Occurrence of antimicrobial resistance among bacterial pathogens and indicator bacteria in pigs in different European countries from year 2002 – 2004: the ARBAO-II study

Background

The project "Antibiotic resistance in bacteria of animal origin – II" (ARBAO-II) was funded by the European Union (FAIR5-QLK2-2002-01146) for the period 2003–05. The aim of this project was to establish a program for the continuous monitoring of antimicrobial susceptibility of pathogenic and indicator bacteria from food animals using validated and harmonised methodologies. In this report the first data on the occurrence of antimicrobial resistance among bacteria causing infections in pigs are reported.

Methods

Susceptibility data from 17,642 isolates of pathogens and indicator bacteria including Actinobacillus pleuropneumoniae, Streptococcus suis and Escherichia coli isolated from pigs were collected from fifteen European countries in 2002–2004.

Results

Data for A. pleuropneumoniae from infected pigs were submitted from five countries. Most of the isolates from Denmark were susceptible to all drugs tested with the exceptions of a low frequency of resistance to tetracycline and trimethoprim – sulphonamide.Data for S. suis were obtained from six countries. In general, a high level of resistance to tetracycline (48.0 – 92.0%) and erythromycin (29.1 – 75.0%) was observed in all countries whereas the level of resistance to ciprofloxacin and penicillin differed between the reporting countries. Isolates from England (and Wales), France and The Netherlands were all susceptible to penicillin. In contrast the proportion of strains resistant to ciprofloxacin ranged from 12.6 to 79.0% (2004) and to penicillin from 8.1 – 13.0% (2004) in Poland and Portugal.Data for E. coli from infected and healthy pigs were obtained from eleven countries. The data reveal a high level of resistance to tetracyclines, streptomycin and ampicillin among infected pigs whereas in healthy pigs the frequency of resistance was lower.

Conclusion

Bacterial resistance to some antimicrobials was frequent with different levels of resistance being observed to several antimicrobial agents in different countries. The occurrence of resistance varied distinctly between isolates from healthy and diseased pigs, with the isolates from healthy pigs generally showing a lower level of resistance than those from diseased pigs.The study suggests that the choice of antimicrobials used for the treatment of diseased animals should preferably be based on knowledge of the local pattern of resistance.     

Effects of cyclosporine A on clinical and histologic abnormalities in dogs with sebaceous adenitis

OBJECTIVE: To evaluate the effects of cyclosporine A in the treatment of sebaceous adenitis in dogs. DESIGN: Open-label clinical trial. ANIMALS: 12 dogs with sebaceous adenitis. PROCEDURE: Dogs were treated with cyclosporine A at a dosage of 5 mg/kg/d (2.3 mg/lb/d), PO, for 12 months and reevaluated every 4 months. A clinical score was calculated by grading the extent of alopecia and severity of follicular casts as absent, mild, moderate, or severe in each of 17 body regions. Biopsy specimens were obtained and examined histologically and by means of immunohistochemical staining. RESULTS: Mean clinical score was significantly decreased, compared with baseline score, after 4 months of treatment and remained low after 8 and 12 months. Histologically, the severity of inflammation was significantly decreased, as were numbers of macrophages, CD3+ T cells, and major histocompatibility complex class II-expressing cells. The percentage of hair follicles with sebaceous glands increased, suggesting regeneration of sebaceous glands. Clinical signs recurred when cyclosporine administration was discontinued. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that administration of cyclosporine A at a dosage of 5 mg/kg/d may reduce the inflammation associated with sebaceous adenitis in dogs. Long-term treatment appears to be neccessary to control the disease.     

Characterizing behavioral sleep using actigraphy in adult dogs of various ages fed once or twice daily

Adult dogs possess strong diurnal locomotor activity/rest rhythms, and sleep/wake patterns have been characterized. However, behavioral sleep/wake data are lacking related to aging and daily feeding pattern. Three groups (young adults [Y], 1.5–4.5 years; middle-aged adults [M], 7–9 years; and senior, 11–14 years) of beagles (N = 48) wore the Actiwatch activity monitoring system (Respironics Co., Inc., Bend, OR) for 3 days while housed indoors with 12-hour light/dark schedule and fed once or twice daily. Actiware-Rhythm software (version 5.52; Respironics Co., Inc., Bend, OR) was used to estimate behavioral sleep or wake from locomotor activity data. All dogs demonstrated diurnal sleeping patterns. Total wake minutes during the light phase declined with age (P < 0.05) and differed by 7.7% and 10.2% for middle-aged adults and seniors, respectively, compared with young adults. Further analysis revealed that increased light phase nap bouts (P < 0.008), not increased nap duration, caused this decline. Total sleep minutes during the night increased with age, as middle-aged adults and seniors slept at least 38 (P = 0.01) more minutes than young adults. Increased sleep time at night resulted from a longer sleep interval duration (P = 0.05), delayed morning activity onset time (P = 0.02), and marginally fewer waking bouts (P = 0.07). Independent of age, twice-daily feeding significantly influenced daytime sleeping patterns but did not affect total minutes recorded as sleep during the day. Interestingly, napping bouts decreased significantly (P = 0.01) and napping duration increased (P = 0.0001) when fed twice-daily. Twice-daily feeding was also associated with earlier sleep onset time at night and onset of morning activity, as well as shortened sleep interval. Clear changes in behavioral sleep patterns were observed with age and daily feeding schedule.     

Integrating single-species management and landscape conservation using regional habitat occurrence models: the northern goshawk in the Southwest,USA

Conservation planners and land managers are often confronted with scale-associated challenges when assessing the relationship between land management objectives and species conservation. Conservation of individual species typically involves site-level analyses of habitat, whereas land management focuses on larger spatial extents. New models are needed to more explicitly integrate species-specific conservation with landscape or regional scales. We address this challenge with an example using the northern goshawk (Accipiter gentilis), a forest raptor with circumpolar distribution that is the focus of intense debate regarding forest management on public lands in the southwestern USA. To address goshawk-specific habitat conservation across a management area of 22,800-km² in northern Arizona, we focused on the territory scale rather than individual nest sites. We compiled a 17-year database of 895 nest sites to estimate territory locations. We then estimated the likelihood of territory occurrence for the entire management area using multiple logistic regression within an expert-driven, spatially balanced, and information-theoretic framework. Our occurrence model incorporated forest structure variables that were derived from USFS Forest Inventory and Analysis plots and high-resolution satellite imagery. Results indicated that high canopy-bulk density, intermediate canopy-base heights, and low variation in tree density were strong predictors of territory occurrence. We used model-averaged parameter estimates for these variables to map and explore patterns of territory distribution across multiple land jurisdictions and ecological subregions. Our iterative modeling approach complements previous demographic studies in the region. It also provides a robust framework for integrating species conservation and landscape management in ongoing and future regional planning efforts.     

Capturing genetic diversity of wild populations for <Emphasis Type="Italic">ex situ</Emphasis> conservation: Texas wild rice (<Emphasis Type="Italic">Zizania texana</Emphasis>) as a model

Genebanks complement other conservation programs because they preserve genetic diversity needed for future breeding and restoration. We evaluated efficiency of capturing genetic diversity, using endangered Zizania texana (Texas wild rice) as a model for plants with recalcitrant seeds. This perennial aquatic grass is restricted to 4 km of the San Marcos River in Texas. An early conservation collection included plants from stands throughout the river, based on the assumption stands would be unique genotypes. Using microsatellite markers, we found that genetic diversity was concentrated in five of 15 large, demographically stable stands; 96 stands smaller than 2 m² contributed no unique alleles. High heterozygosity and few duplicate genotypes suggested that sexual reproduction occurs more often than presumed. Simulations of stratified sampling of large stands captured all alleles in only 45 individuals, while random sampling along the river captured much less diversity. The early conservation collection captured as much diversity as expected from random sampling. Texas wild rice stands resemble a mainland-island metapopulation; our analyses suggest that stratified sampling maximizes genetic diversity for this population dynamic. Demographic and genetic information is important for validating the design of efficient ex situ collections and guiding in situ conservation.     

Fundamental study on protein changes taking place during malting of oats

During the malting process, storage proteins are degraded by proteolytic enzymes into small peptides and amino acids. The activity of these enzymes was measured during malting of oats and was found to be increased. To quantify proteolytic degradation, proteins of unmalted, germinating and malted grains were fractionated. After extracting the oat proteins (Osborne fractionation), protein fractions were analysed using a Lab-on-a-Chip technique, which separates the proteins – based on their molecular weight – by capillary electrophoresis. This new technique for the analysis of proteins was supported by using two-dimensional gel electrophoresis. In addition, amino acid analysis was carried out. In general a degradation of proteins to small peptides and amino acids could be observed in the globulin, prolamin and glutelin fractions. In the albumin fraction a protein increase was observed, which is due to the fact that this fraction contains the majority of the metabolically active proteins. Amino acid analysis supported the observation of increased protein amount in the albumin fraction and decreased protein amounts in the other fractions. Some proteins, which have not been described in the literature, were detected in the albumin and glutelin fraction, since Lab-on-a-Chip technique allows detection of proteins with low molecular weights of 4.5 kDa.     

