Acta Parasitologica最新文献

Background: Leishmaniasis is a deadly protozoan parasitic disease and a significant health problem in underdeveloped and developing countries. The global spread of the parasite, coupled with the emergence of drug resistance and severe side effects associated with existing treatments, has necessitated the identification of new and potential drugs.

Objective: This study aimed to identify promising compounds for the treatment of leishmaniasis by targeting two essential enzymes of Leishmania donovani: trypanothione reductase (Try-R) and trypanothione synthetase (Try-S).

Methods: High-throughput virtual and in vitro screening of in-house and commercial databases was conducted. A pharmacophore model with seven features was developed and validated using the Guner-Henery method. The pharmacophore-based virtual screening yielded 690 hits, which were further filtered through Lipinski's rule, ADMET analysis, and molecular docking against Try-R and Try-S. Molecular dynamics studies were performed on selected compounds, and in vitro experiments were conducted to evaluate their activity against the promastigote and amastigote forms of L. donovani.

Results: The virtual screening and subsequent analysis identified 33 promising compounds. Molecular dynamics studies of two compounds (comp-1 and comp-2) demonstrated stable binding interactions with the target enzymes and high affinity. In vitro experiments revealed that 13 compounds exhibited moderate activity against both the promastigote (IC₅₀, 41 µM-76 µM) and the amastigote (IC₅₀, 44 µM-72 µM) forms of L. donovani. Compounds 1 and 2 showed the highest percent inhibition and the lowest IC₅₀ values.

Conclusion: The identified compounds demonstrated significant inhibitory activity against Leishmania donovani and stable interactions with target enzymes. These findings suggest that the compounds could serve as promising leads for developing new treatments for leishmaniasis.

Purpose: Crenosoma vulpis (Dujardin,1845) is a lungworm which has spread worldwide in canines and is associated with upper respiratory infections. In a majority of cases, the infections are accompanied with chronic cough. Diagnosis of lungworms is often underdiagnosed and can be misinterpreted as other respiratory diseases.

Methods: The Small Animal Clinic of the University Veterinary Hospital admitted an 11-month-old dog presented with persistent cough associated with difficulty in breathing and even asphyxia. Based on clinical symptoms, the patient underwent radiological and bronchoscopic examination. Bronchoscopy revealed the presence of lungworms obturating the branches of the tracheobronchial tree. Larvae were collected by bronchoscopic lavage and subjected to parasitological and molecular examination.

Results: Microscopic detection and morphological identification of the worms removed during the bronchoscopy confirmed the presence of female adult worms. The subsequent molecular characterisation of the mitochondrial (cytochrome c oxidase subunit I gene (cox1) and 12S ribosomal DNA (rDNA)), nuclear (18S rDNA) genes, as well as the analysis of the second internal transcribed spacer (ITS-2) region of the ribosomal DNA, confirmed the Crenosoma vulpis species. Faecal samples were processed using the Baermann method, which confirmed the presence of the larval stage 1 of C. vulpis. The therapy with fenbendazole at a dose of 50 mg/kg of live weight once daily for the period of 7 days was initiated for the patient.

Conclusion: This paper presents the first molecularly confirmed clinical case of a Crenosoma vulpis infection in an 11-month-old female dog of the Miniature Schnauzer breed in Slovakia.

Purpose: Blastocystis sp. is a single-celled, anaerobic, parasitic protozoan commonly found in the intestinal tract of animals and humans globally. Genetic analysis has revealed significant diversity within its species, leading to the identification of at least 40 subtypes (ST1-ST40). This study aimed to identify and differentiate Blastocystis in faeces samples from various animal hosts in Algeria.

Methods: A total of 403 fecal samples, collected from both domestic and zoo animals, were subjected to PCR amplification and sequencing of Blastocystis-specific small subunit ribosomal RNA (SSU-RNA) gene.

Results: The overall prevalence of Blastocystis in animals was found to be 38.9%. Through comprehensive phylogenetic and phylogeographic analyses, we identified four distinct subtypes (ST1 in both domestic and zoo animals, and ST3, ST4, and ST5 exclusively in zoo animals), encompassing nine different haplotypes, including five that appear original to Algeria.

Conclusion: This study represents the first epidemiological molecular investigation of Blastocystis sp. in animals in Algeria.

Background: Theileriosis is a tick-borne disease caused by protozoon species in the Theileria genus of the Theileriidae family. The biochemical changes induced by infection are considered to be an important understanding of the pathophysiology of caprine theileriosis. In this study, it was aimed to determine oxidative stress, thyroid hormones, trace elements, and biochemical parameters in theileriosis infection.

Materials and methods: A sample of 14 goat was used for this purpose, of which 7 were healthy and 7 were infected with Theileria ovis. Theileria infection was diagnosed from the polymerase chain reaction (PCR). Sera from blood samples was tested for total antioxidant capacity (TAC), total oxidant capacity (TOC), oxidative stress index (OSI), alanine aminotransferase (ALT), aspartate transaminase (AST), gamma glutamyl transferase (GGT), total protein, albumin, triglyceride, cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), urea, blood urea nitrogen (BUN), creatinine, triiodothyronine (T3), thyroxine (T4), copper (Cu), zinc (Zn), cobalt (Co), manganese (Mn), selenium (Se), iron (Fe).

Result: TOC, OSI, AST, ALT and GGT values were higher in the patient group than in the healthy group (P < 0.05). On the other hand, there were decreases in TAC, T3, T4, total protein, albumin, creatinine, Cu, Zn, Se, and Co values (P < 0.05). However, there was not found to be a statistical difference between the healthy and patient groups in terms of triglyceride, cholesterol, HDL, LDL, urea, BUN, Mn, and Fe values (P > 0.05).

Conclusions: It can be stated that oxidative stress is a complication of caprine theileriosis and it may be accompanied with hypothyroidism and deficits in trace minerals.

The recent discovery of disease caused by Nucleospora braziliensis in Nile tilapia (Oreochromis niloticus) is important as it has highlighted the high prevalence of infection and associated mortality in cultured fish. Thus, this study conducted an experimental infection of this microsporidium to evaluate pathological alterations and conduct proteomic analysis. For pathological observation, samples of brain, eyes, gall bladder, gut, heart, kidney, liver, muscle, skin, spleen, and stomach tissue, were collected, and liquid chromatography-mass spectrometry (LC-MS/MS) was performed for proteomic analysis. The most prevalent lesions were brownish color of the liver, gill filament fusion, gut ischemia, hemorrhage of the lips and fins, hepatomegaly, spleen atrophy, splenomegaly, and stomach congestion. The most common microscopic lesions were degeneration, hemorrhage, and inflammation in the brain, gills, gut, kidney, liver, muscle, spleen, and stomach. The digested peptides were identified by LC-MS/MS and the intersection of each group showed that in the spleen there were 121 exclusive proteins in the infected sample and 252 in the control, while in the kidney, 129 proteins were identified in the infected specimen compared to 83 in the control. In conclusion, this study demonstrates the proteome profile of O. niloticus kidney and spleen tissue in response to infection with N. braziliensis.

Objectives: This study is aimed to determine the geospatial, seasonal, age and gender prevalence and intensity of UgS; and to establish disease maps in the Ase-Niger River communities for effective drug administration.

Study design: This study employed a 24 months longitudinal study design for parasitological investigations in 11 riparian communities of the Ase-Niger River basin, taking into cognizance their GPS locations imported into QGIS software for schistosomiasis mapping.

Methods: A total of 7,219 urine samples with WHO structured questionnaires were retrieved and subjected to parasitological evaluation using swinnex urine filtration techniques.

Results: An overall prevalence of 48.10% was established. Geospatially, prevalence ranges from 34.27% (Ivrogbo) to 52.29% (Ase) with seasonal significant difference (p < 0.05) accounting for 76.19% of the total variance. Ashaka had the highest prevalence for both males (55.73%) and females (53.32%) with significant difference in the study sites (p < 0.05) accounting for 96.47% of the total variance. Age-group 11-20 years consistently maintain a high prevalence at all sites. The peak geometric mean intensity of 105.69 was obtained in the dry season at Lagos Iyede. Ashaka, Igbuku, Iyede-Ame, and Onogboko had heavy-intensity levels in both seasons. Overall, the intensity was lower during the wet season than the dry season, with significant variations (p < 0.05) at Awah and Itobi-Ige. Geospatial prevalence and intensity have a robust and strong positive correlation (r = 0.7178; p = 0.0129), with 51.53% of intensity variability being influenced by prevalence (R² = 0.5153).

Conclusion: UgS is a significant public health issue in the Ase-Niger River basin, with prevalences surpassing the national average of 29.0% which calls for MDA in these settlements.

Purpose: Dientamoeba fragilis (D. fragilis) is a common intestinal protozoan with a global distribution. In the present study, we aimed to determine genetic diversity of D. fragilis isolates with multilocus sequence typing (MLST) in the southwest of Turkey and analyse the clinical findings.

Materials and methods: The study included faecal samples from 200 individuals in Aydin, Turkey. The positivity of D. fragilis was determined with 18 S rRNA gene-based PCR assay. Six nested-PCR reactions were set to amplify partial D. fragilis housekeeping genes in the positive samples. The sequences were aligned with the references from GenBank to detect nucleotide polymorphisms and haplotypes. Additionally, the clinical findings and demographic characteristics of patients were statistically analysed between D. fragilis-infected and non-infected cases.

Results: The positivity of D. fragilis was 16% (32 out of 200 cases) with 18 S rRNA based-PCR, and all were classified as "genotype 1". The analysis of six MLST loci revealed different haplotypes only at one locus; the remaining five loci exhibited no polymorphisms. The haplotypes in the present study were identical to at least one previously reported reference, except the locus "large subunit of RNA polymerase II" locus. There were no significant differences in any of the clinical findings or demographic characteristics between the infected and non-infected groups.

Conclusions: Our study revealed a low genetic diversity of D. fragilis isolates from Turkey, like other countries including Italy, Denmark, the UK, Australia, and Brazil. The high degree of sequence similarity in housekeeping genes indicated the clonal distribution of D. fragilis.

Purpose: At least thirty species of wild carnivores have been recorded harboring Bartonella, and one of the most common pathogenic species infecting them is Bartonella rochalimae, which can cause endocarditis in humans and dogs. This bacterium can infect various mammals including wild carnivores, as well as ectoparasitic vectors such as fleas and ticks. Here we report the presence of B. rochalimae, in a Pulex simulans flea collected from a Mephitis macroura skunk in the municipality of Santa Cruz in Sonora, Mexico.

Methods: Fleas were collected from a M. macroura in Sonora, Mexico, in October 2019. They were identified to species level and subsequently tested for the presence of Bartonella using molecular tools including conventional PCR, sequencing, and phylogenetic analysis.

Results: A total of 10 P. simulans fleas (one male, nine females) were collected from the M. macroura skunk. The PCR and phylogenetic analysis indicated a prevalence of 10% (1/10) and a sequence clustered with the clade of B. rochalimae.

Conclusions: We confirmed the presence of B. rochalimae in a P. simulans flea collected from a M. macroura skunk in the area of Santa Cruz, Sonora, Mexico. Based on our results and previous studies in northern Mexico, which are consistent, it is necessary to continue monitoring Bartonella in M. macroura skunks and their fleas, since they could be important reservoirs of this bacterium in northern Mexico.

Purpose: Coccidiosis caused by eimerian parasites results in lethal watery or bloody diarrhea in hosts, and markedly impairs the growth of and feed utilization by host animals. We previously investigated detailed the life cycle of Eimeria krijgsmanni as a mouse eimerian parasite. Only second-generation meronts, as an asexual stage, were morphologically detected in the epithelium of the host cecum for at least 8 weeks after infection, even though oocyst shedding finished approximately 3 weeks after infection. The presence of zoites was of interest because infection by eimerian parasites is considered to be self-limited after their patent period.

Methods: To clarify the significance of residual second-generation meronts in E. krijgsmanni infection, we performed infection experiments using immunocompetent mice under artificial immunosuppression and congenital immunodeficient mice.

Results: The number of oocysts discharged and the duration of oocyst discharge both increased in immunosuppressed mice. In immunodeficient mice, numerous oocysts were shed over a markedly longer period, and oocyst discharge did not finish until 56 days after inoculation.

Conclusions: The present results suggest that the second-generation meronts survived in the epithelial cells of the cecum after the patent period, thereby contributing to extended infection as an asexual stage. The results obtained on E. krijgsmanni indicate that infections by Eimeria spp. are not self-limited and potentially continue for a long period of time.

Purpose: The aim of the present study is to assess the molluscicidal, larvicidal and genotoxicological activities of papain and how it can affect the host-parasite interactions.

Methods: Toxicity of papain on snails by making series of concentrations to calculate LC₅₀, and then study its larvicide effect on the free larval stages of S. mansoni and infection rate of snails.

Results: Papain has a molluscicidal activity on adult snails of Biomphalaria alexandrina with a lethal concentration LC₅₀ equals to 43.1 mg/L. In addition, it has activity on miracidia with half Lethal time (LT₅₀) of 16.11 min., and on cercariae with 12.1 min. compared to control ones. The sub lethal concentration LC₁₀ and LC₂₅ (6.9 or 24.1 mg/L, respectively) decreased the survival rate of snails at the first cercarial shedding, the rate of infection, the average total number of cercariae per snail, the shedding period and the life span of snails, while the prepatent period was significantly increased than the control ones. The morphological alterations in cercariae after exposure to papain were occurred where the cercariae lacked motility and some had a dark tail with complete detachment of head and tail. Compared to the control group, the levels of cytochrome oxidase subunit I (COI) and (ND1) genes significantly decreased in snails after exposure to papain.

Conclusions: Papain could be used as a potential molluscicide for elimination of schistosomiasis and decrease its transmission and deterioration of host-parasite interaction.