1
|
Del Carmen Guarneros Martínez T, Cáceres-Martínez J, Cruz-Flores R, López-Carvallo JA, Ángel Del Río-Portilla M, Guerrero Rentería Y. Prevalence and intensity of a Rickettsiales-like organism in cultured pleasure oyster, Crassostrea corteziensis, from Nayarit, Mexico. J Invertebr Pathol 2024; 204:108093. [PMID: 38479454 DOI: 10.1016/j.jip.2024.108093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 01/24/2024] [Accepted: 03/10/2024] [Indexed: 05/23/2024]
Abstract
Fastidious endosymbiotic Rickettsiales-like organisms (RLOs) have been observed in the digestive diverticula of the cultured pleasure oyster (Crassostrea corteziensis) from Nayarit, Mexico since 2007. In a few mollusk species, these bacteria have been associated with mortality events and production losses. The type of relationship between the RLOs and the pleasure oyster is largely unknown and further investigations are needed to determine if these bacteria warrant management concern in C. corteziensis. In this study, the morphological characteristics of the RLOs were studied by histology and SEM, and the taxonomic affiliations of the bacteria were evaluated by 16S rRNA amplicon sequencing. In addition, the prevalence and intensity of the RLOs was recorded from 2007 to 2017 by histology. The RLOs were observed inside circular basophilic cytoplasmic membrane bound vacuoles (MBVs) that had an average length and width of 15.70 ± 15.24 µm and 15.42 ± 14.95 µm respectively. Apart from cellular hypertrophy, no tissue alterations were observed in the areas adjacent to the RLOs. Individual bacteria within the MBVs were coccoid in shape with an average length of 0.65 ± 0.12 µm and an average width of 0.38 ± 0.09 µm. The bacterial microbiota of a selected number of samples (one sample without RLOs and two samples with RLOs) showed the presence of intracellular parasite OTUs corresponding to the families Rickettsiaceae and Anaplasmataceae, suggesting that the RLOs from the pleasure oyster is associated with the order Rickettsiales. A mean prevalence of 5 % was observed throughout the study period and the majority of the organisms (89 %) presented low intensity of Grade 1 (30-61 RLOs) of the MBVs. A higher prevalence of the RLOs was observed during warmer months. The lack of tissue alterations, the low prevalence and the low intensity of the MBVs suggest that the RLOs from C. corteziensis is a commensal endosymbiont that presents little risk for oyster production in Nayarit, México. However, regular monitoring is needed to detect if any variation in this relationship occurs, mainly in a scenario where extreme environmental fluctuations may occur.
Collapse
Affiliation(s)
- Teresita Del Carmen Guarneros Martínez
- Centro de Investigación Científica y de Educación Superior de Ensenada, (CICESE), Carretera Ensenada-Tijuana No. 3918, Zona Playitas 22860 Ensenada, Baja CA, México
| | - Jorge Cáceres-Martínez
- Centro de Investigación Científica y de Educación Superior de Ensenada, (CICESE), Carretera Ensenada-Tijuana No. 3918, Zona Playitas 22860 Ensenada, Baja CA, México
| | - Roberto Cruz-Flores
- Centro de Investigación Científica y de Educación Superior de Ensenada, (CICESE), Carretera Ensenada-Tijuana No. 3918, Zona Playitas 22860 Ensenada, Baja CA, México.
| | - Jesús Antonio López-Carvallo
- Laboratorio de Fisiología y Genética Marina, Departamento de Acuicultura, Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
| | - Miguel Ángel Del Río-Portilla
- Centro de Investigación Científica y de Educación Superior de Ensenada, (CICESE), Carretera Ensenada-Tijuana No. 3918, Zona Playitas 22860 Ensenada, Baja CA, México
| | - Yanet Guerrero Rentería
- Centro de Investigación Científica y de Educación Superior de Ensenada, (CICESE), Carretera Ensenada-Tijuana No. 3918, Zona Playitas 22860 Ensenada, Baja CA, México
| |
Collapse
|
2
|
Wooldridge B, Orland C, Enbody E, Escalona M, Mirchandani C, Corbett-Detig R, Kapp JD, Fletcher N, Cox-Ammann K, Raimondi P, Shapiro B. Limited genomic signatures of population collapse in the critically endangered black abalone (Haliotis cracherodii). Mol Ecol 2024:e17362. [PMID: 38682494 DOI: 10.1111/mec.17362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/05/2024] [Accepted: 04/09/2024] [Indexed: 05/01/2024]
Abstract
The black abalone, Haliotis cracherodii, is a large, long-lived marine mollusc that inhabits rocky intertidal habitats along the coast of California and Mexico. In 1985, populations were impacted by a bacterial disease known as withering syndrome (WS) that wiped out >90% of individuals, leading to the closure of all U.S. black abalone fisheries since 1993. Current conservation strategies include restoring diminished populations by translocating healthy individuals. However, population collapse on this scale may have dramatically lowered genetic diversity and strengthened geographic differentiation, making translocation-based recovery contentious. Additionally, the current prevalence of WS remains unknown. To address these uncertainties, we sequenced and analysed the genomes of 133 black abalone individuals from across their present range. We observed no spatial genetic structure among black abalone, with the exception of a single chromosomal inversion that increases in frequency with latitude. Outside the inversion, genetic differentiation between sites is minimal and does not scale with either geographic distance or environmental dissimilarity. Genetic diversity appears uniformly high across the range. Demographic inference does indicate a severe population bottleneck beginning just 15 generations in the past, but this decline is short lived, with present-day size far exceeding the pre-bottleneck status quo. Finally, we find the bacterial agent of WS is equally present across the sampled range, but only in 10% of individuals. The lack of population genetic structure, uniform diversity and prevalence of WS bacteria indicates that translocation could be a valid and low-risk means of population restoration for black abalone species' recovery.
