Efficacy of a single-dose albendazole against lancet liver fluke Dicrocoelium dendriticum and liver enzymes activity in naturally infected sheep.

Infections with D. dendriticum are distributed worldwide and mostly associated with ruminant livestock. Depending on the length and strength of the infection it can be manifested with losses in milk production, reductions in milk and wool quality, decreased weight gains, reproductive performance and poor carcass quality. The objective of this study was to determine the efficacy of albendazole (ABZ) against the lancet liver fluke Dicrocoelium dendriticum in naturally infected sheep using parasitological methods. Twenty-four sheep were divided into four groups: two untreated control groups (C1, C2) and two treated groups (T1, T2), with six animals in each group. The sheep in the treated groups were administered a single oral dose (15 mg/kg bwt) of ABZ suspension. After ABZ treatment the animals were slaughtered on Day 14 (groups C1, T1) and Day 30 (groups C2, T2) and were necropsied. Coprological therapeutic ABZ efficacy reached 92.4% on Day 14 (P < 0.001) and 88.5% on Day 30 (P < 0.001). On Day 30, the serum activities of hepatic and cholestatic enzymes including serological analysis of total protein concentration (TP) and protein fractions were evaluated. Significant decrease of aspartate aminotransferase (AST) (P < 0.01) and gamma-glutamyltransferase (GGT) (P < 0.05) activity by 36.9% and 34.6%, respectively, were detected for sheep in T2 group. These enzymes showed a strong positive correlation to fluke burden: AST (r = 0.654) and GGT (r = 0.768), respectively (P < 0.05). Additionally, the electrophoretic analysis of serum total protein and protein fraction concentrations revealed minimal hypoproteinemia and hyperalbuminemia after ABZ treatment. The decrease of liver enzyme activities and their correlation with fluke burden may indicate recovery of hepatocellular and biliary damage following the reduction of fluke burdens after ABZ therapy. A decline in AST and GGT activity could serve as a valuable adjunct bioindicator of liver damage and fluke reduction after treatment of dicrocoeliosis in naturally infected sheep.

Diversity of RNA viruses in the cosmopolitan monoxenous trypanosomatid Leptomonas pyrrhocoris.

BACKGROUND: Trypanosomatids are parasitic flagellates well known because of some representatives infecting humans, domestic animals, and cultural plants. Many trypanosomatid species bear RNA viruses, which, in the case of human pathogens Leishmania spp., influence the course of the disease. One of the close relatives of leishmaniae, Leptomonas pyrrhocoris, has been previously shown to harbor viruses of the groups not documented in other trypanosomatids. At the same time, this species has a worldwide distribution and high prevalence in the natural populations of its cosmopolitan firebug host. It therefore represents an attractive model to study the diversity of RNA viruses. RESULTS: We surveyed 106 axenic cultures of L. pyrrhocoris and found that 64 (60%) of these displayed 2-12 double-stranded RNA fragments. The analysis of next-generation sequencing data revealed four viral groups with seven species, of which up to five were simultaneously detected in a single trypanosomatid isolate. Only two of these species, a tombus-like virus and an Ostravirus, were earlier documented in L. pyrrhocoris. In addition, there were four new species of Leishbuviridae, the family encompassing trypanosomatid-specific viruses, and a new species of Qinviridae, the family previously known only from metatranscriptomes of invertebrates. Currently, this is the only qinvirus with an unambiguously determined host. Our phylogenetic inferences suggest reassortment in the tombus-like virus owing to the interaction of different trypanosomatid strains. Two of the new Leishbuviridae members branch early on the phylogenetic tree of this family and display intermediate stages of genomic segment reduction between insect Phenuiviridae and crown Leishbuviridae. CONCLUSIONS: The unprecedented wide range of viruses in one protist species and the simultaneous presence of up to five viral species in a single Leptomonas pyrrhocoris isolate indicate the uniqueness of this flagellate. This is likely determined by the peculiarity of its firebug host, a highly abundant cosmopolitan species with several habits ensuring wide distribution and profuseness of L. pyrrhocoris, as well as its exposure to a wider spectrum of viruses compared to other trypanosomatids combined with a limited ability to transmit these viruses to its relatives. Thus, L. pyrrhocoris represents a suitable model to study the adoption of new viruses and their relationships with a protist host.

Variation in allele frequencies in benzimidazole resistant and susceptible isolates of Haemonchus contortus during patent infection in lambs.

We evaluated the variation in the frequency of benzimidazole (BZ) resistance-associated alleles at codons 200, 167 and 368 (F200Y, F167Y, V368L) of the ß-tubulin isotype 1 gene during the patent period in isolates of Haemonchus contortus susceptible and resistant to BZ using pyrosequencing. Four lambs 5-6 months old were infected with 5000-6000 infective third-stage larvae (L3) of the susceptible MHco1 and the multi-resistant MHco4 isolates, respectively. Faecal samples were collected 28-times during 20-90 days post-infection (dpi). Coprocultures were subsequently prepared to produce L3 for genotyping. The frequency of the resistant allele (TAC) at codon 200 in MHco1 was lowest at 43 and 76 dpi with at each time point 0% and highest at 36 dpi with 10.85%, with a mean of 6.47% ± 2.39 and a coefficient of variation of 37.01%. The frequency of the TAC at codon 200 in MHco4 was lowest at 76 dpi with 25.6% and highest at 90 dpi with 49.25%, with a mean of 35.7% ± 4.42 and a coefficient of variation of 12.39%. No resistance alleles were detected in MHco1 at either codon 167 or 368. For MHco4 isolate, resistance alleles were detected only on codon 167 with a mean of 8.00% ± 4.83 and a mean coefficient of variation of 60.40%. Our results demonstrate the considerable variation in the frequency of resistant alleles in the susceptible and resistant isolates during the patent period. This variation should be considered when testing for the presence of BZ resistance in populations of gastrointestinal parasites, especially those with a low frequency of TAC.

Molecular identification of Taenia hydatigena from domestic and free-living animals in Slovakia, Central Europe.

Taenia hydatigena is a cosmopolitan tapeworm that uses canids or felines as definitive hosts, while the larval stage (metacestode), formerly referred to as cysticercus tenuicollis, infects a wide variety of intermediate hosts, in particular ruminants. In the present study, we used partial nucleotide sequences of the cox1 and nad1 genes of T. hydatigena from different animal species to analyse the intraspecies genetic diversity of this economically important parasite. Twenty-four samples of metacestodes or adults of T. hydatigena from infected sheep, chamois, roe deer, fallow deer, wild boar, and dogs from Slovakia were collected and further analysed. Several haplotypes of T. hydatigena were identified with unique mutations that have not been previously recorded in Slovakia. Analysis of nucleotide polymorphism revealed the existence of 9 and 13 haplotypes, with relatively low nucleotide pairwise divergence ranging between 0.3-1.3 and 0.2-1.8% for the Hcox and Hnad haplotypes, respectively. In general, low nucleotide and high haplotype diversities in the overall population of T. hydatigena from the study indicate a high number of closely related haplotypes within the explored population; nucleotide diversity per site was low for cox1 (Pi = 0.00540) and slightly higher for nad1 (Pi = 0.00898). A molecular study confirmed the existence of genetic variation within T. hydatigena isolates from Slovakia. However, further investigations with more samples collected from different intermediate and definitive hosts are required in order to investigate the epidemiological significance of the apparent genetic differences observed in this study.

Impact of Sainfoin (Onobrychis viciifolia) Pellets on Parasitological Status, Antibody Responses, and Antioxidant Parameters in Lambs Infected with Haemonchus contortus.

Our study analyzed the parasitological status, antibody responses, and antioxidant parameters of lambs experimentally infected with a gastrointestinal nematode during the consumption of sainfoin pellets (SFPs) for 14 d. Twenty-four lambs infected with Haemonchus contortus were separated into two groups: untreated animals (control) and animals treated with SFPs (600 g dry matter/d). SFP treatment began on day (D) 30 post-infection. The number of eggs per gram (EPG) of feces was quantified on D18, D23, D26, D30, D33, D37, D40, and D44. The mean reductions in EPG on D40 and D44 were 33.6 and 36.7%, respectively. The number of abomasal worms was lower for the SFP than the control group (p < 0.05). SFP treatment did not significantly affect either the total or the local antibody response (p > 0.05). The blood activity of glutathione peroxidase was affected by the treatment (p < 0.022). Adult worms were selected for scanning electron microscopy after necropsy, but surface structures of adult H. contortus females did not differ between the groups. The treatment of lambs with SFPs directly affected the dynamics of infection, probably indirectly by mobilizing the antioxidant defensive system and antibody response thus improving animal resistance.

Assessing the Efficacy of Albendazole against Fasciola hepatica in Naturally Infected Cattle by In Vivo and In Vitro Methods.

This study was performed on a cattle farm with a long-term use of albendazole (ABZ) and a permanent history of fasciolosis for comparing in vivo and in vitro methods for the detection of anthelmintic resistance and drug efficacy. A selected group of 10 Charolais cows was treated in autumn 2020 with ABZ at a dose of 7.5 mg/kg body weight. Another group of 10 cows remained untreated as a control. The faecal egg count reduction test was used to determine in vivo efficacy. The percentage reduction of eggs on day 14 after treatment ranged from 77 to 81.8%, depending on the formula used for calculation. The in vitro egg hatch test (EHT) was used as a second diagnostic method. F. hepatica eggs for the EHT were isolated from faecal samples. The test was performed in two versions differing in the length of incubation with ABZ (12 h and 15 d). The percentage of eggs with inhibited development at a concentration of 0.5 µM in both versions of the EHT agreed with the in vivo results. Ovicidal activity at a concentration of 0.5 µM in the 12-h version suggested a reduced efficacy of ABZ (65.40%). An EHT prepared using pooled faecal samples was a prospective method for the detection of efficacy and ABZ resistance in F. hepatica.

Effects of Medicinal Plants and Organic Selenium against Ovine Haemonchosis.

The objective of this study was to determine the effect of traditional medicinal plants typical to Central Europe as well as organic selenium on increasing the resistance of lambs to gastrointestinal nematode (GIN) infection with Haemonchus contortus. 21 female lambs were infected with third-stage larvae of H. contortus on the day (D) 0 and re-infected on D49 and D77. The animals were divided into three groups based on a treatment diet: a basal diet (control), a diet enriched with dry plants (Herbmix), and a diet enriched with selenized yeast (Selplex). The number of eggs per gram (EPG) of feces was quantified on D21, D28, D35, D42, D49, D56, D63, D70, D77, D84, D91, D98, D105, D112, and D119. The mean reductions in EPG on D28 were 43.4 and 28.6% for Selplex and Herbmix, respectively. The reduction in egg output was nearly uniform throughout the experiment for Selplex. However, for Herbmix the mean reduction was only 19.8% up to D91 and 46.1% after D91. Glutathione peroxidase activity in the blood from D35 to D98 was two to three-fold higher for Selplex than the other groups. Both supplements slowed the dynamics of GIN infection and gradually increased the resistance of lambs against ovine haemonchosis.

Natural chemotherapeutic alternatives for controlling of haemonchosis in sheep.

BACKGROUND: Parallel in vitro and in vivo experiments were designed to evaluate promising chemotherapeutic alternatives for controlling haemonchosis in ruminants. In vitro anthelmintic activities (egg hatch test - EHT; larval development test - LDT) of aqueous and methanolic herbal extracts Mix1 and Mix2 were investigated. The in vivo effects of dietary supplementation with Mix1 and Mix2 on the parasitological status, inflammatory response, antioxidant parameters and microbial community of the lambs infected experimentally with Haemonchus contortus were investigated. Lambs were divided into four groups for the in vivo study: uninfected control lambs (C), infected lambs (I), infected lambs supplemented with Mix1 (I + Mix1) and infected lambs supplemented with Mix2 (I + Mix2). The experimental period was 70 days. RESULTS: The number of eggs per gram (EPG) of feces was quantified 22, 30, 37, 44, 51, 58, 65 and 70 days post-infection, and mean abomasal worm counts were assessed 70 days post-infection. Quantitative analyses identified 57.3 and 22.2 mg/g phenolic acids, 41.5 and 29.5 mg/g flavonoids and 1.4 and 1.33 mg/g protoberberine-type alkaloids in Mix1 and Mix2, respectively. The methanolic extracts of the herbal mixtures in both in vitro tests had higher anthelmintic effects (P < 0.01) than the aqueous extracts, but the effects did not differ significantly between Mix1 and Mix2 (P > 0.05). I + Mix1 and I + Mix2 lowered mean EPGs between 44 and 70 d by 58.1 and 51.6%, respectively. The level of IgG antibodies against H. contortus increased significantly after infection in each infected group. CONCLUSION: These results represent the first monitoring of the in vitro anthelmintic effects of herbal mixtures on H. contortus. The in vivo experiment indicated that the anthelmintic effect was not sufficient for the elimination of parasites, but this herbal treatment may affect the host over a longer term, reducing the parasitic infection in the host.

Molecular evidence of infection with air sac nematodes in the great tit (Parus major) and the captive-bred gyrfalcon (Falco rusticolus).

Serratospiculiasis is a parasitic disease caused by filariid nematodes of the genus Serratospiculum that parasitise the air sacs of various species of falcons, bald eagles and Cooper's hawks around the world. An infection with Serratospiculum was recently confirmed in a nonspecific host, the great tit, in Slovakia. Parasitic material from this host was fixed for molecular analysis. Nematode found in the air sacs from a captive-bred gyrfalcon was also stored. Analysis of small subunit (18S) ribosomal DNA (18S rDNA) gene indicated that sequences from Serratospiculum sp. and Serratospiculoides amaculata were closely related to a reference sequence from Serratospiculum tendo, in agreement with morphology. This study is the first to generate molecular data and infer the phylogenetic position of S. amaculata as the first representative of the genus Serratospiculoides.