Antioxidant effect and acaricidal potential against camel tick, Hyalomma dromedarii of the essential oil hydrodistilled from Myristica fragrans Houtt. (Nutmeg)
Nowadays, ticks are considered to be one dangerous blood-sucking ectoparasite for poultries, livestocks and even some wild animals. Therefore, the objectives of this study were to investigate the insecticidal activity of the essential oil extracted from Myristica fragrans Houtt. with the popular name nutmeg (NEO) against the camel ticks, Hyalomma dromedarii. When the engorged female ticks were immersed in 10 mL of NEO solution of the concentration 800 mg/mL for 5 min, the essential oil could not only decrease the viability and mobility of them, but also decrease their blood digestion. Meanwhile, the acaricide efficacy of NEO against the engorged female ticks was demonstrated as well. When the eggs produced collected, weighed, deposited in the bottles covered by cotton gauze and subjected to the incubator for hatching, the essential oil was demonstrated to have the prominent inhibitory effect against the oviposition, hatchability and fertility of the engorged female ticks, when the engorged female ticks were immersed in 10 mL of NEO solution of the concentration 400 and 800 mg/mL for 5 min. In consequence, the employment of NEO as the potential insecticide against the ticks, H. dromedarii, is prospective in the future.
Proteomic analysis of extracellular vesicles and extracellular vesicle-depleted excretory-secretory products of Toxocara canis and Toxocara cati larval cultures
Toxocara canis and Toxocara cati are parasitic nematodes in the order Ascaridida, which inhabit the small intestines of dogs and cats, respectively, as adults. Although often nonpathogenic as adults, nematodes within this genus are capable of causing widespread disease throughout the host while in a larval stage, during which time larvae migrate throughout the body in a process termed larva migrans. Larvae are also capable of surviving within host tissues in an encysted arrested stage, without immune clearance by the host. The ability of larvae to survive within host tissues during migration and encystment may be attributed to immunomodulatory molecules released by the excretory cells of larvae in excretory-secretory (ES) products. ES products of parasites contain a variety of molecules, including proteins, lipids, and extracellular vesicles (EVs). Toxocara excretory-secretory (TES) products have been studied to some degree, with proteomic analysis of TES proteins described previously; however, investigation of the EVs within TES is lacking, despite the suggested role for these molecules in host interaction and potential immunomodulation. To further characterize the protein cargo within EVs in TES, EVs were isolated from larval cultures of T. canis and T. cati via ultrafiltration, with concurrent collection of EV-depleted TES filtrate for additional study. Isolated EVs and EV-depleted TES from both T. canis and T. cati were submitted for proteomic analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS). Proteomic identification results revealed 140 proteins across all samples, with 16 shared by all samples, and 76 total proteins shared between T. canis and T. cati, present within EVs and EV-depleted TES. There were 17 proteins shared exclusively by EV samples, and 15 were shared exclusively between EV-depleted TES samples. Many shared proteins were associated with the host immune response. Several proteins were specific to either T. canis or T. cati, highlighting the potential use of these proteins as diagnostic tools in the differentiation of etiologic agents in cases of toxocariasis. The results of this study build upon previously reported proteomic evaluations of TES, contributing new information in regards to newly identified proteins, EV protein cargo within TES, and potential immunomodulatory functions of these proteins.
Efficacy of the fungus Purpureocillium lilacinum applied via drone onto pasture for controlling the tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)
In the southeastern region of Brazil, ticks of the species Rhipicephalus (B.) microplus are constantly present on cattle throughout the year. This is due to climatic conditions that favor the biology of these ticks and resistance to the acaricides in use that has developed. The aim of this study was to evaluate the efficacy of the fungus Purpureocillium lilacinum (IBCB 130) in powdered form, applied via a drone, from the bioFUNGUS spray dispenser (NCB Sistemas Embarcados Ltda), onto pasture for controlling these ticks. This experiment was conducted at Aptaregional, Regional Research and Development Unit of Pindamonhangaba, São Paulo, Brazil. To evaluate the efficacy of treatment, two groups were formed (treated and control), each with ten calves of the Girolando breed, which were kept in two separate paddocks in which the main grass species was Brachiaria decumbens. The treated paddock received seven monthly applications (November-May) of the fungus Purpureocillium lilacinum (5 g de P. lilacinum in 200 g of wheat flour). The control paddock did not receive any treatment. Tick counts performed on the animals every two weeks showed that, over the entire period, the treatment had a mean efficacy of 48.59 %. The months of December and January presented the highest efficacy rates, of 63.50 % and 83.87 %, respectively.