Collapse
Affiliation(s)
- Brock Wooldridge
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, California, USA
| | - Chloé Orland
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
| | - Erik Enbody
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, USA
| | - Merly Escalona
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, USA
| | - Cade Mirchandani
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, USA
| | - Russell Corbett-Detig
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, USA
- Genomics Institute, University of California Santa Cruz, Santa Cruz, California, USA
| | - Joshua D Kapp
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
| | - Nathaniel Fletcher
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
| | - Karah Cox-Ammann
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
| | - Peter Raimondi
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
| | - Beth Shapiro
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, California, USA
- Genomics Institute, University of California Santa Cruz, Santa Cruz, California, USA
| |
Collapse
|
3
|
Wooldridge B, Orland C, Enbody E, Escalona M, Mirchandani C, Corbett-Detig R, Kapp JD, Fletcher N, Ammann K, Raimondi P, Shapiro B. Limited genomic signatures of population collapse in the critically endangered black abalone ( Haliotis cracherodii). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.26.577275. [PMID: 38352393 PMCID: PMC10862700 DOI: 10.1101/2024.01.26.577275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/19/2024]
Abstract
The black abalone, Haliotis cracherodii, is a large, long-lived marine mollusc that inhabits rocky intertidal habitats along the coast of California and Mexico. In 1985, populations were impacted by a bacterial disease known as withering syndrome (WS) that wiped out >90% of individuals, leading to the species' designation as critically endangered. Current conservation strategies include restoring diminished populations by translocating healthy individuals. However, population collapse on this scale may have dramatically lowered genetic diversity and strengthened geographic differentiation, making translocation-based recovery contentious. Additionally, the current prevalence of WS is unknown. To address these uncertainties, we sequenced and analyzed the genomes of 133 black abalone individuals from across their present range. We observed no spatial genetic structure among black abalone, with the exception of a single chromosomal inversion that increases in frequency with latitude. Genetic divergence between sites is minimal, and does not scale with either geographic distance or environmental dissimilarity. Genetic diversity appears uniformly high across the range. Despite this, however, demographic inference confirms a severe population bottleneck beginning around the time of WS onset, highlighting the temporal offset that may occur between a population collapse and its potential impact on genetic diversity. Finally, we find the bacterial agent of WS is equally present across the sampled range, but only in 10% of individuals. The lack of genetic structure, uniform diversity, and prevalence of WS bacteria indicates that translocation could be a valid and low-risk means of population restoration for black abalone species' recovery.
Collapse
Affiliation(s)
- Brock Wooldridge
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
| | - Chloé Orland
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Erik Enbody
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Merly Escalona
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Cade Mirchandani
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Russell Corbett-Detig
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
- Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Joshua D Kapp
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Nathaniel Fletcher
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Karah Ammann
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Peter Raimondi
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Beth Shapiro
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
- Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| |
Collapse
|
4
|
Potts RWA, Gutierrez AP, Penaloza CS, Regan T, Bean TP, Houston RD. Potential of genomic technologies to improve disease resistance in molluscan aquaculture. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200168. [PMID: 33813884 PMCID: PMC8059958 DOI: 10.1098/rstb.2020.0168] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2020] [Indexed: 01/04/2023] Open
Abstract
Molluscan aquaculture is a major contributor to global seafood production, but is hampered by infectious disease outbreaks that can cause serious economic losses. Selective breeding has been widely used to improve disease resistance in major agricultural and aquaculture species, and has clear potential in molluscs, albeit its commercial application remains at a formative stage. Advances in genomic technologies, especially the development of cost-efficient genomic selection, have the potential to accelerate genetic improvement. However, tailored approaches are required owing to the distinctive reproductive and life cycle characteristics of molluscan species. Transgenesis and genome editing, in particular CRISPR/Cas systems, have been successfully trialled in molluscs and may further understanding and improvement of genetic resistance to disease through targeted changes to the host genome. Whole-organism genome editing is achievable on a much greater scale compared to other farmed species, making genome-wide CRISPR screening approaches plausible. This review discusses the current state and future potential of selective breeding, genomic tools and genome editing approaches to understand and improve host resistance to infectious disease in molluscs. This article is part of the Theo Murphy meeting issue 'Molluscan genomics: broad insights and future directions for a neglected phylum'.
