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PubMed2004

Prevalence of Brucella pinnipediae in healthy hooded seals (Cystophora cristata) from the North Atlantic Ocean and ringed seals (Phoca hispida) from Svalbard.

Investigations for Brucella-infections were conducted in 29 hooded seals (Cystophora cristata) caught between Svalbard and Greenland (North Atlantic Ocean; Greenland Sea) autumn 2002, and from 20 ringed seals (Phoca hispida) caught in Billefjord, Svalbard, spring 2003. All animals were apparently healthy and were caught in their natural habitat. Bacteriology on tissue samples from ringed seals was negative, whereas Brucella sp. were recovered in tissues from 11 of the 29 hooded seals (38%), with the highest tissue prevalence in spleen (9/29) and lung lymph nodes (9/24). Anti-Brucella antibodies were detected in sera from 9 hooded seals (31%) (EDTA-modified Slow Agglutination test of Wright, Rose Bengal test, Complement Fixation Test, and Protein-A ELISA). The bacterial isolates all belonged to the genus Brucella according to classical biotyping and PCR analysis based on Insertion Sequence IS711, and were shown to be typical marine mammal strains, based on the occurrence of an IS711 element downstream of the bp26 gene. Their dependency on CO2 for growth, and the presence of one copy each of the omp2a and omp2b gene finally classified them as Brucella pinnipediae. Furthermore, all the hooded seal isolates showed an A+ M+ agglutination profile, which is different from the profile of reference seal strain 2/94 (harbour seal, Phoca vitulina). Thus, these results indicate that B. pinnipediae may contain different biovars. The present results suggest that infection with B. pinnipediae is enzootic in this population. Since the hooded seal is commercially hunted and consumed in Norway, the pathological impact of such infections and their zoonotic potential should be further addressed.

Agglutination Tests↗
PubMed2000

Lipid composition of blood platelets and erythrocytes of southern elephant seal (Mirounga leonina) and antarctic fur seal (Arctocephalus gazella).

Erythrocyte and blood platelet phospholipid compositions were studied in three elephant seals and two fur seals, two species of marine mammals living in the Subantarctic region feeding on preys rich in (n-3) polyunsaturated fatty acids. Results were compared with those reported for related species and humans. In erythrocytes, the phospholipid (PL) and cholesterol (CHOL) contents were lower in pinnipeds than in humans. Phosphatidylcholine (PC) levels were higher in elephant seals than in fur seals, with a reverse trend for phosphatidylethanolamine (PE) and phosphatidylserine (PS). Both species had lower SM/PC ratios and PE plasmalogen concentrations than human. Erythrocytes were richer in (n-3) fatty acids (FA) in pinnipeds than in humans. In platelets, the PL content was lower and the CHOL content higher in elephant seals than in humans or in other phocid seal species studied to date. The SM/PC ratio was much higher than in other seal species or in man. In both species, the proportion of PE plasmalogens was higher in platelets than in erythrocytes. PL were more saturated in elephant seals than in fur seals. These results suggest that the erythrocytes and platelets of wild marine mammals may prove useful models to study the influence of dietary lipids on the structure and hemostatic function of these cells.

Animals↗
PubMed2000

Amoxicillin pharmacokinetics in harbor seals (Phoca vitulina) and northern elephant seals (Mirounga angustirostris) following single dose intravenous administration: implications for interspecific dose scaling.

