Changes in the risk management of Salmonella enterica subspecies diarizonae serovar 61:(k):1, 5, (7) in Swedish sheep herds and sheep meat due to the results of a prevalence study 2012

Background

The prevalence of Salmonella in food producing animals is very low in Sweden due to rigorous control programmes. However, no active surveillance is in place in sheep. The authorities decided to perform a prevalence study in sheep herds because findings at slaughter indicated that sheep associated S. diarizonae (S. enterica subspecies diarizonae serovar 61:(k):1, 5, (7)) might be common in sheep. Sampling was stratified by herd size in two groups, small herds with ≤ 30 animals and large herds with > 30 animals. In each stratum, 237 herds were selected at random. Faecal samples received from 244 out of the 474 randomly selected herds were analysed.

Results

A total of 40 of 100 (40%) of large herds and 17 of 144 (12%) of small herds were positive. The overall adjusted prevalence was 17.6% (95% CI, 12.9-22.2). Sheep associated S. diarizonae was detected in all counties (n = 21). Scientific opinions and an evaluation of on-farm control measures performed concluded that the impact of sheep associated S. diarizonae on human health is very low, and that risk management measures applied in response to findings of sheep associated S. diarizonae in sheep or sheep meat can be expected to have very little impact on reducing risks to human health. As a result, Swedish authorities decided to make an exemption for sheep associated Salmonella diarizonae in sheep and sheep meat in the current Salmonella control measures.

Conclusions

Sheep associated S. diarizonae is endemic in Swedish sheep herds. It is more common in large herds and not limited to certain parts of the country. The responsible authorities concluded that current risk management actions regarding sheep associated S. diarizonae in sheep and sheep meat are not proportional to the risk. This is the first time in the history of the Swedish Salmonella control programme that an exemption from the legislation has been made for a specific serovar. If there is any future indication of an increasing risk, due to e.g. change in the pathogenicity or development of antimicrobial resistance, the risk assessment will be re-evaluated and control measures reinforced if needed.     

Combining information from surveys of several species to estimate the probability of freedom from Echinococcus multilocularis in Sweden,Finland and mainland Norway

Background

The fox tapeworm Echinococcus multilocularis has foxes and other canids as definitive host and rodents as intermediate hosts. However, most mammals can be accidental intermediate hosts and the larval stage may cause serious disease in humans. The parasite has never been detected in Sweden, Finland and mainland Norway. All three countries require currently an anthelminthic treatment for dogs and cats prior to entry in order to prevent introduction of the parasite. Documentation of freedom from E. multilocularis is necessary for justification of the present import requirements.

Methods

The probability that Sweden, Finland and mainland Norway were free from E. multilocularis and the sensitivity of the surveillance systems were estimated using scenario trees. Surveillance data from five animal species were included in the study: red fox (Vulpes vulpes), raccoon dog (Nyctereutes procyonoides), domestic pig, wild boar (Sus scrofa) and voles and lemmings (Arvicolinae).

Results

The cumulative probability of freedom from EM in December 2009 was high in all three countries, 0.98 (95% CI 0.96-0.99) in Finland and 0.99 (0.97-0.995) in Sweden and 0.98 (0.95-0.99) in Norway.

Conclusions

Results from the model confirm that there is a high probability that in 2009 the countries were free from E. multilocularis. The sensitivity analyses showed that the choice of the design prevalences in different infected populations was influential. Therefore more knowledge on expected prevalences for E. multilocularis in infected populations of different species is desirable to reduce residual uncertainty of the results.     

Reconstitution of pilus assembly reveals a bacterial outer membrane catalyst

Type 1 pili from uropathogenic Escherichia coli are a prototype of adhesive surface organelles assembled and secreted by the conserved chaperone/usher pathway. We reconstituted type 1 pilus biogenesis from purified pilus proteins. The usher FimD acted as a catalyst to accelerate the ordered assembly of protein subunits independently of cellular energy. Its activity was highly dependent on the adhesin subunit FimH, which triggered the conversion of FimD into a high-efficiency assembly catalyst. Furthermore, a simple kinetic model adequately rationalized usher-catalyzed pilus assembly in vivo. Our results contribute to a mechanistic understanding of protein-catalyzed biogenesis of supramolecular protein complexes at the bacterial outer cell membrane.     

