Psoroptes cuniculi mite is an important ectoparasite in rabbit breeding. Extra virgin olive oil (EVOO) is a vegetable oil with anti-inflammatory and regenerative properties, and linoleic acid (LA) also has beneficial properties for health. The activity against P. cuniculi mites of EVOO was evaluated at concentrations of 1, 5, 10, 30, 60 and 100 %; LA was evaluated at 50, 100, 150, 200, 300 and 400 mg/mL. The effectiveness was evaluated by the immersion technique using 11 mites and four replicates, and post-treatment mortality was analyzed after 24 and 48 h. Also, the composition of EVOO was determined by gas chromatography-mass spectrometry; seven compounds were identified, with the major compounds being: 1) oleic acid (47.4 %), 2) glycidol oleate (34.2 %), 3) linoleic acid (7.0 %). Pure EVOO caused a mortality of 74.4 % after 24 h and 100 % after 48 h of treatment. LA caused 94.6 % and 98.4 % of mortality at 24 and 48 h, respectively, at a concentration of 400 mg/mL. Based on the results of the current investigation, EVOO and LA are proposed as potential effective treatments for the control of P. cuniculi mites.
{"title":"Olive oil and linoleic acid as potential acaricidal agents against Psoroptes cuniculi mites","authors":"Montañez-Palma Lilia Francisca , Hallal-Calleros Claudia , Castañeda-Ramírez Gloria Sarahí , Hernández-Núñez Emanuel , Wong -Villarreal Arnoldo , Aguilar-Marcelino Liliana , Flores-Pérez Fernando Iván","doi":"10.1016/j.exppara.2025.109025","DOIUrl":"10.1016/j.exppara.2025.109025","url":null,"abstract":"<div><div><em>Psoroptes cuniculi</em> mite is an important ectoparasite in rabbit breeding. Extra virgin olive oil (EVOO) is a vegetable oil with anti-inflammatory and regenerative properties, and linoleic acid (LA) also has beneficial properties for health. The activity against <em>P. cuniculi</em> mites of EVOO was evaluated at concentrations of 1, 5, 10, 30, 60 and 100 %; LA was evaluated at 50, 100, 150, 200, 300 and 400 mg/mL. The effectiveness was evaluated by the immersion technique using 11 mites and four replicates, and post-treatment mortality was analyzed after 24 and 48 h. Also, the composition of EVOO was determined by gas chromatography-mass spectrometry; seven compounds were identified, with the major compounds being: 1) oleic acid (47.4 %), 2) glycidol oleate (34.2 %), 3) linoleic acid (7.0 %). Pure EVOO caused a mortality of 74.4 % after 24 h and 100 % after 48 h of treatment. LA caused 94.6 % and 98.4 % of mortality at 24 and 48 h, respectively, at a concentration of 400 mg/mL. Based on the results of the current investigation, EVOO and LA are proposed as potential effective treatments for the control of <em>P. cuniculi</em> mites.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"277 ","pages":"Article 109025"},"PeriodicalIF":1.6,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145039455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-09DOI: 10.1016/j.exppara.2025.109022
Basma M. Elmansory , Hager S. Zoghroban , Dina M. El-Guindy , Dina A. El-Guindy
Treatment of trichinellosis is still challenging. Lack of an established effective and safe treatment for trichinellosis, directed attention towards repurposing the already available drugs. Thus, the aim of this study was to evaluate the effectiveness of nitrofurantoin (NF) as compared to albendazole (ABZ) and their combination in treatment of trichinellosis in mice. Mice were divided into five groups; Group I: negative control; Group II: positive control; Groups III, IV and V: infected and treated with ABZ, NF, and combined ALB with NF respectively. They were subdivided into subgroups (a) started treatment on 3rd day postinfection (PI) and were sacrificed on 6th day PI, and subgroups (b) started treatment on 21st day PI and were sacrificed on 35th day PI. Parasitological, histopathological, immunohistochemical, immunological and biochemical studies were done. The results showed that NF was potential effective in treatment of trichinellosis and its combination with ABZ achieved the best results as compared to ABZ alone. This combination significantly reduced adults (66.5 %) and larvae (87.1 %) counts in the intestinal and muscular phases respectively. Also, it significantly decreased the inflammation and serum interferon gamma (IFN-γ) levels with mean of 11.6 ± 0.43 and 15.8 ± 0.74 in the early and late stages of trichinellosis respectively. Additionally, it had antiangiogenic effects evidenced by decreasing the microvessel density/HPF with a reduction rate of 91.65 %, antioxidant effects by decreasing malondialdehyde (MDA) with mean ± SD of 0.73 ± 0.09 and increasing superoxide dismutase (SOD) with mean ± SD of 156.6 ± 5.2 in addition to its apoptotic effects by decreasing B-cell lymphoma (BCL-2) levels with mean ± SD of 0.81 ± 0.08 in the infected muscle cells. Thus, It was concluded that NF could be a promising anti-trichinellosis drug and its combination with ABZ could be an efficient treatment for early and late experimental trichinellosis.
