Yersinioz hastalığından korunmada aşı uygulamaları ve bu uygulamaların sonuçlarının değerlendirilmesi
Küçük Resim Yok
Tarih
1994
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
ÖZET Yersinioz 1950 yılından beri bilinen alabalıkların kontagiyöz bir hastalığıdır. Yersinia ruckeri'nin ilk izolasyonundan sonra hastalık Amerika, Avrupa, Asya ve Avusturalya'da bir çok ülkede bildirildi. Hastalık Türkiye'de 1990 yılında teşhis edildi (Çağırgan ve Yüreklitürk). îlk izolasyondan sonra enfeksiyon Ege Bölgesindeki alabalık çiftliklerinin hemen hemen hepsinde görüldü. Bir çok ülkede hastalığın yayılmasını önlemek için balık hareketlerinde yasaklamalar, kemoterapi ve aşılama gibi bazı önlemler alındı. Fakat bu önlemlerin hiç birisi aşılama kadar etkin değildir. Aşılama maliyet, çok az veya hiç ölüm olmaksızın uzun süre koruyuculuk, toksisiteye ve rezidüye neden olmama, ilaçlara direnç şekillendirmeme ve çevre üzerine olumsuz etkileri bulunmaması yönlerinden kemoterapiden avantajlıdır. Yersinioza karşı aşılama halen bir çok ülkede enfeksiyonları önlemek amacıyla yapılmaktadır. Ne yazık ki Türkiye'de yersinioz aşısı ve bu konuda herhangi bir çalışma yoktur. Aşılama için oral hiperozmotik infıltrasyon, anal intubasyon, enjeksiyon, püskürtme ve direkt banyo olmak üzere bir çok metot bildirilmiştir (Johnson ve Amend, 1983a). Ticari aşıların hepsi direkt banyo şeklinde uygulanmaktadır (Ellis, 1988b). Elbette ki direkt banyo en mükemmel metot değilsede uygulaması kolay olup yeterli bağışıklık vermektedir. Bu araştırmanın amacı Türkiye'de yersinioz hastalığın kontrolü için ekonomik öneme sahip ticari aşılara denk kalitede bir aşı geliştirmek ve bazı ticari aşıların koruyuculuğunu tesbit etmektir. Bu çalışma ile Avrupa'da üretimi yapılan iki ticari aşı ve yeni geliştirilen ERM aşılarının saha ve laboratuvar şartlarında sağladıkları bağışıklık, toksisite ve diğer kalite kriterleri test edildi. Denemeler Türkiyedeki hasta alabalıklardan izole edilen Y. rnckeri Tip Tin LDgg dozunun deneme balıklarına verilmesiyle yapıldı. Deneysel enfeksiyonlar yersinioz geçirmediği tahmin edilen 2,5 g ağırlığındaki sağlıklı alabalık yavrularının su içersinde 1 dakika süreyle etkene maruz bırakılmasıyla yapıldı. LD60 dozun belirlenmesi 18 ± 2 °C sıcaklığında klordan arındırılmış çeşme suyu içeren ve havalandırılan 100 litre hacmindeki akvaryumlarda yapıldı. Deneysel enfeksiyonlarda verilen LD6q dozu balık gruplarına göre değişmek üzere 2 x 106 ile 4 x 107 cfu/ml arasındaydı. Deneme akvaryumlanndaki suyun kalitesi kimyasal ve fiziksel kriterlerine bakılarak devamlı kontrol edildi. Su kalitesi bozulduğunda kontrollü olarak değiştirildi. Enfekte edilen balıklar ve kontrol grublan her grupta 30 adet balık olacak şekilde iki paralelli grup halinde akvaryumda tutuldu.Balıklar %4 oranında ticari yemle beslendi (Pınar Yem San., İzmir, Türkiye) ve deneysel enfeksiyondan sonra 15 gün izlendi. Ölen balıklar her gün 80akvaryumlardan dışarı alındı ve ölen balıkların böbreğinden SW medyum ile TSA üzerine ekim yapılmak suretiyle besi yerleri 21±l°Cde 2 gün inkube edilerek etken reizole edildi. Y. ruckeri izole edilen ölü balıklar spesifik mortalite olarak kabul edildi. Aşıların koruyuculuğu nisbi hayatta kalma yüzdesi (RPS) olarak adlandırılan Amend,in (1981) bildirdiği formüle göre değerlendirildi. Aşılar bakterinin TSB içersinde üremesini takiben Ellis, (1988b) tarafından bildirilen yönteme uyularak hazırlandı ve direkt banyo tarzında çiftlik veya çeşme suyunda 1:10 oranında dilue edilerek 1 dakika süreyle uygulandı. Aşıların sağladığı bağışıklık 25. 76 ve 125. günlerde patojene maruz bırakılarak çiftlik ve akvaryum koşullarında tesbit edildi. 