The prevalence of Cladosporium species in indoor environments

Ndlangalavu, Gcobisa (2019-04)

Thesis (MSc)--Stellenbosch University, 2019.

Thesis

ENGLISH ABSTRACT: Cladosporium is among the largest and most diverse genera of hyphomycetes, previously reported to include over 772 names. The olive-green to brown or sometimes black colonies are usually the easiest characteristics used to recognise species of this genus. Cladosporium are usually found on both living and dead plant material, and recently in human specimens and indoor environments. Furthermore, Cladosporium are associated with allergenic rhinitis, asthma, subcutaneous infections and other infections in both immunocompetent and immunocompromised individuals. Nevertheless, some Cladosporium species are useful for the production of antibiotics that work against Bacillus subtilis and Candida albicans, while some are efficient biological insecticides targeting insects that are resistant to chemical insecticides. Ambient air pollution has been recognised as the primary source of respiratory illnesses with regards to air pollution. However, in recent years, indoor air has proven to be a potential threat to human health. Indoor environments encompass a lot of gases and microorganisms that may be hazardous to humans. Cladosporium, often referred to as outdoor fungi has been commonly isolated in indoor environments over the last few years. This study investigated the prevalence of a potent allergenic genus, Cladosporium, in South African indoor environments. In an attempt to achieve this, air samples collected from different areas of the Western Cape and Gauteng provinces were studied. Following a polyphasic approach used by several authors, isolates were identified and new species described. Species were represented in all species complexes but mostly resolved in the Cladosporium cladosporioides species complex, the largest complex of the genus. Here, we present 110 isolates from indoor air samples identified as 18 different species of Cladosporium, three of which have been introduced and described as novel. This study has demonstrated that South African indoor environments contain a large diversity of described and undescribed Cladosporium species. Moreover, there is a need for more studies concerning indoor environments with particular regard to this genus.

AFRIKAANSE OPSOMMING: Cladosporium is van die grootste en mees diverse hyphomycetes genera. Daar is voorheen gerapporteer dat dit meer as 772 name bevat. Die olyfgroen tot bruin of soms swart kolonies is gewoonlik die maklikste eienskap wat gebruik word om die spesies van hierdie genus te herken. Cladosporium kom gewoonlik op beide lewende en dooie plantmateriaal voor en is onlangs gekry in menslike monsters en binnenshuise omgewings. Verder word Cladosporium ook met allergiese rhinitis, asma, onderhuidse infeksies en ander infeksies in beide immuuntoereikende en immuun gekompromiteerde indiwidue geassosieer. Desnieteenstaande is sommige Cladosporium-spesies nuttig vir die vervaardiging van antibiotika teen bakterieë en giste, terwyl sommige doeltreffende insekdoders is teen insekte wat weerstandbiedend teen chemiese insektedoders is. Omringende lugbesoedeling word erken as die primêre bron van lugwegsiektes a.g.v. lugbesoedeling. In die laaste jare is egter bewys dat binnenshuise lug ‗n potensiële bedreiging vir die mens se gesondheid is. Binnenshuise omgewings sluit baie gasse en mikroörganismes in wat skadelik vir mense kan wees. Cladosporium, wat algemeen as ‗n buitenshuise fungus beskou word, is oor die laaste paar jaar dikwels uit binnenshuise omgewings geïsoleer. Tydens hierdie studie is die voorkoms van ‗n sterk allergeniese genus, Cladosporium, in Suid-Afrikaanse binnenshuise omgewings bestudeer. In ‗n poging om dit uit te voer, is lugmonsters wat in verskillende areas in die Wes-Kaap en Gauteng ingesamel is, bestudeer. Met ‗n polifase benadering, wat deur verskeie outeurs gebruik is, is isolate geïdentifiseer en nuwe species beskryf. Species was verteenwoordigend van al die species komplekse, maar het meestal deel van die Cladosporium cladosporioides kompleks, die grootste kompleks in die genus, gevorm. Hier lê ons 110 isolate voor, wat vanaf binnenshuise lugmonsters verkry en geïdentifiseer is, as 18 verskillende Cladosporium species, waarvan drie voorgehou en beskryf word as nuwe species. Hierdie studie bewys dat Suid-Afrikaanse binnenshuise omgewings ‗n groot verskeidenheid beskryfde en onbeskryfde Cladosporium species bevat. Voorts is daar ‗n behoefte aan meer studies rakende binnenshuise omgewings waarin daar spesifiek op hierdie genus gekonsentreer word.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/105625
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