No abstract

Recombinant human erythropoietin (rhEPO) and darbepoetin alpha (DPO) are protein-based drugs for the treatment of anemia by stimulating red blood cell production. Consequently, they are abused in human and equine sports. To deter their abuse in the horse racing industry, a sensitive and reliable method for confirmation of these agents in equine plasma has been in urgent need. Such a method by LC-MS/MS is described in this paper. The method involved analyte enrichment by immunoaffinity separation using anti-rhEPO antibody linked to magnetic beads, digestion by trypsin, and analysis by LC-MS/MS. Two specific proteotypic peptides, 46VNFYAWK52 and 144VYSNFLR150 from rhEPO and DPO were employed for confirmation of the analytes based on chromatographic retention times and major product ions. The limit of confirmation of this method was 0.2 ng/mL, and the limit of detection was 0.1 ng/mL for rhEPO and DPO in equine plasma. This method was successful in confirming the presence of rhEPO and DPO in plasma samples collected from research horses to which rhEPO or DPO was administered and from racehorses following competition and in noncompetition samples in North America. To our knowledge, this is the first LC-MS method with adequate sensitivity and specificity in providing unequivocal confirmation of rhEPO and DPO in equine plasma samples. This method provides a powerful enforcement tool that was lacking in the fight against the abuse of rhEPO and DPO in the horse racing industry.

A daunting challenge facing the water industry and regulators is how to simultaneously control microbial pathogens, residual disinfectant, and disinfection byproducts in drinking water, and to do so at an acceptable cost. Of the different pathogens, viruses are especially problematic due to their small size, high mobility, and resistance to chlorination and filtration. In the past decade, zerovalent iron has been used to treat a wide variety of organic and inorganic contaminants from groundwater. However, iron has not been tested against biological agents. This study examined the effectiveness of commercial zerovalent iron to remove two viruses, phiX174 and MS-2, from water. Removal of these viruses by iron granules in batch reactors was first-order, and the rate was likely controlled by external mass transfer. Most of the viruses removed from solution were either inactivated or irreversibly adsorbed to iron. In a flow-through column containing zerovalent iron (with 20 min of iron contact time), the removal efficiency for both viruses was 4-log in an initial pulse test, and over 5-log in the second pulse test after passage of 320 pore volumes of artificial groundwater. We assume that the improved efficiency was due to continuous formation of new iron (oxyhydr)oxides which served as virus adsorption sites. To our knowledge, this is the first demonstration of biological agent removal from water by zerovalent iron. Results of this study suggest zerovalent iron may be potentially useful for disinfecting drinking water and wastewater, thereby reducing our dependence on chlorine and reducing the formation of disinfection byproducts.

Salmonella enterica serovar Newport has undergone a rapid epidemic spread in dairy cattle. This provides an efficient mechanism for pathogen amplification and dissemination into the environment through manure spreading on agricultural land. The objective of this study was to determine the survival characteristics of Salmonella serovar Newport in manure and manure-amended soils where the pathogen may be amplified. A multidrug-resistant (MDR) Salmonella serovar Newport strain and a drug-susceptible (DS) strain, both bovine isolates, were inoculated into dairy manure that was incubated under constant temperature and moisture conditions alone or after being mixed with sterilized or nonsterilized soil. Salmonella serovar Newport concentrations increased by up to 400% in the first 1 to 3 days following inoculation, and a trend of steady decline followed. With manure treatment, a sharp decline in cell concentration occurred after day 35, possibly due to microbial antagonism. For all treatments, decreases in Salmonella serovar Newport concentrations over time fit a first-order kinetic model. Log reduction time was 14 to 32 days for 1 log 10 , 28 to 64 days for 2 log 10 , and 42 to 96 days for 3 log 10 declines in the organisms' populations from initially inoculated concentrations. Most-probable-number monitoring data indicated that the organisms persisted for 184, 332, and 405 days in manure, manure-amended nonsterilized soil, and manure-amended sterilized soil, respectively. The MDR strain and the DS strain had similar survival patterns.