2014 Fiscal Year Final Research Report
Investigation of infection of Staphylococcus aureus controlled by network for stringent regulation
| Project/Area Number |
24791029
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Infectious disease medicine
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| Research Institution | Juntendo University |
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Principal Investigator |
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Keywords | MRSA / バンコマイシン耐性 / 黄色ブドウ球菌 / 院内感染症 / slow-VISA / VISA |
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| Outline of Final Research Achievements |
The Vancomycin(VCM)-intermediate Staphylococcus aureus (VISA) strains generally grow slowly, and form colonies on VCM-containing agar-plates after 48 h of incubation in population analysis. However, we have found a curious group of VISA strains whose colonies appear only after 72 h incubation. We designated them ‘slow-VISA’(sVISA) . As compared to extant VISA strains, sVISA strains had prolonged doubling-times and unstable resistance and growth phenotype. Whole genome sequencing of a representative sVISA strain Mu3-6R-P, which was obtained from hVISA strain Mu3 by selection with 6 mg/L of VCM, revealed a single mutation (R512P), in the rpoB gene encoding beta subunit of RNA polymerase (RNAP), as the responsible mutation for the sVISA phenotype . The sVISA strain had VCM MIC of 16 mg/L. However, after two days of drug-free passage, it generated large colonies, which showed hVISA phenotype carrying mutations (R512L)
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| Free Research Field |
感染症 微生物
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