2 Practical Up to Date and Clear Mold Books with Solutions by Dr. Schaller
1: J Appl Microbiol. 2007 Nov 15 [Epub ahead of print]
Related Articles, Links
Fungi and selected mycotoxins from pre- and postfermented corn silage.
Gonz�lez Pereyra ML, Alonso VA, Sager R, Morlaco MB, Magnoli CE, Astoreca AL, Rosa CA, Chiacchiera SM, Dalcero AM, Cavaglieri LR.
Departamento de Microbiolog�a e Inmunolog�a, Universidad Nacional de R�o Cuarto, R�o Cuarto, C�rdoba, Argentina.
Aim: To determine fungal genera, Aspergillus and Fusarium species and aflatoxin B(1) (AFB(1)), zearalenone (ZEA), deoxynivalenol (DON), fumonisin B(1) (FB(1)) contamination from pre- and postfermented corn silage produced in the most important region of Argentina where silage practice is developed. Methods and Results: Sampling of corn silos was performed manually through silos in transects at three levels: upper, middle and low sections. AFB(1) and FB(1) were quantified by high-performance liquid chromatography, zearalenone by enzyme-linked immunosorbent assay and DON by gas chromatography. Over 90% of the samples showed counts higher than 1 x 10(4) CFU g(-1). Aspergillus flavus and Fusarium verticillioides were the prevalent species. Some tested samples were contaminated with AFB(1), ZEA, DON and FB(1). Conclusions: This study demonstrates the presence of fungi and AFB(1), ZEA, DON and FB(1) contamination in corn silage in Argentina. Significance and Impact of the Study: This manuscript makes a contribution to the knowledge of mycotoxins in Argentinean silage in particular because the environmental conditions in this country differ from those of most reports. The comparison of pre- and postfermentation silage is also outstanding. Therefore, information on fungi and mycotoxins present in silage - an increasingly popular commodity - is useful to estimate potential risk for animal and human health.
PMID: 18005347 [PubMed - as supplied by publisher]
2: Sci Total Environ. 2007 Dec 15;388(1-3):16-23.
Related Articles, Links
Ochratoxin A production in relation to ecophysiological factors by Aspergillus section Nigri strains isolated from different substrates in Argentina.
Astoreca A, Magnoli C, Barberis C, Chiacchiera SM, Combina M, Dalcero A.
Departamento de Microbiolog�a e Inmunolog�a, Facultad de Ciencias Exactas, F�sico-Qu�micas y Naturales, Universidad Nacional de R�o Cuarto, R�o Cuarto, C�rdoba, Argentina. aastoreca@exa.unrc.edu.ar
Contamination of foodstuff with mycotoxins such as ochratoxins is a major matter of concern for human and animal health. In Aspergillus species, ochratoxin synthesis depends on several environmental factors. The aims of this work were to evaluate the effect of water activity (0.995-0.85), temperature (15, 25 and 30 degrees C), incubation time (7, 14 and 21 days) and their interactions on OTA production on peanut, maize kernels, dried grapes and coffee beans meal extract agar medium by eight strains of Aspergillus section Nigri isolated from human food in Argentina. The optimum temperature for OTA production was 25 or 30 degrees C depending on the strains assayed, in most cases the highest OTA levels were achieved after 7 days of incubation, whereas this situation occurred at 15 degrees C after 14 days of incubation for only one strain. The maximum OTA level was obtained at earlier growth states when incubation temperature increased. In general, OTA concentration increased as water activity (a(W)) increased with no significant production at 0.85-0.91 a(W) under all temperature levels tested. Production occurred over a range of temperatures (15-30 degrees C) with optimum production at 30 degrees C depending on a(W) assayed. The knowledge of Aspergillus section Nigri ecophysiology is critical in the development and prediction of the risk models of raw material and final product contamination by these species under fluctuating and interacting environmental parameters.
Publication Types:
- Research Support, Non-U.S. Gov't
PMID: 17920659 [PubMed - in process]
3: Allergy Asthma Proc. 2007 Jul-Aug;28(4):489-96.
Related Articles, Links
Using rare diseases as models for biobehavioral research: allergic bronchopulmonary aspergillosis.
Greenberger PA, Yucha CB, Janson S, Huss K.
