Molecular characterization and pathogenicity of Streptococcus agalactiae serotypes Ia ST7 and III ST283 isolated from cultured red hybrid tilapia in Malaysia
Streptococcus agalactiae is one of the most important pathogens infecting tilapia worldwide. In this study, we determined the serotype, sequence type (ST), virulence gene profile and pathogenicity of S. agalactiae isolated from cultured fish. A collection of 256 S. agalactiae that were previously is...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2020
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| Online Access: | http://psasir.upm.edu.my/id/eprint/86808/ http://psasir.upm.edu.my/id/eprint/86808/1/Molecular%20characterization%20and%20pathogenicity%20of%20Streptococcus.pdf |
| _version_ | 1848860292670291968 |
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| author | R., Syuhada Saad, M. Zamri Md Yasin, Ina Salwany Mustafa, Muskhazli Nasruddin, N. N. Mohd Desa, Mohd Nasir Amin Nordin, Syafinaz Barkham, T. Azmai, Mohammad Noor Amal |
| author_facet | R., Syuhada Saad, M. Zamri Md Yasin, Ina Salwany Mustafa, Muskhazli Nasruddin, N. N. Mohd Desa, Mohd Nasir Amin Nordin, Syafinaz Barkham, T. Azmai, Mohammad Noor Amal |
| author_sort | R., Syuhada |
| building | UPM Institutional Repository |
| collection | Online Access |
| description | Streptococcus agalactiae is one of the most important pathogens infecting tilapia worldwide. In this study, we determined the serotype, sequence type (ST), virulence gene profile and pathogenicity of S. agalactiae isolated from cultured fish. A collection of 256 S. agalactiae that were previously isolated from outbreaks of streptococcosis in red hybrid tilapia in Peninsular Malaysia were studied. The genotype and ST of the isolates were determined by molecular serotyping of the capsular polysaccharide (cps) gene clusters, and multi-locus sequence typing (MLST). The virulence gene profiles were constructed using m-PCR for 14 standard virulence genes with published primers. Two serotypes, with different associated STs, were identified in this study: serotypes Ia ST7 and III ST283. Serotype Ia ST7 lacks lmb, scpB, pavA, fbsB, cyl, bca, cspA and bac genes, which were present in serotype III ST283. The LD50–240h of S. agalactiae in red hybrid tilapia for serotypes Ia ST7 and III ST283 were 8.7 × 103 CFU/mL and 6.3 × 103 CFU/mL, respectively. The histopathological findings were consistent with meningitis, necrosis of hepatocytes, coagulative tubular necrosis and hypocellular of the spleen. Histopathological scores revealed significant differences (p < 0.05) between the two serotypes in all lesions in the brain, liver (except hepato-necrosis) and spleen, but not the kidney. This study revealed that S. agalactiae serotypes Ia ST7 and III ST283 currently exist in cultured tilapia in Malaysia. This molecular epidemiology study could be useful for the future development of cross protective vaccines against streptococcosis in the region. |
| first_indexed | 2025-11-15T12:42:55Z |
| format | Article |
| id | upm-86808 |
| institution | Universiti Putra Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T12:42:55Z |
| publishDate | 2020 |
| publisher | Elsevier |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | upm-868082021-11-17T10:59:05Z http://psasir.upm.edu.my/id/eprint/86808/ Molecular characterization and pathogenicity of Streptococcus agalactiae serotypes Ia ST7 and III ST283 isolated from cultured red hybrid tilapia in Malaysia R., Syuhada Saad, M. Zamri Md Yasin, Ina Salwany Mustafa, Muskhazli Nasruddin, N. N. Mohd Desa, Mohd Nasir Amin Nordin, Syafinaz Barkham, T. Azmai, Mohammad Noor Amal Streptococcus agalactiae is one of the most important pathogens infecting tilapia worldwide. In this study, we determined the serotype, sequence type (ST), virulence gene