1 Mycologi (Dr. Umi)

By

H.RAMLAN SADELI,dr.MS,SpMK

CLINICAL MYCOLOGY

• Introduction to Mycology :

1. History, and development of mycology

2. Structure, morphology, classification and taxonomy of fungi

3. Growth and cultivation of fungi

4. Diagnostic and examination of fungal disease

• Introduction to Mycology

In modern mycology, the fungi are placed within a separate Kingdom :

1. Monera

2. Protista

3. Fungi

4. Plantae

5. Animalia

Phyllum Eumycota, the four classes of fungi in which the human pathogens are placed :

Fungi (Kingdom)Eumycota (Phylum)

Classes : ZygomycetesAscomycetes - yeastBasidiomycetes - mushroomsDeuteromycetes - asexual (anamorph)

state only

Classes :

1. Zygomycetes : is characterized by the production of large, non-septate (coenocytic) hyphae and sporangia are found everywhere, they produce diseases most often in diabetics

2. Ascomycetes : are identified by their sexual (teleomorphic) state since this state is not often seen in the laboratory, the fungi found as human pathogens usually are not identified in this class telemorph state is characterized by production of ascus (or sac) within which sexual spore are produced (ascospores)

Classes :

3. Basidiomycetes : are identified by their sexual (teleomorphic) state the teleomorphic structure is the basidium and sexual spores, basidiospores, are produced on the outside of the basidium

4. Deuteromycetes (fungi imperfecti) : no sexual state is seen are identified by the type of conidia and other asexual structures formed in culture on standard media

Structures :

1. Yeast : may bud from another mature cell or from the septal area of certain hyphal fungi

2. Hyphae : is the thread-like structure that form the cell body of most fungi may be large ang without cross-walls (septae) : non-septate or coenocytic; is found in the Zygomycetes may be thinner and produced cross-walls (septae) : septate hyphae; are formed by all other fungi

Structures :

3. Conidia : may be small (microconidia) or large (macroconidia) blastoconidia : form as buds arthroconidia : form directly from hyphal fragmentation chlamydospore : form directly from the hyphae by a rounding up and thickening of the wall

4. Sporangiospores : asexual cells developed within a sporangium produced by the Zygomycetes

5. Vesicle : is the swollen tip of a conidiophore or sporangiophore

6. Phialide : flask-shaped structure which produces phialoconidia

BASIC LABORATORY PROCEDURES

Successful isolation of a fungus causing deseases is dependent upon each of the following factors :

proper collection of specimen

proper handling and correct processing of the specimen (including the inoculation of the specimen into the appropriate culture medium and incubation at a suitable temparature

the expertise of the technologist for identifying the fungus

Collection of specimens :

1. Skin scrapings : clean the lesion of dirt or any topical medicines scrape the outer edge of the lesion with a scalple collect the scrapings in a clean container

2. Hair : remove hair from the infected site with clean forceps collect in a clean container

3. Biopsied tissue : placed in a sterile containers; add steril water or saline to keep the tissue moist do not freeze the tissue

4. Exudate or pus : should be aspirated from an unopened abscess placed in a steril tube and taken directly to the laboratory never let the specimen dry


5. Sputum :

collect sputum early in the morning as soon as the patient awakens

before collecting the sputum, the patient should brush his teeth or remove his dentures, then thoroughly rinse his mouth

ask the patient to take a deep cough and raise sputum from the lung

collect the sputum in a wide-mouthed, sterile container that can be tightly closed to prevent leakage

send the specimen directly to the laboratory


6. Blood : should be collected aseptically

placed in the culture medium at the patient’s bedside

7. Spinal fluid : collect aseptically and place into a sterile tube

do not refrigerate spinal fluid

8. Urine : collect in asterile container

take directly to the laboratory

Processing of specimens :

Specimens should be processed as soon as possible : to ensure that the infecting fungus does not die to control contaminating organism

If the specimen cannot be promtly processed, it should be refrigerated (except spinal fluid).

1. Sputum and bronchial washings : examine specimen grossly for purulent or caseous material or particles prepare smears and wet mounts and inoculate this material onto appropriate culture media


2. Spinal fluid, urine and pleural fluid : concentrate the specimen by centrifugation make a wet preparation of the sediment and inoculate the appropriate media with the remaining sediment

3. Tissue taken by surgical procedure : remove any caseous or purulent material and place onto the appropriate media & prepare wet preparation & smears cut the tissue into small pieces with sterile scissors and grind the tissue with a sterile mortar and pestle transfer the homogenized tissue to appropriate media


Direct microscopic examination :

is an essential step in diagnosing a fungal disease

often provide a rapid, tentative diagnosis (without having to wait for the culture to grow)

culture must always be made to correctly identify the fungus

most mycological specimens are examined in the fluid state (wet mount), include a KOH (or NaOH) preparation, India ink. lactophenol-cotton blue


Culture media for isolation and identification :The proper selection of isolation media is critical to obtaining a laboratory diagnosis of a fungal disease. If the wrong medium is used, the fungus causing disease may not grow.

Culture media routinely used may be divided into two main primary isolation media (non-selective or selective ---> may contain antibiotics to inhibit rapidly growing fungi) differential media; are used to identify selected genera or or species (by stimulation of characteristic growth/sporulation; or by the production of physiological reaction on these media)


Culture media for isolation and identification : the isolation medium selection depends upon :

the type of specimen (heavily contaminated, or sterile) the suspected etiological agent A non selective medium like Sabouraud dextrose agar (SDA) should be routinely used because it will support the growth of almost all the medically important fungi.However, without the addition of selective agent (such as chloramphenicol and cycloheximide) this medium is practically useless.


Temparature of incubation :

is important in the primary isolation of fungi

may be room temparature (25 - 27°C) but prefarably 30°C

can act as a selective factor (incubation at 45°C will inhibit most fungi and bacteria, but not Aspergillus fumigatus)

Processing of specimes :

Primary isolation media : non-selective : Sabouraud dextrose agar

Brain heart infusion agarBlood agar base

selective : Sabouraud dextrose agar with antibiotics )* Brain heart infusion agar or antibiotics and Blood base agar cycloheximide

)* penicillin, streptomycin or chloramphenicol

Differential media : Neger seed agar Yeast assimilation media

Sporulation media : cornmeal agar yeast extract agar potato dextrose agar Czapek agar

MYCOSES

Superficial mycosesCutaneous mycosesSubcutaneous mycosesSystemic mycoses : pathogenic

opportunistic

SUPERFICIAL MYCOSES

Disease Agent

Pityriasis versicolor Malassezia furfur

Pityriasis nigra Exophiala hortae

Black piedra Piedraia hortae

White piedra Trichosporon beigelii

PITYRIASIS VERSICOLOR = Tinea versicolor

caused by Malassezia furfur (Pityrosporum obiculare) is part of normal flora of

the skin & scalp ---> the infections may be endogenous

the organism is lipophilic, requiring lipid for growth

Pityriasis versicolor is a chronic, mild, asymptomatic infection of the stratum corneum; lesion are sharply delineated, noninflamatory & cover with furfuraceous scales

PITYRIASIS VERSICOLOR

the term versicolor is particularly appropriate, since color of the lesion varies according to the normal skin pigmentation, exposure to sunlight & severity of infection

lesion occur more often on the upper body, face, neck, arm

the reason for a change from normal flora status to a pathogenic agent are not clear

PITYRIASIS VERSICOLOR

Laboratory diagnosis :

under uv ligth (Wood’s lamp) ---> Fluoresence : yellow

wet mount of skin scales : lesion contain short typical elements & spherical cells (yeast) & this observation is virtually pathognomonic (spaghetti & meat ball appearance)

culture identification is not diagnostic (may be positive from non-infective person); but the organism can be cultured onto SDA (Sabouraud dextrose agar)

covered with olive oil

Treatment : selenium sulfide, sodium thiosulfate, miconazole; but recurrent is frequent.

SUPERFICIAL MYCOSES

PITYRIASIS NIGRA = Tinea nigra = Tinea nigra palmaris

is caused by Exophiala werneckii; a dematiaceous fungus

is a superficial, chronic & asymptomatic infection of the stratum corneum; is frequently found in the palm of the hand, characterized by brownish color which is often darker at the edge of the macule

because infection may resemble melanoma or other types of skin cancer; a diagnosis of a fungal etiology is important

skin scraping examined for fungal element, reveal pigmented hyphae

Treatment : keratolytic agent such as salicylic acid or sulfur have been used;

topical miconazol

SUPERFICIAL MYCOSIS

BLACK PIEDRA

caused by Piedraia hortae; mostly in tropical climate

infection of hair shaft (of the scalp), characterized by black, hard nodules on the hair shaft; very difficult to remove the nodules

in some area of the world, the infection may be encouraged for cosmetic purpose

diagnosed by direct examination of the hair & nodules; reveals hyphal strands are often aligt along the periphery of the mature nodules; and the center of the mass resembles organized tissue with area in which asci are produced

Treatment : by cutting the hair

SUPERFICIAL MYCOSIS

WHITE PIEDRA

caused by Trichosporon beigelii; mostly in temperate climate

infection of hair shaft (moustache; axilla; pubis); characterized by soft, light-colored nodules of the hair sharf, easily to remove

direct examination of the hair sharf reveal the mass of intertwined hyphae of the nodules; often fragmented into arthroconidia

Treatment : by cutting the hair

CUTANEUS MYCOSES

• may be dermatophytosis, caused by dermatophytes (Trichophyton, Microsporum, Epidermophyton); or candidiasis, caused by Candida sp.

