The morphology of attachment organs in Monogenea is an essential source of evidence for taxonomic assessments and understanding of ecology and evolutionary history. It has been demonstrated that geometric morphometry analysis of the haptoral attachment organs provides rich and precise information about monogeneans morphology. In this study, we consider three monogenean species of Urocleidoides, U. simonae, U. vaginoclaustrum, U. vaginoclaustroides, and the incertae sedis species U. strombicirrus that parasitize fish of the Poeciliidae, Profundulidae and Characidae in neotropical rivers in southern Mexico. We aimed to identify new morphological characteristics that can be used to describe these populations with greater certainty and to test whether these characteristics present geographic variation. Anchor shape data (n = 69) were generated using geometric morphometric methods. We discriminated species using principal components and canonical variate analysis of shape data. Our results showed that there was discernible interspecific variation. The four species contributed four new morphological characteristics: anchor point length, short versus long anchor roots, elongated versus wide anchor shape, and the relative length of inner versus outer roots. Intraspecific variation was relatively low compared to interspecific anchor shape variation in Urocleidoides spp. These new morphological characteristics may also be useful for delimiting other similar species in Monogenea.

Chagas disease (CD), or American trypanosomiasis, is a parasitic disease caused by Trypanosoma cruzi, primarily transmitted by triatomine bugs. Increased travels and migrations introduced CD to non-endemic regions, including Europe. In Italy, the disease has raised public attention mainly in northern regions, where Latin American migrant population is larger. This study aims to describe a CD screening initiative in Turin, Piedmont, during the World Chagas disease Day. We focused on migrants from CD endemic countries of Latin America.

Fascioliasis is a globally distributed zoonotic parasitic disease that affects ruminants, including sheep. This study conducted from January to December 2023, aimed to determine the prevalence of Fasciola hepatica in sheep across three governorates in Egypt's Nile Delta and to assess associated risk factors. A total of 455 serum samples were analyzed using a commercial ELISA kit, revealing antibodies against F. hepatica in 22.2 % of the tested sheep. There was no significant association between locality or sex and the seroprevalence of F. hepatica in sheep; however, the highest prevalence was observed in Kafr ElSheikh and in female sheep. Concerning risk factors, poor conditioned sheep aged between 1 and 2 years showed 2.1 and 3.8 times higher of infection probability than others. In addition, the risk of F. hepatica infection in sheep increased significantly in winter season (OR = 6.6, 95 %CI: 2.6-16.8), in absence of prophylactic treatment (OR = 2.2, 95 %CI: 1.3-3.3) and in presence of snail (OR = 3, 95 %CI: 3-5.4). The existence of antibodies against F. hepatica in examined sheep raising in Nile Delta indicating that the disease is reported in the studied areas and needs to be managed on farms through control and preventative measures.

Enterocytozoon bieneusi belongs to the phylum Microsporidia, a parasite reported to infect various domestic animals, wildlife and humans, thereby causing an intestinal disease characterized by severe or chronic diarrhea and malabsorption. The typical mode of transmission is contaminated water and food. Few studies on E. bieneusi infections have been reported in reptiles, however, our report focuses on the molecular characterization of E. bieneusi infection in snakes in China. We collected a total of 603 fecal samples from snakes in China. The samples were tested for the presence of E. bieneusi through PCR amplification of the internal transcribed spacer (ITS) locus. Our analysis showed E. bieneusi overall prevalence rate of 15.59 %, the highest prevalence was recorded in Eastern rat snake (21.99 %), followed by Corn snake (19.63 %) while the prevalence of 18.39 %, 15.79 %, 13.56 % were recorded in Common garter snake, Pine snake, Hognose snake respectively. Eastern kingsnake has the lowest infection rate of 5.71 %. Genotype analysis identified 26 distinct genotypes: 8 known and 18 novel. Phylogenetic analysis revealed that 25 genotypes belonged to Group 1, which includes isolates from various animal hosts and humans. However, genotype GX29 was classified under Group 9. Our study indicates that pet snakes are one of the potential sources of transmission of zoonotic microsporidiosis in China.