profile and pathogenicity of S. agalactiae isolated from cultured fish. A collection of 256 S. agalactiae that were previously isolated from outbreaks of streptococcosis in red hybrid tilapia in Peninsular Malaysia were studied. The genotype and ST of the isolates were determined by molecular serotyping of the capsular polysaccharide (cps) gene clusters, and multi-locus sequence typing (MLST). The virulence gene profiles were constructed using m-PCR for 14 standard virulence genes with published primers. Two serotypes, with different associated STs, were identified in this study: serotypes Ia ST7 and III ST283. Serotype Ia ST7 lacks lmb, scpB, pavA, fbsB, cyl, bca, cspA and bac genes, which were present in serotype III ST283. The LD50–240h of S. agalactiae in red hybrid tilapia for serotypes Ia ST7 and III ST283 were 8.7 × 103 CFU/mL and 6.3 × 103 CFU/mL, respectively. The histopathological findings were consistent with meningitis, necrosis of hepatocytes, coagulative tubular necrosis and hypocellular of the spleen. Histopathological scores revealed significant differences (p < 0.05) between the two serotypes in all lesions in the brain, liver (except hepato-necrosis) and spleen, but not the kidney. This study revealed that S. agalactiae serotypes Ia ST7 and III ST283 currently exist in cultured tilapia in Malaysia. This molecular epidemiology study could be useful for the future development of cross protective vaccines against streptococcosis in the region. Elsevier 2020-01-15 Article PeerReviewed text en http://psasir.upm.edu.my/id/eprint/86808/1/Molecular%20characterization%20and%20pathogenicity%20of%20Streptococcus.pdf R., Syuhada and Saad, M. Zamri and Md Yasin, Ina Salwany and Mustafa, Muskhazli and Nasruddin, N. N. and Mohd Desa, Mohd Nasir and Amin Nordin, Syafinaz and Barkham, T. and Azmai, Mohammad Noor Amal (2020) Molecular characterization and pathogenicity of Streptococcus agalactiae serotypes Ia ST7 and III ST283 isolated from cultured red hybrid tilapia in Malaysia. Aquaculture, 2020 (515). pp. 1-11. ISSN 0044-8486 https://www.sciencedirect.com/science/article/abs/pii/S0044848619318216 10.1016/j.aquaculture.2019.734543 |
| spellingShingle | R., Syuhada Saad, M. Zamri Md Yasin, Ina Salwany Mustafa, Muskhazli Nasruddin, N. N. Mohd Desa, Mohd Nasir Amin Nordin, Syafinaz Barkham, T. Azmai, Mohammad Noor Amal Molecular characterization and pathogenicity of Streptococcus agalactiae serotypes Ia ST7 and III ST283 isolated from cultured red hybrid tilapia in Malaysia |
| title | Molecular characterization and pathogenicity of Streptococcus agalactiae serotypes Ia ST7 and III ST283 isolated from cultured red hybrid tilapia in Malaysia |
| title_full | Molecular characterization and pathogenicity of Streptococcus agalactiae serotypes Ia ST7 and III ST283 isolated from cultured red hybrid tilapia in Malaysia |
| title_fullStr | Molecular characterization and pathogenicity of Streptococcus agalactiae serotypes Ia ST7 and III ST283 isolated from cultured red hybrid tilapia in Malaysia |
| title_full_unstemmed | Molecular characterization and pathogenicity of Streptococcus agalactiae serotypes Ia ST7 and III ST283 isolated from cultured red hybrid tilapia in Malaysia |
| title_short | Molecular characterization and pathogenicity of Streptococcus agalactiae serotypes Ia ST7 and III ST283 isolated from cultured red hybrid tilapia in Malaysia |
| title_sort | molecular characterization and pathogenicity of streptococcus agalactiae serotypes ia st7 and iii st283 isolated from cultured red hybrid tilapia in malaysia |
| url | http://psasir.upm.edu.my/id/eprint/86808/ http://psasir.upm.edu.my/id/eprint/86808/ http://psasir.upm.edu.my/id/eprint/86808/ http://psasir.upm.edu.my/id/eprint/86808/1/Molecular%20characterization%20and%20pathogenicity%20of%20Streptococcus.pdf |