ArticleBMC infectious diseases2014
Virulence difference between the prototypic Schu S4 strain (A1a) and Francisella tularensis A1a, A1b, A2 and type B strains in a murine model of infection.
Article in BMC infectious diseases, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 18 papers.
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18 citing papers in PubMed, 25 citations in OpenAlex.
- Animal modelling with theMicrobiology (Reading, England) · 2025Article
- An Outbreak of Pulmonary Tularemia in Slovenia in Summer 2024.Epidemiologia (Basel, Switzerland) · 2025Article
- Thoracic manifestations of tularaemia: a case series.Infection · 2024Article
- Vector-Borne Tularemia: A Re-Emerging Cause of Cervical Lymphadenopathy.Tropical medicine and infectious disease · 2022Review
- Identification of an Attenuated Substrain ofPathogens (Basel, Switzerland) · 2021Article
- Differential Immune Response Following Intranasal and Intradermal Infection withMicroorganisms · 2021Review
- Development, Phenotypic Characterization and Genomic Analysis of aFrontiers in microbiology · 2021Article
- Virulence ofMicroorganisms · 2020Article
- Appendix R: Guidelines for Verifying and Documenting the Relationships Between Microbial Cultures.Journal of AOAC International · 2020Article
- The Francisella tularensis Polysaccharides: What Is the Real Capsule?Microbiology and molecular biology reviews : MMBR · 2020Review
- Differentiation of Francisella tularensis Subspecies and Subtypes.Journal of clinical microbiology · 2020Article
- Genetic Diversity and Spatial Segregation ofFrontiers in cellular and infection microbiology · 2019Article
- Article
- The Cynomolgus Macaque Natural History Model of Pneumonic Tularemia for Predicting Clinical Efficacy Under the Animal Rule.Frontiers in cellular and infection microbiology · 2018Article
- An Immature Myeloid/Myeloid-Suppressor Cell Response Associated with Necrotizing Inflammation Mediates Lethal Pulmonary Tularemia.PLoS pathogens · 2016Article
- From the Outside-In: The Francisella tularensis Envelope and Virulence.Frontiers in cellular and infection microbiology · 2015Review
- Francisella tularensis Subtype A.II Genomic Plasticity in Comparison with Subtype A.I.PloS one · 2014Article
- Tularemia vaccine development: paralysis or progress?Vaccine (Auckland, N.Z.)Article
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7 authors at 2 institutions in 1 country.
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Abstract
backgroundThe use of prototypic strains is common among laboratories studying infectious agents as it promotes consistency for data comparability among and between laboratories. Schu S4 is the prototypic virulent strain of Francisella tularensis and has been used extensively as such over the past six decades. Studies have demonstrated virulence differences among the two clinically relevant subspecies of F. tularensis, tularensis (type A) and holarctica (type B) and more recently between type A subpopulations (A1a, A1b and A2). Schu S4 belongs to the most virulent subspecies of F. tularensis, subspecies tularensis.
methodsIn this study, we investigated the relative virulence of Schu S4 in comparison to A1a, A1b, A2 and type B strains using a temperature-based murine model of infection. Mice were inoculated intradermally and a hypothermic drop point was used as a surrogate for death. Survival curves and the length of temperature phases were compared for all infections. Bacterial burdens were also compared between the most virulent type A subpopulation, A1b, and Schu S4 at drop point.
resultsSurvival curve comparisons demonstrate that the Schu S4 strain used in this study resembles the virulence of type B strains, and is significantly less virulent than all other type A (A1a, A1b and A2) strains tested. Additionally, when bacterial burdens were compared between mice infected with Schu S4 or MA00-2987 (A1b) significantly higher burdens were present in the blood and spleen of mice infected with MA00-2987.
conclusionsThe knowledge gained from using Schu S4 as a prototypic virulent strain has unquestionably advanced the field of tularemia research. The findings of this study, however, indicate that careful consideration of F. tularensis strain selection must occur when the overall virulence of the strain used could impact the outcome and interpretation of results.
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