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Shigella Diversity and Changing Landscape: Insights for the Twenty-First Century.

Anderson M, Sansonetti PJ, Marteyn BS - Front Cell Infect Microbiol (2016)

Bottom Line: Shigella is a pathovar of Escherichia coli comprising four groups, Shigella flexneri, Shigella sonnei, Shigella dysenteriae, and Shigella boydii, each of them, with the exception of S.sonnei, comprising several serotypes.Host-cell invasion is the final step of the infection process, as Shigella's virulence strategy relies also on its ability to survive hostile conditions during its journey through the gastro-intestinal tract, to compete with the host microbiota and to cross the intestinal mucus layer.The recent development of high-throughput screening and sequencing methods will facilitate these complex comparison studies.

View Article: PubMed Central - PubMed

Affiliation: Institut Pasteur, Unité de Pathogénie Microbienne MoléculaireParis, France; Institut National de la Santé et de la Recherche Médicale, Unité 786Paris, France.

ABSTRACT
Shigella is a pathovar of Escherichia coli comprising four groups, Shigella flexneri, Shigella sonnei, Shigella dysenteriae, and Shigella boydii, each of them, with the exception of S.sonnei, comprising several serotypes. Shigella accounts for the majority of dysentery causing infections occurring world-wide each year. Recent advancements in the Shigella field have led to a better understanding of the molecular mechanisms underlying host epithelial cell invasion and immune cell function manipulation, mainly using S. flexneri as a model. Host-cell invasion is the final step of the infection process, as Shigella's virulence strategy relies also on its ability to survive hostile conditions during its journey through the gastro-intestinal tract, to compete with the host microbiota and to cross the intestinal mucus layer. Hence, the diversity of the virulence strategies among the different Shigella species has not yet been deeply investigated, which might be an important step to understand the epidemiological spreading of Shigella species worldwide and a key aspect for the validation of novel vaccine candidates. The recent development of high-throughput screening and sequencing methods will facilitate these complex comparison studies. In this review we discuss several of the major avenues that the Shigella research field has taken over the past few years and hopefully gain some insights into the questions that remain surrounding this important human pathogen.

No MeSH data available.


Related in: MedlinePlus

During Shigella infection, the colonic microbiota and mucus layers stand as the first barriers protecting the epithelium lineage. (A) The microbiota colonizes the colonic lumenal compartment, and the outer mucus layer. The inner mucus sterile remains sterile probaly due to its mechanical properties and accumulation of secreted antimicrobial peptides (AMPs). (B) Shigella secrete proteins belonging to the SPATE family, including Pic characterized in S. flexneri 2a (Henderson et al., 1999; Gutiérrez-Jiménez et al., 2008; Navarro-Garcia et al., 2010; Ruiz-Perez et al., 2011) and SepA identified in S. flexneri 5a (Benjelloun-Touimi et al., 1995). Shigella SPATE proteins cleave mucins to allow the bacteria to reach the epithelial layer. Shigella Type III secretion apparatus (T3SA) is required for epithelium invasion.
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Figure 3: During Shigella infection, the colonic microbiota and mucus layers stand as the first barriers protecting the epithelium lineage. (A) The microbiota colonizes the colonic lumenal compartment, and the outer mucus layer. The inner mucus sterile remains sterile probaly due to its mechanical properties and accumulation of secreted antimicrobial peptides (AMPs). (B) Shigella secrete proteins belonging to the SPATE family, including Pic characterized in S. flexneri 2a (Henderson et al., 1999; Gutiérrez-Jiménez et al., 2008; Navarro-Garcia et al., 2010; Ruiz-Perez et al., 2011) and SepA identified in S. flexneri 5a (Benjelloun-Touimi et al., 1995). Shigella SPATE proteins cleave mucins to allow the bacteria to reach the epithelial layer. Shigella Type III secretion apparatus (T3SA) is required for epithelium invasion.

Mentions: The gut microbiome of healthy individuals comprises the most complex interface between microbes and human tissues in the body. Over 1000 different species of bacteria reside at varying amounts and locations throughout the GI tract and 70% of the host immune system is dedicated to maintaining its integrity (Vighi et al., 2008; Rajilić-Stojanović and de Vos, 2014). The colonic microbiota can vary significantly between individuals but is dominated at the phyla level by Bacteroidetes (~30%) and Firmicutes (~30%), with lower levels of Proteobacteria, Fusobacteria, Actinobacteria, Cyanobacteria, and Verrucomicrobia (Bäckhed et al., 2005; Andersson et al., 2008; Arumugam et al., 2011; Sankar et al., 2015; Figure 3). The microbiota is further stratified based on proximity to the mucosal lining of the colon with genera such as Coriobacteriaceae, Lachnospiraceae, and Ruminococcaceae showing greater abundance in the mucus layer whereas Bacteroidaceae is more prevalent in the lumen of the intestine (Lavelle et al., 2015). Significant amounts of research have worked to characterize the role of the gut microbiome in both health and disease states and a picture of this complex community is beginning to take shape.


