All of the following are beneficial functions of human normal microbial flora EX
ID: 177621 • Letter: A
Question
All of the following are beneficial functions of human normal microbial flora EXCEPT:
A.They secrete antibiotics that help combat infectious pathogens
B. They occupy host habitats that might otherwise be available to pathogens.
C. They may transfer antibiotic resitance genes to pathogenic taxa.
D. They can provide some vitamins and trace nutrients.
2. which of the following is the correct sequence of steps for a pathogen to cause disease include:
a. attachment, exposure, colonization & growth, invasion
b. exposure, colonization & growth, attachment, invasion
c. invasion, exposure, attachment, colonization & growth
d. exposure, attachment, invasion, colonization & growth
3. Which of the following is NOT a virulence factor expressed by pathogenic bacteria?
a. fimbriae for attachment and colonization
b. exotoxin production
c. ability to sporulate
d. proteins to inhibit phagocyte killing
Please provide explanations.
Explanation / Answer
All of the following are beneficial functions of human normal microbial flora EXCEPT:
C. They may transfer antibiotic resistance genes to pathogenic taxa. As transfer antibiotic resistance is not benifical.
2. which of the following is the correct sequence of steps for a pathogen to cause disease include:
d. exposure, attachment, invasion, colonization & growth
3. Which of the following is NOT a virulence factor expressed by pathogenic bacteria?
The ability of a microbial agent to cause disease is called pathogenicity, and the degree to which an organism is pathogenic is called virulence. Virulence is a continuum. On one end of the spectrum are organisms that are avirulent (not harmful) and on the other are organisms that are highly virulent, (lumenlearning)
a. fimbriae for attachment and colonization , hence they are Adhesins are cell-surface components or appendages of bacteria that facilitate virulence
Bacterial Toxins as Pathogen Weapons Against Phagocytes, (do Vale, 2016)
b. Exotoxin production are responsible for virulence
c. ability to sporulate
d. proteins to inhibit phagocyte killing are Exotoxins only like the botulinum toxin produced by Clostridium, since it is a repetition of option b hence it should not be included.