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Flashcards in Microbiology Deck (92):
1

What are the 2 types of staph?

Coagulase positive
Coagulase negative

2

Example of coagulase positive staph

Staph aureus

3

Examples of coagulase negative staph

Staph. epidermis
Staph. saprophyticus

4

What are gram positive cocci in chains more commonly known as?

Streptococci

5

What are the 3 categories of strep?

a-haemolytic
B-haemolytic
non-haemolytic

6

What are the 2 a-haemolytic strep?

Strep. pneumoniae
Strep.viridans

7

Which organism is non-haemolytic strep?

Enterococcus sp.

8

Common infections caused by staph aureus?

Wound
Skin
Bone
Joint

9

What infections tend to be caused by staph epidermis?

Artificial joints
Artificial heart valves
IV catheters

10

What infections are caused by group A beta-haemolytic strep?

Throat
Severe skin infections

11

What infections are caused by group B beta-haemolytic strep?

Meningitis in neonates

12

What infections does enterococcus tend to cause?

UTI

13

What bacterial skin infections is staph aureus associated with?

Infected eczema
Impetigo
Wound infection
Staphylococcal scalded skin syndrome
Cellulitis

14

What skin infections can be caused by strep pyogenes?

Infected eczema
Impetigo
Cellulitis
Erysipelas
Necrotising fasciitis

15

Treatment of choice for skin infections caused by staph aureus

Flucloxacillin

16

Treatment of choice for strep pyogenes

Penicillin

17

What is necrotising fasciitis?

Bacterial infection spreading along fascial planes below skin surface = rapid tissue destruction

18

What are the organisms that cause type 1 necrotising fasciiitis?

Mixed anaerobes & coliforms

19

When does type 1 necrotising fasciitis normally occur?

Post-abdominal surgery

20

What organisms cause type II necrotising fasciitis?

Group A strep

21

Treatment of necrotising fasciitis

Urgent surgical opinion & debridement

22

What type of ringworm infects the scalp?

Tinea capitis

23

What type of ringworm infects the beard?

Tinea barbae

24

What type of ringworm infects the body?

Tinea corporis

25

What type of ringworm infects the hand?

Tinea manuum

26

What type of ringworm infects the nails?

Tinea unguium

27

What type of ringworm infects the groin?

Tinea cruris

28

What type of ringworm infects the foot?

Tinea pedis (athletes foot)

29

Pathogenesis of dermatophyte

Fungus enters abraded or soggy skin
Hyphae spread in stratum corneum
Infects keratinised tissue only (skin, hair, nails)
Increased epidermal turnover causes scaling
Inflammatory response provoked (dermis)
Hair follicles & shafts invaded
Lesion grows outward and heals in centre ('ring' appearance)

30

Who does scalp ringworm mainly affect?

Children

31

Are dermatophyte infections more common in men or women?

Men

32

What are the 3 sources of dermatophyte infection?

Other humans
Animals
Soil

33

What is wood's light.,

A UV light used in a darkened room

34

What organisms is a woods light used to identify?

Fungi

35

Treatment for dermatophyte infections of small areas of infected skin

Clotrimazole cream
Amorolfine (topical nail paint)

36

Treatment of scalp dermatophyte infections

Terbinafine orally
Itraconazole orally

37

Where on the body are candida infections seen?

Under breasts in females
Groin areas
Abdominal skin folds
Nappy area in babies

38

Treatment of candida skin infection

Clotrimazole cream
Oral fluconazole

39

What is the highly infectious chronic crusted form of scabies called?

Norwegian scabies

40

What is the incubation period of scabies?

6 weeks

41

Clinical presentation of scabies

Intensely itchy rash affecting finger webs, wrists, genital area

42

Treatment of scabies

Malathion lotion (applied all over body and left overnight then washed the next day)
Benzyl benzoate

43

Who should benzyl benzoate be avoided in?

Children

44

What are pediculus capitis?

Head lice

45

What are pediculus corporis?

