Vibrio parahaemolyticus is an important cause of diarrheal disease due to the consumption of imporperly prepared seafood. Although the pathogenesis of disease due to this species is uncertain, a consistent finding in strains isolated from disease is the presence of a hemolysin designated thermostable direct hemolysin (TDH) or the """"""""Kanagawa Phenomenon"""""""" (KP) associated hemolysin. Previous research on this project has resulted in the cloning and sequencing of genes encoding TDH (tdh), the development and testing of a DNA probe for tdh genes and the construction of isogenic strains which do not produce TDH. The proposed continuation of this project will answer additional questions that have arisen concerning the genetics of TDH production and investigate the role of a recently discovered shiga-like toxin in the pathogenesis of disease due to V. parahaemolyticus. The proposed research will focus on the cloning and sequencing of genes encoding the shiga-like toxin and assess the significance of this toxin in the disease process.
The specific aims of this project are as follows: 1) To investigate the phenomenon of gene duplication of the gene encoding TDH (tdh). 2) To clone and sequence the single gene copy present in strains of V. parahaemolyticus which produce very low amounts of TDH and compare this gene to tdh genes found in strains which produce high amount of TDH. 3) To investigate the role of plasmids in the transfer of tdh genes. 4) To clone and characterize genes encoding a shiga-like toxin in V. parahaemolyticus. 5) To construct isogenic strains of V. parahaemolyticus which do not produce the shiga-like toxin and assess their potential pathogenicity. 6) To develop a DNA probe capable of detecting genes encoding shiga-like toxin and employ it to survey the incidence of these genes in environmental and clinical isolates of V. parahaemolyticus and in other Vibrio species pathogenic for man.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI019165-06
Application #
3128561
Study Section
Bacteriology and Mycology Subcommittee 1 (BM)
Project Start
1982-09-01
Project End
1989-08-31
Budget Start
1987-09-01
Budget End
1988-08-31
Support Year
6
Fiscal Year
1987
Total Cost
Indirect Cost
Name
University of Maryland Baltimore
Department
Type
Schools of Medicine
DUNS #
003255213
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Nishibuchi, M; Kaper, J B (1995) Thermostable direct hemolysin gene of Vibrio parahaemolyticus: a virulence gene acquired by a marine bacterium. Infect Immun 63:2093-9
Nishibuchi, M; Fasano, A; Russell, R G et al. (1992) Enterotoxigenicity of Vibrio parahaemolyticus with and without genes encoding thermostable direct hemolysin. Infect Immun 60:3539-45
Nishibuchi, M; Kumagai, K; Kaper, J B (1991) Contribution of the tdh1 gene of Kanagawa phenomenon-positive Vibrio parahaemolyticus to production of extracellular thermostable direct hemolysin. Microb Pathog 11:453-60
Nishibuchi, M; Kaper, J B (1990) Duplication and variation of the thermostable direct haemolysin (tdh) gene in Vibrio parahaemolyticus. Mol Microbiol 4:87-99
Nishibuchi, M; Khaeomanee-iam, V; Honda, T et al. (1990) Comparative analysis of the hemolysin genes of Vibrio cholerae non-01, V. mimicus, and V. hollisae that are similar to the tdh gene of V. parahaemolyticus. FEMS Microbiol Lett 55:251-6
Nishibuchi, M; Hill, W E; Zon, G et al. (1986) Synthetic oligodeoxyribonucleotide probes to detect Kanagawa phenomenon-positive Vibrio parahaemolyticus. J Clin Microbiol 23:1091-5
Honda, T; Nishibuchi, M; Miwatani, T et al. (1986) Demonstration of a plasmid-borne gene encoding a thermostable direct hemolysin in Vibrio cholerae non-O1 strains. Appl Environ Microbiol 52:1218-20
Nishibuchi, M; Kaper, J B (1985) Nucleotide sequence of the thermostable direct hemolysin gene of Vibrio parahaemolyticus. J Bacteriol 162:558-64
Nishibuchi, M; Ishibashi, M; Takeda, Y et al. (1985) Detection of the thermostable direct hemolysin gene and related DNA sequences in Vibrio parahaemolyticus and other vibrio species by the DNA colony hybridization test. Infect Immun 49:481-6