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Members of the genus Rickettsia possess the ability to invade host cells and promptly escape from phagosomal vacuoles into the host cell cytosol, thereby avoiding destruction within the endosomal pathway. The mechanism underlying rickettsial phagosomal escape remains unknown, although the genomic sequences of several rickettsial species have allowed for the(More)
The human vaginal microbiome plays a critical but poorly defined role in reproductive health. Vaginal microbiome alterations are associated with increased susceptibility to sexually-transmitted infections (STI) possibly due to related changes in innate defense responses from epithelial cells. Study of the impact of commensal bacteria on the vaginal mucosal(More)
Surface proteins of the obligate intracellular bacterium Rickettsia typhi, the agent of murine or endemic typhus fever, comprise an important interface for host-pathogen interactions including adherence, invasion and survival in the host cytoplasm. In this report, we present analyses of the surface exposed proteins of R. typhi based on a suite of predictive(More)
Human granulocytic ehrlichiosis (HGE) is a potentially fatal, tick-borne disease caused by a bacterium related or identical to Ehrlichia phagocytophila. To identify and characterize E. phagocytophila group-specific protein antigen genes, we prepared and screened HGE agent and Ehrlichia equi genomic DNA expression libraries using polyclonal equine E. equi(More)
Quick and accurate identification of microbial pathogens is essential for both diagnosis and response to emerging infectious diseases. The advent of next-generation sequencing technology offers an unprecedented platform for rapid sequencing-based identification of novel viruses. We have developed a customized bioinformatics data analysis pipeline,(More)
Six novel insect-specific viruses, isolated from mosquitoes and phlebotomine sand flies collected in Brazil, Peru, the United States, Ivory Coast, Israel, and Indonesia, are described. Their genomes consist of single-stranded, positive-sense RNAs with poly(A) tails. By electron microscopy, the virions appear as spherical particles with diameters of ∼45 to(More)
Septic shock due to Salmonella and other gram-negative enteric pathogens is a leading cause of death worldwide. The role of lipopolysaccharide in sepsis is well studied; however, the contribution of other bacterial outer membrane components, such as Braun (murein) lipoprotein (Lpp), is not well defined. The genome of Salmonella enterica serovar Typhimurium(More)
A proposed new small-animal (rodent) model for studying the pathogenesis and treatment of severe orthopoxvirus infections is described. Thirteen-lined ground squirrels (Spermophilus tridecemlineatus) were infected intraperitoneally and intranasally with monkeypox virus (MPXV). A fulminant illness developed in all animals, and they died 6-9 days after(More)
BACKGROUND The obligately intracellular bacterium Ehrlichia chaffeensis that resides in mononuclear phagocytes is the causative agent of human monocytotropic ehrlichiosis. Ehrlichia muris and Ixodes ovatus Ehrlichia (IOE) are agents of mouse models of ehrlichiosis. The mechanism by which Ehrlichia are transported from an infected host cell to a non-infected(More)
Rickettsial diversity is intriguing in that some species are transmissible to vertebrates, while others appear exclusive to invertebrate hosts. Of particular interest is Rickettsia felis, identifiable in both stored product insect pests and hematophagous disease vectors. To understand rickettsial survival tactics in, and probable movement between, both(More)