Impacts of virulence factors of Streptococcus mutans isolates on the pathogenesis of acute vaginitis

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Mohammed Sh. Jebur
Keyword(s):  
Streptococcus Mutans ◽  
Virulence Factors

Contribution of Streptococcus Mutans Virulence Factors and Saliva Agglutinating Capacity to Caries Susceptibility in Children: A Preliminary Study

2018 ◽  
Vol 42 (3) ◽  
pp. 188-194 ◽  
Author(s):  
Eloa Ramalho de Camargo ◽  
Jonas Bitencourt Canalle ◽  
Rodriguo Capozzoli ◽  
Tanila Wood dos Santos ◽  
Margareth Bulhman Ballini ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Virulence Factors ◽  
Low Income ◽  
Acid Tolerance ◽  
Adhesive Properties ◽  
Dental Biofilm ◽  
Gene Coding ◽  
Preliminary Study ◽  
Low Income Families ◽  
Caries Lesions

Background: Many factors contribute to caries development in humans, such as diet, host factors – including different saliva components – and the presence of acidogenic bacteria in the dental biofilm, particularly Streptococcus mutans (S. mutans). Despite the influence of S. mutans in caries, this bacterium is also prevalent among healthy individuals, suggesting the contribution of genetic variation on the cariogenic potential. Based on this hypothesis, the present work investigated the influence of S. mutans virulence factors and saliva agglutinating capacity on caries susceptibility in children. Study design: Saliva samples of 24 children from low income families (13 caries-free and 11 caries-active individuals) were collected and tested for their ability to agglutinate S. mutans. The bacteria were isolated from these samples and analyzed for the presence of the gene coding for mutacin IV (mut IV). Biofilm formation and acid tolerance were also investigated in both groups (caries-free and caries-active). Results: Saliva samples from caries-free children showed an increased capacity to agglutinate S. mutans (p=0.006). Also, bacteria isolated from the caries-free group formed less biofilm when compared to the caries-active group (p=0.04). The presence of mut IV gene did not differ between bacteria isolated from caries-free and caries-active individuals, nor did the ability to tolerate an acidic environment, which was the same for the two groups. Conclusions: Altogether, the results suggest that the adhesive properties of S. mutans and the agglutinating capacity of the saliva samples correlated with the presence of caries lesions in children.

scholarly journals Effects of compounds found in Nidus Vespae on the growth and cariogenic virulence factors of Streptococcus mutans

2012 ◽  
Vol 167 (2) ◽  
pp. 61-68 ◽  
Author(s):  
Xiaoxu Guan ◽  
Yi Zhou ◽  
Xue Liang ◽  
Jin Xiao ◽  
Libang He ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Virulence Factors

scholarly journals Pleiotropic Regulation of Virulence Genes in Streptococcus mutans by the Conserved Small Protein SprV

2017 ◽  
Vol 199 (8) ◽  
Author(s):  
Manoharan Shankar ◽  
Mohammad S. Hossain ◽  
Indranil Biswas
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Normal Growth ◽  
Hypothetical Protein ◽  
Bacteriocin Production ◽  
Transcript Levels ◽  
Content Type ◽  
Tooth Surfaces