{"title":"Efficacy of nitrofurantoin in treatment of murine model of trichinellosis","authors":"Basma M. Elmansory , Hager S. Zoghroban , Dina M. El-Guindy , Dina A. El-Guindy","doi":"10.1016/j.exppara.2025.109022","DOIUrl":"10.1016/j.exppara.2025.109022","url":null,"abstract":"<div><div>Treatment of trichinellosis is still challenging. Lack of an established effective and safe treatment for trichinellosis, directed attention towards repurposing the already available drugs. Thus, the aim of this study was to evaluate the effectiveness of nitrofurantoin (NF) as compared to albendazole (ABZ) and their combination in treatment of trichinellosis in mice. Mice were divided into five groups; Group I: negative control; Group II: positive control; Groups III, IV and V: infected and treated with ABZ, NF, and combined ALB with NF respectively. They were subdivided into subgroups (a) started treatment on 3rd day postinfection (PI) and were sacrificed on 6th day PI, and subgroups (b) started treatment on 21st day PI and were sacrificed on 35th day PI. Parasitological, histopathological, immunohistochemical, immunological and biochemical studies were done. The results showed that NF was potential effective in treatment of trichinellosis and its combination with ABZ achieved the best results as compared to ABZ alone. This combination significantly reduced adults (66.5 %) and larvae (87.1 %) counts in the intestinal and muscular phases respectively. Also, it significantly decreased the inflammation and serum interferon gamma (IFN-γ) levels with mean of 11.6 ± 0.43 and 15.8 ± 0.74 in the early and late stages of trichinellosis respectively. Additionally, it had antiangiogenic effects evidenced by decreasing the microvessel density/HPF with a reduction rate of 91.65 %, antioxidant effects by decreasing malondialdehyde (MDA) with mean ± SD of 0.73 ± 0.09 and increasing superoxide dismutase (SOD) with mean ± SD of 156.6 ± 5.2 in addition to its apoptotic effects by decreasing B-cell lymphoma (BCL-2) levels with mean ± SD of 0.81 ± 0.08 in the infected muscle cells. Thus, It was concluded that NF could be a promising anti-trichinellosis drug and its combination with ABZ could be an efficient treatment for early and late experimental trichinellosis.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"277 ","pages":"Article 109022"},"PeriodicalIF":1.6,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145039517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-09DOI: 10.1016/j.exppara.2025.109024
Salwa S. Younis , Ghada A. Gamea , Gamal M. El Maghraby , Mona F. Arafa , Rana A. Khalifa , Sara M. Shoeib , Rehab M. El-Gohary , Basma M. Elmansory
Till now, there is no well-established vaccine for toxoplasmosis in humans. This study evaluated the efficacy of niosomes to enhance the immunogenicity of Toxoplasma gondii excretory/secretory antigens (ESAs) vaccine in mice. The mice were divided into the following groups: group I (naïve), group II (naïve challenged), group III (alum), group IV (niosomes), group V (ESAs), group VI (ESAs and alum) and group VII (ESAs-loaded niosomes). All immunized mice received three doses of vaccine intraperitoneally two weeks apart. Two weeks later, mice were challenged with intraperitoneal injection of 103 viable tachyzoites of virulent RH strain. Parasitological, histopathological, and immunological studies were done. ESAs-loaded niosomes offered the best protection as they significantly decreased the mean parasitic count in liver and spleen with reduction rates of 85 and 90 %, respectively. Also, it reduced efficiently the inflammation and parenchymal injury in liver with intense iNOS immunostaining expression. In addition, it was effective in stimulation of humoral and cellular immune responses evidenced by the high significant anti-Toxoplasma IgG, increasing of CD4+ and CD8+ percentages by flowcytometry and serum IFN-γ levels. Therefore, niosomes were proved to be promising vaccine candidates due to enhancing the antigenicity of ESA and their long acting antiparasitic effect.