60 RPS nin altındaki değerlerin koruma sağlamadığı kabul edildi. Bütün deneysel enfeksiyonlar çiftliği kontaminasyondan korumak için akvaryumlarda yapıldı. Üretilen aşıların toksisiteleri Y. ruckerfnin uzaklaştırıldığı kültür filtratında balıkların banyo yaptınlmasıyla test edildi. Deneme sonuçlan aşıların yavru alabalıklar için toksik olmadığını gösterdi. Diğer ticari aşılar firmanın tavsiyesine uyularak kullanıldı. Y. ruckeri Hagerman susundan (Serotip I) üretildiği etiketinde bildirilen İngiltere'den temin edilen aşı bizim patojenik Y. ruckeri Serotip I susuna karşı bağışıklık sağlamadı. Bu aşı, aşılamanın 25, 76 ve 125. günlerinde labaratuvar şartlarında sırasıyla 65, 48, 38 RPS, saha şartalrında ise 68, 51 ve 45 RPS değerlerini verdi. Fransada üretilen ve Y. ruckeri Serotip I den imal edildiği bildirilen aşı ise labaratuvar ve saha şartlarında başarılıydı. Aşılamadan sonraki 25, 76 ve 125. günlerde labaratuvar şartlarında sırasıyla 83, "70, 69 saha şartannda 89, 79 ve 72 RPS verdi. Bu aşı ile aşılanan balıkların bulunduğu çiftlikte aşılamadan sonraki 185. günde doğal bir Y. ruckeri serotip I enfeksiyonuna karşı koruma sağladığı görüldü. Hastalık çıkan bir çiftlikten izole edilen Y. ruckeri serotip II den hazırlanan otovaksin ile aşılama, balıklan 155 gün sonra çıkan doğal serotip I enfeksiyonuna karşı etkili bulunmadı. Labaratuvar ve saha denemeleri 25 76 ve 125. günlerde hesaplanan RPS değerleri sırasıyla 31, 16, 5 ve 31, 20, 8 olarak bulundu. Aşılar içinde en başanlısı, yurdumuzdan izole ettiğimiz patojen Y. ruckeri Serotip I den hazırlanan Y-l 1 aşısıydı. Bu aşı saha ve laboratuvarda deneme günlerinde sırasıyla 96, 89, 85 ve 94, 88, 79 RPS verdi. Aynı zamanda bu aşının uygulandığı ve daha önceden yersinioz nedeniyle büyük kayıplann yaşandığı işletmelerde balıklar aşılandıktan satılıncaya kadar yersinioz görülmedi. Bu aşı labaratuvarda çıkan yersinioz enefeksiyonundan sonra tedaviyi mütaakiben uygulandığında bile etkin koruma sağladı. 81
SUMMARY Yersiniosis is a contagious disease of all salmonid fish and known since 1950's. After the first isolation of Y. ruckeri the disease was reported from several countries of continent America, Europe, Asia and Australia. The disease had diagnosed in Turkey at the end of the 1990 (Çağırgan and Yüreklitürk, 1991). After this first isolation infection was found nearly all of the trout farm of West Anatolia in Turkey. Several measures were encountered to prevent to spread the disease including regulations of fish movement, chemotherapy and vaccinations in many contries. However none of the cautions were not effective to prevent the disease as vaccinations. Vaccination is over to chemotherapy in cost, long term of prophilaxie without losses or a few loss, without toxicity and residues problems, without drug resistance problem and no environmental impaction. Vaccinations have been being used to prevent ERM infection in many countries. Unfortunately up to date there is no ERM vaccine and vaccination research in Turkey. Many methods were reported for ERM vaccine including orally, hyper osmotic infiltration, anal intubation injection spray shower and direct immersion (Johnson and Amend, 1983a). All the commercial vaccines are applied by direct immersion (DI) (Ellis, 1988b). Certainly DI is not the best method, but the usage is easy and gives enough protection. The aim of this project to determine potency of some commercial vaccines and develop an equal quality new ERM vaccine, which has economical importance to prevent ERM infection in Turkey. By this reason 2 commercial vaccines which produced in European countries and also new developed ERM vaccines were tested in protection, toxicity, and the other quality criteria by both laboratory and field tests. The researches were carried out by the determination of LDg0 of pathogenic Yersinia ruckeri serotype I which isolated from diseased rainbow trout in Turkey. Experimental infections were fulfilled by water borne challenge for 1 minutes to healthy looking 2-5 g of rainbow trout fry which no ERM history reported in same population. Determinations of l£>60 were done m *00 liter constant aerated and declorinated tap water containing aquarium maintaining at 18 ± 2 °C. LDgQ was changing between 2 x 106 - 4 x 107 depending lot to lot. In the aquarium researches water quality was monitored in chemical and physical characteristics. The water was immediately changed when chemical characteristics were unsuitable Challenged fish and controls were kept in the aquarium establishing 2 parallel groups and each group was containing 30 fish. The fish were fed 4% commercial feed (Pınar Feed Company, İzmir, Turkey) and kept for 15 days after experimental infection. 