Publications by authors named "Azmi Al-Jubury"

18 Publications

  • Page 1 of 1

Eye fluke effects on Danish freshwater fish: Field and experimental investigations.

J Fish Dis 2021 Jul 21. Epub 2021 Jul 21.

Laboratory of Aquatic Pathobiology, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.

Eye flukes in fish are common in freshwater lakes. Fish become infected by the penetration of cercariae released from freshwater snails, and high infection pressures may be associated with mortalities in a Danish lake. Examination of two other freshwater lakes, combined with laboratory study, supported the notion. We investigated 77 freshwater fish from two lakes and the infection level suggested the occurrence of a high cercarial infection pressure in the Danish lakes. Dominant genera were Tylodelphys and Diplostomum covering a range of species identified by PCR and sequencing of the 18S (partial)-ITS1-5.8S-ITS2-28S (partial) of the rDNA. Cercariae of the prevalent species Diplostomum pseudospathaceum were used to infect zebrafish Danio rerio for the elucidation of short-term effects on the fish host. Zebrafish did not display abnormal behaviour when exposed to 200-400 cercariae, but a dosage of 600 and 1,000 cercariae/fish proved lethal. When fish were exposed to sublethal dosages, 19 out of 27 immune genes were significantly regulated and three genes encoding cytokine (IL 4/13B, IL-6 and IL-8) were upregulated at 3 hr post-infection (hpi), whereas others were downregulated especially at a later time point. We suggest that direct massive cercarial penetration of fish surfaces may be detrimental and may represent a threat to fish populations.
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http://dx.doi.org/10.1111/jfd.13496DOI Listing
July 2021

Trematode diversity reflecting the community structure of Danish freshwater systems: molecular clues.

Parasit Vectors 2021 Jan 12;14(1):43. Epub 2021 Jan 12.

Laboratory of Aquatic Pathobiology, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Via Stigbøjlen 7, 1870, Frederiksberg C, Copenhagen, Denmark.

Background: Digenean trematodes are parasitic platyhelminths that use several hosts in their life cycles and are thereby embedded in various ecosystems affected by local environmental conditions. Their presence in a habitat will reflect the presence of different host species and, as such, they can serve as ecological indicators. Only limited information on the occurrence of trematodes and their link to other trophic levels in the Danish freshwater ecosystems is currently available.Therefore, the main aim of the present study was to increase our knowledge in this field.

Methods: Snails were sampled from 21 freshwater lakes in Denmark, following which shedding procedures were performed, cercariae were recoved and the released parasites were identified using molecular tools (PCR and sequencing).

Results: A total of 5657 snail hosts belonging to ten species were identified, revealing a highly diverse parasite fauna comprising 22 trematode species. The overall trematode prevalence was 12.6%, but large variations occurred between host species. The snail host Lymnaea stagnalis showed the highest prevalence and also exhibited the highest diversity, accounting for 47.6% of the species richness.

Conclusions: This survey contributes updated information on parasite-host relations and compatibility and may assist in describing the ecological structure of the investigated Danish freshwater ecosystems.
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http://dx.doi.org/10.1186/s13071-020-04536-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7805065PMC
January 2021

Evidence for mitochondrial pseudogenes (numts) as a source of contamination in the phylogeny of human whipworms.

Infect Genet Evol 2020 12 9;86:104627. Epub 2020 Nov 9.

Department of Clinical Medicine, Health, Aarhus University, Denmark; Department of Infectious Diseases, Aarhus University Hospital, Aarhus, Denmark.

Trichuris trichiura and T. suis are whipworms of humans and pigs, respectively, but it has recently been suggested that humans may be infected with multiple genotypes or species of Trichuris and cross-infection with Trichuris of pig origin has also been reported. In addition, the species status of Trichuris in non-human primates is unsettled and it is unknown how many whipworm species we share with other primates. Herein, we inferred the phylogeny of Trichuris collected from human, baboon and pig based on nuclear (18S and beta-tubulin) and mitochondrial (cox1) genes and evaluated the use of three PCR linked restriction fragment length polymorphism (PCR-RFLP) to identify worms. We found that all baboon worms clustered with human worms and that all these primate worms are different from T. suis. In general, there was an agreement between the phylogeny established based on the nuclear and mtDNA genes. However, we found evidence for non-targeted cox1 gene amplification for a subset of the human worms and suggest the presence of mitochondrial pseudogenes (numts) of pig cox1 gene in the human Trichuris genome. In conclusion, phylogenetic characterization of human whipworm based on the cox1 gene alone may be problematic without suitable preceded measures to avoid the numts amplification.
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http://dx.doi.org/10.1016/j.meegid.2020.104627DOI Listing
December 2020

Temperature and light effects on Trichobilharzia szidati cercariae with implications for a risk analysis.

