1
|
Mandrioli L, Codotto V, D’Annunzio G, Volpe E, Errani F, Eishi Y, Uchida K, Morini M, Sarli G, Ciulli S. Pathological and Tissue-Based Molecular Investigation of Granulomas in Cichlids Reared as Ornamental Fish. Animals (Basel) 2022; 12:ani12111366. [PMID: 35681830 PMCID: PMC9179505 DOI: 10.3390/ani12111366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary The global ornamental fish trade has an estimated value of USD 15–30 billion per year and more than a 10% average annual growth. Despite their economic importance, the management of ornamental fish is challenged by a paucity of information, including data on the fish health status. Pathological and microbiological investigations were conducted on ornamental cichlids sampled during routine management activities held at an aquarium commercial facility, in order to evaluate the presence of granuloma in the organs. Cutibacterium acnes and Mycobacterium spp. were detected by molecular methods and immunohistochemistry. These bacteria represent potential zoonotic agents, and the advancement of their knowledge could significantly improve the management of ornamental fish and reduce the risk of exposure for people, such as hobbyists, fish handlers, aquarists, and dedicated personnel. Abstract Cichlids include hundreds of species with a high economic value for aquaculture. These fish are subjected to intensive trade and farming that expose them to the risk of infectious diseases. This work focuses on ornamental cichlids held in an aquarium commercial facility presenting emaciation, in order to evaluate the presence of lesions in fish skin and organs. The fish were sampled during routine management activities and subjected to pathological and molecular investigations. The presence of lymphocystis disease virus, typically associated with cutaneous nodular disease, was ruled out. Histologically, they presented granulomas in the spleen, sometimes extending to the other visceral organs. Bacterial heat-shock protein 65 PCR products were detected in tissues associated, in the majority of cases, with granulomas; molecular investigation identified Mycobacterium spp. in two cases and Cutibacterium acnes in seven cases. Immunoreactivity to anti-Mycobacterium and anti-C. acnes antibodies was detected within granulomas. The presence of C. acnes within granuloma is elucidated for the first time in fish; however, similarly to what is found in humans, this bacterium could be harmless in normal conditions, whereas other contributing factors would be required to trigger a granulomatogenous response. Further confirmation by bacterial culture, as well as using large-scale studies in more controlled situations, is needed.
Collapse
Affiliation(s)
- Luciana Mandrioli
- Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, 40126 Bologna, Italy; (V.C.); (G.D.); (E.V.); (F.E.); (M.M.); (G.S.); (S.C.)
- Correspondence: ; Tel.: +39-051-207972
| | - Victorio Codotto
- Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, 40126 Bologna, Italy; (V.C.); (G.D.); (E.V.); (F.E.); (M.M.); (G.S.); (S.C.)
| | - Giulia D’Annunzio
- Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, 40126 Bologna, Italy; (V.C.); (G.D.); (E.V.); (F.E.); (M.M.); (G.S.); (S.C.)
| | - Enrico Volpe
- Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, 40126 Bologna, Italy; (V.C.); (G.D.); (E.V.); (F.E.); (M.M.); (G.S.); (S.C.)
| | - Francesca Errani
- Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, 40126 Bologna, Italy; (V.C.); (G.D.); (E.V.); (F.E.); (M.M.); (G.S.); (S.C.)
| | - Yoshinobu Eishi
- Department of Human Pathology, Graduate School and Faculty of Medicine, Tokyo Medical and Dental University, Yushima 1-5-45, Tokyo 113-8519, Japan; (Y.E.); (K.U.)
| | - Keisuke Uchida
- Department of Human Pathology, Graduate School and Faculty of Medicine, Tokyo Medical and Dental University, Yushima 1-5-45, Tokyo 113-8519, Japan; (Y.E.); (K.U.)
| | - Maria Morini
- Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, 40126 Bologna, Italy; (V.C.); (G.D.); (E.V.); (F.E.); (M.M.); (G.S.); (S.C.)
| | - Giuseppe Sarli
- Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, 40126 Bologna, Italy; (V.C.); (G.D.); (E.V.); (F.E.); (M.M.); (G.S.); (S.C.)
| | - Sara Ciulli
- Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, 40126 Bologna, Italy; (V.C.); (G.D.); (E.V.); (F.E.); (M.M.); (G.S.); (S.C.)
| |
Collapse
|
2
|
Chang CH, Poudyal S, Pulpipat T, Wang PC, Chen SC. Pathological Manifestations of Francisella orientalis in the Green Texas Cichlid ( Herichthys cyanoguttatus). Animals (Basel) 2021; 11:ani11082284. [PMID: 34438742 PMCID: PMC8388529 DOI: 10.3390/ani11082284] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 07/22/2021] [Accepted: 07/30/2021] [Indexed: 11/26/2022] Open
Abstract
Simple Summary The following study demonstrates the pathological manifestations of an emerging virulent bacterium, Francisella orientalis, in an ornamental cichlid fish, the green Texas cichlid (Herichthys cyanoguttatus). This study was conducted to prove that Francisella orientalis can cause a disease in the green Texas cichlid that is similar to natural infection. Francisella orientalis was discovered for the first time in green Texas cichlid by our team in Taiwan in 2015. The present study simply tried to prove the susceptibility of Francisella orientalis in green Texas cichlid by conducting a challenge experiment, where healthy fish were injected with a dose of the bacteria. After the challenge, the healthy fish showed the same disease progression as was seen in the case of natural outbreak. The mortality rate, clinical symptoms, gross findings, and histopathological findings were similar to natural infection. Francisella orientalis could also be recovered in artificial media from challenged fish, thus indicating that the bacteria had multiplied inside the fish. These findings prove that green Texas cichlid (Herichthys cyanoguttatus) is susceptible to Francisela orientalis, and new management and vaccination strategies are necessary in the farming of this fish. This study also helps by adding to the knowledge of the growing host base for Francisella orientalis. Abstract Francisella orientalis (Fo) 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, Fo 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 Francisella orientalis in ornamental cichlid fish. This study fulfills Koch’s postulates by showing that a strain of Fo obtained from green Texas cichlid (Herichthys cyanoguttatus) 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 Fo at a dose of 8.95 × 105 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 Fo can indeed infect green Texas cichlid and produce a disease typical of francisellosis.
Collapse
Affiliation(s)
- Chia-Hsuan Chang
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan;
| | - Sayuj Poudyal
- International Degree Program of Ornamental Fish Technology and Aquatic Animal Health, International College, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan;
| | - Theeraporn Pulpipat
- Department of Farm Resources and Production Medicine, Faculty of Veterinary Medicine, Kasetsart University Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand;
| | - Pei-Chi Wang
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan;
- Southern Taiwan Fish Diseases Research Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Research Center for Fish Vaccine and Diseases, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Correspondence: (P.-C.W.); (S.-C.C.); Tel.: +886-8-7740569 (P.-C.W. & S.-C.C.)
| | - Shih-Chu Chen
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan;
- International Degree Program of Ornamental Fish Technology and Aquatic Animal Health, International College, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan;
- Southern Taiwan Fish Diseases Research Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Research Center for Fish Vaccine and Diseases, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Research Center for Animal Biologics, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Correspondence: (P.-C.W.); (S.-C.C.); Tel.: +886-8-7740569 (P.-C.W. & S.-C.C.)
| |
Collapse
|
3
|
McDermott C, Palmeiro B. Updates on Selected Emerging Infectious Diseases of Ornamental Fish. Vet Clin North Am Exot Anim Pract 2020; 23:413-428. [PMID: 32327045 DOI: 10.1016/j.cvex.2020.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Emerging infectious diseases of ornamental fish are discussed with special focus on clinical relevance, detection, and treatment, where applicable. Important emerging infectious diseases of fish include goldfish herpesvirus, koi herpesvirus, carp edema virus, Erysipelothrix, Edwardsiella ictaluri, Edwardseilla piscicida, and Francisella. Some diseases are more species or genus specific, but many emerging diseases do not seem to have a species preference and affect a variety of species worldwide. Proper husbandry and biosecurity with a disease detection plan for ornamental fish is essential to monitor and prevent future outbreaks.
Collapse
Affiliation(s)
- Colin McDermott
- Zodiac Pet and Exotic Hospital, Victoria Centre, Shop 101A, 1/F, 15 Watson Road, Fortress Hill, Hong Kong.
| | - Brian Palmeiro
- Lehigh Valley Veterinary Dermatology & Fish Hospital, Pet Fish Doctor, 4580 Crackersport Road, Allentown, PA 18104, USA
| |
Collapse
|
4
|
Poudyal S, Pulpipat T, Wang PC, Chen SC. Comparison of the pathogenicity of Francisella orientalis in Nile tilapia (Oreochromis niloticus), Asian seabass (Lates calcarifer) and largemouth bass (Micropterus salmoides) through experimental intraperitoneal infection. JOURNAL OF FISH DISEASES 2020; 43:1097-1106. [PMID: 32700447 DOI: 10.1111/jfd.13217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 06/20/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
Francisella orientalis is a highly virulent, emerging bacterium that causes mass mortalities in tilapia. This pathogen also affects numerous other warm-water fish species, including three-line grunt, hybrid striped bass and various ornamental fish. This study sheds light on two new species of fish that are susceptible to F. orientalis. Asian seabass and largemouth bass showed variable levels of susceptibility in a bacterial challenge experiment. After intraperitoneally injected with a dose of 106 CFU/fish, a total of 64.28% and 21.42% mortalities were obtained in Asian seabass and largemouth bass, respectively. Meanwhile, Nile tilapia showed acute mortality of 100%. All fish showed typical lesions of francisellosis, including multifocal granulomas in the spleen and head kidney. Immunohistochemical analysis revealed strong positive signals inside the granulomas of all fish. The bacterial recovery in solid media from infected fish was highest in Nile tilapia (85.71%), followed by Asian seabass (35.71%) and largemouth bass (21.42%). PCR results tested 100% positive for Nile tilapia, and 78.57% and 21.42% for Asian seabass and largemouth bass, respectively. In conclusion, Asian seabass and largemouth bass are susceptible to this pathogen, which warrants new management strategies when employing predation polyculture systems of these species with tilapia.
Collapse
Affiliation(s)
- Sayuj Poudyal
- International Degree Program of Ornamental Fish Technology and Aquatic Animal Health, International College, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Theeraporn Pulpipat
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Pei-Chi Wang
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
- Southern Taiwan Fish Diseases Research Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
- Research Center for Fish Vaccine and Diseases, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Shih-Chu Chen
- International Degree Program of Ornamental Fish Technology and Aquatic Animal Health, International College, National Pingtung University of Science and Technology, Pingtung, Taiwan
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
- Southern Taiwan Fish Diseases Research Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
- Research Center for Fish Vaccine and Diseases, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
- Research Center for Animal Biologics, National Pingtung University of Science and Technology, Pingtung, Taiwan
| |
Collapse
|
5
|
López-Crespo RA, Martínez-Chavarría LC, Lugo-García AT, Romero-Romero LP, García-Márquez LJ, Reyes-Matute A. Outbreak of francisellosis (Francisella noatunensis subsp. orientalis) in cultured neon jewel cichlids Hemichromis bimaculatus from Morelos, Mexico. DISEASES OF AQUATIC ORGANISMS 2019; 137:125-130. [PMID: 31854330 DOI: 10.3354/dao03429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Francisellosis is a disease caused by different species of the bacterial genus Francisella and has been diagnosed in a wide variety of animals, including fish. Francisellosis in fish is characterized by the development of non-specific clinical signs as well as the presence of numerous granulomas in several organs (mainly spleen and kidney). Ten neon jewel cichlids Hemichromis bimaculatus were submitted for diagnosis from a farm located in Morelos, Mexico. Gross examination, wet preparations, cytology, histopathology and PCR were performed. Affected fish showed lethargy, erratic swimming, imbalance and gasping. At the post mortem examination, multiple granulomas were observed in the kidney and spleen. Microscopically, granulomatous inflammation was observed in several organs. Species-specific PCR assay using DNA from the affected tissues of H. bimaculatus as a template demonstrated the presence of F. noatunensis subsp. orientalis (Fno) by amplifying a hypothetical protein gene of the Fno species. The end diagnosis of francisellosis is important for Mexican ornamental aquaculture, since it is necessary to implement measures for treatment, prevention, control and diagnosis. This is the first report of francisellosis in the neon jewel cichlid.
