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Pulkkinen K, Taskinen J. Nutrient enrichment increases virulence in an opportunistic environmental pathogen, with greater effect at low bacterial doses. FEMS Microbiol Ecol 2024; 100:fiae013. [PMID: 38305097 PMCID: PMC10959552 DOI: 10.1093/femsec/fiae013] [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: 08/25/2023] [Revised: 01/29/2024] [Accepted: 01/31/2024] [Indexed: 02/03/2024] Open
Abstract
Eutrophication of aquatic ecosystems is associated with an increased risk of pathogen infection via increased pathogen growth and host exposure via increased pathogen doses. Here, we studied the effect of nutrients on the virulence of an opportunistic bacterial pathogen of fish, Flavobacterium columnare, in challenge experiments with rainbow trout fingerlings. We hypothesized that removing all nutrients by washing the bacteria would reduce virulence as compared to unwashed bacteria, but adding nutrients to the tank water would increase the virulence of the bacterium. Nutrient addition and increase in bacterial dose increased virulence for both unwashed and washed bacteria. For unwashed bacteria, the addition of nutrients reduced the survival probability of fish challenged with low bacterial doses more than for fish challenged with higher bacterial doses, suggesting activation of bacterial virulence factors. Washing and centrifugation reduced viable bacterial counts, and the addition of washed bacteria alone did not lead to fish mortality. However, a small addition of nutrient medium, 0.05% of the total water volume, added separately to the fish container, restored the virulence of the washed bacteria. Our results show that human-induced eutrophication could trigger epidemics of aquatic pathogens at the limits of their survival and affect their ecology and evolution by altering the dynamics between strains that differ in their growth characteristics.
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Affiliation(s)
- Katja Pulkkinen
- Department of Biological and Environmental Science, P.O. Box 35 (Survontie 9), University of Jyväskylä, Jyväskylä, Finland
| | - Jouni Taskinen
- Department of Biological and Environmental Science, P.O. Box 35 (Survontie 9), University of Jyväskylä, Jyväskylä, Finland
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2
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Carril G, Winther-Larsen HC, Løvoll M, Sørum H. Cohabitation of Piscirickettsia salmonis genogroups (LF-89 and EM-90): synergistic effect on growth dynamics. Front Cell Infect Microbiol 2023; 13:1253577. [PMID: 37953796 PMCID: PMC10634514 DOI: 10.3389/fcimb.2023.1253577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 09/25/2023] [Indexed: 11/14/2023] Open
Abstract
Piscirickettsia salmonis, the biological agent of Salmonid Rickettsial Septicemia (SRS), is a facultative intracellular bacterium that can be divided into two genogroups (LF-89 and EM-90) with different virulence levels and patterns. Studies have found co-infection of these genogroups in salmonid farms in Chile, but it is essential to assess whether this interaction within the host is related to virulence and changes in pathogen dynamics. In this study, we studied four isolates from EM-90 and one LF-89 isolate chosen based on their genomic differences. The aim was to evaluate how co-cultivation affects bacterial growth performance and virulence factor expression in Atlantic salmon (Salmo salar) in vitro and in vivo. In vitro results using FN2 medium, showed a similar growth curve between co-cultures of LF-89 and EM-90 compared to EM-90 monocultures. This was explained by the higher ratio of EM-90 to LF-89 in all co-cultures. When evaluating the expression of virulence factors, it was discovered that the luxR gene was expressed only in EM-90-like isolates and that there were significant differences between mono- and co-cultures for flaA and cheA, suggesting a response to cohabitation. Moreover, during in vivo co-cultures, transcriptomic analysis revealed an upregulation of transposases, flagellum-related genes (fliI and flgK), transporters, and permeases that could unveil novel virulence effectors used in the early infection process of P. salmonis. Thus, our work has shown that cohabitation of P. salmonis genogroups can modulate their behavior and virulence effector expression. These data can contribute to new strategies and approaches to improve the current health treatments against this salmonid pathogen.
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Affiliation(s)
- Gabriela Carril
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Hanne C. Winther-Larsen
- Department of Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | | | - Henning Sørum
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
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3
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Williams M, Shamsi S, Williams T, Hernandez-Jover M. Bacteria of Zoonotic Interest Identified on Edible Freshwater Fish Imported to Australia. Foods 2023; 12:foods12061288. [PMID: 36981215 PMCID: PMC10048124 DOI: 10.3390/foods12061288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/06/2023] [Accepted: 03/10/2023] [Indexed: 03/22/2023] Open
Abstract
Previous research has shown that freshwater edible fish imported into Australia are not compliant with Australian importation guidelines and as a result may be high risk for bacterial contamination. In the present study, the outer surface of imported freshwater fish were swabbed, cultured, confirmatory tests performed and antimicrobial patterns investigated. Channidae fish (Sp. A/n = 66) were contaminated with zoonotic Salmonella sp./Staphylococcus aureus (n = 1/66) and other bacteria implicated in cases of opportunistic human infection, these being Pseudomonas sp. (including P. mendocina and P. pseudoalcaligenes (n = 34/66)); Micrococcus sp. (n = 32/66); Comamonas testosteroni (n = 27/66) and Rhizobium radiobacter (n = 3/66). Pangasiidae fish (Species B/n = 47) were contaminated with zoonotic Vibrio fluvialis (n = 10/47); Salmonella sp. (n = 6/47) and environmental bacteria Micrococcus sp. (n = 3/47). One sample was resistant to all antimicrobials tested and is considered to be Methicillin Resistant S. aureus. Mud, natural diet, or vegetation identified in Sp. A fish/or packaging were significantly associated with the presence of Pseudomonas spp. The study also showed that visibly clean fish (Sp. B) may harbour zoonotic bacteria and that certain types of bacteria are common to fish groups, preparations, and contaminants. Further investigations are required to support the development of appropriate food safety recommendations in Australia.
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Affiliation(s)
- Michelle Williams
- School of Agricultural, Environmental and Veterinary Sciences & Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, NSW 2650, Australia
- Correspondence: or
| | - Shokoofeh Shamsi
- School of Agricultural, Environmental and Veterinary Sciences & Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, NSW 2650, Australia
| | - Thomas Williams
- Institute for Future Farming Systems, CQUniversity, Rockhampton, QLD 4701, Australia
| | - Marta Hernandez-Jover
- School of Agricultural, Environmental and Veterinary Sciences & Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, NSW 2650, Australia
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4
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Xu H, Zeng YH, Yin WL, Lu HB, Gong XX, Zhang N, Zhang X, Long H, Ren W, Cai XN, Huang AY, Xie ZY. Prevalence of Bacterial Coinfections with Vibrio harveyi in the Industrialized Flow-through Aquaculture Systems in Hainan Province: A Neglected High-Risk Lethal Causative Agent to Hybrid Grouper. Int J Mol Sci 2022; 23:ijms231911628. [PMID: 36232925 PMCID: PMC9570405 DOI: 10.3390/ijms231911628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/08/2022] [Accepted: 09/22/2022] [Indexed: 11/16/2022] Open
Abstract
Vibrio harveyi is one of the most serious bacterial pathogens to aquatic animals worldwide. Evidence is mounting that coinfections caused by multiple pathogens are common in nature and can alter the severity of diseases in marine animals. However, bacterial coinfections involving V. harveyi have received little attention in mariculture. In this study, the results of pathogen isolation indicated that bacterial coinfection was a common and overlooked risk for hybrid groupers (♀ Epinephelus polyphekadion × ♂ E. fuscoguttatus) reared in an industrialized flow-through pattern in Hainan Province. The artificial infection in hybrid groupers revealed that coinfections with V. harveyi strain GDH11385 (a serious lethal causative agent to groupers) and other isolated pathogens resulted in higher mortality (46.67%) than infection with strain GDH11385 alone (33.33%), whereas no mortality was observed in single infection with other pathogens. Furthermore, the intestine, liver and spleen of hybrid groupers are target organs for bacterial coinfections involving V. harveyi. Based on the infection patterns found in this study, we propose that V. harveyi may have a specific spatiotemporal expression pattern of virulence genes when infecting the host. Taken together, bacterial coinfection with V. harveyi is a neglected high-risk lethal causative agent to hybrid groupers in the industrialized flow-through aquaculture systems in Hainan Province.
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Affiliation(s)
- He Xu
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
- Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou 570228, China
- College of Marine Sciences, Hainan University, Haikou 570228, China
| | - Yan-Hua Zeng
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
- Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou 570228, China
| | - Wen-Liang Yin
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
- Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou 570228, China
- College of Marine Sciences, Hainan University, Haikou 570228, China
| | - Hong-Bin Lu
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
- Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou 570228, China
- College of Marine Sciences, Hainan University, Haikou 570228, China
| | - Xiao-Xiao Gong
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
- Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou 570228, China
- College of Marine Sciences, Hainan University, Haikou 570228, China
| | - Na Zhang
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
- Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou 570228, China
- College of Marine Sciences, Hainan University, Haikou 570228, China
| | - Xiang Zhang
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
- Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou 570228, China
- College of Marine Sciences, Hainan University, Haikou 570228, China
- Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou 570228, China
| | - Hao Long
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
- Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou 570228, China
| | - Wei Ren
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
- Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou 570228, China
- College of Marine Sciences, Hainan University, Haikou 570228, China
- Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou 570228, China
| | - Xiao-Ni Cai
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
- Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou 570228, China
- College of Marine Sciences, Hainan University, Haikou 570228, China
- Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou 570228, China
| | - Ai-You Huang
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
- Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou 570228, China
- College of Marine Sciences, Hainan University, Haikou 570228, China
- Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou 570228, China
| | - Zhen-Yu Xie
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
- Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou 570228, China
- College of Marine Sciences, Hainan University, Haikou 570228, China
- Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou 570228, China
- Correspondence: ; Tel.: +86-136-4866-9016
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Apex Predators Enhance Environmental Adaptation but Reduce Community Stability of Bacterioplankton in Crustacean Aquaculture Ponds. Int J Mol Sci 2022; 23:ijms231810785. [PMID: 36142697 PMCID: PMC9506085 DOI: 10.3390/ijms231810785] [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: 09/01/2022] [Accepted: 09/13/2022] [Indexed: 11/25/2022] Open
Abstract
Aquaculture environments harbor complex bacterial communities that are critical for the growth and health of culture species. Apex predators are frequently added to aquaculture ponds to improve ecosystem stability. However, limited research has explored the effects of apex predators on the composition and function of bacterioplankton communities, as well as the underlying mechanisms of community assembly. Using 16S ribosomal RNA (rRNA) high-throughput sequencing, we investigated bacterioplankton communities of crustacean aquaculture ponds with and without apex predators (mandarin fish, Siniperca chuatsi) throughout the culture process. In addition to investigating differences in bacterioplankton communities, we also explored variations in environmental adaptation, functional redundancy, and community stability. Significant differences were observed in bacterioplankton composition among different cultural stages; there was an increase in Bacteriobota and fermentation-related bacteria, but a decrease in Firmicutes and pathogens in the middle stages of aquaculture. Apex predators increased the abundance of organic matter degradation bacteria and decreased pathogens. Bacterioplankton communities under apex predator disturbances had a wider environmental breadth, indicating broader environmental adaptation. Moreover, functional prediction and network analyses revealed that communities under apex predator disturbances were less functionally redundant and unstable. Based on the null model, stochastic processes drove community assembly during aquaculture, whereas apex predators elevated the contribution of deterministic processes. Greater changes in nitrate in culture ponds caused by apex predator disturbances were decisive in controlling the balance between stochasticity and determinism in community assembly. Our study provided insight into the mechanisms underlying bacterioplankton community assembly in aquaculture systems in response to apex predator disturbances.
