1、1.Definitions2.Epidemiology3.Etiology4.Pathogenesis 5.Pathology6.Clinical presentation 7.Diagnosis8.Treatments9.Complication10.PreventionUTI is defined as the presence of micro-organisms in the urinary tract.Most patients with UTI have significant bacteriuria,i.e.bacterial colony counts 105/ml,in a
2、mid-stream“clean catch”urine.Conversely,colony counts 105/ml of midstream urine are occasionally due to specimen contamination.Acute urethral syndrome:dysuria,urgency,and frequency,but without bacteriuria.lLower UTI:1.urethritis2.cystitis(mucosal infection)lUpper UTI:1.pyelonephritis2.prostatitis3.i
3、ntrarenal and perinephric abscesses(tissue invasion)lUncomplicated UTI:1.Lack structural or functional abnormalities of the urinary tract2.Normal flow of urine3.NO interference with the normal defenseslComplicated UTI:1.Predisposing lesion of the urinary tract,structural or functional abnormalities,
4、e.g.congenital abnormality of the urinary tract,stone,obstruction,catheter.2.Interference with the normal defenses,e.g.immunosuppression,renal disease,or diabetes.lCatheter-associated（nosocomial）infections:1.Symptomatic 2.Asymptomtic lNon Catheter-associated（community-acquired）infections:1.Symptomat
5、ic 2.AsymptomticlAlmost half of all women will have at least one UTI in their lives.lUTI is uncommon in men under the age of 50,but very common among women.lAsymptomatic bacteriuria is more common among elderly men and women.Community-Acquired UTIgram-negative bacilli is the most common agentE.coliE
6、nterobacterEnterococcusProteusStaphylococcus KlebsiellaE.coli Causative organisms:Escherichia coli Klebsiella,proteus and pseudomonas 1-Bacteria S.aureus,Staphylococcus epidermidis and S.saprophyticus Enterococci(Streptococcus faecalis粪链球菌粪链球菌)Mycobacterium tuberculosis Chlamydia trachomatis,Neisser
7、ia gonorrhoeae 2-Virus Herpes simplex virus ,HIV 3-Fungus Candida,Histoplasma capsulatum 4-Protozoon Trichomonas vaginalis,Schistoma haematobium CASE 1 32 year-old woman;Dysuria and frequency;P y u r i a i n t h e u r i n e sediment;Gram negative bacilli.Escherichia coli (E.coli).CASE 2 65 year-old
8、woman;Dysuria and frequency;Pyuria;Gram positive cocci.Enterococcus faecalisCASE 318 year-old woman Dysuria and frequency;Pyuria;Gram positive cocci;Staphylococcus.CASE 4 42 year-old diabetic woman with a catheter.Gram positive yeasts.Candida grew.Ascending route (the most common)Colonization of ure
9、thraThe urinary tract above the urethra is normally sterile.The urethral meatus and surrounding perineum are colonized with a mixture of skin and bowel flora.Vaginal flora or pathogens may contaminate the urethra.Host defense mechanisms:1.Urine:low pH,high osmolality,high urea&organic acid concentra
10、tion inhibit and kill microorganisms2.Regular urine flow:dilute and expel pathogens3.Bladder epithelial cells:coated with mucus (glycosaminoglycan)prevent bacteria from adhering to bladder walllGender and sexual activity.lPregnancy.lObstruction.（tumor,stricture,stone,BPH）lNeurogenic bladder dysfunct
11、ion.lVesicoureteral refluxlBacterial virulence factorslGenetic factors（details in the following）Gender and sexual activity lThe female urethra appears to be prone to colonization with colonic gram-negative bacilli because of its proximity to the anus,its short length,and its termination beneath the
12、labia.lVoiding after intercourse reduces the risk of cystitis.lAn important factor predisposing to bacteriuria in men is urethral obstruction due to prostatic hypertrophy.PregnancylUTIs are detected in 2 to 8%of pregnant women.lPregnant women with asymptomatic bacteriuria.lBladder catheterization du
13、ring or after delivery causes additional infections.Obstruction lTumorlStricturelStonelBenign prostatic hypertrophy(BPH)These conditions result in hydronephrosis and increase frequency of UTI.Neurogenic Bladder DysfunctionlInterference with bladder enervation,as in spinal cord injury,multiple sclero
14、sis,diabetes.lThe infection may be initiated by the use of catheters for bladder drainage.lThe infection is favored by the prolonged stasis of urine in the bladder.Vesicoureteral RefluxlVesicoureteral reflux occurs during voiding or with elevation of pressure in the bladder.lCommon among children wi
15、th anatomic abnormalities of the urinary tract.lRenal damage correlates with marked reflux,not with infection.Bacterial Virulence factorslSpecific O,K,and H serogroups.lAdherence of bacteria to uroepithelial cells is a critical first step in the initiation of infection.lFimbriae mediate the attachme
