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Andrew Hemphill - One of the best experts on this subject based on the ideXlab platform.
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Repurposing of an old drug: In vitro and in vivo efficacies of buparvaquone against Echinococcus multilocularis.
International journal for parasitology. Drugs and drug resistance, 2018Co-Authors: Reto Rufener, Andrew Hemphill, Dominic Ritler, Luca Dick, Laura D'ascoli, Amani Hizem, Timothy N. C. Wells, Britta Lundström-stadelmannAbstract:The metacestode stage of the fox tapeworm Echinococcus multilocularis causes the lethal disease alveolar echinococcosis. Current chemotherapeutic treatment options are based on benzimidazoles (albendazole and mebendazole), which are insufficient and hence alternative drugs are needed. In this study, we screened the 400 compounds of the Medicines for Malaria Venture (MMV) Pathogen Box against E. multilocularis Metacestodes. For the screen, we employed the phosphoglucose isomerase (PGI) assay which assesses drug-induced damage on Metacestodes, and identified ten new compounds with activity against the parasite. The anti-theilerial drug MMV689480 (buparvaquone) and MMV671636 (ELQ-400) were the most promising compounds, with an IC50 of 2.87 μM and 0.02 μM respectively against in vitro cultured E. multilocularis Metacestodes. Both drugs suggested a therapeutic window based on their cytotoxicity against mammalian cells. Transmission electron microscopy revealed that treatment with buparvaquone impaired parasite mitochondria early on and additional tests showed that buparvaquone had a reduced activity under anaerobic conditions. Furthermore, we established a system to assess mitochondrial respiration in isolated E. multilocularis cells in real time using the Seahorse XFp Analyzer and demonstrated inhibition of the cytochrome bc1 complex by buparvaquone. Mice with secondary alveolar echinococcosis were treated with buparvaquone (100 mg/kg per dose, three doses per week, four weeks of treatment), but the drug failed to reduce the parasite burden in vivo. Future studies will reveal whether improved formulations of buparvaquone could increase its effectivity.
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Repurposing of an old drug: In vitro and in vivo efficacies of buparvaquone against Echinococcus multilocularis
Elsevier, 2018Co-Authors: Reto Rufener, Andrew Hemphill, Dominic Ritler, Luca Dick, Laura D'ascoli, Amani Hizem, Timothy N. C. Wells, Britta Lundström-stadelmannAbstract:The metacestode stage of the fox tapeworm Echinococcus multilocularis causes the lethal disease alveolar echinococcosis. Current chemotherapeutic treatment options are based on benzimidazoles (albendazole and mebendazole), which are insufficient and hence alternative drugs are needed. In this study, we screened the 400 compounds of the Medicines for Malaria Venture (MMV) Pathogen Box against E. multilocularis Metacestodes. For the screen, we employed the phosphoglucose isomerase (PGI) assay which assesses drug-induced damage on Metacestodes, and identified ten new compounds with activity against the parasite. The anti-theilerial drug MMV689480 (buparvaquone) and MMV671636 (ELQ-400) were the most promising compounds, with an IC50 of 2.87 μM and 0.02 μM respectively against in vitro cultured E. multilocularis Metacestodes. Both drugs suggested a therapeutic window based on their cytotoxicity against mammalian cells. Transmission electron microscopy revealed that treatment with buparvaquone impaired parasite mitochondria early on and additional tests showed that buparvaquone had a reduced activity under anaerobic conditions. Furthermore, we established a system to assess mitochondrial respiration in isolated E. multilocularis cells in real time using the Seahorse XFp Analyzer and demonstrated inhibition of the cytochrome bc1 complex by buparvaquone. Mice with secondary alveolar echinococcosis were treated with buparvaquone (100 mg/kg per dose, three doses per week, four weeks of treatment), but the drug failed to reduce the parasite burden in vivo. Future studies will reveal whether improved formulations of buparvaquone could increase its effectivity. Keywords: Pathogen box, MMV671636, MMV689480, Drug screening, Seahorse XFp analyzer, Cytochrome bc1 comple
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2011. In vitro and in vivo efficacies of mefloquinebased treatment against alveolar echinococcosis
