Urinary Tract Infections (UTI) - Preparation for Tutorials PDF

Urinary tract infections Department of Microbiology UTI – urinary tract infection  Lower urinary tract infections  Cystitis (bladder)  Urethritis (urethra)  Prostatis (prostate)  Upper urinary tract infections  Pyelonephritis (kidney and its pelvis) UTI...

Urinary tract infections Department of Microbiology UTI – urinary tract infection  Lower urinary tract infections  Cystitis (bladder)  Urethritis (urethra)  Prostatis (prostate)  Upper urinary tract infections  Pyelonephritis (kidney and its pelvis) UTI – urinary tract infection  40-50% of hospital-acquired infections  10-20% of community-acquired infections  newborns – more common in boys  middle-age - 10-times more common in women than in men  > 60-year-old – more common in men Urinary tract - defence mechanisms  flushing mechanism that wash the bacteria from epithelial surface every time urine is voided  the presence of normal flora  protection given by the mucus epithelium  the presence of Tamm-Horsfall protein UTI – predispositing factors  Upper part  Structural abnormalities  Urinary reflux  The presnce of renal calculi UTI – predispositing factors  Lower part  Bladder obstruction, bladder tumor  Pregnancy  Catheterization  Autoinfection  Anatomical abnormalities  Neurological defects  Sexual activity  Age UTI – route of infection  ascending – most cases  haematogenous (Staphylococcus aureus)  lymphpatic  tissue contiguous  by fistula:  uretero-vesico-intestinal  between the urinary tract and the vagina or uterus UTI - symptoms  50% of infections do not produce recognizable illness  Newborn - non-specyfic symptoms  Fever  Vomiting  Failure to thrive UTI – symptoms (child > 1-year-old, adults)  Lower UTI:  Painful urination (dysuria)  Frequent voiding (frequency)  Blood in the urine (haematuria - 50% of cases)  Fever – usually absent  may be present in catheterized patients UTI – symptoms (child > 1-year-old, adults)  Phelonephrits  Fever (> 38.5°C)  Chills  Pain in the area of the kidneys  More severely ill patients: vomiting, diarrhea, tachycardia The consequences of UTIs  Uro (sepsis):  UTI (after RTI), most common source of sepsis  20 – 30 % of newbon with sepsis  Renal failure  Hypertension  Complications of pregnancy and childbirth UTI – principal pathogens Community-acquaired infections Hospital-acquaired infecions ▪ E. coli (90%), ▪ E. coli (50%), ▪ Staphylococcus saprophyticus, ▪ Enterobacter spp., Proteus spp., ▪ Proteus spp., Klebsiella spp., Serratia marcescens, Acinetobacter ▪ Staphylococcus spp., Streptococcus spp., Pseudomonas spp., spp., Enterococcus spp., Stenotrophomonas maltophilia, Providencia stuartii, ▪ Rary: viruses, fungi, parasites ▪ Staphylococcus spp., Enterococcus spp., ▪ Corynebacterium urealyticum, ▪ fungi Candida spp. UTI - diagnosis  symptoms  urinalysis  urine strip tests  microscopis observation  flow cytometry  urine sample culture  imaging methods (USG)  blood cultures in the case of pyelonephritis UTI - diagnosis  Urine examinations  microscopis examiantion  pyuria (presence of leucocytes in urine) > 5 cells/immersion field  haematuria (presence of red cells in urine) > 5-10 cells/immersion field  the presence of proteins  urine strips :  leucocytes esterase (pyuria)  nitrates (+) = the presence of bacteria  the presence of proteins  urine pH > 7 – urease - positive bacteria (Klebsiella spp., Proteus spp., Staphylococcus saprophyticus, Providencia stuarti, Corynebacterium urealyticum)  urine culture!!! UTI - diagnosis Recognition of UTI in community acquired patients based on symptoms AND Strip test AND/OR microscopic examination/flow cytometry of urine sediment (+) (-) adults possibility of infection children No infection culture  Urine culture  Types of specimen:  Midstream urine / clean catch urine - early morning urine  Catheter urine sample  Bag urines (children) – not recommended  Suprapubic (bladder) aspiration (SPA)  Transport – to 30 minutes, room temperature  Storage (only if necessary):  in sterile container - to 24 hours, 4°C / to 48 hours, 4°C +boric acid  in uromedium (transport-growth medium for determining urine bacterial count) –in 37°C / room temperature  Urine culture  Specimen containers:  Urine is a medium for microorganisms!!!  Storage - only if it’s nessessary  Uromedium , Uricult, Uroline – 37˚C or room temperature http://mojurolog.pl/wp-content/uploads/2014/12/posiew%C3%B3wka.jpg https://www.roche.de/res/content/7810/2a-schritt-uricult.jpg https://www.roche.de/res/content/7810/1-schritt-uricult.jpg https://www.roche.de/res/content/7810/5-sch Incubation 37 °C Urine culture  Microscopic observation in microbiological examinations  on request the physician  positives results if >10^5 CFU/ml in urine sample  helpful to determine the reason of sterile pyuria  prepared with not centrifuged urine Sterile pyuria  Definition: presence of 10 or more white cells / µl of urine in the absence of bacteria, as determined by means of aerobic laboratory techniques  Reasons:  The presence of antimicrobial substances in the urine (Gold’s test)  STD (Gardnerella vaginalis, Mobiluncus spp., Trichomonas vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, Ureaplasma