Corrigendum to "In vitro evaluation of the potential of mites of the family Macrochelidae (Acari: Mesostigmata) as macrobiological agents against the nematode Haemonchus contortus (Strongylida: Trichostrongylidae)" [Vet. Parasitol. 328 (2024) 110191]
Evaluation of the efficacy of disinfectants and disinfection methods against Ascaris suum eggs
Ascaris is highly adaptable, allowing its offspring to thrive in various conditions and posing significant health risks widely among animal populations. Most studies regarding the efficacy of disinfectants against Ascaris eggs in animal houses have been limited and lack a systematic and comprehensive evaluation. Currently, Ascaris suum is one of the most extensively studied helminths in the context of parasitology. Here, 8 disinfectants, UV radiation and quicklime were used to treat A. suum eggs, which were subsequently incubated at a room temperature of 22-25ºC for 15 days. The inactivation rate of A. suum eggs (expressed as a percentage) was measured to assess the efficacy of disinfectants, UV radiation, and quicklime in inactivating A. suum eggs. The results indicated that 1 %-10 % povidone iodine, 5 %-25 % ammonia solution, 0.5-2 % chlorine dioxide, 75 % ethanol and formalin in long-term (15 days), as well as the 5 % and 10 % povidone iodine, 25 % ammonia solution and UV irradiation in short-term (30-120 min) completely inhibited the normal development of A. suum eggs up to L2 stage. In conclusion, 75 % ethanol, povidone iodine, chlorine dioxide, ammonia solution, formalin, and UV irradiation are effective in inactivating A. suum eggs for dual disinfection of parasites and microorganisms. Among them, povidone iodine and UV irradiation are relatively efficient and environmentally friendly disinfection methods, and chlorine dioxide, a relatively harmless and broad-spectrum disinfectant, is an alternative choice for A. suum eggs elimination.
A 50-year-old question: Can imidocarb chemoprophylaxis ensure seroconversion for babesiosis in cattle under field conditions?
Bovine babesiosis, caused by Babesia bovis or Babesia bigemina, is a major tick-borne disease affecting livestock. In regions with limited vaccine availability, imidocarb is widely used as a chemoprophylactic drug. Although it is assumed that chemoprophylaxis allows for the development of immunity shortly after treatment, the extent of seroconversion during the imidocarb administration protocol remains largely unexplored, with most investigations emphasizing symptom prevention. This research endeavors to verify the seroconversion rate (humoral immunity) of cattle undergoing imidocarb chemoprophylaxis while exposed to tick vectors in field conditions. Fifteen tick-naïve heifers were used, with twelve receiving imidocarb (experimental group) on day 0 of the experiment, and the remaining three serving as controls. On day one of the study, all animals were introduced into a tick-infested pasture. Subsequently, at 28-day intervals (days 28, 56, 84, 112, 140, and 168), the experimental group received imidocarb treatments (1.2 mg/Kg). The detection of antibodies against B. bovis and B. bigemina was performed using commercial ELISA kits. Throughout the study, all animals were exposed to natural infestation by Rhipicephalus microplus ticks. By the 56th day, after two imidocarb doses, 25 % of the experimental group had seroconverted for B. bovis, and 41 % for B. bigemina. By the 84th day, 66 % were seropositive for B. bovis and B. bigemina. By the 112th day, 75 % were seropositive for B. bovis. Notably, one heifer (8 %) failed to seroconvert for either species, while 41 % remained seropositive for only one Babesia species. These findings underscore certain limitations of the chemoprophylaxis protocol for bovine babesiosis. While the majority of treated cattle become seropositive for at least one Babesia species after four successive treatments, exposure to the parasite while receiving imidocarb chemoprophylaxis does not guarantee seroconversion for all treated animals.
