Vankomisine dirençli enterokoklarda moleküler epidemiyolojik analiz
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Date
2011
Authors
Karakeçili, Faruk
Journal Title
Journal ISSN
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Publisher
Uludağ Üniversitesi
Abstract
Enterokoklar, birçok bakteri türünde bulunan virülans faktörlerine sahip olmamalarına rağmen çevre şartlarına oldukça dirençlidir. Çeşitli antibiyotiklere karşı doğal veya kazanılmış direnç göstermeleri, enterokokların son yıllarda nozokomiyal enfeksiyonlarda önemli etyolojik ajanlar arasında yer almasına neden olmuştur. Vankomisine dirençli enterokok (VRE) enfeksiyonlarının kontrolünde, bu bakteri ile kolonize olan hastaların erken tespiti ve nozokomiyal salgın ile ilişkilerinin gösterilmesi önemlidir. Nozokomiyal epidemiler sırasında izole edilen VRE suşları arasındaki klonal ilişkinin tespiti için moleküler yöntemler kullanılmalıdır. Pulsed Field Jel Elektroforezi (PFGE); nozokomiyal salgın sürveyansında, salgın suşları arasındaki ilişkinin gösterilmesi ve salgın kaynağının tespitinde ?altın standart? yöntem olarak kabul edilmektedir. Bu çalışmada hastanede yatan hastalardan izole edilen VRE suşlarının, hastane enfeksiyonları epidemiyolojisi açısından PFGE ve Arbitrarily primed-PCR (AP-PCR) yöntemleri kullanılarak klonal ilişkilerinin tespiti amaçlanmıştır.Ocak 2001 ile Aralık 2009 yılları arasında hastanede yatan hasta örneklerinden izole edilen tüm VRE türleri içinde Enterococcus faecium'un %98'lik bir oranla baskın tür olduğu saptandı. Çalışmaya 9 yıllık periyot boyunca, 5 ayrı muhtemel epidemi döneminde izole edilen suşlardan 83 adet E. faecium suşu dahil edildi. Tüm suşların yüksek düzey glikopeptit direncine sahip olduğu saptandı.PFGE yöntemiyle 2001 ile 2002 yılı epidemilerinde izole edilen birçok suş arasında anlamlı benzerlik olduğu, bu klonun varlığını uzun süre koruduğu ve bu iki epidemi döneminde baskın hale geldiği saptandı. Diğer 3 epidemi döneminde izole edilen suşların kendi içinde benzediği, ancak farklı epidemiler arasında anlamlı bir suş benzerliği olmadığı belirlendi. Özellikle 2009 yılındaki epidemi döneminde tüm suşların tek bir klonal kümede toplandığı, daha önce hasta örneklerinde izole edilmeyen yeni bir suşun tüm hastaneye yayıldığı saptandı.PFGE, ayrım gücü yüksek, tekrarlanabilirliği çok iyi, laboratuvarlar arası standardize edilebilen ve salgın sürveyansında güvenilir bilgiler sunan bir moleküler epidemiyolojik yöntem olarak değerlendirildi.
Enterococci are highly resistant to environmental conditions, though they do not have the virulence factors in many bacterial species. In recent years, Enterococci have caused to take part between important etiologic agents at nosocomial infections since they have natural or acquired the resistance to various antibiotics.It is important of the early detection of patients colonized with these bacteria and the demonstration of relations with nosocomial epidemic in the control of vancomycin-resistant enterococci (VRE) infections. Molecular methods should be used to detect the clonal relationship between isolated VRE strains during epidemics of nosocomial. Pulsed Field Gel Electrophoresis (PFGE), is considered as golden standard method for demonstration of relationship between the epidemic strains and determining the source of the epidemic in the surveillance of nosocomial epidemic. In this study, it is aimed to detect clonal relationships of VRE strains isolated from the hospitalized patients by PFGE and arbitrarily primed PCR (AP-PCR) methods in terms of the epidemiology of hospital infections.Between January 2001 and December 2009, Enterococcus faecium was found to be the dominant species in all VRE isolated from hospitalized patients, which have rate of 98%. 83 strains of E. faecium were included in the study, which isolated from 5 different possible epidemic periods during 9 years. It was found that all strains have high-level glycopeptide resistance.Through PFGE method, it was determined that there was a significant similarity between many strains isolated from between 2001 and 2002 epidemics, this clone was maintained the existence for a long time and it had become the dominant in these two epidemics. It was also determined that the strains isolated in other 3 epidemic periods were similar to themselves, but there was no significant similarity to a strain between different epidemics. Especially during the 2009 epidemic period, it was found that all strains were collected in a single clonal cluster, the new strain which were not previously isolated from samples of patients was spread to all units of the hospital.It was evaluated that PFGE was a molecular epidemiological method which have high separation power, can be standardized between laboratories and provide reliable information on the epidemic surveillance.
Enterococci are highly resistant to environmental conditions, though they do not have the virulence factors in many bacterial species. In recent years, Enterococci have caused to take part between important etiologic agents at nosocomial infections since they have natural or acquired the resistance to various antibiotics.It is important of the early detection of patients colonized with these bacteria and the demonstration of relations with nosocomial epidemic in the control of vancomycin-resistant enterococci (VRE) infections. Molecular methods should be used to detect the clonal relationship between isolated VRE strains during epidemics of nosocomial. Pulsed Field Gel Electrophoresis (PFGE), is considered as golden standard method for demonstration of relationship between the epidemic strains and determining the source of the epidemic in the surveillance of nosocomial epidemic. In this study, it is aimed to detect clonal relationships of VRE strains isolated from the hospitalized patients by PFGE and arbitrarily primed PCR (AP-PCR) methods in terms of the epidemiology of hospital infections.Between January 2001 and December 2009, Enterococcus faecium was found to be the dominant species in all VRE isolated from hospitalized patients, which have rate of 98%. 83 strains of E. faecium were included in the study, which isolated from 5 different possible epidemic periods during 9 years. It was found that all strains have high-level glycopeptide resistance.Through PFGE method, it was determined that there was a significant similarity between many strains isolated from between 2001 and 2002 epidemics, this clone was maintained the existence for a long time and it had become the dominant in these two epidemics. It was also determined that the strains isolated in other 3 epidemic periods were similar to themselves, but there was no significant similarity to a strain between different epidemics. Especially during the 2009 epidemic period, it was found that all strains were collected in a single clonal cluster, the new strain which were not previously isolated from samples of patients was spread to all units of the hospital.It was evaluated that PFGE was a molecular epidemiological method which have high separation power, can be standardized between laboratories and provide reliable information on the epidemic surveillance.
Description
Keywords
Moleküler epidemiyolojik analiz, PFGE, AP-PCR, Molecular epidemiological analysis, VRE
Citation
Karakeçili, F. (2011). Vankomisine dirençli enterokoklarda moleküler epidemiyolojik analiz. Yayınlanmamış uzmanlık tezi. Uludağ Üniversitesi Tıp Fakültesi.