Characterization of extraintestinal Escherichia coli isolated from a peacock (Pavo cristatus) with colisepticemia

Extraintestinal infections by avian pathogenic strains of Escherichia coli (APEC) are commonly reported in poultry, but there is little information on infections by APEC in other bird species. Here we report on the characterization of extraintestinal E. coli isolated from a domesticated peacock, from the south of Brazil, that died of colisepticemia. Necropsy examination revealed congested liver, hypertrophied kidneys, peritonitis, severe typhlitis suggestive of coligranuloma, pneumonia, and airsacculitis--typical signs of colisepticemia. The isolates from lungs, kidney, heart, intestine, liver, and bone marrow all harbored the same virulence-associated factors (iucD, colV, iss, mat, fimC, ompA, traT crl, csgA vgrG, and hcp), yielded the same band pattern in amplified ribosomal DNA restriction analysis, and were allocated to the Escherichia coli Reference Collection group B1. The isolates were resistant to bacitracin, trimethoprim, and tetracycline, but displayed slight differences in their resistance to other antimicrobials. The isolates also differed in their virulence in 1-day-old chickens, but none displayed high virulence in vivo. We conclude that the peacock died of colisepticemia after it was infected with an extraintestinal E. coli strain of low virulence that nevertheless harbored virulence factors generally associated with APEC. This study represents the first characterization of an APEC isolated from a nonpoultry bird species.     

An experimental assessment of landscape configuration effects on frog and toad abundance and diversity in tropical agro-savannah landscapes of southeastern Brazil

Amphibians are an imperiled group of vertebrate animals that typically have biphasic life histories involving a shift from aquatic larval habitats to terrestrial adult habitats. Habitat loss is the greatest threat to amphibians and the importance of the spatial configuration of terrestrial and breeding habitats upon the landscape in determining amphibian persistence is poorly known. The information gap is particularly acute in tropical landscapes that simultaneously host the greatest and most imperiled amphibian fauna on Earth. We installed 125 artificial ponds at different distances from forest fragments embedded in an agricultural matrix in southeastern Brazil. Constructed ponds attracted 13 anuran species; ponds at the forest fragment-matrix transition hosted a greater abundance and higher species richness of frogs and toads than those installed either far from or well within forest fragments. Forest fragments larger than 70 ha in agricultural areas harbored more individuals than smaller fragments. Our results indicate that landscape configuration has an important influence on frog and toad distribution and abundance in tropical agricultural landscapes and we suggest guidelines for maintaining favorable configurations of aquatic and terrestrial habitats for conserving this rich and imperiled species suite.     

Comparative study of equine bone marrow and adipose tissue-derived mesenchymal stromal cells

Reasons for performing study: Mesenchymal stromal cells (MSCs) represent an attractive source for regenerative medicine. However, prior to their application, fundamental questions regarding molecular characterisation, growth and differentiation of MSCs must be resolved. Objectives: To compare and better understand the behaviour of equine MSCs obtained from bone marrow (BM) and adipose tissue (AT) in culture. Methods: Five horses were included in this study. Proliferation rate was measured using MTT assay and cell viability; apoptosis, necrosis and late apoptosis and necrosis were evaluated by flow cytometry. The mRNA expression levels of 7 surface marker genes were quantified using RT‐qPCR and CD90 was also analysed by flow cytometry. Differentiation was evaluated using specific staining, measurement of alkaline phosphatase activity and analysis of the mRNA expression. Results: High interindividual differences were observed in proliferation in both cell types, particularly during the final days. Statistically significant differences in viability and early apoptosis of cultured AT‐ and BM‐MSCs were found. The highest values of early apoptosis were observed during the first days of culture, while the highest percentage of necrosis and late apoptosis and lowest viability was observed in the last days. Surface marker expression pattern observed is in accordance to other studies in horse and other species. Osteogenic differentiation was evident after 7 days, with an increasing of ALP activity and mRNA expression of osteogenic markers. Adipogenic differentiation was achieved in BM‐MSCs from 2 donors with one of the 16 media tested. Chondrogenic differentiation was also observed. Conclusions: Proliferation ability is different in AT‐MSCs and BM‐MSCs. Differences in viability and early apoptosis were observed between both sources and CD34 was only found in AT‐MSCs. Differences in their osteogenic and adipogenic potential were detected by staining and quantification of specific tissue markers. Potential relevance: To provide data to better understand AT‐MSCs and BM‐MSCs behaviour in vitro.     

