Characteristics of the diseases 29 Enterobacteriaceae representatives

Characteristics of the diseases 29 enterobacteriaceae

This preview shows page 53 - 54 out of 594 pages.

Characteristics of the diseases 29 Enterobacteriaceae representatives Citrobacter freundii Diseased sunfish displayed erratic swimming, inappetence, eroded skin, surface haemorrhages, enteritis, deep red spleen, pale liver and tumorous masses (granulo- mas) on the kidney (Sato et ai, 1982). Similar signs have been observed in salmonids within the U.K. (B. Austin, unpubHshed data). In the initial disease outbreak, 25/29 animals (=86% of the total) died (Sato et al, 1982). Edwardsiella ictaluri Although Edw. ictaluri is primarily a disease of catfish, with time other fish groups have been reported to become infected: for example, brown bullhead (Amieurus nebulosus) in the U.S.A. (Iwanowicz et ai, 2006). The disease has spread from its original focal point in the U.S.A. to include cultured striped catfish (Pangasius hypophthalmus) in Sumatra, Indonesia (Yuasa et al, 2003) and catfish in Vietnam (Crumlish et al, 2002). It is apparent that there is a great variability in the clinical signs associated with the disease. Just prior to death, the fish may hang listlessly in an almost vertical position at the water surface, spin rapidly in circles, or exhibit spiral swimming. External signs, often absent in fish over 15 cm in length, include the presence of petechial (pin-prick) haemorrhages on the skin in the vicinity of the throat and mouth, pale gills, exophthalmia and open lesions on the head, particularly on the frontal bone of the skull between the eyes and on the lateral body surface. Internally, there may be swelling of the kidney and spleen, haemorrhaging and necrotic areas in the liver, blood-filled ascitic fluid in the peritoneum, and petechial haemorrhages throughout the internal muscle walls (Hawke, 1979). In Vietnam, the disease is referred to as "bacillary necrosis of Pangasius"" with which there are irregular white lesions on the kidney, liver and spleen, and the involvement of parasites and bacteria including Bacillus and Edw. ictaluri (Crumlish et ai, 2002). Edwardsiella tarda Excellent desriptions of the clinical manifestation of Edw. tarda infections in channel catfish were pubHshed by Meyer and Bullock (1973). These authors reported that with mild infections the only external signs of disease are the presence of small cutaneous lesions of approximately 3-5 mm in diameter, which are located in the postero-lateral region of the body. With progression of the disease, abscesses develop in the muscle of the body and tail. These abscesses may enlarge, and develop into gas- filled hollow areas. From the surface, these are seen as poorly pigmented, convex swollen areas which, if punctured, emit a foul odour. This condition has given rise to the name emphysematous putrefactive disease of catfish. Although catastrophic losses of catfish have not been recorded, the disease has a severe economic effect on infected sites. When infected fish enter processing plants, the noxious odours effectively stop production by necessitating disinfection and deodorisation. Thus, heavy financial losses to the processors may result from the presence of only a small number of infected animals (Meyer and Bullock, 1973).
Image of page 53
Image of page 54

You've reached the end of your free preview.

Want to read all 594 pages?

  • Spring '20
  • Bacteria, representative, gram-negative bacteria

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors