Streptococcus pyogenes and re-emergence of scarlet fever as a public health problem

Genome-wide analysis of Streptococcus pyogenes associated with pharyngitis and skin infections. (c2015)

“…With the advent of NGS techniques, research shifted to generating whole genome sequences of the organism in study (Beretelli & Greub, 2013). S. pyogenes genomes are known for their plasticity and genomic variation, namely due to horizontal gene transfer between bacterial cells, and the presence of prophages (Wong & Yuen, 2012). All of these features can confer virulence and resistance capabilities to GAS strains, in addition to influencing the regulation of existing genetic elements (Vjotek et al, 2008), a fact that further necessitates a broader look at the bacterial genome, rather than a localized one.…”

“…The exact factors intrinsic to the global reemergence of group A streptococcal infections are yet to be answered (Efstratiou, 2000). Even though, modern medicine is now better suited to manage such infections, streptococcal infections are still on the rise in all parts of the world (Wong & Yuen, 2012).…”

“…The B region is considered to be a semi-variable region, while the A region is known as the hypervariable region, both of which located on the surface-exposed N terminus of the protein molecule (Fischetti, 1989). Since then, the M protein has been employed as an epidemiological marker for GAS (Luca-Harari et al, 2009) and a new system of classification was proposed based on the sequence analysis of the emm gene (Wong & Yuen, 2012). Today, after nearly 60 year of being adopted, there exists 139 named emm types, with a corresponding 941 subtypes, in addition to 326 sequence types that remain unnamed (CDC, 2015).…”

“…These include pili, M proteins, leukocidins, streptolysins, complement inhibiting proteins, immunoglobulin-degrading enzymes, and superantigens (Cunningham, 2000;Walker et al, 2014). Coupled with efflux pumps and leukocyte evasion strategies, GAS isolates present a formidable opponent to the human immune system (Wong & Yuen, 2012). When studying the streptococcal genome, the successful detection and identification of all of these factors becomes of great importance.…”

“…Successful treatment faces another major hurdle in cases where identification of the causative organism and diagnosis of the condition are delayed. S. pyogenes infections are mostly treatable when rapidly and accurately diagnosed, however non-supportive and supportive sequelae can arise from late identification, and develop into invasive complications (Centor et al, 1981;Wong & Yuen, 2012).…”