Podcast
Questions and Answers
Which of the following bacteria is a genus of high G+C Gram-positive bacteria?
Which of the following bacteria is a genus of high G+C Gram-positive bacteria?
- Mycobacterium (correct)
- Staphylococcus
- Escherichia
- Clostridium
Which of the following has been historically classified as Gram-negative bacteria but is genetically more similar to low 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?
- Escherichia
- Mycoplasmas (correct)
- Salmonella
- Shigella
What is one feature that differentiates Staphylococcus aureus from other species of staphylococci?
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?
Over 90% of Staphylococcus aureus bacteria can withstand the effect of penicillin. Why?
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?
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?
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?
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?
Streptococci are frequently classified by?
Streptococci are frequently classified by?
How do group A streptococci camouflage themselves from white blood cells?
How do group A streptococci camouflage themselves from white blood cells?
Which of the following diseases is considered an autoimmune disease triggered by bacterial infection?
Which of the following diseases is considered an autoimmune disease triggered by bacterial infection?
Which of the following statements about 'flesh-eating' streptococci is FALSE?
Which of the following statements about 'flesh-eating' streptococci is FALSE?
Streptococcus agalactiae is associated with which of the following diseases?
Streptococcus agalactiae is associated with which of the following diseases?
Which of the following statements regarding Streptococcus pyogenes is FALSE?
Which of the following statements regarding Streptococcus pyogenes is FALSE?
What differentiates virulent strains of Streptococcus pneumoniae from nonvirulent strains?
What differentiates virulent strains of Streptococcus pneumoniae from nonvirulent strains?
Untreated streptococcal pharyngitis may progress to?
Untreated streptococcal pharyngitis may progress to?
The Quellung reaction is used to diagnose?
The Quellung reaction is used to diagnose?
Otitis media may lead to dangerous meningitis in children due to infection with?
Otitis media may lead to dangerous meningitis in children due to infection with?
Which of the following staphylococcal virulence factors produce the signs and symptoms of scalded skin syndrome?
Which of the following staphylococcal virulence factors produce the signs and symptoms of scalded skin syndrome?
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?
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?
Which of the following streptococci is associated with dental caries?
Which of the following streptococci is associated with dental caries?
Anthrax, which means 'charcoal', derives its name from?
Anthrax, which means 'charcoal', derives its name from?
Which of the following statements about Bacillus anthracis is FALSE?
Which of the following statements about Bacillus anthracis is FALSE?
Which of the following bacteria produce one of the most deadly bacterial toxins known?
Which of the following bacteria produce one of the most deadly bacterial toxins known?
Which of the following bacteria can cause life-threatening pseudomembranous colitis?
Which of the following bacteria can cause life-threatening pseudomembranous colitis?
How does the toxin from Clostridium tetani produce its action?
How does the toxin from Clostridium tetani produce its action?
Which of the following statements concerning tetanus is FALSE?
Which of the following statements concerning tetanus is FALSE?
Listeria's virulence is directly related to its ability to?
Listeria's virulence is directly related to its ability to?
Which of the following bacteria divide by 'snapping division' in which daughter cells remain attached in characteristic V-shapes?
Which of the following bacteria divide by 'snapping division' in which daughter cells remain attached in characteristic V-shapes?
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.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
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.