Mycobiota and Aflatoxin B1 in Feed for Farmed Sea Bass (Dicentrarchus labrax)

Abstract

Thesafety characteristics of feed used in fish and crustacean aquaculture systems are an essential tool to assure the productivity of those animal exploitations. Safety of feed may be affected by different hazards, including biological and chemical groups. The aim of this preliminary study was to evaluate fungi contamination and the presence of aflatoxins in 87 samples of feed for sea bass, collected in Portugal. Molds were found in 35 samples (40.2%) in levels ranging from 1 to 3.3 log10 CFU∙g−1. Six genera of molds were found. Aspergillus flavus was the most frequent, found in all positive samples, with a range from 2 to 3.2 log10 CFU∙g−1. Aspergillus niger was found in 34 samples (39.1%), ranging from 1 to 2.7 log10 CFU∙g−1. Aspergillus glaucus was found in 26 samples (29.9%) with levels between 1 and 2.4 log10 CFU∙g−1. Penicillium spp. and Cladosporium spp. were both found in 25 samples (28.7%). Fusarium spp. was found in 22 samples (25.3%), ranging from 1 to 2.3 log10 CFU∙g−1. All feed samples were screened for aflatoxins using a HPLC technique, with a detection limit of 1.0 μg∙kg−1. All samples were aflatoxin negative.

Evaluation of Nephrotoxic Effects of Aflatoxins on Common Carp (Cyprinus carpio)

“…Depending on the aflatoxin level in feed, the major effects of poisoning with aflatoxin in trout are a decrease in protein synthesis, changes in lipid metabolism, disturbance in mitochondrial respiration, liver cancer, inhibition of nucleic acids, and an increase in lipid accumulation in liver [4]. However, the toxic effects of mycotoxins may differ depending on the fish species and age.…”

“…Symptoms of acute aflatoxin toxicity are pale gills, disturbance in blood clotting, anemia, generalized weakness and reduced growth rate [4]. Long-term exposure to low concentrations of aflatoxin B1 may lead to liver tumors (in the form of yellow nodules even found in the kidney), neoplasia, and an increase in mortality rate of fish [5][6][7].…”

“…Long-term exposure to low concentrations of aflatoxin B1 may lead to liver tumors (in the form of yellow nodules even found in the kidney), neoplasia, and an increase in mortality rate of fish [5][6][7]. A decrease in plasma total protein, globulin and antibody titer in rohu (Labeo rohita) [1], a decrease in growth rate, specific growth rate (SGR) and an increase in feed conversion rate (FCR) in beluga, Huso huso [8], as well as immunosuppression and increased sensitivity of fish to bacterial, viral and parasitic infections are other consequences of aflatoxicosis [4].…”

Effects of Aflatoxin-Contaminated Feed on Immunological Parameters of Common Carp (Cyprinus Carpio)

“…Therefore, these animals are likely to be intoxicated with aflatoxins. Loss of appetite, reduced growth rate, and a decrease in the efficiency of food is reported in many fish treated with aflatoxin-contaminated diets [12]. Aflatoxincontaminated feed makes histopathological changes 8…”

“…Consumption of food contaminated with aflatoxins increases the production rate of free radicals and leads to oxidative stress [16]. Moreover, aflatoxin intoxication may suppress the immune system [12], change gene expression [17], lead to blood disorders [14] and result in fish mortality [15]. Since aflatoxin toxicity can weaken the immune system of fish and increase their vulnerability to pathogens, investigating the influence of aflatoxins on non-specific immune parameters is essential.…”