An investigation into the analytical, cytotoxicity and immunotoxicity of mycotoxins found in commercially available pelleted pet foods in Durban, South Africa.

Doctoral Degree. University of KwaZulu-Natal, Durban.Introduction: Dry pelleted dog food in the South African market is available via supermarket, pet stores (standard brands - SB) and veterinary channels (premium brands-PB). Similarly, cat food were viewed in two market segments. Methodology: Representative feeds from both categories were analysed for four main mycotoxins viz. aflatoxins (AF), fumonisin (FB), ochratoxin A (OTA), and zearalenone (ZEA) using standard well-described extraction, characterisation and quantitation processes. Results: All foods showed contamination with fungi (mainly Aspergillus flavus, Aspergillus fumigatus and Aspergillus parasiticus) and mycotoxins (the most prevalent being aflatoxins and fumonisins), irrespective of the brand. This study determined the immunotoxicity of extracts from pelleted dog and cat feed for mycotoxins. Isolated dog peripheral blood mononuclear cells (PBMCs) were treated with feed extracts to determine mitochondrial function, oxidative stress, and markers of cell death using luminometry and flow cytometry. Glutathione was significantly depleted by SB extracts. Markers of apoptosis and necrosis were elevated by both SB and PB feeds when compared to controls, with SB extracts being significantly higher than PB. ATP levels decreased with increased mitochondrial depolarization in cells that were exposed to both feed extracts with SB showing the greatest differences when compared to the control. Cat peripheral blood mononuclear cells (PBMCs) were isolated and treated with various feed extracts to determine oxidative stress (TBARS and GSH assay), mitochondrial integrity and cell death (Luminometry and Flow cytometry). Both PB and SB extracts showed significantly decreased ATP levels and increased mitochondrial depolarization except for the PB acid fraction. Lipid peroxidation was significantly increased in both PB and SB extracts with a concomitant decrease in GSH levels. Phosphatidylserine externalization and necrosis levels were increased in both PB and SB extracts when compared to the control. Executioner caspases-3/7 was also elevated following extract exposure except for the PB acid fraction. Conclusion: There were high levels of fungal contamination and mycotoxins in both categories of feed, regardless of the notion that higher priced PB’s were of a higher quality

A Focus on Aflatoxins in Feedstuffs: Levels of Contamination, Prevalence, Control Strategies, and Impacts on Animal Health

Aflatoxins are mold-synthetized secondary metabolites that are ubiquitously present in agricultural commodities, such as cereals which in turn are substantial part of feed formulation. These toxins are capable of causing disease, exert severe toxic effects, and even death in humans and other animals. Aflatoxins are the only mycotoxins with the regulatory framework, hence we present the legal threshold uphold till now by international and regional control organizations. Additionally, herein we discuss worldwide prevalence of aflatoxins in feeds to demonstrate a global issue and major risks involved in toxin contamination. Furthermore, we present recent data regarding negative effects usually presented by food-producing and companionship animals when ingested. Also, we discuss briefly practical approaches to mitigate aflatoxin burden during feed processing focusing in Good Manufacturing Practice (GMP) and hazard analysis critical control point (HACCP) and we include novel approaches reported in literature to decontaminate feed-containing aflatoxins. Finally, we cite the literature so far published describing the effects of changing climate on aflatoxin production and contamination

Report from the 5th international symposium on mycotoxins and toxigenic moulds : challenges and perspectives (MYTOX) held in Ghent, Belgium, May 2016

The association research platform MYTOX “Mycotoxins and Toxigenic Moulds” held the 5th meeting of its International Symposium in Ghent, Belgium on 11 May 2016.[...

An investigation into the chemopreventive properties of an indigenous herb, Amaranthus lividus, using cancerous cell lines.

