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Nhinh DT, Hoa DT, Giang NTH, Van Van K, Dang LT, Crumlish M, Dong HT, Hoai TD. Synergistic infection of Edwardsiella ictaluri and Flavobacterium oreochromis in cage cultured tilapia (Oreochromis sp.). JOURNAL OF FISH DISEASES 2023; 46:1125-1136. [PMID: 37410863 DOI: 10.1111/jfd.13832] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 07/08/2023]
Abstract
Widespread distribution of a highly pathogenic Edwardsiella ictaluri strain in farmed tilapia in northern Vietnam has recently been reported. The subsequent investigation noticed a disease outbreak occurred at five nearby tilapia farms with floating cages, in which the clinical signs of both edwardsiellosis and columnaris diseases were observed on the same infected fish and caused 65% to 85% fish mortality. Naturally diseased fish (n = 109) were sampled from the five infected farms for bacterial identification and conducting challenge tests. The two bacteria Edwardsiella ictaluri and Flavobacterium oreochromis were identified by a combination of biochemical tests, PCR and 16SrRNA sequencing methods. Experimental challenge tests on Nile tilapia resulted in the median lethal dose (LD50 ) of E. ictaluri and F. oreochromis at 70 CFU/fish by intraperitoneal (i.p.) injection and 3.6 × 106 CFU/mL by immersion, respectively. The experimentally co-infected challenged fish exposed to LD50 doses resulted in 83% ± 6% mortality, with the infected fish exhibiting clinical signs of both edwardsiellosis and columnaris diseases, mimicking the naturally diseased fish. This finding suggests that the co-infection of E. ictaluri and F. oreochromis may interact in a synergistic manner, to enhance the overall severity of the infection and elevates the need for efficient methods to control both pathogens.
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Affiliation(s)
- Doan Thi Nhinh
- Faculty of Fisheries, Vietnam National University of Agriculture, Hanoi, Vietnam
- Research Institute for Aquaculture No 1, Bac Ninh, Vietnam
| | - Dang Thi Hoa
- Faculty of Fisheries, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Nguyen Thi Huong Giang
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Kim Van Van
- Faculty of Fisheries, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Lua Thi Dang
- Research Institute for Aquaculture No 1, Bac Ninh, Vietnam
| | - Mags Crumlish
- Institute of Aquaculture, University of Stirling, Stirling, UK
| | - Ha Thanh Dong
- Department of Food, Aquaculture and Aquatic Resources Management, Agriculture and Bioresources, School of Environment, Resources & Development (SERD), Asian Institute of Technology (AIT), Klong Luang, Thailand
| | - Truong Dinh Hoai
- Faculty of Fisheries, Vietnam National University of Agriculture, Hanoi, Vietnam
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Lavrinenko IV, Shulga LV, Peredera OO, Zhernosik IA. Analysis of the treatment regimen efficacy for columnaris disease in Pterophyllum scalare. REGULATORY MECHANISMS IN BIOSYSTEMS 2020. [DOI: 10.15421/022033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The article presents the results of studies on the treatment scheme efficacy for columnaris in Pterophyllum scalare, common under private aquarium husbandry conditions. To establish the diagnosis, the clinical features of the diseased fish, pathological and anatomical changes and the results of microscopic and microbiological studies were taken into account. Separate chemical and microbiological parameters of aquarium water were also studied. It was established that fish disease developed against the background of adverse changes in the chemical composition and microbiocenosis of aquarium water. High alkalinity and excess of phosphates compared to the norm provoked accumulation of opportunistic microbiota, resulting in a balance disorder in the parasite-host system and development of clinical manifestation of the fish disease. During the disease outbreak, bacteriological indices of water indicated a high level of organic contamination and a low intensity of water self-purification processes. Clinically, the disease was manifested in P. scalare by decrease in appetite and motor activity, onset of ulcerative lesions of various shapes and sizes on the surface of the body and on the gill covers. Selected pure cultures of Flavobacterium columnare showed sensitivity to enrofloxacin (growth retardation zone 31.3 ± 1.0 mm); moderate resistance was found to tylosin. The microorganisms were resistant to amoxicillin, doxycycline, benzylpenicillin and tetracycline. Microscopic studies of intestinal specimens of dead P. scalare revealed numerous motile flagellates. It has been shown that an effective treatment regimen that provides recovery for 70% of diseased P. scalare is the use of enroxil 10% solution for five days, metronidazole three times a day, and “API MelaFix” for seven days. It is proved that the following measures are effective to restore the disrupted hydro-balance: periodic water replacement in the amount of 20% of the total volume, providing the aquarium with active aeration systems, planting slow-growing plants and reducing the amount of fish food provided. The measures developed were efficient, they led to elimination of the outbreak of columnaris in the P. scalare and to restoration of biological equilibrium in a closed aquatic ecosystem.
