Parasite最新文献

Canine sarcoptic mange, caused by Sarcoptes scabiei, is a highly contagious and intensely pruritic skin disease in dogs. It is prevalent worldwide and has zoonotic potential. Therefore, effective treatment is important to safeguard animal welfare and public health. The present clinical field study aimed to confirm the efficacy of NexGard^® Plus, an oral combination of afoxolaner, moxidectin and pyrantel pamoate, in treating dogs naturally infested with S. scabiei. It was a blinded, randomised, single-centre, negative-controlled efficacy study. Twenty naturally infested dogs were allocated into two groups: a group treated on Day 0 and Day 26/28 at the label dose, and an untreated control group. Skin scrapings were conducted similarly, once between Day -6 to 0, then on Days 26/28 and 56 for mite counts. Assessments of clinical signs were conducted at the same time intervals. In the treated group, mite infestations were reduced by 97% after the first treatment and were eliminated (100%) after the second treatment (p < 0.0005), while all dogs in the untreated control group remained infested for the whole study. Treated dogs had no pruritus, papules or crusts and clear evidence of hair regrowth by Day 56, unlike the dogs in the control group. This study demonstrated the elimination of S. scabiei mites and significant improvement of sarcoptic mange clinical signs in naturally infested dogs treated with the oral combination of afoxolaner, moxidectin and pyrantel.

Toxoplasma gondii is an intracellular protozoan parasite known to infect a wide range of hosts, including humans, and is a significant cause of health issues, particularly in pregnant women and immunocompromised individuals. However, it has garnered attention for its potential in cancer treatment due to its diverse anti-cancer mechanisms. Toxoplasma gondii induces key cytokines such as IL-12 and IFN-γ, triggering robust Th1 immune responses that effectively target tumor cells. Furthermore, it modulates the immunosuppressive tumor microenvironment (TME), reduces inhibitory immune cells, promotes activated immune cells, induces apoptosis in tumor cells, inhibits proliferation, and disrupts tumor angiogenesis through regulatory signaling pathways. Despite these promising antitumor attributes, significant limitations hinder its translation into clinical practice. These include strain-dependent differences in virulence and therapeutic efficacy, ethical and biosafety concerns associated with wild-type strains, limited applicability of animal data to human therapy, and the possibility that the parasite may promote tumorigenesis under certain conditions. Innovative approaches such as engineered strains for precise tumor targeting, exploitation of its bioactive agents, use as a drug carrier for brain tumors, and combination therapies with other anti-cancer modalities show promise. These advances, coupled with comprehensive cost-effectiveness assessments, present new opportunities and hope for integrating T. gondii into cancer therapy.

Human cysticercosis is a serious zoonosis caused by infection with larvae (cysticerci) of the pork tapeworm, Taenia solium. Infection can involve the nervous system, causing chronic headache and intracranial hypertension, focal neurological deficits, epileptic seizures, and paralysis. The disease is found in developing countries, where porcine cysticercosis is prevalent and undercooked pork is habitually consumed. This study aimed to develop immunochromatography-based test (ICT) kits, using low-molecular-weight antigens purified from cyst fluids of Latin American and Asian genotypes of T. solium. To evaluate the kits, we used 164 serum samples, including 24 from proven/confirmed cysticercosis cases, 110 from cases with other parasitoses, and 30 from healthy individuals. Diagnostic performances were calculated. The sensitivity, specificity, and accuracy were 83.3% (95% CI [62.6-95.3]), 93.6% (95% CI [88.1-97.0]), and 92.1% (95% CI [86.8-95.7]), respectively for the American genotype-based ICT kit, while for the Asian genotype-based ICT kit, they were 87.5% (95% CI [67.6-97.3]), 98.6% (95% CI [94.9-99.8]), and 97.0% (95% CI [93.0-99.0]), respectively. The sensitivity and specificity did not significantly differ between the two ICT kits (exact McNemar's test; p > 0.05), with a concordance of 93.9%, represented by a Cohen's kappa of 0.77 (p < 0.001), indicating substantial agreement. These results indicate that affinity-purified antigens from different geographical isolates can be used for the diagnosis of human cysticercosis. The diagnostic specificities were better than for a previously reported ICT kit that used crude antigen.

