445
LD 50 corresponding to containing 5 × 10
3 and 5 × 10
4 cells/ml for isolates from sole
(serogroup O3) and turbot (serogroup O2), respectively (Avendaño-Herrera et al.
2004b ). Abrading the dorsal skin of Japanese fl ounder ( Paralichthys olivaceus ) with
a blade or by clipping the tip of dorsal fi n followed by immersion in 10
6 CFU/ml led
to100% mortality (Rahman et al. 2015 ). In contrast, i.p. injection failed to establish
an infection (Avendaño-Herrera et al. 2004b ). Other evidence has pointed to a role
for the direct introduction of high numbers (4 × 10
11 cells/fi sh) of bacteria onto gill
abrasions for establishing infection (Powell et al. 2004 , 2005 ). ECP, subcellular
components (Wakabayashi et al. 1984 ), the ability to take up iron via siderophores
and by utilization of heme groups (Avendaño-Herrera et al. 2005a ) and the adherence [clumping ability] of cells (van Gelderen et al. 2010 ) have been implicated
with pathogenesis. Haemolysin (26.5 μg/fi sh) and ECP (25.5 μg/fi sh) killed black
sea bream. Pathological signs included the presence of ascitic fl uid, enlarged spleen,
petechial haemorrhages in the visceral fat and intestine, and suppurating (= pus
fi lled) liver. Also, mortalities ensued following i.p. injection of crude LPS with
protease (but not when administered separately) (Wakabayashi et al. 1984 ). ECPs of
T. maritimum have been linked to pathology in Atlantic salmon (Van Gelderen et al.
2009b ).
Disease Control
Vaccine Development A formalised suspension of T. maritimum containing
~1.79 × 10
10 cells/ml with (RPS = 79.6 %) and without (RPS = 27.7 %) FIA was used
to vaccinate Atlantic salmon (0.1 ml amounts by i.p. injection) followed by challenge (Van Gelderen et al. 2009a , b ). Apart from the success of the adjuvanted version at combating mortalities, side effects of the use of FIA were noted, and included
the development of black/brown pigment, most likely melanin, on the stomach with
infl ammation in the form of granulomas and cysts (Van Gelderen et al. 2009a ).
Plant-based Immunostimulants 1.0–2.0 mg amounts of water and ethanol
extracts of the Asian plant, big blue lilyturf ( Liriope platyphylla ) were administered
to olive fl ounder ( Paralichthys olivaceus ) leading to immunostimulation (enhanced
erythrocyte, lymphocyte and monocyte counts; increased haemoglobin content, and
heightened complement and phagocytic activities) (Harikrishnan et al. 2012 ).
Whereas these data are encouraging, the effect on protection against challenge
awaits determination.
Antimicrobial Compounds From an examination of 75 isolates, it was determined that T. maritimum was highly susceptible to ampicillin, erythromycin, josamycin, nifurpirinol, penicillin G and sodium nifurstyrenate, moderately sensitive to
chloramphenicol, doxycycline, oleandomycin, oxytetracycline, sulphamonomethoxine and thiamphenicol, weakly sensitive to nalidixic acid, oxolinic acid, spiramycin and sulphisoxazole, and resistant to colistin and streptomycin (Baxa et al.
Tenacibaculum maritimum (= Flexibacter maritimus = Cytophaga marina)
LD 50 corresponding to containing 5 × 10
3 and 5 × 10
4 cells/ml for isolates from sole
(serogroup O3) and turbot (serogroup O2), respectively (Avendaño-Herrera et al.
2004b ). Abrading the dorsal skin of Japanese fl ounder ( Paralichthys olivaceus ) with
a blade or by clipping the tip of dorsal fi n followed by immersion in 10
6 CFU/ml led
to100% mortality (Rahman et al. 2015 ). In contrast, i.p. injection failed to establish
an infection (Avendaño-Herrera et al. 2004b ). Other evidence has pointed to a role
for the direct introduction of high numbers (4 × 10
11 cells/fi sh) of bacteria onto gill
abrasions for establishing infection (Powell et al. 2004 , 2005 ). ECP, subcellular
components (Wakabayashi et al. 1984 ), the ability to take up iron via siderophores
and by utilization of heme groups (Avendaño-Herrera et al. 2005a ) and the adherence [clumping ability] of cells (van Gelderen et al. 2010 ) have been implicated
with pathogenesis. Haemolysin (26.5 μg/fi sh) and ECP (25.5 μg/fi sh) killed black
sea bream. Pathological signs included the presence of ascitic fl uid, enlarged spleen,
petechial haemorrhages in the visceral fat and intestine, and suppurating (= pus
fi lled) liver. Also, mortalities ensued following i.p. injection of crude LPS with
protease (but not when administered separately) (Wakabayashi et al. 1984 ). ECPs of
T. maritimum have been linked to pathology in Atlantic salmon (Van Gelderen et al.
2009b ).
Disease Control
Vaccine Development A formalised suspension of T. maritimum containing
~1.79 × 10
10 cells/ml with (RPS = 79.6 %) and without (RPS = 27.7 %) FIA was used
to vaccinate Atlantic salmon (0.1 ml amounts by i.p. injection) followed by challenge (Van Gelderen et al. 2009a , b ). Apart from the success of the adjuvanted version at combating mortalities, side effects of the use of FIA were noted, and included
the development of black/brown pigment, most likely melanin, on the stomach with
infl ammation in the form of granulomas and cysts (Van Gelderen et al. 2009a ).
Plant-based Immunostimulants 1.0–2.0 mg amounts of water and ethanol
extracts of the Asian plant, big blue lilyturf ( Liriope platyphylla ) were administered
to olive fl ounder ( Paralichthys olivaceus ) leading to immunostimulation (enhanced
erythrocyte, lymphocyte and monocyte counts; increased haemoglobin content, and
heightened complement and phagocytic activities) (Harikrishnan et al. 2012 ).
Whereas these data are encouraging, the effect on protection against challenge
awaits determination.
Antimicrobial Compounds From an examination of 75 isolates, it was determined that T. maritimum was highly susceptible to ampicillin, erythromycin, josamycin, nifurpirinol, penicillin G and sodium nifurstyrenate, moderately sensitive to
chloramphenicol, doxycycline, oleandomycin, oxytetracycline, sulphamonomethoxine and thiamphenicol, weakly sensitive to nalidixic acid, oxolinic acid, spiramycin and sulphisoxazole, and resistant to colistin and streptomycin (Baxa et al.
Tenacibaculum maritimum (= Flexibacter maritimus = Cytophaga marina)