Medical mycology

Medical Mycology

1. Classification, Lab diagnosis and Important diseases caused by Fungi 2/13/2015 1 Mohammad Mukhit Kazi, Lecturer SDCH Pune

2. Objectives To know about important characteristics of fungi To know various classification systems To know medically important fungi To know the lab diagnosis of fungi To know treatment of fungal diseases 2/13/2015 2 Mohammad Mukhit Kazi, Lecturer SDCH Pune

3. Mycology Study of fungi – mycology Mykos – mushroom All fungi are eukaryotic Natural habitat- soil, water and decaying organic debris Obligate or facultative aerobe Chemotrophic organisms 2/13/2015 3 Mohammad Mukhit Kazi, Lecturer SDCH Pune

4. Differences from bacteria Posses rigid cell wall Contain chitin, mannan and polysacharide Cytopalsmic membrane contain sterols True nuclei with Nuclear membrane, mitochondria and endopalsmic reticulum Unicellular or multicellular Divide by asexually, sexually or by both 2/13/2015 4 Mohammad Mukhit Kazi, Lecturer SDCH Pune

5. Classification Taxanomic classification Phyllum Thallophyta Four calsses of fungi B. Morphological classification Yeasts Yeasts like fungi Moulds Dimorphic fungi 2/13/2015 5 Mohammad Mukhit Kazi, Lecturer SDCH Pune

6. Thallophyta Thallophyta Irregular plant masses lacking definite root, stem and leaf structures Fungi Algae (No chlorophyll) (Chlorophyll) 4 classes Zygomycetes Ascomycetes Basidiomycetes Deuteromycetes or fungi imperfecti Lower fungi having non-septate hyphae Forms asexual spores sporangiospores Sexual spores zygospores and oospres Septate hyphae Sexual spores (ascospores) are present within the sac or ascus Septate hyphae Sexual spores are basidiospores on a basidium Septate hyphae Lack a known sexual state. Most fungi medically important fungi belongs to this class 2/13/2015 6 Mohammad Mukhit Kazi, Lecturer SDCH Pune

7. Yeasts Round to oval unicelluar Reproduce by budding Creamy mucoid colonies E.g. Cryptococcus neoformans 2/13/2015 7 Mohammad Mukhit Kazi, Lecturer SDCH Pune

8. Yeasts like fungi Partly as yeasts and partly as elongated budding cells Germ tube to demonstrate pseudohyphae 2/13/2015 8 Mohammad Mukhit Kazi, Lecturer SDCH Pune

9. Moulds Grow as branching filaments – hyphae Hyphae septate or nonseptate Continue growth called as mycelium E.g Dermatophytes, Aspergillus, Penicillium and Rhizophus 2/13/2015 9 Mohammad Mukhit Kazi, Lecturer SDCH Pune

10. Dimorphic fungi They exists as yeasts in host tissue and in cultures as mycelial growth Blastomyces dermatitidis, Paracoccidioides, Coccidiodes immitis, Histoplasma, Sporothrix 2/13/2015 10 Mohammad Mukhit Kazi, Lecturer SDCH Pune

11. Reproduction and sporulation Sexual spores – oospres, ascospores, zygospores and basidiospores Vegetative spores – Blastospores:formed by budding from parent cell Arthrospores: cross septa into hyphae Aerial spores: Conidiospores, Microconidia, Macroconidia, Sporangiospores 2/13/2015 11 Mohammad Mukhit Kazi, Lecturer SDCH Pune

12. Laboratory Diagnosis Direct microscopy KOH preparation Gram staining India ink preparation B. Culture - SDA C. Slide culture test 2/13/2015 12 Mohammad Mukhit Kazi, Lecturer SDCH Pune

13. Classification of fungal diseases Superficial mycoses- skin nails hair Subcutaneous mycoses – myetoma Systemic mycoses - aspergillosis 2/13/2015 13 Mohammad Mukhit Kazi, Lecturer SDCH Pune

14. Dermatophytes They infect superficial keratinized tissue (skin, nail and hair) without involving tissue They break down and utilizes keratin Incapabale of penetrating subcutaneous tissue Cause dermatomycoses also known as ringworm 2/13/2015 14 Mohammad Mukhit Kazi, Lecturer SDCH Pune

15. Cylindrical macroconidia Fusiform macroconidia Club shaped macroconidia 2/13/2015 15 Mohammad Mukhit Kazi, Lecturer SDCH Pune

16. 2/13/2015 16 Mohammad Mukhit Kazi, Lecturer SDCH Pune

17. Classification Trichophyton - hair, skin and nail Microsporum – hair , skin Epidermophyton – skin and nail Lab diagnosis: Specimen: skin, hair or nail Direct microscopy – LPCB mount Culture Treatment 2/13/2015 17 Mohammad Mukhit Kazi, Lecturer SDCH Pune

18. Subcutaneous Mycoses Mycetoma : crhonic granulomatous infection of subcutaneous tissue usually affects foot Also known as Madura foot Mainly in tropical countirs Common in Tamilnadu Caused by Actinomycetes and filamentous fungi Enter through minor trauma Diagnosis made by observing granules Treatment- sulphonamides sometime amputation 2/13/2015 18 Mohammad Mukhit Kazi, Lecturer SDCH Pune

19. Sporotrichosis Is nodular, ulcerating disease of skin and subcutaneous tissue Acces through thorn pricks or injuries Spread through lymphatics upto regional lymph nodes Sporothrix schenckii – dimorphic fungi Lab diagnosis by culture 2/13/2015 19 Mohammad Mukhit Kazi, Lecturer SDCH Pune

20. Rhinosporidiosis Is a chronic granulomatous disease characterized by formation of friable polyps, usually confined to nose, mouth or eye Causative agent Rhinosporidium seeberi Reported from Srilanka and India Mode of infection is not known Lab diagnosis done by demonstration of sporangia 2/13/2015 20 Mohammad Mukhit Kazi, Lecturer SDCH Pune

21. Rhinosporidiosis 2/13/2015 21 Mohammad Mukhit Kazi, Lecturer SDCH Pune

22. Systemic mycoses Histoplasmosis Histoplasma capsulatum Reticuloendothelial system Source – soil with excreta of birds Asymptomatic Sputum, bone marrow, blood, scrapings, biopsies Geimsa stain or Wright stain Culture- SDA Amphotericin B 2/13/2015 22 Mohammad Mukhit Kazi, Lecturer SDCH Pune

23. 2. Blastomycosis Blastomyces dermatitidis- dimorphic fungi Infection mainly to skin, bone and genitourinary tract Inhalation of conidia Asymptomatic Sputum, pus or scrapings 10% KOH, H&E stain and PAS stain Culture-SDA Amphotericin B 2/13/2015 23 Mohammad Mukhit Kazi, Lecturer SDCH Pune

24. 3. Paracoccidiomycosis Paracoccidioides brasilensis- dimorphic fungi Inhalation of spores Same 4. Coccidiodomycosis 5. Crptococcosis - Crptococcus neoformans - Inhalation of dust - Seen in immunocompromised - demosntration of capsule by india ink 6. Opportunistic mycoses- candiasis, aspergillosis, zygomycoses 2/13/2015 24 Mohammad Mukhit Kazi, Lecturer SDCH Pune

25. Aspergillus fumigatus 2/13/2015 25 Mohammad Mukhit Kazi, Lecturer SDCH Pune

26. Aspergillus terreus 2/13/2015 26 Mohammad Mukhit Kazi, Lecturer SDCH Pune

27. Aspergillus fumigatus 2/13/2015 27 Mohammad Mukhit Kazi, Lecturer SDCH Pune

28. ASpergillus niger 2/13/2015 28 Mohammad Mukhit Kazi, Lecturer SDCH Pune

29. Typical growth of Aspergillus spp 2/13/2015 29 Mohammad Mukhit Kazi, Lecturer SDCH Pune

30. ASpergillus flavus 2/13/2015 30 Mohammad Mukhit Kazi, Lecturer SDCH Pune

31. Mucor 2/13/2015 31 Mohammad Mukhit Kazi, Lecturer SDCH Pune

32. Take home message Fungi are eukaryotes Medically important fungi belongs to Fungi imperfecti or Deuteromycetes Sabourauds dextrose agar is used to culture Slide culture to demonstrate better morphological characters KOH mount or LPCB mount for demonstration Mainly opportunistic infections E.g. Candidiasis, Cryptococcosis, Aspergillosis 2/13/2015 32 Mohammad Mukhit Kazi, Lecturer SDCH Pune