Acta Parasitologica最新文献

Background

Clinostomum complanatum (Trematoda: Clinostomidae) infects freshwater fishes, causing metabolic stress and economic loss. Data on its morphology and physiological impact on Channa punctata in Lucknow wetlands are limited.

Objectives

To identify C. complanatum using light and scanning electron microscopy (SEM) and assess its effect on host protein levels.

Methods

Fifty C. punctata were collected from the Kallipaschim wetland, Lucknow. Parasites were morphologically and ultrastructurally characterized. Protein concentrations in liver, muscle, and parasite tissues were analyzed using the Bradford assay and compared between infected and uninfected fish.

Results

C. complanatum showed a dorsoventrally flattened body with distinct oral and ventral suckers and spined tegument. Infected fish exhibited elevated protein concentrations liver (2.5 µg/ml), muscle (5.29 µg/ml), and parasite (3.95 µg/ml) indicating metabolic stress, immune activation, and tissue repair. The parasite’s high protein level reflected dependence on host nutrients.

Conclusion

C. complanatum infection causes significant biochemical and structural alterations in C. punctata, impairing health and reducing aquaculture productivity. Regular monitoring and parasite control are crucial for sustainable fish farming.

Purpose

Enterocytozoon bieneusi is recognized as the most common microsporidian parasite, exhibiting a broad host spectrum that includes a wide range of animal species, as well as humans. However, no comprehensive data are available on the prevalence, age-related distribution, or genotype diversity of E. bieneusi in preweaned calves in Türkiye. Therefore, this study aimed to provide comprehensive data and expand current knowledge on E. bieneusi in preweaned calves from different age groups.

Methods

We screened a total of 240 fecal samples collected from preweaned calves using nested PCR to determine the occurrence and age-related distribution of E. bieneusi. Genotyping of the detected isolates and evaluation of their zoonotic potential were subsequently performed based on ITS sequence analysis.

Results

Enterocytozoon bieneusi was identified in 38 out of 240 fecal specimens, corresponding to an overall prevalence of 15.8%. Sequence analyses revealed the presence of two known genotypes, BEB8 and J. While genotype J was identified as the predominant genotype circulating among calves in the study area, genotype BEB8 was detected for the first time in a mammalian host in Türkiye. Phylogenetic analysis further revealed that both genotypes clustered within Group 2, which includes ruminant-adapted genotypes.

Conclusion

This is the first comprehensive report on the occurrence, age-related distribution, and genotyping of E. bieneusi in preweaned calves in Türkiye, highlighting the potential role of calves as reservoirs or carriers of this pathogen.

Introduction

Given the need to identify parasites that may affect commercially important fish, and to contribute to knowledge of the parasitic fauna in Amazonian fish species, the main objective of this research was to study parasites from the gills of Brachyplatystoma tigrinum (Britski, 1981) (Siluriformes: Pimelodidae) what led to the discovery of a new species.

Material and Methods

Five B. tigrinum with 20–30 (25 cm) were collected in the section between Gran Perú, near the town of Tamishiyacu, in the Amazonas River (3°47′20.70″S 73°15′40.90″W), in Loreto, Peru. The collected fish were transported in boxes with ice to the laboratory for parasitological analyses.

Results

One species of the Dactylogyridae was registered: Peruanella jorgepanduroi n. sp. The new species differs from its congener Peruanella madredediosensis Cruces, Santillán, Silvera, Morey, Rubin and Chero, 2024 by the termination of the MCO and the accessory piece, which in the new species have a pointed, almost straight termination, while in P. madredediosensis, both the MCO and the accessory piece bend forward; additionally, the presence of striations on the surface of the shaft and the point of anchors in P. madredediosensis is absent in the new species.

Conclusions

The results of this study constitute the second report of a dactylogyrid species parasitizing B. tigrinum, and at the same time, the second species of Peruanella Cruces, Santillán, Silvera, Morey, Rubin and Chero, 2024 described. This increases the knowledge of the biodiversity of monogenoids reported for Peru and the Neotropical region.

