. versicolor species complex; due to the small number of isolates, an ECV was not proposed for Aspergillus section Usti. These ECVs may aid in detecting non-WT isolates with reduced susceptibility to isavuconazole due to cyp51A (an A. fumigatus species complex resistance mechanism among the triazoles) or other mutations.

  18. EUCAST和CLSI微量稀释法检测曲霉体外药物敏感试验差异比较%Comparison of susceptibility testing by EUCAST and CLSI broth microdilution methods against Aspergillus isolates

    Institute of Scientific and Technical Information of China (English)

    张明; 陈菲; 孙文逵; 吴婷; 颜文杰; 苏欣; 施毅

    2014-01-01

    目的:比较欧洲抗菌药物敏感试验委员会(European Committee on Antimicrobial Susceptibility Testing,EUCAST)和美国临床实验室标准化协会(Clinical and Laboratory Standards Institute,CLSI)微量稀释法检测曲霉体外药物敏感性的差异。方法分别用EUCAST方法和CLSI方法检测116株曲霉对两性霉素B、伏立康唑、伊曲康唑、卡泊芬净和米卡芬净的敏感性,比较两种方法的基本符合率、药敏符合率、极重大误差率和重大误差率。结果 EUCAST方法和CLSI方法对116株曲霉药敏检测的基本符合率为96.3%~100%。两方法检测烟曲霉对伏立康唑的药敏符合率98.8%,重大误差为1.2%,极重大误差率为0。烟曲霉和黑曲霉对两性霉素B以及烟曲霉和黄曲霉对伊曲康唑的药敏符合率均为100%,重大误差率和极重大误差率均为0。结论 EUCAST方法和CLSI方法对检测曲霉体外药物敏感性具有良好的一致性。%Objective To compare the results of susceptibility testing by European Committee on Antimicrobial Susceptibility Testing (EUCAST)and Clinical and Laboratory Standards Institute (CLSI)broth microdilution methods against Aspergillus isolates.Methods The susceptibilities of 116 Aspergillus isolates were determined for amphotericin B, voriconazole, itraconazole,caspofungin and micafungin according to EUCAST (E.DEF 9.1 )and CLSI (M38-A2)methods.The essential agreement (EA),categorical agreement (CA),very major errors (VME)and major errors (ME)of the two methods were compared.Results The EA was 96.3%-100% between the two methods.The CA ,ME,and VME were 98.8%,0-1.2% and 0 respectively for the susceptibility of Aspergillus fumigatus to voriconazole.The CA,ME and VME was 1 00%,0 and 0 respectively for the susceptibility of Aspergillus fumigatus and Aspergillus niger to amphotericin B,or the susceptibility of Aspergillus fumigatus and Aspergillus flavus to itraconazole.Conclusions The results

  19. Chemodiversity in the genus Aspergillus.

    Science.gov (United States)

    Frisvad, Jens C; Larsen, Thomas O

    2015-10-01

    Isolates of Aspergillus species are able to produce a large number of secondary metabolites. The profiles of biosynthetic families of secondary metabolites are species specific, whereas individual secondary metabolite families can occur in other species, even those phylogenetically and ecologically unrelated to Aspergillus. Furthermore, there is a high degree of chemo-consistency from isolate to isolate in a species even though certain metabolite gene clusters are silenced in some isolates. Genome sequencing projects have shown that the diversity of secondary metabolites is much larger in each species than previously thought. The potential of finding even further new bioactive drug candidates in Aspergillus is evident, despite the fact that many secondary metabolites have already been structure elucidated and chemotaxonomic studies have shown that many new secondary metabolites have yet to be characterized. The genus Aspergillus is cladistically holophyletic but phenotypically polythetic and very diverse and is associated to quite different sexual states. Following the one fungus one name system, the genus Aspergillus is restricted to a holophyletic clade that include the morphologically different genera Aspergillus, Dichotomomyces, Phialosimplex, Polypaecilum and Cristaspora. Secondary metabolites common between the subgenera and sections of Aspergillus are surprisingly few, but many metabolites are common to a majority of species within the sections. We call small molecule extrolites in the same biosynthetic family isoextrolites. However, it appears that secondary metabolites from one Aspergillus section have analogous metabolites in other sections (here also called heteroisoextrolites). In this review, we give a genus-wide overview of secondary metabolite production in Aspergillus species. Extrolites appear to have evolved because of ecological challenges rather than being inherited from ancestral species, at least when comparing the species in the different

  20. Radiosensitivity of A. ochraceus, A. flavus, A. niger, A. parasiticus and A. carbonarius in CYA medium and on grains of rice, oat, wheat and peanuts

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Valeria Barbosa [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Faculdade de Veterinaria. Dept. de Tecnologia de Alimentos]. E-mail: niveam@uol.com.br; Vital, Helio de Carvalho; Hernandes, Nilber Kenup [Centro Tecnologico do Exercito, Rio de Janeiro, RJ (Brazil). Div. de Defesa Quimica, Biologica e Nuclear]. E-mail: vital@ctex.eb.br; Rosa, Carlos Alberto da Rocha [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Inst. de Veterinaria. Dept. de Microbiologia e Imunologia Veterinaria]. E-mail: shalako@ufrrj.br

    2007-07-01

    Irradiation is regarded as an efficient process to delay fungi growth in foods. However information on the resistance of toxigenic molds to gamma radiation is still scarce in the literature. This work investigated the radiosensitivity of five species of Aspergillus spp., namely: A. ochraceus, A. flavus, A. niger, A. parasiticus and A. carbonarius grown and irradiated in CYA medium, peanuts and on grains of rice, oat and wheat. After inoculation the colonies were stored for five days at 25 deg C and gamma irradiated with doses ranging from 0 to 5.5 kGy. Six days later the colonies were analyzed for post-irradiation growth. Survival curves were then determined as linear functions of the absorbed doses. Regardless of the substrates, the radiosensitivities of the five species have been grouped in three different levels. Expressed in terms of the parameters D{sub 50} and Do (the doses needed to reduce the number of active colonies by 50% and 100%, respectively), those groups are: D{sub 50} = 2.2 kGy and D0 = 3.2 kGy for A. ochraceus and A. carbonarius; D{sub 50} = 2.5 kGy and D0 = 4.1 kGy for A. niger and A. flavus; and D{sub 50} = 3.1 kGy and D0 = 4.7 kGy for A. parasiticus. (author)

  1. The effect of humidity after gamma-irradiation on aflatoxin B-1 production of A.flavus in ground nutmeg and peanut

    Energy Technology Data Exchange (ETDEWEB)

    Hilmy, N.; Chosdu, R. [Center for the Application of Isotopes and Radiation, Jakarta (Indonesia); Matsuyama, A. [Tokyo University of Agriculture (Japan). Nodai Research Inst.

    1995-10-01

    The effect of humidity of 75 up to 97% after irradiation on radiosensitivity and aflatoxin B1 production of Aspergillus flavus isolated from Indonesian nutmeg were examined. Irradiation doses used were 0;0.5;1 and 3 kGy. Mould free ground nutmeg and peanut were used as the growth media, and about 10{sup 8} of spores were used to contaminate each of the media. Aflatoxin productions were measured after having incubated 3 days up to 5 months under humidity of 91 and 97%. Prior to HPLC analysis, aflatoxin was cleaned-up using an immunoaffinity column. The results were: (1) A. flavus indicated no or almost no growth under RH of 85% or less. (2) Under 91-97% RH, growth of mycelium and toxin production were inhibited more or less by irradiation up to 1 kGy, although the effectiveness of irradiation varied with different RH and media during postirradiation incubation. (3) By 3 kGy or more, both mycelium growth and toxin production of the mould were found to be completely inhibited. (4) The production of aflatoxin in nutmeg began after having incubated for 25 and 45 days and in peanut for 3 and 6 days under 97 and 91% RH, respectively. (Author).

  2. Effect of essential oils on Aspergillus spore germination, growth and mycotoxin production:a potential source of botanical food preservative

    Institute of Scientific and Technical Information of China (English)

    Negero Gemeda; Yimtubezinash Woldeamanuel; Daniel Asrat; Asfaw Debella

    2014-01-01

    Objective: To investigate effect of essential oils on Aspergillus spore germination, growth and mycotoxin production.Method: In vitro antifungal and antiaflatoxigenic activity of essential oils was carried out using poisoned food techniques, spore germination assay, agar dilution assay, and aflatoxin arresting assay on toxigenic strains of Aspergillus species.Results: Cymbopogon martinii, Foeniculum vulgare and Trachyspermum ammi (T. ammi) essential oils were tested against toxicogenic isolates of Aspergillus species. T. ammi oil showed highest antifungal activity. Absolute mycelial inhibition was recorded at 1 µl/mL by essential oils of T. ammi. The oil also showed, complete inhibition of spore germination at a concentration of 2 µl/mL. In addition, T. ammi oil showed significant antiaflatoxigenic potency by totally inhibiting aflatoxin production from Aspergillus niger and Aspergillus flavus at 0.5 and 0.75 µl/mL, respectively. Cymbopogon martinii, Foeniculum vulgare and T. ammi oils as antifungal were found superior over synthetic preservative. Moreover, a concentration of 5 336.297 µl/kg body weight was recorded for LC50 on mice indicating the low mammalian toxicity and strengthening its traditional reputations.Conclusions:In conclusion, the essential oils from T. ammi can be a potential source of safe natural food preservative for food commodities contamination by storage fungi.

  3. The potential inhibitory effect of cuminum cyminum, ziziphora clinopodioides and nigella sativa essential oils on the growth of Aspergillus fumigatus and Aspergillus.

    Science.gov (United States)

    Khosravi, A R; Minooeianhaghighi, M H; Shokri, H; Emami, S A; S M, Alavi; Asili, J

    2011-01-01

    The goals of this study were to evaluate the effectiveness of Cuminum cyminum, Ziziphora clinopodioides and Nigella sativa essential oils to inhibit the growth of Aspergillus fumigatus and A. flavus and to evoke ultrastructural changes. The fungi were cultured into RPMI 1640 media in the presence of oils at concentrations of 8, 6, 5, 4, 3, 2, 1.5, 1.25, 1, 0.75 and 0.5 mg/ml in broth microdilution and 2, 1.5, 1 and 0.5 mg/ml in broth macrodilution methods with shaking for 48 h at 28(o)C. Conidial and mycelial samples exposed to 0.25, 0.5, 1, 1.5 and 2 mg essential oils/ml for 5 days in 2% yeast extract granulated plus 15% Saccharose media were processed for transmission electron microscopy (TEM). Based on broth dilution methods, C. cyminum and to a lesser extent Z. clinopodioides oils exhibited the strongest activity against A. fumigatus and A. flavus with MIC90 ranging from 0.25 to 1.5 mg/ml, while the oil from N. sativa exhibited relatively moderate activity against two above fungi with MIC90 ranging from 1.5 to 2 mg/ml. The main changes observed by TEM were in the cell wall, plasma membrane and membranous organelles; in particular, in the nuclei and mitochondria. These modifications in fungal structure were associated with the interference of the essential oils with the enzymes responsible for cell wall synthesis, which disturbed normal growth. Moreover, the essential oils caused high vacuolation of the cytoplasm, detachment of fibrillar layer of cell wall, plasma membrane disruption and disorganization of the nuclear and mitochondrial structures. Aspergillus fumigatus and A. flavus growth inhibition induced by these oils were found to be well-correlated with subsequent morphological changes of the fungi exposed to different fungistatic concentrations of the oils. Our results show the anti-Aspergillus activities of C. cyminum, Z. clinopodioides and N. sativa essential oils, which strengthens the potential use of these substances as anti-mould in the future.

