Acta Parasitologica最新文献

Background

Freshwater fish are affected with much parasitic diseases, among the most common are Henneguyosis caused by myxozoans of the genus Henneguya, which exhibit great diversity in fish from South America, particularly in the Brazilian Amazon.

Purpose

In this present study, we describe the morphological and phylogenetic aspects of the small ribosomal subunit (SSU rDNA) of two new species of Henneguya infecting the gills from Hypophthalmus marginatus, a freshwater catfish from the Amazon.

Methods

In 148 specimens, has been observed cyst formation in different regions of the gills, intrafilamentary and intralamellar. These samples were collected for PCR amplification and phylogenetic analysis.

Results

The myxospores from each cyst have an elliptical spore body, consisting of two elliptical polar capsules, but differed in taxonomic morphometric measurements, such as total size, caudal length, spore body length and width, and polar capsule length and width. Phylogenetically, the species formed a clade with Henneguya spp. described in Siluriform fish in Brazil.

Conclusion

These findings support the description of two species, Henneguya matosi n. sp. and H. marginatus n. sp., which infect different regions of the gills of Hypophthalmus marginatus, a commercially important catfish.

Background

Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi are important zoonotic pathogens. In Inner Mongolia, a single pathogen molecular epidemiological survey of these three protozoa was previously conducted on only 176 fecal samples donkeys. In this study, the purpose is to simultaneously evaluate the zoonotic potential of three protozoa.

Methods

Small subunit ribosomal RNA (SSU rRNA) and gp60 from Cryptosporidium; SSU rRNA, gdh, tpi, and bg from G. duodenalis; and ITS of E. bieneusi were analyzed in 300 fecal samples collected from donkeys from two intensive farms in Inner Mongolia in 2022. Sample processing, nucleic acid extraction, polymerase chain reaction, sequencing, and sequence analysis were performed to determine the prevalence and genetic characteristics of the protozoans.

Results

Our results revealed that 75.33% (226/300) of the samples were infected with at least one protozoan, whereas 2.33% (7/300) were simultaneously infected with all three genera. Mixed infection was observed in 20.67% (62/300; Cryptosporidium + G. duodenalis), 5.33% (16/300; Cryptosporidium + E. bieneusis), and 5.67% (17/300; G. duodenalis + E. bieneusis) of the samples. Overall prevalence of Cryptosporidium, G. duodenalis, and E. bieneusi was 56.33% (169/300), 36.33% (109/300), and 13.33% (40/300), respectively. Five Cryptosporidium species were identified, with C. andersoni being the predominant species. The C. parvum subtypes identified were IIdA20G1 (66.67%) and IIdA19G1 (33.33%). Three G. duodenalis assemblages were identified, with assemblage B being predominant. Seven isolates formed two different assemblage B MLGs, two different assemblage A MLGs, and two different assemblage B + E MLGs. Three known and eight novel sequences of E. bieneusis were identified in group 1 (including horse1 and NMG6–NMG8) and group 2 (including J, BEB6, and NMG1–NMG5), with horse1 being the predominant genotype.

Conclusions

To our knowledge, this is the first study to demonstrate that donkeys can be infected with a combination of two or three protozoa, with C. andersoni being the most detected Cryptosporidium species. Meanwhile, assemblage B was predominant among G. duodenalis, whereas horse1 was the dominant genotype for E. bieneusi. Moreover, the prevalence of C. bovis, C. ryanae, C. suis, C. parvum subtype IIdA20G1 and eight novel sequences of E. bieneusis and new features of G. duodenalis assemblages were identified in donkeys for the first time. These findings reconfirmed that donkeys in Inner Mongolia are infected with these three protozoa, emphasizing the risk of disease transmission by these protozoans to humans.

Introduction

Copepods of the genus Colobomatus Hesse, 1873 are parasites associated with subcutaneous spaces of marine fish. To date, around 76 species of the genus have been described in marine ecosystems, but few species have been recorded in the South Atlantic Ocean.

Methods

One hundred and eight specimens of Co. nobilis were purchased along the littoral of Brazil. The copepods were collected from the skull bones associated to the nasal cavities, fixed and preserved in 80% ethanol and for microscopical observation, specimens were cleared in 85% lactic acid. Drawings were made with the aid of an Olympus BX51 microscope equipped with a drawing tube.

Results

Colobomatus conodoni n. sp. can be distinguished from all congeners by the combination of the following characters: (i) two cephalic processes that are longer than the cephalosome, (ii) third abdominal somite with a pair of processes, (iii) caudal rami forked at the tip.

Conclusion

This is the first representative of the family Philichthyidae Vogt, 1877 described parasitizing a species of the teleost genus Conodon Cuvier. Together with the new species, the number of philichthyid species in the South Atlantic Ocean increases to 12 and extends the list of Colobomatus spp. to 77.

Purpose

The aim of this study was to investigate the presence of Clinostomum species in wild birds in Turkey using morphological and molecular methods.

