Because of B. pseudomallefs (Bp's) intrinsic resistance to many antibiotics, melioidosis therapy is difficult and must be continued for extended periods of time. The limited spectrum of antibiotics available for melioidosis treatment, and the emergence of resistant strains during antibiotic therapy call for a better understanding of underlying resistance mechanisms to enable proper therapeutic interventions. Furthermore, successful and proper treatment of infections caused by bioterrorism events involving strains having acquired resistance determinants, whether by natural means or by malicious genetic engineering, may be impossible if the underlying resistance mechanism(s) cannot be readily identified. The hypothesis is that a definition of the mechanisms governing resistance to frontline clinical drugs will allow design of strategies for rapid detection of resistance mechanisms in clinical isolates or in maliciously engineered strains. In turn, then, resistance can be detected early (bioterrorism events) and appropriate treatment initiated or redirected (in clinical settings during melioidosis therapy).
Three aims will be pursued to test the hypothesis:
Aim 1 - Definition of resistance mechanisms in clinical and environmental isolates. RT-PCR, expression of cloned gene products and biochemical approaches will be employed to characterize resistance determinants from clinical and environmental isolates resistant to p-lactams, doxycyline, trimethoprim and sulfamethoxazole.
Aim 2 - Definition of resistance mechanisms in genetically engineered strains. This will be achieved by characterizing transposon-induced resistant mutants, as well as by selecting and characterizing spontaneously resistant mutants to the antibiotics tested in aim 1.
Aim 3 - Design of a directed DNA microarrav as a tool for rapid identification of resistance determinants. Utilizing the information gleaned from aims 1 and 2, a directed DNA microarray will be generated which, in concert with a set of specific PCR primers, will provide a set of diagnostic tools for rapid determination of resistance mechanism in Bp isolates from diverse sources. Bp is an integral part of the RMRCE Bacterial Therapeutics Integrated Research Focus , whose main efforts are geared towards identification of novel therapeutics for this pathogen and a few other Select Agents. The tools, mutants and knowledged gained in this study will directly benefit these efforts.

Public Health Relevance

Overcoming Gram-negative antibiotic resistance will be the major challenge for drug discovery efforts over the next decade;but how can we control antibiotic resistance when we don't understand it? What we learn about antimicrobial resistance with Bp will be directly applicable to similar problems faced with other nonenteric Gram negative pathogens.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Specialized Center--Cooperative Agreements (U54)
Project #
Application #
Study Section
Special Emphasis Panel (ZAI1-DDS-M)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Colorado State University-Fort Collins
Fort Collins
United States
Zip Code
Gibson, Christopher C; Zhu, Weiquan; Davis, Chadwick T et al. (2015) Strategy for identifying repurposed drugs for the treatment of cerebral cavernous malformation. Circulation 131:289-99
Wang, Hong; Siddharthan, Venkatraman; Hall, Jeffery O et al. (2014) Autonomic deficit not the cause of death in West Nile virus neurological disease. Clin Auton Res 24:15-23
Scharton, Dionna; Bailey, Kevin W; Vest, Zachary et al. (2014) Favipiravir (T-705) protects against peracute Rift Valley fever virus infection and reduces delayed-onset neurologic disease observed with ribavirin treatment. Antiviral Res 104:84-92
Shives, Katherine D; Beatman, Erica L; Chamanian, Mastooreh et al. (2014) West nile virus-induced activation of mammalian target of rapamycin complex 1 supports viral growth and viral protein expression. J Virol 88:9458-71
Calvert, Amanda E; Dixon, Kandice L; Delorey, Mark J et al. (2014) Development of a small animal peripheral challenge model of Japanese encephalitis virus using interferon deficient AG129 mice and the SA14-14-2 vaccine virus strain. Vaccine 32:258-64
Richert, Laura E; Rynda-Apple, Agnieszka; Harmsen, Ann L et al. (2014) CD11cýýý cells primed with unrelated antigens facilitate an accelerated immune response to influenza virus in mice. Eur J Immunol 44:397-408
Soffler, Carl; Bosco-Lauth, Angela M; Aboellail, Tawfik A et al. (2014) Pathogenesis of percutaneous infection of goats with Burkholderia pseudomallei: clinical, pathologic, and immunological responses in chronic melioidosis. Int J Exp Pathol 95:101-19
Porta, Jason; Jose, Joyce; Roehrig, John T et al. (2014) Locking and blocking the viral landscape of an alphavirus with neutralizing antibodies. J Virol 88:9616-23
Jones-Carson, Jessica; Zweifel, Adrienne E; Tapscott, Timothy et al. (2014) Nitric oxide from IFN?-primed macrophages modulates the antimicrobial activity of ?-lactams against the intracellular pathogens Burkholderia pseudomallei and Nontyphoidal Salmonella. PLoS Negl Trop Dis 8:e3079
Phillips, Aaron T; Schountz, Tony; Toth, Ann M et al. (2014) Liposome-antigen-nucleic acid complexes protect mice from lethal challenge with western and eastern equine encephalitis viruses. J Virol 88:1771-80

Showing the most recent 10 out of 181 publications