Parasitology Research最新文献

Cutaneous leishmaniasis (CL) stands out as a significant vector-borne endemic in Pakistan. Despite the rising incidence of CL, the genetic diversity of Leishmania species in the country’s endemic regions remains insufficiently explored. This study aims to uncover the genetic diversity and molecular characteristics of Leishmania species in CL-endemic areas of Baluchistan, Khyber Pakhtunkhwa (KPK), and Punjab in Pakistan. Clinical samples from 300 CL patients were put to microscopic examination, real-time ITS-1 PCR, and sequencing. Predominantly affecting males between 16 to 30 years of age, with lesions primarily on hands and faces, the majority presented with nodular and plaque types. Microscopic analysis revealed a positivity rate of 67.8%, while real-time PCR identified 60.98% positive cases, mainly L. tropica, followed by L. infantum and L. major. Leishmania major (p = 0.009) showed substantially greater variation in nucleotide sequences than L. tropica (p = 0.07) and L. infantum (p = 0.03). Nucleotide diversity analysis indicated higher diversity in L. major and L. infantum compared to L. tropica. This study enhances our understanding of CL epidemiology in Pakistan, stressing the crucial role of molecular techniques in accurate species identification. The foundational data provided here emphasizes the necessity for future research to investigate deeper into genetic diversity and its implications for CL control at both individual and community levels.

Sarcocystis is a genus of protozoa with a worldwide distribution infecting a wide range of animals, including humans. Wild boars can harbor at least two species of Sarcocystis, that is, the zoonotic Sarcocystis suihominis, using humans as definitive hosts, and Sarcocystis miescheriana, for which wild and domestic canids serve as definitive hosts. In Portugal, hunting holds significant economic and social importance, and wild boars are among the most appreciated hunted species. As the consumption of wild boar meat can expose humans to several foodborne pathogens, the presence of trained hunters can make a difference in ensuring animal health surveillance and food safety. Herein, we report the detection of macroscopic cystic lesions associated with S. miescheriana in a wild boar hunted for human consumption, resulting in carcass condemnation. To the best of the authors’ knowledge, the presence of S. miescheriana in wild boar tissues has never been associated with macroscopic pathological alterations before. Although S. miescheriana cannot infect humans, carcasses affected by grossly visible pathological changes must be declared unfit for consumption. Therefore, our finding points out the potential economic damage associated with carcass rejection due to the presence of gross lesions associated with generalized sarcocystosis. Nonetheless, further studies are required to investigate these alterations that currently appear to be occasional findings.

Vermamoeba vermiformis (V. vermiformis) is one of the most common free-living amoeba (FLA) and is frequently found in environments such as natural freshwater areas, surface waters, soil, and biofilms. V. vermiformis has been reported as a pathogen with pathogenic potential for humans and animals. The aim is to report a case of non-Acanthamoeba keratitis in which V. vermiformis was the etiological agent, identified by culture and molecular techniques. Our case was a 48-year-old male patient with a history of trauma to his eye 10 days ago. The patient complained of eye redness and purulent discharge. A slit-lamp examination of the eye revealed a central corneal ulcer with peripheral infiltration extending into the deep stroma. The corneal scraping sample taken from the patient was cultured on a non-nutritious agar plate (NNA). Amoebae were evaluated according to morphological evaluation criteria. It was investigated by PCR method and confirmed by DNA sequence analysis. Although no bacterial or fungal growth was detected in the routine microbiological evaluation of the corneal scraping sample that was cultured, amoeba growth was detected positively in the NNA culture. Meanwhile, Acanthamoeba was detected negative by real-time PCR. However, V. vermiformis was detected positive with the specific PCR assay. It was confirmed by DNA sequence analysis to be considered an etiological pathogenic agent. Thus, topical administration of chlorhexidine gluconate %0.02 (8 × 1) was initiated. Clinical regression was observed 72 h after chlorhexidine initiation, and complete resolution of keratitis with residual scarring was noticed in 5 weeks. In conclusion, corneal infections due to free-living amoebae can occur, especially in poor hygiene. Although Acanthamoeba is the most common keratitis due to amoeba, V. vermiformis is also assumed to associate keratitis in humans. Clinicians should also be aware of other amoebic agents, such as V. vermiformis, in keratitis patients.

