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IN THE NAME OF GOD. Urinary Tract infection By Shervin Ghaffary Hoseini MD. PhD.

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Presentation on theme: "IN THE NAME OF GOD. Urinary Tract infection By Shervin Ghaffary Hoseini MD. PhD."— Presentation transcript:


2 Urinary Tract infection By Shervin Ghaffary Hoseini MD. PhD

3 Urinary tract infection Definitions Etiology Clinical manifestations Diagnosis treatment

4 Urinary Tract Infection definition Pathogenic microorganisms in urine, urethra, bladder, kidney, prostate Usually growth > 10 5 organisms per milliliter

5 Urinary Tract Infection Lower urethritis cystitis prostatitis Upper pyelonephritis intrarenal and perinephric abscess

6 categorized in to Non-catheter associated (commum. acquired) Catheter associated (hosp. acquired) OR Complicated UTI Uncomplicated UTI

7 categorization Uncomplicated UTI Young women without underlying U.T or systemic disease Complicated UTI Males,children,chronicly catheterized,women with recurrent infection, urologic abnormality,underlying disease : More resistant to A.B

8 Etiology

9 Most common is Gram neg. bacteria –Enterobacteriaceae –E. coli –Proteus –Klebsiella –Enterobacter –Serratia –Pseudomonas

10 Etiology Gram pos. cocci –Staphylococcus saprophyticus –Staphylococcus Epidermidis –Staphylococcus aureus –Enterococci Gram pos.bacilli –Corynebacterium Urealyticum Mycoplasma spp. –Ureaplasma urealyticum,M.hominis,M.genitalium

11 UTI Etiology Majority of UTI are due to a single pathogen The Enterobacteriaceae responsible for 90% of all UTI - gram negative bacilli - facultatively anaerobic - common intestinal flora Escherichia coli most commonly isolated pathogen ~80% of all UTI

12 Pathogenesis and route of transmission Organisms usually enter the urinary tract by; 1.Direct or ascending route; via the urethra to the urinary bladder and the kidney where they multiply and produce toxins,.

13 Pathogenesis and route of transmission 2.Blood(hematogenous) from septic focus causing bacteremia and UTI. Staph.aureus bacteremia or endocarditis rarely Gr - bacilli

14 E. coli (serotypes: 02, O4, O6) which are fimbrinated strains adhering to uro- epithelial cells, leading to colonization and infection is the commonest cause of urinary tract infections. : Outpatint,Acute infection Escherichia coli


16 : Outpatint,Acute infectio Stoph.saprophiticus Coagulase (-) staph., novobiocin resistance Among Coagulase (-) staphs it is a true UT pathogen causing both upper and lower UTI The second most common cause of UTI representing 11-32% of UTI in female patient.

17 Inpatient,recurrent UTI,structural abnormality Pseudomonas,Proteus,Klebsiella,Serratia infections often follow catheterization and gynecological surgery (nosocomial pathogen). Infection with proteus may be complicated by phosphate stone formation as its urease leads to alkaline pH.

18 Inpatient,recurrent UTI,structural abnormality Enterococci Occasionally in acute uncomplicated Cystitis

19 Inpatient,recurrent UTI, structural abnormality Corynebacterium urealiticum Urea splitting bacillus Important nosocomial path. (renal transplant,immunosupressed) Resistant to A.B Sensitive to Vancomycin

20 Inpatient,recurrent UTI, structural abnormality Staph.aureus Hematogenous route: intrarenal or perinephric abcesses

21 Inpatient,recurrent UTI, structural abnormality Staph. Epidermidis Coagulase (-) staph., novobiocin sensitive Usually catheter associated and occurs in elderly patients with UT instrumentation or surgery, renal transplantation,urolithiasi and UT abnormality

22 Sexually transmitted Mycoplasma hominis, M.genitalium,ureaplasma urealiticum Mycoplasma hominis and ureaplasma urealiticum colonize genitourinary track of male and female from 0% to 77%, depending on age, sex, race, sexual experience and socioeconomic state. They are sexually transmitted germs They have roles in p.p endometrit, L.B.W, prematurity and infertility.