The pharmacokinetics of sodium amoxicillin after a single intravenous dose of 20 mg/kg were determined in ten harbor seals (Phoca vitulina) and ten northern elephant seals (Mirounga angustirostris). The seals ranged in age from 1 to 6 months and the mean weights were 11.7 kg (range, 9.5-18.5 kg) for harbor seals and 47.1 kg (range, 39.5-61.4 kg) for elephant seals. The median half-life of amoxicillin (quartiles) in harbor seals, 1.5 (1.0-3.1) h. was not statistically different from that of elephant seals, 2.0 (1.4-3.8) h, nor were the differences between the terminal elimination rate constants between the two species. The only statistically significant differences between species were for area-under-the-curve (AUC), and total systemic clearance. The lack of statistical significance for differences in the volume of distribution at steady-state (Vss) may have been due to minor differences in the time frame of data collection and dose administered between the two groups. A true physiologic difference in drug handling, possibly related to renal perfusion or tubal secretory efficiency could affect amoxicillin kinetics in these species, and longer administration intervals may be appropriate for elephant seals as compared to harbor seals when administering multiple dose amoxicillin therapy at 20 mg/kg.

Amoxicillin↗
PubMed2002

Hepatic microsomal cytochrome p450s and chlorinated hydrocarbons in largha and ribbon seals from Hokkaido, Japan: differential response of seal species to Ah receptor agonist exposure.

From 16 largha seals (Phoca largha) and 15 ribbon seals (Phoca fasciata) in the coastal waters of Hokkaido, Japan, blubber chlorinated hydrocarbon (CHC) levels and hepatic cytochrome P450 (CYP) catalytic activities and their immunochemically detected protein content levels were measured. Concentrations of DDTs (2,2-bis(4-chlorophenyl)-1,1-dichloroethylene,p,p'-DDE; 2,2-bis(4-chlorophenyl)-1,1-dichloroethane, p,p'-DDD; dichlorodiphenyltrichloroethane, p,p'-DDT), polychlorinated biphenyl congeners (PCBs), and chlordane compounds (oxychlordane, chlordanes, and nonachlors) in both species were in the range of 290 to 5,300, 420 to 4,000, and 130 to 1,500 ng/g lipid weight, respectively. Aryl hydrocarbon receptor (AhR) agonists, non-ortho (IUPAC 77 and 126) and mono-ortho (IUPAC 105, 118, and 156) coplanar PCB congeners, were also detected, and the 2,3,7,8-tetrachlordibenzo-p-dioxin (TCDD) toxic equivalents (TEQs) were 4.9 to 120 pg TEQ/g lipid weight. Cross-reactive proteins with polyclonal antibodies against rat CYP1A1 and CYP3A2 were notably detected in seal liver microsomes. Interestingly, a polyclonal antibody against rat CYP2B1 recognized proteins only at trace levels. In largha seals, both levels of alkoxyresorufin- (methoxy-, ethoxy-, pentoxy-, and benzyloxyresorufin) O-dealkylase (AROD) activities and proteins detected by polyclonal antibodies against rat CYP1A1 were significantly correlated with the concentrations of individual coplanar PCB congeners, total TEQs, and total PCBs. Threshold concentrations for TEQs in blubber of the largha seal to induce hepatic CYP1A protein and EROD activity were estimated to be 8.5 and 19 pg TEQ/g fat weight, respectively. In ribbon seals, similar correlations were not detected, although the TEQ levels were not significantly lower than those in largha seals. These results suggest that AROD activity and CYP1A1 protein in the liver of the largha seal could be a biomarker for the exposure to AhR agonists such as coplanar PCB congeners. This study also indicates differences in AhR-mediated responses to the CHC exposures between largha and ribbon seals.

Adipose Tissue↗
PubMed2005

Levels of non-essential elements in muscle from harp seal (Phagophilus groenlandicus) and hooded seal (Cystophora cristata) caught in the Greenland Sea area.

