Question

What are some mechanisms by which pathogenic bacteria cause diseases? Why is this knowledge important?

Answer 1

Pathogen:-
                        It is a microorganism that is able to cause disease .
✓ Pathogenicity is the ability to produce disease in a host organism.

Mechanism of pathogenicity:-
1. Two broad qualities of pathogenic bacteria underlie the means by which they cause disease:

1. invasiveness:- it is the ability to invade tissues.
It encompasses mechanisms for colonization (adherence and initial multiplication), invasins, and ability ti bypass host defence system.

2.Toxigenesis:- it is the ability to produce toxins. Bacteria may produce two types of toxins-
(a) Exotoxins:- are released from bacterial cells and may act at tissue sites removed from the site of bacterial growth.
(b) Endotoxins are cell-associated substance.
3. Colonization:-
the establishment of the pathogen at the appropriate portal of entry.
✓ Sites of entry in human hosts include the urogenital tract, the digestive tract, the respiratory tract and the conjunctiva.
4. Bacterial adherrnce to mucosal surface :- bacterial adherence or attachment to a eucaryotic cell or tissue surface requires the participation of two factors: a receptor and an ligand. The receptors so far defined are usually specific carbohydrate or peptide residues on the eucaryotic cell surface. The bacterial ligand, called an adhesin.