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1.
Molecules ; 28(14)2023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37513242

RESUMO

Aflatoxin B1 is a secondary metabolite with a potentially devastating effect in causing liver damage in broiler chickens, and this is mainly facilitated through the generation of oxidative stress and malonaldehyde build-up. In the past few years, significant progress has been made in controlling the invasion of aflatoxins. Phytochemicals are some of the commonly used molecules endowed with potential therapeutic effects to ameliorate aflatoxin, by inhibiting the production of reactive oxygen species and enhancing intracellular antioxidant enzymes. Experimental models involving cell cultures and broiler chickens exposed to aflatoxin or contaminated diet have been used to investigate the ameliorative effects of phytochemicals against aflatoxin toxicity. Electronic databases such as PubMed, Science Direct, and Google Scholar were used to identify relevant data sources. The retrieved information reported on the link between aflatoxin B1-included cytotoxicity and the ameliorative potential/role of phytochemicals in chickens. Importantly, retrieved data showed that phytochemicals may potentially protect against aflatoxin B1-induced cytotoxicity by ameliorating oxidative stress and enhancing intracellular antioxidants. Preclinical data indicate that activation of nuclear factor erythroid 2-related factor 2 (Nrf2), together with its downstream antioxidant genes, may be a potential therapeutic mechanism by which phytochemicals neutralize oxidative stress. This highlights the need for more research to determine whether phytochemicals can be considered a useful therapeutic intervention in controlling mycotoxins to improve broiler health and productivity.


Assuntos
Aflatoxinas , Animais , Aflatoxinas/toxicidade , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Aflatoxina B1/toxicidade , Fígado , Galinhas/metabolismo , Estresse Oxidativo , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/metabolismo
2.
Reprod Domest Anim ; 55(3): 301-308, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31894616

RESUMO

Minerals in animal feed occur in variable structures, most of which determine the uptake and usage in biological processes in the body. Effective chemical breakdown of minerals may ensure efficient utilization in metabolism. The aim this study was to evaluate the effects of mineral supplementation on reproduction in cows. A farm was selected for the experiment due to the fact that it previously experienced different reproductive conditions in the farm. The farm comprises cross-breed cows with Bonsmara dominating in the farm. Twelve pregnant primiparous and multiparous cows of different ages, parity and weight, that had previously experienced reproductive conditions, were randomly selected for this study. The cows were then randomly sub-divided into two groups (experimental and control group) of six. The experimental group was injected with MULTIMIN™ + Se + Cu at a dosage of 1 ml/45 kg BW and Calci 50 p.i. at a dosage of 100-150 ml/500 kg BW at an interval of 6 weeks (from June to October 2017). Blood samples were collected before every injection date. The t test was used to relate the mean weight gain and serum metabolite between the experimental and control groups. The body weight gain was significantly higher in the experimental group compared to the non-supplemented group. Supplemented cows had significantly (p < .05) high levels of triglycerides and creatinine kinase. A case of retained placenta and dystocia among non-supplemented cows were noted. Thus, mineral supplementation can be used to improve productivity and reproductive well-being.


Assuntos
Doenças dos Bovinos/prevenção & controle , Oligoelementos/administração & dosagem , Aumento de Peso/efeitos dos fármacos , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos/fisiologia , Creatina Quinase/sangue , Dieta/veterinária , Distocia/veterinária , Feminino , Placenta Retida/veterinária , Gravidez , Distribuição Aleatória , África do Sul , Oligoelementos/sangue , Triglicerídeos/sangue
3.
World J Microbiol Biotechnol ; 35(1): 15, 2019 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-30607686

