Deck 5: Specimen Management

Question 1

Direct examinations such as the Gram stain serve what purpose?

A)To determine the organism's genetic makeup
B)To give the physician an early indication of what may be wrong with the patient
C)To determine the type of flora in the throat and stool specimens
D)To determine the organism's colonial morphologic features

Answer 1

B
Direct examinations enable the laboratory scientist to give the physician an early indication of possible pathogens,enabling him or her to gain insight to guide the work-up of the specimen.

Question 2

Colonies of Streptococcus pneumoniae appear a-hemolytic on blood agar media.Which one of the following statements explains this discrepancy?

A)The lot of blood agar may be expired.
B)Something may be wrong with the strain of S.pneumoniae since it should be b-hemolytic on blood agar.
C)Something may be wrong with the strain of S.pneumoniae;it should be g-hemolytic on blood agar.
D)No discrepancy is present.S.pneumoniae should be a-hemolytic on blood agar.

Answer 2

D
S.pneumoniae produces a-hemolytic on blood agar.

Question 3

Ambient air,which contains 21% oxygen (O₂)and a small amount (0.03%)of carbon dioxide (CO₂),is the environmental condition that best suits which type of organism?

A)Aerobes
B)Anaerobes
C)Capnophiles
D)Microaerophiles

Answer 3

A
Various types of microorganisms require different atmospheric conditions.Aerobes grow best in the presence of ambient air.

Question 4

Between 5% and 10% hydrogen (H₂),5% to 10% CO₂,80% to 90% nitrogen (N₂),and 0% O₂ produce an environmental condition that best suits which type of organism?

A)Aerobes
B)Anaerobes
C)Capnophiles
D)Microaerophiles

Question 5

Which type of media is designed to distinguish microorganisms on the basis of certain growth characteristics?

A)Selective
B)Nutritive
C)Differential
D)Definitive

Question 6

The appropriate storage for a cerebral spinal fluid specimen is ____°C.

A)4
B)22
C)37
D)-70

Question 7

An example of a selective medium for gram-positive organisms is:

A)MacConkey agar.
B)blood agar.
C)colistin and nalidixic acid.
D)thioglycollate broth.

Question 8

Specimens for microbiologic studies should be:

A)transported to the laboratory within 48 hours of collection.
B)collected in nonsterile specimen containers.
C)transported in sealable,leak-proof plastic bags with a separate section for paperwork.
D)sent to the laboratory on ice,no matter what type of specimen.

Question 9

Which specimen culture,if positive,should be immediately reported to the clinician?

A)Urine
B)Blood
C)Throat
D)Stool

Question 10

Which type of media is designed to support the growth of a wide range of microorganisms?

A)Selective
B)Nutritive
C)Differential
D)Definitive

Question 11

A principal role of the clinical microbiologist includes:

A)quickly and accurately communicating information about the patient in both verbal and written formats.
B)assisting nurses and/or phlebotomists on the floor when drawing blood cultures.
C)diagnosing and treating patients.
D)designing software for microbial databases.

Question 12

Increased concentrations of CO₂ (5% to 10%)and approximately 15% O₂ produce an environmental condition that best suits which type of organism?

A)Aerobes
B)Anaerobes
C)Capnophiles
D)Microaerophiles

Question 13

The definitive identification of clinically significant isolates is:

A)always necessary and should be carried out by the laboratory at all times.
B)desirable in most cases;however,limited identification may sometimes be necessary and helpful.
C)often not cost effective and should be performed only when requested by the attending physician.
D)not necessary in most cases and should not be routinely performed by the laboratory.

Question 14

Rejection of inappropriately collected or transported specimens:

A)is the sole responsibility of the laboratory and should be performed without regard to physician requests.
B)should be initiated by laboratory personnel but approved by the nurses or physicians responsible for the care of the patient.
C)is not in the best interest of patient care and should not be considered appropriate.
D)is the responsibility of the nursing staff and should not be an issue for laboratory personnel.

Question 15

Holding media,such as Stuart's medium and Amie's transport medium,are used to:

A)maintain the viability of microorganisms present in a specimen.
B)support the growth and multiplication of any pathogenic organisms that are present.
C)prevent clotting of specimens such as blood,bone marrow,and synovial fluid.
D)allow pathogenic organisms to grow while nonpathogenic organisms die.

Question 16

An example of a b-hemolytic gram-positive organism is:

A)Staphylococcus aureus.
B)S.pneumoniae.
C)Escherichia coli.
D)Enterococcus.

Question 17

Which type of media is designed to support the growth of one group of organisms,but not another,by containing antimicrobials,dyes,or alcohol?

A)Selective
B)Nutritive
C)Differential
D)Definitive

Question 18

Reduced O₂ (5% to 10%)and increased CO₂ (8% to 10%)produce an environmental condition that best suits which type of organism?

A)Aerobes
B)Anaerobes
C)Capnophiles
D)Microaerophiles

Question 19

The best anticoagulant to prevent clotting of specimens,such as blood,bone marrow,and synovial fluid,which are submitted for recovery of all types of microorganisms,is:

A)sodium polyanethol sulfonate (SPS).
B)heparin.
C)citrate.
D)ethylenediaminetetraacetic acid (EDTA).

Question 20

Which specimen is quantitatively plated by using a calibrated loop?

A)Stool
B)Sputum
C)Joint fluid
D)Urine

Question 21

The microbiologist receives a sputum specimen for culture in the microbiology laboratory.Upon receipt the microbiologist should:

A)complete the set-up of media for identification of pathogens.
B)complete a direct Gram stain and preliminary report.
C)complete an abbreviated work-up of the specimen.
D)complete a culture and definitive identification of pathogens.

Question 22

The macroscopic examination for receipt and review of specimens should include all of the following:

A)type of container,leakage,blood or mucus present.
B)type of container,blood or mucus present,consistency and color.
C)leakage,blood or mucus present,viscosity for fluids,color and consistency.
D)type of container,blood or mucus present,viscosity for fluids,and color.

Question 23

A definitive identification of a pathogen typically includes:

A)a description of the colonial and microscopic morphology.
B)a description of the colonial and biochemical reactions.
C)a confirmatory set of reactions that correlates to the preliminary characteristics.
D)a confirmatory set of reactions and antibiogram for all organisms.

Question 24

Routine microbiology cultures should include all of the following media except:

A)nonselective nutritive media.
B)highly selective specialized media such as Löwenstein-Jensen agar.
C)selective and differential media based on site of infection.
D)an enrichment or supplemental broth.

Question 25

The microbiologist receives a sputum specimen that upon preliminary Gram staining review of direct smear,contains numerous squamous epithelial cells and an excessive amount of contaminating normal flora.Based on the microbiologists knowledge,the microbiologist rejects the specimen and requests a new sample.The physician insists that the microbiologist culture the sample as received.The microbiologist should:

A)disregard the physicians request and discard the specimen.
B)notify their supervisor and write-up the physician.
C)set-up the culture as ordered noting the lack of specimen integrity that may compromise culture results.
D)the microbiologist should have not called the physician and process the sample as received.

Question 26

The microbiology laboratory receives a nasopharyngeal specimen.The technologist fails to report the direct Gram stain and inoculates the sample onto routine culture media including blood agar,chocolate agar,and MacConkey agar.The discrepancy is:

A)there is no discrepancy.
B)the microbiologist failed to report the direct Gram stain.
C)the microbiologist failed to report the direct Gram stain and inoculated unnecessary media.
D)the microbiologist inoculated unnecessary media.

Question 27

The microbiology laboratory receives a genital culture from a 28-year-old female.The specimen direct Gram stain reveals,gram-positive cocci in clusters and gram-negative cocci in chains.The microbiologist inoculates a sheep blood agar plate,a chocolate agar plate,a modified thayer martin plate and a LIM Broth (selective enrichment for group B streptococci).The second shift microbiologist identifies the discrepancy and must take corrective action.The discrepancy indicates:

A)there is no discrepancy noted.
B)the preliminary Gram stain was erroneously reported.
C)the microbiologist should cancel this order and reorder a genital screen for group B streptococci.
D)the microbiologist should report out the results from the cultures when growth is evident.

Question 28

Selection of culture media for specific specimens includes a variety of media for all of the following reasons except:

A)a nutritive media is included to insure growth of all potential pathogens.
B)a selective media is often included to suppress normal microbiota or other potential contaminating organisms.
C)as enrichment media is utilized to cultivate organisms that do not grow on routine media.
D)a back-up broth is included to provide inoculum for additional testing.