High Risk Organisms

Steven H. Hinrichs, M.D.
Shortly after the state public health laboratory was relocated to UNMC under contract to the State of Nebraska, departmental researchers became more engaged in issues related to emerging infectious diseases.  This included smallpox and anthrax as well as tularemia.  Programs were developed to increase capability in diagnostics and therapeutics (see Diagnostics and Therapeutics) prior to the appearance of SARS, monkeypox and hemorrhagic fevers such as Sin hombre virus.  Later, procedures were developed for identification of highly pathogenic viruses including avian influenza.  Research also investigated new mechanisms antibiotic resistance.  A statewide program began focusing on greater preparedness for emerging infectious diseases leading to the creation of a human  biocontainment facility at UNMC and Nebraska Medicine.  These teams were responsible for responding to the Ebola crisis in 2014 and 2015 including the treatment of infected individuals.  Dr. Hinrichs and his colleagues have published a number of articles describing their experience with these challenges.  Dr. Hinrichs' research is also listed under Diagnostics and Therapeutics

Marilynn A. Larson, M.Sc., Ph.D.
Dr. Larson’s research is focused on elucidating the molecular mechanisms that allow intracellular pathogens to evade the immune system and persist. These assessments include the use of Francisella tularensis as a model system, since considerable differences in virulence exist between the subpopulations in this species, including select agents, attenuated strains, and avirulent strains. This facultative intracellular bacterium is the etiologic agent of the zoonotic disease tularemia, in which there is no effective vaccine. The highly infective strains are among the most pathogenic bacteria known with the potential to be used as a bioweapon and therefore, are classified as Tier 1 select agents by the Centers of Disease Control and Prevention. Although the genome of the type A.I, A.lI, and B clades within this species share 98% average nucleotide identity, insertion sequence elements have contributed to numerous chromosomal rearrangements between these subpopulations. The resulting changes in gene expression from these translocations, as well as other polymorphisms are being examined using a systems biology approach. These evaluations include the study of host-pathogen interactions elicited during a human macrophage infection. Together these investigations will provide a better understanding of the multifactorial mechanisms utilized by the highly virulent F. tularensis A.I strains, which enhances pathogenicity, and contribute to the development of effective countermeasures against F. tularensis and other intracellular pathogens. Additional research projects include the development of next generation molecular diagnostics for select agent and clinical pathogen identification and characterization, the detection of stable biomarkers that are indicative of an infection or radiation exposure, and the discovery of therapeutics to prevent or treat infections. Dr. Larson's research is also listed under High Risk Organisms and Host-pathogen Interactions.

Joshua L. Santarpia, Ph.D.
Dr. Santarpia’s research is aimed at understanding and countering threats from biological organisms, especially those that pose a threat when dispersed in aerosols. Dr. Santarpia’s research focus is in three main areas to support these goals:

Biodetection and Measurement: Dr. Santarpia’s laboratory works to develop unmanned sensor platforms for the detection of biological weapons, the development of sensor systems for the protection of military installations and the development of new aerosol detection technology. To that end, he also studies the role of atmospheric aging processes on microbial aerosols (airborne particles that contain microbial organisms) and their properties, especially those affecting human health, detection of the organism, and the environment. 

Novel Antibacterials: Dr. Santarpia’s laboratory works to identify and characterize bacteriophages for select bacterial agents and bacteria of public health concern, develops new applications of these bacteriophages for use in decontamination applications and possible future therapeutic use. 

Medical Application: Dr. Santarpia’s laboratory has developed novel methods to study bioaerosol hazards in medical environments, including the Containerized Biological Containment System (CBCS) for the Department of State, the Nebraska Biocontainment Unit, the U.S. Air Force Transportation Isolation System (TIS) and studies for private companies to determine potential aerosol hazards of medical devices in operating rooms.

Schematic (a), photograph (b) and example single particle fluorescence spectra of bacterial and viral agents and simulant aerosols at 266 nm excitation wavelength (c). Taken from Yong-Le Pan, Steven C. Hill, Joshua L. Santarpia, Kelly Brinkley, Todd Sickler, Mark Coleman, Chatt Williamson, Kris Gurton, Melvin Felton, Ronald G. Pinnick, Neal Baker, Jonathan Eshbaugh, Jerry Hahn, Emily Smith, Ben Alvarez, Amber Prugh, Warren Gardner, "Spectrally-resolved fluorescence cross sections of aerosolized biological live agents and simulants using five excitation wavelengths in a BSL-3 laboratory," Opt. Express  22, 8165-8189 (2014)