The influence of climate change and global change has pushed trematodiases to the forefront of infectious disease awareness (Caminade et al. 2015; Chowdhury et al. 2016). This disease causes significant losses in the livestock sector, such as milk and meat production, secondary bacterial infections and expensive anthelmintic treatment (Soulsby 1968; Young et al. 2010). This condition is combated by flux by altering cellular functions through immune evasion and subversion (Ryan et al. 2020; Jiménez et al. 2021; Mei et al. 2022).
Several studies have been conducted on cattle and buffalo against fasciola infection, but a commercial vaccine is still not available (Toet et al. 2014; Akıl et al. 2022). Vaccination with GST can provide 57% protection in sheep infected with Fasciola and Taenia ovis (Johnson et al. 1989). Vaccination of cattle and sheep using cathepsin L1 and L2 antigens resulted in 33 to 79% protection against Fasciola burden and ~60% reduction in egg viability ( Dalton et al. 2003 ).
In another study, the same antigens did not reduce worm burden in sheep, but reduced egg production and egg viability by 70% and 80%, respectively (Wijffels et al. 1994). Cathepsin L showed improved protection (78%) in sheep when combined with LAP, but vaccination with LAP alone elicited the highest level of protection (89%) (Piacenza et al. 1999).
Definition
Etiology
Morphology
It is found worldwide where there is a suitable environment for Laymnaeid snail population in pastures of cattle, sheep and goats (Soulsby 1968) The most important trematode of domestic ruminants and one of the main causes of liver snail disease in temperate regions of the world is F.
Risk factors
Availability of suitable snail habitat
Temperature ……….................................................................... 5-6
Temperature has a significant effect on the growth rate of snails as well as the stages of the parasite that exist outside the definitive host. Fasciola growth inside the snail requires a temperature of at least 10°C day or night, and all activity stops at 5°C. According to research, the snails Fasciola cercaria and lymnaea can live better between 25°C and 30°C, which at least partially reflects why there is a much higher incidence in autumn than in other months (Moazeni et al.
The maturation of fluke eggs, the ability of the miracidium to hunt snails, and the spread of cercariae shed by the snails depend on these circumstances (Sun et al.
Host range
Definitive host
Intermediate host
Life cycle ............................................................................. 7-8
The first phase is associated with liver injury and bleeding and occurs during translocation into the liver parenchyma (Pan et al. 2022). In contrast to the acute phase of the disease, fibrosis (scar tissue), bile duct obstruction, and bile duct inflammation cause damage (Gayo et al. 2020; Lalor et al. 2021). Flux migration is more prevalent in cattle and encapsulated parasites are frequently observed in the lungs (Lalor et al. 2021).
Mechanical (by young snails burrowing into the liver and mature snails irritating the epithelial wall of the bile ducts); toxic (through parasitic secretion and excretory output); and bleeding due to bleeding in the liver (acute type) and blood-sucking feeding behavior of the snails (Hughes et al. 2020). However, they can cause hepatic colic with cough and vomiting, widespread abdominal distress, headache and sweating, irregular temperature, diarrhea, pipe clay, and anemia (Forbes 2017; Matsuda et al. 2020). These chemicals protect parasites from host defense responses and are critical in the parasite-host relationship (Haçariz et al. 2012).
Using proteomics analysis, 575 proteins were discovered in the soluble young fluke extract, 90 proteins in immature fluke E/S products, and 202 proteins in mature E/S products (Robinson et al. 2009; Cwiklinski et al. 2015 ). A key proteins of the entire immature flux secretome include proteases, protease inhibitors, antioxidants, and a variety of immunomodulators that are thought to disarm host innate immune cells (Xu et al., 2020).
Clinical Signs
Acute fasciolosis
It is less widespread than chronic hepatitis and is caused by the simultaneous displacement of a large number of immature flows.
Subacute fasciolosis
Chronic fasciolosis
Diagnosis
History and clinical signs............................................................ 10-11
It causes widespread disease and death in cattle, including weight loss, anemia, and hypoproteinemia (Soulsby 1968; Kumar et al. 2021). However, they must be recognized from the eggs of other flies, especially the huge eggs of Pamphistomum paramphistomum. Investigation using the sedimentation method As Fasciola eggs have a high specific gravity, sedimentation is preferable to flotation.
Fluke egg shedding varies greatly from day to day and within days, and the distribution of eggs in faeces is uneven; a single fecal egg count analysis may result in an inaccurate conclusion (Dias et al. 2014; Webb and Cabada 2018).