Division of Allergy-Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA. p-greenberger@northwestern.edu
Biobehavioral science explores links between biological, psychosocial, and behavioral factors and health. Maintaining positive health outcomes over time and across a variety of populations and settings requires understanding interactions among biological, behavioral, and social risk factors as well as other variables that influence behavior. Some barriers to biobehavioral research are related to performing biobehavioral research along the natural history of an illness, limitations in existing methodologies to assess the biological impact of behavior, the unknowns relating to impact of behavior on biology, and lack of valid and reliable biobehavioral methods to assess outcomes. A rare disease, such as allergic bronchopulmonary aspergillosis (ABPA) can be used as a model of biobehavioral research. ABPA complicates asthma and cystic fibrosis. It is a hypersensitivity reaction to Aspergillus fumigatus in most cases. ABPA can be classified into five stages: acute, remission, exacerbation, steroid-dependent asthma, and fibrotic or end stage. Because of its rarity, there can be delays in diagnosis. Treatment has used oral corticosteroids and antifungal agents in addition to management of asthma or cystic fibrosis. The National Institute of Nursing Research held an invitational 2-day working group meeting on July 15-16, 2004 with biobehavioral, biological, and immunologic science experts to examine current knowledge of biobehavioral research and to provide recommendations for additional research. The focus was on biobehavioral methods of measurement and analysis with interdisciplinary/biobehavioral approaches. This article is an outcome of this meeting.
Publication Types:
- Consensus Development Conference
- Research Support, Non-U.S. Gov't
- Review
PMID: 17883921 [PubMed - indexed for MEDLINE]
4: Int J Food Microbiol. 2007 Oct 20;119(1-2):11-6. Epub 2007 Jul 31.
Related Articles, Links
Biodiversity of complexes of mycotoxigenic fungal species associated with Fusarium ear rot of maize and Aspergillus rot of grape.
Logrieco A, Moretti A, Perrone G, Mul� G.
Institute of Sciences of Food Production, National Research Council, ISPA, Via G. Amendola 122/O, 70126 Bari, Italy.
Fusarium ear rot of maize and Aspergillus rot of grape are two examples of important plant diseases caused by complexes of species of mycotoxigenic fungi. These complexes of species tend to be closely related, produce different classes of mycotoxins, and can induce disease under different environmental conditions. The infection of maize and grape with multiple fungal species and the resulting production of large classes of mycotoxins is an example of mutual aggressiveness of microorganisms toward host species as well as to humans and animals that eat feed or food derived from the infected and contaminated plants. Infection of crop plant with a complex of microbial species certainly represents a greater threat to a crop plant and to human and animal health than infection of the plant with a single fungal species.
PMID: 17765992 [PubMed - in process]
5: Mol Ecol. 2007 Oct;16(20):4401-17.
Related Articles, Links
Recombination, balancing selection and adaptive evolution in the aflatoxin gene cluster of Aspergillus parasiticus.
Carbone I, Jakobek JL, Ramirez-Prado JH, Horn BW.
Center for Integrated Fungal Research, Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA. ignazio_carbone@ncsu.edu
Aflatoxins are toxic and carcinogenic polyketides produced by several Aspergillus species that are known to contaminate agricultural commodities, posing a serious threat to animal and human health. Aflatoxin (AF) biosynthesis is almost fully characterized and involves the coordinated expression of approximately 25 genes clustered in a 70-kb DNA region. Aspergillus parasiticus is an economically important and common agent of AF contamination. Naturally occurring nonaflatoxigenic strains of A. parasiticus are rarely found and generally produce O-methylsterigmatocystin (OMST), the immediate precursor of AF. To elucidate the evolutionary forces acting to retain AF and OMST pathway extrolites (chemotypes), we sequenced 21 intergenic regions spanning the entire cluster in 24 A. parasiticus isolates chosen to represent the genetic diversity within a single Georgia field population. Linkage disequilibrium analyses revealed five distinct recombination blocks in the A. parasiticus cluster. Phylogenetic network analyses showed a history of recombination between chemotype-specific haplotypes, as well as evidence of contemporary recombination. We performed coalescent simulations of variation in recombination blocks and found an approximately twofold deeper coalescence for cluster genealogies compared to noncluster genealogies, our internal standard of neutral evolution. Significantly deeper cluster genealogies are indicative of balancing selection in the AF cluster of A. parasiticus and are further corroborated by the existence of trans-species polymorphisms and common haplotypes in the cluster for several closely related species. Estimates of Ka/Ks for representative cluster genes provide evidence of selection for OMST and AF chemotypes, and indicate a possible role of chemotypes in ecological adaptation and speciation.
Publication Types:
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.
PMID: 17725568 [PubMed - in process]
6: Ann Agric Environ Med. 2007;14(1):173-86.
Related Articles, Links
Factors determining accumulation of mycotoxin producers in cereal grain during harvesting.
Lugauskas A, Raila A, Zvicevicius E, Railiene M, Novosinskas H.
