Gliotoxin natural incidence and toxigenicity of Aspergillus fumigatus isolated from corn silage and ready dairy cattle feed

Abstract

Corn silage is an important feed source for dairy and beef cattle in central Argentina. The presence of thermophilic species Aspergillus fumigatus is among the major problem in silage, as many strains can produce several mycotoxins that affect the health of dairy cattle. The aims of the present study were to determine total fungal counts and relative density of A. fumigatus in silage samples, and to determine the natural incidence of gliotoxin in silage and ready dairy feed samples. The potential gliotoxin production of A. fumigatus isolated from silage was also recorded. A total of 90 samples were investigated, which were taken immediately after opening of the silo and the end of the ensiling period of about after 5 months. Sampling was performed manually through silos in transects at 3 levels per silo. Thirty samples of ready cattle feed (corn silage, ground corn, barley, cotton seed, brewer grains) were collected and investigated as well. Gliotoxin contamination was determined by HPLC. The ability of A. fumigatus to produce gliotoxin was measured using a TLC method. Results show that in all samples, the total number of yeasts and moulds exceeded 1×104 cfu/g. Aspergillus was the most prevalent genus followed by Fusarium and Penicillium spp. Investigations of the isolated A. fumigatus strains showed that many of these strains produced more than one mycotoxin. All samples showed gliotoxin contamination, but the strains isolated from ready cattle feed had higher gliotoxin levels than those isolated from corn silage. The gliotoxin concentrations found in this study exceeded the levels that are known to induce immunosuppressive and apoptotic effects in vitro. Although at present the oral bioavailability of gliotoxin in cattle is not known, the presented data suggest that its presence in feedstuffs could affect productivity and present a health risk for dairy cows.

Mycobiota and mycotoxins contamination in raw materials and finished feed intended for fattening pigs production in eastern Argentina

“…However, Argentinean samples always showed higher F. verticillioides isolation frequency than Brazilian samples. González Pereyra et al (2008) obtained similar with us from finished pig feed samples in central Argentina. However, they did not report the fungal contamination present in raw materials.…”

“…These results are similar to those obtained by other researchers in pig samples feed , Gonzalez Pereyra et al 2008. In general, fungal counts in different kinds of animal feed have been recently informed over 1×10 4 UFC g −1 (Gonzalez Pereyra et al 2008;Rosa et al 2009;Pereyra et al 2008;Pereyra et al 2009). The screening of samples for fungal propagules is a useful exercise in itself as an indicator of contamination but also complements the analysis of mycotoxins that could be present.…”

“…Recently, González Pereyra et al (2008) have informed the mycobiota and mycotoxins of fattening pigs in central Argentina. However, they did not inform the mycobiota and mycotoxins of all involved raw materials intended to pig production.…”

“…Little information concerning mycotoxin contamination in pig feed has been generated from Argentina. Gonzalez Pereyra et al (2008) determined the fungal biota and mycotoxins from pig feed. However, these authors did not evaluate the raw materials contribution to fungal and mycotoxins contaminations of finished feed besides only selected mycotoxins were evaluated in central Argentina.…”

Consumption Data for the Main Cheeses (Mexican-Style Fresh and Oaxaca) for Dietary Exposure Assessment among the Population of Veracruz City, Mexico

“…It has been shown that raw milk products can have high concentrations of pathogenic bacteria, dioxins, heavy metals, hormones, antibiotics and mycotoxins [9][10][11][12][13][14]. Mycotoxins, such as aflatoxins have carcinogenic properties [15,16]. Aflatoxins can be transferred from milk to cheese [17].…”