Mycoflora and Aflatoxin Contamination of Some Foodstuffs

Analysis was made of the mycoflora and aflatoxin contamination of Rice (Oryza sativa), Beans (Phaseolus vulgaris), Corn (Zea mays), and Groundnut (Arachis hypogaea) sold in four different markets in Sango-Ota, Ogun state, Nigeria. Sixty four samples comprising of four samples of each foodstuff from four food vendors in four different markets was assayed. The samples were contaminated with different species of fungi to include Aspergillus flavus, Aspergillus tamarii, Aspergillus niger, Rhizopus nigricans, Rhizopus oryzae, Saccharomyces cerevisiae, Aspergillus parasiticus, Fusarium moniliforme, Fusarium verticilliodes, Aspergillus ochraceus, Cladosporium cladosporioide, Mucor spp, Trichodema spp, Rhizopus arrhizus and Aspergillus fumigates. Aspergillus flavus and Fusarium spp had the highest rate of occurrence among the isolated fungi. Aflatoxins B1, B2, G1 and G2 were found associated with the samples at concentration ranging from 9 - 25 ppb, 8 - 12 ppb, 6 - 21 ppb, 4 - 8 ppb respectively. The fungal counts were between 6.3 x 102 to 7.0 x 103 cfu/g. The moisture content and the pH of samples were between 10.9 to 28.0% and 6.20 to 6.66 respectively. Effective storage and adherence to HACCP principles will help prevent contamination of foodstuffs with aflatoxigenic fungi

New fungal sources for α-L-Rhamnosidase: an important enzyme used in the synthesis of drugs and drug precursors

Two fungal strains were isolated and tentatively identified as Penicillium VY and Aspergillus VY. All the isolated species show the maximum production on third day in a liquid culture media. The pH optimum was found to be 10.0 for Penicillium VY and 11.0 for Aspergillus VY. The temperature optima were 50ºC in both the cases. The enzyme produced by Penicillium VY was found to be stable in the pH range 3.0-7.0 and 3.0–6.0 in case of Aspergillus VY. The enzyme does not loose activity up to 40º C in case of Penicillium VY and 40ºC in case of Aspergillus VY if exposed for 1 h.
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Aspergillus section Flavi and aflatoxins in Algerian wheat and derived products

Wheat and its derivatives are a very important staple food for North African populations. The aim of this study was to analyze populations of Aspergillus section Flavi from local wheat based on aflatoxins (AFs),cyclopiazonic acid (CPA) and sclerotia production, and also to evaluate AFs-contaminated wheat collected from two different climatic regions in Algeria. A total of 108 samples of wheat were collected during the following phases: pre-harvest, storage in silos and after processing. The results revealed that among the Aspergillus species isolated, those belonging to section Flavi were predominant. Of the 150 strains of Aspergillus section Flavi isolated, 144 were identified as Aspergillus flavus and 6 as Aspergillus tamarii. We showed that 72% and 10% of the A. flavus strains produced AFs and CPA, respectively. Among the 150 strains tested, 60 produced amounts of AFB1 ranging from 12.1 to 234.6 lg/g of CYA medium. Also, we showed that most strains produced large sclerotia. AFB1was detected by HPLC in 56.6% of the wheat samples and derived products (flour, semolina and bran) with contamination levels ranging from 0.13 to 37.42 lg/kg

Survey of fungal infestation of some fish species from Tagwai dam, Minna, Niger State

Survey of Fungal infestation of some species of fish in Tagwai Dam Minna was carried out from March to June 2002. Fungi were isolated from the scale/skin, gills and fins. Twenty-one fungi species were identified from 18 species of fish microbial growth was measured by direct cell count using Stuart colony counter. Most of the fungi encountered were of the mould group and infestation occurred among all the species sampled. The infestation was predominantly by Aspergillus species and the scale/skin was most widely affected. The study showed the identified fungi in order of frequency to be as follows. Aspergillius niger. Rrhizopus spp. Mmucor spp Aspergilus flavum. Aspergillus parasitous. Aspergillus fumigatus, Microsporum canis. Penicillum virridicalumand Fusarium spp respectively. Aspergillus niger occurred on all the species of fish sampled. Barrilius spa and Chrysichrhy auratus longifilis had significantly higher (P0.05) in the mean fungal load in different parts of the body of other fish species sample

Lateral Flow Assays for the Diagnosis of Invasive Aspergillosis: Current Status.

