ABSTRACT
A new molecular method for simultaneously rapid detection and differentiation of Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium avium and Mycobacterium paratuberculosis was established by using denaturing high-performance liquid chromatography (DHPLC) combined with multiplex nucleic acid amplification. These 4 important pathogenic mycobacteria were identified by separation of 4 specific PCR-amplified target fragments by DHPLC analysis. A total of 51 Mycobacterium strains and 22 other bacterial species were tested to confirm the specificity of the multiplex PCR-DHPLC assay. The sensitivity of the assay was as low as 10~2-10~3 gene copies. This method rapidly identify the positive clinical samples from human and bovine with higher detection ratio than traditional culture method and was able to identify simultaneously four pathogenic Mycobacterium, which provided a new molecular tool for rapid detection of tuberculosis and paratuberculosis in human and animals.
ABSTRACT
This study was to investigate the effects of the combination of deoxynivalenol (DON) and zearalenone (ZON) on pigs. Twenty-four weaning piglets were divided into a control group fed a diet free of mycotoxins and a toxin group fed a diet containing 1 mg/kg DON and 250 microgram/kg ZON. The results showed that supplementation of DON and ZON in diets had extensive effects on pigs. More specifically, DON and ZON caused levels of total protein, albumin, and globulin in sera to decrease (p < 0.05) by 14.5%, 6.5% and 11.3%, respectively, and at the same time increased (p < 0.05) the serum enzyme activities of gamma-glutamyltransferase, aspartate aminotransferase and alanine aminotransferase by 72.0%, 32.6% and 36.6%, respectively. In addition, DON and ZON decreased (p < 0.05) the level of anticlassical swine fever antibody titers by 14.8%. Real-time PCR showed that DON and ZON caused the mRNA expression levels of IFN-gamma, TNF-alpha, IL-2, to decrease (p < 0.05) by 36.0%, 29.0% and 35.4%, respectively. Histopathological studies demonstrated that DON and ZON caused abnormalities in the liver, spleen, lymph nodes, uterus, and kidney. The concentrations of DON and ZON used in this study are in line with the published critical values permitted by BML. Our study clearly put the standard and adequacy of safety measures for these toxins into question. The authors suggest that with the increasing availability of cellular and molecular technologies, it is time to revisit the safety standards for toxins in feeds so as to make feeds safer, providing consumers with safer products.