Streptomycin dependent Mycobacterium tuberculosis and M. bovis BCG

2014 Fiscal Year Final Research Report

• Project/Area Number: 23790490
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Bacteriology (including Mycology)
• Research Institution: National Institute of Infectious Diseases
• Principal Investigator: HONDA Naoko 国立感染症研究所, 品質保証・管理部, 研究員 (40600911)
• Project Period (FY): 2011-04-28 – 2015-03-31
• Keywords: 結核 / ストレプトマイシン / 休眠

Outline of Final Research Achievements

A SM dependent mutant M. tuberculosis 18b strain has an additional cytosine residue in 16S rRNA and this mutation has been considered to be responsible for SM dependence. As 18b strain replicates in SM containing medium and enters non-replicating state after SM removal even in aerobic cultures, this has been developed as dormancy model to screen new drugs active against non-replicating state in recent years. As BSL3 facility is required to culture 18b and it is not known whether other mutations associated with drug susceptivity exist on 18b, we introduced the same nucleotide insertion on the currently used vaccine strain, M. bovis BCG Tokyo and confirmed that this mutation conferred SM dependence. We further examined the effect of first line drugs on non-replicating SM starved BCG and showed that this strain had phenotypic resistance to isoniazid and will be useful for screening of new drugs in BSL2 facilities.

Free Research Field

細菌　結核