#4: 🍄Mycology: Mycoses and fungal ID - superficial, cutaneous

Stratum corneum

According to the classification criteria of superficial mycoses on your review sheet, these fungal infections are restricted in their localization. Which specific layer of the epidermis do they exclusively affect?

They do not cause inflammation

A medical technologist is reviewing a smear from a suspected superficial fungal lesion. Based on the notes, what type of local tissue reaction or inflammation do these particular fungi typically induce in the host?

The skin or hair only

Superficial fungal pathogens are physically restricted to specific anatomical structures. According to your review sheet, these mycoses involve which components of the human body?

Dead tissues or structures

A handwritten note at the top of your mycology review sheet defines the specific nature of the substrates targeted by superficial fungi. What type of tissues or structures do these organisms infect?

They are not thermally dimorphic

A handwritten annotation contrasts the superficial fungi against other categories like dimorphic molds. What distinction is noted regarding their relationship with environmental and physiological parameters?

Lipid for growth

A baseline characteristic is highlighted on your notes for the Malassezia furfur complex regarding its metabolic demands. What is universally required by these organisms for successful growth?

Malassezia globosa

The Malassezia furfur complex consists of multiple distinct species. According to the handwritten note on the left margin of the table, which species is highlighted as the most common clinical agent?

Pityriasis versicolor

A patient is diagnosed with a Malassezia furfur complex infection. What alternative medical designation is listed in the pathogenicity column for tinea versicolor?

Patchy lesions or scaling of varied pigmentation

When evaluating a clinical case of tinea versicolor, a medical technologist looks for specific clinical features. How are the lesions characteristically described in your notes?

Yellow

During a physical screening of skin lesions on the clinical floor, a medical technologist utilizes a Wood's lamp. What characteristic color fluorescence is exhibited by the Malassezia furfur complex?

Spaghetti and meatballs appearance

Direct microscopic examination of skin scrapings from a tinea versicolor lesion reveals a classic diagnostic arrangement. What famous descriptive nickname is given to this specific fungal presentation?

Branching filaments of variable lengths

The microscopic presentation of the Malassezia furfur complex is made up of distinct vegetative elements. How are the fungal filaments characteristically described under the key characteristics column?

Clusters of small, unicellular, oval and round, budding yeast cells

The "spaghetti and meatballs" appearance of the Malassezia furfur complex incorporates a distinct yeast phase structure. How are these individual yeast cells described under high-power examination?

Malassezia pachydermatis

While the Malassezia furfur complex is famously lipophilic. Which organism can grow without lipid supplementation?

Olive oil

To cultivate typical yeast colonies of the Malassezia furfur complex on solid laboratory media, what specific substance must be overlaid on the culture medium?

Broad-based budding yeast with a collarette

A handwritten annotation accompanied by a drawing illustrates the reproduction style of the Malassezia genus. What type of cellular budding defines these yeast cells?

Black piedra

A patient presents with a superficial mycosis that yields hard, dark nodules on hair shafts. What is the clinical name of the pathogenicity associated with Piedraia hortae?

Hard, dark brown to black gritty nodules

A medical technologist palpates the diagnostic hair nodules collected from a patient suspected of having a Piedraia hortae infection. What are the key physical characteristics of these nodules?

Firmly attached to the hair shaft

The physical positioning of fungal elements on the host hair is an important clinical flag. Where are the nodules of Piedraia hortae typically situated?

Ascospores

Inside the gritty nodules of Piedraia hortae, specific reproductive structures are located. What type of sexual spores are found within these nodules?

Crushing the gritty nodules open

To definitively observe the internal asci and sexual structures of Piedraia hortae during a direct slide workup, what manual manipulation must the medical technologist perform?

Closely septate, dark, and thick walled and vary in diameter

When Piedraia hortae is successfully grown on a culture plate, its mycelial elements display a specific cellular anatomy. How do the hyphae appear under microscopic examination?

Many intercalary chlamydoconidia-like cells

Microscopic analysis of a mature Piedraia hortae culture reveals a high abundance of a specific survival conidium type. What structural variant is characteristically observed along the hyphal strands?

