Microbiology Quiz - Blood Stream Infections PDF

Microbiology Quiz - Blood Stream Infections Part One: Simple MCQs 1. Which term describes the presence of viable bacteria in the blood, regardless of symptoms? ○ (a) Septicemia ○ (b) Toxemia ○ (c) Bacteremia ○ (d) Viremia 2. What is the primary method for diagnosing sepsis? ○ (a) PCR...

Microbiology Quiz - Blood Stream Infections Part One: Simple MCQs 1. Which term describes the presence of viable bacteria in the blood, regardless of symptoms? ○ (a) Septicemia ○ (b) Toxemia ○ (c) Bacteremia ○ (d) Viremia 2. What is the primary method for diagnosing sepsis? ○ (a) PCR ○ (b) Blood culture ○ (c) Urine analysis ○ (d) Lumbar puncture 3. Which Staphylococcus species is coagulase-positive? ○ (a) S. epidermidis ○ (b) S. saprophyticus ○ (c) S. aureus ○ (d) All of the above 4. Which enzyme produced by Staphylococci inactivates toxic hydrogen peroxide? ○ (a) Coagulase ○ (b) Catalase ○ (c) Staphylokinase ○ (d) DNase 5. Which toxin causes scalded skin syndrome in neonates? ○ (a) Enterotoxin ○ (b) Exfoliative toxin ○ (c) Toxic shock syndrome toxin ○ (d) Leukocidin 6. What is the arrangement of Staphylococcus aureus under a microscope? ○ (a) Chains ○ (b) Pairs ○ (c) Clusters ○ (d) Tetrads 7. Which test differentiates Staphylococci (catalase-positive) from Streptococci (catalase-negative)? ○ (a) Coagulase test ○ (b) Catalase test ○ (c) DNase test ○ (d) Novobiocin sensitivity test 8. Which Staphylococcus species is a common cause of urinary tract infections in young females? ○ (a) S. aureus ○ (b) S. epidermidis ○ (c) S. saprophyticus ○ (d) None of the above 9. Which of the following is NOT a toxogenic disease caused by S. aureus? ○ (a) Food poisoning ○ (b) Toxic shock syndrome ○ (c) Pneumonia ○ (d) Scalded skin syndrome 10. Which term describes the presence and multiplication of bacteria in the blood? ○ (a) Bacteremia ○ (b) Septicemia ○ (c) Toxemia ○ (d) Fungemia Part Two: Complex MCQs 11. A patient presents with fever, hypotension, and desquamation of the skin. They recently used tampons. What is the most likely diagnosis and causative agent? ○ (a) Food poisoning caused by S. aureus ○ (b) Toxic shock syndrome caused by S. aureus ○ (c) Scalded skin syndrome caused by S. aureus ○ (d) Pneumonia caused by S. aureus 12. A blood culture taken from a patient 48 hours after hospital admission grows Staphylococcus epidermidis. How would you classify this bloodstream infection? ○ (a) Community-acquired ○ (b) Nosocomial ○ (c) Primary ○ (d) Transient 13. A patient with infective endocarditis has persistent bacteria in their blood. What type of bacteremia is this? ○ (a) Transient ○ (b) Intermittent ○ (c) Continuous ○ (d) Secondary 14. Why does S. aureus cause beta-hemolysis on blood agar? ○ (a) Production of coagulase ○ (b) Production of catalase ○ (c) Production of membrane-damaging toxins ○ (d) Fermentation of mannitol 15. Which virulence factor of S. aureus helps it evade phagocytosis by binding to the Fc portion of IgG? ○ (a) Protein A ○ (b) Capsular polysaccharide ○ (c) Coagulase ○ (d) Staphylokinase 16. A patient develops a bloodstream infection after undergoing a dental procedure. What is the most likely classification of this infection based on its origin? ○ (a) Primary ○ (b) Secondary ○ (c) Nosocomial ○ (d) Community-acquired 17. Which of the following statements about Staphylococci is FALSE? ○ (a) They are Gram-positive cocci arranged in clusters ○ (b) They are non-motile and do not form spores ○ (c) They are all coagulase-positive ○ (d) They can grow in the presence or absence of oxygen 18. A patient with pneumonia develops a bloodstream infection. The blood culture is positive for Streptococcus pneumoniae. How would you classify this bloodstream infection? ○ (a) Primary ○ (b) Secondary ○ (c) Transient ○ (d) Nosocomial 19. Which of the following is NOT a characteristic of enterotoxins produced by S. aureus? ○ (a) Heat stable ○ (b) Cause food poisoning ○ (c) Inactivated by gut enzymes ○ (d) Can cause toxic shock syndrome 20. Which of the following statements regarding S. epidermidis is TRUE? ○ (a) It is coagulase-positive ○ (b) It is a major cause of community-acquired infections ○ (c) It can cause nosocomial infections ○ (d) It is highly virulent 21. A Gram stain of a pus sample shows Gram-positive cocci in clusters. Which of the following organisms is most likely responsible for the infection? ○ (a) Streptococcus pneumoniae ○ (b) Staphylococcus aureus ○ (c) Escherichia coli ○ (d) Neisseria meningitidis 22. Which of the following is a selective medium used to isolate S. aureus? ○ (a) Blood agar ○ (b) Mannitol salt agar ○ (c) Nutrient agar ○ (d) MacConkey agar 23. A patient presents with fever, chills, and positive blood cultures. The causative organism is identified as Escherichia coli. How would you classify this bloodstream infection based on the causative agent? ○ (a) Gram-positive ○ (b) Gram-negative ○ (c) Polymicrobial ○ (d) Fungal 24. Which of the following is NOT a typical specimen collected for the laboratory diagnosis of S. aureus infections? ○ (a) Pus aspirate ○ (b) Blood culture ○ (c) Throat swab ○ (d) Urine sample 25. Which of the following statements about MRSA is TRUE?  ○ (a) It is resistant to methicillin ○ (b) It is often multiple drug-resistant ○ (c) It can be treated with vancomycin ○ (d) All of the above Answer Guide Part One 1. (c) 2. (b) 3. (c) 4. (b) 5. (b) 6. (c) 7. (b) 8. (c) 9. (c) 10. (b) Part Two 11. (b) 12. (b) 13. (c) 14. (c) 15. (a) 16. (b) 17. (c) 18. (b) 19. (c) 20. (c) 21. (b) 22. (b) 23. (b) 24. (c) 25. (d) Done