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1.
J Proteome Res ; 23(7): 2419-2430, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38807289

RESUMEN

Since 1998, California sea lion (Zalophus californianus) stranding events associated with domoic acid toxicosis (DAT) have consistently increased. Outside of direct measurement of domoic acid in bodily fluids at the time of stranding, there are no practical nonlethal clinical tests for the diagnosis of DAT that can be utilized in a rehabilitation facility. Proteomics analysis was conducted to discover candidate protein markers of DAT using cerebrospinal fluid from stranded California sea lions with acute DAT (n = 8), chronic DAT (n = 19), or without DAT (n = 13). A total of 2005 protein families were identified experiment-wide. A total of 83 proteins were significantly different in abundance across the three groups (adj. p < 0.05). MDH1, PLD3, ADAM22, YWHAG, VGF, and CLSTN1 could discriminate California sea lions with or without DAT (AuROC > 0.75). IGKV2D-28, PTRPF, KNG1, F2, and SNCB were able to discriminate acute DAT from chronic DAT (AuROC > 0.75). Proteins involved in alpha synuclein deposition were over-represented as classifiers of DAT, and many of these proteins have been implicated in a variety of neurodegenerative diseases. These proteins should be considered potential markers for DAT in California sea lions and should be prioritized for future validation studies as biomarkers.


Asunto(s)
Biomarcadores , Ácido Kaínico , Leones Marinos , Animales , Ácido Kaínico/análogos & derivados , Ácido Kaínico/toxicidad , Biomarcadores/líquido cefalorraquídeo , Proteómica/métodos
2.
Vet Pathol ; 61(1): 125-134, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37458158

RESUMEN

Phocine distemper virus (PDV) is a significant cause of mortality for phocid seals; however, the susceptibility of otariids to this virus is poorly understood. The authors used a lymph-node explant culture system from California sea lions (Zalophus californianus, CSL) to investigate: (1) the role of signaling lymphocyte activation molecule (SLAM) and nectin-4 in PDV infection and their cellular expression patterns, (2) if PDV induces transcriptional regulation of cell-entry receptors, and (3) the involvement of apoptosis in PDV infection. PDV replicated in the lymph-node explants with peak replication 3 days post-infection (dpi), but the replication was not sustained 4 to 5 dpi. The PDV+ cells co-localized SLAM and nectin-4. These cells expressed IBA1, indicating a histiocytic lineage. Comparison of receptor expression between infected and mock-infected lymph nodes suggested transcriptional downregulation of both receptors during the initial stage of infection and upregulation during the late stage of infection, but the values lack of statistical significance. Cleaved caspase-3+ cells were slightly increased in the infected lymph nodes compared with the mock-infected lymph node from 1 to 4 dpi, but without statistical significance, and a few apoptotic cells co-expressed PDV. The results suggest that lymph-node explants might be an important model to study PDV pathogenesis. CSLs have the potential to be infected with PDV, as they express both cell-entry receptors in histiocytes. The lack of statistical significance in the PDV replication, transcriptional regulation of viral receptors, and changes in apoptosis suggest that although CSL might be infected by PDV, they might be less susceptible than phocid species.


Asunto(s)
Moquillo , Enfermedades de los Perros , Leones Marinos , Phocidae , Perros , Animales , Virus del Moquillo Focino/fisiología , Nectinas , Receptores de Superficie Celular
3.
Dis Aquat Organ ; 155: 159-163, 2023 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-37706646

RESUMEN

Dolphin morbillivirus (DMV) was isolated in striped dolphins Stenella coeruleoalba from the Mediterranean Sea stranded along the coast of Spain during a lethal epidemic that killed thousands of individuals in 1990-1992. Though some of these isolates (MUC, 16A and the reference strain) have been extensively characterised, details on their origin were not reported in the literature, and records for these isolates are often difficult to trace and are, sometimes, erroneous. Here, we provide unpublished biological and histopathological data for these isolates, summarize the literature on their characterization and make suggestions for future studies.


Asunto(s)
Morbillivirus , Stenella , Animales , Mar Mediterráneo , España
4.
J Virol ; 95(16): e0040321, 2021 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-34037419

RESUMEN

To understand susceptibility of wild California sea lions and Northern elephant seals to influenza A virus (IAV), we developed an ex vivo respiratory explant model and used it to compare infection kinetics for multiple IAV subtypes. We first established the approach using explants from colonized rhesus macaques, a model for human IAV. Trachea, bronchi, and lungs from 11 California sea lions, 2 Northern elephant seals, and 10 rhesus macaques were inoculated within 24 h postmortem with 6 strains representing 4 IAV subtypes. Explants from the 3 species showed similar IAV infection kinetics, with peak viral titers 48 to 72 h post-inoculation that increased by 2 to 4 log10 PFU/explant relative to the inoculum. Immunohistochemistry localized IAV infection to apical epithelial cells. These results demonstrate that respiratory tissue explants from wild marine mammals support IAV infection. In the absence of the ability to perform experimental infections of marine mammals, this ex vivo culture of respiratory tissues mirrors the in vivo environment and serves as a tool to study IAV susceptibility, host range, and tissue tropism. IMPORTANCE Although influenza A virus can infect marine mammals, a dearth of marine mammal cell lines and ethical and logistical challenges prohibiting experimental infections of living marine mammals mean that little is known about IAV infection kinetics in these species. We circumvented these limitations by adapting a respiratory tract explant model first to establish the approach with rhesus macaques and then for use with explants from wild marine mammals euthanized for nonrespiratory medical conditions. We observed that multiple strains representing 4 IAV subtypes infected trachea, bronchi, and lungs of macaques and marine mammals with variable peak titers and kinetics. This ex vivo model can define infection dynamics for IAV in marine mammals. Further, use of explants from animals euthanized for other reasons reduces use of animals in research.


Asunto(s)
Virus de la Influenza A/fisiología , Infecciones por Orthomyxoviridae/virología , Infecciones del Sistema Respiratorio/virología , Animales , Perros , Especificidad del Huésped , Virus de la Influenza A/clasificación , Cinética , Macaca mulatta , Células de Riñón Canino Madin Darby , Modelos Biológicos , Sistema Respiratorio/patología , Sistema Respiratorio/virología , Leones Marinos , Phocidae , Especificidad de la Especie , Carga Viral , Tropismo Viral
5.
Dis Aquat Organ ; 149: 59-70, 2022 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-35608510

RESUMEN

Two emaciated male northern elephant seal (NES) Mirounga angustirostris pups were admitted to The Marine Mammal Center (Sausalito, California, USA) and treated for malnutrition. Complete blood counts showed a progressive moderate to marked leukocytosis characterized by a predominance of large monomorphic mononuclear cells of probable lymphoid origin, frequently with flower-shaped nuclei. Both seals were euthanized due to suspected lymphoid neoplasia. At necropsy, most lymph nodes in both pups were markedly enlarged, some with distinct white nodules, the spleens were diffusely enlarged, and the intestinal mucosae were thickened. Histopathologic features consistent with disseminated large cell lymphoma were identified to varying degrees of severity in lymph nodes, bone marrow, liver, tonsils, spleen, liver, intestines, kidneys, lower urinary tract, and several other organs. Immunohistochemical staining of neoplastic cells was most consistent with B lymphocyte origin, with most cells staining positively for Pax 5 and CD20 with admixed small CD3-positive T lymphocytes and CD204-positive macrophages. PCR and sequencing identified a novel gammaherpesvirus, herein called miroungine gammaherpesvirus 3, from affected tissues. This virus is in a clade outside of named genera that utilize hosts in the suborder Caniformia. The present study is the first description of diffuse large B cell lymphoma with leukemic manifestation and concomitant detection of a novel gammaherpesvirus in free-living NESs. Further research regarding the prevalence of this new gammaherpesvirus and its associated pathogenesis in this species is indicated.