  4. Development of a Nested-PCR detection for Bspergillus flavus Based on Aflatoxins Gene aflP%基于毒素编码基因aflp的黄曲霉菌nested-PCR检测

    Institute of Scientific and Technical Information of China (English)

    刘裴清; 蔡茂强; 李本金; 陈庆河; 翁启勇

    2015-01-01

    黄曲霉Aspergillusflavus 产生的黄曲霉毒素是一类毒性极强的物质,严重威胁到人类健康和经济发展,因此建立一套快速、准确、灵敏的黄曲霉检测方法就显得极为迫切。通过以aflP (GenBank:FN398191)为分子靶标,比较黄曲霉菌近缘种aflp的基因序列,以特异性序列为靶标设计2对PCR引物aflP-1-F/aflP-1-R和aflP-2-F/aflP-1-R,由此建立的PCR检测体系对7种黄曲霉菌、5种其他的曲霉菌、21种其他真菌 cDNA 进行扩增,结果只有在7种黄曲霉菌株中扩增出211 bp 的特异性条带,而其余参试菌株均无扩增产物。巢式PCR能使其检测灵敏度达到10 fg,检测灵敏度提高100倍。该检测体系能从人工接种和自然发病的花生和玉米样品中扩增到211 bp的特异片段,实现对黄曲霉菌的快速可靠检测。%Aspergillus flavus is a devastating pathogen for human health and economic development,for the aflatoxins produced by A. flavus has strong toxicity for humans and animals. Therefore,to establish a rapid, accurate and sensitivity detection system for A. flavus,we developed a nested polymerase chain reaction (PCR) based on the aflP (GenBank:FN398191 )gene. In the present study,aflP was used as a molecular target, alignment of the aflP region sequences with other sequences belonging to Aspergillus species closely related to A. flavus and other fungi was used to identify conserved and differing regions,and then two pairs of PCR primers (aflP-1-F/aflP-1-R and aflP-2-F/aflP-1-R)were developed. For specificity testing,DNA extracted from 7 A. flavus,5 different Aspergillus spp. and 21 other fungi were used,and our results showed that a 211bp of specific band can be amplified only in aflatoxins produced A. flavus strains. A nested PCR procedure using aflP-1-F/aflP-1-R as the first-round primers and the followed using aflP-2-F/aflP-1-R increased the detection sensitivity 100- fold to 10 fg. Furthermore,the afl

  5. A trispecies Aspergillus microarray: Comparative transcriptomics of three Aspergillus species

    DEFF Research Database (Denmark)

    Andersen, Mikael Rørdam; Vongsangnak, Wanwipa; Panagiotou, Gianni

    2008-01-01

    The full-genome sequencing of the filamentous fungi Aspergillus nidulans, Aspergillus niger, and Aspergillus oryzae has opened possibilities for studying the cellular physiology of these fungi on a systemic level. As a tool to explore this, we are making available an Affymetrix GeneChip developed...... data identified 23 genes to be a conserved response across Aspergillus sp., including the xylose transcriptional activator XlnR. A promoter analysis of the up-regulated genes in all three species indicates the conserved XInR-binding site to be 5'-GGNTAAA-3'. The composition of the conserved gene......-set suggests that xylose acts as a molecule, indicating the presence of complex carbohydrates such as hemicellulose, and triggers an array of degrading enzymes. With this case example, we present a validated tool for transcriptome analysis of three Aspergillus species and a methodology for conducting cross...

  6. 含有额外拷贝黄曲霉cyp51同源基因的烟曲霉对抗真菌药物的敏感性测定%Antifungal susceptibility of the A.fumigatus transformants containing extra copies of A.flavus cyp51 gene homologues to the common antifungal drugs

    Institute of Scientific and Technical Information of China (English)

    刘伟霞; 孙毅; 万喆; 李若瑜; 刘伟

    2011-01-01

    Objective To investigate the effect of Aspergillus flavus cyp51 genes on antifungal susceptibility by cloning and constucting the extra copies of Aspergillus flavus cyp51 genes. Methods A.flavus cyp5l gene homologues were identified by tblastn searches inA. flavus genome database. PCR fragments composed of the 5'flanking sequence (approximately 1 000 bp) ofcyp51 ,cyp51 ORF, and its 3'flanking sequence (approximately 1 000 bp), were subcloned into shuttle plasmid pRG3-AMAl-NotI to produce recombinant plasmids. These plasmids and empty plasmid pRG3-AMA1-Notl were transformed into A.fumigatus strain AF293.1 (pyrG-) respectively to produce transformants. The Clinical Laboratory Standard Institute broth microdilution method M38-A2 and E-test method were used to assay the minimal inhibitory concentrations (MICs) of itraconazole ( ITC), voriconazole ( VRC), amphotericin B (AMB), and posaconazole (POS), or minimal effect concentration (MEC) of caspofungin (CAS), against these transformants. Results A. flavus genome contains three cyp51 gene homologues, cyp51A ,cyp51B and cyp51 C, of which the ORF size are 1 400-2 000 bp. When these genes were subcloned into shuttle plasmid pRG3-AMA1-NotI, we get plasmids pRG3-AMA1-CYP51 A, pRG3-AMA1-CYP51B and pRG3-AMA1-CYP51C. These plasmids and empty plasmid were transformed into A.fumigatus strain AF293.1 (pyrG-) to produce transformants rCYP51A, rCYP51B, rCYP51C and rpRG. The antifungal susceptibility of these A.fumigatus transformants to the antifungal drugs by broth microdilution assaying and E-test method showed that, rCYP51A and rCYP51B were cross-resistant to VRC and ITC, susceptible to both AM B and CAS; rCYP51C and rpRG were intermediate to ITC and VRC, susceptible to both A MB and CAS. Conclusion In A. fumigatus , extra copies of A.flavus ' cyp51A gene or cyp51B gene have effect on antifungal susceptibility to azoles, have no effect on AMB and CAS. Extra copy ofcyp51C has no obvious effect on all the tested drugs.%目的

  7. The potential of Origanum vulgare L. (Lamiaceae essential oil in inhibiting the growth of some food-related Aspergillus species Potencial do óleo essencial de Origanum vulgare L. (Lamiaceae em inibir o crescimento de algumas cepas de Aspergillus de interesse em alimentos

    Directory of Open Access Journals (Sweden)

    Egberto Santos Carmo

    2008-06-01

    Full Text Available Origanum vulgare L. (Lamiaceae has been currently known for their interesting antimicrobial activity being regarded as alternative antimicrobial for use is food conservation systems. This study aimed to evaluate the effectiveness of O. vulgare essential oil in inhibiting the growth of some food-related Aspergillus species (A. flavus, A. parasiticus, A. terreus, A. ochraceus, A. fumigatus and A. niger. The essential oil revealed a strong anti-Aspergillus property providing an inhibition of all assayed mould strains. MIC values were between 80 and 20 µL/mL being found a MIC50 of 40 µL/mL. The essential oil at concentration of 80 and 40 µL/mL provided a fungicidal effect on A. flavus, A. fumigatus and A. niger noted by a total inhibition of the radial mycelial growth along 14 days of interaction. In addition, the essential oil was able to inhibit the mould spores germination when assayed at concentrations of 80 and 40 µL/mL. Our results showed the interesting anti-Aspergillus activity of O. vulgare essential oil supporting their possible use as anti-mould compound in food conservation.Origanum vulgare L. (Lamiaceae tem sido atualmente reconhecido por sua intensa atividade antimicrobiana sendo considerado como fonte de compostos antimicrobianos alternativos para uso em sistemas de conservação de alimentos. Este estudo objetivou avaliar a efetividade do óleo essencial de O. vulgare em inibir o crescimento de algumas espécies de Aspergillus (A. flavus, A. parasiticus, A. terreus and A. fumigatus de interesse em alimentos. O óleo essencial revelou uma forte atividade atni-Aspergillus provocando a inibição de todas as cepas fúngicas ensaiadas. Os valores de MIC estiveram entre 80 e 20 µL/mL sendo encontrado uma MIC50 de 40 µL/mL. O óleo essencial nas concentrações de 80 e 40 µL/mL causou um efeito fungicida sobre A. flavus, A. fumigatus e A. niger notado por uma total inibição do crescimento micelial radial ao longo de 14 dias de

  8. In vitro activity of a new oral glucan synthase inhibitor (MK-3118) tested against Aspergillus spp. by CLSI and EUCAST broth microdilution methods.

    Science.gov (United States)

    Pfaller, Michael A; Messer, Shawn A; Motyl, Mary R; Jones, Ronald N; Castanheira, Mariana

    2013-02-01

    MK-3118, a glucan synthase inhibitor derived from enfumafungin, and comparator agents were tested against 71 Aspergillus spp., including itraconazole-resistant strains (MIC, ≥ 4 μg/ml), using CLSI and EUCAST reference broth microdilution methods. The CLSI 90% minimum effective concentration (MEC(90))/MIC(90) values (μg/ml) for MK-3118, amphotericin B, and caspofungin, respectively, were as follows: 0.12, 2, and 0.03 for Aspergillus flavus species complex (SC); 0.25, 2, and 0.06 for Aspergillus fumigatus SC; 0.12, 2, and 0.06 for Aspergillus terreus SC; and 0.06, 1, and 0.03 for Aspergillus niger SC. Essential agreement between the values found by CLSI and EUCAST (± 2 log(2) dilution steps) was 94.3%. MK-3118 was determined to be a potent agent regardless of the in vitro method applied, with excellent activity against contemporary wild-type and itraconazole-resistant strains of Aspergillus spp.

  9. Expression Profiling of Non-Aflatoxigenic Aspergillus parasiticus Mutants Obtained by 5-Azacytosine Treatment or Serial Mycelial Transfer

    Directory of Open Access Journals (Sweden)

    Jiujiang Yu

    2011-08-01

    Full Text Available Aflatoxins are carcinogenic secondary metabolites produced by the fungi Aspergillus flavus and Aspergillus parasiticus. Previous studies found that repeated serial mycelial transfer or treatment of A. parasiticus with 5-azacytidine produced colonies with a fluffy phenotype and inability to produce aflatoxins. To understand how these treatments affect expression of genes involved in aflatoxin production and development, we carried out expressed sequence tag (EST-based microarray assays to identify genes in treated clones that are differentially expressed compared to the wild-type. Expression of 183 genes was significantly dysregulated. Of these, 38 had at least two-fold or lower expression compared to the untreated control and only two had two-fold or higher expression. The most frequent change was downregulation of genes predicted to encode membrane-bound proteins. Based on this result we hypothesize that the treatments cause changes in the structure of cellular and organelle membranes that prevent normal development and aflatoxin biosynthesis.

  10. Coinfection by Aspergillus and Zygomycetes Species in a Case of Acute Rhinosinusitis

    Directory of Open Access Journals (Sweden)

    Dhara Vaidya

    2011-01-01

    Full Text Available Invasive mycotic infections can be effectively treated if rapid identification of fungus is obtained. We reported a case of coinfection by Aspergillus and Rhizopus sp. involving nose, paranasal sinuses, orbit, and brain in a 68-year-old known hypertensive male. He was presented to ENT OPD with history of fever and intermittent headache since fifteen days along with history of right-sided nasal obstruction and proptosis since seven days. CT scan of brain and paranasal sinuses showed findings of pansinusitis with cellulitic changes in right orbit. MRI confirmed the same along with features of intracranial extension with focal meningitis in right frontotemporal region. Laboratory parameters did not conclude much except for leucocytosis and hyponatremia. Patient was taken for endoscopic debridement from nose and paranasal sinuses, and tissue was sent for microbiological and histopathological examination. Minced tissue was processed, and after 48 hrs of incubation two types of growth were identified, one was yellowish, granular, and powdery consistent with Aspergillus sp., and another was cottony and woolly consistent with Rhizopus sp. LCB mount confirmed presence of Aspergillus flavus and Rhizopus arrhizus. Patient responded to therapy with IV amphotericin B and surgical debridement. On discharge patient's condition was good.

  11. Aspergillus saccharolyticus sp. nov., a new black Aspergillus species isolated in Denmark

    DEFF Research Database (Denmark)

    Sørensen, Annette; Lübeck, Peter S.; Lübeck, Mette

    2011-01-01

    A novel species, Aspergillus saccharolyticus sp. nov., belonging to the Aspergillus section Nigri group is described. This species was isolated in Denmark from treated hardwood. Its taxonomic status was determined using a polyphasic taxonomic approach including phenotypic (morphology and extrolite...... Aspergillus species that is morphologically similar to Aspergillus japonicus and Aspergillus aculeatus, but has a totally different extrolite profile compared to any known Aspergillus species. The type strain of A. saccharolyticus sp. nov. is CBS 127449T ( = IBT 28509T)....

  12. Clinical Identification of Common Species of Dermatophytes by PCR and PCR-RFLP

    Institute of Scientific and Technical Information of China (English)

    丁娟; 李家文; 刘志香; 谭志建

    2004-01-01

    To find a fast and efficient way of identifying seven common dermatophytes in clinical practice, we used the techniques of polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (RFLP) targeting Topoisomerase Ⅱ gene. The DNA of 7 dermatophytes, along with Candida albicans, Aspergillus terreus and Aspergillus flavus were amplified by consensus primer dPsD1. They were then subjected to a second PCR with primers dPsD2 and species-specific primers PsT and PsME separately. 6 of the products generated by dPsD2 were digested with restriction enzyme Hinc Ⅱ. DNA fragments of 3390 bp and 2380 bp was amplified by using consensus primer dPsD1 and dPsD2 from the genomic DNA of each dermatophyte species separately. By combining the results of the two species-specific primer sets (PsT and PsME), all species of dermatophyte yielded unique sizes-set of PCR products expect for T. mentagrophytes and T. tonsurans.From the restriction profiles of Hinc Ⅱ , 6 of the 7 dermatophytoses were diagnosed to species level including T. mentagrophytes and T. tonsurans. By combining the results of the PCR and PCRRFLP, the 7 common dermatophytes can be identified to species level. It is conclude that the multiplex PCR and PCR-RFLP identification targeting the DNA topoisomerase Ⅱ gene is rapid and efficient.

