Occurrence Of Toxigenic Fungi Research Articles

Occurrence of toxigenic fungi in raw sago starch for commercialisation in Sarawak, Malaysia

Fungi are widely distributed in agricultural settings, and certain species are known to cause infections that can impact public health and agricultural production. This study aims to determine the fungal concentration in the raw sago starch samples and to identify the fungal species in the samples. A total of 50 raw sago starch samples for commercialisation were collected from different districts in Sarawak, Malaysia. Enumeration of the fungal concentration was conducted using the serial dilution technique before identification of the fungal genera using morphological examinations. The fungal species were molecularly confirmed using species-specific polymerase chain reaction targeting the ITS region. The findings of this study found the range of fungal counts was 1.3 × 102 to 2.1 × 104 CFU/g (mean: 8.6 × 103 CFU/g). Morphological examinations followed by molecular confirmation revealed 19 fungal species, including Ceratocystis paradoxa (28.89%; 13/45), and followed by Paecilomyces variotii and Peniophora malaiensis (2.22%; 1/45 of each), Penicillium rolfsii and Pleurostoma richardsiae (8.89%; 4/45 of each), Perenniporia tephropora (4.44%; 2/45), Penicillium brasilianum, Penicillium sumatraense, Penicillium verruculosum, Penicillium citrinum, Paecilomyces niveus, Aspergillus sydowii, Aspergillus caesiellus, Aspergillus terreus, Trichoderma pleuroti, Trichoderma harzianum, Candida blattae, and Phaeoacremonium sp. (2.22%; 1/45 of each). All sago starch samples in this study were contaminated with diverse fungal species including mycotoxin-producing species, and the fungal counts exceeded the permissible limits for human consumption. The outcomes from this study provided a baseline on the level of fungal contamination in sago starch for future risk and mitigation assessment planning and established detailed knowledge of the food safety status in sago starch production from Sarawak, which will form a foundation for future studies.

Efficacy of Gamma Irradiation in Improving the Microbial and Physical Quality Properties of Dried Chillies (Capsicum annuum L.): A Review.

Dried chilli is one of the highly traded spices globally and is well-known for its natural flavour, colour, and unique pungent taste. It is rich in nutrients and has medicinal benefits. During the dehydration and storage process, the proliferation of unwanted microorganisms in dried chilli is unavoidable. Recently, the occurrence of toxigenic fungi and faecal coliforms has been widespread that can cause severe illness and even death. Therefore, sanitation treatment is highly required to decontaminate undesirable microorganisms. Among the common sanitation treatments applied, food irradiation is gaining attention worldwide because of concern for post-harvest loss, foodborne disease, and more stringent regulation in dried chilli trading. Irradiation can successfully preserve dried chilli from pathogenic bacteria with minimal disturbance to critical physical properties, such as pungency and colour. It can also save dried chilli from secondary pollution by storing it into final packing before radiation which helps in distribution to market promptly after treatment. Furthermore, radiation does not leave any chemical residues after the treatment, ensuring the quality and safety of the dried chilli. The efficiency of radiation depends mainly on the initial level of contamination and the persistence of the harmful microorganism. A low irradiation dose is sufficient for dried chili to reduce microbial load to an acceptable level and eliminate pathogens even though a minimum radiation dose of 10 kGy is required for complete sterilization. However, high dosage may affect the colour properties. Gamma radiation, X-ray, and electron beam radiation are the three approved radiation sources for dried chilli in most countries and proven effective for dried chilli preservation. Thus, this review paper highlights the microbial and physical quality properties in gamma radiated dried chillies.