Dermatophytosis :

• may involve the skin, hair, nails (parts of the body which contain keratin)

• may be acquired from animal (zoophilic), soil (geophilic), in which lesion are quite inflammatory & may heal spontaneously

• may be acquired from human (anthropophilic); usually less inflamation but may be chronic

• dermatophytosis are classified by the area of the body involved

DERMATOPHYTES

Antrophophilic Zoophilic Geophilic

E.floccosum M.canis M.gypseum

M.audouinii M.nanum M.fulvum

T.rubrum T.verrucosum T.ajelloi

T.schonleini T.equinum T.terrestre

T.tonsurans M.gallinae

T.violaceum T.mentagrophytes

T.frrugineum var mentagrophytes

T.concentricum

T.mentagrophytes var interdigitale

DERMATOPHYTOSIS

Tinea capitis (ringworm of the scalp) :

• is an infection of the skin and hair of the head

Clinical features :

• graypathes ringworm/epidemic tinea capitis

• blackdot ringworm

• kerion / zoophilic (geophilic) tinea capitis

TINEA CAPITIS

Grapatches ringworm :

• occurs in children & is anthrophilic

• is caused by M.audouinii (Europe) & M.ferrugineum (Asia)

• is usually non-inflammatory; produced gray pathes of hair; the hair shaft breakage above the scalp

• is contagious through head bands, hats and so on; can be epidemic in schools; may heal spontaneously at puberty (prapubertal tinea capitis)

• is treated with oral griseofulvin; topical fungistatic agent such as boric acid

TINEA CAPITIS

Blackdot ringworm :

• caused by T.tonsurans; occurs in adults & is a chronic infection characterized by hair breakage, leaving follicles with dark conidia (the hair shaft breakage right on the surface of the scalp);

• may be results in alopecia; usually treated with griseofulvin or ketoconazol

Kerion :

• occurs primarily in children; usually transmitted by pets; accordingly by farm animals

• is most commonly caused by M.canis or T.mentagrophytes; more inflammatory & occurs with kerion

• may results in inflammation, keloid, kerion, & alopecia

• my heal spontaneously; but usually treated with antifungal

DERMATOPHYTOSIS

TINEA FAVOSA (FAVUS)

• is caused by T.schonleini; occurs in both childrens & adults

• is a severe form, with scutula formation & permanent hairloss cause by scarring & it has a mousy odor

• is treated with griseofulfin & by removal of debris

TINEA BARBAE :

• is an acute or chronic folliculitis of the beard, neck or face

• is most commonly cause by zoophilic dematophytes (T.verrucosum; T.mentagrophytes)

• results in pustular; or dry, scally lesion; my be superinfected with bacteria; treated with griseofulvin

DERMATOPHYTOSIS

TINEA CORPORIS :

• is fungal infection of the glabrous skin; most commonly caused by T.rubrum, T.mentagrophytes & M.canis

• is characterized by annular lesion with active border & may be vesicular or pustular

• is treated with topical antifungal (tolnaftate, myconazol) or griseofulvin (systemic)

TINEA IMBRICATA

• is caused by T.concentricum; occurs on Pacific Ocean Islands & numerous countries of Asia

• is characterized by concentric ring on the skin; may cover large area of the body; the scally often overlap

• is treated by griseofulvin

DERMATOPHYTOSIS

TINEA CRURIS = Jock itch

• is an accute or chronic fungal infection of the groin

• is caused by E.floccosum, T.rubrum, T.mentagrophytes,

• has some predisposing factors such as : hyperhidrosis, obesity, diabetes, pregnancy, fluor albus, neurodermatitis

• is treated with tolnaftate, miconazol, ketoconazol

TINE APEDIS = Athlete foot

• is an acute or chronic fungal infections of the feet; most commonly caused by T.rubrum, T.mentagrophytes, E.floccosum

• may be superinfected with bacteria, which may require antibiotic treatment before tinea pedis is treated

DERMATOPHYTOSIS

TINEA PEDIS

Clinical features : Chronic intertriginous tine pedis :

• results in white mascerated tissue bet ween the toes (the most common form)

• is treated with tolnaftate or imidazole & by keeping the feet dry (by using alumunium chroride) & aerated; if infections persist, griseofulvin or ketoconazole is used.

