420
proposed (Strohl and Tait 1978 ). However, on the basis of phylogenetics, the species was transferred to Flavobacterium, as Fla. hydatis (Bernardet et al. 1996 ).
Pathogenicity
Fla. hydatis, although not a proven fi sh pathogen, produces extracellular, thermostable, glucose-repressible collagenases, which could be involved in pathogenicity
(Strohl, Gibb and Tait, personal communication).
Disease Control
Antimicrobial Compounds Antibiogrammes confi rmed sensitivity to chloramphenicol (30 μg), erythromycin (15 μg), nalidixic acid (30 μg), streptomycin
(10 μg), sulphathiazole (1 mg) and tetracycline (30 μg), but not to lincomycin
(2 μg), methicillin (5 μg), penicillin (10 IU) or sulphadiazine (300 μg) (Strohl and
Tait 1978 ). From the uniform sensitivity to nalidixic acid, sulpha drugs and tetracycline, these could be considered for chemotherapeutic use, should the need arise.
Flavobacterium johnsoniae (= Cytophaga johnsonae)
Characteristics of the Disease
In the initial outbreak in Queensland, Australia, 2–5 % mortalities occurred in
farmed barramundi, Lates calcarifer, over a two week period when the water temperature was 27–28 °C. The fi sh were listless, and displayed elevated scales and
superfi cial erosion of the skin (particularly on the posterior fl ank). Some fi sh presented eroded pectoral fi ns and lower jaws (Carson et al. 1993 ). Flavobacterium
johnsoniae -like organisms have been recovered from diseased fi sh (gill necrosis,
skin ulcers, systemic disease) in South Africa (Flemming et al. 2007 ).
Isolation
Cytophaga agar (Appendix in Chap. 12 ; after Anacker and Ordal 1959 ) is suitable
for the isolation of the pathogen with incubation at 27 °C for 7 days (Carson et al.
1993 ).
7 Flavobacteria and Cytophagas
proposed (Strohl and Tait 1978 ). However, on the basis of phylogenetics, the species was transferred to Flavobacterium, as Fla. hydatis (Bernardet et al. 1996 ).
Pathogenicity
Fla. hydatis, although not a proven fi sh pathogen, produces extracellular, thermostable, glucose-repressible collagenases, which could be involved in pathogenicity
(Strohl, Gibb and Tait, personal communication).
Disease Control
Antimicrobial Compounds Antibiogrammes confi rmed sensitivity to chloramphenicol (30 μg), erythromycin (15 μg), nalidixic acid (30 μg), streptomycin
(10 μg), sulphathiazole (1 mg) and tetracycline (30 μg), but not to lincomycin
(2 μg), methicillin (5 μg), penicillin (10 IU) or sulphadiazine (300 μg) (Strohl and
Tait 1978 ). From the uniform sensitivity to nalidixic acid, sulpha drugs and tetracycline, these could be considered for chemotherapeutic use, should the need arise.
Flavobacterium johnsoniae (= Cytophaga johnsonae)
Characteristics of the Disease
In the initial outbreak in Queensland, Australia, 2–5 % mortalities occurred in
farmed barramundi, Lates calcarifer, over a two week period when the water temperature was 27–28 °C. The fi sh were listless, and displayed elevated scales and
superfi cial erosion of the skin (particularly on the posterior fl ank). Some fi sh presented eroded pectoral fi ns and lower jaws (Carson et al. 1993 ). Flavobacterium
johnsoniae -like organisms have been recovered from diseased fi sh (gill necrosis,
skin ulcers, systemic disease) in South Africa (Flemming et al. 2007 ).
Isolation
Cytophaga agar (Appendix in Chap. 12 ; after Anacker and Ordal 1959 ) is suitable
for the isolation of the pathogen with incubation at 27 °C for 7 days (Carson et al.
1993 ).
7 Flavobacteria and Cytophagas