2016Co-Authors: Britta Stadelmann, Sabrina Scholl, Corina Hermann, Jennifer Keiser, Andrew HemphillAbstract:Alveolar echinococcosis (AE) is caused by the metacestode stage of the fox tapeworm Echinococcus mul-tilocularis and causes severe disease in the human liver, and occasionally in other organs, that is fatal when treatment is unsuccessful. The present chemotherapy against AE is based on mebendazole and albendazole. Albendazole treatment has been found to be ineffective in some instances, is parasitostatic rather than parasiticidal, and usually involves the lifelong uptake of large doses of drugs. Thus, new treatment options are urgently needed. In this study we investigated the in vitro and in vivo efficacy of mefloquine against E. multilocularis Metacestodes. Treatment using mefloquine (20 M) against in vitro cultures of Metacestodes resulted in rapid and complete detachment of large parts of the germinal layer from the inner surface of the laminated layer within a few hours. The in vitro activity of mefloquine was dependent on the dosage. In vitro culture of Metacestodes in the presence of 24 M mefloquine for a period of 10 days was parasiticidal, as determined by murine bioassays, while treatment with 12 M was not. Oral application of mefloquine (25 mg/kg of body weight administered twice a week for a period of 8 weeks) in E. multilocularis-infected mice was ineffective in achieving any reduction of parasite weight, whereas treatment with albendazole (200 mg/kg/day) was highly effective. However, when the same mefloquine dosage was applied intraperitoneally, the reduction in parasite weight was similar to the reduction seen with oral albendazole application. Combined applicatio
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Screening of the Open Source Malaria Box Reveals an Early Lead Compound for the Treatment of Alveolar Echinococcosis
2016Co-Authors: Britta Stadelmann, Bruno Gottstein, Reto Rufener, Markus Spiliotis, Denise Aeschbacher, Andrew HemphillAbstract:The metacestode (larval) stage of the tapeworm Echinococcus multilocularis causes alveolar echinococcosis (AE), a very severe and in many cases incurable disease. To date, benzimidazoles such as albendazole and mebendazole are the only approved chemotherapeutical treatment options. Benzimidazoles inhibit metacestode proliferation, but do not act parasiticidal. Thus, benzimidazoles have to be taken a lifelong, can cause adverse side effects such as hepatotoxicity, and are ineffective in some patients. We here describe a newly developed screening cascade for the evaluation of the in vitro efficacy of new compounds that includes assessment of parasiticidal activity. The Malaria Box from Medicines for Malaria Venture (MMV), comprised of 400 commercially available chemicals that show in vitro activity against Plasmodium falciparum, was repurposed. Primary screening was carried out at 10 μM by employing the previously described PGI assay, and resulted in the identification of 24 compounds that caused physical damage in Metacestodes. Seven out of these 24 drugs were also active at 1 μM. Dose-response assays revealed that only 2 compounds, namely MMV665807 and MMV665794, exhibited an EC50 value below 5 μM. Assessments using human foreskin fibroblasts and Reuber rat hepatoma cells showed that the salicylanilide MMV665807 was less toxic for these two mammalian cell lines than for Metacestodes. The parasiticidal activity of MMV665807 was then confirmed using isolated germinal layer cell cultures as well as metacestode vesicles by employing viability assays, and its effect on Metacestodes was morphologically evaluated by electron microscopy. However, both oral and intraperitoneal application of MMV665807 to mice experimentally infected with E. multilocularis Metacestodes did not result in any reduction of the parasite load.
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TEM of E. multilocularis Metacestodes: Non-treated or treated with 0.4 μM MMV665807.
2016Co-Authors: Britta Stadelmann, Bruno Gottstein, Reto Rufener, Markus Spiliotis, Denise Aeschbacher, Andrew HemphillAbstract:Non-treated Metacestodes (A-C) or Metacestodes treated with 0.4 μM MMV665807 for 5 days (D) are shown. (A) is a low magnification view of a section through a non-treated metacestode wall, showing the laminated layer (LL), tegument (Te) and the germinal layer (GL). Clearly visible are undifferentiated stem cells (uc) and the microtriches protruding from the tegument well into the LL (arrows). Bar = 4 μm. Undifferentiated stem cells are shown at higher magnification in (B). mi = mitochondria; nu = nucleus with nucleolus. Bar = 1.5 μm. Higher magnification view of mitochondria are shown in (C). mi = mitochondria, yellow arrows point towards the cristae embedded in an electron matrix. Bar = 0.3 μm. (D) shows a representative micrograph of a metacestode exposed to 0.4 μM MMV665807 for 5 days. Arrows point towards microtriches, mi = mitochondria, mu = muscle cell. Bar = 2.2 μm.
Vanessa Herder - One of the best experts on this subject based on the ideXlab platform.
