Microbiology

• Which of the following staphylococcal organisms produces coagulase and has been implicated in infections following a dog bite?

  staphylococcus intermedius
• All of the following are important infection control strategies in containing spread of MRSA in hospitals except

  A.aggressive hand hygiene

  B. Routine surveillance for nasal colonization among highrisk individuals

  C. Routine antimicrobial prophylaxis for all patients hospitalized for more than 48 hours

  D. Contact isolation for patients who are colonized or infected with MRSA

  E. Aseptic management of skin lesions

  C. Routine antimicrobial prophylaxis for all patients hospitalized for more than 48 hours
• A 65 year old man deveops an abscess on the bak of his neck. Culture yield S. aureus. The isolate is tested and found to be positive for the mecA gene, which means that:

  The isolate is resistant to nafcillin
•  A group of six children younger than 8 years live in a semitropical country. Each of the children has several crusted weeping skin lesions of impetigo (pyoderma). The lesions are predominantly on the arms and faces. Which of the following microorganisms is this?

  S. aureus
• Both Strep. Pyogenes and S. aureus


   Identify the organism:

  
• An 8 year old boy develops a severe sore throat. On examination, a grayish white exudate is seen on the tonsils and pharynx. If this is group A streptococcal infection what do we expect?

   A catalase-negative Gram-positive coccus that grows in chains
• Important methods for classifyin and speciating streptococci are:

  A.Agglutination using antisera against the cell wall groupspecific substance

  B. Biochemical testing

  C. Hemolytic properties

  D. Capsular swelling (quellung) reaction

  E. All of the above

  E. All of the above
• Action of M protein

  A primary mechanism responsible for the pathogenesis of the boy’s disease on Streptococcal sore throat is?

  
• You observe a 40 year old man begging on a street in a town in india. He has clawing of thefourth and fifth digits with loss of distal parts of the digits of both hands, strongly suggesting leprosy. The causative agent of this disease:

  Grows in parts of the body that are cooler than 37 degrees celsius
• Strep pyogenes


  Identify the possible organism:

  
• measles


  Buccal mucosa of a 5 year old child. What could be the diagnosis?

  
• Brain cells can be infected after 7 years of measles

  Which is true on this figure?

  
• Otitis media is the most common complication


  Which is true of this picture?

  
• lymphadenopathy


  Which is true of this picture?

  
•  Limited immunity in present population


  Which feature of the variola virus makes it an extreme bioterrorism threat?
• german measles


  Forchheimer spot is found in?
• Chicken pox


  Spreads in a centripetal motion. It begins in a person’s chest, moves to their neck and face, then to their abdomen, then their back, and finally their limbs.
• roseola infantum


  Maculopapular rashes after the lysis of fever
• Sporothrix schenckii 


  Probable microbial agent on this gardener with pruritic rash on the hand
• Fungus


  Causative agent of this is?

  
• measles


  Which of the following is a caused by a RNA virus?
• 1. Ribosomes


  Which structure is present in both prokaryotes and eukaryotes?
• Bacillus anthracis


  Robert Koch formulated the Koch's postulate by using which organism?
• Joseph Lister - demonstrated maggots after meat was exposed to flies

  Which of the following associations is INCORRECT?

  1. Louis Pasteur - fermentation
  2. Anton van Leeuwenhoek - animalcules
  3. Joseph Lister - demonstrated maggots after meat was exposed to flies
  4. Dmitri Iwanowski - tobacco mosaic virus
  5. Edward Jenner - vaccination
• Prions


  Acellular infectious agents without nucleic acid and considered as the most resistant to physical and chemical sterilization is identified as
• Lysozyme

  Which antimicrobial peptide destroy the cell walls of bacteria?

  1.  Lysozyme
  2.  Hyaluronidase
  3. Mucin
  4. All choices are correct
• EXOTOXIN


  Highly toxic to animals
• ENDOTOXIN


  Lipopolysaccharide
• EXOTOXIN


  Highly antigenic
• ENDOTOXIN


  Gm (-) bacteria only; released on bacterial death
• ENDOTOXIN


  Relatively heat stable
• TINEA

  Onychomycosis
• Sporothrix schenckii

  Sporothricosis
• Chromoblastomycosis

  Muriform or sclerotic bodies
• Mycetoma

  Local swelling and interconnecting often draining sinuses that contain granules
• Both STAPHYLOCOCCUS& STREPTOCOCCUS

  Gram (+) cocci
• Both STAPHYLOCOCCUS& STREPTOCOCCUS

  
  

  Impetigo
• STAPHYLOCOCCUS

  Catalase (+)
• STAPHYLOCOCCUS

  Coagulase (+)
• Streptococcus


  Virulence with M protein