Collapse
Affiliation(s)
- Robert W. A. Potts
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, UK
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Weymouth Laboratory, Dorset DT4 8UB, UK
| | - Alejandro P. Gutierrez
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, UK
| | - Carolina S. Penaloza
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, UK
| | - Tim Regan
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, UK
| | - Tim P. Bean
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, UK
| | - Ross D. Houston
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, UK
| |
Collapse
|
5
|
Microbiota of the Digestive Gland of Red Abalone ( Haliotis rufescens) Is Affected by Withering Syndrome. Microorganisms 2020; 8:microorganisms8091411. [PMID: 32933183 PMCID: PMC7565822 DOI: 10.3390/microorganisms8091411] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/28/2020] [Accepted: 09/03/2020] [Indexed: 12/30/2022] Open
Abstract
Withering syndrome (WS), an infectious disease caused by intracellular bacteria Candidatus Xenohaliotis californiensis, has provoked significant economic losses in abalone aquaculture. The pathogen infects gastroenteric epithelia, including digestive gland, disrupting the digestive system and causing a progressive wilting in abalone. Nonetheless, our knowledge about WS implications in digestive gland microbiota, and its role in diseases progress remains largely unknown. This study aims to determine whether digestive gland-associated microbiota differs between healthy red abalone (Haliotis rufescens) and red abalone affected with WS. Using high-throughput sequencing of the V4 region of the 16S rRNA gene, our results revealed differences in microbiota between groups. Bacterial genera, including Mycoplasma, Lactobacillus, Cocleimonas and Tateyamaria were significantly more abundant in healthy abalones, whilst Candidatus Xenohaliotis californiensis and Marinomonas were more abundant in WS-affected abalones. Whilst Mycoplasma was the dominant genus in the healthy group, Candidatus Xenohaliotis californiensis was dominant in the WS group. However, Candidatus Xenohaliotis californiensis was present in two healthy specimens, and thus the Mycoplasma/Candidatus Xenohaliotis californiensis ratio appears to be more determinant in specimens affected with WS. Further research to elucidate the role of digestive gland microbiota ecology in WS pathogenesis is required.
Collapse
|
6
|
Lozano‐Huntelman NA, Singh N, Valencia A, Mira P, Sakayan M, Boucher I, Tang S, Brennan K, Gianvecchio C, Fitz‐Gibbon S, Yeh P. Evolution of antibiotic cross-resistance and collateral sensitivity in Staphylococcus epidermidis using the mutant prevention concentration and the mutant selection window. Evol Appl 2020; 13:808-823. [PMID: 32211069 PMCID: PMC7086048 DOI: 10.1111/eva.12903] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 11/14/2019] [Indexed: 01/09/2023] Open
Abstract
In bacteria, evolution of resistance to one antibiotic is frequently associated with increased resistance (cross-resistance) or increased susceptibility (collateral sensitivity) to other antibiotics. Cross-resistance and collateral sensitivity are typically evaluated at the minimum inhibitory concentration (MIC). However, these susceptibility changes are not well characterized with respect to the mutant prevention concentration (MPC), the antibiotic concentration that prevents a single-step mutation from occurring. We measured the MIC and the MPC for Staphylococcus epidermidis and 14 single-drug resistant strains against seven antibiotics. We found that the MIC and the MPC were positively correlated but that this correlation weakened if cross-resistance did not evolve. If any type of resistance did evolve, the range of concentrations between the MIC and the MPC tended to shift right and widen. Similar patterns of cross-resistance and collateral sensitivity were observed at the MIC and MPC levels, though more symmetry was observed at the MIC level. Whole-genome sequencing revealed mutations in both known-target and nontarget genes. Moving forward, examining both the MIC and the MPC may lead to better predictions of evolutionary trajectories in antibiotic-resistant bacteria.