{"title":"Niosomes as a vehicle for excretory/secretory antigens enhance immunization efficacy of Toxoplasma gondii vaccine","authors":"Salwa S. Younis , Ghada A. Gamea , Gamal M. El Maghraby , Mona F. Arafa , Rana A. Khalifa , Sara M. Shoeib , Rehab M. El-Gohary , Basma M. Elmansory","doi":"10.1016/j.exppara.2025.109024","DOIUrl":"10.1016/j.exppara.2025.109024","url":null,"abstract":"<div><div>Till now, there is no well-established vaccine for toxoplasmosis in humans. This study evaluated the efficacy of niosomes to enhance the immunogenicity of <em>Toxoplasma gondii</em> excretory/secretory antigens (ESAs) vaccine in mice. The mice were divided into the following groups: group I (naïve), group II (naïve challenged), group III (alum), group IV (niosomes), group V (ESAs), group VI (ESAs and alum) and group VII (ESAs-loaded niosomes). All immunized mice received three doses of vaccine intraperitoneally two weeks apart. Two weeks later, mice were challenged with intraperitoneal injection of 10<sup>3</sup> viable tachyzoites of virulent RH strain. Parasitological, histopathological, and immunological studies were done<strong>.</strong> ESAs-loaded niosomes offered the best protection as they significantly decreased the mean parasitic count in liver and spleen with reduction rates of 85 and 90 %, respectively. Also, it reduced efficiently the inflammation and parenchymal injury in liver with intense iNOS immunostaining expression. In addition, it was effective in stimulation of humoral and cellular immune responses evidenced by the high significant anti-<em>Toxoplasma</em> IgG, increasing of CD4<sup>+</sup> and CD8<sup>+</sup> percentages by flowcytometry and serum IFN-γ levels. Therefore, niosomes were proved to be promising vaccine candidates due to enhancing the antigenicity of ESA and their long acting antiparasitic effect.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"277 ","pages":"Article 109024"},"PeriodicalIF":1.6,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145039477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-05DOI: 10.1016/j.exppara.2025.109021
Khalid Mehmood , Muhammad Nadir Naqqash , Nimra Batool , Bander Albogami , Hadeer Darwish , Ahmed Noureldeen , Fatemah E. Alajmi
Excessive use of agrochemicals results in contamination of water due to runoff or leaching. Insecticide induced-hormesis, a phenomenon characterized by low dose stimulation following exposure to insecticide, is crucial to insect pest resurgence. In this study, the effects of low or sublethal concentrations of emamectin benzoate and thiamethoxam on biological traits and genes expression were investigated for yellow fever mosquito, Aedes aegypti following 48 h exposures. Bioassay was conducted to compute LC10 and LC20 values for both test insecticides. The low lethal (LC10) and sublethal (LC20) concentrations of emamectin benzoate and thiamethoxam significantly reduced longevity and fecundity of the exposed mosquitoes. However, population parameters showed a negative change in the F1 progeny of emamectin exposed A. aegypti mosquitoes. While, stimulatory effects on pre-adult stage, longevity, and fertility were observed in the progeny generation (F1) of A. aegypti, when parental generation (F0) were exposed to LC10 and LC20 of thiamethoxam. However, at F2 generation the population parameters in all the treatments were statistically similar to the control except in the LC20 treatment of emamectin benzoate. The LC10 and LC20 of thiamethoxam significantly increased the expression level of vitellogenin in progeny generation, while inhibitory effects were observed for both treatments of emamectin benzoate. Additionally, the expression levels of P450 genes including CYP6P15, CYP6BB2, and CYP9J26 were up-regulated in the exposed insects. Taken together, our results show the hormetic effects in thiamethoxam on F1 and F2 individuals, which might be due to the intermittent changes in expression of genes involved in fertility, growth and insecticide detoxification in A. aegypti.
{"title":"Sublethal exposure of emamectin benzoate and thiamethoxam alters the biological parameters and genes expression in Aedes aegypti (Diptera: Culicidae)","authors":"Khalid Mehmood , Muhammad Nadir Naqqash , Nimra Batool , Bander Albogami , Hadeer Darwish , Ahmed Noureldeen , Fatemah E. Alajmi","doi":"10.1016/j.exppara.2025.109021","DOIUrl":"10.1016/j.exppara.2025.109021","url":null,"abstract":"<div><div>Excessive use of agrochemicals results in contamination of water due to runoff or leaching. Insecticide induced-hormesis, a phenomenon characterized by low dose stimulation following exposure to insecticide, is crucial to insect pest resurgence. In this study, the effects of low or sublethal concentrations of emamectin benzoate and thiamethoxam on biological traits and genes expression were investigated for yellow fever mosquito, <em>Aedes aegypti</em> following 48 h exposures. Bioassay was conducted to compute LC<sub>10</sub> and LC<sub>20</sub> values for both test insecticides. The low lethal (LC<sub>10</sub>) and sublethal (LC<sub>20</sub>) concentrations of emamectin benzoate and thiamethoxam significantly reduced longevity and fecundity of the exposed mosquitoes. However, population parameters showed a negative change in the F<sub>1</sub> progeny of emamectin exposed <em>A. aegypti</em> mosquitoes. While, stimulatory effects on pre-adult stage, longevity, and fertility were observed in the progeny generation (F<sub>1</sub>) of <em>A. aegypti</em>, when parental generation (F<sub>0</sub>) were exposed to LC<sub>10</sub> and LC<sub>20</sub> of thiamethoxam. However, at F<sub>2</sub> generation the population parameters in all the treatments were statistically similar to the control except in the LC<sub>20</sub> treatment of emamectin benzoate. The LC<sub>10</sub> and LC<sub>20</sub> of thiamethoxam significantly increased the expression level of vitellogenin in progeny generation, while inhibitory effects were observed for both treatments of emamectin benzoate. Additionally, the expression levels of P450 genes including CYP6P15, CYP6BB2, and CYP9J26 were up-regulated in the exposed insects. Taken together, our results show the hormetic effects in thiamethoxam on F<sub>1</sub> and F<sub>2</sub> individuals, which might be due to the intermittent changes in expression of genes involved in fertility, growth and insecticide detoxification in <em>A. aegypti</em>.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"277 ","pages":"Article 109021"},"PeriodicalIF":1.6,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145014174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rhipicephalus microplus, an important ixodid tick species, poses significant economic and health challenges to the livestock directly by impairing animal productivity and serving as a vector for various pathogens. Although tick control strategies broadly integrate synthetic acaricides and environmental management, the emergence of acaricide resistance undermines these efforts thereby, necessitating alternative approaches. This study evaluated the acaricidal efficacy of six essential oil components (EOCs) such as cedrol, cinnamaldehyde, citral, eugenol, limonene and menthol against deltamethrin and ivermectin resistant R. microplus population by larval packet test. Among the studied EOCs, cinnamaldehyde exhibited the highest acaricide potential (LC50 = 0.042 %), followed by menthol (LC50 = 0.084 %), eugenol (LC50 = 0.171 %) and citral (LC50 = 0.185 %). Cedrol (LC50 = 1.09 %) demonstrated a lower activity, while limonene (LC50 = 22.0 %) was least effective. Probit regression analysis revealed steep dose-response slopes for cinnamaldehyde, citral and eugenol indicating strong acaricidal effects at low concentrations. These findings identify cinnamaldehyde, menthol, eugenol and citral as promising candidates for the development of plant-based acaricides, supporting their potential integration into the sustainable tick management strategies for management of acaricide-resistant R. microplus populations.
{"title":"Acaricidal activity of various essential oil components against acaricide-resistant Rhipicephalus microplus (Acari: Ixodidae)","authors":"Jyoti, Manisha, Harkirat Singh, Nirbhay Kumar Singh","doi":"10.1016/j.exppara.2025.109018","DOIUrl":"10.1016/j.exppara.2025.109018","url":null,"abstract":"<div><div><em>Rhipicephalus microplus</em>, an important ixodid tick species, poses significant economic and health challenges to the livestock directly by impairing animal productivity and serving as a vector for various pathogens. Although tick control strategies broadly integrate synthetic acaricides and environmental management, the emergence of acaricide resistance undermines these efforts thereby, necessitating alternative approaches. This study evaluated the acaricidal efficacy of six essential oil components (EOCs) such as cedrol, cinnamaldehyde, citral, eugenol, limonene and menthol against deltamethrin and ivermectin resistant <em>R. microplus</em> population by larval packet test. Among the studied EOCs, cinnamaldehyde exhibited the highest acaricide potential (LC<sub>50</sub> = 0.042 %), followed by menthol (LC<sub>50</sub> = 0.084 %), eugenol (LC<sub>50</sub> = 0.171 %) and citral (LC<sub>50</sub> = 0.185 %). Cedrol (LC<sub>50</sub> = 1.09 %) demonstrated a lower activity, while limonene (LC<sub>50</sub> = 22.0 %) was least effective. Probit regression analysis revealed steep dose-response slopes for cinnamaldehyde, citral and eugenol indicating strong acaricidal effects at low concentrations. These findings identify cinnamaldehyde, menthol, eugenol and citral as promising candidates for the development of plant-based acaricides, supporting their potential integration into the sustainable tick management strategies for management of acaricide-resistant <em>R. microplus</em> populations<strong>.</strong></div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"277 ","pages":"Article 109018"},"PeriodicalIF":1.6,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145004941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The common parasite Toxoplasma gondii can infect all warm-blooded animals, including humans. Although most infections in humans remain asymptomatic, clinical toxoplasmosis can develop into a fatal disease. Infections are usually contracted by oral ingestion of tissue cysts or oocysts contained in cat feces.
Currently, the mouse bioassay is applied as a final experiment to evaluate meat infectivity. This study aims to establish an alternative cell culture and quantitative polymerase chain reaction (qPCR)-based in vitro infectivity assay for tissue cysts. The phytohormone abscisic acid (ABA) is applied to increase parasite multiplication.