Acta Vet Scand 2020 Sep 15;62(1):54. Epub 2020 Sep 15.

Laboratory of Aquatic Pathobiology, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigbøjlen 7, 1870, Frederiksberg C, Denmark.

Background: Cercarial dermatitis (swimmer's itch) caused by bird schistosome cercariae, released from intermediate host snails, is a common disorder also at higher latitudes. Several cases were observed in the artificial Danish freshwater Ringen Lake frequently used by the public for recreational purposes. The lake may serve as a model system when establishing a risk analysis for this zoonotic disease. In order to explain high risk periods we determined infection levels of intermediate host snails from early spring to late summer (March, June and August) and elucidated the effect of temperature and light on parasite shedding, behavior and life span.

Results: Field studies revealed no shedding snails in March and June but in late summer the prevalence of Trichobilharzia szidati infection (in a sample of 226 pulmonate Lymnaea stagnalis snails) reached 10%. When investigated under laboratory conditions the cercarial shedding rate (number of cercariae shed per snail per day) was positively correlated to temperature raising from a mean of 3000 (SD 4000) at 7 °C to a mean of 44,000 (SD 30,000) at 27 °C). The cercarial life span was inversely correlated to temperature but the parasites remained active for up to 60 h at 20 °C indicating accumulation of cercariae in the lake during summer periods. Cercariae exhibited positive phototaxy suggesting a higher pathogen concentration in surface water of the lake during daytime when the public visits the lake.

Conclusion: The only causative agent of cercarial dermatitis in Ringen Lake detected was T. szidati. The infection risk associated with aquatic activities is low during spring and early summer (March-June). In late summer the risk of infection is high since the release, behavior and life span of the infective parasite larvae have optimal conditions.
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http://dx.doi.org/10.1186/s13028-020-00553-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7493345PMC
September 2020

Gill amoebae from freshwater rainbow trout (Oncorhynchus mykiss): In vitro evaluation of antiparasitic compounds against Vannella sp.

J Fish Dis 2020 Jun 15;43(6):665-672. Epub 2020 Apr 15.

Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.

Gill parasitic infections challenge farming of rainbow trout (Oncorhynchus mykiss, Walbaum) in freshwater facilities. Apart from flagellates (Ichthyobodo, (Pinto) and ciliates (Ichthyophthirius (Fouquet), Ambiphrya (Raabe), Apiosoma (Blanchard), Trichodinella (Sramek-Husek) and Trichodina (Ehrenberg)), we have shown that amoebae are prevalent in Danish trout farms. Gills were isolated from farmed rainbow trout in six fish farms (conventional and organic earth pond and recirculated systems) and placed on non-nutrient agar (NNA) moistened with modified Neff's amoeba saline (AS) (15°C). Gill amoebae from all examined fish colonized the agar and were identified based on morphological criteria showing species within the genera Trinema (Dujardin) (family Trinematidae), Vannella (Bovee) (family Vannellidae). In addition, hartmannellid amoebae were recorded. We established a monoculture of Vannella sp., confirmed the genus identity by PCR and sequencing and performed an in vitro determination of antiparasitic effects (dose-response studies) of various compounds including sodium chloride (NaCl), hydrogen peroxide, peracetic acid, formalin, aqueous garlic and oregano extracts and a Pseudomonas H6 surfactant. All amoebae were killed in concentrations of 16.90 mg/ml (garlic), 17.90 mg/ml (oregano), NaCl (7.5 mg/ml), hydrogen peroxide (100 µg/ml), peracetic acid (0.03 µg/ml), formaldehyde (25 µg/ml) and the Pseudomonas H6 surfactant (250 µg/ml).
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http://dx.doi.org/10.1111/jfd.13162DOI Listing
June 2020

Outbreak of Swimmer's Itch in Denmark.

