Pg 25 -

Question 1

(1) Normal flora of the mouth, throat, large intestine, vagina, skin
(2) Causes mild, opportunistic infections in patients with “mild” metabolic or hormonal disorders (e.g. diabetes, pregnancy, prolonged antibiotic treatment, chronic alcoholism) or those with more extreme moist skin conditions
(3) Can produce life-threatening infections in immunocompromised patients by invading deeper tissues

Answer 1

Candida albicans

Question 2

Etiological agent of various opportunistic infections – Overgrowth due to reduction of normal flora resulting from antibiotics, hormones, or metabolic disorders

Answer 2

Candida albicans

Question 3

White, patchy lesions in the mouth; most common in infants

(a) Pseudomembrane covers tongue, soft palate, buccal mucosa & other surfaces
(b) Patches of pseudomembrane often crumble & have the appearance of milk curds

Answer 3

Oral thrush - candida albicans

Question 4

In oral thrush, _____ covers tongue, soft palate, buccal mucosa & other surfaces

Patches of ___ often crumble & have the appearance of milk curds

Answer 4

pseudomembrane (candida albicans)

Question 5

Especially in diabetics and pregnant women (due to chemical/hormone changes)

May resemble thrush

Answer 5

vaginitis (candida albicans)

Question 6

Thrush found in axilla, groin, mammary folds, interdigital spaces – may produce inflammation such as diaper rash

Answer 6

cutaneous thrush (candida albicans)

Question 7

(a) Nails become hardened, thickened, brownish and discolored
(b) Nail plate is striated or grooved
(c) Mimics tinea u nguim or ringworm of the nails caused by dermatophytes

Answer 7

onychomycosis (candida albicans)

Question 8

If candida albicans goes systemic, what we got?

infrequent (almost all in immunocompromised or severely debilitated)

Answer 8

(a) Bronchial and pulmonary
(b) Septicemia
(c) Meningitis
(d) Endocarditis

Question 9

a. Emerging serious global health threat (684 cases as of 14 June 2019)
b. Causes severe INVASIVE infections of blood, heart, brain, eyes, bones

Answer 9

candida auris

Question 10

c. Often multi-drug resistant
d. Difficult to identify with standard laboratory methods, i.e. misidentification leads to inappropriate medication
e. Causes outbreaks in healthcare settings. Need to rapidly and accurately identify

Answer 10

candida auris

Question 11

Yeast with thick capsule

Answer 11

Cryptococcus neoformans

Question 12

(1) Infection in human is almost always pulmonary following inhalation of this yeast; usually subclinical and transitory; may arise as a complication of other diseases in debilitated patients and become rapidly systemic or even fulminant
(2) Central nervous system - meningitis – predilection (affinity) for brain and meninges (more common in AIDS patients)

Answer 12

Cryptococcus neoformans

Question 13

Laboratory diagnosis

(1) India ink preparation of CSF
(2) Immunodiagnostic test

Answer 13

Cryptococcus neoformans

Question 14

a. Dermatophytic molds
b. Cause tinea capitis (“ringworm” of scalp), tinea pedis (athlete’s foot), tinea corporis, tinea cruis (jock itch), and toenail fungal infection
c. Diagnosis – KOH wet prep; generally no samples sent to the lab

Answer 14

Microsporum, Trichophyton, and Epidermophyton

Question 15

tinea capitis (“ringworm” of scalp)

tinea pedis (athlete’s foot)

tinea corporis

tinea cruis (jock itch)

toenail fungal infection

Answer 15

Microsporum, Trichophyton, and Epidermophyton

Question 16

Fastest fungi growth timelines?

And more importantly, what is the takeaway with fungi growth timelines?

Answer 16

~1 week (many take longer)

Fungus takes much longer to grow/incubate than viruses & bacteria.

So?

Lab growth (and subsequent diagnosis might take time).

