Veterinary Parasitology

Tetrahymena piriformis belongs to the ciliated protists (ciliates), causing severe economic losses in aquaculture. Chemical drugs currently used usually have toxic side effects, and there is no specific drug against Tetrahymena. Therefore, it is an urgent need to identify new antiparasitic lead compounds. In the present study, the in vitro parasiticidal activity of ethyl acetate (EtOAc) extracts and water extracts from 22 selected traditional Chinese medicines (TCMs) were evaluated against T. piriformis. The EtOAc extract of P...

The physiologic increase in some sex hormones has been associated with an increase in the parasite load caused by Haemonchus contortus in ewes, especially prolactin. In lambs that are especially susceptible to hemonchosis, the levels of sex hormones are low; in contrast, the levels of another pituitary hormone, growth hormone (GH), which is structurally very similar to prolactin, are high. In this study, the in vitro and in vivo effects of GH on H. contortus larvae development and establishment were evaluated...

The main objective of cattle breeders in tropical and subtropical regions is to acquire animals with taurine-productive traits adapted to the broad weather range of these regions. However, one of the main challenges on using taurine genetics in these areas is the high susceptibility of these animals to tick-borne diseases. Consequently, the present study evaluated from 10 November 2021-19 April 2022, the over 13 assessments, the Babesia bovis and Babesia bigemina DNA loads and the IgG anti-B. bovis and anti-B...

Gastrointestinal nematodes (GIN), especially Haemonchus contortus, represent a significant challenge for sheep production. Given the global concern about GIN anthelmintic resistance, alternative control methods able to reduce the dependence on these drugs are highly advisable. Since previous studies have shown that sheep carrying the Hb-A allele of β-globin are more resistant to H. contortus, this study aimed to investigate the relationship between the different haplotypes (Hb-AA, Hb-AB and Hb-BB) and phenotypes in Santa Inês (SI), Texel (TX) and White Dorper (DO) breeds infected with H...

The poultry red mite, Dermanyssus gallinae (Arachnida: Dermanyssidae) is a pest that causes significant economic loss in laying hens for which control methods are limited. In this study, the effects of 20 indigenous fungal strains on poultry red mites in chicken farms were investigated. All experiments were conducted under laboratory condition at 28 ± 1 °C and 80 ± 5% humidity. A screening test showed that Metharizium flavoviride strain As-2 and Beauveria bassiana strain Pa4 had the greatest measured effect on D...

Previous vaccination trials have demonstrated that thiol proteins affinity purified from Ostertagia ostertagi excretory-secretory products (O. ostertagi ES-thiol) are protective against homologous challenge. Here we have shown that protection induced by this vaccine was consistent across four independent vaccine-challenge experiments. Protection is associated with reduced cumulative faecal egg counts across the duration of the trials, relative to control animals. To better understand the diversity of antigens in O...

Avian coccidiosis, caused by Eimeria spp., is one of the major parasitic diseases in chicken. Aquaporins (AQP) are essential mediators of water regulation and nutritional intake in parasites, and it may be a suitable molecule for chemotherapeutic target and vaccine candidate. We identified two aquaporin genes in Eimeria tenella (EtAQP1 and EtAQP2) with their full sequence, and the expression profiles were analyzed across different stages of E. tenella life cycle. The expression of EtAQP1 and EtAQP2 in Xenopus oocytes renders them highly permeable for both water and glycerol...

Tapeworm infection in horses can cause serious health concerns, and recent data have documented treatment failures in the most common species, Anoplocephala perfoliata. The threat of anthelmintic resistance in A. perfoliata is of particular concern because of poor diagnostic performance of standard egg counting techniques for detecting this parasite. This study compared the performance of three diagnostic techniques 1) Mini-FLOTAC, 2) Cornell-Wisconsin, and 3) Proudman and Edwards used to detect and quantify A...

Rabbits are highly abundant in many countries and can serve as reservoirs of diseases for a diversity of pathogens including the enteric protozoan parasites, Cryptosporidium and Giardia. Both parasites shed environmentally robust environmental stages (oo/cysts) and have been responsible for numerous waterborne outbreaks of diseases. Cryptosporidium hominis and C. parvum are responsible for most infections in humans, while Giardia duodenalis assemblages A and B, cause most human cases of giardiasis. Cryptosporidium cuniculus, the dominant species infecting rabbits, is the only spceies other than C...

Cats are recognized as significant reservoir hosts for human opisthorchiasis, particularly in areas with a high prevalence of infection. Despite this, the precise role of cats in the transmission of Opisthorchis viverrini between humans and felines remains unclear. This study investigates the association between these two hosts through both spatial and non-spatial analyses in the endemic Thanya sub-district of Thailand. A total of 105 owned cats were randomly sampled from 15 villages within the sub-district for stool examination...