Occurrence of Toxigenic Fungi and Mycotoxins on Root Herbs from Chinese Markets

Herbs derived from roots, leaves, flowers, or fruits of plants are unavoidably contaminated with fungi and mycotoxins during growth, harvest, and storage, thereby posing a health threat to humans. Especially, root herbs (RHs) are more easily contaminated with fungi and mycotoxins because the roots are in direct contact with the soil. Here, we investigated the occurrence of fungi, aflatoxins (AFs), and ochratoxin A (OTA) in eight RHs that are used as medicines, beverages, dietary supplements, and functional foods in China and other countries. Morphological observation and MultiGeneBlast (β-tubulin and calmodulin) were used to identify the potentially toxigenic fungi. Of the 48 samples tested, all were contaminated by fungi, and 1,844 isolates belonging to 25 genera were detected. The genera Aspergillus and Penicillium, which contain potentially toxigenic fungal species, represented a frequency of 10 and 25%, respectively. Thirty-three isolates of Aspergillus flavus, Aspergillus parasiticus, Aspergillus niger, and Penicillium polonicum were arbitrarily selected for analysis of their toxigenic potential. Five of 13 isolates of A. flavus and 1 isolate of A. parasiticus produced AFs, whereas OTA production was not detected for any of the isolates of A. niger and P. polonicum. The occurrence of AFs and OTA in the 48 samples of eight RHs was tested by ultraperformance liquid chromatography-tandem mass spectrometry; 37.50% of samples from six RHs were contaminated with AFs and 16.67% of samples from four RHs were contaminated with OTA. Seven (14.58%) and four (8.33%) samples of ginseng, polygala, and liquorice exceeded the permissible limits of aflatoxin B1 and AFs, respectively. Because ginseng, polygala, and liquorice are widely used as herbs, dietary supplements, and functional foods, the high frequency of AF contamination of these herbs indicated by our current study warrant attention to raise public awareness.

Toxigenic fungal and mycotoxin contamination of maize samples from different districts in Serbia

This study was carried out in order to investigate the natural occurrence of toxigenic fungi and levels of zearalenone (ZEA), deoxynivalenol (DON) and aflatoxin B1 (AFB1) in the maize stored immediately after harvesting in 2016 and used for animal feed in Serbia. A total of 22 maize samples were collected from four different districts across the country: City of Belgrade (nine samples), Sumadija (eight samples), Podunavlje (four samples) and Kolubara (one sample). Toxigenic fungi were identified according to the morphological characteristics whereas the mycotoxins contamination were detected using biochemistry enzyme-linked immuno-sorbent (ELISA) assay. The tested samples were mostly infected with Aspergillus, Fusarium and Penicillium spp., except that one sample originated from Kolubara was not contaminated with Aspergillus species. Fusarium graminearum was the most common species in the maize sample from Kolubara district (60%), F. verticillioides in the maize samples from Podunavlje (43.75%) and City of Belgrade (22.4%) districts, and Penicillium spp. in the maize samples from Sumadija district (26.38%). In the analysed maize samples the presence of Aspergillus species was low (0-1.78%). Mycotoxicological analysis revealed the presence of zearalenone (ZEA), deoxynivalenol (DON) and aflatoxin B1 (AFB1) in all the investigated samples, except that DON and AFB1 were not recorded in the samples from Podunavlje and Kolubara districts, respectively. The investigated samples were highly contaminated with ZEA, with incidence of 100% for the samples from Sumadija, Podunavlje and Kolubara districts and 88.89% for the samples from City of Belgrade district. In addition, the samples contamination with DON was 100% and 22.2% for the samples from Sumadija, Kolubara and City of Belgrade, districts, respectively. The highest number of AFB1 positive samples was found in Sumadija district (87.5%), while in the City of Belgrade and Podunavlje districts, 55.56% and 50% AFB1 positive samples were established, respectively. Generally, remarkable infection of all the tested samples with toxigenic fungal species from Aspergillus, Fusarium and Penicillium genera were recorded. In addition, high contamination with mycotoxins ZEA, DON and AFB1 were also recorded; nevertheless, only in one sample the level of DON exceeded the allowed legal limit (1750 ?g kg-1) according to Regulation for unprocessed maize. Therefore, permanent mycological and mycotoxicological analyses of maize grain are necessary for risk assessment of fungal and mycotoxin contamination throughout the food chain.