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subcutaneous merocercoids of clistobothrium sp in two cape fur seals arctocephalus pusillus pusillus
International journal for parasitology. Parasites and wildlife, 2018Co-Authors: Daniela Klotz, Jörg Hirzmann, Christian Bauer, Joachim Schöne, Maximilian Iseringhausen, Peter Wohlsein, Wolfgang Baumgärtner, Vanessa HerderAbstract:Abstract Fur seals represent intermediate hosts of the cestode Clistobothrium . Large sharks are definitive hosts for these parasites. Two female, 25– and 27-year-old fur seals, caught in the 1980s at the South African coast, were examined pathomorphologically. Both animals showed multifocal, up to 1 cm in diameter large cavities of the thoracic and abdominal subcutaneous adipose tissue containing intraluminal Metacestodes of tapeworms, which were surrounded by a locally extensive, pyogranulomatous panniculitis. The Metacestodes (merocercoids) of one fur seal were isolated from the subcutaneous adipose tissue and characterized morphologically and for the first time from this host by molecular techniques. The morphometric data corresponded with ‘delphini'-morphotype merocercoids, but the sequence of the partial 28S ribosomal RNA gene identified them as conspecific with merocercoids of the morphotype ‘grimaldii ’ . These merocercoid types are morphologically Type XV Metacestodes of marine tapeworms and represent different species of Clistobothrium . Sequence data were generated for 18S, ITS1, 5.8S, ITS2, partial 28S ribosomal DNA and partial mitochondrial cox1 gene and phylogenetic analysis of 18S rRNA and partial 28S rRNA genes identified the fur seal merocercoids as Clistobothrium species. However, it cannot yet be assigned to species level because of limited molecular data from adult stages. Most likely, both fur seals were infected as juveniles in their original habitat, the coastal regions of South Africa. The metacestode infection is probably an incidental finding, however, there is a chronic inflammatory reaction next to the subcutaneous merocercoids. It is noteworthy, that the merocercoids remain in a potentially infective stage even after more than 20 years.
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Subcutaneous merocercoids of Clistobothrium sp. in two Cape fur seals (Arctocephalus pusillus pusillus)
Elsevier, 2018Co-Authors: Daniela Klotz, Jörg Hirzmann, Christian Bauer, Joachim Schöne, Maximilian Iseringhausen, Peter Wohlsein, Wolfgang Baumgärtner, Vanessa HerderAbstract:Fur seals represent intermediate hosts of the cestode Clistobothrium. Large sharks are definitive hosts for these parasites. Two female, 25– and 27-year-old fur seals, caught in the 1980s at the South African coast, were examined pathomorphologically. Both animals showed multifocal, up to 1 cm in diameter large cavities of the thoracic and abdominal subcutaneous adipose tissue containing intraluminal Metacestodes of tapeworms, which were surrounded by a locally extensive, pyogranulomatous panniculitis. The Metacestodes (merocercoids) of one fur seal were isolated from the subcutaneous adipose tissue and characterized morphologically and for the first time from this host by molecular techniques. The morphometric data corresponded with ‘delphini'-morphotype merocercoids, but the sequence of the partial 28S ribosomal RNA gene identified them as conspecific with merocercoids of the morphotype ‘grimaldii’. These merocercoid types are morphologically Type XV Metacestodes of marine tapeworms and represent different species of Clistobothrium. Sequence data were generated for 18S, ITS1, 5.8S, ITS2, partial 28S ribosomal DNA and partial mitochondrial cox1 gene and phylogenetic analysis of 18S rRNA and partial 28S rRNA genes identified the fur seal merocercoids as Clistobothrium species. However, it cannot yet be assigned to species level because of limited molecular data from adult stages. Most likely, both fur seals were infected as juveniles in their original habitat, the coastal regions of South Africa. The metacestode infection is probably an incidental finding, however, there is a chronic inflammatory reaction next to the subcutaneous merocercoids. It is noteworthy, that the merocercoids remain in a potentially infective stage even after more than 20 years. Keywords: Arctocephalus pusillus pusillus, Clistobothrium sp., Fur seal, Cestode, Subcutaneous parasites, Monorygma grimaldi
Ronald Schmaschke - One of the best experts on this subject based on the ideXlab platform.
