Real-time PCR-based methods have been frequently used to detect and enumerate foodborne pathogens. However, these techniques have a major drawback since they cannot differentiate between DNA from live and dead cells. In this study, we developed a propidium monoazide (PMA)-based PCR method to detect and enumerate viable Salmonella cells in the presence of high number of dead cells (up to 108 CFU/g) in cooked ham. Three different specific PCR targets differing in length (95, 285, and 417 bp) were tested. We found that the inhibition effect was dependent on the PCR amplification product length, and only the longer product achieved suppression of 108 CFU/g of heat-killed cells. SYBR® Green and TaqMan® chemistries were compared to develop a highly efficient PMA-quantitative PCR system targeting the 417-bp fragment. Both chemistries showed similar detection (103 CFU/g) and quantification limits (104 CFU/g), but TaqMan® assay showed higher efficiency (98.6 %) than SYBR® Green assay (92.8 %). PMA-quantitative PCR assay developed is a rapid method for the selective detection and enumeration of viable Salmonella cells with further application in postprocessed meat products and safe shelf-life studies.
Plant parasitic nematodes are the most destructive group of plant pathogens worldwide and their control is extremely challenging. Plant Essential oils (EOs) and their constituents have a great potential in nematode control since they can be developed for use as nematicides themselves or can ... more
For over a century, ulcer has been a major cause of morbidity and mortality. Its treatment has progressed from vagotomy to proton pump inhibitors. However, the drugs used produce many adverse effects and are less effective than they ought to be. Therefore, there is a growing interest in alt ... more
Endophytic fungi are ubiquitous organisms found in the plants, residing intercellular or intracellular, at least for a portion of their lives without causing apparent symptoms of infection. Almost all plants are known to harbor endophytes. The choice of the plant to be used for exploring en ... more
Physicists describe how they have synthesized a new material that belongs to the iron-selenide class of superconductors, called LixFe2Se2(NH3)y, in a paper about to be published in EPJ B. The work was carried out by Ernst-Wilhelm Scheidt from the University of Augsburg and colleagues. This ... more
The U.S. federal government is significantly underestimating the costs of carbon pollution because it is using a faulty analytical model, according to a new study published in the Journal of Environmental Studies and Sciences. A more appropriate accounting of costs would pave the way to cle ... more
Springer advisory board member Vladimir V. Dmitriev, along with fellow scientists Yuriy M. Bunkov and Igor A. Fomin, have been named winners of the 2008 Fritz London Memorial Prize for their discovery and understanding of the "Phase Coherent Spin Precession and Spin Superfluidity of 3He-B." ... more