512
humoral response to ECPs, OMP, outer (extremely immunogenic) and cytoplasmic
membranes, LPS and O-antigen.
A bivalent vaccine (with V. harveyi) based on formalised cells and ECP administered to sole by immersion with booster or by i.p. injection led to high levels of
protection (RPS = ~82 %) for 4 months after which the benefi t declined (Arijo et al.
2005 ).
A ribosomal vaccine has been evaluated following administration by i.p. injection into yellowtail. Certainly, the initial evidence pointed to success with ribosomal
antigen P (Kusuda et al. 1988 ; Ninomiya et al. 1989 ). In a further development, this
group experimented with a potassium thiocyanate extract and acetic acid treated
“naked cells” obtained from a virulent culture (Muraoka et al. 1991 ). Yellowtail
were vaccinated twice i.p., at one week intervals with the extract (with or without
the naked cells), and were challenged two weeks after the second injection. Results
indicated partial success for the extract when used alone. However, the extract used
in conjunction with naked cells led to good protection (RPS = 36.5). Yet, the corresponding antibody levels were low, suggesting to the researchers that humoral antibodies did not play an important role in protection (Muraoka et al. 1991 ).
A more modern approach has involved examination of 370 ORFs, which enabled
the identifi cation of eight possible antigens that wer expressed as recombinant proteins. After purifi cation a lipoprotein, PDP_0080, which was involved in adherence
of the pathogen to epithelial cells, was injected in 25 μg amounts into sea bass leading to the production of high antibody titres (Andreoni et al. 2013 ).
Dietary Supplements Garlic powder was fed at 0.5 and 1.5 g/kg body weight to
cobia (Rachycenron canadum) for 28-days, leading to higher growth, and after challenge with Ph. damselae subsp. piscicida lower mortalities were recorded (Guo
et al. 2012 , 2015a ).
Probiotics Sugita et al. (1997) isolated a Vibrio , coined strain NM10, from ponyfi sh (Leiognathus nuchalis ) intestines, and determined antagonism of Ph. damselae
subsp. piscicida by a heat-labile proteinaceous compound of 5 kDa.
Antimicrobial Compounds Little is known about the value of chemotherapeutants. An in vitro study highlighted the value of ampicillin (Kusuda and Inoue 1976 ),
but fi eld trials were not carried out. In a further study, Kusuda et al. ( 1988 ) reported
marked sensitivity to ampicillin and oxolinic acid, moderate sensitivity to nalidixic
acid and sodium nifurstyrenate, but resistance to chloramphenicol, chlortetracycline, oxytetracycline and tetracycline. Again, fi eld evidence was not supplied. Sano
et al. ( 1994 ) noted the value of fosfomycin (MIC = 1.56 − 3.13 μg/ml) at controlling
laboratory infections. An effective dose was 40 mg of fosfomycin/kg body weight
of fi sh/day for 5 days, albeit administered only one hour after infection. This dose
reduced mortalities by Ph. damselae subsp. piscicida to 0 % (Sano et al. 1994 ). R
plasmids have been identifi ed among isolates, conferring resistance to chloramphenicol, kanamycin, sulphamonomethoxine and tetracycline (Aoki and Kitao
1985 ) and fl orfenicol (Kim et al. 1993 ). Although the isolates described by Aoki and
10 Vibrios
humoral response to ECPs, OMP, outer (extremely immunogenic) and cytoplasmic
membranes, LPS and O-antigen.
A bivalent vaccine (with V. harveyi) based on formalised cells and ECP administered to sole by immersion with booster or by i.p. injection led to high levels of
protection (RPS = ~82 %) for 4 months after which the benefi t declined (Arijo et al.
2005 ).
A ribosomal vaccine has been evaluated following administration by i.p. injection into yellowtail. Certainly, the initial evidence pointed to success with ribosomal
antigen P (Kusuda et al. 1988 ; Ninomiya et al. 1989 ). In a further development, this
group experimented with a potassium thiocyanate extract and acetic acid treated
“naked cells” obtained from a virulent culture (Muraoka et al. 1991 ). Yellowtail
were vaccinated twice i.p., at one week intervals with the extract (with or without
the naked cells), and were challenged two weeks after the second injection. Results
indicated partial success for the extract when used alone. However, the extract used
in conjunction with naked cells led to good protection (RPS = 36.5). Yet, the corresponding antibody levels were low, suggesting to the researchers that humoral antibodies did not play an important role in protection (Muraoka et al. 1991 ).
A more modern approach has involved examination of 370 ORFs, which enabled
the identifi cation of eight possible antigens that wer expressed as recombinant proteins. After purifi cation a lipoprotein, PDP_0080, which was involved in adherence
of the pathogen to epithelial cells, was injected in 25 μg amounts into sea bass leading to the production of high antibody titres (Andreoni et al. 2013 ).
Dietary Supplements Garlic powder was fed at 0.5 and 1.5 g/kg body weight to
cobia (Rachycenron canadum) for 28-days, leading to higher growth, and after challenge with Ph. damselae subsp. piscicida lower mortalities were recorded (Guo
et al. 2012 , 2015a ).
Probiotics Sugita et al. (1997) isolated a Vibrio , coined strain NM10, from ponyfi sh (Leiognathus nuchalis ) intestines, and determined antagonism of Ph. damselae
subsp. piscicida by a heat-labile proteinaceous compound of 5 kDa.
Antimicrobial Compounds Little is known about the value of chemotherapeutants. An in vitro study highlighted the value of ampicillin (Kusuda and Inoue 1976 ),
but fi eld trials were not carried out. In a further study, Kusuda et al. ( 1988 ) reported
marked sensitivity to ampicillin and oxolinic acid, moderate sensitivity to nalidixic
acid and sodium nifurstyrenate, but resistance to chloramphenicol, chlortetracycline, oxytetracycline and tetracycline. Again, fi eld evidence was not supplied. Sano
et al. ( 1994 ) noted the value of fosfomycin (MIC = 1.56 − 3.13 μg/ml) at controlling
laboratory infections. An effective dose was 40 mg of fosfomycin/kg body weight
of fi sh/day for 5 days, albeit administered only one hour after infection. This dose
reduced mortalities by Ph. damselae subsp. piscicida to 0 % (Sano et al. 1994 ). R
plasmids have been identifi ed among isolates, conferring resistance to chloramphenicol, kanamycin, sulphamonomethoxine and tetracycline (Aoki and Kitao
1985 ) and fl orfenicol (Kim et al. 1993 ). Although the isolates described by Aoki and
10 Vibrios