Surveillance of toxigenic fungi and ochratoxin A in feedstuffs from Córdoba Province, Argentina.

The aim of this work was to evaluate the incidence of potential ochratoxigenic mycoflora and ochratoxin A (OA) in poultry, pig and rabbit feeds. Eighty poultry, pig and rabbit feed samples were taken at random from factories located from Córdoba province, Argentina, over a period of 8 months. Isolation and quantitative enumeration of fungal propagules were done on DRBC and DG18 media. The predominant species were A. candidus, A. flavus, A. terreus, A. parasiticus, P. implicatum, P. minioluteum, P. crustosum and P. citrionigrum. The distribution of section Nigri species varied according to the feedstuffs analysed. The frequency of A. niger var. niger was noticeably high in poultry feed samples on DRBC medium. The Nigri section species was present at moderate mean colony counts (CFU/g) from three feeds. Mycotoxin analysis of these samples showed that OA was detected in 15%, 10% and 12% of pig, poultry and rabbit feed samples, respectively. The mean levels detected ranged between 15 and 25 ng/g from three feeds. The presence of ochratoxigenic species of Nigri section and OA in feeds indicates the risk of potential exposure of poultry, pigs and rabbits through the ingestion of feeds.

Detection of ochratoxin A in animal feeds and capacity to produce this mycotoxin by Aspergillus section Nigri in Argentina.

Ochratoxin A (OA) is a mycotoxin detected in a variety of food and feeds mostly from countries with a temperate climate because of the fungi that produce it, mainly Aspergillus ochraceus and Penicillium verrucosum. In Argentina, there is no available information about the natural occurrence of OA and ochratoxigenic fungi from feedstuffs. The aim was to evaluate the natural occurrence of OA in poultry, pig and rabbit feeds over 8 months. Likewise, the capacity to produce OA by Aspergillus section Nigri was investigated. Mycotoxin analysis showed that in some months of sampling, OA was detected in three feeds. OA was found in 38% of the poultry feed samples tested with levels ranging from 25 to 30 ng g(-1). From rabbit feed samples, 25% contained OA and the levels ranged from 18.5 to 25 ng g(-1). Only 13% of the pig feed samples were contaminated with similar levels of toxins. Ninety-four black Aspergillus strains from feedstuffs were tested for OA production. Among these, the tested species were A. niger var. niger, A. niger var. awamori, A. japonicus var. japonicus, A. japonicus var. aculeatus and A. foetidus. For the detection of OA, three methodologies were applied: the two TLC methods used for the fast screening of the filamentous fungi for the production of OA were not sensitive enough to detect OA in any of the black Aspergillus strains. When an HPLC methodology was used, the results showed that 46% of the black Aspergillus strains were producers of OA, with levels ranging from 13 to 25 ng ml(-1) culture medium. The highest percentage of ochratoxicogenic strains was isolated from rabbit feeds with 100 and 78% of A. niger var. niger and A. niger var. awamori, with mean levels of 15.5 and 14.6 ng ml(-1), respectively. From pig feeds, 61% of the A. niger var. awamori were producers of this toxin with mean levels of 16 ng ml(-1). In poultry feeds, the lowest percentage of OA producer strains was detected. The results for the occurrence of OA in feeds from different sampling months depended on storage and humidity-temperature conditions. Therefore, a good storage practice becomes very important to prevent OA production

The mycoflora and toxicity of feedstuffs from a production plant in córdoba, Argentina.

Feedstuffs used for poultry nutrition in Argentina were analyzed for fungal flora and natural incidence of mycotoxins. Survey of 120 samples of poultry feeds, taken from May 1998 to April 1999, showed the presence of 15 genera of filamentous fungi. The predominant genera wereFusarium spp. andPenicillium ssp., isolated in 67.5 % of the samples, followed byAspergillus spp. (57.5 %). Yeast, were significantly isolated from most of the samples. Species identification was carried down for the toxigenic genera. Fungal total counts of poultry feeds ranged from 2.0 × 10(3) to 3.0 × 10(5) CFU g(-1) The fungal total counts during two months of sampling, were slightly over the limit value of 1 × 105 CFU g(-1), which ensure the hygienic quality of the feed. Potentially toxicogenic species presented moderate mean colony counts. Many of the fungi isolated from poultry feeds are mycotoxin producers. Fumonisins had the highest incidence, and were found in 97 % of the analyzed samples followed by aflatoxin B1 (46 %), zearalenone (18 %) and deoxynivalenol (6 %). On the co-occurrence of both carcinogenic mycotoxins, all of the FBs contaminated feed samples were co-contaminated with AFB1. The results show the relevance of the samples screening for viable fungi propagules and the surveillance of their associated mycotoxins in poultry feeds.