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Maize ( Zea mays) is a staple in many developing countries but is known to be prone to pest (insects, birds, and rodents) and fungal infestation. In Guatemala, mycotoxin contamination of cultivated products may occur owing to such factors as environmental conditions and the use of traditional agriculture operations. To assess the current maize conditions in Guatemala, a small-scale study was performed. Mold and insect counts and mycotoxin (aflatoxin and fumonisin) concentrations were determined on 25 farms in two townships (Chiantla and Todos Santos) of the Huehuetenango Department. Total fungal counts were 3.6 to 6.83 log CFU/g with no significant differences ( P > 0.05) across farms at different altitudes. Farms where maize was not produced but was purchased were at higher risk of fumonisin contamination, whereas local producers were mostly affected by aflatoxins. Aflatoxin was present in maize from 100% of farms at 1.0 to 85.3 ppb, and fumonisin was detected on 52% of farms at 0.4 to 31.0 ppm. Average mycotoxin consumption amounts were above the recommended maximum intake for aflatoxin in both produced and purchased maize and above the provisional maximum tolerable daily intake for fumonisin in purchased maize. Estimated daily intake was 0.01 to 0.85 μg/kg of body weight per day for aflatoxin and 2.9 to 310.0 μg/kg of body weight per day for fumonisin. An entomological analysis revealed overall 32% prevalence of Ephestia kuehniella (flour moth), 16% prevalence of Sitophilus zeamais (maize weevil), and 8% prevalence of Tribolium sp. (flour beetle) on the analyzed farms. This study highlighted poor agricultural practices used in the highlands of Guatemala. Current practices should be revised for the production of maize that is safe for consumption by the population in this region. [ABSTRACT FROM AUTHOR]

Maize is a staple crop in Guatemala, especially in the rural regions where it is consumed in high amounts. Given that traditional pre- and post-harvest practices lead to exposure to the environmental surroundings where pests and microorganisms may be present, maize quality and safety can be compromised severely. In order to assess the potential degree of risk, an exploratory study involving maize mycobiota from six farms from Huehuetenango, Guatemala was conducted. DNA was extracted from the maize samples, and the ITS1 region was subjected to Illumina sequencing. This survey identified 52 fungal taxa in the 90-day maize storage period. For the samples where the maize moisture content exceeded 20%, a high yeast content was observed which can reflect spoilage during storage. A significant amount of Fusarium and Aspergillus – mycotoxin-producing molds – was found, representing a potential for mycotoxin contamination. This indicates a plausible health risk in a region where maize represents a significant portion of the diet. Potential maize pathogens in the genera Acremonium and Cladosproium, and Stenocarpella maydis, were also common. Results from this study can help better understand the potential health-risk scenario in the Highlands of Guatemala if poor grain handling practices are adopted. [ABSTRACT FROM AUTHOR]

Candida yeasts are the dominant fungi in the healthy human microbiome, but are well-known for causing disease following a variety of perturbations. Evaluation of fungal populations from the healthy human gut revealed a significant negative correlation between the foodborne yeast, Debaryomyces hansenii , and Candida species. D. hansenii is reported to produce killer toxins (mycocins) effective against other yeast species. In order to better understand this phenomenon, a collection of 42 D. hansenii isolates was obtained from 22 cheeses and evaluated for killer activity against Candida albicans and Candida tropicalis over a range of temperatures and pH values. Twenty three strains demonstrated killer activity against both C. albicans and C. tropicalis , which was pH- and temperature-dependent, with no killer activity observed for any strain at pH 6.5 or higher, or at ≥ 35 °C (physiological conditions in the human gastrointestinal tract). A cell-free mycocin preparation showed transient killer activity against C. albicans at 35 °C and a cheese sample containing a killer D. hansenii strain demonstrated sustained killer activity against both C. albicans and C. tropicalis . Together, these observations raise the possibility that D. hansenii could influence Candida populations in the gut. [ABSTRACT FROM AUTHOR]