Survey of Aspergillus and Fusarium species and their mycotoxins in raw materials and poultry feeds from Córdoba, Argentina

Occurrence of pre- and postharvest multi-mycotoxins in durum wheat grains collected in 2020 and 2021 in two climatic regions of Tunisia

Twenty two mycotoxins in 136 durum wheat collected from Tunisia in 2020 and 2021 were investigated. Mycotoxins were analyzed by UHPLCMS/MS. In 2020, 60.9% of the samples were contaminated with Aflatoxin B1 (AFB1) and/or enniatin. Whereas, in 2021, 34.4% were contaminated by enniatins. AFB1 was detected only in 2020, in the continental region (6/46) and all samples exceeded limits. AFB1 was detected in stored wheat (24-37.8 µg/kg) but also in pre-stored wheat (17-28.4 µg/kg) and in one sample collected in the field (21 µg/kg). Enniatin A1, enniatin B and enniatin B1 were detected in wheat collected in the field (30-7684 µg/kg), pre-storage (42-1266 µg/kg) and storage (65.8-498.2 µg/kg) from the continental region also, in sample collected in pre-storage (31.3-1410 µg/kg) and at harvest (48- 1060 µg/kg). Samples had a water activity less than 0.7 and moisture content ranged between 09-14%. AFB1 level represent a health risk to the Tunisian consumers.

Quantitative Estimation of Aflatoxin Level in Poultry Feed in Selected Poultry Farms

Statement of Novelty. Poultry feed contamination due to mycotoxins is one of the major threats to the growing poultry industry. Surveillance of different mycotoxins, including aflatoxin, is very important to control economic and health hazards associated with these toxins. Studies reporting aflatoxin levels in poultry feed are limited. Therefore, this study was conducted to examine the occurrence of total aflatoxin in poultry feed. This study is the first-ever documentation about the frequency and quantitative estimations of total aflatoxin levels in poultry feed consumed to provide solid feedback to the poultry industrialists and researchers involved in studying the mycotoxins. Objective. Contamination of poultry feed with mycotoxins such as aflatoxin is a major concern for the poultry industry that results in a significant economic loss and directly affects consumers. Monitoring the aflatoxin levels in poultry feed is crucial for controlling economic loss and decreasing the health hazards to the population. This study was conducted to examine the occurrence of total aflatoxin in poultry feed in a high consumption area. Three different poultry feeds, i.e., starter, grower, and finisher, were assessed through continuous sampling from farms. The incidence of positive samples for aflatoxin contamination was 92.5%. Grower feed had the highest frequency (100%) of aflatoxin positive samples and aflatoxin levels with a mean value of 56.34 ppb. Further, the range of moisture content was around 6.8%-10.98%. No significant correlation between humidity and aflatoxin contamination was revealed when analyzed by Pearson's correlation coefficient with r² of 0.05 and p value of 0.13. The results warrant the need for constant monitoring programs for the prevention of aflatoxin contamination in local poultry farms

Reduction of Fusarium proliferatum growth and fumonisin accumulation by ZnO nanoparticles both on a maize based medium and irradiated maize grains

