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Journal of Food Protection Oct 2021This study was carried out to evaluate the prevalence of mycobiota and aflatoxin (AF) B1 contamination in sesame seeds from rainfed and irrigated zones of the Punjab,...
ABSTRACT
This study was carried out to evaluate the prevalence of mycobiota and aflatoxin (AF) B1 contamination in sesame seeds from rainfed and irrigated zones of the Punjab, Pakistan. For this purpose, 100 sesame seed samples were collected directly from the fields of major sesame-producing areas in rainfed and irrigated zones. The agar plate method was used for isolation of mycobiota, and thin-layer chromatography was used to determine AFB1 concentrations. Seed samples were then stored for 12 months. After 12 months, the seeds were again analyzed for mycobiota and AFB1 for comparison. All samples were positive for fungal growth under fresh and stored conditions. Twenty-one fungal species of 10 genera were isolated. Aspergillus flavus was the most prevalent contaminant found in fresh and stored sesame seeds from rainfed and irrigated zones, followed by Aspergillus niger, Alternaria alternata, and Fusarium oxysporum. The least prevalent fungi were Aspergillus ochraceus and Cladosporium oxysporum. Analysis revealed that 92% of fresh and 99% of stored seed samples were contaminated with AFB1. In the rainfed zone, 88% of fresh and 100% of stored seed samples were contaminated with AFB1, with mean concentrations of 15.74 and 33.8 ppb, respectively. In the irrigated zone, 96% of fresh and 98% of stored seed samples were contaminated with AFB1, with mean concentrations of 20.5 and 27.56 ppb, respectively. AFB1 concentrations >20 ppb were found in 20% of fresh and 100% of stored seeds samples from the rainfed zone and in 28% of fresh and 60% of stored samples from the irrigated zone and thus were not fit for human consumption as per the maximum limit (20 ppb) assigned by the U.S. Food and Drug Administration and the Food and Agriculture Organization of the United Nations. This report is the first on the mycobiota and AFB1 contamination in sesame seeds from rainfed and irrigated zones of the Punjab, Pakistan. These baseline data are an initial step in the effort to deal with this significant food safety issue.
Topics: Aflatoxin B1; Aflatoxins; Alternaria; Cladosporium; Food Contamination; Fusarium; Humans; Pakistan; Seeds; Sesamum
PubMed: 34086928
DOI: 10.4315/JFP-21-060 -
International Journal of Occupational... Mar 2017The basic care requirement for patients with weakened immune systems is to create the environment where the risk of mycosis is reduced to a minimum.
OBJECTIVES
The basic care requirement for patients with weakened immune systems is to create the environment where the risk of mycosis is reduced to a minimum.
MATERIAL AND METHODS
Between 2007 and 2013 air samples were collected from various wards of a number of hospitals in Kraków, Poland, by means of the collision method using MAS-100 Iso MH Microbial Air Sampler (Merck Millipore, Germany). The air mycobiota contained several species of fungi, and almost 1/3 of it was made up of the species of the . Sixty-one strains of species other than were selected for the research purposes, namely: 28 strains of , 22 strains of and 11 strains of species. Selected fungi underwent a cytotoxicity evaluation with the application of the MTT colorimetric assay (3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide). The assay assesses cell viability by means of reducing the yellow tetrazolium salt to insoluble formazan. A semi-quantitative scale for cytotoxicity grading was adopted: low cytotoxic effect (+) with half maximal inhibitory concentration (IC) for values ranging from 31.251 cm/ml to 7.813 cm/ml, medium cytotoxic effect (++) for values ranging from 3.906 cm/ml to 0.977 cm/ml and the high one (+++) for values ranging from 0.488 cm/ml to 0.061 cm/ml. The absence of cytotoxicity was determined when the IC values was at ≥ 50.
RESULTS
For 48 samples the analyzed fungi displayed the cytotoxic effect with in 26 out of 28 cases, with 11 strains displaying the high cytotoxic effect. The lowest cytotoxicity was displayed by fungi of r in 13 out of 22 cases, and the major fungi of species were toxic (9 out of 11 cases).