A human foreskin fibroblast (HFF) host cell culture was infected with bradyzoites from mouse tissue. Treatment groups included uninfected controls, infected untreated controls, and infected ABA treated groups. The applied ABA concentrations used ranged from 0.2 ng/μl to 20 ng/μl, and ABA incubation times ranged from 2 h to 18 h before ABA removal. At 48 h after infection, T. gondii deoxyribonucleic acid (DNA) in the cell cultures was quantified by qPCR. The results indicate that parasite DNA copy numbers are markedly increased when using ABA at 2 ng/μl for 4–6 h or at 20 ng/μl for 2 h incubation. Our results indicate that this newly established in vitro assay is suitable to determine T. gondii cyst infectivity.
{"title":"Development of an in vitro assay using abscisic acid to study Toxoplasma gondii infectivity","authors":"Tina Wagner , Ildiko Rita Dunay , Arwid Daugschies , Stefanie Wiedmer , Berit Bangoura","doi":"10.1016/j.exppara.2025.109011","DOIUrl":"10.1016/j.exppara.2025.109011","url":null,"abstract":"<div><div>The common parasite <em>Toxoplasma gondii</em> can infect all warm-blooded animals, including humans. Although most infections in humans remain asymptomatic, clinical toxoplasmosis can develop into a fatal disease. Infections are usually contracted by oral ingestion of tissue cysts or oocysts contained in cat feces.</div><div>Currently, the mouse bioassay is applied as a final experiment to evaluate meat infectivity. This study aims to establish an alternative cell culture and quantitative polymerase chain reaction (qPCR)-based <em>in vitro</em> infectivity assay for tissue cysts. The phytohormone abscisic acid (ABA) is applied to increase parasite multiplication.</div><div>A human foreskin fibroblast (HFF) host cell culture was infected with bradyzoites from mouse tissue. Treatment groups included uninfected controls, infected untreated controls, and infected ABA treated groups. The applied ABA concentrations used ranged from 0.2 ng/μl to 20 ng/μl, and ABA incubation times ranged from 2 h to 18 h before ABA removal. At 48 h after infection, <em>T. gondii</em> deoxyribonucleic acid (DNA) in the cell cultures was quantified by qPCR. The results indicate that parasite DNA copy numbers are markedly increased when using ABA at 2 ng/μl for 4–6 h or at 20 ng/μl for 2 h incubation. Our results indicate that this newly established <em>in vitro</em> assay is suitable to determine <em>T. gondii</em> cyst infectivity.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"277 ","pages":"Article 109011"},"PeriodicalIF":1.6,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145008116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-02DOI: 10.1016/j.exppara.2025.109009
Mohammad Tuhin Ali , Tania Rahman , Parag Palit , Muhammad Ikhtear Uddin , Veronique Seidel
Leishmaniasis is a vector-borne parasitic disease caused by Leishmania spp., for which there is no vaccine and an urgent need for better drugs. The zinc metalloprotease gp63 of Leishmania has been identified as an antigenic structure for vaccine design and a promising target for new antileishmanial agents. In this study, immunoinformatics was used to design a full vaccine construct with the cytotoxic T-lymphocyte (CTL) and helper T-lymphocyte (HTL) epitopes of gp63 from Old and New World Leishmania spp. The vaccine construct comprising of these epitopes, with suitable adjuvant and linker sequences, was found to be thermostable, highly antigenic and non-allergenic. A total of 13 linear B-cell epitopes, and 12 continuous and four discontinuous B-cell epitopes, were further identified using the BepiPred and ElliPro prediction programs, respectively. In addition, molecular docking and molecular dynamics simulation studies were performed to identify new antileishmanial molecules with the potential to target gp63. Nareline - a phytomolecule from the antileishmanial plant Alstonia scholaris - showed the best predictive binding affinity for gp63, forming stable interactions with key residues in the active site of this protein. This study highlights the promising role of gp63 in the search for new vaccines and therapeutic agents to combat leishmaniasis.
