WorksheetsPathogenicity of Organisms
Total questions: 20
Worksheet time: 11mins
Which of the following statement is false about the assumptions made in the publication 'Koch Postulates' propounded by Robert Koch?
A. The pathogen must be present in every case of the disease.
B. The pathogen must be isolated and cultured in vitro.
C. The disease must be reproduced when a pure culture of the pathogen is inoculated into a susceptible host.
D. The pathogen must not be recoverable from the experimentally-infected host.
The major significance of Koch's work was that:
A. Microorganisms can't be cultured in laboratory media.
B. Microorganisms are present in diseased animals.
C. Microorganisms can cause diseases.
D. Diseases can be transmitted from one animal to another.
Which of the following is a frequent cause of septic shock?
A. Endotoxin
B. Exotoxin
C. Lymphangitis
D. Septicemia
Which of the following does NOT produce an exotoxin?
A. Bordetella pertussis
B. Corynebacterium diphtheria
C. Mycobacterium tuberculosis
D. Streptococcus pyogenes
Endotoxins are:
A. Associated with gram-positive bacteria
B. Specific in their method of action
C. Part of the gram-negative cell wall
D. Excreted from the cell
Which of the following does NOT produce a gastrointestinal disease due to an exotoxin?
A. Clostridium perfringens
B. Shigella dysenteriae
C. Vibrio cholera
D. Staphylococcus aureus
A nosocomial infection is:
A. Always present, but not apparent at the time of hospitalization
B. Acquired during the course of hospitalization
C. Always caused by medical personnel
D. Always caused by pathogenic bacteria
Which of the following pathogens is mismatched with the disease that it causes?
A. Bordetella pertussis; whooping cough
B. Clostridium perfringens; gas gangrene
C. Vibrio cholera; cholera
D. Salmonella enterica; typhoid fever
Gas gangrene is the result of deep wound infections in anaerobic tissue by Clostridium perfringens.
A. Loss of blood supply to the soft tissues
B. Release of endotoxins by Clostridium
C. Sporulation of Clostridium
D. Phagocytosis
Septic shock usually results from:
A. Release of endotoxin upon lysis of cells
B. Infection with the malaria parasite
C. Failure to be vaccinated
D. Inhalation of endospores
A toxin of Staphylococcus aureus that acts as a protease and is responsible for skin damage (mainly in children) is:
A. Hydrogen peroxide
B. Alpha toxin
C. Beta toxin
D. Exfoliative toxin
Which of the following is NOT true of exotoxins?
A. exotoxins are part of the Gram positive bacterial cell wall
B. Some are neurotoxins
C. They are highly immunogenic
D. They are usually made of protein
This pathogen uses its motility to follow a chemo-tactic gradient to the intestinal mucosa where it attaches but does not penetrate. It is:
A. Vibrio cholera
B. Staphylococcus aureus
C. Sheigella dysentriae
E. Escherichia coli
Two microorganisms that produce toxins in food that can cause symptoms after the food is consumed even without infection by the microorganisms are:
A. Staphylococcus aureus and Clostridium botulinum
B. Streptococcus pyogenes and Clostridium botulinum
C. Staphylococcus aureus and Streptococcus pyogenes
D. Escherichia coli and Shigella dysenteriae
The most common nosocomial infections are
A. Respiratory tract infections
B. Urinary tract infections
C. Gastrointestinal tract infections
D. Skin infections
Which mode of transmission describes getting sick from consuming contaminated water?
A. Droplet transmission
B. Vector transmission
C. Contact transmission
D. Fecal-oral route
Which of the following is not TRUE of Clostridium genus?
A. They produce endotoxin or LPS
B. They are Gram positive bacteria capable of producing spores (endospores)
C. They produce neurotoxins
D. They are obligate anaerobes
