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Parasitol Res ; 117(4): 1079-1086, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29435720


A parasitological survey of 651 northern fur seals Callorhinus ursinus L. from five subpopulations was conducted on St. Paul Island, Alaska, during July-August 2012-2014. Digenean trematodes were found in 210 of 651 fur seals with a total prevalence of 32.3%. Intensity of infection varied from 1 to 1540 parasites with mean intensity 18.4 ± 111.1 SD and median intensity of 2 specimens per host. Significant differences in prevalence and intensity of infection in northern fur seals between separate rookeries was not observed (Mann-Whitney test; p > 0.05). Four species of digeneans belonging to the families Heterophyidae (Apophallus zalophi Price, 1932, Phocitrema fusiforme Goto and Ozaki, 1930, and Galactosomum ubelakeri (Dailey, 1969)) and Troglotrematidae (Nanophyetus salmincola (Chapin, 1926)) were found. Nanophyetus salmincola is reported from C. ursinus for the first time. We obtained partial 28S rDNA sequences for all digenean species and conducted molecular phylogenetic analysis to demonstrate their phylogenetic relationships.

Otárias/parasitologia , Heterophyidae/classificação , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/veterinária , Troglotrematidae/classificação , Alaska/epidemiologia , Animais , Heterophyidae/genética , Heterophyidae/isolamento & purificação , Intestinos/parasitologia , Filogenia , Prevalência , RNA Ribossômico 28S/genética , Infecções por Trematódeos/parasitologia , Troglotrematidae/genética , Troglotrematidae/isolamento & purificação
PLoS One ; 12(1): e0170184, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28085945


We studied the phylogeography and historical demography of the most generalist digenean from cetaceans, Pholeter gastrophilus, exploring the effects of isolation by distance, ecological barriers and hosts' dispersal ability on the population structure of this parasite. The ITS2 rDNA, and the mitochondrial COI and ND1 from 68 individual parasites were analysed. Worms were collected from seven oceanic and coastal cetacean species from the south western Atlantic (SWA), central eastern Atlantic, north eastern Atlantic (NEA), and Mediterranean Sea. Pholeter gastrophilus was considered a single lineage because reciprocal monophyly was not detected in the ML cladogram of all individuals, and sequence variability was <1% for mtDNA and 0% for ITS2. These results rule out a recent suggestion that P. gastrophilus would actually be a cryptic-species complex. The genetic cohesion of P. gastrophilus could rely on the extensive exploitation of wide-ranging and highly mobile cetaceans, with a putative secondary role, if any, of intermediate hosts. Unique haplotypes were detected in SWA and NEA, and an AMOVA revealed significant population structure associated to the genetic variation in these regions. The Equator possibly acts as a significant geographical barrier for cetacean movements, possibly limiting gene flow between northern and southern populations of P. gastrophilus. A partial Mantel tests revealed that the significant isolation of NEA populations resulted from geographic clustering. Apparently, the limited mobility of cetaceans used by P. gastrophilus as definitive hosts in this region, coupled with oceanographic barriers and a patchy distribution of potential intermediate hosts could contribute to significant ecological isolation of P. gastrophilus in NEA. Rather unexpectedly, no genetic differentiation was found in the Mediterranean samples of this parasite. Historical demographic analyses suggested a recent population expansion of P. gastrophilus in the Atlantic Ocean, perhaps linked to initial association and subsequent spreading in cetaceans.

Cetáceos/parasitologia , Variação Genética , Troglotrematidae/genética , Análise de Variância , Animais , Oceano Atlântico , DNA de Helmintos/química , Demografia , Especiação Genética , Funções Verossimilhança , Mar Mediterrâneo , Filogeografia , Dinâmica Populacional , Isolamento Reprodutivo , Análise de Sequência de DNA , Troglotrematidae/classificação , Troglotrematidae/fisiologia
Parasitology ; 144(5): 601-612, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27903316


Human and animal nanophyetiasis is caused by intestinal flukes belonging to the genus Nanophyetus distributed on both North American and Eurasian coasts of Northern Pacific. In spite of the wide geographical distribution and medical and veterinary importance of these flukes, the intra-generic taxonomy of Nanophyetus spp. remains unresolved. The two most widely distributed nominal species, Nanophyetus salmincola and Nanophyetus schikhobalowi, both parasitizing humans and carnivorous mammals, were described from North America and eastern Eurasia, respectively. However, due to their high morphological similarity their interrelationships remained unclear and taxonomic status unstable. In this study, we explored genetic diversity of Nanophyetus spp. from the Southern Russian Far East in comparison with that of samples from North America based on the sequence variation of the nuclear ribosomal gene family (18S, internal transcribed spacers, ITS1-5·8S-ITS2 and 28S). High levels of genetic divergence in each rDNA region (nucleotide substitutions, indels, alterations in the secondary structures of the ITS1 and ITS2 transcripts) as well as results of phylogenetic analysis provided strong support for the status of N. salmincola and N. schikhobalowi as independent species.

