Looking for prognosticators in ovine anaplasmosis: discriminant analysis of clinical and haematological parameters in lambs belonging to differently susceptible breeds experimentally infected with Anaplasma ovis

Background

A study was carried out to evaluate the response of different native sheep breeds to experimental infection with Anaplasma ovis, the most prevalent sheep tick-borne pathogen in Apulia (Southern Italy). Thirty-four lambs belonging to a Northern European breed (Suffolk) and two Southern Italian breeds (Comisana and Altamurana) were infected. Eleven clinical as well as haematological parameters were monitored at different temporal resolutions on the same subjects before and after the infection, resulting in a data set of 435 observations. The present work, aiming to further the research, presents the results of a multivariate analysis carried out to identify which parameters out of the eleven considered are the most reliable parameters to be considered as markers of the disease phenotype as well as prognosticators of practical clinical importance.

Results

Data were analysed by discriminant analysis. Out of the eleven considered variables (red blood cells, packed cell volume, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin content, haemoglobin concentration, white blood cells, neutrophils, leukocytes, platelets, rectal temperature), only seven were included in the step-wise model since significantly increasing the Mahlanobis distance between the two closest groups. Both discriminant functions resulted to be highly significant (P < 0.0001) and the percentage of variation accounted for by the first discriminant function was 63.6% of the variance in the grouping variable.

Conclusions

Taken together, the observed results stress the marked differentiation among the three breeds in terms of physio-pathological phenotypes indicating packed cell volume and red blood cell count as the most informative parameters in the routine clinical practice for A. ovis infection in sheep.     

Insect growth regulators as potential insecticides to control olive fruit fly (Bactrocera oleae Rossi): insect toxicity bioassays and molecular docking approach

BACKGROUND: Olive fruit fly, Bactrocera oleae (Rossi), is a key pest in olive orchards, causing serious economic damage. To date, the pest has already developed resistance to the insecticides commonly applied to control it. Thus, in searching for new products for an accurate resistance management programme, targeting the ecdysone receptor (EcR) might provide alternative compounds for use in such programmes. RESULTS: Residual contact and oral exposure in the laboratory of B. oleae adults to the dibenzoylhydrazine‐based compounds methoxyfenozide, tebufenozide and RH‐5849 showed different results. Methoxyfenozide and tebufenozide did not provoke any negative effects on the adults, but RH‐5849 killed 98‐100% of the treated insects 15 days after treatment. The ligand‐binding domain (LBD) of the EcR of B. oleae (BoEcR‐LBD) was sequenced, and a homology protein model was constructed. Owing to a restricted extent of the ligand‐binding cavity of the BoEcR‐LBD, docking experiments with the three tested insecticides showed a severe steric clash in the case of methoxyfenozide and tebufenozide, while this was not the case with RH‐5849. CONCLUSION: IGR molecules similar to the RH‐5849 molecule, and different from methoxyfenozide and tebufenozide, might have potential in controlling this pest. Copyright © 2012 Society of Chemical Industry     

Glyoxalase 1 expression is downregulated in preimplantation blastocysts of diabetic rabbits

In a diabetic pregnancy, an altered maternal metabolism led to increased formation of reactive α‐dicarbonyls such as glyoxal (GO) and methylglyoxal (MGO) in the reproductive organs and embryos. The enzyme glyoxalase (GLO) 1 detoxifies reactive α‐dicarbonyls thus protecting cells against malfunction or modifications of proteins by advanced glycated end products (AGEs). The aim of this study was to analyse the influence of a maternal insulin‐dependent diabetes mellitus (IDD) on GLO1 expression and activity in preimplantation embryos in vivo and human trophoblast cells (Ac‐1M88) in vitro. Maternal diabetes was induced in female rabbits by alloxan before conception and maintained during the preimplantation period. GLO1 expression and activity were investigated in 6‐day‐old blastocysts from healthy and diabetic rabbits. Furthermore, blastocysts and human trophoblast cells were exposed in vitro to hyperglycaemia, GO and MGO and analysed for GLO1 expression and activity. During gastrulation, GLO1 was expressed in all compartments of the rabbit blastocyst. Maternal diabetes decreased embryonic GLO1 protein amount by approx. 30 per cent whereas the enzymatic activity remained unchanged, indicating that the specific GLO1 activity increases along with metabolic changes. In in vitro cultured embryos, neither hyperglycaemia nor MGO and GO had an effect on GLO1 protein amount. In human trophoblast cells, a stimulating effect on the GLO1 expression was shown in the highest GO concentration, only. Our data show that maternal diabetes mellitus affects the specific activity of GLO1, indicating that GLO1 was post‐translationally modified due to changes in metabolic processes in the preimplantation embryos.     

