Cultures: Respiratory, Eye, Urine, Stool Flashcards Preview

Microbiology > Cultures: Respiratory, Eye, Urine, Stool > Flashcards

Flashcards in Cultures: Respiratory, Eye, Urine, Stool Deck (33)
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1
Q

What are 3 lower respiratory tract specimens?

A

1) Sputum: Contaminated with normal upper-respiratory tract normal flora.
2) Tracheal Aspirate- Suctioned from endotracheal tube or tracheostomy
3) Bronchial Alveolar Lavage- Bronchial brushings and washings- Upper resp. contamination minimized

2
Q

How would you collect a sputum specimen:

A

1) Rinse mouth with water
2) Take deep breaths, and then cough forcefully into specimen container.
3) Examine specimen to contain at least 1 ml of thick mucus. Early morning preferred
4) Send specimen at ambient temperature, refrigerate for delay >1 hr

3
Q

> 25 epithelial cells/LPF in sputum stain means what?

A

Oral contamination- request new specimen

4
Q

Bacterial etiologic agents of eye infections

A

1) H. Influenzae
2) Staph aureus
3) Strep pneumo
4)Pseudomonas aeruginosa
5) Bacillus cereus
Newborn: N. gonorrhoeae, Chlamydia trachomatis

5
Q

Purulent conjunctivitis eye specimen collection

A

Collect purulent material with culturette, place swab into sleeve with transport media and transport at ambient temperature or 2-8 degrees C for viral cultures

6
Q

Corneal infections eye specimen collection

A

Swab conjunctiva, collect multiple corneal scrapings and inoculate directly onto bacterial agar media

7
Q

Urinalysis: Catheterized urine- Nitrite=negative. This specimen result rules out a urinary tract infection?

A

NO- Enterococcus may not have a positive nitrite

8
Q

True/False: Catheterized urine is considered sterile?

A

False: Catheter can introduce bacteria into the bladder as it passes through urethra

9
Q

T/F: Most labs do gram stains on urine:

A

False- If urinalysis indicates UTI, gram stain warranted.

10
Q

Most laboratories will setup what 2 types of culture media

A

Sheep Blood Agar, and MacConkey agar

11
Q

T/F: 60-80% of urine cultures received in the lab will be “No growth” or “growth of contaminants only”

A

True

12
Q

T/F: >100,000 cfu/ml is indicative of a UTI, except when the isolate is contaminant

A

True

13
Q

T/F: 10,000-100,000 cfu/ml does not indicate an infection, especially if only one colony type is growing

A

False- it may indicate infection

14
Q

T/F: If there is growth of three or more different organisms, work-ups are ordered

A

False: consider the specimen contaminated and work-ups are not done

15
Q

Clean catch urine reported as: 10,000 CFU/ml Staphylococcus sp. coag negative, >100,000 CFU/ml diphtheroids, 50,000 CFU/ml lactose-fermenting gram-negative rods.

This culture is interpreted as:

A

Contaminated

16
Q

A suprapubic urine culture interim report: 500 CFU/ml non-lactose fermenting GNR oxidase negative. These results are interpreted as:
A) Colony count too low
B) Colony count significant but organism is not known to cause UTI
C) Colony count significant, organism significant

A

C) Colony count significant, organism significant

17
Q

T/F: A urinalysis result on a voided urine specimen included: many bacteria seen on the microscopic exam. Based on this result, this urine should be cultured due to possible UTI.

A

False: This is a voided urine and not collected properly

18
Q

T/F: If a patient is in the hospital for >3 days and develops diarrhea, a stool culture should be performed.

A

False- Diarrhea usually due to antibiotic therapy, altered diet

19
Q

Routine stool culture for enteric pathogens usually include what 3 organisms?

A

Salmonella, Shigella, and Campylobacter

20
Q

Results of direct specimen biochemical tests performed as part of a routine urinalysis exam that are consistent with UTI are:

A

Nitrite positive, leukocyte esterase positive

21
Q

The interim report of a clean-catch urine culture is:
>100,000 CFU/ml Enterococcus sp.
This is consistent with:

A

A UTI

22
Q

The leading cause of death in the US related to seafood consumption is:

A

Vibrio vulnificus

23
Q

Bacterial diarrhea associated with seafood is caused by:

A

Vibrio parahaemolyticus

24
Q

An organism that effects all age groups that can be asymptomatic or lead to severe inflammatory diarrhea that is associated with incorrect food handling practices, consumption of poorly cooked poultry, and raw milk is:

A

Campylobacter

25
Q

MacConkey Agar selects for what type of pathogens?

A

Enterobacteriaceae and other GNRs

26
Q

MacConkey Agar differentiates for what type of pathogens?

A

Lactose and non-lactose fermenters: Normal enteric flora will ferment lactose (pink colonies). Salmonella and Shigella will not ferment lactose (colorless or transparent colonies).

27
Q

In Hektoen Enteric Agar, Salmonella and Shigella will produce produce what color colonies?

A

Green to blue-green colonies. Non pathogens will ferment one or both carbohydrates (H2S, Lactose and sucrose) to appear bright orange or salmon pink

28
Q

A Gram stain is performed on stool to detect:

A

white blood cells

29
Q

How would you isolate campylobacter species?

A

Blood agar campy-BAP- Brucella agar is base. Antibiotic mixture (vanco to inhibit gram positives), campylobacter species are flat, gray, non-hemolytic colonies.

30
Q

What agr is used to normally isolate E. coli 0157:H7?

A

MacConkey Sorbital Agar- appears colorless while others appear pink to red in color

31
Q

Non-Lactose fermenting GNR H2S+: Suspicious colonies for which organism?

A

Salmonella

32
Q

Non-Lactose fermenting GNR: Suspicious colonies for which organism?

A

Salmonella or Shigella

33
Q

If stool culture negative at 72 hours, it is reported as:

A

No salmonella, Shigella or Campylobacter isolated