Tick saliva modulates host responses during a blood feeding process. We identified a novel chemokine binding protein 1-like (HLCBP1-like) gene from the salivary glands of the Asian longhorned tick, Haemaphysalis longicornis. The HLCBP1-like protein, lacking a well-defined conserved domain, showed structural similarity to evasin, a chemokine binding protein from the brown dog tick, Rhipicephalus sanguineus. A preliminary knockdown study of HLCBP1-like revealed that ticks with reduced expression of this gene, halted feeding in the early feeding phase, and did not fully-engorge, unlike the control dsRNA (malE) injected ticks. Also, knockdown ticks induced cellular immune responses in the host skin, similar to control dsmalE-injected ticks, but did not show hemorrhage. These findings suggest that HLCBP1-like may play a modulatory role in the slow feeding phase.

In the mammalian hosts, Leishmania parasites survive and proliferate within phagolysosomes of macrophages. To avoid being killed by the immune cells, Leishmania parasites utilize their molecules to manipulate macrophages' functions for survival. Targets of such immunomodulatory molecules are not limited to macrophages, as Leishmania-derived molecules sometimes show influence on other immune cells such as neutrophils, dendritic cells, T cells and B cells. This review covers research on immunomodulation of host immunity by Leishmania parasites and introduces some examples of parasite-derived molecules participating in the immunomodulation. For example, Leishmania cell surface lipophosphoglycan (LPG) can modulate TLR2 signaling and PI3K/Akt axis in macrophages leading to induction of Th2 cells. Because chronic secretion of inflammatory cytokines is one of the causes of immune-mediated diseases such as atherosclerosis, Crohn's disease, and rheumatoid arthritis, LPG may be useful as a drug to suppress the inflammatory conditions. The unique characteristics of leishmanial molecules pose a promise as a source of immunomodulatory drugs for controlling diseases other than leishmaniasis.

Bears harbor various endoparasites that pose risks to humans and other animals. However, information on parasitic infections in Asiatic black bears in South Korea (Korea) is limited, and potential hazards still exist because of the close contact between bears and humans on bile farms. The present study was conducted to assess the gastrointestinal parasite infection status in captive Asiatic black bears (Ursus thibetanus) at bile farms in Korea. Additionally, we aimed to characterize the molecular aspects of Baylisascaris transfuga (Nematoda: Ascarididae), the sole species investigated throughout the study. Fecal examinations were performed on a total of 84 fecal samples collected from three bear farms in Hwacheon-gun (gun = County) and Donghae-si (si = City), Gangwon-do (do = Province), and Dangjin-si, Chungcheongnam-do. Eggs were identified morphologically, and an adult worm expelled in the feces was analyzed molecularly using the partial cytochrome c oxidase subunit 1 and 2 (cox1 and cox2) gene markers. The prevalence of helminthic eggs was 10.7 %, identified as B. transfuga based on morphological characteristics. The eggs, which were oval and brown with thick shells, had a mean length of 87.3 ± 8.9 μm on the long axis and 70.7 ± 6.1 μm on the short axis (n = 30). An adult female roundworm found in the feces of one individual, measuring 27 cm in length and 0.4 cm in width, was also identified as same species through genetic methods. Herein, we described the prevalence of B. transfuga in captive bears in Korea and its molecular characteristics for the first time. Additionally, we reviewed the sequences of the genus Baylisascaris available in the International Nucleotide Sequence Database Collection, noting that many of these sequences often have ambiguous or potentially incorrect identifications, complicating the understanding of their phylogenetic status. This investigation is part of disease screening efforts aimed at enhancing the welfare of captive bears prior to their imminent relocation to sanctuaries. Health monitoring and endoparasite control in farmed bears should be carried out in both veterinary and public health contexts.

One of the dense granule proteins named GRA15 in Toxoplasma gondii (T. gondii), is known to support an innate immune response in host through activation of NF-κB. However, little is known about advantages of GRA15 for parasites. By examining the role of GRA15 in the host-parasite interactions, it was clarified that GRA15 in T. gondii suppressed acquired immune responses in host. Wild-type parasite infection to C57BL/6 mice resulted in lower titers of T. gondii antibody and lower plasma cell counts compared to Δgra15 T. gondii. To identify host cells in which GRA15 acts to suppress antibody production, we generated conditional knock-in mice that express GRA15 in specific cell lineages. Anti-T. gondii antibodies were not reduced in macrophages of conditional knock-in mice after infection with Δgra15 T. gondii, while the production of T. gondii antibody was suppressed in dendritic cells of the conditional knock-in mice (CD11c-Cre/GRA15cKI). In the CD11c-Cre/GRA15cKI immunized with ovalbumin (OVA), the titers of anti-OVA antibody were reduced compared to control mice. Furthermore, the number of OVA antigen-specific T cells was also decreased in CD11c-Cre/GRA15cKI. These data showed that GRA15 in dendritic cells suppressed T cell-mediated humoral immunity. These findings might implicate the pathological significance of GRA15 and facilitate Toxoplasma vaccines production.