82Dead fish were taken out daily and reisolations were tried from kidney on SW medium as well as TSA incubating at 21±1 °C for 2 days. Y. ruckeri isolated dead fish were accepted as specific mortality. Potency of the vaccines were calculated using the formula (Amend, 1981), which named relative percentage survival (RPS). The vaccines were prepared growing the bacteria in TSB following the procedure of Ellis (1988b) and used by DI for 1 minute after 1:10 diluting it with farm or tap water. Potency of vaccines were determined in aquarium condition and fish farm challenging at the day of 25, 76 and 125. Less then 60 RPS was assumed as no protection. All the challenges were done in aquarium to prevent contamination offish farms. Prepared vaccine was also tested in toxicity immersing the fish in Y. ruckeri free culture filtrate. The results showed that there is no toxicity of prepared vaccine to rainbow trout fry. Other commercial vaccines were used following the producer's recommendations. The vaccine which kindly provided from UK that labeled as produced from Hagerman serotype of Y. ruckeri so far from the protection against our pathogenic Y. ruckeri serotype I. The British vaccine was giving 65, 48 and 38 RPS in laboratory condition at the vaccination day of 25. 76 and 125 respectively while 68, 51 and 45 RPS in field. The vaccine which kindly provided from France that labeled as produced from Y. ruckeri serotype I was successful in laboratory and field tests. RPS of the vaccine after the vaccination day 25, 76 and 125 was 83, 70, 69 in laboratory and 89, 79 72 in field respectively. It was also protecting the fish in a natural outbreak by Y. ruckeri Serotype I at experimentally vaccinated farm after 185 days. The vaccine which prepared as auto-vaccine from Y. ruckeri serotype II, which was isolated from an outbreak, had not effective to control the natural outbreak by Y. ruckeri Serotype I in the fish farm after 1 55 days of the vaccination. The laboratory and field experiments have showed that 31, 16, 5 and 31, 20, 8 RPS after the vaccination day 25, 76 and 125 respectively. The most successful vaccine was Y-ll which produced from our pathogenic Y. ruckeri Serotype I. The results were showed that 96, 89, 85 RPS in field and 94, 88, 79 RPS in laboratory experiment and there was no outbreak until the fish sold. In these farms high mortality was observed previous years before the vaccination by the reason of yersiniosis. This vaccine was also effective in laboratory condition even it has used after chemotherapy, following a natural infection. 83
SUMMARY Yersiniosis is a contagious disease of all salmonid fish and known since 1950's. After the first isolation of Y. ruckeri the disease was reported from several countries of continent America, Europe, Asia and Australia. The disease had diagnosed in Turkey at the end of the 1990 (Çağırgan and Yüreklitürk, 1991). After this first isolation infection was found nearly all of the trout farm of West Anatolia in Turkey. Several measures were encountered to prevent to spread the disease including regulations of fish movement, chemotherapy and vaccinations in many contries. However none of the cautions were not effective to prevent the disease as vaccinations. Vaccination is over to chemotherapy in cost, long term of prophilaxie without losses or a few loss, without toxicity and residues problems, without drug resistance problem and no environmental impaction. Vaccinations have been being used to prevent ERM infection in many countries. Unfortunately up to date there is no ERM vaccine and vaccination research in Turkey. Many methods were reported for ERM vaccine including orally, hyper osmotic infiltration, anal intubation injection spray shower and direct immersion (Johnson and Amend, 1983a). All the commercial vaccines are applied by direct immersion (DI) (Ellis, 1988b). Certainly DI is not the best method, but the usage is easy and gives enough protection. The aim of this project to determine potency of some