Brainscape's Knowledge GenomeTM

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


See full index

Dermatology > Microbiology > Flashcards

Microbiology Flashcards

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

Describe the key features of Staphylococcus sp.

A

Gram +ve cocci in clusters. Aerobic and facultatively anaerobic. Coagulase + ve (staph aureus) or -ve (staph epidermidis, saprophyticus etc)

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

When would you find enterotoxin being produced?

A

Food poisoning

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

What is SSSST?

A

Toxin produced by staph- Staph Scalded Skin Syndrome Toxin

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

Describe staph epidermidis

A

Skin commensals. May cause infection- artificial materials (Joints, valves, IV catheters)

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

What can staph saprophyticus cause?

A

UTI in women of child bearing age

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

Describe streptococcus sp

A

Gram +ve cocci in chains. Aerobic (and facultatively anaerobic). Classified by haemolysis - Beta = complete, alpha=partial, gamma = non-haemolytic

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

What toxin can be produced by beta-haemolytic strep?

A

Haemolysin- damage tissues

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

What further classification beyond haemolysis can be used in strep?

A

Antigenic structure on surface (serological): Group A- (throat, severe skin infections), Group B- (meningitis in neonates)

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

What are the 2 classes of alpha- haemolytic strep?

A

Strep pneumonia-Pathogen, commonest cause of pneumonia. Viridans- commensals of mouth, throat, vagina

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

What are the non-haemolytic streptococci?

A

Enterococcus sp (E. faecalis, E. faecium)- commensals of bowel, common cause of UTI

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

Name some competitive bacterial flora

A

Staph epidermidid, corynebacterium sp. (diphtheroids), Proprionobacterium sp.

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

When might you find staph. aureus infection of the skin?

A

Boils, carbuncles, minor skin sepsis, cellulitis, infected eczema, impetigo, wound infection, staphylococcal scalded skin syndrome

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

When might you find strep. pyogenes infection of the skin?

A

Infected eczema, impetigo, cellulitis, erysipelas, necrotizing fasciitis (may also be caused by mixed bacterial infection).

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

How might you diagnose a bacterial skin infection?

A

Swab of lesion if surface broken
Pus or tissue if deeper lesion

+/- blood cultures, if appropriate

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

What is the antibiotic of choice for treating sensitive strains of Staph. aureus?

A

Flucloxacillin

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

What antibiotic is used to treat strep. pyogenes?

A

Penicillin (also treated by flucloxacillin)

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

What is the treatment for necrotizing fasciitis?

A

Life threatening. Requires immediate surgical debridement as well as antibiotics

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

What is necrotizing faciitis?

A

Bacterial infection spreading along fascial planes below skin surface > rapid tissue destruction. Not much on surface, severe pain

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

What are the 2 types of necrotizing faciitis?

A

I- Mixed anaerobes & coliforms,usually post abdo surgery. II- Group A strep infection

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

How would you treat leg ulcers?

A

Vascular problem, only swab if signs of cellulitis/infection. Treat strep pyogenes, staph aureus, other beta-haemolytic strep (B,C,G), anaerobes (esp diabetics)

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

What is dermatophyte (fungal) infection?

A

Ringworm

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

Describe the names of ringworm infections and locations

A

Tinea capitis-scalp, Tinea barbae-head, Tinea corporis- body, Tinea manuum- hand, Tinea unguium- nails, Tinea cruris- groin, Tinea pedis - foot (athletes foot)

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

What is the pathogenesis of dermatophyte infection?

A

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

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

Are men or women more commonly affected by dermatophyte infection?

A

Men

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

Who does scalp ringworm mainly affect?

A

Children

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

Who does foot and groin ringworm mainly affect?

A

Men

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

What are some sources of dermatophyte infection?

A

Other infected humans (most likely)- anthropophilic fungi, animals (cats, dogs, cattle)- zoophilic fungi, soil (less common in UK)-geophilic fungi

28
Q

What casual organisms are involved in dermatophyte infection?

A

Trichophyton rubrum (>70%), Trichophyton mentagraphytes (>20%): human-human. Microsporum canis - cats, dogs-humans

29
Q

What is the treatment for dermatophyte infections?

A 
Small areas of infected skin, nails
Clotrimazole (Canestan) cream or similar
Topical nail paint (amorolfine)
Extensive skin infections
Nail infections
Scalp infections
Terbinafine orally
Itraconazole orally
30
Q

Where does candida commonly cause infection?

A

Skin folds where area is warm and moist - candida intertrigo. Under breast, groin areas, abdo skin folds, nappy areas in babies

31
Q

What is the diagnosis and treatment for candida?

A

Swab for culture, treat with clotrimazole cream, oral fluconazole

32
Q

Describe scabies

A

Caused by sarcoptes scabiei. Chronic crusted form Norwegian scabies. Incubation period up to 6 wks. Itchy rash affecting finger webs, wrists, genital area

33
Q

What is the treatment of scabies?

A

Malathion lotion, applied overnight to whole body and washed off next day. Benzyl benzoate (avoid in children)

34
Q

Describe pediculosis (lice infestation)

A

Various types- pediculus capitis/corporis(Vagabonds disease) = head/body. Phthirus pubis -pubic louse. Associated with intense itch, treat using malathion

35
Q

What virus are Chicken pox and Shingles due too? (And which is which?)

