Decoding the molecular epidemiology of group A streptococcus - an Indian perspective

Abraham, Tintu; Sistla, Sujatha

doi:10.1099/jmm.0.001018

Cited by 9 publications

(8 citation statements)

References 49 publications

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“…No new emm types/subtypes were detected. The results obtained align with other findings which reported no dominancy of a single emm type/subtype [53,54]. Moreover, it has been documented that S. pyogenes strains in developing countries have diverse emm types compared to developed countries [55].…”

Section: Tablesupporting

confidence: 89%

Distribution of virulence genes and the molecular epidemiology of Streptococcus pyogenes clinical isolates by emm and multilocus sequence typing methods

Hamzah

Desa

Jasni

et al. 2020

Preprint

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Background: Streptococcus pyogenes has a variety of virulence factors and the predominant invasive strains differ according to specific emm types and geographical orientation. Although emm typing is commonly used as the gold standard method for the molecular characterization, multilocus sequence typing (MLST) has become an important tool for comparing the genetic profiles globally. This study aimed to screen selected virulence genes from invasive and non-invasive clinical samples and to characterize the molecular epidemiology by emm typing and MLST methods. Methods: A total of 42 S. pyogenes isolates from invasive and non-invasive samples collected from 2014 to 2015 from two different tertiary hospitals were investigated for the distribution of virulence factors and their molecular epidemiology by emm and multilocus sequence typing methods. Detection of five virulence genes (speA , speB , speJ , ssa and sdaB) was performed using multiplex polymerase chain reaction (PCR) using the standard primers and established protocol. Results: Multiplex PCR analysis revealed that sdaB/speF (78.6%) and speB (61.9%) were the predominant virulence genes. Regardless of the type of invasiveness, diverse distribution of emm types/subtypes was noted which comprised of 27 different emm types/subtypes. The predominant emm types/subtypes were emm63 and emm18 with each gene accounted for 11.8% whereas 12% for each gene was noted for emm28, emm97.4 and emm91. The MLST revealed that the main sequence type (ST) in invasive samples was ST402 (17.7%) while ST473 and ST318 (12% for each ST) were the major types in non-invasive samples. Out of 18 virulotypes, Virulotype A (five genes, 55.6%) and Virulotype B (two genes, 27.8%) were the major virulotypes found in this study. Phylogenetic analysis indicated the presence of seven different clusters of S. pyogenes. Interestingly, Cluster VI showed that selected emm/ST types such as emm71/ST318 (n=2), emm70.1/ST318 (n=1), emm44/ST31 (n=1) and emm18/ST442 (n=1) have clustered within a common group (Virulotype A) for both hospitals studied. Conclusion: The present study showed that group A streptococci (GAS) are genetically diverse and possess virulence genes regardless of their invasiveness. Majority of the GAS exhibited no restricted pattern of virulotypes except for a few distinct clusters. Therefore, it can be concluded that virulotyping is partially useful for characterizing a heterogeneous population of GAS in hospitals.

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Section: Tablesupporting

confidence: 89%

Distribution of virulence genes and the molecular epidemiology of Streptococcus pyogenes clinical isolates by emm and multilocus sequence typing methods

Hamzah

Desa

Jasni

et al. 2020

Preprint

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“…These results are in agreement with the overall scenario in Europe and the US in contemporary periods, although with some variations in the ranking of the top emm types 7,8,20–26 . In contrast, remarkable heterogeneity is found in the Southern hemisphere and developing regions, where the diversity of emm types is significantly higher, resulting in a much lower estimated coverage of the 30-valent vaccine 27–29 .…”

Section: Discussionmentioning

confidence: 98%

Changes in emm types and superantigen gene content of Streptococcus pyogenes causing invasive infections in Portugal

Friães

Melo‐Cristino

Ramírez

2019

Sci Rep

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Fluctuations in the clonal composition of Group A Streptococcus (GAS) have been associated with the emergence of successful lineages and with upsurges of invasive infections (iGAS). This study aimed at identifying changes in the clones causing iGAS in Portugal. Antimicrobial susceptibility testing, emm typing and superantigen (SAg) gene profiling were performed for 381 iGAS isolates from 2010–2015. Macrolide resistance decreased to 4%, accompanied by the disappearance of the M phenotype and an increase of the iMLSB phenotype. The dominant emm types were: emm1 (28%), emm89 (11%), emm3 (9%), emm12 (8%), and emm6 (7%). There were no significant changes in the prevalence of individual emm types, emm clusters, or SAg profiles when comparing to 2006–2009, although an overall increasing trend was recorded during 2000–2015 for emm1, emm75, and emm87. Short-term increases in the prevalence of emm3, emm6, and emm75 may have been driven by concomitant SAg profile changes observed within these emm types, or reflect the emergence of novel genomic variants of the same emm types carrying different SAgs.

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“…PKCδ can modulate p-STAT3 S727 nucleation and affect its DNA binding and transcriptional activity by phosphorylating STAT S727 in the cytoplasm of cells [39]. Furthermore, PKCδ reportedly phosphorylates eEF1A1 threonine 431 [40,41], and a strong regulatory effect has been demonstrated for eEF1A1-IL-6 in the gp130 receptor-mediated signalling pathway. Therefore, p-STAT3 S727 were measured in this study to assess the activation of PKCδ.…”

Section: Discussionmentioning

confidence: 99%

CagA orchestrates eEF1A1 and PKCδ to induce interleukin-6 expression in Helicobacter pylori-infected gastric epithelial cells

XiaoQian

Zhang

et al. 2020

Gut Pathog

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Background Helicobacter pylori colonises the stomach of approximately 50% of the global population. Cytotoxin-associated gene A protein (CagA) is one of the important virulent factors responsible for the increased inflammation and increases the risk of developing peptic ulcers and gastric carcinoma. The cytokine interleukin-6 (IL-6) has particularly important roles in the malignant transformation of gastric and intestinal epithelial cells as it is upregulated in H. pylori-infected gastric mucosa. In this study, we investigated the underlying mechanisms of CagA-induced IL-6 up-regulation during H. pylori infection. AGS cells, a human gastric adenocarcinoma cell line, lacking eEF1A1 were infected with CagA+H. pylori (NCTC11637), CagA−H. pylori (NCTC11637ΔcagA), or transduced by Ad-cagA/Ad-GFP. The expression and production of IL-6 were measured by quantitative real-time reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The interactions among CagA, eukaryotic translation elongation factor 1-alpha 1 (eEF1A1), protein kinase Cδ (PKCδ), and signal transducer and activator of transcription 3 (STAT3) were determined by western blot or co-immunoprecipitation. Results During H. pylori infection, CagA-M (residues 256‒871aa) was found to interact with eEF1A1-I (residues 1‒240aa). NCTC11637 increased the expression of IL-6 in AGS cells compared with NCTC11637ΔcagA whereas knockdown of eEF1A1 in AGS cells completely abrogated these effects. Moreover, the CagA-eEF1A1 complex promoted the expression of IL-6 in AGS cells. CagA and eEF1A1 cooperated to mediate the expression of IL-6 by affecting the activity of p-STATS727 in the nucleus. Further, CagA-eEF1A1 affected the activity of STAT3 by recruiting PKCδ. However, blocking PKCδ inhibited the phosphorylation of STAT3S727 and induction of IL-6 by CagA. Conclusions CagA promotes the expression of IL-6 in AGS cells by recruiting PKCδ through eEF1A1 in the cytoplasm to increase the phosphorylation of STAT3S727 in the nucleus. These findings provide new insights into the function of CagA-eEF1A1 interaction in gastric adenocarcinoma.

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Decoding the molecular epidemiology of group A streptococcus - an Indian perspective

Cited by 9 publications

References 49 publications

Distribution of virulence genes and the molecular epidemiology of Streptococcus pyogenes clinical isolates by emm and multilocus sequence typing methods

Distribution of virulence genes and the molecular epidemiology of Streptococcus pyogenes clinical isolates by emm and multilocus sequence typing methods

Changes in emm types and superantigen gene content of Streptococcus pyogenes causing invasive infections in Portugal

CagA orchestrates eEF1A1 and PKCδ to induce interleukin-6 expression in Helicobacter pylori-infected gastric epithelial cells

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