title: Prevalence and resistance patterns of commensal S. aureus in community-dwelling GP patients and socio-demographic associations. A cross-sectional study in the framework of the APRES-project in Austria.
abstract: BACKGROUND
  The aim of the present study was to assess the prevalence and resistance of commensal S. aureus in the nasal microbiota of community-dwelling persons in Austria, as well as to identify possible associations with socio-demographic factors. Multi-drug resistance in this population was additionally studied.
  
  
  METHODS
  This cross-sectional study was conducted within the context of the European APRES project. In nine European countries, nasal swabs were collected from 32,206 general practice patients who received care for non-infectious reasons. In Austria, 20 GPs attempted to recruit 200 consecutive patients without infectious diseases, with each patient completing demographic questionnaires as well as providing a nose swab sample. Isolation, identification, and resistance testing of S. aureus were performed. Statistical analyses included subgroup analyses and logistic regression models.
  
  
  RESULTS
  3309 nose swabs and corresponding questionnaires from Austrian subjects were analyzed. S. aureus was identified in 16.6 % (n = 549) of nose swabs, of which 70.1 % were resistant against one or more antibiotics, mainly penicillin. S. aureus carrier status was significantly associated with male sex (OR 1.6; 1.3-2.0), younger age (OR 1.3; 1.0-1.8), living in a rural area (OR 1.4; 1.1-1.7) and working in the healthcare sector (OR 1.5; 1.0-2.1). Multi-drug resistances were identified in 13.7 % (n = 75) of the S. aureus carriers and 1.5 % (n = 8) tested positive for MRSA. The highest resistance rate was observed against penicillin (64.8 %), followed by azithromycin (13.5 %) and erythromycin with 13.3 %.
  
  
  CONCLUSIONS
  This study describes the prevalence and resistance patterns of commensal S. aureus in community-dwelling persons in Austria and shows that differences exist between socio-demographic groups. Demographic associations have been found for S. aureus carriers but not for carriers of resistant S. aureus strains. Only two thirds of S. aureus strains were found to be resistant against small spectrum penicillin. As it is recognized that one of the corner stones for the containment of antibiotic resistance is the appropriate prescription of antibiotics in the outpatient sector, this finding lends support to the avoidance of prescription of broad-spectrum antibiotics to treat S. aureus infections in the community.
authors.affiliation: Department of General Practice and Family Medicine, Centre for Public Health, Medical University of Vienna, Kinderspitalgasse 15/1st floor, 1090, Vienna, Austria. kathryn.hoffmann@meduniwien.ac.at.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Hoffmann
authors.affiliation: Department of Medical Microbiology, Maastricht University Medical Centre/CAPHRI, Maastricht, The Netherlands. casper.den.heijer@mumc.nl.
authors.forename: Casper D J
authors.initials: CD
authors.lastname: den Heijer
authors.affiliation: Department of Community and Family Medicine, Duke Medical Center, Durham, NC, USA. aaron.george@duke.edu.
authors.forename: Aaron
authors.initials: A
authors.lastname: George
authors.affiliation: Institute for Hygiene, Microbiology and Tropical Medicine (IHMT), National Reference Centre for Nosocomial Infections and Antimicrobial Resistance, Elisabethinen Hospital Linz, Linz, Austria. petra.apfalter@analyse.eu.
authors.forename: Petra
authors.initials: P
authors.lastname: Apfalter
authors.affiliation: Department of General Practice and Family Medicine, Centre for Public Health, Medical University of Vienna, Kinderspitalgasse 15/1st floor, 1090, Vienna, Austria. manfred.maier@meduniwien.ac.at.
authors.forename: Manfred
authors.initials: M
authors.lastname: Maier
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000904:Antibiotics, Antitubercular / Q000627:therapeutic use; D001317:Austria / Q000453:epidemiology; D017963:Azithromycin / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003710:Demography; D024901:Drug Resistance, Multiple, Bacterial; D004917:Erythromycin / Q000494:pharmacology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009296:Nasal Cavity / Q000382:microbiology*; D016017:Odds Ratio; D010406:Penicillins / Q000494:pharmacology; D015995:Prevalence; D011320:Primary Health Care; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification*; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D000904:Antibiotics, Antitubercular; D010406:Penicillins; D004917:Erythromycin; D017963:Azithromycin