This study focuses on the interaction of the three components of the Bacillus cereus

Trichothecene cytotoxicity of type A (T-2 toxin and HT-2 toxin), type B (deoxynivalenol, DON, and nivalenol, NIV), and type D (satratoxins G and H) compounds was determined comparatively by using eight permanent human cell lines (Hep-G2, A549, CaCo-2, HEp-2, A204, U937, RPMI 8226, and Jurkat). Viability of cells was measured by a water-soluble tetrazolium (WST-1) reagent cell proliferation assay assessing mitochondrial metabolic activity. Toxicity was expressed as the toxin concentration inhibiting 50% of cell viability (IC50). Depending on the chemotype of the tested trichothecenes, relative cytotoxic activity differed by a factor of 100-1,000, and the corresponding IC50 values were in the range from 2.2 nmol/l (satratoxin H on Jurkat and U937 cells) to 4,900 nmol/l (deoxynivalenol on HEp-2 cells). In contrast, the specific toxicity of each individual mycotoxin towards different cell lines was within remarkable close limits, and between-cell line differences were much smaller than previously reported. For the cell lines tested, IC50 values were 4.4-10.8 nmol/l for T-2 toxin, 7.5-55.8 mol/l for HT-2 toxin, 600-4,900 nmol/l for DON, 300-2,600 nmol/l for NIV, and 2.2-18.3 nmol/l for satratoxins G/H. In addition, for the first time, the toxic activity of trichothecenes on primary cell culture of human endothelial cells (HUVEC) was tested. The susceptibility of this cell line was comparable to the other cell lines tested, with IC50 values ranging from 16.5 nmol/l (T-2 toxin) to 4,500 nmol/l (DON). The results suggest that the current focus of cytotoxicological studies on trichothecenes on lymphoid cell lines may lead to an underestimate of their potential on other target cell systems.

The infectious bronchitis virus Middle-East GI-23 lineage (Var2-like) was observed on a German broiler farm, for the first time. The animals suffered from respiratory and nephropathogenic disease. Gross lesions observed during necropsy included tracheitis, aerosacculitis, and nephritis.Tracheal swabs were tested positive for infectious bronchitis virus Middle-East GI-23 lineage (Var2like) by PCR. Furthermore, sequence analysis of the S1 spike protein showed close relationship to the commercially available vaccine TAbic IBVAR206 and polish isolates.

No abstract

Contamination of cereals with the trichothecene deoxynivalenol (DON) is a global problem in agriculture. DON-related cytotoxicity results from inhibition of translation preceded by a ribotoxic stress response, which is characterized by phosphorylation of the mitogen-activated protein kinases and activation of downstream transcription factors. In this study, we measured the expression of AP-1 associated transcription factor mRNA levels in six human cell lines (Hep-G2, A549, U937, A204, Jurkat, and CaCo-2) by using real-time RT-PCR. Previous work suggested that transcription factors mRNA and protein levels are affected by DON in Hep-G2 cells. In this study, we found significant cell-specific differences in mRNA levels for the transcription factors JUN, JUND, FOS, FOSL2, ATF3, and EGR1. After exposure to 1 µmol/l DON for 3 h, the induction of the transcription factor JUN was highest in the Jurkat (342-fold) and Hep-G2 (84-fold) cell lines. JUND expression was mainly affected in the immunocompetent cell-lines U937 (11-fold) and Jurkat (12-fold), whereas significant FOSL2 induction (5-fold) was only found in Jurkat cells. DON-induced expression of FOS was mainly observed in Hep-G2 (96-fold) and U937 cells (59-fold). In contrast, response of A549 cells to DON was characterized by a distinct induction of ATF3 (44-fold) and EGR1 (92-fold). Time- and concentration-dependent induction of the transcription factors by DON was studied in detail for Hep-G2, A549, A204, and U937 cells. Considering the chronic dietary exposure of humans, broader investigations on DON influence on cell signaling pathways are required to understand the impact of this mycotoxin on human health.