title: Sphygmomanometers and thermometers as potential fomites of Staphylococcus haemolyticus: biofilm formation in the presence of antibiotics.
abstract: BACKGROUND
  The association between Staphylococcus haemolyticus and severe nosocomial infections is increasing. However, the extent to which fomites contribute to the dissemination of this pathogen through patients and hospital wards remains unknown.
  
  
  OBJECTIVE
  In the present study, sphygmomanometers and thermometers were evaluated as potential fomites of oxacillin-resistant S. haemolyticus (ORSH). The influence of oxacillin and vancomycin on biofilm formation by ORSH strains isolated from fomites was also investigated.
  
  
  METHODS
  The presence of ORSH on swabs taken from fomite surfaces in a Brazilian hospital was assessed using standard microbiological procedures. Antibiotic susceptibility profiles were determined by the disk diffusion method, and clonal distribution was assessed in pulsed-field gel electrophoresis (PFGE) assays. Minimum inhibitory concentrations (MICs) of oxacillin and vancomycin were evaluated via the broth microdilution method. Polymerase chain reaction (PCR) assays were performed to detect the mecA and icaAD genes. ORSH strains grown in media containing 1/4 MIC of vancomycin or oxacillin were investigated for slime production and biofilm formation on glass, polystyrene and polyurethane catheter surfaces.
  
  
  RESULTS
  ORSH strains comprising five distinct PFGE types were isolated from sphygmomanometers (n = 5) and a thermometer (n = 1) used in intensive care units and surgical wards. ORSH strains isolated from fomites showed susceptibility to only linezolid and vancomycin and were characterised as multi-drug resistant (MDR). Slime production, biofilm formation and the survival of sessile bacteria differed and were independent of the presence of the icaAD and mecA genes, PFGE type and subtype. Vancomycin and oxacillin did not inhibit biofilm formation by vancomycin-susceptible ORSH strains on abiotic surfaces, including on the catheter surface. Enhanced biofilm formation was observed in some situations. Moreover, a sub-lethal dose of vancomycin induced biofilm formation by an ORSH strain on polystyrene.
  
  
  CONCLUSIONS
  Sphygmomanometers and thermometers are fomites for the transmission of ORSH. A sub-lethal dose of vancomycin may favor biofilm formation by ORSH on fomites and catheter surfaces.
authors.affiliation: Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Rio de Janeiro, RJ, Brasil.
authors.forename: Bruna Pinto Ribeiro
authors.initials: BP
authors.lastname: Sued
authors.affiliation: Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Rio de Janeiro, RJ, Brasil.
authors.forename: Paula Marcele Afonso
authors.initials: PM
authors.lastname: Pereira
authors.affiliation: Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Rio de Janeiro, RJ, Brasil.
authors.forename: Yuri Vieira
authors.initials: YV
authors.lastname: Faria
authors.affiliation: Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Rio de Janeiro, RJ, Brasil.|Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brasil.
authors.forename: Juliana Nunes
authors.initials: JN
authors.lastname: Ramos
authors.affiliation: Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Rio de Janeiro, RJ, Brasil.
authors.forename: Vanessa Batista
authors.initials: VB
authors.lastname: Binatti
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, RJ, Brasil.
authors.forename: Kátia Regina Netto Dos
authors.initials: KR
authors.lastname: Santos
authors.affiliation: Centro Universitário Estadual da Zona Oeste, Laboratório de Tecnologia em Bioquímica e Microscopia, Rio de Janeiro, RJ, Brasil.
authors.forename: Sérgio Henrique
authors.initials: SH
authors.lastname: Seabra
authors.affiliation: Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Rio de Janeiro, RJ, Brasil.
authors.forename: Raphael
authors.initials: R
authors.lastname: Hirata
authors.affiliation: Fundação Oswaldo Cruz-Fiocruz, Instituto Nacional de Controle de Qualidade em Saúde, Rio de Janeiro, RJ, Brasil.|Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brasil.
authors.forename: Verônica Viana
authors.initials: VV
authors.lastname: Vieira
authors.affiliation: Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Rio de Janeiro, RJ, Brasil.
authors.forename: Ana Luíza
authors.initials: AL
authors.lastname: Mattos-Guaraldi
authors.affiliation: Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Rio de Janeiro, RJ, Brasil.
authors.forename: José Augusto Adler
authors.initials: JA
authors.lastname: Pereira
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000254:growth & development*; D003428:Cross Infection / Q000382:microbiology / Q000635:transmission; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D050456:Fomites / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D010068:Oxacillin / Q000494:pharmacology; D019722:Sphygmomanometers / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000382:microbiology / Q000635:transmission; D041162:Staphylococcus haemolyticus / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology*; D013821:Thermometers / Q000382:microbiology*; D014640:Vancomycin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin; D010068:Oxacillin