The Yersinia high-pathogenicity island (HPI): evolutionary and functional aspects

Area of Science:

• Microbiology
• Genomics
• Molecular Biology

Background:

• The high-pathogenicity island (HPI) is a mobile genetic element critical for virulence in Yersinia species and certain Escherichia coli pathotypes.
• Unlike most genomic islands, HPI is widely distributed within the Enterobacteriaceae family.

Purpose of the Study:

• To elucidate the genetic makeup and mobility mechanisms of the high-pathogenicity island.
• To understand the role of HPI in bacterial fitness and pathogenicity.
• To investigate the conjugative transfer of HPI, particularly in E. coli.

Main Methods:

• Bioinformatic analysis of HPI genetic components.
• Characterization of HPI integration and excision mechanisms.
• Investigation of HPI transfer in E. coli strain ECOR31, including its potential as an integrative and conjugative element (ICE).

Main Results:

• HPI encodes a mobility module (integrase, excisionase) and a functional part for yersiniabactin biosynthesis and uptake.
• HPI integrates into specific asn tRNA genes (attB sites) in Yersinia pestis and E. coli.
• A unique HPI in E. coli ECOR31 exhibits characteristics of an ICE, suggesting a conjugative transfer mechanism.

Conclusions:

• The HPI possesses a sophisticated genetic system for integration, excision, and dissemination.
• Conjugative transfer, potentially as an ICE (ICEEcl), is a proposed mechanism for HPI spread among Enterobacteriaceae.
• Understanding HPI mobility is key to comprehending bacterial pathogenicity and evolution.