Nanotechnology: An avenue for combating fish parasites in aquaculture system
The intensification of aquaculture in recent years has led to the rise of infectious fish diseases caused by bacteria, viruses, and parasites. Parasitic diseases, in particular, are widespread and have significant economic impacts globally. Protozoan parasites like Ichthyophthirius multifiliis and Trichodina sp., myxozoans (cnidarians), monogeneans like Dactylogyrus sp. and Gyrodactylus sp., and crustacean parasites like Argulus sp. and Lernaea cyprinacea primarily cause these diseases. Despite advancements and new technologies aimed at understanding and treating these diseases, parasites remain a major health challenge in aquaculture. Traditional antiparasitic agents face limitations, including drug resistance and negative effects on non-target organisms. Recently, nanotechnology has emerged as a novel approach in aquaculture medicine, enabling the development of effective nanoparticles against pathogenic microbes. Silver nanoparticles (AgNPs) are particularly notable for their strong antimicrobial and antiparasitic properties due to their broad mechanisms of action. Although Argulus is a highly destructive crustacean parasite that financially burdens fish farmers, applying nanoparticles to manage this infection in aquaculture is still underexplored. Therefore, this review explores recent efforts to combat parasitic diseases with AgNPs and investigates their potential parasiticidal mechanisms of action, proposing them as a novel tool that could improve the management and control of argulosis diseases. The article underscores the benefits and challenges of this technology, emphasizing its significance in fostering improved health management for sustainable aquaculture.
Levonorgestrel enhanced Toxoplasma gondii infection risk via progesterone receptor upregulation
The numerous stray cats and dogs worldwide pose a huge burden on local governments, keeping residents safe and healthy, and maintaining clean cities with good traffic situations. To effectively control the populations of these stray animals, while considering animal welfare, researchers have suggested the use of levonorgestrel (LNG) as a contraceptive method. However, the potential side effects of LNG on these animals need to be evaluated before widespread application. Since dogs and cats play important roles in the transmission of Toxoplasma gondii as intermediate and definitive hosts, respectively, it is critical to assess the safety of LNG from the perspective of its effect on Toxoplasma susceptibility. In this study, the susceptibility of mice to T. gondii infection was investigated in vivo and in vitro with the presence of LNG. As a result, LNG increased the risk of infection, which was probably associated with the downregulation of IFN-γ levels, but not with the alteration of host sex hormone levels. Concurrently, the presence of LNG enhanced the expression of its ligand, the progesterone receptor (PGR), on the host cells. The promotional effect of LNG on T. gondii infection was attenuated when the PGR gene was knocked down. This investigation represents the inaugural study of LNG's side effects on T. gondii infection in mice, underscoring the significance of choosing or developing suitable contraceptive drugs for stray animals.
The efficacy of essential oil components with ivermectin against Rhipicephalus annulatus: An in-vitro study
Ivermectin (Iv) is widely used to control Rhipicephalus annulatus infestations in cattle in Egypt. However, increasing resistance to ivermectin necessitates alternative approaches. This study aimed to address this resistance by investigating the interactions between ivermectin and essential oil components (EOCs)-carvacrol, cinnamaldehyde, D-limonene, trans-anethole, and thymol-against four R. annulatus tick isolates collected from Beni-Suef, El-Minia, and El-Fayoum. The larval immersion test was conducted using various ivermectin concentrations (3, 1.5, 0.75, 0.38, 0.19, 0.09, 0.045, 0.025, and 0.0125 mg/mL) prepared in EthTX1 %. Additionally, EOCs were tested at different concentrations (20, 10, 5, and 2.5 mg/mL) prepared by dilution in 5 % ethyl alcohol and EthTX 1 %. Ivermectin and each EOC were tested individually against the isolates. Subsequently, the LC50 of ivermectin was combined with the LC50 of each EOC in a 1:1 ratio to evaluate potential synergistic effects. All EOCs demonstrated significant toxicity against the isolates. The combination of carvacrol and thymol with ivermectin increased mortality, but the combination index (CI) exceeded one for all isolates, indicating no synergism. Similarly, while D-limonene, cinnamaldehyde, and trans-anethole also resulted in high mortality rates, including up to 100 %, no synergism was observed (CI > 1). However, these three EOCs exhibited CIs close to 1, suggesting an additive effect when combined with ivermectin. In conclusion, combining ivermectin with certain EOCs, particularly D-limonene, cinnamaldehyde, and trans-anethole, may offer an effective tool for controlling cattle ticks. Developing topical or pour-on formulations of ivermectin-EOC combinations could be an integral part of integrated management strategies to combat resistance to macrocyclic lactones like ivermectin. Further studies, including tests on adult ticks and field trials, are needed to evaluate the efficacy of these combinations.
Risk factors associated with increased Toxoplasma gondii seroprevalence in South Australian Sheep
Toxoplasma gondii (T. gondii) is a protozoan parasite of substantial impact to small ruminants, with reproductive failure a possible outcome of exposure. This observational study assessed T. gondii prevalence within the South Australian sheep population and investigated on-farm risk factors to T. gondii exposure via a cross-sectional survey. 1433 individual animals, consisting of 1282 mixed-age ewes and 151 mixed-age rams were blood sampled and serologically screened for T. gondii-specific antibodies. A risk-analysis questionnaire was conducted for each participating property. Of the 1433 animals sampled, 530 tested positive, with seroprevalence observed to be 39 % (95 % CI 28.7-49.3 %) after accounting for clustering within properties. All properties returned at least one positive result, indicating a flock level seroprevalence of 100 %. T. gondii seroprevalence was found to be higher in sheep on Kangaroo Island (46.6 %; 95 % CI 32.1-61.1 %) compared to the South Australian mainland (31.3 %; 95 % CI 18.4-44.2 %), however this difference was not statistically significant (P=0.125). A significant association was observed between T. gondii seroprevalence and age, with seroprevalence increasing from 30.2 % (95 % CI 17.7-42.6 %) in one year old sheep, to 69.7 % (95 % CI 47.0-92.5 %) in sheep older than six years (P=0.001). T. gondii seroprevalence was significantly higher in animals drinking water from surface water sources (55.9 %; 95 % CI 35.2-76.6 %), compared to those exclusively sourcing reticulated mains water (19.1 %; 95 % CI 0 %-39.0 %) (P=0.028). An individual animal exposed to a surface water source was found to be more than ten times as likely to be exposed to T. gondii, than an animal sourcing only reticulated mains water (odds ratio:10.68; 95 % CI 1.30-87.88). Water source is important in the transmission of T. gondii to South Australian sheep. Mitigation strategies should be developed and targeted at reducing contact between oocysts and water sources and reducing interaction between livestock and contaminated water.
Development and evaluation of egg yolk-derived antibodies for ELISA diagnostics of African Animal Trypanosomiasis
African animal trypanosomiasis (AAT) represents a significant challenge to livestock development in Africa. Reliable and practical techniques are required for the disease's early detection and management. One of the most commonly used tests for this purpose is the Enzyme-Linked Immunosorbent Assay (ELISA). This study sought to create a protocol for producing labelled antibodies from egg yolk. IgG was purified from serum from cattle that were hyperimmune to Trypanosoma brucei brucei before being used to immunise chickens. IgY antibodies were extracted from eggs, labelled with peroxidase, and tested for activity against commercial products. The results revealed that IgY levels were consistently higher than IgG levels, and the experimental antiserum had high diagnostic potential. We also calculated the ratios of commercial and individual egg yolk antisera. The findings allowed us to rank the diagnostic potential of the experimental antisera, with detection rates of 47.33 % for positive samples and 41.47 % for negative samples. Our results show that the experimental antiserum detects target antibodies with comparable accuracy and statistical significance (p < 0.001). Furthermore, the production method based on laying chickens proved to be simple, effective, and economical. This locally synthesised antiserum provides a viable alternative to expensive commercial options, paving the way for more widespread use in serodiagnosis. Further refinement and validation of this methodology could result in the development of a standardised protocol for large-scale production, offering a cost-effective and ethically sound alternative to antiserum production and facilitating wider adoption of ELISA diagnostics in resource-constrained settings.
Exploring cryopreservation alternatives for Dirofilaria immitis microfilariae
Canine Heartworm Disease, caused by Dirofilaria immitis, primarily affects canids and felids. The earliest studies on cryopreservation were carried out at -70°C, achieving acceptable survival rates, however microfilariae (mf) showed alterations both in morphology and motility. Thereafter, liquid nitrogen was used representing an excellent tool for long-term preservation, albeit it is expensive and requires trained personnel. Accordingly, the aim of this study was to develop a protocol for cryopreservation of D. immitis mf at -80°C feasible to laboratories with limited specialized equipment. The cryoprotectant medium was composed by 5 % dimethyl sulfoxide, 20 % of newborn calf serum and 75 % of saline solution. At Study Day (SD) 0 whole blood from a D. immitis naturally infected dog was diluted with the medium at a ratio of 1:1 and stored at -80°C using a freezing container (Nalgene® Mr. Frosty® Cryo 1°C). On the SD1 and then once a month, one cryovial was thawed and examined for survival, motility, length and morphology of mf. On SD 1, the mf showed a survival rate of 99 %. By SD 120 the survival rate gradually decreased (up to 63 %) and a shift in motility patterns between the "medium" and "slow" classes, was observed. On SD 150, the survival rate exceeded 50 % and mf did not exhibit detectable morphological alterations; however, a reduction in length was observed. This study marks the first protocol where the -80°C freezer has been employed for cryopreservation of D. immitis, integrating the application of cryoprotectants and novel techniques for gradual temperature transition.
