Urinary tract infection

Dr. Mai Banakhar

UTI

• inflammatory response of urothelium to bacterial invasion.

• Bacteriuria : bacteria in urine

• Asymptomatic or symptomatic

• Bacteriuria + pyuria= infection

• Bacteriuria NO pyuria = colonization

• Pyuria :

• WBCs in urine.

• Infection

• T.B

• Bladder stone.

Complicated VS uncomplicated

• Un complicated UTI:• UTI structurally &

functionally normal urinary tract.

• Female. • Respond to short

course of antibiotic

• Complicated UTI:• Anatomical or

funtional abnormality.• Male.• Longer time to

respond to ttt

• Isolated UTI:

• 6 months between infections.

• Recurrent UTI:>2 infections in 6 months• 3 UTI in 12 months.• Reinfection by different bacteria.• Persistence : same organism from focus within

the urinary tract.• Struvate stone.• Bacterial prostatitis.• Fistula• Urethral diverticulum.• atrophic infected kidney.

• Unresolved infection:

• in adequate therapy , bacterial resistance to ttt.

Risk factors to bacteriuria

• Female• Age • Low estrogen

( menopause)• Pregnancy.• D.M• Previous UTI.• FC

• Stone • GU malignancy.• Obstruction.• Voiding dysfunction.• Institutionalized

elderly

Microbiology

Faecal-drived bacteria

Uncomplicated UTI

E.Coli, G-ve baccillus, (85%- 50%)

Staph saprophyticus

Enterococ faecalis

Proteus

Klebsiella.

• Complicated UTI• E.coli 505• Enterococ faecalis.• Staph aureus• Staph epidermidis• Pseudomonas

aeruginosa

Route of infection

• Ascending • Short urethra• Reflux• Impair urteric

peristalisis.• Pregnancy• Obstruction• G-ve , Edotoxins• Organism P pili

Route of infection

• Haematogenous:• Uncommon.• Staph aureus.• Candida fungemia.• T.B

• Lymphatics:• Rarely in

inflammatory bowel disease, reteroperitoneal abscess

• Increase UTI risk

• Increase bacterial virulence

• Protect against UTI

• Host defences

Factors increasing bacterial virulence

• Adhesion factors

• Toxins

• Enzyme production.

• Avoidance of host defense mechanisms

Factors increasing bacterial virulence

• Adhesion factors• G-ve bacteria, Pili• Attachment to host

urothelial cells.• Single type or different

types e.x E.coli• Defined functionally be

mediating hemagglutination (HA) of specific erythrocytes

• Mannose –sensitive • (type 1)• Produced by all strains

E.coli

• Certain pathogenic types of E.coli mannose resistant pili

( pyelonephritis)

Factors increasing bacterial virulence

• Avoidance of host defense mechanisms

• E.coli• Extracellular capsule

• Immunogenisity phagocytosis

• M.Tuberculosis reisit phagocytosis by preventing phagolysosome fusion

• Toxins:• E.coli cytokines,

pathogenic effect on host tissues

• Enzyme production:• Proteus ureases• Ammonia struvite

stone formation

Host defences

• Protective • Mechanical (flushing of urine) antegrade flow of

urine• Tamm-Horsfall protein (mucopolysaccharide

coating bladder prevent bacterial attachment)• chemical : Low Urine PH & high osmolality• Urinary Immunoglobulin I gA inhibit adherence

Lower UTI

• Cystitis: infection& inflammation of the bladder

• Frequency, samll volumes, dysuria, urgency, offensive urine SP pain, haematuria, fever & incontinence.

Investigation

• Dipstick of MSU• WBC ( pyuria )• 75 -95% sensitivity

infection• False –ve • False +ve• Other causes of

pyuria

• Nitrite testing:• Bacteriuria.• Specificity >90%• Sensitivity 35- 85%• + test ------- infection• - --------infection

Investigation

• Microscopy :

• Bacteria :

• False –ve low bacterial count

• False +ve contamination (lactobacilli & corynebacteria ) epithelial cells

• RBCs & pyuria

Investigation

Indications for further investigations in LUTI.

• Symptoms of Upper UTI.

• Recurrent UTI.• Pregnancy• Unusal infecting

organism ( proteus suggest infection stone)

• KUB• Ultrasound• IVU• cystoscopy

DD

• Non-infective cystitis:

• radiation cystitis

• Drud cystitis ( cyclophosphamide )

• Haemorrhagic cystitis

• Urethritis

Treatment

• Aim :• Eliminate bacterial

growth from urine.• Empirical ttt before

culture & sensitivity for the most likely organism.

• Adgusted according to the culture & sensitivity.

• Resistance :• Intrinsic (proteus)• Genetically

transferred between bacteria by R plasmids.

Recurrent UTI

• >2 in 6 months or 3 within 12 months

Reinfection Bacterial persistence

Recurrent UTI

• Reinfection ( different bacteria)

• After prolonged interval with adifferent organism

• Reinfection in females• No anatomical nor

functional pathology• In males BOO,

urethral stricture

• Bacterial persistance ( same organism from a focus within tract) within short interval

• Functional or anatomical problem.

• The underlying problem should be treated

Management Reinfection UTI

• Females

• KUB, Ultrasound, cystoscopy

• Simple ReinfectionTTTAvoid spermicidesEstrogen replacement therapyLow dose antibiotic prophylaxisdose antibiotic prophylaxis

Female recurrent reinfection

• Prophylactic antibiotic:• Reduce infection 90% at bed time 6-12

months• Symptomatic reinfection• Trimethoprim• Nitrofurantoin• Cephalexin• Fluoroquinolones

Female recurrent reinfection

• Natural youghart

• Post-intercourse antibiotic prophylactic

• Self-started therapy

Management of bacteria persistance

• Investigations:

• Kub, renal ultrasound.

• C.T, IVU

• Cystoscopy

• Treatment :

• For the functional or anatomical anomaly

Antibiotics

• Empirical therapy.

• Definitive therapy.

• Bacterial resistance to drug therapy.

Acute pyelonephritis

• Clinical Dx:• Flank pain• Fever.• Elevated WBCs

• DD: • acute cholecystitis.• Pancreatitis.

Acute pyelonephritis

• Risk factors: • VUR• UTO• Spinal cord injury• D.M• Malformation• pregnancy• FC

Acute pyelonephritis

• Pathogenisis :

• Initially patchy

• Inflammatory bands from renal papilla to cortex.

• 80% E.coli, others klebsiella, proteus& pseudomonas.

Acute pyelonephritis

• Urine analysis & culture.

• CBC , U&E

• KUB & ultrasoundif no response with I.V antibiotic for 3 days go for CTU

Perinephric abscess

• Pathogenesis.

• Suspected??

• C.T, ultrasound

• PC drainage .

• Open surgical

Pyonephrosis

• Infected hydronephrosis.

• Pus accumulation

• Causes

• Ultrasound. C.T

• Management: PCN, I.V antibiotic, I.V fluids.

Emphysematous pyelonephritis

• Severe form of acute pyelonephritis

• Gas forming organism

• Fever, abdominal pain with radiographic evidence of gas within the kidney.

• D.M

• Urinary obstruction.

• High glucose level-------fermentation,CO2 production

Emphysematous pyelonephritis

• Presentation: sever acute pyelonephritis

• High fever & systemic upset

• E.coli, commonly,

• Klebsiella & proteus less frequent

Management

• KUB

• Ultrasound, C.T

• Patients are unwell

• Mortality is high

Management

• Conservative ?

• I.V antibiotic , IVF

• PC drainage

• Control D.M

• Sepsis is poorly controlled

• Nephrectomy

Xanthogranulomatous pyelonephritis

• Severe renal infection

• Renal calculi & obstruction.

• Result in non-functioning kidney

• E.coli & proteus common.

• Macrophage full of fat deposit around the abscess

• Kidney, perinephric fat

Xanthogranulomatous pyelonephritis

• Acute flank pain

• Fever & tender flank mass

• C.T , Ultrasound

• Stone , mass ?? RCC

Xanthogranulomatous pyelonephritis

• IV antibiotic ,

• Nephrectomy