MICROBIOLOGY- Mycology Flashcards
Which fungus can cause systemic mycoses?
Histoplasmosis Blastomycosis Coccidiodomycosis Paracoccidiodomycosis
What can all the systemic mycoses cause?
Pneumonia and can diseminate
Which forms do all fungus that cause systemic mycoses can have?
All dimorphic fungi: Mold and yeast
Which is the only exception of dimorphic fungi in systemic mycoses?
Coccidiodomycosis, which is spherule (not yeast) in tissue
When do the fungus of systemic mycoses stays in its mold form and when in its yeast form?
Cold (20ºC)= mold Heat (37ºC)= yeast
Which is the treatment for local infection of Mycoses?
Fluconazole or itrazonazole
This is the treatment for systemic mycoses
Amphotericin B
Which disease can systemic mycoses mimic?
TB (granuloma formation)
Which is the difference of systemic mycoses and TB?
Unlike TB, mycoses have no person to person transmission
Which places are endemic of Histoplasmosis?
Mississippi and Ohio River valleys
How is Histoplasmosis seen in the microscope?
Macrophage filled with Histoplasma (smaller than RBC)
How is transmitted histoplasmosis?
Birds and Bats drooppings
Patient with pneumonia, this is what we see in the microscope
Macrophage filled with Histoplasma
Where is more common this pathogen?
It is Broad base budding of Blastomycosis (same size as RBC)
States of Mississipi River and Central America
Which could be the complications of Blastomycosis?
Causes inflammatory lung disease and can disseminate to skin and bone
Clinically how do we identify Blastomycosis?
Forms granulomatous nodules
Which could be the complications of this pathogen?
Coccidioidomycosis spherule (much larger than RBC) filled with endospores
Causes pneumonia and meningitis
Can diseminate to bone and skin
Which other names does Coccidoidomycosis receives?
San Joaquin Valley fever
Where is endemic Coccidiodomycosis?
Southwestern United States and California
When is increase the case rate of Coccidiodomycosis?
After earthquakes (spores dust are thrown up in the air and become spherules in lungs)
What can desert bumps caused by Coccidiodomycosis produce?
Erythema nodosum
Which are the clynical symptoms caused by “Desert rheumatism” caused by Coccidiodomycosis?
Arthralgias
What do you suspect after seeing this pathogen?
Paracoccidioidomycosis
Budding yeast with “captains wheel” formation (much larger than RBC)
Where is more common paracoccidioidomycosis?
Latin America
Which are examples of cutaneous mycoses?
Tinea versicolor
Other Tineae
Which is the microorganisms that causes Tinea versicolor?
Caused by Malassezia furfur
Which is the clinical findings in Tinea versicolor?
Hypopigmented and/or hyperpigmented patches
What is affected in Tenia versicolor?
Degradation of lipids produces acid that damage melanocytes
Which weather conditions are necessary for Malassezia furfur?
Occurs in hot, humid weather
What is seen in this microscopy?
Malassezia Furfur. Spaghetti and meatball appearance
Which is the medical treatment given to Tinea versicolor?
Topical miconazole, selenium sulfide (Selsun)
Name the other tinea
Tinea pedis (foot)
Tinea cruris (groin)
Tinea corporis (ringworm, on body)
Tinea capitis (head, scalp)
Tinea Unguium (onychomycosis, on fingernails)
Who are consider dermatophytes?
Microsporum
Trichophyton
Epidermophyton
Which is the clinica of dermatophytes?
Pruritic lesions with central clearing resembling a ring
Which lab can help to see the dermatophytes?
See mold hypae in KOH prep, not dimorphic
Which are consider oportunistic fungal infectios?
Candida albicans
Aspergillus fumugatus
Cryptococcus neoformans
Mucor and rizopus spp
Pneumocystis jirovecci
Sporothrix schenckii
How is cataloged Candida albicans?
Systemic or superficial fungal infection
Dimorphic yeast
Pseudohyphae and budding yeast at 20º C
Which are the clinical manifestations of Candida albicans?
Oral and esophageal thrush in immunocompromised
Vulvovaginitis
Diaper rash
Endocarditis in IV drug users
Diseminated candidiasis
Chronic mucocutaneous candidiasis
Who are at higher risk of Oral and esophageal trush by Candida albicans?
Immunocompromised
Neonates, steroids, diabetes, AIDS
Which patients are at higher risk of vulvovaginitis infection by Candida albicans?
Diabetic and Antibiotics
Which is the treatment for vaginal candidiasis?
Topical azole
Which is the treatment of esophageal or oral candidiasis?
Fluconazole
Caspofungin
In case of systemic candidiasis, which is the treatment?
