714
• Loach ( Misgurnus anguillicaudatus ), which were cultured in China, were found
to be harbouring a new disease condition that was associated with two bacterial
taxa, i.e. Shewanella putrefaciens and V. anguillarum (Qin et al . 2014 ).
• Moritella viscosa and Ali. wodanis occur in salmon with winter ulcer disease
(Hjerde et al . 2015 ), with the latter – in a cell culture model – adhering to but not
invading fi sh cells (Karlsen et al . 2014 ). Culture supernatant caused the cultured
cells to undergo marked changes, specifi cally vacuolation, retraction, rounding
up and detachment from the culture vessel surface, and the actin fi laments of the
cytoskeleton became re-arranged. The interpretation was that Ali. wodanis
secreted toxins, and infl uenced the development of infection by Moritella viscosa (Karlsen et al . 2014 ).
• In Thailand, 4.8 % of cases of streptococcosis in Nile and red tilapia during
2003–2012 were attributed to mixed infections (Jantrakajorn et al . 2014 ).
• Co-infection of Edw. tarda with aquabirnavirus led to higher mortalities in
Japanese fl ounder (Pakingking et al . 2003 ).
• Ps. anguilliseptica was linked with Delftia acidovorans in European eels (Andree
et al . 2013 ).
• The presence of the protozoan Ichthyophthirius multifi liis led to higher mortalities (80 % mortalities compared to 22 % when the protozoan was absent) when
channel catfi sh were infected with Aer. hydrophila, with gill, kidney, liver, skin
and spleen revealing higher bacterial loading than non-parasitized fi sh (Xu et al .
2012a , b ).
• Cyprinid herpesvirus 2 has been found in association with Aer. sobria in crucian
carp in Italy (Fichi et al . 2013 ).
• Co-infection of bacteria, which were equated with Aer. veronii, Fla. columnare
Plesiomonas shigelloides Str. agalactiae and V. cholerae , and iridovirus have
been found in Nile tilapia farms (Dong et al. 2015b ). Experimental infection
confi rmed the pathogenicity of single cultures of Aer. veronii and less so Fle.
columnare and Str. agalactiae but not so Plesiomonas shigelloides . The fi sh challenged with Aer. veronii or Fle. columnare developed clinical signs of disease
reminiscent of the naturally infected fi sh. The authors suggested that Aer. veronii
and Fle. columnare were the principle pathogens co-responsible for the disease
observed on the Nile tilapia farms; the other bacteria were supposed to be opportunists (Dong et al . 2015a , b ).
• Concurrent infections with Edw. ictaluri and Fla. columnare have been documented in striped catfi sh ( Pangasianodon hypophthalmus ) in Thailand with
identifi cation achieved by phenotyping and sequencing the 16S rDNA gene
(Dong et al . 2015a , b ). Experimental challenges by injection or immersion mimicked the natural disease, and revealed that in combination both bacteria achieved
high mortalities. By immersion, 2.6 × 10
6 CFU of Edw. ictaluri /ml and
1.0 × 10
4 CFU of Fla. columnare /ml led to 96.7 % mortalities among striped catfi sh compared to 80 % and 3.3 % mortalities with the same doses of Edw. ictaluri
and Fla. columnare , respectively, administered separately (Dong et al . 2015a , b ).
15 Conclusions
• Loach ( Misgurnus anguillicaudatus ), which were cultured in China, were found
to be harbouring a new disease condition that was associated with two bacterial
taxa, i.e. Shewanella putrefaciens and V. anguillarum (Qin et al . 2014 ).
• Moritella viscosa and Ali. wodanis occur in salmon with winter ulcer disease
(Hjerde et al . 2015 ), with the latter – in a cell culture model – adhering to but not
invading fi sh cells (Karlsen et al . 2014 ). Culture supernatant caused the cultured
cells to undergo marked changes, specifi cally vacuolation, retraction, rounding
up and detachment from the culture vessel surface, and the actin fi laments of the
cytoskeleton became re-arranged. The interpretation was that Ali. wodanis
secreted toxins, and infl uenced the development of infection by Moritella viscosa (Karlsen et al . 2014 ).
• In Thailand, 4.8 % of cases of streptococcosis in Nile and red tilapia during
2003–2012 were attributed to mixed infections (Jantrakajorn et al . 2014 ).
• Co-infection of Edw. tarda with aquabirnavirus led to higher mortalities in
Japanese fl ounder (Pakingking et al . 2003 ).
• Ps. anguilliseptica was linked with Delftia acidovorans in European eels (Andree
et al . 2013 ).
• The presence of the protozoan Ichthyophthirius multifi liis led to higher mortalities (80 % mortalities compared to 22 % when the protozoan was absent) when
channel catfi sh were infected with Aer. hydrophila, with gill, kidney, liver, skin
and spleen revealing higher bacterial loading than non-parasitized fi sh (Xu et al .
2012a , b ).
• Cyprinid herpesvirus 2 has been found in association with Aer. sobria in crucian
carp in Italy (Fichi et al . 2013 ).
• Co-infection of bacteria, which were equated with Aer. veronii, Fla. columnare
Plesiomonas shigelloides Str. agalactiae and V. cholerae , and iridovirus have
been found in Nile tilapia farms (Dong et al. 2015b ). Experimental infection
confi rmed the pathogenicity of single cultures of Aer. veronii and less so Fle.
columnare and Str. agalactiae but not so Plesiomonas shigelloides . The fi sh challenged with Aer. veronii or Fle. columnare developed clinical signs of disease
reminiscent of the naturally infected fi sh. The authors suggested that Aer. veronii
and Fle. columnare were the principle pathogens co-responsible for the disease
observed on the Nile tilapia farms; the other bacteria were supposed to be opportunists (Dong et al . 2015a , b ).
• Concurrent infections with Edw. ictaluri and Fla. columnare have been documented in striped catfi sh ( Pangasianodon hypophthalmus ) in Thailand with
identifi cation achieved by phenotyping and sequencing the 16S rDNA gene
(Dong et al . 2015a , b ). Experimental challenges by injection or immersion mimicked the natural disease, and revealed that in combination both bacteria achieved
high mortalities. By immersion, 2.6 × 10
6 CFU of Edw. ictaluri /ml and
1.0 × 10
4 CFU of Fla. columnare /ml led to 96.7 % mortalities among striped catfi sh compared to 80 % and 3.3 % mortalities with the same doses of Edw. ictaluri
and Fla. columnare , respectively, administered separately (Dong et al . 2015a , b ).
15 Conclusions