The non-essential elements, arsenic, cadmium, mercury and lead, inevitably accumulate in marine top predators such as seals. The concentration of these elements and the essential element selenium, due to its proposed protective properties against mercury toxicity in marine mammals, were measured in muscle, liver and kidney from reproductive active females of harp seal (Phagophilus groenlandicus) and hooded seal (Cystophora cristata) caught in the drift ice between Iceland and East Greenland. Arsenic levels were below 1 microg/g w.w. in all analysed samples, and were therefore low compared to other seafood products. The concentrations of arsenic found in the present study were comparable to the results reported in a similar study from 1985. Mean concentrations of total mercury in muscle from the present study were higher than levels in other seafood products. The levels of total mercury from the present study showed a tendency of lower levels in all tissue samples compared to the study from 1985. Methyl mercury displayed a trend of a lower ratio of methyl mercury to total mercury as the concentration of total mercury increased, indicating a demethylation of methyl mercury at high total mercury concentrations (e.g. mercury in liver of hooded seal). The concentration ratio of methyl mercury to total mercury in muscle samples was more than 75%, with total mercury concentration less than 0.5 microg/g w.w., whereas the ratio for liver was as low as 0.2% with a total mercury concentration of 128 microg/g w.w. The molar concentration ratios of selenium to mercury showed that selenium was present in a molar surplus to mercury in all tissues with low mercury concentration. However, there seemed to be a general mobilisation of selenium in liver and kidney tissues of harp seal and hooded seal, whereas an extraordinary mobilisation seemed to take place at hepatic mercury concentrations exceeding 50 microg/g w.w. The mean concentrations of lead in muscles in the present study were higher than in fish and other seafood products from the Barents Sea. The lead concentrations from the present study were lower than levels reported in the 1985 study. However, the levels of the non-essential elements analysed in muscle from the two seal species in the present study should not prevent the use of seal meat in human nutrition.

Animals↗
PubMed2002

Cadmium toxicity to ringed seals (Phoca hispida): an epidemiological study of possible cadmium-induced nephropathy and osteodystrophy in ringed seals (Phoca hispida) from Qaanaaq in Northwest Greenland.

The Greenland marine food chains contain high levels of cadmium, mercury and selenium. Concentrations of cadmium in the kidney of ringed seals (Phoca hispida) from the municipalities of Qaanaaq and Upernavik (Northwest Greenland) are among the highest recorded in the Arctic. The purpose of the study was to determine whether cadmium-induced damage in the kidneys and the skeletal system could be detected among 100 ringed seals from Northwest Greenland. The cadmium concentrations in the kidney cortex ranged from 0 to 248 microg/g wet weight (mean=44.5, N=100) in the 99 kidneys examined. Experience from cadmium-poisoned humans and laboratory mammals indicates that concentrations above 50-200 microg/g wet wt. may induce histopathological changes. Overall, 31 of the ringed seals had cadmium concentrations in the kidney cortex above 50 microg/g wet wt., 11 had concentrations above 100 and one had a concentration above 200 microg/g wet wt. Obvious histopathological changes (categorised mainly as glomerulonephritis) were found in 10 of the seals; however, none of these changes could be attributed to cadmium-induced renal damage (mainly tubulopathy) as described for other species. Damage to the proximal kidney tubules is known to induce demineralisation of the skeletal system (Fanconi's syndrome). Therefore, the three lowest lumbar vertebrae were scanned in 91 seals to measure the content of calcium. The 10 cases of nephropathy could neither be linked to the degree of mineralisation of the skeleton nor to the cadmium concentrations. Furthermore, the degree of mineralisation of the skeleton was not correlated with the cadmium concentration, age or sex. It can therefore be concluded that despite high levels of cadmium, none of the ringed seals showed any signs of cadmium-induced nephropathy or osteodystrophy. This might be explained by the composition of the ringed seals diet, which contains high levels of vitamin D, calcium, phosphorus, zinc, selenium and protein. These elements are all likely to counteract cadmium-induced damage. It is speculated that ringed seal are not particularly vulnerable to osteodystrophy, due to their continuous growth (bone mineralisation) throughout life and the oestrogen hormonal activity of females throughout life.

Animals↗
PubMed1993

Seals, seal trainers, and mycobacterial infection.

In 1986, three seals died in a marine park in Western Australia; culture of postmortem tissue suggested infection with Mycobacterium bovis. In 1988, a seal trainer who had been employed at the Western Australian marine park until 1985 developed pulmonary tuberculosis caused by M. bovis while working in a zoo 3,000 km away on the east coast of Australia. Culture characteristics, biochemical behavior, sodium dodecyl sulphate polyacrylamide gel electrophoresis, and restriction endonuclease analysis suggested that the strains of M. bovis infecting the seals and trainer were identical but unique and differed from reference strains and local cattle strains of M. bovis. The infection in both the seals and the trainer had a destructive but indolent course. This is the first time that M. bovis has been observed in seals and the first time that tuberculous infection has been documented to be transmitted from seals to humans. Further investigation of the extent of tuberculous infection in seal populations elsewhere in the world seems warranted, and those working with seals and other marine animals should be monitored for infection.

Animals↗
PubMed1993

The nucleotide sequence of the mitochondrial DNA molecule of the grey seal, Halichoerus grypus, and a comparison with mitochondrial sequences of other true seals.

The sequence of the mtDNA of the grey seal, Halichoerus grypus, was determined. The length of the molecule was 16,797 base pairs. The organization of the molecule conformed with that of other eutherian mammals but the control region was unusually long due to the presence of two types of repeated motifs. The grey seal and the previously reported harbor seal, Phoca vitulina, belong to different but closely related genera of family Phocidae, true (or earless) seals. In order to determine the degree of differences that may occur between mtDNAs of closely related mammalian genera, the 2 rRNA genes, the 13 peptide coding genes, and the 22 tRNA genes of the 2 species were compared. Total nucleotide difference in the peptide coding genes was 2.0-6.1%. The range of conservative difference was 0.0-1.5%. In the inferred peptide sequences the amino acid difference was 0.0-4.5%, and the difference with respect to chemical properties of amino acids was 0.0-3.0%. A gene that showed a limited degree of difference in one mode of comparison did not necessarily show a corresponding limited difference in another mode. The ratio for differences in codon positions 1, 2, and 3 was approximately 2.7:1:16. The corresponding ratio for conservative differences was approximately 1.8:1.1:1. The evolutionary separation of the two species was calculated to have taken place 2-2.5 million years ago. This dating gives the figure approximately 8 x 10(-9) as the mean rate of substitution per site and year in the entire mtDNA molecule. Comparison with the cytochrome b gene of the Hawaiian monk seal and the Weddell seal suggested that the lineage of these two species and that of the grey and harbor seals separated approximately 8 million years ago.

Animals↗
PubMed2006

Relatedness of Streptococcus equi subsp. zooepidemicus strains isolated from harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) of various origins of the North Sea during 1988-2005.

The present study was designed to identify 15 beta-hemolytic streptococci isolated during a period between 1988 and 2005 from nine harbour seals and six grey seals from various origins of the North Sea. All isolates were identified as Streptococcus equi subsp. zooepidemicus. The bacteria were additionally investigated for relatedness by restriction fragment length polymorphism analysis of PCR amplified 16S-23S rDNA intergenic spacer region and gene szp and by macrorestriction analysis of chromosomal DNA of the strains by pulsed field gel electrophoresis. The molecular analysis yielded identical or closely related patterns within the strains of the present study and with the S. equi subsp. zooepidemicus strains isolated from harbour seals of German North Sea which were investigated previously [Akineden, O., Hassan, A.A., Alber, J., El-Sayed, A., Estoepangestie, A.T.S., Lämmler, C., Weiss, R., Siebert, U., 2005. Phenotypic and genotypic properties of S. equi subsp. zooepidemicus isolated from harbor seals (Phoca vitulina) from the German North Sea during the phocine distemper outbreak in 2002. Vet. Microbiol. 110, 147-152]. This indicates that this single or closely related bacterial clone existed during both phocine distemper virus epidemics in 1988 and 2002 and that a direct transmission of the strains has occurred between two seal species and between seal populations of far distant regions possibly with grey seals as a vector.

Animals↗
PubMedDate not supplied

Levels and enantiomeric ratios of alpha-HCH, oxychlordane, and PCB 149 in blubber of harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) from Iceland and further species.

