Week 4 - A(2) - Microbiology of uti Treatment Flashcards
Which bacteria presents with a foul smelling burnt chocolate urine? Which bacteria is common in women of child-bearing age?
Proteus - foul smelling burnt chocolate Looks like swarming on agar Staphlococcus saphrophyticus - women of child bearing age
If a patinet comes in who is elderly or has a catheter, what do you carry out if suspecting a UTI?
Send urine sample to labs for culture
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?
Greater than 10^5 of organisms/ml
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?
Less than 10^3 organisms per ml i not of significance
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?
UTI is not suspected
Asymptomatic bacteriuria is greater than 10^5 but no symptoms – no treatment When is this not the case?
This is not the case in pregnant women - treatment is usually given
What is abacterial cystitis?
Cystitis without infection as the cause
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?
All cephalosporins and almost all penicillins
Again, what antibitoics are EXBL becoming resitant to?
All cephalosporins and alomst all penicillins
Where do extended spectrum beta lactamase producing bacteria tend to come from?
Come from imported chicekn
Gram negative (coliform) bacilli that are resistant to meropenem What are this type of resistant UTI known as?
Carbapenemase producing enterobacteriaceae Meropenem – last choice antibiotic – once resistant to this there is not much that it can be treated with
What are CPE (carbapenemase producing enterobacteraceae) resistant to?
Resistant to meropenem which is like the last line antibiotic so are almost impossible to treat
• 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?
Associated with travel to the indian subcontinent
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?
A 3day course is usually adequate
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?
Do not carry out disptick urinalysis in catheterised/elderly patinet If they have an incidental bacteruria on culture then treatment is not given
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
This would be amoxicillin
Which antibiotic inhibits folic acid synthesis? - inhibiting the dihydrofolate reductase enzyme
This would be trimethoprim
What can trimethoprim be combined with to form co-trimaxazole? What does this combined antibiotic inhbit in the folic acid synthesis?
Can be combined with sulfasalazine Inhibits the dihydropteroate synthetase enzyme paraminobenzoate→dihydropteroate→dihydrofolate→tetrahydrofolate
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?
Does not treat pseudomonas Because it inhibits the folic acid synthesis which could result in the child having spina bifida
Which drug component of co-trimoxazole can increase the risk of Steven Johnson syndrome?
Sulfasalazine
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?
This is nitrofurantoin Avoid in late pregnancy and up to a child reaching age 3months
Which antibiotic is avoided in preganncy and is only given in hospital (as it is IV)?
This would be gentamicin
Due to toxicity of gentamicin, how long should it be given for? What does it not treat?
Should be prescribed for 3 days ONLY (3 days, not 3 doses!!!) Does not treat enterococci
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.
Pivmecillinam (oral) or temocillin (IV)
Combination of amoxicillin and clavulanic acid What does clavulanic acid contain? Why is the use of co-amoxiclav being cut down?
Clavulanic acid contains a beta-lactamase inhibitor The use is being cut down to prevent the occurences of C-difficile
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?
Ciprofloxacin
What are the two treatment options for a uncomplicated female with a lower urinary tract infection?
This would be nitrofurantoin or trimethoprim orally for 3days
What are the two treatment options for an uncatheterised male with a UTI?
Nitrofurantoin or trimethoprim for 7 days
What is the treatment of a complicated UTI/Pylonephritis/Urosepsis in SECONDARY CARE?
IV amoxicillin + gentamicin When results come back Can step down to co-trimoxazole or amoxicillin if patient has enterococcus
Significant bacteriuria (>105 orgs/mL) Patient is asymptomatic, therefore condition is detected incidentally No pus cells in urine What is given?
Dont give treatment unless pregnant
All pregnant women screened at 1st antenatal visit for bacteruria Usually treated with antibiotics in pregnancy. If left untreated what can this cause?
In 20-30% of females - pyelonephritis Can also cause growth retardation to the child (IUGR - intrauterine growth retardation)
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?
Pseudomonas infection
Treatments Asymptomatic bacteruria in first and 3 trimester of pregnancy?
First trimester - give nitrofurantoin Third trimester - give trimethopri
Treatment for an uncomplicated lower UTI in female? Treatment for an uncatheterised male? Treatment for complicated?UTI/Pyelonephritis/UroSepsis?
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
What is given if the patient is penicillin hypersensitive in a complicated/pyelonephritis/Urosepsis?
Give patient IV co-trimoxazole + gentamicin
What is abacterial cystitis tend to be caused by?
- Abacterial cystitis/urethral syndrome–symptoms of UTI + pus cells in urine but no growth on culture – ‘honeymoon cystitis’ – caused by chlamydia, gonorrhoea.
Obviously treat the cause of the abacterial cystitis but what may help with the pain?
Alkalsiing agent may help with the pain
Sterile pyuria is the presence of pyuria (>10 WBCs) with a negative urine culture What does this suggest when looking for a UTI?
This suggests ureithritis due to chlamydia trochomatis or neirrisea gonorrhea
