Parasitology Research最新文献

The entire transcribed sequences (from the 5' terminus of 18S to the 3' terminus of 28S rRNA genes) of the ribosomal transcription units (rTU*) of five Asian Paragonimus species were obtained and characterized. The rTU* length was 7661 bp for P. heterotremus (LC strain, Vietnam), 7422 bp for P. iloktsuenensis (Amami strain, Japan), 6932 bp for P. skrjabini miyazakii (OkuST1 strain, Japan), 7422 bp for P. ohirai (Kino strain, Japan), and three strains of P. westermani: 8616 bp (Megha strain, India), 7292 bp (Bogil strain, South Korea), and 7052 bp (QT2 strain, Vietnam) without intergenic spacer region (IGS). All seven Asian Paragonimus strains' genetic characteristics were described, including the length of individual genes/regions, repeat polymorphism, base composition, and skewness. To investigate the superfamilial relationships in the Xiphidiata, with a focus on the Troglotrematoidea and its associated superfamilies, we used the PhyML software package to create three comprehensive maximum-likelihood phylogenies. The datasets used were 83 concatenated 28S + 18S, 83 single complete 18S, and 157 single, partial 28S rDNA sequences, respectively, from entire rTUs and/or accessible ribosomal sequences of the same species from the suborders Xiphidiata, Echinostomata, and Haplosplanchnata, with a Schistosoma sequence as an outgroup. Three phylogenetic trees revealed that Echinostomata and Haplosplanchnata are monophyletic, while Xiphidiata is polyphyletic and contains the monophyletic Troglotrematoidea. The concatenated 18S + 28S and single 18S phylogenies revealed well-bootstrap supported seven superfamilies (Troglotrematoidea, Haploporoidea, Gorgoderoidea, Brachycladioidea, Microphalloidea, Plagiorchioidea, and Opecoeloidea) that are monophyletic in the Xiphidiata. The Haploporoidea was a basal superfamily nested close to the Gorgoderoidea and Troglotrematoidea and was not supported as a distinct suborder Haploporata. Six of seven xiphidiatan superfamilies were monophyletic in the partial 28S phylogeny, with the exception of Opecoeloidea, which was separated into two different subclades: Opecoelidae and Stenakridae/Zdzitowieckitrematidae. The monophyletic Haploporoidea/Haploporata was separated from the Gorgoderoidea associates and placed in a marginal group in Xiphidiata. There were two notable clusters in the Paragonimidae: mixed-Paragonimus, which included a fairly compact group of P. heterotremus strains, and P. westermani/siamensis, which was divided into geographical/country strain groups. In conclusion, combined ribosomal rDNA sequences were more effective than single rDNA markers in resolving interfamilial and familial relationships. The ribosomal datasets presented here will be useful for taxonomic reassessment, as well as evolutionary and population genetics research in the Troglotrematoidea and other superfamilies in the Xiphidiata and the class Trematoda.

Within the research conducted in the years 2016-2022 in the area of Volovsky Mountains in Slovakia, 63,950 biting midges were collected during 74 trapping sessions. The aim of the study was to identify species composition of biting midges, their host preference and potential transmission of parasites by these insects under natural conditions. The collected biting midges fell into 29 species and the most common were the Culicoides (C. obsoletus/C. scoticus/C. montanus) that accounted for 47.9% of the collected biting midges. Identification of species was based on the morphology of biting midges and the use of molecular methods. We confirmed positive suckling results on red deer in three samples namely C. montanus, C. scoticus and C. deltus. We examined these samples for the presence of Onchocerca worm DNA. We confirmed the presence of O. flexuosa DNA in one C. deltus sample. The host preference of biting midges was identified by molecular technique that involved sequencing a 350-bp sequence of the mitochondrial cytochrome b gene (cyt b). The presence of Onchocerca flexuosa DNA in C. deltus was confirmed by sequencing of fragments of mitochondrial genes cox1. The sequences matched the previously published sequences for O. flexuosa. Data on high prevalence of infections caused by Onchocerca worms in red deer in Slovakia have already been published and indicated favourable conditions for the vectors and a suitable environment for parasite circulation in Slovakia. According to the authors' knowledge, this was the first ever detection of O. flexuosa in C. deltus in wild nature.