The chiral stationary phase beta-TBDM (35% heptakis(6-O-tert.-butyldimethylsilyl-2,3-di-O-methyl)-beta-cyc lod extrin in OV-1701) was applied to study the enantioenrichment of alpha-HCH, oxychlordane, and PCB 149 in blubber of two seal species from Iceland by gas chromatography with electron capture detection. The examined harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) showed alpha-HCH enantiomeric ratios (ER) > 1. The ER of PCB 149 was comparable in the two species from Iceland but for oxychlordane ER < 1 was observed in harbour seals while the oxychlordane ER in grey seals was > 1. In blubber of Weddell seals (Leptonychotes Weddelli) from the Antarctic we determined an alpha-HCH ER < 1 which is in contrast to the Icelandic seal species and a sample from Lake Baikal.

Animals↗
PubMed2002

Isolation of two cytochrome P450 cDNAs, CYP1A1 and CYP1A2, from harp seal (Phoca groenlandica) and grey seal (Halichoerus grypus).

Two cytochrome P450 (CYP), CYP1A1 and CYP1A2, cDNA sequences have been isolated and cloned from harp seal (Phoca groenlandica) and grey seal (Halichoerus grypus). EROD, a model substrate for CYP1A, and heterologous antibodies have been employed as a biomarker in marine mammals, however the CYP1A sequences have not been characterised in these two seal species. mRNA was used as the template in RT-PCR, rather than DNA as this indicates transcription of the CYP1A gene in these seal species exposed to environmental contaminants. Harp and grey seal CYP1A1 amino acid sequences exhibited >99% identity and the CYP1A2 sequences were >98% identical. Phylogenetic analyses of the two seal species with other mammalian, and avian CYP1A sequences, showed the CYP1A1 and CYP1A2 sequences clustered with corresponding sequences in other mammalian species. The closest sequences to the seal CYP1As was dog CYP1A. The CYP1A sequence information presented in this study has provided the necessary data for the future production of species-specific probes for the use as biomarkers of environmental contaminant exposure.

Amino Acid Motifs↗
PubMed2003

Health status of harp seals (Phoca groenlandica) and hooded seals (Cystophora cristata) on Sable Island, Nova Scotia, Canada, concurrent with their expanding range.

Beach surveys for harp (Phoca groenlaandica) and hooded (Cystophora cristata) seals documented a dramatic increase in their numbers on Sable Island in mid 1990s. In the 1980s, no more than five animals of both species were observed on this island each year, however, during late 1994 to 1998, 1,191 harp and 870 hooded seals, mostly young animals, were recorded. Although some of these seals had been killed by sharks, most (roughly 75%) were found alive or as intact carcasses on the beach, and some of the live seals were later found dead. Emaciation/starvation was considered the primary cause of death in seals that were not obviously killed by sharks. Factors that may have compounded this poor body condition included gastric impaction with abnormal ingesta, hemorrhagic diathesis possibly induced by parasitic migration and secondary vasculitis, and stomatitis (in hooded seals only). Some harp and hooded seals expanding their range in recent years may be unable to feed successfully, although the reasons for this are unclear.

Animals↗
PubMed2004

Antibodies to human-related H3 influenza A virus in Baikal seals (Phoca sibirica) and ringed seals (Phoca hispida) in Russia.

Antibodies to influenza A virus were detected using enzyme-linked immunosorbent assay (ELISA) in the sera from two of seven Baikal seals (Phoca sibrica) and from five of six ringed seals (Phoca hispida) in Russia. In a hemagglutination-inhibition test using H1-H15 reference influenza A viruses, ELISA-positive sera from one Baikal seal and four ringed seals reacted to A/Aichi/2/68 (H3N2) and A/Bangkok/1/79 (H3N2) strains. One ringed seal serum sample reacted to A/seal/Massachusetts/1/80 (H7N7). The present results suggested that human-related H3 viruses were prevalent in Baikal seals and ringed seals inhabiting the central Russian Arctic.

