lab 5 Flashcards
Eukaryotes
eukaryotic cell type; Domain Eukarya
Fungi
Protozoans
Helminths
Algae
Some members of these groups are human pathogens.
Types of fungi
Yeasts Molds Mushrooms
Sabouraud dextrose agar (SDA) plate contents
Selective agar used for growing most molds and yeasts
high glucose (dextrose) conc. – preferred by fungi.
acidic environment (pH 5.6) - inhibits most bacteria.
Yeast examples and characteristics
Examples: Candida albicans, Saccharomyces cervisiae
Yeast shapes vary; ovoid shaped are common
Note size, buds (aka blastospore) and bud scars
About 10x bigger than bacteria (e.g., cocci)
Buds form on parent cell
Parent cell is scarred at release site
Typical Mold Colony
Vegetative Mycelium characteristic
Whitish edge growth reveals underlying vegetative mycelium
Typical Mold Colony
Vegetative Mycelium reproductive structures
Darker area shows mold spores produced from underlying reproductive structures
Typical Mold Colony
Vegetative Mycelium comprised of?
Comprised of interwoven hyphae - long branching filaments
appear fuzzy
Typically appears whitish
Typical Mold Colony
Vegetative Mycelium
Fruiting Bodies (Reproductive structures)
Form at various locations along vegetative hyphae
Morphology of structures vary among species
Spores typically give the color (e.g., green, black)
Septated Hyphae
Filaments contain porous septa.
Pore allows cell materials to move.
Cells may be multinucleated
Non-Septated Hyphae
Lacks septa
multinucleated
Conidiospores are often called conidia; occur?
occur in chains
Asexual Mold Spores, 3 types
Aspergillus- condiospores
Penicillium - condiospores
Rhizopus - sporangiospores
Potential health issues related to common household molds
Molds spores are very light and disseminate rapidly in the air.
Some people are sensitive to molds.
Symptoms can include nasal stuffiness, eye irritation, wheezing, or skin irritation
More severe reactions in some include fever and shortness of breath, and potential mold infections in their lungs.
Mold spores are much easier to kill than bacterial endospores
Protozoans - eukaryotes
Protozoan diseases include
Trichomoniasis, Amoebiasis, PAM, Giardiasis, Toxoplasmosis
Protozoans - eukaryotes
Protozoans include non-pathogens and pathogens
Non-pathogen Euglena – using hanging drop technique
Pathogen Trichmonas vaginalis – observe prepared slide
Methods to Determine Motility
Flagella stain
SIM
Wet mount
Hanging drop slide (best method)
Typical Mold Asexual Reproductive Life cycle
- Asexual spores
- Spore germination
- Initial growth of vegetative hyphae
- Vegetative Mycelium development
- Reproductive Structures (aka Fruiting Bodies produce spores)
Compare and contrast Candida albicans vs Trichomonas vaginalis Diseases caused? Similarities? Transmission? Signs and symptoms? Treatment? Prevention?
Candida albicans:
Disease: Volvovaginitis (gram stain). Treatment: Nystatin, clotrimazole
Trichomonas vaginalis:
Disease: Tricomaniasis (wet prep). Treatment: metronidazole
Similarities: BOTH cause vainitis, can be spread sexualty, are eukarotic
Transmission: BOTH sexually transmitted
Signs/symptoms: BOTH itching, burning, and white discharge
Prevention: NO SEX!!
What type of specimen would you collect to diagnose?
tinea barbae?
skin scrapping from the beard (chin) area
What type of specimen would you collect to diagnose?
thrush?
oral cavity, white patches on mucous membranes
What type of specimen would you collect to diagnose?
cryptococcosis?
lung tissue
What type of specimen would you collect to diagnose?
toxoplamosis?
plasma (antibody test)
What type of specimen would you collect to diagnose?
blastomycosis?
chest xray, skin biopsy, sputum culture
Four classes of protozoa?
amoeba,, flagellates, ciliates, sporoza
Describe Sabouraud Dextrose Agar (SDA) plate
media choice for growing mold and yeast
contain increased amounts of glucose and lower acidity around pH 5-6
lower acidity inhibits many bacteria
molds are not streak plated on SDA (use inoculating needle)
yeast uses streak plate
What are molds composed of?
filaments called hyphae which interweave to form the vegetative (non reproductive) mycelium
What develops within the vegetative mycelium?
foot cells develop from which asexual reproductive structures will develop. These reproductive structures are also referred to as fruiting bodiesYeas
Yeast characteristics? Most common?
non motile unicellular fungi that reproduce asexually by forming buds (blastospores) eukaryotes circular, ovoid and rod shaped 5x bigger than bacteria most common: Candida albicans
Protoxoan characteristics?
eukaryotic
classified according to the structures they use for motility
Which of the following media has an acidic pH and increased glucose?
a. Sabouraud dextrose agar (SDA)
b. Chocolate agar (CA)
c. MacConkey agar (MAC)
d. Nutrient agar (NA)
Sabouraud dextrose agar (SDA)
Feedback:
Sabouraud dextrose agar is well suited for cultivating molds and yeats. It provides extra glucose (dextrose), an acidic pH of 4-5, and the humidity required for optimal growth of most fungi.
NOTE: Many bacteria prefer a neutral pH in a growth medium.
In molds, asexual reproduction uses a fruiting body to produce ______.
Select Answer:
a. ova
b. spores
c. rods
d. Blastospores
spores
Which branch of science deals specifically with the study of yeasts, molds, and mushrooms?
Selected Answer:
a. Epidemiology
b. Parasitology
c. Mycology
d. Virology
Mycology
Of the following microbes which one is considered a eukaryotic cell?
Staphylococcus aureus Escherichia coli Candida albicans Klebsiella pneumoniae Pseudomonas species Proteus vulgaris
Candida albicans
Mycelium that extends up off a surface such as an agar medium is referred to as-
a. vegetative mycelium
b. aerial mycelium
c. aggregate mycelium
d. segmented mycelium
aerial mycelium
IS THIS CORRECT????? FROM PRE-LAB 5 QUIZ
Bacterial growth in a nutrient broth that appears particulate is referred to as what type of growth?
a. Turbid
b. Favorable
c. Standard
d. Flocculent
Flocculent