Occurrence of Toxigenic Fungi and Mycotoxins during Smoked Paprika Production

'La Vera' smoked paprika is a traditional Spanish product regulated under a protected designation of origin. Mycotoxins are possible contaminants in paprika, yet there is little information about mycotoxin production during the processing of smoked paprika. In this study, samples of dried peppers collected from six traditional dryers from four producers were evaluated for physicochemical parameters, mycotoxins, and mycotoxin-producing fungi. The moisture content and water activity of the peppers ranged from 11.0 to 16.3% and 0.513 to 0.611, respectively, with significant differences among the dryers (P ≤ 0.05). Culture methods revealed fungal counts of 2.6 to 5.7 log CFU/g, with significant differences among the dryers (P ≤ 0.05), and real-time PCR revealed aflatoxin-producing fungi (2.00 to 3.42 log CFU/g) in all dryers. However, mycotoxins were not detected in dried pepper samples. Sixty-seven mold species isolated from dried peppers were identified by sequencing of the ITS1-5.8S rRNA-ITS2 region and characterized by mycotoxigenic ability. Four isolates of Penicillium expansum, four isolates of Penicillium thomii, and one isolate of Aspergillus parasiticus were producers of patulin, penicillic acid, and aflatoxins, respectively. Toxigenic fungi were inoculated onto smoked dried peppers and stored at 84, 91, 94, and 97% relative humidity (RH) at 20°C for 30 days. Patulin was not detected under any of these conditions. Penicillic acid was detected in dried samples stored at 91 to 97% RH, although the optimum condition was isolate dependent. Aflatoxins G2, B1, and B2 were detected at 91 to 97% RH, with the highest concentrations at 94% RH. According to our results, hazard analysis critical control point systems should be used to control the drying and storage conditions of dried peppers until the milling step to avoid rehydration, which encourages fungal growth and mycotoxin production.

Occurrence of Toxigenic Fungi and Aflatoxin Potential of Aspergillus spp. Strains Associated with Subsistence Farmed Crops in Haiti

Subsistence farming and poor storage facilities favor toxigenic fungal contamination and mycotoxin accumulation in staple foods from tropical countries such as Haiti. The present preliminary study was designed to evaluate the occurrence of toxigenic fungi in Haitian foodstuffs to define the mycotoxin risk associated with Haitian crops. The objectives of this research were to determine the distribution of toxigenic fungi in the Haitian crops maize, moringa, and peanut seeds and to screen Aspergillus section Flavi (ASF) isolates for production of aflatoxins B1 and G1 in vitro. Maize, moringa, and peanut samples were contaminated by potential toxigenic fungal taxa, mainly ASF and Fusarium spp. The isolation frequency of Aspergillus spp. and Fusarium spp. was influenced by locality and thus by farming systems, storage systems, and weather conditions. Particularly for ASF in peanut and maize samples, isolation frequencies were directly related to the growing season length. The present study represents the first report of contamination by toxigenic fungi and aflatoxin in moringa seeds, posing concerns about the safety of these seeds, which people in Haiti commonly consume. Most (80%) of the Haitian ASF strains were capable of producing aflatoxins, indicating that Haitian conditions clearly favor the colonization of toxigenic ASF strains over atoxigenic strains. ASF strains producing both aflatoxins B1 and G1 were found. Understanding the distribution of toxigenic ASF in Haitian crops and foodstuffs is important for determining accurate toxicological risks because the toxic profile of ASF is species specific. The occurrence of toxigenic fungi and the profiles of the ASF found in various crops highlight the need to prevent formation of aflatoxins in Haitian crops. This study provides relevant preliminary baseline data for guiding the development of legislation regulating the quality and safety of crops in this low-income country.

Occurrence of toxigenic fungi and ochratoxin A in Ethiopian coffee for local consumption

Information on the presence of ochratoxin A (OTA) in local Ethiopian coffee is scarce. Therefore, the objective of this study was to type the fungal and mycotoxin contamination levels in Ethiopian coffee consumed by the local community. Coffee samples were collected from six major coffee growing districts in Jimma zone of Oromiya regional state in Ethiopia. Total fungal incidence mounted up to 87% and Aspergillus (79%), Fusarium (8%) and Penicillium (5%) were the predominant toxigenic genera. OTA producing species A. westerdijkiae, Aspergillus ochraceus, and Aspergillus steynii were identified for the first time in Ethiopia and were shown to be the predominant species while aflatoxin (AF) producing Aspergillus species were scarce. Using an in vitro approach, the OTA production potential was assessed under standardized conditions. Based on this experiment, it was concluded that Aspergillus westerdijkiae isolates were clearly the most potent producers of OTA. The median OTA level in the locally sold Ethiopian coffee was 1.53 μg/kg. Notwithstanding this low median value, significant differences in fungal and toxin incidences were observed between the different coffee processing types, coffee sample types, and storage characteristics.

