Regulation of (p)ppGpp and Its Homologs on Environmental Adaptation, Survival, and Pathogenicity of Streptococci

Zhāng, Téngfēi; Zhu, Jiawen; Xu, Jiajia; Shao, Hongxia; Zhou, Rui

doi:10.3389/fmicb.2020.01842

Cited by 7 publications

(8 citation statements)

References 53 publications

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“…The same trends were also observed for TCS‐7 (SMU_1037‐1038c; HKPhoR and RR‐YcbL) between sucrose and lactose versus xylitol (Figure 5c), whose exact role has not been described yet. The opposite trends were observed in the regulation of TCS‐4 (SMU_927‐928; HK‐KinF and RR‐LlrF) involved in acid tolerance and (p)ppGpp metabolism in S. mutans (Zhang et al., 2020). The specific upregulation of the four‐component regulatory system TCS‐9 (SMU_1963‐1966c), including HK‐LevS, RR‐LevR, and carbohydrate‐binding proteins LevQT, in the cells growing with sucrose was consistent with its function in regulating fructan hydrolase genes ( fruA ) (Zeng et al., 2011) (Figure 5c).…”

Section: Resultsmentioning

confidence: 99%

Gene expression and metabolic activity of Streptococcus mutans during exposure to dietary carbohydrates glucose, sucrose, lactose, and xylitol

Jurakova,

Farková,

Kucera

et al. 2023

Molecular Oral Microbiology

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Recent RNA sequencing studies have given us a deeper insight into the cariogenic impact of carbohydrate sources in the bacterium Streptococcus mutans, the principal microbial agent in dental caries etiopathogenesis. The process of dental caries development is facilitated by the ability of this bacterium to ferment some carbohydrates into organic acids contributing to a pH decrease in the oral cavity and the demineralization of the hard tissues of the tooth. Furthermore, in dental caries progression, biofilm formation, which starts and ends with free planktonic cells, plays an important role and has several unique properties called virulence factors. The most cariogenic carbohydrate is sucrose, an easily metabolizable source of energy that induces the acidification and synthesis of glucans, forming typical bacterial cell clumps. We used multifaceted methodological approaches to compare the transcriptomic and metabolomic profiles of S. mutans growing in planktonic culture on preferred and nonpreferred carbohydrates and in fasting conditions. Streptococcus mutans in a planktonic culture with lactose produced the same pH drop as glucose and sucrose. By contrast, xylitol and lactose showed high effectiveness in regulating intracellular polysaccharide metabolism, cell wall structure, and overall virulence involved in the initial phase of biofilm formation and structure but with an opposite pattern compared with sucrose and glucose. Our results confirmed the recent findings that xylitol and lactose play a vital role in biofilm structure. However, they do not reduce its formation, which is related to the creation of a cariogenic environment.

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Section: Resultsmentioning

confidence: 99%

Gene expression and metabolic activity of Streptococcus mutans during exposure to dietary carbohydrates glucose, sucrose, lactose, and xylitol

Jurakova,

Farková,

Kucera

et al. 2023

Molecular Oral Microbiology

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“…To save energy and nutrients, the stringent response decreases RNA synthesis [ 197 ]. It is signalled by the alarmone (p)ppGpp [ 197 , 198 ]. In S. suis , (p)ppGpp is synthesized by two different proteins, RelA and RelQ [ 197 , 199 ].…”

Section: Role Of S Suis Biofilms In Antimicrobial ...mentioning

confidence: 99%

“…Together, down regulation of capsule synthesis and over expression of adhesins, improve the adhesion to and invasion of host epithelial cells [ 200 ]. The response induced by (p)ppGpp helps S. suis to evade phagocytosis by host macrophages [ 199 ], presumably by promoting biofilm formation [ 198 ]. The involvement of the stringent response in antibiotic tolerance and resistance has been shown in many bacteria (reviewed in Hobbs and Boraston [ 201 ]).…”

