2. PARACOCCIDIOIDOMYCOSIS
• It is a sub-acute , acute, chronic granulomatous systemic fungal infection.
• Disease caused by thermally dimorphic fungus , Paracoccidioides.
• has two species P.brasiliensis and P.lutzii.
• It involves primarily lungs
• Subsequently disseminates to various mucosal surfaces, skin , lymph nodes,
occasionally to internal organs.
3. PARACOCCIDIOIDOMYCOSIS…
• Other names
• South American blastomycosis
• Lutz’s mycosis
• Brazilian blastomycosis
• Paracoccidioidal granuloma or
• paracoccidioidal blastomycosis
4. PARACOCCIDIOIDOMYCOSIS…
• HISTORY
• In 1908 Adolfo Lutz cultured and identified causative agent in brazil from
cervical lymph nodes of two patients.
• Lutz initially believed that he had detected Coccidioides.
• WHO officially acknowledged it as Paracoccidioidomycosis in 1971.
5. PARACOCCIDIOIDOMYCOSIS…
• MYCOLOGY
• P.brasiliensis is the etiologic agent
• It’s a thermally dimorphic fungi
• In cultures and in patients at 37oc it adopts a yeast form.
• Lower temperatures behaves as a mold that bear infectious
• The genus paracoccidioids has two species
P.brasilliensis and P. lutzii
6. PARACOCCIDIOIDOMYCOSIS…
• Yeast form( 37℃ )
• Presence of multiple budding yeast cells.
• •In vivo- in human host and experimental animals.
• In vitro- cultures are kept at 37℃.
• On suitable enriched media at 35-37℃ within 1 week yeast like colonies
grown
• Colony Morphology: soft , off- white to cream wrinkled and rough to pasty in
appearance
7. PARACOCCIDIOIDOMYCOSIS…
• Yeast cell morphology
• Round – oval, globose – pyriform
• Variable in size(3-30µm)
• Reproduce by multiple budding
• MARINER’s or PILOT WHEEL appearance
• The spherical mother cell is surrounded by multiple peripheral cells with synchronous thin
necked buds. Means daughter cell all over the surface. produce small buds of 2-10µm.
• MICKEY MOUSE appearance
• Few larger buds may present on same mother cell , giving typically mickey and mouse
appearance
• Differential diagnosis: yeast like fungi such as Candida tropicalis show multiple budding
8. PARACOCCIDIOIDOMYCOSIS…
MYCELIAL FORM
Colonies at 25oc are very slow growing and have to form heaped craters, with agar dug
out within depths of crater.
Microscopy:
• Mycelial form is characterized by hyphae measuring 1-2µm which bear single celled
conidia.
• Numerous intercalary chlamydospores, seen as globose or pyriform conidia similar to
those produced by Blastomyces dermatitidis.
• Production of conidia by mycelial form has been considered as a rare event.
9. MYCELIAL FORM
• When proper substrate and cultural conditions are provided fungus sporulates producing
various types of conidia.
• Conidia production occur after long incubation of about 3-4 weeks at RT.
• The cultures for primary isolation from clinical specimens should be incubated for at least
6 weeks before being discarded as sterile.
• The conversion of M----->Y phase is essential for definitive identification of an isolate.
• Heat shock proteins play an imp. Role in phase transition.
10. Reproduction
• Asexual state : Anamorph
• Perfect state : Teleomorph
• In sexual phase Coiled constricted hyphae and knob like structures have been
observed.
• Indication formation of young ascocarps.
• Multiple nuclei in coiled constricted hyphae – nuclear migration during mating
11. EPIDEMIOLOGY
• PCM is a systemic fungal infection with restricted endemicity to Latin America.
• Brazil accounts for largest number of cases.
• Habitat: P.brasiliensis exists as saprophyte in nature.
• Portal of entry: inhalation of conidia from the air.
• Lung being the site of primary infection.