Fungal and mycotoxin contamination of maize hybrids in different maturity groups

In the present study, the frequency of toxigenic fungi and occurrence of aflatoxin B1 (AFB1), deoxynivalenol (DON) and total fumonisins (FBs) in the kernels of six maize hybrids from different FAO maturity groups (ZP 341, ZP 427, ZP 434, ZP 560, ZP 606, ZP 666) in three localities (Belosavci, Ladjevci and Divci) in Serbia, during the harvest in 2013, was investigated. Using standard mycological tests of maize kernels, the presence of potentially toxigenic fungi species from the genera Aspergillus, Fusarium and Penicillium was found. In the studied localities, species Fusarium verticillioides was the most frequently isolated from the most hybrids, with a maximum frequency of 30%, while the presence of Aspergillus spp. ranged from 0 to 16%, and Penicillium spp. from 0 to 20%. By applying Immunoadsorbent enzymatic assay (ELISA) the concentrations of AFB1, DON and FBs were determined in maize. The differences between tested hybrids in the level of mycotoxins in kernels were statistically significant (P?0.01) for DON and FBs, but not for the content of AFB1. Also, the interaction between the hybrid and location was significant (P?0.01) for the level of DON and FBs, while there was no statistical significance for the level of AFB1. Maximum values of AFB1, DON and FBs level were 1.02 ?g kg-1 (ZP 427), 12 ?g kg-1 (ZP 341) and 1528.56 ?g kg-1 (ZP 427). The concentrations of the tested mycotoxins in kernels did not exceed the maximum allowed limits stipulated by Serbian regulations (Sluzbeni glasnik RS, 2014). Given that agro-ecological conditions in Serbia are favourable for the occurrence of toxigenic fungi and their mycotoxins, it is necessary to exert the control of maize kernels annually, in harvest and postharvest periods.

Occurrence of toxigenic fungi and determination of mycotoxins by HPLC-FLD in functional foods and spices in China markets

Twenty-four samples including 14 functional foods and 10 spices obtained from Chinese markets were examined for their mould profile. The mycotoxin contamination levels were also determined by an optimized HPLC-FLD method. 124 fungal isolates belonging to four different genera were recovered with Aspergillus and Penicillium as predominant fungi, with an incidence of 66.1% and 15.3%, respectively. In functional foods Aspergillus niger section (57.1%) was isolated more frequently, followed by Aspergillus flavi section (50.0%) and Aspergillus ochraceus section (21.4%), with the most contaminated samples being Coix seeds. Similar fungal presence and frequency were encountered in spice with A. niger section group (60.0%) and A. flavi section (40.0%) as main fungi. Cumin and Pricklyash peel samples showed the highest fungal contamination. Four functional foods and three spices were found to be positive at low levels for mycotoxins including aflatoxin B1 (up to 0.26μg/kg) and ochratoxin A (OTA) (5.0μg/kg). The more frequently detected mycotoxin was AFB1 (16.7%).

Occurrence of toxigenic fungi in maize and maize-gluten meal from Pakistan

The present study was designed to isolate and identify toxigenic mycoflora of maize and maize-gluten meal. A total of 82 samples of maize and 8 samples of maize-gluten meal were collected from Faisalabad district of Pakistan over a period of two years. These samples were inoculated on different culture media. Fungal contamination of maize and maize-gluten was 56% and 75% of samples, respectively. Isolation frequencies of different genera isolated from maize were Aspergillus 33%; Penicillium 28%; Fusarium 10%; and Alternaria 1%. Isolation frequency among species was maximum for P. verrucosum , followed by A. niger aggregates, A. ochraceous , A. flavus , P. chrysogenum , A. parasiticus , A. carbonarius , Fusarium spp. and Alternaria spp. Relative density of Aspergillus isolates was maximum for A. niger aggregates and A. ochraceous (30% each) followed by A. flavus (26%), A. parasiticus (11%) and A. carbonarius (3%). Percentage of toxigenic fungi among Aspergillus isolates was 52%. Aflatoxigenic isolates of A. flavus and A. parasiticus were 43 and 67% and ochratoxigenic isolates of A. carbonarius , A. ochraceous and A. niger aggregates were 100, 63 and 38%, respectively. Aspergillus parasiticus produced higher concentrations of AFB1 (maximum 1374.23 ng g-1) than A. flavus (maximum 635.50 ng g-1). Ochratoxin A production potential of A. ochraceous ranged from 1.81 to 9523.1 ng g-1, while in A. niger aggregates it was 1.30 to 1758.6 ng g-1. Isolation frequencies of fungal genera from maize-gluten meal were Aspergillus (63%) and Penicillium (50%). A. flavus was the most frequently isolated species. Percentage of toxigenic fungi among Aspergillus isolates was 40%. Aflatoxigenic isolates of A. flavus were 33% and ochratoxigenic isolates of A. ochraceous were 100%.