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6
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Pulkkinen K, Ketola T, Laakso J, Mappes J, Sundberg L. Rich resource environment of fish farms facilitates phenotypic variation and virulence in an opportunistic fish pathogen. Evol Appl 2022; 15:417-428. [PMID: 35386393 PMCID: PMC8965373 DOI: 10.1111/eva.13355] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 01/27/2022] [Accepted: 02/01/2022] [Indexed: 12/05/2022] Open
Abstract
Phenotypic variation is suggested to facilitate the persistence of environmentally growing pathogens under environmental change. Here, we hypothesized that the intensive farming environment induces higher phenotypic variation in microbial pathogens than natural environment, because of high stochasticity for growth and stronger survival selection compared to the natural environment. We tested the hypothesis with an opportunistic fish pathogen Flavobacterium columnare isolated either from fish farms or from natural waters. We measured growth parameters of two morphotypes from all isolates in different resource concentrations and two temperatures relevant for the occurrence of disease epidemics at farms and tested their virulence using a zebrafish (Danio rerio) infection model. According to our hypothesis, isolates originating from the fish farms had higher phenotypic variation in growth between the morphotypes than the isolates from natural waters. The difference was more pronounced in higher resource concentrations and the higher temperature, suggesting that phenotypic variation is driven by the exploitation of increased outside‐host resources at farms. Phenotypic variation of virulence was not observed based on isolate origin but only based on morphotype. However, when in contact with the larger fish, the less virulent morphotype of some of the isolates also had high virulence. As the less virulent morphotype also had higher growth rate in outside‐host resources, the results suggest that both morphotypes can contribute to F. columnare epidemics at fish farms, especially with current prospects of warming temperatures. Our results suggest that higher phenotypic variation per se does not lead to higher virulence, but that environmental conditions at fish farms could select isolates with high phenotypic variation in bacterial population and hence affect evolution in F. columnare at fish farms. Our results highlight the multifaceted effects of human‐induced environmental alterations in shaping epidemiology and evolution in microbial pathogens.
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Affiliation(s)
- Katja Pulkkinen
- Department of Biological and Environmental Science University of Jyväskylä Finland
| | - Tarmo Ketola
- Department of Biological and Environmental Science University of Jyväskylä Finland
| | - Jouni Laakso
- Faculty of Biological and Environmental Sciences University of Helsinki Finland
| | - Johanna Mappes
- Department of Biological and Environmental Science University of Jyväskylä Finland
- Faculty of Biological and Environmental Sciences University of Helsinki Finland
| | - Lotta‐Riina Sundberg
- Department of Biological and Environmental Science University of Jyväskylä Finland
- Nanoscience Center University of Jyväskylä Finland
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7
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Runtuvuori-Salmela A, Kunttu H, Laanto E, Almeida G, Mäkelä K, Middelboe M, Sundberg LR. Prevalence of genetically similar Flavobacterium columnare phages across aquaculture environments reveals a strong potential for pathogen control. Environ Microbiol 2022; 24:2404-2420. [PMID: 35049114 PMCID: PMC9304149 DOI: 10.1111/1462-2920.15901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/11/2022] [Indexed: 11/28/2022]
Abstract
Intensive aquaculture conditions expose fish to bacterial infections, leading to significant financial losses, extensive antibiotic use and risk of antibiotic resistance in target bacteria. Flavobacterium columnare causes columnaris disease in aquaculture worldwide. To develop a bacteriophage‐based control of columnaris disease, we isolated and characterized 126 F. columnare strains and 63 phages against F. columnare from Finland and Sweden in 2017. Bacterial isolates were virulent on rainbow trout (Oncorhynchus mykiss) and fell into four previously described genetic groups A, C, E and G, with genetic groups C and E being the most virulent. Phage host range studied against a collection of 227 bacterial isolates (from 2013 to 2017) demonstrated modular infection patterns based on host genetic group. Phages infected contemporary and previously isolated bacterial hosts, but bacteria isolated most recently were generally resistant to previously isolated phages. Despite large differences in geographical origin, isolation year or host range of the phages, whole‐genome sequencing of 56 phages showed high level of genetic similarity to previously isolated F. columnare phages (Ficleduovirus, Myoviridae). Altogether, this phage collection demonstrates a potential for use in phage therapy.
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Affiliation(s)
- A Runtuvuori-Salmela
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Hmt Kunttu
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - E Laanto
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland.,Department Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
| | - Gmf Almeida
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland.,Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, Tromsø, Norway
| | - K Mäkelä
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - M Middelboe
- Department of Biology, Marine Biological Section, University of Copenhagen, Helsingør, Denmark
| | - L-R Sundberg
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
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8
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Pandey A, Mideo N, Platt TG. Virulence Evolution of Pathogens That Can Grow in Reservoir Environments. Am Nat 2022; 199:141-158. [DOI: 10.1086/717177] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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9
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Lages MA, Lemos ML, Balado M. The Temperature-Dependent Expression of the High-Pathogenicity Island Encoding Piscibactin in Vibrionaceae Results From the Combined Effect of the AraC-Like Transcriptional Activator PbtA and Regulatory Factors From the Recipient Genome. Front Microbiol 2021; 12:748147. [PMID: 34867865 PMCID: PMC8639528 DOI: 10.3389/fmicb.2021.748147] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/20/2021] [Indexed: 11/13/2022] Open
Abstract
The high-pathogenicity island irp-HPI is widespread among Vibrionaceae encoding the piscibactin siderophore system. The expression of piscibactin genes in the fish pathogen Vibrio anguillarum is favored by low temperatures. However, information about the regulatory mechanism behind irp-HPI gene expression is scarce. In this work, in-frame deletion mutants of V. anguillarum defective in the putative regulators AraC1 and AraC2, encoded by irp-HPI, and in the global regulators H-NS and ToxRS, were constructed and their effect on irp-HPI gene expression was analyzed at 15 and 25°C. The results proved that only AraC1 (renamed as PbtA) is required for the expression of piscibactin biosynthesis and transport genes. PbtA inactivation led to an inability to grow under iron restriction, a loss of the outer membrane piscibactin transporter FrpA, and a significant decrease in virulence for fish. Inactivation of the global repressor H-NS, which is involved in silencing of horizontally acquired genes, also resulted in a lower transcriptional activity of the frpA promoter. Deletion of toxR-S, however, did not have a relevant effect on the expression of the irp-HPI genes. Therefore, while irp-HPI would not be part of the ToxR regulon, H-NS must exert an indirect effect on piscibactin gene expression. Thus, the temperature-dependent expression of the piscibactin-encoding pathogenicity island described in V. anguillarum is the result of the combined effect of the AraC-like transcriptional activator PbtA, harbored in the island, and other not yet defined regulator(s) encoded by the genome. Furthermore, different expression patterns were detected within different irp-HPI evolutionary lineages, which supports a long-term evolution of the irp-HPI genomic island within Vibrionaceae. The mechanism that modulates piscibactin gene expression could also be involved in global regulation of virulence factors in response to temperature changes.
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Affiliation(s)
- Marta A Lages
- Department of Microbiology and Parasitology, Institute of Aquaculture, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Manuel L Lemos
- Department of Microbiology and Parasitology, Institute of Aquaculture, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Miguel Balado
- Department of Microbiology and Parasitology, Institute of Aquaculture, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
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10
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Korkea‐aho TL, Viljamaa‐Dirks S, Heinikainen S, Kuronen H, Tiirola M. Genetic diversity and phenotypic characterization of Iodobacter limnosediminis associated with skin lesions in freshwater fish. JOURNAL OF FISH DISEASES 2021; 44:1711-1724. [PMID: 34218448 PMCID: PMC8596759 DOI: 10.1111/jfd.13490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
The relatively unknown genus Iodobacter sp. has been repeatedly isolated from skin ulcers and saprolegniosis on freshwater fish in Finland, especially farmed salmonids. Genetic characterization verified that all 23 bacterial isolates studied here belonged to the species Iodobacter limnosediminis, previously undescribed from the fish microbiota. Whole-genome pulsed-field gel electrophoresis revealed variability between the I. limnosediminis strains, suggesting that they were most likely of environmental origin. Two I. limnosediminis strains caused lesions in 27%-53% of brown trout (Salmo trutta) injected intramuscularly (p ≤ .05). The lesions represented moderate to severe tissue damage, but for most fish, the tissues had been repaired by the end of the experiment through the accumulation of fibrocytes and macrophages at the site of the lesion. I. limnosediminis was reisolated from some lesions and/or internal organs. Phenotypically and biochemically, I. limnosediminis resembles several common bacterial species found in the aquatic environment, as it grows well on several media as whitish medium-sized colonies, is Gram negative and rod-shaped. Here, we characterized I. limnosediminis strains with several methods, including MALDI-TOF. This characterization will help in further investigations into the occurrence and possible involvement of I. limnosediminis in skin lesions of freshwater fish.