Fasciolosis is a parasitic disease affecting humans and livestock, caused by digenean trematodes of the genus Fasciola, primarily F. hepatica and F. gigantica. This study investigates the coexistence of these species and their hybrids in yaks from Tibet, China. We analyzed the nuclear rDNA internal transcribed spacer (ITS) regions, including ITS1 and ITS2, through Sanger sequencing and Next-Generation Sequencing (NGS) to assess single-nucleotide polymorphisms (SNPs). Our results reveal that one specimen (NM008B) is identical to pure F. hepatica, while another (NM008A) contains genetic information from both F. hepatica and F. gigantica, indicating potential hybridization or introgression. The morphological analysis reveals that the collected adult F. hepatica specimens exhibit distinct characteristics, while the hybrid specimens display "intermediate" features of F. hepatica and F. gigantica. This study is the first to document the coexistence of F. hepatica and hybrid Fasciola forms in a single yak. The findings underscore the complexities of hybridization dynamics and the necessity for advanced molecular techniques in accurately identifying Fasciola species. Future research should focus on mitochondrial DNA and other nuclear gene analysis to further elucidate the nature of these hybrids and their ecological implications.

The literature about mollusc-parasite interactions is focused on species affecting human health, such as trematodes on freshwater snails as intermediate hosts. Far less attention has been paid to parasite-snail interactions in terrestrial habitats. Here we present the first observation of a sciomyzid larva of Limnia unguicornis, parasitizing a vulnerable, tiny air-breading snail, Vertigo moulinsiana (strictly protected by Polish law). Sciomyzids are almost exclusively malacophagous but their biology and ecology are understudied. Thus, we have reviewed the available information on Limnia species and discussed the results of our research.

The East Asian finless porpoise, Neophocaena asiaeorientalis sunameri, is an endangered species that inhabits the coastal marine environments of East Asia. In the present study, we investigated the overall infection status of anisakid nematodes in East Asian finless porpoises from three sea sectors off the Korean Peninsula. The genetic diversity and population genetic structure of the identified nematode species were evaluated. The prevalence of all stages of anisakid nematodes collected from the stomach was 57.55% (61 among the 106 porpoises examined), and 16 of the hosts were found to have adult worms. The mean number of infected adults was 211 (± 419.54, 5-1455 per host). Only one species of anisakids, Anisakis pegreffii, was identified from randomly selected worms by molecular approaches. Analysis of the mitochondrial (mt) cox2 partial gene in 50 newly generated sequences of A. pegreffii revealed 24 haplotypes, including 14 new haplotypes. We observed below-average levels of nucleotide diversity and haplotype diversity compared to other seas around the world. The mtDNA cox2 haplotypes of the species in the three Korean sea areas showed no genetic structure, suggesting well-connected gene flow within these areas. This study represents the first record of a definitive host of A. pegreffii in Korean waters, providing important information regarding anisakids genetic diversity in the cetacean species inhabiting limited regions.

Avian haemosporidian parasites are protozoans transmitted by vectors, belonging to the genera Plasmodium, Haemoproteus, and Leucocytozoon, capable of infecting various bird species. The prevalence of these parasites varies depending on factors such as the habitat and geographical location of the host and vector, as well as across different bird groups. Seabirds typically exhibit low infection rates due to the absence of vectors in marine environments. This study aimed to identify and characterize the molecular diversity of Haemosporida parasites in a population of Brown Boobies (Sula leucogaster) (n = 37) from the Santana Archipelago in Macaé, Rio de Janeiro state. We utilized PCR-based detection methods to confirm the presence of haemosporidian parasites and sequencing (ctyb gene) to delineate the lineages. The results uncovered a notable prevalence (48.6%) of haemosporidian parasites (Plasmodium and Haemoproteus), comprising 12 novel lineages and four previously documented lineages (establishing new host records). Our findings suggest that transmission and infection by these hemoparasites can occur both on and off the island. Overall, this study yields valuable insights into the genetic diversity of haemosporidian parasites in Brown Boobies, enriching our understanding of the ecology and epidemiology of these parasites in seabirds.

Cylicostephanus longibursatus is a common parasite in equine animals. Hosts infected by these nematodes might face disease or death. This study utilized next-generation sequencing technology to sequence the complete mitochondrial genome (mt genome) of C. longibursatus. Through bioinformatics techniques, the genomic base composition, codon usage, tRNA secondary structures, evolutionary relationships, and taxonomic status were analyzed. The results revealed that the mitochondrial genome of C. longibursatus is a double-stranded, 13,807-bp closed circular molecule with an AT content of 76.0%, indicating a clear preference for AT bases. The mitochondrial genome consisted of a total of 12 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 2 non-coding regions. Among the 12 protein-coding genes, TTG and ATT were the common start codons. TAA was the predominant termination codon, except for the ND3 and ND6 coding genes, and the COШ genes used TAG and "T" as termination codons, respectively. All tRNAs exhibited atypical clover-leaf secondary structures, except for tRNA^Lys and tRNA^Leu2, where two tRNA^Ser genes lacked DHU arms and DHU loops, tRNA^met lacked the TΨC-arm, tRNA^Ile lacked the TΨC-loop, and the remaining 16 tRNAs lacked the TΨC-arm and TΨC loop, which were substituted by the "TV-replacement loop". Phylogenetic analyses, based on the 12 protein-coding genes and utilizing maximum likelihood (ML) and Bayesian inference (BI) analyses, indicated that C. longibursatus did not form a monophyletic group with other Cylicostephanus but was instead more closely related to Cyathostomum. These research findings provide fundamental data for exploring the population classification and phylogeny of strongylid nematodes.

