Bacteria in or on the body usually cause some kind of infection. Bacteria in the lungs can cause pneumonia. Bacteria in your skin cells causes a condition known as cellulitis. There are broad spectrum antibiotics that can kill a large variety of bacteria, but it is better if you can culture the bacteria and determine a specific antibiotic for treatment.
Some examples of bacterial diseases are strep throat, meningitis, bacterial vaginosis, Chlamydia, Pertussis, and pneumonia. They are caused by different bacteria, they can not be cured by the same antibiotics.