Brainscape's Knowledge GenomeTM

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


See full index

Musculoskeletal > Microbiology > Flashcards

Microbiology Flashcards

1
Q

What are the 2 most common causative pathogens of acute osteomyelitis?

A 
MSSA (top)
Strep Organisms (eg GAS)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are coliforms?

A

groups of organisms which live in bowel normally

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

What antibiotic switches off the production of PVL in Staph aureus? (MSSA/MRSA)

A

clindamycin

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

What are the 2 most likely pathogens for infections of prosthetic joints?

A

Coagulase negative Staph

Proprionobacteria (diptheroids)

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

What substance do both coagulase neg staph and proprionobacteria produce that allows them to infect prosthetic limbs?

A

thick sticky biofilm

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

What is septic arthritis?

A

infection of the joint space

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

What is osteomyelitis?

A

inflammation (or infection) of the bone + medullary cavity

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

Why should you take cultures in the diagnosis of acute septic arthritis?

A

to target treatment to the specific organisms grown

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

What is the purpose of doing microscopy on the joint fluid aspirate of a patient with suspected acute septic arthritis?

A

to look for:

  • WBC (which shouldn’t be there under normal circumstances)
  • crystals (which suggests gout)
  • gram stain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the empiric treatment for acute septic arthritis for a patient over 5 years old?

A

flucloxacillin

covers MSSA which is most likely

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

What is the empiric treatment of acute septic arthritis for a patient under 5 years old?

A 
flucloxacillin
(covers MSSA)
\+
ceftriaxone
(covers kingella/ haemophilus influenzae)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why do patients rarely present with Haemophilus Influenza B?

A

vaccination program

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

Why does flucloxacillin given for the empirical treatment of acute septic arthritis, need to be given IV?

A

because patients can’t tolerate the high doses needed orally

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

What are the 2 most common causative pathogens of septic arthritis?

A

MSSA

streptococci

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

What are the 3 ways that organisms causing septic arthritis are introduced into the joint space?

A
  • haematogenous spread (blood)
  • contiguous spread (eg primary osteomyelitis)
  • direct innoculation (eg injection/trauma)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the most common causative pathogens of chronic osteomyelitis?

A 
Mycobacterium tuberculosis
Pseudomonas aeruginosa
Salmonella
Brucella
Coliforms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What organism is associated with chronic osteomyelitis in patients with sickle cell disease?

A

Salmonella

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

What bones are more likely to get osteomyelitis?

A

long bones

vertabrae

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

What organism is associated with chronic osteomyelitis in patients drinking unpasteurised goats milk?

A

Brucella

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

What are the 4 ways that organisms causing osteomyelitis are introduced into the bone?

A
  • haematogenous (blood) [most likely]
  • contiguous spread (eg primary septic arthritis)
  • peripheral vascular disease associated
  • prosthesis associated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the time frame of acute osteomyelitis?

A

few days to 2 weeks

anything longer is chronic

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

How long should patients with acute septic arthritis be treated with antibiotics?

A

2-4 weeks

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

what joints are more likely to be affected by osteomyelitis?

ie get a secondary septic arthritis

A

shoulder
elbow
hip
ankle

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

why are the shoulder, elbow, hip and ankle likely to be affected by osteomyelitis?

A

because the metaphysis of bones are intracapsular so may extend into the joint space

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

why are infants more at risk of getting septic arthritis secondary to acute osteomyelitis?

A

because certain metaphyses are intra-articular so infection can spread to the joint

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

Why can you wait until the culture results for antibiotic treatment in chronic osteomyelitis?

A

because there is no SIRS

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

What is the empiric treatment of acute osteomyelitis?

A

high dose flucloxacillin

IV

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

What is the antibiotic treatment length of acute osteomyelitis?

A

4-8 weeks

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

what is the aim in antibiotic treatment of acute osteomyelitis?

A

to stop progression into chronic infection

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

what are the 4 main risk factors for getting an infection in a prosthetic joint?

A
  • rheumatoid arthritis
  • diabetes
  • malnutrition
  • obesity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How many types of implant infection are there?

A

3

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

What is the type of implant infection which occurs 0-3 months after the operation?

A

early postoperative implant infection

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

What is the route of infection in an early postoperative implant infection?

A

perioperative

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

What are the signs of an early postoperative implant infection?

A

fever, effusion, warmth, drainage

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

What are the 3 main causative organisms of early postoperative infection?

A

Staph aureus
Streptococci
Enterococci

36
Q

What is the type of implant infection which occurs 3-24 months after the operation?

A

Delayed (low grade) implant infection

37
Q

What is the route of infection in a delayed implant infection?

A

perioperative

38
Q

What are the signs of a delayed implant infection?

A

persistent pain
device loosening
fistula

39
Q

What are the 2 main causative organisms of a delayed implant infection?

A

Coagulase-neg Staph

P. acnes

40
Q

What is the type of implant infection which occurs over 24 months after the operation?

A

Late implant infection

41
Q

What is the route of infection in a late implant infection?

A

haematogenous

42
Q

What are the 2 main causative organisms of a late implant infection?

A

Staph aureus

E. coli

43
Q

Why are prosthetic joint infections hard to diagnose?

A

often caused by organisms which are common contaminents

rarely have a positive blood culture

44
Q

What is necrotizing fasciitis?

A

an uncommon but acute and severe infection of the subcutaneous soft tissue

45
Q

what is the difference between cellulitis and necrotizing fasciitis?

