title: High-Level Genetic Diversity among Invasive Streptococcus pneumoniae Isolates in Turkey.
abstract: This study obtained information on the serotypes and molecular typing characteristics of Streptococcus pneumoniae strains causing invasive diseases in Turkey. Sixty-eight S. pneumoniae isolates causing invasive pneumococcal diseases were collected from different regions of Turkey from 2009 to 2011. The isolates were characterized by performing multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and capsular serotyping, and 25 different serotypes were identified. Serotypes 19F, 23F, 1, 14, and 7F were common and accounted for 52.9% of all the serotypes. In addition, 54 different PFGE profiles (pulsotypes) were observed. Twenty-three of the 68 (33.8%) isolates were clustered into 9 pulsotypes. MLST analysis yielded 36 sequence types, of which 12 (33.3%) were novel. A comparison of results with the global pneumococcal MLST database by performing eBURST analysis showed that our strains belonged to 20 different clonal complexes and 5 singletons. In addition, we identified 4 new alleles: 2 gdh, 1 xpt, and 1 ddl. Thus, the results of this study highlighted a high level of diversity among pneumococcal isolates. In addition, the study identified a case of possible capsular switching.
authors.affiliation: National Reference Laboratory for Molecular Microbiology, Microbiology Reference Laboratories Department, Public Health Institution of Turkey.
authors.forename: Dilek
authors.initials: D
authors.lastname: Guldemir
authors.forename: Sumeyra
authors.initials: S
authors.lastname: Acar
authors.forename: Selin Nar
authors.initials: SN
authors.lastname: Otgun
authors.forename: Ozlem
authors.initials: O
authors.lastname: Unaldi
authors.forename: Aysegul
authors.initials: A
authors.lastname: Gozalan
authors.forename: Mustafa
authors.initials: M
authors.lastname: Ertek
authors.forename: Riza
authors.initials: R
authors.lastname: Durmaz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D002648:Child; D002675:Child, Preschool; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D065288:Serogroup; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D014421:Turkey / Q000453:epidemiology