Clinical features : chronic dry scally tinea pedis :

• results in hyperkeratotic scales on the heel, sole, or side of the feet; also known as “mocasin foot”

• is treated with hyperkeratotic agent such as whitfield ointment & griseofulvin

DERMATOPHYTOSIS

TINEA PEDIS

Clinical features : vesicular tinea pedis

• is characterized by vesicles & vesiculopustules

• permanganate or Burrow’s solution is used to open vesicle;

• dermatophytid reactions my occur;

• griseofulvin is the treatment of choice

TINEA MANUM :

• is chronic, unilateral fungal infection of the hand, caused by T.rubrum, T.mentagrophytes, E.floccosum

• is characterized by diffuse hyperkeratotic; exfoliative, vesicular;

• treatment = tinea pedis

DERMATOPHYTOSIS

TINEA UNGUIUM :

• is fungal infections of the nails caused by Dermatophytes (if the infections cause by non-dermatophytes, its called Onychomycosis)

• almost always all dermatophytes cause tinea unguium & the most resistant to treatment

• the nails becomes opaque & brittle; usually lose luster; then discolored, thickened, distorted, seperated from its bed, thinned & broken

• treatment : systemic griseofulvin, long-term (a year or more)

topical : K-permanganate 1:4000; phenol; salicylic acid 10%; iodium 1%; operative : ablatio

Tinea unguium Onychomycosis(Dermatophytes) (Candida sp.)

course of disease distal proximal proximal distal

debris + non

pain non +

thickness + non

DERMATOPHYTOSIS


• a diagnosis of fungal etiology based on morphology of individual lesion & their body locations is not always sufficient (except for tine imbricata)

• infections of skin or nails; a scraping is digested in KOH and examined for the presence of hyphal element

• the infections of the hair shatf show arthroconidia outside the shaft (ectothrix) or inside the hair shaft (endothrix)

• some species that infect hair fluorescence under Wood’s lamp

DERMATOPHYTOSIS

Laboartory diagnosis :

• species identification requires culture

• culture identification is based primarily on the appearance of the asexual reproductive conidia or the specific hyphae

• while all of these species grow as molds, they have distinctive features

• the reverse of colonies of some species may be pigmented (red, yellow) and the tops may be fluffy, velvety; white or pigmented

• this characteristics combine with the microscopic morphology generally permit an identification

SUBCUTANEUS MYCOSES

Diseases Agent

• Mycetoma pedis

Eumycetoma Pseudoallescheria boydii; Madurella sp;

Acremonium sp; Fusarium sp;

Actinomycetoma Actinomyces israeli; Nocardia sp;Streptomyces sp; Acinomadura sp;

• Chromoblastomycosis Fonseca pedrosoi; Fonseca compecta;

Cladosporium carionii; Phialophora

verrucosa

• Sporotrichosis Sporothrix schenckii

• Rhinosporidiosis Rhinosporidium seeberi

• Lobomycosis Loboa loboi

SUBCUTANEUS MYCOSES

General characteristic :

• are found worldwide; some of the infection are endemic

• several species of fungi can cause the same clinical syndrome

• the causative agent are common soil saprophytes

• the organism invade the tissue by traumatic implantation

• the course of infection is usually slow & may continue over period of years (chronic infections)

SUBCUTANEUS MYCOSES

MYCETOMA PEDIS = Madura foot = Maduromycosis

• Characterized by : swollen lesion, usually on foot or hand

suppurating abcesses & multiple sinus tracts

exudate contain sulfur granules

• Mycetoma with fungal etiologies = eumycetoma = eumycotic mycetoma

• mycetoma with bacterial etiologies = actnomycetoma

actinomycotic mycetoma

MYCETOMA PEDIS : Etiologies

Eumycetoma : Actinomycetoma :

Pseudoallescheria boydii Actinomyces israeliMadurella sp; Nocardia sp;Acremonium sp; Streptomyces sp;Fusarium sp; Actinomadura sp;……………. ………………….

MYCETOMA PEDIS


direct microscopic examination : granules obtain from the draining tissues are examined for ther gross physical characteristic microscopic examination (wet mount with KOH) reveal that bacterial filament less than 1 um; & fungi filamen (hyphae) greater than 1 um

Treatment :

eumycetoma : amphotericin B; azole compound; & nystatin topical; actinomycetoma : sulfonamide surgical excition or even amputation may indicated

SUBCUTANEUS MYCOSES

CHROMOBLASTOMYCOSIS :

• caused by dematiaceus fungi, such as : F.pendrosoi; F.compacta; C.carionii; P.verrucosa

• the organism occur in soil worldwide; the common fungi found in rotting wood & decaying vegetables

• the disease is encountered most frequently in 30-50 years old; more frequent in men than women

• after the organism introduced into the tissue (by traumatic implantation), there are some latent period (may be many years)

• the lesion begin as small, scally papules at the site of inoculation & gradually develops into : multiple nodules (cauliflower; bloom kol) or verrucous, ulcerative &crusted lesion

CHROMOBLASTOMYCOSIS :


direct microscopic examination : wet mount --> examination of tissue from lesion reveals characteristics pigmented (brown) sclerotic bodies a round, thick- walled form that have cross divisions

culture : is required to identified the etiologic agent specifically

the colonial morphology growth rate & microscopic morphology of conidial productions (sporulations) are characteristic of the species

Treatment : surgical exicition; antifungal drugs

SUBCUTANEUS MYCOSES

SPOROTRICHOSIS

• caused by Sporothrix schenckii, a dimorphic fungus, is found worldwide as inhibitant in soil & decaying vegetation

• is characterized by a lesion that begin as a movable nodule & subsequently became necrotic

• if it is untreated, new lesion appear along the lymphatic draining area (this pattern is pathocnomonic for this form of sporotrichosing)

• the infections is particularly associated with gardener --> rose gardener syndrome

SPOROTRICHOSIS

in endemic area, a non-lymphatic or “fixed” form may be seen single lesion, do not spead, often found on the face, neck or finger (occurs in hypersensitive / allergic person) another form of non-cutaneus, systemic infections is pulmonary infections; is seldom diagnosed & often found in chronic alcoholic; infections is initiated following inhalation of fungal conidia

SPOROTRICHOSIS

Laboartory diagnosis :

the appearance of the lymphatic form is very characteristic; however diagnosis requeres isolation & culture identification diagnosis requires isolation & culture identification

direct microscopic examination : material removed from such lesion can be directly examined for cigar-shaped yeast cells

stain such as calcoflour white & fluorescence antibodies may be useful

however, the number of orgnaism is often too few for releable observation and material should be submitted for fungal culture

SPOROTRICHOSIS


• the organism is thermally dimorphic; in soil or at room temperature is grows as mold with distinctive conidia that are produced in a pattern often described as a daisy head

• at 37°C the organism grows as a budding yeast (yeast colony)

• serologic method are not important indiagnosis

Treatment :

• KI (pottasium iodida), oral; topical

• amphotericin B

SUBCUTANEUS MYCOSES

RHINOSPORIDIOSIS

• is caused by Rhinosporidium seeberi; the organism may have a natural aquatic or perhaps soil habitat; & has not been cultured

• is a chronic, granulomatous infections (may persist for years) in which polyps form in the nasal or conjnuctival; occur primarily in India & Sri Langka

• in tissue, the organism a large (6-300 um), spherical sporangia (sperula) that, when mature, is filled with endospres; on lysis, these endospore then repeat the development sequence

Treatment : surgical excition

SUBCUTANEUS MYCOSES

LOBOMYCOSIS = Lobos’s disease = Keloid blastomycosis

• caused by Loboa loboi; which has not been culture

• the cases have been reported from America & mostly South America

• is chronic infection, localized in the skin & may be spread by autoinoculation; the lesion is a keloid; verrucous & ulcerated may develop over an extended period of time

• the course of infection is slow; may persist for 20-30 years; the organism appears in tissue as yeast cells in chain

Treatment : surgical excition

SYSTEMIC MYCOSIS : Pathogenic

Diseasea Agent

• Blastomycosis Blastomycoss drmatitidis

• Histoplasmosis Histoplasma capsulatum

• Coccidioidomycosis Coccidioides immitis

• Paracoccidioidomycosis Paracoccidoides brasiliansis

BLASTOMYCOSIS= Notrh American Blastomycosis= Gilchist’s disease

Etiologic agent : Blastomyces dermatitidis, a dimorphic fungus that grows as

mold at room temperature and as a yeast at 35 - 370C

Epidemiology :

• B. dermatitidis is saprophytic in nature & grows in the mold fom in soil

• or decaying wood associated with soil, has been isolated several times, but repeated isolation from the same sites were not succesful

• most of the cases have been found in Noth America, but also prevalent in Africa & has been reported in India, occurs most often in adult males

• the lack of a specific skin test antigen has prevented the determination of the prevalence of asymptomatic Blastomycosis in large population

BLASTOMYCOSIS

Cxlinical features :

• the primary site of Blastomycisis is the lung, with mild infiltrat & few clinical symptoms

• in severe disease, pulmonary infiltrate may be more extensive & the patients will have fever, cough & weight lose, nodular pulmonary lesion may occur

• some cases may progres to chronic disease with pulmonary fibrosis & the cavitation

• the fungus may disseminate to any organ of the body, mostly skin & bone

• skin lesion are frequently a manifestationof disseminated disease, with

dry & scaly, extensive granulomatous with vescle or pustule

BLASTOMYCOSISIS



• wet mount : B. dermatitidis appear asa large, thick-walled single-budding yeast ( 8 - 18 m ), the bud has a wide base

• histiphatology : the yeast form is usually easily fount in infected tissue, are best detected with PAS or GMS stain

BLASTOMYCISIS


Culture :

• is the dimorphic fungus, that grws in the mycelial form (mold) at room temperature & as a yeast at 370C

• the mold form grows slowly, became visible in 7 - 10 days, the colony is usually white & cottony

• the yeast-like colony grows on blood agar at 370C after 3 - 4 days

Microscopic morpology :

• the mold produces small, smooth walled cinidia & attached to the conidiophores that arise directly from the hyphae

• yaest are large, thick-walled, single-budding & the bud has a wide base (neck)

the diagnostic structure of B. dermatitidis

BLASTOMYCOSIS

Serology :

• ID test is the most reliable, CFT not detect antibodies in all cases, will

cross-react with antibodies to H. capsulatum

Treatment : Amphoterisin B, Ketoconazole

HISTOPLASMOSIS= reticuloendothelionsis= Darling’s disease

Etiologic agent : Histoplasma capsulatum, a dimorphic fungus, having a mold form at

room temperature & yeast form at 370C

Epidemiology :

• H. capsulatum grows in soil, especially in soil that esriched with bat or bird manure

• often be isolated from old building/caves, where birds/chickens or bats have roosted

• H. capsulatum grows in soil in the mycelial form & large number of conidia are produce

• the disease is acquired by inhaling conidia & reported from most area of the world

HISTOPLASMOSIS

Clinical features :

• is primarily a pulmonary disease; when conidia are inhaled, infections is established in the lungs; the disease may be mild, with few or no symptom (95%)

• may be severe with lung infiltrates, from mild to extensive

• primary pulmonary histoplasmosis progresses to chronic pulmonary disease in about

• 5 % of those with disease; is characterized by fibrosis & cavitation, symptoms

includes : cough, fever, chills & weight lose (resembles to toberculosis, sarcoidosis, & other systemic fungal disease)

• the most severe form of histoplasmosis is disseminated disease; the fungus invade any organs of body

HISTOPLASMOSIS


Direct microskopic examination : wet mount :

• H. capsulatum may be seen in sputum, bronchial washed, or in any body fluids as a small yeast, 4 - 6 m

• histopathology : the yeast form can be found in tissue removed from the infected sites, ussually in the macrophage & in granulomas

• GMS (gomori methenamine silver) stain should be used

( the yeat dark-brown - black )

HISTOPLASMOSIS

Culture :

• colony morphology : H. capsulatum grows slowly in the mold form when incubated at room temperature, appear in 7 - 10 days but conidia is not form until later; on SDA ( sabouraud dextrose agar ) the colony Is ussually white & cottony

• microscopic morphology :

two types of conidia are prodeced by H. capsulatum small, pyriform smoth-walled conidia (microconidia, 4 - 6m ) and large, round, thick-waled tuberculated conidia

( macroconidia, 8 - 18m ) the diagnostic conidia

• to prove the identification of H. capsulatum, convert the mold form - yeast form; be done by transferring the mold colony to blood agar & incubate at 370C in 3 - 5 days the yeast colony will be white brown

HISTOPLASMOSIS

Serology :

• antibodies to the fungus are produced within 10 - 21 days after a person is infected by H. capsulatum

• agglutination test, measures IgM antibodies, is a quantitative test

• CFT, measures both IgM & IgG, is quantitative test; ID test is a quantitative test

Treatment :

• Amphotericin B, Ketoconazole

COCCIDIOIDOMYCOSIS= valley fever

Etiologic agent : Coccidioides immitis, a biphasic fungal pathogen

Epidemiology :

• C. immitis grows in semi-acrid, solid, is known to exist in North, Central,

& South American, especially California; its inhaled into the alveoli, where it produces disease, either benign ( resembles flu ), or acute, depending on many factors ( race; incculum )

Clinical features :

• most is a benign disease, prodeces only mild symptoms; among certain races

( Filipinos, Black ), immunosupressed or the used of corticosteroids, disseminated may occur

• there is no site of predilection for this organism; any body tissue may become infected

COCCIDIOIDOMYCOSIS



• wet mount : specimens in KOH mounts, C. immitis may be seen as sporangia

( spherula ) filled with endospora

• histophatology : the sporangia stain well with HE & PAS stain

COCCIDIOIDOMYCOSIS

Culture : Never work with culture on the laboratory bench OUTSIDE of a biohazard hood !

