This is prepared for my project and im sharing this for useful to others.This slides contain the processing of urine specimens in microbiology.im prepared on basis of our medical college method.sometimes the methods will vary with other hospitals

1. PROCESSING OF URINE

2. PURPOSE OF EXAMINATION
 Diagnosis of urinary tract infection
accomplished by semi-quantitative culture
of urine and antimicrobial susceptibility
testing of potential pathogens present in
significant numbers

3. Clean catch MSU- Mid stream
urine is used because the first
few ml of urine passed will
contain skin flora from the
urethral orifice and will yield
potentially misleading misleading
results.

4.  Foley’s catheter sample-
it is reserved for hospitalized patients and
patients unable to void urine. For
collection the catheter tubing should be
clamped off above the port to allow
collection of freshly voided urine. The
catheter port or wall of the tubing should
then be cleaned with 70% ethanol , and
urine aspirated via needle and syringe and
collect into a sterile container

5. SPECIMENS
 Suprapubic aspirate- it is usually reserved
for infants from whom it is difficult to obtain
urine specimens. For this skin above the bladder
is cleaned with disinfectant. Urine Is withdrawn
directly into the syringe through percutaneously
inserted needle thereby ensuring a contamination
free specimen. The specimen is then collect into a
sterile container

6. SPECIMENS
Cystoscopy specimen -
collected from the bladder during
cystoscopy to avoid urethral
contamination

7. PEDIATRIC URINE CULTURES
COLLECTION OF SPECIMENS
 Urine, which should be obtained before
the initiation of antimicrobial therapy,
can be collected by various method
 1-clean catch midstream urine
 2-urethral catheterization
 3-suprapubic aspiration

8. REJECTION OF SPECIMEN, WHICH ARE
UNSUITABLE FOR CULTURE
 1) bedpan urine
 2) specimen received in non sterile
container
 3) bag urine { because organism can
multiply there , obscuring the true relative
numbers.}
 4) unlabelled and improper labeled
specimens
 5) specimen that have leaked out the
container.

9. SPECIMEN TRANSPORTATION
 Urine should reach lab immediately after
collection and should be cultured within
2 hrs. if it is not possible it can be
refrigerated at 4 degree c maximum for
18 hrs

10. MEDIA USED
 Well dried sheep blood agar
 maCconkey agar
 brain heart infusion agar

11. SPECIMEN PROCESSING

12. SCREENING TEST
 GRAM STAINING
. The gram stain is the easiest, least
expensive, and probably the most
sensitive and reliable screening
method for identifying urine specimens
that contain greater than 10^5
CFU/ml.
A drop of well-mixed urine is allowed to air dry.
The smear is stained and examined under oil
immersion.
Presence of at least one organism per oil immersion
field.
( examining 20 fields ) corelates with significant
bacteriuria (>105 CFU/ml

13. PROCEDURAL STEPS;
Calibrated loop method
a. Gently mix the urine.
b. Hold calibrated sterile loop vertically and
immerse the loop just below the surface of
the urine and there by sucked up into
loop. Do not put loop deep into the urine
c. Streak urine on blood agar and MacConkey
agar without touching the edge of the
plate.

14. d. After culturing place one drop full of
urine for wet mount or gram staining on
clean slide
e. Stab one loop full of urine on BHI plate
with staphylococcus aureus lawn culture
for urine antimicrobial activity.
f. Incubate the plates at 37oc for up to 48 hrs
and check for the growth from 24 hr onwards

16. INTERPRETATION OF RESULT
 Check the growth from 24 hr onwards and incubate
the plates up to 48 hrs. interpretation of result is
correlated with the wet mount and gram stain
report. Identify the predominant bacteria/yeast
colonies by morphology stained preparation and
biochemical tests. Note antimicrobial test positive(
clear zone on BHI plate) or as negative (no zone). Do
sensitivity test of isolate by Kirby-Bauer method.
Bacterial or yeast count per ml is calculated by
multiplying number of colonies by 100.
 Pus cells more than 10, it is suggestive of UTI

17. POTENTIAL PATHOGENS
 Enterobacteriacea such as E.coli, proteus spp., klebsiella spp.
 Pseudomonas aeruginosa
 Staphylococcus aureus
 Staphylococcus saprophyticus
 Beta hemolytic streptococci
 Streptococcus pnuemoniae
 Enterococcus spp
 Yeast spp
 Acinetobacter spp

18. PARASITES
 Schistosoma haematobium
 Trichomonas vaginalis

19.  RESIDENT MICROFLORA OF THE URETHRA
 Coagulase negative staphylococci (excluding staph. Saprophyticus)
 Viridian and non hemolytic streptococci
 Lactobacilli
 Diphtheriods
 These organisms are normally considered
contaminant, but may be significant upon repeat
isolation
 Any female with group B streptococci bacteriuria in
any concentration during her pregnancy should
receive intrapartum antibiotics

20. REPORTING THE RESULT
 Report identified bacterial/yeast isolates with colony
count and antibiotic sensitivity