Types and susceptibility profiles of Cryptococcus neoformans in environmental samples in Croatia and Kosovo

doctoral thesis

• Author: Donjeta Hajdari; VIAF: 30161096367629100618
• Mentor: Ivana Mareković (mentor)
• Committee member: Ana Budimir (predsjednik povjerenstva)
• Committee member: Sanja Popović-Grle (član povjerenstva)
• Committee member: Smilja Kalenić (član povjerenstva)
• Granter: University of Zagreb; School of Medicine; Zagreb
• Defense date and country: 2020-07-27, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Public Health and Health Care; Epidemiology
• Universal decimal classification (UDC): 614 - Public health and hygiene. Accident prevention

Abstract

Cryptococcus neoformans species complex is an opportunistic yeast that causes life-threatening infections in immunocompromised hosts. The aim of the study was to investigate the epidemiological distribution, antifungal susceptibility and molecular characterization of C. neoformans species complex Croatia and Kosovo.
During 2013-2016, 709 samples were collected from trunk hollows and birds’ excreta in the soil beneath the trees in different geographical locations.
Four C. neoformans species complex isolates was found in environmental samples of tree hollows collected in two cities, Krk and Rijeka, on Croatian coast, but not in Kosovo. The tested antifungal compounds demonstrated high in vitro activity against environmental C. neoformans species complex isolates. Three C. gattii species complex were isolated in both, Croatia and Kosovo and belonged to wild type for all tested antifungals as well according to ECVs. Three out of four (3/4; 75%) of C. neoformans species complex isolates in Croatia belonged to serotype A and all (4/4, 100%) had mating type α. The four C. neoformans species complex isolates from Croatia were classified into two different molecular types, VNI (n = 3) and VNIV (n = 1).
This is the first report proving the presence of C. neoformans species complex in the environment of Croatia and determining their susceptibility to antifungals. The results of the study show the potential risk of exposure for inhabitants, especially on the Croatian coast, to molecular types VNI and VNIV, which can be expected in clinical cases of cryptococcosis. Although a limitation of this study is the small number of detected environmental isolates antifungal susceptibility pattern of C. neoformans species complex suggests that no strains with low susceptibility to the most common antifungals should be expected in patients with cryptococcosis.

Abstract (croatian)

Cryptococcus neoformans species complex je oportunistički kvasac koji uzrokuje po život opasne infekcije kod imunokompromitianih bolesnika. Cilj ovog istraživanja je bio istražiti epidemiološku distribuciju, osjetljivost na antifungike i molekularne karakteristike C. neoformans species complex u Hrvatskoj i Kosovu.
U razdoblju od 2013. do 2016. godine, uzeto je 709 uzoraka iz duplji drveća i sasušenih ptičjih sekreta s tla ispod drveća na različitim zemljopisnim lokacijama.
U uzrocima uzetim iz duplji drveća izolirana su četiri izolata C. neoformans species complex u dva grada, Krku i Rijeci, na jadranskoj obali, dok u Kosovu nije utvrđen niti jedan izolat. Testirani antifungici pokazali su dobru in vitro djelotvornost na izolate C. neoformans species complex iz okolišnih uzoraka. Tri izolata C. gattii species complex su izolirana u Hrvatskoj i Kosovu te su također pripadali divljem tipu na temelju epidemioloških graničnih vrijednosti. Tri od četiri (3/4; 75%) izolata C. neoformans complex u Hrvatskoj pripadala su serotipu A a svi (4/4, 100%) su pokazali tip α. Za četiri izolata C. neoformans species complex u Hrvatskoj utvrđeno je da pripadaju molekularnim tipovima VNI (n = 3) and VNIV (n = 1).
Ovo je prvo istraživanje koje je pokazalo prisutnost C. neoformans species complex u okolišnim uzorcima u Hrvatskoj i u kojem je određena njihova osjetljivost na antifungike. Rezultati istraživanja su pokazali potencijalni rizik za izloženost stanovnika, osobito na jadranskoj obali, molekularnim tipovima VNI i VNIV koji se mogu očekivati u kliničkim slučajevima kriptokokoze. Iako je ograničenje ove studije mali broj otkrivenih izolata u okolini, rezultati osjetljivosti na antifungike pokazuju da kod bolesnika s kriptokokozom ne treba očekivati izolate sa samnjenom osjetljivosšću na najvažnije antifungike.

• Keywords: Cryptococcus neoformans; Cryptococcus gattii; environment; molecular typing
• Keywords (croatian): Cryptococcus neoformans; Cryptococcus gattii; environment; molecular typing
• Language: english
• URN:NBN: urn:nbn:hr:105:230847
• Study programme: Title: Biomedicine and Health Sciences; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje biomedicine i zdravstvo (doktor/doktorica znanosti, područje biomedicine i zdravstvo)
• Catalog URL: https://katalog.nsk.hr/F/19IT7Y755V1NXQJPHCLYSQGPF6BLAPPF179HQ7FAXXMYBYGMV5-12172?func=find-e&request=Types+and+susceptibility+profiles+of+Cryptococcus+neoformans+in+environmental+samples+in+Croatia+and+Kosovo&find_scan_code=FIND_NAS&adjacent=N&local_base=MF_WEB&x=49&y=7&filter_code_1=WLN&filter_request_1=&filter_code_2=WYR&filter_request_2=&filter_code_3=WYR&filter_request_3=&filter_code_4=WFM&filter_request_4=
• Type of resource: Text
• Extent: 100 str.
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-03-15 12:05:09