Distinct roles of phenol-soluble modulins in spreading of Staphylococcus aureus on wet surfaces.

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 PSMα3 and PSMγ 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, PSMα3 and PSMγ 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.

Brain abscess associated with Aggregatibacter actinomycetemcomitans: case report and review of literature.

INTRODUCTION: Aggregatibacter actinomycetemcomitans is considered a major pathogen in localized and generalized aggressive periodontitis. A. actinomycetemcomitans has been found in various extra oral infections and most frequently in endocarditis. We report a patient with multiple brain abscesses due to infection with A. actinomycetemcomitans and review the English language literature related to this subject. CASE REPORT: A 42-year-old patient with no underlying medical conditions presented with multiple brain lesions initially thought to be metastatic lesions of a tumour of unknown origin. Findings during drainage and subsequent histopathological conclusions made infection more likely. Culture of drained material remained negative; however, 16S rDNA polymerase chain reaction and sequence analysis on direct material revealed A. actinomycetemcomitans as the causative agent of the infection. The most likely source of infection was the poor dentition of the patient. After repeated drainage of the lesions and antibiotic treatment the patient gradually improved, although cognitive impairment remained. CONCLUSIONS: Our report illustrates that a poor dental condition, notably destructive periodontal disease, can be a risk for life-threatening extra oral disease, and thus contributes to the total inflammatory burden of the body.

Bronchoscopic diagnosis of pulmonary infiltrates in granulocytopenic patients with hematologic malignancies: BAL versus PSB and PBAL.

BACKGROUND: Treatment of patients with hematologic malignancies is often complicated by severe respiratory infections. Bronchoscopy is generally to be used as a diagnostic tool in order to find a causative pathogen. OBJECTIVES: In a prospective study the combination of protected specimen brush (PSB) and protected bronchoalveolar lavage (PBAL) was compared with bronchoalveolar lavage (BAL) for evaluated feasibility and diagnostic yield in granulocytopenic patients with hematologic malignancies and pulmonary infiltrates. METHODS: All specimens from 63 bronchoscopic procedures (35 BAL and 28 PSB-PBAL) were investigated by cytological examination and various microbiological tests. If clinically relevant and feasible, based on the clinical condition and/or the presence of thrombocytopenia, lung tissue samples were obtained. RESULTS: The majority of the 58 included patients were diagnosed as having acute myeloid leukaemia and developed a severe neutropenia (BAL-group: 27 days; PSB-PBAL group: 30 days). Microbiological and cytological examination of 63 bronchoscopic procedures (35 BAL and 28 PSB-PBAL) yielded causative pathogens in 9 (26%) patients of the BAL-group and 8 (29%) patients of the PSB-PBAL group (PSB and PBAL 4 each). Aspergillus fumigatus was the pathogen most frequently (13%) detected. Using all available examinations including the results of autopsy, a presumptive diagnosis was established in 43% of the patients in the BAL group and 57% of those in the PSB-PBAL group; in these cases microbial aetiology was correctly identified in 67% and 57%, respectively. The complication rate was of these procedures were low, and none of the patients experienced serious complications due to the invasive techniques. CONCLUSIONS: 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.

Association of common cold with exacerbations in pediatric but not adult patients with tic disorder: a prospective longitudinal study.

Cross-sectional data and case studies suggest a temporal relationship between fluctuations in tic severity and preceding infections. In this study, we aimed to examine this possible relationship in a prospective longitudinal design. Two groups of tic disorder patients were included, a pediatric group between 7 and 15 years of age (n = 20), and an adult group over 15 years of age (n = 41). During a 24-week period, participants were asked to fill out weekly self questionnaires regarding the presence of tic exacerbations and the experience of the common cold. In addition, 6 throat swabs were taken at monthly intervals and cultured for streptococci; also, 3 serial serum assessments of streptococcal antibodies were performed at 8-week intervals. In the pediatric group, our results indicated a strong association between the self report of a common cold and a symptom exacerbation 4 weeks later (Odds ratio = 4.685; p = 0.001). In the adult group, we found no association between reports of common cold and tic exacerbations. Association with streptococcal infections could not be determined owing to the limited number of observed streptococcal infections. Thus, this study points to a hitherto unknown association of common viral infections with tic exacerbations in children, which may support the involvement of immune dysregulation in tic disorders.

Towards rational use of antibiotics for suspected secondary infections in Buruli ulcer patients.

BACKGROUND: The emerging disease Buruli ulcer is treated with streptomycin and rifampicin and surgery if necessary. Frequently other antibiotics are used during treatment. METHODS/PRINCIPAL FINDINGS: Information on prescribing behavior of antibiotics for suspected secondary infections and for prophylactic use was collected retrospectively. Of 185 patients that started treatment for Buruli ulcer in different centers in Ghana and Bénin 51 were admitted. Forty of these 51 admitted patients (78%) received at least one course of antibiotics other than streptomycin and rifampicin during their hospital stay. The median number (IQR) of antibiotic courses for admitted patients was 2 (1, 5). Only twelve patients received antibiotics for a suspected secondary infection, all other courses were prescribed as prophylaxis of secondary infections extended till 10 days on average after excision, debridement or skin grafting. Antibiotic regimens varied considerably per indication. In another group of BU patients in two centers in Bénin, superficial wound cultures were performed. These cultures from superficial swabs represented bacteria to be expected from a chronic wound, but 13 of the 34 (38%) S. aureus were MRSA. CONCLUSIONS/SIGNIFICANCE: A guide for rational antibiotic treatment for suspected secondary infections or prophylaxis is needed. Adherence to the guideline proposed in this article may reduce and tailor antibiotic use other than streptomycin and rifampicin in Buruli ulcer patients. It may save costs, reduce toxicity and limit development of further antimicrobial resistance. This topic should be included in general protocols on the management of Buruli ulcer.

Tissue is the issue: a solitary cerebral lesion 15 years after kidney transplantation.

Primary toxoplasmosis and reactivation of latent infections occur in solid organ transplant recipients. However, solitary cerebral lesions due to toxoplasmosis are rare. In this case, a patient presented with a haemiparesis and a cerebral lesion. We expected to find cerebral post-transplant lymfoproliferative disorder because of positive Epstein-Barr virus by polymerase chain reaction in cerebrospinal fluid, but histological findings revealed Toxoplasma gondii bradyzoites and tachyzoites, illustrating the necessity of obtaining material for diagnostics in immunocompromised hosts.

Effects of maxillary sinus floor elevation surgery on maxillary sinus physiology.

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.