**1. Introduction**

The soluble protein antigen released by pathogenic gram positive and negative bacterial involved in the pathogenicity is known as toxins. These toxins involved in the balancing of cell capacity, targeting the specific host cell and modify their functions. The bacterial toxins are generally classified into two groups endotoxins and exotoxins. The endotoxins is a lipopolysaccride, an important constituent of outer membrane of gram negative bacteria [1]. Exotoxins are polypeptide diffusible proteins that are located on extra chromosomal genes. They are usually secreted by living bacterial species but also released on bacterial lysis and act locally or at far away from colonization site. They may enter the membrane at the cell surface to cause injury or damage and also involved in the binding to cell receptors or to facilitate/ interact with other bacterial cell types [2]. Bacterial toxins cause microbial infection by damaging or inhibiting the cellular mechanism in host. In this way bacterial toxins take over the control of vital processes of living organisms [3]. They are extremely diverse in their size ranges

more or less from 15 to 2700 amino acids, secretion types, structure (mono, binary, ternary), enzymatic activity, and the receptor recognition or binding sites [1].