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Affiliation(s)
- Tiina Liisa Korkea‐aho
- Veterinary Bacteriology and Pathology UnitLaboratory and Research DivisionFinnish Food AuthorityKuopioFinland
| | - Satu Viljamaa‐Dirks
- Veterinary Bacteriology and Pathology UnitLaboratory and Research DivisionFinnish Food AuthorityKuopioFinland
| | - Sirpa Heinikainen
- Veterinary Bacteriology and Pathology UnitLaboratory and Research DivisionFinnish Food AuthorityKuopioFinland
| | - Henry Kuronen
- Veterinary Bacteriology and Pathology UnitLaboratory and Research DivisionFinnish Food AuthorityKuopioFinland
| | - Marja Tiirola
- Department of Biological and Environmental ScienceNanoscience CenterUniversity of JyväskyläJyväskyläFinland
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11
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Tyagi I, Tyagi K, Bhutiani R, Chandra K, Kumar V. Bacterial diversity assessment of world's largest sewage-fed fish farms with special reference to water quality: a Ramsar site. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:42372-42386. [PMID: 33813698 DOI: 10.1007/s11356-021-13756-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/29/2021] [Indexed: 06/12/2023]
Abstract
Bacterial community structure is one of the essential components of aquaculture dynamics and plays an important role in maintaining wetland health. The present work is an effort to study the structure of bacterial communities in the world's largest sewage-fed fish farms, the East Kolkata Wetlands (EKWs), along with their predicted functional metabolic pathways and correlation with environmental variables. Sequencing data analysis revealed the abundance of genera such as Arcobacter (0-50%), Pseudomonas (0-15%), Sulfurospirillum (0-9%), Cloacibacterium (0-6%), hgcI clade (7-29%), C39 (0-9%), V6 (3-36%), Fluiivicola (1-6%) and Cyanobium (3-8%) in the EKWs. Further, water quality analysis of three treatment groups, i.e. Sewage, Sewage F-1 and Sewage F-2, revealed that dissolved oxygen (DO), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) differed significantly and violated the standard prescribed norms (Central Pollution Control Board, CPCB, New Delhi) for fishery propagation and irrigation in India. Further, the correlation matrix analysis between the abundance of bacterial genera and environmental variables indicated that DO, BOD and COD were mainly responsible for bacterial community structure and their proliferation in the EKWs. Our results indicated that the abundance of genera such as Arcobacter, Pseudomonas, Sulfurospirillum and Cloacibacterium has an inverse relationship with BOD and COD. Our observations based on the bacterial community structure and deteriorated water quality indicate the ineffective functioning and poor management of this man-made constructed wetland.
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Affiliation(s)
- Inderjeet Tyagi
- Centre for DNA Taxonomy, Molecular Systematics Division, Zoological Survey of India, Kolkata, 700053, India
| | - Kaomud Tyagi
- Centre for DNA Taxonomy, Molecular Systematics Division, Zoological Survey of India, Kolkata, 700053, India
| | - Rakesh Bhutiani
- Department of Environmental Sciences, Gurukul Kangri Vishwavidyalaya, Haridwar, 249404, India
| | - Kailash Chandra
- Centre for DNA Taxonomy, Molecular Systematics Division, Zoological Survey of India, Kolkata, 700053, India
| | - Vikas Kumar
- Centre for DNA Taxonomy, Molecular Systematics Division, Zoological Survey of India, Kolkata, 700053, India.
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12
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Kunttu HMT, Runtuvuori-Salmela A, Middelboe M, Clark J, Sundberg LR. Comparison of Delivery Methods in Phage Therapy against Flavobacterium columnare Infections in Rainbow Trout. Antibiotics (Basel) 2021; 10:914. [PMID: 34438964 PMCID: PMC8388691 DOI: 10.3390/antibiotics10080914] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/14/2021] [Accepted: 07/20/2021] [Indexed: 01/21/2023] Open
Abstract
Viruses of bacteria, bacteriophages, specifically infect their bacterial hosts with minimal effects on the surrounding microbiota. They have the potential to be used in the prevention and treatment of bacterial infections, including in the field of food production. In aquaculture settings, disease-causing bacteria are often transmitted through the water body, providing several applications for phage-based targeting of pathogens, in the rearing environment, and in the fish. We tested delivery of phages by different methods (via baths, in phage-coated material, and via oral delivery in feed) to prevent and treat Flavobacterium columnare infections in rainbow trout fry using three phages (FCOV-S1, FCOV-F2, and FCL-2) and their hosts (FCO-S1, FCO-F2, and B185, respectively). Bath treatments given before bacterial infection and at the onset of the disease symptoms were the most efficient way to prevent F. columnare infections in rainbow trout, possibly due to the external nature of the disease. In a flow-through system, the presence of phage-coated plastic sheets delayed the onset of the disease. The oral administration of phages first increased disease progression, although total mortality was lower at the end of the experiment. When analysed for shelf-life, phage titers remained highest when maintained in bacterial culture media and in sterile lake water. Our results show that successful phage therapy treatment in the aquaculture setting requires optimisation of phage delivery methods in vivo.
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Affiliation(s)
- Heidi M. T. Kunttu
- Nanoscience Center, Department of Biological and Environmental Science, University of Jyväskylä, FI-40014 Jyväskylä, Finland; (H.M.T.K.); (A.R.-S.)
| | - Anniina Runtuvuori-Salmela
- Nanoscience Center, Department of Biological and Environmental Science, University of Jyväskylä, FI-40014 Jyväskylä, Finland; (H.M.T.K.); (A.R.-S.)
| | - Mathias Middelboe
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark;
| | | | - Lotta-Riina Sundberg
- Nanoscience Center, Department of Biological and Environmental Science, University of Jyväskylä, FI-40014 Jyväskylä, Finland; (H.M.T.K.); (A.R.-S.)
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Donohoe O, Zhang H, Delrez N, Gao Y, Suárez NM, Davison AJ, Vanderplasschen A. Genomes of Anguillid Herpesvirus 1 Strains Reveal Evolutionary Disparities and Low Genetic Diversity in the Genus Cyprinivirus. Microorganisms 2021; 9:microorganisms9050998. [PMID: 34063135 PMCID: PMC8148134 DOI: 10.3390/microorganisms9050998] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 04/28/2021] [Accepted: 04/28/2021] [Indexed: 12/24/2022] Open
Abstract
Anguillid herpesvirus 1 (AngHV-1) is a pathogen of eels and a member of the genus Cyprinivirus in the family Alloherpesviridae. We have compared the biological and genomic features of different AngHV-1 strains, focusing on their growth kinetics in vitro and genetic content, diversity, and recombination. Comparisons based on three core genes conserved among alloherpesviruses revealed that AngHV-1 exhibits a slower rate of change and less positive selection than other cypriniviruses. We propose that this may be linked to major differences in host species and corresponding epidemiological circumstances. Efforts to derive evolutionary rate estimates for cypriniviruses under various theoretical models were ultimately unrewarding. We highlight the potential value of future collaborative efforts towards generating short-term evolutionary rate estimates based on known sequence sampling dates. Finally, we revealed that there is significantly less genetic diversity in core gene sequences within cyprinivirus species clades compared to species in the family Herpesviridae. This suggests that cyprinivirus species may have undergone much more vigorous purifying selection post species clade divergence. We discuss whether this may be linked to biological and anthropogenic factors or to sampling bias, and we propose that the comparison of short-term evolutionary rates between species may provide further insights into these differences.
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Affiliation(s)
- Owen Donohoe
- Immunology-Vaccinology, Department of Infectious and Parasitic Diseases, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium; (O.D.); (H.Z.); (N.D.); (Y.G.)
- Bioscience Research Institute, Athlone Institute of Technology, Athlone, Co. N37 HD68 Westmeath, Ireland
| | - Haiyan Zhang
- Immunology-Vaccinology, Department of Infectious and Parasitic Diseases, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium; (O.D.); (H.Z.); (N.D.); (Y.G.)
| | - Natacha Delrez
- Immunology-Vaccinology, Department of Infectious and Parasitic Diseases, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium; (O.D.); (H.Z.); (N.D.); (Y.G.)
| | - Yuan Gao
- Immunology-Vaccinology, Department of Infectious and Parasitic Diseases, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium; (O.D.); (H.Z.); (N.D.); (Y.G.)
| | - Nicolás M. Suárez
- MRC-Centre for Virus Research, University of Glasgow, Glasgow G61 1QH, UK; (N.M.S.); (A.J.D.)
| | - Andrew J. Davison
- MRC-Centre for Virus Research, University of Glasgow, Glasgow G61 1QH, UK; (N.M.S.); (A.J.D.)
| | - Alain Vanderplasschen
- Immunology-Vaccinology, Department of Infectious and Parasitic Diseases, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium; (O.D.); (H.Z.); (N.D.); (Y.G.)
- Correspondence: ; Tel.: +32-4-366-42-64; Fax: +32-4-366-42-61
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Karvonen A, Räihä V, Klemme I, Ashrafi R, Hyvärinen P, Sundberg LR. Quantity and Quality of Aquaculture Enrichments Influence Disease Epidemics and Provide Ecological Alternatives to Antibiotics. Antibiotics (Basel) 2021; 10:antibiotics10030335. [PMID: 33810018 PMCID: PMC8004632 DOI: 10.3390/antibiotics10030335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/10/2021] [Accepted: 03/16/2021] [Indexed: 11/16/2022] Open
Abstract
Environmental heterogeneity is a central component influencing the virulence and epidemiology of infectious diseases. The number and distribution of susceptible hosts determines disease transmission opportunities, shifting the epidemiological threshold between the spread and fadeout of a disease. Similarly, the presence and diversity of other hosts, pathogens and environmental microbes, may inhibit or accelerate an epidemic. This has important applied implications in farming environments, where high numbers of susceptible hosts are maintained in conditions of minimal environmental heterogeneity. We investigated how the quantity and quality of aquaculture enrichments (few vs. many stones; clean stones vs. stones conditioned in lake water) influenced the severity of infection of a pathogenic bacterium, Flavobacterium columnare, in salmonid fishes. We found that the conditioning of the stones significantly increased host survival in rearing tanks with few stones. A similar effect of increased host survival was also observed with a higher number of unconditioned stones. These results suggest that a simple increase in the heterogeneity of aquaculture environment can significantly reduce the impact of diseases, most likely operating through a reduction in pathogen transmission (stone quantity) and the formation of beneficial microbial communities (stone quality). This supports enriched rearing as an ecological and economic way to prevent bacterial infections with the minimal use of antimicrobials.
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Affiliation(s)
- Anssi Karvonen
- Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, 40014 Jyvaskyla, Finland; (V.R.); (I.K.); (R.A.); (L.-R.S.)
- Correspondence: ; Tel.: +358-40-8053882; Fax: +358-14-2601021
| | - Ville Räihä
- Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, 40014 Jyvaskyla, Finland; (V.R.); (I.K.); (R.A.); (L.-R.S.)
| | - Ines Klemme
- Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, 40014 Jyvaskyla, Finland; (V.R.); (I.K.); (R.A.); (L.-R.S.)
| | - Roghaieh Ashrafi
- Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, 40014 Jyvaskyla, Finland; (V.R.); (I.K.); (R.A.); (L.-R.S.)
| | - Pekka Hyvärinen
- Natural Resources and Bioproduction, Natural Resources Institute Finland (Luke), Manamansalontie 90, 88300 Paltamo, Finland;
| | - Lotta-Riina Sundberg
- Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, 40014 Jyvaskyla, Finland; (V.R.); (I.K.); (R.A.); (L.-R.S.)
- Nanoscience Center, University of Jyvaskyla, P.O. Box 35, 40014 Jyvaskyla, Finland
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15
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Xu W, Gong L, Yang S, Gao Y, Ma X, Xu L, Chen H, Luo Z. Spatiotemporal Dynamics of Vibrio Communities and Abundance in Dongshan Bay, South of China. Front Microbiol 2020; 11:575287. [PMID: 33324364 PMCID: PMC7726330 DOI: 10.3389/fmicb.2020.575287] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/27/2020] [Indexed: 01/22/2023] Open
Abstract
The Vibrio genus inhabit estuarine and marine ecosystem throughout the world and can cause severe infections in humans and animals. Previous studies have demonstrated the dynamics of Vibrio at both community and population levels and assessed the close relationship between environmental factors and Vibrio diversity and abundance, such as temperature, salinity, and dissolved oxygen. It is also generally believed that aquaculture is the fastest-growing food sector, which is also applying great environmental impacts on microbial communities in aquatic ecosystems. However, our understanding of the spatiotemporal quantification of Vibrio throughout the four seasons in the aquaculture zone and response to environmental factors remains poor. To explore the spatiotemporal distribution and abundance of the Vibrio community with their related environmental factors and detect the relationships among them, we collected 10 seawater sites spanning four seasons across the whole year in Dongshan Bay for investigating the Vibrio community dynamics. Marked differences in diversity and abundance of the Vibrio community were observed between seasons, which were mainly driven by temperature, dissolved oxygen, nitrate, and nitrite. qPCR analysis showed that Vibrio abundance was most abundant in the summer (5.37 × 106 copies/L), compared with the autumn (4.58 × 106 copies/L), spring (1.18 × 106 copies/L), and winter (1.55 × 104 copies/L). A total of 22 Vibrio operational taxonomic units (OTUs) and 28 species were identified by universal bacteria 16S rRNA gene and cultivation methods, with Vibrio fortis the dominant in these aquaculture areas. To summarize, our present study is one of the few studies to research the occurrence of Vibrio in marine aquaculture of South China, and the results indicate that Vibrio are widely distributed in aquaculture environment and that a further risk assessment is needed to be conducted.
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Affiliation(s)
- Wei Xu
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - LinFeng Gong
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Shuai Yang
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Yuanhao Gao
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Xiaowan Ma
- Fourth Institute of Oceanography, Ministry of Natural Resources, Beihai, China
| | - Limei Xu
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Haisheng Chen
- Fishery Technology Promotion Station of Dongshan, Zhangzhou, China
| | - Zhuhua Luo
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China.,Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China.,School of Marine Sciences, Nanjing University of Information Science & Technology, Nanjing, China
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16
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Zhong JR, Wu P, Feng L, Jiang WD, Liu Y, Kuang SY, Tang L, Zhou XQ. Dietary phytic acid weakened the antimicrobial activity and aggravated the inflammatory status of head kidney, spleen and skin in on-growing grass carp (Ctenopharyngodon idella). FISH & SHELLFISH IMMUNOLOGY 2020; 103:256-265. [PMID: 32439508 DOI: 10.1016/j.fsi.2020.05.037] [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: 02/22/2020] [Revised: 04/13/2020] [Accepted: 05/14/2020] [Indexed: 06/11/2023]
Abstract
The present study aimed to explore the effects of phytic acid (PA) on the antimicrobial activity and inflammatory response in three immune organs (head kidney, spleen and skin) of on-growing grass carp (Ctenopharyngodon idella). To achieve this goal, we first conducted a 60-day growth trial by feeding fish with graded levels of PA (0, 0.8, 1.6, 2.4, 3.2 and 4.0%). Then, the fish were challenged with Aeromonas hydrophila for 6 days. Compared with the control group, the following results were obtained regarding supplementation with certain levels of PA in the diet. (1) There was an increase in skin haemorrhage and lesion morbidity in fish. (2) There was a decrease in activities or contents of immune factors, including lysozyme (LZ), complement 3 (C3), C4 and immunoglobulin M (IgM), and there was downregulation of gene expression levels of hepcidin, liver-expressed antimicrobial peptide 2A (LEAP-2A), LEAP-2B, and β-defensin-1 in immune organs. (3) There was upregulation in the gene expression of the following pro-inflammatory cytokines: tumour necrosis factor α (TNF-α), interleukin 1β (IL-1β) (except in the spleen), interferon γ2 (IFN-γ2), IL-6 (except in the spleen), IL-8, IL-12p40, IL-15 and IL-17D. These changes were partly related to the nuclear factor kappa B (NF-κB) signalling pathway, but downregulation of mRNA levels of anti-inflammatory cytokines (transforming growth factor β1 (TGF-β1), TGF-β2, IL-413/A, IL-413/B, IL-10 (except in the skin) and IL-11) occurred in a manner partially related to the target of rapamycin (TOR) signalling pathway. Finally, based on the broken-line analysis of skin haemorrhage and lesion morbidity and IgM content in the head kidney, the maximum tolerance levels of PA for on-growing grass carp (120.56-452.00 g) were estimated to be 1.79 and 1.31% of the diet, respectively.
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Affiliation(s)
- Jing-Ren Zhong
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Pei Wu
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China; Fish Nutrition and Safety Production, University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China; Key Laboratory of Animal Disease-resistant Nutrition, Ministry of Education, China
| | - Lin Feng
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China; Fish Nutrition and Safety Production, University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, China
| | - Wei-Dan Jiang
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China; Fish Nutrition and Safety Production, University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China; Key Laboratory of Animal Disease-resistant Nutrition, Ministry of Education, China
| | - Yang Liu
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China; Fish Nutrition and Safety Production, University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China; Key Laboratory of Animal Disease-resistant Nutrition and Feed, Ministry of Agriculture and Rural Affairs, China
| | - Sheng-Yao Kuang
- Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu, 610066, China
| | - Ling Tang
- Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu, 610066, China
| | - Xiao-Qiu Zhou
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China; Fish Nutrition and Safety Production, University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, China.
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17
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González Plaza JJ. Small RNAs as Fundamental Players in the Transference of Information During Bacterial Infectious Diseases. Front Mol Biosci 2020; 7:101. [PMID: 32613006 PMCID: PMC7308464 DOI: 10.3389/fmolb.2020.00101] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 05/04/2020] [Indexed: 12/24/2022] Open
Abstract
Communication shapes life on Earth. Transference of information has played a paramount role on the evolution of all living or extinct organisms since the appearance of life. Success or failure in this process will determine the prevalence or disappearance of a certain set of genes, the basis of Darwinian paradigm. Among different molecules used for transmission or reception of information, RNA plays a key role. For instance, the early precursors of life were information molecules based in primitive RNA forms. A growing field of research has focused on the contribution of small non-coding RNA forms due to its role on infectious diseases. These are short RNA species that carry out regulatory tasks in cis or trans. Small RNAs have shown their relevance in fine tuning the expression and activity of important regulators of essential genes for bacteria. Regulation of targets occurs through a plethora of mechanisms, including mRNA stabilization/destabilization, driving target mRNAs to degradation, or direct binding to regulatory proteins. Different studies have been conducted during the interplay of pathogenic bacteria with several hosts, including humans, animals, or plants. The sRNAs help the invader to quickly adapt to the change in environmental conditions when it enters in the host, or passes to a free state. The adaptation is achieved by direct targeting of the pathogen genes, or subversion of the host immune system. Pathogens trigger also an immune response in the host, which has been shown as well to be regulated by a wide range of sRNAs. This review focuses on the most recent host-pathogen interaction studies during bacterial infectious diseases, providing the perspective of the pathogen.
