Question

Why might the person’s normal flora cause disease rather than infection?

Answer 1

Ans.

There are certain microorganisms that thrive on other living organism,such as humans or animals, without harming their host. These non disease causing microorganisms are called as Normal Flora.In human body these normal flora plays a vital role in preventing us from other disease causing bacteria by competing for the essential nutrients,thus preventing their colonization.Apart from these they helps us in synthesizing vitamins.

Although there are lots of benefits associated with these normal flora, there are certain harmful effects too.There are possibilities that these normal flora may invade through a compromised tissue where their restriction and toleration by the host cell may not be possible.In such a condition these normal flora being potential pathogens may cause endogenous disease. Also, some of the pathogens that are members of normal flora can get transfered to the susceptible hosts by their help and cause disease.For Example, Neisseria meningitidis are pathogens that can colonize in the upper respiratory tracts, and potential pathogens like Salmonella or Clostridium that resides in the GI tract.

The other way these normal flora can cause disease is by the effect of antibiotic medicines.When we take antibiotics medications to kill a specific bacteria, a large portion of these normal flora is also killed, giving way to other resident bacteria or pathogen to multiply and cause infections. Weakened immunity is also a factor for these normal flora to cause disease like in the case of HIV patients,cancer patients etc.