Microbiology Flashcards
Urine in the kidneys, ureters and bladder is normally sterile. True/False?
True
Which organisms usually colonise the lower end of the urethra?
Coliforms
Enterococci
(from large bowel)
Define “UTI”
Presence of microorganisms in the urinary tract that are causing clinical infection
Lower UTI denotes infection confined to where?
Bladder (cystitis)
Upper UTI denotes infection spreading to where?
Ureters +/- kidneys (pyelonephritis)
Bacteriuria (presence of bacteria in urine) always indicates a UTI. True/False?
False
Especially in elderly, and those with catheters
Why is UTI more common in women? List other risk factors for UTI
Short, wide urethra
Urethra near anus
Pregnancy
Catheterised patients
Abnormality of UT
Diabetes
Immunosuppressed patients e.g HIV/ AIDs
What is the most common route of infection in UTI? Name another route of infection
Ascending infection - bacteria from bowel/bladder rises upwards through ureters to the kidneys
Bloodstream (bacteraemia/ septicaemia)
List the main causal organisms of UTI
E. coli
Klebsiella
Enterococci
Proteus
Which bacteria is associated with the formation of calculi?
Proteus sp.
Produces urease which breaks down urea to form ammonia (increases pH), precipitating salt formation (struvite triple phosphate stones)
Which enterococcus - faecalis or faecium - is quite resistant to antibiotics?
Enterococcus faecium
Which particular strain of Staphylococcus is associated with UTI? Who is it usually found in?
Staph. saphrophyticus (coag. -ve)
Particularly in women of child-bearing age
Which organism is associated with causing UTI in catheterised patients?
Pseudomonas
Which antibiotic is Pseudomonas not resistant to?
Ciprofloxacin
List the main symptoms and signs of (lower) UTI
CYSTITIS
Dysuria
Frequency/nocturia
Haematuria
What clinical features suggest an upper UTI?
PYELONEPHRITIS Fever and chills Loin pain Rigors Nausea, vomiting
When taking a urine sample to check for UTI, the first urine passed is assessed. True/False?
False
First urine is likely to be contaminated; collect mid-stream sample
List different ways of collecting urine specimens
Midstream bowl by patient Clean catch by nurse Bag urine (babies) Catheter specimen Suprapubic aspiration
Which container contains preservative that can prevent bacteria multiplying in a urine sample?
Boricon (red top) container
Works for 24hrs
If a urine sample is collected in a standard universal (white top) container, how quickly must it reach the lab?
Within 2 hours of collection