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Updated: Jun 11, 2026
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Subtyping of Campylobacter jejuni ssp. doylei Isolates Using Mass Spectrometry-based PhyloProteomics MSPP
Published on: October 30, 2016
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Genomic Analysis Points to Multiple Genetic Mechanisms for Non-Transformable Campylobacter jejuni ST-50
Craig T Parker1, David A Villafuerte2, William G Miller1
1Produce Safety and Microbiology Research Unit, Agricultural Research Service, United States Department of Agriculture, Albany, CA 94710, USA.
Microorganisms
|February 24, 2024
Summary
Many Campylobacter strains lose their natural ability to transform DNA due to specific genetic changes. This loss of competence hinders the spread of antimicrobial resistance (AMR) genes in these bacteria.
Area of Science:
- Microbiology
- Genomics
- Bacterial Genetics
Background:
- Campylobacter jejuni and Campylobacter coli are naturally competent bacteria, capable of DNA uptake and transformation.
- Natural competence facilitates genetic exchange, including the spread of antimicrobial resistance (AMR) genes.
Purpose of the Study:
- To identify non-transformable Campylobacter strains from domestic animals.
- To investigate the genetic mechanisms underlying the loss of natural competence in Campylobacter.
- To assess the impact of non-transformability on AMR gene transfer and Campylobacter evolution.
Main Methods:
- Isolation and characterization of non-transformable Campylobacter jejuni and Campylobacter coli strains.
- Genomic analysis to identify genetic markers associated with non-transformability.
- Prevalence studies of genetic markers in global Campylobacter jejuni ST-50 strains.
Main Results:
- Identified non-transformable strains with functional bacteriophage DNase genes and mutations in the cts DNA-uptake system.
- Found a high prevalence of non-transformability in US-based Campylobacter jejuni ST-50 strains, linked to specific genetic markers.
- Observed distinct evolutionary patterns and strong selective pressure for loss of competence in ST-50 strains, particularly in agricultural settings.
Conclusions:
- Genetic factors like bacteriophage DNases and mutations in the DNA-uptake system cause non-transformability in Campylobacter.
- Non-transformability restricts the dissemination of AMR determinants, influencing Campylobacter's evolution.
- The loss of competence in Campylobacter jejuni ST-50 strains, especially in agricultural environments, highlights significant evolutionary pressures.
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