{"title":"Targeting the zinc metalloprotease gp63 of Leishmania for vaccine design and new drug discovery using immunoinformatics, molecular docking and molecular dynamics simulation studies","authors":"Mohammad Tuhin Ali , Tania Rahman , Parag Palit , Muhammad Ikhtear Uddin , Veronique Seidel","doi":"10.1016/j.exppara.2025.109009","DOIUrl":"10.1016/j.exppara.2025.109009","url":null,"abstract":"<div><div>Leishmaniasis is a vector-borne parasitic disease caused by <em>Leishmania</em> spp., for which there is no vaccine and an urgent need for better drugs. The zinc metalloprotease gp63 of <em>Leishmania</em> has been identified as an antigenic structure for vaccine design and a promising target for new antileishmanial agents. In this study, immunoinformatics was used to design a full vaccine construct with the cytotoxic T-lymphocyte (CTL) and helper T-lymphocyte (HTL) epitopes of gp63 from Old and New World <em>Leishmania</em> spp. The vaccine construct comprising of these epitopes, with suitable adjuvant and linker sequences, was found to be thermostable, highly antigenic and non-allergenic. A total of 13 linear B-cell epitopes, and 12 continuous and four discontinuous B-cell epitopes, were further identified using the BepiPred and ElliPro prediction programs, respectively. In addition, molecular docking and molecular dynamics simulation studies were performed to identify new antileishmanial molecules with the potential to target gp63. Nareline - a phytomolecule from the antileishmanial plant <em>Alstonia scholaris</em> - showed the best predictive binding affinity for gp63, forming stable interactions with key residues in the active site of this protein. This study highlights the promising role of gp63 in the search for new vaccines and therapeutic agents to combat leishmaniasis.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"277 ","pages":"Article 109009"},"PeriodicalIF":1.6,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145000028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-02DOI: 10.1016/j.exppara.2025.109008
Enas A.M. Huseein , Fatma A.S. Anwar , Gamal H. Abed , Hossam El-Din M. Omar , Tasneem M. Hassan , Haiam M.M. Farrag , Sary Kh Abdel-Gahfar , Mahmoud Soliman , Alzahraa Abdelraouf Ahmad
Background
Allovahlkampfia spelaea (A. spelaea) is a free-living amoeba that has recently been recognized to cause Acanthamoeba-like keratitis, the treatment of which is complex. The pathogenic potential of Allovahlkampfia spp. remains unexplored. This study characterized A. spelaea through ultrastructural morphological analysis and investigated the pathogenic potential of the A. spelaea strain KS1, which was isolated from a patient with keratitis, in a murine model, with a focus on neuro-pulmonary infections. Additionally, this study assessed the therapeutic effectiveness of ellagic acid (EA) against tissue damage caused by amoebic infections.
Methods
Immunosuppressed male Wister rats were intranasally inoculated with A. spelaea trophozoites (1 × 106/ml) and divided into control, infected untreated, and infected treated (50 mg/kg EA daily) groups. Histopathological and ultrastructural analyses of brain and lung tissues were conducted by scanning and transmission electron microscopy. Additionally, the therapeutic effects of EA were assessed via comparative tissue pathology.
Results
A. spelaea infection induced A. spelaea-induced neural lesions resembling granulomatous amoebic encephalitis (GAE) in the brain, which was characterized by gliosis, vasculitis, and necrosis, in addition to severe pulmonary damage, including suppurative bronchopneumonia and abscesses. Trophozoites presented with pseudopodia, acanthopodia, and amoebostomes, whereas cysts presented with double-layered walls. EA-treated rats presented nearly normal brain and lung histology, with reduced inflammation and gliosis, highlighting the anti-inflammatory and antioxidant properties of EA.
Conclusion
This study highlights the neurotropic and pulmonary pathogenicity of A. spelaea, with ultrastructures parallel to those of Vahlkampfia spp. and Acanthamoeba spp. Ellagic acid significantly reduces infection-induced damage, underscoring its potential as a therapeutic agent for infections caused by free-living amoebae.
{"title":"Ultrastructural characterization and pathogenicity of Allovohlkamfia spelaea in a murine model: Neuropulmonary infections and therapeutic potential of ellagic acid","authors":"Enas A.M. Huseein , Fatma A.S. Anwar , Gamal H. Abed , Hossam El-Din M. Omar , Tasneem M. Hassan , Haiam M.M. Farrag , Sary Kh Abdel-Gahfar , Mahmoud Soliman , Alzahraa Abdelraouf Ahmad","doi":"10.1016/j.exppara.2025.109008","DOIUrl":"10.1016/j.exppara.2025.109008","url":null,"abstract":"<div><h3>Background</h3><div><em>Allovahlkampfia spelaea (A. spelaea)</em> is a free-living amoeba that has recently been recognized to cause <em>Acanthamoeba</em>-like keratitis, the treatment of which is complex. The pathogenic potential of <em>Allovahlkampfia</em> spp. remains unexplored. This study characterized <em>A. spelaea</em> through ultrastructural morphological analysis and investigated the pathogenic potential of the <em>A. spelaea</em> strain KS1, which was isolated from a patient with keratitis, in a murine model, with a focus on neuro-pulmonary infections. Additionally, this study assessed the therapeutic effectiveness of ellagic acid (EA) against tissue damage caused by amoebic infections.