Opportunistic Fungal Infections Flashcards

1
Q

What is the fourth most common cause of nosocomial bloodstream infections?

A

Candida Spp

Candida albicans is the most common species isolated from clinical material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the morphology of Candida species?

A

Exist as oval yeast like forms that produce buds or blastoconidia

C. albicans forms germ tubes and terminal, thick-walled chlamydoconidia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the virulence factors of C. albicans?

A

Ability to adhere

Exhibit yeast-hyphal dimorphism

Cell surface hydrophobicity

Proteinase secretion

Phenotypic switching

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is unique about the hyphae of C. albicans?

A

Exhibit thigmotropism (sense of touch)

Allows them to grow along grooves and through pores and may aid in infiltration of epithelial surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the primary site of colonization for Candida?

A

GI tract from mouth to rectum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is oropharyngeal and oesophageal candidiases?

A

White patches on oral mucosa caused by Candida

Seen in immunocompromised patients like HIV, DM, antibiotics or steroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is Vaginal candidiases?

A

Yeast infection

Does not require immune dysfunction

Causes severe itching/burning and white like patches on the mucosal surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does the pseudomembranous type of candida infection present?

A

Raw bleeding surface when scraped

Erythematous type-flat, red, occasionally sore ares

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is Candidal Leukoplakia?

A

Non-removal white thickening of epithelium due to Candida

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is angular cheilitis?

A

Sore fissures at the corners of the mouth

Caused by Candida

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does a localized skin infection by Candida present?

A

Pruritic rash with erythematous vesiculopustular lesions

Occur in areas where skin surface is occluded and moist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is onychomycosis?

A

Chronic candidiases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the diagnostic tests for Candida albicans?

A

KOH with calcofluor white stain

Germ tube test permits exact identification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does candida look like on culture?

A

White, smooth, creamy

Unique color on chromagar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is Candida treated?

A

Mucosal and cutaneous infections - Azole creams and ointments

Systemic - Amphotericin B IV, Flucytosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the most frequent portal of entry for Aspergillus?

A

The respiratory tract

Their conidia (spore) are ubiquitous and constantly being inhaled

17
Q

How does the clinical syndrome of Aspergillosis present?

A

Allergic manifestations based on the degree of hypersensitivity to Aspergillus antigens

Asthma, pulmonary infiltrates, peripheral eosinophilia, elevated IgE

18
Q

How is aspergillus diagnosed?

A

Demonstration of the organism by both culture and examination of tissue

Immunoassays for the aspergillus galactomannan antigen in serum

19
Q

What is the therapy for aspergillus?

A

Amphotericin B or 5-flucytosine

20
Q

What is mucomycosis?

A

Diseases caused by fungi of the subphyla Mucoromycotina and Entomophothoromycotina

21
Q

How is mucomycetes spread?

A

Nosocomial spread through air-conditioning systems, especially during construction

Focal outbreaks associated with contaminated bandages

22
Q

What is the morphology of mucomycetes?

A

Seen as ribbon-like, aseptate or sparsely septate, nonpigmented hyphae

Haphazard and nonprogressive branching pattern

23
Q

How does invasive mucormycosis present?

A

Clinically similar to aspergilliosis

Organ transplants with underlying DM

24
Q

What is Rhinocerebral mucormycosis?

A

Occurs as terminal event in patient with uncontrolled diabetes

Facial pain, headache, blood-tinged nasal discharge, bulging, discolered eye

25
Q

What is the therapy for mucormycosis?

A

Amphotericin B

Treat underlying condition

26
Q

What are the etiological agents of Cryptococcosis?

A

Crytpococcus neoformans, gattii

27
Q

How is cryptococcosis acquired?

A

Inhaling aerosolized cells of C neoformans/gattii

Disseminates from the lungs to the CNS

28
Q

What is C. neoformans the most common cause of?

A

C. neoformans is the most common cause of fungal meningitis

29
Q

What patient demographic is at high risk for C. neoformans?

A

Patients with AIDS

30
Q

How does cryptococcosis present?

A

Most commonly as a CNS infection secondary to pulmonary infection

Pulmonary cryptococcosis is variable in presentation

31
Q

How is the diagnosis of cryptococcal meningitis made?

A

Detection of capsular polysaccharide antigen in serum or CSF

32
Q

How is cyrptococcal meningitis treated?

A

Amphotericin B plus flucytosine

Effective management of CNS pressure

33
Q

What is Pneumocystis Carinii Pneumonia (PCP)?

A

Often the first opportunistic infection to develop in patients with AIDS

Diffuse interstitial plasma cell pneumonia

34
Q

How is PCP diagnosed?

A

Gomori’s methenamine silver-stain

Demonstrates rounded cup shaped organism

35
Q

What is the treatment for PCP?

A

Trimethoprim-sulfamethoxazole

Pentamidine Isothionate