title: Isolation and antimicrobial resistance of Staphylococcus aureus isolates in a dental clinic environment.
abstract: OBJECTIVE
  To determine the number of Staphylococcus aureus isolates collected in a dental clinical environment and to determine their susceptibility to antimicrobial agents commonly used in dentistry.
  
  
  METHODS
  Undergraduate clinic of the Dental School of Piracicaba, University of Campinas, Brazil.
  
  
  METHODS
  Sterile cotton swabs were used to collect the samples from dental-chair push buttons, light handles, 3-in-1 syringes, computer "Enter" keys, doorknobs, and X-ray tubes before, during, and after clinical procedures. These samples were spread on brain-heart infusion agar and were incubated at 37 degrees C for 24 hours. The resulting S. aureus isolates were counted and classified using Gram staining and biochemical tests. The counts among the 3 periods and the groups were analyzed by Kruskal-Wallis and Dunn tests (alpha =5%). Commercial paper disks containing widely prescribed antimicrobial agents (beta-lactams, macrolides, clindamycin, and vancomycin) were used to perform the antimicrobial susceptibility tests.
  
  
  RESULTS
  An increase in the number of microorganisms was observed during clinical procedures (P<.05). The highest bacterial resistance rates were observed for the beta -lactam group. All isolated strains were sensitive to vancomycin, and 2% of them were resistant to methicillin.
  
  
  CONCLUSIONS
  Clinical procedures increased the number and proportion of antimicrobial-resistant S. aureus isolates dispersed in a dental clinical environment. The present study highlights the need to establish strategies to prevent emergence of drug-resistant bacterial strains in dental settings.
authors.affiliation: Department of Physiologic Sciences, São Leopoldo Mandic, Campinas, Brazil. rogeriomotta@fop.unicamp.br
authors.forename: Rogério Heládio Lopes
authors.initials: RH
authors.lastname: Motta
authors.forename: Francisco Carlos
authors.initials: FC
authors.lastname: Groppo
authors.forename: Cristiane de Cássia
authors.initials: Cde C
authors.lastname: Bergamaschi
authors.forename: Juliana Cama
authors.initials: JC
authors.lastname: Ramacciato
authors.forename: Sinvaldo
authors.initials: S
authors.lastname: Baglie
authors.forename: Thales Rocha
authors.initials: TR
authors.lastname: de Mattos-Filho
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001938:Brazil; D003740:Dental Clinics; D024881:Drug Resistance, Bacterial; D016106:Methicillin Resistance; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification*; D014640:Vancomycin / Q000494:pharmacology; D018440:beta-Lactam Resistance
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin