Identification and Functional Analysis of Genome Mutations in a Fluoride-resistant Streptococcus Mutans Strain
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It is known that fluoride-resistant microorganisms are different from fluoride-sensitive ones in growth, adherence and metabolic activity. It was hypothesized that these phenotypic differences were due to stable genotypic changes in the fluoride-resistant strains. However, until now, no studies have reported these genotypic changes. The aim of this study is to identify such changes in a fluoride-resistant Streptococcus mutans strain (C180-2FR) using whole-genome shotgun (WGS) sequencing and to examine the potential function of the identified mutations by comparing gene expression between the fluoride-sensitive (C180-2) and C180-2FR strains. We performed 50 bp paired-end Illumina shotgun sequencing for both strains. Through extensive bioinformatic analysis, we were able to identify 8 single nucleotide polymorphisms (SNPs) in the genome of C180-2FR, which were further confirmed by Sanger sequencing. Expression of the genes containing or in proximity to the SNPs in C180-2 and C180-2FR was then quantified by real-time PCR. A gene cluster containing genes coding for fluoride antiporters was up-regulated 10-fold in C180-2FR when compared to that in C180-2, independent of growth phase. Two SNPs are located in this gene cluster, one in its promoter region and the other in its protein-coding region. In addition, one gene, which codes for a putative glycerol uptake facilitator protein, was found to be down-regulated by 60% in C180-2FR at an early growth phase. The promoter region of this gene contained a SNP. No difference in expression was found for the other SNP-containing genes. In summary, using WGS sequencing, we were able to uncover genetic changes in the genome of a fluoride-resistant strain. These findings can provide new insights into the mechanism of microbial fluoride resistance.
Sun Y, Chen Y, Du Q, Zhang J, Xu M, Zheng G Front Microbiol. 2024; 15:1399525.
PMID: 39035442 PMC: 11257928. DOI: 10.3389/fmicb.2024.1399525.
Stockbridge R, Wackett L Nat Commun. 2024; 15(1):4593.
PMID: 38816380 PMC: 11139923. DOI: 10.1038/s41467-024-49018-1.
Li X, Yang J, Shi S, Lan H, Zhao W, Hung W Genes (Basel). 2024; 15(4).
PMID: 38674400 PMC: 11154571. DOI: 10.3390/genes15040466.
Banerjee A, Kang C, An M, Koff B, Sunder S, Kumar A mBio. 2024; 15(5):e0018424.
PMID: 38624207 PMC: 11077948. DOI: 10.1128/mbio.00184-24.
Banerjee A, Kang C, An M, Koff B, Sunder S, Kumar A bioRxiv. 2024; .
PMID: 38293214 PMC: 10827179. DOI: 10.1101/2024.01.18.576223.