title: Analysis of different molecular methods for typing methicillin-resistant Staphylococcus aureus isolates belonging to the Brazilian epidemic clone.
abstract: The extensive geographic spread of MRSA isolates belonging to the Brazilian epidemic clone (BEC) limited the value of pulsed-field gel electrophoresis (PFGE) in epidemiological studies of outbreaks caused by these strains. Thus, the discriminatory power of eight different molecular methods was evaluated in an attempt to establish a methodology for genotyping BEC isolates involved in intra-hospital outbreaks. BEC isolates from five hospitals in Teresina City, Piaui State were genotyped by conventional electrophoresis or PFGE of Cla I- or Sma I-digested genomic DNA hybridised with specific labelled mecA, Tn554, IS257 and IS256 probes. The combination of PFGE with Cla I/mecA, Cla I/Tn554, Cla I/IS257, Sma I/mecA and Sma I/IS257 probe-fingerprinting techniques provided a very poor discriminatory power for BEC strains. Although Cla I/IS256 fingerprinting discriminated 17 different polymorphisms among the isolates displaying PFGE A1 pattern, this strategy was not reproducible. In contrast, the combination of PFGE and Sma I/IS256 polymorphisms differentiated BEC isolates into nine stable polymorphisms. Thus combination of PFGE and hybridisation with IS256 probe may be recommended as a useful means of typing BEC strains involved in intra-hospital infections.
authors.affiliation: *Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Prof. Paulo de Góes, Laboratório de Biologia Molecular de Bactérias, CCS, Bloco I, Cidade Universitária, Rio de Janeiro, RJ 21941-590, †Universidade Federal do Piauí, CCS, Departamento de Parasitologia e Microbiologia, SG16, Teresina, PI 64049-550 and ‡Universidade Federal Fluminense, Departamento de Tecnologia Farmacêutica, Faculdade de Farmácia, Niterói, Rio de Janeiro, RJ 24241-002, Brazil.
authors.forename: Maria J Dos Santos
authors.initials: MJDS
authors.lastname: Soares
authors.affiliation: *Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Prof. Paulo de Góes, Laboratório de Biologia Molecular de Bactérias, CCS, Bloco I, Cidade Universitária, Rio de Janeiro, RJ 21941-590, †Universidade Federal do Piauí, CCS, Departamento de Parasitologia e Microbiologia, SG16, Teresina, PI 64049-550 and ‡Universidade Federal Fluminense, Departamento de Tecnologia Farmacêutica, Faculdade de Farmácia, Niterói, Rio de Janeiro, RJ 24241-002, Brazil.
authors.forename: Lenise A
authors.initials: LA
authors.lastname: Teixeira
authors.affiliation: *Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Prof. Paulo de Góes, Laboratório de Biologia Molecular de Bactérias, CCS, Bloco I, Cidade Universitária, Rio de Janeiro, RJ 21941-590, †Universidade Federal do Piauí, CCS, Departamento de Parasitologia e Microbiologia, SG16, Teresina, PI 64049-550 and ‡Universidade Federal Fluminense, Departamento de Tecnologia Farmacêutica, Faculdade de Farmácia, Niterói, Rio de Janeiro, RJ 24241-002, Brazil.
authors.forename: Maria DO Rosário
authors.initials: MDR
authors.lastname: Nunes
authors.affiliation: *Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Prof. Paulo de Góes, Laboratório de Biologia Molecular de Bactérias, CCS, Bloco I, Cidade Universitária, Rio de Janeiro, RJ 21941-590, †Universidade Federal do Piauí, CCS, Departamento de Parasitologia e Microbiologia, SG16, Teresina, PI 64049-550 and ‡Universidade Federal Fluminense, Departamento de Tecnologia Farmacêutica, Faculdade de Farmácia, Niterói, Rio de Janeiro, RJ 24241-002, Brazil.
authors.forename: Maria C DA Silva
authors.initials: MCDS
authors.lastname: Carvalho
authors.affiliation: *Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Prof. Paulo de Góes, Laboratório de Biologia Molecular de Bactérias, CCS, Bloco I, Cidade Universitária, Rio de Janeiro, RJ 21941-590, †Universidade Federal do Piauí, CCS, Departamento de Parasitologia e Microbiologia, SG16, Teresina, PI 64049-550 and ‡Universidade Federal Fluminense, Departamento de Tecnologia Farmacêutica, Faculdade de Farmácia, Niterói, Rio de Janeiro, RJ 24241-002, Brazil.
authors.forename: Bernadete T
authors.initials: BT
authors.lastname: Ferreira-Carvalho
authors.affiliation: *Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Prof. Paulo de Góes, Laboratório de Biologia Molecular de Bactérias, CCS, Bloco I, Cidade Universitária, Rio de Janeiro, RJ 21941-590, †Universidade Federal do Piauí, CCS, Departamento de Parasitologia e Microbiologia, SG16, Teresina, PI 64049-550 and ‡Universidade Federal Fluminense, Departamento de Tecnologia Farmacêutica, Faculdade de Farmácia, Niterói, Rio de Janeiro, RJ 24241-002, Brazil.
authors.forename: Agnes M S
authors.initials: AMS
authors.lastname: Figueiredo
mesh_terms: D015373:Bacterial Typing Techniques / Q000379:methods*; D001938:Brazil; D003428:Cross Infection; D016172:DNA Fingerprinting / Q000379:methods; D017931:DNA Primers; D015342:DNA Probes; D004269:DNA, Bacterial / Q000032:analysis*; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D005838:Genotype; D006801:Humans; D015151:Immunoblotting / Q000379:methods; D016106:Methicillin Resistance; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000145:classification* / Q000235:genetics*
chemical_list: D017931:DNA Primers; D015342:DNA Probes; D004269:DNA, Bacterial