Acta Derm Venereol 2019 Nov;99(12):1116-1120

Department of Dermatology, Aarhus University Hospital, DK-8200 Aarhus, Denmark.

Swimmer's itch, or cercarial dermatitis, is a waterborne non-communicable skin condition caused by schistosome cercariae released by aquatic snails. Cercarial dermatitis appears worldwide, but may be caused by different trematode species. The itchy maculopapular rash develops on exposed areas of the skin and typically resolves within 1-3 weeks. Shedding of infective larvae from snails is temperature dependent, and high temperatures and sunshine increase the risk of encountering the parasite and becoming infected. The unusually warm spring and summer of 2018 led to an increasing number of reports of the condition in Denmark and established a collaboration between the Department of Dermatology and the Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences. This study explored the clinical picture of the disease, and demonstrated the occurrence of infected fresh water snail species in selected Danish water bodies. In conclusion, a risk of swimmer's itch in Denmark was confirmed.
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http://dx.doi.org/10.2340/00015555-3309DOI Listing
November 2019

Protective effect of in-feed specific IgM towards Yersinia ruckeri in rainbow trout.

Fish Shellfish Immunol 2019 Oct 10;93:934-939. Epub 2019 Aug 10.

National Veterinary Institute, Technical University of Denmark, Frederiksberg C, Denmark. Electronic address:

Tightened regulations and an environmentally friendly approaches in fish production have greatly reduced the use of antibiotics but green solutions are continuously being explored. The use of functional feed may have a potential in the aquaculture sector in securing biomass and minimizing the loss from disease. In the present study, we tested the concept that blood from the fish slaughterhouse can be used for mass purification of specific antibodies which subsequently can be used for feeding fish and thereby confer protection against diseases. IgM was purified from serum from Yersinia ruckeri vaccinated rainbow trout and an IgM sandwich ELISA was developed for quantification of rainbow trout IgM. The purified IgM was encapsulated in alginate microparticles and top-coated in fish feed. IgM re-extracted from the alginate microparticles was shown to retain high reactivity towards Y. ruckeri antigens indicating that its bioactivity remained intact after encapsulation. IgM release from the alginate microparticles was only observed at high pH (pH 8.2) and minimal at low pH, indicating protection of IgM at low pH in the fish stomach during passage. In a feeding - challenge experiment (feeding 1 week before Y. ruckeri challenge and for two weeks following challenge), a statistically non-significant 10% lower mortality was observed in the high dose (400 μg IgM/fish/day fed over 3 weeks) group.
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http://dx.doi.org/10.1016/j.fsi.2019.08.024DOI Listing
October 2019

Differential immune gene response in gills, skin, and spleen of rainbow trout Oncorhynchus mykiss infected by Ichthyophthirius multifiliis.

PLoS One 2019 20;14(6):e0218630. Epub 2019 Jun 20.

Department of Veterinary and Animal Science, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.

Infection of rainbow trout with the parasitic ciliate Ichthyopthirius multifiliis induces differential responses in gills, skin and spleen. A controlled experimental infection was performed and expression of immune-relevant genes in skin, gills, and spleen were recorded by qPCR at day 1 and 8 after parasite exposure. Infection induced a marked reaction involving regulation of innate and adaptive immune genes in rainbow trout at day 8 post-infection. The expression level of a total of 22 out of 24 investigated genes was significantly higher in gills compared to skin reflecting the more sensitive and delicate structure of gills. Especially pro-inflammatory cytokines IL-6, IL-17 C1, regulatory cytokines IL-4/13A, IL-10, TGFβ, complement factor C5, chemokines CK10, CK12, acute phase proteins (precerebellin, hepcidin) and immunoglobulins (IgM, IgT) displayed differential expression levels. The spleen, a central immune organ with no trace of the parasite, showed elevated expression of IgM, IgT, complement factor C5 and chemokine CK10 (compared to skin and gills directly exposed to the parasite), indicating an interaction between the infected surface sites and central immune organs. This communication could be mediated by chemokines CK10 and CK12 and cytokine IL-4/13A and may at least partly explain the establishment of a systemic response in rainbow trout against the parasite.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0218630PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6586319PMC
February 2020

A pentavalent vaccine for rainbow trout in Danish aquaculture.

Fish Shellfish Immunol 2019 May 6;88:344-351. Epub 2019 Mar 6.

Department of Veterinary and Animal Science, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.

Mariculture in Denmark is based on production of rainbow trout grown two years in fresh water followed by one growth season in sea cages. Although the majority of rainbow trout are vaccinated against the most serious bacterial pathogens - Aeromonas salmonicida subsp. salmonicida, Vibrio anguillarum and Yersinia ruckeri, by the use of commercially available vaccines, disease outbreaks requiring treatment with antibiotics still occur. The present study tested the potential of a new experimental multicomponent vaccine that is based on local bacterial strains, isolated from rainbow trout in Danish waters, and thus custom-designed for Danish rainbow trout mariculture. The vaccination with the multicomponent vaccine resulted in protection against three relevant bacterial diseases (yersiniosis, furunculosis, vibriosis) under experimental conditions. We showed that i.p. injection of the vaccine induced specific antibody responses in trout against the different bacterial antigens and regulated expression of genes encoding SAA, C3, IL-1β, IL-6, IL-8, IgD and MHCII.
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http://dx.doi.org/10.1016/j.fsi.2019.03.001DOI Listing
May 2019

CK11, a Teleost Chemokine with a Potent Antimicrobial Activity.

J Immunol 2019 02 4;202(3):857-870. Epub 2019 Jan 4.

Animal Health Research Centre, National Institute for Agricultural and Food Research, Valdeolmos 28130, Madrid, Spain;

CK11 is a rainbow trout () CC chemokine phylogenetically related to both mammalian CCL27 and CCL28 chemokines, strongly transcribed in skin and gills in homeostasis, for which an immune role had not been reported to date. In the current study, we have demonstrated that CK11 is not chemotactic for unstimulated leukocyte populations from central immune organs or mucosal tissues but instead exerts a potent antimicrobial activity against a wide range of rainbow trout pathogens. Our results show that CK11 strongly inhibits the growth of different rainbow trout Gram-positive and Gram-negative bacteria, namely , subsp. , and and a parasitic ciliate Similarly to mammalian chemokines and antimicrobial peptides, CK11 exerted its antimicrobial activity, rapidly inducing membrane permeability in the target pathogens. Further transcriptional studies confirmed the regulation of CK11 transcription in response to exposure to some of these pathogens in specific conditions. Altogether, our studies related to phylogenetic relations, tissue distribution, and biological activity point to CK11 as a potential common ancestor of mammalian CCL27 and CCL28. To our knowledge, this study constitutes the first report of a fish chemokine with antimicrobial activity, thus establishing a novel role for teleost chemokines in antimicrobial immunity that supports an evolutionary relationship between chemokines and antimicrobial peptides.
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http://dx.doi.org/10.4049/jimmunol.1800568DOI Listing
February 2019

Transcriptomic analysis of immunity in rainbow trout (Oncorhynchus mykiss) gills infected by Ichthyophthirius multifiliis.

Fish Shellfish Immunol 2019 Mar 1;86:486-496. Epub 2018 Dec 1.

Department of Veterinary and Animal Science, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.

The parasite Ichthyophthirius multifiliis infecting skin, fins and gills of a wide range of freshwater fish species, including rainbow trout, is known to induce a protective immune response in the host. Although a number of studies have reported activation of several immune genes in infected fish host, the immune response picture is still considered incomplete. In order to address this issue, a comparative transcriptomic analysis was performed on infected versus uninfected rainbow trout gills and it showed that a total of 3352 (7.2%) out of 46,585 identified gene sequences were significantly regulated after parasite infection. Of differentially expressed gene sequences, 1796 genes were up-regulated and 1556 genes were down-regulated. These were classified into 61 Gene Ontology (GO) terms and mapped to 282 reference canonical pathways in the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Infection of I. multifiliis induced a clear differential expression of immune genes, related to both innate and adaptive immunity. A total of 268 (6.86%) regulated gene sequences were known to take part in 16 immune-related pathways. These involved pathways related to the innate immunity such as the Chemokine signaling pathway, Platelet activation, Toll-like receptor signaling pathway, NOD-like receptor signaling pathway, and Leukocyte transendothelial migration. Elevated transcription of genes encoding the TLR 8 gene and chemokines (CCL4, CCL19, CCL28, CXCL8, CXCL11, CXCL13, CXCL14) was recorded indicating their roles in recognition of I. multifiliis and subsequent induction of the inflammatory response, respectively. A number of upregulated genes in infected gills were associated with antigen processing/presentation and T and B cell receptor signaling (including B cell marker CD22 involved in B cell development). Overall the analysis supports the notion that I. multifiliis induces a massive and varied innate response upon which a range of adaptive immune responses are established which may contribute to the long lasting protection of immunized rainbow trout.
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http://dx.doi.org/10.1016/j.fsi.2018.11.075DOI Listing
March 2019