This study evaluated the antifungal effect of ZnO nanoparticles (ZnO-NPs) on Fusarium proliferatum growth and fumonisin accumulation both on a maize-based medium (in vitro) and on irradiated maize grains (in situ). The ZnO-NPs were obtained by drop-by-drop synthesis without further thermal treatment and characterized by scanning electronic microscopy/ energy dispersive X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD). SEM analysis showed them as thin flakes of 200 × 200 nm, ~30 nm thickness and its purity were confirmed by XRD. During the in vitro assay ZnO-NPs (0, 0.8; 4, 8 g L^-1) were evaluated at 25 °C during 21 days under darkness or photoperiod incubation (12/12 h light (cold white and black fluorescent lamps)/darkness) to determine its possible photocatalytic influence. Fumonisins were detected by high performance liquid chromatography coupled to mass spectrometry (HPLC- MS/MS). All ZnO-NPs concentrations significantly affected growth rates and FB₁ accumulation by F. proliferatum RCFP 5033 (p < 0.05). Similar reduction of growth and FB₁ (%) was observed at 0.8 and 8 g L^-1 ZnO-NPs under photoperiod or darkness incubation. FB₁ reduction was observed after 14 and 21 days, although the highest reduction occurred after 14 days under photoperiod incubation (84-98%). No clear light enhancing effect on the antifungal and anti-mycotoxin capability of the ZnO-NPs was observed. Morphological alterations in mycelia and conidia were observed by SEM. Under the in situ assay, the effect of the ZnO-NPs (0, 0.4, 0.8, 2 g kg^-1) on growth rates and fumonisin B₁, B₂ and B₃ accumulation by two F. proliferatum strains was evaluated on irradiated maize grains adjusted to 0.995, 0.98 and 0.97 a_W in darkness at 25 °C during 21 days. Also, zinc acetate at 0.8 g kg^-1 was included to compare their antifungal effect against the same ZnO-NPs concentration. Growth rates decreased significantly as ZnO-NPs concentrations increased. Higher than 60% of growth reduction was observed for both F. proliferatum strains. Zinc acetate significantly reduced growth, although it was less efficient that the same ZnO-NPs concentration. ZnO-NPs reduced total fumonisins accumulation by 71-99% at 0.8-2 g kg^-1 ZnO-NPs and 0.98-0.995 a_W. Moreover, 0.4 g kg^-1 ZnO-NPs also produced significant reduction of the 3 fumonisins. This study showed the application of ZnO-NPs in maize grains could be a low cost and environmental impact strategy to control phytopathogen and toxigenic fungi such as F. proliferatum and to reduce fumonisins accumulation, both during crop development at preharvest stage and during maize storage.

Prevalence of mycotoxigenic fungi and assessment of aflatoxin contamination: a multiple case study along the integrated corn-based poultry feed supply chain in Malaysia

BACKGROUND

Corn, a main feed ingredient in the livestock industry, is one of the most susceptible crops to fungal infection and aflatoxin contamination. Livestock feeding on aflatoxin (AF)-contaminated feed have been shown to experience feed refusal, and decreased growth rate, milk production, and feed efficiency. In poultry, AF poisoning causes weight loss, poor feed efficiency, and reduced egg production and egg weight. The present work therefore aimed to determine the prevalence of mycotoxigenic fungi and the occurrence of AF contamination along the integrated corn-based poultry feed supply chain in Malaysia. A total of 51 samples were collected from different points along the feed supply chain from integrated poultry feed companies. The samples were subjected to mycological analyses (fungal isolation, enumeration, identification), and AFs were quantified by high-performance liquid chromatography equipped with a fluorescence detector (HPLC-FLD).

RESULTS

Samples collected from sampling point 1 (company A) and sampling point 9 (company B) yielded the highest total fungal load (>log 4 CFU g^-1 ). The prevalent fungal genera isolated were Aspergillus, Fusarium, and Penicillium spp. Aflatoxin B₁ was detected in 8.3% of corn samples, and 7.4% of corn-based poultry feed samples along the feed supply chain, whereas AFs B₂ , G₁ , and G₂ were not detected.

CONCLUSION

The incidence of mycotoxigenic fungi along the integrated poultry feed supply chain warrant continuous monitoring of mycotoxin contamination to reduce the exposure risk of mycotoxin intake in poultry. © 2020 Society of Chemical Industry.

Toxigenic fungal species and natural occurrence of mycotoxins in crops harvested in Argentina

Mycotoxins are secondary metabolites produced by fungal species that mainly belong to Aspergillus, Fusarium, Penicillium and Alternaria, which can grow in a variety of crops including cereals, oilseeds and fruits. Consequently, their prevalence in foods and by-products not only affects human and animal health but also causes important losses in both domestic and international markets. This review provides data about toxigenic fungal species and mycotoxin occurrence in different crops commonly grown in Argentina. This information will be relevant to establish adequate management strategies to reduce the impact of mycotoxins on human food and animal feed chains and to implement future legislation on the maximum permitted levels of these fungal metabolites.

