The value of including broth cultures as part of a routine culture protocol

Three hundred seventeen clinical specimens from both superficially and deeply infected sites were prospectively examined to assess the true value of including liquid media as part of the routine culture procedure. All broth cultures were subcultured after overnight incubation onto plate media. The isolates obtained from the broth cultures were then compared with the isolates obtained on primary solid media. The isolates obtained from the broth cultures only were evaluated for clinical relevance by review of the patients' records. Twenty-two clinically relevant isolates were obtained from the broth cultures only, but the isolation of these additional organisms altered patient management for only two patients. It would appear from these results that the additional expense and time involved in culturing clinical specimens in fluid media is unwarranted.