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Full-Text Articles in Life Sciences

Sorbitol-Fermenting Bifidobacteria As Indicators Of Diffuse Human Faecal Pollution In Estuarine Waters, Mw Rhodes, H Kator Oct 1999

Sorbitol-Fermenting Bifidobacteria As Indicators Of Diffuse Human Faecal Pollution In Estuarine Waters, Mw Rhodes, H Kator

VIMS Articles

Sorbitol fermenting bifidobacteria were evaluated as indicators of non-point source human faecal pollution to three sub-estuaries with elevated faecal coliform densities. Human-specific bifidobacteria correlated with identifiable human sanitary deficiencies in feeder streams to estuarine creeks in two of three watersheds examined, one rural and one moderately developed. Sorbitol-fermenting bifidobacteria were recovered at densities ranging from 1 to 90 colony-forming-units 100 ml(-1) in 11 of 258 water samples but were undetected in sediment (n = 68) and scat from resident wildlife (deer, muskrat and raccoon, n = 20). Failure to detect sorbitol-fermenting bifidobacteria in water samples during the summer months was …


Antigenic And Functional Characterization Of P57 Produced By Renibacterium Salmoninarum, Gd Wiens, Ms Chien, Jr Winton, Sl Kaattari May 1999

Antigenic And Functional Characterization Of P57 Produced By Renibacterium Salmoninarum, Gd Wiens, Ms Chien, Jr Winton, Sl Kaattari

VIMS Articles

Renibacterium salmoninarum, the causative agent of bacterial kidney disease, produces large quantities of a 57-58 kDa protein (p57) during growth in broth culture and during infection of salmonid fish. Biological activities of secreted p57 include agglutination of salmonid leucocytes and rabbit erythrocytes. We define the location of epitopes on p57 recognized by agglutination-blocking monoclonal antibodies (MAbs) 4C11, 4H8 and 4D3, and demonstrate that the majority of secreted p57 is a monomer that retains salmonid leucocyte agglutinating activity. The 3 MAbs bound a recombinant, amino-terminal fragment of p57 (211 aa) but not a carboxy-terminal fragment (315 aa) demonstrating that the neutralizing …


Elevated Temperature Treatment As A Novel Method For Decreasing P57 On The Cell Surface Of Renibacterium Salmoninarum, Jon D. Piganelli, Gregory D. Weins, Stephen L. Kaattari Apr 1999

Elevated Temperature Treatment As A Novel Method For Decreasing P57 On The Cell Surface Of Renibacterium Salmoninarum, Jon D. Piganelli, Gregory D. Weins, Stephen L. Kaattari

VIMS Articles

Renibacterium salmoninarum is a Gram-positive diplo-bacillus and the causative agent of bacterial kidney disease, a prevalent disease of salmonid fish. Virulent isolates of R. salmoninarum have a hydrophobic cell surface and express the 57-58 kDa protein (p57). Here we have investigated parameters which effect cell hydrophobicity and p57 degradation. Incubation of R, salmoninarum cells at 37 degrees C for >4 h decreased cell surface hydrophobicity as measured by the salt aggregation assay, and decreased the amount of cell associated p57. Incubation of cells at lower temperatures (22, 17, 4 or -20 degrees C) for up to 16 h did not …


Potential Role Of Protease-Antiprotease Interactions In Perkinsus Marinus Infection In Crassostrea Spp., M Faisal, Jl Oliver, Sl Kaataari Jan 1999

Potential Role Of Protease-Antiprotease Interactions In Perkinsus Marinus Infection In Crassostrea Spp., M Faisal, Jl Oliver, Sl Kaataari

VIMS Articles

Perkinsus marinus causes devastating losses in populations of the eastern oyster (Crassostrea virginica). Our studies have demonstrated that P. marinus secretes extracellular serine proteases which enhance parasite propagation and compromise host defences. Crassostrea virginica. however, possesses several inhibitors of these proteases. The Pacific oyster (C. gigas) is resistant to P. marinus and possesses protease inhibitors with significantly higher specific activities than those in C. virginica. Interestingly, Crassostrea spp. themselves, elaborate metalloprotease activities which can be detected in their plasma, and are increased during P. marinus infections. Together our work suggests that there may be a broad spectrum of humoral host …


Teleost Antibody Structure: Simple Prototype Or Elegant Alternative?, Sl Kaattari, Jv Klemer, Da Evans Jan 1999

Teleost Antibody Structure: Simple Prototype Or Elegant Alternative?, Sl Kaattari, Jv Klemer, Da Evans

VIMS Articles

Teleosts possess mechanism(s) by which they can generate considerable structural diversity within their tetrameric antibody molecules. In salmonids, this diversity is generated through a process of random polymerisation of the constituent monomeric subunits rather than dependency upon isotypic gene diversity. Thus, one gene product can give rise to as many as six different structural forms of immunoglobulin. In contrast to mammals, evidence suggests that this polymerisation process occurs late in the secretory process and not within the endoplasmic reticulum. This assembly process is likely to be important in the generation of teleost antibody functional diversity, thereby potentially simulating isotypy.


Use Of Molecular Tools For Mollusc Disease Diagnosis, Fcj Berthe, Em Burreson, M Hine Jan 1999

Use Of Molecular Tools For Mollusc Disease Diagnosis, Fcj Berthe, Em Burreson, M Hine

VIMS Articles

Recently, an increasing number of research teams arc engaged in developing DNA-based diagnostic techniques for mollusc pathogens. These techniques are slowly moving from development in specialised laboratories for research purposes, to routine application and are expected to find an increasing use in routine disease monitoring programs in mollusc aquaculture and in efforts to prevent the spread of pathogens within and between nations. Considering the probable development and interest in these diagnostic techniques, the potential for wide applications in aquaculture and the inherent problems currently associated with their use, it appears necessary to address these issues.


Environmental Factors And The Infectious Disease Caused By The Protozoan Parasite, Perkinsus Marinus, In Eastern Oysters (Crassostrea Virginica), Fle Chu Jan 1999

Environmental Factors And The Infectious Disease Caused By The Protozoan Parasite, Perkinsus Marinus, In Eastern Oysters (Crassostrea Virginica), Fle Chu

VIMS Articles

Temperature and salinity are two important factors limiting the distribution and abundance of Perkinsus marinus, a protozoan parasite of Eastern oysters (Crassostrea virginica). Results of laboratory studies ale consistent with field observations and clearly demonstrate that P. marinus susceptibility and disease advancement are positively correlated with temperature, salinity and in situ number of infective cells. Laboratory findings also suggest that environmental degradation may enhance the epizootic, although disease caused by P. marinus in oysters is known to be predominantly exacerbated by elevated temperature and salinity. Oysters cellular defence mechanisms appear ineffective in defence against P. marinus. Also, pollutant esposure caused …