SYSTEMIC OPPORTUNISTIC MYCOSES Flashcards by leah adarlo

Endogenous causes of systemic opportunistic mycoses

cancer & leukemia

How well did you know this?

Not at all

Perfectly

Exogeneous causes of systemic opportunistic mycoses

immunosuppressive therapy & AIDS

How well did you know this?

Not at all

Perfectly

HIGH RISK GROUPS FOR DEVELOPING SERIOUS FUNGAL INFECTIONS individuals undergoing

BSMI:
Blood and marrow transplant (BMT)
Solid organ transplantation
Major Surgery
Immunosuppressive therapy

How well did you know this?

Not at all

Perfectly

HIGH RISK GROUPS FOR DEVELOPING SERIOUS
FUNGAL INFECTIONS individuals WITH:

ANAP:
Acquired Immunodeficiency Syndrome (AIDS)
Neoplastic disease
Advance Age
Premature birth

How well did you know this?

Not at all

Perfectly

Most well known causes of opportunistic mycoses

Candida albicans, Cryptococcus neoformans, and
Aspergillus fumigatus.

How well did you know this?

Not at all

Perfectly

Causative agents of Candidiasis

Candida albicans (80-90%)

How well did you know this?

Not at all

Perfectly

Most important group of opportunistic fungal pathogens. 3rd most common cause of central line-associated bloodstream infections (BSI),

Candida species

How well did you know this?

Not at all

Perfectly

Ovoid or oval yeastlike form; Produce buds or blastoconidia; Produces pseudohyphae and true hyphae (except ____________) in both culture and tissue. Most form smooth, white, creamy, domed colonies

Candida species; Candida glabrata

How well did you know this?

Not at all

Perfectly

Forms germ tubes and terminal, thick-walled chlamydoconidia

C. albicans

How well did you know this?

Not at all

Perfectly

Incapable of forming pseudohyphae, germ tubes, or
true hyphae

C. glabrata

How well did you know this?

Not at all

Perfectly

Candida species stain poorly with __________?

hematoxylin & eosin (H&E)

How well did you know this?

Not at all

Perfectly

Candida species stain well with:

Periodic acid-Schiff (PAS)
Gomori methenamine silver (GMS)
Gridley fungus stain

How well did you know this?

Not at all

Perfectly

ability of C. albicans to survive in many different environmental microniches within the human host.

Phenotypic switching

How well did you know this?

Not at all

Perfectly

Primary sites of Candida species

GI tract

How well did you know this?

Not at all

Perfectly

iatrogenic, nosocomial infection. Due to impaired epithelial barrier functions

Candidiasis

How well did you know this?

Not at all

Perfectly

Thrush, glossitis, stomatitis and angular cheilitis. Mucosal infections caused by Candida spp. Usually present as white cottage cheese-like patches on
the mucosal surface.

OROPHARYNGEAL CANDIDIASIS

How well did you know this?

Not at all

Perfectly

Type of oropharyngeal candidiasis that reveals a raw bleeding surface when scraped

Pseudomembranous

How well did you know this?

Not at all

Perfectly

Type of oropharyngeal candidiasis that flat, red, occasionally sore areas

Erythematous type

How well did you know this?

Not at all

Perfectly

are non-removable white thickening of the epithelium caused by the Candida species

Candida leukoplakia

How well did you know this?

Not at all

Perfectly

sore features at the corners of the mouth

Angular cheilitis

How well did you know this?

Not at all

Perfectly

present as pruritic rash with erythematous vesiculopustular lesions in areas where the skin surface is occluded and moist, such as the groin, axilla, toe webs, and breast folds.

Cutaneous candidiasis

How well did you know this?

Not at all

Perfectly

common in infants under unhygienic conditions of chronic moisture and local skin maceration associated with amniotic irritation due to irregularly change of unclean diapers.

Diaper candidiasis

How well did you know this?

Not at all

Perfectly

A rare condition marked by deficiency in T-lymphocyte
responsiveness to Candida spp.

Chronic mucocutaneous candidiasis

How well did you know this?

Not at all

Perfectly

severe localized form which may occur with or without endocrinopathy characterized by marked hyperkeratotic granulomatous tissues.

Candida granuloma

How well did you know this?

Not at all

Perfectly

Vulvovaginal candidiasis is a common condition in women. Often associated with_____________?

use of broad-spectrum antibiotics, 3rd trimester of pregnancy, low vaginal pH, and diabetes mellitus.

associated with oral candidiasis may be a presentation of HIV infection or AIDS. with symptoms: intense vulval pruritus, burning, erythema, and dyspareunia associated with a creamy white curd-like discharge

Chronic refractory vaginal candidiasis

principal predisposing conditions for systemic candidiasis in neonates.

Low birth weight and age, prolonged intravascular catheterization, and the use of antibiotic drugs

3rd most common cause of late-onset sepsis in NICU (high risk)

neonatal candidiasis

Usually associated with AIDS and severe immunosuppression following treatment for leukemia or solid tumors with symptoms of burning pain on the substernal area, dysphagia, nausea, and vomiting

Esophageal and gastrointestinal candidiasis

Acquired either hematogenous dissemination causing a diffused pneumonia or by bronchial extensions in patients with oropharyngeal candidiasis.

Pulmonary Candidiasis

Transient asymptomatic candiduria may occur during antibiotic or corticosteroid treatment which promotes the growth of Candida. Usually, a result of a local spread of yeast from gastrointestinal and genital tract

Urinary Tract Candidiasis

fever, rigors, lumbar pain and abdominal pain; is usually the result of either an ascending infection or more frequently, hematogenous dissemination from another organ

Renal candidiasis or pyelonephritis

Criteria of suggestive renal infection

1. The isolation of yeast in urine specimens obtained by suprapubic aspiration. 2. Positive blood cultures and a positive immunodiffusion precipitin test result (seroconversion) in a patient with iatrogenic predisposing factors and or underlying illness

Occurs in patients with severe neutropenia usually acute leukemia with symptoms of fever, hepatosplenomegaly and INC blood conc of alkaline phosphatase

HEPATIC AND HEPATOSPLENIC CANDIDIASIS

Histopathology of hepatosplenic candidiasis

Diffuse hepatic and splenic necrotic lesions or abscesses containing small numbers of pseudohyphae

presence of yeasts in the blood with or without visceral involvement. A characteristic presentation is antibiotic resistant fevers in neutropenic patients with tachycardia and dyspnea.

Candidemia

most common form of cardiac candidiasis

Endocarditis

most sensitive method for the isolation of Candida from the blood.

Lysis centrifugation

globose to elongate yeast-like cells or blastoconidia

Candida albicans

Candida albicans produce by__________?

multilateral budding

T/F Colony pigmentation always present in Candida albicans

FALSE

Prophylaxis for Candida species has been shown to be efficacious when employed in specific high-risk groups such as bone marrow and liver transplant patients

Fluconazole

Treatment for Mucosal and cutaneous candidiasis

topical creams, lotions, ointments, suppositories containing azole agents (e.g., imidazoles and triazoles)

TX for Oral systemic therapy (candidiasis)

fluconazole or itraconazole

TX for Bladder colonization or cystitis (candidiasis)

amphotericin B directly to the bladder or oral fluconazole

A systemic mycoses caused by the encapsulated, basidiomycetous, yeastlike fungi

Cryptococcosis

worldwide in distribution and found as ubiquitous saprophyte of soil, especially soil enriched with pigeon droppings

C. neoformans

capsular serotypes A, D and AD

C. neoformans

capsular serotypes B and C

C. gattii

predominant clinical presentation of cryptococcosis in AIDS patients

Meningitis

Large mass lesions in lung or brain are called as _________?

“cryptococcomas”

affects immunocompromised hosts predominantly, and is the most common cause of fungal meningitis

C. neoformans

Spherical to oval; Encapsulated basidiomycete yeastlike fungus; Germ tubes, hyphae, and pseudohyphae are usually ABSENT in clinical material

Cryptococcus Neoformans / Gatti

C. neoformans & gatti replication via?

budding

Cryptococcus species stains with ______

Indian Ink

Surrounded by optically clear, smoothly contoured, spherical zones, or “halos” that represent the extracellular polysaccharide capsule

Cryptococcus species

The capsule of cryptococcus sp. is a distinctive marker that may have a diameter up to 5 times that of fungal cell and is easily detected with____________.

Mucin (Mayer mucicarmine) PAS GMS stains

The cell wall of C. neoformans contain ___________, which is demonstrated by staining with the____________.

Melanin; Fontana- Masson stain

Individuals with CD4+ lymphocyte counts of _____________ are at high risk for CNS and disseminated cryptococcosis

<200/mm3

worldwide in association with soil contaminated with avian excreta

C. neoformans var. neoformans and var. grubii:

found in tropical and subtropical climates in association with eucalyptus tree

C. gattii:

Conditions with asymptomatic colonization of Cryptococcus:

Bronchitis Bronchiectasis

When present symptoms include cough, low-grade fever, pleuritic chest pain

pulmonary cryptococcosis

dissemination to the brain and meninges; Meningitis, meningoencephalitis or expanding cryptococcoma

CNS CRYPTOCOCCOSIS

localized solid tumor-like masses usually found in the cerebral hemispheres or cerebellum, more rarely in the spinal cord

Cryptococcoma

Lesions: lytic without periosteal reaction and symptoms of dull pain on movement are reported

CRYPTOCOCCOSIS OF THE BONE

Primary isolation media of C. neoformans

Sabouraud’s dextrose agar

Genus Cryptococcus: ð Fermentation of sugar:______________ ð Assimilation of nitrate: ____________ ð Assimilation of inositol: _____________

Negative Variable Positive

Induction therapy for cryptococcosis

Amphotericin B + flucytosine acutely for 2 weeks Followed by 8-week consolidation, with either oral fluconazole (preferred) or itraconazole

TX for cryptococcosis for AIDS patients

Lifelong maintenance with either fluconazole or itraconazole

most common human pathogen among others Aspergillus

A. fumigatus

Aspergillus spp. grow in culture as _________

Hyaline molds

Grow as branched septate hyphae that produce conidial heads when exposed to air in culture and tissue. A conidial head consists of a conidiophore with a terminal vesicle on which are borne one or two layers of phialides, or sterigmata

Aspergillus spp.

In tissue: hyphae of Aspergillus spp. is stained poorly with H&E, but is well visualized by the _________

PAS, GMS and Gridley fungal stains

branches of aspergillus spp are dichotomous and usually arise at what angle?

Acute angle (45 degree)

most frequent and most important portal of entry of Aspergillus

Respiratory Tract

Indolent, slowly progressive, “semi-invasive” with Fever, cough, sputum production and positive serum antibody precipitin may also be detected

CHRONIC NECROTIZING ASPERGILLOSIS

Saprophytic colonization of preformed cavities with symptoms of hemoptysis and many are asymptomatic; Positive immunodiffusion precipitin test to antibody to Aspergillus & Elevated specific IgE against Aspergillus

NON-INVASIVE ASPERGILLOSIS OR ASPERGILLOMA / Fungus ball

Mimics acute bacterial pneumonia with serum antibody precipitins usually negative

Acute invasive pulmonary aspergillosis

Primarily seen in immunocompetent individuals; Predisposing factors: history of chronic sinusitis and poor draining sinuses with excessive mucus

Non-invasive “aspergilloma” form

Usually seen in immunocompromised patients. Has similar clinical setting to that seen in rhinocerebral zygomycosis with a symptoms: fever, rhinitis and signs of invasion into the orbit

Invasive form aspergillosis of the paranasal sinuses

Fast growing colonies with white, yellow, yellow brown, brown to black or green in color ;cultures show colonies with characteristic radiating chains of conidia.

A. fumigatus

single palisade-like layer of phialides

Uniseriate

layer of subtending cells

Metulae

Detects a wide variety of fungal pathogens: Aspergillus, Candida, Fusarium, Trichosporon

(1-3) B-D-Glucan test

Tx for aspergillosis : Amphotericin B (lipid formulation) but A. terreus is resistant to it. What is alternative treatment option that is more efficacious and less toxic than Ampo B

Voriconazole

SYSTEMIC OPPORTUNISTIC MYCOSES Flashcards

(86 cards)