Lecture 1.1.4 Diagnosing Bacterial Infections: Urine Cultures

True/False:

UTIs are the most common infection observed in clinical practice.

True

Which of the following patient populations are more at risk of contracting a UTI?

A) Men

B) Women

B) Women

Which of the following occurs when there is > 10^5 cfu/mL without symptoms?

A) Asymptomatic bacteriuria

B) Acute uncomplicated UTI

C) Complicated UTI

D) Pyelonephritis

A) Asymptomatic bacteriuria

Which of the following occurs when there is bacteriuria with urinary symptoms?

A) Asymptomatic bacteriuria

B) Acute uncomplicated UTI

C) Complicated UTI

D) Pyelonephritis

B) Acute uncomplicated UTI

Which of the following occurs when there is functional or structural abnormalities?

A) Asymptomatic bacteriuria

B) Acute uncomplicated UTI

C) Complicated UTI

D) Pyelonephritis

C) Complicated UTI

Which of the following occurs when the progression of a UTI results in infection of the kidney?

A) Asymptomatic bacteriuria

B) Acute uncomplicated UTI

C) Complicated UTI

D) Pyelonephritis

D) Pyelonephritis

Which of the following is a recurrent UTI after therapy with the SAME organism?

A) Relapse

B) Reinfection

A) Relapse

Which of the following is a recurrent UTI after therapy with a NEW organism?

A) Relapse

B) Reinfection

B) Reinfection

_____ is the presence of increased number of polymorphonuclear leukocytes (PMNs).

Pyruria

* Absence of pyuria eliminates infection (high negative predictive value)

Which of the following collection methods involves cleansing the periurethral area and voiding the first few milliliters of urine into the collection cup?

A) Clean catch

B) Indwelling catheterization

C) Straight catheterization

D) Suprapubic aspiration

A) Clean catch

Which of the following collection methods is the most common?

A) Clean catch

B) Indwelling catheterization

C) Straight catheterization

D) Suprapubic aspiration

A) Clean catch

Which of the following collection methods involves a catheter being threaded into the bladder and urine being collected into a collection bag?

A) Clean catch

B) Indwelling catheterization

C) Straight catheterization

D) Suprapubic aspiration

B) Indwelling catheterization

Which of the following collection methods is common among hospitalized patients?

A) Clean catch

B) Indwelling catheterization

C) Straight catheterization

D) Suprapubic aspiration

B) Indwelling catheterization

Which of the following collection methods involves discarding the first few milliliters of urine after catheter insertion?

A) Clean catch

B) Indwelling catheterization

C) Straight catheterization

D) Suprapubic aspiration

C) Straight catheterization

Which of the following collection methods is typically used when a patient is unable to produce a self-collected specimen?

A) Clean catch

B) Indwelling catheterization

C) Straight catheterization

D) Suprapubic aspiration

C) Straight catheterization

Which of the following collection methods is considered the gold standard due to its low contamination rates?

A) Clean catch

B) Indwelling catheterization

C) Straight catheterization

D) Suprapubic aspiration

D) Suprapubic aspiration

Which of the following collection methods is more commonly performed on infants?

A) Clean catch

B) Indwelling catheterization

C) Straight catheterization

D) Suprapubic aspiration

D) Suprapubic aspiration

Which of the following collection methods involves a sterile needle accessing the bladder through the abdominal wall?

A) Clean catch

B) Indwelling catheterization

C) Straight catheterization

D) Suprapubic aspiration

D) Suprapubic aspiration

Which of the following are valid methods to minimize the growth of contaminates in a urine sample?

A) Rapid processing (within 2 hours)

B) Refrigeration

C) Preservatives

D) All of the above

D) All of the above

A(n) _____ is comprised of various chemical pads to assist with detecting key urinary components.

Urine dipstick

True/False:

Drugs and external conditions (e.g exposure to air) can cause false positives on a urine dipstick.

True

Which of the following would indicate a UTI during a urinalysis?

A) pH too low

B) pH too high

B) pH too high

* Urine is slightly acidic

* Urea-splitting organisms may raise urine pH

Which of the following would indicate a UTI during a urinalysis?

A) Presence of leukocyte esterase

B) Absence of leukocyte esterase

A) Presence of leukocyte esterase

* Enzyme that is a byproduct of neutrophils

* Indicates inflammation

Which of the following would indicate a UTI during a urinalysis?

A) Presence of nitrites

B) Absence of nitrites

A) Presence of nitrites

* Indicates presence of gram-negative bacteria, which can convert nitrates to nitrites

True/False:

A negative nitrite test typically rules out a UTI.

False

* Negative nitrite tests do not necessarily rule out UTIs, but positive nitrite tests strongly indicate infection

Which of the following would indicate a UTI during a urinalysis?

A) Presence of blood

B) Absence of blood

A) Presence of blood

* Indicates tissue damage

Which of the following would indicate contamination during a urinalysis?

A) Presence of bacteria

B) Presence of ketones

C) Presence of squamous epithelial cells

D) Presence of nitrites

C) Presence of squamous epithelial cells

Which two media are preferentially used for urine cultures?

Blood agar

MacConkey agar

* Remember, MacConkey has the bile salts which are good at detecting gram-negative bacteria

In both men and women, equal to or greater than _____ cfu/mL indicates significant bacteriuria.

10^5