- •Hematuria II: causes and investigation
- •Hematospermia
- •Lower urinary tract symptoms (LUTS)
- •Nocturia and nocturnal polyuria
- •Flank pain
- •Urinary incontinence in adults
- •Genital symptoms
- •Abdominal examination in urological disease
- •Digital rectal examination (DRE)
- •Lumps in the groin
- •Lumps in the scrotum
- •2 Urological investigations
- •Urine examination
- •Urine cytology
- •Radiological imaging of the urinary tract
- •Uses of plain abdominal radiography (KUB X-ray—kidneys, ureters, bladder)
- •Intravenous pyelography (IVP)
- •Other urological contrast studies
- •Computed tomography (CT) and magnetic resonance imaging (MRI)
- •Radioisotope imaging
- •Post-void residual urine volume measurement
- •3 Bladder outlet obstruction
- •Regulation of prostate growth and development of benign prostatic hyperplasia (BPH)
- •Pathophysiology and causes of bladder outlet obstruction (BOO) and BPH
- •Benign prostatic obstruction (BPO): symptoms and signs
- •Diagnostic tests in men with LUTS thought to be due to BPH
- •Why do men seek treatment for their symptoms?
- •Watchful waiting for uncomplicated BPH
- •Medical management of BPH: combination therapy
- •Medical management of BPH: alternative drug therapy
- •Minimally invasive management of BPH: surgical alternatives to TURP
- •Invasive surgical alternatives to TURP
- •TURP and open prostatectomy
- •Indications for and technique of urethral catheterization
- •Indications for and technique of suprapubic catheterization
- •Management of nocturia and nocturnal polyuria
- •High-pressure chronic retention (HPCR)
- •Bladder outlet obstruction and retention in women
- •Urethral stricture disease
- •4 Incontinence
- •Causes and pathophysiology
- •Evaluation
- •Treatment of sphincter weakness incontinence: injection therapy
- •Treatment of sphincter weakness incontinence: retropubic suspension
- •Treatment of sphincter weakness incontinence: pubovaginal slings
- •Overactive bladder: conventional treatment
- •Overactive bladder: options for failed conventional therapy
- •“Mixed” incontinence
- •Post-prostatectomy incontinence
- •Incontinence in the elderly patient
- •Urinary tract infection: microbiology
- •Lower urinary tract infection
- •Recurrent urinary tract infection
- •Urinary tract infection: treatment
- •Acute pyelonephritis
- •Pyonephrosis and perinephric abscess
- •Other forms of pyelonephritis
- •Chronic pyelonephritis
- •Septicemia and urosepsis
- •Fournier gangrene
- •Epididymitis and orchitis
- •Periurethral abscess
- •Prostatitis: presentation, evaluation, and treatment
- •Other prostate infections
- •Interstitial cystitis
- •Tuberculosis
- •Parasitic infections
- •HIV in urological surgery
- •6 Urological neoplasia
- •Pathology and molecular biology
- •Prostate cancer: epidemiology and etiology
- •Prostate cancer: incidence, prevalence, and mortality
- •Prostate cancer pathology: premalignant lesions
- •Counseling before prostate cancer screening
- •Prostate cancer: clinical presentation
- •PSA and prostate cancer
- •PSA derivatives: free-to-total ratio, density, and velocity
- •Prostate cancer: transrectal ultrasonography and biopsies
- •Prostate cancer staging
- •Prostate cancer grading
- •General principles of management of localized prostate cancer
- •Management of localized prostate cancer: watchful waiting and active surveillance
- •Management of localized prostate cancer: radical prostatectomy
- •Postoperative course after radical prostatectomy
- •Prostate cancer control with radical prostatectomy
- •Management of localized prostate cancer: radical external beam radiotherapy (EBRT)
- •Management of localized prostate cancer: brachytherapy (BT)
- •Management of localized and radiorecurrent prostate cancer: cryotherapy and HIFU
- •Management of locally advanced nonmetastatic prostate cancer (T3–4 N0M0)
- •Management of advanced prostate cancer: hormone therapy I
- •Management of advanced prostate cancer: hormone therapy II
- •Management of advanced prostate cancer: hormone therapy III
- •Management of advanced prostate cancer: androgen-independent/ castration-resistant disease
- •Palliative management of prostate cancer
- •Prostate cancer: prevention; complementary and alternative therapies
- •Bladder cancer: epidemiology and etiology
- •Bladder cancer: pathology and staging
- •Bladder cancer: presentation
- •Bladder cancer: diagnosis and staging
- •Muscle-invasive bladder cancer: surgical management of localized (pT2/3a) disease
- •Muscle-invasive bladder cancer: radical and palliative radiotherapy
- •Muscle-invasive bladder cancer: management of locally advanced and metastatic disease
- •Bladder cancer: urinary diversion after cystectomy
- •Transitional cell carcinoma (UC) of the renal pelvis and ureter
- •Radiological assessment of renal masses
- •Benign renal masses
- •Renal cell carcinoma: epidemiology and etiology
- •Renal cell carcinoma: pathology, staging, and prognosis
- •Renal cell carcinoma: presentation and investigations
- •Renal cell carcinoma: active surveillance
- •Renal cell carcinoma: surgical treatment I
- •Renal cell carcinoma: surgical treatment II
- •Renal cell carcinoma: management of metastatic disease
- •Testicular cancer: epidemiology and etiology
- •Testicular cancer: clinical presentation
- •Testicular cancer: serum markers
- •Testicular cancer: pathology and staging
- •Testicular cancer: prognostic staging system for metastatic germ cell cancer
- •Testicular cancer: management of non-seminomatous germ cell tumors (NSGCT)
- •Testicular cancer: management of seminoma, IGCN, and lymphoma
- •Penile neoplasia: benign, viral-related, and premalignant lesions
- •Penile cancer: epidemiology, risk factors, and pathology
- •Squamous cell carcinoma of the penis: clinical management
- •Carcinoma of the scrotum
- •Tumors of the testicular adnexa
- •Urethral cancer
- •Wilms tumor and neuroblastoma
- •7 Miscellaneous urological diseases of the kidney
- •Cystic renal disease: simple cysts
- •Cystic renal disease: calyceal diverticulum
- •Cystic renal disease: medullary sponge kidney (MSK)
- •Acquired renal cystic disease (ARCD)
- •Autosomal dominant (adult) polycystic kidney disease (ADPKD)
- •Ureteropelvic junction (UPJ) obstruction in adults
- •Anomalies of renal ascent and fusion: horseshoe kidney, pelvic kidney, malrotation
- •Renal duplications
- •8 Stone disease
- •Kidney stones: epidemiology
- •Kidney stones: types and predisposing factors
- •Kidney stones: mechanisms of formation
- •Evaluation of the stone former
- •Kidney stones: presentation and diagnosis
- •Kidney stone treatment options: watchful waiting
- •Stone fragmentation techniques: extracorporeal lithotripsy (ESWL)
- •Intracorporeal techniques of stone fragmentation (fragmentation within the body)
- •Kidney stone treatment: percutaneous nephrolithotomy (PCNL)
- •Kidney stones: open stone surgery
- •Kidney stones: medical therapy (dissolution therapy)
- •Ureteric stones: presentation
- •Ureteric stones: diagnostic radiological imaging
- •Ureteric stones: acute management
- •Ureteric stones: indications for intervention to relieve obstruction and/or remove the stone
- •Ureteric stone treatment
- •Treatment options for ureteric stones
- •Prevention of calcium oxalate stone formation
- •Bladder stones
- •Management of ureteric stones in pregnancy
- •Hydronephrosis
- •Management of ureteric strictures (other than UPJ obstruction)
- •Pathophysiology of urinary tract obstruction
- •Ureter innervation
- •10 Trauma to the urinary tract and other urological emergencies
- •Renal trauma: clinical and radiological assessment
- •Renal trauma: treatment
- •Ureteral injuries: mechanisms and diagnosis
- •Ureteral injuries: management
- •Bladder and urethral injuries associated with pelvic fractures
- •Bladder injuries
- •Posterior urethral injuries in males and urethral injuries in females
- •Anterior urethral injuries
- •Testicular injuries
- •Penile injuries
- •Torsion of the testis and testicular appendages
- •Paraphimosis
- •Malignant ureteral obstruction
- •Spinal cord and cauda equina compression
- •11 Infertility
- •Male reproductive physiology
- •Etiology and evaluation of male infertility
- •Lab investigation of male infertility
- •Oligospermia and azoospermia
- •Varicocele
- •Treatment options for male factor infertility
- •12 Disorders of erectile function, ejaculation, and seminal vesicles
- •Physiology of erection and ejaculation
- •Impotence: evaluation
- •Impotence: treatment
- •Retrograde ejaculation
- •Peyronie’s disease
- •Priapism
- •13 Neuropathic bladder
- •Innervation of the lower urinary tract (LUT)
- •Physiology of urine storage and micturition
- •Bladder and sphincter behavior in the patient with neurological disease
- •The neuropathic lower urinary tract: clinical consequences of storage and emptying problems
- •Bladder management techniques for the neuropathic patient
- •Catheters and sheaths and the neuropathic patient
- •Management of incontinence in the neuropathic patient
- •Management of recurrent urinary tract infections (UTIs) in the neuropathic patient
- •Management of hydronephrosis in the neuropathic patient
- •Bladder dysfunction in multiple sclerosis, in Parkinson disease, after stroke, and in other neurological disease
- •Neuromodulation in lower urinary tract dysfunction
- •14 Urological problems in pregnancy
- •Physiological and anatomical changes in the urinary tract
- •Urinary tract infection (UTI)
- •Hydronephrosis
- •15 Pediatric urology
- •Embryology: urinary tract
- •Undescended testes
- •Urinary tract infection (UTI)
- •Ectopic ureter
- •Ureterocele
- •Ureteropelvic junction (UPJ) obstruction
- •Hypospadias
- •Normal sexual differentiation
- •Abnormal sexual differentiation
- •Cystic kidney disease
- •Exstrophy
- •Epispadias
- •Posterior urethral valves
- •Non-neurogenic voiding dysfunction
- •Nocturnal enuresis
- •16 Urological surgery and equipment
- •Preparation of the patient for urological surgery
- •Antibiotic prophylaxis in urological surgery
- •Complications of surgery in general: DVT and PE
- •Fluid balance and management of shock in the surgical patient
- •Patient safety in the operating room
- •Transurethral resection (TUR) syndrome
- •Catheters and drains in urological surgery
- •Guide wires
- •JJ stents
- •Lasers in urological surgery
- •Diathermy
- •Sterilization of urological equipment
- •Telescopes and light sources in urological endoscopy
- •Consent: general principles
- •Cystoscopy
- •Transurethral resection of the prostate (TURP)
- •Transurethral resection of bladder tumor (TURBT)
- •Optical urethrotomy
- •Circumcision
- •Hydrocele and epididymal cyst removal
- •Nesbit procedure
- •Vasectomy and vasovasostomy
- •Orchiectomy
- •Urological incisions
- •JJ stent insertion
- •Nephrectomy and nephroureterectomy
- •Radical prostatectomy
- •Radical cystectomy
- •Ileal conduit
- •Percutaneous nephrolithotomy (PCNL)
- •Ureteroscopes and ureteroscopy
- •Pyeloplasty
- •Laparoscopic surgery
- •Endoscopic cystolitholapaxy and (open) cystolithotomy
- •Scrotal exploration for torsion and orchiopexy
- •17 Basic science of relevance to urological practice
- •Physiology of bladder and urethra
- •Renal anatomy: renal blood flow and renal function
- •Renal physiology: regulation of water balance
- •Renal physiology: regulation of sodium and potassium excretion
- •Renal physiology: acid–base balance
- •18 Urological eponyms
- •Index
138 CHAPTER 5 Infections and inflammatory conditions
Urinary tract infection: microbiology
Most UTIs are caused by fecal-derived bacteria that are facultative anaerobes (i.e., they can grow under both anaerobic and nonanaerobic conditions)—see Table 5.3.
Uncomplicated UTI
Most UTIs are bacterial in origin. The most common cause is Escherichia coli (E. coli), a gram-negative bacillus, which accounts for 85% of communityacquired and 50% of hospital-acquired infection.
Other common causative organisms include Staphylococcus saprophyticus and Enterococcus faecalis (also known as Streptococcus faecalis—gram positive), Proteus mirabilis, Klebsiella, and other gram-negative Enterobacteriaceae.
Complicated UTI
E. coli is responsible for up to 50% of cases. Other causes include
Enterococci (e.g., Streptococcus faecalis), Staph. aureus, Staph. epidermidis
(gram positive) and Pseudomonas aeruginosa (gram negative).
Route of infection
Ascending
The vast majority of UTIs result from ascending or retrograde infections up the urethra. The bacteria, derived from the large bowel, colonize the perineum, vagina, and distal urethra. They ascend along the urethra to the bladder (risk is increased in females as the urethra is shorter), causing cystitis, and from the bladder they may ascend, via the ureters, to involve the kidneys (pyelonephritis).
Reflux is not necessary for infection to ascend to the kidneys, but the presence of reflux facilitates ascending infection, as will any process that impairs ureteric peristalsis (e.g., ureteric obstruction, gram-negative organisms and endotoxins, pregnancy).
Infection that ascends to involve the kidneys is also more likely where the infecting organism has P pili (filamentous protein appendages—also known as fimbriae—which allow binding of bacteria to the surface of epithelial cells).
Hematogenous is uncommon, but is seen with Staph. aureus, Candida fungemia, and TB.
Infection via lymphatics is seen rarely in inflammatory bowel disease and retroperitoneal abscess.
Factors increasing bacterial virulence
Adhesion factors
Many gram-negative bacteria contain pili on their surface, which aid attachment to urothelial cells of the host. A typical piliated cell may contain 100–400 pili. Pili are 5–10 nm in diameter and up to 2 µm long.
E. coli produces a number of antigenically and functionally different types of pili on the same cell; other strains may produce only a single type, and, in some isolates, no pili are seen.
Pili are defined functionally by their ability to mediate hemagglutination (HA) of specific types of erythrocytes. Mannose-sensitive (type 1) pili are
URINARY TRACT INFECTION: MICROBIOLOGY 139
Table 5.3 Bacterial classification: uropathogens
Cocci |
Gram-positive |
|
|
|
Staphylococcus, Enterococcus faecalis (also known as Streptococcus |
|
|
|
faecalis) e.g., S. saprophyticus causes approximately 10% of |
|
|
|
symptomatic lower UTIs in young, sexually active women |
|
|
|
Gram-negative |
|
|
|
Aerobes: Neisseria |
|
|
Bacilli (rods) |
Gram-positive |
|
|
|
Anaerobes*: Clostridium, Lactobacillus (usually a vaginal |
|
|
|
commensal) |
|
|
|
Gram-negative |
|
|
|
Aerobes: Enterobacteria (Escherichia, Klebsiella, Proteus), |
|
|
|
Pseudomonas |
|
|
|
Anaerobes*: Bacteroides |
|
|
Others |
Filamentous bacteria: Mycobacterium (M. tuberculosis—acid-fast, |
|
|
|
aerobic, gram-positive) |
|
|
|
Chlamydiae: Chlamydia trachomatis Fungi: Candida albicans |
|
|
|
Mycoplasma: Mycoplasma species, Ureaplasma urealyticum |
|
|
|
(cause UTI in patients with indwelling catheters) |
|
|
|
|
|
|
*Anaerobic infections of the bladder and kidney are uncommon—anaerobes are normal commensals of the perineum, vagina, and distal urethra. However, infections of the urinary system that produce pus (pyogenic) (e.g., scrotal, prostatic, or perinephric abscesses) are often caused by anaerobic organisms (e.g., Bacteroides species such as Bacteroides fragilis,
Fusobacterium species, anaerobic cocci, and Clostridium perfringens).
produced by all strains of E. coli. Certain pathogenic types of E. coli also produce mannose-resistant (P) pili (associated with pyelonephritis).
Avoidance of host defense mechanisms:
An extracellular capsule reduces immunogenicity and resists phagocytosis (E. coli). M. tuberculosis resists phagocytosis by preventing phagolysosome fusion.
Toxins
E. coli releases cytokines with direct effect on host tissues.
Enzyme production
Proteus species produce ureases, which causes breakdown of urea in the urine to ammonia. This contributes to disease processes (struvite stone formation).
Host defenses
Factors protecting against UTI are the following:
•Mechanical flushing effect of urine through the urinary tract (i.e., antegrade flow of urine)
•A mucopolysaccharide coating of the bladder (Tamm–Horsfall protein, glucose amino glycan [GAG layer]) helps prevent bacterial adherence.
•Low urine pH and high osmolarity reduce bacterial growth.
•Urinary immunoglobulin (IgA) inhibits bacterial adherence.
140 CHAPTER 5 Infections and inflammatory conditions
Lower urinary tract infection
Cystitis
Cystitis is infection and/or inflammation of the bladder.
Presentation
There is frequent voiding of small volumes, dysuria, urgency, offensive urine, suprapubic pain, hematuria, fever (uncommon), and incontinence. Up to 33% of women experience an episode of bacterial cystitis by age 24, and 50% of women will have an episode in their lifetime. Bacterial cystitis in healthy men is rare.
Investigation
Dipstick of midstream specimen of urine (MSU)
Not all patients with bacteriuria have significant pyuria (sensitivity of 75–95% for detection of infection, that is, 5–25% of patients with infection will have a negative leukocyte esterase test suggesting, erroneously, that they have no infection). Cloudy urine that is positive for WBCs on dipstick and is nitrite positive is very likely infected.
Microscopy of midstream specimen of urine (MSU)
•False negatives: Low bacterial counts may make it very difficult to identify bacteria, and the specimen of urine may therefore be deemed negative for bacteriuria, when in fact there is active infection.
•False positives: Bacteria may be seen in the MSU in the absence of infection. This is most often due to contamination of the MSU with commensals from the distal urethra and perineum (urine from a woman may contain thousands of lactobacilli and corynebacteria,
and these organisms are derived from the vagina). These bacteria are readily seen under the microscope, and although they are grampositive, they often appear gram-negative (gram-variable) if stained.
The finding of pyuria and red blood cells suggests the presence of active infection.
Noninfective hemorrhagic cystitis
While bacterial cystitis can result in hemorrhagic cystitis, pelvic radiotherapy (radiation cystitis—bladder capacity is reduced and multiple areas of mucosal telangiectasia are seen cystoscopically) and drug-induced cystitis (e.g., cyclophosphamide treatment) are types of noninfectious hemorrhagic cystitis.
Urethritis
Urethritis is inflammation of the urethra. Urethritis in men is a sexually transmitted disease, which presents with dysuria and urethral discharge.
Gonococcal urethritis (GU)
GU is caused by the gram-negative diplococcus Neisseria gonorrhoea (incubation 3–10 days) and commonly associated with concomitant infection with Chlamydia trachomatis. Diagnosis is based on cultures from urethral swab.
LOWER URINARY TRACT INFECTION 141
Treatment involves ceftriaxone 125 mg IM in a single dose or cefixime 400 mg orally in a single dose or 400 mg by suspension (200 mg/ 5 mL) plus treatment for chlamydia if chlamydial infection is not ruled out. Quinolones are no longer recommended in the United States because of resistant strains).1
Sexual contacts must be informed and treated.
Nongonococcal urethritis (NGU)
NGU is mainly caused by Chlamydia trachomatis (incubation 1–5 weeks). Treat with azithromycin, 1 g as a single oral dose; or doxycycline, 100 mg orally twice a day for 7 days.
Transmission to females results in increased risk of pelvic inflammatory disease, abdominal pain, ectopic pregnancy, infertility, and perinatal infection.
Urethral syndrome
Urethral syndrome is a condition of uncertain etiology that only affects women. It manifests as dysuria, frequency, and urgency without evidence of infection, although some cases improve with antibiotics.2
Further reading
Foster RT Sr (2008). Uncomplicated urinary tract infections in women [review]. Obstet Gynecol Clin North Am 35(2):235–248, viii.
1 MMWR Morbid Mortal Wkly Rep April 13, 2007; 56(14);332–336.
2 Kaur H, Arunkalaivanan AS (2007). Urethral pain syndrome and its management. Obstet Gynecol Surv 62(5):348–351.