Identifying Francisella tularensis Genes Required for Growth in Host Cells
| Autor: | Sharon Taft-Benz, Cheryl N. Miller, Thomas H. Kawula, Jason Brunton, E. Lovullo, Shaun Steele |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Male
Transposable element Immunology Mutant Virulence Biology Microbiology Cell Line Tularemia Mice chemistry.chemical_compound Bacterial Proteins Genes Reporter medicine Animals Humans Francisella tularensis Macrophages medicine.disease biology.organism_classification Molecular Pathogenesis Mice Inbred C57BL Mutagenesis Insertional Infectious Diseases chemistry Parasitology Transposon mutagenesis Peptidoglycan Intracellular |
| DOI: | 10.17615/de0m-cb58 |
| Popis: | Francisella tularensis is a highly virulent Gram-negative intracellular pathogen capable of infecting a vast diversity of hosts, ranging from amoebae to humans. A hallmark of F. tularensis virulence is its ability to quickly grow to high densities within a diverse set of host cells, including, but not limited to, macrophages and epithelial cells. We developed a luminescence reporter system to facilitate a large-scale transposon mutagenesis screen to identify genes required for growth in macrophage and epithelial cell lines. We screened 7,454 individual mutants, 269 of which exhibited reduced intracellular growth. Transposon insertions in the 269 growth-defective strains mapped to 68 different genes. FTT_0924 , a gene of unknown function but highly conserved among Francisella species, was identified in this screen to be defective for intracellular growth within both macrophage and epithelial cell lines. FTT_0924 was required for full Schu S4 virulence in a murine pulmonary infection model. The Δ FTT_0924 mutant bacterial membrane is permeable when replicating in hypotonic solution and within macrophages, resulting in strongly reduced viability. The permeability and reduced viability were rescued when the mutant was grown in a hypertonic solution, indicating that FTT_0924 is required for resisting osmotic stress. The Δ FTT_0924 mutant was also significantly more sensitive to β-lactam antibiotics than Schu S4. Taken together, the data strongly suggest that FTT_0924 is required for maintaining peptidoglycan integrity and virulence. |
| Databáze: | OpenAIRE |
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