Reem Montasser Ramadan

BACKGROUND: Trichinella spiralis, a globally widespread zoonotic parasite, poses significant health and economic burdens due to its complex life cycle and the scarcity of effective, multi-stage treatments.

METHODS: This study investigated the therapeutic potential of a novel curcumin-olive oil nanocomposite (CO-NC) against three critical stages of T. spiralis infection in a murine model: adult worms (3-5 days post-inoculation, dpi), newborn larvae (8-10 dpi), and encapsulated larvae (33-35 dpi). CO-NC exhibited potent, stage-specific, and dose-dependent antiparasitic activity.

RESULTS: Remarkably, a 100 mg/kg dose achieved complete eradication of both newborn and encapsulated larvae, mirroring the efficacy of the current standard treatment, albendazole (50 mg/kg). This high dose also significantly reduced adult worm burdens by 91.6%. Even at a lower dose of 50 mg/kg, CO-NC demonstrated substantial activity, reducing adult worms and encapsulated larvae by 55.2% and 43.8%, respectively. Beyond its direct antiparasitic effects, CO-NC (100 mg/kg) significantly mitigated infection-induced oxidative stress by restoring key redox markers in muscle and intestinal tissues, including xanthine oxidase, glutathione, malondialdehyde, and total antioxidant capacity. Furthermore, complementary in vitro studies revealed superior anticancer and anti-inflammatory properties of CO-NC compared to crude curcumin and standard reference compounds at their respective IC values.

CONCLUSIONS: These findings highlight CO-NC as a promising multi-faceted therapeutic candidate for trichinellosis, offering potent antiparasitic efficacy comparable to albendazole alongside valuable antioxidant, anti-inflammatory, and anticancer properties. This integrated approach underscores the potential of CO-NC as an innovative and comprehensive solution for the challenges posed by T. spiralis infections.

Herein, we present the development of a novel plant-based nanotechnology strategy employing Astragalus polysaccharide nanoemulsion (APS-NE) to combat clinostomid excysted metacercariae, metacercarial parasites of major global public health concern. A survey conducted between January and August 2024 on 200 Nile tilapia (Oreochromis niloticus) from Giza, Egypt, revealed a high prevalence of encysted metacercariae infection (43.50 %; 87/200). Morphological and molecular analyses (targeting the cytochrome oxidase subunit I gene) confirmed the presence of Clinostomum phalacrocoracis and Euclinostomum heterostomum (99-100 % sequence identity). The APS-NE was characterized by transmission electron microscopy and dynamic light scattering, which demonstrated well-dispersed nanoemulsions (average size 75.6 nm; polydispersity index (PDI) 0.04; zeta potential -35 mV), indicating robust colloidal stability. In vitro assays revealed a dose- and time-dependent increase in excysted metacercariae mortality. Specifically, Clinostomum spp. mortality increased from 5 % at 0.01 % concentration after 10 min to 100 % at 1 % within 1 h, with lethal concentration 50 % (LC₅₀) values decreasing from 0.488 % to 0.013 %. Euclinostomum spp. exhibited even greater sensitivity, with LC₅₀ values ranging from 0.396 % to 0.004 %. Statistical analysis confirmed significant differences in mortality across concentrations and timepoints (Chi-square, p < 0.05). Ultrastructural damage, including tegumental rupture and sucker edema, was visualized using scanning electron microscopy. Comet assays revealed significant DNA fragmentation in the treated worms. For example, the percentage of DNA in the tail increased from merely 6 % to approximately 12 % for Clinostomum spp., and from approximately 9 % to over 25 % for Euclinostomum spp. (p ≤ 0.05), comparable to praziquantel. Molecular docking simulations revealed strong binding affinities of APS to parasite mitochondrial enzymes (e.g., Euclinostomum cytochrome c oxidase: -8.59 kcal/mol), supporting the proposed mechanism of action. These findings represent the first in vitro evaluation of APS nanoemulsions against excysted metacercariae of Clinostomum and Euclinostomum, underscoring their promising potential for targeted parasite control. However, comprehensive in vivo and ecotoxicological studies are essential to validate their therapeutic efficacy and establish their feasibility for large-scale implementation.

The current investigation was performed to study the incidence, morphological characters and molecular identification of Cryptosporidium species infecting domestic pigeons in the Giza governorate, Egypt. The incidence of Cryptosporidium spp. by modified Ziehl-Neelsen stain technique was 12 % and 14 % of the examined intestinal and bursal samples respectively. Seasonal incidence showed that winter had the highest rate (15.38 % and 21.74 %) while the lowest one was in autumn (7.95 % and 8.33 %) of the intestinal and bursal samples respectively. Two forms of Cryptosporidium spp. were detected. The small oocysts had average size (4.6 ± 0.63 × 4.44 ± 0.76 μm) while the large one had average size (5.64 ± 0.39 × 5.57 ± 0.41 μm). The PCR products of Cryptosporidium spp. were analyzed using two pairs of primers. The analysis revealed that the amplicons of the 18S rRNA region had 830 bp and 760 bp. Sequencing and phylogenetic analysis of the amplified products indicated that the species under investigation were C. meleagridis and C. baileyi with accession numbers OR631411 and OR631417, respectively. To our knowledge, the identification and genetic characterization of C. meleagridis and C. baileyi within the genus Cryptosporidium infecting domestic pigeons is reported for the first time in Egypt.

Canine vector-borne diseases (CVBD) constitute a significant global health challenge, impacting dogs and posing zoonotic risks to humans. These diseases are transmitted through blood-feeding vectors such as ticks, fleas, and mosquitoes. This study, conducted in Cairo and Giza, Egypt, aimed to assess the prevalence, diversity, and clinical impact of CVBD in both domestic and stray dogs. Using microscopic and molecular diagnostic techniques, several pathogens were identified, including two primary zoonotic blood pathogens, Anaplasma platys and Leishmania spp., as well as other blood pathogens with varying degrees of zoonotic potential, such as Ehrlichia canis (E. canis), Anaplasma phagocytophilum, Anaplasma marginale, Babesia canis vogeli (B. canis vogeli), Hepatozoon canis, and Trypanosoma evansi. Stray dogs exhibited a higher prevalence of infection than domestic dogs, frequently presenting with co-infections. Clinically, infected dogs displayed clinical signs including weight loss, pale mucous membranes, lethargy, and anorexia, with more severe manifestations observed in cases with co-infections, particularly involving B. canis vogeli and E. canis. The immune response in these dogs was marked by elevated levels of inflammatory cytokines, such as tumor necrosis factor-α, interferon-γ, and interleukin-1β, which were significantly higher in symptomatic dogs, indicating a robust immune defense against the pathogens. Furthermore, markers of oxidative stress, including glutathione, malondialdehyde, and nitric oxide, were elevated in infected dogs, suggesting increased cellular damage due to prolonged infection and inflammation. The findings underline the key significance of stray dogs in the transmission and maintenance of CVBD and emphasize the necessity for comprehensive diagnostic, preventive, and control strategies to mitigate the prevalence of these diseases in dog populations and their potential zoonotic impact on human health.