Hall Jennifer N, Armitage Edwin P, Senghore Elina, Darboe Saffiatou, Barry Momodou, Camara Janko, Bah Sulayman, Keeley Alexander J, McCarthy James S, Smeesters Pierre, Turner Claire E, Darton Thomas C, Marks Michael, Angyal Adrienn, de Silva Thushan I
Division of Clinical Medicine and National Institute for Health and Care Research Sheffield Biomedical Research Centre, School of Medicine and Population Health, University of Sheffield, Sheffield, United Kingdom.
The Florey Institute of Infection, University of Sheffield, Sheffield, United Kingdom.
J Infect Dis. 2025 Feb 4;231(1):e28-e37. doi: 10.1093/infdis/jiae359.
Streptococcus pyogenes-related skin infections are increasingly implicated in the development of rheumatic heart disease (RHD) in lower-resource settings, where they are often associated with scabies. The true prevalence of S pyogenes-related pyoderma may be underestimated by bacterial culture.
A multiplex quantitative polymerase chain reaction (qPCR) assay for S pyogenes, Staphylococcus aureus, and Sarcoptes scabiei was applied to 250 pyoderma swabs from a cross-sectional study of children aged <5 years in The Gambia. Direct PCR-based emm-typing was used to supplement previous whole genome sequencing (WGS) of cultured isolates.
Pyoderma lesions with S pyogenes increased from 51% (127/250) using culture to 80% (199/250) with qPCR. Compared to qPCR, the sensitivity of culture was 95.4% for S pyogenes (95% confidence interval {CI}, 77.2%-99.9%) in samples with S pyogenes alone (22/250 [9%]), but 59.9% (95% CI, 52.3%-67.2%) for samples with S aureus coinfection (177/250 [71%]). Direct PCR-based emm-typing was successful in 50% (46/92) of cases, identifying 27 emm-types, including 6 not identified by WGS (total 52 emm-types).
Bacterial culture significantly underestimates the burden of S pyogenes in pyoderma, particularly with S aureus coinfection. Molecular methods should be used to enhance the detection of S pyogenes in surveillance studies and clinical trials of preventive measures in RHD-endemic settings.
在资源匮乏地区，化脓性链球菌相关的皮肤感染与风湿性心脏病（RHD）的发生越来越相关，且这些感染常与疥疮有关。细菌培养可能会低估化脓性链球菌相关脓疱病的实际患病率。
应用针对化脓性链球菌、金黄色葡萄球菌和疥螨的多重定量聚合酶链反应（qPCR）检测法，对冈比亚一项针对5岁以下儿童的横断面研究中的250份脓疱病拭子进行检测。基于直接PCR的emm分型用于补充先前对培养分离株的全基因组测序（WGS）。
脓疱病皮损中化脓性链球菌的检出率从培养法的51%（127/250）提高到qPCR法的80%（199/250）。与qPCR相比，在仅感染化脓性链球菌的样本（22/250 [9%]）中，培养法对化脓性链球菌的敏感性为95.4%（95%置信区间{CI}，77.2%-99.9%），但在合并感染金黄色葡萄球菌的样本（177/250 [71%]）中，敏感性为59.9%（95% CI，52.3%-67.2%）。基于直接PCR的emm分型在50%（46/92）的病例中成功，鉴定出27种emm型，包括6种未通过WGS鉴定的（共52种emm型）。
细菌培养显著低估了脓疱病中化脓性链球菌的负担，尤其是在合并感染金黄色葡萄球菌的情况下。在RHD流行地区的监测研究和预防措施临床试验中，应采用分子方法加强对化脓性链球菌的检测。
