Evaluation of Antibiotic Resistence and Rectal Screening Findings in Enterococci

Öz

Enterococci are clinically significant opportunistic pathogens due to their increasing frequency of isolation in hospital-acquired infections and their multidrug resistance characteristics. In this retrospective study, the distribution and antimicrobial resistance profiles of Enterococcus species isolated from various clinical samples, as well as vancomycin-resistant enterococcus (VRE) colonization detected in rectal swab screenings, were evaluated at the Necmettin Erbakan University Faculty of Medicine Hospital Medical Microbiology Laboratory between January 2023 and July 2025. A total of 4,295 Enterococcus spp. isolates were analyzed, with Enterococcus faecalis (54.1%) and Enterococcus faecium (44.7%) identified as the most frequently isolated species. The majority of isolates were recovered from urine (68.4%) and blood (17.7%) cultures. Regarding antimicrobial resistance, the lowest resistance rates were observed against linezolid (0.3%) and tigecycline (2.1%), whereas the highest resistance rates were detected against high-level gentamicin (61.4%) and ciprofloxacin (58.0%). E. faecium isolates exhibited significantly higher resistance rates to all tested antibiotics compared to E. faecalis(p<0.05). During the same period, VRE positivity was detected in 18.6% of the 5,713 rectal swab samples analyzed. Furthermore, VRE growth in clinical samples was observed in 17.3% of the patients who tested positive for VRE in rectal screening. The fact that clinical VRE positivity was most frequently detected in blood cultures (44.0%) indicates that rectal colonization is a significant risk factor for invasive infections. These findings indicate that the increasing antibiotic resistance in enterococcal infections must be closely monitored and that rectal VRE screening programs play a critical role in infection control and in guiding the selection of appropriate empirical treatment strategies

Anahtar Kelimeler

• Antibiotic resistance
• Enterococcus
• Rectal screening
• Surveillance
• Vancomycin-resistant enterococci

ENTEROKOKLARDA ANTİBİYOTİK DİRENCİ VE REKTAL TARAMA BULGULARININ DEĞERLENDİRİLMESİ

Öz

Enterokoklar, hastane kaynaklı enfeksiyonlarda giderek artan sıklıkta izole edilmeleri ve çoklu antibiyotik direnç özellikleri nedeniyle klinik açıdan önemli fırsatçı patojenlerdir. Bu retrospektif çalışmada, Ocak 2023–Temmuz 2025 tarihleri arasında Necmettin Erbakan Üniversitesi Tıp Fakültesi Hastanesi Tıbbi Mikrobiyoloji Laboratuvarı’nda çeşitli klinik örneklerden izole edilen Enterococcus türlerinin dağılımı ve antimikrobiyal direnç profilleri ile aynı döneme ait rektal sürüntü taramalarında saptanan vankomisine dirençli enterokok (VRE) kolonizasyonu retrospektif olarak değerlendirilmiştir. Toplam 4.295 Enterococcus spp. izolatı incelenmiş olup, en sık izole edilen türler Enterococcus faecalis (%54.1) ve Enterococcus faecium (%44.7) olarak belirlenmiştir. İzolatların çoğu idrar (%68.4) ve kan (%17.7) kültürlerinden elde edilmiştir. Antimikrobiyal direnç açısından en düşük direnç linezolid (%0.3) ve tigesikline (%2.1), en yüksek direnç ise yüksek düzey gentamisin (%61.4) ve siprofloksasine (%58.0) karşı saptanmıştır. E. faecium izolatlarının tüm antibiyotiklere karşı E. faecalis’e kıyasla anlamlı derecede daha yüksek direnç gösterdiği belirlenmiştir (p<0.05). Aynı dönemde incelenen 5.713 rektal sürüntü örneğinin %18.6’sında VRE pozitifliği saptanmış, rektal taramada VRE pozitif bulunan hastaların %17.3’ünde klinik örneklerde de VRE üremesi gösterilmiştir. Klinik VRE pozitifliğinin en sık kan kültürlerinde saptanması (%44.0), rektal kolonizasyonun invaziv enfeksiyonlar açısından önemli bir risk faktörü olduğunu göstermektedir. Bu bulgular, enterokok enfeksiyonlarında artan antibiyotik direncinin yakından izlenmesi gerektiğini ve rektal VRE tarama programlarının enfeksiyon kontrolü ile uygun ampirik tedavi stratejilerinin belirlenmesinde kritik bir rol oynadığını ortaya koymaktadır.

Anahtar Kelimeler

• Enterococcus
• Rektal tarama
• Sürveyans
• Vankomisin dirençli enterokok
• Antibiyotik direnci

Kaynakça

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