Alcoholic beverages can be contaminated with mycotoxins. Ochratoxin A (OTA) is the most frequently detected mycotoxinin wine and is produced by several species of Aspergillus. This mycotoxin is nephrotoxic and carcinogenic. In beer, the most commonly identified mycotoxin is deoxynivalenol (DON). Ingestion of food contaminated with DON has been associated with adverse gastrointestinal effects. Despite the harmful effects of mycotoxins on health, there are no regulations regarding their limits in alcoholic beverages in Paraguay. Here we determine the presence of OTA and DON in wine and beer, respectively. Four commercial brands of wine and twenty-nine brands of craft and industrial beerwere tested by the Agra quant ELISA method. One brand of wine was positive for OTA and seven brands of beer (one of them craft) were positive for DON. The values found for both toxins are below the recommended maximum intake proposed by international standards. Giving the high consumption of these products in the country, regulations and monitoring systems mustbe established to check the maximum levels of mycotoxins allowed in alcoholic beverages.

No abstract

Fusarium head blight (FHB), or scab, caused by a Fusarium spp. complex, is an important wheat disease in Paraguay. Among the strategies used to control it, the genetic resistance is considered highly efficient and cost effective. This study aimed to evaluate and compare the effects of F. graminearum on six wheat genotypes, including two comparison varieties, in two seeding dates. The genotypes were artificially inoculated in the spike, at the flowering stage, by injecting a pool of four pathogenic F. graminearum isolates. The FHB development was evaluated by scoring the disease incidence and severity, percentage of diseased spikelets and damaged kernels, as well as using the area under the disease progress curve. Besides the kernel infection, its impact on the development of mycotoxins (deoxynivalenol) and interactions with the genotypes were also evaluated. The results identified an advanced breeding line (Lin 84) with a resistance level to FHB comparable to that of the universally known resistance sources (Sumai 3 and Frontana). The other three genotypes (Caninde 11, Caninde 12 and Caninde 21), in spite of presenting a higher grain yield potential, were evaluated as moderately susceptible to susceptible. These results suggest that, although it is possible to transfer the FHB resistance to a higher agronomic type, combining such resistance with a higher grain yield potential remains an ongoing challenge.

No abstract

Fusarium graminearum is one of the most important pathogens affecting wheat production in Paraguay. This fungus decreases yield and grain quality; the most important consequence is the production of mycotoxins from the trichothecene group, secondary metabolites toxic to humans and other animals. The toxin reported in Paraguay is deoxynivalenol, which has effects on the gastrointestinal tract and immune system. To determine the presence of deoxynivalenol in flour and baked goods, samples of wholemeal flour and white flour, white and wholemeal bread, and bran crackers were carried out in the Gran Asunción Area. The presence of deoxynivalenol was determined by monoclonal antibodies through the use of quantitative test strips. The results were variable and below those established by international standards. Practical applications In the developing countries, the control of the quality and safety of food is practically nonexistent. In Paraguay, there is no legislation on the maximum levels of deoxynivalenol in wheat and derivatives. As this cereal and its derivative products are highly susceptible to contamination by Fusarium and its mycotoxins, it is a priority to initiate controls and establish bases for legislation on maximum acceptable limits in these products. Also highlight the need at country level of the application of high efficiency and sensitive techniques for quantification mycotoxins in food.

The genus Pyricularia contains several fungal species known to cause diseases on plants in the Poaceae family (Klaubauf et al. 2014; Wang et al. 2019). While sampling for P. oryzae during March-2015 and April-2018, common weed Cenchrus echinatus L. was observed with leaf lesions in and around experimental wheat fields in the departments of Canindeyú and Itapúa. C. echinatus samples from both locations displayed similar leaf lesions, varying from small light brown pinpoint to elliptical brown lesions with greyish center. Symptomatic leaves were surface disinfested and cultured on potato dextrose agar (PDA) amended with 1% gentamicin at 25°C. Two monosporic isolates were obtained, one from Itapúa (ITCeh117) and the other from Canindeyú (YCeh55). The isolates were subsequently grown on oatmeal agar (OA) and PDA under a 12-h photoperiod at 25°C and evaluated after ten days for colony diameter, sporulation, macroscopic and microscopic features. Colonies on OA reached up to 4.8 cm diameter and were light grey, whereas colonies on PDA reached up to 5.3 cm diameter and were brown with grey centers, with cottony mycelium and broad white rims. Mycelium consisted of smooth, hyaline, branched, septate hyphae 4-4.5 µm diameter. Conidiophores were erect, straight or curved, unbranched, medium brown and smooth. Conidia were solitary, pyriform, pale brown, smooth, granular, 2-septate, 32-33 × 9-10 μm; truncated with protruding hilum and varied in length from 1.0 to 1.5 μm and diameters from 2.0 to 2.2 μm. Both isolates were similar and identified as Pyricularia pennisetigena, according to morphological and morphometric characteristics (Klaubauf et al. 2014). Subsequently, genomic DNA was extracted from each isolate using the primers described in Klaubauf et al. (2014) to amplify and sequence the internal transcribed spacers (ITS), partial large subunit (LSU), partial RNA polymerase II large subunit gene (RPB1), partial actin gene (ACT), and partial calmodulin gene (CAL). Sequences from each isolate (YCeh55/ITCeh117) were deposited in GenBank with the following submission ID for ITS: MN947521/MN947526, RPB1: MN984710/MN984715, LSU: MN944829/MN944834, ACT: MN917177/MN917182, and CAL: MN984688/MN984693. Phylogenetic analysis was conducted using the software Beast v1.10.4. The results obtained from the concatenated matrix of the five loci placed these isolates in the P. pennisetigena clade. To confirm pathogenicity, each isolate was adjusted to 5×104 conidia/ml of sterile water and C. echinatus plants were sprayed with the conidial suspension for isolate YCeh55, ITCeh117 or sterile water using an oilless airbrush sprayer until runoff. The three treatments were kept in the greenhouse at 25-28°C and about 75% relative humidity under natural daylight. Each treatment included three to five inoculated plants and 10 leaves were evaluated per treatment. Symptoms were observed 8-15 days after inoculation and were similar to those originally observed in the field for both isolates, whereas the control plants remained asymptomatic. P. pennisetigena was re-isolated from the inoculated leaves fulfilling Koch’s postulates. To our knowledge, this is the first report of leaf blight on C. echinatus caused by P. pennisetigena in Paraguay. The occurrence of P. pennisetigena in the region and its ability to infect economically important crops such as wheat and barley (Klaubauf et al. 2014; Reges et al., 2016, 2018) pose a potential threat to agriculture in Paraguay.