Thesis (M.Med.)-University of KwaZulu-Natal, 2005.Chemoprevention may be defined as the inhibition, delay or reversal of carcinogenesis by dietary compounds or their derivatives. "Imifino" is a collective name for many wild plants used predominantly by rural people as herbs in cooking. Many of these herbs possess medicinal properties. As the rural population is at higher risk of exposure to dietary carcinogens, such as mycotoxins, this pilot study was undertaken to determine whether the Amaranthus lividus plant held potential for use in chemopreventive strategies. The plant leaves were extracted to obtain individual solvent fractions. Cytotoxic profiling of the fractions using the SNO oesophageal adenocarcinoma cell line and normal human lymphocytes was achieved using the methylthiazol tetrazolium salt bioreduction assay. The SNO cell line, the A549 lung adenocarcinoma cell line and normal human lymphocytes were utilised for the evaluation of the anti-mycotoxigenic potential of the plant fractions in combination with two important dietary carcinogens, aflatoxin B1 and fumonisin B1. A specific biomarker assay (the induction of reduced glutathione) was employed using the SNO cell line. Flow cytometry was also conducted to determine the apoptotic properties of the acetone fraction on normal human lymphocytes. The results of the anti-mycotoxigenic study showed that certain fractions did have protective effects against both of the carcinogens tested. In addition, these effects were noted in the two cancerous cell lines, which were of different tissue origin. None of the fractions tested were toxic towards the normal human lymphocytes. The glutathione assay indicated that certain acetone fraction dilutions were inducive to reduced glutathione production. This plant is a promising candidate for further investigation concerning chemoprevention and the rural community could be educated on the possible benefits of this herb

Determination of patulin in vegetables and evaluation of its Cytotoxicity on mammalian cells

Monitoring mycotoxin contamination in foods and feeds is important in both human's and animals' health and it is of concern in the regulation of mycotoxins in foods and feeds worldwide. Out of all the contaminants found in food and feeds, mycotoxins are one of the extensively studied contaminants. Mycotoxins are secondary metabolites produced by a wide range of filamentous fungi. Mycotoxins are commonly found in agricultural commodities and derivate. Exposure to high concentrations of mycotoxins may have a toxicological effect on both animals and humans. As mentioned, the major sources of mycotoxin contamination are agricultural commodities and derivative products. For this reason, an ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) method was optimised and validated for the simultaneous determination of patulin, aflatoxins B1, B2, G1, and G2 in vegetable samples. The optimised UHPLC MS/MS method was validated by evaluating the method characteristics such as linearity, limits of detection (LODs), limits of quantification (LOQs), accuracy, and precision. The method exhibited good linearity and it was sensitive with good recoveries. The prevalence and occurrence of fungal and mycotoxin contamination on vegetables from South Africa were determined. A total of hundred and twenty-one vegetable samples such as Carrots, cucumber, onions, potatoes, and sweet potatoes were collected from five South African provinces namely Limpopo Province (LP), Gauteng Province (GP), KwaZulu-Natal (KZN), Eastern Cape Province (EC) and Western Cape Province (WC). The isolated fungal species from the vegetable samples belonged to the Aspergillus, Fusarium, and Penicillium genera. The most predominant fungal isolate in the vegetable samples was Aspergillus fumigatus. Furthermore, the vegetable samples from KZN province were the most susceptible to fungal contamination. Patulin was detected in carrots and peppers. It was found that the level of patulin in these samples was below the LOQ. The presence of patulin in vegetable samples demonstrated its prevalence in the food chain. Thus, it is important to set- Page iii up guidelines for the monitoring of mycotoxins which can be achieved by the use of robust, sensitive, and simple analytical methods. The cytotoxic effect of patulin on humans was evaluated. The results demonstrated that the decrease in the viable cancer cell is dependent on the concentration of patulin. Although the results of this study demonstrated that patulin has the potential to reduce cancer cell lines, prolonged consumption of patulin could have a negative impact on human health.Civil and Chemical Engineerin

Aflatoxins

Aflatoxins are a group of highly toxic and carcinogenic substances that occur naturally and can be found in food substances. Aflatoxins are secondary metabolites of certain strains of fungi Aspergillus flavus and Aspergillus parasiticus as well as the less common Aspergillus nomius. Aflatoxins B1, B2, G1, and G2 are the most important members, which can be categorized into two groups according to chemical structure. As a result of the adverse health effects of mycotoxins, their levels have been strictly regulated, especially in food and feed samples. Therefore, their accurate identification and determination remain a herculean task due to their presence in the complex food matrix. The great public concern and the strict legislation incited the development of sensitive analytical methods that are discussed in this book

