Blastocystis sp. is an opportunistic intestinal protist frequently associated with colorectal cancer (CRC). Its immunomodulatory influence within the immunosuppressive milieu of chemotherapy-treated CRC remains largely unexplored. This study investigated the effects of Blastocystis solubilized antigen (BSA) from subtypes ST1-ST5 on the metabolic activity and cytokine gene expression of peripheral blood mononuclear cells (PBMCs). PBMCs were isolated from healthy donors (HDs; n=5) and CRC patients undergoing 5-fluorouracil-based chemotherapy (CRCPs; n=5) sampled 7-14 days post-cycle to capture the treatment nadir. PBMCs were challenged with BSA (0.001-30 µg/ml) for 48 hours. Metabolic activity was assessed via MTT assay, and transcriptional profiles of cytokines (IL-6, IL-8, TGF-β, IFN-γ, TNF-α) were evaluated using real-time RT-PCR. HD PBMCs exhibited a biphasic metabolic response, shifting to significant stimulation at BSA concentrations exceeding 10 µg/ml. Conversely, CRCP PBMCs displayed a significantly attenuated, predominantly inhibitory metabolic profile across all concentrations (p < 0.001), despite maintaining viability to PHA. Transcriptionally, HDs showed balanced upregulation of effector and pro-tumorigenic transcripts. In contrast, the CRCP cohort exhibited widespread transcriptional blunting. Notably, subtype ST3 was a distinct outlier in CRCPs, uniquely inducing robust IFN-γ and TNF-α expression (p < 0.01) comparable to HDs. While chemotherapy induces systemic hyporesponsiveness, ST3 possesses unique immunogenic properties that bypass immune suppression. This transcriptional escape may facilitate an unbalanced inflammatory milieu conducive to CRC progression.

Acanthamoebae are amphizoic protozoa that can be human pathogens, causing diseases such as granulomatous amoebic encephalitis or Acanthamoeba-keratitis; Therefore, it is critical to have a rapid and reliable diagnostic approach; Following two studies with divergent results, we have aimed to assess the development of a time-saving and cost-effective method for medical parasitological diagnostics to identify Acanthamoebae by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry based on their characteristic protein profiles. Several xenically cultured Acanthamoeba strains were applied; To eliminate the impact of proteins derived from nutrition bacteria, UVC inactivation, heat inactivation, and centrifugal membrane filtration were tested. The achieved mass spectra turned out to be not reproducible in our study; In conclusion, the establishment of a method for the characterization of Acanthamoebae by MALDI-ToF MS was not achieved, and therefore, the method represents, to date, no suitable alternative to the real-time polymerase chain reaction in medical diagnostics of Acanthamoebiasis.

Myxosporean parasites have been identified in amphibians globally; however, in Japan, no amphibian-infecting myxosporeans have been formally recorded. Thus, in this study, 20 native Japanese frog species were surveyed to clarify the diversity of myxosporeans that infect amphibians. A survey of 102 anurans representing 20 species across six families collected in Japan revealed the presence of a myxosporean belonging to the genus Sphaerospora that parasitizes the kidneys of the Japanese rice frog, Fejervarya kawamurai. The myxosporean is described herein as a new species based on its distinct morphological characteristics and phylogenetic position. Spores are spherical to subspherical with an overall dimension of 11.1 (10.2-12.2) × 11.5 (9.3-14.0) µm. The polar capsules are spherical, with a diameter of 3.3 (2.5-4.3) µm. Typical spores possess a characteristic caudal appendage. This discovery is considered the first record of anuran-parasitic Sphaerospora in East Asia and the fifth global record of a frog-parasitic species in this genus. Phylogenetic analysis based on partial SSU rDNA sequences unequivocally placed the new species within a well-supported monophyletic clade of anuran-parasitic Sphaerospora, comprising taxa distributed across the Palaearctic (Asia and Europe), Afrotropical, Nearctic, and Neotropical realms.

Schistosomiasis remains as a parasitic disease with major morbidity, ongoing transmission, and economic burden, particularly in tropical regions. Praziquantel is the first-line treatment but has limited efficacy against juvenile stages of the parasite. In this context, this study assessed the repurposing potential of anthelmintics against Schistosoma mansoni, focusing on the schistosomicidal activity of nitazoxanide (NTZ), levamisole (LVZ), and thiabendazole (TBZ). In vitro, NTZ exhibited a significant schistosomicidal activity, emerging as a repurposing candidate. In contrast, LVZ and TBZ showed no significant schistosomicidal activity. NTZ was active from 40µg/mL, affecting schistosomula and adult worms in a dose-dependent manner. Ultrastructural analysis revealed wrinkling of the oral and ventral suckers and tegumental alterations in male worms, including shortening of ridges near the tubercles and the presence of multiple small protrusions. In vivo, NTZ showed partial efficacy, with 57.14% reduction in adult worm recovery, whereas PZQ achieved complete elimination. Infected animals presented a mean of 541.86 ± 273.13 viable eggs/cm2, while treatment with nitazoxanide (205mg/kg) or praziquantel (400mg/kg) reduced these values to 247.98 ± 109.68 and 144.92 ± 133.46 eggs/cm2, respectively. Combined administration of NTZ and PZQ resulted in the greatest reduction in viable egg counts, with a mean of 96.75 ± 49.55 eggs/cm2. Although praziquantel resistance has been reported, in this study it fully eliminated adult worms, while nitazoxanide showed lower but relevant activity against both schistosomula and adult stages. These findings confirm the efficacy of praziquantel against adult worms and highlight therapeutic potential of nitazoxanide, underscoring the need for further bioavailability studies.

Cyathocotylidae Mühling, 1896 is a cosmopolitan family of diplostomoidean digeneans characterized by a broad range of vertebrate definitive hosts, including fishes, birds, reptiles, and mammals. Cyathocotylid diversity in Australasia remains poorly known. In the present study, we describe a new genus and species of cyathocotylid digenean collected from the small intestine of the Australasian gannet, Morus serrator, in Queensland, Australia. Adult cyathocotylid specimens were collected from the small intestine of an Australasian gannet in Queensland. Specimens were stained, mounted, and examined using DIC microscopy. Genomic DNA was extracted, and a fragment of the large ribosomal subunit (28S) rDNA was sequenced and compared with available sequences from cyathocotylids. A new genus and species, Glandocirrus crikey n. gen., n. sp., is described. It can be readily distinguished from all other cyathocotylid genera by its exceptionally large, strongly glandular cirrus sac. The 28S sequence is identical to previously published unidentified cercariae from Australia, thereby linking larval and adult stages and confirming the distinctiveness of the lineage. This discovery represents the seventeenth genus of Cyathocotylidae and only the second from Australasia supported by DNA data, emphasizing the underexplored diversity of diplostomoideans in the region.

Molecular data on wildlife trypanosomatids in Central America remain limited, constraining our understanding of host associations and sylvatic transmission cycles in the region. We characterized Leishmania and Trypanosoma infections in Costa Rican bats and assessed contemporary circulation of Trypanosoma minasense in howler monkeys within a comparative phylogenetic framework. Whole blood from 98 bats across 11 Costa Rican localities (2013–2014) was screened by PCR for Leishmania kDNA (120 bp), ITS-1 (~ 330 bp), and Trypanosoma 18 S SSU rRNA (nested PCR) with species-level identification based on sequence-confirmed amplicons. ITS-1 and 18 S amplicons were Sanger-sequenced and assigned by BLAST. For context, 18 S sequences from howler monkeys (Alouatta palliata) sampled in Costa Rica (2011–2025), including 20 animals from 2025, were included in phylogenetic analyses. Leishmania kDNA was detected in 4/98 bats (4.1%), but only one (Sturnira parvidens) yielded ITS-1 and clustered within the Leishmania (Viannia) guyanensis complex. Trypanosoma DNA was detected in 9/98 bats (9.2%): T. cruzi (n = 3), T. minasense (n = 3), and undetermined Trypanosoma spp. (n = 3). In 2025, 17/20 howler monkeys were PCR-positive for T. minasense; two were successfully sequenced and clustered within the Costa Rican T. minasense clade alongside bat-derived sequences. We report the first ITS-1- confirmed molecular evidence of the L. (V.) guyanensis complex in Costa Rican bats, supporting evidence of a broader host association and long-term local persistence of T. minasense across bats and primates.