Aflatoxin and cyclopiazonic acid production by Aspergillus section Flavi associated to poultry feed

ASTORECA, A.; DALCERO, A.; VAAMONDE, G.

Merida, MEXICO

Congreso; VI Congreso Latinoamericano de Micotoxicologia; 2010

Sociedad Latinoamericana de Micotoxicologia

AFLATOXIN AND CYCLOPIAZONIC ACID PRODUCTION BY ASPERGILLUS SECTION FLAVI ASSOCIATED TO POULTRY FEED A total of thirty five poultry feeds and their corresponding raw materials (maize, soybean and meat meal) samples from a processing plant in Río Cuarto city were analyzed. The quantitative enumeration of fungal propagules was determined by the surface spread method on DRBC and DG18 medium. The mycological analysis of the samples indicated the presence of six fungal genera (Aspergillus, Penicillium, Fusarium, Cladosporium, Eurotium, yeast). Aspergillus flavus was the predominant species being present in 48.5% of the analyzed samples. Each colony belonging to Aspergillus genus were sub cultured on MEA for subsequent identification to species level, which was performed following the taxonomic keys proposed by Pitt and Hocking (1997), Klich (2002) and Samson (2000). Ninety one strains belonging to Aspergillus section Flavi were isolated; ninety of them were identified as A. flavus and only one as A. parasiticus. The strains were characterized as S or L according to the diameter and number of produced sclerotia. Fifty seven strains were capable to produce sclerotia, of which 41 were identified as L-type strains and 16 as type S. The ability to produce aflatoxins and cyclopiazonic acid by all strains was evaluated by the methods described by Geisen (1996) and Bragulat et al. (2001), respectively. Fifty-seven percent of the strains (52) produced AFB1 levels ranging from 0.05 mg g-1 to 27.7 mg g-1 while the 86.8% (79) were producer of CPA levels that ranging from 0.5 mg g-1 to 137.8 mg g-1. Strains L produced from 0.005 to 14.8 mg g -1 (mean 1.8 mg g -1) of aflatoxin while the Type S produced levels ranging from 0.005 to 1.65 mg g-1 (mean 0, 39 mg g-1). No differences in CPA production among strains of S and L type. The sclerotia-producing strains showed levels ranging between 0.005 and 27.7 mg g-1 (average 2.47 mg g-1) and between 3.8 and 47.3 mg g-1 (average 15.5 mg g -1) of AFB1 and CPA, respectively. The determination of both toxins incidence is being evaluated.