| Project/Area Number |
14406006
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 海外学術 |
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| Research Field |
Bacteriology (including Mycology)
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| Research Institution | OKAYAMA UNIVERSITY |
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Principal Investigator |
SHINODA Sumio OKAYAMA UNIVERSITY, Graduate School of Natural Science and Technology, Professor, 大学院・自然科学研究科, 教授 (50029782)
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| Co-Investigator(Kenkyū-buntansha) |
OKAMOTO Keinosuke OKAYAMA UNIVERSITY, Faculty of Pharmaceutical Sciences, Professor, 薬学部, 教授 (70131183)
TOMOCHIKA Ken-ichi Okayama Gakuin University, Faculty of Human Life, Professor, 人間生活学部, 教授 (00093691)
MIYOSHI Shin-ichi OKAYAMA UNIVERSITY, Graduate School of Natural Science and Technology, Associate Professor, 大学院・自然科学研究科, 助教授 (60182060)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥14,600,000 (Direct Cost: ¥14,600,000)
Fiscal Year 2004: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2003: ¥4,700,000 (Direct Cost: ¥4,700,000)
Fiscal Year 2002: ¥6,900,000 (Direct Cost: ¥6,900,000)
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| Keywords | Cholera / Vibrios / Diarrheal disease / Indian-subcon / Ecology / Molecular epidemiology |
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| Research Abstract |
Vibrio cholerae colonizes aquatic environments in Indian-subcontinent, especially in Ganges Basin, and causes cholera epidemics periodically. Of the 206 serovars of V.cholerae, only O1 and 139 cause epidemic cholera, whereas non-O1/non-O139 strains do not, although sporadic diarrheal cases are observed. To clarify epidemic feature of cholera in these area, V.cholerae strains were isolated from from environmental and clinical origins and analysed.
V.cholerae isolates from both origins in the Bengal region were analyzed with particular emphasis on the molecular epidemiological feature. Presence of the virulence genes (ctxA,tcpA and toxR) in the isolates was analyzed by PCR(polymerase chain reaction) method. PFGE (pulsed-field gel electrophoresis) was performed to determine the clonal relationships between clinical and environmental strains. O1 and O139 strains from both clinical and environmental sources were all positive for the three virulence genes while nonO1/non-O139 strains from both sources were all negative for ctxA and tcpA, except a strain, but positive for toxR. PFGE patterns of recent isolates of O1 and O139 were similar in each serovar regardless of origins, although comparison with past isolates showed some differences. An exceptional non-O1/non-O139 strain. was positive for ctxA and tcpA of classical type. These results indicate that there is a clonal relationship between clinical and environmental strains and the aquatic environments serve as reservoirs of toxigenic V.cholerae.
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