Search Results (433)

Ixodid ticks are blood-sucking ectoparasites of vertebrates. They constitute an integral part of natural foci and are responsible for the worldwide transmission of infections to humans, which can result in severe symptoms. For instance, the Tomsk region, where three abundant tick species (Dermacentor reticulatus, Ixodes pavlovskyi, I. persulcatus) occur, is an endemic area for tick-borne encephalitis virus (TBEV). An increasing number of novel infectious agents carried by ticks have been identified using metagenomic sequencing. A notable example is the Yezo virus (Orthonairovirus yezoense, YEZV), which was discovered in patients with fever after tick bites in Japan and China between 2014 and 2025. For the first time, we have performed metagenomic sequencing of the virome of ticks collected in the Tomsk region. In a sample obtained from a pool of I. pavlovskyi ticks, all three segments of the YEZV genome were detected. The phylogenetic analysis showed that the newly identified isolate formed a sister group to previously described virus isolates, indicating the presence of a new genetic variant. This study presents the first report of YEZV detection in I. pavlovskyi ticks in the Tomsk region, thereby expanding the geographical range and number of vector species for YEZV and highlighting the importance of monitoring viral agents circulating among ticks in Western Siberia. Full article

Background: Leishmaniasis is a zoonotic vector-borne disease and a significant global public health concern worldwide and in Algeria. In this study, we investigated the potential role of ticks and fleas as carriers of Leishmania in endemic regions of Algeria. Methods: Adult ectoparasites were collected from reservoir dogs and cohabiting animals across three provinces: Tizi-Ouzou (northeast), M’Sila (southeast), and Tébessa (extreme east). A subset of 247 ectoparasites was randomly selected for Leishmania DNA screening using ITS1-PCR. Results: Morphological identification revealed two tick species, Rhipicephalus turanicus (378 specimens) and Rhipicephalus sanguineus s.l (127 specimens), and one flea species, Ctenocephalides felis (94 specimens). Dogs were the most heavily infested hosts (74.12%), followed by sheep (9.51%) and cats (9.34%). Leishmania DNA was detected in 36.43% (90/247) of the tested specimens, with higher positivity in ticks (41.32%) compared to fleas (17.64%). Infection rates varied by host species, with dogs harboring the majority of positive ectoparasites (62/90), primarily R. sanguineus s.l (19/30) and R. turanicus (40/115). Leishmania DNA was also detected in ectoparasites collected from cats and sheep, whereas goats and rabbits were free from Leishmania DNA. Conclusions: This investigation highlights the high detection rate of Leishmania DNA in ticks and fleas from animals in Algerian endemic regions, indicating exposure to infected hosts. Together with previous reports, these findings support the view that ticks and fleas may act as incidental hosts or mechanical carriers of the parasite. However, their role in parasite transmission remains unconfirmed and warrant further investigation, particularly through studies assessing vector competence. These results emphasize the need for additional research to clarify the contribution of these ectoparasites to Leishmania transmission and multi-host dynamics. Full article

Background: Essential oils, obtained from plants, are an alternative for controlling ectoparasites, particularly lice, mites and ticks, due to the problems posed by chemical insecticides, such as insect resistance, environmental impacts and concerns related to human and animal health. This study aims to investigate and compare the insecticidal activity of essential oils from Origanum floribundum and Eucalyptus citriodora against the louse Bovicola limbatus. Methods: The chemical composition of the two oils obtained by hydrodistillation was determined by gas chromatography coupled with mass spectrometry (GC-MS) and a flame ionisation detector (FID-MS). To determine insecticidal activity, the essential oils were tested at different concentrations (0.05–0.8 µL/mL), with mortality recorded after 15 min, 30 min, 1 h, 2 h and 4 h of exposure. Results: A corrected mortality rate of 100% was achieved for concentrations of oregano and eucalyptus essential oils of 0.8 µL/mL and 0.4 µL/mL, respectively. The LC₅₀ values were 0.11 and 0.10 µL/mL for oregano and eucalyptus, respectively, after 2 h of treatment. The LC₉₀ values observed are 0.31 and 0.24 µL/mL for oregano and eucalyptus, respectively. Conclusion: Both essential oils have similar and promising insecticidal potential and could be an alternative to chemical insecticides in a control strategy that is more respectful of human and animal health and the environment. Full article

