Lipolytic activity of some dermatophytes.
TL;DR: Thelipolytic activities of four common dermatophytes, Epidermophyton floccosum, Microsporum canis, Trichophyton mentagrophytes and T. rubrum, were tested on agar medium supplemented with one or other of several lipids and the highest lipolytic activity was demonstrated by M. canis.
Abstract: THE HORNY layer of epidermis, which can be colonised by dermatophytes, is covered by surface lipids. The lipolytic activity of dermatophytes may therefore be of particular importance in the early stages of infection, before the fungus has established permanent contact with keratin; but little is known about the possible presence of lipases in these pathogenic fungi. The early observations of Mallinckrodt-Haupt (1927), Tate (1929), Nekam (1935) and, more recently, Pinetti and Lostia (1961) and Bohme (1969) have demonstrated that dermatophytes can hydrolyse lipids of animal and of vegetable origin. The occurrence of lipase has been demonstrated histochemically (Knight, 1957) and in dermatophyte mycelial filtrates (Bohme, 1969). This paper describes the screening of the more common dermatophytes to test for the presence of lipases.
Citations
More filters
TL;DR: The morphology of the fungal elements, such as arthroconidia and hyphae, during the adhesion and invasion stages of the dermatophyte are followed to show their mechanical and biochemical capabilities to invade the skin tissue effectively.
Abstract: Dermatophytes are pathogenic fungi that infect human skin, nails and hair and cause dermatophytosis. Trichophyton mentagrophytes is one of the most widespread species that belong to this group. Infection of the skin tissues include several stages, i.e., adhesion to the surface of the skin, invasion into the sublayers by the penetration of fungal elements and secretion of enzymes that degrade the skin components. In this study we have followed the morphology of the fungal elements, such as arthroconidia and hyphae, during the adhesion and invasion stages. Skin explants were inoculated with the dermatophyte and observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Skin explants were also inoculated with a transgenic isolate of T. mentagrophytes expressing the green fluorescent protein (GFP). The infected sublayers were investigated by confocal scanning laser microscopy (CSLM). As an adaptation to the tissue environment, the dermatophyte produced long fibrils when it is on the open surface of the stratum corneum, while short and thin fibrils are produced inside the dense sublayers. The short and long projections might have a role in adhesion. Invasion may be produced by mechanical and biochemical means. Invasion of the tissue showed hyphal branching and growth in multiple directions. The proteolytic profile was assayed by substrate gel and proteolytic activity. Two serine proteases of similar molecular weight were secreted during growth on the epidermal matrix components keratin and elastin. The dermatophyte may use the proteolytic enzymes to invade the surface and also the deep layer of the skin in immunocompromised patients. Dermatophytes, which are well adapted infectious agents, seem to use their mechanical and biochemical capabilities to invade the skin tissue effectively.
80 citations
TL;DR: In this paper, a taxonomic study was undertaken combining molecular, morphological, and physiological characteristics as evidence of classification of T. indotineae by sequences of the HMG gene.
Abstract: A severe outbreak of highly virulent and multi-resistant dermatophytosis by species in the Trichophyton mentagrophytes/T. interdigitale complex is ongoing in India. The correct identity of the etiologic agent is a much-debated issue. In order to define species limits, a taxonomic study was undertaken combining molecular, morphological, and physiological characteristics as evidence of classification. Molecular characteristics show that T. mentagrophytes s. str. and T. interdigitale s. str. can be distinguished with difficulty from each other, but are unambiguously different from the Indian genotype, T. indotineae by sequences of the HMG gene. The entities were confirmed by multilocus analysis using tanglegrams. Phenotypic characters of morphology and physiology are not diagnostic, but statistically significant differences are observed between the molecular siblings. These properties may be drivers of separate evolutionary trends. Trichophyton mentagrophytes represents the ancestral, homothallic cloud of genotypes with a probable geophilic lifestyle, while T. indotineae and T. interdigitale behave as anthropophilic, clonal offshoots. The origin of T. indotineae, which currently causes a significant public health problem, is zoonotic, and its emergence is likely due to widespread misuse of antifungals.
57 citations
TL;DR: Alkaline phosphatase, esterases and leucine arylamidase may be important for the parasitic growth of dermatophytes and may be helpful for species identification.
Abstract: Summary. Exoenzymes produced by common dermatophytes, in addition to their ability to cause cutaneous inflammation, are thought to contribute to fungal spread. To investigate the patterns of enzymes released by common dermatophytes as well as Scopulariopsis brevicaulis, the fungi were grown in liquid media containing either hair, stratum corneum, neopeptone or lipids, or in RPMI medium. Enzymes recovered from the culture supernatants were compared using the Apizym test. As a result, the widest range of enzymes was seen in protein-containing media, with a maximum of 13 enzymes stimulated by growth on hair. Dermatophytes in all protein media produced high levels of alkaline phosphatase, esterases and leucine arylamidase. In these media the highest total enzymatic activity was released by Microsporum canis, whereas the lowest was released by Epidermophyton floccosum. Although RPMI broth stimulated luxuriant growth of all species, recovery was limited to a maximum of six enzymes. In lipid medium E. floccosum and M. canis failed to grow. When comparing the various nutrients, Scopulariopsis released fewer enzymes than the dermatophytes and only minor quantities of alkaline phosphatase. We conclude that alkaline phosphatase, esterases and leucine arylamidase may be important for the parasitic growth of dermatophytes. The total enzymatic activity of dermatophytes appears to be correlated with the intensity of cutaneous inflammation. Furthermore, enzyme measurements may be helpful for species identification.
Zusammenfassung. Exoenzyme von Dermatophyten tragen sowohl zum Wachstum der Pilze in der Haut bei als auch zur kutanen Entzundungsreaktion. Um die Enzymmuster haufiger Dermatophyten und von Scopulariopsis brevicaulis zu bestimmen, wurden die Erreger in Nahrlosungen mit entweder Haar, Stratum corneum, Neopepton oder Fetten, sowie in RPMI-Medium gezuchtet. Die Enzyme in den Kulturuberstanden wurden mit Hilfe des Api-zymR Tests verglichen. Die breitesten Spektren mit bis zu 13 Enzymen wurden von Haaren induziert, gefolgt von den anderen Proteinsubstraten. In diesen Medien wurden fur alle Dermatophyten hohe Aktivitaten von alkalischer Phosphatase, Esterasen und Leucinarylamidase gemessen. Die hochste Gesamtenzymaktivitat in den Proteinmedien wurde von Microsporum canis, die geringste von Epidermophyton floccosum freigesetzt. Alle Arten wuchsen gut in RPMI-Medium, wenngleich dabei maximal nur 6 Enzyme nachweisbar waren. Im Lipidmedium wuchsen E. floccosum und M. canis nicht. Unter Berucksichtigung aller Nahrmedien setzte Scopulariopsis insgesamt eine geringere Zahl von Enzymen frei als die Dermatophyten und nur eine niedrige Aktivitat von alkalischer Phosphatase. Nach unseren Ergebnissen konnten besonders alkalische Phosphatase, Esterasen und Leucinarylamidase fur das parasitare Wachstum von Dermatophyten bedeutsam sein. Die Enzymaktivitat von Dermatophyten scheint mit der Intensitat der kutanen Entzundung zu korrelieren. Enzymmusterbestimmungen konnten auserdem hilfreich bei der Artdifferenzierung sein.
45 citations
TL;DR: The present review is aimed at discussing the newer advances in the understanding of the pathogenesis of various clinical types of OM apart from the newer and exciting techniques of diagnosing it.
Abstract: Onychomycosis (OM) is the commonest disorder affecting the nail unit. The fact that it affects 3-26% people worldwide goes to show that it is a significant health problem. The prevalence of OM has been reported to be increasing over the years. Although, we know much about various predisposing factors, we are yet unclear about its exact pathogenesis. The peculiarities of the nail unit with respect to its structure and its immune mechanisms make OM an adversary, which once established is difficult to eradicate. There have been many recent advances in our understanding of the pathogenesis of OM and our methods of diagnosing it. The increasingly valuable role of histopathology; refinements in its technique; PCR techniques; Optical coherence tomography and advances in spectrometric techniques have been reported. The present review is aimed at discussing the newer advances in our understanding of the pathogenesis of various clinical types of OM apart from the newer and exciting techniques of diagnosing it.
44 citations
Cites background from "Lipolytic activity of some dermatop..."
...Dermatophytic fungi have been shown to have keratinolytic, proteolytic and lipolytic activities.[6,7] The hydrolysis of keratin by proteinases not only facilitates invasion into tissues, but also provides nutrition to the fungi....
[...]
...However, factors involved in the fungal invasion of skin has been relatively well studied and occurs in several stages.[6,7] Both mechanical and chemical factors have a role to play in the entire process....
[...]
References
More filters
Book•
01 Jan 1956
TL;DR: This is the revision of the classic text in the field, adding two new chapters and thoroughly updating all others as discussed by the authors, and the original structure is retained, and the book continues to serve as a combined text/reference.
Abstract: This is the revision of the classic text in the field, adding two new chapters and thoroughly updating all others. The original structure is retained, and the book continues to serve as a combined text/reference.
35,552 citations
Book•
01 Jan 1948
TL;DR: The measurement of rank correlation was introduced in this paper, and rank correlation tied ranks tests of significance were applied to the problem of m ranking, and variate values were used to measure rank correlation.
Abstract: The measurement of rank correlation introduction to the general theory of rank correlation tied ranks tests of significance proof of the results of chapter 4 the problem of m ranking proof of the result of chapter 6 partial rank correlation ranks and variate values proof of the result of chapter 9 paired comparisons proof of the results of chapter 11 some further applications.
6,404 citations
TL;DR: In this paper, the enzymic activity of Dermatophyte fungi was studied in the following species: Sabouraudites radiolatus, S. lanosus; S. audouini; Trichophyton tonsurans; Grubyella schoenleinii.
Abstract: 1. The enzymic activity was studied in the following Dermatophyte fungi: Sabouraudites radiolatus; S. lanosus; S. audouini; Trichophyton tonsurans; Grubyella schoenleinii. Both the normal and pleomorphic forms of S. radiolatus were studied comparatively.2. An active proteolytic enzyme is present in all the species. This enzyme is active in an alkaline medium and can hydrolyse intact proteins (casein) with the production of free amino-acids (tryptophane), and is very similar to trypsin in its behaviour.3. Pepsin is not present in any of these fungi.4. The amount of the proteolytic enzyme present varies in the different species, and it is particularly abundant in S. radiolatus.5. A keratolytic enzyme was not found in any of these fungi.6. A lipolytic enzyme, lipase, which readily splits tributyrin into fatty acids, is present in all the species. It is about equally strong in all of them.7. Urease is present in all, with the exception of T. tonsurans.8. None of them contains invertase, inulase, lactase or zymase.9. Maltase and diastase are present in all. They are strongest in S. lanosus and T. tonsurans and are weakest in S. radiolatus.10. The species with most proteolytic activity have least carbohydrases, and conversely.11. Amygdalase is present in all the species.12. The normal form of S. radiolatus has greater proteolytic activity than the pleomorphic form. The pleomorphic form has strong urease and amygdalase, both of which are very weak in the normal form. Otherwise the enzymic activity of the two forms is similar.
41 citations
TL;DR: It is suggested that the superficial dermatophytes, serum, and cells of the skin could bring about the hydrolytic cleavage of glycerol esters, which would continue until the resulting low pH and the level of the products became inhibiting-an axiomatic proposition in enzymology.
8 citations
TL;DR: Une méthode simple de préparation des suspensions mycéliales standardisées de dermatophytes a été établie dans des récipents munis de garde à coton.
Abstract: Une methode simple de preparation des suspensions myceliales standardisees de dermatophytes a ete etablie. Le myceliium fut disperse a l'aide d'ultrason et les particules myceliales homogeneisees par filtration sous pression reduite; la suspension myceliale fut standardisee par spectrophotometrie. Les suspensions uniformisees ont pu etre conservees dans des recipents munis de garde a coton.
6 citations