Collapse
Affiliation(s)
| | - Nina Singh
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCAUSA
| | - Alondra Valencia
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCAUSA
| | - Portia Mira
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCAUSA
| | - Maral Sakayan
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCAUSA
| | - Ian Boucher
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCAUSA
| | - Sharon Tang
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCAUSA
| | - Kelley Brennan
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCAUSA
| | - Crystal Gianvecchio
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCAUSA
| | - Sorel Fitz‐Gibbon
- Department of Molecular, Cell, Developmental BiologyUniversity of CaliforniaLos AngelesCAUSA
| | - Pamela Yeh
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCAUSA
- Santa Fe InstituteSanta FeNMUSA
| |
Collapse
|
7
|
Srisapoome P, Chatchaiphan S, Bunnoy A, Koonawootrittriron S, Na-Nakorn U. Heritability of immunity traits and disease resistance of bighead catfish, Clarias macrocephalus Günther, 1864. FISH & SHELLFISH IMMUNOLOGY 2019; 92:209-215. [PMID: 31181340 DOI: 10.1016/j.fsi.2019.05.060] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 05/25/2019] [Accepted: 05/27/2019] [Indexed: 06/09/2023]
Abstract
Disease outbreak is a major obstruction for intensive aquaculture worldwide. One of the promising solutions is genetic improvement by selective breeding, providing that a sufficient proportion of additive genetic variance (measured by heritability-h2) of disease resistance traits exists. In addition, immunity traits are of interest as potential indirect targeted traits for disease resistance. In this study, the genetic parameters of resistance to Aeromonas hydrophila were reported for the first time in the bighead catfish, Clarias macrocephalus Günther, 1864 which is an important parental species for the production of the commercially important hybrid C. macrocephalus × C. gariepinus. The analyses were performed on 736 data records obtained from 74 full-sib families (31 half-sib families) produced by factorial mating design. The results showed that the heritability of survival rate after disease (Aeromonas hydrophila) challenge (intraperitoneal injection with 0.1 ml containing 1 × 106 CFU/ml of A. hydrophila) was low to moderate (0.05 ± 0.02-0.27 ± 0.15). The immune traits (bactericidal activity-BA, lysozyme activity-LA, and alternative complement activity-ACH50) had low to moderate heritability (h2BA = 0.05 ± 0.02; h2LA = 0.16 ± 0.04; h2ACH50 = 0.31 ± 0.06) while heritability of hematocrit (Hct) was also low (h2Hct = 0.17 ± 0.04). The results suggested the possibility to improve resistance to A. hydrophila by selection, while the possibility to use immunity traits as indirect selection criteria for disease resistance is still unclear.
Collapse
Affiliation(s)
- Prapansak Srisapoome
- Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Jatujak, Bangkok, 10900, Thailand
| | - Satid Chatchaiphan
- Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Jatujak, Bangkok, 10900, Thailand
| | - Anurak Bunnoy
- Doctoral Program in Aquaculture, Graduate School of Kasetsart University, Kasetsart University, Jatujak, Bangkok, 10900, Thailand
| | - Skorn Koonawootrittriron
- Department of Animal Science, Faculty of Agriculture, Kasetsart University, Jatujak, Bangkok, 10900, Thailand
| | - Uthairat Na-Nakorn
- Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Jatujak, Bangkok, 10900, Thailand.
| |
Collapse
|
8
|
Vater A, Byrne BA, Marshman BC, Ashlock LW, Moore JD. Differing responses of red abalone ( Haliotis rufescens) and white abalone ( H. sorenseni) to infection with phage-associated Candidatus Xenohaliotis californiensis. PeerJ 2018; 6:e5104. [PMID: 29967748 PMCID: PMC6022723 DOI: 10.7717/peerj.5104] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 06/05/2018] [Indexed: 11/20/2022] Open
Abstract
The Rickettsiales-like prokaryote and causative agent of Withering Syndrome (WS)-Candidatus Xenohaliotis californiensis (Ca. Xc)-decimated black abalone populations along the Pacific coast of North America. White abalone-Haliotis sorenseni-are also susceptible to WS and have become nearly extinct in the wild due to overfishing in the 1970s. Candidatus Xenohaliotis californiensis proliferates within epithelial cells of the abalone gastrointestinal tract and causes clinical signs of starvation. In 2012, evidence of a putative bacteriophage associated with Ca. Xc in red abalone-Haliotis rufescens-was described. Recently, histologic examination of animals with Ca. Xc infection in California abalone populations universally appear to have the phage-containing inclusions. In this study, we investigated the current virulence of Ca. Xc in red abalone and white abalone at different environmental temperatures. Using a comparative experimental design, we observed differences over time between the two abalone species in mortality, body condition, and bacterial load by quantitative real time PCR (qPCR). By day 251, all white abalone exposed to the current variant of Ca. Xc held in the warm water (18.5 °C) treatment died, while red abalone exposed to the same conditions had a mortality rate of only 10%, despite a relatively heavy bacterial burden as determined by qPCR of posterior esophagus tissue and histological assessment at the termination of the experiment. These data support the current status of Ca. Xc as less virulent in red abalone, and may provide correlative evidence of a protective phage interaction. However, white abalone appear to remain highly susceptible to this disease. These findings have important implications for implementation of a white abalone recovery program, particularly with respect to the thermal regimes of locations where captively-reared individuals will be outplanted.
