Analysis of the type VI secretion system in Acinetobacter baumannii

2016 Fiscal Year Final Research Report

• Project/Area Number: 25713017
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Bacteriology (including mycology)
• Research Institution: National Institute of Infectious Diseases
• Principal Investigator: Suzuki Masato 国立感染症研究所, その他部局等, 研究員 (70444073)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 薬剤耐性

Outline of Final Research Achievements

Whole genome sequencing of clinical isolates of Acinetobacter baumannii collected in Japan was performed. Comparative genome-wide association studies using A. baumannii isolates collected and isolates in public databases was performed to identify genetic traits of the pandemic lineages. Most of the pandemic lineages conserved an intact type VI secretion system (T6SS) gene cluster, whereas drug-susceptible non-epidemic isolates frequently lacked the gene clusters. Whole-genome single nucleotide polymorphism-based phylogenetic analysis revealed that pandemic international clone II (IC2) isolates are further divided into several distinct genetic clades. Comparative genomic analysis between IC2 isolates identified that each IC2 clade harbors own specific antibacterial T6SS substrates. Given that T6SS-mediated bacterial competition is known to affect conjugative transfer of drug resistance genes-carrying plasmids, T6SS could be an important key factor for development of high-risk clones.

Free Research Field

細菌学