Whole genome sequencing reveals a prolonged and spatially spread nosocomial outbreak of Panton-Valentine leucocidin-positive meticillin-resistant Staphylococcus aureus (USA300).

BACKGROUND: Whole genome sequencing (WGS) helps to better investigate the transmission and characterization of meticillin-resistant Staphylococcus aureus (MRSA) strains. AIM: We describe the detection and unfolding of a prolonged and spatially distributed nosocomial outbreak of Panton-Valentine leucocidin (PVL)-positive MRSA ST8 (USA300). METHODS: The outbreak was detected by the combination of whole genome sequence (WGS)-based typing, which is implemented for routine surveillance of multidrug-resistant bacteria in our institution, and in-depth epidemiological investigation. To investigate the source, processes were observed and environmental sampling performed. To contain the outbreak, regular and direct personal contact with the healthcare workers (HCWs) was maintained and staff education implemented. FINDINGS: The outbreak took place between October 2016 and November 2017 and included five patients who were treated in two different departments as inpatients and outpatients; three were infected, two were colonized. Additionally, three HCWs carried the outbreak strain. The strain was not found in the hospital environment. Only through non-mediated communication did the source become apparent. Decolonization of HCWs and infection control measures led to a resolution of the outbreak. CONCLUSION: WGS helped to reveal an outbreak that otherwise might have stayed undetected. Nonetheless, epidemiological investigation is needed to trace the nosocomial transmission. The importance of personal communication in infection control cannot be overstated.

White matter disease in children treated for malignant brain tumors.

OBJECTS: The objects of the study reported were to recognize different patterns of white matter disease (WMD) in the follow-up of children after surgery, radiation and/or chemotherapy for malignant primary brain tumors and to evaluate statistical data on the incidence of WMD and various risk factors. METHODS: Magnetic resonance imaging (MRI) records were evaluated retrospectively in the routine follow-up (range 6 months to 15 years after surgery) of 44 children with malignant primary brain tumors treated with surgery and radiotherapy and/or chemotherapy. RESULTS: WMD was diagnosed in 28 children and subclassified into circumscribed white matter lesions (WML) and diffuse atrophy. WML were the most common finding ( n=13), followed by atrophy ( n=7) and the combination of both ( n=8). Statistical analysis revealed slightly more frequent atrophy in children younger than 5 years. WML could be linked with supratentorial location of the tumor, follow-up longer than 5 years, and the presence of a ventricular shunt. Intrathecal chemotherapy was also a factor, but because of the small sample size of the group this might not be valid. None of the children had neurological deficits attributed to these findings, but the impact on neuropsychological development was not determined.

Decreased apoptosis and increased activation of alveolar neutrophils in bacterial pneumonia.

STUDY OBJECTIVES: The central role of apoptosis in the regulation of lung inflammation is increasingly recognized. The aim of this study was to determine the parameters of cell activation and apoptosis on neutrophils from the circulation and the pulmonary compartment in patients with community-acquired pneumonia (CAP), and to assess the role of the Fas system and of complement-regulating molecules in this context. DESIGN AND METHODS: The study population consisted of nine patients with CAP (group 1) and six age-matched control patients without evidence of bronchopulmonary inflammation (group 2). Apoptosis rate and expression of CD11b, CD16, CD55, CD59, CD95, and CD114 surface molecules on systemic and bronchoalveolar neutrophils were assessed ex vivo using fluorescence-activated cell sorter analysis. RESULTS: In patients with CAP, we found a significant decrease of the mean apoptosis rate in pulmonary neutrophils compared to systemic neutrophils, without concomitant changes in Fas expression. In contrast, cell activation markers were significantly increased on pulmonary cells (CD11b, 288 +/- 98.2 relative mean fluorescence intensity [rMFI] vs 53.8 +/- 10.8 rMFI on peripheral cells), and similar changes were observed with respect to the expression of complement-regulating molecules. Pulmonary polymorphonuclear neutrophils of the control group showed analogous changes, compared to systemic neutrophils, but a significantly higher rate of apoptosis and a lower increase of activation-marker expression were found, compared to pulmonary neutrophils of patients with pneumonia. CONCLUSIONS: Pulmonary neutrophils from patients with CAP show a decreased rate of apoptosis and increased activation status in the alveolar compartment, which may be important for effective control of pulmonary inflammation.