Reduction of mycotoxin contamination level during soybean fermentation

This thesis deals with the reduction of mycotoxin contamination level during soybean fermentation (Thua-Nao). Beside this work, isolation, characterization, and ochratoxin A production ability of toxigenic fungi from French grapes were also study. Results of this latter part showed that Aspergillus carbonarius and Aspergillus niger are the most ochratoxin A producer in wine grape from France. Furthermore, Aspergillus japonicus can produce a little bit quantity of ochratoxin A in wine grape too. Regarding to the main part of the work, 23 isolates of Bacillus spp. were isolated from Thai Thua-Nao. An Aspergillus flavus aflatoxin producing strain was also isolated from Thua-Nao whereas an Aspergillus westerdijkiae was chosen as an OTA producing reference strain. The objectives were to find an efficient Bacillus strain for: Growth inhibition of Aspergillus flavus and Aspergillus westerdijkiae NRRL 3174. - Limitation of aflatoxin B1 production. ; - Mycotoxins, aflatoxin B1 and ochratoxin A detoxification. Among the results, Bacillus CM 21, which was identified later by ITS sequencing as Bacillus licheniformis, showed the highest ability on inhibition of growth of both Aspergillus strains and both of mycotoxins removal (decrease of 74% of AFB1 and 92.5% of OTA). Another Bacillus strain, MHS 13, inhibiting both Aspergillus growth and detoxifying 85% of AFB1 was identified as Bacillus subtilis. Finally, culture supernatant and cellular extract from both interested Bacillus strains were tested for aflatoxin B1 and ochratoxin A degradation ability in order to know their degradation mechanisms. Moreover, study on optimal condition for aflatoxin B1 and ochratoxin A degradation were also conducted. All results indicated that OTA was significantly degraded by culture supernatant from Bacillus licheniformis CM 21 (p lower than 0.0001) in OTalpha. The percentage of OTA degradation was 97.5% and the optimal activity of its culture supernatant was found at pH 7.0 and 37°C with 24 h culture incubation time and 2 h contact time. Moreover, OTA was also significantly degraded by culture supernatant from Bacillus subtilis MHS 13 (p lower than 0.0017) at pH 5.0 and 37°C with 48 h culture incubation time and 2 h contact time. The proposed degradation mechanism should be extracellular and carboxypeptidase A probably responsible for this degradation since no activity was found for the intracellular extract. However, AFB1 could be degraded by neither culture supernatant nor cellular extract from both of these microorganisms. Hence, the AFB1 detoxification mechanism may be due to non-enzymatic mechanism

Fungal diversity and mycotoxin contamination of some selected food commodities from Ivory Coast

Abstract: This study surveyed fungi and mycotoxins in important food crops consumed in Ivory Coast. To achieve this, the following local food items (attieke, cassava flakes, chilli, gnangnan, haricot, melon, millet, okra, rice, white maize and yellow maize) were sampled from local markets (Adjame, Cocody and Youpougon) in Abidjan, Ivory Coast. They were screened for fungal contamination based on morphological characters and confirmed by PCR using the internal transcribed spacer 1 and 4 primers (ITS1 and ITS4). A total of 227 isolates were morphologically identified withisolates dominated by species within the genera Aspegillus (54.9 %) followed by Penicillium (23.3 %) and Fusarium (14.3 %). Few isolated species were confirmed in other genera which include Alternaria, Chaetomium, Cladosporium, Epicoccum, Emerica, Rhizopus and Trichoderma spp.The highest mean fungal load of 6.85 x 105 CFU/g was found in white maize while the lowest mean level of 4.39x104CFU/g was recorded in cassava flakes. The subset of isolates were identified using ITS1 and ITS4, as Aspergillus species found to be most frequentin cassava flakes, chilli, gnangnan, haricot, rice and yellow maize. Penicillium species were also found frequent in chilli, haricot and rice, while Fusarium species were frequent in melon and millet...M.A. (Biotechnology

Mycotoxins Occurence in Feed and Their Influence on Animal Health

According to the presented studies, the health condition of animals in rearing and breeding should be regularly monitored. This would allow early detection of delicate deviations in the body of clinically healthy individuals. Unfortunately, regular monitoring of the health of animals in commercial production is not performed. It follows that this type of research should be an introduction to further, more inquisitive steps. This can form the basis for further courses of action, indicating which organs or tissues field doctors or researchers should be interested in and what to pay attention to in order to find the correct answer, concerning the situation in the animal body. In the future, we should determine biomedical markers for use in precision veterinary medicine. In human medicine, this has been practiced with great success. The problem, however, is that we are getting to know more and more substances produced by mold fungi. This causes a build-up of new interpretative problems, causing health conditions (diagnosis), as well as analytical problems. To fully understand the results we need new techniques to assess toxicological and chemical hazards, including those related to undesirable substances. We need a solid knowledge of the biological pathways underlying the toxicity and tolerance to interference factors toxicological processes. We hope that the presented study will allow for a better understanding of mycotoxicoses that bother us and our animals, which will allow for more effective preventive actions