Transition Microbiology Revision

Question 1

Define virulence

Answer 1

Degree of pathogenicity

Question 2

Name the 4 bacteria shapes

Answer 2

Coccus
Bacillus
Fusiform
Spirochaete

Question 3

What is the structure / appearance of gram positive bacteria? What type of toxin do they produce?

Answer 3

Purple
Thick peptidoglycan layer
Produce exotoxin inside cell and export out

Question 4

What is the structure / appearance of gram negative bacteria? What type of toxin do they produce?

Answer 4

Pink
Thin peptidoglycan layer + LPS in outer membrane
Produce endotoxin

Question 5

What is the appearance of strep on film?

Answer 5

Purple gram positive cocci in chains

Question 6

How are strep classified? Be specific

Answer 6

Haemolysis

Alpha partial - green - viridans, pneumoniae
Beta complete - clear - group A strep pyogenes
Gamma none - group B enterococci

Question 7

How are staph classified? Be specific

Answer 7

Coagulate

\+ve = aureus
-ve = others e.g. epidermidis

Question 8

What is the appearance of staph on film?

Answer 8

Purple gram positive cocci in clusters

Question 9

What is the best antibiotic against s. aureus? What is used in allergies?

Answer 9

Fluclox

Allergy vanco

Question 10

What is the appearance of clostridium on film?

Answer 10

Gram positive anaerobic bacilli

Produces spores

Question 11

What is the best antibiotic against clostridium?

Answer 11

Metronidazole

Question 12

What is the appearance of neisseria (gonococcus and meningitides) on film?

Answer 12

Gram negative aerobic diplococci

Question 13

How are gram negative bacilli classified?

Answer 13

Lactose positive = coliform

Lactose negative = h. pylori, pseudomonas

Question 14

What is a coliform? Include examples

Answer 14

Gram negative aerobic bacilli. Some are gut commensals e.g. e.coli, Klebsiella, proteus, enterobacter. Some are pathogens e.g. salmonella, shigella, e.coli 0157

Question 15

What antibiotic is used against coliforms?

Answer 15

IV genta then switch to PO co-trimoxazole

Question 16

Name the 2 strict aerobes

Answer 16

Pseudomonas, legionella

Question 17

What antibiotic is used against strict anaerobes?

Answer 17

Metronidazole

Question 18

Name the 4 C antibiotics? What is the risk?

Answer 18

Cephalosporins e.g. ceftriaxone
Co-amoxiclav
Ciprofloxacin
Clindamycin

C. diff

Question 19

What are the 2 components of co-amoxiclav? What gram negative bacilli does it not protect against?

Answer 19

Amoxicillin + clavulanic acid

Pseudomonas

Question 20

How are penicillins excreted? What is their mechanism?

Answer 20

Renal

Inhibit beta lactamase

Question 21

Give an example of a cephalosporin. What is their mechanism?

Answer 21

Ceftriaxone

Inhibit beta lactamase

Question 22

What antibiotic is only effective against gram positives?

Answer 22

Vancomycin

Question 23

What is the mechanism of vancomycin?
What type of bacteria is it active against?
What routes is it available?

Answer 23

Inhibits peptidoglycan synthesis
Only gram positives
Only IV

Question 24

How is gentamicin excreted?
What is it effective against?
What are the side effects?
What is used if genta is contraindicated?
When is genta contraindicated?

Answer 24

Kidneys
Gram negative aerobes
Kidney / CNVIII damage
Aztreonam
CKD / pregnant

Question 25

Give an example of a tetracycline What routes is it available? How is it excreted? When is it contraindicated?

Answer 25

Doxycycline PO only Liver Pregnancy and children

Question 26

What is metronidazole active against?

Answer 26

True anaerobes and some protozoa

Question 27

Which antibiotic inhibits folic acid synthesis?