Experimental anal infection of rainbow trout with Flavobacterium psychrophilum: A novel challenge model.

J Fish Dis 2018 Dec 11;41(12):1917-1919. Epub 2018 Sep 11.

Department of Veterinary and Animal Science, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.

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http://dx.doi.org/10.1111/jfd.12888DOI Listing
December 2018

Epidemiological investigation of gastrointestinal parasites in dog populations in Basra province, Southern Iraq.

J Parasit Dis 2017 Dec 22;41(4):1006-1013. Epub 2017 May 22.

Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark.

The understanding of the epidemiology of canine parasitic infections is necessary for an efficient control program to minimize the risk of zoonotic transmission. The objectives of this study were (1) to determine the prevalence of canine gastrointestinal helminths and protozoa in Basra province, Southern Iraq, and (2) to identify the association of epidemiological characteristics (age, breed, gender, and feed type) of dogs with the parasitic infections. A total of 93 fecal samples, collected in the period from December 2014 to June 2015, were examined macroscopically and microscopically for the presence of worm eggs and protozoal oocysts, using centrifugal flotation method. The overall prevalence of infected dogs was 77.4% (72/93). About 54.8% (51/93) dogs were infected with more than one genus of parasites. The prevalence of multiple infections with two, three, and four parasites was 30.1% (28/93), 22.6% (21/93), and 2.2% (2/93), respectively. The most frequently detected parasites were (62.4%, 58/93), spp. (28%, 26/93), spp. (26.9%, 25/93), (9.7%, 9/93), and (7.5%, 7/93). (6.5%, 6/93) and spp. (4.3%, 4/93) were the only protozoan parasites identified in this study. infection was significantly associated with sex and age of the dogs ( < 0.05). Feeding type was significantly associated with the occurrence of ( < 0.0001), ( < 0.03) and spp. ( < 0.02). The high prevalence of intestinal helminths in dog's population suggesting the need for more efficient control measures. The high prevalence of , spp. suggested that dogs could play an active role in the transmission of zoonotic parasites in this area of Iraq. Educating the dog owners and increasing their health awareness should be considered in the control program. The results of the present study provide relevant "base-line" data for assessing the effectiveness of future control strategies against canine parasitic infections.
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http://dx.doi.org/10.1007/s12639-017-0926-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5660026PMC
December 2017

Effect of oral booster vaccination of rainbow trout against Yersinia ruckeri depends on type of primary immunization.

Fish Shellfish Immunol 2019 Feb 31;85:61-65. Epub 2017 Oct 31.

Department of Veterinary and Animal Science, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.

Vaccination of rainbow trout against Enteric Redmouth Disease (ERM) caused by Yersinia ruckeri can be successfully performed by administering vaccine (a bacterin consisting of formalin killed bacteria) by immersion, bath or injection. Booster immunization is known to increase the protection of fish already primed by one of these vaccination methods. Oral vaccination of trout (administering vaccine in feed) is an even more convenient way of presenting antigen to the fish but the effect of an oral booster has not previously been described in detail. The present work describes to what extent protection may be enhanced by oral boostering following priming with different administration methods. The study confirms that vaccination by 30 s dip into a bacterin (diluted 1:10) may confer a significant protection compared to non-vaccinated fish. The immunity may be optimized by booster immunization either provided as dip (most effective), bath (less effective) or orally (least effective). Oral immunization may be used as booster after dip but applied as a single oral application it induced merely a slight and statistically non-significant response. It is noteworthy that primary oral immunization followed by an oral booster vaccination showed a trend for an even weaker response. It should be investigated if continued exposure to a low antigen concentration - as performed by two oral immunizations - may induce tolerance to the pathogen and thereby leave the fish more vulnerable.
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http://dx.doi.org/10.1016/j.fsi.2017.10.049DOI Listing
February 2019

Host size-dependent anisakid infection in Baltic cod Gadus morhua associated with differential food preferences.