Globally, the poultry industry is seriously threatened by coccidiosis caused by various species of Eimeria. This protozoan parasite inhabits the epithelial lining of the gastrointestinal tract of poultry globally and can cause serious clinical disease. The present study was carried out on poultry farms located in various regions of Kashmir, India, to investigate the prevalence and phylogenetic relationships of Eimeria species affecting broiler chickens. Over a period of one year, fecal samples were collected from 60 poultry farms in Kashmir and morphological and molecular techniques were employed for Eimeria species identification. Results revealed a high prevalence of coccidiosis, with 58.3% (35/60) of farms positive for Eimeria. The most prevalent species were E. tenella (31/35, 88.6%) followed by E. acervulina (25/35, 71.4%), E. maxima (19/35, 54.3%), E. mitis (18/35, 51.4%), and E. necatrix (9/35, 25.7%). Seasonal variation in prevalence was also observed, with the highest rates in autumn (86.7%) and summer (66.7%). Additionally, younger birds (3–4 weeks) exhibited higher infection rates (85.7%) compared to older birds (57.9%) (5–6 weeks). Mixed infection was found in 94.2% (33/35) of positive farms. Phylogenetic analysis using ITS1 sequences confirmed species clustering and revealed evolutionary relationships among Eimeria species. E. tenella and E. necatrix formed a distinct clade, while E. acervulina formed another. The study underscores the importance of molecular techniques in accurate species identification and provides valuable insights into the epidemiology of coccidiosis in poultry in Kashmir. Effective control strategies, including vaccination and improved management practices, are necessary to mitigate the economic losses associated with this widespread poultry disease.

Initial studies using bioinformatics analysis revealed DNA sequence similarities between Trypanosoma cruzi GenBank® M21331, coding for Antigen 36 (Ag 36), and tripartite motif (TRIM) genes. TRIM40 showed 9.7% identity to GenBank M21331, and four additional TRIM genes had identities greater than 5.0%. TRIM37 showed a continuous stretch of identity of 12 nucleotides, that is, at least 25% longer than any of the other TRIMs. When we extended our analysis on the relationships of GenBank M21331 to further innate immune genes, using the Needleman-Wunsch (NW) algorithm for alignment, identities to human IFN-α, IFN-β, and IFN-γ genes of 13.6%, 12.6%, and 17.9%, respectively, were found. To determine the minimum number of genes coding for proteins closely related to Ag 36, a BLAST-p search was conducted with it versus the T. cruzi genome. The BLAST-p search revealed that T. cruzi GenBank M21331 had 14 gene sequences homologous to microtubule-associated protein (MAP) genes with 100% amino acid sequence identity. To verify the similarities in non-human genes, a study comparing TRIM21 region sequences among mammalian species to the comparable human TRIM21 region showed that related sequences were also present in 11 mammalian species. The MAP genes homologous to Ag 36 form a family of at least 14 genes which mimic human immune genes in the IFN and TRIM families. This mimicry is of gene sequences and not their protein products or epitopes. These results appear to be the first description of molecular mimicry of immune genes in humans by a protozoan parasite.

Several miRNA-based studies on Theileria-transformed bovine cells have been conducted; however, the mechanism by which transformed cells exhibit uncontrolled proliferation is not yet fully understood. Therefore, it is necessary to screen more microRNAs that may play a role in the transformation process of host cells infected with Theileria annulata to better understand the transformation mechanisms of Theileria-infected cells. RNA sequencing was used to analyze miRNAs expression in the host bovine lymphocytes infected with T. annulata at different time points after buparvaquone (BW720) treatment and DMSO treatment (control groups). Differential miRNAs related to cell proliferation and apoptosis were identified through comparison with gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, and a regulatory network of miRNA-mRNA was constructed. In total, 272 differentially expressed miRNAs were found at 36, 60 and 72 h. The miRNAs change of bta-miR-2285t, novel-miR-622, bta-miR-2478, and novel-miR-584 were significant. Analysis of 27 of these co-differential expressed miRNAs revealed that 15 miRNAs were down-regulated and 12 miRNAs were up-regulated. A further analysis of the changes in the expression of each of these 27 miRNAs in the three datasets suggested that bta-miR-2285t, bta-miR-345-5p, bta-miR-34a, bta-miR-150, and the novel-miR-1372 had significantly changed. Predicted target genes for these 27 miRNAs were analyzed by KEGG and the results demonstrated that EZR, RASSF, SOCS1 were mainly enriched in the signaling pathway microRNAs in cancer. MAPKAPK2, RELB, FLT3LG, and GADD45B were mainly enriched in the MAPK signaling pathway, and some genes were enriched in Axon guidance. This study has provided valuable information to further the understanding of the regulatory function of miRNAs in the host microenvironment and host-parasite interaction mechanisms.

The spotted seatrout, Cynoscion nebulosus, is a popular game fish in the southeastern USA. It is estimated that nearly 90% of the adult population in South Carolina estuaries are infected in their skeletal muscle by the myxosporean, Kudoa inornata. However, little is known about this parasite's biology, including the distribution and densities of myxospores within tissues of infected fish, which we expect affect the physiology of their hosts. In order to correlate densities with physiological parameters in future studies, we quantified the myxospores density in muscle and characterized the variation among individual fish. Naïve juvenile seatrout was experimentally infected via presumed K. inornata actinospores exposure to raw seawater. A plug of muscle was extracted from two bilaterally symmetrical regions in the epaxial fillet from fresh and frozen carcasses. Variation in density data was calculated both within and among individuals. Within individuals, density counts were compared between left- and right-side biopsies. There was no significant difference between fresh and frozen plugs, and variation among individuals accounted for the greatest proportion of variation at 68.8%, while variation within individuals was substantial at 25.6%. Simulation and correlation tests confirmed that bilaterally symmetrical replicates varied significantly within individuals. When sampled from areas surrounding the initial biopsies, myxospore density estimates were more similar than between sides. Our findings have important implications for sampling design, particularly for studies investigating physiological parameters at the cellular or molecular level in association with parasite infection.

Schistosomiasis remains a formidable challenge to global public health. This study aims to predict the spatial distribution of schistosomiasis seropositive rates in Hunan Province, pinpointing high-risk transmission areas and advocating for tailored control measures in low-endemic regions. Six machine learning models and their corresponding hybrid machine learning-Kriging models were employed to predict the seropositive rate. The optimal model was selected through internal and external validations to simulate the spatial distribution of seropositive rates. Our results showed that the hybrid machine learning-Kriging model demonstrated superior predictive performance compared to basic machine learning model and the Cubist-Kriging model emerged as the most optimal model for this study. The predictive map revealed elevated seropositive rates around Dongting Lake and its waterways with significant clustering, notably in the central and northern regions of Yiyang City and the northeastern areas of Changde City. The model identified gross domestic product, annual average wind speed and the nearest distance from the river as the top three predictors of seropositive rates, with annual average daytime surface temperature contributing the least. In conclusion, our research has revealed that integrating the Kriging method significantly enhances the predictive performance of machine learning models. We developed a Cubist-Kriging model with high predictive performance to forecast the spatial distribution of schistosomiasis seropositive rates. These findings provide valuable guidance for the precise prevention and control of schistosomiasis.

Mosquito-borne diseases, such as malaria, dengue fever, and the Zika virus, pose significant global health challenges, affecting millions annually. Due to increasing insecticide resistance, there is a growing interest in natural alternatives for mosquito control. Lemongrass essential oil, derived from Cymbopogon citratus, has shown promising repellent and larvicidal properties against various mosquito species. In this study, we investigated the larvicidal effect of lemongrass oil and its major compounds on Anopheles sinensis, the primary malaria vector in China. GC-MS analysis identified the major compounds of lemongrass oil as ( +)-citronellal (35.60%), geraniol (21.84%), and citronellol (13.88%). Lemongrass oil showed larvicidal activity against An. sinensis larvae, with an LC₅₀ value of 119.20 ± 3.81 mg/L. Among the major components, citronellol had the lowest LC₅₀ value of 42.76 ± 3.18 mg/L. Moreover, citronellol demonstrated inhibitory effects on acetylcholinesterase (AChE) activity in An. sinensis larvae, assessed by homogenizing larvae at different time points following treatment. Molecular docking studies further elucidated the interaction between citronellol and AChE, revealing the formation of hydrogen bonds and Pi-Sigma bonds. Aromatic amino acid residues such as Tyr71, Trp83, Tyr370, and Tyr374 played a pivotal role in these interactions. These findings may contribute to understanding lemongrass oil's larvicidal activity against An. sinensis and the mechanisms underlying these effects.

Trypanosoma evansi is a unicellular protozoan responsible for causing a disease known as "surra," which is found in different regions of the world and primarily affects horses and camels. Few information is known about virulence factors released from the parasite within the animals. The organism can secrete extracellular vesicles (EVs), which transport a variety of molecules, including proteins. Before being considered exclusively as a means for eliminating unwanted substances, extracellular vesicles (EVs) have emerged as key players in intercellular communication, facilitating interactions between cells, host cells, and parasites, and even between parasites themselves. Thus, they may be used as potential biomarkers. This study aimed to assess the induction of EVs production by Ca⁺², conduct a proteomic analysis of the EVs released by T. evansi, and identify epitopes that could serve as biomarkers. The findings indicated that Ca⁺² is not an effective promoter of vesiculation in T. evansi. Furthermore, the proteomic analysis has identified multiple proteins that have been investigated as biomarkers or vaccine antigens, previously. A total of 442 proteins were identified, with 7 of them specifically recognizing 9 epitopes that are unique to T. evansi. At least one of these epitopes of TevSTIB805.9.11580 have been previously identified, which increases the possibility of further investigating its potential as a biomarker.