title: Sub-typing of extended-spectrum-β-lactamase-producing isolates from a nosocomial outbreak: application of a 10-loci generic Escherichia coli multi-locus variable number tandem repeat analysis.
abstract: Extended-spectrum β-lactamase producing Escherichia coli (ESBL-E. coli) were isolated from infants hospitalized in a neonatal, post-surgery ward during a four-month-long nosocomial outbreak and six-month follow-up period. A multi-locus variable number tandem repeat analysis (MLVA), using 10 loci (GECM-10), for 'generic' (i.e., non-STEC) E. coli was applied for sub-species-level (i.e., sub-typing) delineation and characterization of the bacterial isolates. Ten distinct GECM-10 types were detected among 50 isolates, correlating with the types defined by pulsed-field gel electrophoresis (PFGE), which is recognized to be the 'gold-standard' method for clinical epidemiological analyses. Multi-locus sequence typing (MLST), multiplex PCR genotyping of bla CTX-M, bla TEM, bla OXA and bla SHV genes and antibiotic resistance profiling, as well as a PCR assay specific for detecting isolates of the pandemic O25b-ST131 strain, further characterized the outbreak isolates. Two clusters of isolates with distinct GECM-10 types (G06-04 and G07-02), corresponding to two major PFGE types and the MLST-based sequence types (STs) 131 and 1444, respectively, were confirmed to be responsible for the outbreak. The application of GECM-10 sub-typing provided reliable, rapid and cost-effective epidemiological characterizations of the ESBL-producing isolates from a nosocomial outbreak that correlated with and may be used to replace the laborious PFGE protocol for analyzing generic E. coli.
authors.affiliation: Department of Clinical Microbiology, Sahlgrenska University Hospital and Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy of the University of Gothenburg, Göteborg, Sweden.
authors.forename: Nahid
authors.initials: N
authors.lastname: Karami
authors.affiliation: Department of Clinical Microbiology, Sahlgrenska University Hospital and Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy of the University of Gothenburg, Göteborg, Sweden.
authors.forename: Lisa
authors.initials: L
authors.lastname: Helldal
authors.affiliation: Department of Clinical Microbiology, Sahlgrenska University Hospital and Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy of the University of Gothenburg, Göteborg, Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Welinder-Olsson
authors.affiliation: Department of Clinical Microbiology, Sahlgrenska University Hospital and Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy of the University of Gothenburg, Göteborg, Sweden ; Infection Control, Sahlgrenska University Hospital and The Swedish Strategic Programme against Antibiotic Resistance (STRAMA), Västra Götaland Region, Göteborg, Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Ahrén
authors.affiliation: Department of Clinical Microbiology, Sahlgrenska University Hospital and Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy of the University of Gothenburg, Göteborg, Sweden.
authors.forename: Edward R B
authors.initials: ER
authors.lastname: Moore
mesh_terms: D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D004196:Disease Outbreaks; D024881:Drug Resistance, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000145:classification / Q000201:enzymology* / Q000235:genetics*; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008826:Microbial Sensitivity Tests; D018598:Minisatellite Repeats; D058885:Multilocus Sequence Typing; D013548:Sweden / Q000453:epidemiology; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D004269:DNA, Bacterial; D001618:beta-Lactamases