Week 4 - A(2) - Microbiology of uti Treatment

Question 1

Which bacteria presents with a foul smelling burnt chocolate urine? Which bacteria is common in women of child-bearing age?

Answer 1

Proteus - foul smelling burnt chocolate Looks like swarming on agar Staphlococcus saphrophyticus - women of child bearing age

Question 2

If a patinet comes in who is elderly or has a catheter, what do you carry out if suspecting a UTI?

Answer 2

Send urine sample to labs for culture

Question 3

A genuine UTI in a non-catheterised patient will usually be caused by a single organism How many organisms/ml of this bacteria will be seen?

Answer 3

Greater than 10^5 of organisms/ml

Question 4

Kass’s criteria states >10^5 organisms / ml significant =probable UTI 10^4 organisms / ml ?contaminated ?infection - repeat specimen How many organisms/ml is not significant of a UTI and therefore no treatment?

Answer 4

Less than 10^3 organisms per ml i not of significance

Question 5

If there is a mixed growth of organisms (ie 2 or more organsims) with greater than 10^5 organisms/ml each, do you think UTI?

Answer 5

UTI is not suspected

Question 6

Asymptomatic bacteriuria is greater than 10^5 but no symptoms – no treatment When is this not the case?

Answer 6

This is not the case in pregnant women - treatment is usually given

Question 7

What is abacterial cystitis?

Answer 7

Cystitis without infection as the cause

Question 8

UTIs are now becoming resistant to antibiotic treatments as the bacteria are evlovling extended-spectrum beta-lactamase (ESBL)-producing enterobacteria is now becoming more common What does this make bacteria resistant to?

Answer 8

All cephalosporins and almost all penicillins

Question 9

Again, what antibitoics are EXBL becoming resitant to?

Answer 9

All cephalosporins and alomst all penicillins

Question 10

Where do extended spectrum beta lactamase producing bacteria tend to come from?

Answer 10

Come from imported chicekn

Question 11

Gram negative (coliform) bacilli that are resistant to meropenem What are this type of resistant UTI known as?

Answer 11

Carbapenemase producing enterobacteriaceae Meropenem – last choice antibiotic – once resistant to this there is not much that it can be treated with

Question 12

What are CPE (carbapenemase producing enterobacteraceae) resistant to?

Answer 12

Resistant to meropenem which is like the last line antibiotic so are almost impossible to treat

Question 13

• Carbapenemase-producing enterobacteriaceae (CPE) o Gram negative (coliform) bacilli that are resistant to meropenem – ie resistant to all current antibiotics What travel are they associated with?

Answer 13

Associated with travel to the indian subcontinent

Question 14

Ideal antibiotic should be: excreted in urine in high concentration oral inexpensive few side effects What is usaully the adequate duration of treating a female with an uncomplicated lower UTI?

Answer 14

A 3day course is usually adequate

Question 15

If a catheterised/elderly patient presents with signs of infection, is dipstick analysis carried out? If they have incidental bacteruria on culture, is treatment given?

Answer 15

Do not carry out disptick urinalysis in catheterised/elderly patinet If they have an incidental bacteruria on culture then treatment is not given

Question 16

Can be given orally or IV Safe, even in pregnancy High concentrations achieved in urine Very cost-effective What antibiotic is this? Not given now 1st line due to increasing sensitivity

Answer 16

This would be amoxicillin

Question 17

Which antibiotic inhibits folic acid synthesis? - inhibiting the dihydrofolate reductase enzyme

Answer 17

This would be trimethoprim

Question 18

What can trimethoprim be combined with to form co-trimaxazole? What does this combined antibiotic inhbit in the folic acid synthesis?

Answer 18

Can be combined with sulfasalazine Inhibits the dihydropteroate synthetase enzyme paraminobenzoate→dihydropteroate→dihydrofolate→tetrahydrofolate

Question 19

Trimethoprim treats most coliforms, staph aureus & MRSA, which gram negative bacilli does it not treat? Why is it not given in the first trimester of preganncy?

Answer 19

Does not treat pseudomonas Because it inhibits the folic acid synthesis which could result in the child having spina bifida

Question 20

Which drug component of co-trimoxazole can increase the risk of Steven Johnson syndrome?

