111
the eyes were ruptured). Internally, the only disease sign was that the brain was
haemorrhagic, and the cranium was full of blood.
Isolation
Brain tissue samples were plated onto BHIA and TSA with incubation at 25 °C for
48–72 h (Baya et al. 1992b ).
Characteristics of the Pathogen
Characteristics of the organism were, as follows:
Identifi cation was achieved using the API-Coryne system, and comparison to the
type culture of Cor. aquaticum ATCC 14665. The fi sh isolate and reference culture
agglutinated with antisera prepared against both strains. Discrepancies with the
named reference culture included growth at 4 °C and in 5 % (w/v) sodium chloride,
degradation of casein and gelatin, nitrate reduction, pyrrolidonyl arylamidase, and
N-acetyl-ß-glucosaminidase (Baya et al. 1992b ). Also, the fi sh isolate differed from
the reference culture in the precise composition of the membrane proteins, as determined by western blotting. However, both cultures shared a 68 kDa major antigenic
protein (Baya et al. 1992b ).
Box 3.6: Corynebacterium aquaticum
Colonies are 1–3 mm in diameter and exhibit a yellow non-diffusible pigment
after incubation at 25 °C for 48 h. Cultures comprise motile, non-sporeforming, non-acid fast, slightly pleomorphic (club shapes and angular arrangements) Gram-positive rods, which are neither fermentative nor oxidative, and
produced alkaline phosphatase, catalase, ß-galactosidase, α-glucosidase, pyrazinamidase, pyrrolidonyl arylamidase, but not N-acetyl-ß-glucosaminidase,
arginine dihydrolase, ß-glucuronidase, H 2 S, indole, lysine or ornithine decarboxylase, oxidase or phospholipase. Aesculin, blood (ß-haemolysis; only at
37 °C,) casein and gelatin are degraded, but not urea. Nitrates are not reduced.
Citrate is not utilised, nor is acid produced from any of the carbohydrates
examined. The Voges Proskauer reaction is positive. Growth occurs at 4–42 °C
and in 0–5 % but not 8 % (w/v) sodium chloride.
Corynebacteriaceae Representatives
the eyes were ruptured). Internally, the only disease sign was that the brain was
haemorrhagic, and the cranium was full of blood.
Isolation
Brain tissue samples were plated onto BHIA and TSA with incubation at 25 °C for
48–72 h (Baya et al. 1992b ).
Characteristics of the Pathogen
Characteristics of the organism were, as follows:
Identifi cation was achieved using the API-Coryne system, and comparison to the
type culture of Cor. aquaticum ATCC 14665. The fi sh isolate and reference culture
agglutinated with antisera prepared against both strains. Discrepancies with the
named reference culture included growth at 4 °C and in 5 % (w/v) sodium chloride,
degradation of casein and gelatin, nitrate reduction, pyrrolidonyl arylamidase, and
N-acetyl-ß-glucosaminidase (Baya et al. 1992b ). Also, the fi sh isolate differed from
the reference culture in the precise composition of the membrane proteins, as determined by western blotting. However, both cultures shared a 68 kDa major antigenic
protein (Baya et al. 1992b ).
Box 3.6: Corynebacterium aquaticum
Colonies are 1–3 mm in diameter and exhibit a yellow non-diffusible pigment
after incubation at 25 °C for 48 h. Cultures comprise motile, non-sporeforming, non-acid fast, slightly pleomorphic (club shapes and angular arrangements) Gram-positive rods, which are neither fermentative nor oxidative, and
produced alkaline phosphatase, catalase, ß-galactosidase, α-glucosidase, pyrazinamidase, pyrrolidonyl arylamidase, but not N-acetyl-ß-glucosaminidase,
arginine dihydrolase, ß-glucuronidase, H 2 S, indole, lysine or ornithine decarboxylase, oxidase or phospholipase. Aesculin, blood (ß-haemolysis; only at
37 °C,) casein and gelatin are degraded, but not urea. Nitrates are not reduced.
Citrate is not utilised, nor is acid produced from any of the carbohydrates
examined. The Voges Proskauer reaction is positive. Growth occurs at 4–42 °C
and in 0–5 % but not 8 % (w/v) sodium chloride.
Corynebacteriaceae Representatives