Klebsiella pneumoniae izolatlarında karbapenemaz ve ESBL durumu ile kapsül serotipleri ve virulans genlerinin klinik dağılımının incelenmesi

Yıl 2025, Cilt: 50 Sayı: 4, 1153 - 1162, 22.12.2025

Başak Baykara , Hamdullah Suphi Bayraktar , Fariz Selimli

https://doi.org/10.17826/cumj.1781009

Öz

Amaç: Bu çalışmanın iki temel amacı vardır: Birincisi, Türkiye’nin Çukurova bölgesindeki hastanelerde Klebsiella pneumoniae enfeksiyonlarında kapsüler serotipler ve virülans genlerinin prevalansını araştırmak; ikinci olarak karbapenemaz ve ESBL üretimi arasındaki ilişkiyi değerlendirmektir.
Gereç ve Yöntem: Toplam 353 K. pneumoniae klinik izolatı yatan ve ayaktan hastaların çeşitli klinik örneklerinden elde edilmiştir. Karbapenem duyarlılığı ve ESBL üretimi, otomatik antimikrobiyal duyarlılık test sistemi kullanılarak ve Kirby–Bauer disk difüzyon yöntemi ile kombinasyon disk testi ile doğrulanarak EUCAST 2025 kılavuzlarına uygun şekilde belirlenmiştir. Genomik DNA, gece boyunca kültürlerden ekstrakte edilmiş ve 16S–23S ITS bölgesine yönelik PCR ile K. pneumoniae varlığı doğrulanmıştır. Kapsüler serotipleri ve virülans genleri, spesifik PCR tabanlı testlerle saptanmıştır.
Bulgular: K. pneumoniae izolatlarının %26,1’inde (n=92) karbapenemaz ve %23,2’sinde (n=82) ESBL üretimi saptanmış olup, her ikisi de izolatların %17,3’ünde (n=61) görülmüştür. Kapsüler serotipler izolatların %11,6’sında tespit edilmiş, en sık K2 (%5,1, n=18) ve K5 (%6,5, n=23) gözlenmiş; K1 saptanmamıştır. Virülans genlerinin prevalansı ise mrkD %90, fimH-1 %80, ybtS %92, iutA %78, rmpA %10 ve iroN %2 olarak bulunmuştur. Direnç fenotipleri ile mrkD, ybtS ve iutA arasında istatistiksel olarak anlamlı bir ilişki saptanmış; bu virülans genleri karbapenemaz/ESBL üretimi ile birlikte görülmüştür.
Sonuç: Çalışma, Çukurova bölgesindeki K. pneumoniae izolatlarında kapsüler serotipler ve virülans genlerinin dağılımını ortaya koyarak, enfeksiyonların önlenmesi ve akılcı antimikrobiyal tedavi açısından sürekli moleküler izlemenin önemini vurgulamaktadır.

Anahtar Kelimeler

Karbapenemaz , Kapsül serotipi , GSBL , Hastane kökenli enfeksiyonlar , Klebsiella pneumoniae , Virulans genleri

Etik Beyan

Karar 09-Hatay Mustafa Kemal Üniversitesi Deneysel Araştırmalar Uygulama ve Araştırma Merkezi Dr. Öğr. Üyesi H. Suphi Bayraktar' ın 'Klebsiella pneumoniae izolatlarında karbapenemaz ve ESBL durumu ile kapsül serotipleri ve virulans genlerinin klinik dağılımının incelenmesi' başlıklı çalışması, gerekçesi, amacı, yöntemi ve yaklaşımı dikkate alınarak incelenmiş ve etik kurallara uygun bulunmuştur. Çalışmanın başvuru dosyasında belirtilen merkezlerde gerçekleştirilmesinde etik ve bilimsel açıdan herhangi bir sakınca bulunmadığına, Girişimsel Olmayan Klinik Araştırmalar Etik Kurulu' nun 27/08/2025 tarihinde yapılan toplantısına katılan üyelerin oy birliğiyle karar verilmiştir.

Destekleyen Kurum

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Proje Numarası

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Teşekkür

Bu çalışmanın yürütülmesinde gerekli izinleri ve desteklerinden ötürü Hatay Eğitim ve Araştırma Hastanesi Başhekimliği ve Hatay Mustafa Kemal Üniversitesi Deneysel Araştırmalar Uygulama ve Araştırma Merkezi Müdürlüğü' ne teşekkürlerimizi sunarız.

Investigation of carbapenemase and ESBL status, capsule serotypes, and clinical distribution of virulence genes in Klebsiella pneumoniae isolates

Öz

Purpose: This study aimed to (i) determine the prevalence of capsule serotypes and virulence genes in Klebsiella pneumoniae clinical isolates obtained from the Çukurova region of Turkey, and (ii) assess their relationship with carbapenemase and extended-spectrum β-lactamase (ESBL) production.
Materials and Methods: A total of 353 K. pneumoniae isolates were recovered from various clinical specimens of both inpatients and outpatients. Carbapenem susceptibility and ESBL production were initially evaluated using an automated antimicrobial susceptibility testing system and subsequently confirmed by the Kirby–Bauer disc diffusion assay and the combined disc method, following EUCAST 2025 guidelines. Genomic DNA was extracted from overnight cultures, and species identification was verified using PCR targeting the 16S–23S ITS region. Capsule serotypes and virulence-associated genes were detected through specific PCR-based assays.
Results: Carbapenemase and ESBL production were identified in 26.1% (n = 92) and 23.2% (n = 82) of isolates, respectively, with 17.3% (n = 61) co-producing both enzymes. Capsule serotypes were detected in 11.6% of isolates, predominantly K2 (5.1%, n = 18) and K5 (6.5%, n = 23), whereas K1 was not found. The frequencies of virulence genes were as follows: mrkD (90%), fimH-1 (80%), ybtS (92%), iutA (78%), rmpA (10%), and iroN (2%). A statistically significant association was observed between antimicrobial resistance phenotypes and selected virulence genes, including mrkD, ybtS, and iutA.
Conclusion: The findings reveal the distribution of capsule serotypes and virulence determinants among K. pneumoniae isolates circulating in the Çukurova region. These results highlight the importance of sustained molecular surveillance to inform infection control strategies and optimize antimicrobial stewardship.

Anahtar Kelimeler

Carbapenemase , Capsule Serotype , ESBL , Hospital-Acquired Infections , Klebsiella pneumoniae , Virulence Genes.

Etik Beyan

Decision 09 – The study entitled “Investigation of Carbapenemase and ESBL Status, Capsule Serotypes, and Clinical Distribution of Virulence Genes in Klebsiella pneumoniae Isolates” by Asst. Prof. Dr. H. Suphi Bayraktar from Hatay Mustafa Kemal University Experimental Research Application and Research Center has been reviewed, taking into account its rationale, aim, method, and approach, and has been found to comply with ethical principles. It has been unanimously decided by the members present at the meeting of the Non-Interventional Clinical Research Ethics Committee held on 27/08/2025 that there is no ethical or scientific objection to conducting the study in the centers specified in the application file.

Destekleyen Kurum

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Proje Numarası

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Teşekkür

We would like to express our gratitude to the Chief Physician’s Office of Hatay Training and Research Hospital and to the Directorate of Hatay Mustafa Kemal University Experimental Research Application and Research Center for their permissions and support in the conduct of this study.

Kaynakça

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