Serology..................................................... 11-12
For characterization purposes, the ProtParam server (https://web.expasy.org/protparam/) was used to predict the physicochemical properties of the vaccine protein (Duvaud et al. 2021). Physicochemical property of the selected protein sequence (AI = aliphatic index, GRAVY = grand average hydropathicity). It was included in the vaccine construct as an adjuvant to increase the antigenicity of the vaccine.
Additionally, the HTL epitopes were linked together using the GPGPG linker, and the adjuvant was linked to the epitopes using the EAAAK linker (Lee and Nguyen 2015). The final subunit vaccine consisted of 386 amino acid residues that contained 1 EAAAK linker, 3 KAAK linkers, 5 AAY linkers and 2 GPGPG linkers. The instability index of the vaccine protein was 18.78, suggesting the stable nature of the protein. The hydrophilic nature of the protein should aid in easy purification and formulation of the vaccine.
The selected amino acid pairs formed the mutant version of the original vaccine (with disulfide bonds) in the DbD2 server (Figure 5). For expression of the vaccine construct in bacterial cells, the pET28a(+) plasmid vector was used. An understanding of the binding energy, dynamics and interaction patterns of the vaccine construct came from computational research.
Extracellular vesicles of the helminth pathogen, Fasciola hepatica: Pathways of biogenesis and cargo molecules involved in parasite pathogenesis. Pathogenicity and virulence of liver fluke Fasciola hepatica and Fasciola Gigantica which cause the zoonosis Fasciolosis. Characterization of pathology, biochemistry and immune response in Kunming mice (KM) after Fasciola gigantica infection.
An integrated transcriptomics and proteomics analysis of the secretome of the helminth pathogen Fasciola hepatica. Flucicide efficacy against Fasciola hepatica of triclabendazole and nitroxinil in cattle of the Central Valley of Chile. Genetic diversity and relationships of the liver fluke Fasciola hepatica (Trematoda) with native and introduced definitive and intermediate hosts.
Necropsy
Treatment
Not all chemicals are extremely useful against all stages of fasciola reproduction in the body. It is essential to select a substance that is extremely effective against minor liver parenchymal damage for the treatment of acute failure. Triclabendazole (12 mg/kg) is the most commonly used drug because of its strong effectiveness against adults and juveniles.
It is ovicidal and will kill any fasciola eggs found in the bile duct or alimentary canal during ivermectin therapy for combined control of flukes and roundworms in herds (Webb and Cabada 2018; Nitroxynil is effective against mature flukes when administered subcutaneously at 10 mg/ kg). , but the dose must be increased by up to 50% to ensure satisfactory control of the acute disease (Romero et al. 2019). Until recently, the therapy was not very effective due to the ineffectiveness of older drugs against the early parenchymal stages.
However, effective drugs are now available, and one of the options is triclabendazole, which eliminates all developmental stages older than a week. Other drugs that will eradicate flukes older than four weeks include Rafoxanide (7.5 mg/kg), Closantel and Nitroxynil (Webb and Cabada 2018; Singh et al. 2021; Wagari 2021).
Control and Prevention
Snail population reduction
Use of anthelmintic
Immunity 14
The epitopes of the selected protein sequences were predicted using the online epitope prediction server, Immune Epitope Database or IEDB (https://www.iedb.org/) and during the predictions all parameters in the server were kept at their default values. (Vita et al. 2019). The antigenicity of the selected epitopes was re-predicted using the VaxiJen v2.0 (http://www.ddg-pharmfac.net/vaxijen/VaxiJen/VaxiJen.html) server, setting the prediction accuracy threshold at 0. 5 was held. The toxicity prediction of the selected epitopes was performed using the ToxinPred server (http://crdd.osdd.net/raghava/toxinpred/), keeping all parameters default (Gupta et al. 2013).
TLR-2 (PDB ID: 5D3I) was used as the receptor molecule for the molecular docking study, and the refined tertiary model of the vaccine construct served as the ligand molecule. To understand the dynamic mobility, binding mode, and structural stability of the vaccine construct at the atomic level, as mentioned previously, molecular dynamics (MD) simulation was performed. The regions of the proteins that are vulnerable to deformation are represented by peaks in the deformability plots.
In silico restriction cloning of the FV vaccine sequence in plasmid pET-28a (+) between HindIII and BamHI restriction enzyme sites. In silico cloning ensured that the vaccine construct could potentially be expressed in a microbial expression system, allowing rapid vaccine scale-up in the event of an outbreak to combat F. Identification of rumen fluke, Calicophoron daubneyi, in GB cattle: potential implications for liver fluke diagnosis.
Regulation of Fasciola hepatica newly excysted juvenile cathepsin L3 (FhCL3) by its propeptide: a proposed 'clamp-like' mechanism of binding and inhibition.
