Mycosis: Any fungal disease. Tend to be chronic because fungi grow slowly. Mycoses are classified into the following categories: I. Systemic mycoses: Fungal infections deep within the body. Can affect a number if tissues and organs. uUsually caused by fungi that live in the soil and are inhaled. Not contagious. uExamples: – Histoplasmosis (Histoplasma capsulatum): Initial infection in lungs. Later spreads through blood to most organs. – Coccidiomycosis (Coccidioides immites): Resembles tuberculosis.
COCCIDIOIDES IMMITIS Disease: Coccidioidomycosis. Reservior: desert areas of western US and Northern Mexico. Transmission: Respiratory Morphology: Dimorphic fungus * mycelia forms with spores at 25°celsius. * yeast forms at 37° Celsius
Disease: Coccidioidomycosis. * asymptomatic( in most patients) *pnuemonia * disseminated: can affect the lungs, bones, skin and meninges. A small percentage of individuals with this infection will develop painful erythematous nodular lesions called ERYTHEMA NODOSUM
DIAGNOSIS BIOPSY OF AFFECTED TISSUE SEROLOGY SKIN TEST( TEST FOR EXPOSURE ONLY) TREATMENT AMPHOTERICIN B
HISTOPLASMA CAPSULATUM RESERVIOUR: MISSISSIPI VALLLEY PRESENT IN BIRDS AND BAT DROPPINGS TRANSMISSION: RESPIRATORY MORPHOLOGY: H capsulatum is a dimorphic fungus that exists as a mold in soil and as a yeast in tissue
HISTOPLASMA CAPSULATUM Disease: histoplasmosis. ASYMPTOMATIC *PNEUMONIA *DISSEMINATED: CAN OCCUR IN ANY ORGAN, ESPECIALLY IN THE LUNG,LIVER OR SPLEEN.
DIAGNOSIS DIAGNOSIS: LUNG BIOPSY SEROLOGY SKIN TEST TREATMENT: ITRACONAZOLE
BLASTOMYCES Disease: blastomycosis * ASYMPTOMATIC *PNEUMONIA *DISSEMINATED(MOST COMMON): PRESENT WITH WEIGHT LOSS, NIGHT SWEATS, LUNG INVOLVEMENTS AND SKIN ULCERS * CUTANEOUS: SKIN ULCERS
Skin lesion following dissemination from the lungs.
DIAGNOSIS BIOPSY OF AFFECTED TISSUE SEROLOGY SKIN TEST( TEST FOR EXPOSURE ONLY) TREATMENT:Itraconazole is the drug of choice for most patients. Amphotericin B should be used to treat severe disease. Surgical excision may be helpful. Prevention: There are no means of prevention.
PARACOCCIDIOIDES BRASILIENSIS Disease: paracoccidioidomycosis P brasiliensis is a dimorphic fungus that exists as a mold in soil and as a yeast in tissue. The yeast is thick-walled with multiple buds (pilot wheel), in contrast to B. dermatitidis, which has a single bud
Transmission: Inhalation of airborne asexual spores. Pathogenesis: The spores are inhaled, and early lesions occur in the lungs. Asymptomatic infection is common. Alternatively, oral mucous membrane lesions, lymph node enlargement, and sometimes dissemination to many organs develop. Laboratory Diagnosis: In pus or tissues, yeast cells with multiple buds (pilot’s wheel) are seen microscopically. A specimen cultured for 2—4 weeks may grow typical organisms. Skin tests are rarely helpful. Serologic testing shows that when significant antibody titers (by immunodiffusion or complement fixation) are found, active disease is present. Treatment: The drug of choice is itraconazole taken orally for several months. Prevention: There are no means of prevention.
CRYPTOCOCCUS NEOFORMANS RESERVIOR: FOUND IN PIGEON DROPPINS TRANSMISSION: RESPIRATORY MORPHOLOGY: Oval, budding yeast surrounded by a wide polysaccharide capsule. Not dimorphic.
DISEASE: Disease: Cryptococcosis, especially cryptococcal meningitis. * SUBACUTE OR CHRONIC MENINNGITIS HEADACHE FEVER VOMITING NEUROLOGICAL OR MENTAL STATUS CHANGES *PNEUMONIA *SKIN LESIONS: LOOK LIKE ACNE
DIAGNOSIS * INDIA- INK STAIN OF CSF: OBSERVE ENCAPSULATED YEAST *CRYTOCOCCAL ANTIGEN TEST OF CSF DETECTS POLYSACCHARIDE ANTIGENS *FUNGAL CULTURE
CUTANEOUS MYCOSES Dermatophytes Diseases: Dermatophytoses Dermatophytes: are classified in three genera: Epidermophyton, Trichophyton, and Microsporum.
FUNGAL DISEASES (Continued) II. Cutaneous mycoses: Fungal infections of the skin, hair, and nails. uSecrete keratinase, an enzyme that degrades keratin. uInfection is transmitted by direct contact or contact with infected hair (hair salon) or cells (nail files, shower floors).
