Deck 36: Bacteremia and Sepsis

Question 1

Development of a vaccine has decreased which major cause of bacteremia in children?

A)Haemophilus influenzae
B)Streptococcus pneumoniae
C)Escherichia coli
D)Hepatitis A

Answer 1

A
Some organisms have become less prevalent causes of bacteremia because of immunization practices that have decreased the risk of infection.For example, infection with H.influenzae b, formerly a major cause of bacteremia and sepsis in children, decreased by over 95% after introduction of the conjugate Hib vaccine.

Question 2

Bacteremias are least often associated with which of the following patient conditions?

A)Patients with hematologic malignancies
B)Those undergoing elective outpatient surgical procedures
C)Those receiving immunosuppressive chemotherapy
D)Patients undergoing bone marrow transplantation

Answer 2

B
Bacteremias are more frequent among persons with neoplasia, especially those with hematologic malignancies, those receiving immunosuppressive chemotherapy, and those undergoing bone marrow transplantation.

Question 3

Lipopolysaccharide in gram-negative bacteria and the lipoteichoic acid and peptidoglycan in gram-positive bacteria cause which of the following to be released in the human body?

A)Tumor necrosis factor
B)Interleukin (IL)-1
C)IL-6
D)All of the above

Answer 3

D
In both cases, a bacterial membrane component (lipopolysaccharide, also known as endotoxin, in the case of gram-negative organisms; lipoteichoic acid and peptidoglycan in the case of gram-positive organisms) interacts with macrophages and causes release of tumor necrosis factor (TNF), interleukin-1 (IL-1), IL-6, and other proinflammatory cytokines, increasing endothelial activation, vascular permeability, blood flow, and recruitment of neutrophils.

Question 4

What condition leads to most (75%) of the cases of bacteremia arising from intra-abdominal infections?

A)Pleurisy
B)Cholecystitis
C)Peritonitis
D)Irritable bowel syndrome

Question 5

Which of the following is an example of a primary bacteremia source?

A)An infected heart valve
B)A case of pneumonia
C)A patient with hepatitis
D)A wound abscess

Question 6

What are two potential consequences of bacteremia?

A)Endocarditis and meningitis
B)Meningitis and encephalitis
C)Encephalitis and hepatitis
D)Sepsis and septic shock

Question 7

The most common sites associated with bacteremia and sepsis include all the following except:

A)reproductive organs.
B)infected intravascular catheters.
C)the lung.
D)the abdomen.

Question 8

Which of the following is an example of a secondary bacteremia source?

A)An infected cardiac valve
B)The lung
C)An infected intravenous catheter
D)The bone marrow

Question 9

All of the following organisms are colonizers of indwelling catheters except:

A)coagulase-negative staphylococci.
B)Streptococcus pyogenes.
C)Staphylococcus aureus.
D)Enterococcus spp.

Question 10

What condition results when there is a procedural manipulation of a body site containing normal flora, causing those bacteria to enter the bloodstream?

A)Continuous bacteremia
B)Intermittent bacteremia
C)Septic shock
D)Transient bacteremia

Question 11

What organism is most commonly associated with bacteremia due to acute pyelonephritis?

A)Escherichia coli
B)Enterobacter aerogenes
C)Pseudomonas aeruginosa
D)Staphylococcus aureus

Question 12

What underlying condition predisposes a person to a polymicrobial bacteremia?

A)Intravenous drug use
B)Burns
C)Gastrointestinal tract sources
D)All of the above

Question 13

All of the following factors are associated with an unfavorable outcome in bacteremia except:

A)surface wound or abscess.
B)polymicrobial bacteremia.
C)presence of malignancy.
D)acquired immunodeficiency syndrome (AIDS).

Question 14

Bacteremias can be classified by all of the following categories except:

A)microbiology.
B)acquisition.
C)pathogenesis.
D)duration.

Question 15

What is the most common clinical manifestation associated with continuous bacteremia?

A)Meningitis
B)Pleurisy
C)Encephalitis
D)Endocarditis

Question 16

All of the following organisms are common causes of pneumonia and which typically produce a concurrent bacteremia except:

A)Enterobacter aerogenes.
B)Escherichia coli.
C)Pseudomonas aeruginosa.
D)Staphylococcus aureus.

Question 17

How does a biofilm protect the organism from host defenses?

A)By inhibiting phagocytosis
B)By inhibiting chemotaxis
C)By suppressing the lymphoproliferative response
D)All of the above

Question 18

Which immunosuppressive agent can increase a patient's risk of bacteremia?

A)Cancer chemotherapy
B)Corticosteroid therapy
C)Transplant maintenance therapy
D)All of the above

Question 19

Bacteremia with which organism often leads to endocarditis, osteomyelitis, septic arthritis, hepatic abscess, or pyomyositis?

A)Streptococcus pneumoniae
B)Escherichia coli
C)Staphylococcus aureus
D)Pseudomonas aeruginosa

Question 20

The patient's immune system attempts to control infection via which of the following mechanisms?

A)Antibodies
B)Complement activation
C)Phagocytosis
D)All of the above

Question 21

Which of the following organisms are inhibited by the anticoagulant sodium polyanethole sulfonate (SPS)?

A)Enterobacter aerogenes
B)Escherichia coli
C)Peptostreptococcus anaerobius
D)Streptococcus pyogenes

Question 22

What type of a medical implant device is commonly associated with osteomyelitis, which will then lead to bacteremia?

A)Prosthetic joints
B)Stainless steel rods
C)Orthopedic screws
D)Orthopedic plates

Question 23

What is the principle of a continuous monitoring blood culture system?

A)The amount of 14CO2 produced is measured as a growth index and compared with a threshold.
B)The amount of increased lipopolysaccharide is measured and compared against the null value.
C)The pH of the media is continuously measured to check for bacterial metabolic by-products.
D)An optical monitor records the number of bacteria and records the growth.

Question 24

SPS performs all the following functions in the blood culture bottles except:

A)anticoagulation.
B)prevention of phagocytosis.
C)act as a bacterial nutrient.
D)inactivate certain antibiotics.

Question 25

What can happen when a transient bacteremia is produced from a dental procedure or a superficial skin infection?

A)Hepatitis can result.
B)Pneumonia can result.
C)Deep vein thrombosis can result.
D)Cardiac valves can be seeded with bacteria.

Question 26

A patient receiving chemotherapy for leukemia has developed a fever causing the physician to request blood cultures times three.Each set of cultures grows an a-hemolytic streptococcal organism? What is the most likely explanation for these results?

A)The patient probably has an infection with a-hemolytic strep.
B)The blood cultures were contaminated with skin flora
C)The blood cultures were probably contaminated in the laboratory.
D)The patient probably has an infection with Bacillus spp.

Question 27

How long are conventional (manually processed) blood cultures held before being discarded as negative?

A)4 days
B)7 days
C)14 days
D)21 days

Question 28

When drawing blood for blood cultures in a child younger than age 10, how much blood should be drawn?

A)1 mL for each year of life
B)5 mL
C)2 mL
D)1 mL for children younger than 2 years old, 3 mL for children younger than 7 years old, and 5 mL for children up to 10 years old

Question 29

Abnormal conditions that may indicate the presence of bacteremia include all the following except:

A)disseminated intravascular coagulation (DIC).
B)thrombocytopenia.
C)coagulopathy.
D)anemia.

Question 30

Separate venipunctures were performed to collect three sets of blood cultures from a patient with an artificial heart valve.The first and third sets grew a gram-positive pleomorphic rod in 1 of 2 bottles while the second set had no growth in either bottle.What is the most likely explanation for these findings?

A)The patient probably has an infection with Clostridium spp.
B)The blood cultures were contaminated with skin flora.
C)The blood cultures were probably contaminated in the laboratory.
D)The patient probably has an infection with Bacillus spp.

Question 31

If a patient with a bacteremia is receiving appropriate antibiotics for a known infection but is not responding to treatment, how does the physician find out if another organism is causing the problem?

A)Redraw the blood cultures.
B)Redraw the blood cultures using an antibiotic removal device (ARD).
C)Switch the patient to another antibiotic that will resolve the clinical symptoms.
D)Perform hemodialysis to remove the organisms from the patient's blood.

Question 32

The recommendation of three sets of blood culture drawn at 1-hour intervals is recommended to diagnose which of the following conditions?

A)Meningitis
B)Infective endocarditis
C)Pneumonia
D)Peritonitis

Question 33

Septi-Chek is which type of blood culture system?

A)Continuous-monitoring blood culture system
B)Lysis-centrifugation blood culture system
C)Aerobic-anaerobic blood culture system
D)Biphasic broth-slide system