Asunto(s)
Linfoma de Células B Grandes Difuso , Phocidae , Animales , Leucocitos , Linfoma de Células B Grandes Difuso/veterinaria , Masculino , Reacción en Cadena de la Polimerasa/veterinaria
6.
Vet Dermatol ; 32(3): 211-e55, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33739551

RESUMEN

BACKGROUND: Southern sea otters (Enhydra lutris nereis) rely on intact pelage for thermoregulation, and thus clinically significant demodicosis and associated alopecia can cause morbidity and death. HYPOTHESIS/OBJECTIVES: This study aimed to describe lesions associated with follicular Demodex sp. infestation, estimate the prevalence and intensity of infestation, describe mite distribution across key anatomical regions, and assess mite presence or absence in relation to lesions and host risk factors. ANIMALS: Twenty necropsied, wild southern sea otters that stranded along the central California coast from 2005 to 2018. METHODS AND MATERIALS: Grossly normal and abnormal integument from the head, perineum, genitals, mamillary papillae and limbs was assessed microscopically for mites and mite-associated pathological findings. RESULTS: Intrafollicular mites were observed in the integument of 55% of otters and 20% had clinical demodicosis. Demodicosis was considered to be contributory to death or euthanasia in two cases. Although Demodex sp. mites often were observed microscopically in grossly normal skin, the presence of multiple densely-packed intrafollicular mites generally was associated with pigmentary incontinence, ectatic follicles, lymphoplasmacytic perifolliculitis, and neutrophilic and lymphoplasmacytic, dermal inflammation. Other findings included epidermal hyperplasia, orthokeratotic hyperkeratosis of epidermis and follicular epithelium, concurrent pyoderma and cell necrosis. Perioral integument, especially of the chin, had the highest prevalence of mites and the highest mite density, suggesting facial contact as a means of mite transmission. CONCLUSIONS AND CLINICAL IMPORTANCE: Our research confirmed demodectic mange as a contributor to morbidity and mortality in sea otters, with important implications for clinical care, rehabilitation and conservation.


Asunto(s)
Infestaciones por Ácaros , Nutrias , Animales , California , Infestaciones por Ácaros/epidemiología , Infestaciones por Ácaros/veterinaria , Factores de Riesgo
7.
J Zoo Wildl Med ; 52(4): 1149-1158, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34998284

RESUMEN

Severe focal to multifocal abscessation of the axillary and inguinal lymph nodes is an important cause of morbidity and mortality in stranded pup and yearling California sea lions (Zalophus californianus; CSLs) at The Marine Mammal Center (TMMC). A retrospective case review was conducted of all pup and yearling CSLs with axillary and/or inguinal lymph node abscesses admitted to this California rehabilitation center between January 2015 and December 2019 (n = 162). Clinical data and cultured isolates were evaluated to (1) characterize the clinical syndrome, (2) report isolated pathogens, and (3) investigate factors associated with clinical outcome (survival to release versus death). Of the 162 CSLs admitted with at least one axillary or inguinal lymph node abscess, almost all were in poor body condition, and overall mortality rate was 63% (102 of 165). Mortality rate was lower for animals presenting with a single abscess and abscess(es) in the inguinal location only; odds of death were significantly lower for animals that had their abscesses surgically drained (P = 0.029) and those that received antimicrobials (P = 0.037). Hematology and serum chemistry parameters at the time of abscess diagnosis reflected inflammation and malnutrition. Radiographic findings associated with abscesses from 45 cases included soft tissue swelling (n = 40), intralesional gas (n = 19), and osteomyelitis (n = 3). Ninety bacterial isolates were recovered from aerobic (n = 48) and anaerobic cultures (n = 17), 48.9% of which were gram negative. The most common gram-negative organisms were Escherichia coli (n = 15), Proteus spp. (n = 8), and Bacteroides ureolyticus (n = 7), and the most common gram-positive organisms were Streptococcus phocae (n = 10) and Staphylococcus spp. (n = 9). Management of lymph node abscesses via surgical drainage and multimodal systemic antimicrobial therapy with a broad-spectrum of activity may be considered to improve survival of these cases.


