Question 1

Polymicrobial presentations in smears require more interpretation and must take into account all the following except:

Accepted Answer

A) smear background. 
B) morphology of the organisms. 
C) anatomic location of the suspected infection. 
D) method used to make the smear. 
A) smear background. 
B) morphology of the organisms. 
C) anatomic location of the suspected infection. 
D) method used to make the smear.

Question 2

Why should laboratory professionals look for contamination of a specimen by normal microbial flora?

Accepted Answer

A) Contaminated specimens will have much amorphous debris that also goes with them. 
B) Normal flora always preclude the possibility of a pathogen infecting the area where they reside. 
C) The normal flora will be found in clumps, and any pathogenic bacteria will be found with the normal flora. 
D) Contamination of specimens with normal flora that are not collected from sterile sites diminishes the value of the culture studies. 
A) Contaminated specimens will have much amorphous debris that also goes with them. 
B) Normal flora always preclude the possibility of a pathogen infecting the area where they reside. 
C) The normal flora will be found in clumps, and any pathogenic bacteria will be found with the normal flora. 
D) Contamination of specimens with normal flora that are not collected from sterile sites diminishes the value of the culture studies.

Question 3

Which is correct about making slides of thin materials such as urine and cerebrospinal fluid (CSF)?

Accepted Answer

A) Spread the material once, let the specimen dry, then spread another layer on top to ensure enough specimen to stain. 
B) Use the two-slide pull method to ensure evenly distributed material over the slides. 
C) Dip a swab into the specimen, then roll the swab over the glass slide to ensure adequate coverage for staining. 
D) Mark the area of the sample drop on the reverse side with a wax pencil, then place a drop of the specimen into the marked area. 
A) Spread the material once, let the specimen dry, then spread another layer on top to ensure enough specimen to stain. 
B) Use the two-slide pull method to ensure evenly distributed material over the slides. 
C) Dip a swab into the specimen, then roll the swab over the glass slide to ensure adequate coverage for staining. 
D) Mark the area of the sample drop on the reverse side with a wax pencil, then place a drop of the specimen into the marked area.

Question 4

A technician is working the night shift and receives a CSF specimen on an infant.The technician makes a Gram stain of the spinal fluid, then reads the smear under the microscope.The report the technician sends to the physician reads as follows: "gram-negative bacillus, small and pleomorphic." What bacteria are being implied as the infecting agent?

Accepted Answer

A) Escherichia coli 
B) Legionella pneumophila 
C) Staphylococcus aureus 
D) Haemophilus influenzae 
A) Escherichia coli 
B) Legionella pneumophila 
C) Staphylococcus aureus 
D) Haemophilus influenzae

Question 5

All of the following steps should be used to prepare a smear from thick, granular, or mucoid materials except:

Accepted Answer

A) place a portion of the sample on the labeled slide, and press a second slide onto the sample to flatten or crush the components. 
B) once the material is flattened and sufficiently thinned, pull the glass slides smoothly away from each other to produce two smears. 
C) take an additional swab and rub it back and forth on the two glass slides to ensure the material is thin enough to read once it is stained. 
D) if the material is still too thick, repeat the first three steps with another (third) glass slide. 
A) place a portion of the sample on the labeled slide, and press a second slide onto the sample to flatten or crush the components. 
B) once the material is flattened and sufficiently thinned, pull the glass slides smoothly away from each other to produce two smears. 
C) take an additional swab and rub it back and forth on the two glass slides to ensure the material is thin enough to read once it is stained. 
D) if the material is still too thick, repeat the first three steps with another (third) glass slide.

Question 6

A cytocentrifuge is an excellent method for preparing nonviscous fluids, because:

Accepted Answer

A) it deposits cellular elements and microorganisms from the specimen onto the surface of a glass slide as a monolayer. 
B) it concentrates the protein evenly throughout the slide surface. 
C) the sediment is mixed with 70% albumin before spreading it on the surface of a slide. 
D) the cytocentrifuge not only spreads the specimen over the surface of a slide but also stains the specimen. 
A) it deposits cellular elements and microorganisms from the specimen onto the surface of a glass slide as a monolayer. 
B) it concentrates the protein evenly throughout the slide surface. 
C) the sediment is mixed with 70% albumin before spreading it on the surface of a slide. 
D) the cytocentrifuge not only spreads the specimen over the surface of a slide but also stains the specimen.

Question 7

Contaminating materials include all the following except:

Accepted Answer

A) crystallized Gram stain. 
B) materials not coming from the collection site. 
C) materials not contributed by the inflammatory response from the tissues. 
D) materials not likely to contain the infecting organism. 
A) crystallized Gram stain. 
B) materials not coming from the collection site. 
C) materials not contributed by the inflammatory response from the tissues. 
D) materials not likely to contain the infecting organism.

Question 8

Pathogens that will grow in culture, but not in routine bacterial culture, can be recognized on the smear and include all the following except:

Accepted Answer

A) Legionella spp. 
B) Mycobacterium spp. 
C) Bartonella spp. 
D) Klebsiella spp. 
A) Legionella spp. 
B) Mycobacterium spp. 
C) Bartonella spp. 
D) Klebsiella spp.

Question 9

The direct microscopic examination of infected materials, along with specimen site and historical information, may suggest modifications in routine culture techniques to allow the isolation of a suspected pathogen.Common modifications include all of the following except:

Accepted Answer

A) ordering other culture tests. 
B) adding special media. 
C) changing incubation temperature or atmosphere. 
D) changing the amount of humidity in the incubator. 
A) ordering other culture tests. 
B) adding special media. 
C) changing incubation temperature or atmosphere. 
D) changing the amount of humidity in the incubator.

Question 10

A specimen that is spread on a slide and appears to have a homogenous constitution is said to:

Accepted Answer

A) be clumped at different areas on the slide. 
B) contain pathogens only in one visual field. 
C) have material spread evenly throughout the slide. 
D) contain normal flora. 
A) be clumped at different areas on the slide. 
B) contain pathogens only in one visual field. 
C) have material spread evenly throughout the slide. 
D) contain normal flora.

Question 11

What is the most common causative agent of pyoderma?

Accepted Answer

A) Staphylococcus aureus 
B) Neisseria gonorrhoeae 
C) Clostridium perfringens 
D) Haemophilus influenzae 
A) Staphylococcus aureus 
B) Neisseria gonorrhoeae 
C) Clostridium perfringens 
D) Haemophilus influenzae

Question 12

What is the most common causative agent of urethritis?

Accepted Answer

A) Staphylococcus aureus 
B) Neisseria gonorrhoeae 
C) Clostridium perfringens 
D) Haemophilus influenzae 
A) Staphylococcus aureus 
B) Neisseria gonorrhoeae 
C) Clostridium perfringens 
D) Haemophilus influenzae

Question 13

A patient comes to the emergency department with a productive cough, shortness of breath, and a fever of 102° F.The patient is diagnosed with pneumonia.What organism commonly encountered in the microbiology laboratory can cause this disease?

Accepted Answer

A) Streptococcus pneumoniae 
B) Staphylococcus aureus 
C) Escherichia coli 
D) Haemophilus influenzae 
A) Streptococcus pneumoniae 
B) Staphylococcus aureus 
C) Escherichia coli 
D) Haemophilus influenzae

Question 14

Which is correct about using a swab to make a smear?

Accepted Answer

A) It is okay to use the swab after it has been used to inoculate culture media. 
B) Ensure the swab has not been used to inoculate culture media first. 
C) Rub the swab back and forth on the glass slide to smear the specimen for easier viewing. 
D) Dip the swab in thioglycollate broth for easier smearing on the slide. 
A) It is okay to use the swab after it has been used to inoculate culture media. 
B) Ensure the swab has not been used to inoculate culture media first. 
C) Rub the swab back and forth on the glass slide to smear the specimen for easier viewing. 
D) Dip the swab in thioglycollate broth for easier smearing on the slide.

Exam 7: Microscopic Examination of Materials From Infected Sites

Polymicrobial presentations in smears require more interpretation and must take into account all the following except:

Why should laboratory professionals look for contamination of a specimen by normal microbial flora?

Which is correct about making slides of thin materials such as urine and cerebrospinal fluid (CSF)?

All of the following steps should be used to prepare a smear from thick, granular, or mucoid materials except:

A cytocentrifuge is an excellent method for preparing nonviscous fluids, because:

Contaminating materials include all the following except:

Pathogens that will grow in culture, but not in routine bacterial culture, can be recognized on the smear and include all the following except:

The direct microscopic examination of infected materials, along with specimen site and historical information, may suggest modifications in routine culture techniques to allow the isolation of a suspected pathogen.Common modifications include all of the following except:

A specimen that is spread on a slide and appears to have a homogenous constitution is said to:

What is the most common causative agent of pyoderma?

What is the most common causative agent of urethritis?

A patient comes to the emergency department with a productive cough, shortness of breath, and a fever of 102° F.The patient is diagnosed with pneumonia.What organism commonly encountered in the microbiology laboratory can cause this disease?

Which is correct about using a swab to make a smear?

Bacterial Cell Structure, Physiology, Metabolism, and Genetics

Host-Parasite Interaction

The Laboratory Role in Infection Control

Control of Microorganisms

Performance Improvement in the Microbiology Laboratory

Specimen Collection and Processing

Use of Colony Morphology for the Presumptive Identification of Microorganisms

Biochemical Identification of Gram-Negative Bacteria

Immunodiagnosis of Infectious Diseases

Applications of Molecular Diagnostics

Antimicrobial Agent Mechanisms of Action and Resistance

Antimicrobial Susceptibility Testing

Staphylococci

Streptococcus, Enterococcus, and Other Catalase-Negative, Gram-Positive Cocci

Aerobic Gram-Positive Bacilli

Neisseria Species and Moraxella Catarrhalis

Haemophilus and Other Fastidious Gram-Negative Bacilli

Enterobacteriaceae

Vibrio, Aeromonas, Plesiomonas, and Campylobacter Species

Nonfermenting and Miscellaneous Gram-Negative Bacilli

Anaerobes of Clinical Importance

The Spirochetes

Chlamydia, Rickettsia and Similar Organisms

Mycoplasma and Ureaplasma

Mycobacterium Tuberculosis and Nontuberculous Mycobacteria

Medically Significant Fungi

Diagnostic Parasitology

Clinical Virology

Agents of Bioterror and Forensic Microbiology

Biofilms: Architects of Disease

Upper and Lower Respiratory Tract Infections

Skin and Soft Tissue Infections

Gastrointestinal Infections and Food Poisoning

Infections of the Central Nervous System

Bacteremia and Sepsis

Urinary Tract Infections

Genital Infections and Sexually Transmitted Diseases

Infections in Special Populations

Zoonotic Diseases

Ocular Infections

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