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Heckman TI, Yazdi Z, Older CE, Griffin MJ, Waldbieser GC, Chow AM, Medina Silva I, Anenson KM, García JC, LaFrentz BR, Slavic D, Toohey-Kurth KL, Yant P, Fritz HM, Henderson EE, McDowall R, Cai H, Adkison M, Soto E. Redefining piscine lactococcosis. Appl Environ Microbiol 2024; 90:e0234923. [PMID: 38597602 PMCID: PMC11107168 DOI: 10.1128/aem.02349-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Accepted: 03/10/2024] [Indexed: 04/11/2024] Open
Abstract
Piscine lactococcosis is a significant threat to cultured and wild fish populations worldwide. The disease typically presents as a per-acute to acute hemorrhagic septicemia causing high morbidity and mortality, recalcitrant to antimicrobial treatment or management interventions. Historically, the disease was attributed to the gram-positive pathogen Lactococcus garvieae. However, recent work has revealed three distinct lactococcosis-causing bacteria (LCB)-L. garvieae, L. petauri, and L. formosensis-which are phenotypically and genetically similar, leading to widespread misidentification. An update on our understanding of lactococcosis and improved methods for identification are urgently needed. To this end, we used representative isolates from each of the three LCB species to compare currently available and recently developed molecular and phenotypic typing assays, including whole-genome sequencing (WGS), end-point and quantitative PCR (qPCR) assays, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), API 20 Strep and Biolog systems, fatty acid methyl ester analysis (FAME), and Sensititre antimicrobial profiling. Apart from WGS, sequencing of the gyrB gene was the only method capable of consistent and accurate identification to the species and strain level. A qPCR assay based on a putative glycosyltransferase gene was also able to distinguish L. petauri from L. garvieae/formosensis. Biochemical tests and MALDI-TOF MS showed some species-specific patterns in sugar and fatty acid metabolism or protein profiles but should be complemented by additional analyses. The LCB demonstrated overlap in host and geographic range, but there were relevant differences in host specificity, regional prevalence, and antimicrobial susceptibility impacting disease treatment and prevention. IMPORTANCE Lactococcosis affects a broad range of host species, including fish from cold, temperate, and warm freshwater or marine environments, as well as several terrestrial animals, including humans. As such, lactococcosis is a disease of concern for animal and ecosystem health. The disease is endemic in European and Asian aquaculture but is rapidly encroaching on ecologically and economically important fish populations across the Americas. Piscine lactococcosis is difficult to manage, with issues of vaccine escape, ineffective antimicrobial treatment, and the development of carrier fish or biofilms leading to recurrent outbreaks. Our understanding of the disease is also widely outdated. The accepted etiologic agent of lactococcosis is Lactococcus garvieae. However, historical misidentification has masked contributions from two additional species, L. petauri and L. formosensis, which are indistinguishable from L. garvieae by common diagnostic methods. This work is the first comprehensive characterization of all three agents and provides direct recommendations for species-specific diagnosis and management.
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Affiliation(s)
- Taylor I. Heckman
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Zeinab Yazdi
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Caitlin E. Older
- USDA-ARS, Warmwater Aquaculture Research Unit, Stoneville, Mississippi, USA
| | - Matt J. Griffin
- College of Veterinary Medicine, Mississippi State University, Stoneville, Mississippi, USA
| | | | - Alexander M. Chow
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Isabella Medina Silva
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Kelsey M. Anenson
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Julio C. García
- USDA-ARS, Aquatic Animal Health Research Unit, Auburn, Alabama, USA
| | | | - Durda Slavic
- Animal Health Laboratory, University of Guelph, Ontario, Canada
| | - Kathy L. Toohey-Kurth
- California Animal Health and Food Safety Laboratory, University of California, Davis, California, USA
| | - Paula Yant
- California Animal Health and Food Safety Laboratory, University of California, Davis, California, USA
| | - Heather M. Fritz
- California Animal Health and Food Safety Laboratory, University of California, Davis, California, USA
| | - Eileen E. Henderson
- California Animal Health and Food Safety Laboratory, University of California, Davis, California, USA
| | | | - Hugh Cai
- Animal Health Laboratory, University of Guelph, Ontario, Canada
| | - Mark Adkison
- California Department of Fish and Wildlife, Rancho Cordova, California, USA
| | - Esteban Soto
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