Asunto(s)
Leones Marinos , Absceso/terapia , Absceso/veterinaria , Animales , Antibacterianos/uso terapéutico , Ganglios Linfáticos , Estudios Retrospectivos
8.
J Zoo Wildl Med ; 52(1): 38-48, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33827159

RESUMEN

The spirochete bacterium Leptospira interrogans serovar Pomona is enzootic to California sea lions (CSL; Zalophus californianus) and causes periodic epizootics. Leptospirosis in CSL is associated with a high fatality rate in rehabilitation. Evidence-based tools for estimating prognosis and guiding early euthanasia of animals with a low probability of survival are critical to reducing the severity and duration of animal suffering. Classification and regression tree (CART) analysis of clinical data was used to predict survival outcomes of CSL with leptospirosis in rehabilitation. Classification tree outputs are binary decision trees that can be readily interpreted and applied by a clinician. Models were trained using data from cases treated from 2017 to 2018 at The Marine Mammal Center in Sausalito, CA, and tested against data from cases treated from 2010 to 2012. Two separate classification tree analyses were performed, one including and one excluding data from euthanized animals. When data from natural deaths and euthanasias were included in model-building, the best classification tree predicted outcomes correctly for 84.7% of cases based on four variables: appetite over the first 3 days in care, and blood urea nitrogen (BUN), creatinine, and sodium at admission. When only natural deaths were included, the best model predicted outcomes correctly for 87.6% of cases based on BUN and creatinine at admission. This study illustrates that CART analysis can be successfully applied to wildlife in rehabilitation to establish evidence-based euthanasia criteria with the goal of minimizing animal suffering. In the context of a large epizootic that challenges the limits of a facility's capacity for care, the models can assist in maximizing allocation of resources to those animals with the highest predicted probability of survival. This technique may be a useful tool for other diseases seen in wildlife rehabilitation.


Asunto(s)
Leptospirosis/veterinaria , Leones Marinos/microbiología , Envejecimiento , Animales , Animales Salvajes , Brotes de Enfermedades , Riñón/microbiología , Leptospira interrogans/aislamiento & purificación , Leptospirosis/microbiología , Leptospirosis/patología , Leptospirosis/orina , Pronóstico , Análisis de Regresión
9.
Dis Aquat Organ ; 139: 93-102, 2020 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-32351240

RESUMEN

Crassicauda spp. (Nematoda) infest the cranial sinuses of several odontocetes, causing diagnostic trabecular osteolytic lesions. We examined skulls of 77 Indian Ocean humpback dolphins Sousa plumbea and 69 Indo-Pacific bottlenose dolphins Tursiops aduncus, caught in bather-protecting nets off KwaZulu-Natal (KZN) from 1970-2017, and skulls of 6 S. plumbea stranded along the southern Cape coast in South Africa from 1963-2002. Prevalence of cranial crassicaudiasis was evaluated according to sex and cranial maturity. Overall, prevalence in S. plumbea and T. aduncus taken off KZN was 13 and 31.9%, respectively. Parasitosis variably affected 1 or more cranial bones (frontal, pterygoid, maxillary and sphenoid). No significant difference was found by gender for either species, allowing sexes to be pooled. However, there was a significant difference in lesion prevalence by age, with immature T. aduncus 4.6 times more likely affected than adults, while for S. plumbea, the difference was 6.5-fold. As severe osteolytic lesions are unlikely to heal without trace, we propose that infection is more likely to have a fatal outcome for immature dolphins, possibly because of incomplete bone development, lower immune competence in clearing parasites or an over-exuberant inflammatory response in concert with parasitic enzymatic erosion. Cranial osteolysis was not observed in mature males (18 S. plumbea, 21 T. aduncus), suggesting potential cohort-linked immune-mediated resistance to infestation. Crassicauda spp. may play a role in the natural mortality of S. plumbea and T. aduncus, but the pathogenesis and population level impact remain unknown.