ABSTRACT Streptococcus mutans, an oral pathogen associated with dental caries, colonizes tooth surfaces as polymicrobial biofilms known as dental plaque. S. mutans expresses several virulence factors that allow the organism to tolerate environmental fluctuations and compete with other microorganisms. We recently identified a small hypothetical protein (90 amino acids) essential for the normal growth of the bacterium. Inactivation of the gene, SMU.2137, encoding this protein caused a significant growth defect and loss of various virulence-associated functions. An S. mutans strain lacking this gene was more sensitive to acid, temperature, osmotic, oxidative, and DNA damage-inducing stresses. In addition, we observed an altered protein profile and defects in biofilm formation, bacteriocin production, and natural competence development, possibly due to the fitness defect associated with SMU.2137 deletion. Transcriptome sequencing revealed that nearly 20% of the S. mutans genes were differentially expressed upon SMU.2137 deletion, thereby suggesting a pleiotropic effect. Therefore, we have renamed this hitherto uncharacterized gene as sprV (streptococcal pleiotropic regulator of virulence). The transcript levels of several relevant genes in the sprV mutant corroborated the phenotypes observed upon sprV deletion. Owing to its highly conserved nature, inactivation of the sprV ortholog in Streptococcus gordonii also resulted in poor growth and defective UV tolerance and competence development as in the case of S. mutans. Our experiments suggest that SprV is functionally distinct from its homologs identified by structure and sequence homology. Nonetheless, our current work is aimed at understanding the importance of SprV in the S. mutans biology. IMPORTANCE Streptococcus mutans employs several virulence factors and stress resistance mechanisms to colonize tooth surfaces and cause dental caries. Bacterial pathogenesis is generally controlled by regulators of fitness that are critical for successful disease establishment. Sometimes these regulators, which are potential targets for antimicrobials, are lost in the genomic context due to the lack of annotated homologs. This work outlines the regulatory impact of a small, highly conserved hypothetical protein, SprV, encoded by S. mutans. We show that SprV affects the transcript levels of various virulence factors required for normal growth, biofilm formation, stress tolerance, genetic competence, and bacteriocin production.

Effects of Ag/ZnO nanocomposite at sub-minimum inhibitory concentrations on virulence factors of Streptococcus mutans

2020 ◽  
Vol 111 ◽  
pp. 104640
Author(s):  
Qiaomu Huang ◽  
Shilei Wang ◽  
Yujun Sun ◽  
Cheng Shi ◽  
Hao Yang ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Virulence Factors ◽  
Minimum Inhibitory Concentrations

Lemon myrtle extract inhibits lactate production by Streptococcus mutans

2021 ◽  
Vol 85 (10) ◽  
pp. 2185-2190
Author(s):  
Yukinori Yabuta ◽  
Yui Sato ◽  
Arisu Miki ◽  
Ryuta Nagata ◽  
Tomohiro Bito ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Dental Caries ◽  
Oral Cavity ◽  
Streptococcus Mutans ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Tooth Enamel ◽  
Lactate Production ◽  
Tooth Decay ◽  
Lactate Dehydrogenase Activity

ABSTRACT Backhousia citriodora (lemon myrtle) extract has been found to inhibit glucansucrase activity, which plays an important role in biofilm formation by Streptococcus mutans. In addition to glucansucrase, various virulence factors in S. mutans are involved in the initiation of caries. Lactate produced by S. mutans demineralizes the tooth enamel. This study investigated whether lemon myrtle extract can inhibit S. mutans lactate production. Lemon myrtle extract reduced the glycolytic pH drop in S. mutans culture and inhibited lactate production by at least 46%. Ellagic acid, quercetin, hesperetin, and myricetin, major polyphenols in lemon myrtle, reduced the glycolytic pH drop and lactate production, but not lactate dehydrogenase activity. Furthermore, these polyphenols reduced the viable S. mutans cell count. Thus, lemon myrtle extracts may inhibit S. mutans-mediated acidification of the oral cavity, thereby preventing dental caries and tooth decay.

Virulence Factors of Mutans Streptococci: Role of Molecular Genetics

1993 ◽  
Vol 4 (2) ◽  
pp. 159-176 ◽  
Author(s):  
Howard K. Kuramitsu
Keyword(s):  
Dental Caries ◽  
Molecular Genetics ◽  
Streptococcus Mutans ◽  
Virulence Factors ◽  
Molecular Genetic ◽  
Mutans Streptococci ◽  
Mutant Analysis ◽  
Novel Approaches

Biochemical approaches were utilized initially to identify the virulence factors of the mutans streptococci (primarily Streptococcus mutans and S. sobrinu). Traditional mutant analysis of these organisms further suggested the important role of several of these factors in cariogenicity. However, because these mutations were not clearly defined, the utilization of cloned genes was necessary to verify their significance. The introduction of molecular genetic approaches for characterizing these factors has led not only to a clearer understanding of the role of these virulence factors in cariogenicity but has also suggested some novel approaches for reducing further the incidence of dental caries.

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