Pathological Manifestations of <i>Francisella orientalis</i> in the Green Texas Cichlid (<i>Herichthys cyanoguttatus</i>)
<i>Francisella orientalis</i> (<i>Fo</i>) is considered to be one of the major pathogens of tilapia because of the high mortalities observed during outbreaks. Other cichlids belonging to the same family (Cichlidae) as tilapia are also quite susceptible to this pathogen. On va...
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MDPI AG
2021-08-01
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| author | Chia-Hsuan Chang Sayuj Poudyal Theeraporn Pulpipat Pei-Chi Wang Shih-Chu Chen |
| author_facet | Chia-Hsuan Chang Sayuj Poudyal Theeraporn Pulpipat Pei-Chi Wang Shih-Chu Chen |
| author_sort | Chia-Hsuan Chang |
| collection | DOAJ |
| description | <i>Francisella orientalis</i> (<i>Fo</i>) is considered to be one of the major pathogens of tilapia because of the high mortalities observed during outbreaks. Other cichlids belonging to the same family (Cichlidae) as tilapia are also quite susceptible to this pathogen. On various occasions, <i>Fo</i> has also been isolated from other warm water fish, including three-line grunt, hybrid striped bass, French grunt, Caesar grunt, and Indo-Pacific reef fish. However, only a few studies have reported the pathogenicity of <i>Francisella orientalis</i> in ornamental cichlid fish. This study fulfills Koch’s postulates by showing that a strain of <i>Fo</i> obtained from green Texas cichlid (<i>Herichthys cyanoguttatus</i>) was able to produce the same pathogenicity in healthy fish. A mortality of 100% was observed after healthy green Texas cichlid were experimentally injected with <i>Fo</i> at a dose of 8.95 × 10<sup>5</sup> CFU/fish. DNA extracted from the organs of predilection (spleen, head kidney) gave positive results by PCR for all fish that died during the experimental period. Spleen and head kidney presented with multifocal white nodules in the affected fish, corresponding to typical vacuolated granulomas on histopathological examination of the tissues. Based on the results of this study, it is evident that <i>Fo</i> can indeed infect green Texas cichlid and produce a disease typical of francisellosis. |
| first_indexed | 2024-03-10T09:04:29Z |
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| last_indexed | 2024-03-10T09:04:29Z |
| publishDate | 2021-08-01 |
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| spelling | doaj.art-9db60e2c61844985a39826de051423ef2023-11-22T06:29:53ZengMDPI AGAnimals2076-26152021-08-01118228410.3390/ani11082284Pathological Manifestations of <i>Francisella orientalis</i> in the Green Texas Cichlid (<i>Herichthys cyanoguttatus</i>)Chia-Hsuan Chang0Sayuj Poudyal1Theeraporn Pulpipat2Pei-Chi Wang3Shih-Chu Chen4Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, TaiwanInternational Degree Program of Ornamental Fish Technology and Aquatic Animal Health, International College, National Pingtung University of Science and Technology, Pingtung 91201, TaiwanDepartment of Farm Resources and Production Medicine, Faculty of Veterinary Medicine, Kasetsart University Kamphaeng Saen Campus, Nakhon Pathom 73140, ThailandDepartment of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, TaiwanDepartment of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan<i>Francisella orientalis</i> (<i>Fo</i>) is considered to be one of the major pathogens of tilapia because of the high mortalities observed during outbreaks. Other cichlids belonging to the same family (Cichlidae) as tilapia are also quite susceptible to this pathogen. On various occasions, <i>Fo</i> has also been isolated from other warm water fish, including three-line grunt, hybrid striped bass, French grunt, Caesar grunt, and Indo-Pacific reef fish. However, only a few studies have reported the pathogenicity of <i>Francisella orientalis</i> in ornamental cichlid fish. This study fulfills Koch’s postulates by showing that a strain of <i>Fo</i> obtained from green Texas cichlid (<i>Herichthys cyanoguttatus</i>) was able to produce the same pathogenicity in healthy fish. A mortality of 100% was observed after healthy green Texas cichlid were experimentally injected with <i>Fo</i> at a dose of 8.95 × 10<sup>5</sup> CFU/fish. DNA extracted from the organs of predilection (spleen, head kidney) gave positive results by PCR for all fish that died during the experimental period. Spleen and head kidney presented with multifocal white nodules in the affected fish, corresponding to typical vacuolated granulomas on histopathological examination of the tissues. Based on the results of this study, it is evident that <i>Fo</i> can indeed infect green Texas cichlid and produce a disease typical of francisellosis.https://www.mdpi.com/2076-2615/11/8/2284Cichlidaegreen Texas cichlid<i>Francisella</i>pathogenicity |
| spellingShingle | Chia-Hsuan Chang Sayuj Poudyal Theeraporn Pulpipat Pei-Chi Wang Shih-Chu Chen Pathological Manifestations of <i>Francisella orientalis</i> in the Green Texas Cichlid (<i>Herichthys cyanoguttatus</i>) Animals Cichlidae green Texas cichlid <i>Francisella</i> pathogenicity |
| title | Pathological Manifestations of <i>Francisella orientalis</i> in the Green Texas Cichlid (<i>Herichthys cyanoguttatus</i>) |
| title_full | Pathological Manifestations of <i>Francisella orientalis</i> in the Green Texas Cichlid (<i>Herichthys cyanoguttatus</i>) |
| title_fullStr | Pathological Manifestations of <i>Francisella orientalis</i> in the Green Texas Cichlid (<i>Herichthys cyanoguttatus</i>) |
| title_full_unstemmed | Pathological Manifestations of <i>Francisella orientalis</i> in the Green Texas Cichlid (<i>Herichthys cyanoguttatus</i>) |
| title_short | Pathological Manifestations of <i>Francisella orientalis</i> in the Green Texas Cichlid (<i>Herichthys cyanoguttatus</i>) |
| title_sort | pathological manifestations of i francisella orientalis i in the green texas cichlid i herichthys cyanoguttatus i |
| topic | Cichlidae green Texas cichlid <i>Francisella</i> pathogenicity |
| url | https://www.mdpi.com/2076-2615/11/8/2284 |
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