Abstract
Objectives: Escherichia coli is the commonest agent of bacteraemia, bacterial
gastroenteritis, and UTIs. The lineages causing UTIs and gastrointestinal disease are well defined, but less is known about those causing bacteraemia. We therefore investigated the population structure of E. coli from bacteraemia in the UK and Ireland between 2001 and 2010.
Methods: E. coli isolates (n = 2166) were submitted to the BSAC Bacteraemia Surveillance Programme from 18 UK and Irish centres from 2001-10. Genotypes were analysed by MLST using the Achtman scheme; MICs, blaCTX-M-group and patient demographics were previously determined in the BSAC surveillance.
Results: 448 sequence types (STs) were identified but five of these, and their associated clonal complexes (CCs), accounted for 58.4% (1264/2166) isolates: CC73 was the most common (20.7%), followed by CC131 (13.9%), CC95 (11.3%), CC69 (6.9%) and CC12 (5.5%). All these, except CC69 (group D), belong to phylogenetic group B2. CC131 isolates were much more often MDR than other STs: they rose from 2.9% of isolates in 2001 to 20.5-20.7% in 2007-8, then declined to 14.3% in 2010. Resistance rates to cephalosporins, aminoglycosides and fluoroquinolones remained below 10% in other major CCs throughout.
Conclusions: The five most prevalent bacteraemia STs have all been associated previously with UTIs. They dominated in all years, but their proportions fluctuated, most notably for ST131, a globally-disseminated high-risk clone that is often MDR.
gastroenteritis, and UTIs. The lineages causing UTIs and gastrointestinal disease are well defined, but less is known about those causing bacteraemia. We therefore investigated the population structure of E. coli from bacteraemia in the UK and Ireland between 2001 and 2010.
Methods: E. coli isolates (n = 2166) were submitted to the BSAC Bacteraemia Surveillance Programme from 18 UK and Irish centres from 2001-10. Genotypes were analysed by MLST using the Achtman scheme; MICs, blaCTX-M-group and patient demographics were previously determined in the BSAC surveillance.
Results: 448 sequence types (STs) were identified but five of these, and their associated clonal complexes (CCs), accounted for 58.4% (1264/2166) isolates: CC73 was the most common (20.7%), followed by CC131 (13.9%), CC95 (11.3%), CC69 (6.9%) and CC12 (5.5%). All these, except CC69 (group D), belong to phylogenetic group B2. CC131 isolates were much more often MDR than other STs: they rose from 2.9% of isolates in 2001 to 20.5-20.7% in 2007-8, then declined to 14.3% in 2010. Resistance rates to cephalosporins, aminoglycosides and fluoroquinolones remained below 10% in other major CCs throughout.
Conclusions: The five most prevalent bacteraemia STs have all been associated previously with UTIs. They dominated in all years, but their proportions fluctuated, most notably for ST131, a globally-disseminated high-risk clone that is often MDR.
| Original language | English |
|---|---|
| Pages (from-to) | 2139-2142 |
| Number of pages | 4 |
| Journal | Journal of Antimicrobial Chemotherapy |
| Volume | 71 |
| Issue number | 8 |
| Early online date | 5 May 2016 |
| DOIs | |
| Publication status | Published - Aug 2016 |
Keywords
- MLST
- antimicrobial resistance,
- Molecular Epidemiology