ABSTRACT
There is worldwide concern about the appearance and rise of bacterial resistance to commonly used antibiotics. Although the gut is an important reservoir for resistant Escherichia coli, data from large-scale epidemiological studies concerning the colonisation dynamics of the normal gut flora with resistant E. coli during and after antibiotic therapy are sparse. Accordingly, a large community-based study was conducted to ascertain changes in the prevalence of resistant E. coli during and after antibiotic treatment. Stool samples before, during and after antibiotic therapy were obtained from 541 patients (aged >/=40 years) with a febrile infection who attended a general practitioner in southern Germany. The MICs of commonly prescribed antibiotics for E. coli isolates from the stools were determined. The prevalence of resistance to the corresponding antibiotics rose from 18% to 38%, from 29% to 58% and from 33% to 67% during treatment with beta-lactam antibiotics, doxycycline and co-trimoxazole, respectively. Prevalences of resistance in the E. coli isolates also rose for other antibiotic classes. With the exception of co-trimoxazole resistance, prevalences of resistance returned to baseline levels in <2 weeks after the cessation of antibiotic therapy. Thus, there was a substantial, but rapidly reversible, increase in the prevalence of resistant E. coli isolates during antibiotic treatment.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Drug Resistance, Bacterial , Escherichia coli Infections/drug therapy , Escherichia coli Infections/microbiology , Escherichia coli/drug effects , Adult , Aged , Aged, 80 and over , Escherichia coli/isolation & purification , Feces/microbiology , Female , Germany , Humans , Longitudinal Studies , Male , Microbial Sensitivity Tests , Middle Aged , OutpatientsABSTRACT
PURPOSE: The aim of the study was to assess the prevalence and determinants of antibiotic-resistant Enterococci in a large group of outpatients in Southern Germany. METHODS: Stool samples were collected from 497 unselected patients aged 40-75 years attending general practitioners. Enterococcus faecium (E. faecium) and Enterococcus faecalis (E. faecalis) were cultured and minimal inhibitory concentrations of antibiotics used inside and outside the clinical sector were tested. RESULTS: E. faecium and E. faecalis could be identified and cultured in 60 (12.4%) and 205 (41.2%) of the stool samples, respectively. Under non-selective culture conditions no vancomycin-resistant Enterococcus (VRE) isolate was found. Only E. faecium isolates showed resistance to fluoroquinolones, 40% were resistant to ciprofloxacin. The prevalences of E. faecium resistance to ampicillin and doxycycline were 3.3% and 13.3%, respectively, whereas 0.5% and 29.6% of the E. faecalis isolates were resistant to ampicillin and doxycycline, respectively. Antibiotic use during the last 3 months was significantly associated with antibiotic resistance (to either ampicillin, imipenem, or doxycycline) of E. faecalis isolates (OR: 2.9; CI: 1.2-6.8). CONCLUSIONS: Prevalences of resistance were generally lower than and patterns of resistance were quite different from previous investigations in the clinical setting. Recent antibiotic use was associated with increased colonization with resistant strains.
Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Enterococcus faecalis/drug effects , Enterococcus faecium/drug effects , Feces/microbiology , Gram-Positive Bacterial Infections/epidemiology , Adult , Aged , Ampicillin/pharmacology , Ciprofloxacin/pharmacology , Doxycycline/pharmacology , Enterococcus faecalis/growth & development , Enterococcus faecalis/isolation & purification , Enterococcus faecium/growth & development , Enterococcus faecium/isolation & purification , Female , Germany/epidemiology , Gram-Positive Bacterial Infections/drug therapy , Humans , Male , Microbial Sensitivity Tests , Middle Aged , PrevalenceABSTRACT
Although the great majority of antibiotics are prescribed outside hospitals, little is known about the prevalence and determinants of antibiotic resistance in the group of outpatients. Nasal swabs were taken from 627 consecutive patients aged 40 years or above attending general practitioners in Southern Germany. Staphylococcus aureus was cultured and minimal inhibitory concentrations to various antibiotics were tested. Nasal swabs of 152 patients were positive for S. aureus. Prevalence of resistance was 68.3, 8.3 and 0.7% for penicillin G, erythromycin, and oxacillin respectively. Antibiotic use within the last month was associated with erythromycin resistance [adjusted odds ratio (OR) 7.4; 95 % confidence interval (CI) 1.0-53]. Besides a high prevalence of resistance to penicillinase-instable antibiotics we found only one (0.7%) methicillin-resistant S. aureus. Recent antibiotic use was associated with increased resistance to erythromycin.