White piedra

The pathogenic species Trichosporon ovoides, Trichosporon inkin, and Trichosporon cutaneum are linked together in the pathogenicity column. What specific superficial disease do these organisms cause?

Polymorphic

A handwritten annotation on the left margin of the Trichosporon section highlights a specific morphological feature. What biological term describes the diverse, changing structural nature of this genus?

True hyphae and pseudohyphae with blastoconidia

Microscopic examination of a young culture of a Trichosporon species reveals a mixture of vegetative elements. Which structures are prominently possessed by these young colonies?

Arthroconidia

While certain diagnostic structures may be absent during the initial growth phases of a Trichosporon species, they reliably appear later. What specific conidia type forms on older cultures?

Urease

A medical technologist performs a screening panel on a suspected yeast isolate. What universal enzymatic marker is positive (+) for all members of the genus Trichosporon?

Trichosporon asahii

A reference laboratory confirms a case of an unusual respiratory illness in Japan diagnosed as summer-type hypersensitivity. Which specific species of Trichosporon is the documented cause of this condition?

Systemic with predilection for hematogenous dissemination

When Trichosporon asahii causes a deep, invasive pathological state in immunocompromised hosts, it displays a distinct pattern of systemic movement. What specific clinical predilection is noted for this species?

0

In the differentiation of Trichosporon species, carbohydrate utilization pathways are highly reliable. What is the expected inositol (Inos) assimilation result for Trichosporon asahii?

0

A technologist reviews the sugar profile of an unknown Trichosporon isolate. What is the expected sorbitol (Sorb) assimilation result for Trichosporon asahii?

+

When performing carbohydrate assimilation panels for a suspected Trichosporon asahii isolate, what reaction should be observed for arabinose (Arab)?

Systemic with preference for central nervous system

Trichosporon mucoidesis an opportunistic pathogen that can cause severe deep infections. According to the differentiation table, what is the systemic preference site for this organism?

Hair and nails

Apart from causing deep systemic infections, Trichosporon mucoides can also localize superficially. Which secondary anatomical structures are documented as infected by this species?

All results are positive (+, +, +)

A medical technologist analyzes the complete row of sugar assimilation data for a suspected Trichosporon mucoidesisolate. What unique pattern defines this organism across inositol, arabinose, and sorbitol?

Underarm hair

A patient presents with soft nodules localized on axillary hair shafts. According to your review sheet notes, Trichosporon cutaneum is rarely isolated from skin lesions but is a known cause of white piedra of which specific hair?

0

Temperature tolerance testing is an essential parameter for separating look-alike yeasts. What is the growth characteristic of Trichosporon cutaneum when incubated at body temperature (37°C)?

+, +, +

When processing an isolate of Trichosporon cutaneum through a sugar assimilation panel, what specific results are generated across the inositol, arabinose, and sorbitol columns?

Trichosporon inkin

A male patient provides a hair specimen showing soft, pale nodules collected from the pelvic region. Which Trichosporon species is primarily associated with white piedra of the pubic hairs?

0 and 0

When processing an isolate of Trichosporon inkin through a sugar assimilation panel, what specific results are generated for arabinose and sorbitol, respectively?

Trichosporon ovoides

A pediatric patient presents with light-colored, soft nodules wrapping around the hairs of the scalp. Which Trichosporon species has a specific site predilection for head hairs?

V

During a differentiation workup, a Trichosporon ovoides isolate is tested for its ability to replicate at body temperature. What is the growth characteristic of this species at 37°C?

0, V, 0

A medical technologist is reviewing the complete row of sugar assimilation data for Trichosporon ovoides. What specific profile defines this head hair isolate across inositol, arabinose, and sorbitol?

Tinea nigra

A medical technologist is reviewing the pathogenicity of Hortaea werneckii. What is the clinical name of the superficial disease caused by this organism?

Palms and soles

When diagnosing tinea nigra, the clinical history and location of the lesions are highly specific. On which anatomical sites do these flat macules occur most frequently?