RESUMO

The invasion of food by toxigenic fungi is a threat to public health. This study aimed at enumerating the microbial profile, detection of aflatoxin producing genes and quantification of the levels of aflatoxin contamination of cashew nuts meant for human consumption. A polyphasic method of analysis using newly formulated ß-Cyclodextrin Neutral Red Desiccated coconut agar (ß-CDNRDCA) and Yeast Extract Sucrose agar (YES) with Thin Layer Chromatography (TLC), Polymerase Chain Reaction (PCR) and High Performance Liquid Chromatographic (HPLC) method was adopted in determining the aflatoxigenic potential of the isolates, the presence of aflatoxin biosynthetic gene (aflM, aflD, aflR, aflJ omt-A) and estimation of the total aflatoxin content of the nuts. The fungal counts ranged from 2.0 to 2.4 log10cfu/g and sixty-three fungal isolates belonging to 18 genera and 34 species were isolated. The Aspergillus spp. were the most frequently isolated (50.79%) while Trichoderma spp. (1.59%) were the least. and fluorescence production was enhanced on the newly formulated ß-CDNRDCA by the aflatoxigenic species. The aflD gene was amplified in all the isolates while aflM, aflR and aflJ gene were each amplified in 77.77% of the isolates and omt-A gene in 70.37%. The aflatoxin content of the nuts ranged from 0.03 to 0.77 µg/kg and were below the 4 µg/kg EU recommended limit for total aflatoxins. The present work confirms that a single method of analysis may not be sufficient to screen for the presence of aflatoxins in foods, as with a combination of different methods.


Assuntos
Anacardium/microbiologia , Aspergillus/metabolismo , Aflatoxinas/metabolismo , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Reação em Cadeia da Polimerase
4.
J Dairy Sci ; 98(10): 6660-7, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26254521

RESUMO

Recently, methods to analyze aflatoxin M1 (AFM1) in milk and dairy products have been developed for both screening purposes (i.e., rapid, economical, and simple methods) and for confirmation by accurate, reproducible, and sensitive quantification. The aim of this study was to evaluate the efficiency of different rapid kits and techniques available on the market by using different analytical methods: thin layer chromatography (TLC), immunoaffinity column, AFM1 immunochromatographic strip, and ELISA; some samples were also submitted to HPLC for comparison of results. One hundred thirty-eight samples were collected from rural subsistence and commercial dairy farms in selected areas of Egypt and South Africa and analyzed for the presence of AFM1. The results obtained by AFM1 immunochromatographic strip indicated the lowest frequency of occurrence, with a detection incidence of 20.45% in Egyptian samples and 16% in South African samples. Aflatoxin M1 was detected by ELISA in 65 (73.9%) Egyptian milk samples, with a range of 8.52 to 78.06 ng/L, and in 34 (68%) South African milk samples, with a range of 5 to 120 ng/L. A higher incidence of AFM1 in Egyptian milk samples was shown by TLC (81.8%) compared with ELISA (73.9%). Samples analyzed by ELISA in South African milk samples demonstrated satisfactory correlation when compared with HPLC coupled with Coring cell (an electrochemical cell for the derivatization of AFM1). Among the positive samples, 18 of the Egyptian samples (20.45%) positive by ELISA had levels of AFM1 above the European Union (EU) regulatory limit (50 ng/L), whereas 65 samples (73.9%) were above the Egyptian regulatory limit (0 ng/L). Six of the South African samples (12%) tested by ELISA were above the South African (50 ng/L) and EU regulatory limits. The mean concentration of AFM1 was 25.79 ng/L in Egyptian samples and 17.06 ng/L by ELISA and 39 ng/L by HPLC in South African samples. These contamination levels would not represent a serious public health hazard according to EU legislation.


Assuntos
Aflatoxina M1/análise , Cromatografia em Camada Fina/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Imunoensaio/métodos , Leite/química , Animais , Cromatografia Líquida de Alta Pressão/métodos , Egito , África do Sul
5.
Toxicol Rep ; 13: 101711, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39262848

RESUMO

Aflatoxins are frequent contaminants of maize especially in the face of climate change with deleterious health and socio-economic impacts. South Africa is ranked 9th maize exporter globally; hence, insights need to be gained in terms of the maize value chain in South Africa with respect to aflatoxin contamination to evaluate consumers' exposure. High-performance liquid chromatography (HPLC) technique was used in this study to quantify aflatoxins in South African commercial maize. One thousand and twenty-eight (1028) maize samples were collected across six distinct agro-climatic regions over five harvest seasons (2017 - 2021). A total of 205 samples (19.94 %) were found to be contaminated with aflatoxins, with mean total aflatoxin concentration of 64.17 ppb amongst the contaminated samples, which is above the SA regulatory limit of 20 ppb for animal consumption. The year 2018 recorded the highest mean total aflatoxin value while North-West agro-climatic region had the highest mean total aflatoxin value. Drastic reduction in average rainfall significantly influence aflatoxin contamination of South African maize.

6.
Onderstepoort J Vet Res ; 91(1): e1-e8, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39099299

RESUMO

The South African government recognises the value of traditional healing and supports an integrated healthcare system. In the veterinary field, successful integration depends on the perceptions of different animal healthcare practitioners (AHCPs). This study aimed to determine the perceptions of ethnoveterinary medicine among state-employed veterinarians and animal health technicians in the North West province. A mixed model questionnaire and non-probability sampling gathered quantitative and qualitative data from 53 participants. Statistical and thematic analysis processes were applied to quantitative and qualitative data, respectively. Overall, 77.4% of participants were aware of ethnoveterinary medicine practices. Approval of the use of ethnoveterinary medicine by farmers was above-average at a mean of 3.57, standard deviation (s.d.) = 1.016 on a 5-point Likert scale. However, 65.9% doubted the effectiveness of ethnoveterinary medicine, which suggests tolerance but no appreciation of its value. The Chi-square test revealed a significant relationship between district municipality of employment and awareness at χ2 = 17.490, df = 3, p = 0.001. Thematic analysis of comments showed that some participants perceived ethnoveterinary medicine as unscientific and interfering with Western veterinary medicine, while some considered it a good complement to Western veterinary medicine. The study also found that 20.8% of AHCPs use ethnoveterinary medicine to treat certain diseases. In conclusion, the lack of appreciation for ethnoveterinary medicine among AHCPs may hinder government-proposed integration, emphasising the need for programmes to improve perceptions among these stakeholders.Contribution: This is first such study to report on perceptions of ethnoveterinary medicine among AHCPs, and assess their readiness for an integrated animal health system.


Assuntos
Médicos Veterinários , Medicina Veterinária , África do Sul , Médicos Veterinários/psicologia , Humanos , Animais , Inquéritos e Questionários , Masculino , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Adulto , Técnicos em Manejo de Animais/psicologia , Pessoa de Meia-Idade , Medicinas Tradicionais Africanas
7.
Artigo em Inglês | MEDLINE | ID: mdl-38109413

RESUMO

This study reports levels of mycotoxins in sorghum from Niger State, Nigeria, and provides a comprehensive assessment of their potential health risks by combining mycotoxin levels and dietary exposure assessment. A total of 240 samples of red and white sorghum were collected from both stores and markets across four microclimatic zones. Fungal species were identified using a dilution plate method. Aflatoxins (AFs), deoxynivalenol, nivalenol, and ochratoxin (OTA) were quantified using HPLC, whereas cyclopiazonic acid, fumonisins (FUMs) and zearalenone were quantified using ELISA. A. flavus and A. fumigatus were dominant fungal species followed by F. verticilloides, A. oryzae and P. verrucosum. Aflatoxins (mean: 29.97 µg/kg) were detected in all samples, whereas OTA (mean: 37.5 µg/kg) and FUMs (mean: 3269.8 µg/kg) were detected in 72% and 50% of the samples, respectively. Mycotoxins frequently co-occurred in binary mixtures of AFs + OTA and AFs + FUMs. Dietary exposure estimates were highest for FUMs at 230% of TDI and margin of exposures (MOEs) for both AFs and OTA (<10,000) indicating a potential risk associated with combined exposure to AFs and OTA. The Risk of hepatocellular carcinoma cases (HCC/year) attributable to AFs and OTA exposure from sorghum was estimated to be 5.99 × 105 and 0.24 × 105 cases for HBsAg + individuals based on 13.6% HBV incidence. Similarly, the HCC/year for AFs and OTA were assessed to be 3.59 × 105 and 0.14 × 105 at an 8.1% prevalence rate. Therefore, the results of this study demonstrate the high prevalence and dietary exposure to mycotoxins through sorghum consumption, raising public health and trade concerns.


