167
Epizootiology
The organism has been recovered from environmental samples in Spain (Esteve
et al. 2012 ).
Pathogenicity
Orozova demonstrated pathogenicity of the type strain to rainbow trout (Orozova
et al. 2009 ). Isolates recovered from diseased eels recorded a LD 50 dose of 3.3 × 10
6
CFU/fi sh following experimental challenge of eels (Esteve et al. 2012 ). The organism killed Nile tilapia; ECPs had DNase, gelatinase, haemolytic and lipase activity
(Soto-Rodriguez et al. 2013 ).
Disease Control
Antimicrobial Compounds
Resistance was recorded to ticarcillin, amoxicillin-clavuranic acid, cefoxitin, and
imipenem (Esteve et al. 2012 ).
Aeromonas hydrophila
Much of the historical literature describing motile aeromonads as fi sh pathogens
identifi es isolates as Aer. hydrophila; the validity of these identifi cations is now
questionable.
Characteristics of the Diseases
Since its initial recognition as the causal agent of haemorrhagic septicaemia
(Sanarelli 1891 ; Schäperclaus 1930 ; Haley et al. 1967 ), Aer. hydrophila has been
recovered as a pathogen from a wide variety of freshwater fi sh species, including
ornamental fi sh (Hettiarachchi and Cheong 1994 ; Pathiratne et al. 1994 ) and occasionally from marine fi sh, e.g. ulcer disease of cod (Larsen and Jensen 1977 ). The
aetiological agent has been considered to be the dominant cause of motile aeromonas disease in China (Nielsen et al. 2001 ), and may well have worldwide distribution. Its presence in channel catfi sh aquaculture in the southeastern USA may refl ect
an introduction from China insofar as phylogenomic analyses point to similarities
Aeromonas hydrophila
Epizootiology
The organism has been recovered from environmental samples in Spain (Esteve
et al. 2012 ).
Pathogenicity
Orozova demonstrated pathogenicity of the type strain to rainbow trout (Orozova
et al. 2009 ). Isolates recovered from diseased eels recorded a LD 50 dose of 3.3 × 10
6
CFU/fi sh following experimental challenge of eels (Esteve et al. 2012 ). The organism killed Nile tilapia; ECPs had DNase, gelatinase, haemolytic and lipase activity
(Soto-Rodriguez et al. 2013 ).
Disease Control
Antimicrobial Compounds
Resistance was recorded to ticarcillin, amoxicillin-clavuranic acid, cefoxitin, and
imipenem (Esteve et al. 2012 ).
Aeromonas hydrophila
Much of the historical literature describing motile aeromonads as fi sh pathogens
identifi es isolates as Aer. hydrophila; the validity of these identifi cations is now
questionable.
Characteristics of the Diseases
Since its initial recognition as the causal agent of haemorrhagic septicaemia
(Sanarelli 1891 ; Schäperclaus 1930 ; Haley et al. 1967 ), Aer. hydrophila has been
recovered as a pathogen from a wide variety of freshwater fi sh species, including
ornamental fi sh (Hettiarachchi and Cheong 1994 ; Pathiratne et al. 1994 ) and occasionally from marine fi sh, e.g. ulcer disease of cod (Larsen and Jensen 1977 ). The
aetiological agent has been considered to be the dominant cause of motile aeromonas disease in China (Nielsen et al. 2001 ), and may well have worldwide distribution. Its presence in channel catfi sh aquaculture in the southeastern USA may refl ect
an introduction from China insofar as phylogenomic analyses point to similarities
Aeromonas hydrophila