Answer 20

Sulfasalazine

Question 21

Cheap, narrow spectrum Only useful in lower uncomplicated UTI as only reaches effective concentrations in bladder urine What is this and when in pregnancy is i avoided?

Answer 21

This is nitrofurantoin Avoid in late pregnancy and up to a child reaching age 3months

Question 22

Which antibiotic is avoided in preganncy and is only given in hospital (as it is IV)?

Answer 22

This would be gentamicin

Question 23

Due to toxicity of gentamicin, how long should it be given for? What does it not treat?

Answer 23

Should be prescribed for 3 days ONLY (3 days, not 3 doses!!!) Does not treat enterococci

Question 24

Which two antibiotics have activity against very antibiotic-resistant coliforms that produce extended spectrum beta-lactamases (ESBLs)? NO activity against Staphs/Streps/Enterococci or Pseudomonas sp.

Answer 24

Pivmecillinam (oral) or temocillin (IV)

Question 25

Combination of amoxicillin and clavulanic acid What does clavulanic acid contain? Why is the use of co-amoxiclav being cut down?

Answer 25

Clavulanic acid contains a beta-lactamase inhibitor The use is being cut down to prevent the occurences of C-difficile

Question 26

Inhibits bacterial DNA gyrase, which prevents “supercoiling” of bacterial DNA Generally safe, but not used in young children or pregnant women It is the only oral anti-psuedomatic What is this?

Answer 26

Ciprofloxacin

Question 27

What are the two treatment options for a uncomplicated female with a lower urinary tract infection?

Answer 27

This would be nitrofurantoin or trimethoprim orally for 3days

Question 28

What are the two treatment options for an uncatheterised male with a UTI?

Answer 28

Nitrofurantoin or trimethoprim for 7 days

Question 29

What is the treatment of a complicated UTI/Pylonephritis/Urosepsis in SECONDARY CARE?

Answer 29

IV amoxicillin + gentamicin When results come back Can step down to co-trimoxazole or amoxicillin if patient has enterococcus

Question 30

Significant bacteriuria (>105 orgs/mL) Patient is asymptomatic, therefore condition is detected incidentally No pus cells in urine What is given?

Answer 30

Dont give treatment unless pregnant

Question 31

All pregnant women screened at 1st antenatal visit for bacteruria Usually treated with antibiotics in pregnancy. If left untreated what can this cause?

Answer 31

In 20-30% of females - pyelonephritis Can also cause growth retardation to the child (IUGR - intrauterine growth retardation)

Question 32

Catheter-related UTI is one of the commonest causes of hospital-acquired infection However, the longer a catheter is in situ, the more likely it is to be “colonised” with bacteria Catheterised patients with >105 orgs/mL should ONLY be given antibiotics if there is supporting evidence of UTI (fever, symptoms etc.) Which infection is associated with catheterisation?

Answer 32

Pseudomonas infection

Question 33

Treatments Asymptomatic bacteruria in first and 3 trimester of pregnancy?

Answer 33

First trimester - give nitrofurantoin Third trimester - give trimethopri

Question 34

Treatment for an uncomplicated lower UTI in female? Treatment for an uncatheterised male? Treatment for complicated?UTI/Pyelonephritis/UroSepsis?

Answer 34

Treatment for an uncomplicated lower UTI in female - nitrofurantoin or trimethoprim Treatment for an uncatheterised male - nitrofurantoin or trimethoprim Treatment for complicated UTI/Pyelonephritis/UroSepsis - IV amoxicillin and Gentamicin Co-trimoxazole or co-amoxiclav if not wanting IV / primary care

Question 35

What is given if the patient is penicillin hypersensitive in a complicated/pyelonephritis/Urosepsis?

Answer 35

Give patient IV co-trimoxazole + gentamicin

Question 36

What is abacterial cystitis tend to be caused by?

Answer 36

• Abacterial cystitis/urethral syndrome–symptoms of UTI + pus cells in urine but no growth on culture – ‘honeymoon cystitis’ – caused by chlamydia, gonorrhoea.

Question 37

Obviously treat the cause of the abacterial cystitis but what may help with the pain?

Answer 37

Alkalsiing agent may help with the pain

Question 38

 Sterile pyuria is the presence of pyuria (>10 WBCs) with a negative urine culture What does this suggest when looking for a UTI?

Answer 38

This suggests ureithritis due to chlamydia trochomatis or neirrisea gonorrhea