Modeling the effect of antibiotic exposure on the transmission of methicillin-resistant Staphylococcus aureus in hospitals with environmental contamination.

In this paper both deterministic and stochastic models are developed to explore the roles that antibiotic exposure and environmental contamination play in the spread of antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), in hospitals. Uncolonized patients without or with antibiotic exposure, colonized patients without or with antibiotic exposure, uncontaminated or contaminated healthcare workers, and free-living bacteria are included in the models. Under the assumption that there is no admission of the colonized patients, the basic reproduction number R0 is calculated. It is shown that when R0 < 1, the infection-free equilibrium is globally asymptotically stable; when R0 > 1, the infection is uniformly persistent. Numerical simulations and sensitivity analysis show that environmental cleaning is a critical intervention, and hospitals should use antibiotics properly and as little as possible. The rapid and efficient treatment of colonized patients, especially those with antibiotic exposure, is key in controlling MRSA infections. Screening and isolating colonized patients at admission, and improving compliance with hand hygiene are also important control strategies.

Preparation and evaluation of a sustained-release buckwheat noodle.

BACKGROUND: Different carbohydrates elicit various effects on the digestibility and the glucose release rate, so it is of interest to develop a sustained-release noodle based on the combination of different carbohydrates and reveal the sustained-release mechanism. RESULTS: The data obtained suggest that xanthan and konjac gum exhibited excellent and synergistic sustained-release properties, whereas cornstarch showed the lowest average digestion rate. The sustained release was particularly evident when the noodle consisted of the following components: 50 g of 25 g kg(-1) hydrophilic colloid mixture solution composed of a 1:1 mass ratio of xanthan:konjac gum and 100 g of reconstructed flour consisting of 200 g kg(-1) buckwheat flour, 400 g kg(-1) cornstarch, and 400 g kg(-1) plain flour. The morphological structure of noodles revealed that the composite hydrophilic colloids strengthened the interaction between the gluten network and starch granules. This buried starch within the three-dimensional structure thereby releasing glucose in a slow and sustained way. The most suitable model to describe glucose release from noodles was the Ritger-Peppas equation, which revealed that matrix erosion contributed to the release mechanism. CONCLUSION: These findings indicate that the controlled use of hydrophilic colloids and starches in manufacturing noodles could modulate the glucose sustained-release. © 2015 Society of Chemical Industry.