Review Articles Current Problems Concerning Parasitology And
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Annals of Parasitology 2012, 58(3), 111–123 Copyright© 2012 Polish Parasitological Society Review articles Current problems concerning Parasitology and Mycology with regard to diseases of the skin and its appendages 1 Joanna Błaszkowska, Anna Wójcik Chair of Biology and Medical Parasitology, Medical University of Lodz, 1 Hallera Square, 90-647 Lodz, Poland Corresponding author: Joanna Błaszkowska; E-mail: [email protected] ABSTRACT. Current issues concerning Parasitology and Mycology with regard to diseases of the skin and its appendages are presented. Aspects of diagnostics, clinical picture and therapy of skin and nail mycoses, as well as difficulties in the diagnosis and treatment of both native parasitoses (toxoplasmosis) and imported human tropical parasitoses (malaria, filariosis) have been emphasised. The clinical importance of environmental mould fungi in nosocomial infections and fungal meningitis, as well as selected properties of fungi isolated from patients with head and neck neoplasms treated by radiotherapy are discussed. Other mycological topics include the characteristics of newly- synthesized thiosemicarbazides and thiadiazoles as potential drugs against toxoplasmosis and their biological activity against Toxoplasma gondii tachyzoites, selected molecular mechanisms of resistance to azoles, Candida albicans strains and a new tool (barcoding DNA) for describing the biodiversity of potential allergenic molds. The importance of environmental factors in pathogenesis of mycoses and parasitoses is noted. The characteristics of pathogenic fungi isolated from natural ponds in Bialystok and potentially pathogenic yeast-like fungi isolated from children’s recreation areas in Lodz are presented. The ongoing problem of anthropozoonoses is considered, as are the roles of stray cats and dogs in contaminating soil with the developing forms of intestinal parasites. The characteristics of the human microbiome, including population composition, activity and their importance in normal human physiology, are presented, as are the major goals of the Human Microbiome Project initiated by National Institutes of Health (NIH). Key words: medical parasitology, mycology, parasitoses, mycoses During the last decades, a permanent increase in The spectrum of dermatophytes isolated from the number of fungal skin infections has been skin lesions has changed in the last 70 years in most observed worldwide. The high prevalence of European countries. Microsporum audouinii and superficial mycoses shows that approximately Epidermophyton floccosum , ranked highest before 20–25% of the world’s population has skin lesions, the Second World War in Germany, have been making these one of the most frequent forms of replaced by Trichophyton rubrum , which nowadays infection. Pathogens responsible for those diseases accounts for 80–90% of the strains, followed by are primarily geophilic, anthropophilic and T. mentagrophytes . This trend, also observed in the zoophilic dermatophytes from the genera Central and Northern Europe, is directly connected Trichophyton , Microsporum and Epidermophyton . with the increased incidence of tinea pedis. In There appears to be considerable inter and intra- contrast, in Southern Europe and in Arabic continental variability in the global incidence of countries, zoophilic dermatophytes, such as these fungal infections. Dermatophytes are Microsporum canis or Trichophyton verrucosum , keratinophilic and keratinolytic fungi, characterized are the most frequently isolated. In Europe, by a high affinity to keratin-containing tissues. In especially in Mediterranean countries, the incidence everyday clinical practice they are responsible for of M. canis infection has strongly increased during superficial mycoses of skin (tinea faciei, tinea the recent years and this dermatophyte is now the barbae, tinea corporis, tinea cruris, tinea manuum or most prevalent in tinea capitis in children [3]. tinea pedis), nails (onychomycosis, tinea unguium) Infections caused by dermatophytes have and hair (tinea capitis) [1,2]. become a very serious problem, not only a clinical 1 The review was supported by Medical University of Lodz, No 503/1-013-01/503-01 112 J. B³aszkowska, A. Wójcik one, but also with epidemiological and therapeutic smaller toenails was induced by T. mentagrophytes aspects. Clinical manifestations of mycoses vary and T. rubrum , whereas mycosis of the large toenail depending on the site of infestation and the type of was often associated with Candida species and also strain and therefore, accurate identification of the moulds of genera Fusarium , Alternaria , strain is crucial in order to facilitate rapid treatment Aspergillus , Scopulariopsis [4] . Interestingly and to prevent spread of the disease. Skin mycoses enough, S. brevicaulis , a common saprophytic often present a typical clinical picture, however, in fungus found in soil, on vegetables and other some cases they may mimic other disorders, such as organic waste, having a wide geographic pityriasis rosea Gibert, granuloma annulare, distribution, may be an etiological factor of skin sarcoidosis, urticaria, erythema annulare lesions in various locations and also generalized centrifugum, lupus erythematosus (especially mycoses. Several case reports have described subacute cutaneous form – SCLE), erythema S. bre vicaulis infections of deep tissue or skin in chronicum migrans, erythema multiforme, immunocompromised hosts and there have been psoriasis, eczema and contact dermatitis. Also, the sporadic cases of ocular infection. A case of slowly previous application of some drugs (such as progressive granulomatous face skin infection in an steroids, antihistamines, antibiotics or zinc otherwise healthy person has also been found [5]. ointment) may modify the presentation of Onychomycosis, infection of the nail plates, is dermatomycoses in some patients. Therefore, it is of caused by dermatophytes, nondermatophytes great importance to collect scrapings for moulds or yeast species. In the majority of patients, microscopy and culture before starting treatment onychomycosis is viewed as more than a mere with oral or topical antifungals (J. Narbutt; Medical cosmetic problem. In spite of improved personal University of Lodz). hygiene and living environment, nail mycoses The commonest risk factors for fungal skin continue to spread and persist. It has been estimated infections are: antibiotic and corticosteroid use, a that nail mycoses may concern nearly 30% of adults depressed immune system due to chemotherapy and in Europe, whereas their prevalence in Australia and HIV infection, the coexistence of diabetes, as well the United States accounts for 10% [6]. as environmental factors like increased moisture, Numerous studies have revealed that nearly 10% lifestyle, contact with soil, form of recreation and of the cases of onychomycosis are caused by taking part in different sports and, in some nondermatophyte molds (NDM): Scopulariopsis individuals, a genetic predisposition towards brevicaulis , Aspergillus spp ., Acremonium spp., mycoses. Religious ceremonies and traditions, like Fusarium sp ., Onychocola canadiensis , Nattrasia ritual ablutions, are also of the great importance. mangiferae , Alternaria spp ., Scytalidium dimidia - The relative occurrence of the etiologic agents and tum , S. hyalinum , Geotrichum candidum or Clado - fungal skin infections varies from country to spo rium carrionii . Unlike dermatophytes, those country and from one climatic region to another. In fungi are not keratolytic and can only invade a nail tropical countries, a warm and humid climate, plate previously destroyed due to trauma, crowded living and poor sanitary conditions all dermatophyte activity or another nail disease. For promote the spread of mycoses. It is worth noting this reason, the incidence of onychomycosis due to that mycoses of the skin covering the trunk and face NDM is estimated from 1.45 to 17.6% [7,8]. have been more frequently observed in those Keratinophilic molds may be either countries, whereas in a moderate climate, fungi contaminants of biological material in the mostly affect the feet and hands, particularly the laboratory or pathogens causing nail lesions, which nails. In Lodz (Poland), a higher prevalence of skin may create serious problems for the correct and nail lesions was noticed in middle-aged and diagnosis of NDM onychomycosis. Moreover, elderly patients as compared to young subjects, with diagnostic criteria are inconsistent between significantly greater occurrence on the hands of mycological laboratories. Based on several studies, women than men (J. Kwaśniewska, E. Szefer, six major diagnostic criteria were identified: A. Jaskółowska; Medical University of Lodz). identification of the NDM in the nail by Mycosis of the large toenail was most frequently microscopy, the presence of mycelium elements diagnosed, while infection of the remaining (using a potassium hydroxide preparation – KOH toenails, foot skin and spaces between toes occurs with Parker ink or Calcofluor White; alternatively more rarely. In the majority of cases, mycosis of the KOH may be replaced by Na 2S or NaOH), isolation Current problems in Parasitology 113 in culture, repeated isolation in culture in different management of Candida related CNS infections time intervals, quantitative evaluation of inoculum, [10]. failure to isolate a dermatophyte in culture and A unique case of fungal meningitis with many histology (periodic acid Schiff). Most studies years’ course, probably stemming