Urinary Tract Infection Microbiology Flashcards
What is a complication UTI?
Upper UTI with or without systemic signs and symptoms
Catheter-associated UTI
What are the criteria for urosepsis?
Temperature over 38
Heart rate >90/min
Respiratory rate >20/min
WBC >15 or <4
What are the at risk groups for developing bacteriuria?
Hospitalised Catheterised Diabetics Anatomical abnormalities Pregnant Preschool aged children (girls > boys)
In which patients should you treat asymptomatic bacteriuria?
Preschool children
Pregnant women
Renal transplant patients
Immunocompromised patients
What are the features of ascending urinary tract infections?
Urethral colonisation
Occurs more in women
Multiplication in the bladder
Ureteric involvement
What are the features of descending UTIs?
Associated with blood-borne infections
Involves the renal parenchyma
In which situations are UTIs most likely to be caused by multiple organisms (<5%)?
Long-term catheters
Recurrent infections
Structural/neurological abnormalities
What are the clinical features of a UTI?
Suprapubic discomfort Dysuria Urgency Frequency Cloudy, blood stained, smelly urine Low-grade fever Sepsis Failure to thrive, jaundice (neonates) Abdominal pain and vomiting (children) Nocturia, incontinence and confusion (elderly)
Name the common causative organisms of UTIs.
Gram negative bacilli - E.Coli - Klebsiella - Proteus - Pseudomonas Gram positive bacteria - Strep (entercoccus) - Staph Anaerobes Candida
What are the investigations for an uncomplicated UTI?
1) Non-pregnant women
On 1st presentation, culture is not mandatory
- dipstick has high false positive rates
- antibiotic for 3-7 days
- culture if there is no response to treatment and change the antibiotic
2) Children and men
- send urine for each and every presentation
- treat
How are UTIs in pregnancy managed?
Send urine sample with each presentation
Treat for 7-10 days
- amoxicillin and cefalexin
Hospital admission and IV antibiotics if severe
Can develop into pyelonephritis (30%)
What antibiotics should you not give a pregnant woman for a UTI?
Trimethoprim
- not in first trimester
Nitrofurantoin
- not near term
What constitutes a recurrent UTI?
Two or more episodes in 6 months
Three or more episodes in a year
How should you manage a recurrent UTI?
Send a sample with each episode
Encourage hydration
Encourage urge initiated and post-coital voiding
Cranberry products
Intravaginal/oral oestrogen
Urology investigation
Self administered single dose/short course therapy
Single dose post-coital antibiotics
Prophylactic antibiotics
- if simple measures fail
- 6 months ideally (trimethoprim or nitrofurantoin)
How do catheter associated UTIs occur?
Disturbance of the flushing system
Colonisation of the urinary catheter
Biofilm production by bacteria
Name some complications of catheters.
CAUTI Obstruction-hydronephrosis Chronic renal inflammation Urinary tract stones Long term risk of bladder cancer
How are catheter infections prevented?
Catheterise only if necessary Remove when no longer needed Remove and replace if causing an infection Catheter care Hand hygiene
How are CAUTIs treated?
Check recent microbiology Start empirical antibiotics Remove catheter is not needed Replace catheter under antibiotic cover - gentamicin and ciprofloxacin May need to be more broad spectrum
What is acute pyelonephritis?
Upper urinary tract infection (moderate/severe)
Ascending infection involving the pelvis of the kidney
Enlarged kidney
Raised abscesses on the surface of the kidney
How is acute pyelonephritis managed?
Check recent microbiology Send urine and blood cultures Image the kidneys Community - trimethoprim, ciprofloxacin or co-amoxiclav Hospital - broad spectrum No response means further investigation is needed Uncomplicated = 7-14 days Complicated = longer than 2 weeks
What causes a renal abscess?
It’s a complication of pyelonephritis (similar symptoms)
Gram negative bacilli (usually)
What are the complications of a renal abscess?
Can become life-threatening
- emphysematous pyelonephritis (severe infection causes gas accumulation in the tissues)
Poor response to antibiotics
What are the risk factors for a perinephric abscess?
Untreated LUTI Anatomical abnormalities Renal calculi Bacteraemia Haematogenous spread
What are the common causative organisms of a perinephric abscess?
E.Coli Proteus S.aureus Strep Candida
How can you detect a perinephric abscess?
Symptoms - similar to pyelonephritis - localised signs and symptoms Positive blood cultures Pyuria with/without bacterial growth
How are perinephric abscesses treated?
Empirically as a complicated UTI
(poor response normally)
Surgical removal/drainage
How are complicated UTIs managed in all patients?
Bloods - FBC, U&es, CRP Urine sample Blood culture - if pyrexic or hypothermic Renal US CT KUB Antibiotic therapy for 2 weeks or more
Describe the interpretation of urine microscopy?
Epithelial cells - contamination Bacteria with no WBC - contamination Bacteria with WBC and no catheter - infection Bacterial with WBC and a cather needs to be assessed clinically Pyuria with no bacteria - previous/recent antibiotic - tumour - calculi - urethritis (chlamydia check) - TB
What are the antibiotic guidelines for a complicated UTI?
IV therapy
- amoxicillin/vancomycin
- gentamicin/aztreonam/temocillin
Drug monitoring in gentamicin
What is acute bacterial prostatitis?
A spontaneous, localised infection of the prostate gland
What are the symptoms of acute bacterial prostatits?
Fever Perineal/back pain UTI Urinary retention Diffuse oedema Micro abscesses
What are the likely causative organisms of acute bacterial prostatitis?
Gram negative bacilli - E.Coli - Proteus S.aureus N.gonorrhoea
What are the investigations for acute bacterial prostatitis?
Urine culture
Blood culture
Trans-rectal US
CT/MRI
What are the complications of acute bacterial prostatits?
Prostatic abscess Spontaneous rupture - urethra or rectum Epidiymitis Pyelonephritis Systemic sepsis
What is the antibiotic management for acute bacterial prostatitis?
Check recent microbiology
Ciprofloxacin or Ofloxacin
What are the common symptoms of chronic prostatitis?
Perineal discomfort/back pain
Low-grade fever possible
UTI symptoms
What is epididymitis?
Inflammatory reaction of the epididymis
- from ascending infection of the urethra
What are the symptoms of epididymitis
Pain Fever Swelling Penile discharge Symptoms of UTI
What are the common causative organisms for epididymitis?
GNB Enterococci Staph TB - in high risk groups Need to rule out urethritis - Chlamydia - N.gonorrhoea
What is orchitis?
Inflammation of one or both testicles
What are the symptoms of orchitis?
Testicular pain and swelling
Dysuria
Discharge
Penile discharge
What is the most common cause of orchitis?
Viral (mumps)
What are the complications of bacterial orchitis?
Testicular infarction
Abscess formation
What is Fournier’s gangrene?
A form of necrotising fasciitis
- rapid onset and spreading infection
Causes systemic sepsis
What are the risk factors for Fournier’s gangrene?
UTI
Complications of IBD
Trauma
Recent surgery
What are the investigations used in Fournier’s gangrene?
Blood cultures
Urine
Tissue/pus
How is Fournier’s gangrene treated?
Surgical debridement
Broad spectrum/combination antibiotics
- Tazocin and gentamicin and metronidazole and clindamycin
