S ‐Aryl‐ l ‐cysteine sulphoxides and related organosulphur compounds alter oral biofilm development and AI ‐2‐based cell–cell communication

Aims To design and synthesize a library of structurally related, small molecules related to homologues of compounds produced by the plant Petiveria alliacea and determine their ability to interfere with AI ‐2 cell–cell communication and biofilm formation by oral bacteria. Many human diseases are associated with persistent bacterial biofilms. Oral biofilms (dental plaque) are problematic as they are often associated with tooth decay, periodontal disease and systemic disorders such as heart disease and diabetes. Methods and Results Using a microplate‐based approach, a bio‐inspired small molecule library was screened for anti‐biofilm activity against the oral species Streptococcus mutans UA 159 , Streptococcus sanguis 10556 and Actinomyces oris MG 1. To complement the static screen, a flow‐based BioFlux microfluidic system screen was also performed under conditions representative of the human oral cavity. Several compounds were found to display biofilm inhibitory activity in all three of the oral bacteria tested. These compounds were also shown to inhibit bioluminescence by Vibrio harveyi and were thus inferred to be quorum sensing ( QS ) inhibitors. Conclusion Due to the structural similarity of these compounds to each other, and to key molecules in AI ‐2 biosynthetic pathways, we propose that these molecules potentially reduce biofilm formation via antagonism of QS or QS ‐related pathways. Significance and Impact of the Study This study highlights the potential for a non‐antimicrobial‐based strategy, focused on AI ‐2 cell–cell signalling, to control the development of dental plaque. Considering that many bacterial species use AI ‐2 cell–cell signalling, as well as the increased concern of the use of antimicrobials in healthcare products, such an anti‐biofilm approach could also be used to control biofilms in environments beyond the human oral cavity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109321/1/jam12616.pd

The Environmental and Economic Impact of Withdrawing Antibiotics from US Broiler Production

Rising consumer interest in how food is produced has resulted in the growth of antibiotic-free meat production and consumption. The antibiotic-free classification is most prominent in the poultry market as several producers and retail-chain companies have moved their marketing in that direction. This study examines the environmental and economic impacts of withdrawing antibiotics (including animal-only ionophores) from U.S. broiler production. Two systems—conventional and 100% antibiotic-free (ABF)—are modeled, examining differences between average survivability, space requirements, days to grow-out a defined sized bird, and days between production cycles. Data were obtained from the USDA, industry sources (e.g., Agri Stats, Vantress, Aviagen), and expert knowledge. Total output is calculated to compare the average quantity of edible broiler meat produced within each system. Results reveal a decline in average production in the ABF system for a given broiler house compared to the conventional system. Compared to broilers produced in a conventional system, birds raised in a single broiler house under ABF conditions will have an annual reduction of between 50,000–100,000 lbs of edible meat (breast, legs, thighs, wings) equivalent to between 265,000–530,000 individual 3 oz. single servings. This loss represents enough to feed 600–1,000 people annually, based on average annual consumption of chicken in the United States in 2012. In order to maintain the same supply of meat under ABF conditions, a typical broiler house will require between 15,000–33,000 more marketed broilers per year. Due to the additional broilers needed, eliminating antibiotic use has an environmental impact. Compared to a conventional house, chickens raised in a single broiler house under ABF conditions will require between 185,000–390,000 additional lbs. of feed per a year; between forty-two and ninety additional acres a year to produce that feed; between 33,000 and 78,000 additional gallons of water consumed; and between 157,000 and 333,000 additional tons of manure produced. In addition, the cost to produce edible prime meat in a broiler house under ABF conditions is between $52,000 and$110,000 per year.Findings suggest that eliminating the use of antibiotics in the raising of broilers may have a negative effect on the conservation of natural resources as well as a negative economic effect via increased prices to the consumer. Results suggest the need to communicate to consumers the supportive role that prudent, responsible use of antibiotics for animal disease treatment, control, and prevention plays in the sustainable production of broilers