Question

question 20 (1 point) ✓ saved
all e.coli variants cause disease.
true
false
question 21 (1 point) ✓ saved
________ does not produce an exotoxin as a virulence factor.
salmonella
shigella
e. coli o157:h7
campylobacter
question 22 (1 point) ✓ saved
which opportunistic fungus of the lungs can cause a secondary infection in tuberculosis or very ill patients?
histoplasma capsulatum
mycoplasma pneumonia
blastomyces dermatitidis
candida albicans

Explanation:

Question 20

Most E. coli variants are harmless and live in the gut. Only certain pathogenic strains cause disease, so the statement "All E. coli variants cause disease" is false.

Salmonella primarily uses other virulence factors (like endotoxins, invasion proteins) and does not produce exotoxins as a main virulence factor. Shigella, E. coli O157:H7, and Campylobacter can produce exotoxins.

Candida albicans is an opportunistic fungus that can cause secondary lung infections in immunocompromised or very ill patients (like those with tuberculosis). Histoplasma capsulatum, Mycoplasma pneumonia (a bacterium, not fungus), and Blastomyces dermatitidis have different infection contexts or are not typical opportunistic lung pathogens in this scenario.

Answer:

False

Question 21