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Kayansamruaj P, Dong HT, Hirono I, Kondo H, Senapin S, Rodkhum C. Comparative genome analysis of fish pathogen Flavobacterium columnare reveals extensive sequence diversity within the species. INFECTION GENETICS AND EVOLUTION 2017. [PMID: 28624550 DOI: 10.1016/j.meegid.2017.06.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Flavobacterium columnare is one of the deadliest fish pathogens causing devastating mortality in various freshwater fish species globally. To gain an insight into bacterial genomic contents and structures, comparative genome analyses were performed using the reference and newly sequenced genomes of F. columnare including genomovar I, II and I/II strains isolated from Thailand, Europe and the USA. Bacterial genomes varied in size from 3.09 to 3.39Mb (2714 to 3101 CDSs). The pan-genome analysis revealed open pan-genome nature of F. columnare strains, which possessed at least 4953 genes and tended to increase progressively with the addition of a new genome. Genomic islands (GIs) present in bacterial genomes were diverse, in which 65% (39 out of 60) of possible GIs were strain-specific. A CRISPR/cas investigation indicated at least two different CRISPR systems with varied spacer profiles. On the other hand, putative virulence genes, including those related to gliding motility, type IX secretion system (T9SS), outer membrane proteins (Omp), were equally distributed among F. columnare strains. The MLSA scheme categorized bacterial strains into nine different sequence types (ST 9-17). Phylogenetic analyses based on either 16S rRNA, MLSA and concatenated SNPs of core genome revealed the diversity of F. columnare strains. DNA homology analysis indicated that the estimated digital DNA-DNA hybridization (dDDH) between strains of genomovar I and II can be as low as 42.6%, while the three uniquely tilapia-originated strains from Thailand (1214, NK01 and 1215) were clearly dissimilar to other F. columnare strains as the dDDH values were only 27.7-30.4%. Collectively, this extensive diversity among bacterial strains suggested that species designation of F. columnare would potentially require re-emendation.
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Affiliation(s)
- Pattanapon Kayansamruaj
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand; Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Bangkok, Thailand.
| | - Ha Thanh Dong
- Department Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
| | - Ikuo Hirono
- Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Hidehiro Kondo
- Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Saengchan Senapin
- Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp), Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Channarong Rodkhum
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand.
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Dong HT, Senapin S, LaFrentz B, Rodkhum C. Virulence assay of rhizoid and non-rhizoid morphotypes of Flavobacterium columnare in red tilapia, Oreochromis sp., fry. JOURNAL OF FISH DISEASES 2016; 39:649-655. [PMID: 25953003 DOI: 10.1111/jfd.12385] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 04/07/2015] [Accepted: 04/07/2015] [Indexed: 06/04/2023]
Abstract
Numerous isolates of Flavobacterium columnare were previously recovered from red tilapia, Oreochromis sp., exhibiting columnaris-like disease in Thai farms, and the phenotypic and genetic characteristics were described. The objective of this study was to determine the virulence of two morphotypes (rhizoid and non-rhizoid colonies) of F. columnare and to determine their ability to adhere to and persist in red tilapia fry. The results showed that the typical rhizoid isolate (CUVET1214) was a highly virulent isolate and caused 100% mortality within 24 h following bath challenge of red tilapia with three different doses. The non-rhizoid isolate (CUVET1201) was avirulent to red tilapia fry. Both morphotypes adhered to and persisted in tilapia similarly at 0.5 and 6 h post-challenge as determined by whole fish bacterial loads. At 24 and 48 h post-challenge, fry challenged with the rhizoid morphotype exhibited significantly higher bacterial loads than the non-rhizoid morphotype. The results suggested that an inability of the non-rhizoid morphotype to persist in tilapia fry may explain lack of virulence.
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Affiliation(s)
- H T Dong
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - S Senapin
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, Thailand
- Center of Excellence for Shrimp Molecular Biology and Biotechnology, Mahidol University, Bangkok, Thailand
| | - B LaFrentz
- Aquatic Animal Health Research Unit, United States Department of Agriculture-Agricultural Research Service, Auburn, AL, USA
| | - C Rodkhum
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
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Dong HT, LaFrentz B, Pirarat N, Rodkhum C. Phenotypic characterization and genetic diversity of Flavobacterium columnare isolated from red tilapia, Oreochromis sp., in Thailand. JOURNAL OF FISH DISEASES 2015; 38:901-913. [PMID: 25287048 DOI: 10.1111/jfd.12304] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 07/08/2014] [Accepted: 07/26/2014] [Indexed: 06/03/2023]
Abstract
Flavobacterium columnare is the aetiological agent of columnaris disease and severely affects various freshwater aquaculture fish species worldwide. The objectives of this study were to determine the phenotypic characteristics and genetic variability among F. columnare isolates isolated from red tilapia in Thailand. Forty-four F. columnare isolates were recovered from diseased fish in different geographical locations. The isolates exhibited homologous phenotypic characteristics but exhibited genetic diversity. One isolate was assigned to genomovar I, and the remainder were assigned to genomovar II, indicating the coexistence of these genomovars but predominance of genomovar II. Phylogenetic analysis of the 16S-23S ISR sequences revealed that a subset of the Thai isolates (n = 25) contained a smaller intergenic spacer region (ISR) (523-537 bp) and formed a unique ISR phylogenetic group. Phylogenetic analysis of the 16S rRNA gene supported the unique cluster of Thai isolates. This is the first description of the phenotypic and molecular characteristics of F. columnare isolated from red tilapia in Thailand as well as five isolates of F. columnare derived from other fish species including Nile tilapia, koi carp and striped catfish.
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Affiliation(s)
- H T Dong
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - B LaFrentz
- United States Department of Agriculture-Agricultural Research Service, Aquatic Animal Health Research Unit, Auburn, AL, USA
| | - N Pirarat
- Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - C Rodkhum
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
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Kumar Verma D, Rathore G. Molecular characterization of Flavobacterium columnare isolated from a natural outbreak of columnaris disease in farmed fish, Catla catla from India. J GEN APPL MICROBIOL 2013; 59:417-24. [DOI: 10.2323/jgam.59.417] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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