scholarly journals Cyathostomin resistance to moxidectin and combinations of anthelmintics in Australian horses

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ghazanfar Abbas ◽  
Abdul Ghafar ◽  
John Hurley ◽  
Jenni Bauquier ◽  
Anne Beasley ◽  
...  
Keyword(s):  
Large Scale ◽  
Anthelmintic Resistance ◽  
Drug Efficacy ◽  
Multidrug Resistant ◽  
Post Treatment ◽  
Parasitic Nematodes ◽  
Efficacy Trials ◽  
Thoroughbred Horses ◽  
Horse Farms ◽  
On Farm

Abstract Background Cyathostomins are the most important and common parasitic nematodes of horses, with > 50 species known to occur worldwide. The frequent and indiscriminate use of anthelmintics has resulted in the development of anthelmintic resistance (AR) in horse nematodes. In this study we assessed the efficacy of commonly used anthelmintics against cyathostomins in Australian thoroughbred horses. Methods Two drug efficacy trials per farm were conducted on two thoroughbred horse farms in the state of Victoria, Australia. In the first trial, the horses on Farm A were treated with single and combinations of anthelmintics, including oxfendazole (OFZ), abamectin (ABM), abamectin and morantel (ABM + MOR), moxidectin (MOX) and oxfendazole and pyrantel (OFZ + PYR), at the recommended doses, whereas the horses on Farm B only received MOX, at the recommended dose. The faecal egg count reduction test (FECRT) was used to determine the efficacy and egg reappearance period (ERP) of anthelmintics. Based on the results of the first trial, the efficacies of MOX and a combination of ABM + MOR were reassessed to confirm their activities against cyathostomins. Results Of the five anthelmintic products tested on Farm A, resistance against OFZ, ABM and OFZ + PYR was found, with efficacies of − 41% (− 195% lower confidence limit [LCL]), 73% (60% LCL) and 82% (66% LCL) at 2 weeks post-treatment, respectively. The FECRT showed high efficacies of MOX and ABM + MOR (100%) at 2 week post-treatment and shortened ERPs for these anthelmintics (ABM + MOR: 4 weeks; MOX: 5 weeks). Resistance to MOX was found on Farm B, with a reduced efficacy of 90% (70% LCL) and 89% (82% LCL) at 2 weeks post-treatment in trials one and two, respectively. Conclusions This study provides the first evidence of MOX- and multidrug-resistant (ABM and combinations of anthelmintics) cyathostomins in Australia and indicates the need for continuous surveillance of the efficacy of currently effective anthelmintics and large-scale investigations to assess the ERP for various anthelmintics. Graphical Abstract

Efficacy of “Worm-X” Herbal Formulation against Naturally Infected Gastrointestinal Nematodes in Goats of Banaskantha District, Gujarat

2020 ◽  
Author(s):  
H.R. Parsani ◽  
B.S. Chandel ◽  
K.P. Shyma
Keyword(s):  
Anthelmintic Resistance ◽  
Drug Efficacy ◽  
Gastrointestinal Nematodes ◽  
Post Treatment ◽  
Chemical Treatments ◽  
Maximum Reduction ◽  
Herbal Formulation ◽  
Major Constraint ◽  
The Cost ◽  
Alternative Solutions

Background: Gastrointestinal nematodosis is a major constraint in economic livestock production. Mostly synthetic anthelmintics are being used to overcome this problem. Besides synthetic anthelmintics, some plants have shown variable anthelmintic properties. Methods: Sixty goats infected with GI nematodes having 1500 EPG were selected and animals were divided into four groups T1 to T4 of 15 animals in each group. Group T1 was given two doses of fenbendazole @ 10 mg/kg BW per os at 15 days interval. In group T2, T3 and T4 herbal formulation “Worm-X” was given @ 0.5, 1.0 and 2.0 ml/kg BW orally respectively, at 15 days interval. Efficacy was assessed on the basis of percentage reduction in EPG count and the FECRT was conducted as per guidelines of WAAVP. Result: When FECR was compared 15 days post treatment, maximum reduction (77.25%) was observed in group T1 followed by group T2 (47.27%), T3 (70.19%), and T4 (72.01%). The reduction in FEC in groupT3 (70.19%) and T4 (72.01%) at 15 days post treatment and at 30 days post treatment were 87.75 and 89.32%, respectively were almost equal. Considering the cost effectiveness and WAAVP recommendations, it will be optimum to administer the drug at the rate of 1.0 ml/kg body weight in two dosages at 15-day interval. However, it is well known that now a day’s modern anthelmintic drug efficacy has been reduced in many cases due to the development of anthelmintic resistance. Therefore, complementary or alternative solutions to the conventional chemical treatments have been implied offering novel approaches to the sustainable control of gastrointestinal nematodes in goats.

