20.500.12556/RUL-175588 Vrednotenje sinergističnega delovanja zaviralcev L,D-transpeptidaz in standardnih antibiotikov Evaluation of synergistic effect of L,D-transpeptidase inhibitors with standard of care antibiotics Protibakterijske učinkovine so spojine, ki zaradi baktericidnega ali bakteriostatičnega delovanja uničujejo patogene, ne da bi poškodovale celice gostitelja. Njihovo učinkovitost merimo z minimalno inhibitorno (MIK) in minimalno baktericidno koncentracijo (MBK). Protibakterijske učinkovine delujejo po različnih mehanizmih. Zaradi pretirane in nepravilne uporabe teh učinkovin so bakterije razvile odpornost, kar resno ogroža javno zdravje. Zato sta iskanje in razvoj novih protibakterijskih učinkovin izjemnega pomena, pri čemer je ena od pomembnejših metod tudi rešetanje (screening) knjižnic spojin za odkrivanje potencialno učinkovitih novih zdravil. L,D-transpeptidaze so prepoznane kot obetavna tarča, saj sodelujejo pri prečnem povezovanju peptidoglikana in ohranjanju stabilnosti celične ovojnice bakterij, obenem pa so večinoma odporne na delovanje klasičnih β-laktamskih antibiotikov. Njihovo selektivno zaviranje bi lahko oslabilo celično steno, povečalo prepustnost zunanje membrane in omogočilo lažji dostop obstoječih antibiotikov do mesta delovanja. V okviru magistrske naloge smo ovrednotili in raziskali sinergistično delovanje med izbranimi antibiotiki in določenimi zaviralci L,D-transpeptidaz. V prvi fazi smo izbranim zaviralcem določili protibakterijsko učinkovitost ter njihovo afiniteto vezave na tarčni encim. Hipoteza raziskave je bila, da selektivno zaviranje L,D-transpeptidaz povzroči oslabitev strukture zunanje membrane, kar omogoči lažji prehod antibiotikov do mesta delovanja in s tem poveča njihovo učinkovitost. Cilj poskusa je bil identificirati spojine brez lastnega protibakterijskega učinka, ki pa učinkovito inhibirajo L,D-transpeptidaze. V nadaljevanju smo izbranim antibiotikom, ki se uporabljajo pri standardnem zdravljenju, dodajali zaviralce L,D transpeptidaz in ocenili morebitno sinergistično delovanje. Delovanje smo opredelili kot sinergistično, če je bil ob dodatku zaviralca zabeležen padec minimalne inhibitorne koncentracije. Preizkusi so bili izvedeni na petih sevih bakterije vrste Escherichiacoli. Rezultati so pokazali, da je kombinacija meropenema z zaviralci L,D-transpeptidaz izkazala sinergističen učinek. Pri ostalih testiranih kombinacijah sinergističnega učinka nismo zaznali. Na podlagi dobljenih rezultatov ocenjujemo, da bi kombinacija meropenema z zaviralci L,D transpeptidaz ob nadaljnji optimizaciji lahko predstavljala obetaven pristop k razvoju novih protibakterijskih učinkovin. Antibacterial agents are compounds that, due to their bactericidal or bacteriostatic activity, destroy pathogens without harming host cells. Their efficacy is assessed by determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). Antibacterial agents act through different mechanisms. However, the excessive and inappropriate use of these agents has led to the emergence of bacterial resistance, which poses a serious threat to public health. Therefore, the discovery and development of new antibacterial agents is crucial, with compound library screening representing one of the key approaches for identifying potentially effective new drugs. L,D-transpeptidases have been recognized as a promising target, as they participate in the peptidoglycan cross-linking and in maintaining the stability of the bacterial cell envelope, while generally being resistant to classical β-lactam antibiotics. Their selective inhibition could weaken the cell wall, increase the permeability of the outer membrane, and facilitate the access of existing antibiotics to their site of action. As part of the master's thesis, we evaluated and investigated the synergistic activity between selected antibiotics and specific L,D-transpeptidase inhibitors. In the first phase, we determined the antibacterial efficacy of selected inhibitors and their binding affinity to the target enzyme. The research hypothesis was that selective inhibition of L,D-transpeptidases leads to the weakening of the outer membrane structure, thereby enabling more efficient penetration of antibiotics to their site of action and thus increasing their effectiveness. The aim of the study was to identify compounds without intrinsic antibacterial activity that effectively inhibit L,D transpeptidases. Subsequently, L,D-transpeptidase inhibitors were combined with antibiotics used in standard treatment, and potential synergistic effects were evaluated. The activity was defined as synergistic if the addition of the inhibitor resulted in a reduction of the minimum inhibitory concentration. Tests were conducted on five Escherichia coli strains. The results showed that the combination of meropenem with L,D-transpeptidase inhibitors exhibited a synergistic effect, whereas no synergy was observed with the other tested combinations. Based on this findings, we conclude that, following further optimization, the combination of meropenem with L,D-transpeptidase inhibitors could represent a promising approach for the development of new antibacterial agents. zaviralci L D-transpeptidaz protibakterijsko delovanje minimalna inhibitorna koncentracija bakterijska odpornost protibakterijske učinkovine L D-transpeptidase inhibitors antibacterial activity minimum inhibitory concentration bacterial resistance antibacterial agents true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2025-11-05 08:45:19 2025-11-05 08:45:27 2025-12-12 03:55:01 0000-00-00 00:00:00 2025 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 121157 256949251 30775.pdf 30775.pdf 1 736824A9CE09B4898CA798D88BE8104A 0bafa9c5b4977fbfea2b25096a44598f126956a2fbee6df3c490bf702099b6a2 13f7f72f-ba1b-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=221357 Fakulteta za farmacijo 0 0 0