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 some less common pathogens that can cause BJI or PJI?

A

Pseudomonas aeruginosa, Kingella in children

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

What are some risk factors of BJI?

A

Implants, immunosuppressed, diabetes, IVDU

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

What is the clinical presentation of acute BJI?

A

Temperature/systemic signs, pain/swelling/redness, reduced mobility/joint movement/held in flexed position.

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

What is the clinical presentation of acute BJI in children, other than the usual symptoms?

A

Listless, not feeding/playing, cranky

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

Two or more or which symptoms are needed for a diagnosis of Systemic Inflammatory Response Syndrome (SIRS)

A

Temp >38 or 90bpm, resp rate >20 or PaCO2 12000 cells/mm3 or

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

What is septic arthritis?

A

Infection of joint space

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

How are organisms introduced in septic arthritis?

A

Haematogenous spread, contiguous spread (via infected bone), direct inoculation (injection or trauma)

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

What organisms commonly cause septic arthritis?

A

Mainly MSSA, streptococci. Rarely haemophilus influenza, Neisseria gonorrhoea

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

What tests are used to diagnose acute septic arthritis?

A

Blood culture if pyrexial (+ve in 30-60%), CRP, FBC, U&E, lactate, ESR etc. Joint fluid aspirate/washout for microscopy& culture, crystals (gout, pseudogout) white cells &gram stain, USS, XR, MRI,CT, Bone scan

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

What is the antibiotic treatment in acute septic arthritis?

A

Empiric treatment for staph aureus-flucox high dose.

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

What is osteomyelitis?

A

Inflammation of bone and medullary cavity, usually long bones or vertabrae

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

What are the common pathogens in acute and chronic osteomyelitis?

A

Acute-MSSA or streptococci, Chronic- Myco tuberculosis, Pseudomonas aeruginosa, salmonella, brucella, coliforms

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

How are organisms introduced in osteomyelitis?

A

Spread- haematogenous, contiguous, PVD associated, prosthesis associated

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

What is the most likely method of spread, and locations of acute osteomyelitis?

A

Haematogenous-especially femur/tibia. Metaphysis is intracapsular so may extend into joint space (shoulder, ankle, hip, elbow).

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

What are infants more at risk of if they have acute osteomyelitis?

A

Septic arthritis due to vessels crossing metaphysis to epiphysis

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

How does chronic osteomyelitis occur?

A

Delay in treating acute infection leads to higher risk of abscess, permanent damage, septicaemia etc.

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

Describe SIRS in chronic osteomyelitis?

A

Usually absent- no immediate need for antibiotic treatment

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

How is osteomyelitis diagnosed?

A

Blood culture if pyrexial, bone biopsy/washout if possible for microscopy/culture.

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

How is osteomyelitis managed?

A

Empiric high dose fluclox. Modify after C&S. 4-8 wks.

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

What are some risk factors for infection in prosthetic joints?

A

Rheumatoid arthritis, diabetes, malnutrition, obesity

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

Describe the timeframe, route, signs and cause of early postop implant infection

A

0-3 months. Perioperative. Fever, effusion, warmth drainage. Staph aureus, strep, enterococci

22
Q

Describe the timeframe, route, signs and cause of early delayed (low grade) implant infection

A

3-24/12. Perioperative. Persistent pain, device loosening, fistula. Coag -ve staph, P. acnes.

23
Q

Describe the timeframe, route, signs and cause of early late implant infection

A

> 24/12. Haematogenous. Acute or subsacute. S. aureus, E. coli

24
Q

When are CoNs likely to cause an infection?

A

If prosthetic material present, or presence of biofilm

25
Q

How do you diagnosis PJI?

A

Cause is often common contaminants. Culture-tissue&bone. Blood culture (rarely +ve), CRP, WCC etc, radiology

26
Q

How are PJI’s treated?

A

Ideally prosthesis removal and cement. 6 wks. Re-implantation after antibiotic treatment.

27
Q

What is necrotizing fasciitis?

A

Acute & severe infection of subcutaneous soft tissues that can effect limbs, abdo wall, perineal & groin area, post op wound. Can cross tissue plains

28
Q

What is the clinical presentation of necrotizing fasciitis?