Assuntos
Aflatoxinas , Carcinoma Hepatocelular , Fumonisinas , Neoplasias Hepáticas , Micotoxinas , Sorghum , Humanos , Micotoxinas/análise , Exposição Dietética/análise , Nigéria , Níger , Contaminação de Alimentos/análise , Aflatoxinas/análise , Fumonisinas/análise , Grão Comestível/química
8.
J Fungi (Basel) ; 9(7)2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37504754

RESUMO

Five Aspergillus sections have members that are established agricultural pests and producers of different metabolites, threatening global food safety. Most of these pathogenic Aspergillus species have been isolated from almost all major biomes. The soil remains the primary habitat for most of these cryptic fungi. This review explored some of the ecological attributes that have contributed immensely to the success of the pathogenicity of some members of the genus Aspergillus over time. Hence, the virulence factors of the genus Aspergillus, their ecology and others were reviewed. Furthermore, some biological control techniques were recommended. Pathogenic effects of Aspergillus species are entirely accidental; therefore, the virulence evolution prediction model in such species becomes a challenge, unlike their obligate parasite counterparts. In all, differences in virulence among organisms involved both conserved and species-specific genetic factors. If the impacts of climate change continue, new cryptic Aspergillus species will emerge and mycotoxin contamination risks will increase in all ecosystems, as these species can metabolically adjust to nutritional and biophysical challenges. As most of their gene clusters are silent, fungi continue to be a source of underexplored bioactive compounds. The World Soil Charter recognizes the relevance of soil biodiversity in supporting healthy soil functions. The question of how a balance may be struck between supporting healthy soil biodiversity and the control of toxic fungi species in the field to ensure food security is therefore pertinent. Numerous advanced strategies and biocontrol methods so far remain the most environmentally sustainable solution to the control of toxigenic fungi in the field.

9.
Front Vet Sci ; 10: 1273562, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38076569

RESUMO

Ethnoveterinary medicine (EVM) has been used by local South African communities for centuries. However, the knowledge of EVM is under threat due to the influence of Western medicine and acculturation. This study aimed to document the knowledge of ethnoveterinary medicinal plants in four villages within the Mahikeng Local Municipality to help preserve this valuable knowledge. The study used a qualitative research approach and targeted practitioners and holders of ethnoveterinary knowledge in four villages. Participants were recruited using key informants and snowball techniques, and in-depth interviews were conducted using semi-structured interview schedules. The data collected was analyzed thematically, and herbarium specimens were prepared from medicinal plants during field walks and sent to the South African National Biodiversity Institute (SANBI) for identification. The study documented the use of thirty-one medicinal plant species, with Senna italica (sebetebete) emerging as the most frequently used species for multiple animal health indications. The most common diseases treated using EVM were gala (general malaise due to bile reflux) and retained placenta. Participants strongly agreed on the cultural significance of plants for treating five animal diseases, including coughs and diarrhea. Although the study revealed a high level of trust in ethnoveterinary medicine among participants, they expressed concern regarding the loss of this knowledge due to the influence of Western medicine and acculturation. The study concluded that the indigenous knowledge and use of ethnoveterinary medicine was prevalent among livestock owners in the communities of the North West Province, and more studies need to be conducted in other areas to preserve this valuable knowledge.

10.
Toxins (Basel) ; 14(8)2022 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-36006236

RESUMO

The dangers of population-level mycotoxin exposure have been well documented. Climate-sensitive aflatoxins (AFs) are important food hazards. The continual effects of climate change are projected to impact primary agricultural systems, and consequently food security. This will be due to a reduction in yield with a negative influence on food safety. The African climate and subsistence farming techniques favour the growth of AF-producing fungal genera particularly in maize, which is a food staple commonly associated with mycotoxin contamination. Predictive models are useful tools in the management of mycotoxin risk. Mycotoxin climate risk predictive models have been successfully developed in Australia, the USA, and Europe, but are still in their infancy in Africa. This review aims to investigate whether AFs' occurrence in African maize can be effectively mitigated in the face of increasing climate change and food insecurity using climate risk predictive studies. A systematic search is conducted using Google Scholar. The complexities associated with the development of these prediction models vary from statistical tools such as simple regression equations to complex systems such as artificial intelligence models. Africa's inability to simulate a climate mycotoxin risk model in the past has been attributed to insufficient climate or AF contamination data. Recently, however, advancement in technologies including artificial intelligence modelling has bridged this gap, as climate risk scenarios can now be correctly predicted from missing and unbalanced data.


