This document discusses urinary tract infections (UTIs), including: 1. Causes of UTIs like E. coli, anatomical factors that predispose to infection, and clinical manifestations like dysuria and flank pain. 2. Diagnosis of UTIs using urine culture and microscopy to look for bacteria, white blood cells, and nitrites. 3. Treatment of UTIs with antibiotics like amoxicillin, ciprofloxacin, and nitrofurantoin depending on the organism and severity of infection.

1. URINARY TRACT
INFECTION (UTI)
A Lecture Presented by: Mr Somvanshi VD

2. Objectives
General Goal: To know the major cause(s) of these
diseases, how they are transmitted, and the major
manifestations of each disease.
Specific Objectives: The student should be able to:
1. To know the common cause(s) of these disease.
2. To know the common means of transmission.
3. To know the major manifestations of this infection.
4. To know how you diagnose, treat and prevent this
infection.

3. UTI
• 2nd in OPD patient visits after RTI
• Leading cause of hospital acquired infections
• Protective Mechanisms in Urinary Tract
• Fast urine flow
• Anatomy – urethral valves prevent backflow of
urine
• Acidic urine
• Inflammatory process – phagocytosis of
pathogens

4. UTI : Predisposing Factors
• Urinary stasis (obstruction to flow)
o Too busy to empty bladder (occupational)
o Urinary stones
o Bladder tumors
o Prostate enlargement
o Pregnancy
o After anaesthezia & major surgery
(reflex ability to void urine is inhibited)
• Urinary catheterization : recurrent UTI
• Anomalies of urinary tract
• Constipation in children and elderly
• Poor perineal hygiene in elderly
• Eight times more common in females (anatomy)

5. UTI : Organisms
A. Cystitis & Pyelonephritis
Common Pathogens
• Escherichia coli (commonest cause)
• Klebsiella pneumoniae
• Proteus species
• Pseudomonas aeruginosa
• Enterobacter species
• Enterococcus fecalis
• Staphylococcus saprophyticus (in young women)
• Proteus : Associated with renal stones
Uncommon Pathogens
• Mycobacterium tuberculosis
• Leptospira interrogans
• Schistosoma species
• Candida albicans : in diabetics and immunocompromised
Usually Hospital acquired

6. B. Urethritis
• Chlamydia trachomatis
• Ureaplasma urealyticum
• Neisseria gonorrhoeae
• Trichomonas vaginalis
UTI : Organisms

7. • Ascending infection : The most
common
• Blood-borne
o M. tuberculosis
o Leptospira interrogans
o Salmonella
UTI : Source of organisms

8. UTI : Clinical Features
Cystitis
• Dysuria
o Dysuria without vaginal discharge have a
UTI
o Vaginal infection and irritation can cause
dysuria
• Urinary frequency and urgency
• Supra-pubic pain and tenderness
• Haematuria

9. Urethritis
• Discomfort during voiding
• Burning micturation
• No supra-pubic discomfort
Pyelonephritis
• Flank pain & fever
• Nausea and vomiting
UTI : Clinical Features

10. Hemorrhagic cystitis (haematuria)
Visible blood in the urine
• Bacterial infection
• Adenovirus types 1-47 infection
• Bladder stones
• Schistosomiasis
• After radiation therapy
• Cancer chemotherapy
• Immunosuppressive medication
UTI : Clinical
Features

11. Complications
• Bacteremia
• Chronic pyelonephritis
• Renal abscess
• Death

12. UTI : Lab Diagnosis
Collection (sterile container)
• Bacterial Infection : first morning midstream
urine
• Schistosomiasis : last 5-10 ml of urine
• Male urethritis : first 5-10 ml of urine
(urethral swab is the correct specimen)
 Instructions to patient for aseptic collection
Transport
Without delay: Otherwise at room temperature
 Bacteria will multiply : false bacterial count
 WBCs, RBCs will start to lyse
 Glucose, protein will alter

