Genomic analysis of a
            Streptococcus dysgalactiae
            subsp.
            equisimilis
            strain associated with mastitis in an 8‐day‐old Arabian filly

Background: Streptococcus dysgalactiae subsp. equisimilis (SDSE) is the causal agent of various diseases that include wound infection, erysipelas, cellulitis, life-threatening necrotizing fasciitis, and streptococcal toxic shock syndrome. It is capable of infecting both humans and animals. In this investigation, we present a comprehensive genomic analysis for the SDSE strain SCDR1 that belongs to Lancefield group G, emm type (stG6) and (MLST) sequence type (ST44) that is the first time to be documented in Saudi Arabia and the middle east. Besides, we present the most comprehensive comparative genomics analysis for the emerging human pathogen SDSE. Methodology: We utilized next-generation sequencing techniques (NGS), bioinformatics, phylogenetic analysis, and comparative pathogenomics to characterize SCDR1 and all publicly available SDES genomes. Results: We found that SCDR1 consisted of a circular genome of 2179136 bp. Comparative analyses among bacterial genomes indicated that SCDR1 was most closely related to AC-2713 and GGS_124. Genome annotation of SCDR-1 strain showed that it contains many genes with homology to known virulence factors, including genes involved in cellular invasion, Antiphagocytosis, immune evasion, invasion of skin and soft tissue, host mortality and tissue damage, toxins, pore-forming proteins, cytotoxins, beta-hemolysis agents. Two CRISPR arrays were identified in SCDR1 that are consist of 35 CRISPR repeats and 33 CRISPR spacers. Two CAS systems were observed in the SCDR-1 genome, namely, CAS-TypeIIA and CAS-TypeIC. SDSE core Resistome is consisting of 22 genes, including folA, gyrA, gyrB, and FabK. SDSE core Virulome consisting of 38 genes including, fba, fbp54, gidA, and lsp. Conclusion: Our study confirmed that the SDSE strains possess different characteristics in producing virulence factors for pathogenicity to humans and based on its genome sequence and close relationship with GAS. Our study shed light on the proposed pathogenic mechanisms of SDSE and may form the basis of molecular epidemiological research on these highly virulent bacteria.

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Comparative Genomic Analysis of Streptococcus dysgalactiae subspecies dysgalactiae Isolated From Bovine Mastitis in China

Frontiers in Microbiology ◽

10.3389/fmicb.2021.751863 ◽

2021 ◽

Vol 12 ◽

Author(s):

Siyu Xu ◽

Yang Liu ◽

Jian Gao ◽

Man Zhou ◽

Jingyue Yang ◽

...

Keyword(s):

Phylogenetic Analysis ◽

16S Rrna ◽

Bovine Mastitis ◽

Genomic Analysis ◽

Subclinical Mastitis ◽

Comparative Genomic ◽

Streptococcus Dysgalactiae ◽

Milk Samples ◽

Comprehensive Information ◽

Sequence Types

Streptococcus dysgalactiae subsp. dysgalactiae (SDSD) is one of the most prevalent pathogens causing bovine mastitis worldwide. However, there is a lack of comprehensive information regarding genetic diversity, complete profiles of virulence factors (VFs), and antimicrobial resistance (AMR) genes for SDSD associated with bovine mastitis in China. In this study, a total of 674 milk samples, including samples from 509 clinical and 165 subclinical mastitis cases, were collected from 17 herds in 7 provinces in China from November 2016 to June 2019. All SDSD isolates were included in phylogenetic analysis based on 16S rRNA and multi-locus sequence typing (MLST). In addition, whole genome sequencing was performed on 12 representative SDSD isolates to screen for VFs and AMR genes and to define pan-, core and accessory genomes. The prevalence of SDSD from mastitis milk samples was 7.57% (51/674). According to phylogenetic analysis based on 16S rRNA, 51 SDSD isolates were divided into 4 clusters, whereas based on MLST, 51 SDSD isolates were identified as 11 sequence types, including 6 registered STs and 5 novel STs (ST521, ST523, ST526, ST527, ST529) that belonged to 2 distinct clonal complexes (CCs) and 4 singletons. Based on WGS information, 108 VFs genes in 12 isolates were determined in 11 categories. In addition, 23 AMR genes were identified in 11 categories. Pan-, core and accessory genomes were composed of 2,663, 1,633 and 699 genes, respectively. These results provided a comprehensive profiles of SDSD virulence and resistance genes as well as phylogenetic relationships among mastitis associated SDSD in North China.

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Genomic analysis of C-type lectins

Biochemical Society Symposium ◽

10.1042/bss0690059 ◽

2002 ◽

Vol 69 ◽

pp. 59-72 ◽

Cited By ~ 85

Author(s):

Kurt Drickamer ◽

Andrew J. Fadden

Keyword(s):

Biological Effects ◽

Cell Signalling ◽

Genomic Analysis ◽

Binding Activity ◽

Immunoglobulin Superfamily ◽

Carbohydrate Binding ◽

Carbohydrate Recognition ◽

Calcium Dependent ◽

Binding Domains ◽

Carbohydrate Recognition Domains

Many biological effects of complex carbohydrates are mediated by lectins that contain discrete carbohydrate-recognition domains. At least seven structurally distinct families of carbohydrate-recognition domains are found in lectins that are involved in intracellular trafficking, cell adhesion, cell–cell signalling, glycoprotein turnover and innate immunity. Genome-wide analysis of potential carbohydrate-binding domains is now possible. Two classes of intracellular lectins involved in glycoprotein trafficking are present in yeast, model invertebrates and vertebrates, and two other classes are present in vertebrates only. At the cell surface, calcium-dependent (C-type) lectins and galectins are found in model invertebrates and vertebrates, but not in yeast; immunoglobulin superfamily (I-type) lectins are only found in vertebrates. The evolutionary appearance of different classes of sugar-binding protein modules parallels a development towards more complex oligosaccharides that provide increased opportunities for specific recognition phenomena. An overall picture of the lectins present in humans can now be proposed. Based on our knowledge of the structures of several of the C-type carbohydrate-recognition domains, it is possible to suggest ligand-binding activity that may be associated with novel C-type lectin-like domains identified in a systematic screen of the human genome. Further analysis of the sequences of proteins containing these domains can be used as a basis for proposing potential biological functions.

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