Animals↗
PubMed1992

The apical seal of root canal sealing cements using a radionuclide detection technique.

The aim of this study was to evaluate the apical seal obtained with various root canal sealing cements using a new method based on the use of a radionuclide and an external detection technique. A total of 150 maxillary incisors and canines, which had been kept in saline solution, were used. The root canals were instrumented with a stepback technique and circumferential filing. Six experimental groups and two control groups were randomly formed. Each experimental group was obturated by a lateral condensation technique with gutta-percha points and a different sealing cement (two based on zinc oxide-eugenol cement, two based on resins and two on calcium hydroxide); the positive control used gutta-percha without sealing cement, while in the negative control the apex was covered with nail varnish, leaving the root canal empty. The apical leakage was measured using an external detection technique after submerging the root apices in a solution containing the radioisotope metastable 99Tc. No leakage was observed in the negative control group. There was a large difference between the leakage observed in the positive control group and the experimental groups. The best seal was obtained using Sealapex cement, which differed significantly from AH26, Tubli-Seal and Diaket; there was no significant difference between the latter. The poorest results were obtained with Endomethasone and CRCS; there was a significant difference between these and the previous three sealing cements.

Administration, Topical↗
PubMed2002

Variations in the severity of phocid herpesvirus type 1 infections with age in grey seals and harbour seals.

The data recorded during an outbreak of phocid herpesvirus type 1 infection among 19 harbour seals and 29 grey seals being nursed in a seal rehabilitation centre in The Netherlands in 1998 were used, together with data from similar outbreaks in previous years, to compare the clinical signs observed in the two species at different ages. The severity of the disease was inversely correlated with age in the harbour seals, and the infected harbour seals generally developed more severe clinical signs than the infected grey seals.

Age Factors↗
PubMed1996

[Seal fingers and other infections transmitted from seals].

Seals and other Pinnipedia my carry a range of infectious agents which could be of clinical interest. A paramyxovirus infection caused epizootic seal death around danish coasts in 1988, but as the population is now recovering more contacts between seal and man must be envisaged. Bites and other forms of direct and indirect contact and carry a risk of development of seal (or blubber) finger. This entity encompasses oedema of the affect finger, swelling of the interphalangeal joint adjacent to the lesion, and no suppuration. The condition is extremely painful and may lead to residual dysfunction or amputation. There is circumstantial evidence that the condition is caused by mycoplasma, and Canadian researchers have identified three species, one of which has been directly linked to blubber finger. At the first medical contact after seal bites and other seal-inflicted lesions thorough cleansing with water and soap is recommended. Systemic therapy with tetracycline is recommended, but both fluorquinolones and macrolides may be efficacious.

Animals↗
PubMed2005

Interaction of bilirubin with sealed and human serum albumin-entrapped sealed membranes.

In order to study the mechanism of entry and localization of bilirubin (BR) into cell membrane, binding of BR to sealed and human serum albumin (HSA)-entrapped sealed membranes was studied by CD spectroscopy. An induced bisignate CD cotton effects (CDCEs) of BR-bound sealed membranes were observed with maxima at 515 nm and minima at 470 nm with a shoulder at 430 nm. BR-bound HSA-entrapped sealed membranes produced CD spectra with additional positive peaks at 450 and 475 nm and negative troughs at 390 and 415 nm. The induced CDCEs of BR-bound sealed membranes and BR-bound HSA-entrapped sealed membranes were perturbed by the addition of drugs (ceftriaxone and sodium salicylate) with the effect of ceftriaxone being more pronounced. Drugs' being the displacer of BR from albumin, their incorporation in the incubation mixture was paralleled by reduction in CDCEs. Taken together, these results suggest that BR can traverse the membrane bilayer towards the inner surface instead of remaining intercalated in the exterior half of the bilayer.

Bilirubin↗