Castor beans hulls as a replacement for Tifton 85 hay in lamb diets

The objective of this study was to evaluate the effect of replacing Tifton 85 hay (0, 33, 66, or 100 %) with by castor bean hulls on the intake and nutrient digestibility and performance of 28 noncastrated lambs, averaging 7 months in age, 19.5?±?2.0 kg average live weight, fed on diets based on forage cactus. The animals were housed in individual pens for 100 days. The digestibility trial occurred 40 days after the start of the performance using LIPE® as an external indicator for estimating fecal dry matter production. The replacement of hay with Castor beans hulls linearly decreased the intakes of dry matter, neutral detergent fiber, organic matter, and crude protein and reduced the digestibility coefficients of the dry matter, neutral detergent fiber, organic matter content, crude protein, and total digestible nutrient content. The hot carcass and true carcass yields were not influenced by the treatments and the feed conversion increased linearly. The empty body weight, live weight at slaughter, hot and cold carcass weights, total gain, and average daily gain decreased linearly with the replacement. The replacement of Tifton 85 hay with castor bean hulls reduced the intake of dry matter, crude protein and energy, consequently reducing the performance of the animals. However, as the regression coefficients were of low magnitude, data were subjected to analysis of variance and means were compared using the Dunnett test with diet without castor bean hulls set as the control treatment. The Tifton 85 hay can be replaced up to 66 % by castor bean hulls in finishing diets for lambs.     

Predicting seed yield in perennial ryegrass using repeated canopy reflectance measurements and PLSR

Abstract

Repeated canopy reflectance measurements together with partial least-squares regression (PLSR) were used to predict seed yield in perennial ryegrass (Lolium perenne L.). The measurements were performed during the spring and summer growing seasons of 2001 to 2003 in three field experiments with first year seed crops using three sowing rates and three spring nitrogen (N) application rates. PLSR models were developed for each year and showed correlation coefficients of 0.71, 0.76, and 0.92, respectively. Regression coefficients showed in these experiments that the optimum time for canopy reflectance measurements was from approximately 600 cumulative growing degree-days (CGDD) to approximately 900 CGDD. This is the period just before and at heading of the seed crop. Furthermore, regression coefficients showed that information about N and water is important. The results support the development of an additional N- and water-application model which will calculate the application rate of N and water according to expected seed yield.     

Do plant species of different resource qualities form dissimilar energy channels below-ground?

This study aimed at examining whether plant species of varying resource quality give rise to a fungal- or bacterial-based energy channel in the plants’ rhizosphere, when planted in soil, in which the plant species naturally occur. In an 18-month large-scale laboratory mesocosm experiment, two plant species (Holcus lanatus and Lotus corniculatus) producing labile litter and two plant species (Picea abies and Calluna vulgaris) producing recalcitrant litter were placed in the same mesocosm. This allowed the decomposer biota (microbes, protozoa, nematodes, collembolans, and enchytraeid worms) to freely choose their preferred plant rhizosphere. Because a fungal-based energy channel is in theory regarded to retain nutrients better in the soil than a bacterial-based energy channel, water was collected underneath the plant species and analyzed for its nutrient (N and P) content.In general, the number of soil biota groups responding significantly to the plant treatment increased with time. Soil microbes were the first group to react, but the ability of the plants to boost a clearly fungal- or bacterial-based energy channel was generally weak. However, at the end of the study, a higher fungal-to-bacterial biomass ratio was found beneath Calluna than beneath the other plant treatments. Of the secondary consumers, nematodes were the most responsive group, with total number and especially plant parasites being more abundant beneath Lotus than beneath Picea and Calluna indicating a root-based energy channel to persist under the legume. Protozoa, enchytraeid worms and collembolans responded weakly and inconsistently to plant treatment. Liberation of plant-available nutrients was plant-dependent. Towards the end of the study, less nitrate and phosphate leached through the Picea soils than through the control, which indicates a more effective nutrient retention to take place under this plant species. We found that plant species can, in a relatively short time, modify the composition of the soil decomposer community. However, no consistent evidence for the plant–soil systems developing to separated detritus energy channels emerged, we found a clearly separated root energy channel under the legume L. corniculatus.