Pub Date : 2026-08-01Epub Date: 2026-02-05DOI: 10.1016/j.parint.2026.103248
Isabella Pereira Pesenato , Ricardo Bassini-Silva , Ana Cláudia Calchi , Sueli Akemi Taniwaki Miyagi , Ester Nascimento da Costa , Carlos Cezar Trigo Nasser-Felix , Glauber Meneses Barboza de Oliveira , Mauricio Claudio Horta , Gabriela Cousandier , Jonas Sponchiado , Ralph Maturano , Graziela Virginia Tolesano-Pascoli , Renata D. Alquezar , Camile Lugarini , Ariane Ferreira , Luciano Moreira-Lima , Erika Hingst-Zaher , Josivania Soares Pereira , Darci Moraes Barros-Battesti , Marcelo B. Labruna , Fernando de Castro Jacinavicius
The expansion of land use in Brazil has caused biodiversity loss and increased human interaction with parasites and pathogens previously restricted to natural ecosystems. Chigger mites are ectoparasites during the larval stage and can cause skin reactions or transmit pathogens to their hosts, including humans. This study aimed to evaluate the diversity of chiggers collected from all five Brazilian biogeographical regions, along with pathogen surveillance. Specimens were subjected to both morphological taxonomy and endogenous control, followed by PCR assays targeting pathogens of the genera Borrelia, Orientia, and Rickettsia. The analyses revealed a high species richness, including two novel records in Brazil: the genus Boshkerria and the species Quadraseta antillarum. Additionally, the genus Quadraseta tested positive for Rickettsia sp., while tests for the other agents were negative. This is the first report of a Rickettsia sp. agent detected in a Quadraseta nymph.
{"title":"Diversity and pathogen surveillance in chigger mites across Brazil's five biogeographic regions","authors":"Isabella Pereira Pesenato , Ricardo Bassini-Silva , Ana Cláudia Calchi , Sueli Akemi Taniwaki Miyagi , Ester Nascimento da Costa , Carlos Cezar Trigo Nasser-Felix , Glauber Meneses Barboza de Oliveira , Mauricio Claudio Horta , Gabriela Cousandier , Jonas Sponchiado , Ralph Maturano , Graziela Virginia Tolesano-Pascoli , Renata D. Alquezar , Camile Lugarini , Ariane Ferreira , Luciano Moreira-Lima , Erika Hingst-Zaher , Josivania Soares Pereira , Darci Moraes Barros-Battesti , Marcelo B. Labruna , Fernando de Castro Jacinavicius","doi":"10.1016/j.parint.2026.103248","DOIUrl":"10.1016/j.parint.2026.103248","url":null,"abstract":"<div><div>The expansion of land use in Brazil has caused biodiversity loss and increased human interaction with parasites and pathogens previously restricted to natural ecosystems. Chigger mites are ectoparasites during the larval stage and can cause skin reactions or transmit pathogens to their hosts, including humans. This study aimed to evaluate the diversity of chiggers collected from all five Brazilian biogeographical regions, along with pathogen surveillance. Specimens were subjected to both morphological taxonomy and endogenous control, followed by PCR assays targeting pathogens of the genera <em>Borrelia</em>, <em>Orientia</em>, and <em>Rickettsia</em>. The analyses revealed a high species richness, including two novel records in Brazil: the genus <em>Boshkerria</em> and the species <em>Quadraseta antillarum</em>. Additionally, the genus <em>Quadraseta</em> tested positive for <em>Rickettsia</em> sp., while tests for the other agents were negative. This is the first report of a <em>Rickettsia</em> sp. agent detected in a <em>Quadraseta</em> nymph.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"113 ","pages":"Article 103248"},"PeriodicalIF":1.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146137771","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 : 2026-08-01Epub Date: 2026-01-12DOI: 10.1016/j.parint.2026.103231
Cemal Çiçek , Elif Tuğçe Güner , Rasime Pelin Kavak , Ayfer Bakır , Murat Aral
Hydatid disease (HD) is a zoonotic parasitic infection caused by the larval stage of Echinococcus granulosus. It remains a major public health issue in many countries, including Türkiye. Diagnosis relies on clinical findings, serological tests, and radiological methods. This study aimed to investigate the relationship between the indirect hemagglutination (IHA) test and radiological imaging in suspected HD cases. In this retrospective study, patients with suspected HD between July 2023 and June 2024 were included. Serum samples were tested using the IHA method, and ultrasonography (US), computed tomography (CT), or magnetic resonance imaging (MRI) was performed within 15 days for seropositive patients. The association between IHA titers and cyst size, localization, and the number of affected organs was analyzed. The study included 1289 cases, and seropositivity was detected in 147 (11.4%) of these cases. Seropositivity was higher in men (12.3%) than in women (10.7%). The majority of cases were in the 41–60 age group (43.5%). US was the most frequently used radiological imaging method, and the most common cyst location was the liver (91.95%). Although descriptive differences in cyst diameters were observed across different IHA titer levels, no statistically significant correlation was identified. These results indicate that IHA titers do not reliably reflect cyst size, disease extent, or radiological severity. Therefore, serological findings should not be interpreted as indicators of disease burden and must be evaluated strictly in conjunction with radiological imaging in the diagnosis, staging, and follow-up of hydatid disease.