Laboratory of Biodeterioration Research, Institute of Botany, Vilnius, Lithuania. lugauskas@botanika.lt
During the meteorologically contrasting period of 2003-2005, the contamination of winter wheat, malt barley and fodder barley grain with micromycetes during grain harvesting and preparation for storage was investigated. Micromycetes of over 70 species ascribed to 16 genera were isolated and identified, the density of their populations in grain was determined. Micromycetes with a population density of >50% were attributed to dominant species. Short biological characteristic, ecological peculiarities of the dominating micromycetes are provided; factors determining intensity of their development and abilities to synthesise and excrete toxic metabolites are indicated. The importance of grain drying for stabilisation of its contamination with micromycete propagules is highlighted. It is noted that in grain dried in shaft dryer using air at 90 degrees C the number of cfu (colony forming units) was reduced from 2.2 to 8.2 times. When active ventilation is applied, conditions favourable for the development of micromycetes remain longest in the upper layers of the mound. The airflow passing through the layer of damp grain inhibits the development of micromycetes, but an increase of comparative air flow for more than 500 m3x(txh)(-1) did not reduce the abundance of micromycete cfu. After drying Alternaria alternata, Fusarium avenaceum, F. culmorum, Penicillum verrucosum dominated in wheat grain; Aspergillus flavus, Bipolaris sorokiniana, Fusarium chlamydosporum, F. culmorum, F. tricinctum in malts barley grain; Fusarium avenaceum, F. culmorum, F. tricinctum, Alternaria alternata in fodder barley grain. It has been determined that all micromycetes recorded on grain after drying are potential producers of toxic metabolites, i.e. are hazardous to human health.
PMID: 17655196 [PubMed - indexed for MEDLINE]
7: J Med Microbiol. 2007 Aug;56(Pt 8):1101-6.
Related Articles, Links
AIDS-related opportunistic mycoses seen in a tertiary care hospital in North India.
Wadhwa A, Kaur R, Agarwal SK, Jain S, Bhalla P.
Department of Microbiology, Maulana Azad Medical College, New Delhi, India. dranupriyawadhwa@gmail.com
Sixty symptomatic confirmed human immunodeficiency virus (HIV)-positive adult patients, of both sexes, suspected of having a fungal infection were taken as a study population, and the clinicomycological profile was correlated with the immunological status of the patients with particular reference to CD4 counts. Relevant samples were collected and subjected to direct microscopy, fungal culture and serology. CD4 counts were determined by flow cytometry. Patients belonged to the age group of 17-65 years, with a male : female ratio of 4.8 : 1. Heterosexuality was the commonest mode of transmission. Candidiasis was the most common diagnosis (41.7 %), followed by cryptococcosis (10.0 %), and pneumocystinosis and aspergillosis (8.3 % each). Two cases of histoplasmosis were also diagnosed. A low mean CD4 count of <200 cells microl(-1) was seen with most fungal infections. A total of 73 % of patients belonged to World Health Organization (WHO) stage 4, while 23.33 % belonged to stage 3. Thirty one patients (51.67 %) belonged to Centers for Disease Control and Prevention (CDC) stage C3. Various fungal infections correlated well with the mean CD4 counts. It was difficult to correlate statistically WHO and CDC staging because of the small sample size. However, it was possible to assess to a limited extent the possibility of using clinical diagnosis to predict the status of progression of HIV infection in a resource-poor outpatient setting.
Publication Types:
- Multicenter Study
PMID: 17644719 [PubMed - indexed for MEDLINE]
8: Rev Iberoam Micol. 2007 Mar;24(1):24-8.
Related Articles, Links
[Nematophagous fungi of Toxocara canis eggs in a public park of La Plata, Argentina]
[Article in Spanish]
Gortari C, Cazau C, Hours R.
CIC-PBA and CINDEFI (CONICET-UNLP) Facultad de Ciencias Exactas, UNLP, La Plata, Argentina.
Fungi have showed a great potential for the biological control of nematodes. However, they have not been evaluated for the control of animal and/or human parasites transmitted by egg contaminated soils. Environmental contamination with Toxocara spp. eggs is a public health problem. Accidental swallowing of Toxocara canis eggs (a nematode of dogs) usually results on a zoonotic infection (toxocarosis). The objectives of this research were: 1) To test the presence of antagonistic fungi against T. canis in the soil in public places of La Plata city, Argentina, infected with eggs of this parasite, 2) To determine the possible association between biotic and abiotic factors of the soil with the presence of fungal parasites of egg nematodes. Soil samples were tested for: textural type, organic matter (%), pH, presence of egg-parasite fungi, of larvae and of nematode eggs, in particular of Toxocara spp. The studied area showed the following characteristics: pH: 6.6-8.0, organic matter: 1.2-70%, with a predominantly loam texture. The following antagonistic fungal genera were identified: Acremonium, Aspergillus, Chrysosporium, Fusarium, Humicola, Mortierella, Paecilomyces and Penicillium. A prevalence of 70% was detected for nematode eggs, of 33% for Toxocara spp. eggs and of 90% for larvae. No association between the presence of egg-parasite fungi and the considered factors was found. More studies are necessary to know the natural antagonism factors to T. canis eggs for its in situ biological control.
Publication Types:
- English Abstract
PMID: 17592887 [PubMed - indexed for MEDLINE]