23 Sexually transmitted Mycoplasma hominis, M.genitalium,ureaplasma urealiticum Ureaplasma urealyticum has frequently been isolated from the urethra and urine of patients with acute dysuria and frequency but is also found in specimens from many patients without urinary symptoms. Ureaplasmas probably account for some cases of urethritis and cystitis. U. urealyticum and Mycoplasma hominis have been isolated from prostatic and renal tissues of patients with acute prostatitis and pyelonephritis, respectively, and are probably responsible for some of these infections as well.

24 Sexually transmitted chlamydia, gonorrhea, HSV Urethritis : acute simptomatic female with sterile pyuria


26 Miscellaneous organisms Candida or other fungal species : commonly assoc. with cath. or DM Mycobacteria Adenoviruses :Hemoragic cystitis in children and in some young adults, often in epidemics. Although other viruses can be isolated from urine (e.g., cytomegalovirus), they are thought not to cause acute UTI.

27 Predisposing conditions to UTI Female –Short urethra, proximity to anus, termination beneath labia –Sexual activity Pregnancy –2-3% have UTI in Pregnancy, 20-30% with asymptomatic bacteriuria may lead to pyelonephritis –Increased risk of pyelonephritis : decreased ureteral tone, decreased ureteral peristalsis, incompetence of vesicoureteral valves

28 Predisposing conditions Neurogenic bladder dysfunction or bladder diverticulum (incomplete emptying) Age - Postmenopausal women with uterine or bladder prolapse (incomplete emptying), lack of estrogen, decreased normal flora, concomitant medical conditions Vesicoureteral reflux Instrumentation and surgery Change in urine nutrients, DM, gout Bacterial virulence Genetics

29 Vesicoureteral reflux

30 Community-Acquired UTI E.coli K.pneumoniae Proteus S.saprophyticus S.epi & gm - enterics Enterococcus

31 Nosocomial UTI catheter associated Short TermLong Term E.coli Pseudomonas Proteus Enterobacter Candida Providencia Morganella S.aureus Enterococcus S.aureus

32 Host parasite interaction: organism Virulence factors : 1.Clonization 2.Invasion 3.Using urine as growth medium: Synthesis of guanine arginine glutamine pathogenicity islands: multigen, duplicated gens Uropathogenic Ecoli clones have certain O,K,H serotypes:O1,O2,O4,O6,O7,O8,O75,O150,O180

33 Virulence factors Clonisation Clonisation =adhesive properties: Selection of bacteria influence severity,anatomic and U.T level of UTI:pyelonephritis or cystitis –The attachment of bacteria to uroepithelial cells initiates a number of important events in the mucosal epithelial cell, including secretion of interleukin (IL) 6 and IL-8 (with subsequent chemotaxis of leukocytes to the bladder mucosa) and induction of apoptosis and epithelial cell desquamation.

34 Virulence factors Clonisation Pilli =fimberia : filamentous surface organeles. In Ecoli: 1) P.fimbriae(MR): binding to globoserries glicosphingolipid(a component of the glycocalix that surrounds epithelial cells =P blood group on RBC & E.c in U.T particularly kidney

35 Virulence factors Clonisation In Ecoli: 2) type 1 fimbriae(MS) : binding to mannose containing glicoproteins 3) G, 1C, S fimbriae 4) Dr hemagglutinin family

36 Virulence factors Clonisation Other species : Proteus Mirabilis & klebseilla : similar adherence factors S.saprophiticus adhers better to U.T than do S.aureus or S.epidermidis (uncommon cystitis & pyelonephritis)

37 Virulence factors invasion Invasion factors: 1. motility 2.Hemolysin production 3.Higher quantity of K Ag (K1,K2,k3) in capsules 4.Endotoxins 5.Production of urease (proteus) 6.Aerobactin(iron scavenging protein)