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Stoppani N, Colussi S, Pastorino P, Prearo M, Sciuto S, Altinok I, Öztürk RÇ, Ture M, Vela AI, Blanco MDM, Kotzamanidis C, Bitchava K, Malousi A, Fariano L, Volpatti D, Acutis PL, Fernández-Garayzábal JF. 16S-23S rRNA Internal Transcribed Spacer Region ( ITS) Sequencing: A Potential Molecular Diagnostic Tool for Differentiating Lactococcus garvieae and Lactococcus petauri. Microorganisms 2023; 11:1320. [PMID: 37317294 DOI: 10.3390/microorganisms11051320] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 05/12/2023] [Accepted: 05/15/2023] [Indexed: 06/16/2023] Open
Abstract
Lactococcus garvieae is the etiological agent of lactococcosis, a clinically and economically significant infectious disease affecting farmed rainbow trout. L. garvieae had been considered the only cause of lactococcosis for a long time; however, L. petauri, another species of the genus Lactococcus, has lately been linked to the same disease. The genomes and biochemical profiles of L. petauri and L. garvieae have a high degree of similarity. Traditional diagnostic tests currently available cannot distinguish between these two species. The aim of this study was to use the transcribed spacer (ITS) region between 16S rRNA and 23S rRNA as a potential useful molecular target to differentiate L. garvieae from L. petauri, saving time and money compared to genomics methods currently used as diagnostic tools for accurate discrimination between these two species. The ITS region of 82 strains was amplified and sequenced. The amplified fragments varied in size from 500 to 550 bp. Based on the sequence, seven SNPs were identified that separate L. garvieae from L. petauri. The 16S-23S rRNA ITS region has enough resolution to distinguish between closely related L. garvieae and L. petauri and it can be used as a diagnostic marker to quickly identify the pathogens in a lactococcosis outbreak.
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Affiliation(s)
- Nadia Stoppani
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, 10154 Turin, Italy
| | - Silvia Colussi
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, 10154 Turin, Italy
| | - Paolo Pastorino
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, 10154 Turin, Italy
| | - Marino Prearo
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, 10154 Turin, Italy
| | - Simona Sciuto
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, 10154 Turin, Italy
| | - Ilhan Altinok
- Faculty of Marine Sciences, Karadeniz Technical University, Sürmene, 61530 Trabzon, Turkey
| | - Rafet Çağrı Öztürk
- Faculty of Marine Sciences, Karadeniz Technical University, Sürmene, 61530 Trabzon, Turkey
| | - Mustafa Ture
- Central Fisheries Research Institute (SUMAE), 61250 Trabzon, Turkey
| | - Ana Isabel Vela
- VISAVET and Department of Animal Health, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Maria Del Mar Blanco
- VISAVET and Department of Animal Health, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | | | - Konstantina Bitchava
- School of Animal Biosciences, Agricultural University of Athens, 11855 Athens, Greece
| | - Andigoni Malousi
- Laboratory of Biological Chemistry, Medical School, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Lucio Fariano
- Azienda Agricola Canali Cavour, 12044 Centallo, Italy
| | - Donatella Volpatti
- Department of Agricultural, Food, Environmental and Animal Sciences (DI4A), University of Udine, 33100 Udine, Italy
| | - Pier Luigi Acutis
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, 10154 Turin, Italy
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Swaminathan TR, Nithyanantham SR, Narendrakumar L, Dharmaratnam A, Sood N, Pradhan PK, Sulumane Ramachandra KS, Lal KK. Co-infection of Lactococcus garvieae and Tilapia lake virus (TiLV) in Nile tilapia Oreochromis niloticus cultured in India. DISEASES OF AQUATIC ORGANISMS 2021; 147:127-140. [PMID: 34913441 DOI: 10.3354/dao03638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Tilapia lake virus (TiLV) and Lactococcus garvieae are 2 major pathogens of cultured Nile tilapia Oreochromis niloticus. In June-July 2018, a disease outbreak was reported in Nile tilapia cultured in brackish water floating cages in Kerala, India. Affected fish died gradually, and cumulative mortality reached ~75% within 1 mo. In the present study, TiLV and L. garvieae were isolated from the infected fish and confirmed. Nucleotide analysis of the partial sequence of segment 3 revealed that the present TiLV isolate showed 100% similarity with TiLV MF574205 and 97.65% similarity with TiLV KU552135 isolated in Israel. The partial 16S rDNA nucleotide sequence of L. garvieae shared 99% similarity with the 16S rDNA nucleotide sequence of L. garvieae isolated from Nile tilapia in Brazil. Eight virulence genes (hly1, hly2, hly3, NADH oxidase, adhPav, LPxTG-1, LPxTG-4, adhC1) were amplified in the present isolate. In the experimental challenge study, the onset of mortality started earlier in fish co-infected with TiLV and L. garvieae (3 d post-infection [dpi]) compared to other groups. Cumulative mortality (90% at 12 dpi) was significantly higher in the co-infected group than in fish infected with TiLV (60% at 12 dpi) and L. garvieae (40% at 12 dpi) alone. This study reveals that synergistic co-infection with TiLV and other bacteria may increase mortality in disease outbreaks. To the best of our knowledge, this is the first reported co-infection of L. garvieae with TiLV associated with mass mortality in Nile tilapia in India.
