Establishment of a tRNA over-expression system in Trypanosoma brucei to study the role of post-transcriptional modifications on function.

Undergraduate Research ScholarshipMayers Summer InternshipDean's Undergraduate Research FundTrypanosomatids are parasitic protozoa which infect millions of humans and animals across the globe every year. The two primary types of these unicellular flagellates are Trypanosoma and Leishmania, and the World Health Organization estimates that approximately 400 million people worldwide are at substantial risk to develop infections caused by these pathogens. Trypanosomes also possess many significant biological and biochemical properties, and in particular the tRNAs of trypanosomatids undergo substantial in vivo chemical modifications. We focus on understanding how one particular set of modifications, i.e. adenosine to inosine changes in the anticodon, impact tRNA function. We are also interested on how other modifications like methylations may affect inosine formation. The goals of this project are two-fold: first, to construct a vector capable of successfully over-expressing tRNA in Trypanosoma brucei, and second, to successfully introduce two non-endogenous, tagged tRNAs into T. brucei in order to further analyze in vivo modifications. To this end, we have engineered two distinct tRNA variants with mutations in the anticodon arm (Tag 22) and anticodon arm and loop (Tag 23). These mutations serve as tags to differentiate them from endogenous tRNAs naturally found in T. brucei cells. Prior to testing our overexpression system, the two "tagged" variants were analyzed for their ability to support known modification reactions in vitro. Since these variants are derived from a tRNA that undergoes adenosine to inosine changes in their anticodon in vivo, we tested and further showed that the mutations used to generate the variants do not interfere with this reaction in vitro. In the next phase of the project, the two variants will be cloned in a plasmid vector and expressed under the control of an endogenous T7 promoter and tetracycline (TET) operator, followed by transfection into Trypanosoma brucei cells. Total RNA isolated from the transfected cells will thus provide a measure of overexpression of our two tRNA variants. Successful completion of this phase of the project will allow further exploration into the in vivo posttranscriptional modifications of tRNAs through analysis of the tagged tRNA constructs. By comparing the tagged tRNA construct to endogenous tRNAs, important modification reactions such as adenosine to inosine and cytidine to uridine editing can be further studied. As mentioned earlier, since these modifications play a vital role in the function of tRNA, their identification could be useful for future design of anti-trypanosomal treatments.American Heart AssociationNational Science Foundatio

Multistate analysis of prospective Legionnaires' disease cluster detection using SaTScan, 2011-2015.

Detection of clusters of Legionnaires' disease, a leading waterborne cause of pneumonia, is challenging. Clusters vary in size and scope, are associated with a diverse range of aerosol-producing devices, including exposures such as whirlpool spas and hotel water systems typically associated with travel, and can occur without an easily identified exposure source. Recently, jurisdictions have begun to use SaTScan spatio-temporal analysis software prospectively as part of routine cluster surveillance. We used data collected by the Active Bacterial Core surveillance platform to assess the ability of SaTScan to detect Legionnaires' disease clusters. We found that SaTScan analysis using traditional surveillance data and geocoded residential addresses was unable to detect many common Legionnaires' disease cluster types, such as those associated with travel or a prolonged time between cases. Additionally, signals from an analysis designed to simulate a real-time search for clusters did not align with clusters identified by traditional surveillance methods or a retrospective SaTScan analysis. A geospatial analysis platform better tailored to the unique characteristics of Legionnaires' disease epidemiology would improve cluster detection and decrease time to public health action

Estimated Effectiveness of JYNNEOS Vaccine in Preventing Mpox: A Multijurisdictional Case-Control Study — United States, August 19, 2022–March 31, 2023

As of March 31, 2023, more than 30,000 monkeypox (mpox) cases had been reported in the United States in an outbreak that has disproportionately affected gay, bisexual, and other men who have sex with men (MSM) and transgender persons (1). JYNNEOS vaccine (Modified Vaccinia Ankara vaccine, Bavarian Nordic) was approved by the Food and Drug Administration (FDA) in 2019 for the prevention of smallpox and mpox via subcutaneous injection as a 2-dose series (0.5 mL per dose, administered 4 weeks apart) (2). To expand vaccine access, an Emergency Use Authorization was issued by FDA on August 9, 2022, for dose-sparing intradermal injection of JYNNEOS as a 2-dose series (0.1 mL per dose, administered 4 weeks apart) (3). Vaccination was available to persons with known or presumed exposure to a person with mpox (postexposure prophylaxis [PEP]), as well as persons at increased risk for mpox or who might benefit from vaccination (preexposure mpox prophylaxis [PrEP]) (4). Because information on JYNNEOS vaccine effectiveness (VE) is limited, a matched case-control study was conducted in 12 U.S. jurisdictions,† including nine Emerging Infections Program sites and three Epidemiology and Laboratory Capacity sites,§ to evaluate VE against mpox among MSM and transgender adults aged 18-49 years. During August 19, 2022-March 31, 2023, a total of 309 case-patients were matched to 608 control patients. Adjusted VE was 75.2% (95% CI = 61.2% to 84.2%) for partial vaccination (1 dose) and 85.9% (95% CI = 73.8% to 92.4%) for full vaccination (2 doses). Adjusted VE for full vaccination by subcutaneous, intradermal, and heterologous routes of administration was 88.9% (95% CI = 56.0% to 97.2%), 80.3% (95% CI = 22.9% to 95.0%), and 86.9% (95% CI = 69.1% to 94.5%), respectively. Adjusted VE for full vaccination among immunocompromised participants was 70.2% (95% CI = -37.9% to 93.6%) and among immunocompetent participants was 87.8% (95% CI = 57.5% to 96.5%). JYNNEOS is effective at reducing the risk for mpox. Because duration of protection of 1 versus 2 doses remains unknown, persons at increased risk for mpox exposure should receive the 2-dose series as recommended by the Advisory Committee on Immunization Practices (ACIP),¶ regardless of administration route or immunocompromise status