Progress in the development of subunit vaccines for gastrointestinal nematodes of ruminants

2016 ◽  
Vol 38 (12) ◽  
pp. 744-753 ◽  
Author(s):  
J. B. Matthews ◽  
P. Geldhof ◽  
T. Tzelos ◽  
E. Claerebout
Parasitology ◽  
2017 ◽  
Vol 144 (14) ◽  
pp. 1845-1870 ◽  
Author(s):  
JASON B. NOON ◽  
RAFFI V. AROIAN

SUMMARYSoil-transmitted helminths (STHs) collectively infect one fourth of all human beings, and the majority of livestock in the developing world. These gastrointestinal nematodes are the most important parasites on earth with regard to their prevalence in humans and livestock. Current anthelmintic drugs are losing their efficacies due to increasing drug resistance, particularly in STHs of livestock and drug treatment is often followed by rapid reinfection due to failure of the immune system to develop a protective response. Vaccines against STHs offer what drugs cannot accomplish alone. Because such vaccines would have to be produced on such a large scale, and be cost effective, recombinant subunit vaccines that include a minimum number of proteins produced in relatively simple and inexpensive expression systems are required. Here, we summarize all of the previous studies pertaining to recombinant subunit vaccines for STHs of humans and livestock with the goal of both informing the public of just how critical these parasites are, and to help guide future developments. We also discuss several key areas of vaccine development, which we believe to be critical for developing more potent recombinant subunit vaccines with broad-spectrum protection.


Author(s):  
Noorzaid Muhamad ◽  
Syahirah Sazeli ◽  
Resni Mona ◽  
Jannathul Firdous

The anthelmintic resistance has limited the control of gastrointestinal nematodes of small ruminants and thus has awakened interest in the study of plants extract as a source of anthelmintics. These experiments were carried out to evaluate the in vitro efficacy of Jatrophacurcas latex extract against Haemonchuscontortus larval motility. To evaluate the larvicidal activity, H.contortus L3 were incubated with the extracts with varying concentration of 5 mg/mL, 10 mg/mL, 15 mg/mL and 20 mg/mL at 27°C for 48, 72 and 96 hrs. The results were subjected to the Kruskal-Wallis test (P less than 0.05). The extracts showed dose-dependent larvicidal effects. These results suggest that J.curcas can be used to control gastrointestinal nematodes of small ruminants.


2020 ◽  
Vol 14 (4) ◽  
pp. 99-103
Author(s):  
V. I. Kolesnikov

The purpose of the research is studying the efficacy of Eprimek (Eprinomectin) against gastrointestinal nematodes in sheep.Materials and methods. A commercial experiment to study the antiparasitic efficacy of Eprimek was carried out in June 2020 on 300 lambs of the North Caucasian breed in a private flock of Filimonovskaya Village, Izobilnensky District, the Stavropol Territory, which were divided into two groups. The experimental group of lambs (290 animals) was injected Eprimek subcutaneously at the earset at a dose of 1 ml/50 kg of live weight (10 mg of Eprinomectin in 1 ml), and 10 lambs were not treated; they were used as control. We collected feces from the lambs of the experimental and control groups before administration of the drugs and after 15 and 30 days. Fecal samples were examined by the flotation technique with a saturated solution of ammonium nitrate with counting nematode eggs in 1 g of feces. The results were processed statistically.Results and discussion. Eprimek showed a decrease in the number of excreted helminth eggs from 225.1±28.2 to 4.1±2.3 in production environment at a dose of 1 ml/50 kg of live weight, according to coprological studies on the 15th day after treatment in the experimental group of lambs. The efficacy was 98.2%, and 70% of the animals were free from the infection. The intensity of infection of the control lambs by gastrointestinal nematodes was 131–151 eggs per 1 g of feces at 100% prevalence.


2014 ◽  
Vol 21 (30) ◽  
pp. 3405-3418 ◽  
Author(s):  
B. Sedaghat ◽  
R. Stephenson ◽  
I. Toth

2014 ◽  
Vol 14 (2) ◽  
pp. 333-339 ◽  
Author(s):  
Lingyang Xu ◽  
Yali Hou ◽  
Derek M. Bickhart ◽  
Jiuzhou Song ◽  
Curtis P. Van Tassell ◽  
...  

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1072
Author(s):  
Raquel Cid ◽  
Jorge Bolívar

To date, vaccination has become one of the most effective strategies to control and reduce infectious diseases, preventing millions of deaths worldwide. The earliest vaccines were developed as live-attenuated or inactivated pathogens, and, although they still represent the most extended human vaccine types, they also face some issues, such as the potential to revert to a pathogenic form of live-attenuated formulations or the weaker immune response associated with inactivated vaccines. Advances in genetic engineering have enabled improvements in vaccine design and strategies, such as recombinant subunit vaccines, have emerged, expanding the number of diseases that can be prevented. Moreover, antigen display systems such as VLPs or those designed by nanotechnology have improved the efficacy of subunit vaccines. Platforms for the production of recombinant vaccines have also evolved from the first hosts, Escherichia coli and Saccharomyces cerevisiae, to insect or mammalian cells. Traditional bacterial and yeast systems have been improved by engineering and new systems based on plants or insect larvae have emerged as alternative, low-cost platforms. Vaccine development is still time-consuming and costly, and alternative systems that can offer cost-effective and faster processes are demanding to address infectious diseases that still do not have a treatment and to face possible future pandemics.