Purpose of reviewDiagnosis during early stages of invasive aspergillosis (IA) and targeted antifungal treatment has the potential to improve survival significantly. Despite advances in the diagnostic arsenal, invasive mold infections remain difficult to diagnose-especially at early stages before typical radiological signs develop. Varying availability and time-to-results are important limitations of current approved biomarkers and molecular assays for diagnosis of IA. Here, we will give an update on the Aspergillus-specific lateral-flow device (LFD) test. We further review promising findings on feasibility of point-of-care (POC) detection of urinary excreted fungal galactomannan-like antigens.Recent findingsPOC LFD assays for detection of Aspergillus antigens are currently in development. The Aspergillus-specific LFD test, which is based on the JF5 antibody (Ab), detects an extracellular glycoprotein antigen secreted during active growth of Aspergillus spp. The test has shown promising results in various studies. In addition, a monoclonal Ab476-based LFD for POC detection of urinary excreted fungal galactomannan-like antigens has been developed but needs further validation.SummaryImportant advances have been made in the development of LFD assays for IA. Most promising is the Aspergillus-specific LFD test; commercial availability is still pending, however. The search for reliable POC tests for other molds, including mucorales, continues

Factors associated with invasive lung aspergillosis and the significance of positive aspergillus culture after liver transplantation

From January 1981 to December 1990, 2180 patients underwent orthotopic liver transplantation at the University of Pittsburgh. Thirty-two patients (1.5%) were identified with invasive aspergillosis (29 lung, 2 intraabdominal, 1 meningitis). Of 29 patients with invasive lung disease, only 23 (79%) had positive culture (Aspergillus fumigatus, 20; Aspergillus flavus, 3). Forty-eight variables were analyzed and compared in 23 patients with invasive disease with positive cultures and 9 patients with colonization only. The variables associated with pulmonary invasive disease, by univariate analysis, were surgical time (P =.03), presence of laparotomies (P =.02), higher creatinine level at time of Aspergillus isolation (P =.01), and use of OKT3 (P =.02). However, in a multivariate analysis, only the last two (creatinine, OKT3) were associated with invasive lung aspergillosis. Of 4 patients with positive abdominal wound culture, 2 had local invasive aspergillosis. Therefore, positive cultures of Aspergillus organisms from respiratory secretions and wound drainage may represent invasive disease and should not be ignored. © 1992 the University of Chicago

Impact of interacting climate change factors on growth and ochratoxin A production by Aspergillus section Circumdati and Nigri species on coffee

The objectives of this study were to evaluate the effect of interacting climate change (CC) factors (water stress [water activity, aw; 0.99-0.90]); temperature [30, 35 °C]; and elevated CO2 [400 and 1000 ppm] on (1) lag phases prior to growth, (2) growth and (3) ochratoxin A (OTA) production by species of Aspergillus sections Circumdati and Nigri on coffee-based media and stored coffee beans. The lag phases, prior to growth, of all strains/species were slightly increased as aw, temperature and CO2 were modified. The interacting CC factors showed that most strains/species examined grew well at 30 °C and slightly less so at 35 °C except for Aspergillus niger (A 1911) which could tolerate the higher temperature. In addition, the interaction of elevated CO2 (1000 ppm) + temperature (35 °C) increased OTA production when compared with 30 °C but only for strains of Aspergillus westerdijkiae (B2), Aspergillus ochraceus (ITAL 14) and Aspergillus steynii (CBS 112814). Most of the strains had optimum growth at 0.95 aw at 35 °C, while at 30 °C the optimum was at 0.98 aw. On stored coffee beans there was only a significant stimulation of OTA production by A. westerdijkiae strains in elevated CO2 (1000) at 0.90 aw. These results suggest differential effects of CC factors on OTA production by species in the Sections Circumdati and Nigri in stored coffee and that for most species there is a reduction in toxin production

Microbiological hazard in buildings based on the example of dwelling houses and public utility buildings in Warsaw

This paper contains preliminary results of mycological research in residential and public buildings in Warsaw and its surroundings. The study focuses on the qualitative survey of fungi in buildings of various categories. It includes research objects divided into six categories depending on the age of the buildings and their use: new buildings and the objects of about twenty years and older, as well as twenty-year single-family houses. Two houses that are in the registry of monuments (National Heritage Institute) were also in the scope of the analysis. There have also been attempts to classify the identified species of fungi into groups of BSL (Biological Safety Level), in order to identify their potential allergenic impact on buildings users. In more than half of the studied objects the most frequently isolated species was Alternaria alternata (55% of cases) and fungi of the genera Aspergillus and Penicillium. Aspergillus niger was identified in 33% of the objects, exclusively in the neglected buildings, including those abandoned for at least one year.W ponad połowie obiektów najczęściej izolowano Alternaria alternata (55% przypadków) oraz grzyby z rodzajów Aspergillus i Penicillium, w tym Aspergillus niger, który zidentyfikowano w 33% badanych obiektów: w budynkach zaniedbanych, w tym niezamieszkałych od przynajmniej rok