Questions and Answers
Which of the following bacteria is a genus of high G+C Gram-positive bacteria?
Which of the following has been historically classified as Gram-negative bacteria but is genetically more similar to low G+C Gram-positive bacteria?
What is one feature that differentiates Staphylococcus aureus from other species of staphylococci?
It can produce coagulase.
Over 90% of Staphylococcus aureus bacteria can withstand the effect of penicillin. Why?
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A woman comes to the ER with fever and vomiting. She soon develops a red rash all over her body, and her blood pressure begins to drop. What is one possible diagnosis?
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What type of bacteria are most likely found in a severe inflammation wound showing Gram-positive cocci in irregular clusters, kinase and coagulase positive, and able to grow in the presence of most antibiotics except vancomycin?
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Streptococci are frequently classified by?
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How do group A streptococci camouflage themselves from white blood cells?
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Which of the following diseases is considered an autoimmune disease triggered by bacterial infection?
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Which of the following statements about 'flesh-eating' streptococci is FALSE?
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Streptococcus agalactiae is associated with which of the following diseases?
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Which of the following statements regarding Streptococcus pyogenes is FALSE?
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What differentiates virulent strains of Streptococcus pneumoniae from nonvirulent strains?
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Untreated streptococcal pharyngitis may progress to?
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The Quellung reaction is used to diagnose?
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Otitis media may lead to dangerous meningitis in children due to infection with?
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Which of the following staphylococcal virulence factors produce the signs and symptoms of scalded skin syndrome?
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During a stay in the hospital, an accident victim develops symptoms of bacteremia. A blood sample shows the presence of Gram-positive cocci in pairs. Lab tests determine that the bacteria are nonhemolytic and bile salt tolerant. The bacteremia is likely due to?
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Which of the following streptococci is associated with dental caries?
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Anthrax, which means 'charcoal', derives its name from?
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Which of the following statements about Bacillus anthracis is FALSE?
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Which of the following bacteria produce one of the most deadly bacterial toxins known?
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Which of the following bacteria can cause life-threatening pseudomembranous colitis?
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How does the toxin from Clostridium tetani produce its action?
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Which of the following statements concerning tetanus is FALSE?
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Listeria's virulence is directly related to its ability to?
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Which of the following bacteria divide by 'snapping division' in which daughter cells remain attached in characteristic V-shapes?
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Study Notes
Bacteria Characteristics and Classification
- Mycobacterium is a genus of high G+C Gram-positive bacteria.
- Mycoplasmas have been historically classified as Gram-negative but are genetically similar to low G+C Gram-positive bacteria.
- Staphylococcus aureus is differentiated from other staphylococci by its ability to produce coagulase.
- MRSA (Methicillin-resistant Staphylococcus aureus) displays Gram-positive cocci in irregular clusters, positive for kinase and coagulase, resistant to most antibiotics except vancomycin.
Staphylococcus and Streptococcus Infections
- Over 90% of Staphylococcus aureus can resist penicillin due to beta-lactamase production.
- Symptoms like fever, vomiting, and a sudden drop in blood pressure can indicate toxic shock syndrome.
- Streptococci are classified based on the Lancefield antigen; group A streptococci use hyaluronic acid capsules to evade white blood cell detection.
- Rheumatic fever is an autoimmune disease triggered by bacterial infection.
Diseases and Complications
- Streptococcus agalactiae is associated with neonatal illnesses, including bacteremia, meningitis, and pneumonia.
- Streptococcus pyogenes does not produce protein A, which would inhibit opsonization; its virulent strains have a protective polysaccharide capsule.
- Untreated streptococcal pharyngitis can lead to scarlet fever or rheumatic fever.
- The Quellung reaction is a diagnostic test for Streptococcus pneumoniae.
Miscellaneous Bacteria and Their Effects
- Otitis media due to Streptococcus pneumoniae can lead to severe meningitis.
- Exfoliative toxin from Staphylococcus causes the symptoms of scalded skin syndrome.
- Enterococcus is indicated in cases of bacteremia characterized by Gram-positive cocci in pairs, nonhemolytic, and bile salt tolerant.
- Viridans streptococci are associated with dental caries.
Toxins and Other Pathogens
- Anthrax, translated as "charcoal," is named for the black eschars it produces on the skin.
- Clostridium botulinum produces one of the most potent bacterial toxins.
- Clostridium difficile is linked to life-threatening pseudomembranous colitis.
- Clostridium tetani's toxin blocks inhibitory neurotransmitter release, causing unopposed muscle contractions.
- Tetanus can be contracted from sources beyond just rusty nails, contradicting the idea of puncture wounds as the sole cause.
Additional Microbial Characteristics
- Listeria can evade the immune system by living within host cells, enhancing its virulence.
- Corynebacterium divides through "snapping division," resulting in daughter cells maintaining a V-shape formation.
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Description
Test your knowledge with these flashcards from Microbiology Chapter 19. Focus on the characteristics and classifications of different bacterial genera. This quiz covers key concepts such as Gram-positive and Gram-negative bacteria as well as specific traits of Staphylococcus aureus.