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Genomic DNA in Prokaryotes

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A Non-Coding Small RNA MicC Contributes to Virulence in Outer Membrane Proteins in Salmonella Enteritidis

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Why Might Bacterial Pathogens Have Small Genomes?

Lucy A Weinert¹, John J Welch²

¹Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK.

Trends in Ecology & Evolution

|October 22, 2017

Summary

This summary is machine-generated.

Many disease-causing bacteria have smaller genomes than their harmless relatives. This review explores reductive genome evolution and its link to bacterial pathogenicity, finding multiple reduction processes may act concurrently.

Keywords:

antivirulence genes population genetics reductive genome evolution

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Area of Science:

Microbiology
Evolutionary Biology
Genomics

Background:

Pathogenic bacteria often exhibit reduced genome sizes compared to their nonpathogenic counterparts.
Genome reduction is a common phenomenon in bacterial evolution, particularly in host-associated species.

Purpose of the Study:

To review the evidence supporting the association between smaller bacterial genomes and pathogenicity.
To summarize the population genetic mechanisms driving reductive genome evolution in pathogens.
To explore the connection between genome reduction processes and the emergence of bacterial virulence.

Main Methods:

Literature review of studies on bacterial genome evolution and pathogenicity.
Analysis of population genetic theories related to genome reduction.
Synthesis of evidence linking specific reduction mechanisms to bacterial disease.

Main Results:

A consistent association exists between reduced genome size and increased pathogenicity in bacteria.
Several population genetic processes, including mutation bias and selection for smaller genomes, contribute to reductive evolution.
Evidence suggests multiple modes of genome reduction can operate simultaneously within a single bacterial lineage.
These processes are frequently observed in bacterial pathogens, influencing their virulence strategies.

Conclusions:

Reductive genome evolution is a significant factor in the adaptation of bacteria to pathogenic lifestyles.
The observed genome reduction in pathogens is driven by predictable population genetic forces.
While multiple reduction mechanisms may act, they do not necessarily imply a single, overarching process driving pathogenicity.