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first report of pulmonary cysticercosis caused by taenia crassiceps in a cape fur seal arctocephalus pusillus
International journal for parasitology. Parasites and wildlife, 2019Co-Authors: Cora Delling, Denny Bottcher, Vivien Schiffbauer, Andreas Bernhard, Ronald SchmaschkeAbstract:The cestode Taenia crassiceps parasitizes in the intestine of domestic and wild carnivores, especially in red foxes. Usually, the metacestode stage, also known as Cysticercus longicollis, is located in muscles, peritoneal and pleural cavity of wild rodents. In this case, larval stages were found in a female Cape fur seal, which lived in a German zoo since June 1998. In January 2019, the animal presented clinical signs in terms of inappetence and reduced mobility and, within a short time, it developed dyspnoea and died. Pathological and parasitological examinations were performed. In a large mass of the right thoracic wall and in nodular lung lesions, Metacestodes with numerous protoscoleces were identified. Morphological and molecular analyses led to the diagnosis of a Taenia crassiceps infection. Probably, the urban fox population was the source of infection. Thus, regarding the zoonotic potential of this cestode, a regularly performed parasitological examination of pet dogs is recommended.
Britta Stadelmann - One of the best experts on this subject based on the ideXlab platform.
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2011. In vitro and in vivo efficacies of mefloquinebased treatment against alveolar echinococcosis
2016Co-Authors: Britta Stadelmann, Sabrina Scholl, Corina Hermann, Jennifer Keiser, Andrew HemphillAbstract:Alveolar echinococcosis (AE) is caused by the metacestode stage of the fox tapeworm Echinococcus mul-tilocularis and causes severe disease in the human liver, and occasionally in other organs, that is fatal when treatment is unsuccessful. The present chemotherapy against AE is based on mebendazole and albendazole. Albendazole treatment has been found to be ineffective in some instances, is parasitostatic rather than parasiticidal, and usually involves the lifelong uptake of large doses of drugs. Thus, new treatment options are urgently needed. In this study we investigated the in vitro and in vivo efficacy of mefloquine against E. multilocularis Metacestodes. Treatment using mefloquine (20 M) against in vitro cultures of Metacestodes resulted in rapid and complete detachment of large parts of the germinal layer from the inner surface of the laminated layer within a few hours. The in vitro activity of mefloquine was dependent on the dosage. In vitro culture of Metacestodes in the presence of 24 M mefloquine for a period of 10 days was parasiticidal, as determined by murine bioassays, while treatment with 12 M was not. Oral application of mefloquine (25 mg/kg of body weight administered twice a week for a period of 8 weeks) in E. multilocularis-infected mice was ineffective in achieving any reduction of parasite weight, whereas treatment with albendazole (200 mg/kg/day) was highly effective. However, when the same mefloquine dosage was applied intraperitoneally, the reduction in parasite weight was similar to the reduction seen with oral albendazole application. Combined applicatio
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Screening of the Open Source Malaria Box Reveals an Early Lead Compound for the Treatment of Alveolar Echinococcosis
2016Co-Authors: Britta Stadelmann, Bruno Gottstein, Reto Rufener, Markus Spiliotis, Denise Aeschbacher, Andrew HemphillAbstract:The metacestode (larval) stage of the tapeworm Echinococcus multilocularis causes alveolar echinococcosis (AE), a very severe and in many cases incurable disease. To date, benzimidazoles such as albendazole and mebendazole are the only approved chemotherapeutical treatment options. Benzimidazoles inhibit metacestode proliferation, but do not act parasiticidal. Thus, benzimidazoles have to be taken a lifelong, can cause adverse side effects such as hepatotoxicity, and are ineffective in some patients. We here describe a newly developed screening cascade for the evaluation of the in vitro efficacy of new compounds that includes assessment of parasiticidal activity. The Malaria Box from Medicines for Malaria Venture (MMV), comprised of 400 commercially available chemicals that show in vitro activity against Plasmodium falciparum, was repurposed. Primary screening was carried out at 10 μM by employing the previously described PGI assay, and resulted in the identification of 24 compounds that caused physical damage in Metacestodes. Seven out of these 24 drugs were also active at 1 μM. Dose-response assays revealed that only 2 compounds, namely MMV665807 and MMV665794, exhibited an EC50 value below 5 μM. Assessments using human foreskin fibroblasts and Reuber rat hepatoma cells showed that the salicylanilide MMV665807 was less toxic for these two mammalian cell lines than for Metacestodes. The parasiticidal activity of MMV665807 was then confirmed using isolated germinal layer cell cultures as well as metacestode vesicles by employing viability assays, and its effect on Metacestodes was morphologically evaluated by electron microscopy. However, both oral and intraperitoneal application of MMV665807 to mice experimentally infected with E. multilocularis Metacestodes did not result in any reduction of the parasite load.
