Parasite最新文献

Biting midges of the genus Culicoides Latreille (Ceratopogonidae) pose a significant threat to veterinary health as vectors of over 60 viruses, most of which affect livestock. In this study, we used light traps to sample Culicoides populations on cattle and goat farms from May to October 2023 at 15 sites in Gyeongsangnam-do, Jeollanam-do, and Jeju Island, South Korea. Diversity and abundance were analysed based on the collection date, environmental conditions, and host species. A total of 124,055 individuals were collected, comprising 14 previously recorded and two newly recorded species: C. asiana and C. palawanensis. The dominant species was C. arakawae, which accounted for 80.60% of the total collected individuals, followed by C. punctatus (10.25%), and C. tainanus (3.36%), while the remaining 13 species constituted 5.80% of the collection. Total Culicoides abundance peaked in August (40.15%), driven largely by fluctuations in C. arakawae abundance, but the seasonal abundances of individual species varied. Culicoides arakawae and C. punctatus were dominant on the mainland, while C. matsuzawai, C. lungchiensis, and C. tainanus were dominant on Jeju Island. The dominant species on cattle farms were C. arakawae and C. punctatus, while C. arakawae dominated in collections from goat farms. The detection of two new species records suggests that the fauna of South Korea is still incompletely understood.

Otodectes cynotis is the agent of otodectic mange, a disease affecting wild and domestic felines, canines and mustelids. It is a highly contagious and pruritic condition and a major cause of otitis externa in dogs. This study was designed to verify the efficacy of NexGard^® PLUS, a combination of afoxolaner, moxidectin and pyrantel pamoate, against natural O. cynotis infestations in dogs. It was a blinded, randomised, single-centre, negative controlled clinical efficacy study. Twenty-four naturally infested dogs were allocated to three groups of eight dogs: an untreated control group, a group treated on Day 0 and a group treated on Days 0 and 29 (both groups were treated per label recommendations). Otoscopic examinations were performed on Days -3, 14, 29, 42 and 55 for clinical otodectic mange evaluation. Ear canal flushings were performed on Day 56 for O. cynotis counts, the primary variable of efficacy, calculated per comparison of live mites in the treated groups, with the untreated control group. The otoscopic examinations revealed treatment effect by Day 14 and a highly significant effect by Day 29, while the conditions remained unchanged or worsened in the untreated control group. The O. cynotis counts revealed reductions of 100% in the group treated once on Day 0 (p = 0.0004) and 99.7% (p = 0.0006) in the group treated on Days 0 and 29, while 48.8 (geometric mean) live mites were collected in the untreated control group. NexGard^® PLUS was demonstrated to be highly efficacious in dogs naturally infested with O. cynotis following one or two treatments.

Vector-borne microbial pathogens previously isolated from Stomoxys spp. are currently considered to be emerging or re-emerging threats to public health and the veterinary sector. Transmission of pathogens by flies in the Stomoxys genus is largely mechanical, indicating that they can transmit a wide range of pathogens to a variety of hosts. This study evaluated the diversity of pathogens demonstrably transmitted by a variety of Stomoxys flies, concerning species diversity, host diversity, and geographic distribution. Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were applied to screen studies based on pathogen type, host species, and experimental transmission outcomes. Journal articles published from 1973 to 2025 were sourced from six electronic databases. After evaluation, 30 studies were eligible for this review. Of these studies, 20% (6/30) reported negative outcomes. Three pathogens (Middle East respiratory syndrome coronavirus, Neorickettsia risticii, and Escherichia coli) were not transmitted by the flies in the experiments. Stomoxys spp. transmitted pathogens to a wide range of hosts (9 mammals) and substrates (blood and tissue culture), but the recorded experiments in camels failed. Three out of ten Stomoxys spp. reported in the studies (S. transvittatus, S. inornatus, and S. omega) failed to transmit pathogens in all attempts. The majority of experimental studies were on S. calcitrans, with very limited studies on other Stomoxys species, highlighting the dearth of information on other species occurring in Africa and Asia. Our study has consolidated the evidence regarding the experimental pathogen transmission by Stomoxys spp., highlighting and demonstrating their epidemiological significance and the need for surveillance and control/prevention strategies.

Host genetic factors influence the severity of infectious diseases, including schistosomiasis, which are major public-health burdens in Africa. While the role of host genetic background in Schistosoma mansoni infection has been clearly established, this link remains poorly explored for S. haematobium infections (Sh). Therefore, this study aims to investigate the relationship between genetic background and morbidity associated with urogenital schistosomiasis using a candidate gene approach. We analyzed urine samples from 334 Beninese men, measuring urinary eosinophil cationic protein (ECP) by ELISA as a marker for bladder inflammation. Abdominopelvic ultrasonography was performed in a subgroup of 146 participants (69 Sh-positive and 77 Sh-negative) to assess morbidities associated with Schistosoma infection. Blood samples were analyzed for TNF-α levels by ELISA and for TNF-α promoter polymorphisms by sequencing to assess associations between genetic variation and morbidity. Results showed that 25.4% of Sh+ had significantly higher mean TNF-α (U = 5888; p = 0.0098) and ECP (U = 912.5; p < 0.0001) levels than Sh-. Positive correlations were observed between egg count and both ECP (Tau = 0.4016; p < 0.0001) and TNF-α levels (Tau = 0.2238; p = 0.014). Morbidity mainly included bladder irregularities (6%), thickening (29%), and kidney dilation (6%). The G mutant allele on the rs3093660 marker was significantly associated with morbidity (χ² = 4.47; p = 0.034; OR = 5.09 [95% CI: 1.04-24.9]). Our results suggest, for the first time, that carriers of the G mutant allele at rs3093660 marker have a five-fold increased risk of developing severe urogenital schistosomiasis.

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.

Innovative control tools are needed against Aedes mosquitoes. The boosted sterile insect technique (bSIT) consists of treating sterile males with a biocide prior to their release to contaminate larval habitats. We compared the efficacy of SIT and boosted SIT to prevent the emergence of adult Aedes albopictus in large cages. We tested two sterile-to-fertile male ratios: 5:1 (SIT5) and 1:1 (SIT1), with and without pyriproxyfen enhancement (bSIT or SIT). The eggs were collected in ovitraps and the immature stages were monitored until adult emergence or up to 15 days after hatching to estimate the relative risk (RR) of adult emergence compared to the control category. The concentration of pyriproxyfen in the ovitrap water did not change when sterile males were released with females or alone (χ² = 0.99, df = 1, p = 0.547). This concentration was higher when the sterile-to-fertile male ratio was increased from 1:1 to 5:1: χ² = 18.8, df = 1, p = 0.006. All four treatment categories were effective in suppressing mosquito populations. With a relative risk RR = 0.194 95% CI [0.128; 0.275], SIT5 was the most effective. Boosted SIT was not as effective as SIT. However, bSIT1 (RR = 0.418 [0.351; 0.492]) and bSIT5 (RR = 0.512 [0.431; 0.596]) were equally effective. Boosted males directly vectored pyriproxyfen to breeding sites. Boosted SIT was more effective than SIT alone with a low sterile-to-fertile male ratio. Under operational conditions, it could be initially deployed to suppress the target population and then switched to standard SIT.