Mycology: basic and applied services and research 

 

Within the framework of the IC Mycosmo, our basic and applied research on fungi in the field include taxonomy, phylogeny and, in particular, identification and description of fungal species that are new to science. Particular emphasis is given to applied research and collaboration with Slovenian and other industries, which often face cumbersome contamination of products with (mycotoxic and opportunistic pathogenic) microfungi. We also collaborate with gallerys, museums, and other cultural institutions, which can often experience deterioration of historically important objects due to fungal contamination. 

 

Analysis and identification of opportunistic pathogenic fungi in household appliances: washing machines, dishwashers, refrigerators, etc. 

 

Human homes represent an appropriate environment for many microorganisms. Previously, scientists focused primarily on the saprophytic microorganisms, and particularly fungi, that can inhabit the walls in our homes and that also have potential impact on human health. Then only recently we became aware that extremophilic fungi can inhabit ecological niches inside house appliances, such as washing machines and dishwashers. Our study of 189 dishwashers in Slovenia and around the globe showed that almost all dishwashers were inhabited with different thermotolerant species of yeast. It is important to emphasise that almost all of these were known as causative agents of systemic infections in immunocompromised patients. Surprisingly, the dominant species belonged to the black yeast of the genus Exophiala, which includes several important pathogenic species. These black yeast are particularly dangerous, because they are thermotolerant and can cause either systemic or local infections, also in healthy individuals. Amongst the black yeast, the most frequently isolated species was Exophiala dermatitidis, which can cause infections of the respiratory system, skin and subcutaneous infections, and infections of the nervous system. The second most frequent fungus was the opportunistic pathogenic yeast Candida parapsilosis. These and other fungi can thus survive the unique combination of parameters in dishwashers, like extreme pH, high temperatures, and high water flow. Almost daily exposure to aerosols and contact with infected surfaces of dishwashers represents an important risk factor for immunocompromised people, and for children and the elderly, and also for healthy individuals. 

 

Within the framework of contract research, the Microbial Culture Collection Ex can perform analyses for the presence of black yeast and other pathogenic fungi in household appliances. 

 

References: 

 

Zalar, P., Novak, M., De Hoog, S., Gunde-Cimerman, N. Dishwashers - a man-made ecological niche accommodating human opportunistic fungal pathogens. Fungal Biol., 2011, 115(10), 997-1007. 

doi: 10.1016/j.funbio.2011.04.007; COBISS.SI-ID 2442063; ISSN 1878-6146; http://dx.doi.org/10.1016/j.funbio.2011.04.007

Gostinčar, C., Grube, M., De Hoog, S., Zalar, P., Gunde-Cimerman, N. Extremotolerance in fungi: evolution on the edge. FEMS Microbiol. Ecol., 2010, 71, 2-11. 

COBISS.SI-ID 2166607; ISSN 0168-6496

NOVAK, Monika, ZALAR, Polona, GUNDE-CIMERMAN, Nina. Dishwashers as an example of the indoor extreme environment for survival and propagation of Exophiala dermatitidis and E. phaeomuriformis. V: Fourth Annual Conference [of] Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, CIPKeBiP, Ljubljana, 10-12 June, 2013. ZOREC, Robert (ur.), et al. Superresolution microscopy. Ljubljana: Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, 2013, str. 29, ilustr. [COBISS.SI-ID 2814799]

 

ZALAR, Polona, NOVAK, Monika, GUNDE-CIMERMAN, Nina. Dishwashers - an indoor extreme environment for survival and propagation of Exophiala dermatitidis. V: 3rd Meeting of the ISHAM working groups on black yeast and chromoblastomycosis, May 14 to May 16, 2010, Ljubljana, Slovenia : emerging potential of black yeasts. Ljubljana: s. n., 2010, str. 23. [COBISS.SI-ID 27347673]

 

GUNDE-CIMERMAN, Nina, ZALAR, Polona, NOVAK, Monika, HOOG, Sybren. Polyextremotolerant human opportunistic black yeasts inhabit dishwashers around the world : The 14th International Symposium on Microbial Ecology, ISME14, Copenhagen, Denmark, 19-24 August, 2012. Copenhagen, 2012. [COBISS.SI-ID 2815055]

 

GUNDE-CIMERMAN, Nina. Dishwashers can be breeding grounds. Bottom line, 

personal, ISSN 0274-4805, 15 Jan. 2013, vol. 34, no. 2, str. 30-31. [COBISS.SI-ID 30430681] 

 

GUNDE-CIMERMAN, Nina (intervjuvanec). Black yeast found lurking in dishwashers : FOX 13 TV, Tampa, Florida, USA, March 19, 2012. Tampa: FOX 13, 2012. [COBISS.SI-ID 30588889] 

 

GUNDE-CIMERMAN, Nina. Dishwashers may harbor toxic fungi. Bottom line/health, ISSN 1092-0129, Mar. 2012, vol. 26, no. 3, str. 7. [COBISS.SI-ID 30247897] 

 

 

 

Identification of fungi isolated from indoor environments: walls, air conditioning systems, and others 

Many species of fungi represent a serious problem because of the economic loss they can cause, and because of their impact on human health. Many fungi synthesise mycotoxins, which can be acutely toxic or cancerogenic. Toxins can be contained within the fungus itself (e.g., mycelium, spores), and they can also be secreted into the substrate (e.g., food) or into the air (e.g., volatile mycotoxins). Due to the fungal contamination, the product itself can deteriorate. Additionally, mycotoxin contamination is dangerous for human health and it represents an important potential danger for workers in the food industry or for inhabitants of contaminated indoor environments. People can inhale airborne spores or volatile cancerogenic substances. The spores of fungi that inhabit humid walls can also be distributed via aeration or via air conditioning systems, where they can contaminate the filter systems. The most recent studies have also shown distribution of fungi via tap water systems and via aerosols released from household appliances and in bathrooms. The correct identification of such opportunistic pathogenic fungi is thus of key importance for adequate reactions and self protection. 

 

In recent years, the Microbial Culture Collection Ex has performed upon request several isolation and identification analyses of fungi that inhabit mouldy walls in indoor environments of private homes and companies, and on industrial objects. We have also peformed monitoring of air in clinical and other environments. 

 

Identification of microbial contamination on objects and artefacts of cultural heritage, and for historical objects and sites. 

 

Objects that are often of great cultural heritage value can become contaminated with microorganisms due to inappropriate storage or sudden exposure to changed climatic conditions. This is particularly the case for fungi, which can damage these objects due to their mechanical decomposition or metabolic activity. The appropriate identification of contaminating microorganisms is of great importance, as only in this way can we take the appropriate actions to protect these valuable objects from further deterioration. Additionally, preliminary analysis of the microbiala communities on attacked stone/ wood/ textile surfaces and in the air in their vicinity can help with the mapping of potential contamination on similar substrates and on other historically important objects. 

 

Within the framework of the Microbial Culture Collection Ex activities, we perform analyses of air and contaminated surfaces, which includes isolation and identification of fungal strains, and in collaboration with different experts, the best procedure for sanitisation of the contaminated objects can be defined. All such isolates obtained are stored in the Microbial Culture Collection Ex, which enables comparisons in cases of further isolation, if additional monitoring follows the sanitisation procedures. 

 

 

Identification of fungi in tap water and in well water 

 

It is well known that humid indoor environments, such as bathrooms and kitchens, are populated with different species of fungi that can cause mouldiness of walls and different objects. Until now, it was considered that such fungi enter indoors via the air, as spores, which germinate when conditions are appropriate. 

 

It is little known, however, that fungi can invade indoor environments and also household appliances via water from the tap-water system, or from well water, as the scientific community has became aware of this only recently. Our recent extremely popular publication on fungi inhabiting dishwashers highlighted this problem, and triggered a search for pathogenic fungi in tap water systems and also in other household appliances. As these fungi can reach high numbers indoors, this represents one of the potential vectors for the transfer of causative agents of serious diseases. As fungi of the genus Exophiala and related black yeast are frequent causative agents of human illness in immuno-compromised (and also healthy) individuals, deminishing or removing potential sources of contamination inside dishwashers can considerably increase the safety of the users. 

 

Applied research 

 

In recent years, the Microbial Culture Collection Ex has performed several mycological projects for industrial needs and for the needs of different Institutions, on a confidential basis. 

 

Other contract research 

 

The IC Mycosmo can carry out research work on the field of the Microbial Culture Collection Ex, including research of extreme biospheres and mycology and general microbiology. Research projects can be short-term or long-term, and are perofrmed on a confidential basis, in accordance with the customers' requests.

 

Overview of collaborations in the medical field 

 

With the University Clinical Centre in Ljubljana, Slovenia, the Microbial Culture Collection Ex has collaborated on two projects:

(i) The role of fungi in chronic osteitis (2001-2004)

(ii) Biosurgery of chronic wounds – healing with larvae of Lucilia sericata flies (2003-2005).