Black fungi

Data is collected and this ppt is Created by Sweta Chaudhary. All rights are reserved to her. Contact [email protected] for more inquiry. Thank you ...

1. BLACK FUNGI (DEMATIACEOUS FUNGI) BY SWETA CHAUDHARY 4 th semester

2. INTRODUCTION “ Black fungi” sometime also called “black yeast” or dematiaceous Fungi, micro colonial Fungi or meristematic Fungi. It is diverse group of slow growing micro fungi which reproduce most asexually . Only few genera reproduce by budding cell, while in other hyphal or meristematic reproduction is preponderant. They are found in soil and generally distributed worldwide.

3. INFECTION CAUSED BY BLACK FUNGI Chromoblastomycosis Phaeophyphomycosis

4. CHROMOBLASTOMYCOSIS Chromoblastomycosis is slowly progressing localized fungal infection of skin and subcutaneous tissue mostly involving exposed part of body without tendency to disseminate. This is caused by dematiaceous fungi and is characterized by polymorphic , verrucoid , crusted or ulcerated lesions. Usually it infect feet and legs.

5. MYCOLOGY Causative fungus -dark brown, olivaceous or black fungi. Family- H erpotrichi E llaceae Order- D othideales Class- B iotonicate P yronomycetes Phylum- D euteromycetes

6. EPIDEMOLOGY Chromoblastomycosis is common diseases among rullar worker in tropical and subtropical countries of central and south A merica as well as Africa. This is found prevalent in Maxico , cuba and other part of latin A merica , Africa and madagascar . This may ocassionally be seen in temperature zone but it is most frequently encountered in warmer climate where people go barefoot and wear minimal clothing. This fungi are widely distributed as saprotrophic organism in soil and decaying vegetation in all type of climate. It is also mostly seen in males residing in rular area . In Japan however , incidence is found to be equal in both sexes.

7. This infection has also been reported in domestic animal like dogs and horses . The infection is non-contagious as it is not transmitted from animal to human or mam to man and infective from of causative fungi in mycelial from whereas in man it is found as sclerotic cells .

8. PATHOGENESIS Chromoblastomycosis is believed to originate in minor trauma to the skin , usually from the vegetative material such as throns or splinters. This trauma implants fungi in the subcutaneous tissue. In many cases , the patients will not notice or remember the initial trauma , as symptoms often do not appear for years. The fungi most commonly observed to cause chromoblastomycosis are:

9. Fonsecaea pedrosoi Phialophora verrocosa Cladophialophora carrionii Fonsecaea compacta Over months to years an Erythematous papule appears at the site of innoculation . Although the mycosis slowly spreads ,it usually remains localized to the skin and subcutaneous tissue. Hematogenous or lymphatic spread may occur. Multiple nodules may appears on the same limb, sometimes coalesling into a large plaque. Secondary bacterial infection may occur ,sometimes inducing lymphatic obstruction The central portion of the lesion may heal ,producing lscar or it may ulcerate.

10. A.Cladosporium type B.Rhinocladiella type C.phialophora type fig: types of sporulation in dematiaceous fungi causing chromoblastomycosis

11. CLINICAL FEATURES Warty papule enlarges to expanding varrucous plaque ,commonly on feet ,legs , neck and face. The verrucose lesions are frequently ulcerated and may be raised about 1- 3 cm above the skin level with rough irregular surfaces giving cauliflower like apperance and hence it is called verrucose dermatitis. The infection is confined to skin and subcutaneous tissue and not disseminated to deeper organs of the body. Satellite lesions may also develop by auto inoculations.

12. The lower legs are frequently affected part of the body and rarely shoulders , arms ,hands buttocks , ears , chest ,face and abdomen may be involved. The hematogenous and lymphatic dissemination is seen in sporotrichosisi srearly observed . Sometimes secondary bacterial infection may result in lymphatic o bstruction and consequently result in elephantiasis of legs . The lesions may parsist for decades if neglected or unsuccessfully treated.

13. Fig: Elephantiasis of leg

14. LABORATORY DIAGNOSIS 1.Clinical material: skin scrapings and /or biopsy. 2.Direct microscopy: Skin scrapings should be examined using 10%KOH and parker ink and calcofluor white mounts. Tissue section should be stained using H&E, PAS digest and Grocitt‘s Methanamine silver (GMS).