CONCLUSIONS
A half of the fungi displayed the low cytotoxic effect. On the basis of the comparison of average cytotoxicity levels it was determined that there were significant differences in the levels of cytotoxicity of the analyzed fungi. However, such statement may not provide grounds for a definite conclusion about the compared species of fungi that display a more cytotoxic effect than others. Int J Occup Med Environ Health 2017;30(2):231-239.
Topics: Air Microbiology; Aspergillus flavus; Aspergillus niger; Aspergillus ochraceus; Hospitals; Mycotoxins; Poland
PubMed: 28366953
DOI: 10.13075/ijomeh.1896.00841 -
Arhiv Za Higijenu Rada I Toksikologiju Jun 2010Fungi produce a large variety of extracellular proteins, organic acids, and other metabolites and can adapt to several environmental conditions. Mycotoxin-producing...
Fungi produce a large variety of extracellular proteins, organic acids, and other metabolites and can adapt to several environmental conditions. Mycotoxin-producing moulds of the genera Aspergillus and Penicillium are common food contaminants. One of the natural ways to protect food from mould contamination is to use essential oils. In this study, we evaluated the effect of essential oils of cinnamon, lavender, rosemary, and sage at 1 % (v/v) concentration in yeast media inoculated with spores (final concentration 106 mL-1 media) of Aspergillus ochraceus ZMPBF 318 and Penicillium expansum ZMPBF 565, alone or in combination, on fungal biomass. Cinnamon showed the best inhibitory effect (100 %). Lavender oil best inhibited the growth of Aspergillus ochraceus (nearly 100 %), and was less successful with Penicillium expansum (having dropped to 57 % on day 28). With cultivation time the inhibitory effect of sage and rosemary oil grew for Aspergillus ochraceus and dropped for Penicillium expansum.These results suggest that fungi can be controlled with essential oils, especially with cinnamon oil.
Topics: Aspergillus ochraceus; Food Microbiology; Oils, Volatile; Penicillium
PubMed: 20587393
DOI: 10.2478/10004-1254-61-2010-2009 -
Applied Microbiology and Biotechnology Nov 2022The fungus Trichoderma arundinaceum exhibits biological control activity against crop diseases caused by other fungi. Two mechanisms that likely contribute to this...
The fungus Trichoderma arundinaceum exhibits biological control activity against crop diseases caused by other fungi. Two mechanisms that likely contribute to this activity are upregulation of plant defenses and production of two types of antifungal secondary metabolites: the sesquiterpenoid harzianum A (HA) and the polyketide-derived aspinolides. The goal of the current study was to identify aspinolide biosynthetic genes as part of an effort to understand how these metabolites contribute to the biological control activity of T. arundinaceum. Comparative genomics identified two polyketide synthase genes (asp1 and asp2) that occur in T. arundinaceum and Aspergillus ochraceus, which also produces aspinolides. Gene deletion and biochemical analyses in T. arundinaceum indicated that both genes are required for aspinolide production: asp2 for formation of a 10-member lactone ring and asp1 for formation of a butenoyl subsituent at position 8 of the lactone ring. Gene expression and comparative genomics analyses indicated that asp1 and asp2 are located within a gene cluster that occurs in both T. arundinaceum and A. ochraceus. A survey of genome sequences representing 35 phylogenetically diverse Trichoderma species revealed that intact homologs of the cluster occurred in only two other species, which also produced aspinolides. An asp2 mutant inhibited fungal growth more than the wild type, but an asp1 mutant did not, and the greater inhibition by the asp2 mutant coincided with increased HA production. These findings indicate that asp1 and asp2 are aspinolide biosynthetic genes and that loss of either aspinolide or HA production in T. arundinaceum can be accompanied by increased production of the other metabolite(s). KEY POINTS: • Two polyketide synthase genes are required for aspinolide biosynthesis. • Blocking aspinolide production increases production of the terpenoid harzianum A. • Aspinolides and harzianum A act redundantly in antibiosis of T. arundinaceum.
