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CONTEXT: The COVID-19 pandemic has affected all sectors and human activities around the World. OBJECTIVE: In this article we present a first attempt to understand the immediate impact of COVID-19 and the sanitary measures taken by governments on farming systems in Central America and Mexico (CAM). METHODS: Through a review of information generated in these initial months of the COVID-19 pandemic (webinars, blogs, electronic publications, media) and 44 interviews with key informants across the region, we have identified the main impacts felt by different types of farming systems in the region. RESULTS AND CONCLUSIONS: From corporate agricultural production systems, to small and medium scale entrepreneurs and smallholder subsistence farm households, all types of farming systems were impacted, more or less severely, by the different measures implemented by governments such as reduced mobility, closure of public and private venues and restrictions in borders. Larger corporate farming systems with vertical market integration and high level of control or coordination within the supply chain, and smallholder or subsistence farming systems with important focus on production for self-consumption and little external input use, were both relatively less impacted and showed greater adaptive capacity than the medium and small entrepreneurial farming systems dependent on agriculture as their primary income and with less control over the upstream and downstream parts of their supply chain. All types of farming systems implemented a series of mechanisms to cope with the COVID-19 pandemic including the development of alternative value chains, food and agricultural products delivery systems and the exponential use of digital means to communicate and maintain the viability of the different agricultural systems. Collective action and organization of farmers also proved to be an important coping mechanism that allowed some farmers to acquire inputs and deliver outputs in the context of restricted mobility, price volatility, and general uncertainty. Some features of the CAM region played an important role in mediating the impact of COVID-19 and associated sanitary measures. We identify as particularly relevant the nature of agricultural exports, the current structure of the agricultural sector, the diversified livelihood strategies of rural households, and the importance of mobility for rural livelihoods. SIGNIFICANCE: The results presented focus only in the immediate effect of COVID-19 pandemic and the mechanisms implemented by farmers in the first months. Whether these impacts and response mechanisms will result in a transformation of the farming systems towards greater resilience and sustainability is still an open question.
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In Mexico little is known about high-altitude glacial psychrotolerant or psychrophilic fungal species, with most glacial fungi isolated from polar environments or Alpine glaciers. It has been documented that some of these species may play an important role in bioremediation of contaminated environments with heavy metals. In the present study, 75 fungi were isolated from glaciers in Citlaltépetl (5675 masl) and Iztaccíhuatl (5286 masl) volcanoes. Combining morphological characteristics and molecular methods, based on ITS rDNA, 38 fungi were partially identified to genus level, 35 belonging to Ascomycota and three to Mucoromycota. The most abundant genera were Cladosporium, followed by Alternaria and Sordariomycetes order. All isolated fungi were psychrotolerant, pigmented and resistant to different concentrations of Cr(III) and Pb(II), while none tolerated Hg(II). Fungi most tolerant to Cr(III) and Pb(II) belong to the genera Stemphylium, Cladosporium and Penicillium and to a lesser extent Aureobasidium and Sordariomycetes. To our knowledge, this is the first report on cultivable mycobiota richness and their Cr and Pb tolerance. The results open new research possibilities about fungal diversity and heavy metals myco-remediation. Extremophilic fungal communities should be further investigated before global warming causes permanent changes and we miss the opportunity to describe these sites in Mexico.
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Camada de Gelo , Altitude , Biodegradação Ambiental , Fungos , México , MicobiomaRESUMO
Biofilms are structures that confer adaptive ability to and facilitate the virulence of fungal pathogens. Certain multi-functional proteins have been shown to be involved in fungal pathogenesis and these proteins may also be implicated in biofilm formation. The aim of this study was to identify a fungal agent isolated from the human cornea, to analyze the ability of this organism to form biofilms in vitro and to investigate protein expression in this condition. The fungus was identified by phylogenetic inference analysis. Biofilm formation and structure were evaluated by colorimetric methods and by optical and electron microscopy. We also resolved proteins obtained from biofilms and planktonic cultures by two-dimensional gel electrophoresis and identified those proteins by mass spectrometry. The fungus was identified as Fusarium falciforme. Colorimetric analysis and microscopy revealed that the highest level of biofilm formation was obtained at a concentration of 1â¯×â¯106 conidia/mL with 96â¯h of incubation at 28⯰C. The biofilm architecture consisted of an extracellular matrix that embedded fungal filaments. We found nineteen proteins that were over-expressed in biofilms, as compared with planktonic cultures, and six proteins with unique expression in biofilms. Among the more abundant proteins identified were: transketolase, a putative antigen 1, enolase, phosphoglycerate kinase and ATP-citrate synthase. Some of these proteins are involved in basal metabolism, function as multi-functional proteins or have been described as potential virulence factors. We focused on the expression in biofilm of the enzyme, enolase, which was determined by real-time PCR. Our findings provide a perspective on the proteins associated with the formation of biofilms in vitro by an F. falciforme keratitis isolate.
