Microbiology of Bone and Joint Infections

Bone and joint infection encompasses various types of infections that can occur, in children or less often in adults, on native joints and tissues or on prosthetic material. These infections can be potentially life-, joint- or limb-threatening, even with proper recognition and treatment. Significant shifts have occurred in terms of incidence, types of infection, characteristics of high-risk patients, and microbiology, with Staphylococcus aureus remaining the most prevalent and destructive pathogen. Due to treatment challenges, having bacteriological documentation is crucial. The quality of this documentation varies depending on different factors such as infection type, sample quality, and laboratory’s expertise. The responsibility of acquiring specimens lies with the clinician, who must possess sufficient knowledge regarding appropriate sampling methods. The microbiologist can employ different techniques, including highly sensitive molecular methods. When determining the interpretation of microbiological findings, several factors need to be considered, such as underlying clinical situation, presence and types of implants, collection and processing of samples, existence or absence of other laboratory or imaging findings suggestive of infection, and prior antibiotic treatment. Considering all this, knowing basic principles is necessary for clinicians, pathologists, and microbiologists to be able to participate in a multidisciplinary discussion and decision-making around microbiological findings interpretation in each specific patient.