Parasitology Research最新文献

In this study, the cDNAs of heat shock cognate 90 protein 1 (HfHspc1) and heat shock cognate 90 protein 4 (HfHspc4) from Haemaphysalis flava (Acari: Ixodidae) were obtained using the rapid amplification of cDNA ends (RACE) approach, and the expression patterns of HfHspc1 and HfHspc4 in different developmental stages, engorgement stages and tick organs were analyzed by qPCR. The full length of HfHspc1 was 2411 bp, and its open reading frame (ORF) was 2196 bp, encoding a protein of 732 aa, containing five HSPC family signatures, with MEEVD motif at its extreme C-terminal. The full length of HfHspc4 was 2800 bp, and its ORF was 2364 bp, encoding a protein of 789 aa, containing a signal peptide and five family signatures, with HEEL motif at its extreme C-terminal. The expression of HfHspc1 and HfHspc4 was the highest in males, while it was significantly the highest in the ovaries of fully engorged females, potentially implying the roles of these proteins in the successful digestion of blood and development of eggs.

Strongylid nematodes represent a major health and performance concern for equids globally. However, the epidemiology of strongylid infections in horse populations remains largely unexplored in Thailand. This study investigated the prevalence of strongylid parasites and the associated risk factors in domesticated horses in Thailand. Additionally, the study utilized ITS-2 rDNA metabarcoding to characterize the diversity and co-occurrence patterns of strongylid species. Of the 408 horses examined, 50.98% tested positive for strongyle infection, with an average intensity of 445.67 ± 639.58 eggs. Notably, only 25.74% exhibited fecal egg counts of ≥ 200 eggs per gram (EPG), highlighting the need for targeted deworming protocols. Significantly higher EPG values were observed in yearling horses (p = 0.001) and those kept in outdoor pastures (p = 0.0001). Metabarcoding identified 15 strongylid species, with Cylicostephanus longibursatus being the most abundant (mean relative abundance: 37.30%, SD = 31.16%). No Strongylus species were detected. Alpha diversity analysis revealed no significant differences in species richness and evenness across horse groups, while beta diversity analysis showed significant dissimilarities (p = 0.004), primarily driven by Cylicostephanus longibursatus, Cyathostomum pateratum, and Cylicostephanus calicatus, which contributed to over 60% of the variation. Species co-occurrence patterns were largely random, with a limited number of positive (n = 5) and negative (n = 2) species pair associations. These findings provide essential insights into the current state of strongylid infections in Thai horses and offer a foundation for future research and management strategies.

The current study was focused on evaluating the in vitro effect of the spore-crystal complex of GP543 Bacillus thuringiensis strain on the viability of Amblyomma cajennense, and the in vivo reduction of the parasite load of this ectoparasite on naturally infested cattle. In vitro, 30 adult ticks were treated with 1.2 mg/ml of B. thuringiensis GP543 strain spore-crystal complex in 10 µl/ml of AGREX F® surfactant and 20% glycerin, subjected to the immersion test to assess their viability every 1.5 h up to 6 h and finally at 12 h post-immersion. GP543 was compared to 125 µg/ml of the commercial drug BOMBARD® (amitraz). In vivo, the same concentrations were tested on naturally infested Swiss-Zebu heifers in grazing conditions. Treatments were applied on the perineal region in an area of 30 × 15 cm on days 0 and 7, and the parasite load was determined on days 0, 3, 7, 9, 14, and 21. In vitro, GP543 decreased the viability rate a 96.6% at 12 h post-immersion, while the commercial drug induced a 100% decrease of viability. On heifers, the parasite load decreased after 21 days in the group treated with GP543 in a similar way to the group treated with amitraz. Considering the above, GP543 strain of B. thuringiensis is proposed as a candidate for the control of Amblyomma cajennense.