{"title":"Correlation between serological tests and radiological imaging in the diagnosis of hydatid disease","authors":"Cemal Çiçek , Elif Tuğçe Güner , Rasime Pelin Kavak , Ayfer Bakır , Murat Aral","doi":"10.1016/j.parint.2026.103231","DOIUrl":"10.1016/j.parint.2026.103231","url":null,"abstract":"<div><div>Hydatid disease (HD) is a zoonotic parasitic infection caused by the larval stage of <em>Echinococcus granulosus</em>. It remains a major public health issue in many countries, including Türkiye. Diagnosis relies on clinical findings, serological tests, and radiological methods. This study aimed to investigate the relationship between the indirect hemagglutination (IHA) test and radiological imaging in suspected HD cases. In this retrospective study, patients with suspected HD between July 2023 and June 2024 were included. Serum samples were tested using the IHA method, and ultrasonography (US), computed tomography (CT), or magnetic resonance imaging (MRI) was performed within 15 days for seropositive patients. The association between IHA titers and cyst size, localization, and the number of affected organs was analyzed. The study included 1289 cases, and seropositivity was detected in 147 (11.4%) of these cases. Seropositivity was higher in men (12.3%) than in women (10.7%). The majority of cases were in the 41–60 age group (43.5%). US was the most frequently used radiological imaging method, and the most common cyst location was the liver (91.95%). Although descriptive differences in cyst diameters were observed across different IHA titer levels, no statistically significant correlation was identified. These results indicate that IHA titers do not reliably reflect cyst size, disease extent, or radiological severity. Therefore, serological findings should not be interpreted as indicators of disease burden and must be evaluated strictly in conjunction with radiological imaging in the diagnosis, staging, and follow-up of hydatid disease.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"113 ","pages":"Article 103231"},"PeriodicalIF":1.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145957774","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}
Mosquitoes have been claimed as the deadliest animals around the globe that cause severe fatal diseases and affect millions of people worldwide. Nowadays, it is well-understood that plant-based products can be used as alternatives to the synthetic insecticides to control a wide range of vectors and pests. The plant derived essential oils, the subject of considerable research and these natural bioactive compounds may replace synthetic insecticides in the consumer markets. Therefore, to enhance the larvicidal toxicity of essential oils, the combined bioassay of leaves and peels essential oils of Citrus limetta, C. limon and C. reticulata were evaluated by using WHO protocol. The findings of present study revealed that all the combinations demonstrated the synergistic effect with combined factor ranging from 1.02 to 1.34 and increased lethal values ranging from 2.09 to 33.90% against both the target species. The highest combined bioefficacy was achieved by CMLEO–CMPEO (1:1) with lowest LC50 values, 12.18 and 21.85 ppm against Anopheles stephensi and Culex quinquefasciatus, respectively after 24 h of exposure. Hence, these different combinations of Citrus essential oils were proved as more toxic and have great capability for the development of a botanical insecticidal formulation to combat the mosquitoes' populations.
