A 51-year-old Caucasian woman was admitted to the Rheumatology Department of our hospital due to a 3-week history of diffuse neck, shoulder and upper torso pain, exacerbated by movements. An outpatient trial of non-steroidal anti-inflammatory medications had been unsuccessful. A few days later, the pain was localised above the manubrium, the left clavicle and sternomastoid muscle and fever up to 39.5°C was reported. The patient had no significant past medical history and lived in a suburban area. She did not work and liked to do gardening in her spare time. There was no history of local trauma or any medications. On examination, there was intense redness, tenderness and swelling of the manubrium and the left sternoclavicular joint. Chest CT revealed osteolytic changes of the manubrium and presence of inflammatory tissue surrounding the manubrium and extending posteriorly. The lung parenchyma was unaffected. Brain and abdominal CT were unremarkable. A triple-phase bone scan was indicative of sternal osteomyelitis without other bone involvement. Blood and urine cultures remained negative. The patient was empirically treated with high-dose intravenous vancomycin and ciprofloxacin with no response. Antibody testing to human immunodeficiency virus and hepatitis viruses was negative. An open biopsy was performed 1 week later, revealing persistent inflammatory tissue around the sternum and fluid collection posteriorly. Multiple bone specimens were sent for histological examination and cultures. Histology showed acute and chronic granulomatous inflammation, while both cultures of the bone marrow and the fluid revealed Nocardia nova. No other pathogen was identified. The patient responded to high-dose intravenous trimethoprim-sulfamethoxazole, which was continued on an outpatient basis for 1 year without further sequelae.

This is the first reported case of primary sternal osteomyelitis due to Nocardia species. The possibility of nocardiosis needs to be included in the differential diagnosis of sternal osteomyelitis, even for apparently immunocompetent adults.

Introduction The aim of this study was firstly to investigate the prevalence of icaABCD-operon which codes the production of the polysaccharide intracellular adhesin(PIA), responsible for biofilm production, in a collection of clinically significant staphylococci isolated from orthopaedic infections and secondly to assess the relationship between biofilm production and the presence or not of ica-operon.

First Step – Material & Methods Between 1/2003 and 12/2005 200 CoNS were isolated from orthopaedic patients associated with soft tissue and bone infections(group I) and 200 CoNS from blood cultures of hospitalized patients from different wards of the same Hospital(group II). Identification was carried out by Gram-stain, catalase and coagulase tests and the API Staph System. Detection of icaADBC genes was performed by PCR. Production of biofilm was tested by the method of Christensen.

Results In group I, 62(31.37%) carried the entire ica-operon; from these isolates biofilm formation was detected in 35(17.5%). 5 isolates, despite biofilm production, did not carry any gene of ica-operon. In group II, 70(35.5%) carried entire the ica-operon; biofilm formation was detected in 37(18.5%) of these isolates. 3 S. capitis, 1 S. epidermidis and 1 S. hominis carried only the icaADB, icaA and icaB genes respectively.

Second Step – Material & Methods Based on the observation of PIA-production only in (50%) of ica(+) CoNS, 20 S. epidermidis isolates recovered from clinical specimens (pus) of orthopaedic patients and belonging to distinct PFGE clones, were selected on the basis of the presence of the entire ica operon. Nevertheless, only 10 of them produced biofilm. Nucleotide sequence analysis of ica-operon was carried out in all isolates; expression of icaADBC genes was also tested by RT-PCR.

Results Sequencing analysis revealed that all isolates carried an intact ica-operon, without point mutations. Concerning icaADBC mRNA production, all genes of ica-operon were expressed in biofilm-producing isolates, whereas in the no-biofilm producing strains the icaA and icaC genes were not expressed, while a faint expression was observed for the icaB and icaD genes.

Discussion Biofilm-forming capacities of CoNS from orthopaedic infections was not significantly greater than those from other infections (p> 0,05). The capacity of ica-operon(+) staphylococcal isolates to form biofilm seems to be dependent on the expression of ica-genes, specifically of icaA and icaC. The inability of ica(+) isolates to produce biofilm emphasizes that some unknown mechanisms influence icaADBC expression. Finally, the recognition of biofilm-producing CoNS without carrying any gene of ica operon underlined the existence of unidentified also mechanisms controlling biofilm production, apart from icaADBC expression.

Aim: The purpose of this study was to evaluate the prevalence of methicillinresistant Staphylococcus aureus (MRSA) isolates in the Orthopaedic Department of a new University Hospital, two years from its opening. Methods: Forty-three consecutive S. aureus isolates, collected from cultures (pus 90%) from consecutive orthopaedic inpatients were included in the study. Resistance to antimicrobial agents was assessed by the disk diffusion method. The mecA-gene was detected by PCR assay, whereas molecular typing of the isolates was performed by PFGE. Results: Only 5 of the 43 strains (11.6%) expressed high level resistance to oxacillin (MIC ≥ 64mg/L). All these isolates possessed mecA-gene and exhibited resistance, except oxacillin, to more than four classes antimicrobial groups. The remaining 38 isolates (34 beta-lactamase positive) were susceptible to oxacillin (MIC ≤ 2mg/L), and expressed a less resistant type than that of MRSA. Molecular typing by PFGE showed apparent heterogeneity among isolates and the absence of predominant clones. Conclusions: The 11.6% prevalence of MRSA is well below the reported average in the literature. Apparently the isolates originated from different sources of contamination. All patients had previous hospitalizations, where they acquired the infections and subsequently transferred the MRSAs to our department. Precautions and measures taken in the wards limited the spread and dissemination of the isolates as demonstrated by the heterogeneity and the absence of predominant clones. These þndings further reiterate the value of the low-cost, standard preventive procedures to control nosocomial infections in a high-risk orthopaedic department.

Purpose: The purpose of this study was to evaluate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) isolates in the Orthopaedic Department of a new University Hospital, two years from its opening.

Material and Methods: Forty-three consecutive S. aureus isolates, collected from cultures (pus 90%) from consecutive orthopaedic inpatients were included in the study. Resistance to antimicrobial agents was assessed by the disk diffusion method. The mecA-gene was detected by PCR assay, whereas molecular typing of the isolates was performed by PFGE.

Results: Only 5 of the 43 strains (11.6%) expressed high level resistance to oxacillin (MIC ≥ 64mg/L). All these isolates possessed mecA-gene and exhibited resistance, except oxacillin, to more than four classes antimicrobial groups. The remaining 38 isolates (34 beta-lactamase positive) were susceptible to oxacillin (MIC ≤ 2mg/D, and expressed a less resistant type than that of MRSA. Molecular typing by PFGE showed apparent heterogeneity among isolates and the absence of predominant clones. Conclusions: The 11.6% prevalence of MRSA is well below the reported average in the literature. Apparently the isolates originated from different sources of contamination. All patients had previous hospitalizations, where they acquired the infections and subsequently transferred the MRSAs to our department.

Precautions and measures taken in the wards limited the spread and dissemination of the isolates as demonstrated by the heterogeneity and the absence of predominant clones. These findings further reiterate the value of the low-cost, standard preventive procedures to control nosocomial infections in a high-risk orthopaedic department.