Background: Argas persicus is a hematophagous ectoparasite of poultry and is the vector of several agents infectious to poultry. This study aims to explore the key genes affecting the ovarian development of A. persicus. Methods: RNA-seq was performed on the ovaries of A. persicus before blood-feeding, on the day of engorgement, and 6 days post-engorgement. Utilizing the threshold padj < 0.05 and|log₂(foldchange)| > 1, differentially expressed genes were identified, and hub genes were determined by constructing protein–protein interaction (PPI) networks. Results: A total of 1008 differentially expressed genes were obtained during the feeding period, including 448 up-regulated and 560 down-regulated genes. Further, 2179 differentially expressed genes were screened in the preoviposition stage, including 1957 up-regulated and 222 down-regulated genes. These genes are mainly annotated in functions such as peptidase activity (especially serine protease activity), protein folding, protein assembly, and cell component assembly, and enriched in pathways such as protein processing in endoplasmic reticulum, lysosome, glutathione metabolism, and sphingolipid metabolism. In addition, some proteins that are closely related to ovarian development, including heat shock protein 70, protein disulfide isomerase, paramyosin, troponin I, hexosaminidase, serine protease, Kunitz serine protease inhibitors, and vitellogenin, were obtained. Conclusions: These findings fill the gap in the biological data for the ovarian development of soft ticks, provide a reference database for subsequent proteomics research, and offer fundamental support for the screening and development of candidate antigens for anti-tick vaccines. Full article

Few studies have investigated gastrointestinal (GI) and external parasites, as well as environmental fungi, in rabbits using a One Health approach. Between September 2023—May 2024, fecal, hair and skin scraping samples were collected from 72 rabbits that attended clinical consultations and from private owners and breeders in Portugal. Diagnostic techniques included Mini-FLOTAC, direct immunofluorescence antibody, and the analysis of the virulence profile of fur fungi. A total of 58% of the rabbits were positive for GI parasites, namely Eimeria spp. (45%), Cryptosporidium spp. (32%), Trichostrongylus retortaeformis (17%), Passalurus ambiguus (13%), Graphidium strigosum (13%), and Giardia spp. (9%), with only 12% of the infected animals showing clinical signs (diarrhea). In addition, 10% of the animals were positive for Cheyletiella sp. infestations. Environmental fungi of the genera Penicillium, Rhizopus, and Scopulariopsis were isolated from 7% of these animals, with the Scopulariopsis sp. isolate S1 testing positive for proteinase, lecithinase, and gelatinase activities. Frequent sanitization and regular deworming emerged as essential factors to minimize parasitic frequency. This integrated diagnosis procedure proved to be effective in the search for parasitic and fungal agents in rabbit medicine. Further research is needed to improve the knowledge on the transmission and pathogenicity of these agents in rabbits. Full article

Rodents are among the most widespread mammals globally and serve as critical reservoirs for a wide array of zoonotic parasites that significantly impact human health. This review explores the growing public health concern of rodent-borne parasitic diseases, encompassing protozoa, helminths, and ectoparasites. Key protozoan parasites include Toxoplasma gondii, Trypanosoma cruzi, Leishmania spp., Giardia intestinalis, and Cryptosporidium spp., all of which are capable of causing severe diseases in humans and are found in rodent populations. Zoonotic helminths such as Hymenolepis spp., Trichinella spiralis, Angiostrongylus cantonensis, Capillaria hepatica, and Baylisascaris procyonis also demonstrate substantial zoonotic potential. Moreover, ectoparasites like Xenopsylla cheopis, Ornithonyssus bacoti, and Ixodes spp. play key roles in the transmission of vector-borne diseases, including plague, murine typhus, and Lyme disease. Anthropogenic factors, including urbanization, poor sanitation, habitat destruction, and climate change, exacerbate the emergence and spread of these infections. These drivers not only disrupt rodent ecology but also increase the frequency of human–rodent interactions, facilitating zoonotic transmission. Despite the severity of these threats, rodent-borne parasitic diseases remain underrecognized, particularly in low-resource settings where surveillance and control efforts are often limited. This review highlights the pressing need for integrated One Health strategies that encompass rodent population control, environmental hygiene, vector management, and public education. Strengthening global surveillance systems and investing in interdisciplinary research are critical for early detection, risk assessment, and prevention of future outbreaks. Tackling the ecological and environmental drivers of rodent-borne parasitic diseases is essential to safeguard both human and animal health in an increasingly interconnected world. Full article