• Hematogenous dissemination to different body sites.
12. EPIDEMIOLOGY…
• The infection acquired at an early age before puberty
• prevalence is equal in both sexes.
• Highest incidence seen in adults predominantly men age 20-50
• Predominance due to adult males engaged in agriculture.
• In female s inhibitory action displayed by estrogen on M--->Y transition
13. EPIDEMIOLOGY…
• IMMUNITY
• Host defence- cell mediated immunity.
• Reactivation of disease- immunodeficiency condition.
• The amount of alpha 1,3 glucan in the cell wall directly correlate with degree
of virulence of fungus.
14. PATHOGENESIS AND PATHOLOGY
• Organism causing disease gets converted into yeast form after taking entry into the
host.
• It’s the primary step of establishment of infection.
• Only small percentage develops clinical disease
bez of variability in host immunity
• Fungus actively phagocytosed by mononuclear cell
is frequently found in cytoplasm of giant cell.
15. PATHOGENESIS …
• In Acute form
• Progressive systemic involvement with abundance of viable fungi.
• Non specific inflammatory infiltrate
• Lack of granulomatous pattern.
• Due to depressed immune response and high levels of specific antibodies
• In Chronic Form
• Localized and systemic involvement
• Lesions present granulomatous pattern with very few fungi.
• It indicates that humoral and cellular immune response in pathogenesis and evolution
of this disease
16. CLINICAL FEATURES
• Infection ranging from asymptomatic infection to disease progress with either acute or
chronic form.
• It is mostly a chronic disease
• Acute and sub acute cases ranging from less than 15% of all
• A. paracoccidioidomycosis : Infection
infection is subclinical
Detected by skin test positivity.
Individuals with skin test positive but no clinical symptoms are under this heading
17. CLINICAL FEATURES
• B. Paracoccidioidal mycosis : disease ( based on duration)
• Disease often present as triad of pulmonary, oral, skin lesions.
• Begins with asymptomatic pneumonia
• Spread via blood stream and lymphatic system to mucocutaneous surfaces,
GIT, LNs and other organs of body.
• 2 types
18. CLINICAL FEATURES
• 1. Acute/sub acute form( juvenile types)
• Most people are in their first three decades of life.
• Usually affect young adults with high mortality rate.
• Characterized by the involvement of RE system.
• Equally present in both sexes.
• Superficial or visceral lymph node enlargement is major manifestation
• 2 subtypes
• Grave-rapid onset, poor general condition affecting LN, spleen , liver, bone marrow
• Moderate- less rapid onset ,better general condition, affecting only one system( GIT)
19. CLINICAL FEATURES…
2. CHRONIC FORM (ADULT FORM)
• Long lasting and slow onset.
• 2 sub types
• Unifocal- that affect one organ or system
• Multifocal- more than one organ or system.
• Affects males of age 30 yrs or more.
• Adult form restricted to lungs
• Starts from lung lesions– dissemination (CNS , bones etc. involved)
20. CLINICAL FEATURES…
3. Quiescent or latent form
• Depends on host and fungal factors
• BASED ON ANATOMICAL SITES
1. MUCOCUTANEOUS LESIONS
• Lesions on skin and mucous membrane are either due to direct inoculation or secondary
manifestations.
• Lesions- painful, ulcerative
• Found in- oral cavity, lips tongue, conjunctiva, eyelids, mucous membrane of body orifices
• Ulcer become granulomatous and spread over mucous membrane- mulberry like erosions
21. BASED ON ANATOMICAL SITES
2. LYMPHATIC LESIONS
• Lymphadenopathy commonly begins in cervical lymph node of one side
• Infection involves sub maxillary, preauricular, supraclavicular areas
• Lymph node enlarge and form bull neck appearance.
