Ireneusz Babiak

Characterization of transcription within sdr region of Staphylococcus aureus

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.

Open tibial fractures grade IIIC treated successfully with external fixation, negative-pressure wound therapy and recombinant human bone morphogenetic protein 7

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.

Infection of Joint Prosthesis and Local Drug Delivery

The rapidly raising number of joint arthroplasties performed around the world yearly is accompanied by the certain percentage of different complications. The infection of the implant is one of the most important clinically, both for the patient and for the treating center. The problem of diagnosis and treatment of the postoperative infection is well known, but there is still lack of optimal, precise guidelines for medical action. Different centers developed their own strategies. Many experimental and clinical trials have been already performed to improve the results of treatment and still many promising concepts and methods are under investigation. Many conferences are organized and many materials are published to enable doctors to exchange their experience in fighting the problem (Langlais 2003; Buchholz et al. 1981).

Comparison of Bone Preserving and Radical Surgical Treatment in 32 Cases of Calcaneal Osteomyelitis

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.

Difficulties in identifying the bacterial species from the genus Clostridium in a case of injury-related osteitis

Most Clostridium species are part of saprophytic microflora in humans and animals; however, some are well-known human pathogens. We presented the challenges in identifying the Clostridium species isolated from a patient with an infected open dislocation of the proximal interphalangeal joint of the fourth digit of the right hand. The clinical materials were intraoperative samples collected from a patient diagnosed with an injury-related infection, with soft tissue loss and tendon sheath involvement. The available biochemical, molecular, and genetic techniques were used in identifying the isolated bacteria. The isolated bacterium was shown to have low biochemical activity; hence, it was not definitively identified via biochemical tests Api 20A or Rapid 32A. Vitek 2 and mass spectrometry methods were equally inconclusive. Clostridium tetani infection was strongly suspected based on the bacterium’s morphology and the appearance of its colonies on solid media. It was only via the 16S rRNA sequencing method, which is non-routine and unavailable in most clinical laboratories, that this pathogen was excluded. Despite appropriate pre-laboratory procedures, which are critical for obtaining reliable test results, the routine methods of anaerobic bacterium identification are not always useful in diagnostics. Diagnostic difficulties occur in the case of environment-derived bacteria of low or not fully understood biological activity, which are absent from databases of automatic bacterial identification systems.

Orthopedic infections caused by obligatory anaerobic Gram-negative rods: report of two cases

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.

Segmental Bone Muscle and Skin Cross Leg Flap for the Treatment of Posttraumatic Infected Segmental Bone Defect in a Child- A Case Report

A mangled limb in a pediatric patient produces therapeutic dilemma whether to amputate or salvage greater than in adult. We herein present a case of a 10 year old child with high energy injury to both lower limbs. The bone muscle and skin segment of the limb planned for amputation has been used as a “spare part” for the contralateral shin defect in order to save at least one weight bearing limb. The cross leg flap has been successful. The patient walks without limp using PTB prosthesis. No recurrence of infection was observed within 10 years post-op. We conclude that the limb salvage attempt in a child should be based more on surgeon decision rather than strict guidelines and is always worth trying.

Intraarticular and serum vancomycin concentration added to acrylic cement

BackgroundVancomycin is the antibiotic of choice in therapy of orthopaedic implant infections caused by methicillin-resistant bacteria but its use poses a risk of toxicity, especially in patients with renal insufficiency. Addition of vancomycin to acrylic cement may cause systemic exposition to this drug eluting from cement to serum, which may require high-flux hemodialysis.MethodsA patient hemodialysed twice a week underwent implantation of a spacer due to methicillin-resistant S. epidermidis infection of knee prosthesis. The spacer was made of acrylic cement loaded with 0,55 g of gentamicin per 40 g of cement and 6 g of vancomycin into totally 120 g of cement. The measurements of vancomycin concentration in serum within 9 days and in intraarticular fluid within 2 days were performed.ResultsMaximal intraarticular vancomycin concentration was reached 7 hours after surgery ( 120 μg/ mL) and was over Minimal Inhibitory Concentration for 47 hours. The serum concentration reached maximal value (2,6 μg/mL) 13 hours after implantation of spacer and was 2,3 μg/mL on 9-th postoperative day.ConclusionThis composition of acrylic cement spacer containing gentamicin and vancomycin was found therapeutically effective and not necessitating high-flux hemodialysis in a hemodialysed patient with chronic renal failure.