  13. Aspergillus fumigatus invasion increases with progressive airway ischemia.

    Directory of Open Access Journals (Sweden)

    Joe L Hsu

    Full Text Available Despite the prevalence of Aspergillus-related disease in immune suppressed lung transplant patients, little is known of the host-pathogen interaction. Because of the mould's angiotropic nature and because of its capacity to thrive in hypoxic conditions, we hypothesized that the degree of Aspergillus invasion would increase with progressive rejection-mediated ischemia of the allograft. To study this relationship, we utilized a novel orthotopic tracheal transplant model of Aspergillus infection, in which it was possible to assess the effects of tissue hypoxia and ischemia on airway infectivity. Laser Doppler flowmetry and FITC-lectin were used to determine blood perfusion, and a fiber optic microsensor was used to measure airway tissue oxygen tension. Fungal burden and depth of invasion were graded using histopathology. We demonstrated a high efficacy (80% for producing a localized fungal tracheal infection with the majority of infection occurring at the donor-recipient anastomosis; Aspergillus was more invasive in allogeneic compared to syngeneic groups. During the study period, the overall kinetics of both non-infected and infected allografts was similar, demonstrating a progressive loss of perfusion and oxygenation, which reached a nadir by days 10-12 post-transplantation. The extent of Aspergillus invasion directly correlated with the degree of graft hypoxia and ischemia. Compared to the midtrachea, the donor-recipient anastomotic site exhibited lower perfusion and more invasive disease; a finding consistent with clinical experience. For the first time, we identify ischemia as a putative risk factor for Aspergillus invasion. Therapeutic approaches focused on preserving vascular health may play an important role in limiting Aspergillus infections.

  14. Disinfection efficacy of chlorine and peracetic acid alone or in combination against Aspergillus spp. and Candida albicans in drinking water.

    Science.gov (United States)

    Sisti, Maurizio; Brandi, Giorgio; De Santi, Mauro; Rinaldi, Laura; Schiavano, Giuditta F

    2012-03-01

    The aim of the present study was to evaluate the fungicidal activity of chlorine and peracetic acid in drinking water against various pathogenic Aspergillus spp. and Candida albicans strains. A. nidulans exhibited the greatest resistance, requiring 10 ppm of chlorine for 30 min contact time for a complete inactivation. Under the same experimental conditions, peracetic acid was even less fungicidal. In this case, A. niger proved to be the most resistant species (50 ppm for 60 min for complete inactivation). All Aspergillus spp. were insensitive to 10 ppm even with extended exposure (>5 h). The combination of chlorine and peracetic acid against Aspergillus spp. did not show synergistic effects except in the case of A. flavus. Complete growth inhibition of C. albicans was observed after about 3 h contact time with 0.2 ppm. C. albicans was less sensitive to peracetic acid. Hence the concentrations of chlorine that are usually present in drinking water distribution systems are ineffective against several Aspergillus spp. and peracetic acid cannot be considered an alternative to chlorine for disinfecting drinking water. The combination of the two biocides is not very effective in eliminating filamentous fungi at the concentrations permitted for drinking water disinfection.

  15. Aspergillus fumigatus in Poultry

    Directory of Open Access Journals (Sweden)

    Pascal Arné

    2011-01-01

    Full Text Available Aspergillus fumigatus remains a major respiratory pathogen in birds. In poultry, infection by A. fumigatus may induce significant economic losses particularly in turkey production. A. fumigatus develops and sporulates easily in poor quality bedding or contaminated feedstuffs in indoor farm environments. Inadequate ventilation and dusty conditions increase the risk of bird exposure to aerosolized spores. Acute cases are seen in young animals following inhalation of spores, causing high morbidity and mortality. The chronic form affects older birds and looks more sporadic. The respiratory tract is the primary site of A. fumigatus development leading to severe respiratory distress and associated granulomatous airsacculitis and pneumonia. Treatments for infected poultry are nonexistent; therefore, prevention is the only way to protect poultry. Development of avian models of aspergillosis may improve our understanding of its pathogenesis, which remains poorly understood.

  16. Aspergillus antigen skin test (image)

    Science.gov (United States)

    ... After 48 to 72 hours the site of injection is evaluated by a physician. If a positive reaction occurs (the test site is inflamed), the person has been exposed to the aspergillus mold and is at risk for developing aspergillosis.

  17. Calcineurin-dependent galactomannan release in Aspergillus fumigatus

    NARCIS (Netherlands)

    Mennink-Kersten, M.A.S.H.; Ruegebrink, D.; Verweij, P.E.; Steinbach, W.J.

    2011-01-01

    The galactomannan assay to diagnose invasive aspergillosis is recommended and clinically utilized, yet the mechanism of galactomannan release from Aspergillus fumigatus is unknown. We used an A. fumigatus strain lacking calcineurin A (cnaA), already shown to be critically important for pathogenicity

  18. Validation of a new Aspergillus real-time PCR assay for direct detection of Aspergillus and azole resistance of Aspergillus fumigatus on bronchoalveolar lavage fluid.

    Science.gov (United States)

    Chong, Ga-Lai M; van de Sande, Wendy W J; Dingemans, Gijs J H; Gaajetaan, Giel R; Vonk, Alieke G; Hayette, Marie-Pierre; van Tegelen, Dennis W E; Simons, Guus F M; Rijnders, Bart J A

    2015-03-01

    Azole resistance in Aspergillus fumigatus is increasingly reported. Here, we describe the validation of the AsperGenius, a new multiplex real-time PCR assay consisting of two multiplex real-time PCRs, one that identifies the clinically relevant Aspergillus species, and one that detects the TR34, L98H, T289A, and Y121F mutations in CYP51A and differentiates susceptible from resistant A. fumigatus strains. The diagnostic performance of the AsperGenius assay was tested on 37 bronchoalveolar lavage (BAL) fluid samples from hematology patients and 40 BAL fluid samples from intensive care unit (ICU) patients using a BAL fluid galactomannan level of ≥1.0 or positive culture as the gold standard for detecting the presence of Aspergillus. In the hematology and ICU groups combined, there were 22 BAL fluid samples from patients with invasive aspergillosis (IA) (2 proven, 9 probable, and 11 nonclassifiable). Nineteen of the 22 BAL fluid samples were positive, according to the gold standard. The optimal cycle threshold value for the presence of Aspergillus was Aspergillus species and 14 A. fumigatus samples). This resulted in a sensitivity, specificity, and positive and negative predictive values of 88.9%, 89.3%, 72.7%, and 96.2%, respectively, for the hematology group and 80.0%, 93.3%, 80.0%, and 93.3%, respectively, in the ICU group. The CYP51A real-time PCR confirmed 12 wild-type and 2 resistant strains (1 TR34-L98H and 1 TR46-Y121F-T289A mutant). Voriconazole therapy failed for both patients. The AsperGenius multiplex real-time PCR assay allows for sensitive and fast detection of Aspergillus species directly from BAL fluid samples. More importantly, this assay detects and differentiates wild-type from resistant strains, even if BAL fluid cultures remain negative.

  19. Single Strand Conformation Polymorphism analysis of PCR-amplified rDNA to differentiate medically important Aspergillus Species

    Directory of Open Access Journals (Sweden)

    K Diba

    2008-09-01

    Full Text Available "nBackground: Aspergillus species are associated with allergic bronchopulmonary disease, mycotic keratitis, otomycosis, na­sal sinusitis and invasive infection. In this study, we developed a PCR-Single Strand Confomational Polymorphism method to identify the most common Aspergillus species and we showed some advantages of this method comparing a PCR-Restric­tion Fragment Length Polymorphism with our designed restriction enzyme. "nMethods: We selected ITS2, as a short fragment within the rDNA region (length size: 330 bp to be amplified as small size PCR product. We mixed 5 ml of the PCR product with an equal volume of loading buffer and followed by incubation for 5 min at 95º C and quenching in an ice bath. The mixture was applied to a 6%-12% Gradient Poly acryl amide gel to run in a verti­cal electrophoresis, then gel was stained with ethidium bromide and silver nitrate which followed by an ethidium bro­mide staining. "nResults: Our results of restriction digestion showed a fine identification of 7 tested Aspergillus species dur­ing 5-6 hours af­ter an overnight mycelial growth. As our results some of tested Aspergillus species: A. nidulans, A. fisheri, A. quad­ricincta, (A. fumigatus and A. niger as a group and (A. flavus, A. tereus and A. ochraceus as another group, can be dis­criminated. More­over SSCP analysis enabled us to identify above Aspergillus species within 8-12 h after an over night growth without us­ing an expensive restriction enzyme."nConclusion: It is concluded that Single Strand Conformational Polymorphism is a simple and rapid method for identifica­tion of some medically important Aspergillus.

  20. Modulation of antimicrobial metabolites production by the fungus Aspergillus parasiticus

    Directory of Open Access Journals (Sweden)

    Adriana A.P. Bracarense

    2014-01-01

    Full Text Available Biosynthesis of active secondary metabolites by fungi occurs as a specific response to the different growing environments. Changes in this environment alter the chemical and biological profiles leading to metabolites diversification and consequently to novel pharmacological applications. In this work, it was studied the influence of three parameters (fermentation length, medium composition and aeration in the biosyntheses of antimicrobial metabolites by the fungus Aspergillus parasiticus in 10 distinct fermentation periods. Metabolism modulation in two culturing media, CYA and YES was evaluated by a 2² full factorial planning (ANOVA and on a 2³ factorial planning, role of aeration, medium composition and carbohydrate concentration were also evaluated. In overall, 120 different extracts were prepared, their HPLC profiles were obtained and the antimicrobial activity against A. flavus, C. albicans, E. coli and S. aureus of all extracts was evaluated by microdilution bioassay. Yield of kojic acid, a fine chemical produced by the fungus A. parasiticus was determined in all extracts. Statistical analyses pointed thirteen conditions able to modulate the production of bioactive metabolites by A. parasiticus. Effect of carbon source in metabolites diversification was significant as shown by the changes in the HPLC profiles of the extracts. Most of the extracts presented inhibition rates higher than that of kojic acid as for the extract obtained after 6 days of fermentation in YES medium under stirring. Kojic acid was not the only metabolite responsible for the activity since some highly active extracts showed to possess low amounts of this compound, as determined by HPLC.

  1. The evolutionary imprint of domestication on genome variation and function of the filamentous fungus Aspergillus oryzae.

    Science.gov (United States)

    Gibbons, John G; Salichos, Leonidas; Slot, Jason C; Rinker, David C; McGary, Kriston L; King, Jonas G; Klich, Maren A; Tabb, David L; McDonald, W Hayes; Rokas, Antonis

    2012-08-01

    The domestication of animals, plants, and microbes fundamentally transformed the lifestyle and demography of the human species [1]. Although the genetic and functional underpinnings of animal and plant domestication are well understood, little is known about microbe domestication [2-6]. Here, we systematically examined genome-wide sequence and functional variation between the domesticated fungus Aspergillus oryzae, whose saccharification abilities humans have harnessed for thousands of years to produce sake, soy sauce, and miso from starch-rich grains, and its wild relative A. flavus, a potentially toxigenic plant and animal pathogen [7]. We discovered dramatic changes in the sequence variation and abundance profiles of genes and wholesale primary and secondary metabolic pathways between domesticated and wild relative isolates during growth on rice. Our data suggest that, through selection by humans, an atoxigenic lineage of A. flavus gradually evolved into a "cell factory" for enzymes and metabolites involved in the saccharification process. These results suggest that whereas animal and plant domestication was largely driven by Neolithic "genetic tinkering" of developmental pathways, microbe domestication was driven by extensive remodeling of metabolism.

  2. In vitro synergistic efficacy of combination of amphotericin B with Myrtus communis essential oil against clinical isolates of Candida albicans.

    Science.gov (United States)

    Mahboubi, M; Ghazian Bidgoli, F

    2010-08-01

    In this study, we evaluated the antifungal activity of the essential oil from Myrtus communis (myrtle) leaves against Candida albicans (eight clinical isolates and one ATCC type strains) and different species of Aspergillus sp (A. niger, A. parasiticus, six isolates of Aspergillus flavus) using broth micro dilution assay. In addition, we evaluated the synergistic effect between the essential oil and the antifungal compound amphotericin B by checkboard micro titer assay. The essential oil was obtained from myrtle leaves by hydrodistillation method and the oil was analyzed by GC and GC-MS methods. Chemical analysis of oil revealed the presence of 70 components, representing 99.23% of the total oil. 1,8-cineole (36.1%), alpha-pinene (22.5%), linalool (8.4%), bornyl acetate (5.2%), alpha-terpineol (4.4%), linalyl acetate (4.2%) and limonene (3.8%) were found to be the major components of the oil. The antifungal evaluating showed that myrtle oil exhibited good antifungal activity against fungi. Myrtle oil showed significant antifungal activity when combined with amphotericin B.

  3. Larval morphology of Metaphycus flavus and its role in host attachment and larval cannibalism.

    Science.gov (United States)

    Tena, A; Kapranas, A; Walker, G P; Garcia-Marí, F; Luck, R F

    2011-06-01

    Metaphycus flavus (Howard) (Hymenoptera: Encyrtidae) is a facultatively gregarious endoparasitoid of soft scales (Hemiptera: Coccidae). When it develops in superparasitised hosts, the larvae often attack and consume brood mates six or more days post oviposition. Under our laboratory conditions (25±1°C and 14 hours of light followed by 18±1°C and ten hours of darkness in 50-70% R.H.), M. flavus eggs hatched three days after oviposition. Measurements of the mandibles and tentorium indicate there are four larval instars, and M. flavus reaches the fourth instar by day six post oviposition, and pupates on day eight. Thus, cannibalism among M. flavus larvae occurs during the fourth instar. During this instar, M. flavus larvae separate from their attachment to the scale cuticle, to which they were tethered by a respiratory structure during the previous three larval instars. Once detached, they are free to move within the scale, which increases the probability of larval encounters and aggressive behaviours. Moreover, the mandibles of the fourth instar are better adapted for fighting than are those of the first three larval instars, since they are larger and more sclerotized. The cranium and mouthparts of M. flavus have four different types of sensory organs, some of which are almost certainly olfactory, an unexpected function for a larva that presumably is surrounded by an aqueous medium where gustatory sensilla would seem to be more appropriate. The cranium also bears two pairs of what appear to be secretory pores.

  4. Occurrence of Aspergillus spp. and aflatoxin B1 in Malaysian foods used for human consumption.

    Science.gov (United States)

    Reddy, Kasa R N; Farhana, Nazira I; Salleh, Baharuddin

    2011-05-01

    Malaysian population widely consumes the cereal-based foods, oilseeds, nuts, and spices in their daily diet. Mycotoxigenic fungi are well known to invade food products under storage conditions and produce mycotoxins that have threat to human and animal health. Therefore, determining toxigenic fungi and aflatoxin B(1) (AFB1) in foods used for human consumption is of prime importance to develop suitable management strategies and to minimize risk. Ninety-five food products marketed in Penang, Malaysia were randomly collected from different supermarkets and were analyzed for presence of Aspergillus spp. by agar plate assay and AFB1 by enzyme-linked immunosorbent assay (ELISA). A. flavus was the dominant fungi in all foods followed by A. niger. Fifty-five A. flavus strains were tested for their ability to produce aflatoxins on rice grain substrate. Thirty-six (65.4%) strains out of 55 produced AFB1 ranging from 1700 to 4400 μg/kg and 17 strains (31%) produced AFB2 ranging from 620 to 1670 μg/kg. Natural occurrence of AFB1 could be detected in 72.6% food products ranging from 0.54 to 15.33 μg/kg with a mean of 1.95 μg/kg. Maximum AFB1 levels were detected in peanut products ranging from 1.47 to 15.33 μg/kg. AFB1 levels detected in all food products were below the Malaysian permissible limits (<35 μg/kg). Aspergillus spp. and AFB1 was not detected in any cookies tested. Although this survey was not comprehensive, it provides valuable information on aflatoxin levels in foods marketed in Malaysia.

  5. Isolation and identification of Aspergillus spp. from brown kiwi (Apteryx mantelli) nocturnal houses in New Zealand.

    Science.gov (United States)

    Glare, Travis R; Gartrell, Brett D; Brookes, Jenny J; Perrott, John K

    2014-03-01

    Aspergillosis, a disease caused by infection with Aspergillus spp., is a common cause of death in birds globally and is an irregular cause of mortality of captive kiwi (Apteryx spp.). Aspergillus spp. are often present in rotting plant material, including the litter and nesting material used for kiwi in captivity. The aim of this study was to survey nocturnal kiwi houses in New Zealand to assess the levels of Aspergillus currently present in leaf litter. Samples were received from 11 nocturnal kiwi houses from throughout New Zealand, with one site supplying multiple samples over time. Aspergillus was isolated and quantified by colony counts from litter samples using selective media and incubation temperatures. Isolates were identified to the species level by amplification and sequencing of ITS regions of the ribosomal. Aspergillus spp. were recovered from almost every sample; however, the levels in most kiwi houses were below 1000 colony-forming units (CFU)/g of wet material. The predominant species was Aspergillus fumigatus, with rare occurrences of Aspergillus niger, Aspergillus nidulans, and Aspergillus parasiticus. Only one site had no detectable Aspergillus. The limit of detection was around 50 CFU/g wet material. One site was repeatedly sampled as it had a high loading of A. fumigatus at the start of the survey and had two recent clinical cases of aspergillosis diagnosed in resident kiwi. Environmental loading at this site with Aspergillus spp. reduced but was not eliminated despite changes of the litter. The key finding of our study is that the background levels of Aspergillus spores in kiwi nocturnal houses in New Zealand are low, but occasional exceptions occur and are associated with the onset of aspergillosis in otherwise healthy birds. The predominant Aspergillus species present in the leaf litter was A. fumigatus, but other species were also present. Further research is needed to confirm the optimal management of leaf litter to minimize Aspergillus

  6. Potential roles of secondary metabolite production in environmental oxidative stress responses revealed in the Aspergillus flavus transcriptome

    Science.gov (United States)

    The contamination of agricultural crops with aflatoxins is exacerbated in the dry and hot season worldwide, and poses a serious food security concern, particularly in developing countries. Drought stress results in the accumulation of reactive oxygen species (ROS) in the tissues of plants. Previousl...

  7. Inhibitory effect of the essential oil of Curcuma longa L. and curcumin on aflatoxin production by Aspergillus flavus Link.

    Science.gov (United States)

    Ferreira, Flavio Dias; Kemmelmeier, Carlos; Arrotéia, Carla Cristina; da Costa, Christiane Luciana; Mallmann, Carlos Augusto; Janeiro, Vanderly; Ferreira, Francine Maery Dias; Mossini, Simone Aparecida Galerani; Silva, Expedito Leite; Machinski, Miguel

    2013-01-15

    Aflatoxins are highly toxic, mutagenic, teratogenic and carcinogenic mycotoxins. Consumption of aflatoxin-contaminated food and commodities poses serious hazards to the health of humans and animals. Turmeric, Curcuma longa L., is a native plant of Southeast Asia and has antimicrobial, antioxidant and antifungal properties. This paper reports the antiaflatoxigenic activities of the essential oil of C. longa and curcumin. The medium tests were prepared with the oil of C. longa, and the curcumin standard at concentrations varied from 0.01% to 5.0%. All doses of the essential oil of the plant and the curcumin standard interfered with mycotoxin production. Both the essential oil and curcumin significantly inhibited the production of aflatoxins; the 0.5% level had a greater than 96% inhibitory effect. The levels of aflatoxin B(1) (AFB(1)) production were 1.0 and 42.7 μg/mL, respectively, for the samples treated with the essential oil of C. longa L. and curcumin at a concentration of 0.5%.

  8. 77 FR 14287 - Aspergillus flavus AF36; Amendment to an Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2012-03-09

    ... practice on cotton in Arizona, California, and Texas without any reports of adverse dermal irritation or... strains, which are already present in the environment. Pistachio is grown in an arid environment, which... various levels of government or between ] the Federal Government and Indian tribes. Thus, EPA...

  9. The Aspergillus Mine - publishing bioinformatics

    DEFF Research Database (Denmark)

    Vesth, Tammi Camilla; Rasmussen, Jane Lind Nybo; Theobald, Sebastian

    so with no computational specialist. Here we present a setup for analysis and publication of genome data of 70 species of Aspergillus fungi. The platform is based on R, Python and uses the RShiny framework to create interactive web‐applications. It allows all participants to create interactive...... analysis which can be shared with the team and in connection with publications. We present analysis for investigation of genetic diversity, secondary and primary metabolism and general data overview. The platform, the Aspergillus Mine, is a collection of analysis tools based on data from collaboration...... with the Joint Genome Institute. The Aspergillus Mine is not intended as a genomic data sharing service but instead focuses on creating an environment where the results of bioinformatic analysis is made available for inspection. The data and code is public upon request and figures can be obtained directly from...

  10. Effect of Essential Oils of Syzygium aromaticum and Melaleuca alternifolia on Isolates of Aspergillus sp.

    Directory of Open Access Journals (Sweden)

    A. Lima

    2014-03-01

    Full Text Available Essential  oils  have  antimicrobial  substances,  lower  cost  and  the  lower  resistance  of microorganism. This study aimed to evaluate the inhibition of mycelial growth of Aspergillus flavus and  A.  niger  with  essential  oils  of  Syzygium  aromaticum  and  Melaleuca  alternifolia.  For  this, aliquots  (0.5,  5,  10  and  15μL  of  essential  oils  from  S.  aromaticum  and  M.  alternifolia   were distributed on the surface of the culture medium Potato Dextrose Agar (PDA with Drigaslsky. In the control treatment were used only plates containing PDA plus chloramphenicol (1%. After 2 hours, a disc (8mm diameter of the isolated mycelium, with 10 days of age on PDA, was peaked to the center of the plates, these plates were sealed and incubated at 282°C, in the dark. The essential  oil  of  S.  aromaticum  inhibited  the  mycelial  growth  of  A.  flavus  and  A.  niger,  in  all aliquots. When using the essential oil of M. alternifolia decreased the mycelial growth of A. flavus in all aliquots, however, showed a low efficiency in control of A. niger. It was concluded that the essential  oil  S.  aromaticum  is  effective  against  A.  flavus  and  A.  niger,  which  can  be  used  in control against these microorganisms, and M. alternifolia not show satisfactory results in relation to reducing the growth of pathogens evaluated.

  11. Regulatory processes in Aspergillus niger

    DEFF Research Database (Denmark)

    Poulsen, Lars

    Filamentous fungi are extensively used in the fermentation industry for synthesis of numerous products. One of the most important, is the fungus Aspergillus niger, used industrially for production of organic acids, and homologous as well as heterologous enzymes. This fungus has numerous of advant......Filamentous fungi are extensively used in the fermentation industry for synthesis of numerous products. One of the most important, is the fungus Aspergillus niger, used industrially for production of organic acids, and homologous as well as heterologous enzymes. This fungus has numerous...

  12. Obstructive cholelithiasis and cholecystitis in a kinkajou (Potos flavus).

    Science.gov (United States)

    Potier, Romain; Reineau, Olivier

    2015-03-01

    A 14.5-yr-old female kinkajou (Potos flavus) was diagnosed with cholelithiasis after an episode of vomiting; diagnostics included biochemical analysis and abdominal ultrasound exam. Despite antimicrobial treatment, cholelithiasis led to cholecystitis. A cholecystotomy was performed to remove choleliths and inspissated bile. Morphological and spectroscopic properties of the choleliths were similar to those of gallstones from the brown pigment family and Streptococcus sp. and Escherichia coli were isolated from the bile. Biliary tract infection is directly related to pathogenesis of brown pigment gallstones. Serial ultrasound exams revealed that cholecystitis developed secondary to the presence of gallstones in the biliary tree. Despite full recovery postsurgery, the patient died 15 mo later from gallbladder necrosis. Based on the progression of this case, a cholecystectomy would be preferred over a cholecystotomy in similar cases, and the efficacy of long-acting antibiotics may not be adequate in nontarget species. Gallstones and biliary tract infection are rarely described in small domestic carnivores, and this is the first reported case in a kinkajou.