Due to their zoonotic potential and close interaction with humans, feline parasitic infections are an important public health concern. This study investigated 2758 domiciled and feral cats sampled across Mexico to assess the occurrence of parasites, coinfections, and associated risk factors. Twelve genera of parasites were identified, with Ancylostoma and Ctenocephalides being the most frequent. Coinfections were common, often involving both intestinal and ectoparasites. Multivariable logistic regression revealed that feral lifestyle, absence of recent antiparasitic treatment, female sex, and climatic conditions were significant predictors of infection. Cats with unrestricted outdoor access and direct contact with other cats, where hunting behavior and the ingestion of prey cannot be ruled out (ESCCAP risk group B), were more than five times as likely to be infected as those cats that live indoors (ESCCAP risk group A). Although antiparasitic use was reported in some cats, inappropriate drug choice and long treatment intervals reduced effectiveness, while nearly seven out of ten cats had never received treatment. These findings highlight major gaps between current practices in Mexico and international guidelines. Strengthening surveillance, promoting owner education, and implementing risk-based strategies are critical to reducing feline parasitism and associated zoonotic risks within a One Health framework. Full article

This study evaluated the performance of a recirculating aquaculture system (RAS) integrated with macroalgae (Ulva ohnoi) cultivation and sea urchin (Paracentrotus lividus) feeding, in a multi-trophic aquaculture approach. This system aimed to enhance sustainability through water bioremediation by macroalgae and valorization of the algal biomass as echinoderms feed. Over a 180-day trial, biomass production of U. ohnoi remained stable, with daily growth rates ranging from 7.4 to 24.4%. Statistical analyses (PCA and GAM) indicated no significant linear or non-linear relationship between macroalgae growth and environmental parameters (temperature, radiation, photoperiod). A theoretical estimate of nutrient production showed fairly stable values that do not statistically explain biomass production variation, highlighting the species’ adaptability. Sea urchins fed with fresh U. ohnoi showed regular growth, supporting the nutritional suitability of this macroalgae. For fish (Sparus aurata), no significant differences in growth or feed conversion ratio were observed between systems with and without algae. Parasitological monitoring revealed lower parasite loads and egg deposition in tanks in recirculation with U. ohnoi during certain periods, suggesting a potential role of macroalgae in reducing monogenean propagation. These findings underscore the feasibility of integrating Ulva cultivation into RAS, contributing to circular aquaculture models with improved sustainability and resource efficiency. Full article

Ticks are hematophagous ectoparasites capable of transmitting a wide array of pathogens. The recent proliferation and geographic expansion of tick populations have intensified concerns regarding the escalating risk of tick-borne pathogen transmission. Among these, Anaplasma phagocytophilum poses a notable threat to both public and veterinary health due to its zoonotic potential. In this study, a total of 4316 ticks were collected from 16 pasture sites near livestock farms in Gyeonggi and Gangwon Provinces, Republic of Korea, between April and October 2024. Molecular epidemiological analysis was subsequently performed. Of the 400 tick pools tested, Ixodes nipponensis accounted for two Anaplasma-positive pools, Haemaphysalis spp. larvae for two pools, and Haemaphysalis longicornis for one pool. This study is the first to examine the infection rate of A. phagocytophilum in ticks collected from pasture sites near livestock farms in Gyeonggi and Gangwon Provinces. Although the observed infection rate was low, the presence of A. phagocytophilum in regions with potential human exposure emphasizes the risk of transmission. Importantly, the detection of A. phagocytophilum in larval-stage ticks suggests the possibility of transovarial transmission, meriting further investigation. These findings underscore the need for conducting surveillance and targeted preventive strategies to reduce the burden of tick-borne diseases in livestock-associated settings. Full article