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Affiliation(s)
- Juan José González Plaza
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czechia
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18
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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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Chen HC, Pan CY, Rajanbabu V, Lee YY, Tsai WR, Chen JY. Lack of Acute Toxicity and Mutagenicity from Recombinant Epinephelus lanceolatus Piscidin Expressed in Pichia pastoris. Mar Drugs 2020; 18:md18040206. [PMID: 32290449 PMCID: PMC7230367 DOI: 10.3390/md18040206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/04/2020] [Accepted: 04/08/2020] [Indexed: 12/20/2022] Open
Abstract
The antimicrobial peptide (AMP) piscidin was identified from Epinephelus lanceolatus and demonstrated to possess antimicrobial and immune-related functions. Supplementation of feed with recombinant Epinephelus lanceolatus piscidin (rEP)-expressing yeast pellets may minimize the excessive use of antibiotics and control pathogens in aquaculture or animal husbandry. However, before implementing rEP as a supplement, it is necessary to understand whether it harbors any toxicity. Since toxicological information on the topic is scarce, the present investigation was carried out to test whether rEP exhibits allergenic and/or toxic effects. In an oral acute toxicity test (OECD 425), Sprague Dawley (SD) rats were administered rEP dissolved in reverse osmosis water, yielding an LD50 > 5000 mg/kg (no observed animal death). The compound was therefore classified as non-toxic by oral administration. In an acute respiratory toxicity test (OECD 403), heads and noses of SD rats were exposed to liquid aerosol for 4 h (the highest concentration that could be administered without causing any animal death), and a lethal concentration (LC50) > 0.88 mg/L was obtained. The mass medium aerodynamics diameter (MMAD) of rEP aerosol particles was 8.18 μm and mass medium aerodynamics diameter (GSD) was 3.04, which meant that 25.90% could enter the airway (<4 μm) of a rat, and 58.06% (<10 μm) could be inhaled by humans. An ocular irritation test (OECD 405) with rEP powder was performed on New Zealand White (NZW) rabbits. Signs of irritation included conjunctival swelling and diffuse flushing 1 h after administration. The signs were less apparent after 24 h and disappeared after 72 h. The classification assigned to the powder was mild eye irritation. Skin sensitization was performed for a local lymphoproliferative test (OECD 442B) using BALB/c mice, with the highest soluble concentration of the rEP considered to be 100% test substance; formulations were diluted to 50% and 25%, and bromodeoxyuridine (BrdU) incorporation was used to measure the degree of lymphocyte proliferation. The stimulation indexes (SIs) were 1.06 (100%), 0.44 (50%), and 0.77 (25%), all of which were less than the cutoff value for a positive sensitization result (1.6). Negative response was also seen in the bacterial reverse mutation test (OECD 471), and no chromosomal effects on Chinese hamster ovary (CHO)-K1 cells were observed (OECD 487). Based on these six toxicity tests, rEP showed neither acute toxic effects in experimental animals nor mutagenicity. Thus, rEP can be considered safe for use in subsequent research on its application as a feed additive for poultry, cattle, or aquatic animals.
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Affiliation(s)
- Hsiao-Ching Chen
- Division of Applied Toxicology, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Taichung City 41358, Taiwan; (H.-C.C.); (Y.-Y.L.)
| | - Chieh-Yu Pan
- Department and Graduate Institute of Aquaculture, National Kaohsiung University of Science and Technology, Kaohsiung 811, Taiwan;
| | - Venugopal Rajanbabu
- Anbil Dharmalingam Agricultural College and Research Institute, Tamil Nadu Agricultural University, Tiruchchirapalli, Tamil Nadu 620027, India;
| | - Yen-Yun Lee
- Division of Applied Toxicology, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Taichung City 41358, Taiwan; (H.-C.C.); (Y.-Y.L.)
| | - Wei-Ren Tsai
- Division of Applied Toxicology, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Taichung City 41358, Taiwan; (H.-C.C.); (Y.-Y.L.)
- Correspondence: (W.-R.T.); (J.-Y.C.); Tel.: +886-988105706 (W.-R.T.); +886-920802111 (J.-Y.C.)
| | - Jyh-Yih Chen
- Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, 23-10 Dahuen Road, Jiaushi, Ilan 262, Taiwan
- The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
- Correspondence: (W.-R.T.); (J.-Y.C.); Tel.: +886-988105706 (W.-R.T.); +886-920802111 (J.-Y.C.)
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20
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A Definition of Aquaculture Intensity Based on Production Functions—The Aquaculture Production Intensity Scale (APIS). WATER 2020. [DOI: 10.3390/w12030765] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aquaculture intensity has been used for years as a means to gauge how much production a site makes using three terms: extensive, semi-intensive and intensive aquaculture production systems. The industry has a relatively coordinated understanding of these terms, but an explicit general definition does not seem to exist. This paper aims to use three kinds of production function groups; the input, treatment and output functions to describe and define the terms extensive, semi-intensive and intensive explicitly. This is done with extensive literature review to find the meaning of the terms. The terms are then mapped onto the three production function groups. The resulting framework accomplishes two things. Firstly, it defines extensive, semi-intensive and intensive aquaculture in terms of production functions. Secondly, it creates an eight level scale, the aquaculture production intensity scale (APIS), that provides three levels of extensive systems, two level of semi-intensive systems and three level of intensive systems. APIS allows mapping of all uses of the terms in current literature to an APIS score, though some results might differ from current usage.
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21
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Karvonen A, Fenton A, Sundberg L. Sequential infection can decrease virulence in a fish-bacterium-fluke interaction: Implications for aquaculture disease management. Evol Appl 2019; 12:1900-1911. [PMID: 31700534 PMCID: PMC6824072 DOI: 10.1111/eva.12850] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 07/10/2019] [Accepted: 07/12/2019] [Indexed: 12/13/2022] Open
Abstract
Hosts are typically infected with multiple strains or genotypes of one or several parasite species. These infections can take place simultaneously, but also at different times, i.e. sequentially, when one of the parasites establishes first. Sequential parasite dynamics are common in nature, but also in intensive farming units such as aquaculture. However, knowledge of effects of previous exposures on virulence of current infections in intensive farming is very limited. This is critical as consecutive epidemics and infection history of a host could underlie failures in management practices and medical intervention of diseases. Here, we explored effects of timing of multiple infections on virulence in two common aquaculture parasites, the bacterium Flavobacterium columnare and the fluke Diplostomum pseudospathaceum. We exposed fish hosts first to flukes and then to bacteria in two separate experiments, altering timing between the infections from few hours to several weeks. We found that both short-term and long-term differences in timing of the two infections resulted in significant, genotype-specific decrease in bacterial virulence. Second, we developed a mathematical model, parameterized from our experimental results, to predict the implications of sequential infections for epidemiological progression of the disease, and levels of fish population suppression, in an aquaculture setting. Predictions of the model showed that sequential exposure of hosts can decrease the population-level impact of the bacterial epidemic, primarily through the increased recovery rate of sequentially infected hosts, thereby substantially protecting the population from the detrimental impact of infection. However, these effects depended on bacterial strain-fluke genotype combinations, suggesting the genetic composition of the parasite populations can greatly influence the degree of host suppression. Overall, these results suggest that host infection history can have significant consequences for the impact of infection at host population level, potentially shaping parasite epidemiology, disease dynamics and evolution of virulence in farming environments.
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Affiliation(s)
- Anssi Karvonen
- Department of Biological and Environmental ScienceUniversity of JyvaskylaJyvaskylaFinland
| | - Andy Fenton
- Institute of Integrative BiologyUniversity of LiverpoolLiverpoolUK
| | - Lotta‐Riina Sundberg
- Department of Biological and Environmental ScienceUniversity of JyvaskylaJyvaskylaFinland
- Nanoscience CenterUniversity of JyvaskylaJyvaskylaFinland
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22
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Almeida GMF, Mäkelä K, Laanto E, Pulkkinen J, Vielma J, Sundberg LR. The Fate of Bacteriophages in Recirculating Aquaculture Systems (RAS)-Towards Developing Phage Therapy for RAS. Antibiotics (Basel) 2019; 8:E192. [PMID: 31652887 PMCID: PMC6963195 DOI: 10.3390/antibiotics8040192] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 10/20/2019] [Accepted: 10/21/2019] [Indexed: 11/17/2022] Open
Abstract
Aquaculture production has increased tremendously during the last decades, and new techniques have been developed, e.g., recirculating aquaculture systems (RAS). In RAS, the majority of water volume is circulated via mechanical and biological filters and reused in the tanks. However, the prevention and treatment of diseases in these systems are challenging, as the pathogens spread throughout the system, and the addition of chemicals and antibiotics disrupts the microbiome of the biofilters. The increasing antibiotic resistance has made phage therapy a relevant alternative for antibiotics in food production. Indeed, as host-specific and self-replicating agent they might be optimal for targeted pathogen eradication in RAS. We tested the survival and spread of Flavobacterium columnare -infecting phage FCL-2 in recirculating aquaculture fish farm with rainbow trout (Oncorhynchus mykiss) in a fully controlled study. After a single addition, phage persisted in water samples collected from tank, fixed bed, moving bed, and aeration unit up to 14 days, and in the water of rearing tanks, rainbow trout mucus, and bioreactor carrier media from the fixed and moving bed biofilters for 21 days. Furthermore, phage adsorbed preferentially to moving bed carrier media, which contained biofilm attached and from which higher phage numbers were recovered. This study shows phages as a potent strategy for maintaining biosecurity in RAS systems.
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Affiliation(s)
- Gabriel M F Almeida
- Department of Biological and Environmental Science, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland.
| | - Kati Mäkelä
- Department of Biological and Environmental Science, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland.
| | - Elina Laanto
- Department of Biological and Environmental Science, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland.
- Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Programme, University of Helsinki, 00014 Helsinki, Finland.
| | - Jani Pulkkinen
- Natural Resources Institute Finland, Production Systems, 40500 Jyväskylä, Finland.
| | - Jouni Vielma
- Natural Resources Institute Finland, Production Systems, 40500 Jyväskylä, Finland.
| | - Lotta-Riina Sundberg
- Department of Biological and Environmental Science, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland.
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23
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Zeng J, Lin Y, Zhao D, Huang R, Xu H, Jiao C. Seasonality overwhelms aquacultural activity in determining the composition and assembly of the bacterial community in Lake Taihu, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 683:427-435. [PMID: 31141745 DOI: 10.1016/j.scitotenv.2019.05.256] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/29/2019] [Accepted: 05/17/2019] [Indexed: 06/09/2023]
Abstract
Aquaculture accounts for an extremely valuable and rapidly expanding sector of global food production, yet its environmental impacts on aquatic ecosystems have attracted much concern. In this study, we collected water samples from eastern Lake Taihu, China. We targeted sites varying in their intensity of aquacultural activities and sampled them over multiple seasons. For each sample, we measured physicochemical variables, and we sequenced the 16S rRNA gene of the respective bacterial communities using an Illumina second-generation sequencing platform. Marked differences in diversity and bacterial community composition were observed between seasons, whereas we observed relatively weak differences between sites. Remarkable differences in the abundance of the bacterial community were observed at the phylum and genus levels across the different seasons. Stochastic processes dominated the assembly of bacterial communities in the aquaculture-influenced systems, and the assembly processes of bacterial community differed between seasons. Our observations highlight the effect of seasonality on bacterial communities and provide a more complete knowledge base for the proper assessment of the effects of aquacultural activities on freshwater ecosystems.
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Affiliation(s)
- Jin Zeng
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
| | - Yuqing Lin
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Joint International Research Laboratory of Global Change and Water Cycle, Hohai University, Nanjing 210098, China
| | - Dayong Zhao
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Joint International Research Laboratory of Global Change and Water Cycle, Hohai University, Nanjing 210098, China
| | - Rui Huang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Joint International Research Laboratory of Global Change and Water Cycle, Hohai University, Nanjing 210098, China
| | - Huimin Xu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Joint International Research Laboratory of Global Change and Water Cycle, Hohai University, Nanjing 210098, China
| | - Congcong Jiao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Joint International Research Laboratory of Global Change and Water Cycle, Hohai University, Nanjing 210098, China
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24
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Wegner KM, Piel D, Bruto M, John U, Mao Z, Alunno-Bruscia M, Petton B, Le Roux F. Molecular Targets for Coevolutionary Interactions Between Pacific Oyster Larvae and Their Sympatric Vibrios. Front Microbiol 2019; 10:2067. [PMID: 31555250 PMCID: PMC6742746 DOI: 10.3389/fmicb.2019.02067] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 08/22/2019] [Indexed: 11/21/2022] Open
Abstract
Bacteria of the Vibrio genus are the most predominant infectious agents threatening marine wildlife and aquaculture. Due to the large genetic diversity of these pathogens, the molecular determinants of Vibrio virulence are only poorly understood. Furthermore, studies tend to ignore co-evolutionary interactions between different host populations and their locally encountered Vibrio communities. Here, we explore the molecular targets of such co-evolutionary interactions by analyzing the genomes of nine Vibrio strains from the Splendidus-clade showing opposite virulence patterns towards two populations of Pacific oysters introduced into European Wadden Sea. By contrasting Vibrio phylogeny to their host specific virulence patterns, we could identify two core genome genes (OG1907 and OG 3159) that determine the genotype by genotype (G × G) interactions between oyster larvae and their sympatric Vibrio communities. Both genes show positive selection between locations targeting only few amino acid positions. Deletion of each gene led to a loss of the host specific virulence patterns while complementation with OG3159 alleles from both locations could recreate the wild type phenotypes matching the origin of the allele. This indicates that both genes can act as a genetic switch for Vibrio-oyster coevolution demonstrating that local adaptation in distinct Vibrio lineages can rely on only few genes independent of larger pathogenicity islands or plasmids.
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Affiliation(s)
- K Mathias Wegner
- Coastal Ecology, Waddensea Station Sylt, Alfred Wegener Institut - Helmholtz-Zentrum für Polar- und Meeresforschung, List, Germany
| | - Damien Piel
- Unité Physiologie Fonctionnelle des Organismes Marins, Ifremer, Plouzané, France.,Integrative Biology of Marine Models, UPMC Paris 06, CNRS, UMR 8227, Sorbonne Universités, Station Biologique de Roscoff, Roscoff, France
| | - Maxime Bruto
- Integrative Biology of Marine Models, UPMC Paris 06, CNRS, UMR 8227, Sorbonne Universités, Station Biologique de Roscoff, Roscoff, France
| | - Uwe John
- Ecolgical Chemistry, Alfred Wegener Institut - Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany.,Helmholtz Institute for Functional Marine Biodiversity (HIFMB), Oldenburg, Germany
| | - Zhijuan Mao
- Biological and Environmental College, Zhejiang Wanli University, Ningbo, China
| | - Marianne Alunno-Bruscia
- Unité Physiologie Fonctionnelle des Organismes Marins, Ifremer, Plouzané, France.,LEMAR UMR 6539, Ifremer, Argenton-en-Landunvez, France
| | - Bruno Petton
- Unité Physiologie Fonctionnelle des Organismes Marins, Ifremer, Plouzané, France.,LEMAR UMR 6539, Ifremer, Argenton-en-Landunvez, France
| | - Frédérique Le Roux
- Unité Physiologie Fonctionnelle des Organismes Marins, Ifremer, Plouzané, France.,Integrative Biology of Marine Models, UPMC Paris 06, CNRS, UMR 8227, Sorbonne Universités, Station Biologique de Roscoff, Roscoff, France
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25
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Räihä V, Sundberg L, Ashrafi R, Hyvärinen P, Karvonen A. Rearing background and exposure environment together explain higher survival of aquaculture fish during a bacterial outbreak. J Appl Ecol 2019. [DOI: 10.1111/1365-2664.13393] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Ville Räihä
- Department of Biological and Environmental Science University of Jyväskylä Jyväskylä Finland
| | - Lotta‐Riina Sundberg
- Department of Biological and Environmental Science and Nanoscience Center Centre of Excellence in Biological Interactions University of Jyväskylä Jyväskylä Finland
| | - Roghaieh Ashrafi
- Department of Biological and Environmental Science University of Jyväskylä Jyväskylä Finland
| | - Pekka Hyvärinen
- Aquatic Population Dynamics Natural Resources Institute Finland (Luke) Paltamo Finland
| | - Anssi Karvonen
- Department of Biological and Environmental Science University of Jyväskylä Jyväskylä Finland
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26
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Behringer DC, Karvonen A, Bojko J. Parasite avoidance behaviours in aquatic environments. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0202. [PMID: 29866915 DOI: 10.1098/rstb.2017.0202] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2018] [Indexed: 02/05/2023] Open
Abstract
Parasites, including macroparasites, protists, fungi, bacteria and viruses, can impose a heavy burden upon host animals. However, hosts are not without defences. One aspect of host defence, behavioural avoidance, has been studied in the terrestrial realm for over 50 years, but was first reported from the aquatic environment approximately 20 years ago. Evidence has mounted on the importance of parasite avoidance behaviours and it is increasingly apparent that there are core similarities in the function and benefit of this defence mechanism between terrestrial and aquatic systems. However, there are also stark differences driven by the unique biotic and abiotic characteristics of terrestrial and aquatic (marine and freshwater) environments. Here, we review avoidance behaviours in a comparative framework and highlight the characteristics of each environment that drive differences in the suite of mechanisms and cues that animals use to avoid parasites. We then explore trade-offs, potential negative effects of avoidance behaviour and the influence of human activities on avoidance behaviours. We conclude that avoidance behaviours are understudied in aquatic environments but can have significant implications for disease ecology and epidemiology, especially considering the accelerating emergence and re-emergence of parasites.This article is part of the Theo Murphy meeting issue 'Evolution of pathogen and parasite avoidance behaviours'.
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Affiliation(s)
- Donald C Behringer
- School of Forest Resources and Conservation, Program in Fisheries and Aquatic Sciences, University of Florida, Gainesville, FL, USA .,Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - Anssi Karvonen
- Department of Biological and Environmental Science, University of Jyvaskyla, PO Box 35, 40014 Jyvaskyla, Finland
| | - Jamie Bojko
- School of Forest Resources and Conservation, Program in Fisheries and Aquatic Sciences, University of Florida, Gainesville, FL, USA.,Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
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27
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Pulkkinen K, Pekkala N, Ashrafi R, Hämäläinen DM, Nkembeng AN, Lipponen A, Hiltunen T, Valkonen JK, Taskinen J. Effect of resource availability on evolution of virulence and competition in an environmentally transmitted pathogen. FEMS Microbiol Ecol 2019; 94:4962392. [PMID: 29659817 DOI: 10.1093/femsec/fiy060] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 04/04/2018] [Indexed: 01/21/2023] Open
Abstract
Understanding ecological and epidemiological factors driving pathogen evolution in contemporary time scales is a major challenge in modern health management. Pathogens that replicate outside the hosts are subject to selection imposed by ambient environmental conditions. Increased nutrient levels could increase pathogen virulence by pre-adapting for efficient use of resources upon contact to a nutrient rich host or by favouring transmission of fast-growing virulent strains. We measured changes in virulence and competition in Flavobacterium columnare, a bacterial pathogen of freshwater fish, under high and low nutrient levels. To test competition between strains in genotype mixtures, we developed a quantitative real-time PCR assay. We found that a virulent strain maintained its virulence and outcompeted less virulent strains independent of the nutrient level and resource renewal rate while a less virulent strain further lost virulence in chemostats under low nutrient level and over long-term serial culture under high nutrient level. Our results suggest that increased outside-host nutrient levels might maintain virulence in less virulent strains and increase their contribution to epidemics in aquaculture. The results highlight a need to further explore the role of resource in the outside-host environment in maintaining strain diversity and driving evolution of virulence among environmentally growing pathogens.