Asunto(s)
Cráneo , Animales , Delfines , Océano Índico , Masculino , Sudáfrica
10.
Vet Pathol ; 56(4): 619-629, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30983529

RESUMEN

A myositis syndrome has been recognized for more than a decade in California sea lions (CSLs; Zalophus californianus) but a detailed description of the lesions and potential causes of this condition is lacking. The tissues of 136 stranded CSLs with rhabdomyositis were examined. Rhabdomyositis was considered incidental in 67% (91/136) of the CSLs, and a factor contributing to the animal stranding (significant rhabdomyositis) in 33% (45/136). Of the 91 cases with incidental rhabdomyositis, lesions consisted of a few small foci of lymphohistiocytic inflammation. Of the 45 cases with significant rhabdomyositis, 28 (62%) also presented with major comorbidities such as leptospirosis (2 animals) and domoic acid toxicosis (6 animals), whereas 17 (38%) had severe polyphasic rhabdomyositis as the only major disease process associated with mortality. In these animals, most striated muscles had multiple white streaks and diffuse atrophy. Microscopically, there was myofiber necrosis surrounded by lymphocytes and histiocytes admixed with areas of myofiber regeneration, and/or moderate to severe rhabdomyocyte atrophy usually adjacent to intact Sarcocystis neurona cysts. At the interface of affected and normal muscle, occasional T lymphocytes infiltrated the sarcoplasm of intact myocytes, and occasional myofibers expressed MHCII proteins in the sarcoplasm. S. neurona antibody titers and cyst burden were higher in animals with significant polymyositis antibody titers of (26125 ± 2164, 4.5 ± 1.2 cysts per section) and active myonecrosis than animals with incidental rhabdomyositis antibody titers of (7612 ± 1042, 1.7 ± 0.82 cysts per section). The presented findings suggest that S. neurona infection and immune-mediated mechanisms could be associated with significant polyphasic rhabdomyositis in CSLs.


Asunto(s)
Atrofia/veterinaria , Miositis/veterinaria , Sarcocystis/aislamiento & purificación , Sarcocistosis/veterinaria , Leones Marinos/parasitología , Animales , Atrofia/diagnóstico , Atrofia/parasitología , Atrofia/patología , California , Femenino , Inmunohistoquímica/veterinaria , Masculino , Músculos/parasitología , Músculos/patología , Miositis/diagnóstico , Miositis/parasitología , Miositis/patología , Estudios Retrospectivos , Sarcocistosis/diagnóstico , Sarcocistosis/parasitología , Sarcocistosis/patología
12.
Vet Pathol ; 54(5): 838-845, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28494705

RESUMEN

Brucella spp infections of marine mammals are often asymptomatic but have been associated with reproductive losses and deaths. Zoonotic infections originating from marine isolates have also been described. Hector's dolphins (Cephalorhynchus hectori) are an endangered species with a declining population, and the role of infectious disease in population dynamics is not fully understood. In this study, 27 Hector's dolphins found dead around the New Zealand coastline between November 2006 and October 2010 were evaluated for lesions previously associated with cetacean brucellosis. Tissues were examined using histological, immunohistochemical, and molecular (polymerase chain reaction [PCR]) techniques. Seven of 27 dolphins (26%) had at least 1 tissue that was positive on PCR for Brucella spp. Lesions consistent with brucellosis were present in 10 of 27 (37%) dolphins, but in 8 of these dolphins Brucella infection could not be demonstrated in lesional tissues. Two dolphins (7%) were diagnosed with active brucellosis: 1 female with placentitis and metritis, and 1 stillborn male fetus. Brucella identified in these 2 dolphins had genetic similarity (99%) to Brucella pinnipedialis. The omp2a gene amplicon from the uterus of the female had 100% homology with ST27 genotype isolates from a human in New Zealand and a bottlenose dolphin of Pacific origin. The remaining 5 PCR-positive dolphins were assessed as having asymptomatic or latent infection. While most Brucella infections identified in this study appeared to be subclinical, the finding of 2 dolphins with reproductive disease due to Brucella infection suggests that this disease has the potential to affect reproductive success in this species.


Asunto(s)
Brucella/aislamiento & purificación , Brucelosis/veterinaria , Delfines/microbiología , Animales , Brucella/genética , Brucelosis/epidemiología , Brucelosis/microbiología , Brucelosis/mortalidad , Especies en Peligro de Extinción , Femenino , Genotipo , Inmunohistoquímica/veterinaria , Masculino , Nueva Zelanda/epidemiología , Reacción en Cadena de la Polimerasa/veterinaria
13.
Emerg Infect Dis ; 20(4): 666-70, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24656203

RESUMEN

Cetacean morbillivirus (CeMV) has caused several epizootics in multiple species of cetaceans globally and is an emerging disease among cetaceans in Australia. We detected CeMV in 2 stranded coastal Indo-Pacific bottlenose dolphins (Tursiops aduncus) in Western Australia. Preliminary phylogenetic data suggest that this virus variant is divergent from known strains.


Asunto(s)
Delfín Mular/virología , Cetáceos/virología , Infecciones por Morbillivirus/virología , Morbillivirus/aislamiento & purificación , Animales , Filogenia , Australia Occidental
14.
J Comp Pathol ; 211: 42-51, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38776614

RESUMEN

Air leak syndrome (ALS) is described in human medicine as a constellation of clinical disorders including pneumomediastinum, pneumopericardium, pulmonary interstitial emphysema, pneumothorax, pneumoperitoneum, pneumoretroperitoneum and subcutaneous emphysema. The pathogenesis of ALS depends on the anatomy of the mediastinum and its associations with thoracic, abdominal and cervical connective tissues, as well as a physical phenomenon referred to as the Macklin effect. Various animal species develop diverse combinations of these lesions, although ALS has not been recognized in animals. However, this term aids pathologists in addressing this disease compilation. The aim of this retrospective study is to illustrate examples of ALS in animals by arbitrarily selecting 13 cases in dogs, cats, pinnipeds, sea otters and harbour porpoises. ALS can be classified into three groups based on aetiology: iatrogenic, secondary or spontaneous. Iatrogenic ALS was diagnosed in two cats with tracheal laceration following endotracheal intubation. Secondary ALS was identified in two dogs, one with acute respiratory distress syndrome and the other due to grass awn migration. Secondary ALS in pinnipeds was diagnosed following severe pulmonary parasitism, uraemic pneumonia and oesophageal perforation. The other marine mammals developed ALS following trauma. Spontaneous ALS was also diagnosed in one cat and one dog without any apparent predisposing causes.


Asunto(s)
Neumotórax , Animales , Gatos , Neumotórax/veterinaria , Neumotórax/etiología , Perros , Enfisema Mediastínico/veterinaria , Estudios Retrospectivos , Enfermedades de los Gatos/patología , Enfermedades de los Perros/patología , Femenino , Masculino , Enfisema Subcutáneo/veterinaria , Enfisema Subcutáneo/etiología , Neumoperitoneo/veterinaria
15.
PLoS One ; 19(3): e0295861, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38536874

RESUMEN

Beginning in December 2018, increased numbers of gray whale (Eschrichtius robustus) strandings were reported along the west coast of Mexico, the United States, and Canada, prompting declaration of a gray whale Unusual Mortality Event (UME) by the United States National Marine Fisheries Service. Although strandings declined in 2020 and 2021 from a peak in 2019, the UME is still ongoing as of fall 2023. Between 17 December 2018 and 31 December 2021, 503 animals stranded along the west coast of North America, with 226 strandings in Mexico, 71 in California, 12 in Oregon, 56 in Washington, 21 in British Columbia, and 117 in Alaska. These included 187 males, 167 females, and 149 whales of undetermined sex; and 193 adults, 194 subadults, 40 calves, 1 fetus, and 75 whales of undetermined age class. We report on 61 of the 503 carcasses (12%) that had external and internal gross necropsy and/or histopathology data: of these 61 whales, findings that contributed to death were identified in 33 (54%) whales. Sixteen of the 61 (26%) were severely emaciated. Gross lesions of blunt force trauma consistent with vessel strike were identified in 11 of the 61 animals (18%), only two of which were emaciated. Two whales (3%) were entangled at time of death, and one died from entrapment. Signs of killer whale (Orcinus orca) interaction were documented in 19 of the 61 animals; five were deemed from recent interactions and three (5%) likely contributed to mortality. A specific cause of death could not be identified in 28 of 61 whales (46%). Additionally, logistical challenges and the advanced state of decomposition of most examined carcasses precluded detection of potential infectious or toxic causes of morbidity or mortality. Up to 2016, the eastern North Pacific population of gray whale population had generally been increasing since the cessation of historic whaling and a prior UME in 1999-2000. However, recent abundance and calf production estimates have declined, a trend that overlaps the current UME. The relative contributions of carrying capacity, environmental change, prey shifts, and infectious, toxic, and other processes to the increased gray whale mortalities have not yet been resolved. Nevertheless, the marked temporal increase in strandings, including findings of malnutrition in some of the whales, along with low calf production, likely represent consequences of complex and dynamic ecological interactions in the ocean impacting the population.


