Mamani Rosalia, Flament-Simon Saskia Camille, García Vanesa, Mora Azucena, Alonso María Pilar, López Cecilia, García-Meniño Isidro, Díaz-Jiménez Dafne, Blanco Jesús E, Blanco Miguel, Blanco Jorge
Laboratorio de Referencia de E. coli, Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela, Lugo, Spain.
Unidade de Microbioloxía Clínica, Hospital Universitario Lucus Augusti, Lugo, Spain.
Front Microbiol. 2019 Jul 16;10:1530. doi: 10.3389/fmicb.2019.01530. eCollection 2019.
The aim of the present study was to examine the prevalence and determine the molecular characteristics of extended-spectrum β-lactamase-producing (ESBL-EC) causing bacteraemia in a Spanish Hospital over a 12-year period (2000 to 2011). As far as we know, this is the first study which has investigated and compared the serotypes, phylogroups, clonotypes, virotypes, and PFGE profiles of ST131 and non-ST131 clones of bacteraemia ESBL-EC isolates. Of the 2,427 bloodstream isolates, 96 (4.0%) were positive for ESBL production: 40 for CTX-M-15, 36 for CTX-M-14, eight for CTX-M-1, four for CTX-M-9, CTX-M-32, and SHV-12. The number of ESBL-EC increased from 1.0% during 2000 to 2005 to 5.5% during 2006-2011 ( < 0.001). The 96 ESBL-EC isolates belonged to 36 different STs. The commonest was ST131 (41 isolates), followed by ST58, ST354, ST393 and ST405 (four isolates each). Most CTX-M-15 isolates (87.5%, 35/40) were ST131, whereas the 36 CTX-M-14 isolates belonged to 23 different STs and only 3 (8.3%) of them were ST131. The 35 ST131 CTX-M-15-producing isolates belonged to the 30Rx subclone and 29 of them showed the virotype A. A drastic change in ST131 virotypes happened in 2011 due to the emergence of the virotypes E (, , , , and ) and F (, , and ) which displaced virotype A (, operon FM955459, , and ). Although the 96 ESBL-EC isolates showed 21 O serogroups and 17 H flagellar antigens, 39 belonged to serotype O25b:H4 (ST131 isolates). The second most prevalent serotype (O15:H1) was found to be associated with another important high-risk clone (ST393). In conclusion, the ST131 was the most frequent sequence type, being the 30Rx subclone responsible for the significant increase of ESBL-EC isolates since 2006. Here, we report two new virotypes (E and F) of the 30Rx subclone emerged in 2011. Future molecular studies are needed to understand the dynamics of expansion of this successful high-risk subclone in order to prevent its spread and establish the importance of the two new virotypes.
本研究的目的是调查西班牙一家医院在12年期间（2000年至2011年）产超广谱β-内酰胺酶（ESBL-EC）导致菌血症的流行情况并确定其分子特征。据我们所知，这是第一项对菌血症ESBL-EC分离株的ST131和非ST131克隆的血清型、系统发育群、克隆型、病毒型和PFGE图谱进行研究和比较的研究。在2427株血流分离株中，96株（4.0%）ESBL检测呈阳性：40株产CTX-M-15，36株产CTX-M-14，8株产CTX-M-1，4株产CTX-M-9、CTX-M-32和SHV-12。ESBL-EC的数量从2000年至2005年期间的1.0%增加到2006 - 2011年期间的5.5%（P<0.001）。96株ESBL-EC分离株属于36种不同的序列型。最常见的是ST131（41株），其次是ST58、ST354、ST393和ST405（各4株）。大多数产CTX-M-15的分离株（87.5%，35/40）是ST131，而36株产CTX-M-14的分离株属于23种不同的序列型，其中只有3株（8.3%）是ST131。35株产CTX-M-15的ST131分离株属于30Rx亚克隆，其中29株显示病毒型A。2011年，由于病毒型E（、、、、和）和F（、、和）的出现取代了病毒型A（、操纵子FM955459、、和），ST131病毒型发生了急剧变化。虽然96株ESBL-EC分离株显示出21种O血清群和17种H鞭毛抗原，但39株属于O25b:H4血清型（ST131分离株）。第二常见的血清型（O15:H1）被发现与另一个重要的高风险克隆（ST393）相关。总之，ST131是最常见的序列型，30Rx亚克隆是自2006年以来ESBL-EC分离株显著增加的原因。在此，我们报告了2011年出现的30Rx亚克隆的两种新病毒型（E和F）。未来需要进行分子研究以了解这个成功的高风险亚克隆的扩张动态，从而防止其传播并确定这两种新病毒型的重要性。