commercial vaccines and develop an equal quality new ERM vaccine, which has economical importance to prevent ERM infection in Turkey. By this reason 2 commercial vaccines which produced in European countries and also new developed ERM vaccines were tested in protection, toxicity, and the other quality criteria by both laboratory and field tests. The researches were carried out by the determination of LDg0 of pathogenic Yersinia ruckeri serotype I which isolated from diseased rainbow trout in Turkey. Experimental infections were fulfilled by water borne challenge for 1 minutes to healthy looking 2-5 g of rainbow trout fry which no ERM history reported in same population. Determinations of l£>60 were done m *00 liter constant aerated and declorinated tap water containing aquarium maintaining at 18 ± 2 °C. LDgQ was changing between 2 x 106 - 4 x 107 depending lot to lot. In the aquarium researches water quality was monitored in chemical and physical characteristics. The water was immediately changed when chemical characteristics were unsuitable Challenged fish and controls were kept in the aquarium establishing 2 parallel groups and each group was containing 30 fish. The fish were fed 4% commercial feed (Pınar Feed Company, İzmir, Turkey) and kept for 15 days after experimental infection. 82Dead fish were taken out daily and reisolations were tried from kidney on SW medium as well as TSA incubating at 21±1 °C for 2 days. Y. ruckeri isolated dead fish were accepted as specific mortality. Potency of the vaccines were calculated using the formula (Amend, 1981), which named relative percentage survival (RPS). The vaccines were prepared growing the bacteria in TSB following the procedure of Ellis (1988b) and used by DI for 1 minute after 1:10 diluting it with farm or tap water. Potency of vaccines were determined in aquarium condition and fish farm challenging at the day of 25, 76 and 125. Less then 60 RPS was assumed as no protection. All the challenges were done in aquarium to prevent contamination offish farms. Prepared vaccine was also tested in toxicity immersing the fish in Y. ruckeri free culture filtrate. The results showed that there is no toxicity of prepared vaccine to rainbow trout fry. Other commercial vaccines were used following the producer's recommendations. The vaccine which kindly provided from UK that labeled as produced from Hagerman serotype of Y. ruckeri so far from the protection against our pathogenic Y. ruckeri serotype I. The British vaccine was giving 65, 48 and 38 RPS in laboratory condition at the vaccination day of 25. 76 and 125 respectively while 68, 51 and 45 RPS in field. The vaccine which kindly provided from France that labeled as produced from Y. ruckeri serotype I was successful in laboratory and field tests. RPS of the vaccine after the vaccination day 25, 76 and 125 was 83, 70, 69 in laboratory and 89, 79 72 in field respectively. It was also protecting the fish in a natural outbreak by Y. ruckeri Serotype I at experimentally vaccinated farm after 185 days. The vaccine which prepared as auto-vaccine from Y. ruckeri serotype II, which was isolated from an outbreak, had not effective to control the natural outbreak by Y. ruckeri Serotype I in the fish farm after 1 55 days of the vaccination. The laboratory and field experiments have showed that 31, 16, 5 and 31, 20, 8 RPS after the vaccination day 25, 76 and 125 respectively. The most successful vaccine was Y-ll which produced from our pathogenic Y. ruckeri Serotype I. The results were showed that 96, 89, 85 RPS in field and 94, 88, 79 RPS in laboratory experiment and there was no outbreak until the fish sold. In these farms high mortality was observed previous years before the vaccination by the reason of yersiniosis. This vaccine was also effective in laboratory condition even it has used after chemotherapy, following a natural infection. 83
Açıklama
Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.
Anahtar Kelimeler
Su Ürünleri, Aquatic Products, Aşılar, Vaccines, Gökkuşağı alabalığı, Rainbow trout, Yersinia ruckeri, Yersinia ruckeri, Yersinioz hastalığı, Yersinioz diseases