Variação Genética , Infecções por Trematódeos/parasitologia , Troglotrematidae/genética , Animais , DNA Ribossômico/química , DNA Ribossômico/genética , Geografia , Humanos , América do Norte , Oceano Pacífico , Filogenia , Federação Russa , Análise de Sequência de DNA , Troglotrematidae/classificação , Troglotrematidae/isolamento & purificação
Parasit Vectors ; 8: 659, 2015 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-26701345


BACKGROUND: Adults and larvae of generalist parasites are exposed to diverse hosts and local environmental conditions throughout their life cycles, thus local adaptation is expected to occur through phenotypic plasticity and/or natural selection. We investigated how the combined effect of cryptic host specificity and local selective pressures could shape reproductive traits of a putative generalist parasite in the oceanic realm. METHODS: The LSU rDNA, ITS2 and the mt-COI of individuals of the digenean Pholeter gastrophilus (Kossack, 1910) Odhner, 1914 (Heterophyidae Leiper, 1909) from oceanic striped dolphins, Stenella coeruleoalba Meyen, and coastal bottlenose dolphins, Tursiops truncatus Montagu, in the western Mediterranean were used to elucidate whether worms were conspecific. Infection parameters were compared between both dolphin species. General Linear Mixed Models were used to analyse the influence of host species on four reproductive traits of P. gastrophilus: body size, maturity stage (non-gravid/gravid), egg size, and number of eggs in utero. AIC values were used to rank competing models, and p-values to assess the effect of specific predictors. RESULTS: Evidence indicated that worms collected from both dolphin species were conspecific. All worms collected were gravid and infection parameters did not differ between dolphin species. However, body size and egg size of individuals of P. gastrophilus were significantly larger in striped dolphins. The number of eggs in utero did not significantly differ between dolphin species but, for a given body size, worms in bottlenose dolphins harboured more eggs. A trade-off between egg size and egg number was found in worms from both dolphin species, with a higher slope in striped dolphins. CONCLUSIONS: Apparently, striped dolphin is a more suitable host for P. gastrophilus, but reproductive investment seems to be adapted to the habitat where the life-cycle develops. Worms from striped dolphins likely face the problem of finding intermediate hosts in the oceanic realm and apparently invest into offspring size to enhance the early survival of larvae and the potential to multiply asexually within the first intermediate host. The small-sized worms from bottlenose dolphins would be adapted to reproduce early because of higher adult mortality, generating smaller and numerous eggs in a coastal habitat where chances of transmission are presumably higher.

Golfinho Nariz-de-Garrafa/parasitologia , Exposição Ambiental , Especificidade de Hospedeiro , Stenella/parasitologia , Troglotrematidae/anatomia & histologia , Troglotrematidae/fisiologia , Zigoto/citologia , Adaptação Fisiológica , Animais , DNA de Helmintos/química , DNA de Helmintos/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Mar Mediterrâneo , Dados de Sequência Molecular , RNA Ribossômico/genética , Análise de Sequência de DNA , Troglotrematidae/classificação , Troglotrematidae/isolamento & purificação
Parasitol Res ; 114(2): 789-93, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25563614


We examined 131 European badgers Meles meles (Linnaeus, 1758) from 67 localities in central Germany for the presence of the cranial trematode Troglotrema acutum, as previous studies based on museum skulls might have underestimated the prevalence of the parasite in this host. We detected the flatworm in only three individuals that originated from the Rhoen Mountains (Thurigina and Bavaria). While the cranium of one host individual showed the lesions and the sponge-like widening of certain regions of the skullcap that are typical of a T. acutum infection, the skulls of the two remaining badgers did not show any deformations. The three badgers were infected by eight, 20, and 49 T. acutum individuals, respectively. Eggs of the trematode parasite were detected in the paranasal sinuses of two badgers. While badgers infected with T. acutum may not show any surface bone lesions, the results of the present study do not contradict the conclusion that the badger is only an accidental host of T. acutum.