The effect of moderate-dose aflatoxin B1 and Salmonella Enteritidis infection on intestinal permeability in broiler chickens

The effect of dietary aflatoxin B₁ (AFB₁) and Salmonella Enteritidis infection on intestinal permeability was investigated. Two hundred 1-day-old male Ross 308 broiler chickens were randomly divided into 4 treatments of 5 replicates each (10 birds per replicate), which were fed ad libitum for 3 weeks with the following treatments: control, chickens fed an AFB₁-free diet; AF, chickens fed an AFB₁-contaminated diet at 470 ng/g; SE, chickens fed an AFB₁-free diet and challenged with 10⁸ cfu of S. Enteritidis per bird at 18 days old; AF + SE, chickens fed an AFB₁-contaminated diet and challenged with 10⁸ cfu of S. Enteritidis per bird at 18 days old. At day 21 of age, chicks received an oral gavage dose of fluorescein isothiocyanate dextran (FITC-dextran) to evaluate gastrointestinal leakage. Blood and intestinal samples were collected to evaluate serum biochemistry and total intestinal IgA secretion, respectively. Liver tissues were aseptically collected to assess bacterial invasiveness and for histomorphological studies. The results showed that chickens receiving AFB₁ presented a significant increment (up to 2.4-fold) in serum FITC-dextran concentration (p < 0.05). Nevertheless, S. Enteritidis infection had no additional effect on gastrointestinal leakage. Furthermore, the ingestion of AFB₁ had no impact on the invasive potential of S. Enteritidis. These results suggest that moderate-dose AFB₁ adversely affects intestinal barrier function resulting in increased gut permeability in broiler chickens.

Development of Indirect Competitive Enzyme-Linked Immunosorbent Assay to Detect Fusarium verticillioides in Poultry Feed Samples

Fumonisins are a group of toxic secondary metabolites that are produced by Fusarium verticillioides which are associated with poultry health hazard and great economic losses. The objective of the present study was to develop an immunological method to detect F. verticillioides in poultry feed samples. An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on a polyclonal antibody against 67 kDa protein of the F. verticillioides 97K exoantigen was developed to detect this fungus. Antibody anti-67 kDa protein showed cross-reactivity against F. graminearum (2⁻7%) and F. sporotrichioides (10%), but no or low cross-reactivity against Aspergillus sp. and Penicillium sp. exoantigens. The detection limit for the 67 kDa protein of F. verticillioides was 29 ng/mL. Eighty-one poultry feed samples were analyzed for Fusarium sp. count, 67 kDa protein of F. verticillioides and fumonisin concentrations. Eighty of the 81 feed samples (98.6%) showed Fusarium sp. contamination (mean 6.2 x 10⁴ CFU/g). Mean 67 kDa protein and fumonisin concentration in the poultry feed samples was 21.0 µg/g and 1.02 µg/g, respectively. The concentration of 67 kDa protein, as determined by ic-ELISA correlated positively (p < 0.05) with fumonisin levels (r = 0.76). These results suggest that this ic-ELISA has potential to detect F. verticillioides and predict fumonisin contamination in poultry feed samples.

Effect of water activity and temperature on the growth of Eurotium species isolated from animal feeds

BACKGROUND

Xerophilic fungi represent a serious problem due to their ability to grow at low water activities causing the spoiling of low and intermediate moisture foods, stored goods and animal feeds, with the consequent economic losses.

AIMS

The combined effect of water activity and temperature of four Eurotium species isolated from animal feeds was investigated.

METHODS

Eurotium amstelodami, Eurotium chevalieri, Eurotium repens and Eurotium rubrum were grown at 5, 15, 25, 37 and 45°C on malt extract agar adjusted with glycerol in the range 0.710-0.993 of water activities.

RESULTS

The cardinal model proposed by Rosso and Robinson (2001) was applied to fit growth data, with the variable water activity at fixed temperatures, obtaining three cardinal water activities (a_wmin, a_wmax, a_wopt) and the specific growth rate at the optimum a_w (μ_opt). A probabilistic model was also applied to define the interface between growth and no-growth. The cardinal model provided an adequate estimation of the optimal a_w to grow and the maximum growth rate. The probabilistic model showed a good performance to fit growth/no-growth cases in the predicted range.

CONCLUSIONS

The results presented here could be applied to predict Eurotium species growth in animal feeds.

Effects of relative humidity on animal health and welfare

Farm animals are sources of meat, milk and eggs for the humans, and animal health ensures the quality and security of these agricultural and sideline products. The animal raising conditions in livestock stations and poultry houses play vital roles in both animal health and production. One of the major factors affecting raising conditions, relative humidity, has not received much attention even though it is important for animal husbandry. In this review, we summarize the impacts of relative humidity on animal health and welfare to draw attention for its importance in the improvement of animal raising conditions in the future.

Effect of γ-irradiation on fumonisin producing Fusarium associated with animal and poultry feed mixtures

Contamination of animal and poultry feeds by Fusarium and the mycotoxin Fumonisin B1 is frequent in the feed supply chain. The present study evaluated the prevalence of fumonisin B1 producing Fusarium among irradiated and non-irradiated animal and poultry feed mixtures. Further, the efficiency of γ-rays (2.5, 5.0, 7.5, and 10.0 kGy) to minimize Fusarium growth and biosynthesis of fumonisin B1 in artificially inoculated feed was evaluated. A total of 108 feed samples were collected in which 45.37% of feed mixtures were contaminated with Fusarium species. Among the contaminated samples, the frequency levels of F. verticillioides and F. proliferatum were 42.59 and 24.07%, respectively. Out of the 98 Fusarium isolates from feed samples, 84.7% of F. verticillioides and 64.28% of F. proliferatum were positive for FUM1 set of primers. Fumonisin B1 biosynthesis by the FUM1 positive isolates in feed was confirmed by LC/MS which recorded 0.1-45 µg/g of feed. Fungal growth and viable count of Fusarium in PDA medium and feed decreased with increasing irradiation dosage. Interestingly, fumonisin content was 11 µg/g of feed in 2.5 kGy irradiated sample as compared to 5 µg/g of feed in non-irradiated control. Ionizing radiation at 7.5 kGy was found lethal for fungal growth and fumonisin production. Our findings suggest that γ-radiation above 7.5 kGy effectively prevented fungal growth in feed mixtures and minimized the exposure of animal and human life to the potential risk of mycotoxin. Also it is necessary to maintain proper storage system for feeds until consumption.

Co-Occurrence of Regulated, Masked and Emerging Mycotoxins and Secondary Metabolites in Finished Feed and Maize-An Extensive Survey

Global trade of agricultural commodities (e.g., animal feed) requires monitoring for fungal toxins. Also, little is known about masked and emerging toxins and metabolites. 1926 samples from 52 countries were analysed for toxins and metabolites. Of 162 compounds detected, up to 68 metabolites were found in a single sample. A subset of 1113 finished feed, maize and maize silage samples containing 57 compounds from 2012 to 2015 from 44 countries was investigated using liquid chromatography and mass spectrometry. Deoxynivalenol (DON), zearalenone (ZEN) and fumonisins showed large increases of annual medians in Europe. Within a region, distinct trends were observed, suggesting importance of local meteorology and cultivars. In 2015, median DON concentrations increased to 1400 μ g·kg - 1 in Austria, but were stable in Germany at 350 μ g·kg - 1 . In 2014, enniatins occurred at median concentrations of 250 μ g·kg - 1 in Europe, at levels similar to DON and ZEN. The latter were frequently correlated with DON-3-glucoside and ZEN-14-sulfate. Co-occurrence of regulated toxins was frequent with e.g., enniatins, and moniliformin. Correlation was observed between DON and DON-3-glucoside and with beauvericin. Results indicate that considerably more than 25% of agricultural commodities could be contaminated with mycotoxins as suggested by FAO, although this is at least partly due to the lower limits of detection in the current survey. Observed contamination percentages ranged from 7.1 to 79% for B trichothecenes and 88% for ZEN.

Inhibitory Effect of Natural Phenolic Compounds onAspergillus parasiticusGrowth

Considering the impact ofAspergillusspecies on crops, it appears to be highly desirable to apply strategies to prevent their growth, as well as to eliminate or reduce their presence in food products. For this reason, the aims of this investigation were to evaluate the effects of ten natural phenolic compounds on theAspergillus parasiticusgrowth and to determine which physicochemical properties are involved in the antifungal activity. According to the results of minimum inhibitory concentration (MIC) values of the individual compounds, isoeugenol, carvacrol, and thymol were the most active phenolic components (1.26 mM, 1.47 mM, and 1.50 mM, resp.), followed by eugenol (2.23 mM). On the other hand, creosol, p-cresol, o-cresol, m-cresol, vanillin, and phenol had no effects on fungal development. Logarithm of the octanol/water partition coefficient (log P), refractivity index (RI), and molar volume (MV) were demonstrated to be the descriptors that best explained the antifungal activity correlated to lipophilicity, reactivity of the components, and steric aspect. These findings make an important contribution to the search for new compounds with antifungal activity.

