Urine samples

Candida spp in urine is often representative of colonisation rather than true infection (particularly in association with indwelling urinary catheters). Managing predisposing risk factors may be sufficient to eliminate candiduria e.g. diabetic glycaemic control or changing the urinary catheter. Candiduria may also be present as a result of recent antibiotic use.

Treatment for candiduria with anti-fungals is not recommended unless the patient belongs to a group at high risk for disseminated infection e.g. neutropenia, low birth weight baby or due to undergo urological manipulation.

Positive culture results on CSU specimens need to be interpreted cautiously as they may represent catheter colonisation rather than a true clinical infection. If a patient has clinical evidence of urinary tract infection then changing the catheter with appropriate antibiotic cover, is often all that is needed to resolve this. The sensitivities on a CSU are suppressed to prompt the clinical team to firstly assess if there is evidence of infection and secondly to prompt a catheter change prior to a course of antibiotics. If following a catheter change, the patient remains symptomatic, then the sensitivities can be obtained by calling the appropriate laboratory.

Heavy mixed growth means that at least 3 organisms were cultured. The absence of 1 or 2 predominant organisms suggests that the urine was contaminated with the patient’s flora.  This result does not necessarily exclude a urinary tract infection, but it means it was not possible to determine the causative organism from the mixture.  If a urinary tract infection is still clinically suspected, a repeat urine specimen should be sent with care taken to ensure optimal collection technique.  Optimal sampling technique and use of boric acid containers can help to reduce the risk of heavy mixed growth cultures.

Asymptomatic bacteruria is common in clinical practice and the incidence increases with age.

Most patients with asymptomatic bacteruria do not develop symptoms and have no adverse consequences as a result of not being treated with antibiotics. Exceptions where treatment IS recommended are pregnant woman with asymptomatic bacteruria, patients due to undergo urological procedures and patients in the first few months post renal transplantation.

Please see SAPG documents below for information and guidance on recurrent UTI prophylaxis

management-of-recurrent-uti-in-non-pregnant-women-v2.pdf (sapg.scot)

management-of-urinary-tract-infections-in-men.pdf (sapg.scot)

Decision aid for diagnosis and management of suspected urinary tract infection (UTI) in women aged 65 years and over (sapg.scot)

UKAS recommends the use of red-topped boric acid containers for all urine samples for microscopy and culture to optimise the quality of microbiological results.  Boric acid preservative ((at a concentration of 1-2%) holds the bacterial population steady for 48-96 hours. 

Boric acid containers should not be used to perform urinary dipstick testing as can inhibit leukocyte esterase. A white topped universal container should be used to perform urinary dipstick testing.

Out-with specific scenarios (e.g pregnancy), clearance samples post antibiotic therapy are inappropriate.

Urine dipstick testing is NOT recommended in >65 age group.  Dipstick testing of non-MSSU urine samples (eg: CSU samples) is NOT recommended