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Insight into the specific virulence related genes and toxin-antitoxin virulent pathogenicity islands in swine streptococcosis pathogen Streptococcus equi ssp. zooepidemicus strain ATCC35246.

Ma Z, Geng J, Yi L, Xu B, Jia R, Li Y, Meng Q, Fan H, Hu S - BMC Genomics (2013)

Bottom Line: Analysis of the genome identified potential Sz35246 virulence genes.Genes of the Fim III operon were presumed to be involved in breaking the host-restriction of Sz35246.Genome wide comparisons of Sz35246 with three other strains and transcriptome analysis revealed novel genes related to bacterial virulence and breaking the host-restriction.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.

ABSTRACT

Background: Streptococcus equi ssp. zooepidemicus (S. zooepidemicus) is an important pathogen causing swine streptococcosis in China. Pathogenicity islands (PAIs) of S. zooepidemicus have been transferred among bacteria through horizontal gene transfer (HGT) and play important roles in the adaptation and increased virulence of S. zooepidemicus. The present study used comparative genomics to examine the different pathogenicities of S. zooepidemicus.

Results: Genome of S. zooepidemicus ATCC35246 (Sz35246) comprises 2,167,264-bp of a single circular chromosome, with a GC content of 41.65%. Comparative genome analysis of Sz35246, S. zooepidemicus MGCS10565 (Sz10565), Streptococcus equi. ssp. equi. 4047 (Se4047) and S. zooepidemicus H70 (Sz70) identified 320 Sz35246-specific genes, clustered into three toxin-antitoxin (TA) systems PAIs and one restriction modification system (RM system) PAI. These four acquired PAIs encode proteins that may contribute to the overall pathogenic capacity and fitness of this bacterium to adapt to different hosts. Analysis of the in vivo and in vitro transcriptomes of this bacterium revealed differentially expressed PAI genes and non-PAI genes, suggesting that Sz35246 possess mechanisms for infecting animals and adapting to a wide range of host environments. Analysis of the genome identified potential Sz35246 virulence genes. Genes of the Fim III operon were presumed to be involved in breaking the host-restriction of Sz35246.

Conclusion: Genome wide comparisons of Sz35246 with three other strains and transcriptome analysis revealed novel genes related to bacterial virulence and breaking the host-restriction. Four specific PAIs, which were judged to have been transferred into Sz35246 genome through HGT, were identified for the first time. Further analysis of the TA and RM systems in the PAIs will improve our understanding of the pathogenicity of this bacterium and could lead to the development of diagnostics and vaccines.

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Schematic representation of the putative PAIs and their expression in S. zoopedemicus ATCC35246 (A), SeseCisland_1; (B), SeseCisland_2; (C), SeseCisland_3; (D), SeseCisland_4. The expression levels of in vitro and in vivo conditions are shown at single-nt resolution in red and green, respectively. All genes are color-coded based on the annotation information as follows: yellow, toxin-Antitoxin system (TA system); blue, phage associated protein; green, other virulence protein; red, virB4 components; cyan, mobile elements; grey, hypothetical protein.
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Figure 5: Schematic representation of the putative PAIs and their expression in S. zoopedemicus ATCC35246 (A), SeseCisland_1; (B), SeseCisland_2; (C), SeseCisland_3; (D), SeseCisland_4. The expression levels of in vitro and in vivo conditions are shown at single-nt resolution in red and green, respectively. All genes are color-coded based on the annotation information as follows: yellow, toxin-Antitoxin system (TA system); blue, phage associated protein; green, other virulence protein; red, virB4 components; cyan, mobile elements; grey, hypothetical protein.

Mentions: SeseCisland_1 contains 54 genes (53,095 bp), 42 of which are Sz35246-specific genes, including mobile elements resembling the IS200 family transposase (SeseC_00874), a prophage site-specific recombinase resolvase family protein (SeseC_00919), a putative conjugal transfer protein (SeseC_00927), a conjugation protein (SeseC_00935) and a tnpX site-specific recombinase family protein (SeseC_00939), suggesting that this island is an integrative conjugative element (Additional file4: Table S4 & FigureĀ 5A). SeseCisland_1 contains 20 structural phage loci, indicating that MGEs, such as phages, are also implicated in HGT in Streptococcus species. Further analysis showed that the island has an abnormal GC skew and that the island-located genes have an average G+C content of 39.42% (Additional file4: Table S4), which is significantly different from the mean value for the genome (41.65%) (p=0.002).


