An abbreviated MLVA identifies Escherichia coli ST131 as the major extended-spectrum β-lactamase-producing lineage in the Copenhagen area

• Published in: European journal of clinical microbiology & infectious diseases 2013-03, Vol.32 (3), p.431-436
• Main Authors: Nielsen, J. B., Albayati, A., Jørgensen, R. L., Hansen, K. H., Lundgren, B., Schønning, K.
• Format: Article
• Language: English
• Subjects: Adult; Age; Aged; beta -Lactamase; beta-Lactamases - secretion; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; capillary electrophoresis; Cefpodoxime; Demography; Denmark - epidemiology; DNA, Bacterial - genetics; Electrophoresis, Capillary - methods; Escherichia coli; Escherichia coli - classification; Escherichia coli - enzymology; Escherichia coli - isolation & purification; Escherichia coli Infections - epidemiology; Escherichia coli Infections - microbiology; Female; Genotype; Humans; Infection; Infectious diseases; Internal Medicine; Male; Medical Microbiology; Medical sciences; Minisatellite Repeats; Molecular Typing - methods; multilocus sequence typing; Polymerase chain reaction; Typing
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-012-1764-x

Rapid bacterial typing is a valuable and necessary tool in the prevention and detection of outbreaks. The purpose of this study was to adapt a multilocus variable number of tandem repeats analysis (MLVA) for analysis on a benchtop capillary electrophoresis instrument and compare the modified assay with multilocus sequence typing (MLST) for typing cefpodoxime-resistant Escherichia coli ( E . coli ). Further, we identified the causative resistance mechanisms and epidemiological type of infection for isolates producing extended-spectrum β-lactamases (ESBLs). A collection of E . coli resistant to cefpodoxime was typed by MLST and a modified MLVA assay using a benchtop capillary electrophoresis instrument. Resistance mechanisms were identified by polymerase chain reaction (PCR) and sequencing. Patient history was examined to establish the epidemiological type of infection for ESBL-producing E . coli . MLVA yielded typing results homologous with MLST and it correctly identified E . coli sequence type (ST) 131 that was accounting for 45 % of all ESBL-producing isolates in the sample collection. The majority (76.7 %) of ESBL-producing isolates was healthcare-related and only 23.3 % of the ESBL-producing isolates were community-onset infections (COI), regardless of the ST. Patients with COI were significantly more often of female gender and younger age compared to healthcare-associated infections (HCAI) and hospital-onset infections (HOI). In conclusion, the modified MLVA is a useful tool for the rapid typing of E . coli and it identified ST131 as the predominating ESBL-producing lineage in Copenhagen. Healthcare-related infections were the predominant infection setting of ESBL-producing E . coli and the demographic characteristics differed between patients with COI and healthcare-related infections.