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Affiliation(s)
- Katja Pulkkinen
- Department of Biological and Environmental Science, P. O. Box 35, (Survontie 9), University of Jyväskylä, Jyväskylä, Finland
| | - Nina Pekkala
- Department of Biological and Environmental Science, P. O. Box 35, (Survontie 9), University of Jyväskylä, Jyväskylä, Finland
| | - Roghaieh Ashrafi
- Department of Biological and Environmental Science, P. O. Box 35, (Survontie 9), University of Jyväskylä, Jyväskylä, Finland.,Centre of Excellence in Biological Interactions, P. O. Box 35, (Survontie 9), University of Jyväskylä, Jyväskylä,Finland
| | - Dorrit M Hämäläinen
- Department of Biological and Environmental Science, P. O. Box 35, (Survontie 9), University of Jyväskylä, Jyväskylä, Finland
| | - Aloysius N Nkembeng
- Department of Biological and Environmental Science, P. O. Box 35, (Survontie 9), University of Jyväskylä, Jyväskylä, Finland
| | - Anssi Lipponen
- A. I. Virtanen Institute for Molecular Sciences, P. O. Box 1627, (Neulaniementie 2), University of Eastern Finland, Kuopio, Finland
| | - Teppo Hiltunen
- Department of Microbiology, P. O. Box 56, (Viikinkaari 9), University of Helsinki, Helsinki, Finland
| | - Janne K Valkonen
- Department of Biological and Environmental Science, P. O. Box 35, (Survontie 9), University of Jyväskylä, Jyväskylä, Finland.,Centre of Excellence in Biological Interactions, P. O. Box 35, (Survontie 9), University of Jyväskylä, Jyväskylä,Finland
| | - Jouni Taskinen
- Department of Biological and Environmental Science, P. O. Box 35, (Survontie 9), University of Jyväskylä, Jyväskylä, Finland
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28
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Sundberg LR, Karvonen A. Minor environmental concentrations of antibiotics can modify bacterial virulence in co-infection with a non-targeted parasite. Biol Lett 2018; 14:20180663. [PMID: 30958249 PMCID: PMC6303518 DOI: 10.1098/rsbl.2018.0663] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 11/22/2018] [Indexed: 12/17/2022] Open
Abstract
Leakage of medical residues into the environment can significantly impact natural communities. For example, antibiotic contamination from agriculture and aquaculture can directly influence targeted pathogens, but also other non-targeted taxa of commensals and parasites that regularly co-occur and co-infect the same host. Consequently, antibiotics could significantly alter interspecific interactions and epidemiology of the co-infecting parasite community. We studied how minor environmental concentrations of antibiotic affects the co-infection of two parasites, the bacterium Flavobacterium columnare and the fluke Diplostomum pseudospathaceum, in their fish host. We found that antibiotic in feed, and particularly the minute concentration in water, significantly decreased bacterial virulence and changed the infection success of the flukes. These effects depended on the level of antibiotic resistance of the bacterial strains. Antibiotic, however, did not compensate for the higher virulence of co-infections. Our results demonstrate that even very low environmental concentrations of antibiotic can influence ecology and epidemiology of diseases in co-infection with non-targeted parasites. Leakage of antibiotics into the environment may thus have more complex effects on disease ecology than previously anticipated.
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Affiliation(s)
- Lotta-Riina Sundberg
- Department of Biological and Environmental Science, University of Jyvaskyla, PO Box 35, 40014 Jyvaskyla, Finland
- Centre of Excellence of Biological Interactions, Department of Biological and Environmental Science and Nanoscience Center, University of Jyvaskyla, PO Box 35, 40014 Jyvaskyla, Finland
| | - Anssi Karvonen
- Department of Biological and Environmental Science, University of Jyvaskyla, PO Box 35, 40014 Jyvaskyla, Finland
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29
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Ashrafi R, Bruneaux M, Sundberg L, Pulkkinen K, Valkonen J, Ketola T. Broad thermal tolerance is negatively correlated with virulence in an opportunistic bacterial pathogen. Evol Appl 2018; 11:1700-1714. [PMID: 30344637 PMCID: PMC6183471 DOI: 10.1111/eva.12673] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 05/31/2018] [Accepted: 06/22/2018] [Indexed: 01/10/2023] Open
Abstract
Predicting the effects of global increase in temperatures on disease virulence is challenging, especially for environmental opportunistic bacteria, because pathogen fitness may be differentially affected by temperature within and outside host environment. So far, there is very little empirical evidence on the connections between optimal temperature range and virulence in environmentally growing pathogens. Here, we explored whether the virulence of an environmentally growing opportunistic fish pathogen, Flavobacterium columnare, is malleable to evolutionary changes via correlated selection on thermal tolerance. To this end, we experimentally quantified the thermal performance curves (TPCs) for maximum biomass yield of 49 F. columnare isolates from eight different geographic locations in Finland over ten years (2003-2012). We also characterized virulence profiles of these strains in a zebra fish (Danio rerio) infection model. We show that virulence among the strains increased over the years, but thermal generalism, and in particular tolerance to higher temperatures, was negatively associated with virulence. Our data suggest that temperature has a strong effect on the pathogen genetic diversity and therefore presumably also on disease dynamics. However, the observed increase in frequency and severity of F. columnare epidemics over the last decade cannot be directly linked to bacterial evolution due to increased mean temperature, but is most likely associated with factors related to increased length of growing season, or other time-dependent change in environment. Our study demonstrates that complex interactions between the host, the pathogen and the environment influence disease virulence of an environmentally growing opportunistic pathogen.
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Affiliation(s)
- Roghaieh Ashrafi
- Department of Biological and Environmental Science (and Nanoscience Center)Centre of Excellence in Biological InteractionsUniversity of JyväskyläJyväskyläFinland
| | - Matthieu Bruneaux
- Department of Biological and Environmental Science (and Nanoscience Center)Centre of Excellence in Biological InteractionsUniversity of JyväskyläJyväskyläFinland
| | - Lotta‐Riina Sundberg
- Department of Biological and Environmental Science (and Nanoscience Center)Centre of Excellence in Biological InteractionsUniversity of JyväskyläJyväskyläFinland
| | - Katja Pulkkinen
- Department of Biological and Environmental ScienceUniversity of JyväskyläJyväskyläFinland
| | - Janne Valkonen
- Department of Biological and Environmental Science (and Nanoscience Center)Centre of Excellence in Biological InteractionsUniversity of JyväskyläJyväskyläFinland
| | - Tarmo Ketola
- Department of Biological and Environmental Science (and Nanoscience Center)Centre of Excellence in Biological InteractionsUniversity of JyväskyläJyväskyläFinland
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30
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Ancestral gene acquisition as the key to virulence potential in environmental Vibrio populations. ISME JOURNAL 2018; 12:2954-2966. [PMID: 30072747 PMCID: PMC6246604 DOI: 10.1038/s41396-018-0245-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 06/30/2018] [Accepted: 07/06/2018] [Indexed: 11/08/2022]
Abstract
Diseases of marine animals caused by bacteria of the genus Vibrio are on the rise worldwide. Understanding the eco-evolutionary dynamics of these infectious agents is important for predicting and managing these diseases. Yet, compared to Vibrio infecting humans, knowledge of their role as animal pathogens is scarce. Here we ask how widespread is virulence among ecologically differentiated Vibrio populations, and what is the nature and frequency of virulence genes within these populations? We use a combination of population genomics and molecular genetics to assay hundreds of Vibrio strains for their virulence in the oyster Crassostrea gigas, a unique animal model that allows high-throughput infection assays. We show that within the diverse Splendidus clade, virulence represents an ancestral trait but has been lost from several populations. Two loci are necessary for virulence, the first being widely distributed across the Splendidus clade and consisting of an exported conserved protein (R5.7). The second is a MARTX toxin cluster, which only occurs within V. splendidus and is for the first time associated with virulence in marine invertebrates. Varying frequencies of both loci among populations indicate different selective pressures and alternative ecological roles, based on which we suggest strategies for epidemiological surveys.
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31
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Nowak BF, Archibald JM. Opportunistic but Lethal: The Mystery of Paramoebae. Trends Parasitol 2018; 34:404-419. [DOI: 10.1016/j.pt.2018.01.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/13/2018] [Accepted: 01/18/2018] [Indexed: 01/09/2023]
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32
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Xavier R, Severino R, Pérez-Losada M, Gestal C, Freitas R, Harris DJ, Veríssimo A, Rosado D, Cable J. Phylogenetic analysis of apicomplexan parasites infecting commercially valuable species from the North-East Atlantic reveals high levels of diversity and insights into the evolution of the group. Parasit Vectors 2018; 11:63. [PMID: 29370873 PMCID: PMC5785827 DOI: 10.1186/s13071-018-2645-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 01/15/2018] [Indexed: 12/31/2022] Open
Abstract
Background The Apicomplexa from aquatic environments are understudied relative to their terrestrial counterparts, and the seminal work assessing the phylogenetic relations of fish-infecting lineages is mostly based on freshwater hosts. The taxonomic uncertainty of some apicomplexan groups, such as the coccidia, is high and many genera were recently shown to be paraphyletic, questioning the value of strict morphological and ecological traits for parasite classification. Here, we surveyed the genetic diversity of the Apicomplexa in several commercially valuable vertebrates from the North-East Atlantic, including farmed fish. Results Most of the sequences retrieved were closely related to common fish coccidia of Eimeria, Goussia and Calyptospora. However, some lineages from the shark Scyliorhinus canicula were placed as sister taxa to the Isospora, Caryospora and Schellakia group. Additionally, others from Pagrus caeruleostictus and Solea senegalensis belonged to an unknown apicomplexan group previously found in the Caribbean Sea, where it was sequenced from the water column, corals, and fish. Four distinct parasite lineages were found infecting farmed Dicentrarchus labrax or Sparus aurata. One of the lineages from farmed D. labrax was also found infecting wild counterparts, and another was also recovered from farmed S. aurata and farm-associated Diplodus sargus. Conclusions Our results show that marine fish apicomplexans are diverse, and we highlight the need for a more extensive assessment of parasite diversity in this phylum. Additionally, parasites recovered from S. canicula were recovered as basal to their piscine counterparts reflecting hosts phylogeny. Electronic supplementary material The online version of this article (10.1186/s13071-018-2645-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Raquel Xavier
- CIBIO, Universidade do Porto, Campus Agrário de Vairão, Rua Padre Armando Quintas, 4486-661, Vairão, Portugal.
