Streptococcus pneumoniae invasive and bronchoalveolar lavage isolates in adult patients in Türkiye (2019-2025): serotype distribution, antibiotic resistance, and serotype coverage of pneumococcal vaccine

Hascelik, Gülsen; ÖZAKIN, CÜNEYT; HAZIROLAN, GÜLŞEN; Hasdemir, Ufuk; Telli, Murat; Aydemir, Sabire; AY ALTINTOP, Yasemin; ÖZKAYA, ESRA; Durmaz, GÜL; ÖZBEK, ÖZGEN; ÖKSÜZ, LÜTFİYE; Karapinar, Deniz; USLU, Hakan; Birinci, Asuman; ÇİZMECİ, Zeynep; Ozhak, Betil; Yaman, Akgun; YILMAZ, Nisel; Akpolat, Nezahat; Ozturk, Candan; KARAHAN, ZEYNEP; GÜDÜCÜOĞLU, HÜSEYİN; Koyuncu Ozyurt, Ozlem; TANRIVERDİ, ELİF; Zer, Yasemin; ARABACI, Çiğdem; ÖCAL, DUYGU; Mart Komurcu, Selen; Ceyhan, Mehmet

doi:10.1016/j.ijid.2026.109073

Streptococcus pneumoniae invasive and bronchoalveolar lavage isolates in adult patients in Türkiye (2019-2025): serotype distribution, antibiotic resistance, and serotype coverage of pneumococcal vaccine

Hascelik G., ÖZAKIN C., HAZIROLAN G., Hasdemir U., Telli M., Aydemir S. S., ...Daha Fazla

International Journal of Infectious Diseases, cilt.172, 2026 (SCI-Expanded, Scopus)

Yayın Türü: Makale / Tam Makale
Cilt numarası: 172
Basım Tarihi: 2026
Doi Numarası: 10.1016/j.ijid.2026.109073
Dergi Adı: International Journal of Infectious Diseases
Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, EMBASE, MEDLINE, Directory of Open Access Journals, Academic Search Ultimate (EBSCO), Health Research Premium Collection (ProQuest)
Anahtar Kelimeler: Adult, Antimicrobial susceptibility, Pneumococcal vaccine, Serotype, Streptococcus pneumoniae, Surveillance
Eskişehir Osmangazi Üniversitesi Adresli: Evet

Özet

Objective To determine the serotype distribution, antibiotic susceptibility, and vaccine serotype coverage of Streptococcus pneumoniae isolates from adult patients in Türkiye. Methods This laboratory study included pneumococcal isolates collected during routine procedures between 2019 and 2025 in 27 tertiary hospitals across 17 cities in Türkiye. Identification was performed using the optochin test and bile lysis test. Serotyping was performed by the Quellung test. Antibiotic susceptibilities were tested according to the Clinical Laboratory Standards Institute (CLSI) criteria. Results Among 462 pneumococcal isolates, 72.7% were from male patients, and 43.9% were from patients aged ≥65 years. The most common diagnosis was bacteremia (55.8%), followed by pneumonia (24%) and meningitis (10.6%). The most frequent serotypes were serotype 3 (17.3%), 9N (9.1%), and 19F (5.4%). Vaccine serotype coverage rates were 34.6%, 35.9%, 47.8%, and 59.5% for PCV13, PCV15, PCV20, and PPSV23, respectively; with significantly higher coverage among patients aged ≥65 years. Most isolates were susceptible to penicillin (96.3%) and cefotaxime (97.8%) using nonmeningitis breakpoints. Moxifloxacin susceptibility was 99.1%. Erythromycin resistance increased from 33.3% in 2019 to 57.5% in 2025. Conclusions Serotype 3 was the predominant serotype. PCV20 may provide broader coverage than PCV13, particularly in older adults. Ongoing pneumococcal surveillance and rational antibiotic use remain essential.