Shigella Diversity and Changing Landscape: Insights for the Twenty-First Century.

Anderson M, Sansonetti PJ, Marteyn BS - Front Cell Infect Microbiol (2016)

During Shigella infection, the colonic microbiota and mucus layers stand as the first barriers protecting the epithelium lineage. (A) The microbiota colonizes the colonic lumenal compartment, and the outer mucus layer. The inner mucus sterile remains sterile probaly due to its mechanical properties and accumulation of secreted antimicrobial peptides (AMPs). (B) Shigella secrete proteins belonging to the SPATE family, including Pic characterized in S. flexneri 2a (Henderson et al., 1999; Gutiérrez-Jiménez et al., 2008; Navarro-Garcia et al., 2010; Ruiz-Perez et al., 2011) and SepA identified in S. flexneri 5a (Benjelloun-Touimi et al., 1995). Shigella SPATE proteins cleave mucins to allow the bacteria to reach the epithelial layer. Shigella Type III secretion apparatus (T3SA) is required for epithelium invasion.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835486&req=5

Figure 3: During Shigella infection, the colonic microbiota and mucus layers stand as the first barriers protecting the epithelium lineage. (A) The microbiota colonizes the colonic lumenal compartment, and the outer mucus layer. The inner mucus sterile remains sterile probaly due to its mechanical properties and accumulation of secreted antimicrobial peptides (AMPs). (B) Shigella secrete proteins belonging to the SPATE family, including Pic characterized in S. flexneri 2a (Henderson et al., 1999; Gutiérrez-Jiménez et al., 2008; Navarro-Garcia et al., 2010; Ruiz-Perez et al., 2011) and SepA identified in S. flexneri 5a (Benjelloun-Touimi et al., 1995). Shigella SPATE proteins cleave mucins to allow the bacteria to reach the epithelial layer. Shigella Type III secretion apparatus (T3SA) is required for epithelium invasion.
Mentions: The gut microbiome of healthy individuals comprises the most complex interface between microbes and human tissues in the body. Over 1000 different species of bacteria reside at varying amounts and locations throughout the GI tract and 70% of the host immune system is dedicated to maintaining its integrity (Vighi et al., 2008; Rajilić-Stojanović and de Vos, 2014). The colonic microbiota can vary significantly between individuals but is dominated at the phyla level by Bacteroidetes (~30%) and Firmicutes (~30%), with lower levels of Proteobacteria, Fusobacteria, Actinobacteria, Cyanobacteria, and Verrucomicrobia (Bäckhed et al., 2005; Andersson et al., 2008; Arumugam et al., 2011; Sankar et al., 2015; Figure 3). The microbiota is further stratified based on proximity to the mucosal lining of the colon with genera such as Coriobacteriaceae, Lachnospiraceae, and Ruminococcaceae showing greater abundance in the mucus layer whereas Bacteroidaceae is more prevalent in the lumen of the intestine (Lavelle et al., 2015). Significant amounts of research have worked to characterize the role of the gut microbiome in both health and disease states and a picture of this complex community is beginning to take shape.

Bottom Line: Shigella is a pathovar of Escherichia coli comprising four groups, Shigella flexneri, Shigella sonnei, Shigella dysenteriae, and Shigella boydii, each of them, with the exception of S.sonnei, comprising several serotypes.Host-cell invasion is the final step of the infection process, as Shigella's virulence strategy relies also on its ability to survive hostile conditions during its journey through the gastro-intestinal tract, to compete with the host microbiota and to cross the intestinal mucus layer.The recent development of high-throughput screening and sequencing methods will facilitate these complex comparison studies.

View Article: PubMed Central - PubMed

Affiliation: Institut Pasteur, Unité de Pathogénie Microbienne MoléculaireParis, France; Institut National de la Santé et de la Recherche Médicale, Unité 786Paris, France.

ABSTRACT
Shigella is a pathovar of Escherichia coli comprising four groups, Shigella flexneri, Shigella sonnei, Shigella dysenteriae, and Shigella boydii, each of them, with the exception of S.sonnei, comprising several serotypes. Shigella accounts for the majority of dysentery causing infections occurring world-wide each year. Recent advancements in the Shigella field have led to a better understanding of the molecular mechanisms underlying host epithelial cell invasion and immune cell function manipulation, mainly using S. flexneri as a model. Host-cell invasion is the final step of the infection process, as Shigella's virulence strategy relies also on its ability to survive hostile conditions during its journey through the gastro-intestinal tract, to compete with the host microbiota and to cross the intestinal mucus layer. Hence, the diversity of the virulence strategies among the different Shigella species has not yet been deeply investigated, which might be an important step to understand the epidemiological spreading of Shigella species worldwide and a key aspect for the validation of novel vaccine candidates. The recent development of high-throughput screening and sequencing methods will facilitate these complex comparison studies. In this review we discuss several of the major avenues that the Shigella research field has taken over the past few years and hopefully gain some insights into the questions that remain surrounding this important human pathogen.

No MeSH data available.


Related in: MedlinePlus