Bacteriology Flashcards

1
Q

Which bacteria are beta-hemolytic?

A

agh

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

Nocardia produce which gas?

A

On triple sugar media H2S.

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

Which bacteria produces H2S?

A

Erythripolocsis rhuisiopathe

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

Which bacteria have gelatinase?

A

Enterococci, Ba

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

Urease positive

A

Corynebacterium urealyticum, Corynebacterium ulcerans, Corynebacterium pseudotuberculiosis, Nocardia

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

Which bacteria are especially dangerous during pregancy?

A

Listeria monocytogenes, Strectociccus pyogenes, S. agalactiae

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

ნოვობიოცინი

A

დიფერენციაცია

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

კლამფინგ ფაქოტირი და კატალაზა

A

ლუნდუნენსი და აურეუსი

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

What type of organisms stain purple/blue with Gram staining?

A

Gram-positive organisms

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

Gram-positive organisms are commonly classified into which two shapes?

A

Cocci or rods (bacilli)

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

Name four gram-positive rods.

A

Clostridium, Listeria, Bacillus, and Corynebacterium

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

Name one gram-positive anaerobic rod.

A

Clostridium

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

Staphylococcus and Streptococcus are differentiated by which enzyme?

A

Catalase; Staphylococcus is catalase positive, and Streptococcus is catalase negative

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

Which gram-positive cocci are found in clusters?

A

Staphylococcus

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

Which gram-positive cocci are found in chains?

A

Streptococcus

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

What differentiates Staphylococcus aureus from and other staph species?

A

Other staph species are coagulase negative

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

Name two coagulase-negative Staphylococcus species.

A

Staphylococcus saprophyticus and Staphylococcus epidermidis

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

Which Staphylococcus species is novobiocin sensitive?

A

Staphylococcus epidermidis

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

Which Staphylococcus species is novobiocin resistant?

A

Staphylococcus saprophyticus

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

If agar shows clear hemolysis, which Streptococcus species could be present?

A

Streptococcus pyogenes or Streptococcus agalactiae

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

What type of hemolysis do both group A and group B streptococci have in common?

A

β-Hemolysis

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

Streptococcus pyogenes is a type of group _____ Streptococcus, whereas Streptococcus agalactiae is a type of group _____ Streptococcus.

A

A, B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How are -hemolytic streptococci differentiated from each other?

A

By their bacitracin sensitivity (Streptococcus pyogenes is sensitive, Streptococcus agalactiae is resistant)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Name two streptococci that are -hemolytic.

A

Enterococcus and Peptostreptococcus (anaerobic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

True or False: Enterococcus faecalis is a -hemolytic, gram-positive, catalase-negative cocci.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Which -hemolytic streptococcal species is bacitracin resistant?

A

Group B Streptococcus (Streptococcus agalactiae)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which -hemolytic streptococcal species is bacitracin sensitive?

A

Group A Streptococcus (Streptococcus pyogenes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Staphylococcus saprophyticus is novobiocin _____ (resistant, sensitive); staphylococcus epidermidis is novobiocin _____ (resistant, sensitive).

A

Resistant; sensitive (remember: On the staph retreat there was NO StRES; Novobiocin: Saprophyticus Resistant, Epidermidis Sensitive)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Group A streptococci are bacitracin _____ (resistant, sensitive); group B streptococci are bacitracin _____ (resistant, sensitive).

A

Sensitive; resistant (remember: Bacitracin: group B are Resistant, whereas group A are Sensitive (B-BRAS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Streptococcus viridans is optochin _____ (resistant, sensitive); streptococcus pneumoniae is optochin _____ (resistant, sensitive).

A

Resistant; sensitive (remember, Optochin: Viridans Resistant and Pneumonia Sensitive; OVRPS- overpass)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What bacterial enzyme degrades hydrogen peroxide?

A

Catalase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What antimicrobial product produced by polymorphonuclear lymphocytes is a substrate for myeloperoxidase?

A

Hydrogen peroxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Which gram-positive cocci are catalase positive?

A

Staphylococci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What differentiates Staphylococcus aureus from Staphylococcus epidermidis and Staphylococcus saprophyticus?

A

Coagulase (Staphylococcus aureus is coagulase positive)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Why do people with chronic granulomatous disease (nicotinamide adenine dinucleotide phosphate oxidase deficiency) get recurrent infections by catalase-producing organisms?

A

Bacterial catalase easily degrades the little hydrogen peroxide produced, compromising the ability of neutrophils to kill bacteria

36
Q

What is the function of Protein A, a Staphylococcus aureus virulence factor?

A

Binding to fragment crystallizable region-immunoglobulin G, to inhibit complement fixation and phagocytosis

37
Q

Name five types of infections caused by Staphylococcus aureus.

A

Skin infections, organ abscesses, pneumonia, acute bacterial endocarditis, and osteomyelitis

38
Q

Staphylococcus aureus can cause which toxin-mediated conditions?

A

Toxic shock syndrome (toxic shock syndrome toxin 1), scalded skin syndrome (exfoliative toxin), and rapid-onset food poisoning (enterotoxins)

39
Q

Which organism produces toxic shock syndrome toxin 1?

A

Staphylococcus aureus

40
Q

What is the pathophysiology of toxic shock syndrome?

A

Toxic shock syndrome toxin 1 acts as a superantigen and causes widespread release of cytokines from T cells

41
Q

Staphylococcus aureus can cause rapid-onset food poisoning as a result of what product?

A

Preformed enterotoxins

42
Q

Methicillin-resistant Staphylococcus aureus is resistant to methicillin because of its altered structure of what protein?

A

Penicillin-binding protein

43
Q

What bacterium found in normal skin flora commonly contaminates blood cultures and infects prosthetic devices and catheters?

A

Staphylococcus epidermis

44
Q

How does Staphylococcus epidermis infect prosthetic devices and intravenous catheters?

A

By producing adherent biofilms

45
Q

What four common infections does Staphylococcus pneumoniae cause?

A

Meningitis, Otitis media, Pneumonia, and Sinusitis (remember: MOPS are Most OPtochin Sensitive)

46
Q

What is distinct about the pneumonia caused by pneumococcus?

A

“Rust”-colored sputum

47
Q

Streptococcus pneumoniae sepsis occurs at a higher rate in what two patient populations?

A

Sickle cell anemia and asplenic patients

48
Q

Name two ways Streptococcus pneumoniae evades the immune system.

A

Immunoglobulin A protease, encapsulation

49
Q

What three pyogenic infections does Streptococcus pyogenes cause?

A

Pharyngitis, cellulitis, and impetigo

50
Q

What two toxigenic diseases does Streptococcus pyogenes cause?

A

Scarlet fever and toxic shock syndrome

51
Q

What two immunologic conditions does Streptococcus pyogenes cause?

A

Rheumatic fever and glomerulonephritis (remember: PHaryngitis gives you rheumatic “PHever” and glomerulonePHitis)

52
Q

Streptococcus pyogenes is associated with what three major classes of disease?

A

Infectious, immunogenic, and toxigenic

53
Q

Human antibodies to Streptococcus M protein enhance host defenses but increase the risk for which complication of streptococcal infection?

A

Rheumatic heart disease

54
Q

What blood test would detect a recent Streptococcus pyogenes infection?

A

An antistreptolysin O titer

55
Q

Rheumatic fever is associated with what five symptoms?

A

Subcutaneous nodules, Polyarthritis, Erythema marginatum, Chorea, and Carditis (remember, there is no “RHEUM” for SPECCulation)

56
Q

Streptococcus agalactiae are bacitracin _____ (sensitive/resistant) and _____(//) -hemolytic.

A

Resistant

57
Q

In what population does group B Streptococcus (Streptococcus agalactiae) cause pneumonia, meningitis, and sepsis?

A

Babies (remember: B for Babies)

58
Q

What two infections do enterococci cause?

A

Urinary tract infection and subacute bacterial endocarditis

59
Q

How can group D enterococci be differentiated from nonenterococcal group D streptococci by lab testing?

A

Enterococci can grow in 6.5% sodium chloride, other group D streptococci cannot

60
Q

Lancefield grouping is based on differences in what components of the bacteria?

