Cyclic nitramines released into all environmental compartments through anthropogenic activities are toxic and possibly carcinogenic and mutagenic. Soils on military ranges, located throughout the world in various climatic regions and close to human activities, are especially susceptible to cyclic nitramine contamination. The properties of soils on military ranges will directly...
Freshwater cyanobacterial blooms are a nuisance and health threat in the Pacific Northwest. The accepted methods of characterizing these blooms by microscopic cell counts cannot differentiate between toxic and non-toxic strains of the cyanobacterium Microcystis. Also, there is limited understanding of freshwater cyanophage that may control bloom dynamics. In order...
While the quorum-sensing (QS) diversity of the opportunistic pathogen Pseudomonas aeruginosa has been well established in cystic fibrosis (CF) lung infections and in vitro experiments, little is known about its QS-diversity in natural environments. One significant QS-deficient behavior is social cheating. Social cheaters contain mutations that prevent them from producing...
Erwinia amylovora is a plant pathogenic bacterium that causes the destructive disease fire blight of apple and pear. We examined the plasmid content of a collection of 305 isolates of E. amylovora from Washington and Oregon with PCR assays and RFLP. Nearly all isolates of E. amylovora carried plasmid pEA29,...
Aquifers are an important storage location and source of fresh groundwater. They may become polluted by a number of contaminants including mobile divalent radionuclides such as strontium-90 which is a byproduct of uranium fission. A method for remediating such divalent radionuclides is sequestration through co-precipitation into calcium carbonate. Calcium carbonate...
Pseudomonas aeruginosa is an environmental bacterium as well as an opportunistic pathogen that primarily infects immunocompromised individuals, including those suffering from cystic fibrosis. The density-dependent regulation of gene expression via cell-to-cell communication, also termed quorum sensing (QS), is an important virulence determinant in this organism. Generally, P. aeruginosa uses three...
Lentisphaera araneosa is a marine microorganism, and its production of expolymer plays an important role in marine ecosystem. The exopolymer production in L. araneosa is studied by measuring the growth of bacteria (in cells/mL) and the viscosity of the medium (in centistokes) under different treatments. The treatment without serine and...
Novel mucosal vaccines (LL-M2e, LL-HAe, SG-HAe) were constructed from live, non-pathogenic Lactococcus lactis or Streptococcus gordonii that express conserved regions of HA or M2 antigens from avian influenza virus (AIV) A. All three vaccines evoked antigen-specific serum immunoglobulin G (IgG) responses in vaccinated chickens. The addition of the adjuvant cholera...
Waterborne fecal contamination poses serious risks to human health and can disrupt aquatic ecosystems. Molecular marker methods are widely used to identify and, in some cases, quantify the sources of contamination and guide management decisions regarding water resource protection. However, methods to detect some likely sources of fecal contamination such...
Social behavior leading to the production of common goods is prone to exploitation. One such behavior in Pseudomonas aeruginosa is quorum sensing (QS), by which the bacteria produce signals to regulate extracellular common goods. Exploitation comes in the form of cheaters which have a mutation in the central quorum sensing...
The pathogen Vibrio cholerae uses cations as a primary currency of virulence
and environmental persistence, using gradients of those cations to move, acquire
nutrients, and control virulence gene expression. An understanding of the overlapping
roles of bioenergetics and chemotaxis in the virulence and environmental survival of
V. cholerae issues from...
Clostridium perfringens is the causative agent of gas gangrene and the 3rd most common cause of type A food borne disease in the United States. Critical to the pathogenicity of C. perfringens is the ability of this bacterium to produce highly resistant, metabolically dormant spores that can resume metabolic function...
Cyanobacterial blooms are a growing concern in the Pacific Northwest because of their
threat to watershed health and drinking water supplies. Bacteriophages are pathogens of
bacteria and may contribute to the growth and decline of seasonal blooms. Bacteriophage
S-CRM01, a lytic T4-type myophage, has been isolated from a freshwater strain...
Cyanobacterial blooms are a growing concern in the Pacific Northwest because of their
threat to watershed health and drinking water supplies. Bacteriophages are pathogens of
bacteria and may contribute to the growth and decline of seasonal blooms. Bacteriophage
S-CRM01, a lytic T4-type myophage, has been isolated from a freshwater strain...
RNA silencing plays a critical role in plant defense against viral infection. Plants use virusderived
small interfering RNA to target and silence invading viruses. The antiviral silencing
pathway can be broken down into three conceptual stages: initiation, amplification, and systemic
movement. The molecular mechanisms of silencing initiation are not well...