</div></div><div><h3>Methods</h3><div>Immunosuppressed male Wister rats were intranasally inoculated with <em>A. spelaea</em> trophozoites (1 × 10<sup>6</sup>/ml) and divided into control, infected untreated, and infected treated (50 mg/kg EA daily) groups. Histopathological and ultrastructural analyses of brain and lung tissues were conducted by scanning and transmission electron microscopy. Additionally, the therapeutic effects of EA were assessed via comparative tissue pathology.</div></div><div><h3>Results</h3><div><em>A. spelaea</em> infection induced <em>A. spelaea</em>-induced neural lesions resembling granulomatous amoebic encephalitis (GAE) in the brain, which was characterized by gliosis, vasculitis, and necrosis, in addition to severe pulmonary damage, including suppurative bronchopneumonia and abscesses. Trophozoites presented with pseudopodia, acanthopodia, and amoebostomes, whereas cysts presented with double-layered walls. EA-treated rats presented nearly normal brain and lung histology, with reduced inflammation and gliosis, highlighting the anti-inflammatory and antioxidant properties of EA.</div></div><div><h3>Conclusion</h3><div>This study highlights the neurotropic and pulmonary pathogenicity of <em>A. spelaea</em>, with ultrastructures parallel to those of <em>Vahlkampfia</em> spp. and <em>Acanthamoeba</em> spp. Ellagic acid significantly reduces infection-induced damage, underscoring its potential as a therapeutic agent for infections caused by free-living amoebae.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"277 ","pages":"Article 109008"},"PeriodicalIF":1.6,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145000084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-02DOI: 10.1016/j.exppara.2025.109010
Nor-Athirah Mohd-Najib , Hasmah Abdullah , Candy Chuah , Basripuzi-Nurul-Hayyan Hassan-Basri , Weng-Kin Wong
Giardia intestinalis trophozoites, the replicative stage responsible for human giardiasis, require anaerobic settings for microtiter plate culture. However, residual ambient oxygen (AAO2) within plates and enclosed compartments could hinder consistent confluence. This study evaluated a vacuum-sealed bag (VS) combined with an anaerobic gas generator sachet (AS) (VS + AS) as an alternative culture method to minimize residual AAO2. The conventional airtight compartment plus AS (AT + AS) served as the reference, while VS without AS (VS–AS) functioned as the negative control. Two-fold serially diluted trophozoites were seeded in 96-well plates, and confluence was scored at 48-, 96-, and 144-h post-seeding using a 5-point scale (0: 0–20 % to 4+: 80–100 %). MTT assays were used to validate the association between seeded cell number and parasite viability, as well as inter-well variation among fully confluent wells. VS + AS cultures achieved ≥3+ confluence within 48 h and maintained this through 96 h, whereas AT + AS required 96–144 h to reach comparable levels. VS–AS consistently showed poor growth. Optimal confluence in the VS + AS system was observed with seeding densities of 6 × 104 to 5 × 105 trophozoites per well. MTT assays confirmed a strong linear correlation between seeded cell number (103.9–105.7) and OD540 readings (r2 = 0.98). The inter-well variation among fully confluence wells was below 10 %. In conclusion, the VS + AS system accelerates trophozoite growth and improves reproducibility compared with conventional methods. This approach provides a reliable platform for studying Giardia trophozoite biology and supports the discovery of novel anti-giardial compounds.
{"title":"Vacuum-sealed anaerobic plate culture enhances growth and confluence of Giardia intestinalis trophozoites","authors":"Nor-Athirah Mohd-Najib , Hasmah Abdullah , Candy Chuah , Basripuzi-Nurul-Hayyan Hassan-Basri , Weng-Kin Wong","doi":"10.1016/j.exppara.2025.109010","DOIUrl":"10.1016/j.exppara.2025.109010","url":null,"abstract":"<div><div><em>Giardia intestinalis</em> trophozoites, the replicative stage responsible for human giardiasis, require anaerobic settings for microtiter plate culture. However, residual ambient oxygen (AAO<sub>2</sub>) within plates and enclosed compartments could hinder consistent confluence. This study evaluated a vacuum-sealed bag (VS) combined with an anaerobic gas generator sachet (AS) (VS + AS) as an alternative culture method to minimize residual AAO<sub>2</sub>. The conventional airtight compartment plus AS (AT + AS) served as the reference, while VS without AS (VS–AS) functioned as the negative control. Two-fold serially diluted trophozoites were seeded in 96-well plates, and confluence was scored at 48-, 96-, and 144-h post-seeding using a 5-point scale (0: 0–20 % to 4+: 80–100 %). MTT assays were used to validate the association between seeded cell number and parasite viability, as well as inter-well variation among fully confluent wells. VS + AS cultures achieved ≥3+ confluence within 48 h and maintained this through 96 h, whereas AT + AS required 96–144 h to reach comparable levels. VS–AS consistently showed poor growth. Optimal confluence in the VS + AS system was observed with seeding densities of 6 × 10<sup>4</sup> to 5 × 10<sup>5</sup> trophozoites per well. MTT assays confirmed a strong linear correlation between seeded cell number (10<sup>3</sup><sup>.</sup><sup>9</sup>–10<sup>5</sup><sup>.</sup><sup>7</sup>) and OD<sub>540</sub> readings (r<sup>2</sup> = 0.98). The inter-well variation among fully confluence wells was below 10 %. In conclusion, the VS + AS system accelerates trophozoite growth and improves reproducibility compared with conventional methods. This approach provides a reliable platform for studying <em>Giardia</em> trophozoite biology and supports the discovery of novel anti-giardial compounds.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"277 ","pages":"Article 109010"},"PeriodicalIF":1.6,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144992074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-01DOI: 10.1016/j.exppara.2025.109007