Body louse

46

What are pthirus pubis?

Pubic lice

47

Treatment of lice

Malathion

48

What virus causes both chicken pox & shingles?

Varicella zoster virus

49

Clinical presentation of chicken pox

Macules to papules to vesicles to scars to recovery
Fever
Itch

50

Complications of chicken pox

Secondary bacterial infection
Pneumonitis
Haemorrhagic
Scarring
Encephalitis

51

What can cause neonatal VSV?

Chicken pox in mother in late pregnancy

52

What is shingles?

Reactivation of Herpes Zoster virus

53

Presentation of shingles

Rash in dermatomal distribution
Often in elderly & immunocomprimised
Neuralgic pain

54

When is an urgent referral to opthamology indicated for shingles?

If the shingles is affecting the opthalamic division of the trigeminal nerve

55

Clinical presentation of Ramsay-Hunt syndrome

Vesicles & pain in auditory canal and throat
Facial palsy
Irritation of CNVIII (deafness, vertigo, tinnitus)

56

How long does primary gingivostomatitis caused by HSB last?

1 week

57

What does HSV type 1 cause?

Oral lesions
Half of genital herpes
Encephalitis

58

What does HSV type 2 cause?

Rare cause of oral lesions
Causes half of genital herpes
Encephalitis/disseminate infection (particularly in neonates)

59

What analogue can be used to treat HSV & VSV?

Aciclovir

60

Triggers of erythema multiforme

Drug interactions
HSV
Mycoplasma pneumoniae bacterium

61

Appearance of erythema multiforme

Target lesions with erythema

62

Appearance of molluscum contagiosum

Fleshy, firm, umbilicated, pearlescent nodules

63

Who is molluscum contagiosum common in?

Children

64

Management of molluscum contagiosum

Self limiting but takes months to disappear
Can be treated with focal liquid nitrogen

65

What virus causes warts?

HPV

66

What can be applied topically to help get rid of warts?

Salicylic acid

67

What HPVs are most associated with genital warts?

Types 6 & 11

68

Which HPVs are associated with cervical cancer?

Types 16 & 18

69

What is herpangina?

Blistering rash at back of mouth

70

What causes herpangina?

Enteroviruses
- coxsackie virus
- echovirus

71

Who does hand, foot and mouth disease typically present in?

Typically children (family outbreaks)

72

What causes hand, foot and mouth disease?

Enteroviruses (especially coxsackie virus)

73

What is erythema infectiosum also known as?

Slapped cheek

74

What causes slapped cheek?

Parvovirus B19

75

Presentation of erythema infectiosum?

Slapped cheek appearance
As facial rash fades a lacy macular rash on the body appears

76

How may erythema infectiosum present particularly in adults?

Acute polyarthritis of the small joints

77

Complications of parvovirus B19

Spontaneous abortion
Aplastic crises (sudden drop in Hb)
Chronic anaemia

78

How is erythema infectiosum diagnosed?

Parvovirus B19 IgM test

79

What is orf?

Virus of sheep
"scabby mouth"

80

Clinical presentation of orf

Farmers
Firm, fleshy nodule on hands

81

What is the presentation of the primary infection of syphilis?

Painless ulcers at the site of entry

82

What is the secondary phase of syphilis infection?

Red rash over body
Prominent on soles & palms of hands
Mucous membrane "snail track" ulcers

83

What bacteria causes syphilis?

Bacterium treponema pallidum

84

How is syphilis diagnosed?

Blood test or swab of chancre for PCR

85

How is syphilis treated?

Penicillin injections

86

What is the vector of lymes disease?

Ticks

87

What bacteria causes lyme disease?

Borrelia burgdorferi

88

Early presentation of lyme disease

Erythema migricans

89

Late presentation of lyme disease

Heart block
Nerve palsies
Arthritis

90

How is lyme disease diagnosed?

Antibody to organism

91

Therapy of lyme disease

Doxycycline or amoxicillin

92

What does staph look like on gram stain?

Gram positive cocci in clusters