Mycology – Microbiology – Flashcards

Pialophora verrucosa

Fonsecaea pedrosoi

Cladosporium carrionii

Rhinocladiella aquaspersa

Males are more likely to contract chromoblastomycoses than females.

(10:1)

No radical predilections

Exposed areas of trauma, exposed cuts, thorns/slivers are the most common means of infection. (a puncture/inoculation must be made for infection)

Dissemination is rare

It could take months to years for the disease to spread to sreious levels.

Generally found in feet and legs.

Even most immuno suppressed patients do not exhibit dissemination

The lesions look like barnacles/corals on the skin (dematiacious fungi -- dark lesions)

Abcess of the skin (fibrous tissues)

Similarities to Blastomycosis and Leishmaniasis

Muroform cells (multi-planar septa)

Blastic cells -- look like salmon eggs when dyed red.

Found in infected tissues

Phialophora

Acrotheca (Rhinocladiella)

Cladosporium

Type of conidia

A cup-like brancing from a hyphae that releases conidia (microconidia)

Condia that bud off of the end and sides of the conidiophore

The conidiophore look like broccoli

Conidiophores look highly branched with budding conidia at the ends of the branches (microconidia)

Pseudallescheria boydii

Madurella mycetomatis

Madurella grisea

Aspergillus spp.

Fusarium spp.

Acremonius spp.

Aerobic actinomycetes (not true fungi) produce similar symptoms -- Actionmadure spp. and Nocardia spp.

Commonly found in tropical and subtropical regions of the world

Sporadically seen in temperate zones

Pseudallescheria boydii and Nocardia predominate in the U.S.

Found mosty in Calif. and Texas

Males are five times more likely to contract the disease

(5:1)

More common in younger active people, farmers, and cattle hearders

Common in feet

Can be found on the head, neck, hands and legs

Generally maintained in the area of inection

Hypertrophy of the skin if left untreated

Hyphae grow in infected tissues

Swelling of the feet -- hyphae multiply inside if the tissues

Dark lesions appear at the skin surface when the hypae emerge -- compacted hyphae emerge from the surface lesions and form grannules

Fatal in some cases

Difficult to treat

Isolation of organism

Identification of grannules

Worldwide distribudion

Mainly found in Temperate, warm and tropical climates

Common in North America

Common in persons under 30

;

Must break the skin to infect

;

Equal probability in males and females

;

Increased infection in alcoholics

;

Tends to infect the outer limbs (cooler)

First appeaars as a papule on the skin and ulcerates

Follows the lymphatic channels -- ulcers form alonf lymph channels

More invasive in men -- more likely to spread throughout the male lumphatic system

Osteoarthricular sporothrichosis

immuno suppression may lead to spread in bones

Antibody response -- asteroid body or Splendore-Hoeppli phenomenon (characteristic antibody responce). Look for a sunflower-like body.

Granulomatous lesions (scattered)

 Oval or cigar shaped yeat cells and Globose Cells resembling Cryptococcus neoformans

Candida albicans

Other Candida

C. glabrata

C. parapsilosis

C. krusei

C. tropicalis

C. dubliniensis

75% of people are carriers (normal flora)

Alcoholism and drug (intravenous) use

Surgery/implants

Imunosuppression

Malignant diseases (cancers)

Diet: those with high protein and low carb. diets are less succeptible

Burns

Mostly Candida krusei

and

C. dubliniensis

Found in GI and GU tracts

More prevalent in pregnant women (vagina)

Normal flora Candida may overgrow and infect patient

Oral candidiasis may be an initial sign in AIDS patients (Oral Thrush)

Presence of a germ tube (hyphal protrusion from C. albicans and C. dubliniensis) -- culture in RPMI medium

 Serology is not clinically helpful (long process)

Carbohydrate assimilation profiles (chrom agar)

Look for appropriate levels of Candida spp. (may not be the culprit)

Lysis centrifugation

Immunosuppressed patients generally experiense great dissemination

Can spread to scalp and lead to permanent hair loss

Spread to organs (deep mycoses)

Cryptococcus neoformans

 Var. neoformans (serotypes A and D)

(often in AIDS patients)

Var. gatti (serotypes B and C)

Antigenic changes (can switch phenotypes quickly -- changes surface antigens)

In tissues, yeast, pseudohyphae, and true hyphae can form (increases invasiveness)

Thigmotropism -- attracted to changes in surface texture or holes (contact sensing)

Filter experiment showed the migration of Candida in and out of pores.

Hydrophobicity of surface molecules increases adherence to host cells.

Mimicry -- produces surfece antigens similar to host antigens or gathers host antigens.

Undemanding nutrient requirement

Rapid growth rate

Lytic enzymes damage host tissues

Dissemination throughout body/organs

Possible Cryptococcal meningitis

4th leading cause of death of AIDS patients

In the U.S. men have more cases -- Men and women equal in Africa (major AIDS epidemic)

Antibodies detected in pigeon breeders (no differences in infection rate)

High levels of adrenal corticosteroids is a predisposing factor

Sarcoidiosis and Lymphoma are also predisposing factors

All age groups

Yeast cells form muoid colonies

Capsules contribute to appearance

Observation of capsules w/ India ink stain

Can grow as a yeast and mold at room temp.

Capsule (the larger the capsule, the more virulent)

Infects the meninges of the brain

Next most common infection in the lungs

Corpuscles observed in infected tissues

Cells are widely separated by capsule

Urease acctivity

Oxidizes Caffeic acid in Niger seed

Inositol assimilation

Agglutination Test

Muci-Carmine stain (capsule)

Rigidity of head and neck area

Double vision

Light sensitivity

Amphoteracin B is commonly used in disseminated cases

Antifungals have to be taken for the duration of the patient's life

Endemic to U.S., Mexico, Guatemala, Honduras, Colombia, Venezuela, Bolivia, Paraguay, and Argentina

(restricted to semi-arid or desert-like regions)

In Kern Co. Calif.

Fungi in the soil become airborne (inhalation of spores)

Outbreaks associated with earthquakes and wildfires

Associated with rodents

Rains bring molds to the surface

People that work around soil in dry regoins are succeptible.

(construction, farming, phone-post diggers, archaeologists)

No racial, sex or age differentiation

However, once infected, those with darker skin seem to experience more serious infection.

Males are four times more likely to be infected except in pregnant women (high levels of estradiol and progesterone)

Prevelance in B type blood (in patients witth disseminated infection)

Mycelial growth on agar

Spherules form in tissues (spore forming)

Dogs are highly susceptible to the disease

A wide variety of wild and domestic animals are succeptible.

Enteroarthric conidia are inhaled

when in the body they swell and become spherules

Spores are released in tissues

in 40% (acute) -- cough, headache, fever, pleuritic chest pain, rashes

60% are asymptomatic

Isolation of organism (biohazard)

X-rays may reveal images similar to that of a person with lung cancer.

Has two life cycles -- saprophytic and parasitic

Saprophytic -- it forms hyphae and the arthro conidia

Parasitic -- formation of spherules and release of spores

Mostly dissminated

Mostly pulmonary infecitions

Histoplasma capsulatum

var. capsulatum and var. duboisii

Temperate and Tropical climates throughout the world

Higher concentrations in Eastern U.S. and Latin America

(Histoplasmic skin test surveys)

H. duboisii is found in the tropical areas of Africa

Old age

The immunosuppressed

AIDS patients at high risk for disseminated disease

Lab acquired forms (pulmonary infection -- inhalation)

Soils enriched with bat guano and bird droppings

Commonly acquired in city parks

Heterothallic/perfect state is seen in Ajellomyces capulatus

(Acsomycota, produces Cleistothecia ascocarps)

Produces macro and microconidia

(the macroconidia contain large lipd drops)

(Tuberculate macroconidia)

(microconidia -- blastoconidia)

Conidia are inhaled and develop into yeasts

Var. capsulatus is intracellular (generally in macrophages)

Var. duboisii is extracellular

Yeast cells multiply by polar budding.

Inhalation of spored generally leads to Acue pulmonary infection or Chronic or Disseminated histoplasmosis

(associated with chronic bronchitis)

Urease positive

Produce ammonia and bicarbonate (adaptations in macrophages)

neutralization of phagolysosome

95% of cases

Generally asymptomatic

Serology diagnosing

Progressive histoplasmosis

Damage to lung tissues

May cough blood

May be confused with tuberculosis

Generally in immuno suppressed of infants

Common spread to tongue and organs

Infection of adrenal glands (the related steroid treatment decreases immunity)

Ascomycete

Blastomyces dermatitidis

Yeast

Overlap with Histoplasmas -- Ajellomyces dermatitidis (telomorph)

South East U.S.

Mississippi River area

Wide areas in Africa (endemic)

Found in Dogs

Unsuccessful recoveries from soil

Male are 9 times more likely to develope chronic infection

Acute infection rates are equal in males and females

No racial distinction

Dissemination in AIDS patients

Isolation

X-rays

Serological testing is poor