Lecture 28 - Intro to Bacteriology Flashcards
T/F: eukaryotes have both cell membranes and cell walls
FALSE - prokaryotes have cell walls
describe the difference in a prokaryote compared to a eukaryote (there are 6)
- small
- single, circular plasmids
- absent nucleus
- 70s ribosomes
- binary fission division
- no organelles
Endosymbiosis hypothesis
primitive eukaryotic cells were phagocytized by bacterial cells to enhance respiratory activity
what evidence supports the endosymbiosis theory
mitochondria have their DNA and membranes
Microbes play a role in
early immune development
health conditions
What is a characteristic of bacteria?
a) nucleus
b) organelles
c) binary fission
d) multiple chromosomes
c) binary fission
Why is bacteriology IMPORTANT to vet med?
a) Food safety
b) Important cause of diseases
c) Appropriate diagnosis and treatment
d) All of the above
d) all of the above
T/F: when naming bacteria, genus, species, and subspecies are italicized
TRUE
coccus
small, round bacteria
rods
elongated bacteria
Describe Leptospira (morphology, health effects, etc.)
spirochete
liver, renal, reproductive failure + hemolysis
maintained in renal tubules
Monomorphic
similar shape and size
pleomorphic
variable, response to environment
what are 4 things bacterial anatomy can tell us
- identification/diagnosis
- understand pathogenic mechanisms
- vaccine development
- targets for control
gram + stains ____ due to a ____ wall
purple; thick
gram - stains ___ due to a ____ wall
pink; thin
describe the cellular wall of gram + cells
thick peptidoglycan wall
describe the cellular wall of gram - cells
outer membrane with lipopolysaccharides
thin peptidoglycan
what do gram + and gram - cells have in common
periplasmic space
cytoplasmic membrane
Why are mycobacterial species considered complex
thick waxy layer of mycolic acids with peptidoglycan
uses acid-fast staining
Why do spores develop
when the cell is put under negative conditions (lack of nutrients, climate, etc.)
what cell classification typically produces spores
gram +
when are spores released into the environment
by the rupture of vegetative cell
what are capsules regarding bacteria
composed of polysaccharides, proteins, glycoproteins
creates a “halo” when stained
protection against phagocytosis and used for attachment
obligate aerobe
oxygen is required
brucella
facultative aerobe
better w/ oxygen
E. coli
microaerophilic aerobe
better w/ less, but still required for growth
campylobacter
aerotolerant anaerobe
oxygen not required, but lives in the presence
necrophorum
obligate anaerobe
oxygen is harmful
Describe fusobacterium necrophorum
gram -
aerotolerant anaerobe
necrosis - anaerobic environment - abscesses
T/F: many bacteria have temperature preferences for which enzymes work best
TRUE
what is a psychrophile? why is this clinically important?
can survive at 10-15 degrees Celcius
many food-borne pathogens - the temperature range is the same as a refrigerator
Siderophore
binds iron and transports it into the bacterium; used for growth
describe the clinical importance of sulfa drugs
inhibits folic acid synthesis, broad-spectrum, bacteriostatic
treats many acute, local and systemic infections but cause of Type IV hypersensitivity
Which stain result indicates a thick, WAXY cell wall?
a) Gram-positive
b) Gram-negative
c) Acid-fast positive
d) Acid-fast negative
c) Acid-fast positive
LIPOPOLYSACCHARIDE is a component of which group?
a) Gram-positive
b) Gram-negative
c) Acid-fast positive
b) gram-negative
Which anatomic feature results in extreme heat resistance, requiring autoclaving?
a) Spore
b) Capsule
c) Waxy cell wall
d) Lipopolysaccharide
a) spore