Brown-black, nonscaly macules

A dermatologist describes the lesions of a patient with a confirmed Hortaea werneckii infection. What are the key physical characteristics of these tinea nigra macules?

Colonies are light colored at first but soon becomes olive-black

A medical technologist monitors the physical appearance of a Hortaea werneckii culture daily. How do the colonies characteristically transform over time on the agar slant?

Does NOT exhibit fluorescence

A patient’s lesions are inspected under ultra-violet light to check for tinea nigra. What is the fluorescence characteristic of Hortaea werneckii under a Wood’s lamp?

Annellides and annelloconidia

Microscopic analysis of a mature Hortaea werneckii colony reveals specialized conidiogenous cells that produce conidia in successional rings. What structural structures define this organism's key microscopy characteristics?

At the end where conidia are formed

The individual conidia of Hortaea werneckii exhibit a highly specific anatomy under the microscope. Where are the diagnostic structural striations located on the elongated annelloconidia?

Tinea corporis

A patient presents with circular, erythematous lesions featuring scaly patches with sharply demarcated margins. The lesions are localized on the trunk, neck, and shoulder, forming a distinctive ring-like appearance. What is the clinical designation for this infection?

Tinea imbricata

A dermatology patient exhibits a specialized form of tinea corporis. Microscopic and physical inspection reveals a presentation where the skin lesions form distinct overlapping circles in shape. What is the diagnostic term for this clinical presentation?

Tinea cruris

A male patient presents with an intensely itchy groin lesion commonly referred to as "jock itch." The lesion is localized to the medial thighs, perineum, and buttocks, appearing scaly, erythematous to tawny brown, and asymmetric with a sharply marginated border studded with small vesicles. What is the clinical diagnosis?

Tinea manuum

Physical assessment of a manual laborer reveals a scaling cutaneous fungal infection confined to the hands, specifically affecting the palms and fingers. What is the correct clinical diagnosis for this site-specific infection?

Tinea pedis

A patient complains of peeling and scaling skin localized exclusively to the soles of the feet and the interdigital toe webs, which has progressed around the sides of the foot to form a "moccasin foot" pattern. What is the medical term for this condition?

Tinea barbae

A patient presents with a highly inflammatory fungal infection localized to the bearded areas of the face and neck. What is the correct diagnostic term for this dermatophyte infection?

Tinea unguium

A medical technologist is reviewing a laboratory request form for a patient with a fungal nail infection. The form uses the specific dermatophytic clinical term for an infection of the nails. Which term is correct?

Tinea capitis

A school-aged child presents with patchy hair loss, inflammation, and scaling localized entirely to the scalp and hair shaft. What is the diagnostic term for this condition?

Endothrix

Microscopic examination of an infected hair shaft demonstrates that the fungal growth begins at the hair follicle and continues entirely within the hair shaft, causing it to weaken. This presentation is clinically known as "black dot ringworm." What type of hair invasion is described?

Favic

A patient presents with a severe scalp condition characterized by the formation of parallel lesions within the hair shaft, branching hyphae throughout the shaft length, and large, inverted cones of hyphae and arthroconidia at the base of the hair follicle. What type of hair infection is described?

Erythematous circular lesions and scaly patches found on the trunk, neck, or shoulder

When evaluating a patient diagnosed with a classic case of tinea corporis, which of the following physical descriptions and anatomical sites should the medical technologist expect to observe?

Lesions which are overlapping circles in shape

Tinea imbricata is a highly distinct dermatophytosis. Which of the following descriptions captures the characteristic physical presentation of the lesions in this condition?

Found on medial thighs, perineum, and buttocks as a scaly, erythematous to tawny brown lesion

A clinician diagnoses a patient with tinea cruris, commonly known as "jock itch." Which of the following characterizations matches the presentation of this specific infection?

Usually affects soles and toe webs and may progress around the sides of the foot

A patient is confirmed to have tinea pedis, also known as "athlete's foot." Which of the following characteristic progression patterns is documented in your review notes for this condition?

The hands, specifically the palm and fingers

When documenting a confirmed case of tinea manuum, which specific anatomical parameters must be affected to fulfill the diagnostic definition?

The bearded areas of the face and neck

Tinea barbae is a distinct category of cutaneous mycoses. Which of the following options defines the exact clinical localization for this condition?

Tinea unguium

Onychomycosis is a general term used for any fungal nail infection. According to your review sheet, what is the specific category name used when this condition is caused by a dermatophyte?

The scalp and hair shaft

A pediatric patient is suspected of having tinea capitis. Which anatomical structures are explicitly involved in the clinical definition of this disease?

Fungus invades outer portion of hair shafts

An ectothrix pattern of hair infection is identified under the microscope. Which of the following descriptions defines this specific type of fungal invasion?

Most severe form showing yellowish-white crusts called scutula that stink

A patient is diagnosed with a favic hair infection. Which of the following features represents the severe clinical presentation and hallmarks highlighted in the handwritten notes for this condition?

Hyphae and air spaces

Microscopic inspection of a hair follicle sample confirms a favic infection. According to the handwritten notes, what elements are visually characteristic inside the hair structures?

Epidermophyton floccosum, Microsporum canis, and Trichophyton rubrum

A patient presenting with tinea corporis yields a dermatophyte culture. Which of the following groups represents the agents explicitly listed in the table as causes of this infection?

Trichophyton concentricum

A clinical isolate is recovered from a specialized form of tinea corporis characterized by concentric, overlapping circles. Which organism is the explicit agent of tinea imbricata?

Epidermophyton floccosum

Skin scrapings collected from an asymmetric, scaly groin lesion studded with small vesicles yield a dermatophyte. Which organism is listed as the agent responsible for tinea cruris?

Epidermophyton floccosum (acute)

A medical technologist isolates a dermatophyte from a patient experiencing an acute form of tinea pedis localized to the toe webs. Which organism is specifically linked to the acute presentation?

Trichophyton rubrum (chronic)

A patient with a long-standing, chronic case of "moccasin foot" tinea pedis undergoes a skin scraping workup. Which organism is listed as the cause of the chronic form of this infection?

T. mentagrophytes, T. rubrum, and E. floccosum

A cutaneous sample from a tinea manuum infection of the palm and fingers is cultured. Which of the following sets of organisms represents the agents associated with this disease?

Trichophyton verrucosum and Trichophyton mentagrophytes

An agricultural worker presenting with a severe inflammatory tinea barbae of the bearded neck regions undergoes a fungal culture. Which two agents are associated with this infection?

Trichophyton rubrum and Trichophyton mentagrophytes

A medical technologist is performing a workup on a nail specimen to diagnose a dermatophytic onychomycosis (tinea unguium). Which two organisms are listed as the agents for this condition?

T. tonsurans, T. violaceum, M. canis, and M. audouinii

A scalp scraping from a child with tinea capitis is cultured in the laboratory. Which of the following groups contains the specific agents listed for this infection?

Microsporum spp. and Trichophyton mentagrophytes

Microscopic analysis of an infected hair shaft reveals a classic ectothrix pattern where the fungus invades the outer portion of the shaft. Which organisms are associated with this ectothrix presentation?

Trichophyton tonsurans and Trichophyton violaceum

A hair sample from a patient with "black dot ringworm" demonstrates an endothrix pattern of invasion, with fungal growth continuing entirely within the hair shaft. Which two agents are responsible?

Trichophyton schoenleinii

A severe hair infection reveals parallel lesions within the hair shaft and the formation of yellowish-white crusts (scutula) that emit a foul odor. Which specific dermatophyte is the causative agent of this favic infection?

Epidermophyton floccosum

A medical technologist observes a mold culture that macroscopically produces yellow to olive-gray or khaki colonies. Microscopic evaluation demonstrates that the organism produces only one size of conidia—smooth, thin-walled, club-shaped macroconidia arranged in clusters or singly. Which organism is identified?

Microsporum canis

Microscopic examination of a dermatophyte culture reveals thick-walled, rough, spindle-shaped, and beak-shaped macroconidia with curved tips, alongside drop-shaped microconidia. Macroscopically, the reverse side of the colony develops a bright lemon-yellow pigment. Which pathogen matches this description?

