The purpose of this study was to characterize the antibiotic resistance, virulence, and genetic diversity among invasive and non-invasive Streptococcus dysgalactiae subsp. equisimilis (SDSE) isolates. SDSE were isolated from clinical samples of outpatients and inpatients cares in La Rioja region (Spain) during 2012–2015. The analyses performed were susceptibility testing by disc diffusion, resistance and virulence genes by PCR, emm typing by PCR and sequencing, and other molecular typing by SmaI-PFGE and MLST. Forty-two SDSE isolates were recovered (64.3% non-invasive, 35.7% invasive) that were grouped in 31 PFGE patterns, 17 ST, and 14 emm types, being stC1400, stG6792, and stG62647 the most frequent, and stC74a and stC5345 exclusive in invasive SDSE. Twenty-one SDSE were resistant to at least one antibiotic. The erm(TR) and erm(B) genes were linked with resistance to macrolides; tet(M) and tet(T) to tetracycline; dfrF to trimethoprim; ant(6)-Ia and aph(3′)-IIIa to aminoglycosides; and the substitutions Asp80Ala in GyrA and Ser79Phe in ParC with resistance to levofloxacin. The sagA, slo, scpA, and ska virulence genes were amplified in 93% SDSE. Streptococcal superantigenic speG^dys gene was identified in 80% of invasive and 63% of non-invasive SDSE and correlated with certain emm types (e.g., stG62647 or stG6792). SDSE invasive infections were most frequent in elderly patients, and half of our SDSE were resistant to at least one antibiotic tested. This work is the first detection of tet(T), dfrF, and new substitution in GyrA protein in SDSE. A high diversity of circulating genetic lineages was found among our SDSE.

本研究的目的是表征侵袭性和非侵袭性停乳链球菌亚种的抗生素耐药性、毒力和遗传多样性。似马链球菌（SDSE）分离物。SDSE 是从 2012-2015 年拉里奥哈地区（西班牙）的门诊和住院患者的临床样本中分离出来的。所进行的分析是通过圆盘扩散进行的敏感性测试、通过 PCR 进行的抗性和毒力基因、通过 PCR 和测序进行的emm分型以及通过SmaI -PFGE 和 MLST 进行的其他分子分型。回收了 42 个 SDSE 分离株（64.3% 非侵入性，35.7% 侵入性），它们分为 31 种 PFGE 模式、17 种 ST 和 14 种emm类型，分别是stC1400、stG6792和stG62647最常见，而stC74a和stC5345在侵入性 SDSE 中是唯一的。21 种 SDSE 对至少一种抗生素具有抗性。的ERM（TR）和ERM（B）基因与对大环内酯类电阻连接; tet (M) 和tet (T) 为四环素；dfrF到甲氧苄啶；ant (6)-Ia 和aph (3')-IIIa 为氨基糖苷类；GyrA 中的 Asp80Ala 和 ParC 中的 Ser79Phe 取代对左氧氟沙星具有抗性。在佐贺，SLO，SCPA和斯卡毒力基因在 93% SDSE 中扩增。链球菌超抗原SPEG ^DYS基因中的侵入性80％，非侵入性的SDSE的63％被确定并与某些相关的EMM类型（例如，stG62647或stG6792）。SDSE 侵袭性感染在老年患者中最为常见，我们有一半的 SDSE 对至少一种测试的抗生素具有抗药性。这项工作是首次在 SDSE 中检测到tet (T)、dfrF和 GyrA 蛋白中的新替代。在我们的 SDSE 中发现了高度多样性的循环遗传谱系。