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:



The 2nd most common infections (after respiratory ones)



In adults: the most common infections



Afflicting mainly females (because of shorter urethra)





                                        Examples of UTIs I

The most common UTI:

Cystitis - develops ascendently caused by intestinal microflora



   Symptoms:

   dysuria (difficult urination with sharp and burning pain)

   pollakisuria (urgent need to urinate accompanied by urination of a small amount of urine only)



                                        Examples of UTIs II

Other UTIs:

   mainly 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

Proportional representation of microbes differs in:



•            non-complicated UTIs



•            infections accompanying structural abnormalities (prostatic hypertrophia, urinary
stones, strictures, pregnancy, congenital defects, permanent catheters)



•            infections accompanying  functional disorders (vesicoureteral reflux, neurological
disorders, diabetes mellitus)

                                 Etiology of non-complicated UTIs

80 % Escherichia coli

10 % enterococci (Enterococcus faecalis)

5 % Proteus mirabilis



       other enterobacteria (Klebsiella pneumoniae,

             Kl. oxytoca, Ent. cloacae, C. freundii etc.)

         Streptococcus agalactiae

         coagulase neg. staphylococci (S. epidermidis,

              S. saprophyticus, S. haemolyticus etc.)

         yeasts (mainly Candida albicans)









                                   Etiology of  complicated UTIs

circa 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

•                          Only after a thorough cleaning of genital incl. external orifficium of
urethra by means of soap and water

•                          Take the middle stream of urine only

•                          Use a guaranteed sterile vessel

•                          Pour it into a sterile tube & stopper promptly

•                          If not possible to process it within 2 hours, place the specimen into 4
°C for 18 hours at most



                       Semi-quantitative examination of the urine sample – I

We are interested

•                          not only in the kind of microbe present in the urine sample, but
especially

•                          in the amount of the microbe



Why are we interested in the number  of microbes in 1 ml of urine?



Because

•                          high numbers only stand for the UTI

•                          low numbers mean usually contamination acquired during
urination

                      Semi-quantitative examination of the urine sample – II

Therefore, the urine is inoculated on culture media by means of a calibrated loop, usually taking 1
μl of urine



In this case

                  1 colony means  10^3 CFU/ml

                10 colonies mean 10^4 CFU/ml

              100 colonies mean 10^5 CFU/ml



(CFU = colony-forming unit = 1 cell)



                          Significant concentrations of bacteria in urine

                                              Therapy

•            Trimethoprim-sulfamethoxazole

•            Nitrofurantoin

•            Cephalexin

•            Fluorochinolones

•            Amoxicillin-clavulanate





•            in complicated UTIs ATB sensitivity assessment

•            ESBL strains

                                       Homework 3 – solution
                Paulus Peeter Rubens (1577-1640): Goddess of health Hygiene (1615)

                                        Homework 3 – detail
                Paulus Peeter Rubens (1577-1640): Goddess of health Hygiene (1615)

                                            Homework 4
                           Who painted this picture and what is its name?