Collapse
Affiliation(s)
- Rubén A López-Crespo
- Departamento de Patología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, CP 04510, Ciudad de México, México
| | | | | | | | | | | |
Collapse
|
6
|
Chang CT, Benedict S, Whipps CM. Transmission of Mycobacterium chelonae and Mycobacterium marinum in laboratory zebrafish through live feeds. JOURNAL OF FISH DISEASES 2019; 36:681-4. [PMID: 31418901 DOI: 10.1111/jfd.12071] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 11/14/2012] [Indexed: 05/04/2023]
Abstract
The zebrafish (Danio rerio) is a popular vertebrate model organism used in a wide range of research fields. Mycobacteriosis, caused by Mycobacterium species, is particularly concerning because it is a common disease associated with chronic infections in these fish. Infections are also a source of uncontrolled experimental variance that may influence research results. Live feeds for zebrafish are common and include paramecia (Paramecium caudatum), brine shrimp (Artemia franciscana) and rotifers (Branchionus spp.). Although nutritionally beneficial, live feeds may pose a biosecurity risk. In this study, we investigate transmission of Mycobacterium chelonae and Mycobacterium marinum through these three live feeds. We show that all three live feeds ingest both M. marinum and M. chelonae and can transmit mycobacterial infections to zebrafish. This observation emphasizes the need for live feeds to be included in the consideration of potential biosecurity risks. This study is of importance to other beyond the zebrafish community, including those of additional aquatic models and those using live feeds for other types of aquaculture.
Collapse
Affiliation(s)
- Carolyn T Chang
- Department of Environment and Forest Biology, State University of New York College of Environmental Science and Forestry, Syracuse, New York
| | - Samuel Benedict
- Department of Environment and Forest Biology, State University of New York College of Environmental Science and Forestry, Syracuse, New York
| | - Christopher M Whipps
- Department of Environment and Forest Biology, State University of New York College of Environmental Science and Forestry, Syracuse, New York
| |
Collapse
|
7
|
Pulpipat T, Lin KH, Chen YH, Wang PC, Chen SC. Molecular characterization and pathogenicity of Francisella noatunensis subsp. orientalis isolated from cultured tilapia (Oreochromis sp.) in Taiwan. JOURNAL OF FISH DISEASES 2019; 42:643-655. [PMID: 30715744 DOI: 10.1111/jfd.12964] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/28/2018] [Accepted: 12/31/2018] [Indexed: 06/09/2023]
Abstract
Francisella noatunensis subsp. orientalis is a causative agent of systemic granulomatous disease in tilapia. The present study was designed to understand the genetic and phenotypic diversities among Taiwanese Fno isolates obtained from tilapia (n = 17) and green Texas cichlid (Herichthys cyanoguttatus) (n = 1). The enzymatic profiles of the isolates were studied using the API ZYM system. Phylogenetic tree analysis of the 16S rRNA and housekeeping gene and pulsed-field gel electrophoresis (PFGE) were carried out to determine the genotypic characters of all isolates. The phylogenetic tree showed similarity of 99%-100% nucleotide sequences of 16S rRNA and housekeeping genes compared to the Fno references genes from GenBank database. Comparatively, the results revealed an identical profile of enzymatic and PFGE pattern which was distincted from that of F. philomiragia. To understand the pathogenicity, the isolates were intraperitoneal injected to tilapia the gross lesions were observed concomitant with natural outbreak. Median lethal dose upon Nile tilapia and red tilapia were 9.06 × 103 CFU/fish and 2.08 × 102 CFU/fish, respectively. Thus, our data provide understanding the epidemiology of Taiwanese Fno isolates, and help in development of future control and prevention.
Collapse
Affiliation(s)
- Theeraporn Pulpipat
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Kuo-Hua Lin
- Animal Protection Office, Taoyuan City, Taiwan
| | | | - Pei-Chi Wang
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
- Southern Taiwan Fish Diseases Research Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Shih-Chu Chen
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
- Southern Taiwan Fish Diseases Research Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
- International Degree Program of Ornamental Fish Technology and Aquatic Animal Health, International College, National Pingtung University of Science and Technology, Pingtung, Taiwan
- Research Center for Animal Biologics, National Pingtung University of Science and Technology, Pingtung, Taiwan
| |
Collapse
|
8
|
Ramírez-Paredes JG, Thompson KD, Metselaar M, Shahin K, Soto E, Richards RH, Penman DJ, Colquhoun DJ, Adams A. A Polyphasic Approach for Phenotypic and Genetic Characterization of the Fastidious Aquatic Pathogen Francisella noatunensis subsp. orientalis. Front Microbiol 2017; 8:2324. [PMID: 29312155 PMCID: PMC5733052 DOI: 10.3389/fmicb.2017.02324] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 11/10/2017] [Indexed: 12/04/2022] Open
Abstract
Francisella noatunensis subsp. orientalis (Fno) is the causative agent of piscine francisellosis, an emerging infectious disease in Asia and Latin America. In this study two outbreaks of francisellosis were diagnosed in the UK on the basis of histopathology, electron microscopy, PCR, bacterial isolation and fulfillment of Koch's postulates. Furthermore, a phenotypic fingerprint based on biochemical analyses, metabolic activity, chemotaxonomic composition, and antimicrobial assays was generated for the novel isolates, the Fno type strain Ehime-1 from Asia and other Fno from Latin America. The genetic relatedness between the novel Fno and other Francisellaceae species was investigated by sequencing and comparing the 16SrRNA gene, 8 housekeeping genes (individually and concatenated) and the 16SrRNA-ITS-23SrRNA sequence. The phenotypic profiling indicated a high degree of similarity among the Fno strains as all were able to metabolize dextrin, N-acetyl-D glucosamine, D-fructose, α-D-glucose, D-mannose, methyl pyruvate, acetic acid, α-keto butyric acid, L-alaninamide, L-alanine, L-alanylglycine, L-asparagine, L-glutamic acid, L-proline, L-serine, L-threonine, inosine, uridine, glycerol, D L-α-glycerol phosphate, glucose-1-phosphate, and glucose-6-phosphate. The chemotaxonomic