Dataset Information

Analysis of Streptococcus dysgalactiae subspecies equisimilis gene transcripts during experimental primate necrotizing myositis

ABSTRACT: Streptococcus dysgalactiae subspecies equisimilis (SDSE) is a Gram-positive bacterial pathogen capable of causing various infections in humans. Recently, isolates of SDSE emm type stG62647 have emerged as a cause of severe invasive infections, including necrotizing myositis. However, the molecular processes underlying these infections remain poorly understood. To address this gap, we performed RNAseq analysis to examine SDSE gene transcript levels during experimental necrotizing myositis infection in non-human primates, an animal phylogenetically closely related to humans. We analyzed the transcriptomes of two related SDSE stG62647 human isolates (MGCS36044 and MGCS36089) during necrotizing myositis infection in six non-human primates. The transcriptome from in vitro growth in nutrient-rich media differed considerably from that of SDSE bacteria grown in vivo in experimental necrotizing myositis, with 254 genes differentially expressed, indicating extensive genetic adaptation in infected skeletal muscle. Notably, we observed marked upregulation of ihk-irr genes encoding a two-component regulatory system that promotes evasion of phagocytosis and resistance to killing by human polymorphonuclear leukocytes in Streptococcus pyogenes. Similarly, genes comprising the sag operon encoding the streptolysin S cytolytic toxin virulence factor demonstrated very high transcript abundance in vivo. Additionally, we present evidence that a 40-nt deletion in fasB alters expression of ska, encoding streptokinase. Collectively, our data provide new insights into the SDSE genes transcribed in vivo, thereby enhancing our understanding of the molecular basis of pathogen and primate host interactions. The SDSE genes identified in this study offer promising targets for future studies on molecular pathogenesis and therapeutics interventions.

ORGANISM(S): Streptococcus dysgalactiae

PROVIDER: GSE296749 | GEO | 2025/07/02

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Streptococcus dysgalactiae subsp. equeisimilis (SDSE) has Lancefield group G or C antigens. Recent epidemiological studies reveal that invasive SDSE infections have been increasing in Asia, Europe and US. Although SDSE possesses similar virulence factors to S. pyogenes including streptolysin S (SLS) and streptolysin O (SLO), some important S. pyogenes virulence factors including active superantigens, SpeB and a hyarulonic acids capsule are missing in SDSE genome. The mechanisms and the key virulence factors for causing invasive diseases by SDSE are poorly understood. Here, we analyzed the transcriptome of SDSE in vivo using the murine sepsis model, revealing the strategy of SDSE to destruct host tissues with the virulence factors and to scavenge depleted nutrients. The expression of SLO operon increased at relatively early stage of infection while the SLS and hyaluronidases upregulated after 4h post infection. Microarray data suggested that SDSE degraded host tissue polysaccharides by streptococcal-secreting poly/oligosaccharide lyases and simultaneously used the Entner-Doudoroff pathway to metabolize acquired carbohydrates. A global negative virulence gene regulator CsrRS of SDSE modulated the expressions of genes encoding SLS and the carbohydrate metabolism enzymes. Moreover, csrS deficient mutant induced sever systemic hemolysis in mice. The most frequently isolated stG6792 strains from invasive disease secreted abundant SLS and SLO rather than other SDSE emm types, indicating the relationship between the SLS and SLO productions and poor outcome by the stG6792 strain infection. Our findings suggest that the concomitant regulation of virulence factors destructing the host tissues and metabolic enzymes play an important role to produce invasive diseases by SDSE. To analyze gene expressions in group G streptococci with the murine infection model, we developed a custom microarray for Streptococcus dysgalactiae subsp. equisimilis (SDSE) based on the genome sequences of three SDSE strains; GGS_124, ATCC12923 and RE378. We intraperitoneally inoculated 10^8 CFU of GGS_124 stain and the csrS deficient mutant into ddY mice. Bacterial cells were collected from the abdominal cavity at 0, 2, 4 and 8 h post infection. GGS_124 cells were also collected from OD600=0.6 culture in brain heart infusion broth as a control.

Dataset Information

Analysis of Streptococcus dysgalactiae subspecies equisimilis gene transcripts during experimental primate necrotizing myositis

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets