Acta Parasitologica最新文献

Purpose

Toxocara canis is a globally distributed zoonotic parasite found in dogs' intestines, leading to various pathological damages, particularly to the intestinal flora. The larval stage causes human toxocariasis, especially in children, and may result in neurological disorders and blindness. Quercetin is a flavonoid with strong secondary metabolites and possesses medicinal advantages and antiparasitic qualities.

Methods

The assay involved  four groups, each of  10 young adult T. canis; Group I was incubated in concentrations of an ethanolic extract of quercetin, Group II in albendazole (0.2 mM/ml) (+ve control), Group III in RPMI 1640 medium with ethanol (control), and Group IV in RPMI 1640 medium only (-ve control). The potential action of quercetin against adult T. canis in vitro was detected using scanning electron microscopy, histological investigations, and enzyme analysis.

Results

SEM declared that exposure to LC90 of quercetin caused body shrinkage, cuticle and caudal papillae swelling, and disfigurement and erosion of cuticular annulations. Compared to albendazole's effect on the treated worm's body wall, results showed that quercetin generates oxidative stress and has an extensive and variable effect on T. canis organs, including the body wall, the gut, and the genitalia.

Conclusion

Quercetin may set the stage for a new class of medications with remarkable potential for treating parasitic nematodes in dogs and could be extended to humans. This is the first time to employ a comprehensive study illuminating the potential action of quercetin against adult Toxocara canis in vitro.

Purpose

Theileria species are tick-borne, intracellular apicomplexan protozoan parasites that pose a significant threat to livestock health and productivity. Theileria orientalis, the etiological agent of oriental theileriosis, is a benign Theileria species with worldwide distribution, including Algeria, where investigations on its prevalence and genetic diversity in domestic ruminants are limited. This study aimed to investigate the molecular and phylogenetic profiles of Theileria spp. in Algeria.

Methods

A total of 149 blood samples were collected from cattle, sheep, and goats in Bouira and Tizi-Ouzou regions. Molecular identification was performed using a PCR assay targeting the Cox3 and Tams1 genes. Positive samples were sequenced to assess their phylogenetic relationships.

Results

Analysis of the Cox3 gene revealed an overall infection rate of 12.75% ± 2.73% (19/149), with all positive cases detected in cattle. Further analysis of the Tams1 gene identified Theileria annulata in 11.40% ± 5.10% (17/149) of the samples. Sequencing of two samples negative for T. annulata showed a 99.84% identity with Theileria orientalis.

Conclusions

This study reports the identification of a novel T. orientalis Cox3 haplotype in Algeria, emphasizing the need for further epidemiologic and phylogenetic analyses to understand better the distribution, diversity, and impact of this pathogen on livestock populations in the region.

Parasites play critical roles in ecosystems, influencing host populations and community dynamics. Despite their ecological significance, the diversity and genetic structure of parasites in the ribbed mussel, Geukensia demissa (Dillwyn), a key species in salt marsh ecosystems, remain poorly understood. This study provides the first record of the trematode Proctoeces maculatus (Looss, 1901) infecting G. demissa in the Herring River estuary, Cape Cod, Massachusetts. Among 50 mussels examined, P. maculatus prevalence was 66%, with infection intensities ranging from light (less than 20 sporocysts per individual) to over 300 sporocysts per individual. Heavily infected mussels displayed mantle discoloration, suggesting potential pathological impacts. Molecular analysis of the 28 S ribosomal RNA gene identified a unique haplotype, GD1, restricted to G. demissa populations in Cape Cod. Haplotype network analysis revealed GD1’s distinctiveness within P. maculatus populations, while genetic divergence (K2P: 0.001–0.003) indicated incipient host-associated differentiation rather than cryptic speciation. These findings highlight the role of ecological partitioning, such as the salt marsh-specific habitat of G. demissa, in shaping parasite genetic structure.

Introduction

China’s Hunan Province, known for its extensive lake and marshland areas, continues to face considerable challenges in eliminating schistosomiasis. This study aims to examine the epidemiological characteristics of schistosomiasis in the province, focusing on seropositive rates across various demographic groups, spatial distribution, and identifying key associated factors to inform targeted control measures.

Methods

From 2020 to 2022, the number of people screened each year using the indirect hemagglutination assay (IHA) was 1,053,973, 682,921, and 729,782, respectively. The Cochran-Armitage test for trend and chi-square test were employed to assess differences in seropositive rates among different times, age groups, genders, educational levels, and occupations. Spatial autocorrelation analysis was conducted to identify clusters of seropositive rates at the village level. A multiple logistic model was used to identify associated factors and generalized estimating equation (GEE) was used to obtain the parameter estimates.

