Microbiology Lab Quiz 4: Fungi, Fermentation Tests, EMB Agar, and Protozoa

Comprehensive vocabulary flashcards covering Fungi anatomy and identification, Multiple Tube Fermentation water tests, EMB agar interpretations, and pathogenic Protozoa life cycles.

Mycology

The study of fungi.

Chemoheterotroph

An organism that acquires carbon and chemical energy from other organisms via absorption.

Thallus

The body of a fungus, which consists of hyphae filaments.

Hyphae

Microscopic fungal filaments.

Mycelium

A visible mass of fungal hyphae.

Septate Hyphae

Hyphae filaments that contain cross-walls (septa) dividing the cells.

Nonseptate (Coenocytic) Hyphae

Hyphae filaments that lack septa (cross-walls) and form continuous, multinucleated tubes.

Vegetative Hyphae

Portions of fungal hyphae responsible for absorbing nutrients.

Aerial Hyphae

Hyphae that project above the surface of the growth medium and are involved in reproduction.

Budding Yeasts

Unicellular, nonfilamentous fungi that divide asymmetrically (such as Saccharomyces).

Fission Yeasts

Unicellular fungi that divide symmetrically.

Pseudohyphae

Chains of false hyphae formed when yeast buds fail to detach from the parent cell.

Candida albicans

An opportunistic fungal pathogen that causes oral candidiasis (thrush).

Rhizopus stolonifer

A common bread mold that reproduces asexually via sporangiospores and sexually via zygospores.

Sporangiospore

An asexual fungal spore produced inside a sporangium pouch in Rhizopus.

Sporangium

A sac-like fungal structure that contains asexual sporangiospores, borne atop a sporangiophore.

Sporangiophore

The specialized reproductive aerial hypha that supports a sporangium in Rhizopus.

Zygospore

A thick-walled sexual spore produced by Rhizopus resulting from the fusion of two nuclei from opposite (+ and -) mating strains.

Conidia (Conidiospores)

Asexual spores arranged in chains at the end of a conidiophore, produced by Penicillium and Aspergillus.

Conidiophore

The specialized aerial hypha that bears chains of conidia in Aspergillus and Penicillium.

Penicillium notatum

A mold known for producing the antibiotic penicillin, characterized by conidia in chains on conidiophores.

Aspergillus niger

An opportunistic mold that produces conidiospores in chains and can cause aspergillosis (allergies and fungus balls).

Multiple Tube Fermentation Test

A microbiological test method used to presumptively identify coliform bacteria in a water sample.

Coliforms

Gram-negative, bacilli-shaped bacteria that ferment lactose using the enzyme beta-galactosidase to produce gas detectable in a Durham tube, serving as fecal contamination indicators.

Selective Media

Culture media formulated to inhibit the growth of certain microbes in order to select for specific ones.

Differential Media

Culture media designed to distinguish between different microbes based on visible biochemical differences.

Lauryl Tryptose Broth (LTB)

A medium used in presumptive coliform identification containing tryptose, lactose, and sodium lauryl sulfate, where a positive test yields turbidity and a gas bubble.

Sodium Lauryl Sulfate

A detergent component of LTB that selectively inhibits the growth of Gram-positive bacteria.

Brilliant Green Lactose Bile (BGLB) Broth

A medium containing brilliant green and bile salts to selectively inhibit Gram-positive bacteria, used to detect coliforms through lactose fermentation and gas production.

EC Broth

A selective and differential medium containing bile salts and incubated at $45^\circ\text{C}$ to inhibit Gram-positive organisms and non-E. coli coliforms, identifying Escherichia coli via gas production.

Eosin Methylene Blue (EMB) Agar

A selective and differential medium containing peptone, lactose, eosin, and methylene blue, used to differentiate possible and probable fecal coliforms.

Metallic Green Sheen (on EMB Agar)

The growth characteristic indicating a probable coliform and vigorous lactose fermenter that produces the endoenzyme beta-galactosidase.

Trophozoite

The active, motile, vegetative feeding stage of a protozoan.

Cyst

The dormant, resistant resting stage of a protozoan that protects it outside a host.

Encystment

The process where an active protozoan trophozoite enters a dormant cyst stage.

Excystment

The process where a protozoan exits the dormant cyst stage and reactivates into a feeding trophozoite.

Definitive Host

The host organism in which a parasite undergoes sexual reproduction (such as the female Anopheles mosquito for Plasmodium).

Intermediate Host

The host organism in which a parasite undergoes only asexual reproduction (such as humans for Plasmodium).

Trichomonas vaginalis

A flagellated protozoan with an undulating membrane that possesses no cyst stage, causes trichomoniasis (STI), and is treated with metronidazole.

Entamoeba histolytica

An amoeboid protozoan motile via pseudopods, transmitted via the oral-fecal route, causing amoebic dysentery with bloody, mucoid stools.

Balantidium coli

A ciliated protozoan transmitted through the oral-fecal route that causes severe dysentery (balantidiasis) and is treated with metronidazole.

Giardia lamblia

A flagellated protozoan causing giardiasis ('beaver fever'), transmitted by ingesting cysts in contaminated water, causing prolonged diarrhea, gas, and abdominal cramps.

Plasmodium falciparum

The apicomplexan protozoan causing the most severe form of malaria ($50\%$ mortality), characterized by spiking fever, chills, anemia, and organ damage.

Sporozoite

The infective stage of Plasmodium that is injected by a female Anopheles mosquito into human blood and invades liver cells.

Merozoite

The stage of Plasmodium produced by schizogony in liver cells that emerges to invade red blood cells.

Toxoplasma gondii

A non-motile protozoan whose definitive host is cats, contracted via ingestion of cysts from cat litter or undercooked meat, capable of causing fetal damage and encephalitis.

Tachyzoite

The crescent-shaped, tissue-invading trophozoite form of Toxoplasma gondii.

Trypanosoma brucei

A flagellated hemoflagellate transmitted by the bite of the tsetse fly that causes African sleeping sickness, leading to neurological symptoms, coma, and death.

Trypomastigote

The infective trophozoite stage of Trypanosoma brucei characterized by a flagellum and an undulating membrane, found circulating in blood, lymph, and spinal fluid.