title: Pulsed-field gel electrophoresis associated to phage typing improves the discrimination of epidemiologically unrelated Salmonella enterica serovar typhimurium isolates.
abstract: A combination of phage typing and pulsed-field gel electrophoresis (PFGE) of Xbal- and Blnl-digested chromosomal DNA has been used to study 18 epidemiologically unrelated human Salmonella enterica serovar Typhimurium isolates, which were collected during 2007 within a single Romanian county. Phage typing could assign only four of the isolates to three definitive phage types (DT41, DT86, and DT116), the rest being untypable by this classical method. PFGE analysis of the double enzyme-digested DNA, performed in an attempt to further discriminate the strains, allowed the typing of all the studied isolates. Xbal-digested genomic DNA segregated the isolates into 7 X-types and Blnl restriction differentiated them into 8 B-types. Our PFGE results documented the circulation of a rather homogeneous population of S. Typhimurium strains within the same county. As in the case of other human pathogens, epidemiological conclusions might be more accurate if based on both phenotypic and genotypic methods, therefore molecular typing should be added within the national laboratory-based surveillance of Salmonella infections.
authors.affiliation: Laboratory of Molecular Microbiology, National Institute of Research-Development for Microbiology and Immunology Cantacuzino, Bucharest. andipalade@cantacuzino.ro
authors.forename: Andi-Marian
authors.initials: AM
authors.lastname: Palade
authors.forename: Codruţa-Romaniţa
authors.initials: CR
authors.lastname: Usein
authors.forename: Stefania
authors.initials: S
authors.lastname: Ceciu
authors.forename: Simona
authors.initials: S
authors.lastname: Ciontea
authors.forename: Dorina
authors.initials: D
authors.lastname: Tatu-Chiţoiu
authors.forename: Maria
authors.initials: M
authors.lastname: Damian
mesh_terms: D001434:Bacteriophage Typing; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D012383:Romania; D012480:Salmonella Infections / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial