magistrsko delo
Aljoša Obreza (Author), Katja Seme (Reviewer), Tadeja Matos (Mentor)

Abstract

Kandidoza je glivna okužba, ki jo povzročajo vrste iz rodu Candida pri imunsko oslabelih bolnikih. Zgodnja uvedba ustreznega protiglivnega zdravljenja je povezana z zmanjšano smrtnostjo. Izbor ustreznega zdravila je odvisen od testiranja občutljivosti kvasovk, ki se večinoma izvaja s komercialno dostopnimi testi. Najboljšo primerljivost in natančnost zagotavljajo referenčne dilucijske metode, kot je mikrodilucija po standardu EUCAST. Rezultat mikrodilucije je minimalna inhibitorna koncentracija (MIK) antimikotika, na podlagi katere lahko opredelimo izolat kot občutljiv, mejno občutljiv ali odporen. V raziskavi smo uporabili komercialno mikrotitrsko ploščico (Merlin Diagnostika, Nemčija) z liozifiranimi antimikotiki. Občutljivost smo določili z različicama mikrodilucije, prilagojenima za EUCAST. MIK smo odčitali vizualno z in brez dodanega barvnega indikatorja ter spektofotometrično pri valovnih dolžinah 450 nm in 492 nm. Rezultate smo primerjali z referenčnimi vrednostmi MIK. Ugotovili smo, da je primernost posamezne metode določanja MIK odvisna od kombinacije izolata kvasovke in antimikotika. Pri določanju MIK ehinokandinov smo dobili prenizke vrednosti v primerjavi s kontrolnimi sevi, ki bi jih lahko popravili z uporabo korekcijskega faktorja 2. Pri antimikotikih, ki delujejo fungistatično, smo dobili z vizualnim odčitavanjem kategorično neprimerljive rezultate z rezultati referenčnega laboratorija. Zaključili smo, da prilagojene metode za EUCAST niso primerne za uvedbo v rutinsko delo v mikoloških laboratorijih, saj se nezadostno ujemajo z referenčnimi vrednostmi. Izjema je amfotericin B.

Keywords

občutljivost izolatov;glivne okužbe;kandidoza;kvasovke;Candida;antimikotiki;amfotericin B;flucitozin;ehinokandini;azoli;mikrodilucija;minimalna inhibitorna koncentracija;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL MF - Faculty of Medicine
Publisher: [A. Obreza]
UDC: 579.24/.25:582.282.28:615.282:577.2.083
COBISS: 4821624 Link will open in a new window
Views: 1225
Downloads: 451
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Other data

Secondary language: English
Secondary title: Comparison of methods for susceptibility testing of invasive yeasts isolates for antimycotics
Secondary abstract: Candidosis is a fungal infection caused by Candida spp. in immunocompromised patients. Early antifungal treatment has been shown to significantly reduce mortality and morbidity. Choice of appropriate therapy depends on antifungal susceptibility testing of yeasts, which is mostly performed with commercially avaible tests. The best interlaboratory comparability is provided by reference dilution methods, such as EUCAST microdilution. The result of microdilution are the minimal inhibitory concentrations (MICs) of antimycotics. On the basis of MIC, the isolates can be interpreted as sensitive, intermediate or resistant. In our study a commercial microtiter plate (Merlin Diagnostika, Germany) with lyophilized antimycotics was used. Susceptibility was determined by two microdilution methods modified for EUCAST. MIC was determined visually with and without added colour indicator and spectrophotometrically at wavelengths of 450 nm and 492 nm. We compared our MIC values with reference values. The most suitable method of determining MIC depends on the combination of yeast isolate and antimycotic. We have determed that low echinocandin MICs could be corrected using correction factor 2. The categorical agreement between visual determination of azole MICs and reference values was low. Modified EUCAST methods are not suitable for routine mycology laboratories due to insufficient agreement of results compared to the reference laboratory values. The exception is amphotericin B.
Secondary keywords: susceptibility of isolates;fungal infection;candidiasis;yeasts;Candida;antimycotics;amphotericin B;flucytosin;echinocandins;azoles;microdilution;minimal inhibitory concentration;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Študij mikrobiologije
Pages: XII, 72 f.
ID: 10910736