Showing papers on "Animal mortality published in 2019"

Framework for Estimating Indirect Costs in Animal Health Using Time Series Analysis

Abstract: Traditionally, cost-benefit analyses (CBAs) focus on the direct costs of animal disease, including animal mortality, morbidity, and associated response costs. However, such approaches often fail to capture the wider, dynamic market impacts that could arise. The duration of these market dislocations could last well after an initial disease outbreak. More generally, current approaches also muddle definitions of indirect costs, confusing debate on the scope of the totalities of disease-induced economic impacts. The aim of this work was to clarify definitions of indirect costs in the context of animal diseases and to apply this definition to a time series methodological framework to estimate the indirect costs of animal disease control strategies, using a foot and mouth disease (FMD) outbreak in Scotland as a case study. Time series analysis is an econometric method for analyzing statistical relationships between data series over time, thus allowing insights into how market dynamics may change following a disease outbreak. First an epidemiological model simulated FMD disease dynamics based on alternative control strategies. Output from the epidemiological model was used to quantify direct costs and applied in a multivariate vector error correction model to quantify the indirect costs of alternative vaccine stock strategies as a result of FMD. Indirect costs were defined as the economic losses incurred in markets after disease freedom is declared. As such, our definition of indirect costs captures the knock-on price and quantity effects in six agricultural markets after a disease outbreak. Our results suggest that controlling a FMD epidemic with vaccination is less costly in direct and indirect costs relative to a no vaccination (i.e., "cull only") strategy, when considering large FMD outbreaks in Scotland. Our research clarifies and provides a framework for estimating indirect costs, which is applicable to both exotic and endemic diseases. Standard accounting CBAs only capture activities in isolation, ignore linkages across sectors, and do not consider price effects. However, our framework not only delineates when indirect costs start, but also captures the wider knock-on price effects between sectors, which are often omitted from CBAs but are necessary to support decision-making in animal disease prevention and control strategies.

Perspective: Something Old, Something New? Review of Wasting and Other Mortality in Asteroidea (Echinodermata)

Abstract: Asteroids (Echinodermata) experience mass mortality events that have the potential to cause dramatic shifts in ecosystem structure. Asteroid wasting describes a suite of body wall abnormalities that can ultimately result in animal mortality. Wasting in Northeast Pacific asteroids has gained considerable recent scientific attention due to its geographic extent, number of species affected, and effects on overall population density in some affected regions. However, asteroid wasting has been observed for over a century in other regions and species. Asteroids are subject to physical injury and adverse environmental conditions, which may result in very similar external manifestations to wasting, making identification of causative processes sometimes problematic. Here we review asteroid health abnormalities reported in years prior to the 2013-present Northeast Pacific wasting mass mortality, and report two additional geographically disparate wasting events that occurred concomitantly with the recent wasting outbreak.

O-GlcNAc stimulation: A new metabolic approach to treat septic shock.

Abstract: Septic shock is a systemic inflammation associated with cell metabolism disorders and cardiovascular dysfunction. Increases in O-GlcNAcylation have shown beneficial cardiovascular effects in acute pathologies. We used two different rat models to evaluate the beneficial effects of O-GlcNAc stimulation at the early phase of septic shock. Rats received lipopolysaccharide (LPS) to induce endotoxemic shock or saline (control) and fluid resuscitation (R) with or without O-GlcNAc stimulation (NButGT–10 mg/kg) 1 hour after shock induction. For the second model, rats received cecal ligature and puncture (CLP) surgery and fluid therapy with or without NButGT. Cardiovascular function was evaluated and heart and blood samples were collected and analysed. NButGT treatment efficiently increased total O-GlcNAc without modification of HBP enzyme expression.Treatment improved circulating parameters and cardiovascular function in both models, and restored SERCA2a expression levels. NButGT treatment also reduced animal mortality. In this study, we demonstrate that in septic shock O-GlcNAc stimulation improves global animal and cardiovascular function outcomes associated with a restoration of SERCA2a levels. This pre-clinical study opens avenues for a potential therapy of early-stage septic shock.

The use of chicken and insect infection models to assess the virulence of African Salmonella Typhimurium ST313.

Abstract: Over recent decades, Salmonella infection research has predominantly relied on murine infection models. However, in many cases the infection phenotypes of Salmonella pathovars in mice do not recapitulate human disease. For example, Salmonella Typhimurium ST313 is associated with enhanced invasive infection of immunocompromised people in Africa, but infection of mice and other animal models with ST313 have not consistently reproduced this invasive phenotype. The introduction of alternative infection models could help to improve the quality and reproducibility of pathogenesis research by facilitating larger-scale experiments. To investigate the virulence of S. Typhimurium ST313 in comparison with ST19, a combination of avian and insect disease models were used. We performed experimental infections in five lines of inbred and one line of outbred chickens, as well as in the alternative chick embryo and Galleria mellonella wax moth larvae models. This extensive set of experiments identified broadly similar patterns of disease caused by the African and global pathovariants of Salmonella Typhimurium in the chicken, the chicken embryo and insect models. A comprehensive analysis of all the chicken infection experiments revealed that the African ST313 isolate D23580 had a subtle phenotype of reduced levels of organ colonisation in inbred chickens, relative to ST19 strain 4/74. ST313 isolate D23580 also caused reduced mortality in chicken embryos and insect larvae, when compared with ST19 4/74. We conclude that these three infection models do not reproduce the characteristics of the systemic disease caused by S. Typhimurium ST313 in humans.

Influence of Landscape Factors on Amphibian Roadkills at the National Level

Abstract: Roads exert multiple effects on wildlife, from animal mortality, habitat and population fragmentation, to modification of animal reproductive behaviour. Amphibians are the most frequently road-killed animal group. Many studies have attempted to analyse the factors driving amphibian casualties on roads, but these factors are limited to the roads themselves (e.g., traffic, type of roads, roads crossing water bodies) or to structures along them (e.g., ditches, walls). Sometimes, roadkills are related to land use along the roads. We analysed the influence of landscape factors on roadkill hotspots at the national level (Slovenia). Specifically, we aimed at: (1) identifying hotspots of roadkills, (2) analysing whether records of amphibian presence on roads are related to the distribution of water bodies and (3) analysing which factors (proximity to water bodies or human factors) explain the distribution of hotspots. Hotspots were identified by Malo’s method. Roadkills were modelled with Maxent for the first time in Slovenia. The relationships between amphibian presence and hotspots with factors were analysed with GLM. A total of 237 road sections were identified as hotspots, corresponding to 8% of road sections and containing 90% of road-killed individuals. Proximity to forests, meadows and agricultural land were the most important variables in Maxent models. The number of roadkills depended on the proximity to agricultural land, forests, water bodies and wetland areas, while the number of hotspots additionally depended on the proximity to urban settlements.

Fine-scale determinants of vertebrate roadkills across a biodiversity hotspot in Southern Spain

Abstract: An increasing number of wildlife-vehicle collisions occur each year worldwide, which involves extensive economic costs and constitutes one of the main anthropogenic causes of animal mortality. Because of this, there is an urgent need to identify the factors leading to collision hotspots and thus implementing effective mitigation measures. By using a stratified random sampling survey, we investigated the fine-scale determinants of roadkill probability in small and medium-sized birds and mammals across a country-size region of Southern Spain, Andalusia (87,000 km2), located within a global biodiversity hotspot. During two consecutive seasons, we regularly surveyed 45 road transects of 10 km each and characterized the site-specific attributes of both roadkill and random points, including traffic density, road design (embankments, medians, fences, roadside vegetation and distance to curves), and adjacent landscape matrix. Based on this information, we investigated variation in collision risk according to landscape and road features, and the life history of the affected taxa. Mortality rates of mammals and birds increased with traffic density, and were also significantly affected by the distance to the nearest curve, slope of embankments, height of roadside vegetation, and land use adjacent to roads. Road mortality of both birds and mammals was related to the presence and typology of fences and center medians, so more densely vegetated medians and smaller mesh sizes reduced roadkill probability. Overall, our results indicate that roadkill risk may vary at exceedingly small spatial scales. The information provided by this extensive survey may be used to identify taxa-specific factors associated to roadkill risk and priority points for action. Our findings will therefore be relevant for the design of safer roads for both drivers and wildlife through the application of effective mitigation measures.

T6SS and ExoA of flesh-eating Aeromonas hydrophila in peritonitis and necrotizing fasciitis during mono- and polymicrobial infections

Abstract: An earlier report described a human case of necrotizing fasciitis (NF) caused by mixed infection with 4 Aeromonas hydrophila strains (NF1-NF4). While the NF2, NF3, and NF4 strains were clonal and possessed exotoxin A (ExoA), the NF1 strain was determined to be phylogenetically distinct, harboring a unique type 6 secretion system (T6SS) effector (TseC). During NF1 and NF2 mixed infection, only NF1 disseminated, while NF2 was rapidly killed by a contact-dependent mechanism and macrophage phagocytosis, as was demonstrated by using in vitro models. To confirm these findings, we developed 2 NF1 mutants (NF1ΔtseC and NF1ΔvasK); vasK encodes an essential T6SS structural component. NF1 VasK and TseC were proven to be involved in contact-dependent killing of NF2 in vitro, as well as in its elimination at the intramuscular injection site in vivo during mixed infection, with overall reduced mouse mortality. ExoA was shown to have an important role in NF by both NF1-exoA (with cis exoA) and NF2 during monomicrobial infection. However, the contribution of ExoA was more important for NF2 than NF1 in the murine peritonitis model. The NF2∆exoA mutant did not significantly alter animal mortality or NF1 dissemination during mixed infection in the NF model, suggesting that the ExoA activity was significant at the injection site. Immunization of mice to ExoA protected animals from NF2 monomicrobial challenge, but not from polymicrobial infection because of NF2 clearance. This study clarified the roles of T6SS and ExoA in pathogenesis caused by A. hydrophila NF strains in both mouse peritonitis and NF models in monomicrobial and polymicrobial infections.

Protective effects of hydrogen‑rich saline against experimental diabetic peripheral neuropathy via activation of the mitochondrial ATP‑sensitive potassium channel channels in rats.

Abstract: It has previously been demonstrated that hyperglycemia-induced oxidative stress and inflammation are closely associated with the development of diabetic complications, including diabetic neuropathy. Additionally, mitochondrial ATP-sensitive potassium (Mito-K-ATP) channels play a homeostatic role on blood glucose regulation in organisms. Molecular hydrogen (H2) exhibits anti-inflammatory, anti-antioxidative and anti-apoptotic properties and can be used to treat more than 71 diseases safely. In addition, the diabetes animal models which are set up using streptozotocin (STZ) injection, is a type of high long-term stability, low animal mortality rate and security method. The aim of the current study was to assess the value of hydrogen-rich saline (HS) in diabetic peripheral neuropathy (DPN) treatment and to determine its associated mechanisms in STZ-induced diabetic experimental rats. Additionally, the effects of the Mito-K-ATP channels, oxidative stress, inflammatory cytokines and apoptosis on DPN were also evaluated. From week 5 of STZ injections, HS (2.5, 5 and 10 ml/kg) was injected into the rat abdominal cavity every day for a period of 4 weeks. The results of the current study demonstrated that HS significantly reduced behavioral, biochemical and molecular effects caused by DPN. However, 5-hydroxydecanoate, a selective Mito-K-ATP channels general pathway inhibitor, partially eliminated the therapeutic effect of HS on DPN. These results indicated that the use of HS may be a novel strategy to treat DPN by activating the Mito-K-ATP pathway and reducing oxidative stress, inflammatory cytokines and apoptosis.

Linezolid Attenuates Lethal Lung Damage during Postinfluenza Methicillin-Resistant Staphylococcus aureus Pneumonia.

Abstract: Postinfluenza methicillin-resistant Staphylococcus aureus (MRSA) infection can quickly develop into severe, necrotizing pneumonia, causing over 50% mortality despite antibiotic treatments. In this study, we investigated the efficacy of antibiotic therapies and the impact of S. aureus alpha-toxin in a model of lethal influenza virus and MRSA coinfection. We demonstrate that antibiotics primarily attenuate alpha-toxin-induced acute lethality, even though both alpha-toxin-dependent and -independent mechanisms significantly contribute to animal mortality after coinfection. Furthermore, we found that the protein synthesis-suppressing antibiotic linezolid has an advantageous therapeutic effect on alpha-toxin-induced lung damage, as measured by protein leak and lactate dehydrogenase (LDH) activity. Importantly, using a Panton-Valentine leucocidin (PVL)-negative MRSA isolate from patient sputum, we show that linezolid therapy significantly improves animal survival from postinfluenza MRSA pneumonia compared with vancomycin treatment. Rather than improved viral or bacterial control, this advantageous therapeutic effect is associated with a significantly attenuated proinflammatory cytokine response and acute lung damage in linezolid-treated mice. Together, our findings not only establish a critical role of alpha-toxin in the extreme mortality of secondary MRSA pneumonia after influenza but also provide support for the possibility that linezolid could be a more effective treatment than vancomycin to improve disease outcomes.

How thyroid hormones and their inhibitors affect cartilage growth and shape in the frog Xenopus laevis.

Abstract: Understanding how skeleton changes shape in ontogeny is fundamental to understanding how its shape diversifies in phylogeny. Amphibians pose a special case because their jaw and throat skeleton consists of cartilages that are dramatically reshaped midway through life to support new feeding and breathing styles. Although amphibian metamorphosis is commonly studied by immersing larvae in thyroid hormones (TH), how individual cartilages respond to TH is poorly understood. This study documents the effects of larval stage and TH type (T4 vs. T3), dose and deprivation on the size, shape and morphogenesis of the lower jaw and ceratohyal cartilages in the frog Xenopus laevis. It uses thyroid inhibitors to isolate the effects of each hormone at specific concentrations. It also deconstructs the TH responses into the effects on individual dimensions, and uses measures of percent change to eliminate the effects of body size and growth rate variation. As stage increases, T4 and T3 responses become increasingly similar to each other and to natural remodeling; the differences at low and intermediate stages result largely from abnormal responses to T3. Most notably, the beak-like lower jaw commonly observed at the lowest stage in other studies results largely from arrested growth of cartilage. TH responses are superimposed upon the growth typical for each stage so that cartilages can attain postmetamorphic shapes through dimensional changes that exceed those of natural metamorphosis. Using thyroid inhibitors alters the outcome of TH-induced remodeling, and T4 has almost the same capacity to induce metamorphic shape changes as T3. The results have implications for understanding how the starting shapes of larval elements affect morphogenesis, how chondrocytes behave to change cartilage shape, and how intracellular processing of TH might contribute to interspecific differences in shape change. Also, the data on animal mortality and which stages and doses most closely replicate natural remodeling have practical value for researchers who treat Xenopus tadpoles with TH.

Assessing patterns of bird roadkills in a high Andean Ecuadorian national park

Abstract: Animal mortality due to collisions with vehicles in roads are a major threat to biodiversity; however, there is still much to learn about this problem in the tropical Andes hot spot. We describe general patterns of bird mortality associated with the presence of a road that bisects Cajas National Park (CNP), in the southern high Andes of Ecuador. We use a published study of the abundance of species in the study area, and explored if there were particular ecological traits that predisposed species to collisions with vehicles. Roadkill data were gathered by collecting carcasses on 15 km of a main road that crosses paramo grasslands. Overall we found carcasses of 23 species. Bird mortality rate was four individuals per km per year. We found an association between roadkills and the abundance of species in areas close to the road. Moreover, forest species were less likely to be road-killed than species with other habitat preferences. Our results can be used to ameliorate roadkills in CNP and to raise concern on the direct effects of roads in the paramo of the Tropical Andes.

Preclinical evaluation of Amblyomin-X, a Kunitz-type protease inhibitor with antitumor activity.

