Allergic and autoimmune diseases had been attributed to lack of exposure to biodiversity, an important factor in regulating immune homeostasis in a healthy host. We posit that the microbiome of healthy dairy farmers (DF) will be richer than non-farmers (NF) living in urban settings due to exposure to a greater biodiversity in the dairy environment. However, no studies have investigated the rela...

Helicobacter pylori colonization is highly prevalent among humans and causes significant gastric disease in a subset of those infected. When present, this bacterium dominates the gastric microbiota of humans and induces antimicrobial responses in the host. Since the microbial context of H. pylori colonization influences the disease outcome in a mouse model, we sought to assess the impact of H. ...

Host resistance to bacterial infections is thought to be dictated by host genetic factors. Infections by the natural murine enteric pathogen Citrobacter rodentium (used as a model of human enteropathogenic and enterohaemorrhagic E. coli infections) vary between mice strains, from mild self-resolving colonization in NIH Swiss mice to lethality in C3H/HeJ mice. However, no clear genetic component...

Given the scale of the contamination associated with 60 years of global nuclear activity, and the inherent high financial and environmental costs associated with invasive physical and chemical clean-up strategies, there is an unparalleled interest in new passive in situ bioremediation processes for sites contaminated with nuclear waste. Many of these processes rely on successfully harnessing ne...

Both anthropogenic nitrogen deposition and exotic annual grass invasion are occurring in the coastal sage scrub vegetation (CSS) of southern California. A study was carried out to determine the effects of these changes on soil microbial communities. Soils were sampled under exotic grasses and the native shrub Artemisia californica along an urban-to-rural N deposition gradient, and in N-fertiliz...

Biology has a big elephant in the room. Researchers are learning that microorganisms are critical for every aspect of the biosphere's health. Even at the scale of our own bodies, we are discovering the unexpected necessity and daunting complexity of our microbial partners. How can we gain an understanding of the form and function of these "ecosystems" that are an individual animal? This essay e...

Information implicating bacterial biofilms as contributory factors in the development of environmental bacterial resistance has been increasing. There is a lack of information regarding the role of biofilms within the microbial ecology of the gastrointestinal tract of food animals. This work used a continuous-flow chemostat model derived from the ceca of 7-day-old chicks to characterize these c...

The diversity of functional and life-history traits of organisms depends on adaptation as well as the legacy of shared ancestry. Although the evolution of traits in macro-organisms is well studied, relatively little is known about character evolution in micro-organisms. Here, we surveyed an ancient and ecologically important group of microbial plant symbionts, the arbuscular mycorrhizal (AM) fu...

Nasopharyngeal colonization is the first step in the interaction between Streptococcus pneumoniae (the pneumococcus) and its human host. Factors that contribute to clearance of colonization are likely to affect the spread of the pneumococcus and the rate of pneumococcal disease in the population. To identify host and bacterial factors contributing to this process, we examined the time course of...

Ranunculus roots were sampled across a latitudinal transect encompassing 52 oN and 82 oN, for years spanning 1963-2007. Samples from 2004 and later were preserved in formalin; earlier samples were taken from herbarium accessions. Roots were examined for colonization by arbuscular mycorrhizae, fine endophyte, and septate endophyte fungi using lactofuchsin-stained material imaged with epifluoresc...