Skeletal deformities associated with nutritional congenital rickets in newborn lambs

Abstract

CASE HISTORY: A group of 545 pregnant rising 2-year-old Coopdale ewes on a Southland sheep farm were grazed over winter on a fodder beet (Beta vulgaris) crop. Subsequently, 45 out of approximately 750 lambs were born with a variety of skeletal deformities, including shortened limbs, varus and valgus angular limb deformities, palmar grade stance and cranial bowing of the carpus. Analysis of the crop showed the fodder beet contained a low percentage of phosphorus. In addition, 60 out of 460 rising 2-year-old ewes that had been grazed on the fodder beet crop as 1-year-olds had incisor abnormalities and malocclusion.

PATHOLOGICAL FINDINGS: Two affected lambs (1-day-old and 3-days-old) with representative clinical signs examined postmortem were found to have markedly enlarged costochondral junctions, and noticeably enlarged long bone metaphyses. In addition, one lamb had a dense band of metaphyseal sclerosis beneath the physes of all long bones examined. Histopathological findings included small islands and columns of chondrocytes and eosinophilic cartilage matrix present in the metaphysis. Metaphyseal trabeculae were disorganised and often lined by accumulations of pale pink osteoid; similar pale pink osteoid was also present in the cortices. Unerupted molar teeth in the affected lambs lacked a layer of enamel, and the dentine was irregular with globular basophilia.

DIAGNOSIS: The gross and histopathological lesions were consistent with a diagnosis of rickets.

CLINICAL RELEVANCE: Nutritional congenital rickets has not been previously diagnosed in sheep, but is a recognised disease of human infants with vitamin D deficient mothers. The rickets in affected lambs was most likely associated with phosphorus deficiency as a result of the pregnant ewes grazing fodder beet during gestation. While vitamin D deficiency was not definitively ruled out in these cases, practitioners are alerted to the possible effects of feeding phosphorus-deficient fodder beet to ewes for long periods during gestation and to 1-year-old sheep during important growth periods.     

Analysis of genetic diversity in Bolivian llama populations using microsatellites

South American camelids (SACs) have a major role in the maintenance and potential future of rural Andean human populations. More than 60% of the 3.7 million llamas living worldwide are found in Bolivia. Due to the lack of studies focusing on genetic diversity in Bolivian llamas, this analysis investigates both the genetic diversity and structure of 12 regional groups of llamas that span the greater part of the range of distribution for this species in Bolivia. The analysis of 42 microsatellite markers in the considered regional groups showed that, in general, there were high levels of polymorphism (a total of 506 detected alleles; average PIC across per marker: 0.66), which are comparable with those reported for other populations of domestic SACs. The estimated diversity parameters indicated that there was high intrapopulational genetic variation (average number of alleles and average expected heterozygosity per marker: 12.04 and 0.68, respectively) and weak genetic differentiation among populations (F_ST range: 0.003–0.052). In agreement with these estimates, Bolivian llamas showed a weak genetic structure and an intense gene flow between all the studied regional groups, which is due to the exchange of reproductive males between the different flocks. Interestingly, the groups for which the largest pairwise F_ST estimates were observed, Sud Lípez and Nor Lípez, showed a certain level of genetic differentiation that is probably due to the pattern of geographic isolation and limited communication infrastructures of these southern localities. Overall, the population parameters reported here may serve as a reference when establishing conservation policies that address Bolivian llama populations.     

Geospatial variation of physical attributes and sugarcane productivity in cohesive soils

Precision Agriculture - Sugarcane productivity is highly variable across space, and knowledge about the spatial distribution of soil physical attributes is important to guide management practices...     

Response of in vitro obtained oil palm and interspecific OxG hybrids to inoculation with Phytophthora palmivora

Bud rot (BR) disease caused by Phytophthora palmivora is the most devastating disease in oil palm cultivation in America. Oil palms that survived BR epidemics were found in areas highly devastated by the disease; these palms were introduced into Cenipalma's in vitro micropropagation (cloning programme). A severity scale was developed for in vitro palms from five ortets inoculated with two different P. palmivora isolates. Then, eight ortets of Elaeis guineensis and two ortets of the OxG interspecific hybrid were evaluated in two inoculation trials under chamber growth conditions. The clone performance response was consistent with that reported in the field for the corresponding ortets, and two contrasting ortets, one susceptible (ortet 57) and one resistant (ortet 34) were identified. We monitored and compared defence responses to P. palmivora in the contrasting ortets. An increase in reactive oxygen species (ROS) production after inoculation with the pathogen was observed, with higher accumulation of H₂O₂ in the resistant plants. Catalase (CAT) activity in resistant plants increased after inoculation with the pathogen from 24 hr post‐infection (hpi) and remained high during the observation time. In the susceptible ortets, there was a significant increase on catalase activity only at 48 hpi. Peroxidase (POS) activity increased in clones from both susceptible and resistant ortets, but the increase was much greater in the susceptible ones. Phenylalanine ammonia lyase activity increased in response to inoculation, and these increases were greater in clones of the susceptible ortet than in clones of the resistant ortet.