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

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.

Microbial Diversity of Source and Point-of-Use Water in Rural Haiti – A Pyrosequencing-Based Metagenomic Survey

“…and Yersinia spp, with high relative abundance in POU water samples. Both of these pathogens may pose a considerable public health threat in less developed countries by causing conditions such as bacillary dysentery, inflammatory autoimmune disorders, and even highly contagious diseases such as plague [49, 50]. Another pathogen Kluyvera spp.…”

Minimum bactericidal concentration of chemically synthesized silver nanoparticles against pathogenic Salmonella and Shigella strains isolated from layer poultry farms

“…Salmonella and Shigella species are Gram-negative rodshaped bacteria that are members of the family Enterobacteriaceae and are considered threatened foodborne pathogens facing food safety and public health (Arena et al, 2017;Pashazadeh et al, 2017). Depending on serology, Salmonella species comprises over 2500 serotypes (Pashazadeh et al, 2017) while Shigella comprises four subspecies: Shigella dysenteriae (serogroup A, 15 serotypes), Shigella flexneri (serogroup B, 14 serotypes), Shigella boydii (serogroup C, 20 serotypes), and Shigella sonnei (serogroup D, a single serotype) (Anderson et al, 2016;Arena et al, 2017).…”

“…Depending on serology, Salmonella species comprises over 2500 serotypes (Pashazadeh et al, 2017) while Shigella comprises four subspecies: Shigella dysenteriae (serogroup A, 15 serotypes), Shigella flexneri (serogroup B, 14 serotypes), Shigella boydii (serogroup C, 20 serotypes), and Shigella sonnei (serogroup D, a single serotype) (Anderson et al, 2016;Arena et al, 2017). Salmonella is a serious threat facing poultry industries as it has the ability to infect chickens causing diarrhea (Hsu et al, 2016).…”

Deoxycholate-Enhanced Shigella Virulence Is Regulated by a Rare π-Helix in the Type Three Secretion System Tip Protein IpaD

“…6 While generally better controlled, Shigella infections are not uncommon in industrialized nations where the rapid emergence of antibiotic resistant Shigella strains make shigellosis a true worldwide threat, underscoring the urgency for better understanding the virulence mechanisms supporting Shigella infection. 7,8 …”

“…Once injected, the effector proteins alter host cell function, support infection, and help the bacteria evade host cell immune responses. 8,11 …”