Shigella is the causative agent of bacillary dysentery in humans and primates. Over 200 million cases are reported annually and about 650,000 persons die of shigellosis each year. No effective vaccine exists. Recent bioterrorism concerns increase the importance of understanding Shigella pathogenesis since Shigella has been classified as a category B agent on the NIAID's list of priority pathogens for biodefense research. Shigella is a classic example of an invasive, facultative intracellular pathogen that is exquisitely adapted to living within the cytoplasm of the host cell. Moreover, Shigella has evolved mechanisms to replicate within and exit the host while avoiding the host inflammatory response. Our long term objectives have focused on post-invasion aspects of Shigella pathogenesis including molecular characterization of secreted effector proteins and their role in modulating the host immune response and facilitating intracellular bacterial growth and survival.
The specific aims of this proposal are to: 1) Characterize the bacterial and host factors responsible for the anti-apoptotic effects of Shigella flexneri infection in epithelial cells;and 2) Characterize the role of the Osp proteins with respect to Shigella pathogenesis and the host immune response. Several models and innovative experimental strategies for testing them are proposed. Genetic, biochemical and molecular and cell biology approaches will be utilized in all aims. This research will fill in important gaps in our knowledge of Shigella pathogenesis. Information on how secreted effectors of Shigella modulate host cell survival (anti- apoptosis) and the host inflammatory response can reveal new targets for the design of therapeutic agents. The results of the proposed studies can serve as a paradigm for understanding similar phenotypic traits of other intracellular bacterial pathogens.
Bacillary dysentery (shigellosis) is an acute diarrheal disease caused by bacteria of the Shigella species. Because shigellosis is easily spread from person to person and ingestion of just a few organisms in contaminated food or water is sufficient to cause disease, Shigella are classified as category B biological agents.
The aims of this project will help us better understand how this pathogen causes disease, which, in turn, may lead to more effective strategies for prevention and treatment.
|Fogolari, Marta; Mavian, Carla; Angeletti, Silvia et al. (2018) Distribution and characterization of Shiga toxin converting temperate phages carried by Shigella flexneri in Hispaniola. Infect Genet Evol 65:321-328|
|Lampel, Keith A; Formal, Samuel B; Maurelli, Anthony T (2018) A Brief History of Shigella. EcoSal Plus 8:|
|Bliven, Kimberly A; Maurelli, Anthony T (2016) Evolution of Bacterial Pathogens Within the Human Host. Microbiol Spectr 4:|
|Gray, M D; Lacher, D W; Leonard, S R et al. (2015) Prevalence of Shiga toxin-producing Shigella species isolated from French travellers returning from the Caribbean: an emerging pathogen with international implications. Clin Microbiol Infect 21:765.e9-765.e14|
|Gray, Miranda D; Lampel, Keith A; Strockbine, Nancy A et al. (2014) Clinical isolates of Shiga toxin 1a-producing Shigella flexneri with an epidemiological link to recent travel to Hispañiola. Emerg Infect Dis 20:1669-77|
|Emanuele, Anthony A; Adams, Nancy E; Chen, Yi-Chen et al. (2014) Potential novel antibiotics from HTS targeting the virulence-regulating transcription factor, VirF, from Shigella flexneri. J Antibiot (Tokyo) 67:379-86|
|Bliven, Kimberly A; Maurelli, Anthony T (2012) Antivirulence genes: insights into pathogen evolution through gene loss. Infect Immun 80:4061-70|
|Faherty, Christina S; Merrell, D Scott; Semino-Mora, Cristina et al. (2010) Microarray analysis of Shigella flexneri-infected epithelial cells identifies host factors important for apoptosis inhibition. BMC Genomics 11:272|
|Zurawski, Daniel V; Mumy, Karen L; Faherty, Christina S et al. (2009) Shigella flexneri type III secretion system effectors OspB and OspF target the nucleus to downregulate the host inflammatory response via interactions with retinoblastoma protein. Mol Microbiol 71:350-68|
|Faherty, Christina S; Maurelli, Anthony T (2009) Spa15 of Shigella flexneri is secreted through the type III secretion system and prevents staurosporine-induced apoptosis. Infect Immun 77:5281-90|
Showing the most recent 10 out of 38 publications