BACTERIOLOGY Flashcards
Smallest units capable of independent existence
Living Cells
Usually less than 5um in length
Prokaryotic Cell
Membrane-bound organelles are present
Eukaryotic Cells
80S ribosomes in cytoplasm; 70S ribosomes in mitochondria and chloroplasts
Eukaryotic Cell
Nucleic acid occurs as a single molecule, often circular
Prokaryotic Cell
Nuclear membrane and nucleolus absent
Prokaryotic Cell
Unicellular and are smaller and less complex than eukaryotic cells such as mammalian red blood cells
Bacteria
Bacteria occur as _______, _______, _________ forms and occasionally as ____________.
rods, cocci, helical ; branching filaments
Readily seen using conventional light microscopy
Red Blood Cell
Rod shaped cells, usually stained by the Gram method. Using bright-field microscopy, a magnification of 1000x is required to observe most bacterial cells.
Bacillus
Spherical-shaped cells, often occuring in chains or in grape -like clusters.
Coccus
Thin, helical bacteria, dark field microscopy (without staining) or special staining methods are required to demonstrate these unusual microorganisms.
Spirochaete
Yeasts, molds and mushrooms belong to a large group of non-photosynthetic eukaryotes.
Fungi
Produce filamentous microscopic structures called molds.
Multicellular fungi
Yeast; spherical or ovoid shape and multiply by budding
Unicellular fungi
Often occur in chains or grape-like clusters
Coccus
Reproduce by budding
Yeast
Branched structures (hyphae) composed of many cells.
Mould
Considered plant-like because they contain chlorophyll; free living in water, others grow on the surfaces of rocks and on other structures in the environment.
Algae
They are not cells and consist of nucleic acid, either DNA or RNA, enclosed in a protein coat called capsid.
Viruses
Viruses which invade bacterial cells.
Bacteriophages
Readily seen at magnification of 1000x
Coccus
devoid of nucleic acid, composed of abnormally folded protein capable of inducing conformational chages in host cell protein then damages long-lived cells such as neurons.
Prions
exhibit remarkable resistance to physical and chemical inactivation procedures.
Prions
Stain of Gram-positive bacteria
purple-blue
Stain of Gram-negative bacteria
red
Gram positive, cluster-forming cocci; nonmotile, facultative anaerobes, catalase-positive; fermentative, grow on non-enriched media.
Staphylococcus species
detects the presence of a bound coagulase or clumping factor on the bacterial surface.
Slide test
detects free coagulase or staphylocoagulase which is secreted by the bacteria into the plasma.
Tube test
Staphylococcus aureus virulence factors
coagulase
protein A
leukocidin
beta and alpha toxin
toxic-shock syndrome toxin (TSST)