Adaptation of Contagious Ecthyma vaccine strain to MDBK cell culture and immunity-stability studies in lambs

Öz

Contagious ecthyma (CE) is a common viral infection in lambs and kids, and still maintains its importance in sheep and goat breeding. Attenuated, live and lyophilized CE vaccines adapted to cell culture are widely used in the fight against CE. The aim of this project was to adapt the CE vaccine strain to Madin Darby Bovine Kidney (MDBK) cell culture and to produce the vaccine, as well as determining the shelf life, stability, innocuity, and immune response in lambs. The titer of the vaccine virus adapted to the MDBK cell culture was determined to be TCID50 106.5/ml. In the innocuity study on mice and guinea pigs, no local or general reactions were observed. . Body temperature of 10 lambs vaccinated by scarification was found to be between normal values (38.2-39.1°C). Neutralizing antibodies belonging to CE virus with VNT could not be detected in blood sera taken on 30th day following the vaccination. As a result of challenge performed with pathogen (E(P)CK5) CE virus, the protection was observed against CE infection in vaccinated lambs. In the stability study, the titers of lyophilized CE vaccine were found to be TCID50 10^6.5/ml from 1 to 15 months and 106.0/ml at 18, 21 and 24 months during the 24-month storage period at + 4/+8°C. It was determined that the vaccine virus remained as stable at TCID50 10^6.5/ml titer for 12 hours at 30, 33, 37 and 40˚C and after 12 hours, the virus titer regressed to TCID50 105.75/ml. at 42°C and 45˚C. This study concluded that CE vaccines could be produced in MDBK cell cultures by adapting CE virus to MDBK cell culture.

Anahtar Kelimeler

• Contagious ecthyma,virus,vaccine,immunity,inocuity,stability

Contagious Ektima Aşı suşunun MDBK hücre kültürüne adaptasyonu ve kuzularda bağışıklık-stabilite çalışmaları

Öz

Contagious ecthyma (CE), kuzu ve oğlaklarda yaygın viral bir enfeksiyondur ve hala koyun ve keçi yetiştiriciliğinde önemini korumaktadır. Hücre kültürüne adapte canlı ve liyofilize CE aşıları mücadelede yaygın olarak kullanılmaktadır. Bu proje CE aşı suşunun Madin Darby Bovine Kidney (MDBK) hücre kültürüne adapte edilmesi ve MDBK hücre kültüründe üretimi yapılan aşısının raf ömrünü, stabilite ve kuzularda bağışıklık düzeyinin saptanması amacıyla gerçekleştirildi. MDBK hücre kültürüne adapte edilen aşı virüsünün titresinin DKID50 106.5/ml olduğu belirlenmiştir. Fareler ve kobaylarda yapılan zararsızlık çalışmalarında lokal veya genel reaksiyonlar gözlenmedi. Scarifikayon yoluyla aşılanan 10 kuzunun vücut ısılarının normal değerler (38.2-39.1°C) arasında olduğu bulundu. Aşılamayı izleyen 30. günde alınan kan serumlarında VNT ile CE virüsüne ait nötralize edici antikorlar tespit edilemedi. Patojen CE virüsü (E(P)CK5) ile yapılan challenge sonucunda aşılanmış kuzuların CE enfeksiyonuna karşı korunduğu gözlenmiştir. Stabilite çalışmasında, +4 /+8°C'de 24 ay süreyle muhafaza edilen liyofilize CE aşısı titrelerinin 18, 21 ve 24. aylarda DKID50 106.5/ ml ve 18, 21 ve 24 aylarda ise 106.0/ml olduğu tespit edildi. Aşı virüsünün 30, 33, 37 ve 40˚C'lerde DKID50 10^6.5/ml titrede 12 saat stabil kaldığı ve 12 saat sonra virüs titresinin 42 ve 45°C'lerde DKID50 10^5.75/ml'ye gerilediği tespit edildi. Bu çalışma sonucu, CE aşı virüsünün MDBK hücre kültürüne adapte edilmesi ile CE aşılarının MDBK hücre kültürlerinde üretilebileceği sonucuna varmıştır.

Anahtar Kelimeler

• Contagious ecthyma,virus,aşı,bağışıklık,immunity,innocuity

Kaynakça

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