Microbiology Review

Question 1

What color are gram (+) bacteria’s when a gram stain is done?

Answer 1

Crystal violet

Question 2

What color are gram (-) bacteria’s when a gram stain is done?

Answer 2

Red

Question 3

Which bacteria (+ or -) has a rigid/thick outer layer? What is the layer called?

Answer 3

Gram positive; peptidoglycan

Question 4

Which bacteria (+ or -) is not easily stained? Why?

Answer 4

Gram (-); a lipopolysaccharide layer does not allow the dye to adhere to peptidoglycan

Question 5

How many layers does a gram (+) bacteria have?

Answer 5

Two

Question 6

How many layers does a gram (-) bacteria have?

Answer 6

Three

Question 7

How many groups of bacteria are divided by gram stains?

Answer 7

Three (Red, Crystal violet, and bacteria that do not stain)

Question 8

How are bacteria named?

Answer 8

With a genus (first name) and species (last name)

Question 9

(T/F) - Nomenclature for bacteria have to be italicized

Answer 9

TRUE

Question 10

(T/F) - Bacteria cannot be grouped under a non-species name

Answer 10

FALSE - they can in some cases; for example: Enterobacteriaceae

Question 11

What common morphology (forms) are Gram (+)?

Answer 11

Cocci

Question 12

(T/F) - Bacilli can occur in gram (+)

Answer 12

True; uncommon though

Question 13

What genus bacteria(s) forms cocci clusters? Is it gram (+ or -)?

Answer 13

Staphylococcus; Gram (+)

Question 14

What genus bacteria(s) form cocci chains? Is it gram (+ or -)?

Answer 14

Streptococci (also Enterococci); Gram (+)

Question 15

What test helps differentiate staphylococcus and streptococcus/enterococcus?

Answer 15

Rapid catalase test

Question 16

If the catalase test comes out positive, what genus is it?

Answer 16

Staphylococcus

Question 17

If the catalase test comes out negative, what genus is it?

Answer 17

Streptococcus or Enterococcus

Question 18

Which test is helpful to differentiate Staphylococcus aureus with Staphylococcus epidermidis?

Answer 18

Coagulase test

Question 19

Which staphylococcus is virulent (deadly), S. epidermidis or S. aureus?

Answer 19

Staphylococcus aureus

Question 20

If a coagulase test is positive, what staph species would that indicate? How would it look like in test tube?

Answer 20

Staphylococcus aureus; coagulated

Question 21

If a coagulase test is negative, what staph species would that indicate? How would it look in a test tube?

Answer 21

Staphylococcus epidermidis; no coagulation

Question 22

Which staph species contaminates the blood more?

Answer 22

Staph. epidermidis

Question 23

What test helps differentiate streptococci species?

Answer 23

Hemolysis

Question 24

How many hemolysis tests are there? Name them

Answer 24

3

• Beta
• Alpha
• Non-hemolytic (gamma)

Question 25

Which hemolysis test is described as complete hemolysis (kills blood cells)

Answer 25

Beta

Question 26

Which hemolysis test is described as an incomplete hemolysis (does not completely kill blood cells)?

Answer 26

Alpha

Question 27

Which hemolysis test cannot lyse blood cells?

Answer 27

Non-hemolytic (gamma)

Question 28

The hemolysis test that results in clear zones around the colonies in an agar plate, is which one?

Answer 28

Beta

Question 29

The hemolysis test that results in no effect in the colonies in an agar plate, is which one?

Answer 29

Non-hemolytic (gamma)

Question 30

The hemolysis test that results in a greenish halo around the colonies in an agar plate, is which one?

Answer 30

Alpha

Question 31

If alpha hemolysis occurs, what streptococcus species could it be?

Answer 31

- Streptococcus pneumoniae | - Viridians streptococcus

Question 32

If non-hemolytic occurs, what genus could it be?

Answer 32

Enterococci

Question 33

If beta hemolysis occurs, what streptococcus could it be?

Answer 33

Group A and B streptococcus

Question 34

Which gram (+) cocci are anaerobe(s)? HINT: 2 types

Answer 34

Peptostreptococcus | Peptococcus

Question 35

Define aerobic bacteria

Answer 35

oxygen is needed as an electron acceptor in the electron transport chain

Question 36

Define obligate aerobes

Answer 36

Must have oxygen

Question 37

Define facultative aerobes

Answer 37

Can live in both aerobic and anaerobic environments

Question 38

Define anaerobic bacteria

Answer 38

Lives in an anaerobic environment (no oxygen)

Question 39

What are two types of resistant strains? Name abbreviation and name

Answer 39

``` MSSA = Methicillin Sensitive Staph aureus MRSA = Methicillin Resistant Staph aureus ```

Question 40

What is the name of the Beta-lactam drug that can ONLY be used for MRSA? What class is it in?

Answer 40

Ceftaroline; 5th generation cephalosporin

Question 41

What are the two most common enterococci?

Answer 41

Enterococcus faecalis | Enterococcus faecium

Question 42

Which enterococcus species (faecalis or faecium) is more resistant?

Answer 42

Enterococcus faecium

Question 43

Which enterococcus species (faecalis or faecium) is more commonly to occur?

Answer 43

Enterococcus faecalis

Question 44

What gram (+) bacilli are aerobes? HINT = 3 types

Answer 44

- Listeria monocytogenes - Bacillis anthracis - Corynebacterium

Question 45

What gram (+) bacilli are anaerobes? HINT = 3 types

Answer 45

- Clostridium - Propionibacterium - Lactobacillus

Question 46

Which aerobic gram (+) bacilli is more common in the very old and very young?

Answer 46

Listeria monocytogenes

Question 47

What common morphology (forms) are in gram (-)?

Answer 47

Bacilli (rods)

Question 48

If gram (-) cocci appears, it could indicate what?

Answer 48

Neisseria meningitidis

Question 49

What test can be used to distinguish fermenter and nonfermenter gram (-) bacteria?

Answer 49

Glucose/lactose fermentation

Question 50

Which gram (-) bacilli family ferments glucose/lactose?

Answer 50

Enterobacteriaceae

Question 51

Gram (-) bacilli that are fermented are also known as:

Answer 51

Enteric gram (-) bacilli

Question 52

Gram (-) coccobacillary are known as (HINT: 3 types)

Answer 52

H. influenzae Moroxella Acinetobacter

Question 53

What are the 4 gram (-) bacilli that are nonfermenters?

Answer 53

Pseudomonas Stenotrophomonas Burkholderia Acinetobacter

Question 54

How are nonfermenters gram (-) bacilli treated?

Answer 54

With a broad spectrum antibiotic

Question 55

Why are nonfermenter gram (-) bacilli treated with a broad spectrum antibiotc?

Answer 55

Because they are very resistant to most antibiotics

Question 56

What are the 3 anaerobic gram (-) bacilli?

Answer 56

- Bacteroides - Prevotella - Fusobacterium

Question 57

What are fastidious organisms in gram (-) bacteria?

Answer 57

They are picky eaters - grow slowly and often require specially supplemented media

Question 58

How is a glucose/lactose fermentation identified in an agar plate? (positive glucose/lactose test)

Answer 58

A dark red color

Question 59

If bacteria do not stain in a gram (-) bacilli, what are they known as?

Answer 59

Atypical organisms

Question 60

Name 3 types of atypical organisms?

Answer 60

Chlamydia spp Mycoplasma Legionella