613
Pathogenicity
Nothing is known about the pathogenic mechanisms of this organism. Due to the
comparative inactivity of cultures, it seems unlikely that exotoxins are implicated.
This leaves a possible role for endotoxins. Nevertheless, it has been established that
pure cultures will reproduce the disease condition. Thus, peptone water cultures,
administered by i.m. injection into Atlantic salmon fi ngerlings, each of 15 g average
weight, resulted in total mortalities of the population within 72 h at a water temperature of 12 °C (Roald and Hastein 1980 ).
Disease Control
Antimicrobial Compounds Oxytetracycline, at a single dose of 100 mg/fi sh,
appeared to be effective for chemotherapy when administered by intramuscular
injection.
Acinetobacter johnsonii and Acinetobacter lwoffi i
Eight isolates were recovered from diseased farmed rainbow trout and common
carp in Poland. Identifi cation was by use of the API 20 NE rapid identifi cation system and by sequencing of the 16S rDNA gene with the result that the isolates were
equated with Acinetobacter calcoaceticus, Acinetobacter johnsonii, Acinetobacter
junii/johnsonii, Acinetobacter lwoffi i and Acinetobacter spp. (Kozinska et al. 2014 ).
In laboratory-based infectivity experiments, Acinetobacter johnsonii and
Acinetobacter lwoffi i were found to be pathogenic, with the disease signs resembling those in aquaculture (Kozinska et al. 2014 ).
Moraxella sp.
Characteristics of the Disease
During winter 1987, mortalities were recorded among juvenile striped bass, Morone
saxatilis, in the Potomac River, Maryland, USA. Gills of diseased fi sh were affected
with the parasites Trichodina and Ergasilus. In addition, a reo-like virus and a bacterium was recovered from some individuals. Large haemorrhagic lesions and missing scales occurred on the dorsal surface of the 11 affected fi sh. Haemorrhages were
apparent in the swim bladder. The liver was enlarged, pale and mottled in appearance. Membranous material appeared to connect the liver with the body wall (Baya
et al. 1990 ).
Moraxellaceae Representatives
Pathogenicity
Nothing is known about the pathogenic mechanisms of this organism. Due to the
comparative inactivity of cultures, it seems unlikely that exotoxins are implicated.
This leaves a possible role for endotoxins. Nevertheless, it has been established that
pure cultures will reproduce the disease condition. Thus, peptone water cultures,
administered by i.m. injection into Atlantic salmon fi ngerlings, each of 15 g average
weight, resulted in total mortalities of the population within 72 h at a water temperature of 12 °C (Roald and Hastein 1980 ).
Disease Control
Antimicrobial Compounds Oxytetracycline, at a single dose of 100 mg/fi sh,
appeared to be effective for chemotherapy when administered by intramuscular
injection.
Acinetobacter johnsonii and Acinetobacter lwoffi i
Eight isolates were recovered from diseased farmed rainbow trout and common
carp in Poland. Identifi cation was by use of the API 20 NE rapid identifi cation system and by sequencing of the 16S rDNA gene with the result that the isolates were
equated with Acinetobacter calcoaceticus, Acinetobacter johnsonii, Acinetobacter
junii/johnsonii, Acinetobacter lwoffi i and Acinetobacter spp. (Kozinska et al. 2014 ).
In laboratory-based infectivity experiments, Acinetobacter johnsonii and
Acinetobacter lwoffi i were found to be pathogenic, with the disease signs resembling those in aquaculture (Kozinska et al. 2014 ).
Moraxella sp.
Characteristics of the Disease
During winter 1987, mortalities were recorded among juvenile striped bass, Morone
saxatilis, in the Potomac River, Maryland, USA. Gills of diseased fi sh were affected
with the parasites Trichodina and Ergasilus. In addition, a reo-like virus and a bacterium was recovered from some individuals. Large haemorrhagic lesions and missing scales occurred on the dorsal surface of the 11 affected fi sh. Haemorrhages were
apparent in the swim bladder. The liver was enlarged, pale and mottled in appearance. Membranous material appeared to connect the liver with the body wall (Baya
et al. 1990 ).
Moraxellaceae Representatives