Nejvíce citovaný článek - PubMed ID 25102356
Focal Philophthalmus gralli infection possibly persists in Melanoides tuberculata over two years following the definitive hosts' removal
Avian Dicrocoeliidae are difficult to identify, even in their adult stages. Molecular analyses have been conducted for only a few species, complicating the accurate identification of juvenile stages. The taxonomy of the family is unresolved, and the status of many dicrocoeliid species is uncertain. Sequences of nuclear and mitochondrial DNA loci of Central European avian Dicrocoeliidae were generated and analyzed. These included representatives of the genera Lyperosomum, Platynosomum, Stromitrema, Brachylecithum, Brachydistomum, and Lutztrema. All the sequences were obtained from morphologically identified adult specimens of dicrocoeliids isolated from avian hosts. Molecular support was obtained to validate Lyperosomum turdia, confirm the rejection of Lyperosomum dujardini and Lyperosomum alagesi, and resurrect Lyperosomum longicauda and Lyperosomum collurionis. The identity of European Platynosomum illiciens from avian hosts with American vouchers of the same species from avian and mammalian hosts was confirmed. Brachylecithum fringillae is not considered valid; the individuals that matched its diagnosis were subadult Brachydistomum ventricosum. Descriptions and comparative data for five new species are provided. These are Lyperosomum hirundinis sp. n., Lyperosomum tenori sp. n., Lyperosomum atricapillae sp. n., Stromitrema acrocephali sp. n., and Lutztrema atricapillae sp. n.. Based on the molecular data, suggestions are provided regarding the validity of dicrocoeliid species that parasitize Central European birds. Further research should address the polyphyletic status of Brachylecithum.
- Klíčová slova
- Bile duct, Bird, Cryptic species, Dicrocoeliidae, Gall bladder, Platyhelminthes,
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Parasitic conjunctivitis caused by Philophthalmus spp. is a common ophthalmic disease in birds, with localized outbreaks occurring worldwide. There is no consensus on treating this disease; mechanical removal is considered a standard recommendation, but is associated with disease relapses within days or weeks. METHODS: From 2015 to 2020, we examined 4295 Larus michahellis and Larus fuscus gulls in southern Portugal for the presence of Philophthalmus spp. Due to the need to treat dozens of infected gulls in the rescue station, we tested three treatment regimens aimed at targeting Philophthalmus lucipetus in the infected gulls: (I) the ophthalmic application of levamisole; (II) the oral application of milbemycin in combination with praziquantel; and (III) the subcutaneous application of ivermectin. RESULTS: The outbreak of philophthalmosis in gulls in southern Portugal has been ongoing since the first cases were reported in 2015-2016. The prevalence of philophthalmosis has fluctuated annually, peaking a maximum of 10.3% in L. fuscus in 2017 and at 2.1% in L. michahellis in 2016. The infection intensity peaked at a median of 11.5 eye-flukes per host bird in L. fuscus in 2016 and a median of six eye-flukes per host bird in L. michahellis in 2017. Nine gulls were infected with >50 eye-flukes. None of the treatment options were effective at treating P. lucipetus infections: the numbers of eye-flukes in the infected birds did not decrease, and the clinical signs of the disease did not change. CONCLUSIONS: An outbreak of philophthalmosis in southern Portugal has massively affected two species of gulls in the region. Two previously suggested philophthalmosis treatments (ocular levamisole and praziquantel given orally), as well as a third mode of treatment with a previously failed compound (ivermectin administered subcutaneously) were used. However, the treatments did not affect the numbers of P. lucipetus in the eyes of the treated gulls. Further research should address ophthalmic gel formulations or sub-conjunctival delivery mode for antihelminthic drugs that are effective against Philophthalmus spp. in vitro.
- Klíčová slova
- Avermectin, Conjunctivitis, Digenea, Freshwater snail, Helminth, Imidazothiazole, Macrocyclic lactone, Philophthalmus lucipetus, Population dynamics, Trematoda,
- MeSH
- anthelmintika * terapeutické užití MeSH
- Charadriiformes * parazitologie MeSH
- epidemický výskyt choroby MeSH
- infekce červy třídy Trematoda * parazitologie MeSH
- ivermektin MeSH
- levamisol MeSH
- praziquantel terapeutické užití MeSH
- ptáci MeSH
- Trematoda * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Portugalsko epidemiologie MeSH
- Názvy látek
- anthelmintika * MeSH
- ivermektin MeSH
- levamisol MeSH
- praziquantel MeSH
BACKGROUND: The cutaneous monostome trematode Collyriclum faba (Bremser in Schmalz, 1831) is a bird parasite with a hitherto unknown life cycle and highly focal occurrence across the Holarctic and Neotropic ecozones. METHODS: Representative specimens of benthic organisms were sampled at multiple sites and dates within the known foci of C. faba occurrence in Slovakia. A combined approach involving detailed morphological examination and sequencing of two independent DNA loci was used for their analysis. RESULTS: We elucidated the complete life cycle of C. faba, which we determined to include the aquatic gastropod mollusk Bythinella austriaca (Frauenfeld, 1857) as the first intermediate host, the mayflies of the family Heptageniidae, Ecdyonurus venosus (Fabricius, 1775) and Rhithrogena picteti Sowa, 1971 x iridina (Kolenati, 1839), as the second intermediate hosts, and birds (primarily but not exclusively passeriform birds) as the definitive hosts. Bythinella austriaca occurs focally in the springs of tributaries of the Danube in the Alpine-Carpathian region. The restricted distribution of B. austriaca explains the highly focal distribution of C. faba noticed previously in spite of the broad distribution of its second intermediate and definitive host species. Utilization of both larval and adult Ephemeroptera spp. as the second intermediate hosts explains the known spectrum of the definitive host species, with the highest prevalence in species feeding on larvae of Ephemeroptera, such as Cinclus cinclus (Linnaeus, 1758) and Motacilla cinerea Tunstall, 1771, or adults of Ephemeroptera, such as Sylvia atricapilla (Linnaeus, 1758) and Regulus regulus (Linnaeus, 1758). In this study, we also determine the prevalence and DNA sequences of other immature trematode specimens found in the examined benthic organisms (particularly the families Microphallidae, Troglotrematidae and Nanophyetidae and Euryhelmis zelleri Grabda-Kazubska, 1980, Heterophyidae), and describe cercariae of C. faba. CONCLUSIONS: We determined the full life cycle of the Central European populations of C. faba. We speculate that other species of Bythinella and the closely related genus Amnicola may serve as first intermediate hosts in other parts of the distribution range of C. faba. Similarly, other Ephemeroptera of the family Heptageniidae may serve as the second intermediate hosts of C. faba in the Americas.
- MeSH
- Ephemeroptera parazitologie MeSH
- hostitelská specificita * MeSH
- infekce červy třídy Trematoda parazitologie veterinární MeSH
- měkkýši parazitologie MeSH
- nemoci ptáků parazitologie MeSH
- ploštěnci genetika růst a vývoj fyziologie MeSH
- ptáci parazitologie MeSH
- stadia vývoje MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH