Acta Parasitologica最新文献

Sarcocystis parasites are intricate intracellular protozoans that present significant health risks to both animals and humans. This study aims to provide a global overview of Sarcocystis prevalence in wild and domestic pigs. A comprehensive search across multiple electronic databases yielded 40 eligible studies from 21 countries around the world. The global pooled prevalence of Sarcocystis infection in pigs was estimated at 0.473 (95% CI = 0.392–0.555). The highest prevalence was found in jaw and diaphragm samples, with molecular detection methods providing the highest pooled prevalence. There were significant geographical and environmental factors influencing infection rates, with higher prevalence observed in European countries, high-income nations, and regions with specific climatic conditions. The findings give reason to enhance diagnostic techniques and control measures to lower the economic and public health burden caused by Sarcocystis infection in pigs, pointing out the need for further investigation regarding the potential of these parasites to be a zoonotic agent and environmental conditions.

Purpose

Morphological anomalies in ticks have been described in various species. Gynandromorphism, asymmetry, and lack of legs are well documented anomalies worldwide. However, only two cases have been reported in Japan. Furthermore, few studies have documented anomalies which could impact the identification of ticks. This study reports morphological anomalies in Haemaphysalis megaspinosa ticks for the first time.

Method

Host-questing H. megaspinosa ticks were collected from the southern part of Hokkaido Prefecture, Japan, using a flannel sheet (70 × 100 cm) dragged over vegetation. Morphological observations were performed using a light microscope.

Results

A total of 1,352 H. megaspinosa nymphs were collected, and morphological anomalies of the capitulum were observed in four individuals (0.3%). Among these, three individuals had a 3/3 dental formula, differing from those of normal individuals which have a 2/2 dental formula. The remaining specimen had a 3/2 dental formula and deformed palps.

Conclusion

Since the dental formula is a key morphological feature for identification of Haemaphysalis nymphs, this anomaly could potentially lead to misidentification. Hence, such anomalies, although potentially rare, are important to document considering accurate morphological identification. Further studies are needed to clarify the actual status of tick morphological anomalies in Japan.

Purpose

This study assessed the impact of different concentrations of thymol-loaded chitosan nanoparticles (TC NPs) on the physiological condition and surface morphology of Toxocara vitulorum infective larvae in vitro.

Methods

Thymol-loaded chitosan nanoparticles were produced utilizing the emulsion-ionic gelation process with sodium tripolyphosphate and then freeze dried. UV-Vis, XRD, TEM, and DLS were used to analyze optical, structural, and size properties, as well as encapsulation efficiency and loading capacity. Toxocara vitulorum worms were gathered from buffaloes, and female worms were employed to extract and hatch eggs in the laboratory. The larvae were exposed to different concentrations of thymol, chitosan NPs, and TC NPs (0, 1000, 2000, 3000, 4000, and 5000 µg/mL) and were kept at 37 °C for 24 h Trypan blue staining and scanning electron microscopy were used to assess the toxicity and larvicidal activity of TC NPs at various doses. The oxidative stress indicators (GSH, MDA, CAT, and NO) were evaluated in treated larvae.

Results

The exposed larvae to TC NPs had an increase in malondialdehyde, catalase and nitric oxide levels, while a depletion in glutathione concentration. Light microscopy analysis indicated that the exposed larvae lost their coiling habit, exhibiting many holes and wrinkles. Moreover, scanning electron microscopy revealed morphological changes in the larvae’s body wall, including numerous erosional and fissured regions, along with both small and large blebs resulting from exposure to TC NPs.

Conclusion

TC NPs at environmentally relevant doses demonstrated considerable antihelminthic action against Toxocara vitulorum infective larvae, establishing a successful model for parasite control research.

Graphical Abstract

Purpose

Bovine babesiosis poses a serious threat to cattle in tropical and subtropical regions. This study compared 3 methods to detect babesiosis in naturally infected cattle; microscopy, loop-mediated isothermal amplification (LAMP), and conventional PCR (cPCR), in Egypt’s New Valley Governorate.

Methods

A total of 339 tick-infested cattle were examined for Babesia infection. Microscopic examination was done. Genomic DNA extraction for the LAMP and PCR assays was carried out. LAMP was performed and compared with cPCR.

Results

Molecular methods revealed higher infection rates than microscopic examination: LAMP detected Babesia DNA in 40.7% (138/339) of samples, cPCR in 41.9% (142/339), while microscopy identified 31.9% (108/339). Clinically infected cattle exhibited fever, hemoglobinuria, pallor, and weight loss. Seasonal variation showed peak prevalence in summer (37.8%) and the lowest in winter (20%). Based on comparative analysis, LAMP showed 97.18% sensitivity, 100% specificity, and almost perfect agreement with cPCR (κ = 0.98, P = 0.13).

Conclusions

These findings demonstrate high Babesia prevalence in tick-infested cattle and underscore LAMP’s value as a rapid, sensitive, and field-friendly tool for surveillance.

Purpose

Centrocestus formosanus Nishigori, 1924 is a zoonotic trematode known to cause centrocestiosis in the gills of fish and is also categorized as an intestinal trematodiosis in humans. Accurate identification of its pleurolophocercous cercariae is essential for assessing and managing public health risks.

Methods

Approximately 400 Balanocochlis glans snails were collected from the Casecnan River, Nueva Vizcaya, Luzon, Philippines. Cercariae were isolated using the crushing method and both morphological and molecular analyses (partial 28S rDNA and cox1 sequences) were performed for parasite identification.

Results

A total of 13.75% of B. glans individuals were found to be infected with pleurolophocercous cercariae of C. formosanus, confirmed through molecular data.

Conclusion

The detection of C. formosanus in B. glans represents a new intermediate host record. These findings provide important baseline data for understanding the parasite's ecology and are critical for developing targeted interventions to mitigate its potential impact on aquatic ecosystems, public health, and local communities.

Purpose

Eosinophilia is a hallmark of many helminthic infections. However, the underlying parasitic etiology often goes undetected—especially in immunosuppressed patients. We aimed to evaluate the helminthic seropositivity in immunosuppressed patients with peripheral eosinophilia at a tertiary care hospital in north India.

Methods

In this retrospective observational cross-sectional study, a total of 115 immunosuppressed patients with eosinophilia were subjected to serological testing for six common helminths, i.e., IgG antibodies against Strongyloides stercoralis, Toxocara canis, Trichinella spiralis, Echinococcus granulosus, and Taenia solium by ELISA; IgG4 antibodies against Wuchereria bancrofti by ELISA; and W. bancrofti antigen by immunochromatographic assay. Absolute eosinophil counts (AEC) and clinical-demographic data were analyzed using non-parametric tests and Spearman correlation statistics.

Results

Overall, 34 patients (29.6%) were positive for at least one parasitic serology, with S. stercoralis being the most common (18.3%), followed by T. canis (11.3%), T. spiralis (6.1%), W. bancrofti (5.2%), E. granulosus (5.2%), and T. solium (1.7%). Multiple seropositivities were detected in 14 (12.2%) patients. Seropositive patients had significantly higher median AEC than seronegatives (3021 vs. 1495 cells/µL, Wilcoxon p = 0.008). A statistically significant correlation was found between AEC and number of positive serologies per patient (Spearman’s ρ = 0.269, p = 0.003). A graded relationship between increasing seropositivity and severity of AEC was noted (Cochran–Armitage trend p = 0.006).

Conclusion

Nearly 30% of immunosuppressed patients with peripheral eosinophilia had serological evidence of helminthic infections. Helminth serology panel testing for persistent or unexplained eosinophilia along with clinical evaluation may facilitate early diagnosis and management in immunocompromised hosts.

Background

The liver fluke Opisthorchis viverrini is a major public health concern in Southeast Asia and a leading cause of cholangiocarcinoma. Its transmission relies on freshwater snails of the genus Bithynia as the first intermediate hosts. However, accurately identifying these morphologically similar snails remains challenging.

Objectives

This study aimed to develop species-specific primers for the accurate molecular identification of Bithynia siamensis siamensis, which serves as an important first intermediate host of O. viverrini.

Methods

Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) was employed to isolate a unique DNA fragment specific to B. siamensis siamensis. A distinct 820 bp RAPD-derived fragment was obtained, sequenced, and analyzed. From this fragment, a conserved internal region was selected and used to design a species-specific primer pair (BSS2F/BSS2R), which produces a 280 bp diagnostic amplicon. The specificity and sensitivity of the newly developed assay were subsequently evaluated against other freshwater snail species.

Results

The designed primers consistently amplified a 280 bp fragment exclusive to B. siamensis siamensis, with no cross-reactivity to B. siamensis goniomphalos, B. funiculata, or other cohabiting snail species. The assay detected as little as 5 ng of genomic DNA and achieved 90% amplification success across samples from four provinces.

Conclusion

The RAPD-derived primer pair provides a rapid, reliable, and cost-effective molecular tool for the specific detection of B. siamensis siamensis. This approach enhances epidemiological surveillance of O. viverrini transmission and supports integrated One Health strategies for controlling opisthorchiasis in endemic regions.