In vivo antischistosomal activity profiling and efficacy of niosomal Spirulina platensis and praziquantel combined remedy against murine Schistosoma mansoni infection
Schistosomiasis is a serious parasite disease with a high rate of mortality and negative financial impacts in subtropical and tropical locations like Egypt. The goal of this study was to investigate the anti-schistosomal effect of Spirulina platensis (SP) and Spirulina loaded niosomes (SPN), either in the presence or absence of praziquantel (PZQ) against S. mansoni in experimentally infected mice. Six groups have been involved in the study, five groups were infected with S. mansoni cercariae and subjected independently to different treatments of SP, SPN, and PZQ or the preceding two combinations, in addition to one untreated group which acts as a control. At the 8th week, mice were euthanized, and besides a histopathological assessment of the liver granuloma, the number of worms, tissue egg load, and oogram pattern were estimated. To evaluate the condition of the liver oxidative stress, the levels of malondialdehyde and reduced glutathione in liver homogenates were investigated. Additionally, to assess the anti-inflammatory properties, serum cytokines (IFN-γ, TNF-α, IL-13, and IL-10) and CD4 immunohistochemistry expression were determined. The results demonstrated that each of the investigated parameters was significantly changed by both SPN and/or SPN with PZQ treatments alongside PZQ. The highest therapeutic effect was obtained in SPN combined with a half dose of PZQ which achieved 100 % reduction in both the total worm burden and the highest reduction in the intestinal (93.22 %) and hepatic (94.4 %) egg content, as well, moreover 40.5 % reduction of the granuloma size. Furthermore, serum cytokine levels {(TNF-α (11 ± 0.5 (P ˂ 0.001)), (IFN-γ (19.7 ± 1.2 (P ˂ 0.001)) and (IL-13 (53.65 ± 1.4 (P ˂ 0.001))}, as well as CD4 cells (6.5 ± 0.65 (P ˂ 0.001)) were reduced. While, IL-10 (61.1 ± 2.1 (P ˂ 0.001)) was increased due to the same treatment additional to its antioxidant properties by reduced lipid peroxidation (LPO) (1.1975 ± 0.05(P ˂ 0.001)) but increased reduced glutathione (GSH) (2.31± 0.15 (P˂0.001)). In conclusion, SPN has a schistosomicidal, antioxidant, and hepatoprotective role. SPN has a strong synergistic effect when combined with PZQ which showed anti-inflammatory action. Hence, SPN + PZQ offers promising alternatives for future schistosomiasis therapeutic research.
Increase in dairy production of goats with subclinical nematode infection using injectable eprinomectin
The effect of the treatment with an injectable product containing eprinomectin on milk yield, milk composition, and somatic cell count (SCC) was investigated in naturally infected dairy goats with low gastrointestinal nematode faecal egg and pulmonary larval counts. The study involved 394 lactating goats and was conducted on a farm in southern Spain. Before treatment, faeces from all animals were analysed to establish two homogeneous groups according to the gastrointestinal nematode egg counts (185 treated and 209 untreated). On day 0, each goat in the treatment group received a single subcutaneous injection of 12 mg of eprinomectin (0.6 ml of Eprecis®, CEVA, Spain). The control goats were left untreated. Faecal egg counts and coprocultures were performed on days 0, 30, 60, and 90 post-treatment. Milk samples were taken on days 0, 30, 60, 90, and 120 and analysed to determine individual production and milk composition parameters, including fat (F), protein (P), lactose (L), total dry extract (TDE), and SCC. Examination of faecal samples indicated that the goats were mainly infected with gastrointestinal strongylids of the genera Teladorsagia and Trichostrongylus and Muellerius lungworms. The percentage reduction of gastrointestinal nematode faecal egg counts on days 30, 60, and 90 was 97.55 % (90 % CI = 95.1 % - 99.9 %), 90.65 % (90 % CI = 83.7 % - 97.6 %) and 87.5 % (90 % CI = 79.5 % - 95.5 %), respectively, and that of lung larval counts in faeces was 98.48 % (90 % CI = 96.3 % - 100 %), 96.91 % (90 % CI = 84.2 % - 98.9 %), and 82.05 % (90 % CI = 66.9 % - 97.2 %), respectively. Milk yield was consistently and significantly higher in the treated group than in the control group (p = 0.004). The treated goats showed a 4 % increase in daily milk yield (60 ml/day) compared with the untreated goats. There was a significant decrease in F and TDE in the treated goats compared with the untreated goats, but eprinomectin did not affect P, L, and SCC. The estimated economic benefit of using injectable eprinomectin was around 6.46€ per goat over the 120-day period. In conclusion, treatment with injectable eprinomectin has an economical positive effect on milk yield in goats, even those infected with a low burden of gastrointestinal and pulmonary nematodes.
In vivo anthelmintic activity of hydroethanolic extract of Piper cubeba fruits in sheep naturally infected with gastrointestinal nematodes
Parasitic infections caused by gastrointestinal nematodes (GINs) are the main cause of production losses in small ruminants, especially sheep. Haemonchus contortus is the most common nematode in tropical regions. The indiscriminate use of synthetic anthelmintics to control helminthosis has led to the development of resistant parasites. As a result, there has been growing interest in using plant extracts and natural products to control gastrointestinal nematodes in sheep. Therefore, this study aimed to evaluate the in vivo anthelmintic activity of the hydroethanolic extract of Piper cubeba fruit in sheep naturally infected with gastrointestinal nematodes. Initially, an experiment was conducted where the Piper cubeba extract was administered at a dose of 2.5 mg/kg body weight three times at 7-day intervals. For this, 18 animals were divided into three groups: a control group, a group treated with levamisole phosphate at 4.7 mg/kg body weight subcutaneously, and a group treated with Piper cubeba extract, which was administered in pure form orally to the animals through a cannula. Based on the results of this experiment, a second experiment was conducted using the same experimental design and same extract, but the effectiveness of the extract was evaluated at a single dose of 5.0 mg/kg body weight administered on day 0. The determination of biochemical parameters for the group treated with extract and the identification of nematode species for all groups were performed on different days of this experiment. The results of the first experiment showed that the extract reduced the FEC by 84 % on day 7 and 83 % on day 35 compared to the control group. These results prompted a second experiment, using the same experimental design, but with the extract administered to the animals in a single dose of 5 mg/kg body weight. The result for the reduction in FEC in the levamisole-treated group was similar to that obtained in the first experiment, whereas in the group treated with a single dose of the extract, the reduction was significant from day 7, reaching 97 % by day 35 compared to the control group, with no significant difference from the levamisole-treated group. Regarding nematode species, on day 0, all treatments in the experiment showed a predominance of Haemonchus contortus, but other species such as Cooperia, and Oesophagostomum were also identified. On day 35, only Haemonchus contortus was identified in the extract-treated group and the levamisole-treated group, whereas Cooperia and Oesophagostomum species were also found in the control group. Toxicity tests for liver and kidney functions showed no alterations after administration of the single dose extract. These results demonstrate the in vivo anthelmintic activity of the hydroethanolic extract of Piper cubeba fruits and suggest its potential use as an alternative to synthetic chemicals in controlling parasites in sheep.
