Smooth-to-rough morphotype switching, a mechanism of phage resistance in <i> <i>Mycobacterium</i> abscessus </i>

J Jun Hao Liew (A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13) A Ayuni Norman (A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13) M Morgane Illouz (Centre National de la Recherche Scientifique, UMR 9004, Institut de Recherche en Infectiologie de Montpellier, Université de Montpellier) T Teck-Hui Teo (A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13) R Riccardo Delli Ponti (A*STAR Bioinformatics Institute, Agency for Science, Technology and Research) C Claire Hamela L Lalit Mohan (A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13) R Renee Lew (Lee Kong Chian School of Medicine, Experimental Medicine Building, Nanyang Technological University) C Chanvutha Ron (A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13) K Kay En Low (Electron Microscopy Unit, Microscopy Cluster, Yong Loo Lin School of Medicine, National University of Singapore) W Wassim Daher (Centre National de la Recherche Scientifique, UMR 9004, Institut de Recherche en Infectiologie de Montpellier, Université de Montpellier) A Aryeh Chiam (A*STAR Bioinformatics Institute, Agency for Science, Technology and Research) J Joanna Maw (Lee Kong Chian School of Medicine, Experimental Medicine Building, Nanyang Technological University) Y Yan Sun R Ria Sorayah (Lee Kong Chian School of Medicine, Experimental Medicine Building, Nanyang Technological University) S Stefan H. Oehlers (A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13) B Byung Woo Jhun (Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine) J Jeanette W. P. Teo (Department of Laboratory Medicine, National University Hospital) A Adeline Goulet I Isabelle Bonne (Electron Microscopy Unit, Microscopy Cluster, Yong Loo Lin School of Medicine, National University of Singapore) R René Wintjens K Kevin Pethe R Roland G. Huber (A*STAR Bioinformatics Institute, Agency for Science, Technology and Research) L Laurent Kremer P Pablo Bifani (A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13)

Abstract

Mycobacterium abscessus infections represent a growing global health concern due to their severe pathology and difficulty of treatment, largely driven by their intrinsic antimicrobial resistance. While phage therapy has emerged as a promising alternative approach, studies have predominantly focused on glycopeptidolipids (GPL)-deficient M. abscessus rough variants instead of the GPL-producing smooth variants predominant in Asia. Here, we aim to develop phage cocktails targeting both smooth and rough morphotypes. In the process, we found that phage treatment of smooth variants can select for rough morphotype switching from smooth-to-rough variants in vitro and in vivo, resulting in phage resistance associated with mutations within the GPL biosynthetic locus. We validated our findings in vitro and in vivo, suggesting a two-layered phage combination that surpasses single-phage treatments and potentially improves clinical phage cocktail strategies. This work underlines the need to better understand mechanisms of phage resistance in phage therapy and associated potential adverse effects and solutions. Phage resistance in M. abscessus through morphotype switching is clinically significant, as it may complicate treatment outcomes but could be averted with proper phage combinations.

Article Details

Volume / Issue Vol. 123, Issue 11
Published March 17, 2026
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (25)

J

Jun Hao Liew

A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13

A

Ayuni Norman

A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13

M

Morgane Illouz

Centre National de la Recherche Scientifique, UMR 9004, Institut de Recherche en Infectiologie de Montpellier, Université de Montpellier

T

Teck-Hui Teo

A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13

R

Riccardo Delli Ponti

A*STAR Bioinformatics Institute, Agency for Science, Technology and Research

C

Claire Hamela

L

Lalit Mohan

A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13

R

Renee Lew

Lee Kong Chian School of Medicine, Experimental Medicine Building, Nanyang Technological University

C

Chanvutha Ron

A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13

K

Kay En Low

Electron Microscopy Unit, Microscopy Cluster, Yong Loo Lin School of Medicine, National University of Singapore

W

Wassim Daher

Centre National de la Recherche Scientifique, UMR 9004, Institut de Recherche en Infectiologie de Montpellier, Université de Montpellier

A

Aryeh Chiam

A*STAR Bioinformatics Institute, Agency for Science, Technology and Research

J

Joanna Maw

Lee Kong Chian School of Medicine, Experimental Medicine Building, Nanyang Technological University

Y

Yan Sun

R

Ria Sorayah

Lee Kong Chian School of Medicine, Experimental Medicine Building, Nanyang Technological University

S

Stefan H. Oehlers

A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13

B

Byung Woo Jhun

Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine

J

Jeanette W. P. Teo

Department of Laboratory Medicine, National University Hospital

A

Adeline Goulet

I

Isabelle Bonne

Electron Microscopy Unit, Microscopy Cluster, Yong Loo Lin School of Medicine, National University of Singapore

R

René Wintjens

K

Kevin Pethe

R

Roland G. Huber

A*STAR Bioinformatics Institute, Agency for Science, Technology and Research

L

Laurent Kremer

P

Pablo Bifani

A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos #05-13