Latest Articles
Research Article | Host-Microbe BiologyRectal Microbiome Composition Correlates with Humoral Immunity to HIV-1 in Vaccinated Rhesus MacaquesThere is considerable effort directed toward evaluating HIV-1 vaccine platforms to select the most promising candidates for enhancing mucosal HIV-1 antibody. The most successful thus far, the RV144 trial provided partial protection due to waning HIV-1 antibody titers. In order to develop an effective HIV vaccine, it may therefore be important to understand how biological factors, such as the microbiome, modulate host immune responses....
Research Article | Molecular Biology and PhysiologyBlocks in Tricarboxylic Acid Cycle of Salmonella enterica Cause Global Perturbation of Carbon Storage, Motility, and Host-Pathogen InteractionWe performed perturbation analyses of the tricarboxylic acid cycle of the gastrointestinal pathogen Salmonella enterica serovar Typhimurium. The defect of fumarase activity led to accumulation of fumarate but also resulted in a global alteration of carbon fluxes, leading to increased storage of glycogen. Gross alterations were observed in proteome and metabolome...
Research Article | Therapeutics and PreventionSpecies-Specific Differences in the Susceptibility of Fungi to the Antifungal Protein AFP Depend on C-3 Saturation of GlycosylceramidesOur data suggest a fundamental role of glycosylceramides in the susceptibility of fungi to AFP. We discovered that only a minor structural difference in these molecules—namely, the saturation level of their fatty acid chain, controlled by a 2-hydroxy fatty N-acyl-Δ3(E)-desaturase—represents a key to understanding the inhibitory activity of AFP. As glycosylceramides are important components of fungal plasma membranes, we propose...
Research Article | Host-Microbe BiologyGut Microbiomes of the Eastern Oyster (Crassostrea virginica) and the Blue Mussel (Mytilus edulis): Temporal Variation and the Influence of Marine Aggregate-Associated Microbial CommunitiesThis work investigates the influence that extrinsic factors, diet, and the environment can have on the microbiomes of shellfish. Over the course of a year, the gut microbial communities of two species of bivalves, oysters and mussels, held under identical conditions in coastal marine waters were compared. While the mussels and oysters harbored gut microbial communities with similar composition, on a functional level, they exhibited...
Research Article | Synthetic BiologyA Targetron-Recombinase System for Large-Scale Genome Engineering of ClostridiaClostridia are anaerobic bacteria with important roles in intestinal and soil microbiomes. The inability to experimentally modify the genomes of clostridia has limited their study and application in biotechnology. Here, we developed a targetron-recombinase system to efficiently make large targeted genomic deletions and insertions using the model Clostridium phytofermentans...
Meeting Highlights | Applied and Environmental ScienceMolecular Detection of Biological Agents in the Field: Then and NowMolecular detection of biological agents in the field has traditionally relied on the use of quantitative real-time PCR (qPCR), which now includes commercially available instruments that can be used in the laboratory or field. Adapting this technology for field-forward applications necessitated innovation to minimize size, weight, and power requirements.
Research Article | Host-Microbe BiologyStaphylococcal Virulence Factors on the Skin of Atopic Dermatitis PatientsFor the first time, we show that secreted staphylococcal virulence factors can be quantified at the protein level directly from skin swabs obtained from the skin of atopic dermatitis patients. This technique eliminates the need to culture Staphylococcus aureus and then test the strain’s potential to produce secreted virulence factors. Our methodology shows that...
Research Article | Therapeutics and PreventionThe Modified Surface Killing Assay Distinguishes between Protective and Nonprotective Antibodies to PspAThe most important finding of this study is that the MSKA can be used as an in vitro functional assay. Such an assay will be critical for the development of PspA-containing vaccines. The other important findings relate to the locations and nature of the protection-eliciting epitopes of PspA. There are limited prior data on the locations of protection-eliciting PspA epitopes, but those data along with the data presented here...
Research Article | Molecular Biology and PhysiologyQuantifying Oxygen Management and Temperature and Light Dependencies of Nitrogen Fixation by Crocosphaera watsoniiCrocosphaera is one of the major N2-fixing microorganisms in the open ocean. On a global scale, the process of N2 fixation is important in balancing the N budget, but the factors governing the rate of N2 fixation remain poorly resolved. Here, we combine a mechanistic model and both previous and present laboratory studies of Crocosphaera to quantify how chemical factors such as C, N, Fe...
Research Article | Molecular Biology and PhysiologyStreptococcus gordonii Type I Lipoteichoic Acid Contributes to Surface Protein BiogenesisDiscovered over a half-century ago, lipoteichoic acid (LTA) is an abundant polymer found on the surface of Gram-positive bacteria. Although LTA is essential for the survival of many Gram-positive species, knowledge of how LTA contributes to bacterial physiology has remained elusive. Recently, LTA-deficient strains have been generated in some Gram-positive species, including the human oral commensal...