Genotyping canine distemper virus (CDV) by a hemi-nested multiplex PCR provides a rapid approach for investigation of CDV outbreaks

CDV is a highly contagious viral pathogen causing a lethal systemic disease in dogs and other carnivores. Several lineages or genotypes of CDV exist that are variously distributed throughout several continents. Legal or uncontrolled trading of animals may modify the epidemiology of CDV, introducing novel strains in CDV-na?ve areas or accounting for the resurgence of CDV in areas where vaccine prophylaxis was effective and successful to control the disease. A hemi-nested PCR system was developed to genotype strains of the major CDV lineages, America-1, Europe, Asia-1, Asia-2 and Arctic. The assay was tested using a collection of 27 laboratory and vaccine strains and of 36 field CDV strains. Distinct lineages could be differentiated by specific primers targeted to the H gene. The method could be useful for molecular epidemiological studies of CDV, providing a tool for large-scale studies, and for the diagnosis of vaccine-related disease.     

Genogroup I picobirnavirus in diarrhoeic foals: Can the horse serve as a natural reservoir for human infection?

ABSTRACT: Picobirnaviruses (PBV) are small, non-enveloped viruses with a bisegmented double-stranded RNA genome. In this study a PBV strain, PBV/Horse/India/BG-Eq-3/2010, was identified in the faeces of a 10 month old weaned female foal with diarrhoea in January 2010 from Kolkata, India. Surprisingly, sequence comparison and phylogenetic analysis of a short stretch of the RNA dependent RNA polymerase gene revealed close genetic relatedness (> 98% nucleotide identity) to a human genogroup I PBV strain (Hu/GPBV1) detected earlier from the same part of India. Our observations together with earlier findings on genetic relatedness between human and animal PBV warrant further studies on zoonotic potential.     

Impact of soil texture on temporal and spatial development of osmotic‐potential gradients between bulk soil and rhizosphere

Solute transport from the bulk soil to the root surface is, apart from changes in soil moisture and plant nutrient uptake, a prerequisite for changes in soil osmotic potential (Ψ_o). According to the convection‐diffusion equation, solute transport depends on a number of parameters (soil moisture–release curve, hydraulic conductivity, tortuosity factor) which are functions of soil texture. It was thus hypothesized that soil texture should have an effect on the formation of Ψ_o gradients between bulk soil and the root surface. The knowledge about such gradients is important to evaluate water availability in the soil‐plant‐atmosphere continuum (SPAC). A linear compartment system with maize grown under controlled conditions in two texture treatments (T1, pure sand; T2, 80% sand, 20% silt) under low and high initial application of salts (S1, S2) was used to measure the development of Ψ_o gradients between bulk soil and the root surface by microscale soil‐solution sampling and TDR sensors. The differences in soil texture had a strong impact on the formation of Ψ_o gradients between bulk soil and the root surface at high and low initial salt application rate. At high initial salt application, a maximum osmotic‐potential gradient (ΔΨ_o) of –340 kPa was observed for the texture treatment T2 compared to ΔΨ_o of –180 in T1. The steeper gradients in osmotic potential in treatment T2 compared to T1 corresponded to higher cumulative water consumption in this treatment which can partly be explained by higher soil hydraulic conductivity in the range of soil matric potentials covered during the duration of the experiments. Differences between texture treatments in Ψ_o at the root surface did not result in differences in plant‐water relations measured as gas‐exchange parameters (transpiration rate, water‐use efficiency) and leaf osmotic potential. If soil osmotic and matric potential are regarded as additive in calculating the driving force for water movement from the soil into the root, the observed differences in water flux between treatments cannot be explained.