Pathological findings of experimental Aeromonas hydrophila infection in Nile tilapia (Oreochromis niloticus)

Abstract

In this study, clinical findings with macroscopic and microscopic pathologic changes of the tissues and organs after necropsy examination at the 1st, 2nd, 3rd, 5th and 7th days following intraperitoneally injection of Nile tilapia (Oreochromis niloticus) with Aeromonas hydrophila was aimed to be observed. Clinically; weakness, anorexia, swimming closer to surface, darkness in color with hyperemia and lysis of the fins were observed. In the macroscopic examination the liver was seen to be yellowish brown and crispy with haemorrhagic and greyish white foci on the surface. The gall bladder was tightly full with emerald green bile. The kidney and hearth had haemorrhagic foci whilst intestine lumina observed to be filled with yellow coloured mucoid liquid. The degenerative changes, cytoplasmic fat vacuols and lymphocyte infiltration in lever with focal necrosis of hepatocytes and pancreatic cells were observed histologically. The skin, spleen, gill and eyes did not reveal any significant symptoms. The haemorrhagies and intensive lymphocyte infiltrations in liver, kidney and hearth both in macroscopic and microscopic levels revealed a visceral haemorrhagic septicemia. In this sense; clinical, macroscopic and microscopic findings observed during the present study complied with the Aeromonas hydrophila infections recorded in the other fresh water fishes

Keywords

• Aeromonas hydrophila
• bacterial haemorrhagic septicemia
• Nile tilapia (Oreochromis niloticus)
• pathology

Nil tilapyalarında (Oreochromis niloticus) deneysel Aeromonas hydrophila enfeksiyonundakipatolojik bulgular

Abstract

Bu çalışmada; intraperitoneal olarak Aeromonas hydrophila ile enfekte edilen Nil tilapyalarında (Oreochromis niloticus), enjeksiyonu izleyen 1., 2., 3., 5. ve 7. günlerdeki klinik bulgular ile ötenaziyi takiben yapılan nekropsiler sonrasında doku ve organlarda gözlenen patolojik bulguların, makroskobik ve mikroskobik düzeyde incelenerek değerlendirilmesi amaçlandı. Klinik olarak halsizlik, iştahızlık, yüzeye yakın yüzme, renkte koyulaşma ile yüzgeç diplerinde hiperemi ve erime gibi bulgular gözlendi. Nekropside karaciğerin sarımsı kahverenkli olduğu ve kıvamının gevrekleşip, üzerinde kanama ve boz beyaz odaklar gözlendi. Safra kesesinin zümrüt yeşili renkli safra sıvısıyla gergin bir şekilde dolu olduğu dikkati çekti. Böbrekte ve kalpte kanama odakları gözlenirken, bağırsak lümenlerinin sarımtırak renkli, mukuslu sıvı ile dolu olduğu izlendi. Histopatolojik olarak karaciğerde dejeneratif değişiklikler, sitoplazmalarında yağ vakuolleri ve lenfosit infiltrasyonu ile hepatosit ve pankreas hücrelerinde fokal nekroz gözlendi. Böbrekte, parankim dejenerasyonu, tubul epitellerinde nekroz ve fokal lenfosit infiltrasyonu görüldü. Deri, dalak, solungaç ve gözlerde belirgin bir bulgu gözlenmedi. Karaciğer, böbrek ve kalpte gerek makroskobik gerekse de mikroskobik düzeyde hemorajilerin ve lenfosit infiltrasyonunun yoğun olarak gözlenmesi visseral bir hemorajik septisemi tablosu çizmektedir. Bu bağlamda mevcut çalışma süresince gözlenen klinik, makroskobik ve mikroskobik bulgular genel itibariyle diğer tatlı su balıklarında şekillenen A. hydrophila enfeksiyonlarındaki temel bulgularla benzerlik gösterdi

Keywords

• Aeromonas hydrophila
• bakteriyel hemorajik septisemi
• Nil tilapyası (Oreochromis niloticus)
• patoloji

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