3. VISCERAL LESIONS
• Disseminated INF
• Fever, weight loss, triad of pulmo- mucosal- and skin lesions CNS, bones, joints eye
• paracoccidioidoma
22. LAB DIAGNOSIS
• Detailed history of travel to endemic areas and clinical examination are relevant before proceeding
for lab diagnosis.
a. DIRECT EXAMINATION
• Specimens: sputum, BAL, CSF, pus, crusts from granulomatous lesions, biopsy materials.
1. 10%KOH or CFW
• Rounded refractile yeast cells of P.brasiliensis,
• Vary in size3-30µm or more.
• Multipolar budding yeast cells seen .
2. Vinyl Adhesive tape preparation (VAT) ( scotch tape) – direct microscopy
23. LAB DIAGNOSIS…
• Immunofluorescent techniques- demonstration of yeast cell.
• For histopathological sections.
• H&E stain- fungal cell wall remain indistinct but nuclei are often delineated
and are basophilic.
• PAS
• GMS- demonstrate the morphology best as budding yeast cells.
24. LAB DIAGNOSIS…
• Granulomata investigation:
• Immunohistochemical techniques and
• Monoclonal Abs against T lymphocytes.
• In Chronic form:
• compact granulomata with epithelioid and giant cells
• Containing characteristic form of P.brasiliensis.
• In juvenile form:
• Histopathology reveals loose granulomata with necrosis and
• Large number of characteristic round thick walled multiple yeast cell.
25. FUNGAL CULTURE
• SDA with antibacterial antibiotics and actidione.
• Yeast form of growth and mycelial form of growth are slow on primary isolation
• Growth at 35-37oc: Growth within a week
• Yeast like, soft , off white to cream coloured, wrinkled and rough to pasty appearance.
• On BHI agar- colonies are butyrous and cerebriform.
• LPCB – oral or globose multiple yeast cells.
• Small buds attached with narrow neck.
• Encircling the parent.
26. FUNGAL CULTURE
• Colonies at 25℃
• Flat & wrinkled
• Leathery at first, and later on developing tufts of aerial mycelia, which eventually cover the
colony.
• The colour of mycelial colony varies from white to tan-yellowish brown reverse.
• Slide culture- used to induce sporulation.
• M- Y conversion --- BHI agar supplemented with 5% sheep blood or glutamine , takes 14
days or more.
• Exoantigen test- using Ag 1,2,&3 useful for specific ID of fungus in early stage of incubation
27. IMMUNODIAGNOSIS
• Based on skin testing and serology
• Not useful for immunocompromised patients bez of less antibody production.
1. SKIN TEST: Intradermal injection of paracoccidioidin
• Local site examined for induration
• Positive skin test- previous exposure of fungus and does not necessarily infer presence of an
active disease.
• Diadv: cross reaction with other fungal diseases.
• -ve result in immunocompromised
28. IMMUNODIAGNOSIS…
• 2. SEROLOGICAL TESTS
• Useful for diagnostic as well as prognostic indicator.
• Based on
The detection of specific Abs and
Various methods for detecting specific Ags
• Main diagnostic Ag is gp43.
29. IMMUNODIAGNOSIS…
• Tests for Ab detection
• Complement fixation, ELISA, Immunodiffusion
• Double immunodiffusion tests for circulating Abs- SN 91% & SP 100%
• No of precipitin band correlate with severity of disease
• CIE- 95% sensitivity and 100% specificity.
• Antigen Detection Tests.
• By using monoclonal Abs.
• More effective in immunocompromised patients.
• Immunoblot and EIA test detect Ags in urine specimens
30. LAB DIAGNOSIS…
• MOLECULAR DIAGNOSTIC TOOLS
• PCR assay 18 S r RNA
• MALDI-TOF
• ANIMAL PATHOGENECITY TESTS
• Mice, guinea pigs, rabbits, rats, hamsters are susceptible for inf.
31. TREATMENT
• Long term antifungal therapy about 6-12 months
• Itraconazole, fluconazole with Amphotericin B followed by sulfamethoxazole