Schistosomiasis is a parasitic disease affecting more than 250 million people worldwide. Schistosomes infect humans by cercariae penetrating the skin in a freshwater environment. Findings obtained more than 100 years prior showed that miracidium develops into cercaria in freshwater snails, though detailed development dynamics have not been elucidated. Although results of histological analyses of development of schistosomes in snails were presented in our previous studies, findings obtained with dynamic imaging have yet to be reported. In the present study, imaging of schistosome infection and dynamics in snails occuring within a short period was performed using fluorescent labeling agents. Labeling of S. mansoni cercariae with carboxyfluorescein succinimidyl ester (CFSE) caused no toxicity, and allowed for monitoring of schistosome dynamics in snails for up to 10 days and release of infective cercariae without fluorescence in 40 days following infection.

The global prevalence of autoimmune diseases has surged in recent decades. Consequently, environmental triggers have emerged as crucial contributors to autoimmune diseases, equally relevant to classical risk factors, such as genetic polymorphisms, infections, and smoking. Sequencing-based approaches have demonstrated distinct gut microbiota compositions in individuals with autoimmune diseases, including multiple sclerosis, rheumatoid arthritis, type 1 diabetes mellitus (T1D), and systemic lupus erythematosus, compared to healthy controls. Furthermore, fecal microbiota transplantation and microbial inoculation experiments have supported the hypothesis that alterations in the gut microbiota can influence autoimmune responses and disease outcomes. Herein, we propose that intestinal helminths may serve as a critical factor in inducing alterations in the gut microbiota. The concept of helminth-mediated suppression of autoimmune diseases in humans is supported by substantial evidence, aligning with the long-standing "hygiene hypothesis." This review focused on T1D to explore the interactions between parasites, gut microbiota, and the immune system-a topic that remains a black box within this intricate triangular relationship.

We previously reported that Plasmodium yoelii 17XNL (Py), a non-lethal rodent malarial parasite, could suppress collagen-induced arthritis (CIA) and increase the production of T cell-derived interleukin (IL)-10. However, it remained unclear whether IL-10 is essential for the Py-induced suppression of CIA. Male IL-10 knockout (KO) DBA/1 J mice were immunized with bovine type II collagen (CII) and subsequently infected with Py at one week post-immunization. The development of arthritis was evaluated by an arthritis score up to 6 weeks post-immunization. At 3 weeks post-immunization, cytokine production from splenocytes and serum anti-CII IgG/IgG1/IgG2a levels were compared between non-infected control mice and Py-infected mice. Py infection inhibited the development of CIA in IL-10KO mice until 4 weeks post-immunization, after which the arthritis score reached levels comparable with the control mice. Both pro-arthritic (IL-17 and TNF-α) and anti-arthritic (IFN-γ and IL-4) cytokines were down-regulated during the periods of parasitemia, while no significant differences were observed in levels of anti-CII IgG antibodies. Our findings indicate that Py alleviates CIA via IL-10-independent mechanisms.

We herein provide a supplemental description of Benedenia seriolae (Yamaguti, 1934) Meserve, 1938 (Monogenoidea: Capsalidae Baird, 1853) based on specimens we collected from the skin of wild-caught greater amberjack (Seriola dumerili) in the northern Gulf of Mexico (GOM). Our specimens of B. seriolae from the GOM resemble those of Benedenia humboldti Baeza, Sepúlveda, and González, 2019 (from yellowtail amberjack, Seriola lalandi Valenciennes, 1833 [Carangidae] off Chile) by having a large body (>7000 μm in total length), non-overlapping anterior and posterior hamuli, an entirely sinistral and convoluted vas deferens, and a common genital pore as well as by lacking glands of Goto. It differs from B. humboldti by the shape of the penis tip. The 28S rRNA gene sequence differed from that of B. seriolae (from Japan) by 8 bp (1.1 %) and B. humboldti by 13 bp (2.8 %-1.7 %). The phylogenetic analysis recovered our sequences of B. seriolae sister to conspecific sequences from Japan, with that clade sister to B. humboldti from Chile. Benedenia was paraphyletic, suggesting some systematic revision to the genus could be warranted. Of 25 Benedenia spp., only Benedenia hendorffii (von Linstow, 1889) Odhner, 1905 had been reported previously from the GOM. Benedenia seriolae had previously not been reported from wild greater amberjack (previous records from greater amberjack were from sea cages only). This is also the first record of B. seriolae from the Northwestern Atlantic Ocean (GOM).

