The Surveillance of Vancomycin- Resistant Enterococci Colonization by (Cepheid) GeneXpert vanA/vanB Test and Culture Method

Abstract

Objectives: Early detection of vancomycin resistant enterococci (VRE) colonization in hospitalized patients plays an important role in controlling enterococcal infections. For this purpose, the detection of VRE from rectal swab specimens can be performed with various methods. Methods: In this study, VRE colonization in the rectal swab samples of patients from intensive care units, burn unit, and infectious diseases clinic in our hospital were evaluated. In total, 2,394 rectal swab samples from 1,627 patients were collected between January 2012 and 2013. A commercial product (Enterococcosel agar) was used for cultivating, and the growing bacteria were identified with conventional methods and/or the VITEK 2 Compact system (BioMerieux, France). The samples of the patients transferred from another hospital and who had a history of VRE infection or carriage were examined with an automated real-time PCR system (Gene Xpert™ vanA/vanB, Cepheid, Sunnyvale, CA). Results: A total of 59 (3.6%) patients were positive for VRE, 25 were diagnosed with PCR, and 34 were diagnosed with culture methods. Among the samples identified by PCR, 19 were only vanA harboring VRE, five were only vanB harboring VRE, and one was both vanA and vanB harboring VRE. All of the VRE isolates were identified as E. faecium. The number of patients admitted with vancomycin therapy before being diagnosed with VRE was 11(18.6%). Conclusions: It is important to determine the appropriate surveillance method for the early diagnosis of VRE carriers among patients at risk according to their patient profile, needs, and resources.

Keywords

• Vancomycin-resistant enterococci, vanA, vanB, Gene Xpert™

The Surveillance of Vancomycin- Resistant Enterococci Colonization by (Cepheid) GeneXpert vanA/vanB Test and Culture Method

Öz

Amaç: Hastanede yatan hastalarda vankomisin dirençli enterokok (VRE) kolonizasyonunun erken tespiti, enterokok enfeksiyonlarının kontrolünde önemli bir yer tutmaktadır. Bu amaçla rektal sürüntü örneklerinde çeşitli yöntemlerle VRE tespiti yapılabilmektedir.Yöntemler: Bu çalışmada hastanemizde Ocak 2012-2013 tarihleri arasında, yoğun bakım ünitelerinde, yanık ve enfeksiyon hastalıkları kliniklerinde yatmakta olan 1627 hastaya ait 2394 rektal sürüntü örneğinde VRE kolonizasyonu araştırıldı. Bu amaçla kültür için Enterokokosel agar kullanıldı. Üreyen bakteriler konvansiyonel yöntemler ve/veya VITEK 2 Compact (BioMerieux, Fransa) ticari sistemi kullanılarak tür düzeyinde tanımlandı. Başka bir hastaneden nakil gelen ve daha önce VRE enfeksiyonu veya taşıyıcılığı öyküsü olanlarda rektal örnekler otomatize gerçek zamanlı polimeraz zincir reaksiyonu (Realtime PCR) cihazı (Gene Xpert™ vanA/vanB, Cepheid, Sunnyvale, CA) ile incelendi.Bulgular: Toplam 59 hastada VRE pozitifliği (%3,6) saptandı. Bunların 25’i PCR, 34’ü ise kültür ile çalışıldı. PCR ile tanı konulanlardan 19’u vanA pozitif, 5’i vanB pozitif, biri ise vanA+vanB pozitif olarak saptandı. Vankomisin dirençli enterokok olarak belirlenen tüm suşlar E. faecium olarak tanımlandı. Hastalardan 11(%18.6)’nın VRE tanısı öncesinde tedavisinde vankomisin kullandığı saptandı.Sonuç: Riskli hastalarda VRE taşıyıcılığını erken dönemde saptayabilmek için her hastanenin kendi hasta profiline, ihtiyaçlarına ve kaynaklarına göre uygun sürveyans yöntemini belirlemesi gerektiğini düşünmekteyiz

Anahtar Kelimeler

• Vankomisine dirençli enterokok, vanA, vanB, Gene Xpert™

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