UTI Flashcards
Bacteriuria
Presence of bacteria in urine
Pyuria
Presence of WBCs in urine
Cystitis
UTI associated with bladder mucosa
Pylenephritis
UTI of renal parenchyma -kidneys
Urethritis
Urethra infection
Normal flora of Urinary Tract
Coagulase-negative staphylococci Diphtheroids Lactobacilli Bacillus species Enterococci Saprophytic yeast
Significant Bacteriuria Concept
Up to 10^4/ml considered normal i.e. Insignificant
Organisms
10^5/ml and above considered to be Significant
Female - Predisposing Factors
- Shortness of female urethra
- Sexual intercourse (honeymoon cystitis)
- Pregnancy & Contraceptive devices
Male - predisposing factors
- Prostatic hypertrophy (prostate enlargement)
Common factors - both genders
Presence of foreign body: stone, catheter, surgical instrumentation. - Obstruction: Urethral stricture . - Neurogenic bladder dysfunction Spinal cord injury Diabetes
Hemolytic uremic syndrome (HUS)
- when BVs in kidneys become damaged and inflamed. This damage can cause clots to form in the vessels. The clots clog the filtering system in the kidneys.
- Linked to O157 EHEC
E coli causing UTI
E coli contributes to 90% of UTI strains
01,02,04,07,18,75
Virulence factors - E coli
- Pili/Fimbriae
- Hemolysins
- Aerobactin
- Biofilm
Pathogenicity
Ascending route - Colonization of perinium and urethral area by enteric (intestinal) m.o.s
Rarely haematogenous (via blood) - Descending route
Entero-Vesical- Fistula - enterovesical fistula is an abnormal connection between the bowel and bladder - Fistulas form when inflammation causes sores, or ulcers, to form on the inside wall of the intestine or nearby organs
Lower UTI
Urethritis & Cystitis
Urethritis
Dysuria - burning sensation / pain during micturition & frequent urination.
Cystitis
Dysuria - characteristic supra pubic pain & tenderness, occasional hematuria. Diminished bladder capacity leads to frequent micturition.
Causes of lower UTI
Staph.saprophyticus
Appropriate Specimen : Cystitis = Urine (Clean Catch)
{Most Appropriate Abx = Cotrimoxazole }
Upper UTI
Acute pyelonephritis
Acute pyelonephritis
Flank / loin pain & fever, renal tenderness on palpation.
Hematuria with fever & chills.
(Sp:Pyelonephritis-Urine)
Helminths - UTI
Schistosoma haematobium.
Trichomonas vaginalis
Fungi - UTI
Candida albicans
Specimen - UTI
Urine- MSU (“clean catch”)
Catheter specimen (CSU)
Suprapubic aspirate
Lab ID - UTI
Gram Stain –GNB/GPC (1 Bacterium / field is significant) Urinalysis- e.g. Pyuria (>5 WBC/HPF) Culture on -- CLED / ( MAC ) , B A. Biochemical Antimicrobial Susceptibility Testing
Significant results
Significant bacteriuria: ≥ 100,000 CFU/ml
ID of anaerobic bacteria- UTI
Extremely foul smelling urine
No response to aerobic antibiotics
No growth on gram stain
E coli - ID
Gram: Gram-negative rods/bacilli (pink)
BA (Blood Agar): Large, white, colonies.
MAC (MacConkey): Lactose fermenting, Pink colonies
CLED (Cystine-Lactose-Electrolyte Deficient) : Lactose fermenting, Yellow colonies.
Motile
Klebsiella pneumoniae
Gram negative bacilli-Non motile
Citrate, Urease positive
Colony-on MC-Lactosfermenting (L.F,), Mucoid ,Large
Pseudomonas aeruginosa
GNR, motile
Proteus spp
Gram: Gram-negative rods / bacilli ( pink )
BA: Single colony showing Swarming
MAC: Non-Lactose fermenting ( NLF )
non-pink colonies
CLED: Non-Lactose fermenting-colonies (translucent blue )
MR +ve , Urease +ve
Motile
Antimicrobial agents - UTI
Co-trimoxazole = ( Most Appropriate Antibiotic ).
Amoxicillin , Tetracycline , Amoxicillin-Clavulanic acid, Cefuroxime , Ciprofloxacin
Prevention - UTI
Plenty water and frequent voiding
- Voiding after sexual intercourse
- Cranberry Juice → →
↑ - Fluid intake → urine output
- Acidifies urine
- Interferes with bacterial attachment to urothelium
-Phenazopyridine ( urogesic ) relieves symptoms.
