title: Properties of novel international drug-resistant pneumococcal clones identified in day-care centers of Lisbon, Portugal.
abstract: In this study, 61 drug-resistant Streptococcus pneumoniae strains were characterized by multilocus sequence typing (MLST). These strains were representatives of 26 major clones (defined using pulsed-field gel electrophoresis) accounting for 93% of the 1,285 drug-resistant Streptococcus pneumoniae isolates recovered from the nasopharynges of healthy children attending day-care centers in Lisbon during 2001 to 2003. Using MLST, 13 of the 26 clones were found to be identical or closely related to 11 Pneumococcal Molecular Epidemiology Network (PMEN) clones, 4 clones were found to be unique as there were no identical or highly related allelic profiles deposited in the MLST database, and the remaining 9 clones had sequence types that matched or differed at a single or double locus from allelic profiles available in the MLST database. These nine clones were of serotypes 33F, 10A, 19A, 19F, 6A, 20, 24F, and 3, one was nontypeable, and, by MLST, they were found to be identical or highly related to isolates from disease origin that were dispersed internationally. Since the majority of these clones had serotypes that are not included in the 7-valent conjugate pneumococcal vaccine, monitoring of these clones is important for surveying their possible spread in the future. We propose the inclusion of these novel international clones in the PMEN.
authors.affiliation: Laboratório de Genética Molecular, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
authors.forename: Natacha G
authors.initials: NG
authors.lastname: Sousa
authors.forename: Raquel
authors.initials: R
authors.lastname: Sá-Leão
authors.forename: M Inês
authors.initials: MI
authors.lastname: Crisóstomo
authors.forename: Carla
authors.initials: C
authors.lastname: Simas
authors.forename: Sónia
authors.initials: S
authors.lastname: Nunes
authors.forename: Nelson
authors.initials: N
authors.lastname: Frazão
authors.forename: João A
authors.initials: JA
authors.lastname: Carriço
authors.forename: Rosario
authors.initials: R
authors.lastname: Mato
authors.forename: Ilda
authors.initials: I
authors.lastname: Santos-Sanches
authors.forename: Hermínia
authors.initials: H
authors.lastname: de Lencastre
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D002648:Child; D002656:Child Day Care Centers; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D007223:Infant; D008826:Microbial Sensitivity Tests; D009305:Nasopharynx / Q000382:microbiology; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D011174:Portugal / Q000453:epidemiology; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents