Page 160 - Ebook-Book JCMS 2025

mab_2009 is Essential for Mycobacterium abscessus Cell
Division and Growth Across Different Environmental Conditions
Azizah Fitriana Nurul Ilmi1, Pornchai Kaewsapsak2, Suwatchareeporn Rotchewaphan3*
1 Medical Sciences Program, Faculty of Medicine, Chulalongkorn University
2 Department of Biochemistry, Faculty of Medicine, Chulalongkorn University
3 Department of Microbiology, Faculty of Medicine, Chulalongkorn University
Introduction: *Corresponding Author E-mail: suwatchareeporn.r@chula.ac.th
Abstract
Cell division is essential for bacterial survival and a target for antimicrobial development.
Mycobacterium abscessus is a highly drug-resistant pathogen and a leading cause of
non-tuberculous mycobacterial infections, yet remains understudied. FtsZ, a key cytoskeletal
protein required for bacterial growth, has been identified in M. abscessus, but its
specific role in this organism’s cell division has not been fully explored, limiting our
understanding of potential therapeutic strategies against this clinically significant pathogen.
Objectives: This project aims to evaluate the effects of gene knockdown of mab_2009, a ftsZ homolog
on viability and cell division of M. abscessus.
Methods: The CRISPR interference (CRISPRi) construct was assembled using the pLJR962 plasmid
and subsequently electroporated into M. abscessus ATCC 199777 strain. Essentiality
was tested by inducing bacteria in Middlebrook 7H10 media supplemented with various
concentration of anhydrotetracycline. To measure the effect of knockdown on bacterial
growth dynamic, bacterial growth was monitored over a period of 3 days in both
Middlebrook 7H9 media and phostate buffer saline (PBS) 1x media. Cellular morphology
was assessed using the acid fast staining method and visualized under light microscopy.
Results: The ftsZ gene is essential for the growth of M. abscessus, as gene knockdown resulted
in cell death when induced with anhydrotetracycline 500 ng/mL in middlebrook 7H10.
Growth dynamic revealed the decreased in cell growth occurred in 12 hours of induction
with ATc 500 ng/mL in middlebrook 7H9 and PBS 1x media.Morphological evaluation of the
surviving cells revealed elongated bacterial cells in 7H9 media compared to control, indicating
a disruption in normal cell division processes.
Conclusion: As observed in other bacteria, the ftsZ homolog in M. abscessus is essential for cell viability
and cell division in both normal laboratory and stressed conditions, highlighting its
potential as a promising target for future drug development.
158 Joint Conference in Medical Sciences 2025