Incorporating prior knowledge improves detection of differences in bacterial growth rate

BACKGROUND: Robust statistical detection of differences in the bacterial growth rate can be challenging, particularly when dealing with small differences or noisy data. The Bayesian approach provides a consistent framework for inferring model parameters and comparing hypotheses. The method captures the full uncertainty of parameter values, whilst making effective use of prior knowledge about a given system to improve estimation. RESULTS: We demonstrated the application of Bayesian analysis to bacterial growth curve comparison. Following extensive testing of the method, the analysis was applied to the large dataset of bacterial responses which are freely available at the web-resource, ComBase. Detection was found to be improved by using prior knowledge from clusters of previously analysed experimental results at similar environmental conditions. A comparison was also made to a more traditional statistical testing method, the F-test, and Bayesian analysis was found to perform more conclusively and to be capable of attributing significance to more subtle differences in growth rate. CONCLUSIONS: We have demonstrated that by making use of existing experimental knowledge, it is possible to significantly improve detection of differences in bacterial growth rate

EFSA Panel on Biological Hazards (BIOHAZ); Scientific Opinion on public health risks represented by certain composite products containing food of animal origin

This Opinion reviews the factors that affect microbial survival and growth in composite products, and in foods in general. It concludes that the main factors to be considered are: water activity, pH, temperature and duration of storage, processing, and intensity and duration of other non-thermal physical processes applied. Prevalence and concentration of the pathogens in food are important to determine the risk for consumers. The opinion presents a review of the quantitative microbiology models and databases that can be used to provide quantitative estimations of the impact of the above factors on the survival and growth of the main bacterial pathogens. In composite products, migration and diffusion of moisture and substances among the ingredients may change their physico-chemical parameters, particularly at the interfaces. Therefore, the assessment of the risk posed by composite products needs to consider the combinations of parameters most permissive to survival and growth of pathogens. Two complementary approaches are proposed for the identification and profiling of microbiological hazards in different specific composite products. The first one is based on past outbreaks and prevalence of hazards in the products and leads to the conclusion that the most frequent hazard-composite product combinations are Salmonella in cakes and bakery products. The second one consists in decision tools based on the impact on the pathogens of food composition and food processing. Categorisation of the risk for composite products requires information on their composition, processing and further handling, which can largely differ for foods belonging to the same category. Further conditions may influence the risk and should be verified, i.e. hygienic conditions during preparation of the composite products and their ingredients, shelf-life conditions, and reliability of cooking by consumers to inactivate pathogens. The decision tools developed apply to all composite products considered by the mandate, as well as to all other foods. © European Food Safety Authority, 201

Cholesterol efflux from Fu5AH hepatoma cells induced by plasma of subjects with or without coronary artery disease and non-insulin-dependent diabetes: Importance of LpA-I:A-II particles and phospholipid transfer protein

We measured the capacity of human plasma to induce cholesterol efflux from Fu5AH rat hepatoma cells in four groups of men with or without non-insulin-dependent diabetes mellitus (NIDDM) and coronary artery disease (CAD). Plasma from men with both NIDDM and CAD (n = 47) had the lowest efflux capacity (17.3 \ub1 3.6%) whereas healthy control subjects with neither diabetes nor CAD (n = 25) had the highest capacity (19.8 \ub1 3.4%). The groups with CAD but no diabetes (n = 44) and with NIDDM but no CAD (n = 35) had intermediate efflux values (18.5 \ub1 3.8 and 18.5 \ub1 3.9%, respectively). In a 2 x 2 factorial ANOVA, the differences were significant with respect to the presence of CAD (P = 0.038) and NIDDM (P = 0.041), with no interaction between the factors. The concentration of HDL particles containing apolipoprotein (apo) A-I but no apo A-II (LpA-I) was not related to efflux capacity in univariate or multivariate analyses. A multivariate regression analysis showed that when controlled for the presence of NIDDM and CAD, the concentration of particles containing both apo A-I and apo A-II (LpA-I:A-II) and plasma phospholipid transfer protein activity were both positively, independently, and significantly (P < 0.001) related to cholesterol efflux capacity

Maintenance therapies in metastatic pancreatic cancer: present and future with a focus on PARP inhibitors

International audienceMetastatic pancreatic ductal adenocarcinomas (PDACs) are now more effectively controlled using chemotherapy combinations such as FOLFIRINOX and gemcitabine plus nab-paclitaxel (NabP) regimens with a subset of patients who achieve a sustained tumor stabilization or response. The next challenge is to design maintenance therapies that result in continued tumor control with minimal toxicity. Quality of life should always be a priority in these patients with prolonged survival. Gradually tapering off the intensity of chemotherapy by suppressing drug(s) in the combination is one option. Thus, maintenance with 5-fluorouracil or gemcitabine as single agents after FOLFIRINOX or gemcitabine-NabP induction, respectively, seems to be a promising approach to minimize neurotoxicity while maintaining efficacy. Another option is to introduce maintenance drug(s) with different anti-tumoral actions. The recent example of olaparib in patients with BRCA mutated PDAC provides a promising proof-of-concept of a switch maintenance strategy in this setting