[Micro] opportunistic mycosis

1. MYCOSIS
OPPORTUNISTIC

2. MYCOSIS
•Superficial
•Cutaneous
•Sub-cutaneous
•Systemic
•Opportunistic:

3. COMMON OPPORTUNISTIC MYCOSIS
ENDOGENOUS
•CANDIDA
•PNEUMOCYSTITIS CARRINI
EXOGENOUS
•ASPERGILLUS
•CRYPTOCOCCUS
•Zygomycetes MUCOR

4. CANDIDIASIS
Also, Monoliasis
•Skin
•Mucosa
•Internal organs
•IMMUNITY: integrity of skin, mm
normal bacterial flora
•DEFENSE: Phagocytosis mainly polymorphs
less in macrophages
T cells: CD4

5. NORMAL FLORA
•Mouth
•GIT
•Vagina
•Skin: 20% individuals carry as flora
•Colonization: increases with age, hospitalization, drugs AB
& birth control pills, pregnancy
•Immunity: T lymphocytes
•Disease: Neutropenia, Myeloper-oxidase deficien
• DM, HIV/AIDS. SCID

6. Candida types
•C albicans
•C tropicalis
•C parapsilosis
•C glabrata
•C gullermondii
•C dubliniensis
•Azole-resistant species: C krusei, C lusitaniae

7. MORPHOLOGY
DIMORPHIC
1.Oval, spherical budding yeast; 3-6um
2.Pseudo-hyphae; buds grow; fail to detach
Chains of elongated cells; pinched at septations
between cells
3.Occasional true, septate hyphae
•MEDIA: Sabouraud’s Glucose Agar
• Nutritionally deficient media
•In vivo: all 3 forms seen as mixture

8. SUPERFICIAL CANDIDIASIS
•CUTANEOUS
•MUCOSAL
•Increase number
•Damage to skin, mucosa
•Local invasion; by yeast, pseudo-hyphae
• Inflammatory reaction
•Pyogenic abscess to chronic granulomas
•Abundant yeasts & pseudo-hyphae

9. ORAL THRUSH

10. PATHOGENESIS
•Mucosal infection: Thrush
• discrete superficial pseudomembranous white patches of yeast, epithelial
cells, pseudo-hyphae patchy to confluent
•ORAL: Tongue, lips, gums, palate: infants, old, AIDS, steroids,AB, immune
deficency
•VAGINAL:
• common
• Vulvo-vaginitis; irritation, pruritis, white discharge, white lesions & soreness
•Pregnancy, AB alter flora, acidity, secretions

11. Cutaneouscandidiasis

12. INTER-DIGITAL CANDIDIASIS

13. AXILLARY CANDIDIASIS

14. Cutaneous: red, moist, vesicles
•Weakened skin:
•Trauma, burns, maceration
•Moist, warm skin: axillae, groin, inter-gluteal, infra
mammary folds
•Common in obese, diabetics
•Inter-digital of fingers/toes; water immersion washer-
men, veges/fish handlers, masons
Nails: Onychomycosis; painful, erythematous swelling of
nail-fold

15. ORAL THRUSH: ONYCHOMYCOSIS

16. CHRONIC MUCO-CUTANEOUS
•Early childhood
•Cellular immuno-deficiency
•Endocrinopathies
•Superficial disfiguring infections of all areas of
skin/ mucosa

17. Post therapy
•Post operative immuno-suppression
•Instrumentation: I/V catheters
• urinary catheters
•Drugs: anti- biotics{ broad-spectrum}
• cytotoxic
• cortico-steroids
•Cross-infections in ICUs

18. SYSTEMIC CANDIDOSIS
•More yeast in Mouth &GIT
•Predisposed individuals
1. anti-biotic, steroid therapy
2. immuno-suppressed
3. organ transplant recipients
4.age: infancy, old, pregnancy, AB therapy
5. bed-ridden with trauma occluding lesions
•Immuno-suppression
•DM, DEFICIENCY; IRON, ZINC

19. CLINICAL FORMS
INVASIVE:
•Candidemia: initial stage. Transient if phagocytic
system intact
•Disseminated, hematogenous candidiasis
If phagocytic system compromised
•Multi organs involved with infection: kidney,
prosthetic heart valves, brain, eye, meninges
•Mortality: 30-40%

22. DIAGNOSIS
SAMPLES:
1. Swabs & scrapings from superficial
Skin/ mucosa lesions
2. blood,
3. CSF or peritoneal fluid
4. Tissue biopsies of organs
5. Urine
6. Exudate/materials from catheters

23. MICROSCOPY
1. Gram Stain:
Centrifuged deposit, tissue biopsies
2.KOH Mount: skin & nail
3. Calcofluor stain

24. CULTURE & ID of C albicans
•Grow at 370 C or room temperature
•Colonies: soft, cream-colour & yeasty odor
•Sub-merged growth: pseudo-hyphae
Germ-tube test:
•incubate in serum for 90 minute at 370 C
•True hyphae; germ tube formed
Nutritionally deficient media: large,spherical
chlamydiospores

25. Yeast/pseudohyphae/hyphae

26. C albicans: Yeast; germ tube

27. Candida; yeast;psedohyphae

28. CHLAMYDIOSPORES C albicans corn-meal
agar

29. GRAM STAIN; CANDIDA YEAST

31. interpretation
•Sterile sites:
Positive cultures significant
•Urine: quantitative weigh out sample integrity
Foleys catheter: false positive
•Blood: transient candidaemia
systemic candidiasis
contaminated i/v catheters
•Sputum? No value ; oral flora
•Skin: culture confirmatory

32. C albicans
•2 sero-types by use of anti-sera
•A & B
•Anti bodies: life long exposure; so +
•Ag detection: cell wall mannan by latex, EIA
• Beta glucan in cell wall is promising
•Immunity:
Muco-cutaneous: CD4 cells
Systemic: Neutrophils

33. TREATMENT
Thrush & muco-cutaneous:
•Topical nystatin
•Oral ketoconazole
•Fluconazole
SYSTEMIC:
Amphotericin B
Oral fluconazole
Prevention: remove moisture, drugs,
Chronic muco-cutaneous: oral ketoconazole; lifelong

34. CRYPTOCOCCUS NEOFORMANS
•C neoformans: pigeon droppings; enrich & resevoir;
birds not effected
•C gatti: tropical trees
•Basidiomycetous yeasts with Large capsules
•Cryptococcosis
•Inhalation of spores, yeast
•Lungs---CNS cause meningo-encephlitis
•Skin, eyes, prostate

35. Susceptibility to C neoformans
•HIV/AIDS
•Hematogeous malignancies
•Immunosuppressive conditions
C gattii: affects normal host

36. MORPHOLOGY
•Microscopy: sperical budding yeast; 5-10um
diameter
•Surrounded by thick non staining capsule
•CULTURE:
•White mucoid colonies in 2-3 days
•UREASE: in all species
•Pathogenic: grow at 370C
• produce laccase; a phenol oxidase

37. VIRULENCE
•CAPSULE
•LACCASE: ake melanin from phenols substrate
Capsular Serotypes: 5
•C neoformans: A-D & AD
•C gattii: B &C
•Capsule: soluble in body fluids
•Detect: latex agglutination with coated AB
• EIA

38. PATHOGENESIS
•Inhalation of yeast cells:
dry, minimum capsule, aerosolized
Primary pulmonary infection:
Asymptomatic
Influenza-like
Resolve spontaneously
Immuno-compromized: multiply, disseminate to
CNS…..meningo-encephlitis, skin, adrenals, Bone,prostate

40. CLINICAL FINDINGS
•Chronic meningitis
•D/D : Brain tumor,
• brain abscess,
• degenerative CNS disease
• mycobacterial meningitis
• fungal meningitis
CSF: Increased pressure, proteins cells
Glucose; normal or low

41. COURSE
•Fluctuant
•Fatal: untreated
•AIDS: 5-8% cases have cryptococcal infection
•NO transmission to contacts
•Inflammatory response: minimal…
granulomatous

42. DIAGNOSIS
•SPECIMEN:
•Csf: centrifuge
•Tissue
•Exudate
•Sputum
•Blood
•Urine
•Cutaneous scrapings

43. MICROSCOPY
•WET MOUNT:
•Direct
•India ink: to delineate capsule
•CULTURE:
•Grow in most media at 37 0 C
•Do not use cyclohexamide
•Urease positive
•Diphenolic substrate: melanin in cell wall ; brown

44. CULTURE C neoformans

49. • capsular Ag detected: CSF & serum
•Latex agglutination:
• 90% positive in meningitis
•Especially high titres in AIDS.
•Other conditions titres drop with T/M

50. TREATMENT
Combination therapy: curative
•Amphotericin B
•Flucytosine
•AIDS:
Relapse on withdrawl of Amphotericin
Flucanazole: suppresses: excellent penetration of CNS
HAART: better prognosis; less cryptococcosis incident