Paulo Watanabe , Vivian Fuguhara de Lima , Amanda Gubert Alves dos Santos , Lucas Casagrande , Vinicius Franca Scanavaca , Priscila Laet Santana , Roberto Kenji Nakamura Cuman , Debora de Mello Gonçales Sant Ana , Gessilda de Alcantara Nogueira-Melo
Toxoplasmosis, caused by the protozoan Toxoplasma gondii (T. gondii), is a common zoonotic disease with a seropositivity rate of up to 60 % in adults. While often asymptomatic, it can cause severe complications in immunocompromised individuals. Oral transmission is the primary route of infection, leading to intestinal inflammation. This study evaluated morphoquantitative changes in the colons of female C57BL/6 mice acutely infected with T. gondii. Mice were divided into control and infected groups and euthanized five days post-infection for colon collection. Histological analyses quantified intraepithelial lymphocytes, goblet cells, mast cells, and collagen fibres, while immunostaining assessed neurons and vasoactive intestinal peptide (VIP) expression. Infected mice exhibited increased intraepithelial lymphocytes and myeloperoxidase activity, alongside a significant reduction in AB-1.0-positive goblet cells, indicating impaired mucus secretion. Notably, the longitudinal muscle layer showed increased thickness, whereas the submucosal layer and crypt depth were reduced. Histopathological evaluation revealed epithelial hyperplasia, mucosal ulceration, and abscess formation. A decrease in myenteric neurons was also observed, although VIP expression remained unchanged. These findings demonstrate that acute T. gondii infection induces substantial alterations in intestinal structure, including immune cell infiltration, goblet cell depletion, and muscle layer remodelling. The reduction in myenteric neurons, despite stable VIP expression, suggests specific neuroimmune interactions in the infected gut. Collectively, this study highlights the profound impact of T. gondii on colonic morphology and function, underscoring the complexity of host–parasite interactions during acute infection.
{"title":"Unmasking the intestinal impact: Acute Toxoplasma gondii infection induces severe morphological and immunological changes in female C57BL/6 mice","authors":"Paulo Watanabe , Vivian Fuguhara de Lima , Amanda Gubert Alves dos Santos , Lucas Casagrande , Vinicius Franca Scanavaca , Priscila Laet Santana , Roberto Kenji Nakamura Cuman , Debora de Mello Gonçales Sant Ana , Gessilda de Alcantara Nogueira-Melo","doi":"10.1016/j.exppara.2025.109007","DOIUrl":"10.1016/j.exppara.2025.109007","url":null,"abstract":"<div><div>Toxoplasmosis, caused by the protozoan <em>Toxoplasma gondii</em> (<em>T. gondi</em>i), is a common zoonotic disease with a seropositivity rate of up to 60 % in adults. While often asymptomatic, it can cause severe complications in immunocompromised individuals. Oral transmission is the primary route of infection, leading to intestinal inflammation. This study evaluated morphoquantitative changes in the colons of female C57BL/6 mice acutely infected with <em>T. gondii</em>. Mice were divided into control and infected groups and euthanized five days post-infection for colon collection. Histological analyses quantified intraepithelial lymphocytes, goblet cells, mast cells, and collagen fibres, while immunostaining assessed neurons and vasoactive intestinal peptide (VIP) expression. Infected mice exhibited increased intraepithelial lymphocytes and myeloperoxidase activity, alongside a significant reduction in AB-1.0-positive goblet cells, indicating impaired mucus secretion. Notably, the longitudinal muscle layer showed increased thickness, whereas the submucosal layer and crypt depth were reduced. Histopathological evaluation revealed epithelial hyperplasia, mucosal ulceration, and abscess formation. A decrease in myenteric neurons was also observed, although VIP expression remained unchanged. These findings demonstrate that acute T. gondii infection induces substantial alterations in intestinal structure, including immune cell infiltration, goblet cell depletion, and muscle layer remodelling. The reduction in myenteric neurons, despite stable VIP expression, suggests specific neuroimmune interactions in the infected gut. Collectively, this study highlights the profound impact of <em>T. gondii</em> on colonic morphology and function, underscoring the complexity of host–parasite interactions during acute infection.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"276 ","pages":"Article 109007"},"PeriodicalIF":1.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144920262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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