The pathology associated with visceral toxicosis of catfish

Abstract

Abstract. Visceral toxicosis of catfish (VTC) syndrome was recognized in the late 1990s and recently has been associated with exposure to Clostridium botulinum type E neurotoxin. Tentative diagnosis is based on clinical presentation and gross findings, and is confirmed by bioassay. In April 2009, channel catfish (Ictalurus punctatus) from 2 different farms presented with abnormal swimming behavior and mortalities. Nine fish were submitted to the Aquatic Research and Diagnostic Laboratory (Stoneville, Mississippi) for evaluation. Bacterial cultures from these fish were negative. Necropsy findings included intestinal intussusceptions, ascites, pale proximal intestines with engorged serosal blood vessels, splenic congestion, and a reticular pattern to the liver. Significant histopathologic findings were limited to cerebral, splenic, and hepatic congestion, splenic lymphoid depletion and perivascular edema, vascular dilation and edema of the gastrointestinal tract, and perivascular edema in the anterior and posterior kidneys. Intoxication from C. botulinum type E neurotoxin was suspected based on the clinical signs and lack of gross and microbiological evidence of an infectious disease process. The toxicosis was confirmed with a positive bioassay using serum collected from the submitted fish.

Multiplex Real-Time PCR for Detecting and Typing Clostridium botulinum Group III Organisms and Their Mosaic Variants

“…[15][16][17][18][19] Fishes seem vulnerable to type E toxin. 4,20 Animal botulism is suspected to be an emerging disease in Europe, and awareness among veterinarians and all competent authorities has increased in the past decade because of the impact its high mortality rates can have on animal welfare and on the economy of zoo-technical divisions. 21 An additional concern may be related to the intentional release of BoNTs and BoNT-producing organisms as biological weapons.…”

Balıkların Başlıca Bakteriyel Zoonozları

“…C. botulinum neurotoksin tip E'nin neden olduğu hastalık tablosu Amerika, Britanya ve Danimarka'da yetiştiriciliği yapılan salmonid balıklarda bildirilmiştir [5,12,21]. Bununla birlikte son yıllarda Güneydoğu Amerika'da kanal yayın balıklarında (Ictalurus punctatus) saptanan bir hastalık vakası viseral toksikozis olarak rapor edilmiştir [29]. Yapılan çalışmalar C. botulinum'un balıkların bağırsaklarında, yüzeylerinde, balık çiftliklerindeki sedimentlerde, balık ürünlerinde ve alglerde bulunabildiğini göstermektedir [19,22,65].…”

Report on intussusception in channel catfish Ictalurus punctatus (Rafinesque, 1818) from commercial farms in Mexico: A case study

“…and channel catfish Ictalurus punctatus (Gaunt et al, 2007;Liu et al, 2008;Rey et al, 2009;Cao et al, 2016) and it is considered as an emerging disease in the latter (Seafood Watch, 2017). A correlation of this condition with bacterial infection (Vazquez-Pineiros et al, 2010;Wang et al, 2011) or exposure to type E botulin toxin (Gaunt et al, 2007;Khoo et al, 2011) has also been reported. Most intussusception cases reported are from Chinese catfish farms (Liu et al, 2008;Geng et al, 2010;Cao et al, 2016) where it is a frequent condition that results in mortalities, thus representing an important production risk (Liu et al, 2008).…”