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Affiliation(s)
- Thangaraj Raja Swaminathan
- Peninsular and Marine Fish Genetic Resources Centre, ICAR National Bureau of Fish Genetic Resources, CMFRI Campus, Kochi, Kerala 682 018, India
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Shahin K, Veek T, Heckman TI, Littman E, Mukkatira K, Adkison M, Welch TJ, Imai DM, Pastenkos G, Camus A, Soto E. Isolation and characterization of Lactococcus garvieae from rainbow trout, Onchorhyncus mykiss, from California, USA. Transbound Emerg Dis 2021; 69:2326-2343. [PMID: 34328271 DOI: 10.1111/tbed.14250] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/17/2021] [Indexed: 11/26/2022]
Abstract
Lactococcus garvieae is an emergent bacterial pathogen of salmonid fish in North America that causes acute infections particularly at water temperatures above 15°C. During 2020, L. garvieae was detected in rainbow trout, Onchorhyncus mykiss, cultured in Southern California and the Eastern Sierras. Infected fish exhibited high mortalities and nonspecific clinical signs of lethargy, erratic swimming, dark skin pigmentation, and exophthalmia. Macroscopic changes included external and internal hemorrhages, mainly in the eyes, liver, coelomic fat, intestine, and brain. Histological examination revealed splenitis, branchitis, panophthalmitis, hepatitis, enteritis, and coelomitis, with variable degrees of tissue damage among evaluated fish. Pure colonies of L. garvieae were isolated from infected trout and specific PCR primers for L. garvieae confirmed the preliminary diagnosis. Multilocus sequence analysis showed that the strains recovered from diseased trout represent a novel genetic group. Isolates were able to form biofilms within 24 h that increased their resistance to disinfection by hydrogen peroxide. Laboratory challenge methods for inducing lactococcosis in steelhead trout, O. mykiss, were evaluated by intracoelomic injection with serial dilutions of L. garvieae. The median lethal dose 21 days post challenge was ∼20 colony-forming units/fish. Experimentally infected trout presented similar clinical signs, gross changes, and microscopic lesions as those with natural disease, fulfilling Koch's postulates and demonstrating the high virulence of the recovered strains.
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Affiliation(s)
- Khalid Shahin
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA.,Aquatic Animal Diseases Laboratory, Aquaculture Department, National Institute of Oceanography and Fisheries, Suez, Egypt
| | - Tresa Veek
- California Department of Fish and Wildlife, Rancho Cordova, California, USA
| | - Taylor I Heckman
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Eric Littman
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | | | - Mark Adkison
- California Department of Fish and Wildlife, Rancho Cordova, California, USA
| | - Timothy J Welch
- National Center for Cool and Coldwater Aquaculture, Kearneysville, West Virginia, USA
| | - Denise M Imai
- Comparative Pathology Laboratory, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Gabrielle Pastenkos
- Comparative Pathology Laboratory, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Alvin Camus
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Esteban Soto
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
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Kotzamanidis C, Malousi A, Bitchava K, Vafeas G, Chatzidimitriou D, Skoura L, Papadimitriou E, Chatzopoulou F, Zdragas A. First Report of Isolation and Genome Sequence of L. petauri Strain from a Rainbow Trout Lactococcosis Outbreak. Curr Microbiol 2020; 77:1089-1096. [PMID: 32008079 DOI: 10.1007/s00284-020-01905-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 01/27/2020] [Indexed: 12/13/2022]
Abstract
Lactococcosis is a disease encountered in a wide variety of fish species causing mortalities and having great economic impact on farmed fish. In this study, we report for the first time the isolation of a strain of the recently described novel species Lactococcus petauri, from rainbow trout suffering from lactococcosis. The aim of this study was to determine the complete genome sequence of L. petauri strain LG_SAV_20 and to characterize its antimicrobial resistance and virulence. The genome of L. petauri LG_SAV_20 consists of 2,078,949 base pair (bp) with a GC content of 38.05%, 1950 predicted coding sequence (CDS), and 60 RNAs (51 tRNAs, 3 ncRNAs, and 6 rRNAs). Phylogenetic analysis revealed that L. petauri LG_SAV_20 shares most of its genome with L. garvieae strains isolated from rainbow trout. Detection of genes associated with antimicrobial resistance indicated that the isolate possesses the multidrug transporter mdt(A) gene, while using comparative analysis we identified several genes that might be related to bacterial pathogenesis. This genomic information provides new insights into the role of this novel species as an etiological agent of lactococcosis.
