title: Molecular characterization of invasive penicillin non-susceptible Streptococcus pneumoniae from Denmark, 2001 to 2005.
abstract: The aim of this study was to characterize invasive penicillin non-susceptible pneumococci (PNSP) isolated in Denmark from 2001 to 2005, describe the genetic changes in the penicillin-binding proteins (PBPs) and compare the isolates to the international recognized PNSP clones. All isolates were characterized using serotyping; 43 isolates were also characterized by multilocus sequence typing (MLST) and sequence determination of the PBP genes, pbp1a, pbp2b and pbp2x. In addition, isolates were tested for susceptibility to various antimicrobial agents. From 2001 to 2005, 178 invasive PNSP isolates were found among all invasive isolates. Of these, 13% were penicillin-resistant pneumococci (PRP). The PRP isolates were different to the penicillin intermediate-resistant pneumococci (PIRP) as they were co-resistant to a higher number of antimicrobial agents, and the serotype diversity was lower for the PRP isolates compared to the PIRP isolates. Changes in the PBPs were found to be the same as those observed in other studies. Most PRP isolates were found to belong to the clonal complex CC156 of which most were ST156 serotype 9V or 14. ST156 is a well known multiresistant widespread international PMEN (Pneumococcal Molecular Epidemiology Network) clone, Spain(9V)-3, which is also present as one of the dominant clones in our neighbour countries of Sweden, Norway and Germany.
authors.affiliation: The Neisseria and Streptococcus Reference Centre, Department for Bacteriology, Mycology and Parasitology, Statens Serum Institut, Copenhagen, Denmark. LLM@ssi.dk
authors.forename: Lotte
authors.initials: L
authors.lastname: Lambertsen
authors.forename: Mette
authors.initials: M
authors.lastname: Brendstrup
authors.forename: Helene
authors.initials: H
authors.lastname: Friis
authors.forename: Jens Jørgen
authors.initials: JJ
authors.lastname: Christensen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D002675:Child, Preschool; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D003718:Denmark / Q000453:epidemiology; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D010403:Penicillin Resistance; D046915:Penicillin-Binding Proteins / Q000235:genetics; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D046915:Penicillin-Binding Proteins