DIAGNOSTIC MICROBIOLOGY MAHON AND
LEHMAN ESSENTIAL STUDY QUESTIONS AND
ANSWERS
◉ Which form of immunity provides the basis for vaccination?
Answer: Specific or adaptive immunity
◉ Which specimens or sites commonly contain normal flora?
Answer: Stool, sputum, skin, vagina, and urine
◉ Which sites are normally sterile?
Answer: Blood, cerebrospinal fluid, peritoneal fluid, bone marrow,
tissue, and joint fluid
◉ Which organisms are listed as normal flora of the nasopharynx?
Answer: Streptococci, Haemophilus, Neisseria, mixed anaerobes,
Candida, and Actinomyces
◉ Which organisms are listed as normal flora of the skin?
Answer: Staphylococci, streptococci, Corynebacteria,
Propionibacteria, and yeasts
,◉ Which organisms are listed as normal flora of the upper bowel?
Answer: Enterobacteriaceae, enterococci, and Candida
◉ Which organisms are listed as normal flora of the lower bowel?
Answer: Bacteroides, Bifidobacteria, Clostridium, and
Peptostreptococci
◉ Which organisms are listed as normal flora of the vagina?
Answer: Lactobacilli, streptococci, Corynebacteria, Candida,
Actinomyces, and Mycoplasma hominis
◉ What is the overall goal of microbiologic diagnostic testing?
Answer: Directly or indirectly demonstrate an infectious agent in a
host sample
◉ What characteristics may be used to identify microorganisms?
Answer: Fermentation profiles, cytopathic effects, microscopic
morphology, proteins, nucleic acid sequences, enzymes, toxins, and
surface polysaccharides
◉ What laboratory methods can amplify microbial targets?
Answer: PCR, transcription-mediated amplification, and enzyme
immunoassays
, ◉ What does direct detection identify?
Answer: The organism itself, its proteins or antigens, or specific
genes
◉ When is direct detection most useful?
Answer: Active or acute infection
◉ What direct detection methods are emphasized in the lecture?
Answer: Culture, PCR, and rapid antigen testing
◉ What does indirect detection identify?
Answer: Host immune components such as antibodies
◉ When is indirect detection most useful?
Answer: Past exposure or later-stage disease
◉ What indirect detection methods are emphasized in the lecture?
Answer: ELISA and Western blot
◉ What is the gold-standard direct detection method for many
organisms?
LEHMAN ESSENTIAL STUDY QUESTIONS AND
ANSWERS
◉ Which form of immunity provides the basis for vaccination?
Answer: Specific or adaptive immunity
◉ Which specimens or sites commonly contain normal flora?
Answer: Stool, sputum, skin, vagina, and urine
◉ Which sites are normally sterile?
Answer: Blood, cerebrospinal fluid, peritoneal fluid, bone marrow,
tissue, and joint fluid
◉ Which organisms are listed as normal flora of the nasopharynx?
Answer: Streptococci, Haemophilus, Neisseria, mixed anaerobes,
Candida, and Actinomyces
◉ Which organisms are listed as normal flora of the skin?
Answer: Staphylococci, streptococci, Corynebacteria,
Propionibacteria, and yeasts
,◉ Which organisms are listed as normal flora of the upper bowel?
Answer: Enterobacteriaceae, enterococci, and Candida
◉ Which organisms are listed as normal flora of the lower bowel?
Answer: Bacteroides, Bifidobacteria, Clostridium, and
Peptostreptococci
◉ Which organisms are listed as normal flora of the vagina?
Answer: Lactobacilli, streptococci, Corynebacteria, Candida,
Actinomyces, and Mycoplasma hominis
◉ What is the overall goal of microbiologic diagnostic testing?
Answer: Directly or indirectly demonstrate an infectious agent in a
host sample
◉ What characteristics may be used to identify microorganisms?
Answer: Fermentation profiles, cytopathic effects, microscopic
morphology, proteins, nucleic acid sequences, enzymes, toxins, and
surface polysaccharides
◉ What laboratory methods can amplify microbial targets?
Answer: PCR, transcription-mediated amplification, and enzyme
immunoassays
, ◉ What does direct detection identify?
Answer: The organism itself, its proteins or antigens, or specific
genes
◉ When is direct detection most useful?
Answer: Active or acute infection
◉ What direct detection methods are emphasized in the lecture?
Answer: Culture, PCR, and rapid antigen testing
◉ What does indirect detection identify?
Answer: Host immune components such as antibodies
◉ When is indirect detection most useful?
Answer: Past exposure or later-stage disease
◉ What indirect detection methods are emphasized in the lecture?
Answer: ELISA and Western blot
◉ What is the gold-standard direct detection method for many
organisms?
