ABD EL-TAWAB, A.A., MAAROUF, A.A., EL HOFY, F. I., and EL MOUGY, E. A., 2017. Detection of some virulence genes in 
A. hydrophila and 
A. caviae isolated from fresh water fishes at Qalubia Governorate. Benha Veterinary Medical Journal 33(2): 489-503. 
https://doi.org/10.21608/bvmj.2017.30598
                                                                                                                 ABDEL-LATIF, H.M., DAWOOD, M.A., MENANTEAU-LEDOUBLE, S., and EL-MATBOULI, M., 2020. The nature and consequences of co-infections in tilapia: A review. Journal of Fish Diseases. 43: 651–664. 
https://doi.org/10.1111/jfd.13164
                                                                                                                 ABDELSALAM, M., ASHEG, A., and EISSA, A. E., 2013. Streptococcus dysgalactiae: An emerging pathogen of fishes and mammals. International Journal of Veterinary Science and Medicine, 1(1): 1-6. 
https://doi.org/10.1016/j.ijvsm.2013.04.002
                                                                                                                 ABOYADAK, I.M. ALI, N.G.M., GODA, A.M.A.S., ABOELGALAGEL, W.H., and SALAM, A. M. E., 2015. Molecular detection of 
Aeromonas hydrophila as the main cause of outbreak in tilapia farms in Egypt. Journal of Aquaculture and Marine Biology 2: 2-5. 
https://doi.org/10.15406/jamb.2015.02.00045
                                                                                                                 ABU‐ELALA, N.M., ABD‐ELSALAM, R.M., and YOUNIS, N.A., 2020. Streptococcosis, Lactococcosis and Enterococcosis are potential threats facing cultured Nile tilapia (
Oreochromis niloticus) production. Aquaculture research 51(10): 4183-4195. 
https://doi.org/10.1111/are.14760
                                                                                                                 ABU-ELALA, N.M., ABD-ELSALAM, R.M., MAROUF, S., ABDELAZIZ, M., and MOUSTAFA, M., 2016. Eutrophication, ammonia intoxication, and infectious disease Interdisciplinary factors of mass mortalities in cultured Nile tilapia. Journal of Aquatic Animal Health 28(3): 187–198. 
https://doi.org/10.1080/08997659.2016.1185050
                                                                                                                 ABU-ELALA, N.M., SAMIR, A., WASFY, M., and ELSAYED, M., 2019. Efficacy of injectable and immersion vaccines against streptococcal infections in broodstock and offspring of Nile tilapia (
Oreochromis niloticus). Fish and Shellfish Immunology 88: 293–300. 
https://doi.org/10.1016/j.fsi.2019.02.042
                                                                                                                 AHMED, S.H.M., and SHOREIT, A.M., 2001. Bacterial hemorrhagic septicemia in 
Oreochromis niloticus at Aswan fish hatcheries. Assiut Veterinary Medical Journa45 (89): 190-206. 
https://doi.org/10.21608/avmj.2001.179674
                                                                                                                 AISYHAH, M.A.S., AMAL, M.N.A., ZAMRI-SAAD, M. SITI-ZAHRAH, A., and SHAQINAH, N. N., 2015. Streptococcus agalactiae isolates from cultured fishes in Malaysia manifesting low resistance pattern towards selected antibiotics. Journal of Fish Diseases. 38: 1093–1098. 
https://doi.org/10.1111/jfd.12351
                                                                                                                 AL-OBAIDI, M.M.J., and DESA, M.N.M., 2018. Mechanisms of blood brain barrier disruption by different types of bacteria, and bacterial–host interactions facilitate the bacterial pathogen invading the brain. Cellular and Molecular Neurobiology 38(7): 1349–1368. 
https://doi.org/10. 1007/s10571-018-0609-2
                                                                                                                                                                                                                                 AOKI, T. 2011. Fish diseases and disorders. viral, bacterial and fungal infections. CABI Publishing. Wallingford. U.K.
                                                                                                                APHA, 1995. Standard Methods for the Examination of Water and Wastewater, 18th edition. APHA-AWWA-WPCF, Washington DC
                                                                                                                AUSTIN, B., and AUSTIN, D.A., 2016. Bacterial Fish Pathogens: Disease of Farmed and Wild Fish. Springer.
                                                                                                                AUSTIN, B., and AUSTIN, D.A., 2012. Vibrionaceae representatives. In Bacterial Fish Pathogens: Disease of Farmed and Wild Fish. Springer, Dordrecht. pp. 357-411
                                                                                                                AZMAI, M.N.A., and SAAD, M., 2011. Streptococcosis in tilapia (Oreochromis niloticus): A review. Journal of Tropical Agricultural Science 34: 195–206.
                                                                                                                BANCROFT, J. D., LAYTON, C., and  SUVARNA, S. K., 2013. Bancroft's theory and practice of histological techniques. Churchill Livingstone Elsevier.
                                                                                                                BARATO, P., MARTINS, E.R., VASQUEZ, G.M., RAMIREZ, M., MELO-CRISTINO, J., MARTINEZ, N., and IREGUI, C., 2016. Capsule impairs efficient adherence of 
Streptococcus agalactiae to intestinal epithelium in tilapias 
Oreochromis sp. Microbial Pathogenesis 100: 30–36. 
https://doi.org/10.1016/j.micpath.2016.08.040
                                                                                                                 BASRI, L., NOR, R.M., SALLEH, A.M.D., YASIN, I.S., SAAD, M.Z., ABD. RAHAMAN, N.Y., BARKHAM, T., and AMAL, M.N.A., 2020. Co-Infections of Tilapia Lake Virus, 
Aeromonas hydrophila and 
Streptococcus agalactiae in Farmed Red Hybrid Tilapia. Animals 10: 2141. 
https://doi.org/10.3390/ani10112141
                                                                                                                 BATDORJ, B., DALGALARRONDO, M., CHOISET, Y., PEDROCHE, J., MÉTRO, F., PREVOST, H., CHOBERT, M., and HAERTLÉ, T., 2006. Purification and characterization of two bacteriocins produced by lactic acid bacteria isolated from Mongolian airag. Journal of Applied Microbiology 101(4): 837-848. 
https://doi.org/10.1111/j.1365-2672.2006.02966.x
                                                                                                                 BOWATER, R.O., FORBES-FAULKNER, J., ANDERSON, I.G., CONDON, K., ROBINSON, B., KONG, F., GILBERT, G.L., REYNOLDS, A., HYLAND, S., and MCPHERSON, G., 2012. Natural outbreak of 
Streptococcus agalactiae (GBS) infection in wild giant Queensland grouper, 
Epinephelus lanceolatus (Bloch), and other wild fish in northern Queensland, Australia. Journal of Fish Diseases 35: 173– 186. 
https://doi.org/10.1111/j.1365-2761.2011.01332.x
                                                                                                                 CHANG, P.H. and PLUMB, J.A., 1996. Effects of salinity on 
Streptococcus infection of Nile tilapia, 
Oreochromis niloticus. Journal of Applied Aquaculture 6: 39-45. 
https://doi.org/10.1300/J028v06n01_04
                                                                                                                 CIPRIANO, R.C., 2001. Aeromonas hydrophila and motile aeromonad septicemias of fish. Fish Disease. Leaf 68: 1-25.
                                                                                                                CLSI., 2017. Performance Standards for Antimicrobial Susceptibility Testing. 27th ed. CLSI document M100–S27. Clinical and Laboratory Standards Institute. Wayne. Pennsylvania.
                                                                                                                DAHDOUH, B., BASHA, O., KHALIL, S., and TANEKHY, M., 2016. Molecular Characterization, Antimicrobial Susceptibility and Salt Tolerance of 
Aeromonas hydrophila from Fresh, Brackish and Marine fishes. Alexandria Journal of Veterinary Sciences 48 (2): 46-53. 
https://dx.doi.org/10.5455/ajvs.208107
                                                                                                                                                                                                                                 DORAN, K.S., LIU, G.Y., and NIZET,V., 2003. Group B streptococcal beta-hemolysin/cytolysin activates neutrophil signaling pathways in brain endothelium and contributes to development of meningitis. The Journal of Clinical Investigation 112(5): 736–744. 
https://doi.org/10.1172/jci17335
                                                                                                                 EISSA, A. E., ATTIAN M. M., ELGENDY, M. Y., ISMAIL, G. A., SABRY, N. M., and PRINCE, A., 2021. Streptococcus, 
Centrocestus formosanus and 
Myxobolus tilapiae concurrent infections in farmed Nile tilapia (
Oreochromis niloticus). Microbial Pathogenesis 158: 105084. 
https://doi.org/10.1016/j.micpath.2021.105084
                                                                                                                 EISSA, A., THARWAT, N., and ZAKI M., 2013. Field assessment of the mid winter mass kills of trophic fishes at Mariotteya stream, Egypt: Chemical and biological pollution synergistic model. Chemosphere;90(3):1061-8. 
https://doi.org/10.1016/j.chemosphere.2012.09.010
                                                                                                                 EISSA, A.E. 2016. Clinical and laboratory manual of fish diseases. LAP LAMBERT Academic Publishing.
                                                                                                                EL-BAHAR, H. M., ALI, N. G., ABOYADAK, I. M., KHALIL, S. A. E. S., and IBRAHIM, M. S., 2019. Virulence genes contributing to 
Aeromonas hydrophila pathogenicity in 
Oreochromis niloticus. Int. Microbiol. 22: 479. 
https://link.springer.com/article/10.1007/s10123-019-00075-3
                                                                                                                 ELGENDY, M. Y., MOUSTAFA, M., GAAFAR, A. Y., and BORHAN, T., 2015. Impacts of extreme cold water conditions and some bacterial infections on earthen-pond cultured Nile tilapia, 
Oreochromis niloticus. RJPBCS, 6: 136-145. 
https://www.cabidigitallibrary.org/doi/full/10.5555/20153064383
                                                                                                                 ENANY, M., EIDAROOS, N., and ELTAMIMY, N., 2019. Microbial causes of summer mortality in farmed fish in Egypt. Suez Canal Veterinary Medical Journal. SCVMJ, 24(1): 45-56.
                                                                                                                                                                                                                                FARUK, M.A.R., ALAM M.J., SARKER M.M.R., and KABIR, M.B., 2004. Status of fish disease and health management practices in rural freshwater aquaculture of Bangladesh. Pakistan Journal of Biological Sciences , 7 (12): 2092-2098. 
http://dx.doi.org/10.3923/pjbs.2004.2092.2098
                                                                                                                                                                                                                                 HARDI, E. H., NUGROHO, R. A., SAPTIANI, G., SARINAH, R., AGRIANDINI, M., and MAWARDI, M., 2018. Identification of potentially pathogenic bacteria from tilapia (
Oreochromis niloticus) and channel catfish (
Clarias batrachus) culture in Samarinda, East Kalimantan, Indonesia. Biodiversitas Journal of Biological Diversity 19 (2): 480-488. 
https://doi.org/10.13057/biodiv/d190215
                                                                                                                 HASIMUNA, O.J., MAULU, S., MPHANDE, J., 2020. Aquaculture health management practices in zambia: status, challenges and proposed biosecurity measures. Journal of Aquaculture Research and Development,11, 1–6. 
https://doi.org/10.35248/2155-9546.19.10.584
                                                                                                                 IKENAGA, T., YOSHIDA, M., and UEMATSU, K., 2005. Morphology and immunohistochemistry of efferent neurons of the goldfish corpus cerebelli. Journal of Comparative Neurology, 487(3), 300–311. 
https://doi.org/10.1002/cne.20553
                                                                                                                 KUMAR, S., STECHER, G., LI, M., KNYAZ, C., and TAMURA, K., 2018. MEGA X: Molecular Evolutionary Genetics Analysis across Computing Platforms. Mol. Biol. Evol. 35(6): 1547-1549. 
https://doi.org/10.1093/molbev/msy096
                                                                                                                 LAGACÉ, L., PITRE, M., JACQUES, M., and ROY, D., 2004. Identification of the bacterial community of maple sap by using amplified ribosomal DNA (RDNA) restriction analysis and RDNA sequencing. Appl. Environ. Microbiol. 70(4): 2052–2060. 
https://doi.org/10.1128%2FAEM.70.4.2052-2060.2004
                                                                                                                 LIAO, P.C., TSAI, Y.L., CHEN, Y.C., WANG, P.C., LIU, S.C., and CHEN, S.C., 2020. Analysis of streptococcal infection and correlation with climatic factors in cultured tilapia 
Oreochromis spp, Taiwan. Applied Sciences 10(11): 2076–3417. 
https://doi.org/10.3390/app10114018
                                                                                                                 LIU, J., GAO, S., DONG, Y., LU, C., and LIU, Y., 2020. Isolation and characterization of bacteriophages against virulent 
Aeromonas hydrophila. BMC Microbiology 20: 141. 
https://doi.org/10.1186/s12866-020-01811-w
                                                                                                                 LUSIASTUTI, A. M., TEXTOR, M., SEEGER, H., AKINEDEN, Ö., and ZSCHÖCK, M., 2014. The occurrence of 
Streptococcus agalactiae sequence type 261 from fish disease outbreaks of tilapia (
Oreochromis niloticus) in Indonesia. Aquac. Res. 45: 1260–1263. 
https://doi.org/10.1111/are.12069
                                                                                                                 MARINHO-NETO, F.A., CLAUDIANO, G.S., YUNIS-AGUINAGA, J.,CUEVA-QUIROZ, V. A., KOBASHIGAWA, K. K., and CRUZ, N. R., 2019. Morphological, microbiological and ultrastructural aspects of sepsis by 
Aeromonas hydrophila in 
Piaractus mesopotamicus. PLoS One 14(9): e0222626. 
https://doi.org/10.1371/journal.pone.0222626
                                                                                                                 MCANDREW, B.J. 2000. Evolution, phylogenetic relationships and biogeography. In: Beveridge, M.C. M., McAndrew, B. J., eds. Tilapias: Biology and Exploitation. Kluwer Academic Publishers, pp. 1-32.
                                                                                                                MIGAUD, H., BELL, G., CABRITA, E., MCANDREW, B., DAVIE, A., BOBE, J., HERRAEZ, M.P., and CARRILLO, M., 2013. Gamete quality and broodstock management in temperate fish. Reviews in Aquaculture,5, pp.S194-S223. 
http://dx.doi.org/10.1111/raq.12025
                                                                                                                 NAGPAL, M.L., FOX, K.F., and FOX, A., 1998. Utility of 16S–23S rRNA spacer region methodology: how similar are interspace regions within a genome and between strains for closely related organisms. J. Microbiol. Methods 33: 211-219. 
https://doi.org/10.1016/S0167-7012(98)00054-2
                                                                                                                 NASR-ALLAH, A. M., DICKSON, M. W., AL-KENAWY, D. A. R., AHMED, M. F. M., and EL-NAGGAR, G. O., 2014. Technical characteristics and economic performance of commercial tilapia hatcheries applying different management systems in Egypt. Aquaculture 426: 222-230. 
https://orcid.org/0000-0003-2181-2625
                                                                                                                 NGUYEN, H.T., KANAI,K., and YOSHIKOSHI, K., 2002. Ecological investigation of Streptococcus iniae in cultured Japanese flounder (
Paralichthys olivaceus) using selective isolation procedures. Aquaculture 205(1): 7–17. 
https://doi.org/10.1016/S0044-8486(01)00667-6
                                                                                                                 OSMAN, K. M., AL-MAARY, K. S., MUBARAK, A. S., DAWOUD, T. M., MOUSSA, I.M., IBRAHIM, M. D., and FAWZY, N. M., 2017. Characterization and susceptibility of streptococci and enterococci isolated from Nile tilapia 
(Oreochromis niloticus) showing septicaemia in aquaculture and wild sites in Egypt. BMC Veterinary Research 13(1): 357. 
https://doi.org/10.1186/s12917-017-1289-8
                                                                                                                 POYART, C., PELLEGRINI, E., GAILLOT, O., BOUMAILA, C., BAPTISTA, M., and TRIEU-CUOT, P., 2001. Contribution of Mn-cofactored superoxide dismutase (SodA) to the virulence of Streptococcus agalactiae. Infection and Immunity,69(8), 5098–5106. PubMed. 
https://doi.org/10.1128/IAI.69.8
                                                                                                                 RAJ, N. S., SWAMINATHAN, T. R., DHARMARATNAM, A., RAJA, S. A., RAMRAJ, D., and LAL, K. K., 2019. Aeromonas veronii caused bilateral exophthalmia and mass mortality in cultured Nile tilapia, Oreochromis niloticus (L.) in India. Aquaculture 512: 734278. 
https://doi.org/10.1016/j.aquaculture.2019.734278
                                                                                                                 RICE, E. W., BRIDGEWATER, L., and AMERICAN PUBLIC HEALTH ASSOCIATION., 2012. Standard methods for the examination of water and wastewater (Volume.10). Washington, DC: American public health association.
                                                                                                                RODKHUM, C., KAYANSAMRUAJ, P., and Pirarat, N., 2011. Effect of water temperature on susceptibility to 
Streptococcus agalactiae serotype Ia infection in Nile tilapia (
Oreochromis niloticus). The Thai Journal of Veterinary Medicine 41(3): 309-314. 
https://doi.org/10.56808/2985-1130.2314
                                                                                                                 SALEH, M. A. 2007. Freshwater fish seed resources in Egypt. In: Bondad-Reantaso, M.G. (Ed.), Assessment of Freshwater Fish Seed Resources for Sustainable Aquaculture, FAO Fisheries Technical Paper. FAO, Rome, pp. 241–255.