Bartonella spp. is a Gram-negative bacterium transmitted by arthropod vectors, implicated in a range of zoonotic infections affecting both humans and animals. Among zoonotic species, B. henselae is primarily associated with domestic cats and B. vinsonii with dogs. In Italy, Bartonella infections have been reported in both southern and northern regions. This study investigates the presence of Bartonella spp. in fleas and ticks collected from companion animals in Piedmont region, northwestern Italy. A total of 176 flea and 85 tick specimens were obtained from 92 animals (dogs and cats) between May 2018 and February 2020. Arthropods were morphologically identified using identification keys, and screened for Bartonella DNA by PCR targeting the 16s rRNA gene. Positive samples were further analyzed by amplifying the rpoB gene. Selected 16s-positive and all rpoB-positive samples were sequenced and subjected to phylogenetic analysis. Fleas were mostly identified as Ctenocephalides felis, recovered from 44 cats and 12 dogs; a single C. canis specimen was found in one cat. Ticks were Ixodes ricinus (from 14 cats and 10 dogs), Rhipicephalus sanguineus s.l. (3 cats, 7 dogs), and Dermacentor marginatus (one dog). Bartonella prevalence was 38.4%, with 34.2% positivity in fleas and 45.6% in ticks. All sequences corresponded to B. henselae. These findings confirm the active circulation of B. henselae in ectoparasites of pets and raise questions about the potential role of ticks in its transmission. Full article

Brazilian porcupinepox virus (BPoPV) is a recently described pathogen associated with severe cutaneous and systemic disease in Coendou spp. porcupines, posing potential conservation and zoonotic risks. Given the solitary behavior of porcupines and the unclear mechanisms of BPoPV transmission, this study investigated the presence of BPoPV DNA in porcupines and their associated ectoparasites (ticks and lice). We analyzed ticks and lice collected from 17 porcupines (C. longicaudatus and C. spinosus), with or without clinical signs of BPoPV infection. Ectoparasites were identified morphologically, separated into distinct pools for ticks and lice by host, and screened by PCR. BPoPV DNA was detected in all symptomatic porcupines and their ectoparasites—including Amblyomma longirostre, A. sculptum ticks, and Eutrichophilus spp. lice—except for one tick pool. Notably, an asymptomatic, BPoPV-negative porcupine harbored A. longirostre ticks that tested positive for the virus. Sequencing confirmed 100% identity with the BPoPV reference strain. These findings suggest that Eutrichophilus lice, A. sculptum, and particularly A. longirostre ticks may play a role in BPoPV transmission. Further studies are needed to elucidate whether these ectoparasites act as biological or mechanical vectors and to assess the zoonotic potential of BPoPV in contact with humans and domestic animals. Full article

Chile is the second-largest producer of Atlantic salmon (Salmo salar), a key industry facing challenges such as infestations by Caligus rogercresseyi, which cause significant economic losses. However, there are no studies exploring how environmental variables in marine culture centers affect salmon’s immune response, considering their poikilothermic characteristics. This study analyzed the effect of the seasonal temperature on the skin transcriptome of Atlantic salmon infested with C. rogercresseyi in fjord-based farms in the Aysén Region during autumn and spring. Two different centers were analyzed (autumn: Farm-A; spring: Farm-S) to ensure the same age of the fish sampled in each season. RNA sequencing (RNA-seq) and functional network analysis revealed notable seasonal transcriptomic differences. In autumn, 253 differentially expressed genes (DEGs) were found, primarily associated with stress response and negative regulation of T-cell proliferation, suggesting an impaired response against the ectoparasite. In spring, 103 DEGs were detected, associated with protein synthesis and the activation of immune mechanisms, including complement activation, granulocyte chemotaxis, and antigen presentation. This is the first study to evaluate the transcriptomic response of healthy skin in C. rogercresseyi-infested salmon under farming conditions, highlighting the importance of considering seasonal variations for the development of more effective management strategies in the aquaculture industry. Full article

