doktorska disertacija
Jerneja Zupančič (Avtor), Nina Gunde-Cimerman (Mentor), Janja Trček (Član komisije za zagovor)

Povzetek

Vodovodna voda, priključena na gospodinjske naprave, predvsem pomivalne stroje, deluje kot vektor zlasti vnosa gliv in tudi bakterij v pomivalni stroj. Glive in predvsem bakterije lahko vstopajo v pomivalni stroj tudi preko prebivalcev in hišnih ljubljenčkov ter ostankov hrane na umazani posodi. Znotraj pomivalnega stroja se zaradi skrajnostnih dejavnikov, kot so visoka temperatura, oksidativni stres, povišane koncentracije soli (NaCl), mehanskih strižnih sil vode, velikega organskega bremena in občasne dehidracije, mikroorganizmi povežejo v preživetvene strukture – biofilme. Ti biofilmi so sestavljeni iz različnih vrst bakterij in gliv. Mikobiota tesnila je globalno konsistentna in jo sestavlja 6 vrst oportuno patogenih gliv E. dermatitidis, E. phaeomuriformis, Candida parapsilosis sensu stricto, Fusarium dimerum species complex in kompleks Saprochaete/Magnusiomyces. Bakterijsko floro tesnil večinoma sestavljajo rodovi Bacillus, Gordonia, Exiguobacterium, Acinetobacter, Stenotrophomonas in Micrococcus. Presenetljivo so na tesnilu pomivalnih strojev prisotne tudi oportuno patogene vrste bakterij, kot so E. coli, P. aeruginosa, S. maltophilia in E. faecium. Začetni naseljevalci tesnil pomivalnih strojev so kvasovke rodu Candida, ki nudijo biotsko površino za nadaljnjo vzpostavitev bakterijsko-glivnih biofilmov. Med bakterijami, izoliranimi iz pomivalnih strojev, smo opazili obsežne sinergije. Vrsti A. junii in P. aeruginosa sta bili najboljši proizvajalki biofilmov v pomivalnih strojih in sta pomembno prispevali k sinergiji v biofilmih in k skupnemu povečanju biomase. Ugotovili smo, da lahko mešani bakterijski biofilmi vključujejo oportunistično patogeno črno kvasovko E. dermatitidis in ji olajšajo naselitev na gumijastih tesnilih pomivalnih strojev in drugih površinah (npr. polipropilen). Mikrobiom tesnil in celotnega pomivalnega stroja se z leti in frekvenco uporabe spreminja. Predvsem na glive bistveno vpliva trdota vodovodne vode. Glive se lahko iz pomivalnega stroja razširjajo v zunanje okolje preko odpadne vodovodne vode in aerosola, ki se sprošča v okolje po končanem ciklu pranja. Pomivalni stroji vplivajo na naselitev kuhinjskih površin z glivami, predvsem na pojavnost črnih kvasovk. Le-teh je občutno manj v kuhinjah brez pomivalnega stroja, kjer prevladuje oportuno patogena bela kvasovka C. parapsilosis.

Ključne besede

gospodinjski aparati;mikrobiota;mikroorganizmi;glive;bakterije;biofilm;sinergija;tesnila;

Podatki

Jezik: Slovenski jezik
Leto izida:
Tipologija: 2.08 - Doktorska disertacija
Organizacija: UL MF - Medicinska fakulteta
Založnik: [J. Zupančič]
UDK: 579.8:648.545(043.3)
COBISS: 296292864 Povezava se bo odprla v novem oknu
Št. ogledov: 1122
Št. prenosov: 336
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarni naslov: Selection of opportunistic microorganisms in the extreme environment of dishwashers
Sekundarni povzetek: Due to extreme environmental factors prevailing inside dishwashers, such as high temperature, oxidative stress, elevated salt concentrations (NaCl), mechanical shear forces, high organic loads and occasional dehydration, microorganisms colonizing dishwashers merge into survival structures - biofilms. They consist of mixed assemblages of various bacteria and fungi. The mycobiota of the rubber seals was globally consistent and it comprised 6 species of opportunistic pathogens such as E. dermatitidis, E. phaeomuriformis, Candida parapsilosis, Fusarium dimerum and Saprochaete/Magnusiomyces complex. Besides rubber seals, fungi populated also doors, walls, drains, sprinkler, side nozzle, rack for cutlery, rinse-air dispenser and detergent dispenser. Bacterial flora of dishwasher rubber seals was comprised of the genera Bacillus, Gordonia, Exiguobacterium, Acinetobacter, Stenotrophomonas and Micrococcus. Surprisingly, bacteriome of rubber seals could include also opportunistic pathogens, such as E. coli, P. aeruginosa, S. maltophilia and E. faecium. The initial settlers of the dishwasher seals were yeasts of the genus Candida, that offer a biotic surface for further establishment of microbes. Extensive synergies were observed among bacteria isolated from dishwashers. The species A. junii and P. aeruginosa were the best producers of biofilms in dishwashers and significantly contributed to the observed synergy in biofilms and to the total increase of biomass. Mixed bacterial biofilms included also the opportunistic pathogenic black yeast E. dermatitidis, enabling an easier settlement of rubber seals of dishwashers and other artificial surfaces (eg polypropylene). Changes of microbiome over time depended on the years of operation and frequency of use, while water hardness essentially influenced the fungal community. Tap water, connected to the household appliances, especially dishwashers, was the main entry point of fungi and to a lesser extent for bacteria. Additional sources of fungal and especially bacterial contamination were inhabitants, pets and food leftovers on dirty dishes. Fungi could be released from the dishwasher to the external environment at the end of the washing cycle via waste water and aerosols. Colonization of kitchen surfaces with fungi was influenced by the presence of dishwashers, resulting in higher incidence of black yeasts, especially E. dermatitidis, that were considerably less frequent in kitchens without dishwashers, where opportunistic pathogenic white yeast C. parapsilosis prevailed.
Sekundarne ključne besede: Household articles;Extreme environments;Biofilms;Rubber;Bacteria;Isolation and purification;Genetics;Fungi;Environmental microbiology;Sequence analysis;Gospodinjski predmeti;Ekstremna okolja;Biofilmi;Guma;Bakterije;Izolacija in čiščenje;Genetika;Glive;Mikrobiologija okolja;Analiza zaporedja;
Vrsta dela (COBISS): Doktorska disertacija
Študijski program: 0
Konec prepovedi (OpenAIRE): 1970-01-01
Komentar na gradivo: Univ. v Ljubljani, Medicinska fak.
Strani: XVII f., 301 str.
ID: 10943273