CRISPR Contributes to Adhesion, Invasion, and Biofilm Formation in Streptococcus agalactiae by Repressing Capsular Polysaccharide Production

Nie, Meng; Dong, Yuhao; Cao, Qing; Zhao, Dan; Ji, Shuting; Huang, Hao; Jiang, Mingguo; Liu, Guangjin; Liu, Yongjie

doi:10.1128/spectrum.02113-21

Cited by 10 publications

(9 citation statements)

References 57 publications

(69 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been previously reported that CRISPR-Cas systems in SEZ likely play a crucial role in maintaining the stability of the bacterial genome (Waller and Robinson, 2013). Additionally, these CRISPR-Cas systems have been characterized in certain pathogenic bacteria, where they act as significant virulence factors, promoting biofilm formation and enhancing virulence (Nie et al, 2022). Cui et al (2020) reported that CRISPR-cas3 of Salmonella plays a role in the regulation of QS genes, which are essential for the biofilm formation and invasion of bacteria.…”

Section: Discussionmentioning

confidence: 99%

Characterization of AI-2/LuxS quorum sensing system in biofilm formation, pathogenesis of Streptococcus equi subsp. zooepidemicus

Xie,

Zhang,

Guo

et al. 2024

Front. Cell. Infect. Microbiol.

View full text Add to dashboard Cite

Streptococcus equi subsp. zooepidemicus (SEZ) is an opportunistic pathogen of both humans and animals. Quorum sensing (QS) plays an important role in the regulation of bacterial group behaviors. The aim of this study was to characterize the LuxS in SEZ and evaluate its impact on biofilm formation, pathogenesis and gene expression. The wild-type SEZ and its LuxS mutant (ΔluxS) were examined for growth, biofilm formation, virulence factors, and transcriptomic profiles. Our results showed that LuxS deficiency did not affect SEZ hemolytic activity, adhesion or capsule production. For biofilm assay demonstrated that mutation in the luxS gene significantly enhances biofilm formation, produced a denser biofilm and attached to a glass surface. RAW264.7 cell infection indicated that ΔluxS promoted macrophage apoptosis and pro-inflammatory responses. In mice infection, there was no significant difference in mortality between SEZ and ΔluxS. However, the bacterial load in the spleen of mice infected with ΔluxS was significantly higher than in those infected with SEZ. And the pathological analysis further indicated that spleen damage was more severe in the ΔluxS group. Moreover, transcriptomics analysis revealed significant alterations in carbon metabolism, RNA binding and stress response genes in ΔluxS. In summary, this study provides the first evidence of AI-2/LuxS QS system in SEZ and reveals its regulatory effects on biofilm formation, pathogenicity and gene expression.

show abstract

Section: Discussionmentioning

confidence: 99%

Characterization of AI-2/LuxS quorum sensing system in biofilm formation, pathogenesis of Streptococcus equi subsp. zooepidemicus

Xie,

Zhang,

Guo

et al. 2024

Front. Cell. Infect. Microbiol.

View full text Add to dashboard Cite

show abstract

“…Dong et al showed that isogenic deletion of the CRISPR array in a piscine GBS isolate led to upregulation of 236 genes and downregulation of 77 genes, with resultant virulence attenuation in in vitro and in vivo models of colonization and infection 32 . A subsequent examination of CRISPR array deficient GBS demonstrated significant upregulation of capsule production in the mutant, with corresponding surface property changes 33 .…”

Section: Detailed Characterization and Extensive Molecular Reengineer...mentioning

confidence: 98%

“…While several studies have shown that GBS Cas9 influences genome-wide transcription [31][32][33] , the mechanism by which this influence occurs is not clear. We created and studied additional Cas9 variants to explore the hypothesis that nonspecific PAM scanning by wild type (WT) Cas9 leads to changes in transcription.…”

Section: Additional Cas9 Variants Show Distinct Phenotypesmentioning

confidence: 99%

“…cas9 31 or the CRISPR array 32,33 are altered. In CNCTC 10/84 Cas9 variants, we observed subtle phenotypic changes in an oxidative stress challenge in vitro (Supplemental Fig.…”

Section: Previous Publications Have Described Phenotypic and Virulenc...mentioning

confidence: 99%

“…Spencer et al (2019) used mouse models of bacteremia and meningitis and a vaginal colonization competition assay, performed with a COH1 WT strain and Δcas9 mutant 31 and reported differences in density of GBS brain invasion and competition indices in the vaginal tract with no differences in bloodstream or lung bacterial burdens. Another group used a hypervirulent piscine GBS variant, which-compared to our non-piscine strains-was extremely aggressive in mouse models of bacteremia and subsequent meningitis, virulence traits that were attenuated in a ΔCRISPR mutant in the same background 32,33 . Surveying the data across all these studies, we find it probable that the transcriptomic changes in GBS with altered Cas9 scanning capacities lead to changes in sensitivity to immune host defenses during colonization and infection, but that these changes are subtle and may not always correspond to severe outcomes such as death.…”

Section: Previous Publications Have Described Phenotypic and Virulenc...mentioning

confidence: 99%

See 2 more Smart Citations

Group BStreptococcusCas9 variants provide insight into programmable gene repression and CRISPR-Cas transcriptional effects

Gopalakrishna

Hillebrand

Bhavana

et al. 2023

Preprint

View full text Add to dashboard Cite

Group B Streptococcus (GBS; S. agalactiae) causes chorioamnionitis, neonatal sepsis,and can also cause disease in healthy or immunocompromised adults. GBS possesses a type II-A CRISPR-Cas9 system, which defends against foreign DNA within the bacterial cell. Several recent publications have shown that GBS Cas9 influences genome-wide transcription through a mechanism uncoupled from its function as a specific, RNA-programmable endonuclease. We examine GBS Cas9 effects on genome-wide transcription through generation of several isogenic variants with specific functional defects. We compare whole-genome RNA-seq from Δcas9 GBS with a full-length Cas9 gene deletion; dcas9 defective in its ability to cleave DNA but still able to bind to frequently occurring protospacer adjacent motifs; and scas9 that retains its catalytic domains but is unable to bind protospacer adjacent motifs. Comparing scas9 GBS to the other variants, we identify nonspecific protospacer adjacent motif binding as a driver of genome-wide, Cas9 transcriptional effects in GBS. We also show that Cas9 transcriptional effects from nonspecific scanning tend to influence genes involved in bacterial defense and nucleotide or carbohydrate transport and metabolism. While genome-wide transcription effects are detectable by analysis of next-generation sequencing, they do not result in virulence changes in a mouse model of sepsis. We also demonstrate that catalytically inactive dCas9 expressed from the GBS chromosome can be used with a straightforward, plasmid-based, single guide RNA expression system to suppress transcription of specific GBS genes without potentially confounding off-target effects. We anticipate that this system will be useful for study of nonessential and essential gene roles in GBS physiology and pathogenesis.

show abstract

Genetics of microbial biofilm development

et al. 2023

View full text Add to dashboard Cite

CRISPR Contributes to Adhesion, Invasion, and Biofilm Formation in Streptococcus agalactiae by Repressing Capsular Polysaccharide Production

Cited by 10 publications

References 57 publications

Characterization of AI-2/LuxS quorum sensing system in biofilm formation, pathogenesis of Streptococcus equi subsp. zooepidemicus

Characterization of AI-2/LuxS quorum sensing system in biofilm formation, pathogenesis of Streptococcus equi subsp. zooepidemicus

Group BStreptococcusCas9 variants provide insight into programmable gene repression and CRISPR-Cas transcriptional effects

Genetics of microbial biofilm development

Contact Info

Product

Resources

About