A

C carbohydrate on the bacterial cell wall

61
Q

True or False? Penicillin G is effective treatment against enterococci.

A

False; enterococci are resistant to penicillin G

62
Q

Enterococci resistant to which antibiotic are an important source of nosocomial infection?

A

Vancomycin

63
Q

What two infections does Streptococcus bovis cause in colon cancer patients?

A

Bacteremia and subacute endocarditis

64
Q

A young patient presents with pseudomembranous pharyngitis; what medium could be used to culture the most likely etiologic agent?

A

Corynebacterium diphtheriae grows on tellurite agar (coryne = club shaped)

65
Q

The symptoms of diphtheria are caused by what kind of toxin?

A

Exotoxin (encoded on the -prophage)

66
Q

How does diphtheria toxin inhibit protein synthesis?

A

By the adenosine diphosphate ribosylation of elongation factor 2

67
Q

What disease is caused by Corynebacterium diphtheriae?

A

Diphtheria; characterized by pseudomembranous pharyngitis (grayish-white membrane) with lymphadenopathy

68
Q

How is a laboratory diagnosis of diphtheria made based on microscopic appearance?

A

The presence of gram-positive rods with metachromatic granules (blue and red in color)

69
Q

How can diphtheria be prevented?

A

Toxoid vaccine; usually administered in combination with tetanus vaccine

70
Q

What type of bacteria form spores?

A

Gram-positive rods

71
Q

What advantages do bacteria gain by taking the form of a spore?

A

They become highly resistant to destruction by heat and chemicals and require no metabolic activity in nutrient-poor settings

72
Q

Why is it important to autoclave surgical equipment?

A

To kill bacterial spores

73
Q

What five soil-dwelling, gram-positive rods are spore formers?

A

Bacillus anthracis, Bacillus cereus, Clostridium perfringens, Clostridium botulinum, and Clostridium tetani

74
Q

Which bacteria are gram-positive, spore-forming, obligate anaerobic bacilli?

A

Clostridia species

75
Q

Name four clostridia species that produce exotoxins.

A

Clostridium tetani, Clostridium botulism, Clostridium perfringens and Clostridium difficile

76
Q

What kind of toxin produced by Clostridium tetani causes symptoms of tetanus?

A

An exotoxin called tetanospasmin

77
Q

Describe the pathogenesis of the symptoms caused by Clostridium tetani?

A

Clostridium tetani toxins block glycine (an inhibitory neurotransmitter) release from Renshaw cells in the spinal cord, leading to spastic paralysis, lockjaw (trismus), and risus sardonicus (remember: TETanus is TETanic paralysis)

78
Q

Which gram-positive bacilli are responsible for the flaccid paralysis caused by exposure to improperly canned foods?

A

Clostridium botulinum (remember: BOTulinum is from bad BOTtles of food)

79
Q

What are the characteristics of the toxin produced by Clostridium botulinum?

A

Preformed, heat-labile toxin

80
Q

What is the predominant symptom of botulism?

A

Flaccid paralysis

81
Q

How does the toxin produced by Clostridium botulinum cause flaccid paralysis?

A

It inhibits acetylcholine release

82
Q

How does the pathogenesis of botulism differ between adults and babies?

A

Adults consume preformed toxin whereas babies consume spores in honey (floppy baby syndrome)

83
Q

Which exotoxin-producing, gram-positive bacillus is responsible for gas gangrene?

A

Clostridium perfringens (remember: PERFringens PERForates a gangrenous leg)

84
Q

What is the effect of the toxin produced by Clostridium perfringens?

A

Toxin (lecithinase) causes myonecrosis, gas gangrene, and hemolysis

85
Q

Which gram-positive bacillus is responsible for pseudomembranous colitis?

A

Clostridium difficile (remember: DIfficile causes DIarrhea)

86
Q

Pseudomembranous colitis often follows a course of which antibiotics?

A

Clindamycin and ampicillin

87
Q

What kind of toxin is produced by Clostridium difficile?

A

A cytotoxin, which is an exotoxin that kills enterocytes and causes pseudomembranous colitis