Alosa immaculata Bennett, 1835, commonly referred to as the Danube shad, is an anadromous pelagic species of the Clupeidae family, and plays a significant economic role for countries bordering the Black Sea. This study investigates the occurrence of both parasites and microplastics in A. immaculata specimens collected from Sfântu Georghe, with the aim of assessing their potential impact on fish health. The overall physiological condition of the fish was evaluated using Fulton’s condition factor (K) to determine whether the presence of parasites or microplastics had any measurable effect. Five parasitic genera were identified, including one ectoparasitic species from the genus Mazocraes, and four endoparasitic species from the genera Pronoprymna, Lecithaster, Hysterotylacium, and Contracaecum. Microplastic analysis showed a dominance of particles measuring 1–5 mm (62.5%), with fibers and foils being the only morphological forms detected. The most common colors were black (45%), transparent (35%), blue (12.5%), and brown (7.5%). The distribution of microplastics was higher in the stomach than intestines. Our findings offer critical insights into the combined effects of parasitic infection and microplastic pollution on this key Black Sea species. The integrated methodology, combining parasite load, microplastic content, and condition factor analysis, marks a novel approach in fish health assessment. Full article

The ionotropic γ-aminobutyric acid (GABA) receptor (GABAR) is a key target for the development of antiparasitic agents, particularly against ectoparasites, such as fleas and ticks. Binding stability and selectivity of sarolaner enantiomers for Ctenocephalides felis RDL receptors (RDLR) were investigated in the current study. Wild-type (WT) C. felis RDLR and its A285S mutant were constructed using homology-based, fragment-based threading and AI-driven approaches, of which, SWISS-MODEL generated the most reliable structures. Molecular docking showed that the sarolaner S-enantiomer had higher binding affinity for both receptors than the R-enantiomer, primarily due to hydrogen bonding with Ile256, π–π stacking with Phe326, and hydrophobic interactions with Ile267 and Ile268. Molecular dynamics simulations confirmed the binding stability of the S-enantiomer-receptor complex in which key residues maintained interactions throughout the trajectories. Binding free energy analysis supported these results and highlighted the role of nonpolar interactions in binding stability. The A285S mutation had minimal impact on the binding pocket, and the S-enantiomer remained selective for and bound to the mutant receptor. Insights into the insecticidal mechanism of sarolaner enantiomers are given, and the current findings may inform the development of veterinary drugs from novel isoxazoline-based NAMs targeting insect GABARs. Full article

Varroa destructor, an ectoparasitic mite of honey bees, is a major contributor to global colony declines. To manage infestations, beekeepers frequently apply both synthetic and organic miticides—sometimes in combination. While much attention has been given to foragers’ pesticide exposure, nurse bees are also at risk due to direct miticide contact and prolonged exposure to residuals in hive matrices. Despite this, little is known about the effects of sequential miticide applications on nurse bees. In this study, we evaluated the toxicities of single and pairwise consecutive applications of three synthetic miticides (fluvalinate, coumaphos, and amitraz) and two organic miticides (formic acid and oxalic acid) at field-realistic concentrations. Miticides were topically applied to nurse bees with 24 h between consecutive treatments. Synthetic miticides caused minimal mortality, while both organic miticides—especially formic acid—significantly reduced survivorship. Consecutive treatments generally produced mortality rates comparable to that of the corresponding organic miticide alone, indicating that observed toxicities were primarily driven by the organic agents. Notably, the fluvalinate–formic acid combination induced no significant adverse effects. These findings highlight the need for caution when using miticides in combination and support the development of safer application strategies to protect vulnerable in-hive bee populations.. Full article