Abstract: Amblyomin-X, a Kunitz-type protease inhibitor, is a recombinant protein that selectively induces apoptosis in tumor cells and promotes tumor reduction in vivo in melanoma animal models. Furthermore, Amblyomin-X was able to drastically reduce lung metastasis in a mice orthotopic kidney tumor model. Due to its antitumor activity, Amblyomin-X potential to become a new drug is currently under investigation, therefore the aim of the present study was to perform preclinical assays to evaluate Amblyomin-X toxicity in healthy mice. Exploratory toxicity assays have shown that treatment with 512 mg/kg of Amblyomin-X lead to animal mortality, therefore two groups of treatment were evaluated in the present work: in the acute toxicity assay, animals were injected once with doses ranging from 4 to 256 mg/kg of Amblyomin-X, while in the subacute toxicity assay, animals were injected with 0.25, 0.57 and 1 mg/kg of Amblyomin-X daily, during 28 days. Following this treatment regimens, Amblyomin-X did not cause any mortality; moreover, toxicity signs were discrete, reversible and observed only at the higher doses, thus establishing a safety profile for administration in mice, which can be further used to determine the dose translation of this novel drug candidate for treatment in other species.

Research and development of 2-ethyl-6-methyl-3-oxypyridine succinate nano-form for the treatment of epilepsy

Abstract: The aim is to develop an antiepileptic drug based on polymer nanoparticles with 2-ethyl-6-methyl-3-oxypyridine succinate to facilitate the drug transport through the blood-brain barrier. Materials and methods. The nano-drug was created using the biologically active substance 2-ethyl-6-methyl-3-hydroxypyridine succinate and polybutyl cyanoacrylate (PBCA) nanoparticles. The advantages of this nano-form over the active ingredient of the same drug were studied using experimental models: the maximum electroshock test (MES), the antagonism test with corazol, models with a cobaltinduced epileptic focus and secondary generalized convulsions, and models of status epilepticus. Results. The antiseizure effects of the nanoform on the experimental models of epilepsy are identified. Conclusion. The nano-drug reduces the number of secondary generalized clonic-tonic seizures by 7.8 times; it also reduces 10-fold the animal mortality and diminishes the seizure manifestations that occur in the interictal period of the epileptic status.

Acute toxicity investigation regarding clinical and pathological aspects following repeated oral administration of iron oxide nanoparticles in rats

Abstract: Iron oxide nanoparticles (IONPS) have potential different applications in nanomedicine. These new applications of IONPS have raised exposure risk of this nanomaterials to humans. Up to now, all aspects of IONPS toxicity are not fully clear following animal’s exposure with these novel compounds. This study aimed to investigate the acute toxicity effects of IONPS in laboratory animals regarding pathotoxicological analysis and clinical aspects. Twenty four male Wistar rats were randomly chosen, and divided into four groups of six rats each. The first, second, and the third groups received 50, 500, and 5000 mg/kg of IONPS solution orally for five days through gavage, respectively. Animal mortality, clinical sings and body weight were evaluated during the study. Fourteen days after the last administration, rats were euthanized for further investigation for histopathological evaluation. There were no death observed in all groups. High and middle dose of the IONPS caused symptoms like lethargy, ataxia, anorexia, isolation, and respiratory arrhythmia over the period of the study. The subjects of the low dose group showed no signs of toxicity. Specific histopathological complications, like hyaline cast in the kidneys, hyperemia and interstitial thickening in the lungs, hemorrhage in the heart and hepatic degeneration in the liver were observed in high dose group. Thus, it can be concluded that, toxicity of IONPS in rats is dose-dependent. This particular size of IONPS can induce serious pathological abnormalities and clinical symptoms in high dose.

Abstract 203: Identification of Immunoregulatory microRNAs in Cardiac Tissue of Septic Mice Treated with Mesenchymal Stem Cells

Abstract: Despite diminution of myocardial dysfunction, organ injury, and animal mortality in polymicrobial models of sepsis upon systemic administration of bone marrow-derived mesenchymal stem cell (MSC), t...

Modelling feedlots using the MEDLI model framework

Abstract: Model for Effluent Disposal using Land Irrigation (MEDLI) is a biophysically-based daily time-step model released in 1996 to facilitate designing effluent irrigation schemes. The model simulates a waste stream generator producing effluent that is treated in a pond system with a wet weather storage pond from which the effluent is irrigated as required to an area of land growing vegetation (Gardner et al. 1996). To complement the existing waste stream generator options, MEDLI is undergoing further development to include rainfall-dependent waste streams, including that generated by rainfall wash-off from feedlot production pens. This will facilitate MEDLI's use for designing effluent irrigation schemes associated with feedlots. The feedlot pen model attempts to model the complex dynamic processes within feedlot production pens that impact on the quantity and quality of runoff using a daily time-step mass balance approach. An early description of the feedlot model for MEDLI, focusing on runoff quantity, was provided by Atzeni et al. (2001). Since then, the hydrology component has been substantially improved to generate daily surface and sub-surface pad moisture output for use in predicting odour emissions (Atzeni et al. 2015), as well as runoff quantity and quality. In this paper, we present the modelling approach and model algorithms used to simulate the waste stream from the feedlot production pens. Supporting references are detailed in Atzeni et al. (2015). The MEDLI feedlot pen model is designed to simulate a modern feedlot yard with equal-sized production pens having adequate slope, and operating within the recommended Australian guidelines. Cattle can be designated to up to four markets, with market-specific entry and exit weights, daily weight gain, proportion of total herd designated, and proportion of pens occupied. Daily calculations are performed on a pen by pen basis, to model the key processes of herd dynamics, manure (faeces+urine) production, assimilation of the fresh manure into the pad, pen hydrology and pen cleaning. Herd dynamics include modelling animal mortality and pen stocking. When animals in a pen reach the exit weight for their market type, the model flags that the pen is vacant and drafts another mob (of the same market type) into another vacant pen if possible, or else the same pen. Manure production relies on BEEFBAL (QPIF 2004) or similar model to provide the market-specific annual manure production (total solids, volatile solids, total nitrogen, total phosphorus, salts and water) of each animal which is then used to determine the solids, nutrient, salt and water loading onto the manure pad. Assimilation of the fresh manure into the pad uses a two-layer model for the manure pad, assuming no loss of water or solids below the lower layer of the pad. The two layers capture the dynamics of pad hydrology and composition, including the impacts of rainfall, evaporation, animal stocking, manure accumulation, volatile solids decay, pen cleaning, runoff and manure erosion during runoff. Pens are cleaned at intervals to remove the excess manure, and involve considering the specified minimum number of days since a pen is cleaned, the pen's pad moisture content, pad depth, and the number of pens being cleaned each day. By modelling these processes, the fate of the nutrients, salts and solids from the manure pads is simulated as shown in Figure 1.Validation of the feedlot pen model hydrology was undertaken using four field-collected data sets from three South East Queensland feedlots. The prediction of runoff quantity appears closely correlated with measured data. However, the runoff quality predictions require calibration of the total nitrogen, total phosphorus, and salt runoff concentrations with actual or expected holding pond chemistry. Data collection is in progress to allow further testing and validation of the feedlot pen module. Copyright © 2019 The Modelling and Simulation Society of Australia and New Zealand Inc. All rights reserved.

Neuroprotective and Antiamnestic Effects of a New Drug Emopag in Rats

Abstract: Emopag, a new drug, preventively administered in doses of 10 and 30 mg/kg/day over 4 days produced a pronounced neuroprotective effect in the model of brain ischemia caused by gravitational overload and reduced animal mortality from 17 to 0%. The preparation more effectively corrected neurological deficit than the reference drugs Mexidol (in considerably larger doses of 30 and 90 mg/kg/day) and antihypoxic drug amtizol (30 mg/kg/day). Moreover, Emopag exhibited considerable antiamnestic activity comparable to that of Mexidol (in 3-fold higher doses); in a dose of 30 mg/kg/day Emopag was more effective than Mexidol and amtizol in the same dose. Thus, Emopag showed marked neuroprotective and antiamnestic effects in the model of gravitational overload in rats.