L23- RTI VIII Flashcards
list the common primary pathogens for fungal pneumonias / RTIs
(healthy and immuno-compromised)
- histoplasma capsulatum
- blastomyces dermatidis
- coccidioides immitis
- paracoccidioides brasiliensis
list the opportunistc pathogens for fungal pneumonias / FTIs
(immuno-compromised)
- cryptococcus neoformans
- aspergillus spp.
- pneumocystis jirovecii
Fungal RTIs are usually transmitted via (1). All infective fungi have the (2) property, allowing it to convert (3). (4) is another key factor to consider when suspecting or diagnosing a fungal RTI.
1- inhalation of spores from the environment (no person to person)
2- thermal dimorphism
3- convert from molds to yeast and back based on temperature
4- geographical relevance
Fungi:
- (1) form in environment
- (2) form in tissues
(1)/(2) is the replicative form
1- molds / mycelial form (30-33C)
2- yeasts (37C) — *replicative form
(indicate what this group represents) list the associated clinical disease for each of the following:
- (1) histoplasma capsulatum
- (2) blastomyces dermatidis
- (3) coccidioides immitis
- (4) paracoccidioides brasiliensis
(primary fungal pathogens --> affect healthy and immuno-compromised) 1- histoplasmosis 2- blastomycosis 3- coccidioidomycosis 4- paracoccidioidomycosis
indicate the fungal species represented by the following geographical areas:
- (1) Mississippi River Valley and Ohio River Valley
- (2) Southwestern USA, Northwestern Mexico
1- histoplasma capsulatum, blastomyces dermatidis
2- coccidioides immitis
Many fungal infections are commonly (1) and others will commonly mimic (2). General lung symptoms include (3) and other symptoms include (4). Although (4) are present, (5) is unusual in fungal infections
1- asymptomatic
2- Tb (or atypical pneumonias)
3- mild dry cough, progressive dyspnea, (hemoptysis- aspergillosis)
4- mild fever, weight loss, granulomatous lesions (skin / mucous membranes), Rheumatological syndromes
5- dissemination (spread into blood)
how does a fungal RTI appear on CXR
- pulmonary nodules
- hilar lymphadenopathy
- patchy infiltrates
_____ respiratory fungi is capable of growth within alveolar macrophages, explain (hint- 3 reasons)
histoplasma capsulatum:
- intracellular microbe (alveolar macrophage), although does not have a capsule
- inc phagolysosomal pH
- interferes with enzyme activity and Ag processing
uptake of _______ into fungi in the body is very important to its growth and development
Fe uptake
Fungal RTI diagnosis:
- (1) are the samples that can be taken
- fungi are placed on (2) agar and observed via (3)
- (4) is another possible diagnostic test
1- sputum, bronchoalveolar lavage, transtracheal aspirate, lung biopsy
2- Sabouraud’s agar
3- direct microscopy (large species) w/ staining (Giemsa, indirect FA stain)
4- PCR (nucleic acid probes)
(1) testing is very limited in terms of fungal RTIs because of (2). (1) is mostly used for testing for (3) infections among of the fungal RTIs, where it tests for Ig(4) from (5) samples.
1- serology
2- false positives, cross-reactions
3- coccidioidomycosis
4- IgM, IgG
5- urine, blood, CSF (Note- hypersensitivity skin tests, like PPD, can be performed)
list the 2 histoplasma capsulatum species and compare them by:
- infection type
- geographic location
- morphological features
H. capsulatum var capsulatum:
- pulmonary, disseminated infections
- eastern US, Latin America
- thinner cell walls, smaller size
H. capsulatum var duboisii:
- skin, bone lesions
- tropical Africa (African histoplasmosis)
- thicker cell walls, larger size
Histoplasma capsulatum is found in (1) in the environment, and the (2) parts can be aerolized and inhaled. (3) are some of the common locations for outbreaks.
1- high nitrogen content soil (bird/bat poop)
2- microconidia, hyphae
3- birds roost areas, caves, old buildings, construction/demolition areas
The clinical features of histoplasmosis depends on (1) and (2). Most result in (3) and a smaller portion develop (4) which can develop a (5) complication.
1- level of exposure (intensity, length of exposure)
2- immunological status
3- asymptomatic (low intensity exposure)
4- fever, cough, chest pain (high intensity exposure)
5- dissemination