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Affiliation(s)
- Charalampos Kotzamanidis
- Hellenic Agricultural Organisation-DEMETER, Veterinary Research Institute of Thessaloniki, Campus of Thermi, 570 01, Thermi, Greece.
| | - Andigoni Malousi
- School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Konstantina Bitchava
- Hellenic Agricultural Organisation-DEMETER, Veterinary Research Institute of Thessaloniki, Campus of Thermi, 570 01, Thermi, Greece
| | - George Vafeas
- Hellenic Agricultural Organisation-DEMETER, Veterinary Research Institute of Thessaloniki, Campus of Thermi, 570 01, Thermi, Greece
| | | | - Lemonia Skoura
- Department of Microbiology, AHEPA University General Hospital of Thessaloniki, S. Kiriakidi Str. 1, 546 36, Thessaloniki, Greece
| | | | - Fani Chatzopoulou
- School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Antonios Zdragas
- Hellenic Agricultural Organisation-DEMETER, Veterinary Research Institute of Thessaloniki, Campus of Thermi, 570 01, Thermi, Greece
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Damnjanovic D, Harvey M, Bridge WJ. Application of colony BOXA2R-PCR for the differentiation and identification of lactic acid COCCI. Food Microbiol 2019; 82:277-286. [PMID: 31027784 DOI: 10.1016/j.fm.2019.02.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 02/12/2019] [Accepted: 02/22/2019] [Indexed: 11/15/2022]
Abstract
Repetitive-PCR (rep-PCR) is a well-established genetic method for bacterial strain fingerprinting that is used mostly with REP, ERIC, (GTG)5, BOXA1R and occasionally BOXA2R repetitive primers. In this study, it was demonstrated that BOXA2R-PCR could effectively discriminate between Lactococcus lactis, Leuconostoc mesenteroides and Streptococcus thermophilus; differentiate Lactococcus lactis strains and subspeciate them into lactis and cremoris in a single reaction; generate unique strain fingerprints of various lactic acid bacteria (LAB species) commonly isolated from fermented dairy products, including occasional spoilage bacteria and yeasts. Furthermore, using direct colony PCR a reproducible and rapid method was developed for the differentiation and identification of lactic acid cocci. The simplicity and speed of this microbial identification method has potential practical value for dairy microbiologists, which was demonstrated through a microbiota investigation of select Australian retail dairy products.
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Affiliation(s)
- Dragica Damnjanovic
- School of Biotechnology and Biomolecular Sciences (BABS), Faculty of Science, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Melissa Harvey
- School of Biotechnology and Biomolecular Sciences (BABS), Faculty of Science, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Wallace John Bridge
- School of Biotechnology and Biomolecular Sciences (BABS), Faculty of Science, University of New South Wales, Sydney, NSW, 2052, Australia.
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Zhang Z, Xing R, Lv Z, Shao Y, Zhang W, Zhao X, Li C. Analysis of gut microbiota revealed Lactococcus garviaeae could be an indicative of skin ulceration syndrome in farmed sea cucumber Apostichopus japonicus. FISH & SHELLFISH IMMUNOLOGY 2018; 80:148-154. [PMID: 29864588 DOI: 10.1016/j.fsi.2018.06.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/21/2018] [Accepted: 06/01/2018] [Indexed: 06/08/2023]
Abstract
Accumulative evidence has supported the pivotal roles of gut microbiota in shaping host health in a wide range of animals. However, the relationship between gut microbiota and sea cucumber disease is poorly understood. Using the Illumina sequencing of bacterial 16 S rRNA gene, we investigated the divergence of gut bacterial communities between healthy and skin ulceration syndrome (SUS) diseased Apostichopus japonicus. The results showed that bacterial phylotypes in both groups were closely related at phylum level with predominant component of Proteobacteria (>90%). However, Firmicutes and Verrucomicrobia displayed opposite trends in two groups with higher abundance of Firmicutes and lower of Verrucomicrobia in diseased group. Further KEGG enrichment revealed that bacterial-mediated infectious diseases and signal transduction pathways were significantly induced in the SUS group. We also identified one OTU of Lactococcus garvieae from Firmicutes exhibited significantly different abundances in diseased sea cucumber as compared to healthy subjects. The relative abundance of the species was 27.67% ± 10.52% in diseased group compared to 2.78% ± 2.59% in healthy sea cucumber. Three virulence genes of hlyⅢ, fbp and pva encoded by L. garvieae were investigated by qPCR, and were found to be significantly induced (P < 0.05) in diseased sea cucumbers as compared to healthy ones. All our results supported that L. garvieae might be a potential pathogen for SUS outbreak and could be served as a bio-indicator for this disease monitoring.
