1987 Fiscal Year Final Research Report Summary
Mechanism and epidemiological significance of high contaminations of Vibrio parahaemolyticus to estuarine molluscs
| Project/Area Number |
60480094
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Applied veterinary science
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| Research Institution | Tottori University |
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Principal Investigator |
KUMAZAWA Norichika Assistant Professor, Tottori University, 農学部, 助教授 (00039926)
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| Co-Investigator(Kenkyū-buntansha) |
UMEMURA Takashi Assistant Professor, Tottori University, 農学部, 助教授 (00151936)
KATO Eiichi Professor, Tottori University, 農学部, 教授 (10001520)
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| Project Period (FY) |
1985 – 1987
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| Keywords | Vibrio parahaemolyticus / Clithon retropictus / Corbicula japonica / colonization / enzyme-linked immunoassay / hemocytes |
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| Research Abstract |
From our evidences that high levels of Vibrio parahaemolyticus were detected from two molluscs, Clithon retropictus and Corbicula japonica, at Hashizu estuary and that many strains detected from C. retropictus were estimated as Kanagawa-positive in immunodiffusion, close relationships between V. parahaemolyticus and estuarine molluscs were suspected. Thus, survivals of V. parahaemolyticus D-3 (Kanagawa-positive) and R-13(Kanagawa-negative) and Escherichia coli YS-2 in these molluscs held in aquaria were investigated. These strains survived in C. retropictus for 21 days. Strains D-3 and R-13, but not YS-2, survived in C. japonica for 14 days. These strains were eliminated from Nerita albicilla, a marine mollusc, within 72 hours.
Method to detect Kanagawa hemolysin from culture-supernatants of V. Parahaemolyticus strains utilizing enzyme-linked immunoassay was developed. inhinitor(s) in the supernatants was inactivated by boiling for 30 min. Among boiled-supernatants of estuarine strains, the hemolysin was detected from 9 strains in 36 strains derived from C. retropictus and from 21 in 35 derived from C. japonica, whose titers were between 40 and 80 units/ml compared with 1280 units/ml in clinical isolates.
As successful colonizations of V. parahaemolyticus strains in the estuarine molluscs was supposed to be derived from defective responses of the molluscan hemocytes, chemotactic responses of the hemocytes to strains D-3 R-13 and YS-2 were measured in blind well chambers. Hemocytes of N. albicilla showed an active migration to all strains while those of C. retropictus showed no migration to any organisms. Of C. japonica hemocytes, adhesive cells showed no migration to any organisms while non-adhesive cells migrated only to YS-2.
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Research Products
(4 results)
