title: Susceptibility Profile of Staphylococcus epidermidis and Staphylococcus haemolyticus Isolated from Blood Cultures to Vancomycin and Novel Antimicrobial Drugs over a Period of 12 Years.
abstract: The aim of this study was to evaluate the antimicrobial susceptibility profile of 85 Staphylococcus epidermidis and 84 Staphylococcus haemolyticus strains isolated from blood cultures to oxacillin, vancomycin, tigecycline, linezolid, daptomycin, and quinupristin/dalfopristin over a period of 12 years. S. epidermidis and S. haemolyticus isolated from blood cultures of inpatients, attended at a teaching hospital, were analyzed for the presence of the mecA gene and by SCCmec typing. The minimum inhibitory concentration (MIC) values of tigecycline, linezolid, daptomycin, quinupristin/dalfopristin, and vancomycin were determined. Isolates exhibiting vancomycin MICs of ≥2 μg/ml were typed by pulsed-field gel electrophoresis (PFGE). The rate of mecA positivity was 92.9% and 100% in S. epidermidis and S. haemolyticus, respectively. The most frequent SCCmec types were type III (53.2%) in S. epidermidis and type I (32.1%) in S. haemolyticus. All isolates were susceptible to linezolid and daptomycin, but 7.1% of S. haemolyticus and 2.3% of S. epidermidis isolates were resistant to tigecycline, and 1.2% each of S. haemolyticus and S. epidermidis were resistant and intermediately resistant to quinupristin/dalfopristin, respectively. S. epidermidis exhibited higher vancomycin MICs (40% with MIC of ≥2 μg/ml). Clonal typing of strains with vancomycin MIC of ≥2 μg/ml revealed the presence of different PFGE types of S. epidermidis and S. haemolyticus over a period of up to 4 years (2002-2004, 2005-2008, 2006-2009, 2010-2011). Despite the observation of a high prevalence of mecA, the clinical strains were fully susceptible to vancomycin and to the new drugs linezolid, daptomycin, tigecycline, and quinupristin/dalfopristin. The PFGE types with vancomycin MIC of ≥2 μg/ml exhibited a great diversity of SCCmec cassettes, demonstrating that S. epidermidis and S. haemolyticus may easily acquire these resistance-conferring genetic elements.
authors.affiliation: 1 Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP) , Botucatu, São Paulo, Brazil .
authors.forename: Luiza
authors.initials: L
authors.lastname: Pinheiro
authors.affiliation: 1 Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP) , Botucatu, São Paulo, Brazil .
authors.forename: Carla Ivo
authors.initials: CI
authors.lastname: Brito
authors.affiliation: 1 Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP) , Botucatu, São Paulo, Brazil .
authors.forename: Valéria Cataneli
authors.initials: VC
authors.lastname: Pereira
authors.affiliation: 1 Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP) , Botucatu, São Paulo, Brazil .
authors.forename: Adilson
authors.initials: A
authors.lastname: Oliveira
authors.affiliation: 1 Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP) , Botucatu, São Paulo, Brazil .
authors.forename: Ariane Rocha
authors.initials: AR
authors.lastname: Bartolomeu
authors.affiliation: 1 Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP) , Botucatu, São Paulo, Brazil .|2 Núcleo de Doenças Entéricas e Infecções por Patógenos Especiais, Centro de Bacteriologia, Instituto Adolfo Lutz , São Paulo, São Paulo, Brazil .
authors.forename: Carlos Henrique
authors.initials: CH
authors.lastname: Camargo
authors.affiliation: 1 Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP) , Botucatu, São Paulo, Brazil .
authors.forename: Maria Lourdes Ribeiro Souza
authors.initials: ML
authors.lastname: Cunha
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D015373:Bacterial Typing Techniques; D000071997:Blood Culture; D001938:Brazil / Q000453:epidemiology; D017576:Daptomycin / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D015870:Gene Expression; D006784:Hospitals, Teaching / Q000706:statistics & numerical data*; D006801:Humans; D000069349:Linezolid / Q000494:pharmacology; D008911:Minocycline / Q000031:analogs & derivatives / Q000494:pharmacology; D009154:Mutation; D010068:Oxacillin / Q000494:pharmacology; D015995:Prevalence; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D041162:Staphylococcus haemolyticus / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D000078304:Tigecycline; D014640:Vancomycin / Q000494:pharmacology; D014769:Virginiamycin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C487495:MecA protein, Staphylococcus epidermidis; D014769:Virginiamycin; C062940:quinupristin-dalfopristin; D014640:Vancomycin; D000078304:Tigecycline; D008911:Minocycline; D000069349:Linezolid; D017576:Daptomycin; D010068:Oxacillin