Bacillus anthracis is the causative agent of anthrax, a serious and globally distributed zoonosis affecting a wide range of wild and domestic animals, invariably also humans. However, although known to humans since biblical times, much remains to be elucidated concerning the ecology and transmission of this bacterium. Of particular interest is the Bacillus anthracis Spore, the uptake of which is the predominant way to contract anthrax and which is legendary for its resilience in the environment and thus crucial for persistence and spread of the disease. Hence, the aim of this study is to review the natural transmission of Bacillus anthracis and investigate potential means by which soil persisting Bacillus anthracis Spores reach concentrations sufficient to infect susceptible hosts. When reviewing the literature, three different theories can be distinguished. Firstly, ?the incubator area? hypothesis suggests that favourable soil factors, possibly in association with amoebas, may constitute an environment supporting repeated Spore-bacterium-Spore cycling, thus increasing the local amount of Spores.

The effectiveness of Phlebiopsis gigantea to prevent Spore infections from Heterobasidionannosum and Heterobasidion parviporum on hybrid larch stumps were investigated in fivestands in southern Sweden. All sites are former forest land and the age of the trees wasbetween 9 and 13 years.The study was implemented in August 2010, a month where Spore dispersal should be great.The five sites were located in previously un?thinned monocultures of hybrid larch. The Sporeload in the air was studied with the help of Spore traps from three different tree species;Norway spruce, Scots pine and hybrid larch. A total of 146 Spore traps, evenly distributed inall five sites were analyzed.

Clostridium difficile is a pathogen for both humans and animals and is often associated with antibiotic-associated diarrhea. Recently, several human cases of C. difficile-infection with increased mortality and morbidity have been reported. In studies performed in different countries C. difficile has been found in meat.

The effectiveness of Phlebiopsis gigantea to prevent Spore infections from Heterobasidionannosum and Heterobasidion parviporum on hybrid larch stumps were investigated in fivestands in southern Sweden. All sites are former forest land and the age of the trees wasbetween 9 and 13 years.The study was implemented in August 2010, a month where Spore dispersal should be great.The five sites were located in previously un?thinned monocultures of hybrid larch. The Sporeload in the air was studied with the help of Spore traps from three different tree species;Norway spruce, Scots pine and hybrid larch. A total of 146 Spore traps, evenly distributed inall five sites were analyzed.

In this thesis, three separate experiments have been performed on different aspects of the interaction between the causal agent of clubroot, Plasmodiophora brassicae, and its hosts. In the first experiment the pathotype of the P. brassicae single Spore isolate, which is currently used to construct a reference genome, has been classified using the ECD bioassay. The disease severity of infected plants was scored according to two different scales and the pathotype was determined according to three previously published guidelines. The results were compared to previous published studies describing the e3 isolate. The life cycle of P. brassicae is not well understood.

Pine twisting rust (Melampsora pinitorqua) is a parasitic rust fungus found all across Sweden causing damage resulting in lower quality and reduced tree growth in pine stands. In Sweden, the fungus is dependent on two alternate hosts; European aspen (Populus tremula) and Scots pine (Pinus sylvestris). Pine twisting rust has five different Spore stages, two of them (uredinio- and telioSpores) on the leaves of aspen. Injures on aspen caused by pine twisting rust is not extensive. On the other hand, when it infects the annual shoots of Scots pine it often results in a bent steam or even a top shoot breakage.

Since the end of the eighteenth century forest damage caused by the pathogen Gremmeniella abietina has been observed and documented. During the latest epidemic in Sweden more than 480 000 hectares forest land have been injured and this has lead to considerable economic losses. For the pathogen to succeed with infection, Spore dispersal and colonization the right environmental conditions is required. The aim of this paper is to describe the diseased stands using site and stand characteristics and to evaluate the effect of these variables on the disease incidence. Further, the thinning performed during the time for Spore dispersal and its relationship to injured stands is examined.

