66
Pathogenicity
Str. parauberis was examined for the presence of putative surface-associated virulence factors relevant to turbot for which the data indicated haemagglutination
activity (against turbot erythrocytes), variable hydrophobicity due possibly to the
presence of capsular material, and the ability to adhere to and invade cultured cells,
e.g. CHSE-214 (Chinook salmon embryo) and SBL (striped bass larvae) cell lines
(Romalde et al. 2000 ). Mutation of the phosphoglucomutase gene impaired capsule
production, and attenuated virulence, thus indicating that expression of the enzyme
is important for virulence by infl uencing bacterial survival against the fi sh defence
mechanisms (Woo and Park 2014 ).
Disease Control
Vaccines A trivalent formalin-inactivated vaccine comprising Edw. tarda, Str. iniae
and Str. parauberis, protected olive fl ounder when administered intraperitoneally in
0.1 ml amounts (Han et al. 2011a ). Subsequently, formalised cells of Str. parauberis
serotype I and II gave complete protection (RPS = 100 %) after 3-weeks when
administered intraperitoneally to Japanese fl ounder and challenged with the homologous serotype; less protection was recorded when challenge was with the heterologous serotype (Mori and Fukuda 2012 ). These data pointed to issues with
cross-protection when heterologous serotypes were present.
Dietary Supplements Material derived from the deciduous tree, kozo (Broussonetia
kazinoki) was administered at 1.0 and 2.0 % as a feed additive to olive fl ounder leading to enhanced immune function (complement, lysozyme, phagocytic and respiratory burst activities) (Kim et al. 2012 ).
Antimicrobial Compounds It was reported that isolates were resistant to fl umequine, oxolinic acid and streptomycin, moderately susceptible to oxytetracycline, tetracycline and sulphamethoxazole-trimethoprim, and highly sensitive to ampicillin,
chloramphenicol, erythromycin, nitrofurantoin and penicillin (Doménech et al. 1996 ).
Streptococcus phocae
Characteristics of the Pathogen
This is a ß-haemolytic streptococcus, which was originally recovered from seals,
but which has been associated with disease of Atlantic salmon in Chile since 1999
(Gibello et al. 2005 ; Romalde et al. 2008 ; Yañez et al. 2013 ). Chilean isolates are
2 Gram-Positive Bacteria (Anaerobes and ‘Lactic Acid’ Bacteria)
Pathogenicity
Str. parauberis was examined for the presence of putative surface-associated virulence factors relevant to turbot for which the data indicated haemagglutination
activity (against turbot erythrocytes), variable hydrophobicity due possibly to the
presence of capsular material, and the ability to adhere to and invade cultured cells,
e.g. CHSE-214 (Chinook salmon embryo) and SBL (striped bass larvae) cell lines
(Romalde et al. 2000 ). Mutation of the phosphoglucomutase gene impaired capsule
production, and attenuated virulence, thus indicating that expression of the enzyme
is important for virulence by infl uencing bacterial survival against the fi sh defence
mechanisms (Woo and Park 2014 ).
Disease Control
Vaccines A trivalent formalin-inactivated vaccine comprising Edw. tarda, Str. iniae
and Str. parauberis, protected olive fl ounder when administered intraperitoneally in
0.1 ml amounts (Han et al. 2011a ). Subsequently, formalised cells of Str. parauberis
serotype I and II gave complete protection (RPS = 100 %) after 3-weeks when
administered intraperitoneally to Japanese fl ounder and challenged with the homologous serotype; less protection was recorded when challenge was with the heterologous serotype (Mori and Fukuda 2012 ). These data pointed to issues with
cross-protection when heterologous serotypes were present.
Dietary Supplements Material derived from the deciduous tree, kozo (Broussonetia
kazinoki) was administered at 1.0 and 2.0 % as a feed additive to olive fl ounder leading to enhanced immune function (complement, lysozyme, phagocytic and respiratory burst activities) (Kim et al. 2012 ).
Antimicrobial Compounds It was reported that isolates were resistant to fl umequine, oxolinic acid and streptomycin, moderately susceptible to oxytetracycline, tetracycline and sulphamethoxazole-trimethoprim, and highly sensitive to ampicillin,
chloramphenicol, erythromycin, nitrofurantoin and penicillin (Doménech et al. 1996 ).
Streptococcus phocae
Characteristics of the Pathogen
This is a ß-haemolytic streptococcus, which was originally recovered from seals,
but which has been associated with disease of Atlantic salmon in Chile since 1999
(Gibello et al. 2005 ; Romalde et al. 2008 ; Yañez et al. 2013 ). Chilean isolates are
2 Gram-Positive Bacteria (Anaerobes and ‘Lactic Acid’ Bacteria)