Background

Trypanosoma evansi, the causative agent of Surra, is a significant emerging zoonotic kinetoplastid protozoan parasite with wide host range and limited chemotherapeutic options. Arginine kinase is mainly responsible for providing metabolic plasticity and maintaining cellular homeostasis of trypanosome under adverse conditions.

Methods

This study investigated the in vitro anti-trypanosomal activity of Vanilloid derivative, Capsaicin against T. evansi and its effect on mRNA expression of arginine kinase enzyme in T. evansi. Herein, we determined the anti-trypanosomal activity of Capsaicin against T. evansi and its safety towards mammalian cells by estimating the selectivity index. From the dataset generated during the experiments, the IC₅₀ values of capsaicin was determined as 115 µM, respectively.

Results

Cytotoxicity assays showed that Capsaicin exhibited moderate cytotoxicity against equine PBMC and Vero cells line with CC₅₀ value of 309.8 µM and 308.3 µM, respectively giving a selectivity index of around 2.68 at the therapeutic dose against T. evansi. Real-time PCR analysis revealed that Capsaicin showed significant alteration of mRNA expression of arginine kinase 1 gene at 24 and 48 h of exposure with IC₅₀ of drug.

Conclusion

The study suggests that Capsaicin may be a potential approach for treating T. evansi infections, warranting further in vivo investigations.

Purpose

As an important component of ecosystems, wildlife plays a crucial role in maintaining ecological balance. However, wild animals are also natural hosts of pathogens. In this study, fecal samples from three of wild animals were collected from Hebei Xiaowutai Mountain National Nature Reserve in Zhangjiakou City, Hebei Province, China. Species identification of these samples was performed, and the infection status of common zoonotic protozoa in these three wild animal species was detected.

Methods

Common zoonotic protozoa were detected after species identification by PCR.

Results

The results of species identification showed that the fecal samples were from red fox (Vulpes vulpes), leopard cat (Prionailurus bengalensis), and wild boar (Sus scrofa). Colpodella spp. was detected in red fox, with the closest phylogenetic relationship being to Colpodella spp. from Lake Luxembourg (NCBI accession number: GU067926.1); Giardia intestinalis (G. intestinalis) was detected in leopard cat, with the closest phylogenetic relationship to G. intestinalis assemblage F (NCBI accession number: LC341258.1).

Conclusions

The results showed that wild animals are affected by intestinal protozoan infection and that there is a risk of parasite transmission. The prevention and control of parasitic diseases in wild animals is not only conducive to the protection of animal welfare but also to public health.

Introduction

Studies concentrating on description, identification, and analysis of monogenoids are required to further our understanding of this group of parasites connected to Amazonian fish. Based on the above, the main objective of this research was to identify new species of monogenoids in the gills of Centromochlus heckelii (De Filippi, 1853) (Siluriformes: Auchenipteridae) collected in the Itaya river, Loreto-Peru.

Materials and methods

Two hundred and forty specimens of C. heckelii were collected in the Itaya River (3°47’20.70"S 73°15’40.90"W), Loreto, Peru in March 2025. The collected fish were transported in boxes with ice to the laboratory for parasitological analyses.

Results

Three species of monogeneans of the family Dactylogyridae were registered, two new species and one previously known: Demidospermus centromochlii Mendoza-Franco & Scholz, 2009 which is proposed to be reassigned into Cosmetocleithrum Kritsky, Thatcher & Boeger, 1986 due to morphological characteristics. The new species Cosmetocleithrum itayensis n. sp. and Cosmetocleithrum iiapensis n. sp. are similar by presenting the MCO as a sigmoid tube and a seed-shaped accessory piece, but they differ from each other in the shape of the MCO, accessory piece, vagina, and the size of the anchors and of the submedial projections in dorsal bar.

Conclusions

The results of the present investigation represent the second report of parasites in C. heckelii, with the discovery of two new dactylogyrid species. This increases the knowledge of the biodiversity of monogenoids reported for Peru and the Neotropical region.

