In this study of toxigenic and non-toxigenic strains of Clostridium
botulinum type E, attempts were made to induce toxin production
in non-toxigenic cultures by exposure to mutagenic agents
and to differentiate the organisms by immunodiffusion. First, cultures
of non-toxic Cl. botulinum type E were exposed to various
mutagenic agents in...
Pseudomonas aeruginosa is an opportunistic human pathogen that infects immunocompromised individuals such as those suffering from burns or the genetic disorder cystic fibrosis. This organism utilizes a cell-cell communication mechanism known as quorum sensing (QS) to coordinate virulence gene expression and biofilm formation. It has three interconnected QS systems, namely...
Crown gall disease is caused by the ubiquitous soil bacterium Agrobacterium tumefaciens which transfers a portion if DNA (T-DNA) into the plant cell. Preventing infection by using the biocontrol strain Agrobacterium radiobacter K84 is currently the only defense for crown gall. Two different resistance strategies were examined in this work....
Clostridium perfringens is a Gram-positive, anaerobic, spore-forming bacterium that can produce as many as 17 different toxins and are responsible to cause a wide array of gastrointestinal (GI) and histotoxic diseases in humans and animals. As individual strains produce a subset of these toxins, C. perfringens strains can be classified...
The prototypal poxvirus vaccinia is a cytoplasmic-replicating DNA
virus which contains a large genome with the capacity to encode 200
polypeptides. Tight temporal regulation coordinates the expression of
this large number of genes throughout a relatively short replication
cycle. As a first step towards identifying and understanding the
regulatory mechanisms...
The transcriptional promoter sequences for the Rhizobium meliloti
nitrogen fixation genes nifA and nifB were cloned to a β-galactosidase gene
fusion plasmid vector and transferred by homologous recombination to a
specialized transducing phage. The promoter fusions were then transduced
to a recombination deficient strain of Escherichia coli as single-copy
lysogens...
The Baculoviridae comprise a diverse group of occluded DNA viruses that contain large double-stranded DNA genomes of 80 - 180 kb and may encode up to 180 gene products. To understand how baculoviruses replicate and process their genomes and the gene products that are involved in these events, a series...
Shotgun metagenomic DNA sequencing is a widely applicable tool for characterizing the functions that are encoded by microbial communities. Several bioinformatic tools can be used to functionally annotate metagenomes, allowing researchers to draw inferences about the functional potential of the community and to identify putative functional biomarkers. However, little is...
Standard methods of measuring fecal pollution in water do not distinguish between human and non-human sources. Molecular technology enabled the development of host-specific markers that distinguish fecal sources. Human specific PCR primers, HF183F and HF134F, were designed based on phylogenetic analyses of partial 16S rRNA gene sequences from the Bacteroidales...
The Mx protein family of rainbow trout (Oncorhynchus mykiss) was characterized at the molecular level. With primers derived from a partial sequence of Perch (Perca fluviatis) Mx genomic DNA, a partial rainbow trout Mx genomic DNA sequence was obtained by polymerase chain reaction (PCR) amplification. All salmonid fish investigated contained...