Comparison of enzyme-linked immunosorbent assay and RT-PCR for the detection of porcine epidemic diarrhoea virus

Porcine epidemic diarrhoea (PED) is a contagious enteric disease of pigs caused by a coronavirus. A double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) based on the use of monoclonal antibodies was developed for the detection of porcine epidemic diarrhoea virus (PEDV). The DAS-ELISA was compared with RT-PCR in the examination of 506 specimens collected during 2006-2007 from pigs originating from different farms located in the Po valley. Both faecal samples obtained directly from the rectum of live animals showing clinical signs and intestinal samples collected from the caecum of deceased pigs were included in the study. The correlation between the two methods was higher when testing faecal samples (K = 0.97, 95% CI: 0.94-1.00) than testing intestinal samples (K = 0.62, 95% CI: 0.35-0.89). The use of ELISA technology provided an efficient and effective mean of evaluating the presence of coronavirus PED antigen in field samples and indicates that this procedure is a very useful tool in epidemiological studies.     

Screening for several potential pathogens in feral pigeons (Columba livia) in Madrid

Background

Pathogens with the zoonotic potential to infect humans, such as Campylobacter jejuni, Campylobacter coli and Chlamydophila psittaci, can be found in feral pigeons (Columba livia). Given the high density of these birds in the public parks and gardens of most cities, they may pose a direct threat to public health.

Methods

A total of 118 pigeons were captured in three samplings carried out in 2006-2007 in public parks and gardens in Madrid, Spain. Standard haematological and morphological analyses were carried out on the pigeons. PCR was used to screen for the presence of Campylobacter jejuni, C. coli and Chlamydophila psittaci. Positive samples were confirmed by DNA sequencing.

Results

The analyses demonstrated a high prevalence of Chlamydophila psittaci (52.6%) and Campylobacter jejuni (69.1%) among the birds captured. In contrast, Campylobacter coli was rarely detected (1.1%).

Conclusions

Pigeons in Madrid can carry Chlamydophila psittaci and Campylobacter jejuni. They may be asymptomatic or subclinical carriers of both pathogens.     

Effect of Gamma Irradiation on the Functional and Nutritive Properties of Rice Flours from Different Cultivars

The purpose of this work was to study the effect of minimal doses of γ‐irradiation to reduce microbial loads (Co⁶⁰, doses of 0, 1.5, and 3 kGy) on flour from three rice cultivars with different amylose contents (AC) grown in Argentina: RP2 (AC 25%), Yeruá (Y) (AC 19%), and Higokumochi (H) (AC 5%). Studies on some starch characteristics such as digestibility (rate of starch hydrolysis in vitro), gel viscosity and syneresis, and scanning electron microscopy (SEM) were performed. Results showed that γ‐irradiation affects rice functional and nutritive characteristics proportionally with the dosage used. With 3 kGy, original digestibility values increased 37.5, 60, and 76%; gel viscosity decreased 52, 77, and 90%; and syneresis increased 0, 193, and 546% on RP2, Y, and H, respectively. Amylopectin was the starch fraction most affected as shown by SEM. Although some of these changes in cultivar attributes might be considered negative for traditional food formulations, they could help in the design of new foods or for fermented beverages.     

Isolation and Characterization of Brenneria quercina, Causal Agent for Bark Canker and Drippy Nut of Quercus spp. in Spain

ABSTRACT The drippy nut disease of oak was first described in California in 1967 and, since then, the causal agent has not been reported in any other area. This study describes for the first time in Europe the isolation of Brenneria (Erwinia) quercina from bark canker in addition to drippy bud and drippy nut in Quercus ilex and Q. pyrenaica. The bark canker and drippy bud symptoms were not previously described as caused by this bacterium. No fungal pathogens were associated with any of the symptoms. Physiological and biochemical characterization identified the pathogenic isolates from Spain as belonging to B. quercina, similar to the reference strain CFBP 1266. Fatty acid profiles of the Spanish isolates also were similar to the strain of B. quercina from California. Serological analysis by indirect immunofluorescence and enzyme-linked immunosorbent assay using polyclonal antisera against the reference strain of B. quercina and one Spanish oak isolate revealed some antigenic heterogeneity between isolates of different origins. Pathogenicity tests demonstrated that the Spanish isolates were able to reproduce internal symptoms of necrosis and acorn exudation in Q. ilex and Q. pyrenaica and suggest that B. quercina may be associated, among other causes, with the oak decline syndrome affecting Spanish oak forests.     

Identification of the bovine alpha1-acid glycoprotein in colostrum and milk

Alpha1-acid glycoprotein (AGP) is an immunomodulatory protein expressed by hepatocytes in response to the systemic reaction that follows tissue damage caused by inflammation, infection or trauma. This paper presents the detection of bovine AGP (boAGP) in mammary secretions (colostrum and milk) and mammary gland tissue. Bovine AGP was detected by Western blotting in all the samples analysed, and could be quantified in colostrum at 162 (+/- 63.7) microg/mL and 114.5 (+/- 67.8) microg/mL during the first 12 h and 24 h respectively. In mature milk, the boAGP concentration clearly decreased and was no longer detectable using the Radial Immunodiffusion (RID) technique. The concentration of mature milk boAGP was therefore semi-quantified using an anion-exchange chromatographic procedure that allowed the concentration of the protein to be determined. The presence of AGP in bovine milk was confirmed by the internal sequence analysis performed following purification to homogeneity of the protein from milk. The concentration of AGP in bovine milk with low SCC (< 250,000) was very similar to that from bovine milk with high SCC (> 250,000). In order to investigate the origin of AGP in bovine milk, a search for mRNA was carried out in somatic cells and mammary gland tissue: mRNA expression of the boAGP gene was detected in mammary gland tissue, but not in somatic cells. Finally, the cDNA sequence of the boAGP was determined, and is hereby presented.     

Soil Phosphorus Variability: Scale-dependence in an Urbanizing Agricultural Landscape

We examine the hypothesis that human activity changes patterns of variance in soil P (Bray-1) concentrations across several spatial scales. We measured soil P concentrations and variability for each of four different land uses at three distinct levels of analysis. Land uses were remnant prairie, lawns, corn fields of cash grain farms, and corn fields of dairies in Dane County, Wisconsin (USA). For each land use type, levels of analysis were sites (an agricultural field, residential lawn or prairie, ranging in size from 100 m² to approximately 20 ha), 10-m plots within a site, and points within the 10-m diameter plot. The rank of mean soil P concentrations was cash grain > dairy > lawn > prairie. For all land use types, most of the variance was accounted for by site-to-site variation. Among-site variance was higher for human-dominated sites (0.55, 0.15, 0.14 [log (mg/kg)]² for cash grain, dairy, and lawn sites, respectively) than it was for prairies (0.07 [log (mg/kg)]²). However, prairies had the highest among-plot variation (0.04 [log (mg/kg)]²) compared to other sites (0.01, 0.002, and 0.01 [log (mg/kg)]² for cash grain, dairy, and lawn sites, respectively). The results indicate that in this watershed, human activity has increased the mean soil P and variance of soil P, and shifted the scale of variance to larger spatial extents. Human impacts on landscape pattern extend to soil properties that affect nutrient flow and eutrophication of surface waters. Because soil P turns over slowly, the legacy of altered soil P patterns may affect freshwaters for centuries.     

Prevalence of intestinal parasites in dogs under veterinary care in Maracaibo, Venezuela

The prevalence of intestinal parasites in dogs presented to the Veterinary Policlinic of the University of Zulia (PVU) was measured between January and December 2001. A total of 614 fecal samples were evaluated by the fecal flotation method. One or more species of parasites was identified in 218 (35.5%) dogs. The parasites most frequently detected were: Ancylostoma spp. (24.5%), Toxocara canis (11.4%) and Isospora spp. (8.1%). Single parasitic infections were present in 149 (24.3%) dogs. The age distribution of intestinal parasites in dogs less than 1 year old had a higher overall prevalence than those dogs over 12 months of age. There was no significant difference in the prevalence between male (38.9%) and female (31.7%) dogs. There was a significantly (P < 0.05) greater prevalence of parasites in mixed-breed dogs (40.3%) as compared with pure-breed dogs (30.8%). A significant difference (P < 0.05) was detected between the general prevalence of January and December compared to August.     

Geminivirus DNA replication and cell cycle interactions

The Geminiviridae family includes a large number of viruses that infect plants and have a unique geminate virion particle, a single-stranded genome of approximately 2.6-3.0 kb, and replicate through a rolling-circle mechanism. Since they encode for just a few proteins (4-6 depending on the members that belong to four different genera), a rich variety of interactions has evolved between viral proteins and host factors to develop the virus replicative cycle. Among them, we have been particularly interested so far: (i). in the interference with cell cycle regulatory proteins of the retinoblastoma-related (RBR)/E2F pathway and (ii). in the interaction with host DNA replication factors necessary for the assembly of a functional replication complex at the viral origin of DNA replication during the rolling-circle stage. Yeast two-hybrid assays revealed that wheat dwarf virus RepA protein, but nor Rep protein, interacts with plant RBR protein. Interestingly, deletion of the C-terminal domain of Rep confers the truncated protein the ability to interact with RBR, suggesting that this domain may hinder the LXCXE RBR-binding motif. Secondary structure predictions support such a possibility.     

Effect of oxytocin treatment in sows on umbilical cord morphology,meconium staining,and neonatal mortality of piglets

OBJECTIVE: To evaluate the effect of 2 oxytocin products administered to sows at the onset of fetal expulsion on the integrity of umbilical cords, meconium staining, and piglet mortality. ANIMALS: 2099 neonatal pigs. PROCEDURE: 180 parturient sows were randomly assigned to 3 stratified groups of 60 sows each. Two groups of sows were injected IM at the onset of fetal expulsion with 1 of 2 oxytocin commercial products (20, 40, or 50 U for sows weighing 120 to 150 kg, 151 to 250 kg, or > or = 251 kg, respectively). Control sows were treated IM with saline (0.9% NaCI) solution. Farrowing time, expulsion intervals, and numbers of stillborn and liveborn piglets were recorded for each sow. Piglets were evaluated for inspiratory effort, heart rates, and degree of meconium staining of skin (nonstained, and moderately or severely stained). Umbilical cords were classified as normal in appearance, edematous, congested, hemorrhagic, or ruptured. RESULTS: Oxytocin-treated sows had a significant decrease in farrowing time and expulsion intervals and also had a significantly higher number of stillborn piglets per litter, compared with control sows. The number of piglets per litter with ruptured and hemorrhagic umbilical cords was significantly greater in oxytocin-treated sows, compared with control sows. In near-death stillborn piglets, oxytocin treatment significantly decreased inspiratory efforts at birth and increased the rate and severity of meconium staining, compared with saline treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Oxytocin given to sows at the onset of fetal expulsion significantly increases the rate of fetal distress, anoxia, and intrapartum death in piglets.