RT Journal Article
T1 Four main virotypes among extended-spectrum-β-lactamase-producing isolates of Escherichia coli O25b:H4-B2-ST131: bacterial, epidemiological, and clinical characteristics.
A1 Blanco, Jorge
A1 Mora, Azucena
A1 Mamani, Rosalia
A1 López, Cecilia
A1 Blanco, Miguel
A1 Dahbi, Ghizlane
A1 Herrera, Alexandra
A1 Marzoa, Juan
A1 Fernández, Val
A1 de la Cruz, Fernando
A1 Martínez-Martínez, Luis
A1 Alonso, María Pilar
A1 Nicolas-Chanoine, Marie-Hélène
A1 Johnson, James R
A1 Johnston, Brian
A1 López-Cerero, Lorena
A1 Pascual, Alvaro
A1 Rodríguez-Baño, Jesús
K1 Escherichia coli
K1 Infecciones por escherichia coli
K1 Epidemiología molecular
K1 Polimorfismo de longitud del fragmento de restricción
K1 beta-Lactamasas
AB A total of 1,021 extended-spectrum-β-lactamase-producing Escherichia coli (ESBLEC) isolates obtained in 2006 during a Spanish national survey conducted in 44 hospitals were analyzed for the presence of the O25b:H4-B2-ST131 (sequence type 131) clonal group. Overall, 195 (19%) O25b-ST131 isolates were detected, with prevalence rates ranging from 0% to 52% per hospital. Molecular characterization of 130 representative O25b-ST131 isolates showed that 96 (74%) were positive for CTX-M-15, 15 (12%) for CTX-M-14, 9 (7%) for SHV-12, 6 (5%) for CTX-M-9, 5 (4%) for CTX-M-32, and 1 (0.7%) each for CTX-M-3 and the new ESBL enzyme CTX-M-103. The 130 O25b-ST131 isolates exhibited relatively high virulence scores (mean, 14.4 virulence genes). Although the virulence profiles of the O25b-ST131 isolates were fairly homogeneous, they could be classified into four main virotypes based on the presence or absence of four distinctive virulence genes: virotypes A (22%) (afa FM955459 positive, iroN negative, ibeA negative, sat positive or negative), B (31%) (afa FM955459 negative, iroN positive, ibeA negative, sat positive or negative), C (32%) (afa FM955459 negative, iroN negative, ibeA negative, sat positive), and D (13%) (afa FM955459 negative, iroN positive or negative, ibeA positive, sat positive or negative). The four virotypes were also identified in other countries, with virotype C being overrepresented internationally. Correspondingly, an analysis of XbaI macrorestriction profiles revealed four major clusters, which were largely virotype specific. Certain epidemiological and clinical features corresponded with the virotype. Statistically significant virotype-specific associations included, for virotype B, older age and a lower frequency of infection (versus colonization), for virotype C, a higher frequency of infection, and for virotype D, younger age and community-acquired infections. In isolates of the O25b:H4-B2-ST131 clonal group, these findings uniquely define four main virotypes, which are internationally distributed, correspond with pulsed-field gel electrophoresis (PFGE) profiles, and exhibit distinctive clinical-epidemiological associations.
PB American Society for Microbiology
SN 0095-1137
YR 2013
FD 2013-10
LK http://hdl.handle.net/10668/2084
UL http://hdl.handle.net/10668/2084
LA en
NO Blanco J, Mora A, Mamani R, López C, Blanco M, Dahbi G, et al. Four main virotypes among extended-spectrum-β-lactamase-producing isolates of Escherichia coli O25b:H4-B2-ST131: bacterial, epidemiological, and clinical characteristics. J. Clin. Microbiol.. 2013; 51(10):3358-67
NO Journal Article; Research Support, Non-U.S. Gov't;
DS RISalud
RD Apr 8, 2025