d'Humières Camille, Bidet Philippe, Levy Corinne, Béchet Stéphane, Bonacorsi Stéphane, Bingen Edouard, Cohen Robert
From the *IAME, UMR 1137, INSERM, †Univ Paris Diderot, Sorbonne Paris Cité, ‡Assistance Publique-Hôpitaux de Paris, Laboratoire de Microbiologie, Hôpital Robert-Debré, Paris, France; §Association Clinique et Thérapeutique du Val-de-Marne (ACTIV), Saint-Maur-des Fossés, ¶CRC, Centre Hospitalier de Créteil, Créteil, France.
Pediatr Infect Dis J. 2015 Jun;34(6):557-61. doi: 10.1097/INF.0000000000000677.
This study aims to analyze the epidemiology of Group A streptococci (GAS) emm-types causing invasive and noninvasive infections in French children.
From September 2009 to May 2011, we analyzed GAS isolates from 585 pharyngitis, 125 invasive infections and, for the first time in France, 32 healthy carriers. M protein gene (emm) typing of the isolates was carried out by a new rapid technique, combining 3 multiplex-polymerase chain reactions (PCRs) coupled to high-resolution melting (HRM) curves, able to detect 13 major emm-types (emm 1, 3, 4, 6, 11, 12, 22, 28, 75, 77, 87, 89 and 102).
GAS belonging to emm-type 1 were more frequently found among invasive infections than among pharyngitis (24.0% vs. 11.5%, P < 0.001); emm 4 and 89 were more common in pharyngitis than in invasive infections (emm-type 4, 17.4% vs. 6.4%, P = 0.002 and emm-type 89, 9.9% vs. 2.4%, P = 0.006, respectively) and emm 3 and 4 were more common in cases of pharyngitis associated with scarlet fever (21.6% vs. 6.0%, P < 0.001 and 29.3% vs. 14.5%, P < 0.001, respectively).
HRM method enables the rapid emm-typing of a large number of isolates in epidemiological studies. Comparison of GAS causing invasive and noninvasive infections in the same population of children displays an unbalanced repartition of emm-types.
本研究旨在分析在法国儿童中引起侵袭性和非侵袭性感染的A组链球菌（GAS）emm型的流行病学特征。
2009年9月至2011年5月，我们分析了来自585例咽炎、125例侵袭性感染以及（法国首次）32例健康携带者的GAS分离株。通过一种新的快速技术对分离株进行M蛋白基因（emm）分型，该技术结合了3种多重聚合酶链反应（PCR）与高分辨率熔解（HRM）曲线，能够检测13种主要的emm型（emm 1、3、4、6、11、12、22、28、75、77、87、89和102）。
emm型1的GAS在侵袭性感染中比在咽炎中更常见（24.0%对11.5%，P<0.001）；emm 4和89在咽炎中比在侵袭性感染中更常见（emm型4，17.4%对6.4%，P = 0.002；emm型89，9.9%对2.4%，P = 0.006），并且emm 3和4在与猩红热相关的咽炎病例中更常见（分别为21.6%对6.0%，P<0.001和29.3%对14.5%，P<0.001）。
HRM方法能够在流行病学研究中对大量分离株进行快速emm分型。对同一儿童群体中引起侵袭性和非侵袭性感染的GAS进行比较，显示出emm型的分布不均衡。
