Ph.D. topics

The academic year 2023-2024

Scientific field Biology (scientific programme Animal Physiology), PF UPJŠ

  • The use of alternative zinc sources in nutrition and their effect on selected physiological processes of animals, advisor RNDr. Klaudia Čobanová, PhD.

Scientific field Veterinary Morphology and Physiology, UVLF

  • Skin health in horses in relation to its microbial colonization, advisor MVDr. Viola Strompfová, DrSc.
  • The use of alternative zinc sources in nutrition and their effect on selected physiological processes of animals, advisor RNDr. Klaudia Čobanová, PhD.
  • Zinc uptake by the microflora of the gastrointestinal tract, advisor RNDr. Dobroslava Bujňaková, PhD.

Annotations

Skin health in horses in relation to its microbial colonization, advisor MVDr. Viola Strompfová, DrSc.

Last statistics from our regions point to the frequent occurrence of skin diseases in horses, which reach almost 7% of individuals in the total horse population, also due to the high exposure of the skin to environmental conditions, which can disturb the sensitive balance of the complex community of microorganisms inhabiting this largest organ by area. Any changes in the population of commensal microorganisms are associated with physiological changes that occur during various dermatological diseases or aging in humans, horses, and other vertebrates. The work will determine the taxonomic composition of the microbiota under physiological and pathological conditions, as well as its in vitro properties, which have rarely been studied. Part of the work will be the search for suitable strategies for optimizing/stabilizing the bacterial population of the skin to preserve the physiological functions of the skin.

The use of alternative zinc sources in nutrition and their effect on selected physiological processes of animals, advisor RNDr. Klaudia Čobanová, PhD.

The zinc form used as a feed additive in animal nutrition can significantly affect its bioavailability in the organism. Therefore, introducing mineral nanoparticles and organic complexes as a source of trace elements represents the current trend in animal nutrition. These alternative microelement sources are considered more bioavailable and absorbed better by the animals compared to the traditionally used inorganic sources. Thus, reducing the current need for mineral additives in diets and minimizing their excretion would be possible. The dissertation will evaluate zinc bioavailability in farm animals (sheep, poultry) by determining intestinal zinc absorption and tissue deposition. The activity of specific metalloenzymes and metalloproteins levels in animal tissues will be measured too. Furthermore, the antioxidant response of animals to feed supplementation with various zinc nanoparticles and the quality of foods of animal origin will also be studied.

Zinc uptake by the microflora of the gastrointestinal tract, advisor RNDr. Dobroslava Bujňaková, PhD.

Zinc is the second most important essential trace element for all living organisms, including bacteria. It plays an important role in host immune responses, but also in the regulation of microbial virulence. Animals and microbes cannot produce it naturally, so strategies for obtaining and using it are essential for their survival and development. Zinc levels are in the micromolar range, and its bioavailability is limited because it is bound to proteins. Similar to the case of iron, the hosts sequester zinc systematically and locally in an attempt to prevent its availability to undesirable microflora, the so-called nutritional immunity. Although zinc is essential, its excess is toxic to the cell. Bacterial cells thus need to achieve a delicate balance between ensuring sufficient concentrations of zinc and at the same time preventing its toxic effects. In bacteria, zinc homeostasis is primarily mediated by a network of zinc uptake and efflux pumps. The main goal of the dissertation will be to study the molecular mechanisms of interactions between gastrointestinal microbiota and zinc through these transport systems. Another goal will be to monitor the relationship between zinc uptake, antibiotic resistance, and virulence factors, including biofilm formation and quorum sensing