Chromosomal mapping of 5S rDNA in two Acanthocephala species was performed for the first time using fluorescence in situ hybridization (FISH) with a 5S rDNA probe. The 5S rDNA PCR products from the genomes of both species were sequenced and aligned and an identical 141 bp long coding region was determined. The same patterns of 5S rDNA gene cluster distribution were observed, with FISH signal restricted to a single autosomal chromosome pair. A preference for distal positioning on the chromosomes (subtelomeric position) was observed in both species. In addition, two-color FISH was performed to examine the mutual positions of 5S and 18S rDNA on the chromosomes. Our knowledge of the organization of the Acanthocephala genome is extremely limited and its chromosomes are poorly studied. Any new information about the location of chromosomal markers as important features of the respective karyotype may be useful in solving evolutionary questions.

Fleas, along with one of their host species, Meriones unguiculatus, possess the capability to act as vectors in the transmission of plague. Parasitism by fleas may markedly influence the physiology and immune system of their hosts. Gut microbiota plays an important role in the growth and development of rodents. However, few studies have explored the impacts of ectoparasitic flea on the gut microbiome of rodents. This study investigated the immunological responses and changes in the gut microbial diversity and composition in both wild and laboratory rodents infested with fleas and laboratory rodents infested with Ctenocephalides felis. We measured immune reactions post-infestation by enzyme-linked immunosorbent assay (ELISA) and explored the effects of ectoparasitic infestation on the diversity and composition of the rodent gut microbiota in microbiome studies by 16S rRNA gene sequencing techniques. After flea infestation, results from 16S rRNA gene sequencing techniques indicated a significant increase in alpha diversity, affecting the composition of the gut microbiota. At the genus level, the abundance of the harmful bacterium Desulfovibrio increased. Beta diversity analyses showed significant differences between the gut microbiota of the experimental and control groups. ELISA results revealed significantly elevated levels of IgG in parasitized mice, while the differences in IgA levels were not significant. Flea infections affect the composition and diversity of the gut microbiota in the M. unguiculatu, and it has been found that the biomarker Desulfovibrio increases following flea infection in these rodents. Our results indicate that the gut microbiota can regulate the stability of the rodent-flea system. These findings may provide a foundation for exploring preventive measures against plague and aid in developing more effective treatments for the infection.

The trematode family Cyathocotylidae infects various hosts worldwide, including birds, mammals, reptiles, and fish. However, the lack of molecular data from adult worms hinders phylogenetic, epidemiological, and host association studies. This study aims to identify the common cyathocotylid trematodes infecting African catfish in Egypt using morphological and molecular evidence. Out of 142 Clarias gariepinus, 123 fish (86.6%) harbored cyathocotylid metacercariae, with a mean metacercarial intensity of 201 ± 38.5/g. Cyathocotylid metacercariae prevalence gradually rose as host size increased. Although there was no significant difference between groups, larger fish had a higher mean metacercarial intensity. The prevalence and intensity were unrelated to the fish gender. Histopathological examination of metacercariae-infected catfish revealed varying degrees of degenerative changes, including intermuscular edema leading to muscle fiber dispersion and atrophy, involving 11% to over 81% of muscle sections. We identified three cyathocotylid metacercariae and eight cyathocotylid adult species from experimental infection using morphometric and molecular data, including internal transcribed spacer (ITS) and/or mitochondrial cytochrome c oxidase subunit 1 (cox1) sequences. We determined the phylogenetic position of these cyathocotylid samples. The ITS sequence analysis linked the isolated Cyathocotylidae sp. 1 and 2 metacercariae to Prohemistomum vivax adults. Mesostephanus appendiculatoides and Paracoenogonimus ovatus were reported for the first time in Egypt. These findings may provide valuable genetic data for future molecular epidemiological and phylogenetic studies of cyathocotylid trematodes.