Nannizzia gypsea

A fast-growing dermatophyte isolate produces cinnamon-colored colonies on the obverse surface. Microscopic analysis shows drop-shaped microconidia and macroconidia that are characteristically fusoid with rounded ends. Which organism is identified?

Microsporum audouinii

A slow-growing, sterile dermatophyte colony displays a salmon-pink to reddish-brown pigment on the reverse side of the agar plate. Microscopic inspection reveals terminal chlamydospores, favic, racquet, or pectinate hyphae, while macroconidia are rare and bizarre in shape if seen at all. Which pathogen matches this descriptive profile?

Trichophyton mentagrophytes

A medical technologist isolates a dermatophyte that produces granular and powdery colonies. Microscopic evaluation demonstrates few thin-walled, smooth-walled, cigar-shaped macroconidia, along with microconidia arranged in grape-like clusters and occasional spiral-shaped hyphae. This isolate tests positive on a hair perforation test. Which organism is described?

Trichophyton rubrum

A flat mold colony develops a highly characteristic cherry-red color on the reverse side of the plate and yields a negative hair perforation test. Under microscopic examination, it features teardrop-shaped microconidia and rare, thin-walled, smooth-walled, cigar-shaped macroconidia. Which organism is identified?

Trichophyton tonsurans

A dermatophyte colony is described macroscopically as buff to brown, wrinkled, and suedelike in appearance, showcasing radial folds and a distinct crater-like depression in the center with deep fissures. Microscopic evaluation reveals few macroconidia and characteristic balloon-shaped microconidia. Which organism is identified?

Trichophyton schoenleinii

A slow-growing fungal isolate produces colonies with a surface that is usually nonpigmented or tan, furrowed, and irregularly folded. Microscopic examination demonstrates an absolute absence of conidia, showing only favic chandeliers or nailhead (knobby) hyphae. Which pathogen is identified?

Trichophyton violaceum

A medical technologist subcultures an organism recovered from a scalp lesion that produces striking violet or port wine-colored colonies. Microscopic examination confirms that both microconidia and macroconidia are completely absent, revealing only sterile, distorted hyphae and chlamydoconidial segments. Which organism matches this profile?

Trichophyton verrucosum

An organism isolated from a cattle rancher presenting with tinea barbae forms gray and waxlike to bright yellow colonies on solid agar. Microscopic evaluation reveals antler hyphae and rare macroconidia that vary considerably in size and shape, described as "rat tail" or "string bean" in appearance. Which organism matches this description?

Colonies are yellow to olive gray or khaki; produces smooth, thin-walled club-shaped macroconidia in clusters or singly

When evaluating a confirmed laboratory culture of Epidermophyton floccosum, which combination of macroscopic and microscopic features should the medical technologist expect to observe?

Reverse side develops a lemon-yellow pigment; macroconidia are thick-walled, rough, and beak-shaped with curved tips

Which of the following selections correctly describes the key diagnostic visual hallmarks of Microsporum canis when evaluated macroscopically and microscopically in the laboratory?

Colonies are cinnamon in color; macroconidia are fusoid with rounded ends and microconidia are drop-shaped

A medical technologist is cross-checking the identification criteria for Nannizzia gypsea (formerly Microsporum gypseum). Which parameters match this specific geophilic species?

Reverse side is salmon-pink to reddish brown; usually does not sporulate, displaying terminal chlamydospores, favic, racquet, or pectinate hyphae

When examining a slide preparation of Microsporum audouinii, which unique set of vegetative mycelial structures and colony descriptions should be identified?

Colonies are granular and powdery; microconidia appear in grape-like clusters with spiral hyphae, yielding a positive hair perforation test

Which of the following profiles represents the definitive macroscopic, microscopic, and biochemical criteria for Trichophyton mentagrophytes?

Reverse side displays a characteristic cherry-red color; microconidia are teardrop-shaped, yielding a negative hair perforation test

The organism Trichophyton rubrum is notoriously common on the mycology bench. Which characteristic patterns distinguish this specific pathogen from other look-alike dermatophytes?