Characterization of the occurrence and abundance of Vibrio vulnificus in Galveston Bay /
Oysters, suspended particulate matter (SPM), sediment and
| Main Author: | |
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1996.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=743274361&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Oysters, suspended particulate matter (SPM), sediment and seawater samples were collected from West Galveston Bay, Texas over a 4-year period and analyzed for the presence of Vibrio vulnificus, a naturally-occurring human marine- pathogen. Detection and enumeration of V vulnificus were performed using a species-specific monoclonal antibody (mAb FRBT37) in an Enzyme-Immunoassay (EIA)-Most Probable Number (MPN) procedure capable of detecting as few as 2000 target organisms. V. vulnificus was not detected during the cold weather months except in sporadic sediment samples, but when oyster samples were subjected to resuscitation conditions (25'C and 15 ppt for 24 and 48-h) the bacterium was brought back to detectable levels. Increased levels of the organism were first observed in early spring in the sediment, followed by SPM and oysters. The major increase in V. vulnificus occurred after the seawater temperature had increased above 20'C and the winter-spring rainfall had lowered the salinity below 16 ppt. The highest V vulnificus levels at each site were associated with SPM. In a series of deputation resuscitation experiments, summer-harvested oysters containing near peak levels of V vulnificus were subjected to winter temperatures and salinity conditions (12'C and 25 ppt) in an attempt to purge the pathogen from the oysters. After one month of deputation, the bacterium was brought to non- detectable levels; however, even after one year of deputation, detectable levels of the bacterium could be cultured following 24-h of resuscitation. Optimum resuscitation conditions were determined through these experiments to be 300C and 15 ppt. A species-specific, fluorescently-labeled nucleic acid probe complementary to a short unique sequence of 23S RRNA was compared with the standard assay procedure for detection of V. vulnificus in field oysters. The 'presence of oyster tissue and filter autofluorescence masked the sensitivity of the technique that was evident when pure cultures of V. vulnificus had been employed. Use of a 32p labled probe overcame most of these problems but is not practical for use in the average testing laboratory. |
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| Item Description: | Vita. "Major Subject: Microbiology". |
| Physical Description: | xvii, 114 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |