Eicker, A.2022-07-262022-07-2619921992*https://repository.up.ac.za/handle/2263/86470Thesis (PhD)--University of Pretoria, 1992.English: In the historical introduction of this manuscript, a worldwide literature review, regarding aspects of mammalian Sporothrix infections, is given. A research programme concentrating on the epidemiology, morphology and ecology of Sporothrix schenckii in the Transvaal, is presented. s Two epidemiological forms of human sporotrichosis extt in the aforementioned province. One type is due to an infection acquired from a source in nature (soil, plants and decaying vegetation), and the other type was found in the Witwatersrand gold mines due to fungal proliferation on the timber props underground, where the disease took on epidemiologic proportions in the early part of the century. Changes in the mining methods have almost eliminated the problem in the latter environment. outbreaks do however still occur. Sporadic cases and small Pathogenic S. schenckii strains derived from human and animal disease could be converted on moist wood to produce triangular and pigmented conidia, similar to those seen in the gold mine isolates. Pigmented conidia proved to be more viable than unpigmented ones, and pigment production was found to be potentially present in all conidium types. The larger numbers of conidia produced in pigmented strains are indicative of higher infectivity rather than increased pathogenicity or virulence. Larger conidium volumes were unrelated to genetic material but were due to an increased cytoplasmic content and cell wall thickening in the older conidia, as confirmed by fluorescent nuclear DNA staining and electron microscopy. Results of this study suggest that S. schenckii possesses an intrinsic polymorphism, as the two types of pathogenic strains could be interconverted solely by altering the nutritional conditions. This study also describes the occurrence of S. schenckii infections in animals and reports on the successful treatment of the disease with two new drugs.Afrikaans: 'n Wereldwye literatuuroorsig wat handel oor die aspekte van soogdier Sporothrix infeksies, word in die historiese inleiding van hierdie proefskrif uiteengesit. 'n Navorsingsprogram wat op die morfologie, ekologie, epidemiologie en behandeling van Sporothrix schenckii infeksies in die Transvaal konsentreer, word aangebied. Twee epidemiologiese vorms van menslike S. schenckii infeksies kom in die Transvaal voor. Die een ui terste van die siekte het sy oorsprong uit 'n omgewingsbron, naamlik besmette grond, plantmateriaal en kompos, terwyl die ander vorm in die Witwatersrandse goudmyne opgedoen word waar die organisme weelderig op ondergrondse houtstutte groei. Die laasgenoemde vorm het epidemiese afmetings in die eerste helfte van die eeu aangeneem. Tans is die probleem feitlik uitgeskakel weens veranderde ontginingsmetodes in die mynbedryf asook 'n meer deeglike kennis van die siektetoestand. Sporadiese gevalle en klein epidemies kom egter nog voor. Patogeniese S.schenckii stamme kan deur hulle op klam hout te laat groei, omgeskakel word na gepigmenteerde kolonies wat driehoekige kodidiums vorm. Laasgenoemde is soortgelyk aan die konidiums wat in die Witwatersrandse goudmyne gevind is. Gepigmenteerde konidiums bly langer lewensvatbaar as die ongepigmenteerde konidiums, alhoewel pigmentproduksie potensieel in alle konidiumtipes teenwoordig is. Die groter aantal konidiums wat deur die gepigmenteerde isolate geproduseer word, dui op 'n hoer infeksie risiko eerder as 'n verhoogde patogenisiteit of virulensie van 'n betrokke stam. Groter konidium volumes by gepigmenteerde konidiums, kon nie met genetiese materiaal gekorreleer word nie maar wel met 'n verhoogde sitoplasmiese inhoud en verdikking van die selwand by ouer en volwasse konidiums. Dit kon met fluoresente kern-DNA-kleurings en elektronmikroskopie bevestig word. Navorsing suggereer dus 'n intrinsieke polimorfisme in S.schenckii, aangesien die twee tipes patogeniese stamme interkonversie kan ondergaan deur slegs die voedingsbronne aan te pas. Enkele gevalle van sporotrigose by diere word ook bespreek.en© 2021 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.UCTDSporothrix schenckiihuman sporotrichosisWitwatersrand gold minesDissertation