Contaminación de alimento comercial seco para perro por Aspergillus flavus y aflatoxinas en Aguascalientes, México

Commercial dry food (CDF) for dogs is a whole grain ration thoroughly mixed and die-cut with heat and pressure to give it the shape of kibble. CDF is formulated with several agro-industrial ingredients and by-products of agricultural and livestock origin. Contamination by Aspergillus flavus and aflatoxins (AFs) in foods has been shown to be a global problem that causes harm to human and animal health. The objective was to evaluate the presence of fungal microbiota and contamination by AFs in CDF. A random sample (n= 77) of marketed CDF was selected in Aguascalientes, Mexico. The samples were processed and cultured by serial dilutions, obtaining monosporic isolates, which were characterized morphologically, toxigenically (HPLC), and molecularly (PCR). The concentration of AFs in CDF was quantified by HPLC. Fungal growth was observed in 53.2 % of CDF, and 7.8 % exceeded the maximum permissible limit (MPL=106 CFU/g). The genera Aspergillus, Penicillium, Cladosporium, Mucor, Alternaria, and Fusarium were found (69.4, 12.9, 9.4, 4.7, 1.7, and 1.1 %, respectively). All CDF samples showed contamination by AFs (14.8 ± 0.3 μg/kg), and 11.8 % exceeded the MPL (20.0 μg/kg) suggested by the regulations; contamination was significantly associated (P<0.05) with some ingredients used, CDF moisture, and inclusion of fungicides and sequestrants. The results obtained suggest that the CDF manufacturing process does not wholly eliminate contamination by fungi or by the AFs present in the ingredients used for its formulation; consequently, these remain in the finished product, putting at risk the health of dogs and the efficacy of the food chain.El alimento comercial seco (ACS) para perro es una ración integral completamente mezclada y troquelada con calor y presión para darle forma de croqueta. El ACS está formulado con diversos ingredientes y subproductos agroindustriales de origen agrícola y pecuario. La contaminación por Aspergillus flavus y por aflatoxinas (AFs) en los alimentos se ha demostrado que es un problema global que causa daños a la salud humana y animal. El objetivo fue evaluar la presencia de microbiota fúngica y contaminación por AFs en el ACS. Una muestra aleatoria (n=77) de ACS comercializado se seleccionó en Aguascalientes, México. Las muestras fueron procesadas y cultivadas por diluciones seriadas, obteniendo aislados monospóricos, los cuales se caracterizaron morfológica, toxigénica (HPLC) y molecularmente (PCR).  La concentración de AFs en ACS se cuantificó por HPLC. En el 53.2 % de ACS se observó crecimiento fúngico y 7.8 % superaron el límite máximo permisible (LMP=106 UFC/g). Se encontraron los géneros Aspergillus, Penicillium, Cladosporium, Mucor, Alternaria y Fusarium (69.4, 12.9, 9.4, 4.7, 1.7 y 1.1%, respectivamente). Todas las muestras de ACS mostraron contaminación por AFs (14.8 ± 0.3 µg/kg) y el 11.8 % excedió el LMP (20.0 µg/kg) sugerido por la normatividad; la contaminación se asoció significativamente (P<0.05) con algunos ingredientes empleados, humedad del ACS e inclusión de fungicidas y secuestrantes. Los resultados obtenidos sugieren que el proceso de elaboración del ACS no elimina completamente la contaminación por hongos ni por las AFs presentes en los ingredientes empleados para su formulación; en consecuencia, éstos permanecen en el producto terminado poniendo en riesgo la salud de los perros y eficacia de la cadena alimenticia

Aspergillus flavus and Total Aflatoxins Occurrence in Dairy Feed and Aflatoxin M1 in Bovine Milk in Aguascalientes, Mexico

Contamination of food chains by toxigenic fungi and aflatoxins is a global problem that causes damage to human health, as well as to crop and livestock production. The objective is to evaluate Aspergillus flavus and total aflatoxins (AFs) occurrence in totally mixed rations (TMRs) for dairy cows and aflatoxin M1 (AFM1) in milk for human consumption. Ninety-nine dairy production units located in Aguascalientes, Mexico, were randomly selected, and samples were collected from TMRs, raw milk, and milk marketed in the city in two consecutive agricultural cycles. AFs were quantified in TMRs and milk by indirect enzyme immunoassay and HPLC; aflatoxigenic and molecular (PCR) capacity of monosporic A. flavus isolates in the feed was characterized. All feed, raw, and pasteurized milk samples showed aflatoxin contamination (26.0 &plusmn; 0.4 &micro;g/kg, 32.0 &plusmn; 1.0, and 31.3 &plusmn; 0.7 ng/L, respectively), and a significant proportion (90.4, 11.3, and 10.3%) exceeded the locally applied maximum permissible limits for feed and milk (20.0 &micro;g/kg and 50 ng/L). Aflatoxin contamination in both TMRs and milk indicated a seasonal influence, with a higher concentration in the autumn&ndash;winter cycle when conditions of higher humidity prevail. The results obtained suggest the existence of contamination by aflatoxigenic A. flavus and aflatoxins in the diet formulated for feeding dairy cows and, consequently, in the dairy food chain of this region of the Mexican Highland Plateau