Brouwer Stephan, Das Swairindhree, Hayes Andrew J, Bertolla Olivia M, Davies Mark R, Walker Mark J, Whiley David M, Irwin Adam D, Tickner Jacob A
Australian Infectious Diseases Research Centre and Institute for Molecular Bioscience.
UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane.
J Infect Dis. 2025 Feb 20;231(2):e375-e384. doi: 10.1093/infdis/jiae437.
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.
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.
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.
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.
化脓性链球菌M1全球基因型正逐渐被新出现的M1英国变种所取代，这是一个全球公共卫生威胁，需要加强监测。M1英国变种与祖先M1全球基因型有27个单核苷酸多态性差异，其特征是在体外超抗原speA表达增加。
开发了一种等位基因特异性实时聚合酶链反应检测方法，用于快速检测M1英国变种菌株。该检测方法与全基因组测序结合使用，以确定51株化脓性链球菌临床分离株（9株侵袭性、42株非侵袭性）的emm（亚）型分布。
在这组临床分离株中，emm1是最常见的化脓性链球菌emm血清型（n = 11），M1英国变种是主要的emm1基因型（4/5侵袭性、3/6非侵袭性分离株）。该检测方法能准确检测出M1英国变种菌株。全基因组测序显示，在亚洲，与引起流行性猩红热的化脓性链球菌相关的澳大利亚M1英国变种亚系持续存在。
我们的研究确定了检测产毒M1英国变种的合适靶点，并证实了M1英国变种菌株在澳大利亚昆士兰州的存在。该检测方法可在实验室中应用，为加强对不断扩大的M1英国变种克隆的监测提供了一种有价值、经济高效的工具。
