Tomasz Skrzypek

Granulomatous Peritonitis in a European Brown Bear Caused by Baylisascaris transfuga

We report a case of granulomatous peritonitis due to Baylisascaris transfuga in a young male European brown bear (Ursus arctus). At necropsy, there were extensive abdominal adhesions and extensive granulomatous tissue on the peritoneum and liver capsule. In the gastrointestinal tract, there were 58 nematodes that were identified as Baylisascaris transfuga using light and scanning electron microscopy.

Structural network of arabinogalactan proteins (AGPs) and pectins in apple fruit during ripening and senescence processes

The cell wall is an essential framework determining the overall form of the plant cell. Our study was focused on the distribution of arabinogalactan proteins (AGPs), arabinan, and homogalacturonan in fruit cells during ripening and storage with emphasis on quantitative analysis of their presence in particular regions of the cell wall - plasma membrane. The localization of the examined compounds was determined with immunohistochemistry techniques and immunogold labelling. Spatio-temporal colocalization between AGPs epitopes - [βGlcA(1→3)-αGalA(1→2)Rha] recognized by JIM13 and MAC207 antibodies, and arabinan labelled by the LM16 antibody was detected in the inner cell wall layer, in association with the plasma membrane. The specific arrangement of AGP and arabinan epitopes differentiated them from homogalacturonan epitopes, consisting of GalA residues recognized by LM19 and LM20 antibodies in all the examined fruit maturity stages. The disruption of cell wall - plasma membrane continuum, observed during ripening-associated softening process, was associated with both the substantial decrease of AGPs, pectins content and with remodeling of their arrangement. The results indicate that the textural properties of fruit during growth and postharvest storage, an attribute of fruit quality becoming selection criteria for consumers, depend on the existence of dynamic network organizing polysaccharides and glycoproteins in the extracellular matrix.

A simplified method of preparation of mammalian intestine samples for scanning electron microscopy

Due to strong tissue hydration and complex architecture of the mucous membrane, appropriate preparation of inhomogeneous gastrointestinal tissues, especially from the intestine, for scanning electron microscopy is still a challenge and requires constant improvement of preparation techniques. In this article, we describe a simplified method of preparation of small intestinal mucosa tissues for observations in a scanning electron microscope. We emphasized the most important points in the preparation process that, when ignored, may result in formation of numerous artifacts and the inability to analyze the samples reliably. The developed technique facilitates proper animal tissue sampling in the field conditions, reducing the time of tissue collection and sample preparation as well as the total process costs. The fixative of choice, that is, buffered formalin, fixes, and stiffens the processed tissues properly, which is especially important in preservation of long, highly hydrated intestinal villi without shrinkage artifacts. The method described has been successfully used in comparative studies of the development of small intestines in mammals (pigs, mice, rats), reptiles, and birds (hens).

Antifungal resistance and physicochemical attributes of apricots coated with potassium sorbate-added carboxymethyl cellulose-based emulsion

Summary Antifungal effectiveness of potassium sorbate (KS) incorporated into edible coating composed of carboxymethyl cellulose and candelilla wax blend (CMC-CnW) was tested on apricots inoculated with fungi. The efficiency of KS-added coating was higher than KS-free formulation. The antifungal action of KS-free coating was likely associated with a reduced access of oxygen to the infection sites and, consequently, modification of the gaseous atmosphere within the fruit tissues. Rhizopus nigricans as the fastest growing fungus was the most resistant to the coating treatment. In turn, KS-loaded coating was very effective against Botrytis cinerea and Monilinia fructigena. Coating significantly delayed softening of apricots. The results of this study demonstrate that KS can be incorporated into coating to control common fungal diseases of apricots. Nevertheless, the CMC-CnW coating treatment inhibited the respiratory functions and caused deterioration in the fruit sensory quality.

Steinernema poinari (Nematoda: Steinernematidae): a new symbiotic host of entomopathogenic bacteria Xenorhabdus bovienii

Three strains of symbiotic bacteria were isolated from an entomopathogenic nematode Steinernema poinari retrieved from soil in eastern Poland. Using 16S rDNA, recA, gltX, gyrB, and dnaN gene sequences for phylogenetic analysis, these strains were shown to belong to the species Xenorhabdus bovienii. The nucleotide identity between the studied S. poinari microsymbionts and other X. bovienii strains calculated for 16S rDNA and concatenated sequences of four protein-coding genes was 98.7–100% and 97.9–99.5%, respectively. The phenotypic properties of the isolates also supported their close phylogenetic relationship with X. bovienii. All three tested X. bovienii strains of different Steinernema clade origin supported the recovery of infective juveniles and subsequent development of the nematode population. However, the colonization degree of new infective juvenile generations was significantly affected by the bacterial host donor/recipient. The colonization degree of infective juveniles reared on bacterial symbionts deriving from a non-cognate clade of nematodes was extremely low, but proved the possible host-switching between non-related Steinernema species.