38 Comment: in presence of underlying structural abnormalities organisms lack virulence factors

39 Host parasite interaction: genetics A maternal history of UTI is more often found among women who have experienced recurrent UTIs than among controls. The number and type of receptors on uroepithelial cells to which bacteria may attach are at least in part genetically determined. –Many of these structures are components of blood group antigens and are present on both erythrocytes and uroepithelial cells..,

40 Host parasite interaction: genetics For example, P fimbriae mediate attachment of E. coli to P-positiveb erythrocytes and are found on nearly all strains causing acute uncomplicated pyelonephritis. Conversely, P blood group–negative individuals, who lack these receptors, have a decreased likelihood of pyelonephritis. nonsecretors of blood group antigens are at increased risk of recurrent UTI; may relate to a different profile of genetically determined glycolipids on uroepithelial cells. Mutations in host genes integral to the immune response (interferon receptors and others) may also affect susceptibility to UTI

41 Clinical manifestations

42 Urethritis ? Acute dysuria, frequency Often need to suspect sexually transmitted pathogens esp. if symptoms last more than 2 days, gradual, no hematuria, no suprapubic pain, new sexual partner, cervicitis

43 Urethritis Approximately 30% of women with acute dysuria, frequency, and pyuria have midstream urine cultures that show either no growth or insignificant bacterial growth. Clinically, these women cannot always be distinguished from those with cystitis. In this situation, a distinction should be made between women infected with sexually transmitted pathogens, such as C. trachomatis, N. gonorrhoeae, mycoplasma spp., or herpes simplex virus, and those with low-count E. coli or staphylococcal infection of the urethra and bladder.

44 Cystitis Symptoms: frequency, dysuria, urgency, suprapubic pain Cloudy, malodorous urine (nonspec.) Leukocyte esterase positive = pyuria Nitrite positive (but not always) WBC (2-5 with Symptoms) and bacteria on urine microscopy

45 Pyelonephritis Fever chills, N/V, diarrhea, tachycardia, muscle tenderness CVAT or tenderness with deep abdominal tenderness Possibly signs of Gram neg. sepsis

46 Pyelonephritis Leukocytosis Pyuria with leukocyte casts, and bacteria and hematuria on microscopy Complications: sepsis, papillary necrosis, ureteral obstruction, abscess, decreased renal function if scarring from chronic infection, in pregnancy – may increase incidence of preterm labor

47 Catheter-Associated Urinary Tract Infections 10-15% of hosp. patients with indwelling catheter develop bacteriuria Risk of infection is 3-5% per day of catheterization UTI after one-time bladder cath approx. 2% Gram neg. bacteremia most significant complication of cath-induced UTI Greater antimicrobial resistance

48 Urinary catheters

49 Diagnosis

50 Diagnosis of UTI History Physical exam Lab –Urinalysis with microscopic exam. –Urine culture –Sensitivities of culture for tailored antibiotic therapy May diagnose acute uncomplicated cystitis based on history and Physical exam and UA alone, no need for culture to treat

51 Specimen collection Samples should be collected before the start of antibiotics. Transport within 2 h. if delay is suspected then refrigeration at 4C or boric acid.

52 Specimen collection Contamination : 1.Bacteria from vagina 2.Perineum 3.Indigenous flora in urethra

53 Contamination Commensals Urinary tract is normally sterile, except of urethra which may contain a few commensals such as acinetobacter species, and diptheriods. Yeast may also be found in the female urethra. Contamination of the urine with skin commensals including staphylococci, dipththeroids, and mycobacterium smegmatis may occur as a specimen is being collected. In female patients, the urine may become contaminated with organisms from the vagina (epithelial cells)

54 Contamination Commensal flora Hemolitic Strep. Bucillus spp. Coagulase-Negative staph. Diphtheroids Lacobacillus spp.

55 Specimen collection Clean catch mid stream specimens - most frequently used method - urethra cleaned prior to collection - first void urine allowed to pass to clear urethra - mid-stream collected in sterile container Collection bags (children) - used in young children lacking bladder control - often contaminated - most meaningful result is a negative culture

56 Specimen collection Suprapubic aspiration / straight catheters - invasive - specimen obtained directly from bladder(full bladder) - neonates and small children Indwelling catheters - urine obtained by inserting needle into catheter - preferable to obtain specimen from new catheter, rather than old catheter

57 Suprapubic aspiration

58 Specimen collection For urethritis : initial portion of voided urine or a swab inserted in to distal urethra (neisseria gonorreae & clamydia ) For prostatitis : prostatic secretions before & after prostatic massage.

