Publications by authors named "Ronald G Toothman"
In the United States in 2021, an outbreak of 4 cases of Burkholderia pseudomallei, the etiologic agent of melioidosis and a Tier One Select Agent (potential for deliberate misuse and subsequent harm), resulted in 2 deaths. The causative strain, B. pseudomallei ATS2021, was unintentionally imported into the United States in an aromatherapy spray manufactured in India.
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- Plague is caused by a bacterium and can show up as different types of disease; antibiotics are essential for treatment, but there's no FDA-approved vaccine yet, and some candidates may work better for certain forms of the disease.
- The study tested new vaccine approaches on male and female mice and found that the best regimen involved an initial vaccination followed by a boost, with notable differences in effectiveness between sexes.
- Results showed that female mice had better protection and immune responses compared to males, who also showed higher bacterial loads and different immune reactions, highlighting the importance of understanding sex differences in vaccine development.
Two clinically important subspecies, subsp. (type A) and subsp. (type B) are responsible for most tularaemia cases, but these isolates typically form a weak biofilm under conditions.
View Article and Find Full Text PDFis one of the several biothreat agents for which a licensed vaccine is needed. To ensure vaccine protection is achieved across a range of virulent strains, we assembled and characterized a panel of isolates to be utilized as challenge strains. A promising tularemia vaccine candidate is rLVS Δ/ (rLVS), in which the vector is the LVS strain with a deletion in the gene and which additionally expresses a fusion protein comprising immunodominant epitopes of proteins IglA, IglB, and IglC.
View Article and Find Full Text PDFis one of several biothreat agents for which a licensed vaccine is needed to protect against this pathogen. To aid in the development of a vaccine protective against pneumonic tularemia, we generated and characterized a panel of isolates that can be used as challenge strains to assess vaccine efficacy. Our panel consists of both historical and contemporary isolates derived from clinical and environmental sources, including human, tick, and rabbit isolates.
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- The study focuses on the bacteria causing tularemia, which poses a high risk to humans due to its infectious nature, lack of vaccines, and potential use in biological warfare, leading to its classification as a Tier 1 select agent.
- Antibiotic resistance to first-line treatments like fluoroquinolones and aminoglycosides has increased, complicating efforts to manage this disease and prompting the need for new therapeutic developments.
- The researchers created antibiotic-resistant strains of the bacteria to investigate their growth and potential for vaccine development, finding that most ciprofloxacin-resistant strains had reduced virulence in test scenarios, highlighting both resistance and fitness challenges.
is the causative agent of tularemia and has gained recent interest as it poses a significant biothreat risk. is commonly used as a laboratory surrogate for tularemia research due to genetic similarity and susceptibility of mice to infection. Currently, there is no FDA-approved tularemia vaccine, and identifying therapeutic targets remains a critical gap in strategies for combating this pathogen.
View Article and Find Full Text PDFMouse models have been essential to generate supporting data for the research of infectious diseases. Burkholderia pseudomallei, the etiological agent of melioidosis, has been studied using mouse models to investigate pathogenesis and efficacy of novel medical countermeasures to include both vaccines and therapeutics. Previous characterization of mouse models of melioidosis have demonstrated that BALB/c mice present with an acute infection, whereas C57BL/6 mice have shown a tendency to be more resistant to infection and may model chronic disease.
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- Francisella tularensis is a dangerous bacterium that causes tularemia and poses a biowarfare threat due to its low infectious dose and ability to infect multiple mammals, including humans.
- Researchers studied a ciprofloxacin-resistant mutant of this bacterium to understand its genetic changes and characteristics that contribute to antibiotic resistance.
- Key findings include a mutation in the kdsD gene, crucial for lipopolysaccharide production, leading to growth defects and reduced virulence, highlighting kdsD as a potential target for new treatments against tularemia.
Characterization of pathogenesis of and immune response to Burkholderia pseudomallei K96243 using both inhalational and intraperitoneal infection models in BALB/c and C57BL/6 mice.
PLoS One
August 2017
Article Synopsis
- - Burkholderia pseudomallei is a dangerous bacteria that causes melioidosis and is prevalent in Southeast Asia and Northern Australia, posing a significant health risk and biodefense concern due to its ability to infect humans and animals through various routes, especially during monsoon rains.
- - There are currently no effective vaccines available for this bacterium, and treatment with antibiotics can be complicated by unclear symptoms and antibiotic-resistant strains, highlighting the need for better medical countermeasures.
- - The study involved testing two mouse strains (BALB/c and C57BL/6) to understand their immune responses after being infected with B. pseudomallei, using various methods to monitor their health and analyze tissue samples, revealing key differences and
Phenotypic Characterization of a Novel Virulence-Factor Deletion Strain of Burkholderia mallei That Provides Partial Protection against Inhalational Glanders in Mice.
Front Cell Infect Microbiol
November 2016
Burkholderia mallei (Bm) is a highly infectious intracellular pathogen classified as a category B biological agent by the Centers for Disease Control and Prevention. After respiratory exposure, Bm establishes itself within host macrophages before spreading into major organ systems, which can lead to chronic infection, sepsis, and death. Previously, we combined computational prediction of host-pathogen interactions with yeast two-hybrid experiments and identified novel virulence factor genes in Bm, including BMAA0553, BMAA0728 (tssN), and BMAA1865.
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