Updating the epidemiology of canine leishmaniosis in the United Kingdom through the use of electronic health data
Dogs infected with Leishmania infantum have been increasingly reported in the UK mostly related to imported/travelled dogs. Up-to-date epidemiologic data are essential for a better control of this zoonotic disease in such emerging areas. This study aimed for the first time, to estimate the percentage and temporal variation of dog and cat samples testing positive for L. infantum infection at commercial diagnostic laboratories, and to describe the travel history of positive dogs and cats positive to leishmaniosis in a network of UK veterinary practices. Leishmania infantum serology and PCR data were collected by the Small Animal Veterinary Surveillance Network (SAVSNET) from five UK national veterinary diagnostic laboratories between 2010 and 2022 and were analysed. In addition, electronic health records (EHRs) were collected from 251 veterinary practices across the UK between March 2014 and September 2022. Text mining tools were used to identify cases compatible with clinical leishmaniosis as recorded in the clinical narratives; these were subsequently manually validated. Data from a total of 25,327 diagnostic samples (25,201 from dogs and 126 from cats) were analysed including 20,517 sera tested by either quantitative ELISA or IFAT, and 4810 by PCR. Leishmania infantum antibodies were detected in 39.7 % of tested dog samples and 1.07 % of cat samples. In dogs, seropositivity increased from 2013 to 2022. Leishmania DNA was only detected by PCR in samples from dogs (11.8 %). A total of 368 dogs with canine leishmaniosis (CanL) were identified from clinical narratives. Of these, 189 had either visited, or were rescued/imported from, Spain, Greece, Cyprus and other southern European countries. Among factors associated with CanL in the UK canine population, dogs between 3 and 6 years of age were 4.71 times more likely to have CanL than those two years or younger. In addition, there was an increased risk of having recorded CanL clinical cases from 2017 to 2022, compared to 2014. Southeast of England was the UK region that accounted for the highest number of CanL cases (34.51 %). This study provides recent trends in Leishmania infection in dogs in the UK, identifies risk factors and countries likely associated with imported cases, and provides important insights to help plan and monitor national intervention strategies.
A safe antiparasitic extract from Psoralea corylifolia for Tetrahymeniasis control
Tetrahymeniasis is a ciliate disease that presents significant economic challenges for the aquaculture industry. Previous research has shown promising control effects on Tetrahymena pyriformis using flavonoids from Psoralea corylifolia (P. corylifolia), but their high cost hinders practical application. This study aims to find an affordable and safe alternative antiparasitic extract derived from P. corylifolia. Initially, six different solvent extracts from P. corylifolia were compared for in vitro antiparasitic activity and toxicity, with ethyl acetate (EtOAc) extract selected for in vivo testing. In vivo tests revealed that effective concentrations of the EtOAc extract approached toxic levels. Chemical analysis identified bakuchiol as the most abundant and toxic compound in these extracts, with the highest solubility in n-hexane. Two optimized extraction protocols, yielding extract I and extract II, were developed based on these findings. Extract II successfully reduced the level of bakuchiol and overall toxicity while maintaining efficacy. At a concentration of 40 mg/L for 24 h, extract II achieved a 100 % antiparasitic effect with a therapeutic index of 2.121, nearly double that before optimization, leading to an increase in survival rate of diseased guppies from 15 % to over 65 %. These results suggest that this bath therapy could be a practical and cost-effective alternative for treating tetrahymeniasis in aquaculture. Futhermore, the optimized extraction method employed in this study offers new possibilities for reducing toxicity and enhancing the effects of Chinese herbal medicine. In summary, this study demonstrated that extract II derived from P. corylifolia has the potential to be developed into a novel commercial drug for the control of Tetrahymena infections in fish.
Ivermectin induces oxidative stress and mitochondrial damage in Haemonchus contortus
Haemonchus contortus poses a severe threat to livestock, leading to substantial economic losses. The extensive use of ivermectin (IVM), an effective anthelmintic drug, has resulted in the development of resistant strains, reducing the drug's effectiveness and making disease management more challenging. Hence, understanding the underlying mechanisms of IVM resistance is crucial. IVM has been shown to induce apoptosis and oxidative stress imbalance in cancer cells, thereby inhibiting tumor growth; however, whether there is a similar impact on H. contortus has not been well-documented. In this study, the biological functions of previously identified resistance-associated genes were investigated, revealing their involvement in apoptosis and oxidative stress. Experiments were conducted to compare cell apoptosis, mitochondrial function, and oxidative stress markers in IVM-treated and untreated sensitive and resistant strains isolated from the field. The findings demonstrated that mitochondrial dysfunction and increased apoptosis were induced by IVM treatment in sensitive strains, as indicated by elevated mitochondrial membrane potential and apoptosis rates. Conversely, stable mitochondrial function and apoptosis levels under IVM exposure were observed in resistant strains. These results provide novel insights into the resistance mechanisms of H. contortus and offer a theoretical basis for future research on overcoming IVM resistance.