analyses indicated that 24:1 (20.3%), 18:1n-9 (16.9%), 24:0 (13.1%) 14:0 (10.9%), 22:0 (7.8%), 16:0 (7.6%), and 18:0 (5.5%) were the predominant structural fatty acids in Fno. The antimicrobial assays showed little variation between the isolates and high susceptibility to enrofloxacin, gentamicin, neomycin, streptomycin, amikacin, ciprofloxacin, gatifloxacin, nitrofurantoin, tobramycin, kanamycin, tetracycline, oxytetracycline, florfenicol, oxolinic acid, and streptomycin in all the Fno analyzed. In all the phylogenetic trees the Fno strains clustered together in independent branches confirming a high degree of homogeneity. Interestingly in five of the 11 trees i.e., mutS, putA, rpoB, 16SrRNA-ITS-23SrRNA, and concatenated sequence the two Francisella noatunensis ssp. diverged more from each other than from the closely related Francisella philomiragia (Fp). The phenotypic and genetic characterization confirmed the Fno isolates represent a solid phylo-phenetic taxon that in the current context of the genus seems to be misplaced within the species Fn. We propose the use of the present polyphasic approach in future studies to characterize strains of Fnn and Fp and verify their current taxonomic rank of Fno and other aquatic Francisella spp.
Collapse
Affiliation(s)
- José G. Ramírez-Paredes
- Faculty of Natural Sciences, Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
| | - Kim D. Thompson
- Aquaculture Research Group, Moredun Research Institute, Edinburgh, United Kingdom
| | | | - Khalid Shahin
- Faculty of Natural Sciences, Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
| | - Esteban Soto
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Randolph H. Richards
- Faculty of Natural Sciences, Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
| | - David J. Penman
- Faculty of Natural Sciences, Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
| | | | - Alexandra Adams
- Faculty of Natural Sciences, Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
| |
Collapse
|
9
|
Assis GBN, de Oliveira TF, Gardner IA, Figueiredo HCP, Leal CAG. Sensitivity and specificity of real-time PCR and bacteriological culture for francisellosis in farm-raised Nile tilapia (Oreochromis niloticus L.). JOURNAL OF FISH DISEASES 2017; 40:785-795. [PMID: 27670740 DOI: 10.1111/jfd.12559] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/09/2016] [Accepted: 08/11/2016] [Indexed: 06/06/2023]
Abstract
Despite the worldwide occurrence of Francisella noatunensis subsp. orientalis (Fno) infection in farmed tilapia, sensitivity and specificity estimates of commonly used diagnostic tests have not been reported. This study aimed to estimate the sensitivity and specificity of bacteriological culture and qPCR to detect Fno infection. We tested 559 fish, sampled from four farms with different epidemiological scenarios: (i) healthy fish in a hatchery free of Fno; (ii) targeted sampling of diseased fish with suggestive external clinical signs of francisellosis during an outbreak; (iii) convenience sampling of diseased and clinically healthy fish during an outbreak; and (iv) sampling of healthy fish in a cage farm without a history of outbreaks, but with francisellosis reported in other farms in the same reservoir. The qPCR had higher median sensitivity (range, 48.8-99.5%) than culture (range, 1.6-74.4%). Culture had a substantially lower median sensitivity (1.6%) than qPCR (48.8%) to detect Fno in carrier tilapia (farm 4). Median specificity estimates for both tests were >99.2%. The qPCR is the superior test for use in surveillance and monitoring programmes for francisellosis in farmed Nile tilapia, but both tests have high sensitivity and specificity which make them fit for use in the diagnosis of Fno outbreaks.
Collapse
Affiliation(s)
- G B N Assis
- AQUAVET, Laboratory of Aquatic Animal Diseases, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - T F de Oliveira
- AQUAVET, Laboratory of Aquatic Animal Diseases, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - I A Gardner
- Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - H C P Figueiredo
- AQUAVET, Laboratory of Aquatic Animal Diseases, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
- AQUACEN - National Reference Laboratory of Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - C A G Leal
- AQUAVET, Laboratory of Aquatic Animal Diseases, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
- AQUACEN - National Reference Laboratory of Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| |
Collapse
|
10
|
Bakkemo KR, Mikkelsen H, Johansen A, Robertsen B, Seppola M. Francisella noatunensis subsp. noatunensis invades, survives and replicates in Atlantic cod cells. DISEASES OF AQUATIC ORGANISMS 2016; 121:149-159. [PMID: 27667812 DOI: 10.3354/dao03043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Systemic infection caused by the facultative intracellular bacterium Francisella noatunensis subsp. noatunensis remains a disease threat to Atlantic cod Gadus morhua L. Future prophylactics could benefit from better knowledge on how the bacterium invades, survives and establishes infection in its host cells. Here, facilitated by the use of a gentamicin protection assay, this was studied in primary monocyte/macrophage cultures and an epithelial-like cell line derived from Atlantic cod larvae (ACL cells). The results showed that F. noatunensis subsp. noatunensis is able to invade primary monocyte/macrophages, and that the actin-polymerisation inhibitor cytochalasin D blocked internalisation, demonstrating that the invasion is mediated through phagocytosis. Interferon gamma (IFNγ) treatment of cod macrophages prior to infection enhanced bacterial invasion, potentially by stimulating macrophage activation in an early step in host defence against F. noatunensis subsp. noatunensis infections. We measured a rapid drop of the initial high levels of internalised bacteria in macrophages, indicating the presence and action of a cellular immune defence mechanism before intracellular bacterial replication took place. Low levels of bacterial internalisation and replication were detected in the epithelial-like ACL cells. The capacity of F. noatunensis subsp. noatunensis to enter, survive and even replicate within an epithelial cell line may play an important role in its ability to infect live fish and transverse epithelial barriers to reach the bacterium's main target cells-the macrophage.