Collapse
Affiliation(s)
- Ashley Vater
- Integrative Pathobiology Graduate Group, University of California, Davis, Davis, United States of America
| | - Barbara A. Byrne
- Pathology, Microbiology, Immunology, School of Veterinary Medicine, University of California, Davis, Davis, United States of America
| | - Blythe C. Marshman
- Shellfish Health Laboratory, California Department of Fish and Wildlife, Bodega Bay, United States of America
| | - Lauren W. Ashlock
- Shellfish Health Laboratory, California Department of Fish and Wildlife, Bodega Bay, United States of America
| | - James D. Moore
- Shellfish Health Laboratory, California Department of Fish and Wildlife, Bodega Bay, United States of America
- Karen C. Drayer Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, Davis, United States of America
| |
Collapse
|
9
|
Winkler FM, García R, Valdivia MV, Lohrmann KB. Assessment of oxytetracycline baths as therapeutic treatment for the control of the agent of withering syndrome (WS) in red abalone (Haliotis rufescens). J Invertebr Pathol 2018; 153:109-116. [PMID: 29501500 DOI: 10.1016/j.jip.2018.02.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 02/14/2018] [Accepted: 02/27/2018] [Indexed: 11/29/2022]
Abstract
Withering Syndrome (WS) is a lethal disease that affects abalone species in both wild and farmed populations. This infection, caused by the rickettsial-like intracellular organism (RLO) Candidatus Xenohaliotis californiensis, can severely impair the normal development of affected animals, and ultimately, their survival. The most common line of action against the WS has been the use of antibiotics, specifically oxytetracycline (OTC), administered via intramuscular injection and per os via medicated feed. In the present study, we have assessed the effectiveness of OTC baths as therapeutic treatment for the control of the WS agent in H. rufescens. Clinical signs of infection were monitored for 11 months in treated juveniles, in addition to feed consumption rate, growth patterns and gonad development. Abalones were asymptomatic until the end of the experiment, when a small number of non-treated animals exhibited clinical signs of infection. Gonad maturity was not observed. OTC treated animals grew significantly less than their non-treated counterparts, being 4.3% shorter and 13.6% lighter at the end of the experiment. They also displayed negative allometry, i.e. for the same shell length, they were lighter than non-treated groups. Furthermore, the weight of muscle and soft tissues in OTC treated animals was lighter than in the other groups, while no differences were found in shell weight. The feed consumption rate was the same for all groups, thus the observed growth patterns cannot be attributed to a decreased feed intake. One possible explanation is that antibiotic treatment may have impacted gut microflora, thus preventing efficient nutrient digestion and absorption and, indirectly, reducing growth. Prevalence of RLOs causing WS (WS-RLO) and the variant form (RLOv), infected with a bacteriophague and non virulent, were significantly lower in the OTC-treated group than in the other groups. Similar results were observed for the mean intensity of RLOv, while for WS-RLO, the intensity in the OTC-treated group was higher, although not statistically significant, than the rest of the groups. These observations may be the consequence of an increased bacterial sensitivity to OTC effects associated with the phage infection or faster reproduction of WS-RLOs than RLOv after OTC treatment. Our results let us infer that the prophylactic use of OTC in abalone to avoid the negative effects of WS on abalone farms could have an undesired negative effect on the biological control exerted by the phage on the bacteria after OTC treatment.
Collapse
Affiliation(s)
- Federico M Winkler
- Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile; Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Larrondo 1281, Coquimbo, Chile; Centro de Innovación Acuícola AquaPacífico, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile.
| | - Ricardo García
- Magister en Gestión Ambiental, Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
| | - María Vicenta Valdivia
- Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile; Centro de Innovación Acuícola AquaPacífico, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
| | - Karin B Lohrmann
- Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile; Centro de Innovación Acuícola AquaPacífico, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
| |
Collapse
|