Occurrence of toxigenic fungi in ochratoxin A contaminated liquorice root

Fungi associated with ochratoxin A (OTA)-contaminated liquorice root and their capabilities for OTA production were investigated. Medicinal materials of mouldy liquorice root were collected from herbal markets located in Jiangxi, Zhejiang, Henan provinces and Beijing, China, respectively. Sixteen fungal species belonging to Penicillium, Aspergillus, Eurotium, Fusarium, Mucor and Scopulariopsis were isolated; the fungal composition was different in each liquorice root sample. Penicillium polonicum was predominant, comprising 54% of the total isolates in the liquorice root sample from Jiangxi province, which was contaminated with OTA at the highest level. In other samples with lower OTA contents, species of Aspergillus and Eurotium were predominant. OTA production of representative strains on rice media was detected by LC-MS/MS; all Penicillium polonicum isolates and a P. chrysogenum were ochratoxigenic; OTA concentrations ranged from 6.94 to 217.37 ng g−1. This is the first study to report P. polonicum as an OTA-producing fungus. OTA contamination of mouldy liquorice root constitutes a major health hazard in consumption. This situation demands urgent and undivided attention.

Occurrence of toxigenic fungi in herbal drugs

The increase in the consumption of natural drugs have made their use a Public Health problem due to the possibility of access to products without adequate conditions of use. The concern with the quality of the natural products is due to the potential fungal contamination and the risk of the presence of mycotoxins. Ninety-one samples of medicinal plants were evaluated for the fungal contamination and the mycotoxigenic potential of Aspergillus and Penicillium isolated from the samples. Results indicated that predominant mycoflora was distributed in 10 genera. From these, 89.9% of the isolates corresponded to genera Aspergillus and Penicillium, which are extremely important from the mycotoxicological standpoint. 21.97% of the Aspergillus and Penicillium isolates proved to have the ability for producing aflatoxins (42.9%), ochratoxin A (22.4%) and citrinine (34.7%). The presence of toxigenic moulds represents a potential risk of mycotoxin contamination and considering the worldwide increased use of herbal products as alternative medicines, it is necessary setting standards for toxigenic moulds in crude herbal drugs in order to reduce the risks for consumers' health.

Mycotoxigenic Aspergillus flavus from ginger and turmeric consumed in the Niger Delta Region of Nigeria

Ginger and turmeric sold in the open markets and retail outlets in southern Nigeria were sampled between April and August, 2017. This period coincided with the first bimodal peak of the rainy season of the 2017 cropping season. Malt extract agar (MEA) and Dichloran 18% glycerol (DG18) media were used to isolate fungi from samples with or without surface sterilisation. Aspergillus spp isolated were examined for the production of orange-yellow pigmentation and blue fluorescence on the reverse side of the plate on CAM under UV light. Aflatoxin production by Aspergillus flavus on yeast extract sucrose (YES) was verified quantitatively using High Performance Liquid Chromatography (HPLC). Data showed that Fusarium, Penicillium and Aspergillus spp were the dominant fungal flora. Toxigenic isolates of A. flavus; AFg1, AFg3, AFt1, and AFt3 produced both orange-yellow pigmentation and blue fluorescence on CAM. The production of AFB1 and AFB2 on YES medium was confirmed using HPLC. The occurrence of toxigenic fungi indicates that there is a potential risk of mycotoxin contamination in ginger and turmeric consumed in southern Nigeria and problems can arise from contamination with aflatoxins.