Furthermore, antimicrobial efforts also take longer (e.g., toenail fungus can takes up to year)

Question 17

a. Subcutaneous mold: fungal infection involving the skin and subcutaneous tissue, generally without dissemination to the internal organs of the body.
b. Source - soil, wood, or vegetation – Usually enters through trauma e.g. rose thorns, wood splinters

Answer 17

Sporothrix schenckii

Question 18

1) Primary lesion - about three weeks after injury
(a) Begins as a small, non-tender, subcutaneous nodule
(b) Nodule ulcerates causing tissue necrosis and infection of nearby lymph channels

(2) Secondary lesions
(a) Develops multiple subcutaneous nodules along lymph channels; may ulcerate
(b) May spontaneously heal but often become chronic, especially if untreated

Answer 18

Clinical presentation of sporothrichosis (Sporothrix schenckii)

Question 19

Sporothrichosis is commonly called ____ This disease process is an occupational hazard to farmers, nursery workers, florists, forest rangers, and mine workers.

Answer 19

“rose gardener’s disease”

Question 20

a. Systemic mold pathogen

b. Transmitted via inhalation of spores –often from bird droppings in warm, moist soil

Answer 20

Histoplasma capsulatum

Question 21

c. Endemic to Ohio River and Mississippi River valleys; also occurs in Africa & Asia

Answer 21

Histoplasma capsulatum

Question 22

Inhaled as a spore?

Answer 22

Histoplasma capsulatum

coccidioides immitis

Aspergillus fumigatus

Question 23

Common around Ohio and Mississippi Rivers?

Answer 23

Histoplasma capsulatum

Question 24

(1) Localized lesions in the lungs – flu-like symptoms (cough, fever) – ~99% of cases
(2) Organism disseminates throughout the body while inside macrophages (inadequate immune response) – < 1% of cases

Answer 24

Histoplasma capsulatum

Question 25

(a) Cell Mediated Immune response is too weak and lesions develop in major organs.
(b) Acute or chronic infection may develop (pneumonia, hepatitis, meningitis) – usually fatal without treatment

Answer 25

systemic infection from histoplasma capsulatum

Question 26

a. Systemic mold pathogen
b. Transmitted via inhalation of spores; especially after dust producing event

c. Endemic to semi-arid climate areas of southwestern USA, northern Mexico, and South America – hot, dry, alkaline soil

Answer 26

Coccidioides immitis

Question 27

Inhaled spores in southwestern USA? Especially after a dust-producing event

Answer 27

Coccidioides immitis

Question 28

Clinical presentation:
(1) Causes pulmonary lesions and flu-like symptoms – 99% of cases

(2) Disseminates to other organs (central nervous system, bone, cutaneous) when CMI is weak – < 1% of cases. High mortality rate.

Answer 28

Coccidioides immitis

Yes, the same as histoplama capsulatum

But different organisms (i.e., look differently under the ‘scope) and different geography

Question 29

San Joaquin Valley Fever, Valley Fever, Desert Fever

Answer 29

Coccidioides immitis

Question 30

A. fumigatus (and other species)

A. flavus

Answer 30

Aspergillus

Question 31

non-pathogens except in immunocompromised persons, and are found worldwide

Answer 31

A. fumigatus

Question 32

(1) Transmission – inhalation of airborne spores
(2) Clinical presentation - Usually sinus infection, pulmonary/bronchial mass; sometimes invasive causing multi-organ disease

Answer 32

A. fumigatus

non-pathogens except in immunocompromised persons, and are found worldwide

Question 33

Aflatoxin when growing in improperly stored (damp) nuts, grains, seeds, and other foods

Answer 33

A. flavus

Question 34

(1) Transmitted by ingestion of toxin

(2) Clinical presentation – liver damage, often severe

Answer 34

A. flavus (from the aflatoxin)

Question 35

(1) Attacks interstitial, fibrous tissue of the lungs leading to significant hypoxia
(2) Non-productive cough, shortness of breath, night sweats, fever
(3) Risk increases when CD4 cells are less than 200 cells/uL (immunocompromised)

Answer 35

Pneumocystis jirovecii pneumonia (PCP)

Question 36

Causes pneumonia in immunocompromised persons, e.g. cancer, chemotherapy, HIV/AIDS – low frequency

Answer 36

Pneumocystis jirovecii pneumonia (PCP)

Question 37

One of the less common molds that may grow inside buildings where moisture is present; and may produce mycotoxins and pose increased risk of allergy and asthma.

Answer 37

Stachybotrys chartarum

Question 38

“black mold”

Answer 38

Stachybotrys chartarum

Question 39

CDC recommends a common-sense approach to prevent and remove mold growth in the home

There is no test that proves an association between Stachybotrys chartarum (Stachybotrys atra) and particular health symptoms

Answer 39

Stachybotrys chartarum