Assuntos
Aflatoxinas , Micotoxinas , África , Inteligência Artificial , Mudança Climática , Contaminação de Alimentos/análise , Insegurança Alimentar , Micotoxinas/análise , Zea mays/microbiologia
11.
Artigo em Inglês | MEDLINE | ID: mdl-35805411

RESUMO

Humans continue to be constantly exposed to mycotoxins, mainly through oral exposure (dietary), inhalation, or dermal contact. Recently, it has been of increasing interest to investigate mycotoxin-linked carcinogenicity. This systematic review was conducted to synthesize evidence of the association between mycotoxin-linked mutations and the risk of cancer, to provide an overview of the data linking exposure to different mycotoxins with human cancer risk, and to provide an update on current research on the risk of cancer associated with human exposure to mycotoxins. PRISMA guidelines were used when conducting the systematic review. PubMed, MEDLINE, and CINAHL electronic databases were comprehensively searched to extract the relevant studies published from inception to May 2022. A total of sixteen relevant studies (4907 participants) were identified and included in this review. Of these, twelve studies were from Asia, while four of the studies were conducted in Africa. The overall meta-analysis result found no significant association, although some of the studies confirmed an association between mycotoxin-linked mutations and primary liver cancer risk. Mainly, the experimental studies have shown associations between mycotoxin-linked mutations and cancer risk, and there is a need for researchers to confirm these links in epidemiological studies in order to guide public health policies and interventions.


Assuntos
Micotoxinas , Neoplasias , África , Dieta , Contaminação de Alimentos/análise , Saúde Global , Humanos , Mutação , Micotoxinas/análise , Micotoxinas/toxicidade , Neoplasias/induzido quimicamente , Neoplasias/epidemiologia , Neoplasias/genética
12.
Foods ; 11(17)2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36076897

RESUMO

South Africa (SA) is a leading exporter of maize in Africa. The commercial maize farming sector contributes to about 85% of the overall maize produced. More than 33% of South Africa's population live in rural settlements, and their livelihoods depend entirely on subsistence farming. The subsistence farming system promotes fungal growth and mycotoxin production. This review aims to investigate the exposure levels of the rural population of South Africa to dietary mycotoxins contrary to several reports issued concerning the safety of South African maize. A systematic search was conducted using Google Scholar. Maize is a staple food in South Africa and consumption rates in rural and urban communities are different, for instance, intake may be 1-2 kg/person/day and 400 g/person/day, respectively. Commercial and subsistence maize farming techniques are different. There exist differences influencing the composition of mycotoxins in food commodities from both sectors. Depending on the levels of contamination, dietary exposure of South Africans to mycotoxins is evident in the high levels of fumonisins (FBs) that have been detected in SA home-grown maize. Other potential sources of exposure to mycotoxins, such as carryover effects from animal products and processed foods, were reviewed. The combined effects between FBs and aflatoxins (AFs) have been reported in humans/animals and should not be ignored, as sporadic breakouts of aflatoxicosis have been reported in South Africa. These reports are not a true representation of the entire country as reports from the subsistence-farming rural communities show high incidence of maize contaminated with both AFs and FBs. While commercial farmers and exporters have all the resources needed to perform laboratory analyses of maize products, the greater challenge in combatting mycotoxin exposure is encountered in rural communities with predominantly subsistence farming systems, where conventional food surveillance is lacking.

