| Project/Area Number |
14572185
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Laboratory medicine
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| Research Institution | Jichi Medical School |
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Principal Investigator |
OHARA Tomoko Jichi Medical School, Department of Clinical Laboratory Medicine, lecture, 医学部, 講師 (10291626)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2002: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | methicillin-resistant Staphylococcus aureus / MRSA enteritis / Antibiotic-related enteritis / diarrheal diseases / 1 / 抗生物質関連腸炎 / 院内感染 |
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| Research Abstract |
The present study was performed in order to determine whether methicillin-resistant Staphylococcus aureus (MRSA) is capable of causing enteritis and whether recovery of MRSA from stool specimens originated from patients with diarrhea implies MRSA enteritis.
Basic study 1)Animal study-We adapted the streptomycin-treated murine model of chronic mucosal colonization. Chronic colonization with MRSA for up to 10 weeks was determined by fecal culture. Stools of MRSA-colonized mouse became soft but not diarrheal. A single day of MRSA ingestion with no combined use of antibiotics was sufficient for enteric colonization with MRSA. Basic study 2)Study using cultured cells Intestinal cells (Caco-2) were injured by incubation with MRSA suspension and cell viability was decreased by 52% after 3 hours of incubation. Post-MRSA incubation cell damage was observed by AFM. Cell arrangement was destroyed and cell volume decreased.
Clinical study 1)We reviewed 163 patients diagnosed with MRSA enteritis. Of the 197 cases, 21 cases were selected using our criteria. Most of the 21 patients showed fever and abnormal white blood cell counts. Nineteen patients had previously been prescribed more than one antibiotic before diarrhea occurred. Although the antibiotics tended to be broad-spectrum, relationships between specific antibiotics and occurrence of enteritis were not observed. Two patients died of multiple organ failure. Clinical study 2)391 stool specimens were selected at random and cultured. The MRSA recovery rate was 15.6%.
Although diarrheal diseases, of which the cause is strongly suggestive of MRSA, actually exist, the clinical courses in the present study were varied. Moreover, MRSA easily colonizes in the gastrointestinal mucosa and colonization is sustained for long periods. Mere recovery of MRSA from stool specimens does not indicate MRSA enteritis and other causative factors may be involved.
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