Epidemiology of third-generation cephalosporin-resistant community-acquired Enterobacteria isolated from elderly patients

Abstract

Aims: This survey was made to study the epidemiology of multiresistant bacteria (MRB) in the French community, among elderly patients 65 years of age or more, carrying third-generation cephalosporin-resistant (3GC-resistant) Enterobacteriaceae, and the co-resistance of prescribed antibiotics.

Methods: The data was collected in 2009 in the West of France by MedQual, a network of 174 private laboratories.

Results: Two thousand one hundred and sixty strains of the 88,255 identified Enterobacteria strains were 3GC-resistant (2.4%) and 945 of these strains (41.8%) were isolated from elderly patients 65 years of age or more. Escherichia coli was the predominant 3GC-resistant strain (72.7%). 51.4% of the 945 patients in whom a 3GC-resistant strain was isolated produced an extended-spectrum β-lactamase (ESBL). The main risk factors for infection with the 3GC-resistant strain were hospitalization and antibiotic treatment in the previous year (58.2 and 86.9%, respectively). Hospitalization during the previous year was more frequent among elderly patients who lived at home compared with those who lived in nursing homes (P<0.05). The production of ESBL, among the 945 patients who carried the 3GC-resistant strains, was similar among patients who lived at home compared with those who lived in nursing homes (51.4% versus 49.7%).

Conclusion: Microbiologists should warn family physicians about MRB isolates with a specific antimicrobial resistance pattern (3GC-resistant, fluoroquinolone-resistant, etc.) to prescribe more effective medications.

Keywords: BLSE; Bactéries multirésistantes; Community ecology; ESBL; Enterobacteria; Entérobactéries; Multi-drug resistant strain; Écologie communautaire.