• C. immitis is a biphasic fungal phatogen, grows at room temperature repidly producing a dirty gray-white colony; at maturity, the hyphae develops arthroconidia wich enlarged & barrel-shaped; alternate cells empty

the hyphae break easilly into separate artrhoconidia float in the air spread by the wind

Serology : used as diagnostic & prognostic tools; include CFT, latex aglutination, ID test

Treatment : Amphotericin B, Ketoconazole

PARACOCCIDIOIDOMYCOSIS= South American blastomycosis

Etiologic agent : Paracoccidioidomycosis brasiliaensis, a domorphic fungus that grows as mold at room temperature & as a yeast at 370C / in infected tissues

Epidemiology :

• the saprophytic habitat of P. brasiliensis is not known; endemic mostly in South America

• most cases of paracodioidomycosis are seen in adult males; is rare in children

& adult women; appears to reflect a host-parasite relasionship by sex hormones

PARACOCCIDIOIDOMYCOSIS

Clinical features :

• the primarily site of infection is the lung; disease may be benign, primary pulmonary form or may disseminate to produce acute & chronic, progresive disease, includes lymph nodes & skin

• the primary benign form may ultimately results with some residual interstitial fibrosis

• acute & chronic, progresive paracoccidioidomycosis, disseminated from of the disease, most prequently recognized on the basic of lesion on oropharynx & gingivae

• progresive chronic pulmonary disease may involve all lobes of the lung; produce extensive fibrosis



Direct microscipic examination :

• wet mount : appears a large, yeast-like cells ( 30 - 360 m ), budding with one or more buds ( multiple buds ) with narrow necks

• histophatology : in infected tissue appears as large cells, multiple buds, connected to the parent cell by narrow necks, it has been called a “pilot wheel“ or

“mickey mouse”



Culture :

• colony morphology : P. brasiliensis is a dimorphic fungus, grows slowly in the mycelial form at room temperature; readily convert to the yeast phase when grown at 370C on enriched media

• microscopic morphology : the mycelial form is thin, septate hyphae, conidia, chlamydospora & arthroconidia may be formed;

yeast phase cultures will demonstrate both mycelial element & yeast; the yeast are characterized by large ( 30 um or more ); multiple-thin-walled buds, with narrow necks



Serology : CFT & ID test have been shown to be reliable; however cross reactions may occur

Tretment : Ketoconazole, Amphotericin B, Sulfadiazine

SYSTEMIC MYCOSES

SYSTEMIC MYCOSIS : Opportunistic

Disease Agents

• Candidiasis Cabdida albicans; Candida sp.

• Cryptococcosis Cryptococcus neoformans

• Aspergillosis Aspergillus fumigatus; Aspergillus sp.

• Zygomycosis Mucor, Rhizopus, Absidia

SYSTEMIC MYCOSES

Pathogenic Opportunistic

• Agent dimorphic fungus non-dimorphic fungus

• Port d’entre lung (per inhalation ) lung & others

• Disease usually chronic usually acute

• Patients could be healthy patients usually ill patient

SYSTEMIC MYCOSES

CANDIDIASIS = Candidosis

• acute / chronic fungal infections, involving, the mouth, vagina, skin nails, bronchi / lung, alimentary tract, urinary tract, blood steam and less commonly, the heart or menungen

• are caused by Candida albicansor other species

• are predisposed by : extremes of age, wasting, & nutritional disease, excessive moisture, pregnancy, diabetes, long-term antibiotics, & steroid use, indwelling catheter, immunosupressed & AIDS

• are generally treated with imidazoles, polyenes or both

CANDIDIASIS

Candida albicans :

• is part of the normal flora of the skin, mucous membranes & GI tract along with other Candida sp.

• normal colonization must be distinguised from infection

• form elongated “budding forms” called pseudohyphae, which are often seen in clinical material along with true hyphae, blastoconidia & yaest cells

CANDIDIASIS

Clinical features :oral thrush :

• is a yeast infectoins of the oral mucocutaneus membranes

• manifest as white curd-like patches in the oral cavity

• occurs in premature infants; older infants beingtreated with antibiotics, immunosuppressed patients, long-term antibiotics & AIDS patients

CANDIDIASIS

Clinical features : Vulvovaginitis :

• is a yeast infection of the vagina; manifest with a thick yellow-white discharge, a burning sensation, curd-like patches on the vaginal mucosa & inflamation of perineum

• is predisposed by diabetes, antibiotic therapy, oral contraceptive use & pregnancy

• may be trasmitted to sexual partner as balanitis

CANDIDIASIS

Clinical features : Cutaneus candidiasis :

• involves the nails ( onychomycosis; paronychis ), skin folds

( intertriginosa ) or groin ( such as diaper rash )

• may be eczematoid or vesicular / pustular; is predisposed by moist condition

Clinical feature : alimetary tract disease :

• is usually an extension of oral thrush & may include esophagitis & ultimately the entire gastrintestinal tract

• is found in patients with AIDS or other immunosuppressive disorder, particularly those patients on long-term antibiotics therapy

CANDIDIASIS

Clinical feature : chronic mucocutaneus candidiasi :

• is a chronic, often disfiguring, infections of the epithelial surfaces of the body

