Micro Clinical Review Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Gram negative, rod-shaped, and facultative anaerobe.

Catalase: +
Oxidase: -
Indole: +
MR: +
VP: -
Citrate: -
Nitrate: +
PYR: -
TSI: A/AG
Urease: -
Lactose: F
Decarboxylase: L+
MUG: +
ONPG: N/A

A

Escherichia Coli

Opportunistic, causes UTI, neonatal meningitis, wound infections, and septicemia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Gram negative, rod-shaped, encapsulated, nonmotile.

Oxidase: -
Indole: -
MR: -
VP: +
Citrate: +
Nitrate: +
TSI: A/AG
Urease: +
Lactose: F
Decarboxylase: L+, O-
MUG: +
ONPG: +

A

Klebsiella pneumonia

Enterobacteriaceae family. Causes nosocomial infections including UTI, bloodstream infections, lower respiratory tract, cardiovascular, wound, ear, nose, and throat infections.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Gram negative rods. Motile.

Oxidase: -
Indole: V
MR: +
VP: -
Citrate: +
Nitrate: +
TSI: A/AG, H2S
Urease: V
Lactose: F (late)
Decarboxylase: L-,O-
MUG: N/A
ONPG: N/A

A

Citrobacter freundii

Enterobacteriaceae family. Natural intestinal microflora, but causes UTI.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Gram negative rods. Motile. Facultative anaerobe.

Oxidase: -
Indole: -
MR: V
VP: V
Citrate: +
Nitrate: +
TSI: A/A (+/-G)
Urease: +
Lactose: F
Decarboxylase: N/A
MUG: N/A
ONPG: N/A

A

Serratia marcescens

Family Enterobacteriaceae. Opportunistic, causing nosocomial respiratory, UTI, or blood infections.

Red pigment called prodigiosin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Gram negative rod.

Indole: -
MR: -
VP: +
Citrate: +
TSI: A/A (+/-G)
Urease: -
Lactose: F
Decarboxylase: Triple (-)
MUG: N/A
ONPG: +

A

Enterobacter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Lactose fermenter

A

Pantoea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Gram negative rods, peritrichous flagella (motile).

Indole: -
MR: +
VP: -
Citrate: -
TSI: K/AG, H2S
Urease: -
Lactose: NF
Decarboxylase: L+
MUG: -
ONPG: -

A

Salmonella

Causes salmonellosis, typhoid fever (S. typhi), or paratyphoid fever (S. paratyphi).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Gram negative rods, non-motile, non-spore forming.

Oxidase: -
Indole: V
MR: +
VP: -
Citrate: -
Nitrate: +
TSI: K/A
Urease: -
Lactose: NF
Decarboxylase: L- (sonnie = O+)
MUG: N/A
ONPG: - (sonnie = +)

A

Shigella

Enterobacteriaceae family. Causes shigellosis, traveler’s diarrhea.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Gram negative, rod-shaped, facultative anaerobe. Swarms on colonies (motile).

Oxidase: -
Indole: -
MR: ++
VP: - -
Citrate: - (v)
Nitrate: +
TSI: K/A, H2S
Urease: + strong
Lactose: NF
Decarboxylase: O+
MUG: N/A
ONPG: N/A

A

Proteus mirabilis

Causes cystitis and pyelonephritis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Indole: +
MR: +
VP: -
Citrate: -
TSI: K/AG
Urease: +
Lactose: NF
Decarboxylase: N/A
MUG: N/A
ONPG: N/A

A

Morganella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Indole: +
MR: +
VP: -
Citrate: +
TSI: K/A (+/-G)
Urease: -
Lactose: NF
Decarboxylase: N/A
MUG: N/A
ONPG: N/A

A

Providencia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Indole: -
MR: +
VP: -
Citrate: -
TSI: K/K
Urease: -
Lactose: NF
Decarboxylase: O-
MUG: N/A
ONPG: N/A

A

Yersinia Pestis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Almost all
Catalase: +
Nitrate: +
Oxidase: -

A

Enterobacteriaceae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What microbes use the Phenylalanine Deaminase Test (PAD test)

A

Differentiates Proteus, Morganella, and Providencia from other Enterobacteriaceae.

Test determines if the organism is able to produce deaminase enzyme, which removes the amine group phenylalanine. When it is removed, it is released as ammonia and phenyl pyruvic acid is produced.

Positive = dark green
Negative = No color change

*Note: most stool pathogens are urease negative.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the principles of the: catalase test?

A

The production of catalase turns hydrogen peroxide into water and oxygen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the principles of the: Oxidase test?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the principles of the: Coagulase test?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the principles of the: DNAse test?

A

The ability of an organism to digest DNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the principles of the: Hippurate hydrolysis test?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the principles of the: Bile esculin hydrolysis test?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the principles of the: CAMP test?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the principles of the: bile solubility test?

A

Differentiates Strep pneumoniae from alpha-hemolytic streptococcus.
S. pneumoniae will lyse in the presence of bile salts where other streptococcus will not.

23
Q

What are the principles of the: IMViC test?

A

A mix of Indole, methyl red, Vogue’s Proskauer, and citrate testing.

24
Q

What are the principles of the: TSI test?

A

The TSI (triple iron agar) test is used to differentiate bacteria based on carbohydrate fermentation (lactose, glucose, and sucrose).
Glucose is on the bottom, sucrose and lactose on the top.
Also detects hydrogen sulfide production.

25
Q

What are the principles of the: nitrate test?

A

Nitrate –> nitrite –> nitrogen, nitrous oxide, or nitric oxide.
Nitrite + sulfanilic acid (reagent A) + alpha naphthylamine (reagent B) –> red complex (prontosil).
If zinc powder results in a red color change, then no reduction took place.
If zinc powder results in no color change, then nitrate was reduced to nitrogen.

26
Q

What are the principles of the: LIA test?

A

The LIA (lysine iron agar) test determines glucose fermentation.
When glucose is fermented, the butt of the tube becomes yellow (acidic).
If the organism produces lysine decarboxylase, then cadaverine (acid neutralizer) is formed and butt of the tube becomes purple (alkaline).

27
Q

Gram negative, rod-shaped, motile.

Catalase: +
Oxidase: -
Indole: -
MR: -
VP: +
Citrate: +
Nitrate: +
TSI: A/A or A/AG
Lactose: F

Intrinsic resistance to ampicillin, amoxicillin, and 1st and 2nd generation cephalosporins.

A

Enterobacter cloacae complex

Naturally found in GI, but causes Nosocomial infections outside GI. UTIs, wound infections pneumonia, and bacteremia.

28
Q

Gram negative rod. Polar flagella (motile), and non-spore forming.

Catalase: +
Oxidase: +
Nitrate: +
TSI: K/NC
Lactose: NF

A

Pseudomonas aeruginosa

Nosocomial infections. Causes folliculitis, otitis externa, otitis media, eye infections, and traumatic wound infections.
Respiratory infections in cystic fibrosis patients.

29
Q

Gram negative rods. Curved, motile, and halophilic (obtained from shellfish, crabs, shrimp, and prawns).

Catalase: +
Oxidase: +
Indole: +
TSI: K/A
Lactose: NF
Nitrate: +
Decarboxylase: L +
Deaminase: O +

What does the string test differentiate?

A

Vibrio

Acute diarrhea and wound infections.

Vibrio cholera has cholera toxin causing watery diarrhea and dehydration.

Differentiates Vibrio cholera (+) from other Vibrio spp (-).

30
Q

Gram negative bacillus, aerobic and non-fermentative. Motile with polar flagella.

Catalase: +,
Oxidase: -
DNAse: +

A

Stenotrophomonas maltophilia

Found in various aquarium environments, soil and plants.

Nosocomial.
Causes: bacteria, Meningitis, UTI, endocarditis,
keratitis, lower respiratory tract infection in patient with cystic fibrosis

30
Q

Gram negative rods,

Resistance to ampicillin, aztreonam and gentamicin.

Colonies are white with a thin, spreading irregular edge.

Oxidase: +
Indole: -

Asaccharolytic nonfermenters.

Which can reduce nitrite, but not nitrate?
Which can reduce both?

A

Alcaligenes faecalis & Alcaligenes-like group 1

Found in water, soil, and moist areas.

A. Faecalis is the most common isolated species and is an occasional cause of nosocomial
infections (UTI’s, pneumonia and septicemia).

A. faecalis can reduce nitrite but not nitrate while CDC Alcaligenes-like group 1
can reduce both nitrate and nitrite

30
Q

Gram negative bacillus that may appear curved (seagull) with single polar flagellum.
Microaerophilic.

Campy-BAP: Grey to white, moist colonies.

Catalase: +
Oxidase: +
Nitrate: +
Hippurate: +

Negative:
H2S: -
Growth on 3.5% NaCl: -

Unique characteristics – grows best at 42C

A

Campylobacter jejuni

Campylobacteriosis – most common foodborne diarrheal illness in the US.

Symptoms: bloody diarrhea, fever, cramps, nausea, vomiting. Self limiting, but some antibiotic resistant strains have been observed. Associated with Guillain-Barre syndrome (GBS) and Reiter’s Syndrome.

31
Q

Gram negative coccobacilli that has small, pinpoint colonies that are grayish and has
a bleach smell when grown on blood agar. Non-motile, non-spore forming.

Oxidase: +
Catalase: -
Indole: -
Urease: -
Nitrate: +

A

Eikenella corrodens

Normal microflora in the mouth, upper respiratory tract and other mucosal sites in the body. It is commonly found with streptococci. It is an opportunistic pathogen associated with human bites, dental extractions or oral trauma.

32
Q

Gram-negative bacilli with variable shape. Small.
Nonmotile, non-spore forming, facultative anaerobes. Fastidious. Non- hemolytic.

Nitrate reduction: +
δ- aminolevulinic acid test: - (does not fluoresce)

Chocolate agar: grayish, semi-opaque, smooth and flat colonies

Blood agar: no growth
Encapsulated strains: dense growth
Non-encapsulated strains: separate colonies
Indole producing strains have a pungent aroma
Non-indole producing strains have a “mouse nest” odor

Quad Plate: ???

Many strains are resistant to ampicillin, other β-lactam antibiotics,
chloramphenicol, and tetracyclin.

A

Haemophilus influenzae

Causes bacterial meningitis, purulent bacterial conjunctivitis, otitis media, sinusitis, and lower respiratory tract infections.

Antiphagocytic due to polysaccharide capsule.

H. influenzae = X factor (hemin) & V factor (NAD) for growth
o δ- aminolevulinic acid test: negative (does not fluoresce)
o Additional methods: Rapid NH or MALDI-TOF

33
Q

Gram negative, coffee-bean shaped diplococci

Catalase: +
Oxidase: +
Glucose: F
Maltose: F
Nitrate: -

Grows on blood agar, chocolate agar and Thayer martin agar.

A

Neisseria meningitidis

Has many virulence factors: pili, IgA protease, produces an endotoxin,
and has a capsule.

Causes Meningococcal disease spread by respiratory droplets from an infected person. Causes inflammation of the meninges. Anyone can be infected, but the highest rate worldwide is in
the “meningitis belt” in sub-Sarahan Africa

34
Q

Gram negative, diplococci

Glucose: F
Maltose: NF
Lactose: NF
Nitrate: -
0.1% nitrite reduction: -

Growth on modified Thayer-Martin
No growth on nutrient agar at 35°C, No growth on blood or chocolate agar at 25°C

A

Neisseria gonorrhoeae

Transmitted sexually or during birth.

Causes acute cervicitis in females and acute purulent urethritis, prostatitis, epididymitis in males.

Can also cause pharyngitis, anorectal infections, and conjunctivitis. Disseminated infections can include pelvic inflammatory disease, bacteremia, arthritis, and
metastatic infection.

35
Q

Gram negative diplococci (coffee bean).
Smooth, large, round, pinkish-brown opaque hockey puck colonies.

Catalase: +
Oxidase: +
Nitrate: +
DNAse: +
MCAT: +

Growth on chocolate agar.

A

Moraxella catarrhalis

Respiratory tract infections:
Upper RT = otitis media, sinusitis, and pneumonia
Lower RT = COPD

36
Q

Gram positive cocci in clusters. Facultative anaerobic.

Catalase: +
Coagulase: -

No hemolysis

A

Staphylococcus epidermidis

Nosocomial infections: UTI

37
Q

Gram positive cocci in clusters.

Catalase: +
Coagulase: +
DNAse: +

A

Staphylococcus aureus

Causes toxic shock syndrome, scalded skin syndrome, food poisoning, skin infections, bacteremia, endocarditis, pneumonia, and osteomyelitis.

38
Q

Gram positive cocci in chains.

Vancomycin: S
LAP: +
PYR: -
Coagulase: -
Catalase: -

A

Streptococcus viridans group

Found as normal flora.

Group includes mitis, salivarius, bovis, mutans, and anginosus

39
Q

Gram positive cocci, facultative anaerobes.
Blood agar: smooth, gray colonies with alpha or gamma hemolysis.

Catalase: -
Oxidase: -
Esculin hydrolysis: +
PYR: +

A

Enterococcus faecalis & Enterococcus faecium

Nosocomial UTIs, bacteremia, pelvic and wound infections, and endocarditis.

Which ferments mannitol?

40
Q

Gram positive cocci in chains.
Large, mucoid colonies.
Beta hemolysis.

Catalase: -
PYR: +
Bacitracin: S

A

Streptococcus pyogenes (group A)

Causes pharyngitis, impetigo, and erysipelas, scarlet fever, toxic shock syndrome, necrotizing fasciitis, glomerulonephritis, rheumatic fever, and carditis.

41
Q

Gram positive cocci in chains. Facultative anaerobe.
Non-motile, non-spore forming.
Beta hemolytic.

Catalase: -
CAMP: +
Hippurate: +
Bile esculin: -

A

Streptococcus agalactiae

Causes meningitis, septicemia, endocarditis, osteomyelitis, pneumonia, skin and soft tissue infections.

42
Q

Gram positive cocci in pairs.
Alpha hemolysis.

Catalase: -
Bile solubility: +
Optochin: S

What does the Quellung test do?

A

Streptococcus pneumoniae

Causes pneumonia, otitis media, meningitis, and septicemia.

Quellung test helps visualize capsule.

43
Q
A

Listeria monocytogenes

44
Q
A

Corynebacterium spp

45
Q
A

Nocardia

46
Q
A

Brucella

47
Q
A

Francisella

48
Q
A

Burkholderia mallei

49
Q
A

Burkholderia pseudomallei

50
Q
A

Bacillus anthracis

51
Q

Gram negative rods, aerobic, peritrichous flagella (motile).

Lactose: NF
Xylose oxidizer

A

Achromobacter

Opportunistic and nosocomial infections of urinary and respiratory tract.