Cuticular composition: An alternative taxonomic approach to differentiate between Argas arboreus and Argas persicus ticks (Acari: Argasidae)
Argas arboreus and A. persicus are blood sucking ectoparasites on domestic birds in Egypt. They cause anemia in birds, in addition to transmitting a variety of pathogens that leads to economical loss in the poultry industry. It is difficult for non-taxonomists to differentiate between these species because of minor morphological characters. Therefore, it is very important to identify tick species for developing a suitable strategy to reduce risks to poultry wealth. This study characterized the female cuticular hydrocarbons of two Argas species using gas chromatography-mass spectrometry. Sixty different hydrocarbons were exclusively identified in A. arboureus, whereas only 51 in A. persicus. Some of the hydrocarbon compounds were stage-specific ones that differentiate between two species. Others shared between all feeding stages of both species that improved they are closely related ones. Genetic variability recorded its maximum value between unfed stages of the two species, and similarity reached only 25 %. The present study provides the first chemotaxonomic data to differentiate between two closely related Argas species according to their cuticular hydrocarbons. Therefore, hydrocarbon composition seems to be a promising tool available as a taxonomic character, in addition improved that feeding stage was the susceptible one to be controlled.
Contribution to host diversity, genetic diversion, and epidemiology of Trichinella pseudospiralis in Slovakia, central Europe
Trichinella pseudospiralis belongs to the non-encapsulated clade of the genus and its epidemiology is influenced by various biotic and abiotic factors. The role of different animal species in the spread and epidemiology of the parasite is still not well understood and further research is needed in the areas where its occurrence has been recorded. In Slovakia, T. pseudospiralis was first documented in 2004 on a poorly maintained industrial pig farm where pigs, rats, and a domestic cat were found to be infected. In the following years, its occurrence was confirmed in foxes, wild boars, and three species of birds of prey. The objective of the present study was to investigate different micromammal and carnivore host species inhabiting the Tatra National Park in the north of Slovakia for the presence of Trichinella parasites. From 2018-2023, 715 small mammals belonging to 19 species and 92 muscle samples from 12 carnivorous species were individually examined for the presence of Trichinella muscle larvae using the artificial digestion method. The research brought new host records and completed the list of sylvatic hosts for T. pseudospiralis in Slovakia - the yellow-necked mouse (Apodemus flavicollis) and raccoon dog (Nyctereutes procyonoides) together with results of the genetic structure study conducted on a fragment of the 28S gene in T. pseudospiralis.
Anthelmintic efficacy of febantel against a monogenean parasite, Gyrodactylus kobayashii
Monogenean parasites pose a significant challenge to aquaculture, leading to adverse effects on fish health and yields. Current anthelmintic treatments for monogeneans have demonstrated limited efficacy and are further complicated by potential issues, which emphasize the necessity for effective and safe therapeutic strategies to manage monogeneans in aquaculture. In this study, in vivo and in vitro anthelmintic activity of febantel against Gyrodactylus kobayashii on goldfish (Carassius auratus), as well as its toxicity to goldfish were evaluated. In vivo assays indicated that febantel exhibited potent anthelmintic activity against G. kobayashii with an EC value of 0.03 mg/L and 100 % anthelmintic efficacy at 0.1 mg/L after 48 h of exposure. Moreover, in vivo trials also revealed a notable post-treatment effect of febantel, where infected goldfish transferred to drug-free water after short 6-h exposure could still result in full eradication of the worms, indicating febantel might induce persistent perturbations in parasite physiology. In vitro assays showed a negative correlation between febantel concentrations and the survival of G. kobayashii. However, increasing the febantel concentration to 2.0 mg/L did not result in the complete death of all worms. Oral administration of febantel demonstrated limited anthelmintic activity, with only 49 % efficacy at a dosage of 200 mg/kg body weight daily over five days. Acute toxicity assays revealed the 48-h LC value of febantel was 5.47 mg/L, which was 182.23 times higher than the 48-h EC value, indicating that febantel has a favorable safety profile. However, febantel exposure potentially interfered with hepatic metabolism and oxidative status, as indicated by variations in SOD, GST, and P450 gene expression. In conclusion, treatment with 0.1 mg/L febantel for 24 h completely eradicated G. kobayashii infection on goldfish, demonstrating febantel's potent anthelmintic activity. Coupled with its safety profile and extended post-treatment effectiveness, febantel is a promising candidate for controlling Gyrodactylus infections in aquaculture.