Collapse
|
11
|
Lewisch E, Menanteau-Ledouble S, Tichy A, El-Matbouli M. Susceptibility of common carp and sunfish to a strain of Francisella noatunensis subsp. orientalis in a challenge experiment. DISEASES OF AQUATIC ORGANISMS 2016; 121:161-166. [PMID: 27667813 DOI: 10.3354/dao03044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Francisellosis, an emerging disease in many fish species, can cause high mortality in affected populations. Here we investigated the susceptibility of common carp Cyprinus carpio and sunfish Lepomis gibbosus to Francisella noatunensis subsp. orientalis (Fno), and possible transmission of the bacteria between the 2 fish species. In a challenge experiment, 3 groups of each species were injected intraperitoneally (IP) with 3 different doses of an Fno strain no. 9449 of the Norwegian Veterinary Institute, recovered from naturally infected ornamental Malawi cichlids. Infected carp were cohabitated with sunfish and vice versa. Control groups were injected with 0.9M phosphate-buffered saline and cohabitated accordingly. Fish were sampled at different time points. Mortality of challenged sunfish was observed during the first 96 h and reached 56.1%. In the control sunfish, 4 of 16 fish (25%) died within 48 h. In carp, no mortalities or clinical signs were observed during the experiment. General clinical and patho-anatomical disease signs of affected sunfish were observed. We detected granulomas in 2 cohabitated sunfish and 1 challenged carp, but could not re-isolate Fno from these fish. Fno was successfully cultured from 6 sunfish and 3 carp specimens until 35 d post injection. PCR of spleen and kidney with 16S rDNA Francisella-like bacterium primers 180f and 485r yielded amplicons in 68.3% of challenged sunfish and only 12.2% of challenged carp. We demonstrated that sunfish were susceptible to Fno infection while the carp were not. Horizontal transmission of the agent between the 2 fish species could not be demonstrated.
Collapse
Affiliation(s)
- E Lewisch
- Clinical Division of Fish Medicine, University of Veterinary Medicine, 1210 Vienna, Austria
| | | | | | | |
Collapse
|
12
|
Dong HT, Gangnonngiw W, Phiwsaiya K, Charoensapsri W, Nguyen VV, Nilsen P, Pradeep PJ, Withyachumnarnkul B, Senapin S, Rodkhum C. Duplex PCR assay and in situ hybridization for detection of Francisella spp. and Francisella noatunensis subsp. orientalis in red tilapia. DISEASES OF AQUATIC ORGANISMS 2016; 120:39-47. [PMID: 27304869 DOI: 10.3354/dao03021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Conventional isolation and identification based on phenotypic characteristics is challenging with the highly fastidious, intracellular bacterium Francisella noatunensis subsp. orientalis (Fno). Here, we developed a duplex PCR method for simultaneous detection of the Francisella genus and Fno in one PCR reaction and an in situ hybridization method for paraffin section based diagnosis of Fno. The PCR results showed genus- and species-specific bands (1140 and 203 bp) from Fno but only one genus-specific band (1140 bp) from F. noatunensis subsp. noatunensis. Sensitivity of the duplex PCR assay revealed a detection limit of 20 to 200 fg genomic DNA (~10 to 100 genome equivalents) depending on DNA template extraction methods. The newly developed duplex PCR assay could be used to detect Fno from clinically sick fish exhibiting signs of visceral granulomas and would also be able to detect Fno infection in naturally diseased fish without symptoms of francisellosis, indicating potential application for diagnosis of field samples. The in situ hybridization assay using Fno species-specific probe revealed positive signals in multiple organs including the spleen, liver, kidney, gills and intestine of infected fish.
Collapse
Affiliation(s)
- Ha T Dong
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Identification of Francisella noatunensis in novel host species French grunt (Haemulon flavolineatum) and Caesar grunt (Haemulon carbonarium). J Zoo Wildl Med 2014; 45:727-31. [PMID: 25314854 DOI: 10.1638/2014-0059r.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Francisella noatunensis is an emerging pathogen of fish that has been isolated from several cultured species worldwide. Here presented is a case involving several hundred marine grunts that were caught near the Florida Keys for display in public aquaria. These fish were maintained in a recirculating system where they began to experience mortalities approximately two weeks post-stocking. Postmortem examination revealed disseminated systemic granulomatous disease most severely affecting spleen and kidney. Splenic and renal tissue homogenates inoculated in modified Thayer Martin agar media yielded colonies consistent with F. noatunensis 4 days post inoculation. Bacterial colonies and tissues were confirmed positive after real-time PCR amplification of the intracellular growth loci gene (iglC) specific for F. noatunensis subspecies orientalis. Consequently, multiple novel host species for this pathogen were identified, including the French grunt (Haemulon flavolineatum) and the Caesar grunt (Haemulon carbonarium).
Collapse
|
14
|
McDermott C, Palmeiro B. Selected emerging infectious diseases of ornamental fish. Vet Clin North Am Exot Anim Pract 2013; 16:261-82. [PMID: 23642862 DOI: 10.1016/j.cvex.2013.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Several emerging infectious diseases have serious implications for the trade and husbandry of ornamental fish. Although many of these diseases have been well studied and described in certain species, there are still many diseases that are not well understood. The following discussion focuses on select important emerging infectious diseases that affect ornamental fish in the aquarium and aquaculture industries: goldfish herpesvirus, koi herpesvirus, Ranavirus, Megalocytivirus, Betanodavirus, Francisella, Cryptobia iubilans, and Exophiala. When possible, the known species affected, clinical signs, diagnosis, treatment, disinfection, and prevention modalities for each disease are discussed.
