Agnieszka Marek

Pathogenic Staphylococcus spp. strains are significant agents involved in mastitis and in skin and limb infections in dairy cattle. The aim of this study was to assess the antibacterial effectiveness of bacteriophages isolated from dairy cattle housing as potential tools for maintaining environmental homeostasis. The research will contribute to the use of phages as alternatives to antibiotics. The material was 56 samples obtained from dairy cows with signs of limb and hoof injuries. Staphylococcus species were identified by phenotypic, MALDI-TOF MS and PCR methods. Antibiotic resistance was determined by the disc diffusion method. Phages were isolated from cattle housing systems. Phage activity (plaque forming units, PFU/mL) was determined on double-layer agar plates. Morphology was examined using TEM microscopy, and molecular characteristics were determined with PCR. Among 52 strains of Staphylococcus spp., 16 were used as hosts for bacteriophages. Nearly all isolates (94%, 15/16) showed resistance to neomycin, and 87% were resistant to spectinomycin. Cefuroxime and vancomycin were the most effective antibiotics. On the basis of their morphology, bacteriophages were identified as class Caudoviricetes, formerly Caudovirales, families Myoviridae-like (6), and Siphoviridae-like (9). Three bacteriophages of the family Myoviridae-like, with the broadest spectrum of activity, were used for further analysis. This study showed a wide spectrum of activity against the Staphylococcus spp. strains tested. The positive results indicate that bacteriophages can be used to improve the welfare of cattle.

Despite the many beneficial properties of legume plants, their use in diets for poultry is limited by the presence of antinutritional factors. The aim of the study was to determine the activity of DT-diaphorase, ethoxycoumarin O-deethylase, and catalase, and the concentration of malondialdehyde in liver tissue, as well as the activity of SOD and CAT in the serum of Hy-line Brown hens fed a diet supplemented with various doses of Lupinus angustifolius seeds. The results indicate that the use of large amounts of lupin in the diet resulted in an increase in MDA concentration in the liver and the lipid vacuolization of hepatocytes. A significant increase in DTD activity was observed in chickens receiving 15% lupin. Regardless of lupin dose, no increase in SOD activity was observed in chicken serum after 33 days of the experiment. From the 66th day of the experiment, an increase in catalase activity in the serum of laying hens was observed, while low activity of this enzyme was found in the liver. It can be concluded that the short-term use of lupin in the diet of laying hens does not affect the activity of antioxidant enzymes and, therefore, does not affect the oxidative–antioxidant balance of their body.

The aim of the study was to determine differences in the proteome and peptidome and zinc concentrations in the serum and tissues of chickens supplemented with a multi-strain probiotic and/or zinc glycine chelate in ovo. A total of 1400 fertilized broiler eggs (Ross × Ross 708) were divided into four groups: a control and experimental groups injected with a multi-strain probiotic, with zinc glycine chelate, and with the multi-strain probiotic and zinc glycine chelate. The proteome and peptidome were analyzed using SDS-PAGE and MALDI—TOF MS, and the zinc concentration was determined by flame atomic absorption spectrometry. We showed that in ovo supplementation with zinc glycine chelate increased the Zn concentration in the serum and yolk sac at 12 h post-hatch. The results of SDS-PAGE and western blot confirmed the presence of Cu/Zn SOD in the liver and in the small and large intestines at 12 h and at 7 days after hatching in all groups. Analysis of the MALDI—TOF MS spectra of chicken tissues showed in all experimental groups the expression of proteins and peptides that regulate immune response, metabolic processes, growth, development, and reproduction.

The aim of the study was to determine the occurrence and characteristics of coagulase-positive Staphylococcus strains in the carcasses of wild birds and aviary capercaillies in Southeastern Poland. In total, samples taken from 333 birds were examined. The material consisted of swabs from the internal organs of dead birds (heart, liver, and spleen), the tarsal joints, and mucous membranes (conjunctiva and palatine fissure), as well as from unhatched embryos. The isolated Staphylococcus strains were tested for sensitivity to nine antimicrobial agents and the presence of selected virulence genes. An analysis of the similarity of isolates within species was performed using pulsed-field gel electrophoresis (PFGE). The result indicates that coagulase-positive strains accounted for 5.7% and belonged to the species: Staphylococcus aureus, Staphylococcus pseudintermedius, and Staphylococcus delphini. Among isolated strains, 15.8% were multidrug resistant. The most frequently detected virulence genes were hla in 58% of isolates and hlb and hld in 47.4% of isolates. The results of multiplex PCR showed the presence of genes responsible for the production of enterotoxins C, B, E, and J, in single isolates. It can be concluded that coagulase-positive Staphylococcus strains accounted for a small percentage of staphylococci isolated from free-living birds in the study area. The occurrence of multidrug-resistant coagulase-positive Staphylococcus strains in aviary capercaillies suggests that they play a role in the transmission and spread of resistant strains into the environment. Free-living birds may also be a reservoir of enterotoxigenic Staphylococcus strains.

