Zearalenone [KLH]

Fusarium meridionale and F. boothii cause Gibberella Ear Rot (GER) in maize. This study determined the effects of temperature (5-35 degrees C) and water activity (0.90-0.995 a(w)) on the growth, and deoxynivalenol (DON) and nivalenol (NIV) production of F. meridionale and F. boothii strains in maize grains. Fusarium graminearum sensu stricto strains from wheat were also tested. The three Fusarium species grew best at 0.995 a(w) and 25 degrees C. Growth was absent or marginal at 0.90 a(w) regardless of temperature. F. meridionale and F. boothii were sensitive to 30 degrees C and more affected by water stress than F. graminearum sensu stricto. The highest DON levels were at 0.995-0.97 a(w) and 30 degrees C and at 0.97 a(w) and 20 degrees C for F. graminearum sensu stricto, and at 0.995-0.97 a(w) and 20 degrees C for F. boothii. Fusarium meridionale reached maximum NIV accumulation at 0.995 a(w) and 20 degrees C. This produced DON at negligible levels compared to the other two Fusarium species. Growth of F. meridionale and F. boothii was well adapted to the usual autumn high humidity and mild temperatures associated with GER in northwest Argentina. Control strategies during grain development should be taken into account to reduce the risk of the presence of DON and NIV in the harvested grains.

Mycotoxin contamination is a major concern in developing countries such as South Africa, with pelleted pet foods often being contaminated with mycotoxins that have a negative impact on pet health. This study investigated the cytotoxicity of some common mycotoxins found in commercial cat food. A total of 12 cat food samples consisting of six samples each from standard grocery store lines (SB) and premium veterinarian lines (PB) were collected from supermarkets and veterinary practices, respectively. Samples of pelleted cat food were extracted for mycotoxins. Cat peripheral blood mononuclear cells (PBMCs) were isolated and treated with various feed extracts for 24 h to determine the oxidative stress and antioxidant status, using the thiobarbituric acid (TBARS) and glutathione assays, mitochondrial integrity and cell death using caspsase 3/7 luminometry and Annexin V flow cytometry assays, respectively. Both PB and SB extracts decreased ATP levels (P<0.05) and increased mitochondrial depolarization (P<0.05) except for the PB acid fraction. Lipid peroxidation was increased in both PB and SB extracts (P <0.05) with a concomitant decrease in glutathione levels (P<0.05). Apoptosis and necrosis of PBMCs were also increased (P<0.05) in PB and SB extracts, with executioner caspases-3/7 elevated (except for the PB acid fraction). Interestingly, initiator caspases were decreased (P <0.05). This study found that both PB and SB display immune toxicity in feline lymphocytes; however, PB fared better by demonstrating lower levels of cytotoxicity.