{"title":"Assessment of co-toxicity and synergistic action mechanism of essential oils derived from Citrus plants against Anopheles stephensi and Culex quinquefasciatus","authors":"Shivani Sharma, Shweta Gupta, Mahima Chaudhary, Neha Loach, Lalit Mohan","doi":"10.1016/j.parint.2026.103241","DOIUrl":"10.1016/j.parint.2026.103241","url":null,"abstract":"<div><div>Mosquitoes have been claimed as the deadliest animals around the globe that cause severe fatal diseases and affect millions of people worldwide. Nowadays, it is well-understood that plant-based products can be used as alternatives to the synthetic insecticides to control a wide range of vectors and pests. The plant derived essential oils, the subject of considerable research and these natural bioactive compounds may replace synthetic insecticides in the consumer markets. Therefore, to enhance the larvicidal toxicity of essential oils, the combined bioassay of leaves and peels essential oils of <em>Citrus limetta</em>, <em>C. limon</em> and <em>C. reticulata</em> were evaluated by using WHO protocol. The findings of present study revealed that all the combinations demonstrated the synergistic effect with combined factor ranging from 1.02 to 1.34 and increased lethal values ranging from 2.09 to 33.90% against both the target species. The highest combined bioefficacy was achieved by CMLEO–CMPEO (1:1) with lowest LC<sub>50</sub> values, 12.18 and 21.85 ppm against <em>Anopheles stephensi</em> and <em>Culex quinquefasciatus</em>, respectively after 24 h of exposure. Hence, these different combinations of <em>Citrus</em> essential oils were proved as more toxic and have great capability for the development of a botanical insecticidal formulation to combat the mosquitoes' populations.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"113 ","pages":"Article 103241"},"PeriodicalIF":1.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146046650","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 : 2026-08-01Epub Date: 2026-02-01DOI: 10.1016/j.parint.2026.103246
Débora Maria Soares de Souza , Maria Bárbara Galdino-Silva , Karine Maria Moreira Almeida , Maria Cláudia Silva , João Santana Silva , André Talvani
Chagasic cardiomyopathy, caused by Trypanosoma cruzi, is influenced by host-parasite genetics and environmental factors such as diet. High-fat diets can intensify inflammation via pathways involving IRAK-1 and PPARs (α/γ). This study examined the impact of monounsaturated (olive oil) and saturated (lard) fat-rich diets on the expression of IRAK-1, PPAR-α, and PPAR-γ in cardiac and adipose tissues of mice infected with the Colombian strain of T. cruzi. Mice received control, olive oil, or lard diets during the experiment, and the infection was evaluated for 30 or 100 days. Infection increased IRAK-1 expression in both tissues at 30 dpi and a cardiac reduction at 100 dpi. PPAR-α and PPAR-γ were suppressed at both time points, while PPARs were decreased in the presence of T. cruzi. In infected mice, fat-rich diets further decreased PPAR-α in cardiac tissue, while olive oil upregulated PPAR-γ in cardiac tissue (30 dpi), and lard did so with both PPARs in adipose tissues (100 dpi). These results highlight the phase-specific and fat-type-specific modulation of inflammatory pathways by lipid diets, underlining the potential role of nutrition in Chagas disease progression.
{"title":"Dietary regulation of peroxisome proliferator-activated receptors (α and γ) and IL-1R-associated kinase proteins in experimental Trypanosoma cruzi infection: Insights into one health","authors":"Débora Maria Soares de Souza , Maria Bárbara Galdino-Silva , Karine Maria Moreira Almeida , Maria Cláudia Silva , João Santana Silva , André Talvani","doi":"10.1016/j.parint.2026.103246","DOIUrl":"10.1016/j.parint.2026.103246","url":null,"abstract":"<div><div>Chagasic cardiomyopathy, caused by <em>Trypanosoma cruzi</em>, is influenced by host-parasite genetics and environmental factors such as diet. High-fat diets can intensify inflammation via pathways involving IRAK-1 and PPARs (α/γ). This study examined the impact of monounsaturated (olive oil) and saturated (lard) fat-rich diets on the expression of <em>IRAK-1</em>, <em>PPAR-α</em>, and <em>PPAR-γ</em> in cardiac and adipose tissues of mice infected with the Colombian strain of <em>T. cruzi</em>. Mice received control, olive oil, or lard diets during the experiment, and the infection was evaluated for 30 or 100 days. Infection increased <em>IRAK-1</em> expression in both tissues at 30 dpi and a cardiac reduction at 100 dpi. <em>PPAR-α</em> and <em>PPAR-γ</em> were suppressed at both time points, while PPARs were decreased in the presence of <em>T. cruzi</em>. In infected mice, fat-rich diets further decreased <em>PPAR-α</em> in cardiac tissue, while olive oil upregulated <em>PPAR-γ</em> in cardiac tissue (30 dpi), and lard did so with both PPARs in adipose tissues (100 dpi). These results highlight the phase-specific and fat-type-specific modulation of inflammatory pathways by lipid diets, underlining the potential role of nutrition in Chagas disease progression.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"113 ","pages":"Article 103246"},"PeriodicalIF":1.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146113673","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}
