Staphylococcus aureus is an opportunistic pathogen responsible for various infections in humans and animals. It causes localized and systemic infections, such as abscesses, impetigo, cellulitis, sepsis, endocarditis, bone infections, and meningitis. S. aureus virulence factors responsible for the initial contact with host cells (MSCRAMMs—microbial surface components recognizing adhesive matrix molecules) include three Sdr proteins. The presence of particular sdr genes is correlated with putative tissue specificity. The transcriptional organization of the sdr region remains unclear. We tested expression of the sdrC, sdrD, or sdrE genes in various in vitro conditions, as well as after contact with human blood. In this work, we present data suggesting a separation of the sdr region into three transcriptional units, based on their differential reactions to the environment. Differential reaction of the sdrD transcript to environmental conditions and blood suggests dissimilar functions of the sdr genes. SdrE has been previously proposed to play role in bone infections, whilst our results can indicate that sdrD plays a role in the interactions between the pathogen and human immune system, serum or specifically reacts to nutrients/other factors present in human blood.

Introduction. Radical procedures like calcanectomy and amputation performed for calcaneal osteomyelitis are regarded as effective in eradication of infection even though potentially functionally disabling. Bone sparing procedures offer better functional result at the expense of potentially worse infection control. The aim of the study has been to assess the influence of the surgical radicalism as much as the extent of bone infection on the final outcome in the surgical therapy of chronic calcaneal osteomyelitis (CO). Material and method. 32 patients with chronic CO have comprised the group under study: 8 with superficial type, 12 localised type and 12 with diffuse type according to Cierny-Mader classification. The aim of the treatment was to heal infection, preserve the heel shape and achieve good skin coverage over the calcaneus. The therapy consisted of 9 debridement surgeries with or without flaps, 8 drilling-operations of the calcaneus with application of collagen-gentamicin-sponge in bore holes, 15 partial and 2 total calcanectomies, and 4 below-the knee amputations. Results. The healing of infection and wound has been achieved after 7 of 9 debridements, 6 of 8 drilling-operations, 13 of 15 partial and all total calcanectomies. Conclusion. Bone preserving operations in chronic calcaneal osteomyelitis provided inferior infection control (76,47% vs 88,24%) and worse patient satisfaction (88,24% vs 100%) and almost camparable ambulation (100% vs 93,33%). Drilling of the calcaneus with application of collagen sponge containing gentamicin performed in chronic diffuse calcaneal osteomyelitis seems to offer a viable alternative to partial or radical calcanectomy. Level of evidence: V.

No abstract

Anaerobic bone and joint infections are uncommon, although the number of anaerobic infections is presumably underestimated because of difficulties with isolation and identification of obligate anaerobes. This study describes two cases of complicated Bacteroides fragilis peri-implant infection of the lumbar spine, infection of the hip and osteomyelitis. Bacteria were identified with the use of a mass spectrometer, VITEK MS system. Drug susceptibility was performed with the use of E-test. The EUCAST breakpoints were used for interpretation with B. fragilis ATCC 25285 as a control. In the two described cases clinical samples were collected for microbiological examination intraoperatively and simultaneously empirical treatment was applied. B. fragilis was isolated in monoculture or in a combination with other bacteria. The treatment was continued according to the susceptibility tests. In a case one clindamycin failure was observed and clindamycin resistance of the isolate was likely due to inadequate time of therapy. Difficulties in collecting an adequate samples and culturing anaerobic bacteria cause that not all infections are properly recognized. In a successful therapy, identification and determination of the susceptibility of the pathogen are essential as well as an appropriate surgical debridement.

The aim of the therapy in open tibial fractures grade III was to cover the bone with soft tissue and achieve healed fracture without persistent infection. Open tibial fractures grade IIIC with massive soft tissue damage require combined orthopaedic, vascular and plastic-reconstructive procedures. Negative-pressure wound therapy (NPWT), used in two consecutive cases with open fracture grade IIIC of the tibia diaphysis, healed extensive soft tissue defect with exposure of the bone. NPWT eventually allowed for wound closure by split skin graft within 21-25 days. Ilizarov external fixator combined with application of recombinant human bone morphogenetic protein-7 at the site of delayed union enhanced definitive bone healing within 16-18 months.