Question

Why is so many diseases caused by prokaryotic organisms?

Answer 1

Prokaryotes consists of the archaebacteria and eubacteria, simply these are bacteria.For an organism to cause pathogenicity in case of pathogenic bacteria is dependent on various factors which includes

a) The ability to enter the host

b) Posses mechanism by which the organism can adhere to and multiply inside the cell

c) Can cause deletrious effect to the host by specific molecules or mechanism and thereby cause tissue damage leading to pathogenicity.

Bacteria are seen as ideal organisms that can exhibit all these properties which are described as:

a) Due to the small size of prokaryotes and the fact that they survive in almost all types of environment,the entry in a host is easy.It can be through food,water, feaco oral route, air and touching any surface that cast host these organism.

b)Bacteria posses special structure like pili,fimbrae flagella,capsule etc.. which helps them withstand the various conditions in the host and by this means they can adhere to the host cell easily without dessication and further helps in division and colonization.

c) Bacteria produce certain toxins (endotoxin by Gram negative organism and exotoxin by Gram positive bacteria) which are primarily responsible to cause disease by damaging the host tissue.

An example is the H.pylori infection which causes peptic ulcer diseases

The pathogen can eneter through oral,faeco oral routes or through contaminated water and food.Once they eneter the host the flagella helps in the adhering and colonization of these organisms specially in the duodenal wall.After which they secrete urease which neutralizes the stomach acid by producing ammonia and hence lead to ulcers.