scholarly journals Drug efficacy of ivermectin against primary nematodes parasitizing captive Przewalski’s horse (Equus ferus przewalskii) after ten years of annually treatment

2020 ◽  
Vol 57 (1) ◽  
pp. 57-62
Author(s):  
L. Tang ◽  
Y. Xiu ◽  
L. Yan ◽  
Y. Cui ◽  
X. Ma ◽  
...  
Keyword(s):  
Natural Habitat ◽  
Drug Efficacy ◽  
Post Treatment ◽  
Parasitic Nematodes ◽  
Captive Population ◽  
Reintroduced Species ◽  
Fecal Egg Count ◽  
Counting Data ◽  
Przewalski's Horse ◽  
Przewalski’S Horse

SummaryReintroduction of endangered species to natural habitat is considered as an important tool for conservation. The effect of drug management on captive population of reintroduced species is largely neglected. Decreased drug efficacy could pose a substantial threat to health of animals. More importantly, captive population without proper drug administration could act as transmission medium of resistance nematodes to wild population, making it important to delay the occurrence of drug resistance in captive population. Ivermectin have been used in captive Przewalski’s horse (Equus ferus przewalskii) to eradicate intestinal parasitic nematodes annually, while no available studies describing the drug efficacy in the recent ten years. Here, fecal egg counts pre- and post-treatment were performed with ivermectin through individual trace. Both large and small strongyles were identifi ed by larval culture. The fecal egg count reduction was almost 100% based on egg counting data of 448 samples from 13 Przewalski’s horses. Feces of two Przewalski’s horses were sampled for successive 20 days. Eggs per gram feces usually increased dramatically at the period of 1 – 2 post-treatment days and declined persistently to 0.0 within 15 days. A sustained high ivermectin efficacy against neither Parascaris equorum nor strongyles was indicated, which can be partly explained by the low deworm frequency.

Novel Pharmacotherapeutics for Stress-Related Disorders

2019 ◽  
pp. 642-672
Author(s):  
Jamie E. Mondello ◽  
Jenny E. Pak ◽  
Dennis F. Lovelock ◽  
Terrence Deak
Keyword(s):  
Mental Health Problems ◽  
Drug Efficacy ◽  
Careful Consideration ◽  
Pharmacological Intervention ◽  
Pharmacological Interventions ◽  
Diverse Range ◽  
Disease States ◽  
Efficacy Trials ◽  
Participant Selection ◽  
The Relationship

Most mental health problems associated with psychological distress originate with activation of centrally regulated stress pathways, yet a diverse range of central nervous system and somatic disease states can be influenced by exposure to severe or unrelenting stress. The goal of this chapter is to provide a conceptual framework to guide the development of pharmacological intervention strategies. We propose that careful consideration of the relationship between the timing of stressful life experiences, pharmacological intervention, and the ultimate expression of disease symptomatology is critical for the development of pharmacological interventions to treat stress-related disorders. We review a range of physiological systems that are known to be activated by stress, offering potentially new targets for drug development efforts, and argue that participant selection is a key predictor of drug efficacy trials. In doing so, we point toward inflammatory signaling pathways as a potential final common mediator of multiple stress-related disease states.