Anisakis occasionally parasitizes extra-gastrointestinal organs, including the liver, pancreas, and ovary. We herein report a case of hepatic anisakiasis in which the route of hepatic invasion by Anisakis was histologically confirmed. A 50-year-old Japanese man with a history of left testicular seminoma underwent follow-up contrast-enhanced dynamic computed tomography, which revealed a liver mass suspicious for metastasis. The scan showed a low-attenuation area near the liver surface in segment 7. Laparoscopic partial hepatectomy was performed for diagnosis and treatment. Histologically, the mass showed necrosis and inflammatory infiltration, mainly by lymphocytes and neutrophils, with a parasite observed within the lesion. The parasite exhibited characteristic features—bifurcated Y-shaped lateral cords and a prominent renette cell—diagnostic of Anisakis larvae. A continuous linear band of granulation tissue connecting the liver surface to the lesion suggested the route of invasion. Retrospective imaging review confirmed that the hypodense linear band extending from the liver surface to the mass represented the direct invasion pathway. This case provides clear evidence of the hepatic invasion route in anisakiasis. Although rarely encountered, recognition of this feature may help distinguish hepatic anisakiasis from malignant liver tumors.
{"title":"Histopathological evidence of direct hepatic invasion by Anisakis from the liver surface: A case report","authors":"Hiroki Takahashi , Reina Miyazawa , Mai Iwaya , Megumi Nobuoka , Tsuyoshi Terashima , Tsuyoshi Notake , Akira Shimizu , Yuji Soejima , Takeshi Uehara","doi":"10.1016/j.parint.2026.103244","DOIUrl":"10.1016/j.parint.2026.103244","url":null,"abstract":"<div><div><em>Anisakis</em> occasionally parasitizes extra-gastrointestinal organs, including the liver, pancreas, and ovary. We herein report a case of hepatic anisakiasis in which the route of hepatic invasion by <em>Anisakis</em> was histologically confirmed. A 50-year-old Japanese man with a history of left testicular seminoma underwent follow-up contrast-enhanced dynamic computed tomography, which revealed a liver mass suspicious for metastasis. The scan showed a low-attenuation area near the liver surface in segment 7. Laparoscopic partial hepatectomy was performed for diagnosis and treatment. Histologically, the mass showed necrosis and inflammatory infiltration, mainly by lymphocytes and neutrophils, with a parasite observed within the lesion. The parasite exhibited characteristic features—bifurcated Y-shaped lateral cords and a prominent renette cell—diagnostic of <em>Anisakis</em> larvae. A continuous linear band of granulation tissue connecting the liver surface to the lesion suggested the route of invasion. Retrospective imaging review confirmed that the hypodense linear band extending from the liver surface to the mass represented the direct invasion pathway. This case provides clear evidence of the hepatic invasion route in anisakiasis. Although rarely encountered, recognition of this feature may help distinguish hepatic anisakiasis from malignant liver tumors.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"113 ","pages":"Article 103244"},"PeriodicalIF":1.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146019226","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 : 2026-08-01Epub Date: 2026-01-14DOI: 10.1016/j.parint.2026.103242
Ana Paula Peres Lopes Romariz , Diogo Tiago da Silva , Julia Cristina Benassi , João Augusto Franco Leonel , Julio Cesar Pereira Spada , Carla Monadeli Filgueira Rodrigues , Herakles Antonio Garcia Pérez , Nathalia Frigo de Almeida Paula , Marta Maria Geraldes Teixeira , Trícia Maria Ferreira de Sousa Oliveira , Wilma Aparecida Starcke Buzetti
Trypanosomatids are protozoan parasites that include the genera Trypanosoma and Leishmania, which infect a wide range of mammalian species, including humans and ruminants. This study aimed to assess the presence of Trypanosomatid parasites in water buffaloes (Bubalus bubalis) using molecular techniques. Blood samples and conjunctival swabs from the right and left eyes were collected from 100 buffaloes (44 females and 56 males). PCR analysis detected Trypanosomatids in 32% (32/100) of the buffaloes: 29% (29/100) tested positive for DNA extracted from blood, and 4% (4/100) tested positive from conjunctival swab samples. Using the Fluorescent Fragment Length Barcoding (FFLB) technique, 38% (38/100) of blood samples were positive for Trypanosomatids, with 35% (35/100) identified as Trypanosoma theileri and 3% (3/100) as Trypanosoma vivax. Direct sequencing and analysis of PCR amplicons from four buffaloes revealed that three samples matched 100% with Trypanosoma theileri, while one matched 100% with Leishmania infantum. Our findings confirm that buffaloes can serve as hosts for Trypanosomatids and support previous observations that these parasites are often underdiagnosed. This is the first report of Leishmania infantum DNA in buffalo conjunctival swabs in Brazil and the first detection of Trypanosoma vivax DNA in buffaloes in the city of Andradina and in São Paulo state. These findings underscore the need for further studies to clarify the role of buffaloes in the epidemiology and dissemination of trypanosomatids in livestock populations.