The tick Rhipicephalus microplus is a parasite of great importance in cattle breeding. It is responsible for huge economic losses. The application of synthetic acaricides is used as a form of control. However, resistant strains have been selected over the years, making it necessary to search for new alternative formulations. The present study aimed to formulate biodegradable films impregnated with the terpenes carvacrol and thymol and evaluate their efficacy on larvae and adults of R. microplus through in vitro tests...

Extensive farming systems form an integral part of sheep production systems across Europe. However, with innate production handicaps, declining sheep numbers and narrow economic margins, production is becoming increasingly challenging threatening the future sustainability of the industry. Gastrointestinal nematodes (GINs) are a significant cause of production losses to the global sheep industry, with well-established resistance to the major anthelmintic groups. Traditionally, extensive farming systems are not thought to have a significant parasite challenge compared with intensive farms, but there is a need to identify the scale and importance of GINs on extensive farms to inform the need for sustainable control strategies...

This study aimed to evaluate the effects of natural extracts from nine medicinal herbs (SMA) on the growth performance, immunity, and intestinal integrity of broilers experimentally infected with Eimeria tenella. A total of 252 one-day-old broiler chicks were divided into 7 groups with 3 replicates per group and 12 broilers per cage. The groups were uninfected-untreated blank control group (BC), infected-untreated negative control group (NC), SMA treatment groups, Chinese medicine positive control group (CM), and chemical drug positive control group (CD)...

Our understanding of anthelmintic resistance in the gastrointestinal nematodes of Australian cattle relies exclusively on small-scale phenotypic reports utilising traditional faecal egg count reduction tests. This approach is not readily scalable to establish the national prevalence of resistance, nor is it conducive of routine longitudinal surveillance for the emergence of resistance in its early stages. This study introduces the benefits of applying mixed amplicon metabarcoding longitudinally for timely and cost-efficient molecular surveillance of multiple anthelmintic resistance mutations, as they emerge on farms...

Blastocystis is a ubiquitous intestinal protist in humans and animals worldwide. The traditional livestock free-roaming raising system in rural communities increases the risk of infection with contact with a wider range of pathogens transmitted via the faecal-oral route associated with that wildlife-livestock-human interface. However, no studies have been conducted to determine the occurrence and subtype distribution of Blastocystis in livestock in Portugal. Here, we collected 180 faecal samples from herbivore livestock (cattle, goats, horses, and sheep) in different regions of the country to investigate Blastocystis prevalence and subtype diversity using PCR and next-generation amplicon sequencing...

The larvae of the nasal bot, Oestrus ovis, mainly parasitize sheep and goats and some species of wild Caprinae but other mammals and humans are also vulnerable to infestation. Eprinomectin 5 mg/mL topical solution (EPRINEX® Multi, Boehringer Ingelheim) administered at 1 mg eprinomectin per kg body weight pour on was recently authorized as an anthelmintic for sheep and goats with zero hours milk withdrawal in several countries in Europe. As the product in cattle has claims against a broad range of parasites including insect parasites and activity against O...

The faecal egg count reduction test (FECRT) is the most widely used method to assess treatment efficacy against gastrointestinal nematodes (GIN). Information on genera composition of the GIN community is not available with this test and it is commonly obtained by identifying cultured third-stage larvae (L3) or through molecular assays in the post-treatment survey, but results provided are usually only qualitative or semi-quantitative. The updated WAAVP guidelines now recommend assessing anthelmintic efficacy for each GIN genus/species separately (genus-specific FECRT), but this approach is poorly employed in Europe and in goats especially...

Eimeria tenella is the most pathogenic and harmful intestinal parasitic protozoan. Recombinant DNA vaccines open options for promising strategies for preventing avian coccidiosis, replacing chemical drugs and live oocyst vaccines. Two important antigenic proteins, EtAMA3 (also known as SporoAMA1) and EtRON2L2 , act together to promote the invasion of E. tenella sporozoites. In this study, a recombinant DNA vaccine, designated pcDNA3.1(+)-AR, was constructed based on EtAMA3DII, EtRON2L2 D3, and EtRON2L2 D4. Chickens were intramuscularly immunized with different doses (25, 50, or 100 μg) of pcDNA3...

Coccidiosis is one of the leading morbidity causes in chickens, causing a reduction of body weight and egg production. Backyard chickens are at risk of developing clinical and subclinical coccidiosis due to outdoor housing and scavenging behaviour, jeopardizing food security in households. The objectives of this study were to estimate clinical prevalence of coccidiosis at country and regional levels in the Horn of Africa in extensive backyard chickens. A binomial random effects model was developed to impute prevalence of coccidiosis...

Infections with liver and rumen flukes are among the most frequent parasitic diseases in cattle worldwide. In Europe, the predominant liver fluke species is Fasciola hepatica, and the recently rapidly spreading rumen flukes are mostly Calicophoron daubneyi and occasionally Paramphistomum leydeni. In this study, 1638 faecal samples from individual dairy cows from 24 northern and 18 southern German farms as well as one central German farm, all preselected for potential F. hepatica infection, were examined to determine in-herd prevalences of liver and rumen fluke infections...