Comparison of Prevalence, Antimicrobial Resistance, and Occurrence of Multidrug-Resistant Salmonella in Antimicrobial-Free and Conventional Pig Production

2006 ◽  
Vol 69 (4) ◽  
pp. 743-748 ◽  
Author(s):  
WONDWOSSEN A. GEBREYES ◽  
SIDDHARTHA THAKUR ◽  
W. E. MORGAN MORROW
Keyword(s):  
Antimicrobial Resistance ◽  
Production Systems ◽  
Multidrug Resistant ◽  
Resistance Pattern ◽  
Swine Production ◽  
Significant Difference ◽  
Conventional Farms ◽  
Resistance Patterns ◽  
Conventional Systems ◽  
On Farm

Conventional swine production evolved to routinely use antimicrobials, and common occurrence of antimicrobial-resistant Salmonella has been reported. There is a paucity of information on the antimicrobial resistance of Salmonella in swine production in the absence of antimicrobial selective pressure. Therefore, we compared the prevalence and antimicrobial resistance of Salmonella isolated from antimicrobial-free and conventional production systems. A total of 889 pigs and 743 carcasses were sampled in the study. Salmonella prevalence was significantly higher among the antimicrobial-free systems (15.2%) than the conventional systems (4.2%) (odds ratio [OR] = 4.23; P < 0.05). Antimicrobial resistance was detected against 10 of the 12 antimicrobials tested. The highest frequency of resistance was found against tetracycline (80%), followed by streptomycin (43.4%) and sulfamethoxazole (36%). Frequency of resistance to most classes of antimicrobials (except tetracycline) was significantly higher among conventional farms than antimicrobial-free farms, with ORs ranging from 2.84 for chloramphenicol to 23.22 for kanamycin at the on-farm level. A total of 28 antimicrobial resistance patterns were detected. A resistance pattern with streptomycin, sulfamethoxazole, and tetracycline (n = 130) was the most common multidrug resistance pattern. There was no significant difference in the proportion of isolates with this pattern between the conventional (19.5%) and the antimicrobial-free systems (18%) (OR = 1.8; P > 0.05). A pentaresistance pattern with ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline was strongly associated with antimicrobial-free groups (OR = 5.4; P = 0.01). While showing the higher likelihood of finding antimicrobial resistance among conventional herds, this study also implies that specific multidrug-resistant strains may occur on antimicrobial-free farms. A longitudinal study with a representative sample size is needed to reach more conclusive results of the associations detected in this study.

scholarly journals Improving the Role and Contribution of Pharmacokinetic Analyses in Antimalarial Drug Clinical Trials

2014 ◽  
Vol 58 (10) ◽  
pp. 5643-5649 ◽  
Author(s):  
Katherine Kay ◽  
Eva Maria Hodel ◽  
Ian M. Hastings
Keyword(s):  
Antimalarial Drug ◽  
Theoretical Data ◽  
Drug Efficacy ◽  
Cost Effective ◽  
Field Studies ◽  
World Health ◽  
Efficacy Trials ◽  
Drug Concentrations ◽  
Health Organization ◽  
Study Designs

ABSTRACTIt is now World Health Organization (WHO) policy that drug concentrations on day 7 be measured as part of routine assessment in antimalarial drug efficacy trials. The rationale is that this single pharmacological measure serves as a simple and practical predictor of treatment outcome for antimalarial drugs with long half-lives. Herein we review theoretical data and field studies and conclude that the day 7 drug concentration (d7c) actually appears to be a poor predictor of therapeutic outcome. This poor predictive capability combined with the fact that many routine antimalarial trials will have few or no failures means that there appears to be little justification for this WHO recommendation. Pharmacological studies have a huge potential to improve antimalarial dosing, and we propose study designs that use more-focused, sophisticated, and cost-effective ways of generating these data than the mass collection of single d7c concentrations.

scholarly journals Prospects of Using High-Throughput Proteomics to Underpin the Discovery of Animal Host–Nematode Interactions

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 825
Author(s):  
Tao Wang ◽  
Robin Gasser
Keyword(s):  
Mass Spectrometry ◽  
High Throughput ◽  
Anthelmintic Resistance ◽  
Nematode Species ◽  
Economic Losses ◽  
Future Research ◽  
Parasitic Nematodes ◽  
Public Health Burden ◽  
Host Parasite Interactions ◽  
Host Parasite

Parasitic nematodes impose a significant public health burden, and cause major economic losses to agriculture worldwide. Due to the widespread of anthelmintic resistance and lack of effective vaccines for most nematode species, there is an urgent need to discover novel therapeutic and vaccine targets, informed through an understanding of host–parasite interactions. Proteomics, underpinned by genomics, enables the global characterisation proteins expressed in a particular cell type, tissue and organism, and provides a key to insights at the host–parasite interface using advanced high-throughput mass spectrometry-based proteomic technologies. Here, we (i) review current mass-spectrometry-based proteomic methods, with an emphasis on a high-throughput ‘bottom-up’ approach; (ii) summarise recent progress in the proteomics of parasitic nematodes of animals, with a focus on molecules inferred to be involved in host–parasite interactions; and (iii) discuss future research directions that could enhance our knowledge and understanding of the molecular interplay between nematodes and host animals, in order to work toward new, improved methods for the treatment, diagnosis and control of nematodiases.

scholarly journals Genomic landscape of drug response reveals novel mediators of anthelmintic resistance

2021 ◽  
Author(s):  
Stephen R Doyle ◽  
Roz Laing ◽  
David Bartley ◽  
Alison Morrison ◽  
Nancy Holroyd ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Genetic Basis ◽  
Parasitic Nematode ◽  
Anthelmintic Resistance ◽  
Forward Genetics ◽  
Parasitic Nematodes ◽  
Genomic Landscape ◽  
Genetic Cross ◽  
Novel Alleles ◽  
Host Parasite

Understanding the genetic basis of anthelmintic drug resistance in parasitic nematodes is key to tracking and combatting their spread. Here, we use a genetic cross in a natural host-parasite system to simultaneously map resistance loci for the three major classes of anthelmintics. This approach identifies novel alleles for resistance to benzimidazoles and levamisole and implicates the transcription factor, cky-1, in ivermectin resistance. This gene is within a locus under selection in ivermectin resistant populations worldwide; functional validation using knockout and gene expression experiments supports a role for cky-1 overexpression in ivermectin resistance. Our work demonstrates the feasibility of high-resolution forward genetics in a parasitic nematode, and identifies variants for the development of molecular diagnostics to combat drug resistance in the field.

scholarly journals In Vitro Efficacy of Aqueous and Methanol Extract of Cassia siamea Against the Motility of Caenorhabditis elegans

2020 ◽  
Vol 31 (3) ◽  
pp. 145-159
Author(s):  
Haladu Ali Gagman ◽  
Nik Ahmad Irwan Izzauddin Nik Him ◽  
Hamdan Ahmad ◽  
Shaida Fariza Sulaiman ◽  
Rahmad Zakaria ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Methanol Extract ◽  
Anthelmintic Resistance ◽  
Gastrointestinal Nematode ◽  
Parasitic Nematodes ◽  
Cassia Siamea ◽  
Methanol Extracts ◽  
C Elegans ◽  
Significant Difference

Gastrointestinal nematode infections can cause great losses in revenue due to decrease livestock production and animal death. The use of anthelmintic to control gastrointestinal nematode put a selection pressure on nematode populations which led to emergence of anthelmintic resistance. Because of that, this study was carried out to investigate the efficacy of aqueous and methanol extract of Cassia siamea against the motility of C. elegans Bristol N2 and C. elegans DA1316. Caenorhabditis elegans Bristol N2 is a susceptible strain and C. elegans DA1316 is an ivermectin resistant strain. In vitro bioassay of various concentrations of (0.2, 0.6, 0.8, 1.0 and 2.0 mg mL–1) aqueous and methanol extracts of C. siamea was conducted against the motility of L4 larvae of C. elegans Bristol N2 and C. elegans DA1316. The L4 larvae were treated with 0.02 μg mL–1 of ivermectin served as positive control while those in M9 solution served as negative control. The activity of the extracts was observed after 24 h and 48 h. A significant difference was recorded in the extract performance compared to control at (P < 0.001) after 48 h against the motility of the larvae of both strains. The methanol extracts inhibited the motility of C. elegans Bristol N2 by 86.7% as well as DA1316 up to 84.9% at 2.0 mg mL–1 after 48 h. The methanol extract was more efficient than aqueous extract (P < 0.05) against the motility of both strains of C. elegans. Cassia siamea may be used as a natural source of lead compounds for the development of alternative anthelmintic against parasitic nematodes as well ivermectin resistant strains of nematodes.

scholarly journals Description of on-farm treatment compliance and risk factors for culling in sows

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Magnus R. Campler ◽  
Jeremiah L. Cox ◽  
Heather L. Walker ◽  
Andréia G. Arruda
Keyword(s):  
Treatment Guidelines ◽  
Treatment Compliance ◽  
Drug Dosage ◽  
Post Treatment ◽  
Individual Treatment ◽  
Treatment Protocols ◽  
Logistic Regression Models ◽  
Sow Longevity ◽  
Complete Treatment ◽  
On Farm

Abstract Background In commercial pig farming, sick or injured sows are often treated by producers or hired staff. To date, limited quantitative data exists on treatment compliance and the possible effect on sow longevity post-treatment. The objective of the study was to quantify on-farm compliance of treatment selection, frequency, and dosage, as well as to investigate the association between body condition scores (BCS) and other sow-level factors on post-treatment cull risk. Results On-farm treatment records, including culling reason or reason of death up to 6 months post-treatment, production records and sow characteristics were obtained for 134 sows over an 8-week period. Treatment compliance was based on the accuracy of recorded treatments compared to the herd veterinarian’s established treatment guidelines. Univariable and multivariable logistic regression models including treatment reason, treatment compliance, BCS, parity, production stage and production metrics, were constructed to investigate associations between those variables and sow culling or death. This study found low compliance for on-farm sow treatment protocols, with only 22.4% (30/134) of the sows receiving correct and complete treatment during the duration of the study. No effect of individual treatment components (drug, dosage, or frequency) on sow culling was observed. A trend for an interaction between treatment compliance and BCS was found, and parity and number of piglets born alive were identified as predictors for sow maintenance in the herd. Conclusions On-farm sow treatment compliance was low, resulting in that approximately 80% of the enrolled sows were not treated according to existing guidelines. Non-compliance of treatment guidelines did not seem to affect the risk of culling in treated sows but may have prolonged any associated pain, recovery time and negatively impacted the sow welfare during that time period.

scholarly journals Nanosilver in Biomedicine: Advantages and Restrictions

2021 ◽  
Author(s):  
Olga V. Morozova ◽  
Dmitry V. Klinov
Keyword(s):  
Gene Expression ◽  
Immune Response ◽  
Surface Layer ◽  
Drug Efficacy ◽  
Multidrug Resistant ◽  
Deionized Water ◽  
Sensitivity Threshold ◽  
Specific Interactions ◽  
Anti Cancer ◽  
Potential Formation

Nanosilver (in a range 1–100 nm) binds with thyol-, amino- and carboxy-groups of aminoacid residues of proteins and nucleic acids, thus providing inactivation of pathogenic multidrug-resistant microorganisms. Besides antibacterial, antiviral, antifungal and anti-cancer properties Ag-based nanomaterials possess anti-inflammatory, anti-angiogenesis and antiplatelet features. Drug efficacy depends on their stability, toxicity and host immune response. Citrate coated Ag nanoparticles (NPs) remain stable colloid solutions in deionized water but not in the presence of ions due to replacement of Ag+ by electrolyte ions, potential formation of insoluble AgCl, subsequent catalyzed oxidative corrosion of Ag and further dissolution of surface layer of Ag2O. Protein shells protect core of AgNPs from oxidation, dissolution, aggregation and provide specific interactions with ligands. These nanoconjugates can be used for immunoassays and diagnostics but the sensitivity threshold does not exceed 10 pg Cytotoxicity of AgNPs conjugated with proteins is associated with the rate of intracellular Ag+ release, a ‘Trojan horse’ effect, and exceeds one of Ag+ because of endocytosis uptake of NPs but not ions. Relatively toxic nanosilver causes immunosuppression of the majority of cytokines with a few exceptions (IL-1β, G-CSF, MCP-1) whereas AgNO3 additionally activate TNFα and IL8 gene expression.

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