59 Specimen transport Sent to and processed by lab as quickly as possible - Require: method of collection time of collection patients antibiotics Specimens not received by lab in 1-2 hours MUST be refrigerated Urines not received within 24 hours or not refrigerated will be rejected by laboratory

60 U/A Microscopic exam Urine sediment with or without gram stain or uncetrifuged urine –Centrifuge for 5 m. at 2000 rmp –Examine under high power Pyuria : 5 WBC is upper limit of normal and nonspecific Bacteria : 1 in h.p.f in centrifuged stained smire = 10*5 per ml urine WBC cast : pyelonephritis Hematuria : UTI, calculi, tumor, vasculitis, glumeronephritis, T.B

61 U/A Leucocyte esterase activity : positive if WBC > 10 –False + :ascorbic acid, albumine>300 g/dl in urine, preservatives, detergents –False - :marginal WBC count Nitrite test : bacteria reduce nitrate in urine –False + :delayed test, drug –False - :enterococoss spp., vegetable free diet

62 Urine culture Media : combination of 5% blood agar & MacConkey agar In ambulatory patients: EMB agar

63 Urine culture Semiquantitive colony counts –Streaking technique Non ferrous (nichrome or platinum) inoculating loops, calibrated in to an either 0.01 or ml of fluid are immersed in to an uncentrifuged urine sample

64 Urine culture Streaking technique After 18 to 24 h. of incubation : counting number of colonies on the agar number of colony * 100 (for 0.01 ml) number of colony * 1000 (for ml)

65 Streaking technique

66 Urine culture in symptomatic patient In symptomatic patient one titer of 10*5 org/ml or more, carries a 95% probability of UTI. In suprapubic or catheterized urine : low colony count (10*2) and multiple org. is important. in lower colony counts with symptomatic patient : acute urethral syndrome.

67 Urine culture in symptomatic patient The Infectious Disease Society of America consensus definition : –10*3 cfu of uropathogens :cystitis –10*4 cfu of uropathogens :pyelonephritis

68 Urine culture In urethral syndrome About one-third of women with dysuria and frequency have either an insignificant number of bacteria in midstream urine cultures or completely sterile cultures and have been previously defined as having the urethral syndrome. About three-quarters of these women have pyuria, while one-quarter have no pyuria and little objective evidence of infection. In the women with pyuria, two groups of pathogens accountfor most infections.

69 Urine culture In urethral syndrome 1. Low counts (102 to 104/mL) of typical bacterial uropathogens such as E. coli, S. saprophyticus, Klebsiella, or Proteus are found in midstream urine specimens from most of these women. –These bacteria are probably the causative agents in these infections because they can usually be isolated from a suprapubic aspirate, are associated with pyuria, and respond to appropriate antimicrobial therapy.

70 Urine culture In urethral syndrome 2. In other women with acute urinary symptoms, pyuria, and urine that is sterile (even when obtained by suprapubic aspiration), sexually transmitted urethritis-producing agents such as Chlamydia trachomatis, Neisseria gonorrhoeae, mycoplasma, ureoplasma and herpes simplex virus are etiologically important. - These agents are found most frequently in young, sexuallyactive women with new sexual partners.

71 Urine culture in asymptomatic patient More than 10*5 org/ml of enterobacteriaceae in two clean-catch specimens confirms infection : asymptomatic bacteriuria 10*4 to 10*5 of enterobacteriaceae represents contamination 10*4 to 10*5 of gram(+) organisms (staph. Saprophiticus), fungi, and fastidious org. represents infection Less than 10*4 org/ml often :saprophytic skin org. In males 10*3 org/ml is suggestive of infection.