15. Fig 1:sclerotic bodies seen in wet mount Fig 2:sclerotic bodies seen in H &E

16. TREATMENT Chromoblastomycosis responds very poorly the available therapies. The therapeutic modalities may be cryotharpy ,thermotherapy, laser therapy , chemotherapy and surgery. The most commonly used is flucytosine which act by inhibatating nuclic acid synthesis and is given orally as 50-150 mg/kg per day in far divided dose. Newerazoles like itraconuzole and fluconazole have been used efficitively .

17. PHAEOHYPHYOMYCOSIS Phaeohyphyomycosis is subcutaneous and systemic infection , caused by various heterogenous group of dematiaceous fungi . These fungi are found in hyphal form in tissue and not thick walled muriform cell and seen in chromoblast mycosis. The term phaeohyphomycosis is derived from Greek word ‘ Phaios ’ means dark and refer to brownish black colour and fungi in vivo and cell in in vitro . It compare group of infection ranging from superficial , cutaneous or subcutaneous infection to disseminated invas have diseases whose etiological agent produce yeast like cell , pseudohyphae or septate hyphae in tissues but certainly contain sclerotic body .

18. EPIDEMOLOGY The dematiaceous fungi are widelly present in nature as contaminant and are not common human pathogens. The fungi are found in soil ,decaying vegetation and rotten wood. These saprotrophic fungi are ubiquitus in nature and are being recognized with increasing frequency and cause of human diseases. Expanding population of immuno compressed patients is likely to be responsible due to dematiaceous fungi in nature.

19. PATHOGENESIS AND PATHOLOGY Multiple stellate abscesses progress to single circumscribed lesion with central cavity filled with pus and surrounded by fibrous wall. The margins of these abscesses and granulomas are composed of gaint cells , and lymphocytes plasma cells and lymphocytes . The fungi are found in adjacent purulent areas. Despite phaeoid nature of causative fungi ,brown pigment may not always be apparent and hyphae may also appear hyaline in lesions in H&E. GMS ( Grocott’s Methenamines Silver stain) marks natural brown colour of phaeoid hyphae .

20. There confirmation of presence of these hyphae can be achieved by using melaning specific stain , such as messon - fontana stain . In cladophialophora bantiana besides formation of most common phaeomycotic cyst there may be pseudoepitheliomatous hyperplasia , mixed inflammation with granulomatous components and intraepidermal neutrophilic microabscess formation.

21. CLINICAL FEATURES The fungal agents causing phaeolyphomycosis are mostly plant pathogens and in soil infecting subcutaneous tissue by producing solitary lesions. These are four clinical types which have been described on the basis of site of involvement and degree of tissue invasions by causative fungi. The lesions are superficial confined to stratum. Cutaneous corneum /corneal- invasion and destruction of keratinized tissue . Subcutaneous and disseminated-generally occuring in immuno compressed host are associated with high mortality.

22. According to phaeoid fungus involved and anatomical site effected phaeophomycosis can be classified as follows : - Cutaneous P haeohyphomycosis -Subcutaneous P haeohyphomycosis -Invasive and cerebral P haeohyphomycosis - P aranasal Sinus Phaeohyphomycosis

23. Fig1:cutaneous phaeohyphomycosis fig2:subcutaneous phaeohyphomycosis

24. Fig1:invasive and cerebral fig2:paranasal sinus phaeohyphomycosis phaeohyphomycosis

25. LABORATORY DIAGNOSIS Specimen : pus, biopsy tissue Direct microscopic examination :KOH and smear brown septate hyphae Culture on SDA and,it’s very slow growing black or grey colonies.

26. TREATMENT The subcutaneous form of phaeohyphomycosis are usually treated by local excision but invasive infection require combination theraphy with intravenous amphotericin B and oral flucytosine . The antifungal drug such as : amphotericin B, flucytosin ketoconazole , fluconazole , traconazole and terbinatine have been used with variable success. Patient with non life threatening deep seated a systemic form of phaeohyphomycosis should resceve traconazole in dose of 200-600 mg per day .