13.
Heliyon ; 8(12): e12243, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36593860

RESUMO

Zinc oxide (ZnO) and silver-zinc oxide (Ag/ZnO) nanocomposite were synthesized by a green method using Zn(CH3COO)2 and AgNO3 as precursors for zinc and silver respectively; and Urginea epigea bulb extract as a reducing/capping agent. The nanomaterials were characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared spectrophotometer (FTIR), ultraviolet-visible spectrophotometer, scanning, and transmission electron microscopy (SEM and TEM). Their elemental composition was studied using EDX analysis, while elementary mapping was used to show the distribution of the constituent elements. The powder X-ray diffraction confirmed hexagonal phase ZnO, while the Ag/ZnO nanocomposites identified additional planes due to cubic phase Ag nanoparticles. The absorption spectrum of the nanocomposite indicated a red shifting of the absorption band of the metallic ZnO and a surface plasmon resonance (SPR) band's appearance in the visible region due to the metallic Ag nanoparticles. The analysis from the TEM image showed the particles were of spherical morphology with a mean size of 35 nm (ZnO) and 33.50 nm (Ag/ZnO). The biological activity of the nanoparticles was studied for their antibacterial and antioxidant capacity so as to assess their ability to hinder bacterial growth and capture radical species respectively. The results demonstrated that the modification of ZnO with silver nanoparticles enhanced the antibacterial potency but reduced the antioxidant activity. This biogenic method offers a facile approach to nanoparticles for biological purposes, and the strategy may be extended to other metal oxide and their composites with metallic silver nanoparticles as a more effective approach compared to the physical and chemical routes.

14.
Plants (Basel) ; 11(13)2022 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-35807736

RESUMO

Ethnoveterinary practices and ethnobotanical knowledge serve as potential therapeutic approaches used to manage and prevent cattle diseases within poor communities in developing nations. Most of the knowledge and practices remain inadequately documented and threatened with extinction in the future. This study aimed to explore the ethnoveterinary practices and knowledge on plants used to treat cattle diseases in two communities of the Ramotshere Moiloa local municipality, South Africa. A semi-structured interview guide, snowball, and purposive technique were used to collect data and recruit 90 participants. Three ethnobotanical indices (informant consensus factor (Fic), use-value (UV), and relative frequency of citation (RFC) were used for quantitative analysis. A total of 64 medicinal plants from 32 families (dominated by Compositae, Fabaceae, and Asparagaceae) were used to treat 27 cattle diseases. The plants with a high frequency of citation and RFC were Gomphocarpus fruticosus (75, 0.83), Opuntia ficus-indica (74, 0.82), Schkuhria pinnata and Portulaca oleracea (73, 0.81), Solanum lichtensteinii (70, 0.77), and Senna italica. In addition, Schkuhria pinnata and Aloe greatheadii (0.077) had the highest UV. About 28.13% of 64 identified plants were documented as ethnoveterinary medicine for treating cattle ailments, for the first time. The remedies were mainly either prepared as a decoction (52.04%), ground, or prepared as an infusion (16.33%). The plants were administered either orally (69.79%) or topically (30.2%). The ailments with a high frequency of citations were: wounds and constipation (76); arthralgia and retained placenta (69); and lumpy skin disease (68). The categories with the highest number of plants used were gastrointestinal problems (53), skin problems (33), respiratory problems (25), and fertility/reproduction disorders (21). The highest Fic score was cited for tick-borne diseases (1), followed by musculoskeletal systems (Fic = 0.89), and general system infection (Fic = 0.88). The current findings contribute to the documentation and preservation of valuable knowledge from indigenous communities for extensive use. Additionally, ethnoveterinary uses of Portulaca oleracea, Securidaca longipedunculata, and Plumbago zeylanica were recorded for the first time. Further scientific evaluation of the most cited and indigenous/native plants is recommended to establish their therapeutic potential and possible integration into the conventional veterinary sector for the welfare of cattle.

15.
Toxins (Basel) ; 14(5)2022 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-35622564

RESUMO

Africa is one of the regions with high mycotoxin contamination of foods and continues to record high incidences of liver cancers globally. The agricultural sector of most African countries depends largely on climate variables for crop production. Production of mycotoxins is climate-sensitive. Most stakeholders in the food production chain in Africa are not aware of the health and economic effects of consuming contaminated foods. The aim of this review is to evaluate the main factors and their degree of contribution to the high levels of mycotoxins in African foods. Thus, knowledge of the contributions of different factors responsible for high levels of these toxins will be a good starting point for the effective mitigation of mycotoxins in Africa. Google Scholar was used to conduct a systemic search. Six factors were found to be linked to high levels of mycotoxins in African foods, in varying degrees. Climate change remains the main driving factor in the production of mycotoxins. The other factors are partly man-made and can be manipulated to become a more profitable or less climate-sensitive response. Awareness of the existence of these mycotoxins and their economic as well as health consequences remains paramount. The degree of management of these factors regarding mycotoxins varies from one region of the world to another.


Assuntos
Micotoxinas , África/epidemiologia , Ração Animal/análise , Contaminação de Medicamentos , Contaminação de Alimentos/análise , Humanos , Micotoxinas/análise
16.
Analyst ; 136(19): 4059-69, 2011 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-21833409

RESUMO

The duplicate method for estimating uncertainty from measurement including sampling is presented in the Eurachem/CITAC guide. The applicability of this method as a tool for verifying sampling plans for mycotoxins was assessed in three case studies with aflatoxin B(1) in animal feedingstuffs. Aspects considered included strategies for obtaining samples from contaminated lots, assumptions about distributions, approaches for statistical analysis, log(10)-transformation of test data and applicability of uncertainty estimates. The results showed that when duplicate aggregate samples are formed by interpenetrating sampling, repeated measurements from a lot can be assumed to approximately follow a normal or lognormal distribution. Due to the large variation in toxin concentration between sampling targets and sometimes very large uncertainty arising from sampling and sample preparation (U(rel) ≥ 50%), estimation of uncertainty from log(10)-transformed data was found to be a more generally applicable approach than application of robust ANOVA.


Assuntos
Aflatoxinas/análise , Ração Animal/análise , Técnicas de Química Analítica/métodos , Animais , Sensibilidade e Especificidade
17.
Microbiol Resour Announc ; 10(7)2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33602735

RESUMO

The de novo metagenome assembly for C1-TPA is 68,577,389 bp long spread over 10,108 contigs, while that of C3-TPA is 55,517,929 bp distributed over 9,415 contigs. A total of 8 metagenome-assembled genomes (MAGs) were extracted from C1-TPA, and 10 were extracted from C3-TPA. Both samples have a Flavobacterium sp. and a Pseudomonas sp. in common among their bacterial communities.

18.
Int J Food Microbiol ; 357: 109369, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34474198

RESUMO

Aspergillus parasiticus is a pre-harvest and postharvest pathogen that is known to produce aflatoxin; however, it is less studied compared to A. flavus. Inappropriate storage conditions are a cause of food spoilage and growth of mycotoxigenic fungi especially in low moisture foods thus constituting hazards to health. Hence, this study investigated the behaviour of A. parasiticus on aflatoxin production in inoculated wheat flour as influenced by storage conditions using the response surface methodology. Twenty experimental runs consisting of independent variables (incubation temperature (A), time (B) and (C) moisture content) and responses (aflatoxin concentrations, i.e., AFB1, AFB2, AFG1, AFG2 and AFTOT) were developed. A central composite face-centered design was used with lower and upper limits: A (25-35 °C), B (7-15 days) and C (15-25%), while the non-inoculated wheat flour served as the negative control. Aflatoxin production was determined using High Performance Liquid Chromatography (HPLC) according to standard procedures. Numerical and graphical process variables were optimized, adequate models were predicted and optimal point prediction for aflatoxin concentration was determined. AFG1 concentrations ranged from 1.10 to 360.06 µg/g, AFG2 (0.91-446.94 µg/g), AFB2 (7.95-488.77 µg/g), AFB1 (17.21-20,666.6 µg/g) and AFTOT (15.91-21,851.09 µg/g). Aflatoxin concentration increased with increase in 'B' and 'A' but decreased with prolonged increase in 'B'. AFB1 concentrations in A. parasiticus inoculated wheat flour increased at prolonged 'B' and 'A' at constant moisture (12.09%). A reduced cubic model was significantly adequate to describe the relationship between process variables and responses (AFG1 and AFG2), cubic model (AFB1 and AFTOT) and a transformed square root cubic model for AFG2 concentrations (p ≤ 0.05). 'A' influenced AFG1 production more than 'C' while 'C' and 'A' had no significant effect on AFG2 production. Process variables 'AB' influenced AFB2 concentrations more than 'C' while 'A' had a more significant effect on the AFTOT production than 'B' (p ≤ 0.05). The predicted (R2) and adjusted coefficient of regression (adj R2) were in reasonable agreement. After optimal point prediction and validation, minimum aflatoxin concentration ≤ 0 µg/g could be achieved at the predicted conditions (A = 30.42 °C, B = 10.58 days and C = 14.49%) except in AFG2 (3.33 µg/g).


Assuntos
Aflatoxinas , Aflatoxina B1/análise , Aflatoxinas/análise , Aspergillus , Aspergillus flavus , Farinha , Triticum
19.
Front Vet Sci ; 8: 710884, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34490402

RESUMO

Cattle farming is a traditional agricultural system that contribute to the rural economic, social and cultural values of the communities. Cattle as common with other livestock, are affected by many diseases that cause mortality and economic losses. In many rural households, the use of plants and associated knowledge are popular for managing cattle diseases especially in areas experiencing challenges with conventional veterinary medicine. Evidence on the documentation of indigenous knowledge and biological evaluation of plants used against cattle diseases remain understudied and fragmented. The aim of the review is to collate and analyse the ethnoveterinary knowledge and biological evaluation of plants used against cattle diseases in South Africa. Different scientific databases were systematically explored to extract data from 37 eligible studies. A total of 310 medicinal plants from 81 families used to treat 10 categories of cattle diseases across seven (7) provinces in South Africa. Leguminosae (Fabaceae), Compositae (Astereceae), Asparagaceae, and Xanthorrhoeaceae were the most frequently used plant families. Common plant parts used were leaves and roots. Twenty-seven (27) combination remedies involving 2-6 plants were identified as treatment regimes against cattle diseases. Common preparation methods were infusion and decoction while the administration mode was predominantly unspecified (52%) while oral and topical contributed 26 and 22%, respectively. In terms of diseases, the most treated ones were general systems infection, reproduction disorders and gastrointestinal problems. Currently, an estimated 21% of the 310 plants have been evaluated for diverse biological activities using relevant bioassays related to cattle diseases. Antibacterial activity remained the most studied biological activity. Evidence from the review revealed the significance of ethnoveterinary medicine against cattle diseases especially in rural areas of South Africa. Nevertheless, the use of plants for cattle diseases among other ethnic groups, particularly in the Northern Cape and Western Cape, remain under-studied.

20.
Artigo em Inglês | MEDLINE | ID: mdl-34831498

RESUMO

The genus Fusarium produces a number of mycotoxins of diverse chemical structures. Fusariotoxins are secondary metabolites produced by toxigenic fungi of the genus Fusarium. The important and commonly encountered fusariotoxins are trichothecenes, fumonisins, and zearalenone. Fusarium mycotoxins pose varying toxicities to humans and/or animals after consumption of contaminated grain. They can cause acute or chronic illness and, in some cases, death. For instance, a range of Fusarium mycotoxins can alter different intestinal defense mechanisms, such as the epithelial integrity, cell proliferation, mucus layer, immunoglobulins, and cytokine production. Of recent concern is the occurrence of emerging and masked Fusarium mycotoxins in agricultural commodities, which may contribute to toxic health effects, although the metabolic fate of masked mycotoxins still remains a matter of scientific discussion. These mycotoxins have attracted attention worldwide because of their impact on human and animal health, animal productivity, and the associated economic losses. In this paper, we review Fusarium mycotoxins and their metabolites with the aim of summarizing the baseline information on the types, occurrence, and health impacts of these mycotoxins in order to encourage much-needed research on integrated management of this unavoidable food contaminant as concerns for food safety continues to grow worldwide.


Assuntos
Fumonisinas , Fusarium , Micotoxinas , Tricotecenos , Animais , Contaminação de Alimentos/análise , Inocuidade dos Alimentos , Fumonisinas/toxicidade , Humanos , Micotoxinas/análise , Tricotecenos/análise
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