72 Diagnosis 6.Diagnostic Tests for adults who have recurrent infections or persistent bacteriuria a.Intravenous pyelography (IVP) or excretory urography 1.Evaluates structure and excretory function of kidneys, ureters, bladder 2.Kidneys clear an intravenously injected contrast medium that outlines kidneys, ureters, bladder, and vesicoureteral reflux

73 Diagnosis b.Voiding cystourethrography: instill contrast medium into bladder and use xray to assess bladder and urethra when filled and during voiding c.Cystoscopy 1.Direct visualization of urethra and bladder through cystoscope 2.Used for diagnostic, tissue biopsy, interventions d.Manual pelvic or prostate examinations to assess structural changes of genitourinary tract, such as prostatic enlargement, cystocele, rectocele

74 treatment

75 Treatment Medications a.Short-course therapy: 3 day course of antibiotics for uncomplicated lower urinary tract infection; (single dose associated with recurrent infection) b.7 – 10 days course of treatment: for pyelonephritis, urinary tract abnormalities or stones, or history of previous infection with antibiotic-resistant infections; clients with severe illness may need hospitalization and intravenous antibiotics

76 Treatment c.Antibiotics commonly used for short and longer course therapy include trimethoprim-sulfamethoxazole (TMP- SMZ), or quinolone antibiotic such as ciprofloxacin (Cipro) d.Intravenous antibiotics used include ciprofloxacin, gentamycin, ceftriaxone (Rocephin), ampicillin

77 Treatment Possible outcomes of treatment for UTI, determined by follow-up urinalysis and culture 1.Cure: no pathogens in urine 2.Unresolved bacteriuria: pathogens remain 3.Persistent bacteriuria or relapse: persistent source of infection causes repeated infection after initial cure 4.Reinfection: development of new infection with different pathogen

78 Treatment f.Prophylactic antibiotic therapy with TMP-SMZ, TMP alone or nitrofurantoin (Furadantin, Nitrofan) may be used with clients who experience frequent symptomatic UTIs g.Catheter-associated UTI: removal of indwelling catheter followed by 10 – 14 day course of antibiotic therapy

79 Treatment Asymptomatic Bacteriuria Empiric treatment of all asymptomatic bacteriuria (ASB) in pregnancy. Screening at first visit. ASB if untreated increases preterm labor and LBW, 20-30% develop pyelonephritis Do U/A in 2 weeks and each trimester. Screen Sickle cell trait each trimester. Twofold increase risk of ASB

80 Treatment Asymptomatic Bacteriuria Treatment failures: repeat treatment based on sensitivities for 1 week, then prophylactic therapy for remainder of pregnancy Prophylaxis: Nitrofurantoin, Ampicillin, TMP/SMX

81 Treatment Surgery Surgical removal of large calculus from renal pelvis or cystoscopic removal of bladder calculi which serve as irritant and source of bacterial colonization; may also use percutaneous ultrasonic pyelolithotomy or extracorporeal shock wave lithotripsy (ESWL

82 Treatment Surgery b. Ureteroplasty: surgical repair of ureter for stricture or structural abnormality; reimplantation if vesicoureteral reflux; clients usually return from surgery with catheter and ureteral stent in place for 3 – 5 days

83 Treatment Nursing Care: Health promotion to prevent UTI a.Fluid intake 2 – 2.5 L daily, more if hot weather or strenuous activity is involved b.Empty bladder every 3 – 4 hours

84 Treatment Nursing Care: Health promotion to prevent UTI c.Females 1.Cleanse perineal area from front to back 2.Void before and after sexual intercourse 3.Maintain integrity of perineal tissues a. Avoid use of commercial feminine hygiene products or douches b. Wear cotton underwear d. Maintain acidity of urine (use of cranberry juice, take Vitamin C, avoid excess milk and milk products, sodium bicarbonate


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