In the US and Europe, bacteremia are ranked the 7th leading cause of death from all causes. E. coli is one of the main microorganism involved, responsible for 30% to 45% of bacteremia. In Europe, bacteremia E. coli, including BLSE phenotype, have a strong impact on public health, causing increased mortality, particularly in the elderly, and an increase in the average hospital stay. However, few studies have specifically concerned with the criteria associated with mortality of elderly patients with BLSE E. coli bacteremia. Finally, improving epidemiological knowledge of the elderly patients with bacteremia due to BLSE E. coli has importance in terms of public health and is a prerequisite to the development of preventive strategies and to improve the short-term prognosis.

Inclusion Criteria:

• All patients with positive blood culture E. coli BLSE will be included in the study. Bacteremia E. coli BLSE will be defined as the identification of one or more blood cultures positive for E. coli BLSE in patients with clinical criteria of systemic inflammatory response, at least two of the following 4 criteria:

  • temperature> 38 ° C or < 36 ° C;
  • heart rate> 90 beat / min;
  • respiratory rate > 20 c / min or PaCO2 < 32 mmHg;
  • WBC > 12,000 / microL or < 4000 / microL or 10% immature forms

Exclusion Criteria:

• For each patient included, only the first episode of bacteremia will be included in the study

All data concerning blood cultures analyzed in the bacteriology department of University Hospital of Nantes are stored digitally, particularly E. coli ESBL. Thus, the extraction of these data will allow the retrospective inclusion of patients and enhance the feasibility of the study.