| | - Ricardo Severino
- Piscicultura Vale da Lama, Sapal do Vale da Lama, Odiáxere, Lagos, 8600-258, Nigeria
| | - Marcos Pérez-Losada
- CIBIO, Universidade do Porto, Campus Agrário de Vairão, Rua Padre Armando Quintas, 4486-661, Vairão, Portugal.,Department of Invertebrate Zoology, US National Museum of Natural History, Smithsonian Institution, Washington, DC, 20013, USA
| | - Camino Gestal
- Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas (IIM-CSIC), Eduardo Cabello, 6, 36208, Vigo, Spain
| | - Rita Freitas
- CIBIO, Universidade do Porto, Campus Agrário de Vairão, Rua Padre Armando Quintas, 4486-661, Vairão, Portugal
| | - D James Harris
- CIBIO, Universidade do Porto, Campus Agrário de Vairão, Rua Padre Armando Quintas, 4486-661, Vairão, Portugal
| | - Ana Veríssimo
- CIBIO, Universidade do Porto, Campus Agrário de Vairão, Rua Padre Armando Quintas, 4486-661, Vairão, Portugal.,Virginia Institute of Marine Science, College of William and Mary, Route 1208, Greate Road, 23062 Gloucester Point, Virginia, USA
| | - Daniela Rosado
- CIBIO, Universidade do Porto, Campus Agrário de Vairão, Rua Padre Armando Quintas, 4486-661, Vairão, Portugal
| | - Joanne Cable
- School of Biosciences, Cardiff University, Cardiff, CF10 3AX, UK
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Long-term genomic coevolution of host-parasite interaction in the natural environment. Nat Commun 2017; 8:111. [PMID: 28740072 PMCID: PMC5524643 DOI: 10.1038/s41467-017-00158-7] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 06/02/2017] [Indexed: 12/14/2022] Open
Abstract
Antagonistic coevolution of parasite infectivity and host resistance may alter the biological functionality of species, yet these dynamics in nature are still poorly understood. Here we show the molecular details of a long-term phage-bacterium arms race in the environment. Bacteria (Flavobacterium columnare) are generally resistant to phages from the past and susceptible to phages isolated in years after bacterial isolation. Bacterial resistance selects for increased phage infectivity and host range, which is also associated with expansion of phage genome size. We identified two CRISPR loci in the bacterial host: a type II-C locus and a type VI-B locus. While maintaining a core set of conserved spacers, phage-matching spacers appear in the variable ends of both loci over time. The spacers mostly target the terminal end of the phage genomes, which also exhibit the most variation across time, resulting in arms-race-like changes in the protospacers of the coevolving phage population.Arms races between phage and bacteria are well known from lab experiments, but insight from field systems is limited. Here, the authors show changes in the resistance and CRISPR loci of bacteria and the infectivity, host range and genome size of phage over multiple years in an aquaculture environment.
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Mennerat A, Ugelvik MS, Håkonsrud Jensen C, Skorping A. Invest more and die faster: The life history of a parasite on intensive farms. Evol Appl 2017; 10:890-896. [PMID: 29151880 PMCID: PMC5680424 DOI: 10.1111/eva.12488] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/11/2017] [Indexed: 01/05/2023] Open
Abstract
Organisms are expected to respond to alterations in their survival by evolutionary changes in their life history traits. As agriculture and aquaculture have become increasingly intensive in the past decades, there has been growing interest in their evolutionary effects on the life histories of agri‐ and aquacultural pests, parasites, and pathogens. In this study, we used salmon lice (Lepeophtheirus salmonis) to explore how modern farming might have affected life history evolution in parasites. We infected salmon hosts with lice from either farmed or unfarmed locations, and monitored life history traits of those parasites in laboratory conditions. Our results show that compared to salmon lice from areas unaffected by salmon farming, those from farmed areas produced more eggs in their first clutch, and less eggs later on; they achieved higher infestation intensities in early adulthood, but suffered higher adult mortality. These results suggest that salmon lice on farms may have been selected for increased investment in early reproduction, at the expense of later fecundity and survival. This call for further empirical studies of the extent to which farming practices may alter the virulence of agricultural parasites.
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Affiliation(s)
- Adèle Mennerat
- Department of Biology University of Bergen Bergen Norway.,Ecologie et Dynamique des Systèmes Anthropisés (FRE 3498) CNRS/Université de Picardie Jules Verne Amiens France
| | | | | | - Arne Skorping
- Department of Biology University of Bergen Bergen Norway
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Ugelvik MS, Skorping A, Moberg O, Mennerat A. Evolution of virulence under intensive farming: salmon lice increase skin lesions and reduce host growth in salmon farms. J Evol Biol 2017; 30:1136-1142. [DOI: 10.1111/jeb.13082] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 03/28/2017] [Accepted: 03/29/2017] [Indexed: 01/05/2023]
Affiliation(s)
- M. S. Ugelvik
- Department of Biology; University of Bergen; Bergen Norway
| | - A. Skorping
- Department of Biology; University of Bergen; Bergen Norway
| | - O. Moberg
- Department of Biology; University of Bergen; Bergen Norway
| | - A. Mennerat
- Department of Biology; University of Bergen; Bergen Norway
- Ecologie et Dynamique des Systèmes Anthropisés (FRE 3498); CNRS/Université de Picardie Jules Verne; Amiens France
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36
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Ashrafi R, Bruneaux M, Sundberg LR, Pulkkinen K, Ketola T. Application of high resolution melting assay (HRM) to study temperature-dependent intraspecific competition in a pathogenic bacterium. Sci Rep 2017; 7:980. [PMID: 28428555 PMCID: PMC5430548 DOI: 10.1038/s41598-017-01074-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 03/22/2017] [Indexed: 01/18/2023] Open
Abstract
Studies on species’ responses to climate change have focused largely on the direct effect of abiotic factors and in particular temperature, neglecting the effects of biotic interactions in determining the outcome of climate change projections. Many microbes rely on strong interference competition; hence the fitness of many pathogenic bacteria could be a function of both their growth properties and intraspecific competition. However, due to technical challenges in distinguishing and tracking individual strains, experimental evidence on intraspecific competition has been limited so far. Here, we developed a robust application of the high-resolution melting (HRM) assay to study head-to-head competition between mixed genotype co-cultures of a waterborne bacterial pathogen of fish, Flavobacterium columnare, at two different temperatures. We found that competition outcome in liquid cultures seemed to be well predicted by growth yield of isolated strains, but was mostly inconsistent with interference competition results measured in inhibition tests on solid agar, especially as no growth inhibition between strain pairs was detected at the higher temperature. These results suggest that, for a given temperature, the factors driving competition outcome differ between liquid and solid environments.
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Affiliation(s)
- Roghaieh Ashrafi
- Department of Biological and Environmental Science (and Nanoscience Center), University of Jyvaskyla, Centre of Excellence in Biological Interactions, P.O. Box 35, FI-40014, Jyvaskyla, Finland.
| | - Matthieu Bruneaux
- Department of Biological and Environmental Science (and Nanoscience Center), University of Jyvaskyla, Centre of Excellence in Biological Interactions, P.O. Box 35, FI-40014, Jyvaskyla, Finland
| | - Lotta-Riina Sundberg
- Department of Biological and Environmental Science (and Nanoscience Center), University of Jyvaskyla, Centre of Excellence in Biological Interactions, P.O. Box 35, FI-40014, Jyvaskyla, Finland
| | - Katja Pulkkinen
- Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, FI-40014, Jyvaskyla, Finland
| | - Tarmo Ketola
- Department of Biological and Environmental Science (and Nanoscience Center), University of Jyvaskyla, Centre of Excellence in Biological Interactions, P.O. Box 35, FI-40014, Jyvaskyla, Finland
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Kinnula H, Mappes J, Sundberg LR. Coinfection outcome in an opportunistic pathogen depends on the inter-strain interactions. BMC Evol Biol 2017; 17:77. [PMID: 28288561 PMCID: PMC5348763 DOI: 10.1186/s12862-017-0922-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 02/22/2017] [Indexed: 11/11/2022] Open
Abstract
Background In nature, organisms are commonly coinfected by two or more parasite strains, which has been shown to influence disease virulence. Yet, the effects of coinfections of environmental opportunistic pathogens on disease outcome are still poorly known, although as host-generalists they are highly likely to participate in coinfections. We asked whether coinfection with conspecific opportunistic strains leads to changes in virulence, and if these changes are associated with bacterial growth or interference competition. We infected zebra fish (Danio rerio) with three geographically and/or temporally distant environmental opportunist Flavobacterium columnare strains in single and in coinfection. Growth of the strains was studied in single and in co-cultures in liquid medium, and interference competition (growth-inhibiting ability) on agar. Results The individual strains differed in their virulence, growth and ability for interference competition. Number of coinfecting strains significantly influenced the virulence of infection, with three-strain coinfection differing from the two-strain and single infections. Differences in virulence seemed to associate with the identity of the coinfecting bacterial strains, and their pairwise interactions. This indicates that benefits of competitive ability (production of growth-inhibiting compounds) for virulence are highest when multiple strains co-occur, whereas the high virulence in coinfection may be independent from in vitro bacterial growth. Conclusions Intraspecific competition can lead to plastic increase in virulence, likely caused by faster utilization of host resources stimulated by the competitive interactions between the strains. However, disease outcome depends both on the characteristics of individual strains and their interactions. Our results highlight the importance of strain interactions in disease dynamics in environments where various pathogen genotypes co-occur. Electronic supplementary material The online version of this article (doi:10.1186/s12862-017-0922-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hanna Kinnula
- Department of Biological and Environmental Science (and Nanoscience Center), Jyvaskyla, Finland
| | - Johanna Mappes
- Department of Biological and Environmental Science (and Nanoscience Center), Jyvaskyla, Finland
| | - Lotta-Riina Sundberg
- Department of Biological and Environmental Science (and Nanoscience Center), Jyvaskyla, Finland.
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Bayliss SC, Verner-Jeffreys DW, Bartie KL, Aanensen DM, Sheppard SK, Adams A, Feil EJ. The Promise of Whole Genome Pathogen Sequencing for the Molecular Epidemiology of Emerging Aquaculture Pathogens. Front Microbiol 2017; 8:121. [PMID: 28217117 PMCID: PMC5290457 DOI: 10.3389/fmicb.2017.00121] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 01/17/2017] [Indexed: 01/23/2023] Open
Abstract
Aquaculture is the fastest growing food-producing sector, and the sustainability of this industry is critical both for global food security and economic welfare. The management of infectious disease represents a key challenge. Here, we discuss the opportunities afforded by whole genome sequencing of bacterial and viral pathogens of aquaculture to mitigate disease emergence and spread. We outline, by way of comparison, how sequencing technology is transforming the molecular epidemiology of pathogens of public health importance, emphasizing the importance of community-oriented databases and analysis tools.
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Affiliation(s)
- Sion C Bayliss
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath Bath, UK
| | | | - Kerry L Bartie
- Institute of Aquaculture, University of Stirling Stirling, UK
| | - David M Aanensen
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College LondonLondon, UK; The Centre for Genomic Pathogen Surveillance, Wellcome Genome CampusCambridge, UK
| | - Samuel K Sheppard
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath Bath, UK
| | - Alexandra Adams
- Institute of Aquaculture, University of Stirling Stirling, UK
| | - Edward J Feil
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath Bath, UK
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