                                                                                                                SEBASTIÃO, F. D. A., LEMOS, E. G., and PILARSKI, F., 2015. Validation of absolute quantitative real-time PCR for the diagnosis of 
Streptococcus agalactiae in fish. Journal of microbiological methods, 119, 168-175. 
https://doi.org/10.1016/j.mimet.2015.10.021
                                                                                                                 SHAALAN, M., EL-MAHDY, M., SALEH, M., and EL-MATBOULI, M., 2018. Aquaculture in Egypt: insights on the current trends and future perspectives for sustainable development. Reviews in Fisheries Science and Aquaculture 26: 99–110. 
https://doi.org/10.1080/23308249.2017.1358696
                                                                                                                 SHOURBELA, R.M., KHATAB, S.A., HASSAN, M.M., VAN DOAN,H. and DAWOOD, M.A.O., 2021. The effect of stocking density and carbon sources on the oxidative status, and nonspecific immunity of Nile tilapia (
Oreochromis niloticus) reared under biofloc conditions. Animals 11: 184. 
https://doi.org/10.3390/ani11010184
                                                                                                                 SMALL, B., and BILODEAU, A., 2005. Effects of cortisol and stress on channel catfish (
Ictalurus punctatus) pathogen susceptibility and lysozyme activity following exposure to 
Edwardsiella ictaluri. General and comparative endocrinology 142(1-2): 256-62. 
https://doi.org/10.1016/j.ygcen.2004.12.004
                                                                                                                 SOTO, E., WANG, R., WILES, J., BAUMGARTNER, W., GREEN, C., PLUMB, J., and HAWKE, J., 2015. Characterization of isolates of 
Streptococcus agalactiae from diseased farmed and wild marine fish from the US Gulf Coast, Latin America, and Thailand. Journal of Aquatic Animal Health 27(2): 123–134. 
https://doi.org/10.1080/08997659.2015.1032439
                                                                                                                 STRATEV, D., GUROVA, E., VASHIN, I., and DASKALOV, H., 2016. Multiplex PCR detection of heamolysin genes in β-heamolytic 
Aeromonas hydrophila strains isolated from fish and fish products. Bulgarian J. Agricultural Science. 22 (2): 308-314. 
https://www.agrojournal.org/22/02-23.pdf
                                                                                                                 SUDPRASEART, C., WANG, P.C., and CHEN, S.C., 2021. Phenotype, genotype and pathogenicity of 
Streptococcus agalactiae isolated from cultured tilapia (
Oreochromis spp.) in Taiwan. Journal of fish diseases 44(6): 747-756. 
https://doi.org/10.1111/jfd.13296
                                                                                                                 VOS, P., GARRITY, G., JONES, D., KRIEG, N. R., LUDWIG, W., RAINEY, F. A., and WHITMAN, W. B., 2011. Bergey's manual of systematic bacteriology: Volume 3: The Firmicutes (Vol. 3). Springer Science and  Business Media.
                                                                                                                WAMALA, S. P., MUGIMBA, K. K., MUTOLOKI, S., EVENSEN, Ø., MDEGELA, R., BYARUGABA, D. K., and SØRUM, H., 2018. Occurrence and antibiotic susceptibility of fish bacteria isolated from 
Oreochromis niloticus (Nile tilapia) and 
Clarias gariepinus (African catfish). Uganda Fisheries and Aquatic Sciences 21: 6-16. 
https://doi.org/10.1186/s41240-017-0080-x
                                                                                                                 YARDIMCI, B., and  AYDIN, Y., 2011. Pathological findings of experimental Aeromonas hydrophila infection in Nile tilapia (Oreochromis niloticus). Ankara Üniversitesi Veteriner Fakültesi Dergisi, 58(1), pp.47-54. 
http://dx.doi.org/10.1501/Vetfak_0000002448
                                                                                                                 YEN-HSI LIU, G., and NIZET, V., 2004. Extracellular virulence factors of group B streptococci. Frontiers in Bioscience: A Journal and Virtual Library, 9, 1794–1802. 
https://doi.org/10.2741/1296
                                                                                                                 ZHAO, Y., HUANG, J., MA, L., and WANG, F., 2017. Development and validation of a simple and fast method for simultaneous determination of aflatoxin B1 and sterigmatocystin in grains. Food chemistry 221: 11-17. 
https://doi.org/10.1016/j.foodchem.2016.10.036