16、nt of bacteria to specific receptors on epithelial cells.lE.coli strains usually produce hemolysin and aerobactin.Genetic factorslHost genetic factors influence susceptibility to UTI.lThe number and type of receptors on uroepithelial cells are in part genetically determined.lGender and sexual activi
17、ty.lPregnancy.lObstruction.（tumor,stricture,stone,BPH）lNeurogenic Bladder Dysfunction.lVesicoureteral RefluxlBacterial Virulence factorslGenetic factorsCystitisMucosal hyperemiaEdemaLeukocyte infiltrationEasy bleedingGranular surfaceSuperficial ulcerPurulent exudateAcute PyelonephritisAcute inflamma
18、tionHyperemia and edemaVolume increase Red colour Yellowish abscess Purulent exudateChronic PyelonephritisChronic inflammationPelvis deformed Cortex scarsVolume shrink Asymmetric Parenchyma atrophyInterstitial edema Neutrophil infiltration White blood cell castIn microscopyCystitislBurning painlFreq
19、uency,urgencylSuprapubic painlDysuriaUrethritis lBurning painlFrequency,urgencylDysurialInfected with sexually transmitted pathogens Acute PyelonephritislAll cystitis symptoms（+）or（-）lFever,shaking chillslNausea,vomiting,diarrhealTachycardia,hypotentionlMuscle tendernesslCostovertebral angle（CVA）pai
20、nlGram-negative sepsis,LeukocytosislLeukocyte casts in the urineCatheter-Associated UTIs lBacteriuria develops in at least 10 to 15%of hospitalized patients with indwelling urethral catheterslThe risk of infection is 3 to 5%per day of catheterization.lMany infecting bacteria display markedly great a
21、ntimicrobial resistance.How is it diagnosed?Diagnosis1.Patient history 2.Complete physical examination 3.Urine culture 4.Urine analysis 5.Other examinations Microscopic ExaminationDiagnosisDiagnosisLeukocyte esterase+Nitrite+Urine routine:pH,sg,protein,glucose,blood,ket,etc.Clean urine culture:bacte
22、rial counts 105/mlSuprapubic puncture,catheter collected urine 102/mlSignificant bacteriuria Microscopic bacteriuria(very important)Diagnosis（No definite standard method）Ultrasonography Intravenous pyelography（IVP）Abdominal CT/MRIStaphylococcus saprophyticus(5-15%)Enterobacteriaceae lE.coli(86%)lKle
23、bsiella pneumoniaelProteus Enterococcus Single-dose therapy is less effectivelEspecially with -lactams3-day course recommendedlTMP-SMX,fluoroquinolone,nitrofurantoinlNOT appropriate for male patients and complicated UTIs7-day course:Diabetes,age 65 years,MalesIf untreated:may lead to acute uncomplic
24、ated pyelonephritis treatmentEnterobacteriaceaelE.coli lKlebsiella pneumoniaelProteus Staphylococcus saprophyticus Mild or moderate symptoms:lOutpatient treatment(714 days)lOral treatment:Fluoroquinolone,TMP/SMX,third generation cephalosporinSevere ill patient:lHospitalization requiredlParenteral th
25、erapy(14 days)lBroad-spectrum cephalosporins or FluoroquinolonesEnterobacteriaceaelE.Coli lKlebsiella pneumoniaelProteusEnterococciPseudomonasStaphylococciMinimal or mild symptoms(10-14d).lOral therapy:fluoroquinolone(ciprofloxacin or ofloxacin)Severe ill patient,parenteral therapy(10-21d).lHospital
26、ization required,Imipenem alone lP e n i c i l l i n o r c e p h a l o s p o r i n p l u s aminoglycosidel Third generation cephalosporin:Ceftriaxone or ceftazidimeLow urinary tract infection(acute cystitis):l 7 days course antibioticsl Amoxicillin,cephalosporine,nitrofurantoinPyelonephritis:l 2-4 w
27、eeks course antibioticsl Cephalosporins,extended spectrum penicillinsl Parenteral treatmentl Follow-up urine culture tests,monthlyl Low-dose prophylaxis to recurrent infectionsAsymptimatic bacteriurial Antibiotics treatments are needed.For bacteriuria in asymptomatic catheterized patient:lCatheter r
28、emoved as soon as possible.lThe bacteriuria should be ignored.If becomes symptomatic:lRemove catheterlTreatment as described for complicated infectionslIf the catheter cannot be removed,antibiotic therapy usually proves to be unsuccessful.Renal Papillary necrosislPatients with diabetes,sickle cell d
29、isease,chronic alcoholism,and vascular diseaselHematuria,pain in the flank or abdomen,chills and feverlAcute renal failure with oliguria or anurialIVP:ring shadowlOften bilaterallDrink plenty of fluids and frequent urination.lKeeping the perineal area clean.lDo not take invasive method of examinatio
30、n if possible.lProphylactic low-dose antibiotics,daily or thrice-weekly administration of a single dose of TMP-SMX,TMP,nitrofurantoin,fluoroquinolone.lPatient who suffer refluence of bladder-ureter should change the urination habit（twice urination，i.e.after urination for several minutes,to urinate again）
