AI Article Synopsis

  • The study highlights the emergence of the M1UK variant of Streptococcus pyogenes as a significant global health threat, differing from the original M1global genotype by 27 SNPs and showing increased virulence through speA superantigen expression.
  • Researchers developed a rapid allele-specific real-time PCR assay to detect M1UK strains and used whole-genome sequencing on 51 clinical isolates to assess the distribution of various emm (sub)types, finding M1UK dominant among the invasive and non-invasive strains.
  • The findings confirm the ongoing presence of M1UK strains in Queensland, Australia, and suggest that the assay can be effectively used for enhanced surveillance of this particular pathogen.

Article Abstract

Background: The gradual replacement of the Streptococcus pyogenes M1global genotype by a newly emergent M1UK variant is a global public health threat warranting increased surveillance. M1UK differs from progenitor M1global genotype by 27 single-nucleotide polymorphisms and is characterized by increased speA superantigen expression in vitro.

Methods: An allele-specific real-time polymerase chain reaction assay was developed for the rapid detection of M1UK strains. The assay was used in combination with whole genome sequencing to determine emm (sub)type distribution for 51 invasive (n = 9) and noninvasive (n = 42) S pyogenes clinical isolates.

Results: Emm1 was the most prevalent S pyogenes emm serotype (n = 11) in this set of clinical isolates, with M1UK being the dominant emm1 genotype (4/5 invasive, 3/6 noninvasive isolates). The assay accurately detected M1UK strains. Whole genome sequencing revealed continued presence of Australian M1UK sublineages associated with epidemic scarlet fever-causing S pyogenes in Asia.

Conclusions: Our study establishes a suitable target for detection of the toxigenic M1UK and confirms the maintenance of M1UK strains in Queensland, Australia. This assay can be deployed in laboratories and provides a valuable, cost-effective tool to enhance surveillance of the expanding M1UK clone.

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Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11841628PMC
http://dx.doi.org/10.1093/infdis/jiae437DOI Listing

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