Author(s):  
Gerardo Jiménez-Penago ◽  
Roberto González-Garduño ◽  
Luciano Martínez-Bolaños ◽  
Ema Maldonado-Siman ◽  
Alvar A. Cruz-Tamayo ◽  
...  

Author(s):  
Anupama M. Gudadappanavar ◽  
Jyoti Benni

AbstractA novel coronavirus infection coronavirus disease 2019 (COVID-19) emerged from Wuhan, Hubei Province of China, in December 2019 caused by SARS-CoV-2 is believed to be originated from bats in the local wet markets. Later, animal to human and human-to-human transmission of the virus began and resulting in widespread respiratory illness worldwide to around more than 180 countries. The World Health Organization declared this disease as a pandemic in March 2020. There is no clinically approved antiviral drug or vaccine available to be used against COVID-19. Nevertheless, few broad-spectrum antiviral drugs have been studied against COVID-19 in clinical trials with clinical recovery. In the current review, we summarize the morphology and pathogenesis of COVID-19 infection. A strong rational groundwork was made keeping the focus on current development of therapeutic agents and vaccines for SARS-CoV-2. Among the proposed therapeutic regimen, hydroxychloroquine, chloroquine, remdisevir, azithromycin, toclizumab and cromostat mesylate have shown promising results, and limited benefit was seen with lopinavir–ritonavir treatment in hospitalized adult patients with severe COVID-19. Early development of SARS-CoV-2 vaccine started based on the full-length genome analysis of severe acute respiratory syndrome coronavirus. Several subunit vaccines, peptides, nucleic acids, plant-derived, recombinant vaccines are under pipeline. This article concludes and highlights ongoing advances in drug repurposing, therapeutics and vaccines to counter COVID-19, which collectively could enable efforts to halt the pandemic virus infection.


2021 ◽  
Vol 95 ◽  
Author(s):  
A.I.P. Sousa ◽  
C.R. Silva ◽  
H.N. Costa-Júnior ◽  
N.C.S. Silva ◽  
J.A.O. Pinto ◽  
...  

Abstract The continuous use of synthetic anthelmintics against gastrointestinal nematodes (GINs) has resulted in the increased resistance, which is why alternative methods are being sought, such as the use of natural products. Plant essential oils (EOs) have been considered as potential products for the control of GINs. However, the chemical composition and, consequently, the biological activity of EOs vary in different plant cultivars. The aim of this study was to evaluate the anthelmintic activity of EOs from cultivars of Ocimum basilicum L. and that of their major constituents against Haemonchus contortus. The EOs from 16 cultivars as well the pure compound linalool, methyl chavicol, citral and eugenol were used in the assessment of the inhibition of H. contortus egg hatch. In addition, the composition of three cultivars was simulated using a combination of the two major compounds from each. The EOs from different cultivars showed mean Inhibition Concentration (IC50) varying from 0.56 to 2.22 mg/mL. The cultivar with the highest egg-hatch inhibition, Napoletano, is constituted mainly of linalool and methyl chavicol. Among the individual compounds tested, citral was the most effective (IC50 0.30 mg/mL). The best combination of compounds was obtained with 11% eugenol plus 64% linalool (IC50 0.44 mg/mL), simulating the Italian Large Leaf (Richters) cultivar. We conclude that different cultivars of O. basilicum show different anthelmintic potential, with cultivars containing linalool and methyl chavicol being the most promising; and that citral or methyl chavicol isolated should also be considered for the development of new anthelmintic formulations.


2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 36-36
Author(s):  
James E Miller ◽  
Joan M Burke ◽  
Thomas H Terrill

Abstract Nematode-trapping fungi are biological control agents used against the larval stages of gastrointestinal nematodes in livestock feces. These fungi are normal soil inhabitants where they feed on a variety of non-parasitic soil nematodes. Of the various fungi tested, Duddingtonia flagrans spores (BioWorma, International Animal Health Products, Australia) have been shown to survive passage through the gastrointestinal tract of ruminants. After defecation, the spores germinate and grow in the feces to form sticky, sophisticated traps/loops which are able to trap the developing larval stages in the fecal environment. This form of control has been successfully applied under field conditions and is an environmentally safe biological approach for forage-based feeding systems. BioWorma has recently been approved for use in the United States. The primary delivery system is mixing BioWorma into supplement feedstuffs daily where each animal has the opportunity to consume an adequate amount of the mixture. To achieve optimum control of larvae during the transmission season (May–October), BioWorma needs to be fed for a period of no shorter than 60 days, starting at the beginning of the grazing season (especially young after weaning). Feeding BioWorma to dams during late pregnancy and lactation will also help to reduce pasture contamination, especially for growing young that will graze the same pasture. Another delivery system is mixing BioWorma into loose mineral supplement where animals will consume it free choice. The mineral needs to be kept covered and dry. The spores cannot be incorporated into pellets as the heat of the pelleting process will kill the spores. One drawback in using BioWorma is the relatively high cost. Research is being conducted to evaluate other delivery schemes that could be more cost effective. This product is the only control method that targets nematodes on pasture, where a majority of the total population reside.


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