Presence of moulds and mycotoxins in pigs feed: significance in risk assessment | Prisustvo plesni i mikotoksina u hrani za ishranu svinja - značaj u proceni rizika

The aim of this paper was to provide detailed insight into the level of contamination of complete feeding mixtures intended for fattening pigs with mycotoxins-producing fungi and mycotoxins (n = 18). Isolation and enumeration of fungal propagules were done on solid media using the standard microbiological procedure. These plates were incubated, the number of colonies was determined and moulds genera and species identification was carried out using colonies morphological determination and microscopic analysis. Isolates identified as Aspergillus and Penicillium species were subjected to molecular characterization for the presence of genes responsible for the synthesis of OTA (polyketide synthase gene-PKS). Total fungal counts (CFU/g) ranged from 0.5x10**5 to 4x10**6. From a total samples analyzed, seven samples had fungal counts higher than the limit established by Serbian regulations (3x10**5). During a mycological analysis of complete feeding mixtures intended for fattening pigs, a total of six genera and 14 species of moulds were identified and the most frequent one was genus Penicillium (94.4%). The moulds from genus Fusarium were isolated in 55.5% and Paecilomyces in 44.4% of the samples from investigated localities. Other fungi from the genera Aspergillus (22%), Mycor (11.1%) and Alternaria (5.5%) were represented in a lesser amount. Polymerase chain reaction (PCR) was performed on 18 isolates of the DNA belonging to families Penicillium and Aspergillus. The sequences of PCR reaction products in three samples were compared with nucleotide sequences of genes for polyketide synthase gene (PKS) from Penicillium dance and found that the samples possessed PKS sequence. The traditional methods for identification of ochratoxin-producing fungi are time-consuming and labor-intensive. Rapid and specific detection of ochratoxin-producing fungi is important for ensuring microbiological quality and safety of feed and food.