Veterinary parasitology最新文献

Cystic echinococcosis, caused by Echinococcus granulosus sensu stricto (G1/G3), is a major zoonosis with a complex transmission cycle. This study aimed to evaluate the mitochondrial genetic stability of E. granulosus s.s. across different life stages and host species using a controlled experimental infection model. To achieve this, mitochondrial genetic variation was analyzed separately in protoscoleces (naturally infected sheep), adult worms (experimentally infected dogs), and hydatid cysts (experimentally infected lambs), to assess within- and between-group genetic stability. Mitochondrial gene regions CO1 (875 bp) and NADH1 (1009 bp) were amplified and sequenced. Phylogenetic, haplotype, and neutrality analyses revealed that all isolates clustered within a single monophyletic group. While CO1 showed moderate haplotype (Hd = 0.730) and low nucleotide diversity (π = 0.00267), NADH1 displayed higher haplotypic and nucleotide diversity (Hd = 0.983; π = 0.00876). Significantly negative Fu's Fs values for both markers suggested a recent demographic expansion, potentially driven by clonal amplification under low evolutionary pressure. Despite the presence of several haplotypes, no host- or tissue-specific genetic differentiation was observed. These findings demonstrate the genetic continuity of E. granulosus s.s. throughout its life cycle and confirm the suitability of mitochondrial markers for molecular tracking and epidemiological studies in endemic regions.

There are various parasite pathogens that infect cattle, buffaloes, sheep, and goats, with fasciolosis being one of the most common. This article established a glutathione s-transferase (GST) evaluation for Fasciola spp infection and explored its application value as diagnostic tool for assess the hepatic damage, linking it with histopathological findings and the lesion score for the degree of infection with Fasciola spp. Thirty-two animals of cattle species were assigned. The investigation gathered fecal samples for sedimentation counts, blood samples for serum (GST quantification), and two tissue samples from a fasciolosis-infected liver (one in formalin for histopathological examination and the other for homogenate preparation for GST estimation). The animals were divided into four groups (8 each): Severely infected group (SG), Moderate infected group (MoG), Mild infected group (MiG), and non-infected group (C-ve). In sedimentation, SG showed a significantly higher fecal egg count but lower serum and homogenate GST values compared to other groups, while serum and homogenate GST values were lower in SG and MoG than in other groups. MiG group had higher values than C-ve, MoG and SG groups, respectively. Furthermore, pathological lesion scores were gradually increased from low to high in groups viz. (MiG, MoG, and SG, respectively). Hepatic fasciolosis is still a big economic problem in the veterinary field. GST could assess hepatic damage in the case of chronic fasciolosis.

LAMP is a highly sensitive technique and is a useful and applicable tool for DNA detection. This study presents and compares alternative evaluations of the PAR-LAMP for paramphistome DNA detection using electrochemical signal measurements of methylene blue (MB) on screen-printed graphene electrodes (SPGEs) among the other LAMP applications. Two LAMP-MB signal evaluations are (i) the dropping LAMP-MB mixture and (ii) MB-DNA probe on SPGEs. These assays revealed a decrease in the current change (∆I) for positive result using square wave voltammetry (SWV). The dropping LAMP-MB mixture evaluation showed a higher fold current change difference (∆∆I/I₀) than the other evaluation and showed that the positive and negative results can be significantly discriminated. The analytical specificity assay revealed that the target paramphistome DNAs were detectable by the dropping LAMP-MB mixture assay, leading to an increase of the ∆∆I, which was significantly higher than the negative LAMP (P < 0.05). For analytical sensitivity, the gradient DNA concentrations of two paramphistomes were used to construct calibration curves and standard linear regression equations, and these revealed the lowest detected DNA compared with the other LAMP applications, including agarose gel electrophoresis and colorimetry. The electrochemical evaluation can detect a paramphistome egg, as well as the contaminated egg in the host's faeces. In addition, the estimated DNA for a paramphistome egg was calculated using a faeces-interfered factor. This is the first known application of electrochemical assay for parasite egg detection and the DNA quantification in faeces. Therefore, the application of the electrochemical LAMP-MB measurement using SPGEs, particularly the dropping LAMP-MB mixture assay, presented an effective diagnostic tool for DNA quantification in faeces as clinical specimens.