Collapse
Affiliation(s)
- Colin McDermott
- National Aquarium in Baltimore, Pier 3, Baltimore, MD 21202, USA.
| | | |
Collapse
|
15
|
Soto E, Baumgartner W, Wiles J, Hawke JP. Francisella asiatica as the causative agent of piscine francisellosis in cultured tilapia (Oreochromis sp.) in the United States. J Vet Diagn Invest 2011; 23:821-5. [DOI: 10.1177/1040638711407058] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Francisella asiatica is a Gram-negative, pleomorphic, facultative intracellular, bacterial pathogen that causes acute to chronic disease in a wide variety of warm-water cultured and wild fish species. Outbreaks of francisellosis in warm water fish have been documented in Taiwan, Japan, United Kingdom, Hawaii, and Latin America (including Costa Rica) but the organism has only been reported from the United States on one occasion from hybrid striped bass in California. In 2010, the bacterium was detected from diseased tilapia by culture on cystine heart agar supplemented with hemoglobin and by utilizing an F. asiatica–specific real-time polymerase chain reaction assay. The tilapia ( Oreochromis niloticus) were cultured in an indoor, closed, recirculating aquaculture facility in the Midwest of the United States. The identity of isolates recovered from diseased fish was confirmed as F. asiatica by amplification and sequence comparison of the 16S ribosomal RNA and intracellular growth locus C ( iglC) gene. Gross and microscopic examination of affected tissues revealed the presence of marked anterior renomegaly and splenomegaly with severe granulomatous disease.
Collapse
Affiliation(s)
- Esteban Soto
- Louisiana State University, Department of Pathobiological Sciences, School of Veterinary Medicine, Baton Rouge, LA (Soto, Baumgartner, Wiles, Hawke)
- Ross University, Department of Pathobiology, School of Veterinary Medicine, St. Kitts, West Indies (Soto)
| | - Wes Baumgartner
- Louisiana State University, Department of Pathobiological Sciences, School of Veterinary Medicine, Baton Rouge, LA (Soto, Baumgartner, Wiles, Hawke)
- Ross University, Department of Pathobiology, School of Veterinary Medicine, St. Kitts, West Indies (Soto)
| | - Judy Wiles
- Louisiana State University, Department of Pathobiological Sciences, School of Veterinary Medicine, Baton Rouge, LA (Soto, Baumgartner, Wiles, Hawke)
- Ross University, Department of Pathobiology, School of Veterinary Medicine, St. Kitts, West Indies (Soto)
| | - John P. Hawke
- Louisiana State University, Department of Pathobiological Sciences, School of Veterinary Medicine, Baton Rouge, LA (Soto, Baumgartner, Wiles, Hawke)
- Ross University, Department of Pathobiology, School of Veterinary Medicine, St. Kitts, West Indies (Soto)
| |
Collapse
|
16
|
Colquhoun DJ, Duodu S. Francisella infections in farmed and wild aquatic organisms. Vet Res 2011; 42:47. [PMID: 21385413 PMCID: PMC3060124 DOI: 10.1186/1297-9716-42-47] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 03/08/2011] [Indexed: 01/08/2023] Open
Abstract
Over the last 10 years or so, infections caused by bacteria belonging to a particular branch of the genus Francisella have become increasingly recognised in farmed fish and molluscs worldwide. While the increasing incidence of diagnoses may in part be due to the development and widespread availability of molecular detection techniques, the domestication of new organisms has undoubtedly instigated emergence of clinical disease in some species. Francisellosis in fish develops in a similar fashion independent of host species and is commonly characterised by the presence of multi-organ granuloma and high morbidity, with varying associated mortality levels. A number of fish species are affected including Atlantic cod, Gadus morhua; tilapia, Oreochromis sp.; Atlantic salmon, Salmo salar; hybrid striped bass, Morone chrysops × M. saxatilis and three-lined grunt, Parapristipoma trilinineatum. The disease is highly infectious and often prevalent in affected stocks. Most, if not all strains isolated from teleost fish belong to either F. noatunensis subsp. orientalis in warm water fish species or Francisella noatunensis subsp. noatunensis in coldwater fish species. The disease is quite readily diagnosed following histological examination and identification of the aetiological bacterium by culture on cysteine rich media or PCR. The available evidence may indicate a degree of host specificity for the various Francisella strains, although this area requires further study. No effective vaccine is currently available. Investigation of the virulence mechanisms and host response shows similarity to those known from Francisella tularensis infection in mammals. However, no evidence exists for zoonotic potential amongst the fish pathogenic Francisella.
Collapse
Affiliation(s)
- Duncan J Colquhoun
- Section for Fish health, National Veterinary Institute, Postbox 750 sentrum, 0106 Oslo, Norway.
| | | |
Collapse
|
17
|
Birkbeck TH, Feist SW, Verner-Jeffreys DW. Francisella infections in fish and shellfish. JOURNAL OF FISH DISEASES 2011; 34:173-187. [PMID: 21306585 DOI: 10.1111/j.1365-2761.2010.01226.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A series of recent reports have implicated bacteria from the family Francisellaceae as the cause of disease in farmed and wild fish and shellfish species such as Atlantic cod, Gadus morhua L., tilapia, Oreochromis spp., Atlantic salmon, Salmo salar L., three-line grunt, Parapristipoma trilineatum (Thunberg), ornamental cichlid species, hybrid striped bass Morone chrysops x M. saxatilis and, recently, a shellfish species, the giant abalone, Haliotisgigantea Gmelin. The range of taxa affected will very probably rise as it is likely that there has been considerable under-reporting to date of these disease agents. In common with other Francisella species, their isolation and culture require specialized solid and liquid media containing cysteine and a source of iron. This likely restricted earlier efforts to identify them correctly as the cause of disease in aquatic animals. The most information to date relates to disease in cod, caused by F. noatunensis and tilapia, caused by F. noatunensis subsp. orientalis (also termed F. asiatica), both causing granulomatous inflammatory reactions. Mortalities in both species can be high and, as the disease can likely be transferred via live fish movements, they pose a significant threat to tilapia and cod aquaculture operations. Although the fish-pathogenic Francisella species are classified in the same genus as the human pathogens F. tularensis, causative agent of tularemia, and F. philomiragia, the risk to humans from the fish and shellfish pathogenic Francisella species is considered very low.
