Detection of hepatitis E virus RNA in rats caught in pig farms from Northern Italy

Hepatitis E virus (HEV) strains belonging to the Orthohepevirus genus are divided into four species (A–D). HEV strains included in the Orthohepevirus A species infect humans and several other mammals. Among them, the HEV‐3 and HEV‐4 genotypes are zoonotic and infect both humans and animals, of which, pigs and wild boar are the main reservoirs. Viruses belonging to the Orthohepevirus C species (HEV‐C) have been considered to infect rats of different species and carnivores. Recently, two studies reported the detection of HEV‐C1 (rat HEV) RNA in immunocompromised and immunocompetent patients, suggesting a possible transmission of rat HEV to humans. The role of rats and mice as reservoir of HEV and the potential zoonotic transmission is still poorly known and deserves further investigation. To this purpose, in this study, the presence of HEV RNA was investigated in the intestinal contents and liver samples from 47 Black rats (Rattus rattus) and 21 House mice (Mus musculus) captured in four pig farms in Northern Italy. The presence of both Orthohepevirus A and C was investigated by the real‐rime RT‐PCR specific for HEV‐1 to HEV‐4 genotypes of Orthohepevirus A species and by a broad spectrum hemi‐nested RT‐PCR capable of detecting different HEV species including rat HEV. The intestinal content from two Black rats resulted positive for HEV‐C1 RNA and for HEV‐3 RNA, respectively. None of the House mice was HEV RNA positive. Sequence analyses confirmed the detection of HEV‐C1, genotype G1 and HEV‐3 subtype e. The viral strain HEV‐3e detected in the rat was identical to swine HEV strains detected in the same farm. Liver samples were negative for the detection of either rat HEV or HEV‐3.     

Pedology-based management class establishment: a study case in Brazilian coffee crops

Precision Agriculture - This work proposes an approach for establishing coffee management classes mainly supported by pedological information (soil survey) and land parcels, taking into account...     

Genetic analysis of growth,visual scores,height, and carcass traits in Nelore cattle

Covariance components were estimated for growth traits (BW, birth weight; WW, weaning weight; YW, yearling weight), visual scores (BQ, breed quality; CS, conformation; MS, muscling; NS, navel; PS, finishing precocity), hip height (HH), and carcass traits (BF, backfat thickness; LMA, longissimus muscle area) measured at yearling. Genetic gains were obtained and validation models on direct and maternal effects for BW and WW were fitted. Genetic correlations of growth traits with CS, PS, MS, and HH ranged from 0.20 ± 0.01 to 0.94 ± 0.01 and were positive and low with NS (0.11 ± 0.01 to 0.20 ± 0.01) and favorable with BQ (0.14 ± 0.02 to 0.37 ± 0.02). Null to moderate genetic correlations were obtained between growth and carcass traits. Genetic gains were positive and significant, except for BW. An increase of 0.76 and 0.72 kg is expected for BW and WW, respectively, per unit increase in estimated breeding value (EBV) for direct effect and an additional 0.74 and 1.43, respectively, kg per unit increase in EBV for the maternal effect. Monitoring genetic gains for HH and NS is relevant to maintain an adequate body size and a navel morphological correction, if necessary. Simultaneous selection for growth, morphological, and carcass traits in line with improve maternal performance is a feasible strategy to increase herd productivity.     

Enlightened Mannhemia haemolytica lung inflammation in bovinized mice

Polymorphonuclear cells diapedesis has an important contribution to the induced Mannhemia haemolytica (M. haemolytica) infection lung inflammation and IL-8 is the primary polymorphonuclear chemoattractant. Using a bovine IL-8/luciferase transiently transgenized mouse model, the orchestration among M. haemolytica, IL-8 promoter activation and neutrophilia was followed in real time by in vivo image analysis.     

Conservation of freshwater macroinvertebrate biodiversity in tropical regions

1. Motivated by recent global initiatives for biodiversity conservation and restoration, this article reviews the gaps in our understanding of, and the challenges facing, freshwater macroinvertebrate biodiversity and conservation in tropical regions.
2. This study revealed a lack of adequate taxonomic, phylogenetic, and ecological information for most macroinvertebrate groups, and consequently there are large‐scale knowledge gaps regarding the response of macroinvertebrate diversity to potential climate change and other human impacts in tropical regions.
3. We propose ideas to reduce the impact of key drivers of declines in macroinvertebrate biodiversity, including habitat degradation and loss, hydrological alteration, overexploitation, invasive species, pollution, and the multiple impacts of climate change.
4. The review also provides recommendations to enhance conservation planning in these systems (as well as providing clear management plans at local, regional, and national levels), integrated catchment management, the formulation of regulatory measures, the understanding of the determinants of macroinvertebrate diversity across multiple scales and taxonomic groups, and the collaboration between researchers and conservation professionals.
5. It is suggested that the integrated use of macroinvertebrate biodiversity information in biomonitoring can improve ecosystem management. This goal can be facilitated in part by conservation psychology, marketing, and the use of the media and the Internet.

     

Characterization of transgenic male sterility in alfalfa

Dependable male sterility would help to make hybrid cultivar development a reality in alfalfa once higher levels of heterosis are attained. Alfalfa plants obtained by genetic transformation with a construct containing the Barnase gene under the control of a tobacco anther tapetum specific promoter were studied. Vacuolization and degeneration of the tapetal cell cytoplasm at a premeiotic stage of development were observed in all five transformed plants (T₀)examined, but the severity of the abnormalities varied greatly among pollen sacs of a genotype. During the meiotic stage, some pollen sacs showed reduction in size, and the tapetum generally appeared thinner when compared to those of the non transgenic plants; tapetal cells showed abnormal vacuolization and signs of cytoplasm degeneration. Despite this, some microspores were formed and some pollen grains were shed in all the T₀ plants, but these were highly variable in size and had very low in vitro germinability. Self-fertility was negligible. The T₀ plants were crossed with one or two unrelated non transgenic male-fertile plants. Mendelian segregation was observed with two exceptions. Instability of the trait in F₁ progenies was noticed, varying for different T₀ parents. F₁ plants exhibiting higher sterility than the primary transformants were observed, indicating that it should be possible to obtain good male sterile plants by backcrossing this trait into different genetic backgrounds. The possible use of this transgenic male sterility in alfalfa breeding is briefly discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Location and stability of a recombinant ovine prion protein in synthetic humic-like mineral complexes

Location and stability of a recombinant prion protein (recPrP) and its interaction with humic-like complexes were investigated by low-temperature ashing (LTA), thermal gravimetric (TG), and scanning electron microscopy (SEM) analyses. Humic-like complexes were obtained by abiotic polymerization of catechol, one of the possible precursors of soil humic matter, through the catalysis of birnessite, a manganese oxide common in soil environment. The recPrP was immobilized in organomineral complexes via sorption or entrapment. Complexes were treated by LTA, allowing the controlled removal of organic matter layer by layer, from the external to the internal side, with minimal disturbance of mineral constituents. Thermal gravimetric and SEM analyses were performed on specimens before and after LTA treatment. Entrapped recPrP, compared with sorbed, resulted less easily accessible to LTA treatment and showed a higher thermal stability by TGA analyses. On the basis of these findings, we hypothesize that the processes leading to newly formed organic complexes can enhance prion stability in soil and thus influence the environmental diffusion of infectivity.     

A novel green chemistry method for nonaqueous extraction and high-performance liquid chromatography detection of first-, second-, and third-generation tetracyclines, 4-epitetracycline, and tylosin in animal feeds

Although tetracyclines and macrolides are common additives for animal nutrition, methods for their simultaneous determination in animal feeds are nonexistent. By coupling an organic extraction and solid-phase extraction cleanup to a high-performance liquid chromatography separation and a nonaqueous postcolumn derivatization, we succeeded in detecting from 0.2 to 24.0 μg kg(-1) of tetracycline, oxytetracycline, chlortetracycline, doxycycline, tigecycline, and 4-epitetracycline in this complex and heterogeneous matrix. Minocycline and tylosin could also be detected with our procedure, but using UV spectrophotometry (1.5 ≤ LOD ≤ 1.9 mg kg(-1)). Linear responses with correlation coefficients between 0.996 and 0.999 were obtained for all analytes in the 0.5-10 mg kg(-1) concentration range. Average recoveries between 59 and 97% and between 98 and 102% were obtained for the tetracyclines and tylosin, respectively. Replicate standard deviations were typically below 5%. When this method was applied to 20 feeds marketed in Costa Rica, we detected labeling inconsistencies, banned mixtures of tetracyclines, and tetracycline concentrations that contravene international regulation.