504
punctipinnis have been established by removing 4 to 6 scales from the fl ank, scarifying the dermis, and swabbing the wound with 10
7
–10
8 viable cells of Ph. damselae.
At water temperatures of 16.0–16.5 °C, the fi sh developed large ulcers in 3 days,
with death following 24 h later. Similar data were recorded after experimental challenge of unscarifi ed animals. However in the initial study, fi sh from other families
appeared to be unaffected by Ph. damselae, pointing to host specifi city of the pathogen. Thus, representatives of Atherinidae, Clinidae, Cottidae, Embiotocidae,
Girellidae and Gobiidae resisted experimental challenge. This is interesting because
representatives of these families co-habited the reefs with blacksmith (Love et al.
1981 ). However, Grimes et al. ( 1984a ) and Labella et al. ( 2006 ) successfully
infected dogfi sh and red banded sea bream (LD 50 = 3.9 × 10
5 CFU/g of fi sh) by i.p.
injection with Ph. damselae. Death ensued in the dogfi sh within 18 h at an unspecifi ed water temperature. Virulence to rainbow trout was highly variable, with LD 50
doses of 3.9 × 10
3 to 1.5 × 10
8 CFU at 20 °C that was more pronounced than at 13 °C
(Pedersen et al. 2009 ). The LD 50 dose for Asian sea bass was determined as
8.1 × 10
5 CFU/g of fi sh (Kanchanopas-Barnette et al. 2009 ). Grimes et al. ( 1984a )
reported that the organism was highly cytotoxic. A neurotoxic acetylcholinesterase
has been described (Peréz et al. 1998 ). The most virulent strains to rainbow trout
were haemolytic (Pedersen et al. 2009 ), for which the haemolysins damselysin (= a
cytotoxin encoded by the dly gene with lethality to mice) and the pore-forming toxin
HlyA are encoded within a newly described 153,429 bp virulence plasmid pPHDD1,
the presence of both toxins being necessary for full virulence (Rivas et al. 2011 ).
ECPs, such as amylase, lipase, phospholipase, alkaline phosphatase, esterase
lipase, acid phosphatase and β-glucosaminidase but not damselysin, have been
implicated with cytotoxicity (Labella et al. 2010 ), with the LD 50 dose ranging from
0.02 to 0.43 μg of protein/g of fi sh within death occurring between 4 and 72 h after
administration (Fouz et al. 1993 ). The ECP were considered to have low proteolytic
activity, without evidence of any caseinase, elastinase or gelatinase. In contrast,
pronounced phospholipase and haemolytic activity was recorded for turbot (and
human and sheep) erythrocytes. It was possible that LPS contributed to heat stability of the toxic fractions (Fouz et al. 1993 ).
A siderophore-mediated iron sequestering system has now been described, and
almost certainly contributes to the pathogenicity of the organism (Fouz et al. 1994 ,
1997 ).
Photobacterium damselae subsp. piscicida
(= Pasteurella piscicida)
Characteristics of the Disease
During the summer of 1963, an epizootic was reported in white perch and striped
bass in the upper region of the Chesapeake Bay, USA from which 30 cultures of an
organism were recovered which possessed some of the salient features of Pasteurella
10 Vibrios
punctipinnis have been established by removing 4 to 6 scales from the fl ank, scarifying the dermis, and swabbing the wound with 10
7
–10
8 viable cells of Ph. damselae.
At water temperatures of 16.0–16.5 °C, the fi sh developed large ulcers in 3 days,
with death following 24 h later. Similar data were recorded after experimental challenge of unscarifi ed animals. However in the initial study, fi sh from other families
appeared to be unaffected by Ph. damselae, pointing to host specifi city of the pathogen. Thus, representatives of Atherinidae, Clinidae, Cottidae, Embiotocidae,
Girellidae and Gobiidae resisted experimental challenge. This is interesting because
representatives of these families co-habited the reefs with blacksmith (Love et al.
1981 ). However, Grimes et al. ( 1984a ) and Labella et al. ( 2006 ) successfully
infected dogfi sh and red banded sea bream (LD 50 = 3.9 × 10
5 CFU/g of fi sh) by i.p.
injection with Ph. damselae. Death ensued in the dogfi sh within 18 h at an unspecifi ed water temperature. Virulence to rainbow trout was highly variable, with LD 50
doses of 3.9 × 10
3 to 1.5 × 10
8 CFU at 20 °C that was more pronounced than at 13 °C
(Pedersen et al. 2009 ). The LD 50 dose for Asian sea bass was determined as
8.1 × 10
5 CFU/g of fi sh (Kanchanopas-Barnette et al. 2009 ). Grimes et al. ( 1984a )
reported that the organism was highly cytotoxic. A neurotoxic acetylcholinesterase
has been described (Peréz et al. 1998 ). The most virulent strains to rainbow trout
were haemolytic (Pedersen et al. 2009 ), for which the haemolysins damselysin (= a
cytotoxin encoded by the dly gene with lethality to mice) and the pore-forming toxin
HlyA are encoded within a newly described 153,429 bp virulence plasmid pPHDD1,
the presence of both toxins being necessary for full virulence (Rivas et al. 2011 ).
ECPs, such as amylase, lipase, phospholipase, alkaline phosphatase, esterase
lipase, acid phosphatase and β-glucosaminidase but not damselysin, have been
implicated with cytotoxicity (Labella et al. 2010 ), with the LD 50 dose ranging from
0.02 to 0.43 μg of protein/g of fi sh within death occurring between 4 and 72 h after
administration (Fouz et al. 1993 ). The ECP were considered to have low proteolytic
activity, without evidence of any caseinase, elastinase or gelatinase. In contrast,
pronounced phospholipase and haemolytic activity was recorded for turbot (and
human and sheep) erythrocytes. It was possible that LPS contributed to heat stability of the toxic fractions (Fouz et al. 1993 ).
A siderophore-mediated iron sequestering system has now been described, and
almost certainly contributes to the pathogenicity of the organism (Fouz et al. 1994 ,
1997 ).
Photobacterium damselae subsp. piscicida
(= Pasteurella piscicida)
Characteristics of the Disease
During the summer of 1963, an epizootic was reported in white perch and striped
bass in the upper region of the Chesapeake Bay, USA from which 30 cultures of an
organism were recovered which possessed some of the salient features of Pasteurella
10 Vibrios