urealyticum)  Tuberculosis  Urinary tract injuries  Systemic diseases (cancer in UT, sarcoidosis, malignant hypertension) Urine culture  quantitative examination:  transport-growth medium (CLED/MCA)  dilution method  Hoeprich method https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcQVywyKgJVkPy3ewUtrqRD_P3WkL_fJuH12S7Yf9qr6d2AmM3R5 http://www.sharinginhealth.ca/images/urine_culture_loops.jpg x 10^2 x 10^3 Bacterial colony counts Urine culture – contamination of urine sample  Specimen collected using non-invasive methods  < 103 CFU/ml  Specimen collected using invasive methods  < 102 CFU/ml Urinare culture – significant bacteriuria  Midstream urine - adults Complicated UTI  105 CFU/ml urine Recurrent UTI (women) Upper UTI with symptoms (without complications)  104 CFU/ml urine Lower UTI with symptoms  103 CFU/ml urine (men and women) Urinare culture – significant bacteriuria  catheter-collected urine – collected always by new catheter - adults UTI with symptoms  103 CFU/ml urine UTI without symptoms  105 CFU/ml urine Urinare culture – significant bacteriuria  children Catheter or suprapubic bladder puncture  5*104 CFU/ml urine Catheter or suprapubic bladder puncture  5*104 CFU/ml urine AND pyuria in children 2-24 months old Midstream sample AND symptoms of UTI  105 CFU/ml urine Urinare culture - asymptomatic bacteriuria  Asymptomatic bacteriuria:  If in midstream urine sample  In women: in two consecutive (after 24 h) urine samples (midstream sample) the same species ≥ 105 CFU/ml,  In Men: in one urine sample ≥ 105 CFU/ml  If in once-catheterized patients (men and women): in one urine sample ≥ 102 CFU/ml  without pyuria  without clinical symptoms Urinare culture - asymptomatic bacteriuria  Asymptomatic bacteriuria:  recommended treatment for:  pregnant women  patients before planned surgery on urinary tract  catherized patients – only if bacteriuria remains 48 hours after removal of the catheter UTI - definitions  Recurrent UTI - the same species within 10-14 days after completion of therapy. Recurrent uncomplicated UTI may be defined as 3 or more uncomplicated UTIs in 12 months  Reinfection:  another species or  the same species within 2-3 weeks after completion of therapy Prophylactic measures against recurrent uncomplicated UTI 1. Conservative measures including limiting spermicide use and postcoital voiding lack evidence for their efficacy but are unlikely to be harmful 2. Cranberry products have conflicting evidence for their 3. Continuous antibiotic prophylaxis is effective at preventing UTI. 4. Postcoital antibiotic prophylaxis within 2 hours of coitus is also effective at preventing UTI Guidelines for the diagnosis and management of recurrent urinary tract infection in women; 2011 Prophylactic measures against recurrent uncomplicated UTI 5. Self-start antibiotic therapy with a 3-day treatment dose antibiotic at the onset of symptoms is another safe option for the treatment of recurrent uncomplicated UTI 6. Vaginal estrogen creams or rings may also reduce the risk of clinical UTI relative to placebo or no treatment in postmenopausal women. 7. Due to a lack of comparative evidence, the decision to begin therapy, choice of therapy and duration should be based on patient preference, allergies, local resistance patterns, prior susceptibility, cost and side effects. Guidelines for the diagnosis and management of recurrent urinary tract infection in women; 2011 Recurrent uncomplicated UTI - antibiotic prophylaxis Postcoital (within 2 hours of Continuous coitus) Trimethoprim/sulfamethoxazole TMP/SMX (40 mg/200 mg to 80 mg/400 (TMP/SMX) (40 mg/200 mg daily or mg) thrice weekly) Trimethoprim (100 mg daily) Cephalexin (125 mg to 250 mg daily) Cephalexin (250 mg) Cefaclor (250 mg daily) Nitrofurantoin (50 mg to 100 mg) Nitrofurantoin (50 mg–100 mg daily) Norfloxacin (200 mg daily) Norfloxacin (200 mg) Guidelines for the diagnosis and management of recurrent urinary tract infection in women; 2011  Treatment – simply lower UTI  Co-trimoxazole  fluoroquinolones (norfloxacin) Ist - line drugs  nitrofurantoin  furagin  cephalosporins I (cephalexin, cefadroxil)  II generation (cefaclor) IInd- line drugs  fluoroquinolones  Treatment – simply upper UTI  Co-trimoxasole Ist - line drugs  fluoroquinolones  penicillins with beta-lactamases inhibitors  cephalosporins II and III generation IInd- line drugs Treatment – complicated lower UTI per oss in vena Ist line IInd line Ist line IInd line Penicillins with Penicillins with beta-lactamases beta-lactamases inhibitors+/- Co-trimoxasole inhibitors ampicilin + aminogiycosides aminoglycosids II generation of ciprofloxacin cephalosporins +/- aminoglycosides Treatment Pseudomonas spp.:  ceftazidime+/- aminoglycosides  piperacilin or carbenicillin +/- aminoglycisides  carbapenem +/- aminoglycosides Gram-positive cocci:  cephalosporins I or II generation +/- aminoglycosides  penicillins with beta-lactamases inhibitors +/- aminoglycosides Treatment Methicillin Resistant Staphylococcus (MRSA/MRCNS):  glycopeptides Enterococcus spp.:  Aminoglycosides + glycopeptides  aminoglycosides + ampicillin Candida spp.: (treat or not?)  fluconasol +/- flucytosine  amphotericin B +/- flucytosine