MYCOSIS

OPPORTUNISTIC

MYCOSIS

• Superficial• Cutaneous• Sub-cutaneous• Systemic• Opportunistic:

COMMON OPPORTUNISTIC MYCOSIS

ENDOGENOUS• CANDIDA• PNEUMOCYSTITIS CARRINIEXOGENOUS• ASPERGILLUS• CRYPTOCOCCUS• Zygomycetes MUCOR

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

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

Candida types

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

MORPHOLOGYDIMORPHIC

1.Oval, spherical budding yeast; 3-6um2.Pseudo-hyphae; buds grow; fail to detachChains of elongated cells; pinched at septations

between cells3.Occasional true, septate hyphae• MEDIA: Sabouraud’s Glucose Agar• Nutritionally deficient media• In vivo: all 3 forms seen as mixture

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

ORAL THRUSH

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

Cutaneouscandidiasis

INTER-DIGITAL CANDIDIASIS

AXILLARY CANDIDIASIS

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, masonsNails: Onychomycosis; painful, erythematous

swelling of nail-fold

ORAL THRUSH: ONYCHOMYCOSIS

CHRONIC MUCO-CUTANEOUS

• Early childhood• Cellular immuno-deficiency• Endocrinopathies• Superficial disfiguring infections of all areas of

skin/ mucosa

Post therapy

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

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

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%

DIAGNOSIS

SAMPLES: 1. Swabs & scrapings from superficial Skin/ mucosa lesions2. blood, 3. CSF or peritoneal fluid4. Tissue biopsies of organs5. Urine6. Exudate/materials from catheters

MICROSCOPY

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

CULTURE & ID of C albicans

• Grow at 370 C or room temperature• Colonies: soft, cream-colour & yeasty odor• Sub-merged growth: pseudo-hyphaeGerm-tube test: • incubate in serum for 90 minute at 370 C• True hyphae; germ tube formedNutritionally deficient media: large,spherical

chlamydiospores

Yeast/pseudohyphae/hyphae

C albicans: Yeast; germ tube

Candida; yeast;psedohyphae

CHLAMYDIOSPORES C albicans corn-meal agar

GRAM STAIN; CANDIDA YEAST

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

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

TREATMENT

Thrush & muco-cutaneous:• Topical nystatin• Oral ketoconazole• FluconazoleSYSTEMIC:Amphotericin B Oral fluconazolePrevention: remove moisture, drugs,Chronic muco-cutaneous: oral ketoconazole; lifelong

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

Susceptibility to C neoformans

• HIV/AIDS• Hematogeous malignancies• Immunosuppressive conditions C gattii: affects normal host

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

VIRULENCE

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

PATHOGENESIS

• Inhalation of yeast cells: dry, minimum capsule, aerosolizedPrimary pulmonary infection: AsymptomaticInfluenza-likeResolve spontaneouslyImmuno-compromized: multiply, disseminate to

CNS…..meningo-encephlitis, skin, adrenals, Bone,prostate

CLINICAL FINDINGS

• Chronic meningitis• D/D : Brain tumor, • brain abscess, • degenerative CNS disease• mycobacterial meningitis• fungal meningitisCSF: Increased pressure, proteins cellsGlucose; normal or low

COURSE

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

granulomatous

DIAGNOSIS

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

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

CULTURE C neoformans

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

TREATMENT

Combination therapy: curative• Amphotericin B• Flucytosine• AIDS: Relapse on withdrawl of AmphotericinFlucanazole: suppresses: excellent penetration of

CNSHAART: better prognosis; less cryptococcosis

incident