Methods

51 birds of 18 species from seven orders previously reported as definitive hosts of the Clinostomum spp. were collected. Identification of the species was made by morphological characteristics and partial sequence of the cox1 gene.

Results

This study concludes that Ardea alba and Ardea cinerea were infected with Clinostomum complanatum, while Ardea purpurea was infected with Clinostomum tilapiae.

Conclusion

Clinostomum complanatum has been reported for the first time in the definitive hosts in Turkey. This study is the first molecular report of C. tilapiae in definitive hosts and the first report in Turkey. The present work indicates that Clinostomum species in the Afrotropic and Palearctic regions can also be found in Turkey.

Purpose

Flotation methods are widely used to detect oocysts/cysts of protozoans and eggs of helminths, except trematodes. However, details regarding the concentration and recovery rates of these parasites are poorly understood.

Methods

Using Eimeria tenella oocysts as a model parasite, the present study evaluated three check points: (1) the proportion of parasites that remain floating in flotation solution (sucrose or saturated saline) during centrifugation, (2) the proportion of oocysts that naturally float after addition of flotation solution after centrifugation, and (3) the rate of recovery on cover slips after completion of the flotation protocol.

Results

After centrifugation in sucrose solution and saturated saline solution, 82.4% and 60.3% of oocysts floated, respectively. After addition of flotation solution after the final centrifugation step, the recovery rates for oocysts that naturally floated again for 30 min in sucrose and saturated saline were 39.2% and 38.2%, respectively. The recovery rate on cover slips as the final step after performing a commonly used flotation method was 36.4% in sucrose solution (the rate for saturated saline solution could not be assessed due to rapid crystallization).

Conclusion

Our results suggest that floating oocysts could have become dispersed by the addition of flotation solution, and not all of these oocysts remained floating after an additional 30 min of settling time although collection on cover slips could be effective for accurate recovery.

Purpose

The objective of the study was to establish the prevalence of Sarcocystis (Apicomplexa, Sarcocystidae) in brown rats from Jleeb Al-Shuyoukh, Kuwait, and to describe detected parasites using morphological and DNA analysis methods.

Methods

Ninety-eight brown rats (Rattus norvegicus) were examined for Sarcocystis spp. Obtained sarcocysts were investigated using light microscopy and electron microscopy. The detected Sarcocystis species was characterised at nuclear 18S and 28S ribosomal RNA (rRNA), internal transcribed spacers 1 and 2, (ITS1 and ITS2), mitochondrial cytochrome c oxidase subunit I (cox1) and cytochrome b (cytb), and apicoplast RNA polymerase beta subunit (rpoB).

Results

Sarcocysts were found in thigh muscles of 13.3% of the animals examined, while no oocysts/sporocysts were detected in faecal samples. Under a light microscope, sarcocysts were spindle-shaped, 850–3152 × 73–125 μm (1781 ± 763 × 99 ± 15 μm) in size and had thin (up to 0.9 μm) and apparently smooth cyst wall. By transmission electron microscopy, sarcocyst wall was 0.7–1.1 μm in thickness with numerous osmiophilic bleb-like protrusions. Based on DNA sequencing the sarcocysts examined were identified as S. cymruensis. Notably, ITS2 and rpoB sequences of S. cymruensis were obtained for the first time. No intraspecific variation was detected comparing 28S rRNA, ITS1, cox1 and cytb sequences of S. cymruensis isolated from Kuwait, Grenada and China. According to phylogenetic analysis, S. cymruensis was most closely related to S. muris, S. myodes and S. ratti using rodents as their intermediate hosts and cats as their identified or predatory mammals as their presumed definitive hosts.

Conclusion

We present the first report of S. cymruensis in Kuwait and in Persian Gulf area. The study shed light on the usefulness of different genetic loci for the characterization of Sarcocystis spp. from rodents.

Objective

Different Acanthamoeba species are among the most ubiquitous organisms causing serious diseases in humans including central nervous system (CNS) and eye infections. Contact lenses, lens care solutions and the hospital environments particularly the indoor and outdoor environments of ophthalmology wards where people are present with different types of eye diseases, are the potential sources of human infection. The purpose of the present study was the molecular investigation of free-living amoebae in the used contact lenses, lens care solutions and hospital samples from the ophthalmology wards and operating rooms in a referral hospital in southeastern Iran.

Methods

Samples were collected from the lens care solutions, used contact lenses, and from indoor and outdoor environments of the ophthalmology ward and operating room of a major referral hospital in Kerman, Southeastern Iran. The samples were cultured on non-nutrient agar (NNA) in 28-30^oC and microscopically studied. Molecular study including PCR-sequencing and phylogenetic analysis on partial 18 S rDNA were performed on positive culture samples.

Result

In total 70 samples were collected from the used contact lenses and lens care solutions, as well as the hospital environment of which 11.4% (8 out of 70) were found positive using NNA culture. Two out of 40 samples (5.0%) from the used contact lenses and the care solutions were found positive for the presence of Acanthamoeba T4 genotype. Acanthamoeba cysts were identified in two out of 22 dust samples (9.1%) collected from the ophthalmology ward and operating rooms. Protacanthamoeba bohemica was found in the soil samples from outdoor environment of the ophthalmology ward.

Conclusion

This study identified Acanthamoeba species in contact lenses and in indoor environmental samples from the ophthalmology ward. T4 genotype was found on the contact lenses examined in this study. In the dust sampled from within the ophthalmology ward Acanthamoeba sp. was identified.

Purpose

Hypoderma pantholopsum is a parasite that parasitizes Tibetan antelopes (Pantholops hodgsonii). This study aims was to reveal the genetic diversity within H. pantholopsum and contribute to the protection of Tibetan antelope.

Methods

H. pantholopsum was subjected to mitochondrial genome sequencing, annotation, and phylogenetic analysis. PhyloSuite and BEAST were used to construct phylogenetic tree and divergence time for the parasite.

Results

The complete H. pantholopsum genome was 16,265 bp in length. The complete mitochondrial genomes contained 37 typical genes, which included 13 protein-coding genes (PCGs), 22 tRNAs, and 2 rRNAs. Phylogenetic trees constructed based on the 18S rRNA, 28S rRNA, and mitochondrial genome sequences showed that H. pantholopsum clustered on the same branch as the Hypoderma species in the GenBank database. According to the divergence time for the COI gene, H. pantholopsum emerged and differentiated approximately 11.59 million years ago (Mya), which indicates that H. pantholopsum appeared much earlier than H. bovis and H. sinense in the genus Hypoderma.

Conclusion

The present study explored that the complete mitochondrial genome of H. pantholopsum, along with the phylogenetic evolution, and divergence time estimation, provide valuable data for future investigations into the phylogeny and differentiation of Hypoderma species on the Qinghai-Tibetan Plateau.

Graphical Abstract

Purpose

Schistosomiasis remains a parasitic disease affecting millions of people worldwide, requiring interventions like vaccination. In previous work, our group used reverse vaccinology to identify two epitopes from the Schistosoma mansoni proteins, Sm050890 (44–58) and Sm141290 (225–239). This study evaluated the immune response profile and protection induced by peptides, as a mixture of immunogens, in murine vaccination trials. Additionally, the diagnostic potential of these peptides was assessed on immunoassays.

Methods

Mice were immunized with a formulation containing the mixture of the peptides, subsequently infected, and perfused for worm burden recovery and quantification. Liver and blood samples from animals were used to evaluate the effect of immunization on the formation of granulomas and specific anti-peptide antibodies (IgG). Additionally, cytokine measurement was performed in splenocyte cultures from immunized mice, and peripheral blood serum from individuals infected with S. mansoni was used to assess the recognition of the peptides by IgG antibodies.

Results

The vaccine stimulated an increase in the production of IgG and IgG2c antibodies, associated with a significant reduction of 44 − 29% in worm burden. Although the vaccine did not reduce liver pathology, it enhanced the production of IFN-γ while decreasing IL-10 production by splenocytes. Furthermore, the peptides Sm050890 (44–58) and Sm141290 (225–239) were not recognized by IgG antibodies in the serum from infected individuals.

Conclusion

Overall, our data suggest that the peptides Sm050890 (44–58) and Sm141290 (225–239) are promising vaccine candidates against schistosomiasis and can be used to compose a multiepitope/chimeric vaccine in future studies.

Purpose

The present paper reports the nematodes of the suborder Trichostrongylina collected from the common spiny bandicoot, Echymipera kalubu, in Arso, Papua Indonesia. The description of Kalubustrongylus arsoensis gen. et sp. n. (Trichostrongylidae: Filarinematinae) is given herein.

Materials and methods

The specimens were collected from three common spiny bandicoots at Arso, Papua Indonesia, captured using traditional snap traps in August 1993. The new taxon is described and illustrated by light and scanning electron microscopy. Type and voucher specimens were deposited in the Museum Zoologicum Bogoriense (MZB), Bogor, Indonesia.

Results

The new genus Kalubustrongylus is classified as a member of the subfamily Filarinematinae in the family Trichostrongylidae by having a bilaterally symmetrical synlophe and an uncoiled body, and by lacking a cephalic vesicle. It resembles Peramelistrongylus but is distinguished by having additional ridges in the synlophe, an elliptical bursa, an apically divided dorsal ray and minute extra-dorsal rays. Besides Ka. arsoensis, Mackerrastrongylus biakensis, Peramelistrongylus skedastos, Beveridgiella spp., Dessetostrongylus sp. and Herpetostrongylinae sp. were collected. Dessetostrongylus is recorded for the first time outside of Australia and from non-dasyurid marsupials.

Conclusions

The present findings add a genus to the three genera previously known in the subfamily Filarinematinae in the family Trichostrongylidae.