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The 759 bp srtA gene, which encodes sortase A - infl uences the correct positioning of surface proteins in bacterial cells, was cloned, and a mutant constructed via
allelic exchange mutagenesis. This mutant was used as a live vaccine, administered
to Nile tilapia intraperitoneally, which after challenge resulted in a RPS of 95.5 %
(Wang et al. 2014b ).
On a less positive note, the health of the fi sh at the initiation of vaccination is of
paramount importance insofar as parasitism of Nile tilapia with Gyrodactylus cichlidarum , Ichthyophthirius multifi liis and Trichodina heterodentata led to reduced
protection (Martins et al. 2011 ).
Immunostimulants/Dietary Supplements
Yeasts Yeasts have furnished nucleotides, which have shown promise with controlling infections caused by Str. iniae. Using a commercial product, Ascogen, which
comprises oligonucleotides from brewer’s yeast, feeding trials were carried out for
7–8 weeks with hybrid striped bass followed by bath challenge with Str. iniae, with
the result that experimental groups showed a higher level of protection when compared to the controls (Li et al. 2004 ).
Garlic Garlic (Allium sativum) powder administered at 1.3 % [4 % was less effective] in feed for 14 days to orange-spotted grouper ( Epinephelus coioides ) gave
better weight gain, and protection to challenge with Str. iniae (Guo et al. 2012 ).
Garlic powder was fed at 1.2 g/kg body weight to cobia (Rachycenron canadum) for
21-days, leading to lower mortalities after challenge with Str. iniae (Guo et al.
2012 ).
Rosemary Rosemary ( Rosmarinus offi inalis) was used as dried and powdered
leaves and as ethyl acetate extracts in feeds in a ratio of 1:17 and 1:24, respectively,
to tilapia for 5 days followed by infection with Str. iniae and feeding with the rosemary and its extract for a further 10 days with a resulting marked reduction in mortalities (Abutbul et al. 2004 ). This was substantiated in a later study when feeding
dried leaves to tilapia led to reduced mortalities following challenge with Str. iniae
(Zilberg et al. 2010 ).
Indian Lettuce Indian lettuce ( Lactuca indica ) fed to kelp grouper ( Epinephelus
bruneus ) at 1 and 2 % enhanced immune function (lysozyme, phagocytic and respiratory burst activities) at 2 weeks, and led to lower mortalities after challenge with
Str. iniae (Harikrishnan et al. 2011 ).
Sweet Orange Essential oil extracted from sweet orange ( Citrus sinensis ) peel was
fed at 0.1 %, 0.3 % and 0.5 % for 90-days to Mossambique tilapia leading to protection from challenge (Acar et al. 2015 ).
Streptococcaceae Representatives
The 759 bp srtA gene, which encodes sortase A - infl uences the correct positioning of surface proteins in bacterial cells, was cloned, and a mutant constructed via
allelic exchange mutagenesis. This mutant was used as a live vaccine, administered
to Nile tilapia intraperitoneally, which after challenge resulted in a RPS of 95.5 %
(Wang et al. 2014b ).
On a less positive note, the health of the fi sh at the initiation of vaccination is of
paramount importance insofar as parasitism of Nile tilapia with Gyrodactylus cichlidarum , Ichthyophthirius multifi liis and Trichodina heterodentata led to reduced
protection (Martins et al. 2011 ).
Immunostimulants/Dietary Supplements
Yeasts Yeasts have furnished nucleotides, which have shown promise with controlling infections caused by Str. iniae. Using a commercial product, Ascogen, which
comprises oligonucleotides from brewer’s yeast, feeding trials were carried out for
7–8 weeks with hybrid striped bass followed by bath challenge with Str. iniae, with
the result that experimental groups showed a higher level of protection when compared to the controls (Li et al. 2004 ).
Garlic Garlic (Allium sativum) powder administered at 1.3 % [4 % was less effective] in feed for 14 days to orange-spotted grouper ( Epinephelus coioides ) gave
better weight gain, and protection to challenge with Str. iniae (Guo et al. 2012 ).
Garlic powder was fed at 1.2 g/kg body weight to cobia (Rachycenron canadum) for
21-days, leading to lower mortalities after challenge with Str. iniae (Guo et al.
2012 ).
Rosemary Rosemary ( Rosmarinus offi inalis) was used as dried and powdered
leaves and as ethyl acetate extracts in feeds in a ratio of 1:17 and 1:24, respectively,
to tilapia for 5 days followed by infection with Str. iniae and feeding with the rosemary and its extract for a further 10 days with a resulting marked reduction in mortalities (Abutbul et al. 2004 ). This was substantiated in a later study when feeding
dried leaves to tilapia led to reduced mortalities following challenge with Str. iniae
(Zilberg et al. 2010 ).
Indian Lettuce Indian lettuce ( Lactuca indica ) fed to kelp grouper ( Epinephelus
bruneus ) at 1 and 2 % enhanced immune function (lysozyme, phagocytic and respiratory burst activities) at 2 weeks, and led to lower mortalities after challenge with
Str. iniae (Harikrishnan et al. 2011 ).
Sweet Orange Essential oil extracted from sweet orange ( Citrus sinensis ) peel was
fed at 0.1 %, 0.3 % and 0.5 % for 90-days to Mossambique tilapia leading to protection from challenge (Acar et al. 2015 ).
Streptococcaceae Representatives