Human African trypanosomiasis (HAT) and Animal African trypanosomiasis (AAT), transmitted by Glossina species, remain major health and economic burdens in Africa. Accurate vector identification is essential for effective control strategies. However, current identification methods of Glossina species based on morphological and/or molecular techniques have several limitations that often hinder reliable species-level classification. This study assessed matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as an alternative or complementary approach to morphological and molecular methods for Glossina species identification and explored its ability to detect infection status. A total of 265 tsetse flies were collected and morphologically classified into the Glossina palpalis group (n = 200) and the Glossina fuscipes group (n = 65), later confirmed by molecular analysis as Glossina palpalis palpalis and Glossina fuscipes quanzensis, respectively. Spectra were generated from wings, legs, and thoraxes to identify the most suitable body parts. For G. p. palpalis, high-quality spectra were obtained from wings (98.0%), legs (96.5%), and thoraxes (93.5%); for G. f. quanzensis, corresponding values were 89.2%, 87.7%, and 72.3%. Blind testing showed that 89.5% of spectra for G. p. palpalis and 95.2% for G. f. quanzensis matched morphological identification, with 87.0% and 94.6%, respectively, reaching relevant score thresholds. Molecular screening detected Trypanosoma congolense DNA in nine specimens, but MALDI-TOF MS spectra could not distinguish infected from uninfected flies. These findings demonstrate that MALDI-TOF MS is a rapid, reliable tool for Glossina species identification, particularly using wings and legs, but is unsuitable for infection status determination.

Trematode metacercariae are the most abundant and frequently encountered helminths in freshwater fish. Yet, accurate species identification remains challenging, potentially leading to an underestimation of trematode diversity. Using data from parasitological examinations of 1,030 fish (47 species) collected from diverse freshwater habitats in Lithuania (2022-2024), we assessed the contemporary diversity of trematode metacercariae, host associations, microhabitat preferences, and changes in diversity patterns and transmission dynamics. Through integrated morphological and molecular techniques, we identified metacercariae belonging to 51 species from eight families, more than doubling previously reported diversity (25 species). While trematode family composition remained largely unchanged - the Diplostomidae and Strigeidae remained the most diverse families - notable differences were observed at the species level. Metacercariae of the Echinochasmidae and Echinostomatidae were detected for the first time, while previously reported Clinostomidae were absent. Fish of the Leuciscidae hosted the highest trematode diversity. Host specificity of metacercariae was generally low, with most species being euryxenous. At the microhabitat level, eyes harboured the highest number of species, while muscles showed the highest metacercarial density. Notably, we detected species first genetically characterised in North America (Echinoparyphium sp. 2 and Ichthyocotylurus sp. 2) and species potentially belonging to the genus Neogogatea, previously known only from Asia and North America, highlighting potential invasion risks and suggesting that European trematode diversity remains substantially underestimated. Future efforts should obtain molecular data from correctly identified adult specimens to resolve the identity of species currently identified only to the genus or family level, thereby enabling assessment of their geographical distributions and ecological roles.

The genus Oswaldocruzia represents a taxonomically diverse group of nematodes with global distribution. Although Oswaldocruzia species are widespread and exhibit a remarkably wide host range in some species, their genetic diversity and biogeographic patterns remain poorly understood. This study investigated the genetic variability and distribution of Oswaldocruzia spp. in nine anuran species from the genera Bufo, Bufotes, Pelophylax, and Rana across Central Europe and the Balkans. Two species were identified: Oswaldocruzia filiformis and O. ukrainae, each exhibiting a different range of host associations. Phylogenetic analyses based on mitochondrial COI sequences revealed significant haplotype diversity in the generalist O. filiformis, with low geographic and host-associated genetic structuring. In contrast, O. ukrainae, which is closely associated with Bufotes viridis, exhibited only one genetic variant across all samples, highlighting its restricted genetic diversity. The findings emphasize contrasting genetic diversities among nematode parasites exhibiting different levels of host-specificity and expand the known distribution of O. filiformis into new regions of the Balkans. In addition, they highlight the need for additional studies on the ecological and evolutionary factors that influence the genetic diversity of parasites in amphibians.

Tritrichomonas foetus and Pentatrichomonas hominis are two causative agents of trichomoniasis in dogs and cats, manifesting primarily through diarrhea symptoms. However, information on the prevalence and identification of T. foetus and P. hominis in dogs and cats in China is limited. Thus, to investigate the prevalence of trichomoniasis in dogs and cats in Nanchang city, South China, a total of 405 fecal samples were collected from 111 cats and 294 dogs. The presence of T. foetus and P. hominis were determined using the nested polymerase chain reaction (PCR) method, targeting the ITS1-5.8SrRNA-ITS2 of T. foetus, and 18SrRNA of P. hominis. The overall prevalence of T. foetus was 15.3% (62/405), with a prevalence of 5.8% (17/294) in dogs and 40.5% (45/111) in cats. The total prevalence of P. hominis was 17.3% (70/405), with a prevalence of 22.4% (66/294) in dogs and 3.6% (4/111) in cats. Statistical analysis revealed significant correlations between the prevalence of T. foetus and factors including breed, season and environmental conditions in dogs; in cats, there was a significant correlation with season, breeds and age. For P. hominis, the different sampling sites of dogs showed a significant correlation. Our results reveal that T. foetus is predominantly found in cats and P. hominis is predominantly found in dogs in Nanchang city. These findings contributed to effective prevention and control of trichomoniasis in dogs and cats in this region.

Dactylogyrus Diesing, 1850 is the most speciose genus of platyhelminths with more than 900 species, and over a hundred species recorded from Africa. Of the latter, six are from the straightfin barb, Enteromius paludinosus (Peters). Dactylogyrus teresae Mashego, 1983 and Dactylogyrus dominici Mashego, 1983 were collected from E. paludinosus in the Vaal River system, Gauteng, South Africa and their taxonomic data revised using standard protocols and modern approaches, alongside the type material. Whole worms were mounted on glass slides with glycerine ammonium picrate (GAP) and studied using light microscopy (LM). For scanning electron microscopy (SEM), whole worms were placed on concavity slides and the soft tissue digested to release the sclerotised copulatory organs and haptoral sclerites. A combination of these approaches (LM and SEM) was employed for the first time to study the sclerotised structures of GAP-mounted material. Soft tissues of SEM analysed specimens were genetically characterised using CO1 mtDNA, 18S-ITS1-5.8S rDNA and partial 28S rDNA fragments. Phylogenetic topologies were constructed using Bayesian inference. Results confirmed the morphologic and genetic distinctness of D. dominici and D. teresae, highlighting the importance of studying the varying orientations of specifically the vagina and transverse bar. This study presents a new locality record, the first SEM study of isolated sclerotised structures, as well as the first molecular data for the Dactylogyrus afrobarbae-like species. The multifaceted approaches applied to the same specimen in this study enabled improved resolution of individual specimens, showing promise for studies where limited specimens are available.

Microcotylids have rarely been reported along the South African coast, even though the Microcotylidae is one of the dominant polyopisthocotylan families. The present study focused on elucidating the parasite diversity of the Cape white seabream, Diplodus capensis (Smith), from various localities along the South African coast. By combining molecular and morphological techniques, two previously undescribed species of the Microcotylidae were identified. Atriaster ibamba n. sp. primarily differs from its congeners by the number and size of the hooks surrounding the genital atrium. Polylabris dassie n. sp. has a single vagina and is unique to most others of this genus by having a smaller male copulatory organ, and by the shape of this organ. This is the first report of species of Atriaster from South Africa, as well as the first report of any polyopisthocotylan from D. capensis. The present study also contributes the first genetic sequences of marine microcotylids from South Africa.

Toxoplasma gondii is the protozoan parasite responsible for toxoplasmosis, a zoonosis that represents a health risk for mammals, including marine species. Felines are the only definitive hosts of this parasite, playing a critical role in the introduction and maintenance of the pathogen in a new environment. Recent data demonstrate the contamination by T. gondii of the terrestrial and seawater environment of the Galapagos archipelago, in the Pacific Ocean. Little is known about the exposure of Galapagos' threatened species to T. gondii, although introduced domestic cats in the archipelago are known to be seropositive for T. gondii. We documented for the first time exposure to T. gondii of Galapagos sea lions (Zalophus wollebaeki), an endemic and emblematic species of the archipelago. The modified agglutination test revealed the presence of antibodies against T. gondii in 61 of 77 plasma samples collected in 2016-2017 from 2- to 4-year-old wild sea lions live-handled in their breeding sites on the inhabited island of San Cristóbal. Antibodies were also detected in 4 of 19 serum samples (21%) from sea lions whose corpses were found in 2021 on the same island. In addition, T. gondii DNA was detected in a lung sample from one necropsied pup and a tissue cyst-like structure was found in another, suggesting infection. These results, together with the high prevalence of antibodies in 2 to 4-year-olds, indicate that Galapagos sea lions are frequently exposed to T. gondii and raise concerns that toxoplasmosis may pose a threat to this endemic species.