Biofilm formation on enteral feeding tubes by Cronobacter sakazakii, Salmonella serovars and other Enterobacteriaceae

WHO (2007) recommended that to reduce microbial risks, powdered infant formula should be reconstituted with water at temperatures >70 °C, and that such feeds should be used within 2 h of preparation. However, this recommendation does not consider the use of enteral feeding tubes which can be in place for more than 48 h and can be loci for bacterial attachment. This study determined the extent to which 29 strains of Cronobacter sakazakii, Salmonella serovars, other Enterobacteriaceae and Acinetobacter spp. can adhere and grow on enteral feeding tubes composed of polyvinyl chloride and polyurethane. The study also included silver-impregnated tubing which was expected to have antibacterial activity. Bacterial biofilm formation by members of the Enterobacteriaceae was ca. 105-106 cfu/cm after 24 h. Negligible biofilm was detected for Acinetobacter gensp. 13; ca. 10 cfu/cm, whereas Cr. sakazakii strain ATCC 12868 had the highest biofilm cell density of 107 cfu/cm. Biofilm formation did not correlate with capsule production, and was not inhibited on silver-impregnated tubing. Bacteria grew in the tube lumen to cell densities of 107 cfu/ml within 8 h, and 109 cfu/ml within 24 h. It is plausible that in vivo the biofilm will both inoculate subsequent routine feeds and as the biofilm ages, clumps of cells will be shed which may survive passage through the neonate's stomach. Therefore biofilm formation on enteral feeding tubes constitutes a risk factor for susceptible neonates

Microbiological assessment and evaluation of rehydration instructions on powdered infant formulas, follow-up formulas, and infant foods in Malaysia

A total of 90 samples comprised of powdered infant formulas (51), follow-up formulas (21) and infant foods (18) from 15 domestic and imported brands were purchased from various retailers in Klang Valley, Malaysia and evaluated in terms of microbiological quality and the similarity of rehydration instructions on the product label to guidelines set by the World Health Organization. Microbiological analysis included the determination of aerobic plate count (APC) and the presence of Enterobacteriaceae and Cronobacter spp. Isolates of interest were identified using ID 32E (bioMerieux®). In this study 87% of powdered infant formulas, follow-up formulas and infant foods analyzed had aerobic plate counts below the permitted level of 70°C for formula preparation as specified by the 2008 revised World Health Organization guidelines. Six brands instructed the use of water at 40-55°C, a temperature range which would support the survival and even growth of Enterobacteriaceae

Second order gradient ascent pulse engineering

We report some improvements to the gradient ascent pulse engineering (GRAPE) algorithm for optimal control of quantum systems. These include more accurate gradients, convergence acceleration using the BFGS quasi-Newton algorithm as well as faster control derivative calculation algorithms. In all test systems, the wall clock time and the convergence rates show a considerable improvement over the approximate gradient ascent.Comment: Submitted for publicatio

On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

Scholarly publishing depends on peer reviewers

The peer-review crisis is posing a risk to the scholarly peer-reviewed journal system. Journals have to ask many potential peer reviewers to obtain a minimum acceptable number of peers accepting reviewing a manuscript. Several solutions have been suggested to overcome this shortage. From reimbursing for the job, to eliminating pre-publication reviews, one cannot predict which is more dangerous for the future of scholarly publishing. And, why not acknowledging their contribution to the final version of the article published? PubMed created two categories of contributors: authors [AU] and collaborators [IR]. Why not a third category for the peer-reviewer?Scopu