Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Y2 - Dermatology > Microbiology > Flashcards

Microbiology Flashcards

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

How do staph and strep bacteria tend to enter the body?

A

Staph - through sebaceous glands

Strep - through damage in skin

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

What can toxins on staph aureus cause?

A

Toxic shock

Scalded skin syndrome

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

What skin infections can staph aureus cause?

A 
Rash
Folliculitis
Abscess
Carbuncle
Impetigo
Scalded skin syndrome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which staphylococcus is coagulase positive?

A

Staph aureus

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

What are virulence factors?

A

The ways in which bacteria kill

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

What are examples of staph aureus virulence factors?

A 
Coagulase
Fibrinogen binding protein
Superantigens
Toxinoses (PVL (Panton-Valentine Leukotoxin), gamma and alpha toxin)
Protease
Capsule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are examples of staph aureus virulence factors?

A 
Coagulase
Fibrinogen binding protein
Toxinoses
Adhesions
PVL (Panton-Valentine Leukotoxin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does coagulase aid pathogenesis?

A

Physical protection that allows better adherence to a site

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

What is TSST-1?

A

A toxin released by staph aureus that causes toxic shock syndrome
Gets into blood and causes rapidly progressing, life-threatening illness
Overstimulates immune response

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

What are the clinical features of toxic shock syndrome?

A

Fever (39˚)
Diffuse malar rash and desquamation
Hypotension
>3 organ systems involved

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

Why is toxic shock syndrome associated with menstrual toxic shock?

A

If a tampon is contaminated with staph aureus, TSST-1 gets into the blood stream via the vagina

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

How do adhesions contribute to pathogenesis?

A

Increase ability to colonise a site

Bind to fibrinogen-binding, fibrontectin-binding and collagen-binding molecules

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

What does PVL positive staph aureus cause?

A

Sepsis
Necrotising fasciitis
- very severe, life-threatening

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

Who are at risk of staph epidermidis infection?

A

Immunocompromised

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

Does staph epidermidis coagulate plasma?

A

No - coagulase negative

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

What is MRSA?

A

Methylin resistant staph aureus associated with hospitals

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

Describe streptococcus pyogenes?

A 
Group A strep
Gram positive cocci in chains
Catalase negative
Beta haemolysis
Lancefield classification A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are examples of skin infections does strep pyogenes cause?

A

Impetigo
Cellulitis
Necrotising fasciitis

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

What are examples of non skin conditions that strep pyogenes causes?

A

Pharyngitis, tonsillitis (sore throat)
Rheumatic fever
Glomerulonephritis

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

What are the virulence factors of strep pyogenes?

A 
Capsule
M-protein (lets it bind to several proteins)
Haemolysins
Superantigenic toxins
DNAases
Fibronectin-binding proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is impetigo?

A

Contagious infection of the superficial skin

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

What is cellulitis?

A

Deeper skin infection with invasion oft he dermis and subcutaneous fat
Patients have fever, rights, nausea

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

What is necrotising fasciitis?

A

Infection that penetrates deep, into muscles and other subcutaneous structures
Rapid destruction of connective tissue can lead to toxic shock, amputation

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

What are the causative organisms for type 1 and 2 necrotising fasciitis?

A

1 - clostridia

2 - strep pyogenes, staph aureus

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

What is streptomycin S (SLS)?

A

Pore-forming cytolysin - secretes substance that is toxic to cells

26
Q

How does a capsule contribute to pathogenesis?

A

Anti-phagocytic

27
Q

How does fibrinogen binding protein contribute to pathogenesis?

A

Adhesion

28
Q

How do haemolysins alpha, beta, delta and gamma contribute to pathogenesis?

A

Cytolytic

29
Q

How does coagulase contribute to pathogenesis?

A

Clots plasma

30
Q

How does fibrinolysin contribute to pathogenesis?

A

Digests fibrin

31
Q

How does leukocidin (PVL) contribute to pathogenesis?

A

Kills leukocytes

32
Q

How does protein A contribute to pathogenesis?

A

Anti-phagocytic

33
Q

What is the best antibiotic for staph aureus?

A

Flucloxacillin

34
Q

What antibiotics are effective against MRSA?

A

Doxycycline
Co-trimoxazole
Clindamycin
Vancomycin (if more sick)

35
Q

Which antibiotic that is effective against MRSA should be avoided, and why?

A

Clindamycin - one of the 4Cs, carries risk of C. diff

36
Q

What is the key thing to know about staph epidermidis?

A

It is not as likely to be pathogenic as staph aureus - often just commensal

37
Q

What skin conditions can be caused by strep pyogenes (group A strep)?

A 
Infected eczema
Impetigo
Cellulitis
Necrotising fasciitis
Erysipelas
38
Q

What is the treatment for strep pyogenes infection?

A

Penicillin

or flucloxacillin

39
Q

What is suspected if there is a little bit of redness in skin which looks like cellulitis but patient in much more pain than you would expect?

A

Necrotising fasciitis

40
Q

What is the treatment for necrotising fasciitis?

A

Immediate surgical debridement

41
Q

What are the most important fungal diseases?

A

Candidisais

Tinea

42
Q

What is the pathogenesis of fungal infections?

A

Fungus enters abraded or soggy skin
Hyphae spread in stratum corner
Infects keratinised tissues only
Increased epidermal turnover causes scaling
Inflammatory response provoked in the dermis
Hair follicles and shafts involved
Lesions grows outwards and heals in the centre, giving a ‘ring’ appearance

43
Q

What is the most common organism to cause fungal infections?

A

Trichophyton rubrum

44
Q

How are fungal infections diagnosed?

A

Clinical appearance
Woods light
Skin scrapings, nail clippings, hair

45
Q

Which part of a lesion should a sample be taken from?

A

The edge - as it grows outwards and heals in the centre, the outside is where the organisms are

46
Q

Why are fungal infections usually not cultured?

A

Can usually tell from appearance, takes ages and doesn’t change treatment

47
Q

What is the treatment for a small fungal infection?

A

Clotrimazole cream

Topical amorolfine nail paint

48
Q

What is the treatment for an extensive fungal infection?

A

Oral terbinafine or itraconazole

49
Q

Which areas are candida infections common in?

A

Under breasts, groin, abdominal skin folds, nappy area in babies

50
Q

How is diagnosis of candida infection done?

A

Swab for culture

51
Q

What is the treatment for candida infection?

A

Clotrimazole cream

Oral fluconazole

52
Q

What are the most common examples of parasitic infections?

A

Lice

Scabies

53
Q

How does scabies present?

A

Intensely itchy rash affecting finger webs, wrists, genital area

54
Q

What is the treatment for parasitic infections?

A 
malathion lotion
Benzyl benzoate (not in children)
55
Q

What are examples of viral diseases that present in the skin?

A

HSV
HPV
Varicella-Zoster virus (chicken pox)
Viral exanthems

56
Q

What are examples of viral exanthems?

A 
Enterovirus
Rubella
EBV
Adenovirus
Dengue virus
HIV
57
Q

What are the erythematous exanthems that tend to start on the face?

A

Measles (with bit of conjunctivitis)

Rubella

58
Q

What are the erythematous exanthems that tend to start on the trunk?

A

Scarlet fever

59
Q

What are the paulo-vesicular exanthems (raised bumps with fluid)?

A

Chickenpox

60
Q

What are exanthems of the extremities?

A

Hand foot and mouth disease

Y2 - Dermatology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions