The Effects of Modeled Microgravity on Growth Kinetics, Antibiotic Susceptibility, Cold Growth, and the Virulence Potential of aYersinia pestis ymoA-Deficient Mutant and Its Isogenic Parental Strain
| Autor: | Michelle L. Kirtley, Christina J. van Lier, Jason A. Rosenzweig, Elena V. Kozlova, Ashok K. Chopra, Abidat Lawal, Tatiana E. Erova, Jian Sha |
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| Rok vydání: | 2013 |
| Předmět: |
Pore Forming Cytotoxic Proteins
Rotation Yersinia pestis Mutant Virulence Microbial Sensitivity Tests medicine.disease_cause Microbiology Type three secretion system Mice Bacterial Proteins medicine Animals Humans Pathogen Research Articles Antigens Bacterial Plague Mutation biology Strain (chemistry) Weightlessness Drug Resistance Microbial biology.organism_classification Agricultural and Biological Sciences (miscellaneous) Anti-Bacterial Agents Cold Temperature Phenotype Space and Planetary Science Cell culture Female HeLa Cells |
| Zdroj: | Astrobiology. 13:821-832 |
| ISSN: | 1557-8070 1531-1074 |
| DOI: | 10.1089/ast.2013.0968 |
| Popis: | Previously, we reported that there was no enhancement in the virulence potential (as measured by cell culture infections) of the bacterial pathogen Yersinia pestis (YP) following modeled microgravity/clinorotation growth. We have now further characterized the effects of clinorotation (CR) on YP growth kinetics, antibiotic sensitivity, cold growth, and YP's virulence potential in a murine model of infection. Surprisingly, none of the aforementioned phenotypes were altered. To better understand why CR did not enhance YP's virulence potential as it did for other bacterial pathogens, a YP ΔymoA isogenic mutant in the KIM/D27 background strain that is unable to produce the histone-like YmoA protein and influences DNA topography was used in both cell culture and murine models of infection. YmoA represses type three secretion system (T3SS) virulence gene expression in the yersiniae. Similar to our CR-grown parental YP strain data, the CR-grown ΔymoA mutant induced reduced HeLa cell cytotoxicity with concomitantly decreased Yersinia outer protein E (YopE) and low calcium response V (LcrV) antigen production and secretion. Important, however, were our findings that, although no significant differences were observed in survival of mice infected intraperitoneally with either normal gravity (NG)- or CR-grown parental YP, the ΔymoA mutant induced significantly more mortality in infected mice than did the parental strain following CR growth. Taken together, our data demonstrate that CR did enhance the virulence potential of the YP ΔymoA mutant in a murine infection model (relative to the CR-grown parental strain), despite inducing less HeLa cell rounding in our cell culture infection assay due to reduced T3SS activity. Therefore, CR, which induces a unique type of bacterial stress, might be enhancing YP's virulence potential in vivo through a T3SS-independent mechanism when the histone-like YmoA protein is absent. Key Words: Type three secretion system (T3SS)—Low-shear modeled microgravity—High-aspect ratio vessel—Cell culture infection models—Mouse infection model. Astrobiology 13, 821–832. |
| Databáze: | OpenAIRE |
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