title: Virulence profiles of bacteremic extended-spectrum β-lactamase-producing Escherichia coli: association with epidemiological and clinical features.
abstract: There is scarce data about the importance of phylogroups and virulence factors (VF) in bloodstream infections (BSI) caused by extended-spectrum β-lactamase-producing Escherichia coli (ESBLEC). A prospective multicenter Spanish cohort including 191 cases of BSI due to ESBLEC was studied. Phylogroups and 25 VF genes were investigated by PCR. ESBLEC were classified into clusters according to their virulence profiles. The association of phylogropus, VF, and clusters with epidemiological features were studied using multivariate analysis. Overall, 57.6%, 26.7%, and 15.7% of isolates belonged to A/B1, D and B2 phylogroups, respectively. By multivariate analysis (adjusted OR [95% CI]), virulence cluster C2 was independently associated with urinary tract source (5.05 [0.96-25.48]); cluster C4 with sources other than urinary of biliary tract (2.89 [1.05-7.93]), and cluster C5 with BSI in non-predisposed patients (2.80 [0.99-7.93]). Isolates producing CTX-M-9 group ESBLs and from phylogroup D predominated among cluster C2 and C5, while CTX-M-1 group of ESBL and phylogroup B2 predominantes among C4 isolates. These results suggest that host factors and previous antimicrobial use were more important than phylogroup or specific VF in the occurrence of BSI due to ESBLEC. However, some associations between virulence clusters and some specific epidemiological features were found.
authors.affiliation: Unidad Clínica de Enfermedades Infecciosas y Microbiología, Hospital Universitario Virgen Macarena, Sevilla, Spain. jesusrb@us.es
authors.forename: Jesús
authors.initials: J
authors.lastname: Rodríguez-Baño
authors.forename: Jesús
authors.initials: J
authors.lastname: Mingorance
authors.forename: Natalia
authors.initials: N
authors.lastname: Fernández-Romero
authors.forename: Lara
authors.initials: L
authors.lastname: Serrano
authors.forename: Lorena
authors.initials: L
authors.lastname: López-Cerero
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pascual
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000890:Anti-Infective Agents / Q000494:pharmacology; D016470:Bacteremia / Q000382:microbiology* / Q000473:pathology*; D024881:Drug Resistance, Bacterial / Q000187:drug effects / Q000235:genetics; D004926:Escherichia coli / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000473:pathology; D005260:Female; D005798:Genes, Bacterial / Q000235:genetics; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D005810:Multigene Family / Q000235:genetics; D015999:Multivariate Analysis; D010802:Phylogeny; D013030:Spain; D014774:Virulence / Q000187:drug effects / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D000890:Anti-Infective Agents; D037521:Virulence Factors; D001618:beta-Lactamases