Asunto(s)
Ballenas , Animales , Femenino , Masculino , América del Norte , México , Colombia Británica , Alaska
16.
J Wildl Dis ; 59(1): 121-127, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36584338

RESUMEN

Recently, a novel gammaherpesvirus, miroungine gammaherpesvirus 3 (MirGHV3), was described in two juvenile elephant seals (Mirounga angustirostris) with diffuse large B-cell lymphoma. We developed and validated a quantitative (q)PCR for rapid detection of MirGHV3 and investigated its potential association with lymphoma. We developed a duplex probe-hybridization qPCR with MirGHV3 DNA polymerase (pol) as the target gene. Each primer-probe combination was cross-validated against the others. Interference was not seen when they were run in the same well as a duplex assay. Twenty-three samples from seven northern elephant seals were tested using the duplex assay. Viral DNA was detected by the assay in 9 of 9 (100%) tissues affected by lymphoma and in 6 of 14 (43%) samples from tissues unaffected by lymphoma. There was a strong correlation between viral copies detected with each of the assays (P=0.0002). Viral load was significantly higher in tissues affected by lymphoma than in those unaffected (P<0.0001). Excluding the virus-negative samples, viral load was still significantly higher in tissues affected by lymphoma than in those unaffected (P=0.0004). This is consistent with a potential role of MirGHV3 in oncogenesis in northern elephant seals, although more studies are needed to determine this definitively. The qPCR developed has utility for further investigations of MirGHV3.


Asunto(s)
Gammaherpesvirinae , Linfoma de Células B Grandes Difuso , Reacción en Cadena de la Polimerasa , Phocidae , Infecciones Tumorales por Virus , Animales , Reacción en Cadena de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa/veterinaria , Phocidae/virología , Reproducibilidad de los Resultados , Linfoma de Células B Grandes Difuso/veterinaria , Linfoma de Células B Grandes Difuso/virología , Gammaherpesvirinae/genética , Gammaherpesvirinae/aislamiento & purificación , Infecciones Tumorales por Virus/veterinaria , Infecciones Tumorales por Virus/virología , ADN Viral/aislamiento & purificación , Masculino , Femenino
17.
Adv Mar Biol ; 96: 85-114, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37980130

RESUMEN

Little is known about the biology of pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales as these animals are difficult to observe in the wild. However, both species strand frequently along the South African, Australian and New Zealand coastlines, providing samples for these otherwise inaccessible species. The use of DNA samples from tissue and DNA extracted from historical material, such as teeth and bone, allowed a first analysis of the population structure of both species in the Southern Hemisphere. A 279 base pair consensus region of the mitochondrial cytochrome b gene was sequenced for 96 K. breviceps (53 tissue and 43 teeth or bone samples) and 29 K. sima (3 tissue and 26 teeth or bone samples), and 26 and 12 unique haplotypes were identified, respectively. K. breviceps showed a higher nucleotide diversity of 0.82% compared to 0.40% in K. sima. Significant genetic differentiation was detected in the Southern Hemisphere between K. breviceps from South Africa and New Zealand (ФST = 0.042, p < 0.05). Mitochondrial control region sequences (505 bp) were available for 44 individuals (41 K. breviceps and 3 K. sima) for comparative purposes. A comprehensive global phylogenetic analysis (maternal lineage) of our sequences together with all available Kogia mtDNA sequences largely supported previously published phylogenetic findings, but highlighted some changed inferences about oceanic divergences within both species. The higher nucleotide diversity and low population differentiation observed in K. breviceps may result from its broad foraging ecology and wide distribution, which may indicate a more opportunistic feeding behaviour and tolerance towards a larger range of water temperatures than K. sima.


