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

Abstract

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.

• Authors: J B Nielsen, A Albayati, R L Jørgensen, K H Hansen, B Lundgren, K Schønning
• Journal: European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology (Eur J Clin Microbiol Infect Dis) Vol. 32 Issue 3 Pg. 431-6 (Mar 2013) ISSN: 1435-4373 [Electronic] Germany
• PMID: 23129461 (Publication Type: Comparative Study, Evaluation Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Bacterial
• beta-Lactamases

Topics

• Adult
• Aged
• DNA, Bacterial (genetics)
• Denmark (epidemiology)
• Electrophoresis, Capillary (methods)
• Escherichia coli (classification, enzymology, isolation & purification)
• Escherichia coli Infections (epidemiology, microbiology)
• Female
• Genotype
• Humans
• Male
• Minisatellite Repeats
• Molecular Typing (methods)
• beta-Lactamases (metabolism)