1. UTIs-Definition Infectious diseases of the urinary tract:
cystitis (bladder)
pyelonephritis (kidney)
prostatitis (prostate)

2. Etiology Usually Acute Majority due to a single pathogen
Usually an Enterobacteriaceae
90% of all UTI
gram negative bacilli
common intestinal flora
Escherichia coli most commonly isolated pathogen ~80% of all UTI

3. Gram staining
Gram +ve S. aureus
Gram –ve E. coli

4. Organisms: Gram -ve Gram +ve Cause 90-95% of UTI’s
most often, E. coli.
Others include:
Proteus mirabilis and Klebsiella.
Gram +ve
pathogens include:
Staph saprophyticus,
Staph aureus,
group A beta hemolytic streptococci and enterococci.

5. Features of UTI Common affliction to seek medical attention.
Infancy to old age
Bacturia:
bacteria in urine
does not necessarily imply infection

6. Features of UTI Pyuria Presence of WBCs in urine
Evidence of inflammatory response to infection.

7. Epidemiology Populations with increased incidences: School age girls
Young women>men
>50% have a UTI during their lifetime
>10% per year have a UTI
Pregnant women
Elderly of both sexes
Diabetes
Abnormal urine flow

8. Who to screen for UTI? Children with recurrent infection
Monitoring antibiotic therapy
High risk individual

9. How do we screen for UTIs?
Collect midstream urine
use fresh or refrigerate.
Pour about 10 ml in tube and dipstick.
Microscopy
Culture

10. Chemical Analysis Dip-stick testing Quick Efficient Inexpensive
Large number of substances

11. Chemical Analysis

12. Chemical Analysis

13. Chemical Analysis

14. Urinalysis Dipstick findings: leukocyte esterase + with pyuria
nitrite + with Enterobacteriaceae
alkaline pH with urea splitting bacteria, e.g., Proteus mirabilis
high specific gravity if patient is volume depleted
protein often +
blood may be +

15. What are the most useful test?
Leukocyte Esterase
Enzyme found WBCs
More reliable than microscopic analysis for WBCs
Positive results indicate inflammation in the path taken by urine.
Includes urethra, prostate, cervix and vagina
Occur in 90 to 95% of symptomatic UTI
Less sensitive asymptomatic UTI in elderly and pregnancy
Significant result: positive

16. What are the most useful test?
Nitrite
Some bacteria will convert Nitrate to Nitrite
Good indicator of contact of urine with bacteria
Detects 2/3 to ¾ of all UTIs
But…
Gram +ve bacteria do not cause a positive result
Negative results do not rule out infection
Significant Result: Positive

17. Microscopic Urinalysis

18. Urinalysis
Centrifuge for 5 min at 2000 rpm, pour off supernatant; examine sediment with microscope using high power objective.
Microscopic findings:
<5 leukocytes per high power field (hpf)
more = pyuria
1 bacterium per hpf correlates with >100,000 per ml;
1 bacterium = 1 colony forming unit (cfu)
hematuria

19. Urine Culture
Quantitative: uncentrifuged urine inoculated on an agar plate to do a colony count.
Appropriate agars: 5% sheep blood and eosin-methylene blue or MacConkey.
Incubate: at 35-37o C for 24 hours.

20. E. Coli in Urine Culture

21. Urine Culture Significant bacteriuria: Species identification.
by 24 hour colony count
cystitis: >100 cfu per ml
pyelonephritis: >100,000 cfu/ml
Species identification.
Susceptibility testing
urine for C&S.

22. A secure diagnosis of UTI requires a urine culture

23. How the test is done

24. Urinary Bacteria Detection Kits
Two Uses
Patients susceptible to UTI
Monitor effectiveness of Treatment
Detect urinary nitrites associated with gram-negative bacterial infections.

25. How the Test Works: Nitrites
Gram -ve Pathogen
Nitrite
Nitrate in Acidic Urine
Meat, Fish & Eggs
P-Arsanilic
Acid
Diazonium Compound
Pink Color
N-(1-naphthyl)
-ethylenediamine

26. How the Test Works: Leukocytes
White Blood Cells in Urinary Tract
White Blood Cells in Urine
INFECTION/INFLAMMATORY
RESPONSE
Pyrrole Ester Compound
Leukocyte
esterase
Color
Diazo Reagent
Pyrrole

27. Sampling precautions Clean Dry Container
First Morning Urine or in Bladder >4 hrs
Fresh sample
Follow-up: Regardless of result.
Test Sensitivity
90% - 3 consecutive mornings
10% - False negative rate

28. Factors Affecting Test
Concentration of Gram -ve Bacteria
> 100,000/mL of urine
Time in the Bladder
Contamination
Blood
Adequate Dietary Nitrates
Most people Consume sufficient Quantities
Drug interference
Alkaline Urine
Ascorbic Acid (Vitamin C)>250 mg
Antibiotics and Drugs that turn urine red

29. Home Cholesterol Tests
Two Uses
Monitor progress on Lipid lowering drugs and diet
Save Time and Costs of Physician Visits
Err on the side of false positives
Multiple measurements should be evaluated
Measurement errors and day to day biological and behavioral changes contribute to variations in cholesterol levels

31. How the Test Works Few Drops of Blood Step 110
Filter
Step 1
Plasma (Cholesterol & Cholesterol esters)
Step 2a
1. Wick Flow of Plasma
2. Cholesterol Oxidase/Esterase
3.2
Step 2b
Cholest-4-ene-3-one
H2O2
Colored Dye
Peroxidase

32. Factors Affecting Test
Finger Pricking Technique
Hanging Drops
Squeezing and Milking
Time to Collect
Low results if > 5 min.
Blood Volume

33. ?Usefulness Test only measures Total Cholesterol
Laboratories measure LDL, HDL, triglyceride, and cholesterol.
All are required.
You cannot make a judgement on cardiovascular risk on Cholesterol alone.
If values >5.2 : Discuss with physician
If values<5.2: Check Cholesterol again at next visit with a physician

34. Other kits Drugs of Abuse Home tests for STDs
Cannabinoids
Cocaine
Amphetamines
Benzodiazepines
Barbiturates
Opiates
Combinations
Home tests for STDs
Home tests for monitoring DM complications

35. This new product measures cholesterol plus other things using a test strip
Predict in as greatest detail you can how it might works…
What factors do you think could affect the reliability of the test results?