Micro Basics
What happens to normal flora is broad spectrum antibiotics are taken?
eliminate beneficial flora, leading to overgrowth of opportunistic pathogens (e.g., Clostridium difficile infection).
What is a bacteria embedded in a protective matrix on surfaces that increases antibiotic resistance and is seen on medical devices (catheters, implants)?
biofilm
Which phase of bacterial growth has rapid growth?
Exponential phase
What is the pathway that the Central Dogma describes?
DNA - RNA - Protein
(transcription & translation)
What is a qualitative sensitivity test?
Kirby-Bauer test
Temporarily present type of flora that does not establish long-term colonization
Transient Flora
What type of cell has no nucleus, single circular chromosome, 70S ribosome, and no organelles?
Prokaryotes
What type of bacteria has a higher salt environmental requirement?
Halophilic
Continuous replication in 5-3 direction (using the 3-5 strand)
Leading strand
What type of cell wall inhibitors bind Transpeptidase enzymes called Penicillin-binding Proteins: inhibit formation of protein bridges
Beta-lactams
What are the 3 roles of normal flora?
Competes with pathogens for resources (antagonism).
Produces vitamins (K, B) in the gut.
Stimulates the immune system (priming).
What gram has thin peptidoglycan, outer membrane with LPS, and periplasmic space?
Bonus if you know what color it stains
Gram-negative
What type of -phile prefers elevated CO2?
Capnophile
What are the numbers for prokaryotic ribosome subunits?
(__s +__s = __s)
30S+50S=70S
What is a protein synthesis inhibitor that
-Block attachment of tRNA to ribosome
-Gram-negative and gram-positive
-Many bacteria resistant
-Bone-seeking; cause yellow discoloration in teeth
-Don’t use in kids under 12, pregnant women (liver necrosis)
Tetracyclines (30S, bacteriostatic)
Where are Staphylococcus epidermidis and Propionibacterium acnes primarily found?
Skin
What are cell structure is dormant, highly resistant, and seen in Bacillus and Clostridium?
Endospores
What type of metabolism does not require oxygen, has low ATP yield, produces acids, gases, alcohols, and uses ORGANIC molecules as the final electron acceptor?
Fermentation
What type of gene transfer allows for uptake of naked DNA from the environment and requires bacterial competence?
Transformation
-What is a Nucleic Acid Synthesis Inhibitor that
-Works against gram-negative aerobes and facultative anaerobes
-Oral absorption
-Adverse effects: GI, rash and crystalluria
-Not for children, pregnant or nursing, epilepsy, CNS problems, patients who have had a stroke, QT prolongation
Fluoroquinolones (DNA gyrase)
Where are Streptococci and Neisseria spp found?
Mouth/Throat
What gives the cell wall shape and strength in prokaryotic cells?
Peptidoglycan
What type of media distinguishes species based on biochemical properties?
BONUS if you can give an example of a differential agar
Differential
Ex: Blood agar
What type of mobile genetic element carries antibiotic resistance or virulence genes and is self-replicating?
Plasmids
What metabolic pathway inhibitor inhibits folic acid synthesis?
Sulfamides and trimethoprim