  13. Diagnóstico de ABPA em pacientes portadores de fibrose cística: utilidade clínica da pesquisa de IgE específica contra alérgenos recombinantes do Aspergillus fumigatus ABPA diagnosis in cystic fibrosis patients: the clinical utility of IgE specific to recombinant Aspergillus fumigatus allergens

    Directory of Open Access Journals (Sweden)

    Marina B. Almeida

    2006-06-01

    lung disease progresses. The overlap between the signs and symptoms of the two conditions makes diagnosis problematic, even if standardized criteria are used. The objective of this study was to identify, in a group of cystic fibrosis patients, cases of ABPA by assaying IgE specific to recombinant Aspergillus fumigatus antigens and to compare the method with the Cystic Fibrosis Foundation diagnostic criteria. METHODS: Fifty-four patients, aged 2 to 20 years, presenting characteristics that could occur with ABPA in isolation, were systematically assessed based on the following: clinical data, a chest CT scan, immediate hypersensitivity skin test for A. fumigatus; total serum IgE assay, RAST for A. fumigatus and serum IgE specific for the recombinant allergens Asp f1, f2, f3, f4 and f6. RESULTS: Thirty-nine patients were eligible for the study. Thirty-two of these were investigated. Sensitization to A. fumigatus was observed in 34%. Both the Cystic Fibrosis Foundation criteria and the recombinant antigen specific IgE assay defined three patients as suffering from ABPA; however, only two of these patients were diagnosed by both methods. CONCLUSIONS: The detection of A. fumigatus recombinant antigen specific IgE was a useful tool for the early detection of sensitization and diagnosis of ABPA. Nevertheless, diagnostic confirmation cannot be divorced from clinical findings, and before this method can be used for ABPA diagnosis, for detecting relapses and for defining cure criteria, longitudinal studies with larger numbers of patients are required.

  14. Novel mixed-format real-time PCR assay to detect mutations conferring resistance to triazoles in Aspergillus fumigatus and prevalence of multi-triazole resistance among clinical isolates in the Netherlands.

    NARCIS (Netherlands)

    Klaassen, C.H.; Valk, H.A. de; Curfs-Breuker, I.M.; Meis, J.F.G.M.

    2010-01-01

    OBJECTIVES: The aim of this study was: (i) to study the prevalence of triazole-resistant Aspergillus fumigatus isolates in the Netherlands; and (ii) to design rapid real-time PCR methods to identify such isolates. METHODS: A novel mixed-format real-time PCR assay is described for the detection of mu

  15. Selection arena in Aspergillus nidulans

    NARCIS (Netherlands)

    Bruggeman, J.; Debets, A.J.M.; Hoekstra, R.F.

    2004-01-01

    The selection arena hypothesis states that overproduction of zygotes-a widespread phenomenon in animals and plants-can be explained as a mechanism of progeny choice. As a similar mechanism, the ascomycetous fungus Aspergillus nidulans may overproduce dikaryotic fruit initials, hereafter called dikar

  16. Effect of γ-radiation on the production of aflatoxin B1 by Aspergillus parasiticus in raisins (Vitis vinifera L.)

    Science.gov (United States)

    Kanapitsas, Alexandros; Batrinou, Anthimia; Aravantinos, Athanasios; Markaki, Panagiota

    2015-01-01

    Aflatoxin B1 (AFB1) mostly produced by Aspergillus flavus and Aspergillus parasiticus, is an extremely toxic and carcinogenic metabolite. The effect of gamma irradiation at dose of 10 kGy on the production of aflatoxin B1 (AFB1) inoculated by Aspergillus parasiticus in raisins (Vitis vinifera L.) and on AFB1 in contaminated samples, was investigated. Values of the amount of aflatoxin B1 produced on the 12th day of incubation, after irradiation, showed that gamma radiation exposure at 10 kGy decreased AFB1 production at 65% compared with the non-irradiated sample, on the same day. The application of 10 kGy gamma radiation directly on 100 ng of AFB1 which were spiked in raisins resulted in ~29% reduction of AFB1. According to the risk assessment analysis the Provisional Maximum Tolerable Daily Intake (PMTDI) of 1.0 ng AFB1 kg-1bw, indicates that consumers are less exposed to AFB1 from the irradiated raisins.

  17. Identification of Aspergillus species in Central Europe able to produce G-type aflatoxins.

    Science.gov (United States)

    Baranyi, Nikolett; Despot, Daniela Jakšić; Palágyi, Andrea; Kiss, Noémi; Kocsubé, Sándor; Szekeres, András; Kecskeméti, Anita; Bencsik, Ottó; Vágvölgyi, Csaba; Klarić, Maja Šegvić; Varga, János

    2015-09-01

    The occurrence of potential aflatoxin producing fungi was examined in various agricultural products and indoor air in Central European countries including Hungary, Serbia and Croatia. For species identification, both morphological and sequence based methods were applied. Aspergillus flavus was detected in several samples including maize, cheese, nuts, spices and indoor air, and several isolates were able to produce aflatoxins. Besides, three other species of Aspergillus section Flavi, A. nomius, A. pseudonomius and A. parasiticus were also isolated from cheese, maize and indoor air, respectively. This is the first report on the occurrence of A. nomius and A. pseudonomius in Central Europe. All A. nomius, A. pseudonomius and A. parasiticus isolates were able to produce aflatoxins B1, B2, G1 and G2. The A. nomius isolate came from cheese produced very high amounts of aflatoxins (above 1 mg ml⁻¹). All A. nomius, A. pseudonomius and A. parasiticus isolates produced much higher amounts of aflatoxin G1 then aflatoxin B1. Further studies are in progress to examine the occurrence of producers of these highly carcinogenic mycotoxins in agricultural products and indoor air in Central Europe.

  18. Retraction of colonies and structures of Aspergillus Spp. as a possible high dose sensor

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Valeria B., E-mail: valeriabborges@hotmail.com [Coordenacao dos Programas de Pos-Graduacao em Processos Quimicos e Bioquimicos (EQ/UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica; Vital, Helio C., E-mail: vital@ctex.eb.br [Centro Tecnologico do Exercito (DDQBN/CTEx), Rio de Janeiro, RJ (Brazil). Div. de Defesa Quimica, Biologica e Nuclear. Secao de Defesa Nuclear; Moraes, Aurea M.L., E-mail: ltbbf@ioc.fiocruz.br [Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Departamento de Micologia

    2013-07-01

    Changes in the length of macro-and microscopic structures of irradiated Aspergillus spp. colonies were investigated in this work in search for correlations with radiation dose. Effects related to growth and morphology produced by exposure to radiation doses ranging from 0.0 up to 8.0 kGy on strains of A. flavus (CMT 00079), A. parasiticus (CMT 00064) and A ochraceus (CMT 00145) were analyzed. Fungal colonies were inoculated on fresh peanut seeds and incubated for 5 days at 25°C. On the sixth day the samples were irradiated and moved to Petri dishes containing PDA culture medium where they remained incubated for 7 days at 25°C Post irradiation growth was periodically monitored by visual inspections and measurements of mycelial diameters. In addition, microscopic analyses were performed to determine the length of the major structures of the colonies. It has been found that irradiation causes a decrease in the diameter of colonies as well as in the length of microscopic structures of the fungus. The amount of retraction has been found to be strongly correlated to radiation dose. Such findings hint at the possibility of using in situ Aspergillus spp. colonies as high-dose living dosimeters in the event of massive radiation exposures. (author)

  19. Nutritional limitation and resistance to opportunistic Aspergillus parasites in honey bee larvae.

    Science.gov (United States)

    Foley, Kirsten; Fazio, Géraldine; Jensen, Annette B; Hughes, William O H

    2012-09-15

    Honey bees are threatened by land use changes which reduce the availability and diversity of pollen and nectar resources. There is concern that poor nutrition may be involved in recent population declines, either directly or due to indirect effects on immunocompetence. The larval stage is likely to be the most vulnerable to a poor diet, but the effects of larval nutrition on the disease susceptibility of bees are not well known. In this study we used laboratory-reared honey bee larvae to investigate the effects of diet quality on disease susceptibility to the opportunistic fungal parasites Aspergillus flavus, Aspergillus phoenicis and A. fumigatus. Larvae fed on a nutritionally poor diet were found to be significantly more susceptible to A. fumigatus. Larval resistance to A. fumigatus was enhanced by feeding with a diet supplemented with either dandelion or polyfloral pollens. This indicates that dandelion and polyfloral pollens contain elements that enhance resistance to this fungal disease, illustrating an interaction between nutrition and parasitism and emphasising the benefit of diverse floral resources in the environment to maintain honey bee health.

  20. Requirement of monooxygenase-mediated steps for sterigmatocystin biosynthesis by Aspergillus nidulans.

    Science.gov (United States)

    Keller, N P; Watanabe, C M; Kelkar, H S; Adams, T H; Townsend, C A

    2000-01-01

    Sterigmatocystin (ST) and aflatoxin B(1) (AFB(1)) are two polyketide-derived Aspergillus mycotoxins synthesized by functionally identical sets of enzymes. ST, the compound produced by Aspergillus nidulans, is a late intermediate in the AFB(1) pathway of A. parasiticus and A. flavus. Previous biochemical studies predicted that five oxygenase steps are required for the formation of ST. A 60-kb ST gene cluster in A. nidulans contains five genes, stcB, stcF, stcL, stcS, and stcW, encoding putative monooxygenase activities. Prior research showed that stcL and stcS mutants accumulated versicolorins B and A, respectively. We now show that strains disrupted at stcF, encoding a P-450 monooxygenase similar to A. parasiticus avnA, accumulate averantin. Disruption of either StcB (a putative P-450 monooxygenase) or StcW (a putative flavin-requiring monooxygenase) led to the accumulation of averufin as determined by radiolabeled feeding and extraction studies.

  1. Influence of physical and chemical characteristics of wine grapes on the incidence of Penicillium and Aspergillus fungi in grapes and ochratoxin A in wines.

    Science.gov (United States)

    Freire, Luísa; Passamani, Fabiana Reinis Franca; Thomas, Ariela Betsy; Nassur, Rita de Cássia Mirela Resende; Silva, Lais Mesquita; Paschoal, Fabiano Narciso; Pereira, Giuliano Elias; Prado, Guilherme; Batista, Luís Roberto

    2017-01-16

    The incidence of filamentous fungi and toxin levels in grapes and wines varies depending on the variety of grapes, the wine region, agricultural practices, weather conditions, the harvest and the winemaking process. In this sense, the objective of this study was to evaluate the diversity of Aspergillus and Penicillium fungi isolated from wine grapes of the semi-arid tropical region of Brazil, evaluate the presence of ochratoxin A (OTA) in the experimental wine and verify if there is a correlation between occurrence of these fungi and the physicochemical characteristics of the wine grapes grown in the region. For the isolation of fungi we used the direct plating technique. The presence of OTA in the experimental wine was detected by high-performance liquid chromatography. The species found were Aspergillus niger, A. carbonarius, A. aculeatus, A. niger Aggregate, A. flavus, A. sojae, Penicillium sclerotiorum, P. citrinum, P. glabrum, P. decumbens, P. solitum and P. implicatum. All isolates of A. carbonarius were OTA producers and all P. citrinum were citrinin producers. The highest concentration of OTA was found in red wine (0.29μg/L). All species identified in this study, except A. flavus, showed a positive correlation with at least one physicochemical parameter assessed, highlighting the pectin content, total sugar, total acidity and phenolic compounds.

  2. Environmental fungicides and triazole resistance in Aspergillus.

    Science.gov (United States)

    Bowyer, Paul; Denning, David W

    2014-02-01

    Fungal diseases are problematic in both human health and agriculture. Treatment options are limited and resistance may emerge. The relatively recent recognition of triazole resistance in Aspergillus fumigatus has prompted questioning of the origin of resistance. While multiple mechanisms are described in clinical isolates from triazole-treated patients, some de novo resistance is also recognised, especially attributable to TR34 /L98H. Such strains probably arose in the environment, and, indeed, multiple studies have now demonstrated TR(34) /L98H triazole resistance strains of A. fumigatus from soil. Docking and other in vitro studies are consistent with environmental resistance induction through exposure to certain triazole fungicides, notably difenoconazole, propiconazole, epoxiconazole, bromuconazole and tebuconazole. This article addresses the potential implications of this issue for both human health and food security.

  3. Myrmecophilous pygmephoroid mites (Acari: Pygmephoroidea) associated with Lasius flavus (Hymenoptera: Formicidae) in Russia.

    Science.gov (United States)

    Khaustov, Alexander A

    2015-11-19

    Twenty four species of pygmephoroid mites (Acari: Pygmephoroidea: Neopygmephoridae, Scutacaridae, Microdispidae) are recorded from the ant Lasius flavus (Fabricius) or from its nests from Western Siberia and Crimea. Four of them of the genus Scutacarus Gros, 1845 (Acari: Scutacaridae), S. insolitus sp. nov., S. heterotrichus sp. nov., S. moseri sp. nov. and S. sibiriensis sp. nov. are described as new for science. Four species of scutacarid mites are recorded for the first time in Russia. The comparison of pygmephoroid mite communities associated with Lasius flavus from Crimean and West Siberian populations and notes on phoresy of pygmephoroid mites on ants are provided.

  4. Iatrogenic aspergillus infection of the central nervous system in a pregnant woman

    Directory of Open Access Journals (Sweden)

    Lokuhetty Menaka

    2009-07-01

    Full Text Available A healthy postnatal woman succumbed to fulminant iatrogenic Aspergillus infection of the central nervous system, following accidental inoculation into the subarachnoid space at spinal anesthesia, during an outbreak of Aspergillus meningitis in Sri Lanka. Autopsy revealed extensive Aspergillus meningitis and culture confirmed Aspergillus fumigatus. The thalamic parenchyma in the brain was invaded by fungal hyphae producing necrotizing angitis with thrombosis, thalamic infarcts and fungal abscesses. The directional growth of fungal hyphae from the extra-luminal side of blood vessels towards the lumen favored extension from the brain parenchyma over hematogenous spread. The spinal parenchyma was resistant to fungal invasion in spite of the heavy growth within the spinal meninges and initial inoculation at spinal level. Modulation of the immune response in pregnancy with depression of selective aspects of cell-mediated immunity probably contributed to rapid spread within the subarachnoid space, to involve the brain parenchyma leading to clinical deterioration and death.

  5. Identification of thermostable β-xylosidase activities produced by Aspergillus brasiliensis and Aspergillus niger

    DEFF Research Database (Denmark)

    Pedersen, Mads; Lauritzen, Henrik Klitgaard; Frisvad, Jens Christian

    2007-01-01

    Twenty Aspergillus strains were evaluated for production of extracellular cellulolytic and xylanolytic activities. Aspergillus brasiliensis, A. niger and A. japonicus produced the highest xylanase activities with the A. brasiliensis and A. niger strains producing thermostable beta...

  6. Identification of thermostable beta-xylosidase activities produced by Aspergillus brasiliensis and Aspergillus niger

    DEFF Research Database (Denmark)

    Pedersen, Mads; Lauritzen, H.K.; Frisvad, Jens Christian

    2007-01-01

    Twenty Aspergillus strains were evaluated for production of extracellular cellulolytic and xylanolytic activities. Aspergillus brasiliensis, A. niger and A. japonicus produced the highest xylanase activities with the A. brasiliensis and A. niger strains producing thermostable beta...

  7. Pulmonary infections by the fungus aspergillus

    Directory of Open Access Journals (Sweden)

    Rao P

    1979-01-01

    Full Text Available Five cases of respiratory infection by Aspergillus fumigates are described. Species of aspergillus is ubiquitous in nature. Therefore, repeated demonstration of fungus, serological evidence tend radiological findings are essential for diagnosis. Potassium iodide is a useful drug in aspergillus infection of the lung when other drugs are not available. Injection Emetine hydrochloride is promising as a therapeutic agent in pulmonary aspergillosis, where the lung parenchyma is involved.

  8. Anti-Aspergillus activity of green coffee 5-O-caffeoyl quinic acid and its alkyl esters.

    Science.gov (United States)

    Suárez-Quiroz, M L; Alonso Campos, A; Valerio Alfaro, G; González-Ríos, O; Villeneuve, P; Figueroa-Espinoza, M C

    2013-01-01

    The antifungal activities of 5-O-caffeoyl quinic acid (5-CQA) and of methyl, butyl, octyl, and dodecyl esters or 5-CQA, were tested on five toxigenic moulds from the Aspergillus genus (Aspergillus flavus, Aspergillus nomius, Aspergillus ochraceus, Aspergillus parasiticus, Aspergillus westerdijkiae). These mycotoxin producers' moulds may contaminate many types of food crops throughout the food chain posing serious health hazard to animals and humans. The use of chemical methods to decrease mycotoxin producer moulds contamination on food crops in the field, during storage, and/or during processing, has been proved to be efficient. In this work, the antifungal effect of 5-CQA and a homologous series of 5-CQA esters (methyl, butyl, octyl, dodecyl), was investigated using the microdilution method and the minimum inhibitory concentrations (MIC50 and MIC80). All molecules presented antifungal activity, and two esters showed a MIC for all fungi: octyl (MIC50 ≤ 0.5-0.75 mg/mL, MIC80 = 1.0-1.5 mg/mL) and dodecyl (MIC50 = 0.75-1.25 mg/mL) chlorogenates. Dodecyl chlorogenate showed a MIC80 (1.5 mg/mL) only for A. parasiticus. The maximum percent of growth inhibition on aspergillii was observed with octyl (78.4-92.7%) and dodecyl (54.5-83.7%) chlorogenates, being octyl chlorogenate the most potent antifungal agent. It was thus concluded that lipophilization improved the antifungal properties of 5-CQA, which increased with the ester alkyl chain length, exhibiting a cut-off effect at 8 carbons. As far as we know, it is the first report demonstrating that lipophilization may improve the antifungal activity of 5-CQA on five toxigenic moulds from the Aspergillus genus. Lipophilization would be a novel way to synthesize a new kind of antifungal agents with a good therapeutic value or a potential use as preservative in food or cosmetics.

  9. Immobilization of wild kinkajous (Potos flavus) with medetomidine-ketamine and reversal by atipamezole.

    Science.gov (United States)

    Fournier, P; Fournier-Chambrillon, C; Vié, J C

    1998-06-01

    As part of a wildlife rescue during the filling of a lake created by a hydroelectric dam (Petit Saut, French Guiana), 10 wild kinkajous (Potos flavus) were immobilized with medetomidine and ketamine for clinical examination and collection of biological samples. A mean (+/-SD) i.m. dose of 0.11+/-0.01 mg/kg medetomidine and 5.5+/-0.6 mg/kg ketamine rapidly induced complete immobilization (3.0+/-0.9 min) with good muscle relaxation and loss of corneal and pedal withdrawal reflexes. The duration and the quality of the anesthesia allowed procedures including minor surgery. Rectal temperature, heart and respiration rates, and relative oxyhemoglobin saturation (SpO2) were monitored at 5 min, 15 min, and 30 min after the medetomidine ketamine injection. Rectal temperature and heart rate significantly decreased during this time (P < 0.05). Low values of SpO2 (<90%) were recorded shortly after the injection. Hypoxemia partially resolved with time, confirmed by an increase in most SpO2 values. Atipamezole given i.m. at 5 mg/mg of medetomidine reversed the effects of the medetomidine in kinkajous. No adverse effects were observed during recovery. In group I, the antagonist was injected at 40.6+/-3.9 min. In group II, the animals showed signs of spontaneous recovery 37.9+/-6.9 min before antagonist injection at 52.2+/-6.1 min. Time from antagonist injection to ambulatory state was significantly shorter (P < 0.05) in group II (2.8+/-1.1 min) than in group I (6.9+/-1.2 min).

  10. Xanthobacter flavus employs a single triosephosphate isomerase for heterotrophic and autotrophic metabolism

    NARCIS (Netherlands)

    Meijer, WG; deBoer, P; vanKeulen, G

    1997-01-01

    The expression of the cbb and gap-pgk operons of Xanthobacter flavus encoding enzymes of the Calvin cycle is regulated by the transcriptional regulator CbbR. In order to identify other genes involved in the regulation of these operons, a mutant was isolated with a lowered activity of a fusion betwee

  11. Biocontrol of Aspergillus species on peanut kernels by antifungal diketopiperazine producing Bacillus cereus associated with entomopathogenic nematode.

    Science.gov (United States)

    Kumar, Sasidharan Nishanth; Sreekala, Sreerag Ravikumar; Chandrasekaran, Dileep; Nambisan, Bala; Anto, Ruby John

    2014-01-01

    The rhabditid entomopathogenic nematode associated Bacillus cereus and the antifungal compounds produced by this bacterium were evaluated for their activity in reducing postharvest decay of peanut kernels caused by Aspergillus species in in vitro and in vivo tests. The results showed that B. cereus had a significant effect on biocontrol effectiveness in in vitro and in vivo conditions. The antifungal compounds produced by the B. cereus were purified using silica gel column chromatography and their structure was elucidated using extensive spectral analyses. The compounds were identified as diketopiperazines (DKPs) [cyclo-(L-Pro-Gly), cyclo(L-Tyr-L-Tyr), cyclo-(L-Phe-Gly) and cyclo(4-hydroxy-L-Pro-L-Trp)]. The antifungal activities of diketopiperazines were studied against five Aspergillus species and best MIC of 2 µg/ml was recorded against A. flavus by cyclo(4-hydroxy-L-Pro-L-Trp). To investigate the potential application of cyclo(4-hydroxy-L-Pro-L-Trp) to eliminate fungal spoilage in food and feed, peanut kernels was used as a food model system. White mycelia and dark/pale green spores of Aspergillus species were observed in the control peanut kernels after 2 days incubation. However the fungal growth was not observed in peanut kernels treated with cyclo(4-hydroxy-L-Pro-L-Trp). The cyclo(4-hydroxy-L-Pro-L-Trp) was nontoxic to two normal cell lines [fore skin (FS) normal fibroblast and African green monkey kidney (VERO)] up to 200 µg/ml in MTT assay. Thus the cyclo(4-hydroxy-L-Pro-L-Trp) identified in this study may be a promising alternative to chemical preservatives as a potential biopreservative agent which prevent fungal growth in food and feed. To the best of our knowledge, this is the first report demonstrating that the entomopathogenic nematode associated B. cereus and cyclo(4-hydroxy-L-Pro-L-Trp) could be used as a biocontrol agents against postharvest fungal disease caused by Aspergillus species.

  12. Ecophysiological characterization of Aspergillus carbonarius, Aspergillus tubingensis and Aspergillus niger isolated from grapes in Spanish vineyards.

    Science.gov (United States)

    García-Cela, E; Crespo-Sempere, A; Ramos, A J; Sanchis, V; Marin, S

    2014-03-03

    The aim of this study was to evaluate the diversity of black aspergilli isolated from berries from different agroclimatic regions of Spain. Growth characterization (in terms of temperature and water activity requirements) of Aspergillus carbonarius, Aspergillus tubingensis and Aspergillus niger was carried out on synthetic grape medium. A. tubingensis and A. niger showed higher maximum temperatures for growth (>45 °C versus 40-42 °C), and lower minimum aw requirements (0.83 aw versus 0.87 aw) than A. carbonarius. No differences in growth boundaries due to their geographical origin were found within A. niger aggregate isolates. Conversely, A. carbonarius isolates from the hotter and drier region grew and produced OTA at lower aw than other isolates. However, little genetic diversity in A. carbonarius was observed for the microsatellites tested and the same sequence of β-tubulin gene was observed; therefore intraspecific variability did not correlate with the geographical origin of the isolates or with their ability to produce OTA. Climatic change prediction points to drier and hotter climatic scenarios where A. tubingensis and A. niger could be even more prevalent over A. carbonarius, since they are better adapted to extreme high temperature and drier conditions.

  13. Monoclonal Antibodies to Hyphal Exoantigens Derived from the Opportunistic Pathogen Aspergillus terreus

    Science.gov (United States)

    Aspergillus terreus has been difficult to identify in cases of aspergillosis, and clinical identification has been restricted to the broad identification of aspergillosis lesions in affected organs or the detection of fungal carbohydrates. As a result, there is a clinical need to...

