Path Lab 5,6 - Fungal Infections

Front 1

Why do molds generally have an irregular border ?

Back 1

Branching of hyphae results in intertwining mass of strands

Front 2

Do microconidia evolve in macro ?

Back 2

No

Front 3

What element is essentially required for the formation of fruiting heads ?

Back 3

Oxygen

Front 4

Does Rhizopus have a sporangium ?

Back 4

Yes

Front 5

Where are histoplasma capsulatam usually found ?

Back 5

Intracellularly

Front 6

Which type of conidia are more resistant to environmental change ?

Back 6

Macroconidia

Front 7

What two fungi produce fruiting heads ?

Back 7

Penicillin and Aspergillus. They are both molds

Front 8

Characteristic features of Zygomycetes ?

Back 8

Broad thick, ribbon like hyphae

Front 9

Characteristic feature of yeast ?

Back 9

Thick cellular wall

Front 10

Characteristic feature of Curvularia ?

Back 10

Macroconidia

Front 11

Features of tinea versicolor

Back 11

Superficial mycoses, chronic, asymptomatic

Front 12

What organism causes tinea versicolor ?

Back 12

Malassezia fur fur

Front 13

What is chromomycosis ?

Back 13

Infection of the skin and soft tissue caused by fungi that produce characteristic pigment. Produces an exhophytic warty lesion that resembles a squamous cell carcinoma

Front 14

What are the characteristics of actinomycosis ?

Back 14

They are filamentous bacteria that cause Madura foot. They are gram positive bacteria. Their filaments are much thinner than fungi, and they shouldn’t be confused with the latter

Front 15

What are the classical symptoms of brain infection/meningitis ?

Back 15

Seizure
Stiff neck and Fever

Front 16

What does cryptococcus most commonly infect ?

Back 16

Lung and CNS, however it presents exclusively as an opportunistic infection in the Brain

Front 17

Why does cryptococcus meningitis not elicit an immune response ?

Back 17

Since it occurs most commonly as an opportunistic infection in the Brain

Front 18

Which fungi are capable of invading and destroying blood vessels resulting in thrombosis and subsequent infarction ?

Back 18

Rhizopus, Mucor and Aspergillus

Front 19

Source of Infection
Predisposing condition
Usual site of infection
Pathological Reaction

Back 19

Possible sources of infection were esophagus and urinary bladder. The predisposing conditions would be either immunosuppression or the catherization, which would have promotoed colonization in the skin. Primary infection of the lung with candidiasis is rare, and most pulmonary cases result from hematogenous spread

Front 20

Systemic mycoses

Front 21

Opportunistic infections

Front 22

Fungus ball

Back 22

When a preexisting lung cavity is subsequently occupied by aspergillus it forms a fungus ball

Front 23

Systemic Candidiasis

Back 23

Source – Endogenous flora in skin, oropharynx, GI tract or vagina
Predisposing conditions – indwelling catheters, drug abuse and cardiac surgery. Some infections are secondary to parenteral nutrition administration and antibiotics
Common sites for hematogenous disseminated candidiasis are heart, lung and kidney

Front 24

Most common form of fungal endocarditis

Back 24

Candidiasis

Front 25

Aspergillus

Back 25

45 degree branching angle filamentous organism without thick ribbon like filaments present

Front 26

Where is aspergillus found ? Is it dangerous ?

Back 26

It is found in the soil, leaves, hay and plants. It is usually not causing disease

Front 27

Who is susceptible to aspergillosis ?

Back 27

People with a suppressed immmune system or debilitated individuals or those with a chronic disease

Front 28

Where are the primary lesions in aspergillosis ?

Back 28

Lung

Front 29

Most common aspergillus pathogen ?

Back 29

Aspergillus Fumigatus

Front 30

Is there tissue invasion in an aspergillus fungus ball ?

Back 30

Noooo, they just lay there , free in the pulmonary cavity

Front 31

Are disseminations of aspergillomas common ?

Back 31

No! They are usually rare even in immunosuppressed patients

Front 32

What is SAME for all fungi ?

Back 32

Predisposing factors

Front 33

In which two cases can a fungal infection be diagnosed from tissue morphology alone ?

Back 33

Histoplasmosa infection – due to it being found inside macrophage w/ silver stain. Another case is cryptococcus which can be identified from a mucicarmine positive capsule

Front 34

How does histoplasma exist in nature ?

Back 34

It exists as spores in the soil

Front 35

How does histoplasma exist in the human body ?

Back 35

It exists in the yeast form and is confined to the lung with CMI. It replicates in the non activated macrophages and develops into a disseminated disease when immunosuppressed. This can involve granulomas in the lung with Langerhan cells which are numerous white lesions present in the lung parenchyma

Front 36

Where would you have to be to commonly see H. Capsulatam infections ?

Back 36

Geographic distribution centers in the central US along the Mississippi and Ohio rivers and Appalachian Mountains.

Front 37

Which is the most common endemic mycosis in the US ?

Back 37

Histoplasmosis

Front 38

Where would you have to be to commonly see blastomycosis infections ?

Back 38

most commonly in the southeastern United States and around the Great Lakes and the Ohio and Mississippi rivers

Front 39

What is the source and pathology related to blastomycosis ?

Back 39

Same as Histoplasma, blastomycosis dermatidies exists as a dimporphic fungus in the soil as spores.
These spores when inhaled germinate as yeast producing a suppurative or granulamatous PNEUMONIA

Front 40

What are the histological characteristics of blastomycosis ?

Back 40

Thick walled unicellular organisms with broad based budding

Front 41

Can blastomycosis occur as the primary infection of the skin ?

Back 41

Yes cutaneous blastomycosis is found on exposed body surfaces

Front 42

What are the histological characteristics of blastomycosis at room temperature ?

Back 42

That of mold. Septated hyphae with microconidia

Front 43

What is the most common cause of fungal esophagitis and where is it obtained from ?

Back 43

Candida from endogenous flora ?

Front 44

Which of the following occur in immunocompetent people ? Disseminated histoplasmosis,dermatophytosis,aspergillosis,systemic candidiasis,cryptococcosis

Back 44

Answer –dermatophytoses

Front 45

What organism can cause thrombophlebitis ?

Back 45

Candida