Section: Role Of S Suis Biofilms In Antimicrobial ...mentioning

confidence: 99%

How Streptococcus suis escapes antibiotic treatments

Uruén

Garcia

Fraile

et al. 2022

Vet Res

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Streptococcus suis is a zoonotic agent that causes sepsis and meningitis in pigs and humans. S. suis infections are responsible for large economic losses in pig production. The lack of effective vaccines to prevent the disease has promoted the extensive use of antibiotics worldwide. This has been followed by the emergence of resistance against different classes of antibiotics. The rates of resistance to tetracyclines, lincosamides, and macrolides are extremely high, and resistance has spread worldwide. The genetic origin of S. suis resistance is multiple and includes the production of target-modifying and antibiotic-inactivating enzymes and mutations in antibiotic targets. S. suis genomes contain traits of horizontal gene transfer. Many mobile genetic elements carry a variety of genes that confer resistance to antibiotics as well as genes for autonomous DNA transfer and, thus, S. suis can rapidly acquire multiresistance. In addition, S. suis forms microcolonies on host tissues, which are associations of microorganisms that generate tolerance to antibiotics through a variety of mechanisms and favor the exchange of genetic material. Thus, alternatives to currently used antibiotics are highly demanded. A deep understanding of the mechanisms by which S. suis becomes resistant or tolerant to antibiotics may help to develop novel molecules or combinations of antimicrobials to fight these infections. Meanwhile, phage therapy and vaccination are promising alternative strategies, which could alleviate disease pressure and, thereby, antibiotic use.

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“…Such features result in biofilms inducing a lower host inflammatory response compared with their planktonic counterparts, and facilitate immune escape [ 6 ]. Bacteria inside the biofilm initiate the stringent response, enter dormancy, express efflux pumps and transfer drug-resistant genes horizontally, all of which contribute to resistance against adverse stressors [ 7 ]. Hence, the biofilm mode of growth is often associated with persistent infection and acts as a reservoir for recurrent infection.…”

Section: Introductionmentioning

confidence: 99%

The morphology and metabolic changes of Actinobacillus pleuropneumoniae during its growth as a biofilm

Zhang

Lü

Han

et al. 2023

Vet Res

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Actinobacillus pleuropneumoniae is an important swine respiratory pathogen. Previous studies have suggested that growth as a biofilm is a natural state of A. pleuropneumoniae infection. To understand the survival features involved in the biofilm state, the growth features, morphology and gene expression profiles of planktonic and biofilm A. pleuropneumoniae were compared. A. pleuropneumoniae in biofilms showed reduced viability but maintained the presence of extracellular polymeric substances (EPS) after late log-phase. Under the microscope, bacteria in biofilms formed dense aggregated structures that were connected by abundant EPS, with reduced condensed chromatin. By construction of Δpga and ΔdspB mutants, polymeric β-1,6-linked N-acetylglucosamine and dispersin B were confirmed to be critical for normal biofilm formation. RNA-seq analysis indicated that, compared to their planktonic counterparts, A. pleuropneumoniae in biofilms had an extensively altered transcriptome. Carbohydrate metabolism, energy metabolism and translation were significantly repressed, while fermentation and genes contributing to EPS synthesis and translocation were up-regulated. The regulators Fnr (HlyX) and Fis were found to be up-regulated and their binding motifs were identified in the majority of the differentially expressed genes, suggesting their coordinated global role in regulating biofilm metabolism. By comparing the transcriptome of wild-type biofilm and Δpga, the utilization of oligosaccharides, iron and sulfur and fermentation were found to be important in adhesion and aggregation during biofilm formation. Additionally, when used as inocula, biofilm bacteria showed reduced virulence in mouse, compared with planktonic grown cells. Thus, these results have identified new facets of A. pleuropneumoniae biofilm maintenance and regulation.

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Regulation of (p)ppGpp and Its Homologs on Environmental Adaptation, Survival, and Pathogenicity of Streptococci

Cited by 7 publications

References 53 publications

Gene expression and metabolic activity of Streptococcus mutans during exposure to dietary carbohydrates glucose, sucrose, lactose, and xylitol

Gene expression and metabolic activity of Streptococcus mutans during exposure to dietary carbohydrates glucose, sucrose, lactose, and xylitol

How Streptococcus suis escapes antibiotic treatments

The morphology and metabolic changes of Actinobacillus pleuropneumoniae during its growth as a biofilm

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