{"title":"Water buffaloes (Bubalus bubalis): potential reservoirs of trypanosomatids in endemic areas","authors":"Ana Paula Peres Lopes Romariz , Diogo Tiago da Silva , Julia Cristina Benassi , João Augusto Franco Leonel , Julio Cesar Pereira Spada , Carla Monadeli Filgueira Rodrigues , Herakles Antonio Garcia Pérez , Nathalia Frigo de Almeida Paula , Marta Maria Geraldes Teixeira , Trícia Maria Ferreira de Sousa Oliveira , Wilma Aparecida Starcke Buzetti","doi":"10.1016/j.parint.2026.103242","DOIUrl":"10.1016/j.parint.2026.103242","url":null,"abstract":"<div><div>Trypanosomatids are protozoan parasites that include the genera <em>Trypanosoma</em> and <em>Leishmania,</em> which infect a wide range of mammalian species, including humans and ruminants. This study aimed to assess the presence of Trypanosomatid parasites in water buffaloes (<em>Bubalus bubalis</em>) using molecular techniques. Blood samples and conjunctival swabs from the right and left eyes were collected from 100 buffaloes (44 females and 56 males). PCR analysis detected Trypanosomatids in 32% (32/100) of the buffaloes: 29% (29/100) tested positive for DNA extracted from blood, and 4% (4/100) tested positive from conjunctival swab samples. Using the Fluorescent Fragment Length Barcoding (FFLB) technique, 38% (38/100) of blood samples were positive for Trypanosomatids, with 35% (35/100) identified as <em>Trypanosoma theileri</em> and 3% (3/100) as <em>Trypanosoma vivax</em>. Direct sequencing and analysis of PCR amplicons from four buffaloes revealed that three samples matched 100% with <em>Trypanosoma theileri</em>, while one matched 100% with <em>Leishmania infantum</em>. Our findings confirm that buffaloes can serve as hosts for Trypanosomatids and support previous observations that these parasites are often underdiagnosed. This is the first report of <em>Leishmania infantum</em> DNA in buffalo conjunctival swabs in Brazil and the first detection of <em>Trypanosoma vivax</em> DNA in buffaloes in the city of Andradina and in São Paulo state. These findings underscore the need for further studies to clarify the role of buffaloes in the epidemiology and dissemination of trypanosomatids in livestock populations.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"113 ","pages":"Article 103242"},"PeriodicalIF":1.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145990250","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 : 2026-08-01Epub Date: 2026-01-14DOI: 10.1016/j.parint.2026.103243
Nguyen Thi Thu Hang , Vo Quang Vinh , Nguyen Dac Dai , Nguyen Thi Quynh , Nguyen Manh Hung , Nguyen Thi Hong Nhung , Sho Shirakashi , Nguyen Ngoc Chinh
During a survey of myxosporean parasites infecting freshwater fishes in the Mekong River Delta, Vietnam, myxospores of the genus Henneguya were discovered in the gills of the giant gourami Osphronemus goramy Lacepède (Anabantiformes: Osphronemidae). White, spherical plasmodia were found within the gill lamellae of 10 out of 25 examined fish (40% prevalence) and measured 650–950 μm in diameter. Mature myxospores are elongate with two equal caudal appendages, and measure 68.5 ± 3.4 (64.8–79.4) μm in total length. The spore body measures 16.3 ± 0.9 (15.0–18.1) μm in length, 5.6 ± 0.3 (5.1–6.0) μm in width, and 4.8 ± 0.2 (4.5–5.0) μm in thickness. Each caudal appendage is 51.6 ± 3.3 (46.5–58.9) μm in length. The spore wall is smooth, and two equal ovoid nematocysts, each 6.1 ± 0.3 (5.6–6.6) μm long and 1.6 ± 0.2 (1.3–1.8) μm wide, are located anteriorly. Histological sections revealed no inflammatory response but showed local deformation of the gill lamellae at infection sites. Phylogenetic analysis of the SSU rDNA sequences placed this species in a distinct clade closely related to Myxobolus neurophilus, Myxobolus pharyngeus, and Henneguya voronini. Based on morphological and molecular evidence, the parasite is described herein as a new species, Henneguya luci n. sp.
