Institute for Microbiology, Medical Faculty of Masaryk University     and St. Anna Faculty Hospital
in Brno
Agents of urinary tract infections

Urinary tract infections (UTIs)
Frequency of UTIs:
2nd most common infections
In adults: the most common infections
Afflicting mainly females (shorter urethra)




Cystitis
- the most common UTI:
- develops ascendently caused by intestinal microflora
- symptoms:
   dysuria (difficult urination with sharp  burning pain)
pollakisuria (urgent need to urinate accompanied by urination of a small amount of urine only)

Pyelonephritis
- more serious
- origin: ascendent or hematogenous
-  symptoms:
   fever, chills, flank pain, or costovertebral tenderness, urinary frequency, dysuria, hematuria
...urethritis – will be dealt with STD

Etiology of UTIs
Differs in:
•non-complicated UTIs
•structural abnormalities (prostatic hypertrophia, urinary stones, strictures, pregnancy,
congenital defects, permanent catheters)
•functional disorders (vesicoureteral reflux, neurological disorders, diabetes mellitus)

Etiology of non-complicated UTIs
1. 80 % Escherichia coli
2. 10 % enterococci (Enterococcus faecalis)
3. 5 % Proteus mirabilis
         - other enterobacteria (Klebsiella pneumoniae,
             Kl. oxytoca, Ent. cloacae, C. freundii etc.)
      - Streptococcus agalactiae
          - coagulase neg. staphylococci
      - yeasts (mainly Candida albicans)







http://biology.clc.uc.edu



Etiology of  complicated UTIs
     80 %       Escherichia coli
                 Klebsiella pneumoniae
                 Proteus mirabilis
                    Pseudomonas aeruginosa
                     enterococci
                     other enterobacteria
                 acinetobacters
                     other G-neg. non-fermenting rods
                 candidae

Lege artis taking a urine sample
•after a thorough cleaning incl. external orifficium of urethra by soap and water
•middle stream of urine
•sterile vessel
•sterile tube & stopper promptly
•process it within 2 hours, or place into 4 °C for 18 hours at most

http://www.naturalnews.com/cartoons/Expensive_Urine_600.jpg



Semi-quantitative examination – I
•the kind of microbe in the urine sample
•the amount of the microbe
Because
•high numbers only stand for the UTI
•low numbers mean usually contamination acquired during urination

Semi-quantitative examination – II
The urine is inoculated on culture media by a calibrated loop taking 1 μl of urine
In this case
    1 colony means  103 CFU/ml
  10 colonies mean 104 CFU/ml
100 colonies mean 105 CFU/ml
(CFU = colony-forming unit = 1 cell)




Significant concentrations of bacteria in urine
Type of specimen,  symptoms
Type of microbe
Significant number (CFU/ml)
Middle stream, symptoms  present
Primary urine pathogen
103
Dubious urine pathogen
105
Middle stream, no symptoms
Any
105
Suprapubic punction
Any
101

Therapy
•Trimethoprim
•Nitrofurantoin
•Cephalexin
•Amoxicillin
•in complicated UTIs ATB sensitivity assessment
•ESBL strains


Paulus Peeter Rubens (1577-1640): Goddess of health Hygiene (1615)


Detail
Paulus Peeter Rubens (1577-1640): Goddess of health Hygiene (1615)