Molecular epidemiology of the nasal colonization by methicillin-susceptible Staphylococcus aureus in Swiss children

Nasal carriage of Staphylococcus aureus contributes to an increased risk of developing an infection with the same bacterial strain. Genetic regulatory elements and toxin-expressing genes are virulence factors associated with the pathogenic potential of S. aureus. We undertook an extensive molecular characterization of methicillin-susceptible S. aureus (MSSA) carried by children. MSSA were recovered from the nostrils of children. The presence of Panton-Valentine leukocidin (PVL), exfoliatins A and B (exfoA and exfoB), and the toxic-shock staphylococcal toxin (TSST-1) and agr group typing were determined by quantitative PCR. A multiple-locus variable-number of tandem repeat analysis (MLVA) assay was also performed for genotyping. Five hundred and seventy-two strains of MSSA were analysed. Overall, 30% were positive for toxin-expressing genes: 29% contained one toxin and 1.6% two toxins. The most commonly detected toxin gene was tst, which was present in 145 (25%) strains. The TSST-1 gene was significantly associated with the agr group 3 (OR 56.8, 95% CI 32.0-100.8). MLVA analysis revealed a large diversity of genetic content and no clonal relationship was demonstrated among the analysed MSSA strains. Multilocus sequence typing confirmed this observation of diversity and identified ST45 as a frequent colonizer. This broad diversity in MSSA carriage strains suggests a limited selection pressure in our geographical area.

Horizontal partial laryngectomy for supraglottic squamous cell carcinoma

Between 1981-1999, 75 patients treated for supraglottic SCC with horizontal supraglottic laryngectomy (HSL) at the Otolaryngology Head and Neck Surgery Department of Lausanne University Hospital were retrospectively studied. There were 16 patients with T1, 46 with T2 and 13 with T3 tumors. Among these, 16 patients (21%) had clinical neck disease corresponding to stage I, II, III and IV in 12, 39, 18 and 6 patients, respectively. All patients had HSL. Most patients had either elective or therapeutic bilateral level II-IV selective neck dissection. Six patients (8%) with advanced neck disease had ipsilateral radical and controlateral elective II-IV selective neck dissections. Adjuvant radiotherapy was given to 25 patients (30%) for either positive surgical margins (n=8), pathological nodal status (n=14) or both (n=3). Median follow-up was 48 months (range, 24-199). Five-year disease-specific survival and locoregional and local control were 92, 90 and 92.5%, respectively. Among five patients who were diagnosed with local recurrence, one had a total laryngectomy (1.4%); the others were treated by endoscopic laser surgery. Two patients had both a local and regional recurrence. They were salvaged with combined surgery and radiotherapy, but eventually died of their disease. Cartilage infiltration seems to influence both local control (P=0.03) and disease-specific survival (P=0.06). There was a trend for worse survival with pathological node involvement (P=0.15) and extralaryngeal extension of the cancer (P=0.1). All patients except one recovered a close to normal function after the treatment. Aspiration was present in 16 patients (26%) in the early postoperative period. A median of 16 days (7-9) was necessary to recover a close to normal diet. Decannulation took a median of 17 days (8-93). Seven patients kept a tracheotomy tube for up to 3 months because of persistent aspiration. There was no permanent tracheostomy or total laryngectomy for functional purposes. Horizontal supraglottic laryngectomy remains an adequate therapeutic alternative for supraglottic squamous cell carcinoma, offering an excellent oncological outcome. The postoperative functional morbidity is substantial, indicating the need for careful patient selection, but good laryngeal function recovery is the rule. The surgical alternative is endoscopic laser surgery, which may offer comparable oncological results with less functional morbidity. Nevertheless, these two different techniques need to be compared prospectively.

[Long-term complications of radiotherapy after mandibular reconstruction with vascularized bnoe graft]

INTRODUCTION

The use of vascularised composite free flaps (VCFF) has become a widely accepted method for primary reconstruction of mandibular defects. Adjuvant or neo-adjuvant radiotherapy (RTH) increases susceptibility to trauma and infections. The aim of this study is to compare the incidence of local complications after mandibular reconstruction with vascularised composite free flaps, related to pre- or postoperative radiotherapy. The effects of these complications on functional rehabilitation with a dental prosthesis fixed on bone implants are also studied.

METHODS

Between 1990 and 1999, 49 vascularised composite free flaps were used for mandibular reconstructions (41 iliac crest flaps and 8 fibula flaps). 31 patients (63%) underwent preoperative (8) or postoperative (23) radiotherapy. Short (6-12 months) and long-term (over 12 months) outcomes are analysed separately. The incidence of complications depending on the timing of radiotherapy (neo vs adjuvant) was compared.

RESULTS

In the first 12 months the complication rates among the irradiated and non-irradiated patients were 26 and 11% respectively. During short-term evaluation complications were seen in 26% of the irradiated patients and 11% of the non-irradiated group. After 12 months the rate of complications rises to 45% for the irradiated and 18% for the non-irradiated patients. 27% of irradiated patients presented with fistula, 27% with exposed metallic plates and 9% developed osteoradionecrosis of the graft. Dental implants were inserted in 29 grafts, among which 9 had secondary radiotherapy. 90% of the non-irradiated patients and 56% of the irradiated patients chewed with the dental prosthesis fixed on bone implants.

DISCUSSION

Regardless of pre- or postoperative timing, radiotherapy clearly augments complications, the incidence of which increases with time. Only in one patient did osteoradionecrosis necessitate removal of the dental prostheses. Inability to chew is linked more to the amount of resection of the mobile tongue than to complications of radiotherapy. We therefore recommend systematically placing dental implants during the initial surgery, unless large soft tissue resection preventing adequate swallowing is required.

[Madelung disease and obstructive sleep apnea syndrome: apropos of a case]

Madelung's disease, or benign symmetric lipomatosis, is an uncommon disease. It is an unencapsulated fatty infiltration which in rare cases extends into the perilaryngeal space and mediastinum. The authors present a case complicated by an obstructive syndrome and sleep apnoea syndrome, which was successfully treated by continuous positive airway pressure. The literature is reviewed.