Molecular identification, phylogenetic analysis and histopathological study of pathogenic free-living amoebae isolated from discus fish (Symphysodon aequifasciatus) in Iran: 2020–2022
Abstract Free-living amoebae (FLA) are capable of inhabiting diverse reservoirs independently, without relying on a host organism, hence their designation as “free-living”. The majority of amoebae that infect freshwater or marine fish are amphizoic, or free-living forms that may colonize fish under...
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| Format: | Article |
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BMC
2024-02-01
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| Series: | BMC Veterinary Research |
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| Online Access: | https://doi.org/10.1186/s12917-024-03902-6 |
| _version_ | 1827327136118079488 |
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| author | Hooman Rahmati-Holasoo Maryam Niyyati Marziye Fatemi Fatemeh Mahdavi Abhari Sara Shokrpoor Alireza Nassiri Amin Marandi |
| author_facet | Hooman Rahmati-Holasoo Maryam Niyyati Marziye Fatemi Fatemeh Mahdavi Abhari Sara Shokrpoor Alireza Nassiri Amin Marandi |
| author_sort | Hooman Rahmati-Holasoo |
| collection | DOAJ |
| description | Abstract Free-living amoebae (FLA) are capable of inhabiting diverse reservoirs independently, without relying on a host organism, hence their designation as “free-living”. The majority of amoebae that infect freshwater or marine fish are amphizoic, or free-living forms that may colonize fish under particular circumstances. Symphysodon aequifasciatus, commonly referred to as the discus, is widely recognized as a popular ornamental fish species. The primary objective of the present study was to determine the presence of pathogenic free-living amoebae (FLA) in samples of discus fish. Fish exhibiting clinical signs, sourced from various fish farms, were transferred to the ornamental fish clinic. The skin, gills, and intestinal mucosa of the fish were collected and subjected to culturing on plates containing a 1% non-nutrient agar medium. The detection of FLA was conducted through morphological, histopathological and molecular methods. The construction of the phylogenetic tree for Acanthamoeba genotypes was achieved using the maximum likelihood approach. The molecular sequence analysis revealed that all cultures that tested positive for FLA were T4 genotype of Acanthamoeba and Acanthamoeba sp. The examination of gill samples using histopathological methods demonstrated the presence of lamellar epithelial hyperplasia, significant fusion of secondary lamellae, and infiltration of inflammatory cells. A multitude of cysts, varying in shape from circular to elliptical, were observed within the gills. The occurrence of interlamellar vesicles and amoeboid organisms could be observed within the epithelial tissue of the gills. In the current study, presence of the Acanthamoeba T4 genotype on the skin and gills of discus fish exhibiting signs of illness in freshwater ornamental fish farms was identified. This observation suggests the potential of a transmission of amoebic infection from ornamental fish to humans, thereby highlighting the need for further investigation into this infection among ornamental fish maintained as pets, as well as individuals who interact with them and their environment. |
| first_indexed | 2024-03-07T14:56:39Z |
| format | Article |
| id | doaj.art-9b8bc0f1bca843e994948a66c7cf30a5 |
| institution | Directory Open Access Journal |
| issn | 1746-6148 |
| language | English |
| last_indexed | 2024-03-07T14:56:39Z |
| publishDate | 2024-02-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Veterinary Research |
| spelling | doaj.art-9b8bc0f1bca843e994948a66c7cf30a52024-03-05T19:24:43ZengBMCBMC Veterinary Research1746-61482024-02-0120111110.1186/s12917-024-03902-6Molecular identification, phylogenetic analysis and histopathological study of pathogenic free-living amoebae isolated from discus fish (Symphysodon aequifasciatus) in Iran: 2020–2022Hooman Rahmati-Holasoo0Maryam Niyyati1Marziye Fatemi2Fatemeh Mahdavi Abhari3Sara Shokrpoor4Alireza Nassiri5Amin Marandi6Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of TehranDepartment of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical SciencesDepartment of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical SciencesStudent Research Committee, School of Medicine, Shahid Beheshti University of Medical SciencesDepartment of Pathology, Faculty of Veterinary Medicine, University of TehranDepartment of Aquatic Animal Health, Faculty of Veterinary Medicine, University of TehranDepartment of Aquatic Animal Health, Faculty of Veterinary Medicine, University of TehranAbstract Free-living amoebae (FLA) are capable of inhabiting diverse reservoirs independently, without relying on a host organism, hence their designation as “free-living”. The majority of amoebae that infect freshwater or marine fish are amphizoic, or free-living forms that may colonize fish under particular circumstances. Symphysodon aequifasciatus, commonly referred to as the discus, is widely recognized as a popular ornamental fish species. The primary objective of the present study was to determine the presence of pathogenic free-living amoebae (FLA) in samples of discus fish. Fish exhibiting clinical signs, sourced from various fish farms, were transferred to the ornamental fish clinic. The skin, gills, and intestinal mucosa of the fish were collected and subjected to culturing on plates containing a 1% non-nutrient agar medium. The detection of FLA was conducted through morphological, histopathological and molecular methods. The construction of the phylogenetic tree for Acanthamoeba genotypes was achieved using the maximum likelihood approach. The molecular sequence analysis revealed that all cultures that tested positive for FLA were T4 genotype of Acanthamoeba and Acanthamoeba sp. The examination of gill samples using histopathological methods demonstrated the presence of lamellar epithelial hyperplasia, significant fusion of secondary lamellae, and infiltration of inflammatory cells. A multitude of cysts, varying in shape from circular to elliptical, were observed within the gills. The occurrence of interlamellar vesicles and amoeboid organisms could be observed within the epithelial tissue of the gills. In the current study, presence of the Acanthamoeba T4 genotype on the skin and gills of discus fish exhibiting signs of illness in freshwater ornamental fish farms was identified. This observation suggests the potential of a transmission of amoebic infection from ornamental fish to humans, thereby highlighting the need for further investigation into this infection among ornamental fish maintained as pets, as well as individuals who interact with them and their environment.https://doi.org/10.1186/s12917-024-03902-6AcanthamoebaDiscus fishEpithelial hyperplasiaIranNodular gill disease |
| spellingShingle | Hooman Rahmati-Holasoo Maryam Niyyati Marziye Fatemi Fatemeh Mahdavi Abhari Sara Shokrpoor Alireza Nassiri Amin Marandi Molecular identification, phylogenetic analysis and histopathological study of pathogenic free-living amoebae isolated from discus fish (Symphysodon aequifasciatus) in Iran: 2020–2022 BMC Veterinary Research Acanthamoeba Discus fish Epithelial hyperplasia Iran Nodular gill disease |
| title | Molecular identification, phylogenetic analysis and histopathological study of pathogenic free-living amoebae isolated from discus fish (Symphysodon aequifasciatus) in Iran: 2020–2022 |
| title_full | Molecular identification, phylogenetic analysis and histopathological study of pathogenic free-living amoebae isolated from discus fish (Symphysodon aequifasciatus) in Iran: 2020–2022 |
| title_fullStr | Molecular identification, phylogenetic analysis and histopathological study of pathogenic free-living amoebae isolated from discus fish (Symphysodon aequifasciatus) in Iran: 2020–2022 |
| title_full_unstemmed | Molecular identification, phylogenetic analysis and histopathological study of pathogenic free-living amoebae isolated from discus fish (Symphysodon aequifasciatus) in Iran: 2020–2022 |
| title_short | Molecular identification, phylogenetic analysis and histopathological study of pathogenic free-living amoebae isolated from discus fish (Symphysodon aequifasciatus) in Iran: 2020–2022 |
| title_sort | molecular identification phylogenetic analysis and histopathological study of pathogenic free living amoebae isolated from discus fish symphysodon aequifasciatus in iran 2020 2022 |
| topic | Acanthamoeba Discus fish Epithelial hyperplasia Iran Nodular gill disease |
| url | https://doi.org/10.1186/s12917-024-03902-6 |
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