mltG gene deletion mitigated virulence potential of Streptococcus mutans: An in-vitro, ex-situ and in-vivo study

AMB Express

Original Article

Yadya M. Chawla¹  Asad U. Khan²  Sahar Zaidi²  Khursheed Ali² 

[1] ICGEB-Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India;Medical Microbiology and Molecular Biology Laboratory, Interdisciplinary, Biotechnology Unit, Aligarh Muslim University, 202002, Aligarh, UP, India;

关键词: S. mutans;    mltG;    Virulence;    Biofilm;    Proteins;    Dental caries;   

DOI  :  10.1186/s13568-023-01526-x

 received in 2023-02-03, accepted in 2023-02-07,  发布年份 2023

来源: Springer

【 摘 要 】

Bacterial cells are surrounded by a peptidoglycan (PG) cell wall, which is essential for cell integrity and intrinsic biogenesis pathways; hence, the cell wall is a potential target for several antibiotics. Among several lytic transglycosylases (LTs), the mltG gene plays a crucial role in the synthesis of peripheral PG. It localises the re-modelled PGs for septum formation and cleavage across the bacterial cell wall during daughter cells separation. However, the role of mltG gene in bacterial virulence, particularly in Gram-positive bacteria during dentine biofilm and caries development, has remained unexplored. Hence, we exploited Gram-positive Streptococcus mutans cells for the very first time to construct a mltG knock-out bacterial strain, e.g., ΔmltG S. mutans. Systematic comparative investigations revealed that doubling time (Td), survival, enzymatic efficiencies, pH tolerance, bio-synthesise of lipid, proteins and DNA, biofilm formation and dentine lesions were significantly (p < 0.001) compromised in case of ΔmltG S. mutans than wild type strain. The qRT-PCR based gene expression profiling revealed that transcriptional expression of critically important genes involved in biofilm, metabolism, and stress response were dysregulated in the mutant. Besides, an incredible reduction in dentine caries development was found in the molar teeth of Wistar rats and also in human extracted teeth. Concisely, these trends obtained evidently advocated the fact that the deletion of mltG gene can be a potential target to impair the S. mutans virulence through severe growth retardation, thereby reducing the virulence potential of S. mutans.Graphical Abstract

【 授权许可】

CC BY   
© The Author(s) 2023

【 图 表 】

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