Fungos e micotoxinas presentes em amostras de pólen de abelhas melíferas do estado do Rio de Janeiro

Abstract

The bee’s pollen is a product rich in essential nutrients to feed the bees. In the hive it goes through chemical processes and becomes the bee’s bread, of extreme importance for the growth of larvae. Currently, the use of pollen in the human’s cuisine has been increasing for its therapeutic properties, and by its use in the food industry. To produce quality pollen the hive needs to be healthy, and bees, like any other animal, are susceptible to various diseases, parasites and predators, which can affect their development and productivity. The The Brazilian Sac Brood (BSB) is one of these diseases, which in Brazil affects honeybee larvae. In apiaries of Rio de Janeiro state, a high mortality of larvae with symptoms similar to the BSB is occurring, and until now, there is no definite conclusion regarding the etiologic agent of this disease in the state. Therefore, the objectives of this study was to clarify two issues: 1) provide a mycological research, through a study case, of bees’ bread samples, adult bees and bees’ pollen in areas affected and not affected by the BSB, aiming the elucidation of its etiologic agent, 2) verify the hygienic quality of dehydrated pollen samples sold in Rio de Janeiro state. A total of 48 samples of bees’ bread, 15 of adult bees and 12 of pollen were collected from endemic regions of the BSB. The samples were collected in the months before, during and after the period of the disease. The dehydrated pollen samples were also purchased in commercial stores of the state, totaling 27 samples. Fungal species enumeration (cfu g-1) was through decimal dilution method using general culture media and selective ones. The isolation frequency and relative density of species were determined. The toxigenic profile of strains was determined, as also the detection and quantification of aflatoxin B1 in bread and bees’ pollen. The results obtained from the study case samples showed that the bees’ bread was the best vehicle of contamination for the hive. It was also observed a high fungal counts and the presence of mycotoxins and entomopathogenic fungi such as Aspergillus flavus, A. niger aggregate and A. fumigatus, which cause a decrease of the immune response, leaving them susceptible to various diseases, including the BSB itself. Pollen dehydrated samples showed a high fungal contamination with 92% of the samples in unsatisfactory hygienic conditions according to legal standards. A total of 25% of the A. flavus strains showed to be aflatoxigenic. The high percentage of unhygienic samples combined with the presence of a large variety of fungal contaminants, including mycotoxin-producing species, evidences that the legislation needs to be updated so that it can be safely commercialized. It is considered that the whole line production of bees’ pollen, since its extraction until its storage should be monitored in order to minimize risks to human health.