192
(increase in erythrocyte number, myeloperoxidase level, and immunoglobulin, haemoglobin, albumin and globulin content, but a reduction in alanine aminotransferases, serum aspartate aminotransferases, acid and alkaline phosphatase activity) and
protection of rohu ( Labeo rohita) against challenge with Aer. hydrophila (Mohapatra
et al. 2014 ). The best survival was with the group fed with the mixture of viable
cells. Diets containing optimally 45 % crude protein and 2.0 g of Sacharmyces cerevisiae /kg of diet were fed twice a day for 5 days each week for 12 weeks to Nile
tilapia fry leading to improve growth and resistance to experimental challenge with
Aer. hydrophila (Abdel-Tawwab 2012a , b ). A mixture of Aspergillus oryzae
(2.0 × 10
9 CFU/g) , Bac. subtilis (1.5 × 10
9 CFU/g) and Saccharomyces cerevisiae
(10
9 CFU/g) were administered orally at 5 g/kg and 10 g/kg for 6-weeks to Nile
tilapia leading to immunostimulation (enhanced leucocyte numbers, and respiratory
burst activity) and protection against experimental challenge (Iwashita et al. 2015 ).
Bac. licheniformis KADR5 and Bac. pumilus KADR6 were isolated from the gut
of rohu and injected intraperitoneally with subcellular components, cell wall proteins, ECPs, and whole cell proteins, and orally with live cells, i.e. 10
8 CFU/g of
feed for 14 days before challenge resulting in immunostimulation (enhanced lysozyme and respiratory burst activities) and a reduction in mortalities (mortalities of
20–40 % and 23–33 % for the fi sh receiving subcellular components [especially
whole cell and cell wall proteins], and live cells, respectively, compared with 80 %
mortalities of the controls) (Ramesh et al. 2015 ).
Snakehead ( Channa striata ) fi ngerlings were fed with a commercial Lactobacillus
acidophilus probiotic at 1 g/kg of feed together with 1 % yeast, 0.1 % ß-glucan, 1 %
galacto-oligosaccharide and 0.2 % mannan oligosaccharide for 12-weeks before
challenge. The results demonstrated superior growth, immunostimulation (increased
numbers of erythrocytes and leucocytes; larger amounts of haemoglobin, serum
protein and immunogobulin; increased lysozyme activity) and reduced mortalities
after challenge (Talpur et al. 2014 ).
Antimicrobial Compounds
Chemotherapy of Aer. hydrophila infections corresponds closely to that of Aer. salmonicida. For example, the relevance of oxytetracycline has been well documented
(Meyer 1964 ). Unfortunately, plasmid-mediated resistance by means of 20–30 mDa
plasmids is similarly widespread in fi sh farms, e.g. eel ponds (Aoki 1988 ), and may
negate the potential benefi t of some antimicrobial compounds (Aoki and Egusa
1971 ; Toranzo et al. 1983 ). It is alarming that R plasmids with common sequence
DNA structures have now been found in several unrelated species of fi sh pathogens,
including Aer. hydrophila, Aer. salmonicida and Edw. tarda (Aoki 1988 ). Resistance
in Aer. hydrophila has been recorded to a wide range of antimicrobial compounds,
including ampicillin, chloramphenicol, erythromycin, nitrofurantoin, novobiocin,
streptomycin, sulphonamides and tetracycline (Aoki 1988 ; De Paola et al. 1988 ).
Indeed, it has been estimated that as many as 38 % of the Aer. hydrophila isolates
4 Aeromonadaceae Representatives (Motile Aeromonads)
(increase in erythrocyte number, myeloperoxidase level, and immunoglobulin, haemoglobin, albumin and globulin content, but a reduction in alanine aminotransferases, serum aspartate aminotransferases, acid and alkaline phosphatase activity) and
protection of rohu ( Labeo rohita) against challenge with Aer. hydrophila (Mohapatra
et al. 2014 ). The best survival was with the group fed with the mixture of viable
cells. Diets containing optimally 45 % crude protein and 2.0 g of Sacharmyces cerevisiae /kg of diet were fed twice a day for 5 days each week for 12 weeks to Nile
tilapia fry leading to improve growth and resistance to experimental challenge with
Aer. hydrophila (Abdel-Tawwab 2012a , b ). A mixture of Aspergillus oryzae
(2.0 × 10
9 CFU/g) , Bac. subtilis (1.5 × 10
9 CFU/g) and Saccharomyces cerevisiae
(10
9 CFU/g) were administered orally at 5 g/kg and 10 g/kg for 6-weeks to Nile
tilapia leading to immunostimulation (enhanced leucocyte numbers, and respiratory
burst activity) and protection against experimental challenge (Iwashita et al. 2015 ).
Bac. licheniformis KADR5 and Bac. pumilus KADR6 were isolated from the gut
of rohu and injected intraperitoneally with subcellular components, cell wall proteins, ECPs, and whole cell proteins, and orally with live cells, i.e. 10
8 CFU/g of
feed for 14 days before challenge resulting in immunostimulation (enhanced lysozyme and respiratory burst activities) and a reduction in mortalities (mortalities of
20–40 % and 23–33 % for the fi sh receiving subcellular components [especially
whole cell and cell wall proteins], and live cells, respectively, compared with 80 %
mortalities of the controls) (Ramesh et al. 2015 ).
Snakehead ( Channa striata ) fi ngerlings were fed with a commercial Lactobacillus
acidophilus probiotic at 1 g/kg of feed together with 1 % yeast, 0.1 % ß-glucan, 1 %
galacto-oligosaccharide and 0.2 % mannan oligosaccharide for 12-weeks before
challenge. The results demonstrated superior growth, immunostimulation (increased
numbers of erythrocytes and leucocytes; larger amounts of haemoglobin, serum
protein and immunogobulin; increased lysozyme activity) and reduced mortalities
after challenge (Talpur et al. 2014 ).
Antimicrobial Compounds
Chemotherapy of Aer. hydrophila infections corresponds closely to that of Aer. salmonicida. For example, the relevance of oxytetracycline has been well documented
(Meyer 1964 ). Unfortunately, plasmid-mediated resistance by means of 20–30 mDa
plasmids is similarly widespread in fi sh farms, e.g. eel ponds (Aoki 1988 ), and may
negate the potential benefi t of some antimicrobial compounds (Aoki and Egusa
1971 ; Toranzo et al. 1983 ). It is alarming that R plasmids with common sequence
DNA structures have now been found in several unrelated species of fi sh pathogens,
including Aer. hydrophila, Aer. salmonicida and Edw. tarda (Aoki 1988 ). Resistance
in Aer. hydrophila has been recorded to a wide range of antimicrobial compounds,
including ampicillin, chloramphenicol, erythromycin, nitrofurantoin, novobiocin,
streptomycin, sulphonamides and tetracycline (Aoki 1988 ; De Paola et al. 1988 ).
Indeed, it has been estimated that as many as 38 % of the Aer. hydrophila isolates
4 Aeromonadaceae Representatives (Motile Aeromonads)