{"title":"A new species of the genus Henneguya Thélohan, 1892 (Myxozoa: Myxobolidae) parasitizing the gill lamellae of the giant gourami Osphronemus goramy Lacepède (Anabantiformes: Osphronemidae) from the Mekong River Delta, Vietnam","authors":"Nguyen Thi Thu Hang , Vo Quang Vinh , Nguyen Dac Dai , Nguyen Thi Quynh , Nguyen Manh Hung , Nguyen Thi Hong Nhung , Sho Shirakashi , Nguyen Ngoc Chinh","doi":"10.1016/j.parint.2026.103243","DOIUrl":"10.1016/j.parint.2026.103243","url":null,"abstract":"<div><div>During a survey of myxosporean parasites infecting freshwater fishes in the Mekong River Delta, Vietnam, myxospores of the genus <em>Henneguya</em> were discovered in the gills of the giant gourami <em>Osphronemus goramy</em> Lacepède (Anabantiformes: Osphronemidae). White, spherical plasmodia were found within the gill lamellae of 10 out of 25 examined fish (40% prevalence) and measured 650–950 μm in diameter. Mature myxospores are elongate with two equal caudal appendages, and measure 68.5 ± 3.4 (64.8–79.4) μm in total length. The spore body measures 16.3 ± 0.9 (15.0–18.1) μm in length, 5.6 ± 0.3 (5.1–6.0) μm in width, and 4.8 ± 0.2 (4.5–5.0) μm in thickness. Each caudal appendage is 51.6 ± 3.3 (46.5–58.9) μm in length. The spore wall is smooth, and two equal ovoid nematocysts, each 6.1 ± 0.3 (5.6–6.6) μm long and 1.6 ± 0.2 (1.3–1.8) μm wide, are located anteriorly. Histological sections revealed no inflammatory response but showed local deformation of the gill lamellae at infection sites. Phylogenetic analysis of the SSU rDNA sequences placed this species in a distinct clade closely related to <em>Myxobolus neurophilus</em>, <em>Myxobolus pharyngeus</em>, and <em>Henneguya voronini</em>. Based on morphological and molecular evidence, the parasite is described herein as a new species, <em>Henneguya luci</em> n. sp.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"113 ","pages":"Article 103243"},"PeriodicalIF":1.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145990300","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 : 2026-06-01Epub Date: 2025-12-03DOI: 10.1016/j.parint.2025.103204
Judith V. Bentancourt Rossoli , Lucía María Campero , Gastón Moré , Agustina Soto-Cabrera , Dadín P. Moore , Eleonora L. Morrell , María V. Scioli , Walter Basso , Yanina P. Hecker , Nathalia P. Scioscia
Rodents serve as reservoir hosts for many parasites, including the closely related intracellular protozoan parasites Toxoplasma gondii and Neospora caninum, which are regarded as major causes of abortion in ruminants. This study investigated T. gondii and N. caninum infections in synanthropic (Muridae) and wild (Cricetidae) rodents from rural areas in the Pampas Region, Argentina, using histological, serological, and molecular methods. We also genetically characterized T. gondii isolates. A total of 356 rodents were captured, comprising both murid (Mus musculus, Rattus norvegicus, R. rattus) and cricetid (Oxymycterus rufus, Necromys spp., Akodon azarae, Oligoryzomys flavescens, Calomys musculinus, C. laucha) species. Histological examination did not reveal tissue cysts of these parasites. However, antibodies for T. gondii and N. caninum were detected in 9.8 % (35/356) and 1.7 % (6/356) of the samples using the indirect immunofluorescent antibody test (IFAT). T. gondii DNA was detected by qPCR in brain samples from two of the 41 seropositive rodents. Multilocus PCR-RFLP revealed atypical T. gondii genotypes in both samples. N. caninum DNA was not detected by PCR in any sample. This study provides the first serological and molecular evidence of T. gondii and N. caninum in Cricetidae rodents from Argentina, including the first genotyping data. The detection of T. gondii DNA exclusively in wild rodents highlights the role of wildlife in parasite transmission.
