Clinical Approach to Treatment of Bacterial Infections

Abstract

The determination that a patient has a bacterial infection can be made on the basis of the history, physical examination, and clinical setting, or it can be made on the basis of either histopathologic or microbiologic diagnostic tests. Histologic analysis of infected tissues will often yield information as to the staining characteristics of the bacteria. Even before the microbiology laboratory identifies the strain of bacteria, the organism will be reported as gram negative or gram positive. Clinical clues can also suggest whether the likely infection is caused by gram-negative or gram-positive organisms. For example, infections of the skin are likely to be caused by Streptococcus or Staphylococcus, both of which are aerobic gram-positive organisms. Infections of the gastrointestinal tract, on the other hand, are likely to be caused by either aerobic or anaerobic gram-negative organisms since these are the dominant flora of the gut.