Faecal carriage of extended-spectrum b-lactamase-producing Escherichia coli: prevalence and risk factors in different populations

Abstract number: 1732_281

Rodríguez-Baño J., Navarro M.D., López-Cerero L., Morillo C., Muniain M.A., Pascual A.

Objectives: Extended-spectrum b-lactamase-producing Escherichia coli (ESBLEC) is an emerging cause of community acquired infections. We investigated the prevalence of faecal carriage of ESBLEC in different groups of patients and the variables associated with carriage.

Methods: Faecal carriage of ESBLEC was investigated from June 2005 to September 2006 in 4 groups of persons: outpatients from whom ESBLEC had been isolated from a clinical sample (group A); living-together relatives (group B1); non-living-together relatives (group B2); and patients randomly chosen among those being attended at the emergency department (group C). Rectal swabs were obtained from all of them and inoculated in MacConkey-cefotaxime (2 mg) and MacConkey-ceftazidime (2 mg). ESBL production was studied following CLSI recommendations. The following data were collected: demographics, previous healthcare relation, co-morbidities, previous use of antimicrobials and proton-pump inhibitors, invasive procedures, feeding habits, and pets. Multivariate analysis of the association of the different variables with faecal carriage were performed using logistic regression.

Results: We included 54, 74, 32, and 54 patients in groups A, B1, B2 and C, respectively. Rectal colonisation by ESBLEC was detected in 36 (68%), 22 (30%), 5 (16%) and 4 (7%) persons from groups A, B1, B2 and C, respectively. The prevalence rates were significantly different between group A and all others (p < 0.001), and between groups B1 and C (p = 0.02). Among people in groups B1, B2 and C, multivariate analysis showed higher risk of colonisation in relatives of group A patients, either living with them (OR = 16.1; 95% CI: 4.1–63.6; p < 0.001) or not (OR = 6.2; 95% CI: 1.2–29.8; p = 0.02), and in those with co-morbidities (OR = 3.8; 95% CI: 1.4–10.2; p = 0.008), and lower risk in those eating out more frequently (OR = 0.3; 95% CI: 0.1–0.9; p = 0.02) and eating pork more frequently (OR = 0.6; 95% CI: 0.3–1.0; p = 0.06). Previous antimicrobial use was not associated with increased risk.

Conclusions: Faecal carriage of ESBLEC is more frequent in relatives of patients from which ESBLEC is isolated from a clinical sample than in non relatives, suggesting either person to person transmission of isolates/genetic elements, or acquisition from a common source. Some feeding habits were associated with carriage, but previous antimicrobial use was not. Molecular studies are progress to further elucidate the epidemiology of faecal carriage of ESBLEC.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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