2011 micro Flashcards
A cattle farmer presented with a fever (rising and falling). Laboratory tests showed a gram negative coccobacillus that grows on a blood agar with carbon dioxide. What is this organism? A) Brucella melitensis B) Brucella abortus C) Brucella suis D) Brucella canis
Brucella abortus
Which of the following is carried by sheep and goats? A) Brucella melitensis B) Brucella abortus C) Brucella suis D) Brucella canis
Brucella melitensis
An 18-month old child presented with diarrhea, which was described and nonspecific and neither bloody nor watery. Lab results showed the bacteria “escherechia coli” with characteristic attaching and effacing lesions in the intestine. What type of E.coli is this?
A) Enterotoxigenic E. coli
B) Enteroinvasive E. coli
C) Enteropathogenic E. coli
Enteropathogenic E. coli
What event coincides with fever in a typhoid infection?
A) primary/transient bactermia
B) secondary bacteremia
C) cholecystitis
Secondary bacteremia (it says septicemia in our slides)
Which of the following organisms result in hemolytic uremic syndrome? A) Enterohemorrhagic E.coli B) shigella dysenteriae type-1 C) stenotrophomonas maltophilia D) A and B E) B and C
D
A child was admitted to the hospital with respiratory distress. An examination showed necrotic pharyngeal tissue with exudate pseudomembranous. When the mother was asked she said that she didn’t vaccinate him. What is the likely cause for the child’s condition?
A) Listeria monocytogenes
B) Corynebacterium diptheriae
C) Corynebacterium diphtheroid
Corynebacterium diptheriae
A man and his wife went to a Chinese restaurant and ate rice. Shortly after they developed abdominal pain and vomiting. What is the cause of their condition?
Bacillus cereus
Food poisoning bacteria with preformed toxin; associated with reheated fried rice or tacos
What causes lyme disease?
A) borrelia burgdorferi
B) Treponema carateum
C) leptospira interrogans
borrelia burgdorferi
What is the causative agent of chancroid?
A) Haemophilus aegypticus
B) Bacteroides fragilis
C) Haemophilus ducreyi
Haemophilus ducreyi
Haemophilus species need the X and V factors for growth. What medium can provide both of these factors? A) charcoal media B) chocolate agar C) blood agar D) milk chocolate agar
chocolate agar
What anaerobic bacteria produces double zone of hemolysis on a blood agar?
A) clostridium perfringens
B) clostridium tetani
C) clostridium botulinum
clostridium perfringens
why? because of the theta toxin
A man presented with urethral discharge. Microscopy of the discharge showed a lot of pus cells but no stainable microorganisms in gram smear. What could be the causative agent?
Chlamydiae trachomatis
What enzyme do anaerobic bacteria lack?
A) Nucleases
B) Proteases
C) Superoxide dismutase
Superoxide dismutase
What is a characteristic of mycoplasma species?
A) they’re bipolar
B) they lack proteases
C) they lack a cell wall
they lack a cell wall
What is the clumping factor in staphylococcus aureus involved in?
clot formation
What allows staphylococcus epidermidis to adhere to artificial heart valves, prosthesis, and catheters?
A) antigen 85 complex
B) polysaccharide slime
polysaccharide slime
What is the reservoir for Neisseria meningitides in humans?
A) GI tract
B) Nasopharynx
C) cervix
Nasopharynx
What is the reservoir for helicobacter pylori? A) pigs B) cattle C) sheep/goats D) humans
humans
What is the most important factor that causes disease in a vibrio cholera infection?
A) Enterotoxin
B) Alpha toxin
C) Theta toxin
Enterotoxin
What allows Neisseria gonorrhea to adhere to the urethral surface?
A) Biofilm
B) Fimbriae
C) Pillus
Fimbriae
What stain do we use to visualize mycobacterium tuberculosis?
A) Dark-ground microscopy
B) Silver stain
C) Ziehl neelsen
Ziehl neelsen