{"title":"Toxoplasma gondii and Neospora caninum in naturally infected synanthropic (Muridae) and wild (Cricetidae) rodents from Argentina","authors":"Judith V. Bentancourt Rossoli , Lucía María Campero , Gastón Moré , Agustina Soto-Cabrera , Dadín P. Moore , Eleonora L. Morrell , María V. Scioli , Walter Basso , Yanina P. Hecker , Nathalia P. Scioscia","doi":"10.1016/j.parint.2025.103204","DOIUrl":"10.1016/j.parint.2025.103204","url":null,"abstract":"<div><div>Rodents serve as reservoir hosts for many parasites, including the closely related intracellular protozoan parasites <em>Toxoplasma gondii</em> and <em>Neospora caninum,</em> which are regarded as major causes of abortion in ruminants. This study investigated <em>T. gondii</em> and <em>N. caninum</em> infections in synanthropic (Muridae) and wild (Cricetidae) rodents from rural areas in the Pampas Region, Argentina, using histological, serological, and molecular methods. We also genetically characterized <em>T. gondii</em> isolates. A total of 356 rodents were captured, comprising both murid (<em>Mus musculus, Rattus norvegicus, R. rattus</em>) and cricetid (<em>Oxymycterus rufus, Necromys</em> spp., <em>Akodon azarae, Oligoryzomys flavescens, Calomys musculinus, C. laucha</em>) species. Histological examination did not reveal tissue cysts of these parasites. However, antibodies for <em>T. gondii</em> and <em>N. caninum</em> were detected in 9.8 % (35/356) and 1.7 % (6/356) of the samples using the indirect immunofluorescent antibody test (IFAT). <em>T. gondii</em> DNA was detected by qPCR in brain samples from two of the 41 seropositive rodents. Multilocus PCR-RFLP revealed atypical <em>T. gondii</em> genotypes in both samples. <em>N. caninum</em> DNA was not detected by PCR in any sample. This study provides the first serological and molecular evidence of <em>T. gondii</em> and <em>N. caninum</em> in Cricetidae rodents from Argentina, including the first genotyping data. The detection of <em>T. gondii</em> DNA exclusively in wild rodents highlights the role of wildlife in parasite transmission.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"112 ","pages":"Article 103204"},"PeriodicalIF":1.9,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145687849","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}
Toxoplasmosis, a parasitic infection caused by Toxoplasma gondii, is widely distributed worldwide. Although it generally remains asymptomatic in immunocompetent individuals, it can lead to severe complications in immunocompromised patients, particularly those infected with HIV. These individuals are at increased risk of developing encephalitis, primarily due to the reactivation of a latent infection. Genotyping of T. gondii in humans is an essential tool for studying the epidemiology of this parasitosis. Previous studies have identified three main archetypal (classical) lineages or genotypes: type I, II, and III, as well as strains that show distinct and broader genetic variations.
In this study, we report for the first time in Algeria the isolation and genetic characterization of the Africa 4 lineage of Toxoplasma gondii using microsatellites genotyping in an HIV-positive patient. This recently described clonal lineage in animal and human highlights the genetic diversity of T. gondii. This work underscores the need for studies to explore the prevalence and distribution of genotypes in the Maghreb region.