Schistosomiasis mekongi is endemic in a restricted area in Northern Cambodia and the Southern Lao People's Democratic Republic. Severe hepatobiliary morbidity is associated with chronic untreated S. mekongi infection. Since the 1980s extensive control efforts have been employed in endemic areas, resulting in substantial reduction of infection rates and disease burden. We report on a patient with a fatal course of clinically-assessed chronic schistosomiasis. This report underscores that patients with severe chronic Mekong schistosomiasis may still exist and may need treatment support.

Taenia asiatica, utilizing pigs as an intermediate host, degenerates and/or calcifies within a few months after infection in pigs, whereas Taenia solium, also using pigs as an intermediate host, can develop into a mature metacestode within a couple of months and can survive for prolong periods in pigs. This raises the question of whether pigs are suitable intermediate hosts for T. asiatica. The host-parasite relationships between T. asiatica and pig strains, such as infection rates and development of metacestodes, have been reported in previous studies: however, little is known about the pathological changes that occur in T. asiatica metacestodes in pigs. Therefore, in the present study, the pathological changes in T. asiatica within 30 days of infection were observed using CLAWN miniature pigs as model animals. Metacestodes were observed on the diaphragmatic surface and throughout the parenchyma of the pig liver 9 days after infection; however, these metacestodes were surrounded by eosinophilic abscesses, and some had already begun to degenerate. By day 20 and 30 post-infection, metacestodes were surrounded by eosinophilic abscesses and had completely degenerated without forming a scolex. These results indicate that although T. asiatica infected miniature pigs, the metacestodes degenerated owing to strong immune responses from the pigs. Therefore, the CLAWN miniature pig are not a suitable intermediate host for T. asiatica. The possible reasons why T. asiatica metacestodes were degenerated and the potential roles of pigs in transmitting the parasite to humans in T. asiatica-endemic regions are discussed in this study. Additionally, data debating whether pigs are suitable intermediate hosts for T. asiatica are provided.

The honeybee is one of the most important pollinators in the world. The frequently observed poor health of honeybee colonies can be caused by various factors, e.g. environmental pollution, nutritional stress, and climate changes. Moreover, honeybees are constantly exposed to a wide spectrum of pathogens, such as parasites, bacteria, and viruses. We examined the occurrence of various diseases in different-aged worker honeybees from two colonies kept in natural and laboratory conditions during spring, summer, and autumn in Poland. The honeybees were examined by PCR to detect infection with selected pathogens: Nosema ceranae, N. apis, N. bombi, Acarapis woodi, trypanosomatids, and neogregarines (Mattesia or Apicystis species) and by RT-PCR to identify deformed wing virus (DWV), black queen cell virus (BQCV), and acute bee paralysis virus (ABPV). DWV and N. ceranae turned out to be the dominant pathogens. Trypanosomatids and BQCV were also found in several samples. We did not detect the presence of the other pathogens: N. apis, N. bombi, A. woodi, neogregarines, or ABPV. As shown in the present study, the dynamics and occurrence of pathogens are influenced by keeping conditions, honeybee age, and seasonality.