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Biofilmes/crescimento & desenvolvimento , Proteínas Fúngicas/análise , Fusarium/química , Fusarium/crescimento & desenvolvimento , Proteoma/análise , Córnea/microbiologia , Eletroforese em Gel Bidimensional , Infecções Oculares Fúngicas/microbiologia , Fusariose/microbiologia , Fusarium/isolamento & purificação , Humanos , Ceratite/microbiologia , Espectrometria de MassasRESUMO
BACKGROUND: In recent years, human keratitis caused by fungal plant pathogens has become more common. Biofilm is a structure that confers adaptations and virulence to fungi in keratitis. Neoscytalidium spp. are phytopathogenic and recently have been recognised as a human pathogen, using biofilm formation as a virulence factor. OBJECTIVES: The aim of this study was isolation, identification (at the species level) and characterisation of a new fungal keratitis agent. PATIENTS/METHODS: The fungus was isolated from a 67-year-old male patient with a corneal ulcer. Biofilm formation and structure were evaluated by colorimetric methods and microscopy. To identify the fungus, morphological characteristics were examined and a phylogenetic analysis was performed. RESULTS AND CONCLUSIONS: We report the identification of a fungus, a member of the genus Neoscytalidium which is associated with human keratitis. Phylogenetic analysis and morphological observations on conidiogenous cells, which occur only in arthric chains in aerial mycelium and the coelomycetous synasexual morph is absent, identified a new species, Neoscytalidium oculus sp. nov. The fungus formed biofilm at a concentration of 1 × 106 conidia/mL, during 96 hours of incubation at 37°C, and also manifested haemolysis and melanin production. This is the first report in Latin America of a new species of Neoscytalidium from a clinical isolate has been identified.
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Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Biofilmes/crescimento & desenvolvimento , Úlcera da Córnea/microbiologia , Micoses/microbiologia , Idoso , Ascomicetos/genética , Ascomicetos/crescimento & desenvolvimento , Úlcera da Córnea/patologia , Humanos , Masculino , Técnicas Microbiológicas , Microscopia , Micoses/patologia , FilogeniaRESUMO
We present an assessment of the extent, diversity, and nutritional contribution of the milpa through a quantitative analysis of data from a survey conducted in 989 small scale farm households in the Western Highlands of Guatemala (WHG). The milpa is a traditional agricultural system in which maize is intercropped with other species, such as common beans, faba beans, squashes or potatoes. Our study shows that more than two-thirds of the 1,205 plots recorded were under the milpa system, with a great diversity of crop combinations. As shown with the 357 plots for which specific yields were available, milpa systems present higher total productivity than monocropped maize, expressed as total energy yield of the harvested crops in the respective system, and were also better at providing the recommended daily allowances of fourteen essential nutrients, based on a Potential Nutrient Adequacy (PNA) indicator. Maize-bean-potato, maize-potato, and maize-bean-faba intercrops had the highest PNAs, and monocropped maize, the lowest. These results support the implementation of milpa systems tailored to different agro-ecologies in order to improve nutrition in the WHG and a variety of similar regions.
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Due to complexity of smallholder farms, many times technologies with great potential fail to achieve the desired impact in leveraging productivity and profitability of the farming community. In the Indo-Gangetic Plains there is an urgent need to understand the diversity of farm households, identifying the main drivers deciding their system thus, classifying them into homogenous groups. In the present study, the diversity of smallholder farms was assessed using crop, livestock and income related characteristics and associated farm mechanization. Using principal component analysis and cluster analysis for 252 farm households, 4 farm types were identified i.e. Type 1. Small Farm households with cereal-based cropping system and subsistence livestock (39%), Type 2. Small Farm households with diversified cropping system dominated by cereal and fodder crops with only cattle herd (9%), Type 3. Marginal Farm household with diversified cropping system dominated by cash crop and herd comprising of only cattle (39%), Type 4. Marginal Farm household with diversified cropping system dominated by cereal crops and herd dominated by small ruminants (12%). Based on the constraints identified for different components of farming systems, low-cost interventions were planned for each farm type. These interventions have resulted in 84.8-103.2 per cent increase in the income of the farm HH under study suggesting usefulness of typology-based intervention planning in increasing income of small farm holders.
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Little is known about extremophilic microorganisms from glaciers found in subtropical regions, and to our knowledge, no reports have identified glacial bacteria in this ecosystem in Mexico. Herein, we report a 16S rRNA gene amplicon data set demonstrating bacterial diversity of three samples from the Iztaccihuatl volcanic complex (Mexico) with a total of 115,701 to 138,805 high-quality reads. The bacterial population was classified at the phylum level in all samples.