Topics: Polyketide Synthases; Gene Expression Regulation, Fungal; Antifungal Agents; Trichoderma; Terpenes; Sesquiterpenes; Lactones; Polyketides
PubMed: 36166052
DOI: 10.1007/s00253-022-12182-9 -
Frontiers in Microbiology 2021G-protein-coupled receptors (GPCRs) are transmembrane receptors involved in transducing signals from the external environment inside the cell, which enables fungi to... (Review)
Review
G-protein-coupled receptors (GPCRs) are transmembrane receptors involved in transducing signals from the external environment inside the cell, which enables fungi to coordinate cell transport, metabolism, and growth to promote their survival, reproduction, and virulence. There are 14 classes of GPCRs in fungi involved in sensing various ligands. In this paper, the synthesis of mycotoxins that are GPCR-mediated is discussed with respect to ligands, environmental stimuli, and intra-/interspecific communication. Despite their apparent importance in fungal biology, very little is known about the role of ochratoxin A (OTA) biosynthesis by and the ligands that are involved. Fortunately, increasing evidence shows that the GPCR that involves the AF/ST (sterigmatocystin) pathway in fungi belongs to the same genus. Therefore, we speculate that GPCRs play an important role in a variety of environmental signals and downstream pathways in OTA biosynthesis. The verification of this inference will result in a more controllable GPCR target for control of fungal contamination in the future.
PubMed: 33643259
DOI: 10.3389/fmicb.2021.631392 -
BMC Microbiology Mar 2021Meat-products are considered an enriched media for mycotoxins. This study aimed to investigate the prevalence of toxigenic Aspergillus species in processed meat samples,...
BACKGROUND
Meat-products are considered an enriched media for mycotoxins. This study aimed to investigate the prevalence of toxigenic Aspergillus species in processed meat samples, HPLC-quantitative measurement of aflatoxin B and ochratoxin A residues, and molecular sequencing of aflR1 and pks genes. One hundred and twenty processed beef meat specimens (basterma, sausage, and minced meat; n = 40 for each) were collected from Ismailia Province, Egypt. Samples were prepared for total mold count, isolation, and identification of Aspergillus species. All samples were analyzed for the production of both Aflatoxin B and Ochratoxin A mycotoxins by HPLC. Molecular identification of Aspergillus flavus and Aspergillus ochraceus was performed using PCR amplification of the internal transcribed spacer (ITS) region; furthermore, the aflR1 and pks genes were sequenced.
RESULTS
The total mold count obtained from sausage samples was the highest one, followed by minced meat samples. The prevalence of A. flavus was (15%), (7.5%), and (10%), while the prevalence of A. ochraceus was (2.5%), (10%), and (0%) in the examined basterma, sausage, and minced meat samples, respectively. Using PCR, the ITS region was successfully amplified in all the tested A. flavus and A. ochraceus strains. Aflatoxin B was detected in six basterma samples (15%). Moreover, the ochratoxin A was detected only in four sausage samples (10%). The aflR1 and pks genes were amplified and sequenced successfully and deposited in the GenBank with accession numbers MF694264 and MF694264, respectively.
CONCLUSIONS
To the best of our knowledge, this is the first report concerning the HPLC-Molecular-based approaches for the detection of aflatoxin B and ochratoxin A in processed beef meat in Egypt. The production of aflatoxin B and ochratoxin A in processed meat constitutes a public health threat. Aflatoxin B is commonly associated with basterma samples. Moreover, ochratoxin A was detected frequently in sausage samples. The routine inspection of mycotoxins in processed meat products is essential to protect human consumers.
Topics: Aflatoxin B1; Animals; Aspergillus; Chromatography, High Pressure Liquid; Food Analysis; Food Microbiology; Meat Products; Ochratoxins
PubMed: 33715621
DOI: 10.1186/s12866-021-02144-y -
Journal of Clinical Microbiology Oct 2014Aspergillus spp. are among the most common causes of opportunistic invasive fungal infections in tertiary care hospitals. Little is known about the prevalence and in...
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.
Topics: Antifungal Agents; Aspergillosis; Aspergillus; Brazil; Calmodulin; Cluster Analysis; DNA, Fungal; DNA, Ribosomal Spacer; Humans; Itraconazole; Microbial Sensitivity Tests; Molecular Sequence Data; Phylogeny; Prevalence; Sequence Analysis, DNA; Triazoles; Tubulin; Voriconazole
PubMed: 25078909
DOI: 10.1128/JCM.01582-14 -
ChemistryOpen Jun 2021Two novel alkaloids compounds together with fifteen know metabolites were identified from Aspergillus ochraceus. The stereochemistry features of the new molecules were...