The aim of the study was to determine the occurrence and characteristics of coagulase-positive Staphylococcus strains in the carcasses of wild birds and aviary capercaillies in south-eastern Poland. Samples from capercaillies and wild birds belonging to 12 orders and 26 species were tested. The resistance of the strains and the presence of selected virulence genes were examined. Similarity analysis of the isolates was performed using pulsed-field gel electrophoresis (PFGE). Coagulase-positive Staphylococcus strains accounted for 5.7% and belonged to the species: Staphylococcus aureus, Staphylococcus pseudintermedius and Staphylococcus delphini. Among isolated strains, 15.8% were multidrug resistant. The most frequently detected virulence genes were hla in 58% of isolates and hlb and hld in 47.4% of isolates., The results of multiplex PCR showed the presence of genes responsible for the production of enterotoxins C, B, E, and J, in single isolates. It can be concluded that coagulase-positive Staphylococcus strains accounted for a small percentage of staphylococci isolated from free-living birds in the study area. The occurrence of multidrug-resistant coagulase-positive Staphylococcus strains in aviary capercaillies suggests that they play a role in the transmission and spread of resistant strains into the environment. Free-living birds may be also a significant reservoir of enterotoxigenic Staphylococcus strains.

The aim of this study was to determine the effect of in ovo co-supplementation of chicken embryos with a multi-strain probiotic containing effective microorganisms and zinc glycine chelate on total antioxidant capacity; concentrations of sulfhydryl groups, bityrosine bridges, formylkynurenines, hydroperoxides, proteins, corticosterone, pro- and anti-inflammatory cytokines and heat shock proteins; and the activity of catalase and superoxide dismutase in the serum, yolk sac and tissues of broiler chickens at 12 h and at 7 days after hatching. The results indicate high SOD activity in the small and large intestines of chicks at 12 h post-hatch in the groups receiving the multi-strain probiotic and in the small intestine and yolk sac of birds receiving the multi-strain probiotic and Zn-Gly chelate. High concentrations of TNF-α and IFN-γ in the yolk sac and serum after in ovo administration of Zn-Gly chelate were observed 12 h after hatching. The use of a probiotic and a probiotic with Zn-Gly chelate increased the total antioxidant capacity in the tissues of chickens. It can be concluded that in ovo administration of a multi-strain probiotic and Zn-Gly chelate can maintain the oxidant/antioxidant balance in chickens and increase the defense capacity against oxidative stress.

The use of feed additives containing glutamine can influence the growth and development of piglets during the weaning period. The aim of this study was to determine the effect of feed supplementation with 0.5% L-glutamine on selected parameters of the nonspecific immune response of pigs. The research was carried out on 60 pigs (Polish Large White × Polish Landrace), from 28 days of age to slaughter. The obtained results showed an increased percentage of phagocytic cells (monocytes and granulocytes) and oxygen blast cells in pigs between 28 and 70 days of age, proving that non-specific immune mechanisms were stimulated, which contributed to the improvement of the processes of antigen elimination from the body. The increase in the percentage of cells expressing SWC3, CD11b/CD18⁺, CD14⁺ and CD14⁺CD16⁺ molecules on granulocytes and monocytes during this period resulted in the enhancement of the host defense mechanisms by stimulating phagocytosis and enhancing the mechanisms of a non-specific immune response. The high concentration of TNF-α and IL-1β as well as Il-10 in the experimental group indicates the cellular phenotype of the Th1-type response, and the maintenance of the immune balance between the pro-inflammatory and anti-inflammatory responses and ensuring the homeostasis of the organism.

The prohibition of certain coccidiostats in poultry has created a need to seek an alternative to control Eimeria infection. The aim of this study was to evaluate the effects of effective microorganisms (EM) in a multi-strain probiotic (Bokashi^®), with clinoptilolite as a feed supplement on the mRNA expression of tight junction proteins and redox enzymes in the caecal tissue of chickens infected with E. tenella. The integrity of the intestinal barrier was tested by determining the concentration of fluorescein isothiocyanate dextran (FITC-d) in the chicken’s serum. A total of 600 1-day-old Ross 308 male chickens received diets with a 0.5% or 0.8% concentration of the probiotic together with clinoptilolite. The experiment used 5 treatment groups, and a control group, each with 5 replicates with 20 birds. The results indicate that the use of the 8 kg/t of feed multi-strain probiotic together with clinoptilolite in the diet of poultry caused a significant reduction in the number of E. tenella oocysts in the faeces and caecum and significantly improved the growth rate of chicken broilers infected with E. tenella. In addition, the probiotic and clinoptilolite enhanced antioxidant processes in the caecal mucosa and reduced oxidative stress induced by E. tenella infection.