Purpose

Canine hemoplasma species, Mycoplasma haemocanis and Candidatus Mycoplasma haematoparvum, have been identified in various parts of the world. These pathogens can lead to mild to severe infections, even death, in dogs. To date, several pathogens caused clinical infection in dog have been detected in Türkiye, but limited data are present about canine hemoplasma species in the country. The aim of this study was to investigate canine hemoplasma species in different parts of Türkiye, and to perform phylogenetic analyses of positive samples.

Methods

In the current work, 300 dog blood samples were obtained from different parts of Türkiye. DNA extraction was obtained from blood samples with a commercial kit. The obtained DNA was researched in terms of the presence of canine hemoplasma species with species-specific PCR assay. Partial parts of 16S rRNA gene of randomly selected six samples, three positive samples for each pathogen, were sequenced.

Results

PCR assay revealed that 3.67% of animals (11/300) were infected with canine hemoplasma species. The prevalence of M. haemocanis and Ca. Mycoplasma haematoparvum was determined as 2% (6/300) and 0.67% (2/300), respectively. Co-infection rate was 1% (3/300). After DNA sequence analyses obtained consensus sequences were uploaded to the GenBank under accession numbers: PV798019-PV798021 (M. haemocanis) and PV798022-PV798024 (Ca. Mycoplasma haematoparvum). BLAST analysis revealed 98.44–100% nucleotide similarity between M. haemocanis isolates identified in this work and other M. haemocanis isolates. The 97.41–100% nucleotide identities were seen between our Ca. Mycoplasma haematoparvum isolates and other Ca. Mycoplasma haematoparvum isolates present in the GenBank.

Conclusion

Considering that these two species may cause clinical infection in both animals and humans, it is thought that veterinarians and physicians living in the region should take the necessary precautions to reduce the harmful effects of M. haemocanis and Ca. Mycoplasma haematoparvum.

Purpose

Pirenella cingulata- a snail from an intertidal mudflat serves as the first intermediate host of digenean trematode parasites. These trematode parasites castrate their host and alter the host's physiology for their own success and proliferation. In this study, we investigate the interaction between Pirenella cingulata and the trematode Acanthotrema tridactyla using a de novo transcriptomic approach.

Methods

RNA was extracted from both infected and non-infected Pirenella cingulata. High-throughput RNA sequencing was performed, and only healthy individuals were used for de novo assembly of the transcriptome. Furthermore, the transcripts were annotated, followed by the identification of differentially expressed genes using the DESeq2 package.

Results

We have identified 91 differentially expressed host genes that mostly suppress immune responses, altering metabolic and cytoskeletal-related functions. Downregulation of immune-related genes, including Cathepsin L, beta 1,3-glucan binding protein, scavenger receptors, and histone 3 (H3) suggest immune suppression. Gluconeogenesis, a key metabolic pathway, was compromised by downregulating the activity of alkaline phosphatase and lipase. Gastropods mediate immune-related ‘oxidative burst’ by generation of ROS- a mechanism to cope with parasites, which trematodes countered by downregulating xanthine hydrogenase/oxidase. Cytoskeletal proteins like actins was downregulated, used for encapsulation and phagocytosis, implying a compromised immune system.

Conclusion

This study provides insights into host-parasite interaction with the understanding of the immune functional response, metabolic and cytoskeletal-related processes of parasitised gastropods.

Purpose

The cell culture technology for Theileria annulata schizont-infected cells plays a vital role in basic research and control of bovine theileriosis. T. annulata is an intracellular parasite transmitted by some species of ticks.

Methods

Unlike other Apicomplexa parasites, T. annulata can infect and transform host B cells, dendritic cells and macrophages, further induce the transformed cells yield some cancer-like phenotypes. The attenuated parasites were obtained through in vitro culture technology, which can effectively prevent T. annulata infection.

Results

The cell culture has evolved from initial adherent culture to rolling bottle culture and then to suspension culture at present. In addition, the suspension culture has also been upgraded from basic serum-containing culture to serum-free culture.

Conclusion

This paper highlights the past, present and perspective about the cell culture technology with T. annulata schizont-infected cells, which will strongly underpin application of T. annulata vaccines and control of the parasite in the future.