Toxoplasma gondii is considered the second most common pathogen causing abortions in sheep, resulting in great economic losses. Thus, timely, sensitive and specific diagnosis of ovine toxoplasmosis is very important. In this study, diagnostic performance of an ELISA using a T. gondii GRA6 peptide (GRA6 ELISA) was investigated using serum samples (n = 61) collected from sheep diagnosed with toxoplasmosis using a commercial ELISA kit. Additionally, an in house ELISA using T. gondii tachyzoite lysate antigen (TLA ELISA) was also used to compare its performance with that of the GRA6 ELISA. Using the commercial ELISA kit as reference, the TLA ELISA and the GRA6 ELISA showed sensitivities of 83.7% and 88.4%, and specificities of 85% and 80.0%, respectively. Cohen’s kappa coefficient between TLA ELISA/ GRA6 ELISA and commercial ELISA kit was 0.652 and 0.675, respectively, indicating that both tests have good agreements. When we analyzed serum samples (n = 19) collected from a sheep group that had experienced abortions and were diagnosed with toxoplasmosis using a commercial ELISA kit, sensitivity values for the TLA ELISA and the GRA6 ELISA reached 100% and 89.5%, respectively. According to the seroprevalence results in serum samples analyzed, the commercial ELISA kit detected seroprevalence as 68.2% whereas the GRA6 ELISA and TLA ELISA detected seroprevalence as 66.7% and 61.2%, respectively. Furthermore, among the serum samples that yielded compatible results across the three different ELISA assays (n = 45), 31 were identified as seropositive, corresponding to a seroprevalence rate of 68.9% (31/45). In conclusion, the GRA6 ELISA detected ovine toxoplasmosis with high sensitivity and specificity.

Purpose

Present investigation was designed to report the PCR based presence of Hepatozoon spp., Plasmodium spp., Haemoproteus spp., Leucocytozoan spp., Toxoplasma gondii and Neospora caninum nd phylogenetic diversity of detected pathogens in the blood samples of four wild rodent species (Meriones rex, Acomys dimidiatus, Myomys yemeni and Rattus rattus). Ectoparasites infesting these rodents were also reported.

Methods

A total of 54 rodents and 365 ecto-parasites infesting them were collected during August till October 2020 from Al Makhwah governorate in Saudi Arabia. PCR-base approached was used for the detection of parasites in rodent bloods followed by their DNA sequence based confirmation and phylogenetic analysis.

Results

Hepatozoon spp. and T. gondii were detected by PCR in seven (13%), and one (2%) out of 54 analyzed rodents, respectively. Meriones rex and Myomys yemeni were found infected with Hepatozoon spp., while T. gondii was detected only in Myomys yemeni. Phylogenetic analysis of both pathogens showed that Saudi isolates were closely related to isolates previously reported from various countries worldwide. Ecto-parasites infesting three rodent species included ticks (Haemaphysalis and Rhipicephalus spp.), fleas (Parapulex chephrensis), mites (Laelaps echidninus) and lice. Myomys yemeni had no ecto-parasite infestation. Female Meriones rex was significantly more prone to Hepatozoon spp. infection than males.

Conclusion

This is the first report that Saudi rodents are infected with Hepatozoon spp. and T. gondii. More large scale studies are recommended for the better understanding of the host-parasite interactions.

Purpose

The flagellar parasite Trichomonas vaginalis is the main cause of trichomoniasis cases globally and is associated with a broad range of complications. Due to the diverse range of virulence factors participating in the attachment, proliferation and resistance of this pathogen, preventive and well-tolerated compounds are necessary. One of the virulence factors in T. vaginalis, the legumain-like cysteine protease LEGU-1 is of particular interest as a target due to its potential influence on trichomoniasis and tumor development in urogenital systems, as well as its closely related to the avian strain T. gallinae. Previous studies on antineoplastic proton pump inhibitors revealed they also have legumain (LGMN) inhibitory activities.

Methods

Therefore, this study aimed to compare the molecular interactions of T. vaginalis/gallinae LEGU-1 and H. sapiens LGMN with proton pump inhibitor drugs (lansoprazole, omeprazole, and esomeprazole) through sequence analysis, 3D modeling, and molecular docking.

Results

Although sequence analyses revealed low homology between T. vaginalis/gallinae LEGU-1 and H. sapiens LGMN, secondary and 3D structural comparisons uncovered their structural conservation. Possible binding sites in all three proteins identified via CB-DOCK2 were compared to the previously described sites for LGMN, followed by targeted docking using Autodock Vina. Identification of amino acids mutually interacting with all three ligands by both programs revealed the overall conservation of the binding pockets. The variations in the number of amino acids within the binding sites for all three proteins displayed the variations in the binding energies for each ligand. Lansoprazole, omeprazole and esomeprazole were shown to bind T. vaginalis/gallinae LEGU-1 and H. sapiens LGMN, with lansoprazole having the highest binding energy.

Conclusion

Conclusion Beyond our promising bioinformatics results, this study can guide further research on the development of alternative therapeutic methods against trichomoniasis and concomitant conditions.

Graphical Abstract