Insight into the specific virulence related genes and toxin-antitoxin virulent pathogenicity islands in swine streptococcosis pathogen Streptococcus equi ssp. zooepidemicus strain ATCC35246.

Ma Z, Geng J, Yi L, Xu B, Jia R, Li Y, Meng Q, Fan H, Hu S - BMC Genomics (2013)

Schematic representation of the putative PAIs and their expression in S. zoopedemicus ATCC35246 (A), SeseCisland_1; (B), SeseCisland_2; (C), SeseCisland_3; (D), SeseCisland_4. The expression levels of in vitro and in vivo conditions are shown at single-nt resolution in red and green, respectively. All genes are color-coded based on the annotation information as follows: yellow, toxin-Antitoxin system (TA system); blue, phage associated protein; green, other virulence protein; red, virB4 components; cyan, mobile elements; grey, hypothetical protein.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750634&req=5

Figure 5: Schematic representation of the putative PAIs and their expression in S. zoopedemicus ATCC35246 (A), SeseCisland_1; (B), SeseCisland_2; (C), SeseCisland_3; (D), SeseCisland_4. The expression levels of in vitro and in vivo conditions are shown at single-nt resolution in red and green, respectively. All genes are color-coded based on the annotation information as follows: yellow, toxin-Antitoxin system (TA system); blue, phage associated protein; green, other virulence protein; red, virB4 components; cyan, mobile elements; grey, hypothetical protein.
Mentions: SeseCisland_1 contains 54 genes (53,095 bp), 42 of which are Sz35246-specific genes, including mobile elements resembling the IS200 family transposase (SeseC_00874), a prophage site-specific recombinase resolvase family protein (SeseC_00919), a putative conjugal transfer protein (SeseC_00927), a conjugation protein (SeseC_00935) and a tnpX site-specific recombinase family protein (SeseC_00939), suggesting that this island is an integrative conjugative element (Additional file4: Table S4 & FigureĀ 5A). SeseCisland_1 contains 20 structural phage loci, indicating that MGEs, such as phages, are also implicated in HGT in Streptococcus species. Further analysis showed that the island has an abnormal GC skew and that the island-located genes have an average G+C content of 39.42% (Additional file4: Table S4), which is significantly different from the mean value for the genome (41.65%) (p=0.002).

Bottom Line: Analysis of the genome identified potential Sz35246 virulence genes.Genes of the Fim III operon were presumed to be involved in breaking the host-restriction of Sz35246.Genome wide comparisons of Sz35246 with three other strains and transcriptome analysis revealed novel genes related to bacterial virulence and breaking the host-restriction.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.

ABSTRACT

Background: Streptococcus equi ssp. zooepidemicus (S. zooepidemicus) is an important pathogen causing swine streptococcosis in China. Pathogenicity islands (PAIs) of S. zooepidemicus have been transferred among bacteria through horizontal gene transfer (HGT) and play important roles in the adaptation and increased virulence of S. zooepidemicus. The present study used comparative genomics to examine the different pathogenicities of S. zooepidemicus.

Results: Genome of S. zooepidemicus ATCC35246 (Sz35246) comprises 2,167,264-bp of a single circular chromosome, with a GC content of 41.65%. Comparative genome analysis of Sz35246, S. zooepidemicus MGCS10565 (Sz10565), Streptococcus equi. ssp. equi. 4047 (Se4047) and S. zooepidemicus H70 (Sz70) identified 320 Sz35246-specific genes, clustered into three toxin-antitoxin (TA) systems PAIs and one restriction modification system (RM system) PAI. These four acquired PAIs encode proteins that may contribute to the overall pathogenic capacity and fitness of this bacterium to adapt to different hosts. Analysis of the in vivo and in vitro transcriptomes of this bacterium revealed differentially expressed PAI genes and non-PAI genes, suggesting that Sz35246 possess mechanisms for infecting animals and adapting to a wide range of host environments. Analysis of the genome identified potential Sz35246 virulence genes. Genes of the Fim III operon were presumed to be involved in breaking the host-restriction of Sz35246.

Conclusion: Genome wide comparisons of Sz35246 with three other strains and transcriptome analysis revealed novel genes related to bacterial virulence and breaking the host-restriction. Four specific PAIs, which were judged to have been transferred into Sz35246 genome through HGT, were identified for the first time. Further analysis of the TA and RM systems in the PAIs will improve our understanding of the pathogenicity of this bacterium and could lead to the development of diagnostics and vaccines.

Show MeSH
Related in: MedlinePlus