Identifying the Gene Regulatory Network of the Starvation-Induced Transcriptional Activator Nla28.

Myxococcus xanthus copes with starvation by producing fruiting bodies filled with dormant and stress-resistant spores. Here, we aimed to better define the gene regulatory network associated with Nla28, a transcriptional activator/enhancer binding protein (EBP) and a key regulator of the early starvation response. Previous work showed that Nla28 directly regulates EBP genes that are important for fruiting body development.

Bacterial glycocalyx integrity drives multicellular swarm biofilm dynamism.

Exopolysaccharide (EPS) layers on the bacterial cell surface are key determinants of biofilm establishment and maintenance, leading to the formation of higher-order 3D structures that confer numerous survival benefits to a cell community. In addition to a specific cell-associated EPS glycocalyx, we recently revealed that the social δ-proteobacterium Myxococcus xanthus secretes a novel biosurfactant polysaccharide (BPS) to the extracellular milieu. Together, secretion of the two polymers (EPS and BPS) is required for type IV pilus (T4P)-dependent swarm expansion via spatio-specific biofilm expression profiles.

ICP-MS characterization of seven North American snake venoms.

Snake venoms are inherently complex. They are mixtures of multiple enzymes, peptides, lipids, carbohydrates, nucleosides, and metal ions. Metal ions make up a small portion of a snake's venom but play outsized roles in enzyme function and stability.

The Effect of Simulated Field Storage Conditions on Dental Restorative Materials for Military Field Use.

Introduction: Dental readiness, one critical component of medical readiness, is adversely impacted by dental emergencies. Many dental emergencies require restorative materials such as glass ionomers, resins, and zinc oxide eugenols to remedy them. The Authorized Dental Allowance List (ADAL) and Authorized Medical Allowance List (AMAL) contain the equipment and materials used by Navy dentists to treat Sailors and Marines.

Construction of a genetically modified T7Select phage system to express the antimicrobial peptide 1018.

Bacteriophage therapy was an ascendant technology for combating bacterial infections before the golden age of antibiotics, but the therapeutic potential of phages was largely ignored after the discovery of penicillin. Recently, with antibiotic-resistant infections on the rise, these phages are receiving renewed attention to combat problematic bacterial infections. Our approach is to enhance bacteriophages with antimicrobial peptides, short peptides with broad-spectrum antibiotic or antibiofilm effects.

Bacterial Surface Spreading Is More Efficient on Nematically Aligned Polysaccharide Substrates.

Biofilm-forming bacteria typically deposit layers of polysaccharides on the surfaces they inhabit; hence, polysaccharides are their immediate environment on such surfaces. Previously, we showed that many biofilm-forming bacteria preferentially spread in the direction of aligned and densely packed polysaccharide fibers in compressed substrates, a behavior we referred to as polymertropism. This arrangement of polysaccharide fibers is likely to be similar to that found in the "slime" trails deposited by many biofilm-forming bacteria and would explain previous observations that bacteria tend to follow these trails of polysaccharides.

Polymertropism of rod-shaped bacteria: movement along aligned polysaccharide fibers.

In nature, bacteria often live in surface-associated communities known as biofilms. Biofilm-forming bacteria typically deposit a layer of polysaccharide on the surfaces they inhabit; hence, polysaccharide is their immediate environment on many surfaces. In this study, we examined how the physical characteristics of polysaccharide substrates influence the behavior of the biofilm-forming bacterium Myxococcus xanthus.

Intestinal barrier dysfunction in human necrotizing enterocolitis.

Background: Intestinal barrier dysfunction has been implicated in necrotizing enterocolitis (NEC), but has not been directly measured in human NEC.

Methods: Small intestines removed during surgery were immediately mounted in an Ussing chamber. mRNA expression of tight junction (TJ) proteins was measured with RT-PCR.

Modeling Legionnaires' disease outbreaks: estimating the timing of an aerosolized release using symptom-onset dates.

Background: Over the last 30 years, there have been a number of reported Legionnaires' disease outbreaks resulting from the release of causative organisms from aerosol-producing devices.

Methods: We model a Legionnaires' disease epidemic curve as the convolution of an infection-time distribution (representing the aerosolized release) and an incubation-period distribution. The model is fitted to symptom-onset data from specific outbreaks to estimate the start and end dates of the release.

Risk determinants for catheter-associated blood stream infections in children and young adults with cancer.

Background: Catheter-associated blood stream infections (CABSI) are frequent complications encountered with cancer treatment. In order to understand which factors might predispose to CABSIs in children and young adults, we evaluated risk for infection in association with tumor type, catheter type, and setting of occurrence.

Methods: All pediatric oncology patients having a central venous catheter (CVC) with a tunneled external (TE) or totally implantable design (TID) were prospectively followed for the occurrence of a CABSI for 12 months.