Results

From 2020 to 2022, the seropositive rate of schistosomiasis in Hunan Province were 1.53% (95% CI: 1.51–1.55), 2.22% (95% CI: 2.19–2.26), and 2.06% (95% CI: 2.03–2.10), respectively. The seropositive rate in Hunan Province was spatially clustered in each year, with high-high clustering areas mainly distributed around the southern Dongting Lake region, the tributary areas of Dongting Lake, as well as along the Yangtze River. The seropositive rate increased with age, with individuals aged 60–69 showing the highest seropositive rate (adjusted odds ratio [OR] when compared to < 10 years old: 47.94; 95% CI: 30.04–76.52). Males had higher seropositive rate compared to females (adjusted OR: 1.72; 95% CI: 1.69–1.76). Compared to farmers, fishermen (adjusted OR: 2.54; 95% CI: 2.40–2.70) and business/service staff (adjusted OR: 1.63; 95% CI: 1.52–1.74) had higher seropositive rate. The seropositive rate decreased with increasing educational level. Individuals using tap water and sanitary toilets had lower seropositive rate compared to those who did not use (tap water: adjusted OR: 0.66; 95% CI: 0.64–0.68; sanitary toilets: adjusted OR: 0.95; 95% CI: 0.93–0.97). Additionally, those who raised sheep had a higher seropositive rate compared to those who did not (adjusted OR: 4.67; 95% CI: 4.04–5.39).

Conclusions

Schistosomiasis remains a significant public health issue in Hunan Province, with the seropositive rate remaining clustered in certain regions and high-risk populations. Achieving schistosomiasis elimination requires sustained targeted interventions, improved sanitation infrastructure, enhanced health education, and long-term monitoring and comprehensive control measures for high-risk areas and vulnerable populations to reduce transmission risk and ensure sustainable disease elimination.

Purpose

Parasitism influences the metabolic and physiological processes of host organisms and potentially affects their health and reproductive capabilities. This study examines the impact of the nematode parasite Hysterothylacium sp. on nutritive reserves of Chelidonichthys lucerna.

Methods

Total lipid, fatty acids, protein, and glycogen contents in the liver and ovary of parasitized were compared to unparasitized female C. lucerna during the pre-spawning period.

Results

This study revealed that total lipid content in the liver in parasitized female pre-spawns is statistically lower than the unparasitized specimens. The same applies to fatty acid contents, which are generally lower in parasitized fish at the level of the two organs studied, liver and ovary. The comparison of protein content in parasitized and unparasitized fish showed a lower content in parasitized ovary and liver, but that was not statistically proven. Regarding glycogen, the parasite did not influence the carbohydrate content of the ovary but doubled that of the liver in parasitized specimens.

Conclusion

The findings suggest that parasitism particularly affects lipids, fatty acids and glycogen reserves in the liver and gonads of C. lucerna, with potential consequences for the fish’s reproductive capacity. Further research is needed to assess the long-term effects of parasitism on fish metabolism during other reproductive stages.

Purpose

Isopods of the genus Pleurocrypta Hesse, 1865 are branchial parasites of squat lobsters and porcelain crabs. Here, we record Ple. petrolisthis Markham, 1988 from Brazil for the first time, infesting the porcelain crab Petrolisthes galathinus (Bosc, 1801), and provide new morphological and ecological data.

Methods

Samplings were conducted in Pernambuco and São Paulo, Brazil, between 2021 and 2022, using active and passive methods. Illustrations of Ple. petrolisthis were made with a drawing tube mounted on a stereomicroscope and a compound microscope, then traced using Adobe Illustrator. Statistical analyses were conducted on prevalence, side preference and the relationship between parasite and host size.

Results

Specimens conform well with the original description of Ple. petrolisthis, with few morphological differences in the females. In the males, the segmentation of pleon varied from fully fused to five-segmented, and the maxillipeds are present. Prevalence is higher than for other species of Pleurocrypta, and no preference for side of the branchial chamber was observed. Parasite size influenced host size, probably due to the deformation of the carapace in infested hosts.

Conclusion

The study expands the distribution of Ple. petrolisthis from its type locality in Bonaire to Brazil. The variation in the pleon segmentation of the males is described for the first time, and the presence of maxillipeds is added to the original description. This is the first study to provide ecological data for any of the Western Atlantic species of Pleurocrypta, widening our knowledge of the relationship between bopyrids and their hosts.

Purpose

The study aimed to detect benzimidazole (BZ) resistance in Ancylostoma caninum in dogs from Thrissur district, Kerala, India, using amplification refractory mutation system- polymerase chain reaction (ARMS-PCR). The primary objective was to determine the presence and frequency of mutations at codon 200 of the isotype-1 β-tubulin gene, associated with BZ resistance, in adult worms and infective larvae.

Methods

A total of 75 adult A. caninum worms were collected during post-mortem, and 280 infective larvae (L3) from 35 faecal samples positive for strongyle ova were obtained from various locations. Amplification of the isotype-1 β-tubulin gene at codon 200 was performed by ARMS PCR, followed by Sanger sequencing to confirm of single nucleotide polymorphisms (SNPs). Genotypes were analysed using EMBOSS and NCBI BLAST tools.

Results

All 75 adult worms exhibited the homozygous susceptible genotype at codon 200. Out of 280 larvae genotyped, two were homozygous resistant, one was heterozygous, and 277 were homozygous susceptible. The overall frequencies of the resistant (TAC) and susceptible (TTC) alleles were 0.01 and 0.99, respectively. Both homozygous and heterozygous resistant larvae were found in a household with recurring ancylostomosis. No mutations were observed at codon 198.

Conclusion

The study identified a low frequency of BZ-resistant alleles in A. caninum larvae in Thrissur, Kerala, marking the first such report in India. Although resistance remains at an early stage, ongoing monitoring is essential to mitigate its spread in the canine population.

Introduction

Hydatidosis is a zoonotic neglected disease caused by the larval stage of Echinococcus granulosus. Evidence suggests a communication between hydatid cyst (HC) and hosts via extracellular vesicles (EVs). However, a little is known about the communication between EVs derived from HC fluid (HCF) and host cells. The current study aimed to investigate the effect of HCF derived EVs on expression of fibrotic and anti-fibrotic miRNAs in THP-1 cell line.

Methods

In the current study, EVs were isolated using ultracentrifugation from wild-infected sheep HCF and characterized by western blot, electron microscope, and size distribution analysis. The effects of EVs on the expression levels of microRNAs (mir-16, mir-29a, and mir-155) involved in liver fibrosis were investigated using quantitative real-time PCR (qRT-PCR), 3 and 24 h after incubation.

Results

Western blot analyses confirmed the expression of CD63 marker, while Calnexin and CD81 were absent in EVs samples. The SEM and morphology revealed round shape vesicles. The DLS analysis showed average size distribution 130.6 nm diameter. The expression levels of mir-16 and mir-29a were significantly upregulated after 3 h for 8.66 and 3.420, respectively, while they were significantly downregulated after 24 h for 3.853 and 1.859, respectively.

Conclusion

The main mechanism of the communication between EVs derived from HCF and their host remains unclear. Our results suggest that HC may modulate the expression of miRNAs, involved in liver fibrosis via EVs.

Propose

Acanthamoebaspp. are widespread free-living protists found in various natural and man-made habitats. At times, they can become parasitic, leading to conditions such as Acanthamoeba keratitis (AK), granulomatous amoebic encephalitis (GAE), and systemic infections in humans and animals. In veterinary medicine, infections caused by Acanthamoeba spp. are frequently underdiagnosed, necessitating a high degree of clinical vigilance and laboratory technical skill for accurate diagnosis and treatment.

Methods

This review aimed to provide an overview of documented natural infections in animals with Acanthamoeba spp. to enhance veterinary professionals' awareness of these organisms' potential risks.

Results

This review records natural infections of animals with Acanthamoeba and its interaction with pathogenic bacteria, highlighting the importance of Acanthamoeba spp. in veterinary medicine.

Conclusion

Acanthamebiasis should be considered in the differential diagnosis of systemic diseases, especially with neurologic involvement. Since this neglected infection can impact the lives and livelihoods of many animals, informing veterinarians and animal owners is necessary.

Purpose

Anaplasmosis is a tick-borne disease which is caused by different Anaplasma species. Among Anaplasma species, A. ovis which can infect sheep and goats cause ovine anaplasmosis. In this study, the prevalence of Anaplasma spp. was investigated in 31 different breeds of sheep from different regions of Türkiye.

Method

Anaplasma spp. was investigated by PCR targeting MSP-4 gene in blood samples of sheep breeds (n = 366) collected from different regions of Türkiye. Also, some Anaplasma spp. positive samples were sequenced for species identification and sub-cluster analyses.

Results

The molecular prevalence of Anaplasma spp. was 43.9% (161/366). In Anatolian Merino (n = 10) and Akkaraman (n = 11) breeds, the molecular prevalence of Anaplasma spp. reached to 100%. Also, the highest molecular prevalence was detected in Black Sea region by 70% (28/40) and the lowest molecular prevalence was detected in Marmara region by 32% (16/50). While the prevalence of Anaplasma spp. was 59.7% in sheep produced in the extensive system, it was found as 39.2% and 9.8% in sheep produced in semi-extensive and intensive systems, respectively. Accordingly, these findings suggest that the production of sheep in the intensive system protects them from tick-borne diseases, which are of great economic importance. According to BLAST results, all sequenced Anaplasma spp. positive samples (n = 29) were identified as A. ovis. Also, mixed infections were detected in 6 positive samples. The phylogenetic tree constructed by 38 sequence data showed the presence of three different sub-clusters for A. ovis (Sub-cluster 1, 2, and 3). Sub-cluster 2 was found as the most prevalent sub-cluster with 42.1% frequency compared to the other sub-clusters.

Conclusion

This study showed that sheep grown in different regions of Türkiye have a high molecular prevalence value for Anaplasma spp.