After ileocolectomy, colonization of the neoterminal ileum is increased. Our data suggest that increases in the populations of specific bacteria such as E. coli, enterococci, bacteroides, and fusobacteria may be important in postoperative recurrence of Crohn's disease.

To determine if there is any change with age in the distribution of Bi dobacterium and Enterobacteriaceae species in human intestinal micro ora, strains were isolated from a total of 54 samples of human faeces (15 children, 3-15 years old; 17 adults, 30-46 years old; 22 elderly, 69-89 years old). The bi dobacteria were identi ed at species level using a numerical phenotypic identi cation system developed on the Internet (http:::kounou.lille.inra.fr) and DNA-DNA hyridization. The enterobacteria were identi ed using the API 20E system (Biomérieux, France). Escherichia coli was present in 93% of samples. Enterobacter and Klebsiella species were more frequently found in children while Proteus and Pro×idencia species were typically found in the elderly. The species Bi dobacterium longum was the most frequently species isolated in children and adults, whereas Bi dobacterium adolescentis was the most encountered species in the elderly. The distribution of B. adolescentis was signi cantly split between the children and the elderly age groups. There is a noticeable trend whereby Bi dobacterium pseudocatenulatu m occurs more frequently in children than in the elderly. The species Bi dobacterium infantis, Bi dobacterium gallicum and Bi dobacterium angulatum have never been isolated, while Bi dobacterium bre×e has only been isolated on one occasion.

No abstract

This article is a review of how to quantify mold spoilage and consequently shelf life of a food product. Mold spoilage results from having a product contaminated with fungal spores that germinate and form a visible mycelium before the end of the shelf life. The spoilage can be then expressed as the combination of the probability of having a product contaminated and the probability of mold growth (germination and proliferation) up to a visible mycelium before the end of the shelf life. For products packed before being distributed to the retailers, the probability of having a product contaminated is a function of factors strictly linked to the factory design, process, and environment. The in-factory fungal contamination of a product might be controlled by good manufacturing hygiene practices and reduced by particular processing practices such as an adequate air-renewal system. To determine the probability of mold growth, both germination and mycelium proliferation can be mathematically described by primary models. When mold contamination on the product is scarce, the spores are spread on the product and more than a few spores are unlikely to be found at the same spot. In such a case, models applicable for a single spore should be used. Secondary models can be used to describe the effect of intrinsic and extrinsic factors on either the germination or proliferation of molds. Several polynomial models and gamma-type models quantifying the effect of water activity and temperature on mold growth are available. To a lesser extent, the effect of pH, ethanol, heat treatment, addition of preservatives, and modified atmospheres on mold growth also have been quantified. However, mold species variability has not yet been properly addressed, and only a few secondary models have been validated for food products. Once the probability of having mold spoilage is calculated for various shelf lives and product formulations, the model can be implemented as part of a risk management decision tool.