High-Level Genetic Diversity among Invasive Streptococcus pneumoniae Isolates in Turkey

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Guldemir D., Acar S., Otgun S. N., Unaldi O., Gozalan A., Ertek M., ...More

JAPANESE JOURNAL OF INFECTIOUS DISEASES, vol.69, no.3, pp.207-212, 2016 (SCI-Expanded) identifier identifier identifier


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.