A superficial wound culture is used to test for aerobic bacteria (capable of growing in the presence of air). Some of these bacteria can cause disease (pathogens) while others are normal (normal skin flora).
The report indicates whether the culture is positive (presence of pathogenic bacteria) or negative (absence of bacteria or presence of normal skin bacteria only). A culture is considered negative if no growth is observed after 48 hours of culturing. For each strain identified, an antibiogram is added to determine whether the strain will be sensitive (S) or resistant (R) to different antibiotics available for treatment. Typically, only one type of bacteria will be responsible for the infection, but occasionally there will be two or more types of bacteria involved. If more than two organisms are present, an antibiogram is performed only on the main pathogenic strain. If only normal skin flora is present, the infection could be due to these normal bacteria, the pathogenic bacteria may not have been present in sufficient concentration in the sample collected, or the infection could be due to another cause. Weak growth may be considered significant, especially when the infection is in an area of the body that is considered sterile (the eye, for example).