On the Role of Enterococci in the Bloodstream: Results of a Single-Center, Retrospective, Observational Study at a German University Hospital.

This study assesses the clinical relevance of vancomycin-susceptible enterococci in bacteremic patients and compares it with bacteremia due to Staphylococcus aureus and Escherichia coli. During a 5-year-study interval, clinical and diagnostic features of patients with enterococcal bacteremia were compared to those of patients with E. coli or S. aureus bacteremia. Each patient was only counted once per hospital stay. During the 5-year study interval, data from 267 patients with enterococcal bacteremia and from 661 patients with bacteremia due to E. coli or S. aureus were evaluated. In spite of a comparable risk of death, patients with enterococci more frequently needed catecholamines and invasive ventilation. Furthermore, enterococci were more frequently associated with a mixed bacterial flora in bloodstream infections. While fatal sepsis due to E. coli and S. aureus was associated with typical shock symptoms, this association was not confirmed for enterococci. Although enterococcal bacteremia is associated with a risk of dying comparable to that with bacteremia due to E. coli and S. aureus, a lower pathogenic potential of enterococci in bloodstream has to be acknowledged. Enterococci in the bloodstream are more likely to be an epiphenomenon of impending death than its major cause.

Utilizing Moist or Dry Swabs for the Sampling of Nasal MRSA Carriers? An In Vivo and In Vitro Study.

This study investigates the quantitative bacterial recovery of Methicillin-resistant Staphylococcus aureus (MRSA) in nasal screenings by utilizing dry or moistened swabs within an in vivo and an in vitro experimental setting. 135 nasal MRSA carriers were each swabbed in one nostril with a dry and in the other one with a moistened rayon swab. Quantitative bacterial recovery was measured by standard viable count techniques. Furthermore, an anatomically correct artificial nose model was inoculated with a numerically defined suspension of MRSA and swabbed with dry and moistened rayon, polyurethane-foam and nylon-flocked swabs to test these different settings and swab-materials under identical laboratory conditions. In vivo, quantities of MRSA per nostril in carriers varied between <101 and >107 colony forming units, with a median of 2.15x104 CFU. However, no statistically significant differences could be detected for the recovery of MRSA quantities when swabbing nasal carriers with moist or dry rayon swabs. In vitro testing confirmed the in vivo data for swabs with rayon, polyurethane and nylon-flocked tips, since pre-moistening of swabs did not significantly affect the quantities of retrieved bacteria. Therefore, pre-moistening of swabs prior to nasal MRSA sampling provides no advantage in terms of recovering greater bacterial quantities and therefore can be omitted. In addition, this situation can be mimicked in an in vitro model, thereby providing a useful basis for future in vitro testings of new swab types or target organisms for screening approaches.

Neurodegeneration in newborn rats following propofol and sevoflurane anesthesia.

Propofol and sevoflurane are commonly used drugs in pediatric anesthesia. Exposure of newborn rats to a variety of anesthetics has been shown to induce apoptotic neurodegeneration in the developing brain. Newborn Wistar rats were treated with repeated intraperitoneal injections of propofol or sevoflurane inhalation and compared to controls. Brains were examined histopathologically using the De Olmos cupric silver staining. Additionally, a summation score of the density of apoptotic cells was calculated for every brain. Spatial memory learning was assessed by the Morris Water Maze (MWM) test and the hole board test, performed in 7 weeks old animals who underwent the same anesthetic procedure. Brains of propofol-treated animals showed a significant higher neurodegenerative summation score (24,345) when compared to controls (15,872) and to sevoflurane-treated animals (18,870). Treated animals also demonstrated persistent learning deficits in the hole board test, whereas the MWM test revealed no differences between both groups. Among other substances acting via GABAA agonism and/or NMDA antagonism propofol induced neurodegeneration in newborn rat brains whereas a sevoflurane based anesthesia did not. The significance of these results for clinical anesthesia has not been completely elucidated. Future studies have to focus on the detection of safe anesthetic strategies for the developing brain.