Clostridium difficile is a grampositive, anaerobe bacteria with a Spore-forming ability. The bacteria is present in the environment, can be isolated from animals and is common in hospitals, where it is a known cause of severe diarrhoea in compromised patients. Lately scientists have been discussing whether Cl. difficile could be a new food-borne pathogen. The bacteria has been isolated from food-producing animals and from meat products. In this pilot study 82 meat products, bought from swedish shops during a periode of four months, were investigated.

The spatial population structure of the saprotrophic basidiomycete Tulostoma brumale was investigated at a site in south eastern Sweden. Sporocarps were mapped and collected, and somatic incompatibility tests between mycelial cultures cultivated from the sporocarps were used to identify genets. Calculations of the size and numbers of genets and their distribution were performed. The spatial distribution of the tested sporocarps and the identified genets are presented graphically in a grid. The total number of identified genets within the investigated area (1210 m2) was 27 based on 48 tested sporocarps.

The bean bruchid, Acanthoscelides obtectus is a major threat to bean production. In Ethiopia, where this study was performed, the damage by bruchids on stored beans has been reported to reach up to 38%. To use the isolates Beauveria bassiana and Metarhizium anisopliae in the management of A. obtectus can be an environmentally safe alternative for controlling the pest. In the present work the aim was to examine if the four chosen fungal isolates, B.

The Lodgepole pines susceptibility to Heterobasidion spp. was investigated in three parts ofthis study. In the first part, discs from freshly cut stumps were collected and analyzed to seeif the fungi can spread and grow naturally in Lodgepole pine stands. In the second part, rootsamples were collected from Lodgepole pines planted in former infected Norway sprucestands to see if the fungi can spread through root contacts. For the third part, new stumpswas created and artificially infected with Spores of both the S?type (H.

In two feeding experiments Bacillus induced priming of plant defense was tested for its effect against the generalist insect pest Spodoptera littoralis. The main hypothesis for the study was that Bacillus induced priming would enable the plant Arabidopsis thaliana to defend itself better against this insect herbivore since this priming seems to involve jasmonic acid, known to be important for plant defense to insects. A secondary objective of the study was to examine if any differences in a primed defense capability could be seen between different natural genetic variants (ecotypes) of A. thaliana reflecting habitat differences in pest pressure. The methods used for plant cultivation and Bacillus inoculation were aimed at reflecting conditions that can be expected in an agricultural cropping system. This meant that all plants were cultivated in soil, and the feeding experiments were conducted with the plants growing intact in the soil system.

Root rot causes large economical losses for Swedish forestry. The spread of root rot can partly be prevented by treating the spruce stumps in thinnings. Late pre-commercial thinning (PCT) is one of the forestry measures where stump treatment is not used. Late PCT can be defined as: The act of cleaning the stand with the aim of improving accessibility and sight within the stand, and so to increase the mean stem´s volume during the first conventional thinning. The aim of this study was to examine how late PCT is performed, its spatial extent and if it aids the spreading of root rot. The study was limited to encompass late PCT before first conventional thinnings in spruce stands in southern Sweden. Samples of spruce stumps were taken from four stands where late PTC had been carried out.

Stem rust, Puccinia graminis, has caused enormous yield losses throughout history which have had significant consequences for oat and wheat production. Today in Sweden stem rust is only reported from rye, oats and wild grasses. Stem rust infections in wheat have become unusual due to the general use of resistant wheat varieties and also due to the eradication of barberry, Berberis vulgaris, the alternate host for P. graminis. According to international sources, new races of P.

Root rot is a big hurter and a huge economic problem for the Swedish and European forestry. The severest hurter is Heterobasidion annosum (Fr.) Bref and it occurs as two different species in Sweden. Commonly referred to as the P-type (Heterobasidion annosum s.s. (Fr.) Bref.) and the S-type (Heterobasidion parviporum Niemelä & Korhonen). Therefore a lot of research has been carried out in this topic to find a solution and reduce this problem, one alternative that have shown to be profitable is stump treatment in thinnings.