Answer 27

Trimethoprim

Question 28

Define sepsis

Answer 28

Life-threatening organ dysfunction due to dysregulated host response to infection

Question 29

What would an ABG show in sepsis? Why?

Answer 29

Metabolic acidosis Lactic acid from hypoperfusion and anaerobic metabolism

Question 30

What effect does sepsis have on TPR, CO and the circulation volume?

Answer 30

Decreased TPR Decreased CO Hyperdynamic circulation

Question 31

How is sepsis diagnosed?

Answer 31

NEWS >5 + presumed infection

Question 32

qSOFA is only used as a prognostic indicator in ICU. T or F

Answer 32

True

Question 33

What is the sepsis 6? What time frame should it be done in?

Answer 33

Less than 1 hour ``` Oxygen IV empirical ABx Blood culture Fluid 0.9% 500ml NaCL FBC, lactate, biochemistry Monitor UO ```

Question 34

How many fluid boluses should be given in sepsis? What type of fluid should never be given?

Answer 34

Till normal BP | Never 5% dextrose

Question 35

In sepsis management, if hypotension persists despite euvolaemia, what drugs (name and class) should be initiated? By what route?

Answer 35

Inotrope/ vasoconstrictor; Noradrenaline alpha agonist Adrenaline alpha/ beta agonist Central venous catheter

Question 36

What is the management of mild and severe CAP? Include penicillin allergies

Answer 36

Mild 1st PO amox 2nd PO doxy Severe 1st IV co-amox + PO doxy 2nd IV levofloxacin

Question 37

What test is done to diagnose C. diff?

Answer 37

Stool toxin test

Question 38

What is the management of severe and non-severe c. diff?

Answer 38

Non-severe PO metron Severe PO vanco

Question 39

What is c. diff infection? Why does it recur?

Answer 39

ABx induced pseudomembranous colitis Spores

Question 40

What is the management of peritonitis? Include penicillin allergy, what each is against and the PO switch

Answer 40

Amox - gram +ve enterococci Genta - coliforms Metron - anaerobes Allergy vanco + genta + metron PO switch to co-trimox + metron

Question 41

What criteria diagnoses endocarditis? What investigations (par blood tests) are done?

Answer 41

Duke criteria 6 cultures Echo

Question 42

What is the commonest cause of the following endocarditis scenarios - Native valve acute - Native valve subacute - Intra-op - Prosthetic valve - PWID

Answer 42

- Native valve acute S. AUREUS - Native valve subacute VIRIDANS / ENTEROCOCCI - Intra-op EPIDERMIDIS - Prosthetic valve EPIDERMIDIS - PWID S. AUREUS

Question 43

What valve is effected in PWID endocarditis?

Answer 43

Tricuspid

Question 44

What is the management of the following endocarditis scenarios? - Mild native valve - Septic native valve - Prosthetic valve How long are ABx given?

Answer 44

- Mild native valve IV amox + genta - Septic native valve IV fluclox - Prosthetic valve IV vanco + PO rifampicin + IV genta 6 weeks

Question 45

What is the management of severe and non severe HAP?

Answer 45

Non-severe PO amox + metron Severe AGM

Question 46

What is the management of mild and severe DM foot? Include penicillin allergy

Answer 46

Mild 1st fluclox 2nd doxy Severe 1st fluclox + metron 2nd doxy + metron

Question 47

What is the bacillus cereus buzzword? What is the management?

Answer 47

Reheated rice no ABx

Question 48

What infection is associated with petting zoos and BBQs?

Answer 48

E coli 0157

Question 49

What is the management of E coli O157 infection? What are the complications?

Answer 49

No ABx HUS AKI

Question 50

"Disproportionate pain to wound"

Answer 50

Necrotizing fasciitis

Question 51

Define septic shock

Answer 51

Hypotension on vasopressor + lactate>2 despite euvolemia

Question 52

What is the likely organism and Mx of septic arthritis and osteomyelitis?

Answer 52

IV 4-6wk fluclox