Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CAM202 Microbiology > UTIs > Flashcards

UTIs Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Routes of Infection UTIs

A

Ascending: Bacterial pathogens enter the urinary tract from the bowel reservoir via ascent through the urethra into the bladder

Haematogenous: Infection of the urinary tract, especially the kidneys, by organisms originating in the bloodstream

Lymphatic: Direct extention of bacteria from the adjacent organs via lymphatics. Usually rare, but can occur in unusual circumstances, such as severe bowel infection/abscesses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Uncomplicated UTI

A

– Infection in a healthy patient with a structurally and functionally normal urinary tract

– Majority of patients are women with cystitis, or those with acute pyelonephritis

– Organisms are usually susceptible to antimicrobial therapies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Recurrent UTIs

A

Infection that occurs after documented successful resolution of an infection

  1. Bacterial persistence(relapse):UTI caused by the same bacteria that reemerge from a focus within the urinary tract (from an infectious stone [calculus/calculi], or prostate infection). Infections usually occur at close intervals
  2. Reinfection: Recurrent infections caused by new (different) bacteria and occur at varying and sometimes long intervals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Complicated UTIs

A

– Associated with factors that increase the chances of acquiring bacteria and decrease the efficacy of antimicrobial therapies. In this case, the urinary tract is functionally and structurally abnormal

– Majority of cases are men

– Organisms are usually resistant to one or more antimicrobial therapies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Risk factors for UTIs

A

1. Reduced Urine Flow

  • Outflow obstruction, prostatic hyperplasia, prostatic carcinoma, urethral stricture, foreign body (calculus)
  • Neurogenic bladder
  • Inadequate fluid uptake (dehydration)

2. Promote Colonisation

  • Sexual activity – increased inoculation Spermicide – increased binding
  • Estrogen depletion – increased binding
  • Antimicrobial agents – decreased indigenous flora

Facilitate Ascent

  • *Catheterisation
  • Urinary incontinence
  • Faecal incontinence
  • Residual urine with ischemia of bladder wall
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Factors suggesting complicated UTIs

A
  • Functional or anatomic abnormality of urinary tract Male gender
  • *Pregnancy
  • Elderly patient
  • *Diabetes
  • Immunosuppression
  • Childhood UTI
  • Recent antimicrobial agent use
  • *Indwelling urinary catheter
  • Urinary tract instrumentation
  • Hospital-acquired infection
  • Symptoms for more than 7 days at presentation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Types of lower urinary tract infections

A
  • Urethritis
  • Cystitis
  • Prostatitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Types of upper urinary tract infections

A
  • Ureteritis
  • Pyelonephritis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cystitis

A

Superficial infection of the bladder mucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Cystitis symptoms

A
  • Dysuria
  • Frequency and/or urgency » Suprapubic tenderness
  • Haematuria
  • Nocturia
  • Cloudy,foul-smellingurine
  • Fever and chills are not usually present
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Cystitis diagnosis

A

Microscopic urinalysis, which usually indicates pyuria, bacteriuria, and haematuria

*Urine culture remains definitive test; presence of ≥ 108 bacteria/L usually indicates infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Cystitis ddx

A
  • Volvovaginitis
  • Urethritis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Volvovaginitis

A
  • Dysuria subacute in onset;
  • Vaginal discharge or odor; fluid shows presence of inflammatory cells
  • Frequency, urgency, haematuria, and suprapubic pain are usually not present
  • History reveals new or multiple sexual partners
  • Common microbial causes include, Chlamydia, Gonorrhoeae, Trichomoniasis, and yeast infections
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Urethritis

A
  • Dysuria is subacute in onset and is associated with urethral discharge with inflammatory cells
  • History reveals new or multiple sexual partners
  • Common microbial causes of urethritis include, Neisseria gonorrhoeae, Chlamydia, Herpes Simplex Virus (HSV), and Trichomoniasis
  • Less pronounced frequency/urgency than that associated with acute cystitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Pyelonephritis

A

Inflammation of the kidney and renal pelvis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Pyelonephritis symptoms

A
  • Abrupt onset of chills
  • Accompanied by dysuria frequency, and urgency
  • Fever (≥ 38oC)
  • Nausea and vomiting
  • Unilateral/bilateral flank (costovertebral angle) pain
17
Q

Laboratory diagnosis of pyelonephritis and further investigations

A

Urinalysis reveals

  • Bacteriuria
  • Numerous WBCs often in ‘casts’

Blood cultures should be performed in both mena nd women with systemic toxicity (i.e. in the clinical setting of SIRS). If blood cultures remain positive in the presence of persistent high fever and toxicity, urological evaluation is needed to exclude urinary obstruction/intrarenal abscess (consider: ultrasound, MRI, CT scan)

18
Q

Prostatitis clinical syndromes

A
  1. Acute bacterial prostatitis
  2. Chronic bacterial prostatitis
  3. Represents a complicated UTI
19
Q

Symptoms of acute prostatitis

A
  • Perineal pain
  • Dysuria, frequency, urgency
  • Fever
  • Prostatic tenderness
20
Q

Laboratory diagnosis prostatitis and further investigations.

A

Urine analysis reveals pyuria and bacteriuria.

Exclude complications

  • Bacteraemia
  • Abscess formation (ultrasound)
21
Q

Specimen collection

A
  • Female patients should be encouraged to clean the urethral opening prior to collection of specimen.
  • Multiple specifimens may be required for an accurate diagnosis to be made
  • The doubling time of bacteria at RT can be <60 minutes
    • Specimens must be delivered to the lab promptly
    • If unable to deliver immediately, specimens should be refrigerated
22
Q

Causative organisms of UTIs in community.

A
  1. E. coli (80%)
  2. Coagulase negative staph (10%)
  3. Other gram positives
23
Q

Caustive organisms hospital acquired UTIs

A
  1. E. coli (40%)
  2. Other gram negatives (25%): e.g. Klebsiella, Enterobacter
  3. Othe gram positives (16%)
24
Q

E. coli UTIs

A
  • Normal flora in the gut
  • 80% of community acquired UTIs
  • 40% of nosocomial UTIs
  • Gut –> peruneum –> vagina –> urethra

Treatment: generally sensitive to antimicrobials

25
Q

*Proteus mirabilis *

A
  • 5% of community acquired UTIs
  • 11% of nosocomial UTIs
  • Normal flora in the gut
  • Strong urease producer (causes renal calculi)

Urea –> Amonia

Treatment: generally sensitive to antimicrobials

26
Q

Gram negative rods

A
  • 3% of community acquired UTIs
  • 25% of nosocomial UTIs

Normal flora in gut. Includes bacteria:

– Klebsiella species

– Serratia marcescens

– Enterobacter species

Treatment: some are highly resistant to antimicrobials (esp. Nosocomial strains)

27
Q

Pseudomonas aeruginosa

A

**Gram negative rod. **

Can be normal flora in the gut, especially when patient has been on antimicrobial therapy. Sometimes acquired from hospital environment (especially when catheterised - forms biofilms on catheters).

Treatment: often highly resistant to antimicrobials

28
Q

Coagulase-negative Staphylococci

A
  • 10% of community acquired UTIs.
  • 3% of nosocomial UTIs
  • Thsi includes S. saprophyticus
  • Normal skin flora and urethral flora
  • Forms biofilms on plastic (including urinary catheters)
  • Treatment: defer to laboratory results
29
Q

*Staphylococcus saprophyticus *

A
  • 5-10% of community acquired UTI
  • Belongs to the Coagulase negative Staphylococcus group
  • Sensitive to the laboratory antimicrobial agent ‘novobiocin’

Causes honeymoon cystitis

Treatment: generall sensitive to amoxycillin

30
Q

*Staphylococcus aureus *

A
  • Coagulase positive Staphylococcus
  • Rare cause of UTI
  • When causing UTI, infection generally occurs via the haematogenous route
    • Exclude septicaemia/bacteraemia
    • Local infection in setting of indwelling catheter

Treatment: defer to laboratory sensitivity report

Watch out for: methicillin resistant staphylococcusaureus (MRSA)

31
Q

Enterococcus species

A

More common in hospital than community

  • E. faecalis
  • E. faecium

​Normal flora in the gut.

Treatment: amoxycillin (variable sensitivity), nitrofurantoin or vancomycin.

Intrinsically resistant to:

– All cephalosporins, gentamicin, trimethoprim and cotrimoxazole

Watch out for: vanvomycin resistant enterococci (VRE)

32
Q

Steptococcus agalactiae

A
  • 2% of community and nosocomial UTIs
  • Group B streptococcus
  • Normal flora of the gut (+/- vagina)
  • Important neonatal pathogen - always treat in pregnant women (even if reported as part of mixed growth)

Treatment: generally sensitive to antimicrobials used in treatment of UTI - only use classes of antimicrobial allowable if pregnant.

33
Q

Candida spp

A
  • 5% of nosocomial UTIs
  • Candida is a yeast (fungi)
  • Exclude local infection - volvovaginitis
  • Candida may occur in association with infection of the upper urinary tract and/or systemic candidiasis
  • Colonises catheter: esp. important in immunosuppressed/intensive therapy patients

Treatment: Fluconazole

34
Q

Laboratory diagnosis methods for UTIs

A
  1. Microscopic examination of urine
  2. Rapid indirect (Dipstick) methods
35
Q

UTI microscopic examination of the urine findings

A

Urine might show presence of:

– Pyuria: defined as ≥ 10 x 106 leukocytes / L

– Haematuria: erythrocytes ≥ 12 x 106 / L

NOTE: Presence of RBC might also be indicative of other disorders like

tumours, vasculitis, and glomerulonephritis

– Bacteriuria : bacteria present at ≥ 108 / L*

36
Q

When may microscopic examination of the urine yield false results?

A

Contamination of sample: squamous epithelial cells present at ≥ 10 x 106 / L

**Women exhibiting urethral syndrome: **

  • Signs of lower tract infection (dysureia, frequency etc)
  • Usually <108 bacteria/L

<108 bacteria/L may also indicate…

  • previous antibiotic therapy
  • slower growing (fastidious) organisms
37
Q

Rapid indirect (Dipstick) findings with UTI

A

Presence of urine nitrate:

  • Bacteria convert nitrate present in the medium to nitrite
  • Puresence of pyuria detected by leukocyte esterase test

NOTE: A negative leukocyte test plus negative nitrite test are strongly predictive of the absence of UTI

CAM202 Microbiology (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions