Doktorske disertacije

Ispitivanje uticaja različitih sastava i formulacija prostirke na proizvodnju štetnih gasova u brojlerskom tovu živine

Wed, 01 Jan 2025 00:00:00 GMT

Ispitivanje uticaja različitih sastava i formulacija prostirke na proizvodnju štetnih gasova u brojlerskom tovu živine Knežević, Slobodan

Uticaj učestalosti flebotomije na parametre crvene krvne loze i metaboličku adaptaciju ovnova

Wed, 26 Jun 2024 00:00:00 GMT

Uticaj učestalosti flebotomije na parametre crvene krvne loze i metaboličku adaptaciju ovnova Grubač, Siniša

Seroprevalencija i faktori rizika za pojavu emergentnih oboljenja u prihvatilištima za napuštene pse

Sat, 01 Jan 2022 00:00:00 GMT

Seroprevalencija i faktori rizika za pojavu emergentnih oboljenja u prihvatilištima za napuštene pse Marčić, Doroteja Of the emergent and re-emergent zoonotic diseases that pose a threat to public health, vector-borne diseases occupy a significant place. The reservoir of infection for vectors, and thus for other types of animals and humans, are abandoned dogs and dogs from shelters.This is due to their lifestyle, zoohygienic conditions in shelters, irregular implementation of preventive measures, mixing of dogs from different environments, as well as climate changes that favor breeding and maintenance of vectors of various diseases. Canine monocytic ehrlichiosis, Lyme borreliosis, leishmaniasis and dirofilariasis are among the vector-borne emergent diseases of dogs with zoonotic potential. In previous years in the Republic of Serbia, partial studies of vector-borne diseases in dogs from different populations were carried out. Considering the large number of abandoned dogs and dogs placed in shelters in our country, the need for additional studies emerged. The aim of this dissertation was to obtain more precise data on the presence and circulation of the causative agents Ehrlichia canis, Borrelia burgdorferi, Leishmania infantum and Dirofilaria immitis in the population of dogs from 5 shelters located in two districts of the Autonomous Province of Vojvodina. 432 dogs that were selected by simple randomization were included in the research. Epidemiological, clinical andlaboratory tests were carried out, as well as the identification of risk factors for the onset of infection. The analysis of the obtained results revealed positive serological findings for Ehrlichia canis, Borrelia burgdorferi and Dirofilaria immitis in a certain number of dogs in all 5 shelters, while specific antibodies to Leishmania infantum were not detected in dogs from 2 shelters, which were detected in the other ones. Furthermore, no correlation was established between the selected biochemical and hematological parameters in the blood of dogs with positive serological findings for Ehrlichia canis, Borrelia burgdorferi, Leishmania infantum and Dirofilaria immitis. Most of the registered symptoms, during the clinical examination of dogs with a positive serological finding, were of a general nature and did not directly indicate the accompanying diseases. When comparing all 5 shelters, the lowest number of seropositive dogs was found in the shelter where the dogs are kept in controlled conditions with the application of zooprophylactic and immunoprophylactic measures, and the highest number of seropositive dogs was found in the shelter where the dogs are kept in fenced yards with an insufficient number of shelters, occasional use of anti-endoparasitic drugs but without the regular implementation of immunoprophylactic measures, use of anti-ectoparasitic drugs and testing for infectious diseases. In accordance with the obtained results, this research indicated the need for continuous monitoring of vector-borne emergent diseases with zoonotic potential in the population of abandoned and sheltered dogs, with the aim of establishing a timely and accurate diagnosis, as well as implementing adequate therapy. Also, this research indicates the importance of collecting and monitoring epidemiological data related to the spread and movement of this group of infectious diseases due to the existence of a risk to public health.

Uticaj etarskih ulja na odabrane patogene bakterije izolovane u procesu proizvodnje mesa

Fri, 15 Jul 2022 00:00:00 GMT

Uticaj etarskih ulja na odabrane patogene bakterije izolovane u procesu proizvodnje mesa Vidaković Knežević, Suzana Foodborne illnesses, caused by Salmonella Enteritidis, Salmonella Typhimurium, Listeria monocytogenes and Yersinia enterocolitica, are a major public health problem worldwide. In this doctoral dissertation, the selected foodborne pathogens isolated from meat processing, were confirmed by MALDI-TOF MS, while the composition of 18 essential oils was determined using gas chromatography-mass spectrometry (GC-MS). The antibacterial activity of 18 essential oils was evaluated against 16 bacterial strains, followed by determination of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. All of the isolates formed biofilm on two common surfaces found in the meat industry, polystyrene and stainless steel. Formation of biofilm was found to be dependent on the availability of nutrients and the temperature. After treatment with selected essential oils, the reduction in biofilm biomass was in the range between 30.93% and 90.28%. Micromorphological changes on the isolates of the bacteria treated by oregano and thyme essential oils were observed in the form of impaired cell integrity and cell lyses using SEM. Oregano and thyme essential oils (MIC and 2MIC) significantly (p < 0.05) reduced the population of S. Enteritidis, L. monocytogenes, and Y. enterocolitica in minced pork meat during the storage. On the other hand, the effect of oregano and thyme essential oils was not observed against S. Typhimurium in same conditions. Sensory evaluation of oregano and thyme essential oils on minced pork as a food model was conducted and panelist considered that they improved sensory properties, such as color and off-odor, during storage at 4 ± 1 °C under aerobic conditions. The obtained results indicate that the selected essential oils can be effectively used in the meat industry as a natural alternative to synthetic additives and disinfectants.