Francis F. Busta

Carbohydrate source and bifidobacteria influence the growth of Clostridium perfringens in vivo and in vitro

Abstract The purpose of this study was to test the effects of administering bifidobacteria with either 2% fructooligosaccharide (FOS), 2% wheat bran oligosaccharide (WBOS), 2% soybean oligosaccharide (SBOS) or no added oligosaccharide (control) on cecal populations of bifidobacteria and C. perfringens , a potential pathogen and normal inhabitant of the mammalian colon, in the rat. Rats were randomly assigned to one of four treatment groups: basal diet + 1 ml daily gavage of skim milk containing 10 8 bifidobacteria, 2% FOS + bifidobacteria, 2% SBOS + bifidobacteria or 2% WBOS + bifidobacteria. The rats were fed the diets for 4 wk, after which cecal concentrations of bifidobacteria and C. perfringens were assessed. WBOS and SBOS feeding resulted in higher concentrations of bifidobacteria and C. perfringens relative to FOS-feeding or control. However, no differences in either bifidobacteria or C. perfringens were detected between control and FOS groups. Parallel to this animal study, in vitro competition experiments with bifidobacteria and C. perfringens were performed in growth media containing either glucose, FOS or WBOS as the primary carbon source. The concentrations of bifidobacteria and C. perfringens were determined at each hour for 10 h and specific growth rates (μ) were calculated. The μ for C. perfringens , co-cultured with bifidobacteria in glucose-based or WBOS-based media was significantly decreased relative to C. perfringens alone. However, no significant difference was found between the μ for C. perfringens co-cultured in FOS-based media with bifidobacteria and the C. perfringens grown alone in FOS-based media. These findings indicate that different oligosaccharides have differential effects on the populations of bifidobacteria and C. perfringens in vivo and that certain oligosaccharides may potentiate an inhibitory action of bifidobacteria against C. perfringens .

Defending the Safety of the Global Food System from Intentional Contamination in a Changing Market

Intentional contamination of the food supply poses a real and potentially catastrophic threat to society. Overall, it has the potential to result in disastrous and far-reaching effects, including direct morbidity and/or mortality, disruption of food distribution, loss of consumer confidence in government and the food supply, business failures, trade restrictions, and ripple effects on the economy. Key interrelated factors specific to food and the food system create this unusual vulnerability, both structural and social. The efficiency of the food system enables products derived from a wide range of global sources to be sourced, produced, and distributed rapidly due to the speed of national and global just-in-time supply chains. The food industry’s routine food safety measures are not designed to protect against high-impact deliberate contamination. When contamination occurs, identification of its nature and extent may take days, weeks, or even longer. Unintentional foodborne illness can further complicate recognition of intentional contamination events due to the delay in positive association of illnesses to the intentional event. The food/agriculture sector’s infrastructure must be strengthened to mitigate potential harm resulting from deliberate contamination, thereby making the food system less vulnerable to attack or destructive economic outcomes. New upward price pressures, declining economies, and constantly changing global trade along the food system supply chain have introduced a new urgency for greater diligence in food defense against deliberate contamination with either economic or terrorist motives. Initiatives include the development of specific countermeasures to minimize or eliminate vulnerabilities, as well as the development of practical solutions that enhance the capability to rapidly identify, contain, respond to, and recover from intentional contamination, both real and threatened. These activities must encompass the entire worldwide farm-to-table food system, from pre-farm inputs through retail sale, consumer food consumption, and public health system response.