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This study was conducted to determine the prevalence of Campylobacter spp. isolated from dogs' faecal samples. From June 2012 to June 2013, a total of 210 faecal samples from pet dogs living in different kennels (n = 210) were collected by the owners in Greater Poland Voivodeship, Poznań District, Poland. The study revealed that 105 out of 210 faecal samples (50%) contained Campylobacter. The highest prevalence of Campylobacter spp. occurred in spring (81%), followed by winter (64%). The cadF gene was found in 100% of the isolates tested. The occurrence of the other genes was variable. The isolates from young dogs were characterised by higher occurrence of virulence genes.

We describe the synthesis of nanocomposites, based on nanofibers of silicon carbide, silver nanoparticles, and cellulose. Silver nanoparticle synthesis was achieved with chemical reduction using hydrazine by adding two different surfactants to obtain a nanocomposite with silver nanoparticles of different diameters. Determination of antibacterial activity was based on respiration tests. Enzymatic analysis indicates oxidative stress, and viability testing was conducted using an epifluorescence microscope. Strong bactericidal activity of nanocomposites was found against bacteria Escherichia coli and Bacillus cereus, which were used in the study as typical Gram-negative and Gram-positive bacteria, respectively. It is assumed that reactive oxygen species generation was responsible for the observed antibacterial effect of the investigated materials. Due to the properties of silicon carbide nanofiber, the obtained nanocomposite may have potential use in technology related to water and air purification. Cellulose addition prevented silver nanoparticle release and probably enhanced bacterial adsorption onto aggregates of the nanocomposite material.

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In the present study, the presence of flaA, cadF, cdtB, and iam genes of Campylobacter sp. were analysed using PCR. Material for analyses comprised 100 Campylobacter sp. isolates obtained from healthy broiler chickens, fatteners, and calves, among which 84 isolates were ascribed to Campylobacter jejeuni and 16 to Campylobacter coli. All isolates (100%) had the cadF gene responsible for adhesion and the flaA gene determining the motility of the analysed bacteria. The frequency of occurrence of the cdtB gene responsible for the production of the cytolethal distending toxin (CDT) was determined to be high (98.6% in broiler chickens, 75% in fatteners, 62.5% in calves). In case of the iam gene, the highest frequency was recorded in Campylobacter sp. isolated from broiler chickens (84.7%), while in strains collected from fatteners and calves it was lower, amounting to 41.7% and 18.8%, respectively.

Wheat, which is scientifically known as Triticum aestivum L., is a very nutritious grain that serves as a key component of the human diet. The use of mutation breeding as a tool for crop improvement is a reasonably rapid procedure, and it generates a variety that may be used in selective breeding programs as well as functional gene investigations. The present experiment was used to evaluate the potential application of a conventional chemical mutagenesis technique via sodium azide (NaN3) for the germination and seedling growth stage in wheat. Experiments with NaN3 mutagenesis were conducted using four different treatment periods (0, 1, 2, and 3 h) and five different concentrations (0, 0.5, 1, 1.5, and 2 mM). The genomic instability and cytosine methylation of wheat using its seeds were investigated after they were treated. In order to evaluate the genomic instability and cytosine methylation in wheat that had been treated, interprimer binding site (iPBS) markers were used. The mutagenic effects of NaN3 treatments had considerable polymorphism on a variety of impacts on the cytosine methylation and genomic instability of wheat plants. The results of the experiment showed considerable changes in the iPBS profiles produced by the administration of the same treatments at different dosages and at different times. Coupled restriction enzyme digestion interprimer binding site (CRED-iPBS) assays identified changes in gDNA cytosine methylation. The highest polymorphism value was obtained during 1 h + 2 mM NaN3, while the lowest (20.7%) was obtained during 1 h + 1.5 mM NaN3. Results showed that treatments with NaN3 had an effect on the level of cytosine methylation and the stability of the genomic template in wheat plants in the germination stage. Additionally, an integrated method can be used to for mutation-assisted breeding using a molecular marker system in wheat followed by the selection of desired mutants.

AbstractThe aim of this study is to determine the influence of a commercial bacterial inoculant (L1) and a preparation (L2) containing three Lactobacillus strains capable of producing 1,2-propanediol and short-chain fatty acids on maize silage aerobic stability improvement. The research showed that during 90-day ensilage, the applied preparations significantly reduced the content of DM, water-soluble carbohydrates (WSCs), pH and DM recovery (P < 0.05). The concentration of lactic acid (LA), acetic acid (AA) and propionic acid (PA) in the inoculated samples increased significantly (P < 0.05). 1,2-Propandiol and 1-propanol were not found in control silages (without additives). The addition of L1 and L2 significantly (P < 0.05) increased the concentration of these substances. The L1 and L2 mixtures significantly extended (P < 0.05) the silage aerobic stability.

The aim of the study was to determine the role of dogs as a potential reservoir of Campylobacter spp. At the next stage of the research the frequency of occurrence of selected virulence genes, i.e. cadF, flaA and iam as well as genes responsible for the formation the cytolethal distending toxin (CDT), i.e. cdtA, cdtB and cdtC was determined. The isolates obtained in the research were tested for their resistance to selected antibiotics: ciprofloxacin (CIP), enrofloxacin (EF), erythromycin (E) and tetracycline (TE). Campylobacter spp. was found in 63 (12.6%) out of a total number of 500 isolates. 61 (12.2%) isolates were identified as C. jejuni. The number of C. jejuni isolates found in the younger animals was smaller (p <0.05) than in the older ones. The frequency of occurrence of virulence genes and the genes responsible for the formation of CDT was significantly (p <0.05) higher in the older dogs. A comparison of the effect of antibiotics showed that the isolates obtained from both age groups exhibited low resistance to erythrosine (13.5% in the group aged under 1 year and 8.6% in the group aged over 1 year). Both groups exhibited the highest resistance to ciprofloxacin and enrofloxacin.