Collapse
Affiliation(s)
- T H Birkbeck
- University of London Marine Biological Station, Millport, Isle of Cumbrae, Scotland, UK
| | | | | |
Collapse
|
18
|
Brevik ØJ, Ottem KF, Nylund A. Multiple-locus, variable number of tandem repeat analysis (MLVA) of the fish-pathogen Francisella noatunensis. BMC Vet Res 2011; 7:5. [PMID: 21261955 PMCID: PMC3037875 DOI: 10.1186/1746-6148-7-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Accepted: 01/24/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Since Francisella noatunensis was first isolated from cultured Atlantic cod in 2004, it has emerged as a global fish pathogen causing disease in both warm and cold water species. Outbreaks of francisellosis occur in several important cultured fish species making a correct management of this disease a matter of major importance. Currently there are no vaccines or treatments available. A strain typing system for use in studies of F. noatunensis epizootics would be an important tool for disease management. However, the high genetic similarity within the Francisella spp. makes strain typing difficult, but such typing of the related human pathogen Francisella tullarensis has been performed successfully by targeting loci with higher genetic variation than the traditional signature sequences. These loci are known as Variable Numbers of Tandem Repeat (VNTR). The aim of this study is to identify possible useful VNTRs in the genome of F. noatunensis. RESULTS Seven polymorphic VNTR loci were identified in the preliminary genome sequence of F. noatunensis ssp. noatunensis GM2212 isolate. These VNTR-loci were sequenced in F. noatunensis isolates collected from Atlantic cod (Gadus morhua) from Norway (n = 21), Three-line grunt (Parapristipoma trilineatum) from Japan (n = 1), Tilapia (Oreochromis spp.) from Indonesia (n = 3) and Atlantic salmon (Salmo salar) from Chile (n = 1). The Norwegian isolates presented in this study show both nine allelic profiles and clades, and that the majority of the farmed isolates belong in two clades only, while the allelic profiles from wild cod are unique. CONCLUSIONS VNTRs can be used to separate isolates belonging to both subspecies of F. noatunensis. Low allelic diversity in F. noatunensis isolates from outbreaks in cod culture compared to isolates wild cod, indicate that transmission of these isolates may be a result of human activity. The sequence based MLVA system presented in this study should provide a good starting point for further development of a genotyping system that can be used in studies of epizootics and disease management of francisellosis.
Collapse
Affiliation(s)
- Øyvind J Brevik
- Department of Biology, University of Bergen, Post box 7800, N-5020 Bergen, Norway
| | - Karl F Ottem
- Department of Biology, University of Bergen, Post box 7800, N-5020 Bergen, Norway
| | - Are Nylund
- Department of Biology, University of Bergen, Post box 7800, N-5020 Bergen, Norway
| |
Collapse
|
19
|
Kulkarni A, Caipang CMA, Korsnes K, Brinchmann MF, Kiron V. Molecular diagnosis of francisellosis, a systemic granulomatous inflammatory disease in Atlantic cod, Gadus morhua L. Vet Res Commun 2010; 35:67-77. [PMID: 21125329 DOI: 10.1007/s11259-010-9451-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2010] [Indexed: 10/18/2022]
Abstract
A PCR-based assay for the detection of Francisella noatunensis causing francisellosis in Atlantic cod, Gadus morhua has been developed. Seven sets of primers targeting the flanking regions of the genes (rpoA, sdhA, atpA, rpoB, pgm, groEL and 16S rRNA) of the pathogen were designed. Among the primers, groEL was found to be the most suitable gene candidate for detecting the pathogen, due to its high sensitivity at various annealing temperatures and specificity in detection. The detection limit of the assay was 100 pg of bacterial DNA per milliliter or 100 fg bacterial DNA (approximately 50 genome equivalents) per PCR reaction, however, the sensitivity of the reaction decreased by 1 log dilution in the presence of 1 mg mL(-1) of serum and mucus samples as inhibitors. Nevertheless, the assay can potentially be used as a direct and non-lethal method to detect the pathogen in fish. Thus this PCR assay is a specific and sensitive molecular method to diagnose francisellosis in Atlantic cod, and will be helpful for controlling the infection through prompt detection of the disease in farms.
Collapse
Affiliation(s)
- Amod Kulkarni
- Faculty of Biosciences and Aquaculture, Bodø University College, Bodø 8049, Norway
| | | | | | | | | |
Collapse
|
20
|
Verhoeven AB, Durham-Colleran MW, Pierson T, Boswell WT, Van Hoek ML. Francisella philomiragia biofilm formation and interaction with the aquatic protist Acanthamoeba castellanii. THE BIOLOGICAL BULLETIN 2010; 219:178-188. [PMID: 20972262 DOI: 10.1086/bblv219n2p178] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The bacterium Francisella philomiragia has been isolated from environmental samples originating from around the globe. F. philomiragia-related strains cause francisellosis of both farmed and wild fish. In addition, occasional human infections caused by F. philomiragia are found in victims of near-drowning and patients with chronic granulomatous disease. We have shown that F. philomiragia forms in vitro biofilms with increased formation at 25 °C over 37 °C conditions. We found that F. philomiragia can form a biofilm in a co-culture with live Acanthamoeba castellanii, an aquatic amoeba. Interestingly, amoeba-conditioned supernatant has an inhibitory effect on production of biofilm by F. philomiragia, whereas Francisella-conditioned supernatant has no effect on growth of amoebae. We have shown that F. philomiragia can infect A. castellanii after only 5 days of co-incubation and that it infects A. castellanii more quickly than the related species F. novicida does. Our studies point to a potentially overlooked interaction between F. philomiragia and Acanthamoeba. This relationship in the marine lifecycle of F. philomiragia may support the persistence of the bacterium in waterways and its ability to infect fish. An understanding of the persistence of this organism in aquatic systems through biofilm formation and its interaction with Acanthamoeba will be important in developing prevention strategies for this pathogen.
