Bioluminescent Imaging of Trypanosoma brucei Shows Preferential Testis Dissemination Which May Hamper Drug Efficacy in Sleeping Sickness

Monitoring Trypanosoma spread using real-time imaging in vivo provides a fast method to evaluate parasite distribution especially in immunoprivileged locations. Here, we generated monomorphic and pleomorphic recombinant Trypanosoma brucei expressing the Renilla luciferase. In vitro luciferase activity measurements confirmed the uptake of the coelenterazine substrate by live parasites and light emission. We further validated the use of Renilla luciferase-tagged trypanosomes for real-time bioluminescent in vivo analysis. Interestingly, a preferential testis tropism was observed with both the monomorphic and pleomorphic recombinants. This is of importance when considering trypanocidal drug development, since parasites might be protected from many drugs by the blood-testis barrier. This hypothesis was supported by our final study of the efficacy of treatment with trypanocidal drugs in T. brucei-infected mice. We showed that parasites located in the testis, as compared to those located in the abdominal cavity, were not readily cleared by the drugs

Listeria monocytogenes in Milk Products

peer-reviewedMilk and milk products are frequently identified as vectors for transmission of Listeria monocytogenes. Milk can be contaminated at farm level either by indirect external contamination from the farm environment or less frequently by direct contamination of the milk from infection in the animal. Pasteurisation of milk will kill L. monocytogenes, but post-pasteurisation contamination, consumption of unpasteurised milk and manufacture of unpasteurised milk products can lead to milk being the cause of outbreaks of listeriosis. Therefore, there is a concern that L. monocytogenes in milk could lead to a public health risk. To protect against this risk, there is a need for awareness surrounding the issues, hygienic practices to reduce the risk and adequate sampling and analysis to verify that the risk is controlled. This review will highlight the issues surrounding L. monocytogenes in milk and milk products, including possible control measures. It will therefore create awareness about L. monocytogenes, contributing to protection of public health

Development and assessment of a physics-based simulation model to investigate residential PM2.5 infiltration across the US housing stock

The Lawrence Berkeley National Laboratory Population Impact Assessment Modeling Framework (PIAMF) was expanded to enable determination of indoor PM concentrations and exposures in a set of 50,000 homes representing the US housing stock. A mass-balance model is used to calculate time-dependent pollutant concentrations within each home. The model includes size- and species-dependent removal mechanisms. The particle model was applied to the housing samples of the Relationship of Indoor, Outdoor, and Personal Air (RIOPA) and The Detroit Exposure and Aerosol Research Study (DEARS) studies to compare model- and measurement-based estimates of indoor PM of outdoor origin. Model-derived distributions of infiltration factors (ratio of indoor PM of outdoor origin to outdoor PM ) are compared to measurement-based distributions obtained in studies conducted in 11 US cities. 2.5 2.5 2.5 2.