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Affiliation(s)
- Zhen Zhang
- School of Marine Sciences, Ningbo University, Ningbo, 315211, PR China
| | - Ronglian Xing
- College of Life Sciences, Yantai University, Yantai, 264005, PR China
| | - Zhimeng Lv
- School of Marine Sciences, Ningbo University, Ningbo, 315211, PR China
| | - Yina Shao
- School of Marine Sciences, Ningbo University, Ningbo, 315211, PR China
| | - Weiwei Zhang
- School of Marine Sciences, Ningbo University, Ningbo, 315211, PR China
| | - Xuelin Zhao
- School of Marine Sciences, Ningbo University, Ningbo, 315211, PR China
| | - Chenghua Li
- School of Marine Sciences, Ningbo University, Ningbo, 315211, PR China.
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Meyburgh CM, Bragg RR, Boucher CE. Lactococcus garvieae: an emerging bacterial pathogen of fish. DISEASES OF AQUATIC ORGANISMS 2017; 123:67-79. [PMID: 28177294 DOI: 10.3354/dao03083] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Lactococcus garvieae is the causative agent of lactococcosis, a hyperacute, haemorrhagic septicaemia of fish. This bacterium is also considered an emerging zoonotic pathogen, as reports of human infection are increasing. Significant economic loss in aquaculture is suffered as a result of lactococcosis, as numerous freshwater and marine species of commercial interest are affected. Development of antibiotic resistance in L. garvieae to several chemotherapeutic agents complicates and restricts treatment options. Effective, sustainable treatment and prevention options are thus needed, but progress is impeded by the lack of knowledge concerning several aspects of the disease and the pathogen. This review aims to present the latest research on L. garvieae, with specific focus on pathogenesis, virulence factors, risks associated with chemotherapeutic administration and possible control options.
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Affiliation(s)
- C M Meyburgh
- Department of Microbial, Biochemical & Food Biotechnology, University of the Free State, Bloemfontein, South Africa
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Fichi G, Cardeti G, Cersini A, Mancusi C, Guarducci M, Di Guardo G, Terracciano G. Bacterial and viral pathogens detected in sea turtles stranded along the coast of Tuscany, Italy. Vet Microbiol 2016; 185:56-61. [DOI: 10.1016/j.vetmic.2016.02.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 01/30/2016] [Accepted: 02/08/2016] [Indexed: 11/26/2022]
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Thanh HD, Park HK, Kim W, Shin HS. Development of a 16S-23S rRNA intergenic spacer-based quantitative PCR assay for improved detection and enumeration of Lactococcus garvieae. FEMS Microbiol Lett 2012; 339:10-6. [PMID: 23106479 DOI: 10.1111/1574-6968.12038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 10/23/2012] [Accepted: 10/23/2012] [Indexed: 11/29/2022] Open
Abstract
Lactococcus garvieae is an important foodborne pathogen causing lactococcosis associated with hemorrhagic septicemia in fish worldwide. A real-time quantitative polymerase chain reaction (qPCR) protocol targeting the 16S-23S rRNA intergenic spacer (ITS) region was developed for the detection and enum-eration of L. garvieae. The specificity was evaluated using genomic DNAs extracted from 66 cocci strains. Fourteen L. garvieae strains tested were positive, whereas 52 other strains including Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. hordniae and Lactococcus lactis ssp. cremoris did not show a specific signal. The minimal limit of detection was 2.63 fg of purified genomic DNA, equivalent to 1 genome of L. garvieae. The optimized protocol was applied for the survey of L. garvieae in naturally contaminated fish samples. Our results suggest that the qPCR protocol using ITS is a sensitive and efficient tool for the rapid detection and enumeration of L. garvieae in fish and fish-containing foods.
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Affiliation(s)
- Hien Dang Thanh
- Department of Microbiology, Chung-Ang University College of Medicine, Seoul, Korea
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