STANDARD OPERATING PROCEDURES FOR URINE CULTURE

1. SPECIMEN:

1. Clean-catch Midstream urine collected in a sterile dry leak-proof container

(Note- add a measured amount of boric-acid powder (0.1gm/ 10 ml of urine) to preserve the specimen and mix well)

2. CULTURE MEDIA:

1. Cystine lactose electrolyte-deficient (CLED) agar

3. PROCEDURE:

1. Mix the urine by routing the container.

2. Using a calibrated wire loop that can hold for example 0.002ml, innoculate a loopful of urine on a

quarter plate of CLED agar (note- if microscopy shows many bacteria, use a half palte of media)

3.Incubate the plate aerobically at 35-37C overnight.

4.Next day, observe the appearance of some urinary pathogens on the agar plate:

(Note -

- Opague colonies with slightly deeper colored center = E. coli

- Large mucoid yellow or yellow-white colonies = Klebsiella species

- Translucent blue-grey colonies = Proteus species

- Green colonies with rough periphery = P. aeruginosa

- Small yellow colonies = E.faecalis

- Deep yellow colonies of uniform color = S. aureus

- Yellow to white colonies = S.saprophyticus )

5.Count the approximate numbers of colonies and estimate the number of bacteria and report the

bacterial count as per ml of urine.

(Note -

*less than 10,000 organisms/ml is not significant

*10,000 – 1,00,000 organisms/ml is doubtful, repeat test

*more than 1,00,000 organisms/ml is significant bacteria )