Within-Host Evolution of Burkholderia pseudomallei in Four Cases of Acute Melioidosis

Little is currently known about bacterial pathogen evolution and adaptation within the host during acute infection. Previous studies of Burkholderia pseudomallei, the etiologic agent of melioidosis, have shown that this opportunistic pathogen mutates rapidly both in vitro and in vivo at tandemly repeated loci, making this organism a relevant model for studying short-term evolution. In the current study, B. pseudomallei isolates cultured from multiple body sites from four Thai patients with disseminated melioidosis were subjected to fine-scale genotyping using multilocus variable-number tandem repeat analysis (MLVA). In order to understand and model the in vivo variable-number tandem repeat (VNTR) mutational process, we characterized the patterns and rates of mutations in vitro through parallel serial passage experiments of B. pseudomallei. Despite the short period of infection, substantial divergence from the putative founder genotype was observed in all four melioidosis cases. This study presents a paradigm for examining bacterial evolution over the short timescale of an acute infection. Further studies are required to determine whether the mutational process leads to phenotypic alterations that impact upon bacterial fitness in vivo. Our findings have important implications for future sampling strategies, since colonies in a single clinical sample may be genetically heterogeneous, and organisms in a culture taken late in the infective process may have undergone considerable genetic change compared with the founder inoculum

Broad based genomic screening for microbes in Salish Sea juvenile Chinook salmon

Juvenile Chinook salmon entering the Salish Sea demonstrate high inter-annual variation in marine survival. Variation in productivity in the early marine environment is hypothesized to be key for survival, with biological stressors such as pathogens potentially acting as secondary factors affecting mortality. Applying genomic technologies, the Molecular Genetics Lab (DFO) has developed a novel high throughput monitoring platform to assess the prevalence and abundance of 45 known or suspected microbes associated with diseases in salmon in British Columbia or worldwide. These include both freshwater and marine origin viruses, bacteria, protozoa, myxozoans, microsporidia and flukes. Here we present a preliminary survey of the stock specific, seasonal prevalence and loads of microbes for juvenile Chinook salmon in the first year at sea originating from Salish sea stocks. Between 2008-2012, fish (n=1870) were sampled in freshwater from hatcheries, in the Salish Sea and along northward migration pathways up to Northern British Columbian coastal waters. Individual genetic stock identification (DFO) was applied so that genomic assessments could track the status of microbes in individual stocks over time and space. At least one microbe of interest was detected in over 90% of juvenile Chinook salmon sampled. While both individual stocks and microbes displayed variant patterns, there was a general trend of increased prevalence, load and microbe abundance as seasons progressed. This survey will form the basis for a larger scope analysis (sample years 2007-2015 on stocks of interest and concern) integrating Chinook salmon origin and life-history as well as spatial and temporal sources of variation in microbe patterns and ultimately relating the presence of microbes to survival trends for Salish Sea stocks

The Minority Training Program in Cancer Control Research: Impact and Outcome Over 12 Years

trol Research (MTPCCR) encourages underrepresented master's level students and professionals in the social, be-havioral, and public health sciences to pursue doctoral train-ing and careers in cancer disparities research. This paper reports new data on the program outcome after 12 years. A web-based survey was sent to all 462 program alumni. The questions addressed current academic status and plans, job status and plans, research focus, and influence of the MTPCCR. The survey response rate was 79 %. Overall, 30 % of alumni are enrolled in or have completed doctoral programs; 88 % of whom report involvement in research related to cancer. Scaled and open-ended responses indicate a strong influence of the program on doctoral program enrollment and cancer focus. The MTPCCR model is successful because it targets underrepresented minorities who are capable of doctoral studies but have not yet chosen that path