MULTIPLE CHOICE
1. When reading culture plates from respiratory specimens, what must the microbiologist take into consideration?
a. The types of organisms normally found at the culture site
b. The amount of media i
...
MULTIPLE CHOICE
1. When reading culture plates from respiratory specimens, what must the microbiologist take into consideration?
a. The types of organisms normally found at the culture site
b. The amount of media inoculated
c. The quality control performed on the media
d. The patient’s physician
A
Laboratory professionals must consider the types of organism normally found at the site from which a microbiologic specimen was collected to be able to determine whether diagnostic data indicate the presence of a pathogen. Analysis of microbiologic data requires a working knowledge of the normal microbial flora, the clinical setting, and the patient’s presentation.
REF: 769 OBJ: Level 2: Interpretation
2. If a patient has a throat culture done and the culture reveals the presence of -hemolytic colonies, what does this indicate?
a. These organisms are pathogenic and must be treated.
b. These organisms are normally found in the pharynx and are normal.
c. The patient is suffering from a viral pharyngitis.
d. The patient has mouth ulcers that require antiviral treatment.
B
Isolation of -hemolytic colonies from a pharyngeal culture from a patient with pharyngitis arouses little clinical interest, because -hemolytic streptococci are normal flora in the oropharynx.
REF: 767 OBJ: Level 2: Interpretation
3. What should a microbiologist do if he or she finds -hemolytic colonies on a properly collected sputum specimen on a patient suspected of having lobar pneumonia?
a. Ignore the colonies because they are normal flora.
b. Ignore the colonies because no known pathogens for pneumonia are -hemolytic.
c. Do a full workup to identify the organism.
d. Suspect a bioterror agent, and send the isolate to a laboratory response network (LRN) reference laboratory.
C
Isolation of an -hemolytic colony from a properly collected sputum specimen or bronchial aspirate in the clinical setting of lobar pneumonia should prompt full identification of the organism and perhaps initiation of empirical therapy for possible pneumococcal infection.
REF: 767 OBJ: Level 2: Interpretation
4. A patient’s normal pharyngeal flora can be altered by all of the following except:
a. broad-spectrum antibiotics.
b. recent hospitalization.
c. chronic illness.
d. visiting a nursing home.
D
Normal upper respiratory tract flora in an asymptomatic patient may change depending on the clinical setting. Patients who have previously received broad-spectrum antibiotics, have been hospitalized recently, or who have chronic illnesses may have different pharyngeal flora.
REF: 767 OBJ: Level 1: Recall
5. All of the following factors can help the microbiologist differentiate between colonization and infection except:
a. presence of a pure culture or mixed flora on the culture plates.
b. method and site of collection of the specimen.
c. presence of white blood cells (WBCs) and the number of organisms seen on Gram stain.
d. A compatible clinical syndrome.
A
The isolation of certain organisms from respiratory specimens may represent either colonization or disease, depending on the circumstances. An interpretation must be based on several factors. The method and site of collection of the specimen can influence the risk of contamination with organisms that are part of the normal flora. Characteristics of the specimen such as the presence of white blood cells and the number of organisms in the specimen can help distinguish between colonization and infection. Most important, a compatible clinical syndrome should be present to determine whether the presence of a potential pathogen is clinically relevant.
REF: 768 OBJ: Level 2: Interpretation
6. Which of the immunocompromised circumstances listed here is a form of functional immunodeficiency?
a. Sex
b. Age
c. Chronic illness
d. Pregnancy
B
Age is a form of functional immunodeficiency. Infants and the elderly are more susceptible to certain respiratory tract infections and are more likely to develop complications of these infections.
REF: 768 OBJ: Level 1: Recall
7. What is the cause of reduced clearance of respiratory secretions that predisposes people to respiratory infections?
a. Obstruction of a foreign body
b. Alterations in the viscosity of the mucus
c. Immature anatomic development
d. All of the above
D
In addition to age as a compromising factor, reduced clearance of secretions or obstruction of an area in either the upper or the lower respiratory tract predisposes to infection and can, on occasion, seriously compromise respiratory tract function. Decreased clearance of respiratory secretions may result from the following: immature anatomic development, transient reduction in function of the mucociliary mechanism, obstruction by a foreign body, previous disease that alters the normal respiratory tract anatomy, and alterations in the viscosity of mucus.
REF: 769 OBJ: Level 1: Recall
8. What bacteria may cause up to 50% of all cases of pneumonia in the summer months?
a. Mycoplasma pneumoniae
b. Streptococcus pneumoniae
c. Klebsiella pneumoniae
d. Haemophilus influenzae
A
Diseases associated with M. pneumoniae typically occur throughout the year, without marked seasonal variability. The incidence of viral infections and secondary bacterial pneumonias is reduced during the summer months; therefore M. pneumoniae may cause up to 50% of all pneumonias in the summer months.
REF: 769 OBJ: Level 1: Recall
9. What is helpful when initiating empiric antimicrobial therapy?
a. Knowing the patient’s age
b. Knowing the pathogens most likely to cause a particular type of infection
c. Knowing a patient’s medical history
d. Knowing the anatomy of the respiratory tract
B
When empiric antimicrobial therapy is necessary, it is important to have a working knowledge of the organisms most likely to cause the type of infection observed and of the antibiotics that are most likely to be effective.
REF: 769 OBJ: Level 2: Interpretation
10. Elements of the respiratory tract that can help prevent infection include which of the following?
a. Nasal hair
b. Normal flora
c. Coughing
d. All of the above
D
Elements of the respiratory tract that help prevent infection include nasal hair, mucociliary cells that line mucosal surfaces, coughing, normal flora, and phagocytic inflammatory cells.
REF: 766 OBJ: Level 2: Interpretation
11. All the following are virulence factors that allow microorganisms to produce disease except:
a. adherence.
b. toxin elaboration.
c. mucus production.
d. host evasion.
C
Virulence factors involved in disease-producing mechanisms, such as adherence, toxin elaboration, and host evasion, enable the microorganism to complete this process.
REF: 770 OBJ: Level 1: Recall
12. Why is pharyngitis produced by group A Streptococcus treated with antibiotics?
a. To prevent rheumatic fever and acute glomerulonephritis
b. To prevent epiglottis
c. To prevent swelling of tonsils
d. To prevent swelling of soft tissues in the pharynx
A
The goals of antibiotic treatment of streptococcal pharyngitis include amelioration of the symptoms, limitation of transmission of the infection to contacts (especially in school-age children), and prevention of the serious complications of acute rheumatic fever and acute glomerulonephritis.
REF: 772 OBJ: Level 2: Interpretation
13. What are the two most frequently identified bacterial causes of community-acquired sinusitis?
a. Staphylococcus aureus and Escherichia coli
b. Streptococcus pneumoniae and Haemophilus influenzae
c. S. pneumoniae and Mycoplasma pneumoniae
d. H. influenzae and Neisseria meningitidis
B
Common viruses causing acute sinusitis include rhinovirus, parainfluenza, and influenza viruses. S. pneumoniae and H. influenzae are the bacterial pathogens identified most frequently in community-acquired infections.
REF: 773 OBJ: Level 1: Recall
14. Acute sinusitis usually occurs as a complication of:
a. bacterial pneumonia.
b. viral pneumonia.
c. the common cold.
d. streptococcal pharyngitis.
C
Acute sinusitis is usually a complication of common colds or other viral infections of the upper respiratory tract.
REF: 773 OBJ: Level 1: Recall
15. What common condition will predispose individuals to acute sinusitis?
a. Cold sores
b. Ear infections
c. Nosebleeds
d. Allergies
D
Respiratory allergies also predispose individuals to acute sinusitis.
REF: 773 OBJ: Level 1: Recall
16. All of the following are complications of acute sinusitis except:
a. acute pharyngitis.
b. meningitis.
c. osteomyelitis.
d. orbital cellulitis.
A
Complications of acute sinusitis result from extension of the infection to adjacent areas or structures. These complications include orbital cellulitis, osteomyelitis, meningitis, brain abscess, and cavernous sinus thrombosis.
REF: 774 OBJ: Level 1: Recall
17. What organisms are most frequently isolated from cultures of individuals with otitis media?
a. Staphylococcus aureus and Escherichia coli
b. Streptococcus pneumoniae and Haemophilus influenzae
c. S. pneumoniae and Mycoplasma pneumoniae
d. H. influenzae and Neisseria meningitidis
B
Considering the similarities in their pathogenesis, it is not surprising that the same group of pathogens is involved in both acute otitis media and acute sinusitis. S. pneumoniae and H. influenzae account for more than 50% of the isolates from cases of acute otitis media.
REF: 775 OBJ: Level 1: Recall
18. What is the most common localized infection of the upper respiratory tract in preschool-age patients?
a. Orbital cellulitis
b. Acute sinusitis
c. Otitis media
d. Mastoiditis
C
Otitis media is the most common localized infection of the upper respiratory tract in pre-school-age patients. One study showed that almost a third of all visits by preschool children to pediatricians involved diseases of the middle ear.
REF: 775 OBJ: Level 1: Recall
19. Why do most physicians treat otitis media empirically instead of obtaining cultures before prescribing antibiotics?
a. It is hard to hard to obtain cultures from children.
b. Cultures do not always correlate with the true pathogen.
c. Pathogens causing otitis media never become resistant to antibiotics.
d. The predominant infection causing organisms are known.
D
Because the predominant pathogens for acute otitis media are known, obtaining specimens for culture before initiating therapy is unnecessary in the average case.
REF: 776 OBJ: Level 1: Recall
20. What organism causes epiglottis?
a. Haemophilus influenzae
b. Streptococcus pneumoniae
c. Moraxella catarrhalis
d. Bordetella pertussis
A
H. influenzae type b is uniquely associated with epiglottis.
REF: 776 OBJ: Level 1: Recall
21. What is the most common complication of pertussis?
a. Otitis media
b. Pneumonia
c. Acute sinusitis
d. Streptococcal pharyngitis
B
The most common complication of pertussis is the pneumonia that occurs in young children.
REF: 778 OBJ: Level 1: Recall
22. What is the specimen of choice for recovery of Bordetella pertussis?
a. Sputum specimens
b. Throat swabs
c. Nasopharyngeal swabs
d. Bronchial aspirate
C
Isolation of B. pertussis in culture from nasopharyngeal secretions is the historical standard for diagnosis and exhibits high specificity. Specimens should be collected early in the course of disease (preferably within the first 2 weeks of the onset of cough) from the posterior nasopharynx and should be plated directly onto selective media, such as Bordet-Gengou or Regan-Lowe (RL) for optimal recovery.
REF: 778 OBJ: Level 1: Recall
23. What virus causes community-wide seasonal outbreaks of bronchiolitis in infants?
a. Rhinovirus
b. Parainfluenza virus
c. Respiratory syncytial virus (RSV)
d. Influenzae virus
C
RSV also causes community-wide seasonal outbreaks of bronchiolitis in infants.
REF: 779 OBJ: Level 1: Recall
24. What is the major cause for chronic bronchitis?
a. Acute bronchitis
b. Respiratory allergies
c. Pneumonia
d. Smoking
D
Whereas acute bronchitis is usually of infectious etiology, chronic bronchitis is usually caused by long-term cigarette smoking and occasionally by other toxic exposures.
REF: 781 OBJ: Level 1: Recall
25. How is acute bronchitis differentiated from acute pneumonia?
a. The degree and extent of involvement of the lower respiratory tract with the infectious process
b. The involvement of the bronchial tree with the infectious process
c. The degree of obstruction of the alveoli with the purulent secretions
d. The amount of mucus secretion produced by the lower respiratory tract
A
The distinction between acute bronchitis and acute pneumonia may be subtle. Both of these conditions are lower respiratory tract infections. The differentiation between acute bronchitis and pneumonia depends on the degree and extent of involvement of the lower respiratory tract with the infectious process.
REF: 785 OBJ: Level 2: Interpretation
26. What type of pneumonia has been associated with Staphylococcus aureus that produces Panton-Valentine leukocidin?
a. Methicillin-resistant pneumonia
b. Necrotizing pneumonia
c. Bacterial
d. Viral
B
Necrotizing pneumonia with pulmonary hemorrhage has been associated with S. aureus isolates that produce Panton-Valentine leukocidin.
REF: 786 OBJ: Level 1: Recall
27. What usually causes community-acquired pneumonias in children during the winter months?
a. Haemophilus influenzae
b. Streptococcus pneumoniae
c. Viral pathogens
d. Legionella spp.
C
Community-acquired pneumonias in children are usually attributable to viral pathogens that cause respiratory tract infections in the community during the winter months.
REF: 785 OBJ: Level 1: Recall
28. To what does infection with influenza predispose patients?
a. Secondary otitis media
b. Secondary sinusitis
c. Secondary pharyngitis
d. Secondary bacterial pneumonia
D
During the winter season, the elderly and patients with underlying heart and lung disease, diabetes, renal disease, or immunosuppression are at increased risk for developing primary influenza pneumonia. Additionally, influenza infection predisposes patients to developing a secondary bacterial pneumonia.
REF: 783 OBJ: Level 1: Recall
29. The clinical picture of this condition includes an incubation period of 2 to 10 days, fever, with or without cough, and dyspnea. The condition may resolve or progress to a more severe form. What is this condition?
a. Severe acute respiratory syndrome (SARS)
b. Streptococcal pneumonia
c. Viral pneumonia
d. Viral bronchitis
A
A characteristic clinical picture is associated with SARS, although distinguishing SARS from other causes of pneumonia remains a challenge. After an incubation period of approximately 2 to 10 days, the most characteristic symptom is fever, with or without cough, or dyspnea. In most cases, symptoms resolve spontaneously after the first week; however, in more than 20% of patients, symptoms progress to the more severe respiratory distress syndrome, and patients require intensive care and respiratory support.
REF: 784 OBJ: Level 3: Synthesis
30. Nosocomial pneumonia are commonly caused by all of the following except:
a. Pseudomonas aeruginosa.
b. Streptococcus pneumoniae.
c. Acinetobacter baumannii.
d. methicillin-resistant Staphylococcus aureus (MRSA).
B
Patients with nosocomial pneumonia are at greater risk for colonization and infection with a wider spectrum of multidrug-resistant bacterial pathogens, such as Pseudomonas aeruginosa, extended-spectrum -lactamase Klebsiella pneumoniae, Acinetobacter baumannii, and MRSA.
REF: 789 OBJ: Level 1: Recall
31. Empyema is a collection of:
a. fluid in the lung resulting from the pathogenesis of bacterial pathogens.
b. fluid in the lung resulting from the pathogenesis of viral pathogens.
c. purulent fluid in the pleural space between the lung and the chest wall.
d. purulent fluid in the bronchii and alveoli.
C
Empyema is defined as a collection of purulent fluid in the pleural space between the lung and the chest wall. Although the accumulation of pleural fluid is fairly common in association with acute bacterial pneumonia, most such accumulations are sterile, only a small percentage of which qualify as empyemas.
REF: 787 OBJ: Level 1: Recall
32. Chronic pneumonia is a:
a. viral pneumonia that lasts for months.
b. pneumonia that is caused by a slow-growing bacteria such as Bacillus anthracis and takes months to resolve.
c. bacterial pneumonia that becomes resistant to antibiotic therapy.
d. pneumonia that appears to resolve clinically, but where radiographic lung abnormalities persist for a long period.
D
Bacterial pneumonias usually resolve completely over a period of weeks. On occasion, however, resolution of pneumonia is delayed, with radiographic lung abnormalities persisting far beyond the improvement of clinical symptoms.
REF: 792 OBJ: Level 1: Recall
33. What organism is the most common opportunistic pathogen that routinely infects patients with HIV/AIDS?
a. Pneumocystis (carinii) jirovecii
b. Mycoplasma pneumoniae
c. Serratia marcescens
d. Respiratory syncytial virus (RSV)
A
Pneumocystis jirovecii pneumonia remains the most common AIDS-associated opportunistic infection, although its incidence has decreased.
REF: 796 OBJ: Level 1: Recall
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