13. UTI : Lab diagnosis
Pyuria without bacteriuria
• Patient on antimicrobial treatment
• Renal stones
• Renal tuberculosis
• Gonococcal urethritis
• Chlamydia trachomatis infection
• Leptospirosis
• Scistosomiasis
Bacteriuria without pyuria
• Urine contamination
• Bacterial endocarditis
• Diabetes mellitus
• Enteric fever

14. Recurrent Infection Vs Re-infection
Recurrent infection
• Occurs within 2 weeks of completing
antimicrobial therapy
• Caused by the original pathogen
• Causes scarring and shrinkage of kidneys :
An important cause of kidney failure
Re-infection
• Occurs after 2 weeks of completing antimicrobial
therapy
• May be caused by the same or a different
organism

15. Differentiation between UTI and
bacteriuria
• Pyuria alone = inflammation
• Bacteriuria without pyuria = colonization
• Pyuria + bacteriuria + nitrites = infection
UTI : Lab diagnosis

16. Physical appearance
• Cloudy
o Bacterial UTI
• Red & cloudy
o Bacterial UTI & Schistosomiasis
• Yellow-brown
o Acute viral hepatitis &
o obstructive jaundice
• Milky white
o Bancroftian filariasis
UTI : Lab Diagnosis

17. Microscopy
Examined as wet preparation to detect:
• Significant pyuria : WBCs >10 cells/ul of urine
• RBCs
• Epithelial cells
• Yeast cells
• Trichomonas vaginalis trophozoites
• Schistosoma haematobium eggs
• Crystals
• Casts
UTI : Lab Diagnosis

20. Culture
• Not more than 24 h
• Significant bacteriuria
• <104 CFU (colony forming unit) bacteria/ml and/or
More than one bacterial types
• >/=105 CFU bacteria/ml of urine : UTI
Dipsticks
• Nitrite test : for enterobactericeae
• Leucocyte-esterase test : for WBCs
• Protein
UTI : Lab Diagnosis
contamination

21. • Cystitis : easily treated in few days
• Pyelonephritis : Prolonged treatment
• Complicated UTI : Prolonged
treatment
• Is accompanied by an underlying risk
factors :
o Prostatic enlargement
o Urologic dysfunction
o Resistant pathogens
• Recurrent UTI : Prolonged + Combination
therapy
UTI : Treatment

22. UTI : Treatment
Beta-lactams
• Amoxicillin
• Amoxicillin/clavulanate
• Cephalexin, cefixime
Quinolones
• Nalidixic acid
• Norfloxacin
Nitrofurantoin
• Spares disruption of normal vaginal flora and
• Consistent efficacy against E coli and Staphylococcus
saprophyticus
• Should be avoided after the 36th week of gestation due to
risk for hemolysis if the fetus is G6PD-deficient

23. Case study
A 77 year-old surgical patient, who had been discharged to a
long-term care facility 6 months earlier, developed dementia
with a concomitant elevated temperature (39.50C), and mildly
elevated WBC (12,000 WBC/ml). Peripheral blood culture and
clean catch urine specimens were collected. The urine specimen
was sent on ice to laboratory.
A screening urine analysis indicated a moderate level of yeast and
rods and yielded a positive result on leukocyte esterase test. A
Gram stain performed, revealed several gram –negative rods of
similar morph type and a few WBC. Culture performed at 24 h
showed 100,000 CFU/ml mixed colonies of E. coli and Klebsiella
pneumonia, fewer than 10,000 of lactobacilli, viridians
streptococci, and yeast. Blood culture result were negative

24. Questions
1. How would the urine culture be worked up and reported?
2. Where do these organisms originate?
3. What is the difference between single episode UTI and
recurrent UTI?
4. What is the value of screening urinalysis an Gram stain
procedures?
5. What is the optimum incubation period for routine urine
culture?
6. What may occur if routine urine culture are incubated longer
than 24 hours?
7. What is the significance of yeast quantitation in a urine
specimens?
8. What is the definition of contaminated urine?
9. Should susceptibility test be performed for all organisms
isolated from urine?