  14. Investigation of malic acid production in Aspergillus oryzae under nitrogen starvation conditions.

    Science.gov (United States)

    Knuf, Christoph; Nookaew, Intawat; Brown, Stephen H; McCulloch, Michael; Berry, Alan; Nielsen, Jens

    2013-10-01

    Malic acid has great potential for replacing petrochemical building blocks in the future. For this application, high yields, rates, and titers are essential in order to sustain a viable biotechnological production process. Natural high-capacity malic acid producers like the malic acid producer Aspergillus flavus have so far been disqualified because of special growth requirements or the production of mycotoxins. As A. oryzae is a very close relative or even an ecotype of A. flavus, it is likely that its high malic acid production capabilities with a generally regarded as safe (GRAS) status may be combined with already existing large-scale fermentation experience. In order to verify the malic acid production potential, two wild-type strains, NRRL3485 and NRRL3488, were compared in shake flasks. As NRRL3488 showed a volumetric production rate twice as high as that of NRRL3485, this strain was selected for further investigation of the influence of two different nitrogen sources on malic acid secretion. The cultivation in lab-scale fermentors resulted in a higher final titer, 30.27 ± 1.05 g liter(-1), using peptone than the one of 22.27 ± 0.46 g liter(-1) obtained when ammonium was used. Through transcriptome analysis, a binding site similar to the one of the Saccharomyces cerevisiae yeast transcription factor Msn2/4 was identified in the upstream regions of glycolytic genes and the cytosolic malic acid production pathway from pyruvate via oxaloacetate to malate, which suggests that malic acid production is a stress response. Furthermore, the pyruvate carboxylase reaction was identified as a target for metabolic engineering, after it was confirmed to be transcriptionally regulated through the correlation of intracellular fluxes and transcriptional changes.

  15. Infectious keratitis caused by Aspergillus tubingensis

    NARCIS (Netherlands)

    Kredics, L.; Varga, J.; Kocsube, S.; Rajaraman, R.; Raghavan, A.; Doczi, I.; Bhaskar, M.; Nemeth, T.M.; Antal, Z.; Venkatapathy, N.; Vagvolgyi, C.; Samson, R.A.; Chockaiya, M.; Palanisamy, M.

    2009-01-01

    PURPOSE: To report 2 cases of keratomycosis caused by Aspergillus tubingensis. METHODS: The therapeutic courses were recorded for 2 male patients, 52 and 78 years old, with fungal keratitis caused by black Aspergillus strains. Morphological examination of the isolates was carried out on malt extract

  16. Sporulation inhibited secretion in Aspergillus niger

    NARCIS (Netherlands)

    Krijgsheld, P.

    2013-01-01

    Aspergillus niger is abundantly found in nature. It degrades dead material of plants and animals but can also be a pathogen of these organisms. Aspergillus niger is also important for mankind because it is one of the main organisms used for the industrial production of enzymes. These enzymes are rel

  17. Pyopneumothorax Secondary to Aspergillus Infection: A Case Report

    Directory of Open Access Journals (Sweden)

    Surya Kant

    2012-11-01

    Full Text Available A 32 -year- old male presented with complaints of fever, dry cough, breathlessness and right sided chest pain of two months duration. Chest radiograph showed right sided hydropneumothorax which revealed frank pus on diagnostic thoracocentesis, for which tube thoracostomy was done. Despite vigorous broad spectrum antibiotic coverage, postural drainage and chest physiotherapy, there was no clinical improvement. Further work up included serology, pleural fluid culture, closed as well as thoracoscopic guided pleural biopsy revealed growth of Aspergillus fumigatus. Patient was prescribed antifungal medication (Voriconazole and subsequent thoracotomy with right sided pneumonectomy showed good clinical recovery.

  18. New taxa in Aspergillus section Usti

    DEFF Research Database (Denmark)

    Samson, R. A.; Varga, J.; Meijer, M.

    2011-01-01

    Based on phylogenetic analysis of sequence data, Aspergillus section Usti includes 21 species, inducing two teleomorphic species Aspergillus heterothallicus (=Emericella heterothallica) and Fennellia monodii. Aspergillus germanicus sp. nov. was isolated from indoor air in Germany. This species has...... identical ITS sequences with A. insuetus CBS 119.27, but is clearly distinct from that species based on beta-tubulin and calmodulin sequence data. This species is unable to grow at 37 degrees C, similarly to A. keveii and A. insuetus. Aspergillus carlsbadensis sp. nov. was isolated from the Carlsbad Caverns...... National Park in New Mexico. This taxon is related to, but distinct from a dade including A. calidoustus, A. pseudodeflectus, A. insuetus and A. keveii on all trees. This species is also unable to grow at 37 degrees C, and acid production was not observed on CREA. Aspergillus californicus sp. nov...

  19. Conidial Hydrophobins of Aspergillus fumigatus

    OpenAIRE

    Paris, Sophie; Debeaupuis, Jean-Paul; Crameri, Reto; Carey, Marilyn; Charlès, Franck; Prévost, Marie Christine; Schmitt, Christine; Philippe, Bruno; Latgé, Jean Paul

    2003-01-01

    The surface of Aspergillus fumigatus conidia, the first structure recognized by the host immune system, is covered by rodlets. We report that this outer cell wall layer contains two hydrophobins, RodAp and RodBp, which are found as highly insoluble complexes. The RODA gene was previously characterized, and ΔrodA conidia do not display a rodlet layer (N. Thau, M. Monod, B. Crestani, C. Rolland, G. Tronchin, J. P. Latgé, and S. Paris, Infect. Immun. 62:4380-4388, 1994). The RODB gene was cloned...

  20. Glucoamylase I of Black Aspergillus

    OpenAIRE

    Medda, Sukumar; Saha, Badal Chandra; Ueda, Seinosuke

    1982-01-01

    Glucoamylase I of black Aspergillus was purified by (NH_4)_2SO_4 precipitation, ethanol fractionation, ion exchange chromatography on DEAE-cellulose, preparative isoelectric focusing and Sephadex G-100 gel filtration. The enzyme thus purified was found to contain no α-amylase and appeared to be homogeneous in polyacrylamide gel electrophoresis. The isoelectric point of glucoamylase I was at pH 3.4. The optimum conditions for its action on boiled soluble starch were at 60℃ and pH 4.5. The enzy...

  1. Two novel species of Aspergillus section Nigri from indoor air

    Science.gov (United States)

    Aspergillus collinsii, Aspergillus floridensis, and Aspergillus trinidadensis are described as novel uniseriate species of Aspergillus section Nigri isolated from air samples. To describe the species we used phenotypes from 7-d Czapek yeast extract agar culture (CYA) and malt extract agar culture (M...

  2. Evaluation of the Aspergillus Western blot IgG kit for diagnosis of chronic aspergillosis.

    Science.gov (United States)

    Oliva, A; Flori, P; Hennequin, C; Dubus, J-C; Reynaud-Gaubert, M; Charpin, D; Vergnon, J M; Gay, P; Colly, A; Piarroux, R; Pelloux, H; Ranque, S

    2015-01-01

    Immunoprecipitin detection (IPD) is the current reference confirmatory technique for anti-Aspergillus antibody detection; however, the lack of standardization is a critical drawback of this assay. In this study, we evaluated the performance of the Aspergillus Western blot (Asp-WB) IgG kit (LDBio Diagnostics, Lyon, France), a recently commercialized immunoblot assay for the diagnosis of various clinical presentations of chronic aspergillosis. Three hundred eight serum samples from 158 patients with aspergillosis sensu lato (s.l.) were analyzed. More specifically, 267 serum samples were derived from patients with Aspergillus disease, including 89 cases of chronic pulmonary aspergillosis, 10 of aspergilloma, and 32 of allergic bronchopulmonary aspergillosis, while 41 samples were from patients with Aspergillus colonization, including 15 cystic fibrosis (CF) and 12 non-CF patients. For blood donor controls, the Asp-WB specificity was 94%, while the kit displayed a sensitivity for the aspergillosis s.l. diagnosis of 88.6%, with a diagnostic odds ratio (DOR) of 119 (95% confidence interval [CI], 57 to 251). The DOR values were 185.22 (95% CI,78.79 to 435.45) and 43.74 (95% CI, 15.65 to 122.20) for the diagnosis of Aspergillus disease and Aspergillus colonization, respectively. Among the patients, the sensitivities of the Asp-WB in the diagnosis of Aspergillus colonization were 100% and 41.7% in CF and non-CF patients, respectively. The Asp-WB yielded fewer false-negative results than did IPD. In conclusion, the Asp-WB kit performed well for the diagnosis of various clinical presentations of aspergillosis in nonimmunocompromised patients, with an enhanced standardization and a higher sensitivity than with IPD, which is the current reference method.

  3. Decolorization of molasses spent wash by the white-rot fungus Flavodon flavus, isolated from a marine habitat

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Rivonkar, G.

    Flavodon flavus (Klotzsch) Ryvarden, a basidiomycete (NIOCC strain 312) isolated from decomposing leaves of a sea grass, decolorized pigments in molasses spent wash (MSW) by 80% after 8 days of incubation, when used at concentrations of 10% and 50...

  4. Natural hybrids of the madtoms, Noturus flavus and Noturus insignis, from the Monongahela River drainage, West Virginia

    Science.gov (United States)

    Welsh, S.A.; Cincotta, Dan A.

    2004-01-01

    Natural hybridization is rare in the family Ictaluridae. Putative hybrids of the madtoms Noturus flavus and N. insignis were collected from Blackwater River, Monongahela River drainage, WV. Noturus flavus is native to the Monongahela River drainage, whereas N. insignis is nonnative. We quantified morphological differences among N. flavus, N. insignis, and putative hybrids by sheared principal components analysis of morphometric characters. Putative hybrids were intermediate in tooth patch dimensions, caudal fin pigmentation, length of the dorsal fin base, distance between the adipose/caudal notch and base of caudal fin, and position of anal fin. Hybridization between N. flavus and N. insignis is supported by morphological intermediacy, and may be linked to higher abundances of N. insignis or degraded habitat in the Blackwater River.

  5. Interaction of Wild Strains of Aspergilla with Aspergillus parasiticus ATCC15517 and Aflatoxin Production †

    Science.gov (United States)

    Martins, H. Marina; Almeida, Inês; Marques, Marta; Bernardo, Fernando

    2008-01-01

    Aflatoxins are secondary metabolites produced by some competent mould strains of Aspergillus flavus, A. parasiticus and A. nomius. These compounds have been extensively studied with regards to their toxicity for animals and humans; they are able to induce liver cancer and may cause a wide range of adverse effects in living organisms. Aflatoxins are found as natural contaminants of food and feed; the main line of the strategy to control them is based on the prevention of the mould growth in raw vegetable or during its storage and monitoring of each crop batch. Mould growth is conditioned by many ecological factors, including biotic ones. Hazard characterization models for aflatoxins in crops must take into consideration biotic interactions between moulds and their potential effects on growth development. The aim of this work is to study the effect of the biotic interaction of 14 different wild strains of Aspergilla (different species), with a competent strain (Aspergillus parasiticus ATCC 15517) using an in vitro production model. The laboratory model used was a natural matrix (humidified cracked corn), on which each wild strain challenged the aflatoxin production of a producer strain. Cultures were incubated at 28°C for 12 days and sampled at the 8th and 12th. Aflatoxin detection and quantification was performed by HPLC using a procedure with a MRPL = 1 μg/kg. Results of those interactive cultures revealed both synergic and antagonistic effects on aflatoxin biosynthesis. Productivity increases were particularly evident on the 8th day of incubation with wild strains of A. flavipes (+ 70.4 %), A. versicolor (+ 54.9 %) and A. flavus 3 (+ 62.6 %). Antagonistic effects were found with A. niger (− 69.5%), A. fumigatus (− 47.6 %) and A. terreus (− 47.6 %) on the 12th day. The increased effects were more evident on the 8th of incubation and the decreases were more patent on the 12th day. Results show that the development of Aspergilla strains concomitantly with

  6. Aspergillus Pericarditis with Tamponade in a Renal Transplant Patient

    Science.gov (United States)

    Lekkham, Rapeepat; Climaco, Antoinette

    2017-01-01

    Aspergillus pericarditis is a rare and life-threatening infection in immunosuppressed patients. It has nonspecific clinical manifestations that often mimic other disease entities especially in patients who have extensive comorbidities. Diagnosis is oftentimes delayed and rarely done antemortem. A high degree of suspicion in immunocompromised patients is necessary for evaluation and timely diagnosis. This is a case of Aspergillus pericarditis with cardiac tamponade in a renal transplant patient with liver cirrhosis. Two months after transplant, he developed decompensation of his cirrhosis from hepatitis C, acute cellular rejection, and Kluyvera bacteremia, followed by vancomycin-resistant Enterococcus faecium (VRE) bacteremia. Four months after transplant, the patient presented with lethargy and fluid overload. He subsequently developed shock and ventilator-dependent respiratory failure. An echocardiogram showed pericardial effusion with cardiac tamponade. He had emergent pericardiocentesis that showed purulent drainage. He was started on broad-spectrum antibiotics. Amphotericin B was initiated when the pericardial fluid grew mold that was later identified as Aspergillus fumigatus. The patient quickly decompensated and expired. PMID:28316844

  7. Aspergillus niger contains the cryptic phylogenetic species A. awamori

    DEFF Research Database (Denmark)

    Perrone, Giancarlo; Stea, Gaetano; Epifani, Filomena

    2011-01-01

    Aspergillus section Nigri is an important group of species for food and medical mycology, and biotechnology. The Aspergillus niger ‘aggregate’ represents its most complicated taxonomic subgroup containing eight morphologically indistinguishable taxa: A. niger, Aspergillus tubingensis, Aspergillus...... acidus, Aspergillus brasiliensis, Aspergillus costaricaensis, Aspergillus lacticoffeatus, Aspergillus piperis, and Aspergillus vadensis. Aspergillus awamori, first described by Nakazawa, has been compared taxonomically with other black aspergilli and recently it has been treated as a synonym of A. niger....... Phylogenetic analyses of sequences generated from portions of three genes coding for the proteins β-tubulin (benA), calmodulin (CaM), and the translation elongation factor-1 alpha (TEF-1α) of a population of A. niger strains isolated from grapes in Europe revealed the presence of a cryptic phylogenetic species...

  8. In Vitro Interaction between Alginate Lyase and Amphotericin B against Aspergillus fumigatus Biofilm Determined by Different Methods

    OpenAIRE

    Bugli, Francesca; Posteraro, Brunella; Papi, Massimiliano; Torelli, Riccardo; Maiorana, Alessandro; Paroni Sterbini, Francesco; Posteraro, Patrizia; Sanguinetti, Maurizio; De Spirito, Marco

    2013-01-01

    Aspergillus fumigatus biofilms represent a problematic clinical entity, especially because of their recalcitrance to antifungal drugs, which poses a number of therapeutic implications for invasive aspergillosis, the most difficult-to-treat Aspergillus-related disease. While the antibiofilm activities of amphotericin B (AMB) deoxycholate and its lipid formulations (e.g., liposomal AMB [LAMB]) are well documented, the effectiveness of these drugs in combination with nonantifungal agents is poor...

  9. Ribonuclease Production by Aspergillus species

    Directory of Open Access Journals (Sweden)

    Gomes Eleni

    1998-01-01

    Full Text Available Ribonuclease production by Aspergillus flavipes, A. sulphureus and A. fischeri in semi-synthetic medium, after 24-144 hours at 30ºC under shaking, was studied. After cultivation, the medium was separated from micelia by filtration and the resultant solution was used as enzymatic extract. The highest amount of biomass and RNase was obtained after 96 hours of cultivation. The enzymes produced by three species presented similar characteristics, with optimum temperature at 55ºC and two peaks of activity at pH 4.5 and 7.0. A. flavipes RNases were more sensitive to temperature: 50% of the initial activity was lost after 1 hour at 70ºC. After this heat treatment, RNase of A. sulphureus lost 30% of this activity and that of A. fischeri only 16%. The nucleotides released by enzimatic hydrolysis of RNA were separated by ion exchange chromatography in a AG-1X8-formiate column and identified by paper chromatography. This procedure indicated that the raw enzymatic extract of Aspergillus flavipes is able to hydrolyze RNA, releasing 3'-nucleotides monophosphate at pH 4.5 and 3' and 5'-nucleotides monophosphate at pH 7.0 and 8.5. This result suggests that this strain produces two different types of RNase, one acidic and other alcaline, with different specificities.

  10. Enhancement of Seed Dehiscence by Seed Treatment with Talaromyces flavus GG01 and GG04 in Ginseng (Panax ginseng)

    Science.gov (United States)

    Kim, Min-Jeong; Shim, Chang-Ki; Kim, Yong-Ki; Hong, Sung-Jun; Park, Jong-Ho; Han, Eun-Jung; Kim, Seok-Cheol

    2017-01-01

    Seed dehiscence of ginseng (Panax ginseng C. A. Mayer) is affected by moisture, temperature, storage conditions and microbes. Several microbes were isolated from completely dehisced seed coat of ginseng cultivars, Chunpoong and Younpoong at Gumsan, Korea. We investigated the potential of five Talaromyces flavus isolates from the dehiscence of ginseng seed in four traditional stratification facilities. The isolates showed antagonistic activities against fungal plant pathogens, such as Cylindrocarpon destructans, Fusarium oxysporum, Rhizoctonia solani, Sclerotinia nivalis, Botrytis cinerea, and Phytophthora capsici. The dehiscence ratios of ginseng seed increased more than 33% by treatment of T. flavus GG01, GG02, GG04, GG12, and GG23 in comparison to control (28%). Among the treatments, the reformulating treatment of T. flavus isolates GG01 and GG04 showed the highest of stratification ratio of ginseng seed. After 16 weeks, the reformulating treatment of T. flavus isolates GG01 and GG04 significantly enhanced dehiscence of ginseng seed by about 81% compared to the untreated control. The candidate’s treatment of T. flavus GG01 and GG04 showed the highest decreasing rate of 93% in seed coat hardness for 112 days in dehiscence period. The results suggested that the pre-inoculation of T. flavus GG01 and GG04 found to be very effective applications in improving dehiscence and germination of ginseng seed. PMID:28167883

  11. Aspergillus uvarum sp. nov., an uniseriate black Aspergillus species isolated from grapes in Europe

    DEFF Research Database (Denmark)

    Perrone, Giancarlo; Varga, János; Susca, Antonia

    2008-01-01

    A novel species, Aspergillus uvarum sp. nov., is described within Aspergillus section Nigri. This species can be distinguished from other black aspergilli based on internal transcribed spacers (ITS), beta-tubulin and calmodulin gene sequences, by AFLP analysis and by extrolite profiles. Aspergillus...... uvarum sp. nov. isolates produced secalonic acid, common to other Aspergillus japonicus-related taxa, and geodin, erdin and dihydrogeodin, which are not produced by any other black aspergilli. None of the isolates were found to produce ochratoxin A. The novel species is most closely related to two...... atypical strains of Aspergillus aculeatus, CBS 114.80 and CBS 620.78, and was isolated from grape berries in Portugal, Italy, France, Israel, Greece and Spain. The type strain of Aspergillus uvarum sp. nov. is IMI 388523(T)=CBS 127591(T)= ITEM 4834(T)= IBT26606(T)....

  12. Influence of herbicide glyphosate on growth and aflatoxin B1 production by Aspergillus section Flavi strains isolated from soil on in vitro assay.

    Science.gov (United States)

    Barberis, Carla L; Carranza, Cecilia S; Chiacchiera, Stella M; Magnoli, Carina E

    2013-01-01

    The effect of six glyphosate concentrations on growth rate and aflatoxin B1 (AFB1) production by Aspergillus section Flavi strains under different water activity (aW) on maize-based medium was investigated. In general, the lag phase decreased as glyphosate concentration increased and all the strains showed the same behavior at the different conditions tested. The glyphosate increased significantly the growth of all Aspergillus section Flavi strains in different percentages with respect to control depending on pesticide concentration. At 5.0 and 10 mM this fact was more evident; however significant differences between both concentrations were not observed in most strains. Aflatoxin B1 production did not show noticeable differences among different pesticide concentrations assayed at all aW in both strains. This study has shown that these Aspergillus flavus and A. parasiticus strains are able to grow effectively and produce aflatoxins in high nutrient status media over a range of glyphosate concentrations under different water activity conditions.

  13. Rapid detection of aflatoxigenic Aspergillus sp. in herbal specimens by a simple, bendable, paper-based lab-on-a-chip.

    Science.gov (United States)

    Chaumpluk, Piyasak; Plubcharoensook, Pattra; Prasongsuk, Sehanat

    2016-06-01

    Postharvest herbal product contamination with mycotoxins and mycotoxin-producing fungi represents a potentially carcinogenic hazard. Aspergillus flavus is a major cause of this issue. Available mold detection methods are PCR-based and rely heavily on laboratories; thus, they are unsuitable for on-site monitoring. In this study, a bendable, paper-based lab-on-a-chip platform was developed to rapidly detect toxigenic Aspergillus spp. DNA. The 3.0-4.0 cm(2) chip is fabricated using Whatman™ filter paper, fishing line and a simple plastic lamination process and has nucleic acid amplification and signal detection components. The Aspergillus assay specifically amplifies the aflatoxin biosynthesis gene, aflR, using loop-mediated isothermal amplification (LAMP); hybridization between target DNA and probes on blue silvernanoplates (AgNPls) yields colorimetric results. Positive results are indicated by the detection pad appearing blue due to dispersed blue AgNPls; negative results are indicated by the detection pad appearing colorless or pale yellow due to probe/target DNA hybridization and AgNPls aggregation. Assay completion requires less than 40 min, has a limit of detection (LOD) of 100 aflR copies, and has high specificity (94.47%)and sensitivity (100%). Contamination was identified in 14 of 32 herbal samples tested (43.75%). This work demonstrates the fabrication of a simple, low-cost, paper-based lab-on-a-chip platform suitable for rapid-detection applications.

  14. Radiação gama sobre a micobiota de ração avícola e Aspergillus spp. Gamma radiation on the mycoflora of poultry feed and Aspergillus species

    Directory of Open Access Journals (Sweden)

    Jéssika Mara Martins Ribeiro

    2009-08-01

    Full Text Available O objetivo deste experimento foi investigar o efeito da radiação gama sobre a micobiota natural de ingredientes e ração avícola e seu impacto sobre espécies de Aspergillus spp. Para tanto, fubá, farelo de soja e ração foram expostos a uma fonte de césio-137 nas doses 0; 3,5; 8 e 15kGy. Amostras de milho, inoculadas com suspensão de conídios de Aspergillus spp., foram irradiadas com doses de 0 a 8kGy. Observou-se redução das contagens com o aumento da dose, obtendo-se eliminação da micobiota com 8kGy. Uma maior radiossensibilidade de leveduras foi observada em comparação a fungos filamentosos, e aqueles que resistiram à dose de 3,5kGy pertenciam, em sua maioria, aos gêneros Cladosporium spp., Curvularia spp., Fusarium spp. e Aspergillus spp. As espécies A. flavus e A. parasiticus mostraram-se mais radiorresistentes que as demais avaliadas. Redução na conidiogênese e presença de estruturas de resistência foram detectadas logo após a irradiação. Constatou-se também que, após repiques em meios nutritivos, os isolados irradiados recuperaram a taxa de crescimento normal. Verificou-se ainda que o estresse metabólico induzido pela irradiação promoveu aumento na produção de aflatoxina B1 e ocratoxina A.This experiment investigated the effects of gamma radiation on the mycoflora of natural ingredients and poultry feed, and its impact on species of Aspergillus spp. Corn meal, soybean meal, feed and maize (inoculated with spore suspension of Aspergillus spp. were irradiated with 0, 3.5, 8 and 15kGy by exposure to a 137Cs source. Increasing radiation doses led to lower counts so elimination of mycoflora was observed at 8kGy. In addition, filamentous fungi exhibited a greater resistance to radiation than yeasts and those that withstood 3.5kGy were mostly Cladosporium spp., Curvularia spp., Fusarium spp. or Aspergillus spp. A. flavus and A. parasiticus have been found to be the most resistant among the species studied. Post

  15. Progress in Aspergillus biofilms%曲霉生物膜研究进展

    Institute of Scientific and Technical Information of China (English)

    唐梦丹; 郑建锋; 赵敬军

    2012-01-01

    Fungal biofilms are an escalating clinical problem associated with mortality rates.In recent years,Aspergillus biofilm has attracted more and more attention from researchers.It has been evidenced that biofilms are associated with the invasive infection by Aspergillus.Biofilms may help Aspergillus to escape host immune response and make it difficult to eliminate Aspergillus and control Aspergillus infection.This paper describes the formation and structure of Aspergillus biofilm,factors influencing biofilm formation and mechanisms underlying the biofilm-induced antifungal resistance of Aspergillus.%真菌生物膜的形成是与临床死亡率密切相关的一个重要问题.近年来,曲霉生物膜日益受到研究人员的关注,研究发现,在侵袭性曲霉病感染中大多数存在着生物膜的感染源.曲霉形成生物膜以后可以逃逸宿主的免疫作用,在感染部位难以清除,是临床上难治性感染的重要原因.概述曲霉生物膜形成过程及结构、曲霉生物膜形成的影响因素以及生物膜形成导致抗真菌药耐药的机制等几个方面的研究进展.

  16. Rabia en Potos flavus identificados en el departamento de madre de dios, Perú

    Directory of Open Access Journals (Sweden)

    Elena Vargas-Linares

    Full Text Available El Potos flavus es un mamífero nocturno que habita en bosques neotropicales desde Centroamérica hasta Sudamérica. Se realizó un estudio de cuatro caso