Staphylococcus aureus isolates from Eurasian Beavers (Castor fiber) carry a novel phage-borne bicomponent leukocidin related to the Panton-Valentine leukocidin

Staphylococcus aureus can be a harmless coloniser, but it can also cause severe infections in humans, livestock and wildlife. Regarding the latter, only few studies have been performed and knowledge on virulence factors is insufficient. The aim of the present study was to study S. aureus isolates from deceased wild beavers (Castor fiber). Seventeen isolates from eleven beavers, found in Germany and Austria, were investigated. Antimicrobial and biocide susceptibility tests were performed. Isolates were characterised using S. aureus-specific DNA microarrays, spa typing and whole-genome sequencing. From two isolates, prophages were induced by mitomycin C and studied by transmission electron microscopy. Four isolates belonged to clonal complex (CC) 8, CC12, and CC398. Twelve isolates belonged to CC1956 and one isolate was CC49. The CC49 and CC1956 isolates carried distinct lukF/S genes related to the Panton-Valentine leukocidin (PVL) from human isolates of S. aureus. These genes were located on related, but not identical, Siphovirus prophages. The beavers, from which those isolates originated, suffered from abscesses, purulent organ lesions and necrotising pneumonia, i.e., clinical manifestations resembling symptoms of severe PVL-associated disease in humans. It might thus be assumed that the “Beaver Leukocidin (BVL, lukF/S-BV)”-positive strains are beaver-specific pathogens, and further studies on their clinical role as well as on a possible transmissibility to other species, including humans, are warranted.

Dyeing of Agro-Waste Castor Fibres with Eclipta Prostrata Dye

Fiber extracted from castor plant is a bast fiber like hemp, jute, flax and kenaf. Based on the chemical constitutes; physical and chemical properties of these eco-friendly fibers extracted from agro waste are used in making different materials like union fabrics and reinforcement materials. In the present study, castor fiber was dyed with Eclipta prostrata plant extract and evaluated for colorfastness and color strength properties. The colorfastness properties of castor fiber dyed with pre, simultaneous and post-mordanting methods using four mordants aluminum potassium sulfate (commonly called alum) (KAI(SO4)2 .12H2O),stannous Chloride (SnCl2), copper sulfate (CuSO4) and ferrous sulfate (FeSO4) were tested. The colorfastness to light, wash, crock and perspiration was found to be good for CuSO4 and FeSO4 dyed fibers. Color strength properties for the samples were also assessed and found to be good.

The response of a brown trout (Salmo trutta) population to reintroduced Eurasian beaver (Castor fiber) habitat modification

Globally, freshwaters are the most degraded and threatened of all ecosystems. In northern temperate regions, beaver (Castor spp.) reintroductions are increasingly used as a low-cost and self-sustaining means to restore river corridors. River modifications by beavers can increase availability of suitable habitat for fish, including salmonids. This study investigated the response of a population of brown trout (Salmo trutta) to reintroduced Eurasian beaver (Castor fiber) habitat modifications in northern Scotland. The field site comprised two streams entering a common loch; one modified by beavers, the other unaltered. Electrofishing and PIT telemetry surveys indicated abundance of post-young-of-the-year (post-YOY) trout was higher in the modified stream. Considering juvenile year groups (YOY and post-YOY) combined, abundance and density varied with year and season. In the modified stream, fork length and mass were greater, there was a greater variety of age classes, and mean growth was positive during all seasons. Beavers had profound effects on the local brown trout population that promoted higher abundances of larger size classes. This study provides important insight into the possible future effect of beavers on freshwater ecosystems.

Staphylococcus Aureus Isolates From Eurasian Beavers (Castor Fiber) Carry a Novel Phage-borne Bicomponent Leukocidin Related to the Panton-valentine Leukocidin

Staphylococcus aureus can be a harmless coloniser, but it can also cause severe infections in humans, livestock and wildlife. Regarding the latter, only few studies have been performed and knowledge on virulence factors is insufficient. The aim of the present study was to study S. aureus isolates from deceased wild beavers (Castor fiber). Seventeen isolates from eleven beavers, found in Germany and Austria, were investigated. Antimicrobial and biocide susceptibility tests were performed. Isolates were characterised using S. aureus-specific DNA microarrays, spa typing and whole-genome sequencing. From two isolates, prophages were induced by Mitomycin C and studied by transmission electron microscopy.Four isolates belonged to clonal complex (CC) 8, CC12, and CC398. Twelve isolates belonged to CC1956 and one isolate was CC49. The CC49 and CC1956 isolates carried distinct lukF/S genes related to the Panton-Valentine leukocidin (PVL) from human isolates of S. aureus. These genes were located on related, but not identical, Siphovirus prophages. The beavers, from which those isolates originated, suffered from abscesses, purulent organ lesions and necrotising pneumonia, i.e., clinical manifestations resembling symptoms of severe PVL-associated disease in humans. It might thus be assumed that the “Beaver Leukocidin (BVL, lukF/S-BV)”-positive strains are beaver-specific pathogens, and further studies on their clinical role as well as on a possible transmissibility to other species, including humans, are warranted.

Monitoring and prospects for conservation and rational use of the resources of the Eurasian beaver (Castor fiber Linnaeus, 1758) on the example of the Samara Region

The paper examines characteristics of the Eurasian beaver population (Castor fiber Linnaeus, 1758) on territories with different anthropogenic load. Monitoring the beaver population and habitat, including the landscape basis and natural zoning with the allocation of natural, natural-anthropogenic and anthropogenic territories as natural ecological systems allows you to manage and rationally use the resources of these animals. Previously there were mainly natural territories in the studied region, however with the growth of the human population and its economic activity their properties have changed. According to biotic criteria, geochemical circulation, significant (formerly natural) territories functionally already correspond to natural-anthropogenic and anthropogenic objects, since the supply of fodder, population density and density of animals have changed. According to natural zoning, taking into account the identified changes in the habitat of beavers (by biotic criteria), we have examined their territorial distribution as well as the number of settlements in various natural objects of the region. On the studied rivers the density of the beaver population in the channel decreases in the following order: natural territory natural-anthropogenic anthropogenic, but the indicator of private abundance (the density of animals on the territory where beavers live directly) and aggregation (crowding of individuals) increases. The population density of the river bed of the studied rivers by beavers on anthropogenic territories is from 0,9-3,7 individuals/km, which is lower than on natural and natural-anthropogenic territories, where this indicator is from 1,5 to 6 individuals/km. The length of the river bed, where beavers live directly, without taking into account significant buffer zones, varies in natural areas from 60 to 100%, which is more than in areas with anthropogenic load, where this indicator in the study area decreases to 40%. A decrease in the size of river channel sections suitable for beaver colonization leads to overcrowding (aggregation) of individuals. Compared with the total density of beaver population in the river channel 0,9-3,7 individuals/km of the channel (excluding the Kondurcha River - 6 individuals/km of the channel) the population density, locally, on anthropogenic and natural-anthropogenic territories increases to 4-7,5 individuals/km.