Collapse
Affiliation(s)
- Anne B Verhoeven
- Department of Molecular and Microbiology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110, USA
| | | | | | | | | |
Collapse
|
21
|
Soto E, Wiles J, Elzer P, Macaluso K, Hawke JP. Attenuated Francisella asiatica iglC mutant induces protective immunity to francisellosis in tilapia. Vaccine 2010; 29:593-8. [PMID: 20600508 DOI: 10.1016/j.vaccine.2010.06.040] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 05/15/2010] [Accepted: 06/10/2010] [Indexed: 11/18/2022]
Abstract
Francisella asiatica is a Gram-negative, facultative intracellular bacteria that causes fish francisellosis. Fish francisellosis is a severe sub-acute to chronic granulomatous disease with high mortalities and high infectivity rates in cultured and wild fish. To date, there is no approved vaccine for this widespread emergent disease. The goal of this study was to characterize the efficacy of a defined F. asiatica mutant (ΔiglC) as a live attenuated vaccine against subsequent immersion challenge with the wild-type (WT) organism. In previous work, the ΔiglC was found to be attenuated upon intraperitoneal injection and immersion challenges. In vitro, the ΔiglC exhibited reduced growth in tilapia head-kidney derived macrophages, and was significantly attenuated (p<0.001) as demonstrated by cytopathogenic and apoptosis assays. In this study, the ΔiglC was tested to determine its ability to protect tilapia against challenge with high doses (lethal dose 80) of WT bacteria. Naïve tilapia vaccinated by immersion with a suspension of the ΔiglC and subsequently challenged with WT F. asiatica were protected (90% mean percent survival) from the lethal challenges. F. asiatica-specific antibodies produced in response to immunization with the ΔiglC were subsequently found to protect naïve tilapia against high-dose F. asiatica challenge in passive immunization experiments. Significant protection (p<0.001) was obtained when fish were passively immunized and challenged with 10(4) and 10(5)CFU/fish of WT F. asiatica; but not when challenged with 10(6)CFU/fish. This is the first report of a defined live attenuated strain providing protection against F. asiatica in fish.
Collapse
Affiliation(s)
- Esteban Soto
- Department of Pathobiological Sciences, Louisiana State University (LSU)-School of Veterinary Medicine, Skip Bertman Dr., Baton Rouge, LA 70803, USA
| | | | | | | | | |
Collapse
|
22
|
Detection of Francisella piscicida in Atlantic cod (Gadus morhua L) by the loop-mediated isothermal amplification (LAMP) reaction. Vet J 2010; 184:357-61. [DOI: 10.1016/j.tvjl.2009.03.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2008] [Revised: 03/15/2009] [Accepted: 03/19/2009] [Indexed: 11/20/2022]
|
23
|
Soto E, Hawke JP, Fernandez D, Morales JA. Francisella sp., an emerging pathogen of tilapia, Oreochromis niloticus (L.), in Costa Rica. JOURNAL OF FISH DISEASES 2009; 32:713-722. [PMID: 19515205 DOI: 10.1111/j.1365-2761.2009.01070.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Francisella sp. is an emergent bacterial pathogen that causes acute to chronic disease in warm and cold water cultured and wild fish species. During the past 3 years, the bacterium has been detected in tilapia, Oreochromis niloticus, cultured in Costa Rica. Infected fish presented non-specific clinical signs, such as erratic swimming, anorexia, anaemia, exophthalmia and high mortality. Upon macroscopic and microscopic examination, several internal organs (mainly spleen and kidney) were enlarged and contained white nodules. Histological examination revealed the presence of multifocal granulomatous lesions, with the presence of numerous small, pleomorphic, cocco-bacilli. The bacteria were isolated from infected tilapia on selective media and grown on several media with and without antibiotics. Specific PCR primers to the Francisella genus were used to confirm the preliminary diagnoses. In comparison with several bacterial 16S rRNA sequences, our isolate was found to share 99% identity with other Fransicella spp. isolated from fish, and more than 97% identity to the human pathogen Francisella tularensis. Koch's postulates were fulfilled after experimental intraperitoneal and gill exposure challenges.
Collapse
Affiliation(s)
- E Soto
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Skip Bertman Drive, Baton Rouge, LA 70803, USA
| | | | | | | |
Collapse
|
24
|
Ottem KF, Nylund A, Isaksen TE, Karlsbakk E, Bergh Ø. Occurrence of Francisella piscicida in farmed and wild Atlantic cod, Gadus morhua L., in Norway. JOURNAL OF FISH DISEASES 2008; 31:525-534. [PMID: 18482383 DOI: 10.1111/j.1365-2761.2008.00930.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Francisellosis, caused by the bacterium Francisella piscicida, has become one of the most serious diseases in Atlantic cod production in Norway. The major aim of this study was to determine the distribution of F. piscicida in farmed and wild fish in areas with cod farming along the Norwegian coast, and its occurrence in cod from areas without cod farming. Two real-time PCR assays, targeting the 16S rRNA gene and the FopA gene of F. piscicida, were developed since sensitive and specific diagnostic tools are required for detecting asymptomatic carriers of the bacterium. A total of 422 wild cod from 13 sampling areas and 955 farmed cod from 10 areas along the coast of Norway were examined. Using the real-time polymerase chain reaction (PCR) assays, F. piscicida was detected in wild populations of cod from all counties examined south of Sogn og Fjordane in southern Norway (overall prevalence 13%, n = 221). Wild cod north of Sogn og Fjordane were negative for the bacterium (n = 201). Farmed cod from most parts of Norway were F. piscicida positive. The apparent absence of the bacterium in wild populations of cod in the northern parts of Norway and its widespread occurrence in wild cod from southern parts of Norway is believed to relate to differences in seawater temperatures.
Collapse
Affiliation(s)
- K F Ottem
- Department of Biology, University of Bergen, Bergen, Norway.
| | | | | | | | | |
Collapse
|