Introducción: Las micotoxicosis son enfermedades producidas por micotoxinas, metabolitos secundarios tóxicos producidos por hongos filamentosos. Los lactantes son especialmente susceptibles a este tipo de toxinas debido a la inmadurez anatómica y funcional de sus sistemas digestivo e inmune, lo que se refleja en la relación entre la cantidad de alimento ingerida y su peso. Objetivo: Determinar la presencia de micotoxinas en alimentos para lactantes comercializados en farmacias y supermercados del Área Metropolitana. Materiales y métodos: Se colectaron al azar 66 unidades de productos de seis marcas diferentes de preparados y colados comerciales importados, dulces y salados, de farmacias y supermercados del Área Metropolitana. Posteriormente, fueron analizados mediante el ensayo de inmunoafinidad ligado a enzimas (ELISA). Se realizó el análisis de varianza y la posterior comparación de medias de las concentraciones de micotoxinas mediante la prueba de Tukey (IC= 95%), con el estadístico InfoStat®. Resultados: Las micotoxinas prevalentes fueron aflatoxinas (AF) y Toxina T2, que se presentaron en 39% de las unidades muestrales analizadas, tanto en preparados como en colados. En tercer orden de importancia se encuentra ocratoxina A (OTA), detectada en 18% de las mismas. En cuarto lugar, deoxinivalenol (DON) se detectó en 4% los productos. Se presentaron diferencias significativas entre los preparados y los colados, siendo los colados los que en media presentaron niveles más altos de concentraciones de todas las micotoxinas estudiadas. Conclusiones: Se constataron niveles variables de AF, OTA, T2 y DON en los alimentos para lactantes comercializados en el Área Metropolitana. Los colados presentaron concentraciones más elevadas de micotoxinas en media en todos los productos analizados. Tanto AF como OTA superaron los límites máximos permitidos por las normas internacionales. Correspondencia: Andrea Alejandra Arrúa Correo: aaarrua@gmail.com Conflicto de interés: Man Mohan Kholi, asesor científico de la Cámara Paraguaya de Exportadores y Comercializadores de Cereales y Oleaginosas; los demás autores declaran no tener conflicto de interés. Recibido: 30/03/2019 Aprobado: 17/07/2019

Paraguay is a non-traditional wheat-producing country in one of the warmest regions in South America. Fusarium Head Blight (FHB) is a critical disease affecting this crop, caused by the Fusarium graminearum species complex (FGSC). A variety of these species produce trichothecenes, including deoxynivalenol (DON) and its acetylated forms (3-ADON and 15-ADON) or nivalenol (NIV). This study characterized the phylogenetic relationships, and chemotype diversity of 28 strains within FGSC collected from wheat fields across different country regions. Phylogenetic analysis based on the sequence of elongation factor-1α gene (EF-1α) from 28 strains revealed the presence of four species in the FGSC: F. graminearum sensu stricto, F. asiaticum, F. meridionale and F. cortaderiae. Ten strains selected for further analysis revealed that all F. graminearum strains were 15-ADON chemotype, while the two strains of F. meridionale and one strain of F. asiaticum were NIV chemotype. Thus, the 15-ADON chemotype of F. graminearum sensu stricto was predominant within the Fusarium strains isolated in the country. This work is the first report of phylogenetic relationships and chemotype diversity among Fusarium strains which will help understand the population diversity of this pathogen in Paraguay.