Piroplasmids are vector-borne hemoprotozoan parasites belonging to the phylum Apicomplexa that are of veterinary and medical importance. Wild carnivores are hosts for diverse piroplasmids, some of which are highly pathogenic for domestic dogs and cats. A large-scale survey including samples from 244 individuals belonging to eleven different species that were opportunistically obtained between 1993 and 2015 in four Autonomous Regions in Spain were tested for piroplasmid DNA with two different nested-PCR assays targeting the 18S rRNA gene. Sixty of 85 Eurasian badgers (Meles meles), 11 of 42 red foxes (Vulpes vulpes), and 1 of 10 stone martens (Martes foina) resulted positive. In contrast, 46 wolves (Canis lupus), 26 genets (Genetta genetta), 22 pine martens (Martes martes), and other less-represented species were negative. Sequencing revealed that all foxes and one badger were parasitized by Babesia vulpes, and the remaining badgers and the stone marten by Babesia sp. badger type A (BBTA). The prevalence of BBTA in Catalonian badgers was significantly lower in Alpine than in Continental and Mediterranean climates. This study confirms that badgers and ref foxes constitute the natural hosts of BBTA and B. vulpes, respectively, with occasional spillovers to other species.

There is a growing number of reports on the occurrence of benzimidazole resistance-associated single nucleotide polymorphisms (SNPs) in the β-tubulin isotype 1 gene of various helminths of veterinary, and public health concerns. However, a comprehensive analysis of their occurrence, and their contributions to conferring benzimidazole resistance among hookworms has yet to be done. The objectives of this systematic review are to summarize and synthesize peer-reviewed evidence on the occurrence of these resistance-associated mutations in hookworms, document their geographical distribution, and assess their contributions to conferring phenotypic resistance. Three databases were systematically searched using specific keywords. Research that assessed the occurrence of benzimidazole resistance-associated SNPs in hookworms, papers that reported the geographical distribution of these SNPs, and studies that investigated the SNPs' resistance-associated phenotypic effects were included in the review. Research that was not done in hookworms, papers not in the English language, and literature reviews and book chapters were excluded. Critical appraisal checklists were used to determine the risk of bias in the selected papers. Data were extracted from the selected studies and analyzed. PROSPERO Systematic Review Protocol Registration No.: CRD42024510924. A total of 29 studies were included and analyzed. Of these, four were conducted in a laboratory setting, eight described the development and validation of SNP detection methods, and the remaining 17 involved field research. Seven SNP-induced amino acid substitutions at four loci were reported among several hookworm species: Q134H, F167Y, E198A, E198K, E198V, F200Y, and F200L. SNPs have been reported in isolates occurring in the United States, Canada, Brazil, Haiti, Australia, New Zealand, Kenya, Ghana, Mozambique, and Tanzania. Resistance mutations have not been reported in Asia. E198A and F200L were reported in Ancylostoma ceylanicum with laboratory-induced resistance. F167Y and Q134H conferred resistance in A. caninum, as revealed by in vitro investigations and field assessments. There is insufficient peer-reviewed evidence to prove the association between SNP occurrence and resistance. Mutations in the β-tubulin isotype 1 gene confer benzimidazole resistance in A. caninum and A. ceylanicum, but similar evidence is lacking for other human hookworms. Understanding benzimidazole resistance through further research can better inform treatment, prevention, and control strategies.

The mitochondrial permeability transition pore (mPTP) significantly impacts mitochondrial responses to cell death signals through its structural opening. Cyclophilin D (CypD) serves as a key regulator of the mPTP and plays a pivotal role in governing mitochondrial responses to cell death. In this study, we have demonstrated that Toxoplasma expresses a homolog of cyclophilin D, named TgCypD, which is localized in the mitochondria. Depletion of TgCypD resulted in a modest inhibition of tachyzoite invasion and proliferation, with no notable effect on mitochondrial morphology. However, TgCypD deficiency led to the inhibition of cytochrome c release from mitochondria into the cytosol, thereby imparting resistance to oxidative stress-induced cell death. Our findings suggest that T. gondii contains the mPTP component protein TgCypD, which is intricately involved in regulating mitochondrial responses to cell death.

Invasive alien species have the potential to introduce pathogens of economic and health importance in new environments. In Brazil, parasites from the non-native European brown hare can be a threat to humans, domestic animals, and wildlife. Therefore, we aimed to describe the helminth fauna of the invasive European brown hare in three Brazilian states (São Paulo, Paraná, and Rio Grande do Sul). For this, 90 brown hares were collected and examined for helminths. Helminth specimens recovered were morphologically identified and genetically characterized based on the DNA of male specimens using three genetic regions (28S rDNA, ITS-2, and cox-1 mtDNA). Descriptors of infection were calculated, and statistical analysis was performed. Parasites were found only in the small intestine of 14.4% (13/90) of brown hares and low parasite loads per animal were recorded (range = 1-530). The obtained specimens were morphologically identified as Trichostrongylus colubriformis and Bunostomum trigonocephalum. There was a high level of agreement between phylogenetic analysis and morphology for T. colubriformis. The geographical region was the only significant factor for infection; the State of Rio Grande do Sul had a higher general prevalence, higher T. colubriformis specific prevalence, and higher mean abundance than the other states evaluated. All hares were in a good body condition. To our knowledge, this is a new host record for B. trigonocephalum. This is the first study on the helminthological diversity of European brown hares in Brazil, and our results indicate that their helminth fauna is represented by parasites of domestic ruminants with zoonotic potential.

Despite the long history of experimental trials to combat schistosomiasis, it remains a significant burden due to drug resistance and the effectiveness of the standard treatment only against the mature stage, while skipping other early developmental stages thus leading to severe permanent pathological sequelae. Therefore, repurposing a commonly used well-known safe drug would be a wise alternative. We investigated the potential anti-schistosomal drug activity of Daflon® (DAF) against different schistosomal developmental stages. DAF was administrated at a dose of 100 mg/kg/mouse on days zero, 21, and 42 post-infection towards the invasive, immature, and mature stages of Schistosoma mansoni respectively in comparison to the standard anti-schistosomal drug (Praziquantel). All mice were sacrificed on day 49 post-infection. DAF induced a significant reduction in the total and female worm count, hepatic granuloma size, and number, the extent of liver parenchymal injury and fibrosis as well as intestinal and hepatic egg count compared to the infected untreated control. Liver malondialdehyde (MDA) levels significantly decreased in all DAF-treated groups. Scanning electron microscope findings revealed edema, tegumental blebs, cracks, and fissures in male tegument in all DAF-treated groups with distortion of the ventral suckers and disarrangement of the spines of the oral sucker. The female worm from DAF-treated groups showed tegumental edema with loss of the spines at the posterior end. Compared to the documented reduction of testosterone levels and distortion of testicular architecture in the S. mansoni-infected untreated group, DAF significantly restored testosterone levels and testicular architecture.

Acanthamoeba species are responsible for serious human infections, including Acanthamoeba keratitis (AK) and granulomatous amoebic encephalitis (GAE). These pathogens have a simple life cycle consisting of an infective trophozoite stage and a resistant cyst stage, with cysts posing significant treatment challenges due to their resilience against harsh conditions and chemical agents. Current treatments for AK often involve combining diamines, such as propamidine, and biguanides, such as chlorhexidine (CLX), which exhibit limited efficacy and significant toxicity. Thus, the effect of new therapeutic molecules, such as multifunctional systems (e.g., carbosilane dendritic molecules), should be studied as potential alternatives due to their biocidal properties and lower toxicity. This study evaluates various dendritic compounds against trophozoites and cysts of two Acanthamoeba clinical isolates, both alone and in combination with CLX, and assesses their cytotoxicity on HeLa cells. The results indicated that certain dendritic compounds, especially BDSQ024, were effective against both trophozoites and cysts. Additionally, combinations of dendritic molecules and CLX showed enhanced efficacy in eliminating trophozoites and cysts, suggesting potential for synergistic treatments. The study underscores the promise of dendritic molecules in developing more effective and less toxic therapies for Acanthamoeba infections.