20.500.12556/DKUM-97936 Večkratno odporne po Gramu negativne bakterije v izbranih vodah in prsti poplavnih območij Ptujsko-dravskega polja magistrsko delo Multidrug-Resistant Gram-Negative Bacteria in Selected Waters and Soils of Flooded Areas in the Ptuj-Drava Plain Odpornost proti antibiotikom predstavlja eno največjih groženj javnemu zdravju, pri čemer imajo pomembno vlogo po Gramu negativne večkratno odporne bakterije (VOB). Njihova prisotnost v naravnem okolju, predvsem v povezavi s poplavnimi dogodki, je še vedno slabo raziskana. Namen naše raziskave je bil preučiti prisotnost po Gramu negativnih VOB v rečnih poplavnih vodah Ptujsko-dravskega polja ter oceniti njihov potencialni vpliv na okolje in zdravje ljudi ter širjenje na bližnje kmetijske površine. V magistrski nalogi smo vzorčili tekočo vodo reke Drave ter potokov Studenčnice in Dravinje, njihove poplavne vode in prst po umiku poplavnih vod iz poplavljenih kmetijskih območij. Po obdelavi posameznih vzorcev in osamitvi bakterij na selektivno-diferencialnih gojiščih smo izolate identificirali in jih fenotipsko karakterizirali z disk-difuzijsko metodo v skladu s smernicami EUCAST. Izvedli smo presejalno testiranje za določanje bakterij, ki sintetizirajo β-laktamaze razširjenega spektra (ESBL), ter proti karbapenemom odpornih bakterij in/ali tistih, ki izločajo karbapenemaze (CR(E)-CP(E)). Izolate s sumom na tvorbo karbapenemaz smo analizirali z izbranimi fenotipskimi testi (zCIM, Blue-Carba in CARBA 5 NG). Sledila je molekularna analiza, kjer smo izolate VOB genotipizirali z metodo ERIC-PCR in s PCR v realnem času določili gene za β-laktamaze. Osamili smo skupno 203 izolate. Med identificiranimi izolati jih je največ pripadalo rodu Pseudomonas (46,7 %), Serratia (15,0 %), Aeromonas (12,2 %) in Escherichia (10%). Določili smo skupno 13 ESBL pozitivnih izolatov vrst Escherichia coli (n=6), Klebsiella pneumoniae (n=2), Serratia fonticola (n=3) in Raoultella spp. (n=2). Medtem ko nismo zaznali nobene proti karbapenemom odporne bakterije ali VOB s karbapenemazami. Iz tekoče vode smo osamili šest izolatov ESBL, iz poplavne vode tri in iz prsti poplavljenih tal štiri. Na posameznih vzorčnih mestih so se vrste izolatov VOB med določenimi vrstami vzorci prekrivale (primer Raoultella ornythinolytica ESBL v poplavni vodi in prsti Studenčnice). Kljub temu, med genotipi VOB iz različnih vrst vzorcev na posameznih vzorčnih mestih nismo določili nobenega prekrivanja. Raziskava predstavlja pomembno sistematično pilotno raziskavo po Gramu negativnih VOB v poplavnih vodah v Sloveniji in poudarja pomen okoljskih rezervoarjev v okviru koncepta »Eno zdravje«. Antibiotic resistance represents one of the greatest threats to public health, with Gram-negative multidrug-resistant bacteria (MDR) playing a significant role. Their presence in the natural environment, especially in connection with flooding events, remains poorly studied. The aim of our research was to investigate the presence of Gram-negative MDR bacteria in the floodwaters of the Ptuj–Drava Plain and to assess their potential impact on the environment and spread to nearby agricultural areas. In this master’s thesis, we sampled flowing water from the Drava River and the Studenčnica and Dravinja streams, their floodwaters, and soil after the withdrawal of floodwaters from flooded agricultural land. Following processing of collected samples and isolation of bacteria on selective differential media, isolates were identified and phenotypically characterized using the disk diffusion method in accordance with EUCAST guidelines. Screening tests were performed to detect ESBL (extended-spectrum β-lactamase)-producing bacteria as well as carbapenem-resistant bacteria and/or those producing carbapenemases (CR(E)-CP(E)). Isolates suspected of carbapenemase production were further analyzed using selected phenotypic tests (zCIM, Blue-Carba, and CARBA 5 NG). This was followed by molecular analysis, in which MDR isolates were genotyped using ERIC-PCR, and β-lactamase genes were identified by real-time PCR. A total of 203 isolates were obtained. Among the identified isolates, the majority belonged to the genera Pseudomonas (46.7%), Serratia (15.0%), Aeromonas (12.2%), and Escherichia (10%). In total, 13 ESBL-positive isolates were identified, including Escherichia coli (n=6), Klebsiella pneumoniae (n=2), Serratia fonticola (n=3), and Raoultella spp. (n=2). No carbapenem-resistant bacteria or carbapenemase-producing MDR isolates were detected. Six ESBL isolates were recovered from flowing water, three from floodwater, and four from soil of flooded areas. At individual sampling sites, an overlap of MDR isolate species was observed between certain sample types (e.g., Raoultella ornithinolytica ESBL in both floodwater and soil from Studenčnica). However, no overlap in MDR genotypes was found between different sample types at the same sampling locations. This study represents an important systematic pilot investigation of Gram-negative MDR bacteria in floodwaters in Slovenia and highlights the significance of environmental reservoirs within the framework of the “One Health” concept. okolje poplavne vode tekoče nadzemne vode prst večkratno odporne bakterije enterobakterije ESBL β-laktamaze karbapenemaze environment floodwaters running surface water soil multidrug-resistant bacteria enterobacteria ESBL β - lactamases carbapenemases true true false V. Pavličič Slovenski jezik Angleški jezik Ptuj (Slovenija); Magistrsko delo/naloga 2026-04-28 17:55:09 2026-05-19 22:43:32 2026-05-20 03:16:18 0000-00-00 00:00:00 2026 0 Maribor 0 Maribor IV, 81 f. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 579.68(497.4Ptuj)(043.2) 278706179 MAG_Pavlicic_Vita_2026.pdf MAG_Pavlicic_Vita_2026.pdf 1 A5CF2AF3FAADA48C665FC938A8328688 15afa1e385c1d6be78db212f4785cb06c23ebf449361f80c68ee4ed91d2ce04e 847f1a6b-431b-11f1-b28d-00155d0001a1 https://dk.um.si/Dokument.php?lang=slv&id=205674 Fakulteta za naravoslovje in matematiko 0 0 0