• is diagnosed microscipically & by the lack of cell mediated immunity

Clinical feature : Bronchopulmonary infections :

• occurs in patient with chronic lung disease; its usually manifested by persistent cough

CANDIDIASIS

Clinical feature : Candidemia / blood borne infections :

• occurs most commonly in patients with indwelling catheter; these infections are manifested by fever, macronodular skin lesion & endopthalmitis

Clinical feature : Endocarditis :

• occurs in patient who have manipulated or damaged valves, or in IV drug abusers

Clinical feature : Cerebrospinal infections :

• may occur in compromised patients

CANDIDIASIS


• direct microscopic examination : wet mount of the skin / nail scraping or exudate, demonstration of the presence of pseudohyphae / hyphae, & yeast in the tissue

• culture : of the specimens on to SDA at room temperature, Candida will grows as yaest-like colony

• C. albicans be identified by :

* germ tube test -- yeast germination in serum at 370C

* culture on corn-meal-agar -- reveals chlamydospres

* culture on Eosin-methylen-blue-agar : reveals spider colony

* fermentation test of : glucose, lactose, maltose, sacharose

• serologic : high levels of Candida precipitins or antigens

SYSTEMIC MYCOSES : Opportunistic

CRIPTOCOCCOSIS

• include subacute or chronic fungal infections involving the lungs, meninges, or less commonly the skin, bones & other tissues

• most commonly occur as cryptococcal meningtis; often occuring in AIDS patients

• is caused by Cryptococcus neoformans; yeast that posseses an antigenic polysaccharidae capsule

• is associated with pigeon feces; considered to be an opportunist in the present of underlying disease in patients with Hodgkin’s disease, leukomias; or leucocyte enzyme deficiency disease

CRYPTOCOCCOSIS = Busse-Buschke’s disease = European Blastomycosis

Clinical feature :

• pulmonary infections : are ussually asymptomatic; & self resolving; most common in pigeon breeder

• meningitis ( most often ) or meningoencephalitis occurs in AIDS patients most commonly with headache, ussually with fever, followed by typical sign of meningitis

CRYPTOCOCCOSIS


• microscopic examination : wet mount, demonstration of encapsulated yeast in CSF sediment in india-ink

• detection of the capsular material in the CSF ( the cryptococcal antigen ) by latex agglutination test

• culture : in SDA ( Sabouraud dextrase agar ) revealyeast colony

Treatment : Amphotericin B, 5- fluorocytosisn or fluconazol


ASPERGILLOSIS

• caaused by Aspergillus fumigatus, an opportunistic organism

• is a ubiquitous filmentous fungus whose airborne spores are contantly in the air

• is recognized both in tissue & in culture by its characteristic septate hyphae with dichotomous branching, produced conidial heads with numerous conidia

ASPERGILLOSIS

Clinical feature : Aspergilloma = fungus ball :

• is a roughly spherical growth of Aspergillus in pre existing lung cavities & does not invade the lung tissue

• occurs clinically as reccurent hemoptysis & diagnosed by radiologig method

Treatment : surgical ( lobectomy )

ASPERGILLOSIS

Clinical features : invasive aspergillosis :

• occurs most commonly during severe neotropenic in leukemia & transplantm patients; most commonly occurs as fever of unknown origin in patient with neutropenia fewer than 500/mm3 & pneumonia

• it may begin as sinisitis or lungs; it disseminate to any part of the body, most frequently brain

• is diagnosed by microscopy & culture of lung biopsy material

• is trested with amphotericin B or intraconzole & has a high fatality rate

ASPERGILLOSIS

Clinical features : Allergic bronchopulmonary aspergillosis

• is an allergic disease, in which the organism colonies the mucous plugs form in the lung, but does not invade lung tissue

• is diagnosed by finding of high titer of IgE antibodies


ZYGOMYCOSIS = Mucormycosis + Phycomycosis

• caused by the genera Rhizopus, Mucor & Absidia; non-septate fungi; phylum Zygomycota; grow repidly & predilection for invading blood vessels & the brain

Clinical features : thoracic infectoins

• occur in leukemia & lymphoma patients

• abdominal-pelvic infections occurs in malnourish patients

• cutaneus infections occurs in patients with leukemia

ZYGOMYCOSIS

Clinical features : Rhinocerebral infections

• is the common form; occurs in patients with acidotic diabetes

• presents with facial swelling & blood tinged exudate in the turbinate bones & eyes; lethargy & fixated pupil

• is a fatal infections & spreads rapidly

• must be diagnosed rapidly; ussually by a KOH mount of necrotic tissue or exudate from the eye, nose, or ear

Treatment : control of diabetes; surgical debridement; amnphotericin B

Documents

1 Mycologi (Dr. Umi)