Hepatozoonosis is a tick-borne infection caused by protozoan species of the Hepatozoon genus in the family Hepatozoidae. This study aimed to determine the presence and prevalence of Hepatozoon spp. in domestic cats and their ticks, to characterize the genotypes, to reveal phylogenetic relationships, and to assess the risk factors associated with infection. Blood samples were collected in EDTA tubes from 311 cats that were brought to the Veterinary Faculty, Animal Hospital for treatment or routine control purposes. Smears were prepared from the buffy coat and examined microscopically for the presence of Hepatozoon spp. gamonts. Ticks were collected during the clinical examination of the cats and the species were identified. Genomic DNA obtained from buffy coats and ticks were analyzed using PCR analyses targeting the 18S rRNA gene region of Hepatozoon spp. The results showed that Hepatozoon spp. gamonts in neutrophils were determined in five samples as 1.6 % (5/311). A total of 58 (18.64 %, 58/311) were positive for the PCR analyses. Twelve ticks were collected from the cats, and all were identified as Rhipicephalus turanicus. Hepatozoon spp. were found in seven (58.3 %) ticks by molecular analyses. Sequence analysis of the 18S rRNA gene region of 58 positive isolates revealed the presence of H. felis (n = 25, 43.1 %) and H. silvestris (n = 33, 56.9 %) species in cats and H. felis in Rh. turanicus (n = 7). This study also presents the first report of H. silvestris in domestic cats from Türkiye. Phylogenetic analyses showed that our H. felis isolates clustered in H. felis genotype I and our H. silvestris were stated in the same cluster with Italian isolates.

The investigation of important prevalent tick-borne pathogens is central to the control of tick-borne diseases. To understand the prevalence of Borrelia burgdorferi s.l., Borrelia miyamotoi, and the Alongshan virus in ticks and patients in Shaanxi Province, China, a total of 670 adult ticks and 524 patient blood samples were collected in the region between 2022 and 2023. In this study, PCR was used to estimate the prevalence of the three pathogens. The results revealed that the overall positive rates of B. burgdorferi s.l, B. miyamotoi, and ALSV infection in the collected ticks were 13.58 %, 2.46 %, and 4.17 %, respectively. Three genospecies of B. burgdorferi s.l. were detected in this study, namely, B. garinii, B. afzelii, and B. bavariensis, with positive rates of 4.63 %, 3.58 %, and 5.37 %, respectively. The prevalence rates of B. miyamotoi, ALSV  and B. burgdorferi s.l. in the patients were 0.38 %, 0.95 %, and 15 %, respectively. Moreover, B. burgdorferi s.l. and ALSV coinfection was also detected in three patients. Evolutionary analysis revealed that the isolate of B. miyamotoi belongs to the Asian type (Siberian type) and that of ALSV is closely related to that of Finland. To our knowledge, this is the first report on B. miyamotoi and ALSV detection in both ticks and humans in Shaanxi Province; the prevalence indicates that the regions in this province might be endemic areas. The results also suggest that humans in these regions are at risk of infection with these three tick-borne diseases.

The parasite Rhabdosynochus viridisi (Platyhelminthes: Monogenea) infects the Pacific white snook Centropomus viridis gills and can cause adverse effects in the aquaculture industry. The immune responses of Pacific white snook to monogenean infections are poorly understood. Thus, this study aimed to identify differentially expressed genes (DEGs) in the gills of Pacific white snook juveniles experimentally infected with R. viridisi, emphasizing immune-related genes and pathways activated or suppressed during the infection. RNA sequencing was performed on the gills of uninfected (control) and infected fish. The algorithm Seq2Fun was selected without a reference transcriptome to map the reads to transcripts of fishes available from a database for gene orthologs (EcoOmics) and obtain the counting table. The ExpressAnalyst software was used for differential expression and functional analyses. A total of 20,106 transcripts were found, and 1430 (7 %) were differentially expressed genes (DEGs) between infected and control groups. We identified 860 (60 %) downregulated and 570 (40 %) upregulated genes. Thirteen canonical pathways after the Kyoto Encyclopedia of Genes and Genomes (KEGG) database were overrepresented, and most of the DEGs were downregulated, suggesting the inactivation of these pathways. The functions of most of the DEGs with higher fold change found in this study are poorly understood in fish. Even though the well-known pro-inflammatory cytokines remained unchanged in infected gills of C. viridis, and transforming growth factor β (tgfβ) was downregulated, interleukin-17 ligands il17d and il17a/f1, as well as C-X-C motif chemokine receptor 2 (cxcr2) genes were upregulated, indicating that the infection with R. viridisi promotes Th17-like immunity. Overexpression of plasma B cell activity markers such as immunoglobulin light chain-like genes and the v-set pre-B cell surrogate light chain 3 (vpreb3) was also detected in this study. The possible implications of DEGs related to calcium imbalance, hypoxia adaptation, hemostasis, and immunity are discussed. These results will support future studies to improve the prevention and treatment of monogenean infections in finfish aquaculture.

Rodents are the reservoirs of the plague bacterium Yersinia pestis, which is transmitted through the bites of infected fleas. In this paper, we studied the distribution and abundance of fleas and rodents in the erstwhile endemic states and seaports of India from 2009 to 2019. The analysis showed that the Rattus rattus (Rr) was the major rodent species found in both Western (66.52 %) and Eastern (48.95 %) seaports of India and the other rodent species recorded were Bandicota indica (Bi) (16.68 % & 34.24 %), Bandicota bengalensis (Bb) (8.88 % & 16.02 %) Rattus norvegicus (Rn) (6.83 % & 0.70 %), Murines hurriane (Mh) (1.08 % & 0 %), Mus musculus (Mm) (0 % & 0.09 %), respectively. Only two flea species namely, Xenopsylla cheopis (X.c) and Xenopsylla astia (X.a) were recorded during the study period in Eastern and Western seaports. Among them, X. astia was found to be the dominant species (55.56 %) and followed by X. cheopis (44.44 %). Further, the female population of X. cheopis and X. astia was higher in both Western and Eastern seaports than the male population. Similarly, Rattus rattus (Rr) (82.43 %,) was the major rodent species found in erstwhile endemic states of India, followed by Tetera indica (Ti) (11.99 %,). Only northern endemic states (HP and UK) reported Rattus rattus terkiminasis (R.rt) (0.01 %). Four flea species namely, Xenopsylla cheopis (64.89 %), Xenopsylla astia (34.89 %), Stivalius ahalae (0.18 %), and Nosopsyllus fasciatus (0.02 %) were recorded from endemic states. The presence of rodents and vector fleas warrants sustained plague surveillance in and around seaports and endemic states.

Cryptosporidium spp., an important food and waterborne protozoan pathogen, can cause severe diarrhea and extraintestinal manifestations in immunocompromised individuals. The case of a 75 -years old patient diagnosed as a late presenter with advanced HIV infection and multiple opportunistic illnesses associated to HIV: cryptosporidiosis, intestinal and pulmonary, Cytomegalovirus colitis and pulmonary tuberculosis is presented. Cryptosporidium parvum was identified in fecal sample and bronchoalveolar lavage using rapid tests, PCR diagnosis, and sequencing, the two sequences being identical. In spite of adequate treatment for all associated infections, including Nitazoxanide for Cryptosporidium spp. infection, antiretroviral therapy, and management in the intensive care unit, the patient evolution was unfavorable, without immune reconstitution, leading to death on the 30th day of hospitalization. This case describes a rare localization of pulmonary cryptosporidiosis in association with pulmonary tuberculosis in a patient with advanced HIV infection. Clinicians should be aware of the possible pulmonary localization of this opportunistic parasite in immunodeficient patients.

A significant complication of angiostrongyliasis remains eosinophilic meningoencephalitis, leading to patients' neurological deterioration, cerebral palsy, and respiratory changes, resulting in death. Clinically, A. cantonensis-infected patients sometimes showed decreased CSF glucose levels. Animal models infected with A. cantonensis have also reported a reduced serum glucose profile. While the brain uses glucose as the primary fuel source, glycolysis is essential for various neural activities in the brain. The defection of the glycolytic pathway has also been found to closely correlate to neurodegenerative diseases such as Alzheimer's disease. However, the role of glycolysis in the pathology and neurological declines associated with A. cantonensis infection remains unknown. Our current study has shown that A. cantonensis infection increases glucose content in the brain and suppresses the expression of the glycolytic enzymes in the brain. Glycolytic products such as pyruvate and ATP were also decreased in their level in the brain. This suppression of brain glycolysis was found to be correlated to the host's histopathology and neurological symptoms. Further analysis using mice infected with a different number of third-stage larvae (L3) A. cantonensis revealed that the defection of glycolysis was indeed caused by the presence of fifth-stage larvae (L5) of A. cantonensis in the brain of experimental mice. However, it may not be directly related to the damage that L5 caused to the brain. Our study delineates some aspects of the pathophysiology of angiostrongyliasis and may provide potential therapeutic targets for the future.