{"title":"First identification of the Africa 4 genotype of toxoplasma gondii in Algeria: Investigation of its origin and rarity","authors":"Nabil Mohamdi , Sihem Benaissa , Anis Benyahia , Karine Passebosc-Faure , Hélène Yéra , Gilles Gargala , Damien Costa , Loic Favennec","doi":"10.1016/j.parint.2025.103212","DOIUrl":"10.1016/j.parint.2025.103212","url":null,"abstract":"<div><div>Toxoplasmosis, a parasitic infection caused by <em>Toxoplasma gondii</em>, is widely distributed worldwide. Although it generally remains asymptomatic in immunocompetent individuals, it can lead to severe complications in immunocompromised patients, particularly those infected with HIV. These individuals are at increased risk of developing encephalitis, primarily due to the reactivation of a latent infection. Genotyping of <em>T. gondii</em> in humans is an essential tool for studying the epidemiology of this parasitosis. Previous studies have identified three main archetypal (classical) lineages or genotypes: type I, II, and III, as well as strains that show distinct and broader genetic variations.</div><div>In this study, we report for the first time in Algeria the isolation and genetic characterization of the Africa 4 lineage of <em>Toxoplasma gondii</em> using microsatellites genotyping in an HIV-positive patient. This recently described clonal lineage in animal and human highlights the genetic diversity of <em>T. gondii</em>. This work underscores the need for studies to explore the prevalence and distribution of genotypes in the Maghreb region.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"112 ","pages":"Article 103212"},"PeriodicalIF":1.9,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145701441","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 : 2026-06-01Epub Date: 2026-01-08DOI: 10.1016/j.parint.2026.103233
Kaito Seki , Ryota Kawanishi , Atsushi Sogabe
The ability to recognize and successfully infest an appropriate host during its early life is under strong natural selection in parasitic organisms, as it directly affects the parasite's fitness. Although many cymothoid isopods that parasitize fishes exhibit high host specificity at the species level, it remains unclear whether the manca (i.e., infective early-life stage) can actively recognize and selectively infest an appropriate host species. We conducted controlled aquarium experiments in which mancae were simultaneously presented with their primary host and a non-primary host species to assess host-selection behavior in the cymothoid isopod Mothocya parvostis, a gill-dwelling species that primarily parasitizes the Japanese halfbeak Hyporhamphus sajori but has also been found at immature stages on several non-primary host fishes. When given a choice between the primary host H. sajori and the non-primary host blackhead seabream Acanthopagrus schlegelii, M. parvostis mancae infested H. sajori significantly more often. When presented with H. sajori and another non-primary host, the largescale blackfish Girella punctata, all infestations occurred exclusively on H. sajori. In contrast, when the two offered host species were non-primary, manca infestation was rare and showed no clear preference between the two fishes. Notably, predation on mancae by non-primary host fishes occurred in a substantial number of trials, whereas no predation by the primary host H. sajori was observed. These findings demonstrate strong host specificity in mancae of M. parvostis toward H. sajori, suggesting that host choice occurs at this early life stage, which likely contributes to enhancing the infestation efficiency.
{"title":"Host preference of an obligate fish parasitic isopod, Mothocya parvostis","authors":"Kaito Seki , Ryota Kawanishi , Atsushi Sogabe","doi":"10.1016/j.parint.2026.103233","DOIUrl":"10.1016/j.parint.2026.103233","url":null,"abstract":"<div><div>The ability to recognize and successfully infest an appropriate host during its early life is under strong natural selection in parasitic organisms, as it directly affects the parasite's fitness. Although many cymothoid isopods that parasitize fishes exhibit high host specificity at the species level, it remains unclear whether the manca (i.e., infective early-life stage) can actively recognize and selectively infest an appropriate host species. We conducted controlled aquarium experiments in which mancae were simultaneously presented with their primary host and a non-primary host species to assess host-selection behavior in the cymothoid isopod <em>Mothocya parvostis</em>, a gill-dwelling species that primarily parasitizes the Japanese halfbeak <em>Hyporhamphus sajori</em> but has also been found at immature stages on several non-primary host fishes. When given a choice between the primary host <em>H. sajori</em> and the non-primary host blackhead seabream <em>Acanthopagrus schlegelii</em>, <em>M. parvostis</em> mancae infested <em>H. sajori</em> significantly more often. When presented with <em>H. sajori</em> and another non-primary host, the largescale blackfish <em>Girella punctata</em>, all infestations occurred exclusively on <em>H. sajori</em>. In contrast, when the two offered host species were non-primary, manca infestation was rare and showed no clear preference between the two fishes. Notably, predation on mancae by non-primary host fishes occurred in a substantial number of trials, whereas no predation by the primary host <em>H. sajori</em> was observed. These findings demonstrate strong host specificity in mancae of <em>M. parvostis</em> toward <em>H. sajori</em>, suggesting that host choice occurs at this early life stage, which likely contributes to enhancing the infestation efficiency.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"112 ","pages":"Article 103233"},"PeriodicalIF":1.9,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145948874","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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