Pathogen-Infection-Antibiotic Matching 1

Question 1

What do antibiotics target

Answer 1

• Cell wall
• Translation process
• RNA polymerase
• DNA replication

Question 2

Beta lactams

Answer 2

• penicillin, cephalosporin, carbapenem

- prevent bacteria from building up a peptidoglycan wall

Question 3

Resistance and amoxicillin

Answer 3

• Bacteria that are resistant produce Beta lactamase which breaks down beta lactams
• Co-amoxiclav (Amoxicillin + Clavulanic acid) is useful against β-lactamase producers as Clavulanic acid is a β-lactamase inhibitor

Question 4

ESBL =

Answer 4

extended spectrum β-lactamase. Organisms that produce these are not easily treated. For these, these combined drugs are not used as a first line treatment

Question 5

Spectrum of activity of β-lactam antibiotics

Answer 5

• Penicillin is the most narrow spectrum ones – kill only specific species of bacteria
• Carbapenems are the most broad spectrum ones

Question 6

MRSA treatment

Answer 6

• methicillin resistant staph. aureus
• resistance to flucloxacillin
• Can’t use β-lactams to treat MRSA, have to use another class e.g. vancomycin (glycopeptide)

Question 7

Pneumonia treatment

Answer 7

• High risk – co-amoxiclav + clarithromycin
• Low risk – amoxicillin
• After you have tested to find the pathogen – give a more specific antibiotic

Question 8

C. difficile treatment

Answer 8

• Broad spectrum antibiotics kill gut flora and allow C.difficile to infect - names that start with C
• Stop current antibiotics and start oral metronidazole

Question 9

UTIs treatment

Answer 9

• Upper – fever, loin pain, tachycardia, low BP - treat with IV cefuroxime
• Lower – dysuria, frequency, treat with nitrofurantoin, trimethoprim, pivmecillinam

Question 10

Meningitis treatment

Answer 10

• Treat with IV ceftriaxone until you know pathogen; use a good broad spectrum β-lactam

Question 11

SIRS diagnosis

Answer 11

• systemic inflammatory response syndrome
• Requires 2 of the following:
  Temp >38, Heart rate >90, Resp rate >20, WBC >12

Question 12

Sepsis diagnosis

Answer 12

SIRS AND a suspected focus of infection

Question 13

Septic shock =

Answer 13

sepsis and low BP (<90/60)

Question 14

Management of sepsis

Answer 14

BUFALO

• B = blood cultures – 2 sets
• U = urine output – catheterise to measure usually bad urine output
• F = fluids – 500ml IV saline over 15 mins.
• A = antibiotics – as per suspected infection
• L = lactate – ABGs for lactate and pH which shows underperfusion of patient
• O = oxygen – 15 l/m via reservoir face mask

Question 15

Cellulitis treatment

Answer 15

• Skin and soft tissue infection (SSTI) caused by gram positive cocci –Staph aureus or Strep pyogenes. Treated with flucloxacillin

Question 16

Necrotising fasciitis

Answer 16

• Severe SSTI caused by a polymicrobial mix but usually involving Strep pyogenes
• Treat by debridement, meropenem and clindamycin

Question 17

Infective endocarditis

Answer 17

• Infection of heart valves

- Most common Staph aureus and Strep viridans; Treat using 6 week combo of IV antibiotics depending on cause

Question 18

Brain abscess treatment

Answer 18

drainage and antibiotics for 4+ wks, depending on cause

Question 19

Antibiotics and pregnancy

Answer 19

• β-lactams are most well tolerated antibiotics and safe in pregnancy
  AVOID:
• Quinolones e.g. ciprofloxacin – damage to cartilage
• Trimethoprim – folic acid antagonist leads to neural tube defects
• Tetracyclines – deposits and stains bones/teeth