Isolation, characterization and evaluation of significant mycoflora and mycotoxins in pig feed from Serbian farms

Abstract

This paper provides a brief review of approaches for the early detection and prevention strategies which have been employed in Serbia for the control of ochratoxogenic fungi and its metabolites in feed in the context of a hazard analysis critical control point (HACCP) framework. During a mycological analysis of complete feedmixes intended for fattening swine (n = 18), a total of six genera and 14 species of moulds were identified. Penicillium was present in considerably more samples than any other genus (94.4%), followed by the genera Fusarium (55.5%) and Paecilomyces (44.4%). Other fungi from the genera Aspergillus (22%), Mucor (11.1%) and Alternaria (5.5%) were represented in a smaller amount. Total fungal counts ranged from 10⁵ to 40 × 10⁵ c.f.u./g. The mycotoxins deoxynivalenol, ochratoxin A and zearalenone were detected, while aflatoxins were not present. Deoxynivalenol was detected in 10 samples in the concentration range 0.25–2.5 mg/kg. Ochratoxin A and zaralenone were detected in nine and eight samples, respectively, in the concentration range 0.057–0.27 and 0.2–5.0 mg/kg, respectively. 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) using polymerase chain reaction (PCR) applied to a set of 18 isolates. The sequences of PCR reaction products in three samples were compared with nucleotide sequences of genes for polyketide synthase (PKS) from Penicillium species and it was found that the samples possessed the PKS sequence. These findings indicate that there may be a risk of animal exposure to mycotoxins through the consumption of mouldy infected feeds.