Host-Microbe Biology
Observation | Host-Microbe BiologyClostridial Butyrate Biosynthesis Enzymes Are Significantly Depleted in the Gut Microbiota of Nonobese Diabetic MiceAlterations of the gut microbiota early in age have been hypothesized to impact T1D autoimmune pathogenesis. In the NOD mouse model, protection from T1D has been found to operate via modulation of the composition of the intestinal microbiota during a critical early window of ontogeny, although little is known about microbiota functions related to T1D development. Here, we show which gut microbial functions are specifically associated...
Research Article | Host-Microbe BiologyCyclic Diguanylate Regulates Virulence Factor Genes via Multiple Riboswitches in Clostridium difficileIn Clostridium difficile, the signaling molecule c-di-GMP regulates multiple processes affecting its ability to cause disease, including swimming and surface motility, biofilm formation, toxin production, and intestinal colonization. In this study, we used RNA-seq to define the transcriptional regulon of c-di-GMP in...
Research Article | Host-Microbe BiologyOral Administration of Porphyromonas gingivalis Alters the Gut Microbiome and Serum MetabolomeIncreasing evidence suggest that alterations of the gut microbiome underlie metabolic disease pathology by modulating gut metabolite profiles. We have shown that orally administered Porphyromonas gingivalis, a representative periodontopathic bacterium, alters the gut microbiome; that may be a novel mechanism by which periodontitis increases the risk of various...
Research Article | Host-Microbe BiologyImpact of Engineered Expression of Mitochondrial Association Factor 1b on Toxoplasma gondii Infection and the Host Response in a Mouse ModelThe parasite Toxoplasma gondii currently infects approximately one-third of the world’s population and causes life-threatening toxoplasmosis in individuals with undeveloped or weakened immune systems. Current treatments are unable to cure T. gondii infection, leaving infected individuals with slow-...
Research Article | Host-Microbe BiologyMost Sinorhizobium meliloti Extracytoplasmic Function Sigma Factors Control Accessory FunctionsFixed (reduced) soil nitrogen plays a critical role in soil fertility and successful food growth. Much soil fertility relies on symbiotic nitrogen fixation: the bacterial partner infects the host plant roots and reduces atmospheric dinitrogen in exchange for host metabolic fuel, a process that involves complex interactions between the partners mediated by changes in gene expression in each partner. Here we test the roles of a family of...
Research Article | Host-Microbe BiologyThe Genetic Transformation of Chlamydia pneumoniaeThe absence of tools for the genetic manipulation of C. pneumoniae has hampered research into all aspects of its biology. In this study, we established a novel reproducible method for C. pneumoniae transformation based on a plasmid shuttle vector system. We constructed a...
Research Article | Host-Microbe BiologyHighly Reduced Genome of the New Species Mycobacterium uberis, the Causative Agent of Nodular Thelitis and Tuberculoid Scrotitis in Livestock and a Close Relative of the Leprosy BacilliM. uberis is an emerging skin pathogen in dairy animals. Its genome underwent massive reduction and gene decay, leading to a minimal set of genes required for an obligatory intracellular lifestyle, which highly resembles the evolution of the leprosy agents M. leprae and...
Perspective | Host-Microbe BiologyBats Are an Untapped System for Understanding Microbiome Evolution in MammalsMammals evolved in a microbial world, and consequently, microbial symbionts have played a role in their evolution. An exciting new subdiscipline of metagenomics considers the ways in which microbes, particularly those found in the gut, have facilitated the ecological and phylogenetic radiation of mammals.
Research Article | Host-Microbe BiologyThe Toxoplasma gondii Active Serine Hydrolase 4 Regulates Parasite Division and Intravacuolar Parasite ArchitectureThis work defines the function of an enzyme in the obligate intracellular parasite Toxoplasma gondii. We show that this previously uncharacterized enzyme is critical for aspects of cellular division by the parasite and that loss of this enzyme leads to parasites with cell division defects and which also are disorganized inside their vacuoles. This leads to defects in...
Research Article | Host-Microbe BiologyThe Interferon-Induced Exonuclease ISG20 Exerts Antiviral Activity through Upregulation of Type I Interferon Response ProteinsThe host immune responses to infection lead to the production of type I interferon (IFN), and the upregulation of interferon-stimulated genes (ISGs) reduces virus replication and virus dissemination within a host. Ectopic expression of the interferon-induced 20-kDa exonuclease ISG20 suppressed replication of chikungunya virus and Venezuelan equine encephalitis virus, two mosquito-vectored RNA alphaviruses. Since the replication of...