1998 Fiscal Year Final Research Report Summary
Immunological-molecular biological analysis of the pathogenesis by using a newly established murine model of heamatogenouspulmonary infection by intravenous injection of S.aureus
| Project/Area Number |
09670621
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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 |
Respiratory organ internal medicine
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| Research Institution | Nagasaki University |
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Principal Investigator |
TOMONO Kazunori Nagasaki University, School of Medicine Hospital Assistant, 医学部附属病院, 助手 (40202204)
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| Co-Investigator(Kenkyū-buntansha) |
KOHNO Shigeru Nagasaki University, School of Medicine Professor, 医学部, 教授 (80136647)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Staphylococcus aureus / alpha hemolysin / coagulase / Agar beads / evaninomicin |
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| Research Abstract |
We developed a new murine model of pulmonary infection of Staphylococcus aureus including methicillin-resistant S.aureus (MRSA) by intravenous injection of the bacteria enmeshed in agar beads. Using this model, we investigated the virulence of the organisms in the lung and treatment of syaphylococcal pulmonary infection. We injected 0.20 to 0.25 ml of agar beads (DIFCO) per mouse containing the bacteria suspended in saline in the tail vein. Septic emboli wet-c detected in the peripheral regions of the lungs. MRSA and methicillin-scestible S.aureus (MSSA) of standard strains and clinical isolates were examined. Although several studies have examined staphylococcal toxins and enzymes, their role in staphylicoccal pneumonia are still not clear. Our results suggest that stsphylocoagulase may play a role in the development of blood-borne staphylococcal pneumonia at the proliferation stage in the lungs and staphylococcal alpha-hemolysin may play a role in the development of cavity formation in hematogenous staphylococcal pneumonia.
gamma hemolysin destruct murine neutrophil as leukotoxin. gamma hemolysin productive strain is related histological necrosis of around bacteria, so we are going to examin this phenomenon by using mutant strain or Abs.
We evaluated the effect of evaninomicin, a new oligosaccharide antibiotics, against MRSA in vitro and in vivo Comparison between evaninomicin and vancomycin and teicoplanin showed that the in vitro and in vivo activities of evaninomicin were superior to other two antibiotics. The in vivo activity to MRSA are better than in vitro activity . In addition, evaninomicin is effective late timing of initial treatment compared with vancomycin treated mice. The reason for the difference in activities is the difference of pharmacokinetics of drugs may be a possibility. Evaninomicin could be an effective against resistant bacteria as a newly therapy.
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