Fluids and tissue specimens can usually be obtained in the controlled setting of the operating room and represent higher quality specimens than swabs. Culture of swab specimens is associated with increased false negative results, as they are inferior in recovering anaerobic bacteria, mycobacteria and fungi, and provide inadequate volumes to perform all necessary diagnostic tests. To encourage collection of fluid and/or tissue samples, consideration should be given to making swabs unavailable in the operating room without specific request.
Sources:
Baron EJ, et al. A guide to utilization of the microbiology laboratory for diagnosis of infectious diseases: 2013 recommendations by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM). Clin Infect Dis. 2013 Aug;57(4):e22-e121. PMID: 23845951.
Koneman EW. Koneman’s Color Atlas and Textbook of Diagnostic Microbiology. Lippincott Williams & Wilkins, 2006.