Urinary Tract Infection (UTI)
- 2. Introduction • Urinary tract lined by epithelium – Protection • Microorganism enter thro’ epithelial surface. • Affected areas: • Bladder – Cystitis • Renal pelvis • Kidneys - Pyelonephritis
- 3. Types Upper UTI Acute Pyelitis Acute Pyelonephritis Lower UTI Urethritis Cystitis Prostatitis
- 4. Predisposing Factors • Age • Sex • Pregnancy • Structural and functional abnormality of kidney • Metabolic • Intervention • Bacterial Virulence
- 5. Clinical Presentation • Asymptomatic: • 5-7% pregnant women • May lead to complications-untreated • Symptomatic: • Common symptoms • Pyelonephritis (Upper UTI) • Fever, flank and loin pain • Cystitis (Lower UTI) • Dysuria, fever with chills
- 7. Etiology • Community acquired UTI: • Infection contracted outside the healthcare settings • Hospital acquired UTI: • Catheter associated • Poor aseptic insertion
- 8. Causative Organism • Gram -ve Bacilli • E.Coli • Proteus • Gram +ve Cocci • Staphhylococcus • Enterococcus • Gram –ve cocci • N. gonorrhoea • Others • M. Tuberculosis • Salmonella Bacteria • Adenovirus Virus • Candida albicans Fungi • Trichomonas vaginalis • Schistosoma haematobium • Enterobius vermicularis Parasites
- 9. Lab Diagnosis • Collection and transport of specimen • Microscopy • Screening • Culture • Antibiotic Sensitivity Test
- 10. Collection of Specimen Collection Midstream urine Male Female Catheter sample urine During cystoscopy Early morning Urine TB of urinary tract Suprapubic Aspirate Children, infant and older women Initial Flow Urethritis, Prostatitis
- 11. Transport of Specimen • At room temp - half an hour • Refrigerated at 4⁰- 4 hrs • Not processed beyond this time • No immediate access – Spl. container with 1.8% boric acid • Contamination-False +ve
- 12. Microscopy • Urine centrifuged and deposit examined under microscope • The following can be seen: • Pus cells ( > 5/hpf) • Bacteria • Epithelial cells • RBC
- 13. Culture: • Semi-quantitative cultures • Standard loop technique • Involves a ‘standard calibrated loop’ – transfers fixed, small quantity of urine • Culture Media: • Mac Conkey Agar • Blood Agar • Mac Conkey- quantitative measurement • Blood- presumptive diagnosis
- 14. • Colony count of 105/ml – Significant • 104/ml – 105/ml – Doubtful significance • < 104/ml – Significant only if: • On prior antibiotics • Obstruction in UT • Fungal infection/pyelonephritis • Specimen is suprapubic aspiration • ≥ 3 types of organism - Contaminants Fixed and small amount of uncentrifuged urine is transferred to BLOOD and MacCONKEY AGAR Incubate at 37⁰ C for 24 hours Next day, the number of colonies grown is counted and total count per ml is calculated
- 15. Screening • Necessity: • UTI is a common problem and facilities are not always available • Used for presumptive diagnosis Catalase Test Griess Nitrite Test TTC (Triphenyltet razolium chloride) Gram Stain Dip Slide Culture Glucose Paper Test
- 16. 1. Griess Nitrite Test: • Normal urine does not contain nitrite • Is based on nitrate reducing enzyme produced by bacteria during infection 2. Catalase Test • Certain bacteria have catalase enzyme which acts on hydrogen peroxide to release oxygen • +ve rection evident by formation of bubble • Only in catalase +ve organism
- 17. 3. Triphenyl tetrazolium chloride: • Is based on production of pink red precipitate in the reagent • Caused by respiratory activity of growing bacteria 4. Gram stain: • Microscopic demonstration of bacteria in gram stained films of urine
- 18. 3. Glucose Paper Test: • Is based on utilization of minute amount of glucose in the normal urine utilized by the bacteria causing infection 4. Dip Slide Culture: • CLED agar on one side and MacConkey on another coated slide → immersed in urine → incubated at 37⁰C → growth estimated by colony counting or color change
- 19. Antibiotic Sensitivity: • E. coli and other urinary pathogens – multi drug resistance; transferable variety • Necessary to administer proper antibiotics • Primary susceptibility test with urine specimen is done • Confirmed by AST using bacteria recovered in culture
- 20. Thank You !
Editor's Notes
- #8: Periurethral flora inserted into bladder, migration of bacteria along the tubes