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Relationships between phylogenetic groups of Escherichia coli isolates and clinical characteristics in 161 patients with bacteraemia

Abstract number: p1172

Jaureguy  F., Carbonnelle  E., Bonacorsi  S., Bingen  E., Picard  B., Nassif   X., Lortholary  O.

Objectives: 

The aim of this study was to assess the relationship between phylogenetic groups of Escherichia coli strains isolated from bacteraemia and clinical characteristics of the sepsis.

Methods: 

A prospective study was conducted between December 2002 and December 2003 on 161 patients (including 14 children) with E. coli bacteremia in Necker and Avicenne University Hospitals, Paris, France. Clinical data included primary source of bacteremia, underlying diseases including any immunodeficiency, hospital versus community acquired origin and outcome. Bacteriological data included determination of phylogenetic groups performed by triplex PCR (chuA, yjaA, DNA fragment TSPE4) and antibiotic susceptibility to amoxicillin (AMX), ofloxacin (OFX) and trimethoprim-sulfamethoxazole (STX).

Results: 

Among the 161 case patients, 51 % were older than 65 years, 36% were immunocompromised and their severity sepsis scoring according to Bone's criteria was: Stage 2 (81.4 %), Stage 3 (7.5 %) and Stage 4 (11.5 %). Of the 161 E. coli blood infections, 38. 5% were of nosocomial origin. The most frequent source of bacteremia was the urinary tract (41 %) followed by the digestive tract (10.6%). The 161 strains were distributed into phylogenetic groups B2 (49.7%), D (22.4 %), A1 (21.7 %) and B1 (6.2 %). Sixty three percent of these isolates were resistant to AMX, 38 % to STX and 17 % to OFX. A factorial analysis of correspondence conducted on the data allowed the distinction of 2 groups of strains. The strains belonging to the phylogenetic group B2 were more frequently associated to the following characteristics: susceptibility to the 3 tested antibiotics, community acquired infection, urinary tract origin, immunocompetent host and favourable outcome. The strains belonging to the phylogenetic groups A, B1 and D were more frequently associated to: resistance to the 3 tested antibiotics, hospital acquired infection, non urinary tract origin, immunocompromised host, Stage 4 and higher mortality.

Conclusion: 

Results distinguished: (i) urosepsis due to B2 group susceptible strains infecting immunocompetent patients with favourable outcome, (ii) bacteraemia of others sources due to non-B2 group resistant strains infecting older and immunocompromised patients with severe outcome.

Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Subject:
Location: Oxford, UK
Presentation type:
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