The human pathogen Staphylococcus aureus is renowned for the rapid colonization of contaminated wounds, medical implants, and food products. Nevertheless, little is known about the mechanisms that allow S. aureus to colonize the respective wet surfaces. The present studies were therefore aimed at identifying factors used by S. aureus cells to spread over wet surfaces, starting either from planktonic or biofilm-associated states. Through proteomics analyses we pinpoint phenol-soluble modulins (PSMs) as prime facilitators of the spreading process. To dissect the roles of the eight PSMs produced by S. aureus, these peptides were chemically synthesized and tested in spreading assays with different psm mutant strains. The results show that PSM␣3 and PSM␥ are the strongest facilitators of spreading both for planktonic cells and cells in catheter-associated biofilms. Compared to the six other PSMs of S. aureus, PSM␣3 and PSM␥ combine strong surfactant activities with a relatively low overall hydropathicity. Importantly, we show that PSM-mediated motility of S. aureus facilitates the rapid colonization of wet surfaces next to catheters and the colonization of fresh meat. S taphylococcus aureus is an opportunistic human pathogen thatcan cause a wide range of acute and chronic diseases, which range from superficial skin infections to life-threatening endocarditis and sepsis (1, 2). The ability of this Gram-positive bacterium to cause these infections depends on the production of secreted and cell wall-associated virulence factors. Of increasing concern is the ability of S. aureus to acquire resistance against antibiotics, as underscored by the global spread of methicillin-resistant S. aureus (MRSA) lineages.Intriguingly, recent proteomics studies have revealed an enormous diversity in the production of virulence factors by different isolates of S. aureus, and only a few of these seem to be invariantly produced (3-5). Among the most commonly identified staphylococcal virulence factors, especially in the community-associated (CA)-MRSA lineages, are the so-called phenol-soluble modulins (PSMs) (6). These PSMs are short, amphipathic, ␣-helical peptides that have leukocidal activity and biosurfactant properties (7-9). The growth media of S. aureus cultures contain both N-terminally formylated and deformylated PSMs, suggesting that these virulence factors are substrates for the bacterial N-formylmethionine deformylase (9, 10).To date, eight PSMs have been identified in S. aureus. These include the four PSM␣1 to PSM␣4 peptides (22 residues each), the PSM␤1 and PSM␤2 peptides (44 residues each), PSM␥ (25 residues) and the recently reported PSM-mec (22 residues). The PSM␣ peptides are encoded by the psm␣ operon, the PSM␤ peptides by the psm␤ operon, and PSM␥ by the hld gene. Notably, the hld gene is embedded within the regulatory RNAIII molecule that is encoded by the agr locus. The gene for PSM-mec was identified in MRSA strains carrying the staphylococcal cassette chromosome mec (SCCmec) types II or III. The expression of all ps...

In a prospective study, the effects of elevation surgery of the maxillary sinus floor on maxillary sinus physiology were assessed. Seventeen consecutive patients without preoperative anamnestic, clinical and radiological signs of maxillary sinusitis underwent sinus floor elevation surgery with iliac crest bone grafts. All patients were subjected to unilateral endoscopic examination of the maxillary sinus, taking of a biopsy specimen from the sinus floor mucosa, and collection of a sinus lavage-fluid aspirate. This triad of evaluations was performed immediately preceding the elevation procedure, and 3 months (at implant insertion) and 9 months (at uncovering of implants) postoperatively. All procedures were performed under general anesthesia. Preoperatively, three out of 17 patients showed pre-existing mucosal pathology endoscopically, while the 3- and 9-month results revealed the presence of mucosal pathology in four and two patients, respectively. The 3-month microbiological evaluation showed a significant increase in cultures with bacterial growth, while the 9-month culture results were comparable to the preoperative status of the maxillary sinus. Morphologically, neither fibrosis nor an altered inflammatory response or thickening of the epithelium and lamina propria was observed postoperatively. The number of goblet cells in the epithelial layer was increased. From this study it is concluded that the effect of maxillary sinus floor elevation surgery with autogenous bone grafts does not appear to have clinical consequences in patients without signs of pre-existing maxillary sinusitis.

Mucositis is an acute inflammation of the oral mucosa because of radiotherapy and/or chemotherapy. All patients receiving radiotherapy in the head and neck region develop oral mucositis. The aim of this study was to analyse the effects of selective oral flora elimination on radiotherapy-induced oral mucositis, in a double-blind, randomised, placebo-controlled trial. Sixty-five patients with a malignant tumour in the head and neck regions to be treated with primary curative or postoperative radiotherapy participated in this study. The patients received either the active lozenges of 1 g containing polymyxin E 2 mg, tobramycin 1.8 mg and amphotericin B 10 mg (PTA) (33 patients) or the placebo lozenges (32 patients), four times daily during the full course of radiotherapy. Mucositis, changes in the oral flora, quality of feeding and changes of total body weight were assessed. Mucositis score did not differ between the groups during the first 5 weeks of radiotherapy. Nasogastric tube feeding was needed in six patients (19%) of the placebo group and two patients (6%) of the PTA group (P ¼ 0.08). Mean weight loss after 5 weeks of radiation was less in the PTA group (1.3 kg) (s.d.: 3.0) than in the placebo group (2.8 kg) (s.d.: 2.9) (P ¼ 0.05). Colonisation index of Candida species and Gram-negative bacilli was reduced in the PTA group and not in the placebo group (Po0.05). No effect on other microorganisms was detected. In conclusion, selective oral flora elimination in head and neck irradiation patients does not prevent the development of severe mucositis.

Our results showed that modern bronchoscopic techniques such as PSB and PBAL did not yield better diagnostic results compared to BAL in granulocytopenic patients with hematologic malignancies and pulmonary infiltrates. In approximately half of the cases a presumptive diagnosis was made by bronchoscopic procedures.