Phage resistance profiling identifies new genes required for biogenesis and modification of the corynebacterial cell envelope

  1. Amelia C McKitterick
  2. Thomas G Bernhardt  Is a corresponding author
  1. Howard Hughes Medical Institute, Harvard University, United States


Bacteria of the order Corynebacteriales including pathogens such as Mycobacterium tuberculosi and Corynebacterium diphtheriae are characterized by their complex, multi-layered envelope. In addition to a peptidoglycan layer, these organisms possess an additional polysaccharide layer made of arabinogalactan and an outer membrane layer composed predominantly of long-chain fatty acids called mycolic acids. This so-called mycolata envelope structure is both a potent barrier against antibiotic entry into cells and a target of several antibacterial therapeutics. A better understanding of the mechanisms underlying mycolata envelope assembly therefore promises to reveal new ways of disrupting this unique structure for the development of antibiotics and antibiotic potentiators. Because they engage with receptors on the cell surface during infection, bacteriophages have long been used as tools to uncover important aspects of host envelope assembly. However, surprisingly little is known about the interactions between Corynebacteriales phages and their hosts. We therefore made use of the phages Cog and CL31 that infect Corynebacterium glutamicum (Cglu), a model member of the Corynebacteriales, to discover host factors important for phage infection. A high-density transposon library of Cglu was challenged with these phages followed by transposon sequencing to identify resistance loci. The analysis identified an important role for mycomembrane proteins in phage infection as well as components of the arabinogalactan and mycolic acid synthesis pathways. Importantly, the approach also implicated a new gene (cgp_0396) in the process of arabinogalactan modification and identified a conserved new factor (AhfA, Cpg_0475) required for mycolic acid synthesis in Cglu.

Data availability

Sequencing data generated from this study have been deposited in the NCBI Sequence Read Archive under BioProject PRJNA834153. All other data generated or analyzed during this study are provided in the manuscript and supporting files.

The following data sets were generated
The following previously published data sets were used

Article and author information

Author details

  1. Amelia C McKitterick

    Department of Microbiology, Howard Hughes Medical Institute, Harvard University, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Thomas G Bernhardt

    Department of Microbiology, Howard Hughes Medical Institute, Harvard University, Boston, United States
    For correspondence
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-3566-7756


Howard Hughes Medical Institute

  • Thomas G Bernhardt

Life Sciences Research Foundation

  • Amelia C McKitterick

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Bavesh D Kana, University of the Witwatersrand, South Africa

Version history

  1. Received: May 4, 2022
  2. Preprint posted: May 17, 2022 (view preprint)
  3. Accepted: October 23, 2022
  4. Accepted Manuscript published: November 9, 2022 (version 1)
  5. Version of Record published: November 17, 2022 (version 2)


© 2022, McKitterick & Bernhardt

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.


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  1. Amelia C McKitterick
  2. Thomas G Bernhardt
Phage resistance profiling identifies new genes required for biogenesis and modification of the corynebacterial cell envelope
eLife 11:e79981.

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