A

Highly painful, some inflammation. Rapid tissue spread. Systemic toxicity

29
Q

What pathogens cause type 1 necrotizing fasciitis?

A

Anaerobes plus multiple other bacteria-synergistic gangrene

30
Q

What pathogens cause type 2 necrotizing fasciitis (flesh eating bacteria)

A

Group A strep, alone or in combination with S.aureus

31
Q

How is necrotizing fasciitis diagnosed?

A

Pain disproportionate to superficial appearances. Swabs & tissue biopsy for microbiology gram stain/culture. Blood cultures. CRP, FBC, clotting, U&E etc

32
Q

What is the treatment for necrotizing fasciitis?

A

Surgical debridement.
Strep pyogenes- penicillin + clindamycin. Pen kills actively multiplying bacteria in exponential growth phase, clindamycin stops bacterial protein production-switches off toxin. Syngergistic: pip-taz, clindamycin, gentamicin

33
Q

What pathogen commonly causes gas gangrene?

A

Clostridium perfringens (gram +ve strictly anaerobic rods)- spores

34
Q

What is the aetiology of gas gangrene?

A

Spores into tissue. Predisposing factors- dead tissue and anaerobic conditions. Spores germinate-leads to accumulation of bubbles in tissues-space gas gangrene ‘crepitus’

35
Q

What is the treatment of gangrene?

A

Urgent debridement. Antibiotics in high doses-penicillin, metronidazole (either/both). +/- hyperbaric oxygen

36
Q

What pathogen commonly causes tetanus?

A

Clostridium tetani-gram +ve strictly anaerobic rods. Spores are found in soil, gardens, animal bites etc

37
Q

What is the clinical presentation of tetanus?

A

Spastic paralysis as neurotoxin. Lock jaw-muscles spasm. Incubation period - 4 days to several wks

38
Q

How does spastic paralysis occur in tetanus?

A

Neurotoxin released by pathogen binds to inhibitory neurones, preventing release of neurotransmitters

39
Q

What is the antibiotic choice for staph/strep infections?

A

Flucloxacillin: vancomycin, also for diptheroids, CoNS, MRSA. Clindamycin if pen allergic. Used for antitoxin properties (PVL, Group A strep), tissue penetration

40
Q

What is the antibiotic choice for coliforms?

A

Gentamicin, sometimes cephalosporin-ceftriazxone, sometimes ciprofloxaxin (oral)

41
Q

What is biofilm?

A

Slow growing: bacteria coated in ‘slime’ (protein plus polysaccharide)

42
Q

What does biofilm do?

A

Protects bacteria from immune system and antibiotics

43
Q

What is common of bacteria in abscesses or biofilms?

A

Phenotypically resistant to antibiotics

44
Q

What is the Tayside protocol for PJI?

A

No antibiotic pre-operatively
Minimum three bone/ tissue/ pus samples for culture
Minimum 6 weeks antibiotics before clean surgery

45
Q

What is the antibiotic of choice for gram +ve PJI, and if pen allergic or methicillin resistant?

A

Flucloxacillin, vancomycin and teicoplanin

46
Q

What is the antibiotic choice for gram -ve PJI?

A

Cotrimoxazole, amoxicillin, ciprofloxacin, ceftriaxone

47
Q

How do you assess response of treatment in PJI?

A

Continue treatment for 2 weeks after resolution of infection clinical signs. Repeat MRI/CT. Bone scans unhelpful till 1y after surgery. Can’t be sure of cure till 2y post treatment

48
Q

What prophylaxis is needed in orthopaedics?

A

Essential for prosthetic joint/implant-co amoxiclax 1.2g peri op & 2 post op doses. Screen for MRSA post op-decolonize if +ve. If pen allergy-co-trimoxazole. Start 24h

49
Q

What is an involucrum?

A

Bone forming on the outside of existing bone

50
Q

What are the first line antibiotics for cellulitis?

A

Flucloxacillin and benzylpenicillin

Musculoskeletal (16 decks)

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