Dermanyssus gallinae is a haematophagous mite species of major concern in the egg industry across the world and there has been a recent surge in studies to find new control methods for this parasite. To provide mites for these experiments, D. gallinae is often raised on hens with the attendant welfare and ethical issues that this entails. Alternatively, mites are collected from infested farm buildings which can lead to variability in mite provenance and quality as well as biosecurity issues. To attempt to overcome these issues in mite supply, we describe a method for maintenance of an in vitro colony of D. gallinae. Mites were maintained, in vitro, for up to 12 weeks and were fed several times per week with goose blood as a food source. The expansion of the colony was monitored weekly and the biomass of mites increased linearly during the initial 8 weeks of culture. To determine the ability of such in vitro-raised mites to feed and thrive if they were exposed to a hen host, mites that had been maintained in this way were used in an "on-hen mite feeding assay" to establish any differences in mite feeding rates, fecundity and mortality between in vitro-raised mites and mites freshly collected from a poultry farm. Feeding rate comparisons were significantly-different between experimental repetitions (p < 0.001), demonstrating the repeatability issues associated with different batches of farm-caught mites. Significantly higher feeding rates on hens were observed for one comparison of farm-caught, compared to in vitro-raised, deutonymphs (p = 0.012) and for adult females (p = 0.002); but no significant difference between the mite sources was demonstrated in feeding rates for protonymphs (p = 0.608) or adult females (p = 0.715) in another experiment. Following on-hen feeding, there were no statistically significant differences between experiments, or between in vitro-raised or farm-caught fed mites, for mite mortality in any life stage or for egg laying.

The effects of doxycycyline administered orally at 10 mg/kg twice daily for 30-day periods in 20 Beagles with SC-induced infections of Brugia pahangi and the effects of treatment on in vivo development of L3 fed on blood from these dogs was studied. Doxycycline was administered on Days 0-29, 40-69 or 65-94, with an untreated control. No worms were recovered from dogs treated on Days 0-29, while all dogs treated on Days 40-69 and 65-94 had some live, stunted worms at necropsy on 218-22 days PI. All control dogs had normal worms. Mosquitoes were fed blood from dogs to assess the ability of L3 to develop in jirds and dogs. L3 from treated and untreated groups were injected IP into jirds. Worm recovery for the treated group at Day 35 PI was somewhat lower than for controls, while recovery for the treated group at Day 60 PI was significantly lower. When L3 from treated and control groups were injected SC into dogs, none of the dogs in the treated group had Mf or live adult worms at necropsy on Day 88 PI, while all control dogs were microfilaremic and had live worms. In conclusion, doxycycline treatment of dogs infected with B. pahangi killed all developing larvae, most immature adults, and some mature adults and disrupted embryogenesis. L₃ from mosquitoes fed on dogs treated with doxycycline were unable to complete development when injected into dogs, and IP inoculation into jirds revealed short-term growth, stunting and gradual reduction in survival of the worms.

Bovicola caprae, the goat biting louse, is a permanent, obligate ectoparasite of goats. It causes dermatitis, irritation, hypersensitivity and lower productivity in goats. Problems associated with chemical insecticide use such as insecticide resistance and environmental concerns indicate that alternative methods (e.g., biological control) are needed. The objective of this study was to investigate the relative potential of different entomopathogenic nematode (EPN) species to control B. caprae. Five EPN species, Steinernema carpocapsae, S. feltiae, S. riobrave, Heterorhabditis bacteriophora and H. indica were tested in the laboratory. We measured relative EPN host attraction, virulence and reproductive capacity. A series of application rates were used to measure EPN virulence. Infective juvenile (IJ) reproduction was assessed in lice cadavers. Results indicated that all the EPNs tested were attracted, infected and killed adult lice; however, louse survival was dependent on EPN species, rate and exposure time. After 48 h, the lowest B. caprae survival was observed in S. riobrave and S. carpocapsae at 200 IJs/insect, with H. bacteriophora and H. indica exhibiting intermediate levels of virulence. In the reproduction assay, greater numbers of IJs were produced in the S. riobrave treatment followed by S. carpocapsae, H. bacteriophora and H. indica. No IJs were found in S. feltiae treated lice. In conclusion, EPNs can invade and kill B. caprae, with S. riobrave and S. carpocapsae exhibiting the most promise for biocontrol efficacy. Future studies will explore the use of EPNs against B. caprae in live animal applications.