E. coli Bacteremia Strains - High diversity and Associations with Agerelated Clinical PhenomenaWester AL1*, Melby KK2,3, Wyller TB2,4 and Dahle UR1
- *Corresponding Author:
- Astrid Louise Wester
Division for Infectious Disease Control
Norwegian institute of public health
P.O. Box 4404 Nydalen, N-0403 Oslo, Norway
Tel: +47 21077000
Fax: +47 22353605
E-mail: [email protected]
Received date: January 20, 2014; Accepted date: February 17, 2014; Published date: February 25, 2014
Citation: Wester AL, Melby KK, Wyller TB, Dahle UR (2014) E. coli Bacteremia Strains - High diversity and Associations with Age-related Clinical Phenomena. Clin Microbial 3:140. doi: 10.4172/2327-5073.1000140
Copyright: © 2014 Wester AL, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Advanced age is associated with an increased proportion of Escherichia coli in bacteremia as well as an increased risk of death from E. coli blood stream infection. Age-associated differences in normal flora E. coli indicate that elderly persons may be diseased by other groups of E. coli than do younger patients. We studied a historical cohort of 212 patients with community-acquired E. coli bacteremia. The bacterial strains were tested for antimicrobial resistance and analyzed by a generic Multi-Locus Variable-Tandem Repeats Analysis (MLVA). The available 212 strains showed a great diversity, and clustered into ten different MLVA-type complexes (MTC). MTC-b, containing 97 of the strains, was associated with ≥1 comorbid illness (OR 2.02, 95% CI 1.12-3.64), and with to ≥1 atypical symptom (OR 0.46, 95% CI 0.27-0.80). MTC-c, containing 31 strains, was associated with urinary origin of infection (OR 3.28, 95% CI 1.345-8.00) and was preventive against gastrointestinal origin of infection (OR 0.11, 95% CI 0.01-0.83). MTC-g, containing only eight strains, was associated with leukopenia (OR 6.43, 95% CI 1.15-36.00). The strains showed low level of antimicrobial resistance. Fifteen of the 212 patients (7.1%) died within 14 days after admission to hospital. Neither MTC nor antimicrobial resistance was associated with hospital mortality. In conclusion, our study showed a great degree of diversity of the strains and that one of the MTCs was associated with age-related clinical phenomena. None of the MTCs were associated with outcome, indicating that patient characteristics are more important than microbial characteristics.