Sequence Types, Clonotypes, Serotypes, and Virotypes of Extended-Spectrum β-Lactamase-Producing Escherichia coli Causing Bacteraemia in a Spanish Hospital Over a 12-Year Period (2000 to 2011)

Rosalia Mamani; Saskia Camille Flament-Simon; Vanesa García; Azucena Mora; María Pilar Alonso; Cecilia López; Isidro García-Meniño; Dafne Díaz-Jiménez; Jesús E Blanco; Miguel Blanco; Jorge Blanco

doi:10.3389/fmicb.2019.01530

Sequence Types, Clonotypes, Serotypes, and Virotypes of Extended-Spectrum β-Lactamase-Producing Escherichia coli Causing Bacteraemia in a Spanish Hospital Over a 12-Year Period (2000 to 2011)

Front Microbiol. 2019 Jul 16:10:1530. doi: 10.3389/fmicb.2019.01530. eCollection 2019.

Affiliations

¹ Laboratorio de Referencia de E. coli, Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela, Lugo, Spain.
² Unidade de Microbioloxía Clínica, Hospital Universitario Lucus Augusti, Lugo, Spain.

Abstract

The aim of the present study was to examine the prevalence and determine the molecular characteristics of extended-spectrum β-lactamase-producing Escherichia coli (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 E. coli 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 (P < 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 H30Rx 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 (sat, papGII, cnf1, hlyA, and kpsMII-K5) and F (sat, papGII, and kpsMII-K5) which displaced virotype A (afa/draBC, afa operon FM955459, sat, and kpsMII-K2). 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 H30Rx subclone responsible for the significant increase of ESBL-EC isolates since 2006. Here, we report two new virotypes (E and F) of the H30Rx 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.

Keywords: E. coli; ESBL; ExPEC; H30Rx subclone; ST131 clonal group; clonotypes.