RESERVIOR: DEPENDING ON THE PARTICULAR SPECIES 1. SOIL 2. ANIMALS 3. HUMANS
Dermatophytoses (Tinea- Ringworm ) Characteristics: caused by fungi that infect only superficial keratinized structures (skin, hair, and nails), not deeper tissues. Transmission: spread from infected persons by direct contact. Microsporum is also spread from animals such as dogs and cats. This indicates that to prevent reinfection, the animal must be treated also. Pathogenesis: Dermatophytoses (tinea, ringworm) are chronic infections favored by heat and humidity, eg, athlete’s foot, moist skin and jock itch. Are characterized by broken hairs, and thickened, broken nails.
DIAGNOSIS 10% KOH on a glass slide show hyphae under microscopy. Tinea capitis lesions caused by Microsporum species can be detected by seeing fluorescence when the lesions are exposed to ultraviolet light from a Wood’s lamp. TREATMENT: TOPICAL IMIDAZOLE ORAL GRISEOFULVIN FOR TINEA UNGUIUM
SUBCUTANEOUS MYCOSES. Fungal infections beneath the skin. uCaused by saprophytic fungi that live in soil or on vegetation. uInfection occurs by implantation of spores or mycelial fragments into a skin wound. uCan spread to lymph vessels.
SUBCUTANEOUS MYCOSES Sporothrix schenckii These are caused by fungi that grow in soil and on vegetation and are introduced into subcutaneous tissue through trauma.
Sporothrix schenckii Diseases: Sporotrichosis Characteristics: Sporothrix schenckii is a dimorphic fungus that lives on vegetation. Trauma to the skin, typically by a thorn. Pathogenesis: local pustule or ulcer with nodules along the draining lymphatics Laboratory Diagnosis: round or cigar-shaped budding yeasts are seen in tissue specimens. In culture, hyphae occur bearing oval conidia. Treatment: with itraconazole. Prevention: protecting skin when touching plants, moss, and
SUPERFICIAL TINA VERSICOLOR (Malssenzia furfur) MORPHOLOGY : SPAGHETTI AND MEAT BALLS CLINICAL : HYPO OR HYPERPIGMENTED PATCHES ON THE SKIN; SURROUNDING SKIN DARKENS WITH SUNLIGHT WHILE THE PATCHES REMAIN WHITE
OPPORTUNISTIC MYCOSES Opportunistic mycoses: Caused by organisms that are generally harmless unless individual has weakened defenses: – AIDS and cancer patients – Individuals treated with broad spectrum antibiotics – Very old or very young individuals (newborns). u Examples: – Aspergillosis: Inhalation of Aspergillus spores. – Yeast Infections or Candidiasis: Caused mainly by Candida albicans. Part of normal mouth, esophagus, and vaginal flora.
Mucor & Rhizopus species Disease: Mucormycosis. Characteristics:Molds with nonseptate hyphae with right angle branching. Not dimorphic. Habitat: is the soil. Transmission:Inhalation of airborne sporangiospores.
Disease: Mucormycosis 1. rhinocerebral ( associated with diabetes): starts on nasal mucosa and invades the sinus and orbit 2. pulmonary mucormycosis Diagnosis: biopsy and black nasal discharge
Aspergillus fumigatus Diseases: infections of the skin, eyes, ears and other organs; “fungus ball” in the lung and allergic bronchopulmonary aspergillosis. Exist only as mold with septate hyphae that branch at a V-shaped angle. Habitat: is the soil. Transmission:Inhalation of airborne condidia.
Clinical 1. allergic bronchopulmonary aspergillosis( shortness of breath and high fever) 2. aspergilloma( fungus ball) associated with hemoptysis(bloody cough) 3. invasive aspergilossis 4. aflatoxin consumption( produced by aspergillus flavus) can cause liver damage and liver cancer
Treatment: Corticosteroids Surgery Amphoteric b
CANDIDA ALBICANS Reserviour : normal inhabitant of the skin, mouth and gastrointestinal tract Morphology: Pseudohyphae and yeast
CLINICAL Candidiasis in a normal Host 1. oral thrush 2. vulvovaginal candidiasis 3. cutaneous *diaper rash * rash in the skin folds of obese individuals
Laboratory Diagnosis: yeasts and pseudohyphae. colonies of yeasts on Sabouraud’s agar. The yeast form produces germ tubes when incubated in serum at 37 0 C: distinguish C albicans from other candida species. Treatment: 1- Skin and mucous membrane disease can be treated with oral or topical antifungal agents such as miconazole. 2- Disseminated disease requires amphotericin B. 3- Chronic mucocutaneous candidiasis: ketoconazole. 4- The drug of choice for oropharyngeal or esophageal thrush is fluconazole Prevention:Predisposing factors should be reduced. Oral thrush can be prevented by using clotrimazole.