Marmara Bölgesinde Koyunlarda Small Ruminant Lentivirus Enfeksiyonunun Moleküler Karakterizasyonu
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Dosyalar
Tarih
2023
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Sağlık Bilimleri Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Small Ruminant Lentivirus (SRLV), Maedi-Visna hastalığına neden olan, Lentivirus genusunda
yer alan enfeksiyöz viral etkendir. Koyunlarda verim kaybı nedeni ile ekonomik kayıplara sebep olan ve
yavaş ilerleyen persiste karaktere sahip enfeksiyon oluşturmaktadır. Ülkemizde varlığı bildirilen
enfeksiyon dünya genelinde görülmektedir.
Bu çalışmada, Marmara Bölgesi’nde enfeksiyonun yaygınlığının ve virusun moleküler
karakterizasyonunun gösterilmesi ile serolojik teşhis yöntemlerinin karşılaştırılması amaçlandı. Bu
kapsamda enfeksiyonun yaygınlığı, SRLV etkenine karşı oluşan spesifik antikor varlığı 16 adet sürüden
293 adet koyun serum örneğinden ELISA test metoduyla araştırıldı. ELISA test ile 12 adet sürü (%75)
içerisinden 54 adet örnek (%18.43) seropozitif tespit edildi. Virusun moleküler karakterizasyonu için 6
adet sürüden 12 adet koyun defibrine kan örnekleri ile 4 adet koyun organ örnekleri SRLV etkeninin LTR
gen bölgesini hedefleyen PCR analizi ile araştırıldı. Optimize edilen PCR analizi ile 2 adet örnekte viral
DNA varlığı tespit edildi. Pozitif bulunan örneklere DNA dizileme analizleri yapılarak LTR dizinleri elde
edildi. LTR dizinleri filogenetik analizler ile referans suşlar ve farklı saha izolatları karşılaştırılarak
filogenetik ağaçlar oluşturuldu. Sekans ve filogenetik analizler ile pozitif tespit edilen 2 adet izolatın da
Genotip A ile karakterize olduğu tespit edildi. Filogenetik ağaç içerisinde izolatların A24 alt tipi ile
kümelendiği görüldü. Serolojik teşhis yöntemlerinin karşılaştırılması amacıyla ELISA test metodu ile
AGID test metodu 100 adet koyun serum örneğinin analizleri yapılarak değerlendirildi. ELISA testi ile
pozitif (n=54) ve negatif (n=46) tespit edilen örneklerin 43 adeti AGID testi ile pozitif tespit edilirken 57
adeti negatif tespit edildi. AGID ve ELISA testinin kappa değeri 0.7824 olarak hesaplandı. Güven sınırı
(%95) içerisinde 0.6641 ile 0.9008 alt ve üst değerlere sahip bulundu. AGID ve ELISA testlerinin doğruluk
oran değerleri %89 olarak bulundu. AGID testinin spesifite değeri ELISA testinden daha yüksek iken
ELISA testinin ise sensitivite değeri AGID testinden daha yüksek olduğu hesaplandı.
Bu çalışmada Marmara Bölgesi’nde yetiştirilen koyunlarda SRLV enfeksiyonunun seroprevalans
oranı %18.43 olarak tespit edildi. Yerel virus izlotlarının Genotip A varlığı gösterildi. Yerel sürülerde
SRLV enfeksiyonunun teşhis ve epidemiyolojik çalışmalarında fayda sağlayacak serolojik yöntemlerin
karşılaştırılması yapıldı. Bu çalışmada elde edilen verilerin koyunlarda SRLV enfeksiyonlarının etiyolojik,
epidemiyolojik ve eradikasyon çalışmalarına katkı sağlayacağı ifade edilebilir.
Small Ruminant Lentivirus (SRLV) is an infectious viral agent in the genus Lentivirus that causes Maedi-Visna disease. It is a slowly progressive, persistent infection that causes economic losses due to yield loss in sheep. The infection, which has been reported in our country, is seen worldwide. In this study, it was aimed to show the prevalence of infection and molecular characterization of the virus in the Marmara Region and to compare serological diagnostic methods. In this context, the prevalence of infection and the presence of specific antibodies against SRLV were investigated by the ELISA test method in 293 sheep serum samples from 16 flocks. By ELISA test, 54 samples (18.43%) from 12 flocks (75%) were seropositive. For molecular characterization of the virus, 12 sheep defibrinated blood samples and 4 sheep organ samples from 6 flocks were investigated by PCR (polymerase chain reaction) analysis targeting the LTR gene region of SRLV. The presence of viral DNA was detected in 2 samples by optimized PCR analysis. DNA sequencing analyses were performed on the positive samples, and LTR sequences were obtained. Phylogenetic trees were created by comparing LTR sequences with reference strains and different field isolates using phylogenetic analyses. It was determined that 2 isolates, which were found positive by sequence and phylogenetic analyses, were characterized by Genotype A. In the phylogenetic tree, the isolates were clustered under subtype A24. In order to compare serological diagnostic methods, the ELISA test method and the AGID test method were evaluated by analyzing 100 sheep serum samples. Of the samples that were positive (n=54) and negative (n=46) by ELISA test, 43 were positive by AGID test, and 57 were negative. The kappa value of the AGID and ELISA tests was calculated as 0.7824. Within the confidence limit (95%), 0.6641 and 0.9008 were found to have lower and upper values, respectively. The accuracy rates of the AGID and ELISA tests were found to be 89%. The specificity value of the AGID test was higher than the ELISA test, while the sensitivity value of the ELISA test was higher than the AGID test. As a result of the study, it was observed that the seroprevalence rate of SRLV infection in sheep in the Marmara Region was 18.43%. Genotype A presence of local virus isolates was shown. A comparison of serological methods that will be useful in the diagnosis and epidemiological studies of SRLV infection was made. It can be stated that this study will contribute to the etiological, epidemiological, and eradication studies of SRLV infections in sheep.
Small Ruminant Lentivirus (SRLV) is an infectious viral agent in the genus Lentivirus that causes Maedi-Visna disease. It is a slowly progressive, persistent infection that causes economic losses due to yield loss in sheep. The infection, which has been reported in our country, is seen worldwide. In this study, it was aimed to show the prevalence of infection and molecular characterization of the virus in the Marmara Region and to compare serological diagnostic methods. In this context, the prevalence of infection and the presence of specific antibodies against SRLV were investigated by the ELISA test method in 293 sheep serum samples from 16 flocks. By ELISA test, 54 samples (18.43%) from 12 flocks (75%) were seropositive. For molecular characterization of the virus, 12 sheep defibrinated blood samples and 4 sheep organ samples from 6 flocks were investigated by PCR (polymerase chain reaction) analysis targeting the LTR gene region of SRLV. The presence of viral DNA was detected in 2 samples by optimized PCR analysis. DNA sequencing analyses were performed on the positive samples, and LTR sequences were obtained. Phylogenetic trees were created by comparing LTR sequences with reference strains and different field isolates using phylogenetic analyses. It was determined that 2 isolates, which were found positive by sequence and phylogenetic analyses, were characterized by Genotype A. In the phylogenetic tree, the isolates were clustered under subtype A24. In order to compare serological diagnostic methods, the ELISA test method and the AGID test method were evaluated by analyzing 100 sheep serum samples. Of the samples that were positive (n=54) and negative (n=46) by ELISA test, 43 were positive by AGID test, and 57 were negative. The kappa value of the AGID and ELISA tests was calculated as 0.7824. Within the confidence limit (95%), 0.6641 and 0.9008 were found to have lower and upper values, respectively. The accuracy rates of the AGID and ELISA tests were found to be 89%. The specificity value of the AGID test was higher than the ELISA test, while the sensitivity value of the ELISA test was higher than the AGID test. As a result of the study, it was observed that the seroprevalence rate of SRLV infection in sheep in the Marmara Region was 18.43%. Genotype A presence of local virus isolates was shown. A comparison of serological methods that will be useful in the diagnosis and epidemiological studies of SRLV infection was made. It can be stated that this study will contribute to the etiological, epidemiological, and eradication studies of SRLV infections in sheep.
Açıklama
Anahtar Kelimeler
Agar Jel Immunodiffüzyon, Moleküler Karakterizasyon, Seroprevalans, Small Ruminant Lentivirus, Agar Gel Immunodiffusion, Molecular Characterization, Seroprevalence, Visna Maedi Virus
Kaynak
WoS Q Değeri
Scopus Q Değeri
Cilt
Sayı
Künye
Türkdoğan, M., (2023). Marmara Bölgesinde Koyunlarda Small Ruminant Lentivirus Enfeksiyonunun Moleküler Karakterizasyonu. (Doktora). Selçuk Üniversitesi, Sağlık Bilimleri Enstitüsü, Konya.