Dis Aquat Organ 2016 Jun;120(1):69-75

Laboratory of Aquatic Pathobiology, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark.

A significant increase in the infection level of Baltic cod Gadus morhua with the anisakid nematode larvae Contracaecum osculatum and Pseudoterranova decipiens has been recorded during recent years due to the expanding local population of grey seals Halichoerus grypus, which act as final hosts for these parasites. Here, we report from an investigation of 368 cod (total length [TL] 6-49 cm; caught in ICES Subdivision 25) that the infection level of juvenile cod (TL 6-30 cm) with larvae of C. osculatum and P. decipiens is absent or very low, whereas it increases drastically in larger cod (TL 31-48 cm). A third nematode Hysterothylacium aduncum was rarely found. The study indicates that the prey animals for large cod act as transport hosts for the parasite larvae. Analyses of stomach contents of cod caught in the same area (2007-2014) showed that small benthic organisms (including polychaetes Harmothoë sarsi) are preferred food items by small cod, the isopod Saduria entomon is taken by all size classes, and sprat Sprattus sprattus are common prey items for cod larger than 30 cm. Parasitological investigations (microscopic and molecular analyses) of H. sarsi (100 specimens) and S. entomon (40 specimens) did not reveal infection in these invertebrates, but 11.6% of sprat (265 specimens examined) was shown to be infected with 1-8 C. osculatum third stage larvae per fish. Analyses of sprat stomach contents confirmed that copepods and cladocerans are the main food items of sprat. These observations suggest that the C. osculatum life cycle in the Baltic Sea includes grey seals as final hosts, sprat as the first transport host and cod as second transport host. It may be speculated that sprat obtain infection by feeding on copepods and/or cladocerans, which could serve as the first intermediate hosts. One cannot exclude the possibility that the size-dependent C. osculatum infection of cod may contribute (indirectly or directly) to the differential mortality of larger cod (>38 cm) compared to smaller cod (<30 cm) recently recorded in the Baltic cod population.
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http://dx.doi.org/10.3354/dao03002DOI Listing
June 2016

Whipworms in humans and pigs: origins and demography.

Parasit Vectors 2016 Jan 22;9:37. Epub 2016 Jan 22.

Department of Veterinary Disease Biology, Faculty of Health Sciences, Copenhagen University, Dyrlaegevej 100, DK-1870, Frederiksberg C, Copenhagen, Denmark.

Background: Trichuris suis and T. trichiura are two different whipworm species that infect pigs and humans, respectively. T. suis is found in pigs worldwide while T. trichiura is responsible for nearly 460 million infections in people, mainly in areas of poor sanitation in tropical and subtropical areas. The evolutionary relationship and the historical factors responsible for this worldwide distribution are poorly understood. In this study, we aimed to reconstruct the demographic history of Trichuris in humans and pigs, the evolutionary origin of Trichuris in these hosts and factors responsible for parasite dispersal globally.

Methods: Parts of the mitochondrial nad1 and rrnL genes were sequenced followed by population genetic and phylogenetic analyses. Populations of Trichuris examined were recovered from humans (n = 31), pigs (n = 58) and non-human primates (n = 49) in different countries on different continents, namely Denmark, USA, Uganda, Ecuador, China and St. Kitts (Caribbean). Additional sequences available from GenBank were incorporated into the analyses.

Results: We found no differentiation between human-derived Trichuris in Uganda and the majority of the Trichuris samples from non-human primates suggesting a common African origin of the parasite, which then was transmitted to Asia and further to South America. On the other hand, there was no differentiation between pig-derived Trichuris from Europe and the New World suggesting dispersal relates to human activities by transporting pigs and their parasites through colonisation and trade. Evidence for recent pig transport from China to Ecuador and from Europe to Uganda was also observed from their parasites. In contrast, there was high genetic differentiation between the pig Trichuris in Denmark and China in concordance with the host genetics.

