Background: Screening for bacterial colonization among risk populations could provide better estimates of the volume of the bacteria-related disease reservoir and the level of antimicrobial resistance, than do conventional laboratory reports. Methods: Two hundred and one participants at 10 Swedish nursing homes were screened for colonization with Staphylococcus aureus between January and October 2009. Of the 201 participants, 61 (30%) were male. The median age was 86 y. All participants were systematically sampled from the nasal mucosa, the pharyngeal mucosa, the groin, and active skin lesions, if any. Results: Ninety-nine of 199 participants (50%) were colonized with S. aureus. The colonization rate was 34% for the nose, 35% for throat, 10% for groin, and 54% for active skin lesions. An antibiotic-resistant S. aureus isolate was identified in 8.5% of all participants regardless of colonization status. A total of 24 resistant isolates were detected, and 21 of these were resistant to fluoroquinolones. There was no case of colonization with methicillin-resistant S. aureus (MRSA). Conclusions: The presence of resistant isolates was generally low, and the greater part of the resistance was fluoroquinolone-related. To achieve reasonable precision, screening programmes of this kind must include samples from both the nose and throat, and, although low, the prevalence of antimicrobial resistance in Swedish nursing homes still calls for reflection on how to use the fluoroquinolones wisely. © 2012 Informa Healthcare.

Knowledge of carriage and population dynamics of Staphylococcus aureus is crucial for infection risk assessment and to reveal transmission patterns of strains. We report the prevalence and molecular epidemiology of S. aureus in elderly people (n = 290) living in nursing homes in three cities in the south of Sweden. The overall carriage prevalence rate was 48% when results from nares (31%) and throat (34%) samples were combined. Common spa types were equally distributed but a frequent type, t160, was found only in one of the regions. Carriage of different spa types was detected in 23% of individuals and antimicrobial resistance rates were higher in S. aureus isolates from those carrying more than one spa type. Five of the 21 individuals who carried different spa types were colonized simultaneously with resistant and non-resistant strains. Seventeen per cent of the individuals carried S. aureus of the same spa type on all occasions. Methicillin resistance was not detected. In conclusion we found a high prevalence of S. aureus in this elderly population with a high rate of dual colonization with different spa types. We also found signs of institutional spread of one strain.

Background: Screening for bacterial colonization and antimicrobial resistance (AMR) among a defined population could aid in the identification of at-risk populations and provide targets for antibiotic stewardship and infection control programmes. Methods: Two hundred and sixty-eight participants at 11 Swedish nursing homes underwent serial screening for colonization with Escherichia coli between March 2008 and September 2010. Seventy-two of the 268 participants (27%) were male. The median age was 85 y. Samples were collected from urine, the rectal mucosa, the groin, and active skin lesions. Results: Two hundred and nine of 268 participants (78%) were colonized with E. coli at any body site/fluid. The specific colonization rates were 81% (rectum), 48% (urine), 30% (groin), 59% (unknown), and 13% (skin lesion). An antibiotic-resistant E. coli isolate was identified in 18% of all participants regardless of colonization status; all together, 87 resistant isolates were detected. Only 1 participant carried isolates with resistance to third-generation cephalosporins (cefotaxime and ceftazidime). Conclusions: The presence of resistance was generally low, and the greater part of the resistant cases was connected with 3 common antibiotics: ampicillin, trimethoprim/sulfamethoxazole, and ciprofloxacin. In spite of generally increasing resistance against third-generation cephalosporins in E. coli in Sweden, this study does not implicate residence at a Swedish nursing home as a risk factor for the acquisition of expressed cephalosporin resistance.