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TEM of E. multilocularis Metacestodes: Non-treated or treated with 0.4 μM MMV665807.
2016Co-Authors: Britta Stadelmann, Bruno Gottstein, Reto Rufener, Markus Spiliotis, Denise Aeschbacher, Andrew HemphillAbstract:Non-treated Metacestodes (A-C) or Metacestodes treated with 0.4 μM MMV665807 for 5 days (D) are shown. (A) is a low magnification view of a section through a non-treated metacestode wall, showing the laminated layer (LL), tegument (Te) and the germinal layer (GL). Clearly visible are undifferentiated stem cells (uc) and the microtriches protruding from the tegument well into the LL (arrows). Bar = 4 μm. Undifferentiated stem cells are shown at higher magnification in (B). mi = mitochondria; nu = nucleus with nucleolus. Bar = 1.5 μm. Higher magnification view of mitochondria are shown in (C). mi = mitochondria, yellow arrows point towards the cristae embedded in an electron matrix. Bar = 0.3 μm. (D) shows a representative micrograph of a metacestode exposed to 0.4 μM MMV665807 for 5 days. Arrows point towards microtriches, mi = mitochondria, mu = muscle cell. Bar = 2.2 μm.
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profound activity of the anti cancer drug bortezomib against echinococcus multilocularis Metacestodes identifies the proteasome as a novel drug target for cestodes
PLOS Neglected Tropical Diseases, 2014Co-Authors: Britta Stadelmann, Markus Spiliotis, J Muller, Denise Aeschbacher, Cristina Huber, Andrew HemphillAbstract:A library of 426 FDA-approved drugs was screened for in vitro activity against E. multilocularis Metacestodes employing the phosphoglucose isomerase (PGI) assay. Initial screening at 20 µM revealed that 7 drugs induced considerable metacestode damage, and further dose-response studies revealed that bortezomib (BTZ), a proteasome inhibitor developed for the chemotherapy of myeloma, displayed high anti-metacestodal activity with an EC50 of 0.6 µM. BTZ treatment of E. multilocularis Metacestodes led to an accumulation of ubiquinated proteins and unequivocally parasite death. In-gel zymography assays using E. multilocularis extracts demonstrated BTZ-mediated inhibition of protease activity in a band of approximately 23 kDa, the same size at which the proteasome subunit beta 5 of E. multilocularis could be detected by Western blot. Balb/c mice experimentally infected with E. multilocularis Metacestodes were used to assess BTZ treatment, starting at 6 weeks post-infection by intraperitoneal injection of BTZ. This treatment led to reduced parasite weight, but to a degree that was not statistically significant, and it induced adverse effects such as diarrhea and neurological symptoms. In conclusion, the proteasome was identified as a drug target in E. multilocularis Metacestodes that can be efficiently inhibited by BTZ in vitro. However, translation of these findings into in vivo efficacy requires further adjustments of treatment regimens using BTZ, or possibly other proteasome inhibitors.
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activities of fenbendazole in comparison with albendazole against echinococcus multilocularis Metacestodes in vitro and in a murine infection model
International Journal of Antimicrobial Agents, 2014Co-Authors: Tatiana Kuster, Britta Stadelmann, Denise Aeschbacher, Andrew HemphillAbstract:The current chemotherapeutic treatment of alveolar echinococcosis (AE) in humans is based on albendazole and/or mebendazole. However, the costs of treatment, life-long consumption of drugs, parasitostatic rather than parasiticidal activity of chemotherapy, and high recurrence rates after treatment interruption warrant more efficient treatment options. Experimental treatment of mice infected with Echinococcus multilocularis Metacestodes with fenbendazole revealed similar efficacy to albendazole. Inspection of parasite tissue from infected and benzimidazole-treated mice by transmission electron microscopy (TEM) demonstrated drug-induced alterations within the germinal layer of the parasites, and most notably an almost complete absence of microtriches. On the other hand, upon in vitro exposure of Metacestodes to benzimidazoles, no phosphoglucose isomerase activity could be detected in medium supernatants during treatment with any of these drugs, indicating that in vitro treatment did not severely affect the viability of metacestode tissue. Corresponding TEM analysis also revealed a dramatic shortening/retraction of microtriches as a hallmark of benzimidazole action, and as a consequence separation of the acellular laminated layer from the cellular germinal layer. Since TEM did not reveal any microtubule-based structures within Echinococcus microtriches, this effect cannot be explained by the previously described mechanism of action of benzimidazoles targeting β-tubulin, thus benzimidazoles must interact with additional targets that have not been yet identified. In addition, these results indicate the potential usefulness of fenbendazole for the chemotherapy of AE.