A case of biphasic mesothelioma with osseous and chondromatous differentiation in a cat

An 11-year-old domestic short hair cat with dyspnea, cyanosis, and pleural effusion died. Necropsy revealed several nodules and masses on the parietal pleura, pericardium, and diaphragm. The tumor contained epithelial and mesenchymal components and displayed osseous and chondromatous differentiation. Tumors cells were positive for pancytokeratin and vimentin. This is the first report of a biphasic mesothelioma with osseous and chondromatous differentiation in this species.     

Back to basics: Considerations in evaluating the outcomes of community forestry

Evaluations on community forestry outcomes are important to observe whether the program community forestry produces what it has promised. For the evaluation -as an alternative to the comprehensive criteria and indicators on sustainable community forestry-, we propose an approach based on the core policy objectives of the program. In fact, community forestry is very much connected to the following three objectives of: 1) alleviating the poverty of forest users, 2) empowering them, and 3) improving the condition of the forests. Based on field tests in two community forests in Indonesia, the focus on the core policy objectives appears to provide a more practical approach than the use of complex criteria and indicators. We conclude that our approach allows rapid evaluations and eventually reduces the associated costs and time without compromising the goals of the evaluation.     

Increased Levels of Aluminium in Forest Soils: Effects on the Stores of Soil Organic Carbon

Acid atmospheric deposition results in increased levels of mobile aluminium (Al) in forest soils. Laboratory studies suggest that increased binding of Al to soil organic matter (SOM) in the forest floor results in decreased mobility of organic matter in soil water, viz. lower concentrations of dissolved organic carbon (DOC). Other laboratory studies indicate decreased decomposition rates of SOM as a result of Al binding. So far, little field evidence supporting these effects of Al on the lability of SOM have been reported. Here we present a field manipulation experiment in mature Norway spruce forest in Norway, where the content of Al in soil and soil water was increased. Increased Al in the forest floor caused a pronounced decrease in the leaching of DOC. Simultaneously, the decomposition rate of SOM decreased by 30% to 40%. This suggests that elevated Al in the forest floor stimulates accumulation of SOM. In a companion paper we present the effect of increased Al on forest vitality.     

New compounds obtained by evolution and oxidation of malvidin 3-O-glucoside in ethanolic medium

Two new colorless phenolic compounds were formed from malvidin 3- O-glucoside incubated in an ethanolic solution. Their structures were characterized by means of one- and two-dimensional NMR analysis and through electrospray ionization-mass spectrometry. As compared to the structure of the initial anthocyanin skeleton, the first new compound showed the presence of two fused five-membered rings replacing the pyran ring and of a carbonyl function on the 2-position. The first five-membered ring was shown to result from the formation of a new linkage between the B ring 6'-position and the C ring 4-position, while the second was a dihydro furan ring with an oxygenated ether linkage between the 8a-position and the 3-position. The second isolated compound was shown to have similar structure with an ethyl ether moiety in the 3-position instead of the glucose moiety. A mechanism explaining the formation of the isolated compounds involving the passage through the chalcone form of the anthocyanin and an oxidation process is proposed.     

Cover Crops and Soil Phosphorus Availability

Plants affect soil phosphorus (P) solubility through root exudates, but studies are lacking on species used as relay or cover crops in tropical environments. We evaluated the effect of cover crops on soil phosphorus (P) availability in an oxisol. Ruzigrass (Brachiaria ruziziensis), pearl millet (Pennisetum glaucum), peanut (Arachis hypogaea), crambe (Crambe abyssinica), and sorghum (Sorghum bicolor) were grown in pots with soil. Phosphorus uptake, soil inorganic and organic P, maximum P adsorption capacity, and plant root systems were assessed. When root length density is high, the efficiency of P uptake is low due to root competition. Crambe results in greater soil P availability, while peanut and sorghum decrease the soil maximum P adsorption capacity, probably by exuding or stimulating microbial production of organic acids and phenolic compounds. Hence, crambe, peanut, and sorghum are species that may be of interest to increase P use efficiency in cropping systems.