Vibrio cholerae is the causative agent of cholera, a serious diarrheal disease in developing countries. V. cholerae has a unique redox driven respiration-linked sodium pump, Na⁺ translocating NADH:quinone oxidoreductase (NQR). Several reports previously showed that NQR plays an important role in virulence, metabolism, and sodium homeostasis of V. cholerae. This...
Vibrio cholerae, a Gram-negative bacterium, is the etiological agent of cholera. V.
cholerae shuttles between the human host and the aquatic reservoir, where it associates
with marine organisms such as copepods and vertebrate fish. The bacteria use the Type II
Secretion System (T2SS) to release proteins that facilitate V. cholerae...
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...
We previously reported that inhibition of the Na⁺ translocating NADH:ubiquinone oxidoreductase (NQR), either by chemical inhibition or mutation, increased toxT transcription in Vibrio cholerae. In this study, we revealed that the nqr mutant strain showed similar phenotypes as the Escherichia coli NADH dehydrogenase I (nuo) mutant strain (e.g. growth defect...
For the enrichment and enumeration of Vibrio fluvialis, a
broth medium was designed by modifying alkaline peptone (AP)
medium. This new V. fluvialis enrichment medium (FEM) was shown to
be more effective than AP medium in field samplings where a total
of 177 samples (estuarine waters and sediment, sewage, and...
Pathogenesis and immunity involved in fowl cholera were studied
with the turkey, one of the most susceptible natural hosts. The
causative agent, Pasteurella multocida, was analyzed in terms of its
virulence and immunogenic factors, using a highly virulent, encapsulated
strain P-1059.
Protective immunity was induced by lipopolysaccharide (LPS)-
protein complex...
Vibrio bacteria are commonly found in freshwater, marine, and estuarine environments. Members of this genus can exist in commensal relationships with marine animals or as planktonic bacteria, however, they are well known for their roles as pathogens towards humans and animals. In this dissertation, I investigated aspects of host-bacteria relationships...
The ability to move towards favorable environmental conditions, called chemotaxis, is common among motile bacteria. In particular aerotaxis has been extensively studied in Escherichia coli. Three putative aer gene homologs were identified in the V. cholerae genome designated VCAer-1 (VC0512) VCAer-2 (VCA0658), and VCAer-3 (VCA0988). Deletion analyses indicated that only...
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...