Context-Dependent Effect of Dietary Phytochemicals on Honey Bees Exposed to a Pesticide,Thiamethoxam

Honey bees continue to face challenges relating to the degradation of natural flowering habitats that limit their access to diverse floral resources. While it is known that nectar and pollen provide macronutrients, flowers also contain secondary metabolites (phytochemicals) that impart benefits including increased longevity, improved gut microbiome abundance, and pathogen tolerance. Our study aims to understand the role of phytochemicals in pesticide tolerance when worker bees were fed with sublethal doses (1 ppb and 10 ppb) of thiamethoxam (TMX), a neonicotinoid, in 20% (w/v) sugar solution supplemented with 25 ppm of phytochemicals—caffeine, kaempferol, gallic acid, or p-coumaric acid, previously shown to have beneficial impacts on bee health. The effect of phytochemical supplementation during pesticide exposure was context-dependent. With 1 ppb TMX, phytochemical supplementation increased longevity but at 10 ppb TMX, longevity was reduced suggesting a negative synergistic effect. Phytochemicals mixed with 1 ppb TMX increased mortality in bees of the forager-age group but with 10 ppb TMX, mortality of the inhive-age group increased, implying the possibility of accumulation effect in lower sublethal doses. Given that the phytochemical composition of pollen and nectar varies between plant species, we suggest that the negative impacts of agrochemicals on honey bees could vary based on the phytochemicals in pollen and nectar of that crop, and hence the effects may vary across crops. Analyzing the phytochemical composition for individual crops may be a necessary first step prior to determining the appropriate dosage of agrochemicals so that harm to bees Apis mellifera L. is minimized while crop pests are effectively controlled.     

Pharmacokinetics after intravenous, intramuscular and subcutaneous administration of moxifloxacin in sheep

The disposition kinetics of moxifloxacin, a fluoroquinolone antibiotic, after intravenous (IV), intramuscular (IM) and subcutaneous (SC) administration was determined in sheep at a single dose of 5 mg/kg. The concentration-time data were analysed by compartmental (after IV dose) and non-compartmental (after IV, IM and SC administration) pharmacokinetic methods. Plasma concentrations of moxifloxacin were determined by high performance liquid chromatography with fluorescence detection. Steady-state volume of distribution (V_ss) and clearance (Cl) of moxifloxacin after IV administration were 2.03 ± 0.36 L/kg and 0.39 ± 0.04 L/h kg, respectively. Following IM and SC administration, moxifloxacin achieved maximum plasma concentration of 1.66 ± 0.62 mg/L and 0.90 ± 0.19 mg/L at 2.25 ± 0.88 h and 3.25 ± 1.17 h, respectively. The absolute bioavailabilities after IM and SC routes were 96.12 ± 32.70% and 102.20 ± 23.76%, respectively. From these data (kinetic parameters and absence of adverse reactions) moxifloxacin may be a potentially useful antibiotic in sheep.     

Effect of environmental conditions on polychlorinated biphenyl transformations and bacterial communities in a river sediment

Purpose  

The aim of this study was to evaluate polychlorinated biphenyl (PCB) removal in relation to the associated bacterial community composition in Ohio River sediments (USA) using field and laboratory approaches.     

Utility of landscape mosaics and boundaries in forest conservation decision making in the Atlantic Forest of Brazil

We evaluated changes in the Atlantic Forest landscape over the last 40 years based on changes in boundaries and mosaics, including the hypothetical landscape resulting from the application of Brazilian laws for forest protection. Mosaics were identified as sets of land-use patches with a similar pattern of boundaries. Landscapes of different years, therefore, can be distinguished by differences in mosaics. We developed a technique to identify boundaries between patches from land-use maps using ArcGis^® and to build the patch x boundary matrix required for mosaic identification by means of a factorial and cluster analysis. The mosaics were characterized by some key uses as well as by their boundaries with other land uses. The mosaics were scored for forest conservation according to five issues: landscape permeability, cover, availability, quality, and fragmentation of forest. The values were based on land use and boundary patterns. Although Brazilian laws regarding forest protection have promoted conservation and the hypothetical legal landscape has presented the highest forest habitat availability, this expansion perpetuates a boundary pattern that complicates conservation and management, thus increasing the pressure on forest patches and favoring the further fragmentation of protected forest patches. These conclusions cannot be reached by simply recording changes in land uses.