@article{article_602015, title={PATHOGENICITY AND PATHOLOGY OF Streptococcus agalactiae IN CHALLENGED MOZAMBIQUE TILAPIA Oreochromis mossambicus (PETERS 1852) JUVENILES}, journal={Aquatic Research}, volume={2}, pages={182–190}, year={2019}, DOI={10.3153/AR19017}, url={https://izlik.org/JA88ZM37YF}, author={Abraham, Thangapalam Jawahar and Namdeo, Meshram Supradhnya and Adıkesavalu, Harresh and Banerjee, Sayani}, keywords={Oreochromis mossambicus,Streptococcus agalactiae,Meningoencephalitis,Pathogenicity,Granulomatous-like lesions}, abstract={<p class="MsoNormal" style="margin-top:6pt;margin-right:10.7pt;margin-bottom:3pt;margin-left:7.1pt;text-align:justify;line-height:normal;"> <span lang="en-gb" style="font-family:’Times New Roman’, serif;" xml:lang="en-gb">Streptococcosis
is one of the most important bacterial diseases of tilapia. The present study
assessed the histopathological changes induced by <i>Streptococcus agalactiae </i> challenge in the brain, kidney, spleen,
and liver of <i>Oreochromis mossambicus </i>.
When challenged intraperitoneally at 10 <sup>7 </sup>-10 <sup>8 </sup>cells/fish, <i>S. agalactiae </i> strains (TKT <sub>1 </sub>
and TBT <sub>2 </sub>) caused 40-100% mortalities in <i>O. mossambicus. </i>The LD <sub>50 </sub> values of <i>S. agalactiae </i> TKT <sub>1 </sub> and TBT <sub>2 </sub> strains were
1.60×10 <sup>7 </sup> and 7.33×10 <sup>7 </sup> cells/fish, respectively.
Histological sections of the challenged <i>O.
mossambicus </i> brain exhibited meningoencephalitis, marginated haemocytes,
extensive haemorrhages, oedema and neurons with marginated nuclei. The kidney
of challenged tilapia showed glomerulopathy, dilation of Bowman’s capsule,
nephritis, haematopoietic tissue necrosis, melanization and granulomatous-like
lesions. The spleen was characterized by extensive melanomacrophage
aggregation, necrosis and vasodilation. The liver had dilated and ruptured
blood capillary, melanization and disintegrated tissue. The intrahepatic
exocrine pancreatic tissue was disintegrated. Our results demonstrated that <i>S. agalactiae </i> caused a systemic
infection and meningoencephalitis in the Mozambique tilapia juveniles. </span> </p> <p> </p>}, number={4}, organization={ICAR, New Delhi}