Conclusions: We found evidence for an African origin of T. trichiura which were then transmitted with human ancestors to Asia and further to South America. A host shift to pigs may have occurred in Asia from where T. suis seems to have been transmitted globally by a combination of natural host dispersal and anthropogenic factors.
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http://dx.doi.org/10.1186/s13071-016-1325-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4724142PMC
January 2016

Effects of adjuvant Montanide™ ISA 763 A VG in rainbow trout injection vaccinated against Yersinia ruckeri.

Fish Shellfish Immunol 2015 Dec 19;47(2):797-806. Epub 2015 Oct 19.

Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.

Enteric redmouth disease (ERM) caused by the fish pathogen Yersinia ruckeri is a major threat to freshwater production of rainbow trout (Oncorhynchus mykiss) throughout all life stages. Injection vaccination of rainbow trout against Y. ruckeri infection has been shown to confer better protection compared to the traditionally applied immersion vaccination. It may be hypothesized, based on experience from other vaccines, that adjuvants may increase the protective level of ERM injection vaccines even more. Controlled comparative vaccination studies have been performed to investigate effects of the oil adjuvant Montanide™ ISA 763 A VG (Seppic) when added to an experimental Y. ruckeri bacterin (containing both biotype 1 and 2 of serotype O1). A total of 1000 fish with mean weight 19 g was divided into five different groups (in duplicated tanks 2 × 100 fish per group) 1) non-vaccinated control fish (NonVac), 2) fish injected with a commercial vaccine (AquaVac(®) Relera™) (ComVac), 3) fish injected with an experimental vaccine (ExpVac), 4) fish injected with an experimental vaccine + adjuvant (ExpVacAdj) and 5) fish injected with adjuvant alone (Adj). Injection of the experimental vaccine (both adjuvanted and non-adjuvanted) induced a significantly higher antibody (IgM) level, increased occurrence of IgM(+) cells in spleen tissue and significant up-regulation of several immune genes. Additional experiments using a higher challenge dosage suggested an immune enhancing effect of the adjuvant as the challenge produced 100% mortality in the NonVac group, 60% mortality in both of ComVac and Adj groups and only 13 and 2.5% mortalities in the ExpVac and the ExpVacAdj groups, respectively.
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http://dx.doi.org/10.1016/j.fsi.2015.10.023DOI Listing
December 2015

Genetic analysis of Trichuris suis and Trichuris trichiura recovered from humans and pigs in a sympatric setting in Uganda.

Vet Parasitol 2012 Aug 20;188(1-2):68-77. Epub 2012 Mar 20.

Section for Parasitology, Health and Development, Department of Veterinary Disease Biology, Faculty of Life Sciences, University of Copenhagen, Groennegaardsvej 15, DK-1870 Frederiksberg C, Denmark.

The whipworms Trichuris trichiura and Trichuris suis in humans and pigs, respectively, are believed to be two different species yet closely related. Morphologically, adult worms, eggs and larvae of the two species are indistinguishable. The aim of this study was to examine the genetic variation of Trichuris sp. mainly recovered from natural infected pigs and humans. Worm material isolated from humans and pigs living in the same geographical region in Uganda were analyzed by PCR, cloning and sequencing. Measurements of morphometric characters were also performed. The analysis of the ITS-2 (internal transcribed spacer) region showed a high genetic variation in the human-derived worms with two sequence types, designated type 1 and type 2, differing with up to 45%, the type 2 being identical to the sequence found in pig-derived worms. A single human-derived worm showed exclusively the type 2-genotype (T. suis-type) and three cases of 'heterozygote' worms in humans were identified. However, the analysis showed that sympatric Trichuris primarily assorted with host origin. Sequence analysis of a part of the genetically conserved β-tubulin gene confirmed two separate populations/species but also showed that the 'heterozygote' worms had a T. suis-like β-tubulin gene. A PCR-RFLP on the ITS-2 region was developed, that could distinguish between worms of the pig, human and 'heterozygote' type. The data suggest that Trichuris in pigs and humans belong to two different populations (i.e. are two different species). However, the data presented also suggest that cross-infections of humans with T. suis takes place. Further studies on sympatric Trichuris populations are highly warranted in order to explore transmission dynamics and unravel the zoonotic potential of T. suis.
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http://dx.doi.org/10.1016/j.vetpar.2012.03.004DOI Listing
August 2012
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