Fluconazole
Amphotericin B
Caspofungin
What do you suspect if you see this microorganism?
Pseudohyphae
Candida Albicans
Who are at higher risk for invasive aspergilosis?
Immunocompromissed and those with chronic granulomatous disease
Which could be the clinical manifestations of Aspergillus fumigatus?
Allergic bronchopulmonary aspergillosis (ABPA)
Which diseases are associated to Allergic bronchopulmonary aspergillosis?
Asthma and cystic fibrosis
If associated with asthma and cystic fibrosis, What can Allergic bronchopulmonary aspergillosis cause?
Bronchiectasis and eosinophilia
When are more common the Aspergillomas in lungs cavities?
After TB infection
Who produces Aflatoxins?
Aspergillus fumigatus
Aflatoxins produced by Aspergillus are associated to…
Hepatocellular carcinoma
Is Aspergillus a dimorphic fungus?
NO
What is seen in the microscope?
Septate hyphae that brancj at 45º angle
Aspergillus fumigatus
What do you suspect after seeing this in the microscope?
Conidiophore with radiating chain of spores
Aspergillus fumigatus
How do you classify Cryptococcus neoformans?
Heavily encapsulated yeast. Not dimorphic
Which diseases are caused by Cryptococcus neoformans?
Cryptococcal meningitis
Cryptococcosis
Where is foun cryptococcus neoformans?
Found in soil
Pigeon droppings
How is adquired and which is the progress of Cryptococcus neoformans?
Acquired through inhalation with hematogenous dissemination to meninges
Which is the special culture for Cryptococcus neoformans?
Sabouraud agar
Which stains help for Cryptococcus neoformans?
Stains with India ink and mucicarmine
Which test is more specific for Cryptococcus neoformans?
Latex agglutination test
What does the latex agglutination test detects of Cryptococcus neoformans?
Polysaccharide capsular antigen
Which kind of lesions can Crypococcus neoformans cause in the brain?
Soap bubble lesions in brain
Is this fungus consider dimorphic
No, it isn´t dimorphic
5-10 m yest with wide capsular halos and unequal budding in india ink stain
Cryptococcus neoformans
Which disease can Mucor and Rhizopus cause?
Mucormycosis
Which patiens are at higher risk for mucormycosis?
Ketoacidotic diabetic and leukemic patients
What happens to the mucor and rhizopus when there is excess ketone and glucose?
Fungi proliferate in blood vessel walls, penetrate cribiform plate and enter brain
Once penetrated the cribiform plate by Mucormycosis, what can we see?
Rhinocerebral, frontal lobe abscesses
Which are the clinicial findings of Mucormycosis?
Headache
Facial pain
Black necrotic eschar on face
Cranial nerve involvement
This is the treatment for Mucormycosis
Amphotericin B
Describe what you see in this image
Irregular broad nonseptate hyphar branching at wide angles
Which stain is used for this fungus?
Methenamina silver stain of lung tissue
Disc shaped forms
Pneumocystis jirovecii
Which disease can pneumocystis jirovecii causes?
Pneumocystis pneumonia
Which pneumonia can pneumocystis jirovecii cause?
A diffuse interstitial pneumonia
How do you classify pneumocystis jirovecii?
Yeast (originally classified as protozoan)
Who is pneumocystis jirovecii adquired?
Inhalation
Which symptoms can pneumocystis jirovecii causes?
Most infections asymptomatic
Which patients are predisposed to have Pneumocystis pneumonia?
Immunosuppresed (AIDS)
Which apperance does Pneumocystis pneumonia has in CXR?
Diffuse bilateral apperance
Who is diagnosed Pneumocystus jirovecci?
By lung biopsy or lavage
Which treatment is given to Pneumocystis jirovecii infection?
TMP-SMX, pentamidine
Which is the selected prophylaxis treatment for Pneumocystis jirovecii?
Dapsone
Atovaquone
When is administer the prophylaxis treatmet for Pneumocystis jirovecii?
Start when CD4 count drops <200 cells / mm3 in HIV patients
Which disease can this fungus cause?
Sporothichosis
cigar shaped budding yeast
Sporothrix schenckii
Where does sporothrix schenckii lives?
Vegetation
Is sporothrix schenckii a dimorphic fungus?
Yes
How is adquired sporothrix schenckii?
Traumatically introduced into the skin, typically by a thorn
What is the Rose gardener´s disease?
When sporothrix schenckii are traumatically introduced into the skin typically by a thorn
Afer sporothrix schenckii is introduce through the skin what happens next?
Causes local pustule or ulcer with nodules along draining lymphatics (ascending lymphangitis)
Which is the treatment for sporothrix schenckii?
Itraconazole of potassium iodide