Asunto(s)
Cachalote , Ballenas , Humanos , Animales , Filogenia , Australia , ADN , Nucleótidos
18.
Front Vet Sci ; 10: 1245864, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37850065

RESUMEN

Introduction: Domoic acid (DA) is a glutaminergic excitatory neurotoxin that causes the morbidity and mortality of California sea lions (Zalophus californianus; CSL) and other marine mammals due to a suite of effects mostly on the nervous and cardiac systems. Between 1998 and 2019, 11,737 live-stranded CSL were admitted to The Marine Mammal Center (TMMC; Sausalito, CA, USA), over 2,000 of which were intoxicated by DA. A plethora of clinical research has been performed over the past 20 years to characterize the range of toxic effects of DA exposure on CSLs, generating the largest dataset on the effects of natural exposure to this toxin in wildlife. Materials and methods: In this study, we review published methods for diagnosing DA intoxication, clinical presentation, and treatment of DA-intoxicated CSL and present a practical, reproducible scoring system called the neuroscore (NS) to help assess whether a DA-affected CSL is fit for release to the wild following rehabilitation. Logistic regression models were used to assess the relationships between outcome (released vs. euthanized or died) and multiple variables to predict the outcome for a subset of 92 stranded CSLs. Results: The largest proportion of DA-intoxicated CSLs was adult females (58.6%). The proportions of acute and chronic cases were 63.5 and 36.5% respectively, with 44% of affected CSL released and 56% either dying naturally or euthanized. The average time in rehabilitation was 15.9 days (range 0-169) for all outcomes. The best-performing model (85% accuracy; area under the curve = 0.90) assessing the relationship between outcome and predictor variables consisted of four variables: final NS, change in NS over time, whether the animal began eating in rehabilitation, and the state of nutrition on admission. Discussion: Our results provide longitudinal information on the symptomatology of CSL intoxicated by domoic acid and suggest that a behavioral scoring system is a useful tool to assess the fitness for the release of DA-intoxicated CSL.

19.
PLoS One ; 18(3): e0283049, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36996074

RESUMEN

From 2011-2018, we conducted surveillance in marine mammals along the California coast for influenza A virus (IAV), frequently detecting anti-influenza antibodies and intermittently detecting IAV. In spring 2019, this pattern changed. Despite no change in surveillance intensity, we detected IAV RNA in 10 samples in March and April, mostly in nasal and rectal swabs from northern elephant seals (Mirounga angustirostris). Although virus isolation was unsuccessful, IAV sequenced from one northern elephant seal nasal swab showed close genetic identity with pandemic H1N1 IAV subclade 6B.1A.1 that was concurrently circulating in humans in the 2018/19 influenza season. This represents the first report of human A(H1N1)pdm09 IAV in northern elephant seals since 2010, suggesting IAV continues to spill over from humans to pinnipeds.


Asunto(s)
Caniformia , Subtipo H1N1 del Virus de la Influenza A , Virus de la Influenza A , Gripe Humana , Phocidae , Animales , Humanos , Gripe Humana/epidemiología , California/epidemiología
20.
Emerg Infect Dis ; 18(10): 1625-8, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23017505

RESUMEN

Echinococcus multilocularis is a zoonotic parasite in wild canids. We determined its frequency in urban coyotes (Canis latrans) in Alberta, Canada. We detected E. multilocularis in 23 of 91 coyotes in this region. This parasite is a public health concern throughout the Northern Hemisphere, partly because of increased urbanization of wild canids.


Asunto(s)
Coyotes/parasitología , Equinococosis/veterinaria , Echinococcus multilocularis/aislamiento & purificación , Alberta/epidemiología , Animales , Equinococosis/epidemiología , Equinococosis/parasitología
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