Microbiology

Question 1

gram (+) bacteria is what color & what does it indicate

Answer 1

purple, has thick cell walls

Question 2

acid-fast stains are used for

Answer 2

mycobacteria (tuberculosis)

Question 3

what are the 4 nonselective culture media

Answer 3

blood agar, chocolate agar, thioglycolate broth, sabouraud dextrose agar

Question 4

which nonselective culture media grows most bacteria & fungi

Answer 4

blood agar

Question 5

which nonselective culture media grows most bacteria, including haemophilus & neisseria

Answer 5

chocolate agar

Question 6

which nonselective culture media is an enrichment broth for anaerobic bacteria

Answer 6

thioglycolate broth

Question 7

which nonselective culture media is used for recovering fungi

Answer 7

sabouraud dextrose agar

Question 8

MacConkey agar is selective for what bacteria

Answer 8

gram-negative bacteria

Question 9

what amplifies single copies of viral DNA & is very useful for detecting retroviruses, herpesviruses, & papillomaviruses

Answer 9

polymerase chain reaction (PCR)

Question 10

what is used to quantify the amount of DNA or RNA in a sample & is useful for quantifying the number of HIV genes in a patient’s blood

Answer 10

real-time PCR

Question 11

what structure in bacteria is involved in antibiotic resistance

Answer 11

plasmids

Question 12

how are symptoms from bacterial infections produced

Answer 12

by excessive innate, immune, & inflammatory responses triggered by the infection

Question 13

are staphylococci & streptococci gram-positive or gram-negative

Answer 13

gram-positive (thick cell wells)

Question 14

what are the most common gram-positive cocci

Answer 14

staph aureus, staph epidermis

strep pneumonia, strep pyogenes, strep viridians

Question 15

actinomyces & nocardia are what kind of pathogens

Answer 15

gram-positive filaments

Question 16

neisseria is what kind of pathogen

Answer 16

gram-negative cocci

Question 17

which gram-negative bacilli causes purulent conjunctivitis & angular blepharitis

Answer 17

moraxella

Question 18

what gram-negative bacilli is found in decaying plant material & stagnant fresh water

Answer 18

pseudomonas aeruginosa

Question 19

hemophilus influenzae is gram ____ & can cause what that involves the eye

Answer 19

gram negative bacilli

causes orbital cellulitis

Question 20

what is an enterobacteria that can contaminate CL solutions

Answer 20

serratia marcescens

Question 21

what spirochete causes Lyme disease

Answer 21

borrelia burgdorferi

Question 22

what kind of pathogen is treponema pallidum, what is it sensitive to, & what does it cause

Answer 22

spirochete, sensitive to penicillin, causes syphilis

Question 23

what are the 3 tests used to diagnose syphilis

Answer 23

VDRL, RPR, FTA-Abs

Question 24

which syphilis diagnostic test is specific & will remain positive even after treatment

Answer 24

FTA-Abs

Question 25

what is the difference between VDRL & RPR

Answer 25

VDRL - detects non-treponemal antibodies | RPR - detects non-treponemal antibodies made against T. pallidum

Question 26

why do mycobacterium require acid-fast staining

Answer 26

they have a lipid-rich cell wall that's resistant against disinfectants, sterilization, heat & chemicals

Question 27

is chlamydia a bacteria or a virus

Answer 27

bacteria that behaves like a virus

Question 28

chlamydia trachomatis serotypes A-C cause _____ & D-K cause ______

Answer 28

A-C: trachoma | D-K: inclusion conjunctivitis

Question 29

what causes symptoms in viral diseases

Answer 29

the immune reaction against the virus

Question 30

what are the 3 things viruses consist of

Answer 30

viral genome (DNA or RNA), capsid (protein shell), lipoproteins (envelopes surrounding capsid in SOME viruses)

Question 31

why are viruses obligate intracellular parasites

Answer 31

they depend on host cell's biochemical machinery for replication

Question 32

naked capsid allows a virus to

Answer 32

spread easily, survive GI passage, & resist dryness & detergents

Question 33

enveloped capsid allows a virus to

Answer 33

spread through body fluids & organs

Question 34

which virion type is suceptible to antibiotics

Answer 34

naked capsid

Question 35

which virion type requires a more complex immune response

Answer 35

enveloped capsid

Question 36

which virion type requires cell lysis for replication

Answer 36

naked capsid

Question 37

which virion type causes more hypersensitivity reactions

Answer 37

enveloped capsid

Question 38

where do viruses replicate

Answer 38

host's nucleus or cytoplasm

Question 39

describe the lytic life cycle

Answer 39

for naked capsid viruses → enters cell → transcribed → fills cell with capsid → cell bursts & releases the capsids

Question 40

describe the lysogenic life cycle

Answer 40

virus inserts itself into host's genome → gradually produces & releases viruses over time

Question 41

which life cycle allows the host cell to survive longer & why

Answer 41

lysogenic → virus incorporates itself into the cell | the longer the host cell lives → the longer it can sustain infection

Question 42

what are some viruses that use the lysogenic life cycle

Answer 42

HIV, herpes viruses

Question 43

what bacterial element allows for transfer of DNA from one bacterium to another?

Answer 43

pili