A

Varicella Zoster Virus (Chickenpox is Varicella, Shingles is Zoster)

36
Q

Describe Chickenpox

A

Primary infection typically in childhood. Generalised rash/fever. Virus establishes latency in sensory nerve roots

37
Q

Describe Shingles

A

Reactivation later in life, typically old age. Rash is dermatomal

38
Q

Describe the symptoms of Chickenpox

A

Macules-papules-vesicles-scabs-recovery/ Centripetal, varying density, inflammed skin, fever, itch

39
Q

What complications can occur as a result of chickenpox?

A 
Complications-
secondary bacterial
pneumonitis
haemorrhagic
scarring, absent or minor
encephalitis
40
Q

What are the predictors of severity of chickenpox?

A

Extremes of age, depressed cell mediated immunity

41
Q

Describe neonatal VZV

A

Secondary to chickenpox in mother in late pregnancy
Higher mortality
Prevention with Varicella Zoster Immune Globulin in susceptible women in contact

42
Q

Describe the symptoms of Shingles

A

Dermatomal distribution of rash. Tingling/pain to erythema to vesicles to crusts

43
Q

What is the pain in Shingles known as, and what kind of pain is it?

A

Zoster associated (after wk4 Post herpetic neuralgia), neuralgia often effecting trigeminal

44
Q

What should you look out for regarding the trigeminal nerve and shingles?

A

Shingles effecting particular divisions of the nerve, effecting the relevant part of the face

45
Q

Describe Ramsay-Hunt Syndrome

A

Vesicles and pain in auditory canal and throat. Facial palsy (7th nerve), irritation of CNVIII-deafness, vertigo, tinnitus. Aka geniculate or otic herpes zoster

46
Q

What virus causes primary gingivostomatitis, who does it commonly and symptoms?

A

HSV- pre school children. Causes extensive ulceration in and around mouth for ~1 wk

47
Q

What can HSV cause in general?

A

Blistering rash at vermillion border. Can spread- to finger or eczema: herpetic whitlow, eczema herpeticum

48
Q

What can HSV Type 1 cause?

A

Main cause of oral lesions, causes half of genital herpes, causes encephalitis

49
Q

What can HSV Type 2 cause?

A

Rare cause of oral lesions, causes half of genital cases, encephalitis/disseminated infection (particularly neonates)

50
Q

What drug can be used as an antiviral against VZV and HSV?

A

Aciclovir

51
Q

Describe aciclovir

A

Analogue of guanosine. Selectively incorporated into viral DNA inhibiting replication. Early/good example of non-toxic effective anti-viral. Does not eliminate latent virus

52
Q

What are some triggers of erythema multiforme?

A

Drug reactions, and some infections : HSV, Mycoplasma pneumoniae bacterium

53
Q

Describe Molluscum contagiosum

A

Fleshy, firm, umbilicated, pearlescent nodules- 1-2mm in diameter. Self limiting, but can take months. Common in children, can also be sexually transmitted

54
Q

What can be used to treat molluscum contagiosum?

A

Local application of liquid nitrogen

55
Q

Describe the causes, groups effected, and treatment of warts

A

Caused by HPV, commonest in children. Self limiting, uncomplicated- topical salicylic acid can be used. If on feet- verrucas

56
Q

Name some diseases that can be caused by HPV

A

HPV 1-4 warts/verrucas. Genital warts HPV 6 and 11. Cervical cancer HPV 16 and 18. Head and neck cancer.

57
Q

What is Herpangina, what causes it and tests used to identify it?

A

Blistering raash of back of mouth. Caused by enterovirus- coxsackie virus, echovirus. Self limiting. Swab of lesion, sample of stool for enterovirus PCR

58
Q

What is the cause and groups effected by Hand, Foot and Mouth disease?

A

Enteroviruses (esp coxsackie viruses). Typically children, family outbreaks. Not same as animal disease

59
Q

Describe erythema infectiosum

A

Aka slapped cheek, parvovirus B19. Rash on face, fades and lacy macular rash on body appears. In adults rash may be absent, and acute polyarthritis of small joints may be prominent.

60
Q

What are the complications of parvovirus B19?

A 
spontaneous abortion
fetal hydrops as precursor
Aplastic crises
sudden drop in haemoglobin
seen in patients with short red cell life span
Thalassaemia
Hereditary spherocytosis
Sickle cell anaemia
Chronic anaemia
in immunosuppressed patients
61
Q

How is the presence of parvovirus b19 confirmed?

A

Antibody testing rather than skin swabs- parvovirus B19 IgM test

62
Q

What is Orf, symptoms and diagnosis?

A 
Virus of sheep “scabby mouth”
Firm, fleshy nodule on hands of farmers
Constitutional symptoms rare
Self limiting
Clinical diagnosis, lab confirmation not used
63
Q

Describe the primary infection presentation of syphillis

A

Chancre formed- painless ulcers at site of entry

64
Q

Describe the secondary infection presentation of syphilis

A

Red rash over body
Prominent on soles of feet and palms of hands
Mucous membrane “snail track” ulcers

65
Q

Describe the tertiary infection presentation of syphilis

A

CNS, cardiovascular, gummatous etc etc

66
Q

What causes syphilis, and how it is diagnosed and treated?

A

STI with bacterium Treponema pallidum, diagnosed by blood test or swab of chancre for PCR. Treated using penicillin injections

67
Q

What is the vector, cause, presentation, lab confirmation and therapy for Lyme disease?

A

Vector
Ticks
Cause: bacterial
Borrelia burgdorferi
Presentation
Early: erythema migrans(diagnostic, no lab confirmation needed)
Late: heart block, nerve palsies, arthritis.
Lab confirmation: mainly for late presentations and is a blood test for antibody to organism
Therapy: doxycycline or amoxicillin

Dermatology (14 decks)

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