Bacterial pathogenesis infects the host. Bacterial Infections forms biofilms with its pathogenic nature it may increases. But few pathogens like Pseudomonas syringe injects virulence in the plant host causes diseases. All the bacterias are not pathogens but few have the ability for pathogenesis. For the Diagnosis of Pathogenic microorganisms, direct Examinations and Techniques includes Immunofluorescence, immuno-peroxidase staining, and other immunoassays may detect specific microbial antigens.