Project description:We sequenced mRNA transcripts from three isogenic M3 serotype GAS strains, parental (MGAS10870), complement (10870::rocAM1), and deletion (10870?rocA). There were no significant changes between the parental and revertant strain. Comparison of the parental and complemented strain revealed several virulence factors were up-regulated in the parental strain where RocA function was diminished. We concluded that RocA, through direct or indirect mechanisms, is able to control numerous virulence genes and this lack of RocA regulation increases expression of virulence factors, which contributes to the hyper-virulent state of serotype M3 GAS. GAS strains were grown to mid-exponential phase, total RNA isolated, rRNA depleted, cDNA libraries synthesized, and libraries analyzed using Illumina MiSeq and CLC Genomics Workbench version 7.5.1 RNA-seq software.
Project description:We sequenced mRNA transcripts from three isogenic M3 serotype GAS strains, parental (MGAS10870), complement (10870::rocAM1), and deletion (10870ΔrocA). There were no significant changes between the parental and revertant strain. Comparison of the parental and complemented strain revealed several virulence factors were up-regulated in the parental strain where RocA function was diminished. We concluded that RocA, through direct or indirect mechanisms, is able to control numerous virulence genes and this lack of RocA regulation increases expression of virulence factors, which contributes to the hyper-virulent state of serotype M3 GAS.
Project description:A new variant of group A Streptococcus (GAS) serotype M1 (designated ‘M1UK’) has been reported in the United Kingdom, linked with seasonal scarlet fever surges, marked increase in invasive infections, and exhibiting enhanced expression of the superantigen SpeA. The progenitor GAS ‘M1global’ and M1UK clones can be differentiated by 27 SNPs and 4 indels, yet the mechanism for speA upregulation is unknown. Here we investigate the previously unappreciated expansion of M1UK in Australia, now isolated from the majority of serious infections caused by serotype M1 GAS. M1UK sub-lineages circulating in Australia also contain a novel toxin repertoire associated with epidemic scarlet fever causing GAS in Asia. A single SNP in the M1UK tmRNA gene ssrA drives enhanced SpeA superantigen expression as a result of ssrA terminator readthrough in the M1UK lineage. This represents a new paradigm of toxin expression and urges enhanced international surveillance.
Project description:A new variant of group A Streptococcus (GAS) serotype M1 (designated ‘M1UK’) has been reported in the United Kingdom, linked with seasonal scarlet fever surges, marked increase in invasive infections, and exhibiting enhanced expression of the superantigen SpeA. The progenitor GAS ‘M1global’ and M1UK clones can be differentiated by 27 SNPs and 4 indels, yet the mechanism for speA upregulation is unknown. Here we investigate the previously unappreciated expansion of M1UK in Australia, now isolated from the majority of serious infections caused by serotype M1 GAS. M1UK sub-lineages circulating in Australia also contain a novel toxin repertoire associated with epidemic scarlet fever causing GAS in Asia. A single SNP in the M1UK tmRNA gene ssrA drives enhanced SpeA superantigen expression as a result of ssrA terminator readthrough in the M1UK lineage. This represents a new paradigm of toxin expression and urges enhanced international surveillance.
Project description:A new variant of group A Streptococcus (GAS) serotype M1 (designated ‘M1UK’) has been reported in the United Kingdom, linked with seasonal scarlet fever surges, marked increase in invasive infections, and exhibiting enhanced expression of the superantigen SpeA. The progenitor GAS ‘M1global’ and M1UK clones can be differentiated by 27 SNPs and 4 indels, yet the mechanism for speA upregulation is unknown. Here we investigate the previously unappreciated expansion of M1UK in Australia, now isolated from the majority of serious infections caused by serotype M1 GAS. M1UK sub-lineages circulating in Australia also contain a novel toxin repertoire associated with epidemic scarlet fever causing GAS in Asia. A single SNP in the M1UK tmRNA gene ssrA drives enhanced SpeA superantigen expression as a result of ssrA terminator readthrough in the M1UK lineage. This represents a new paradigm of toxin expression and urges enhanced international surveillance.
Project description:A new variant of group A Streptococcus (GAS) serotype M1 (designated ‘M1UK’) has been reported in the United Kingdom, linked with seasonal scarlet fever surges, marked increase in invasive infections, and exhibiting enhanced expression of the superantigen SpeA. The progenitor GAS ‘M1global’ and M1UK clones can be differentiated by 27 SNPs and 4 indels, yet the mechanism for speA upregulation is unknown. Here we investigate the previously unappreciated expansion of M1UK in Australia, now isolated from the majority of serious infections caused by serotype M1 GAS. M1UK sub-lineages circulating in Australia also contain a novel toxin repertoire associated with epidemic scarlet fever causing GAS in Asia. A single SNP in the M1UK tmRNA gene ssrA drives enhanced SpeA superantigen expression as a result of ssrA terminator readthrough in the M1UK lineage. This represents a new paradigm of toxin expression and urges enhanced international surveillance.
