Bacterial pathogens are a major cause of infectious diseases. It is important to be able to identify them in patients in order to provide an effective treatment. The subject explores topics such as identification and quantitative methods, possible automation of the techniques or efficiency of available treatments while providing a clinical knowledge. The studies cover notably staphylococci, streptococci, corynebacteria, mycobacteria, neisseria, enteric bacteria, pasteurellae, pseudomonads and spirochaetes and their mechanisms of action in the context of the disease they cause. The main aim of clinical bacteriology is to diagnose the disease by using specimens. These specimens may be urine, feces, body fluids, tissue etc. Manual testing is done by using this specimen to find out the infectious disease. The infectious diseases were mainly caused by the bacteria like s.pneumonia, h.pylori, t.palladium, l.borreliosis. Clinical bacteriology concerns of detection, prevention of infectious disease and to study the characteristic of the pathogen.