Record Details
Thermal resistance and characterization of Vibrio parahaemolyticus by gel electrophoresis of culture supernatants
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Thermal resistance and characterization of Vibrio parahaemolyticus by gel electrophoresis of culture supernatants |
| Names |
Freitas Leitao, Mauro Faber de
(creator) Anderson, A. W. (advisor) |
| Date Issued | 1970-05-01 (iso8601) |
| Note | Graduation date: 1970 |
| Abstract | Concentrated culture supernatants from strains of Vibrio parahaemolyticus of gastroenteric origin, "suspected" V. parahaemolyticus isolated from cases of skin infection, nonpathogenic marine Vibrio, V. anguillarum and V. alginolyticus, were submitted to flat gel electrophoresis, followed by the examination of the polyacrylamide gels for total protein and enzyme patterns. Variations related to the presence of single and multimolecular forms of proteolytic enzymes, lipases, esterases, phosphatases, amylases and deoxyribonucleases, permitted a differentiation among the cultures being examined. A close similarity was observed between the pathogenic cultures isolated from skin infections and the V. parahaemolyticus strains of gastroenteric origin. This group was well differentiated from the nonpathogenic Vibrio, V. anguillarum and V. alginolyticus, but under the conditions of the experiment these last three groups could not be easily differentiated. The tests involving the detection of DNase, amylase, egg yolk lipase (mainly related to time and intensity of reaction) appeared to be the most useful for the characterization of V. parahaemolyticus and these results suggested that the application of gel electrophoresis of culture supernatants, might be of importance in the rapid identification of this bacterium. No evidence was found indicating the presence of the hemolytic factor responsible for the "Kanagawa phenomenon". Another purpose of the present study was the determination of the heat resistance of V. parahaemolyticus, the strain ATCC 17802 being used as a test organism. The flask method was employed and peptone salt water, pH 7.2 was the suspending menstruum. Decimal reduction time (D value) was the parameter used to express the heat resistance, with values of 38.2, 2.01, and 0.51 min being observed at the temperatures of 113°, 118.4°, and 122°F, respectively. A study to determine the influence of the composition of the recovery medium on the apparent heat resistance, showed that higher counts and survival rates were observed when Vibrio Maintenance Medium was employed for counting the heated cells, with a statistically significant difference (at five percent level) being observed when compared with Brain Heart Infusion Agar plus 2.5 percent NaCl and Trypticase Soy Agar plus 2.5 percent NaCI, without a significant difference between the last two media. |
| Genre | Thesis/Dissertation |
| Topic | Sanitary microbiology |
| Identifier | http://hdl.handle.net/1957/46301 |