A

cellulitis stays confined to the subcutaneous tissue, necrotizing fasciitis doesn’t so causes necrosis

46
Q

What type of pain is typical in necrotizing fasciitis?

A

pain which is disproportional to what can be seen on the skin

47
Q

What are the two types of necrotizing fasciitis?

A

type 1:
anaerobes plus multiple other bacteria (synergistic gangrene)

type 2:
GAS
+/-staph aureus

48
Q

What is the treatment of necrotizing fasciitis?

A

surgical debridement

antibiotics

49
Q

What is the main antibiotic treatment for type 1 necrotizing fasciitis?

A

clindamycin + gentamycin + others

high level, broad spectrum

50
Q

What is the main antibiotic treatment for type 2 necrotizing fasciitis?

A

penicillin + clindamycin

51
Q

which necrotizing fasciitis is more common- type 1 or 2?

A

type 1: anaerobes plus others

52
Q

What bacteria causes gas gangrene?

A

Clostridium perfringens

part of normal bowel flora

53
Q

describe Clostridium perfringens?

A

gram positive, strictly anaerobic rods which produce spores

54
Q

Why can you feel crepitus in a patient with gas gangrenes?

A

accumulation of gas bubbles in tissue space

55
Q

What is the treatment of gas gangrene?

A

surgical debridement
high dose antibiotics (penicillin and/or metronidazole)
hyperbaric oxygen

56
Q

What bacteria causes tetanus?

A

Clostridium tetani

57
Q

What causes the spastic paralysis in tetanus?

A

the neurotoxin produced

bacteria is non-invasive, all toxin related

58
Q

What is the treatment of tetanus?

A 
surgical debridement
antitoxin
supportive measures
antibiotics (penicillin and/or metronidaxole)
booster vaccination (toxoid)
59
Q

If patient is penicillin allergic, what is the best antibiotic to use for a Staph or Strep infection?

A

vancomycin

60
Q

If patient has a MRSA infection, what is the best antibiotic to use?

A

vancomycin

61
Q

What antibiotics should be used for a coliform infection?

A

gentamicin

sometimes ceftriaxone or ciprofloxain

62
Q

What type of antibiotic is gentamicin?

A

aminoglycoside

63
Q

what are the 2 serious side effects of long term gentamicin use?

A

ototoxic

nephrotoxic

64
Q

What is the only oral available agent for pseudomonas aerginosa?

A

ciprofloxacin

65
Q

What is the serious side effect of cephlasporins such as ceftriaxone?

A

C. dif risk

66
Q

what is the serious side effect of ciprofloxacin?

A

C. dif risk

67
Q

What is the main con of ceftriaxone use in MSK infections?

A

once daily slow IV infusion

68
Q

What is the main pro of ciprofloxacin use in MSK infection?

A

can be taken orally

69
Q

What protection does biofilm give to bacteria?

A

protects from immune system and antibiotics

70
Q

what is the general pH of slime?

A

low pH (about 5)

71
Q

What are the 2 types of surgical debridement of a prosthetic joint infection?

A
  • retention of prosthesis (debridement and implant retention- DAIR)
  • removal of prosthesis
72
Q

What is the 3 step Tayside Protocol for prosthetic joint infection?

A
  1. no antibiotic pre-op
  2. minimum 3 bone/tissue/pus samples for culture
  3. 6 minimum weeks antibiotics before clean surgery
73
Q

In the tayside protocol for prosthetic joint infections, what is the antibiotic of choice for gram positive infection?

A

flucloxacillin

74
Q

In the tayside protocol for prosthetic joint infections, what is the antibiotics of choice for MRSA or penicillin allergic patients with gram positive infections?

A

vancomycin

then teicoplanin when patient is stabilised

75
Q

In the tayside protocol for prosthetic joint infections, what is the antibiotic of choice for gram negative organisms?

A

ciprofloxain
ceftriaxone
(cotrimoxazole
amoxicillin)

76
Q

what is the duration of antibiotic treatment for prosthetic joint infection?

A

12 weeks

knee 24 weeks

77
Q

What bacteria mutc you screen for before undertaking prosthetic surgery?

A

MRSA

78
Q

If a patient about to undergo prosthetic surgery is screened and MRSA is found, what is done?

A

operation is pus on hold,

patient is decolonised using antibiotic nose and body cream for 5 days- screen again

79
Q

who is more prone to osteomyelitis?

A

immunocompromised
those with chronic disease
extremes of age

80
Q

why are children more likely to get osteomyelitis?

A

because the metaphyses of long bones contain abundant tortuous vessels with sluggish flow allowing the accumulation of bacteria

81
Q

why can infants get abscesses which extend widely along the subperiosteal space?

A

because the periosteum in infants is only loosely applied

82
Q

what is a Brodie’s abscess?

A

where the bone reacts by wailing off the abscess with a thin rim of sclerotic bone
a more sub-acute presentation of osteomyelitis
-occurs in children

83
Q

in adults, what bones does chronic osteomyelitis tend to affect?

A

axial skeleton (spine or pelvis)

84
Q

where does TB most commonly cause infection? + through what spread?

A

spine through haematogenous spread from primary lung infection

85
Q

where is the location that poorly controlled diabetics, IV drug abusers and other immunocompromised patients are at particular risk or osteomyelitis?

A

spine (particularly lumbar spine)

Musculoskeletal (16 decks)

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