HYALINE MOLDS, MUCORALES, ENTOMOPHTHORALES, DERMATOPHYTES, AND OPPORTUNISTIC AND SYSTEMIC MYCOSES

Question 1

Q: What class do Mucorales belong to?

Answer 1

A: Zygomycetes.

Question 2

They produce large, ribbonlike hyphae that are irregular in diameter and contain occasional septa.

Answer 2

Mucorales

Question 3

How are Mucorales organisms specifically identified?

Answer 3

By observing the characteristic
- saclike fruiting structures (sporangia), which produce internally spherical,
- yellow or brown spores (sporangiospores).

Question 4

Where is each sporangium formed in Mucorales?

Answer 4

At the tip of a supporting structure called a sporangiophore.

Question 5

What connects sporangiophores in Mucorales?

Answer 5

stolons, which attach at contact points where rootlike structures (rhizoids) may appear and anchor the organism to the agar surface.

Question 6

How common are Mucorales infections compared to aspergilli?

Answer 6

They are a less common cause of infection than aspergilli.

Question 7

In which patients are Mucorales infections an important cause of morbidity and mortality?

Answer 7

In immunocompromised patients.

Question 8

Where are Mucorales commonly found?

Answer 8

On decaying vegetable matter, old bread (bread mold), or in soil.

Question 9

How do Mucorales infections progress?

Answer 9

They are rapidly progressive.

Question 10

How might immunocompetent individuals acquire Mucorales skin infections?

Answer 10

After traumatic injection with contaminated material.

Question 11

: What is the marked propensity of mucormycosis?

Answer 11

Vascular invasion,
rapidly producing thrombosis
and necrosis of tissue.

Question 12

What is the most common presentation of mucormycosis?

Answer 12

The rhinocerebral form, involving the nasal mucosa, palate, sinuses, orbit, face, and brain.

Question 13

How can mucormycosis be acquired?

Answer 13

Through injury and contamination with spores or soil.

Question 14

Are blood cultures appropriate for diagnosing mucormycosis?

Answer 14

No

Question 15

What types of specimens should be collected for diagnosing mucormycosis?

Answer 15

-deep lesions or tissues and sterile sites,
-nasal discharge or scrapings,
-sinus aspirate,
-tissue specimens from vascularized tissue, -sputum,
- bronchoalveolar lavage fluids.

Question 16

How should tissue biopsy specimens be transported?

Answer 16

They should be moistened by adding a few drops of sterile saline to the container and transported to the laboratory within 2 hours of collection.

Question 17

What are some direct detection methods for mucormycosis?

Answer 17

nucleic acid–based testing,
recovery of the fungus from tissue, body fluids, and exudates.

Question 18

What stains are used for detecting mucormycosis?

Answer 18

Calcofluor white and potassium hydroxide preparation.

Question 19

What molecular methods are used for diagnosing mucormycosis

Answer 19

Nucleic acid testing on
- formalin-fixed,
-paraffin-embedded,
-fresh or frozen tissue samples,
- polymerase chain reaction (PCR) amplification.

Question 20

What type of growth media should be avoided for cultivating Mucorales species?

Answer 20

Growth media containing high concentrations of carbohydrates.

Question 21

What are the characteristics of Mucorales colonies?

Answer 21

-Fluffy,
-white to gray or brown hyphal growth that resembles cotton candy
-diffusely covers the surface of the agar within 24 to 96 hours

Question 22

Mucorales also known as?

Answer 22

lid lifter

Question 23

What direct detection methods are used for Entomophthorales?

Answer 23

Similar methods to those used for Mucorales, including the Splendore-Hoeppli phenomenon.

Question 24

The formation of eosinophilic crystals that appear radiate, starlike, asteroid, or club-shaped around a fungal infection.

Answer 24

Splendore-Hoeppli phenomenon

Question 25

On what media should tissue samples be cultivated for Entomophthorales?

Answer 25

Potato dextrose agar or Sabouraud agar.

Question 26

At what temperatures should cultures of Conidiobolus spp. and Basidiobolus sp. be incubated

Answer 26

Conidiobolus spp. at 37°C and Basidiobolus sp. at 25°C to 30°C.

Question 27

Slightly yellow pigmented with radial folds, no aerial hyphae, and produce aseptate mycelia with free uninucleated hyphal elements after 7 to 10 days.

Answer 27

Basidiobolus ranarum.

Question 28

What are the characteristics of primary and secondary conidia in Basidiobolus ranarum?

Answer 28

Primary conidiophores have swollen apices with globose spores that are forcibly discharged;

Secondary conidia appear pyriform with a knoblike adhesive tip and are passively discharged.

Question 29

Fast-growing, hyaline, radially folded colonies that initially appear waxy and become powdery when mycelia begin to develop.

Answer 29

Conidiobolus spp.

Question 30

How can Conidiobolus coronatus be differentiated from other species?

Answer 30

By the absence of zygospores when grown on potato dextrose agar.

Question 31

Name the species of Entomophthorales.

Answer 31

Conidiobolus coronatus,
Conidiobolus lamprauges,
Conidiobolus incongruous,
Basidiobolus ranarum.

Question 32

Where are Entomophthorales primarily found?

Answer 32

In the soil, decaying vegetable material, and animal feces.

Question 33

In which climates are Entomophthorales infections more commonly identified?

Answer 33

Warm climates.

Question 34

Where are Conidiobolus species commonly found?

Answer 34

Africa, Madagascar, Mayotte, India, China, Japan, and South America.

Question 35

Where is Basidiobolus ranarum commonly found?

Answer 35

India, Myanmar, and Africa.

Question 36

is an infection primarily localized to subcutaneous tissue, caused by Basidiobolus ranarum.

Answer 36

Basidiobolomycosis

Question 37

What are the common sites of basidiobolomycosis infection?

Answer 37

Arms, legs, buttocks, trunk, perineum, face, or neck.

Question 38

How does basidiobolomycosis present?

Answer 38

a woody, hard, painless nodule.

Question 39

What type of infections can Conidiobolus species cause?

Answer 39

Infections primarily around the nose and on the face.

Question 40

How are Conidiobolus infections acquired?

Answer 40

By inhalation of spores in the nasal cavity or inoculation after trauma.

Question 41

What symptoms occur after Conidiobolus infection?

Answer 41

Swelling that extends to the nose, cheeks, eyebrows, upper lip, palate, and pharynx.