Daniela Klotz - One of the best experts on this subject based on the ideXlab platform.
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subcutaneous merocercoids of clistobothrium sp in two cape fur seals arctocephalus pusillus pusillus
International journal for parasitology. Parasites and wildlife, 2018Co-Authors: Daniela Klotz, Jörg Hirzmann, Christian Bauer, Joachim Schöne, Maximilian Iseringhausen, Peter Wohlsein, Wolfgang Baumgärtner, Vanessa HerderAbstract:Abstract Fur seals represent intermediate hosts of the cestode Clistobothrium . Large sharks are definitive hosts for these parasites. Two female, 25– and 27-year-old fur seals, caught in the 1980s at the South African coast, were examined pathomorphologically. Both animals showed multifocal, up to 1 cm in diameter large cavities of the thoracic and abdominal subcutaneous adipose tissue containing intraluminal Metacestodes of tapeworms, which were surrounded by a locally extensive, pyogranulomatous panniculitis. The Metacestodes (merocercoids) of one fur seal were isolated from the subcutaneous adipose tissue and characterized morphologically and for the first time from this host by molecular techniques. The morphometric data corresponded with ‘delphini'-morphotype merocercoids, but the sequence of the partial 28S ribosomal RNA gene identified them as conspecific with merocercoids of the morphotype ‘grimaldii ’ . These merocercoid types are morphologically Type XV Metacestodes of marine tapeworms and represent different species of Clistobothrium . Sequence data were generated for 18S, ITS1, 5.8S, ITS2, partial 28S ribosomal DNA and partial mitochondrial cox1 gene and phylogenetic analysis of 18S rRNA and partial 28S rRNA genes identified the fur seal merocercoids as Clistobothrium species. However, it cannot yet be assigned to species level because of limited molecular data from adult stages. Most likely, both fur seals were infected as juveniles in their original habitat, the coastal regions of South Africa. The metacestode infection is probably an incidental finding, however, there is a chronic inflammatory reaction next to the subcutaneous merocercoids. It is noteworthy, that the merocercoids remain in a potentially infective stage even after more than 20 years.
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Subcutaneous merocercoids of Clistobothrium sp. in two Cape fur seals (Arctocephalus pusillus pusillus)
Elsevier, 2018Co-Authors: Daniela Klotz, Jörg Hirzmann, Christian Bauer, Joachim Schöne, Maximilian Iseringhausen, Peter Wohlsein, Wolfgang Baumgärtner, Vanessa HerderAbstract:Fur seals represent intermediate hosts of the cestode Clistobothrium. Large sharks are definitive hosts for these parasites. Two female, 25– and 27-year-old fur seals, caught in the 1980s at the South African coast, were examined pathomorphologically. Both animals showed multifocal, up to 1 cm in diameter large cavities of the thoracic and abdominal subcutaneous adipose tissue containing intraluminal Metacestodes of tapeworms, which were surrounded by a locally extensive, pyogranulomatous panniculitis. The Metacestodes (merocercoids) of one fur seal were isolated from the subcutaneous adipose tissue and characterized morphologically and for the first time from this host by molecular techniques. The morphometric data corresponded with ‘delphini'-morphotype merocercoids, but the sequence of the partial 28S ribosomal RNA gene identified them as conspecific with merocercoids of the morphotype ‘grimaldii’. These merocercoid types are morphologically Type XV Metacestodes of marine tapeworms and represent different species of Clistobothrium. Sequence data were generated for 18S, ITS1, 5.8S, ITS2, partial 28S ribosomal DNA and partial mitochondrial cox1 gene and phylogenetic analysis of 18S rRNA and partial 28S rRNA genes identified the fur seal merocercoids as Clistobothrium species. However, it cannot yet be assigned to species level because of limited molecular data from adult stages. Most likely, both fur seals were infected as juveniles in their original habitat, the coastal regions of South Africa. The metacestode infection is probably an incidental finding, however, there is a chronic inflammatory reaction next to the subcutaneous merocercoids. It is noteworthy, that the merocercoids remain in a potentially infective stage even after more than 20 years. Keywords: Arctocephalus pusillus pusillus, Clistobothrium sp., Fur seal, Cestode, Subcutaneous parasites, Monorygma grimaldi