00:00 In our discussion of urinary tract infections, we turn to cystitis. 00:06 To define it we'd call it a clinical syndrome characterized by dysuria, frequency, urgency, and occasionally suprapubic tenderness caused by inflammation and infection of the bladder. 00:21 It's a disease that's much more common in women than men. 00:25 In fact, women have an incidence of asymptomatic bacteriuria of around 1 to 3%. 00:35 Up to 60% of women have had at least one episode of cystitis during their lifetime. 00:43 And 10% have it once a year. 00:46 The peak incidence is among young, sexually active women, 18-24 years of age and 2-5% have recurrent problems with cystitis. 01:00 Men, on the other hand, have a very low prevalence of cystitis -- less than 0.1 %. 01:09 And when a man has cystitis, we have to look for a complication because there's usually some kind of obstructive uropathy duplicating collecting system, some kind anatomical explanation for cystitis and we have to work them up for urologic abnormalities. 01:30 The lack of circumcision predisposes some men to cystitis and among men who have sex with men anal insertive sexual intercourse is a predisposing factor. 01:47 95% of the time, the cause is a single species of bacterium, so polymicrobial infections are unusual. 01:56 The most common bug is, as you might expect, Escherichia coli. 02:02 Now, we have lots of E. coli in our intestine -- lots of them. 02:07 But only about 20% of this E. coli are what we would call uropathogenic E. coli. 02:16 So these E. coli are different. 02:19 They possess virulence factors that the other E. coli do not have that allow them to colonize and invade the urinary tract. 02:28 Most of them have what we call Type 1 fimbriae -- this fringe that surrounds the surface. 02:34 And this group of fimbria can attach to mannose residues which we find commonly on the glycoproteins on urothelium. 02:44 And so they can attach to urothelium and they're not washed away in the urinary stream. 02:51 These are called mannose-sensitive E. coli, and the other E. coli's don't have them. 03:00 Furthermore, the normal urinary tract has a defense mechanism. 03:07 There is a glycoprotein present in trace amounts in urine. 03:12 It's called uromodulin. 03:14 The old name is Tamm-Horsfall protein, and this uromodulin has mannose residues on it. 03:23 So these mannose-sensitive E. coli will bind to the uromodulin and then be washed away in the urine stream. 03:33 So they never get a chance to attach because of the uromodulin that's present normally in urine. 03:42 Now recurrent and complicated cystitis leads to an increased incidence of more resistant organisms, that we don't usually find causing cystitis. 03:55 That would be, for example, Proteus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter species, and even some resistant E. coli, and among the Gram-positives -- Enterococcus.
The lecture Cystitis: Definition, Epidemiology & Etiology by John Fisher, MD is from the course Urinary Tract Infections. It contains the following chapters:
Which of the following patients is most likely to develop cystitis?
Which of the following pathogens is the most common cause of uncomplicated cystitis?
Which of the following substances within the normal urine may provide defense against urinary tract infections with some types of Escherichia coli?
Which of the following statements regarding the epidemiology and risk factors of urinary tract infection is MOST ACCURATE?
Which of the following is a surface virulence factor of uropathogenic Escherichia coli?
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If I´m paying for people to read the slides, Im out of this, TBH this whole Lecturio actually is super good only for just a few doctors, like Dr. Raj, and some others, but this man... really? reading everything? I´m actually pissed off.
an easy and clear concept in brief.His speech quality is sharp.