Mustelidae/parasitologia , Seios Paranasais/parasitologia , Crânio/patologia , Crânio/parasitologia , Infecções por Trematódeos/veterinária , Troglotrematidae/isolamento & purificação , Animais , Tecido Conjuntivo/parasitologia , Feminino , Alemanha , Masculino , Doenças dos Seios Paranasais/epidemiologia , Doenças dos Seios Paranasais/parasitologia , Doenças dos Seios Paranasais/patologia , Doenças dos Seios Paranasais/veterinária , Contagem de Ovos de Parasitas , Prevalência , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/patologia , Troglotrematidae/anatomia & histologia , Troglotrematidae/crescimento & desenvolvimento
J Helminthol ; 86(2): 222-7, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21729381


A total of 109 badger Meles meles skulls from Catalonia (north-eastern Iberian Peninsula) were studied for helminths. The tremadode Troglotrema acutum is reported here for the first time in the Eurasian badger in the Iberian Peninsula and southern Europe. Three methodologies were used to detect this trematode: an examination for surface lesions, axial computed tomography and fresh skull dissection. The damage caused in the affected skulls is described, along with details regarding the use of computed tomography to detect hyperostosis, leakage in the sinus structure and bone surface erosion in the affected skulls.

Mustelidae/parasitologia , Crânio/patologia , Crânio/parasitologia , Troglotrematidae/classificação , Troglotrematidae/isolamento & purificação , Animais , Hiperostose/patologia , Crânio/diagnóstico por imagem , Espanha , Tomografia Computadorizada por Raios X
Acta Trop ; 72(1): 79-89, 1999 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-9924963


A study of metacercariae and adult Paragonimidae revealed the existence in West-Africa of four species, of which two are largely recorded in literature (Paragonimus africanus and Paragonimus uterobilateralis), one was suspected (Paragonimnus westermani-like) and one remained unrecorded in Africa (Euparagonimus sp). Among the two last ones, P. westermani-like was probably confused with P. africanus, and Euparagonimus sp. with P. uterobilateralis. P. westermani-like adult worms differed from P. africanus by the morphology of ovary, testes and the size of the metraterm eggs. Euparagonimus could be identified by a short excretory bladder in metacercariae. The discriminant functions established on eggs measurements (average, maximum and minimum length, average, maximum and minimum width) were able to separate the isolates into four groups. The largest eggs (97 x 59 microm) belonged to P. westermani-like, the medium sized eggs were ascribed to P. africanus (91 x 49 microm) and to Euparagonimus sp. (84 x 50 microm), and the smaller eggs (69 x 42 microm) were identified as P. uterobilateralis. Three Paragonimidae were identified in Cameroon: P. westermani-like, P. africanus and Euparagonimus sp. Additionally, P. uterobilateralis, P. westermani-like, and Euparagonimus sp. were found in the Congo, Gabon, and the Ivory Coast, respectively.

Paragonimíase/parasitologia , Paragonimus/classificação , Infecções por Trematódeos/parasitologia , Troglotrematidae/classificação , África Ocidental , Animais , Gatos , Análise Discriminante , Herpestidae/parasitologia , Humanos , Análise Multivariada , Óvulo/citologia , Paragonimíase/veterinária , Paragonimus/isolamento & purificação , Paragonimus/fisiologia , Contagem de Ovos de Parasitas , Ratos , Infecções por Trematódeos/veterinária , Troglotrematidae/isolamento & purificação , Troglotrematidae/fisiologia
J Helminthol ; 73(4): 295-9, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10654398


The status of the genera Euparagonimus Chen, 1963 and Pagumogonimus Chen, 1963 relative to Paragonimus Braun, 1899 was investigated using DNA sequences from the mitochondrial cytochrome c oxidase subunit I (CO1) gene (partial) and the nuclear ribosomal DNA second internal transcribed spacer (ITS2). In the phylogenetic trees constructed, the genus Pagumogonimus is clearly not monophyletic and therefore not a natural taxon. Indeed, the type species of Pagumogonimus, P. skrjabini from China, is very closely related to Paragonimus miyazakii from Japan. The status of Euparagonimus is less obvious. Euparagonimus cenocopiosus lies distant from other lungflukes included in the analysis. It can be placed as sister to Paragonimus in some analyses and falls within the genus in others. A recently published morphological study placed E. cenocopiosus within the genus Paragonimus and probably this is where it should remain.

Troglotrematidae/classificação , Troglotrematidae/genética , Animais , DNA de Helmintos/genética , Humanos , Paragonimus/classificação , Paragonimus/genética , Filogenia , Análise de Sequência de DNA