Two novel alkaloids compounds together with fifteen know metabolites were identified from Aspergillus ochraceus. The stereochemistry features of the new molecules were determined via HRESIMS, NMR, ECD, and XRD analyses. Amongst these, compounds two compounds exhibited potential efficacy as anti-Parkinson's disease with the EC values of 2.30 and 2.45 μM, respectively. ADMET prediction showed that these compounds owned favorable drug-like characteristics and safe toxicity scores towards CNS drugs. Virtual screening analyses manifested that the compounds exhibited not only robust and reliable interactions to adenosine receptors A , but also higher binding selectivity to A receptors than to A and A receptors. Molecular dynamics simulation demonstrated the reliability of molecular docking results and the stability of the complexes obtained with the novel compounds and A receptors in natural environments. It is the first time that anti-PD lead compounds have been identified from Aspergillus ochraceus and targeting adenosine A receptors.
Topics: Adenosine A2 Receptor Antagonists; Animals; Antiparkinson Agents; Aspergillus ochraceus; Cell Line, Tumor; Drug Evaluation, Preclinical; Female; Humans; Male; Mice; Molecular Docking Simulation; Molecular Dynamics Simulation; Neuroprotective Agents; Rats; Receptor, Adenosine A2A; Stereoisomerism
PubMed: 34102706
DOI: 10.1002/open.202100022 -
FEBS Open Bio Dec 2023Proteins in tears, including human lactoferrin (HLF), can be deposited and denatured on contact lenses, increasing the risk of microbial cell attachment to the lens and...
Proteins in tears, including human lactoferrin (HLF), can be deposited and denatured on contact lenses, increasing the risk of microbial cell attachment to the lens and ocular complications. The surfactants currently used in commercial contact lens care solutions have low clearance ability for tear proteins. Chitosan oligosaccharide (COS) binds to a variety of proteins and has potential for use in protein removal, especially in contact lens care solutions. Here, we analyzed the interaction mechanism of COSs hydrolyzed from chitosan from different resources with HLF. The molecular weights (MWs) and concentrations of COSs were key factors for the formation of COS-HLF complexes. Lower MWs of COSs could form more stable COS-HLF complexes. COS from Aspergillus ochraceus had a superior effect on HLF compared with COS from shrimp and crab shell with the same MWs. In conclusion, COSs could bind to and cause a conformational change in HLF. Therefore, COSs, especially those with low MWs, have potential as deproteinizing agents in contact lens care solution.
Topics: Humans; Lactoferrin; Chitosan; Molecular Weight; Oligosaccharides
PubMed: 37872003
DOI: 10.1002/2211-5463.13722 -
Toxins Jan 2023Ochratoxin (OTA) is widely present in a wide range of foods and feeds, causing adverse effects on animals and humans. This study aims to explore the toxicokinetics of...
Ochratoxin (OTA) is widely present in a wide range of foods and feeds, causing adverse effects on animals and humans. This study aims to explore the toxicokinetics of OTA-contaminated materials on the Dezhou male donkey. Donkeys received a single orally dose of 2500 μg OTA/kg BW, obtained from culture material. The concentrations of OTA in plasma collected at 0, 5, 10, 15, 20, 30, 45 min, and at 1, 1.5, 2, 3, 6, 9, 12, 24, 48, 72, 96 and 120 h were detected by HPLC. OTA eliminated in urine and feces were quantified at 6-h intervals up to 24 h and then at 4-h intervals up to 120 h. The results suggested that the maximum concentration of OTA in plasma was observed at 12 h after administration, with a mean value of 10.34 μg/mL. The total excretion in both urine and feces was about 10% of the intake until 120 h.
Topics: Male; Humans; Animals; Toxicokinetics; Ochratoxins; Food Contamination; Aspergillus ochraceus; Feces
PubMed: 36828403
DOI: 10.3390/toxins15020088