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.