Mycotoxins and mycotoxigenic fungi in poultry feed for food-producing animals

Moulds are capable of reducing the nutritional value of feedstuff as well as elaborating several mycotoxins. Mycotoxin-contaminated feed has adverse effects on animal health and productivity. Also, mycotoxins may be carried over into meat and eggs when poultry are fed with contaminated feed. In a point prevalence study feedstuff used for poultry nutrition in Argentina was analyzed for fungal flora, natural incidence of selected mycotoxins, and nutritional quality. Ten mould genera were recovered, six of them known to be mycotoxigenic. More than 28 species were determined. Fumonisins were detected in all the samples (median 1,750 ppb). Forty-four out of 49 samples (90%) were contaminated with DON (median 222 ppb) and OTA (median 5 ppb). Also, 44 out of 49 samples were contaminated with aflatoxins (median 2.685 ppb), 42 samples (86%) with ZEA (median 50 ppb), and 38 samples (78%) with T2-toxin (median 50 ppb). Ninety percent of the samples had at least one type of nutritional deficiency. This study indicates the need for continuous assessment of the mycological status of animal feed production, in order to feed animals for optimal performance ensuring food safety.

Exposure of laying hens to mycotoxins through naturally contaminated feed

The objective of the present study was to assess the degree of exposure of laying hens to mycotoxins through naturally contaminated feed and the hygienic quality of feeds. For this purpose, the natural mycoflora and the occurrence of aflatoxins and fumonisins were evaluated in 95 feed samples intended for laying hens collected from January to December 2010 at the Experimental Farm of the State University of Londrina, Northern Paraná State, Brazil. Fusarium was the prevalent genus (99%), followed by Aspergillus (89%). Fusarium spp. were detected at a low contamination level (<103 to <104 colony forming units (cfu)/g) in 54% of the samples. Aspergillus spp. were detected in 73% of the samples at the same contamination range. The total mould and yeast count ranged from 5.0×102 to 8.7×105 cfu/g; in 60% of the samples the values exceeded 1.0×104 cfu/g, the maximum limit established to ensure good hygienic quality of the product. Aflatoxins and fumonisins were detected in 69.7 and 89.5% of the samples, with mean values of 9.61 ng/g and 1.28 µg/g, respectively. The estimated daily intake of fumonisin B1 for laying hens (0.038 mg/kg body weight/day) was below the lowest observed adverse effect level (2 mg/kg body weight/ day). Regarding aflatoxins, most of the positive samples (85.1%) showed aflatoxin levels below the maximum level laid down by the European Commission. Nevertheless, continuous monitoring of mycotoxin levels in laying hen feed is essential to minimize threats to human and animal health. To our knowledge, this is the first report on the degree of exposure of laying hens to mycotoxins through naturally contaminated feed in Brazil.

Natural co-occurrence of fungi and mycotoxins in poultry feeds from Entre Ríos, Argentina

A total of 120 pelleted poultry feed samples from Entre Ríos Province, Argentina, were evaluated. The aims were to investigate (1) the presence of relevant toxigenic fungi, as well as to determine the ability to produce aflatoxins (AFs) by Aspergillus section Flavi isolated strains; and (2) the natural co-occurrence of AFs, fumonisins (FBs), gliotoxin, diacetoxyscirpenol (DAS), HT-2 and T-2 toxin by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Total fungal counts were below the established value (1 × 10⁴ CFU g⁻¹). Aspergillus flavus and A. parasiticus were the only aflatoxigenic species isolated. Co-occurrence of fumonisin B₁ (FB₁), HT-2 and T-2 toxin was detected in 100% of the feeds, with mean levels from 4502 to 5813; 6.7 to 21.6 and 19.6 to 30.3 µg kg⁻¹, respectively. A large number of starter samples were co-contaminated with aflatoxin B₁ (AFB₁), FB₁, HT-2 and T-2 toxins. Gliotoxin and DAS were not found in this survey.