Mathematical Model of Plasmid-Mediated Resistance to Ceftiofur in Commensal Enteric Escherichia coli of Cattle

Antimicrobial use in food animals may contribute to antimicrobial resistance in bacteria of animals and humans. Commensal bacteria of animal intestine may serve as a reservoir of resistance-genes. To understand the dynamics of plasmid-mediated resistance to cephalosporin ceftiofur in enteric commensals of cattle, we developed a deterministic mathematical model of the dynamics of ceftiofur-sensitive and resistant commensal enteric Escherichia coli (E. coli) in the absence of and during parenteral therapy with ceftiofur. The most common treatment scenarios including those using a sustained-release drug formulation were simulated; the model outputs were in agreement with the available experimental data. The model indicated that a low but stable fraction of resistant enteric E. coli could persist in the absence of immediate ceftiofur pressure, being sustained by horizontal and vertical transfers of plasmids carrying resistance-genes, and ingestion of resistant E. coli. During parenteral therapy with ceftiofur, resistant enteric E. coli expanded in absolute number and relative frequency. This expansion was most influenced by parameters of antimicrobial action of ceftiofur against E. coli. After treatment (>5 weeks from start of therapy) the fraction of ceftiofur-resistant cells among enteric E. coli, similar to that in the absence of treatment, was most influenced by the parameters of ecology of enteric E. coli, such as the frequency of transfer of plasmids carrying resistance-genes, the rate of replacement of enteric E. coli by ingested E. coli, and the frequency of ceftiofur resistance in the latter

Independent poultry processing in Georgia: survey of producers' perspective

A survey was presented to Georgia independent poultry farmers to evaluate current processing options as well as desired future changes. A total of 82 Georgia farmers participated in the survey, 31 of whom were raising broilers at the time of the survey. Most of the farmers surveyed who were growing broilers at the time (81%) processed on-farm, but these were also the farmers who processed less than 1000 birds per year. The larger independent Georgia farmers processed off-farm in South Carolina and Kentucky, where there were processors that served small-scale farmers and provided USDA inspection. These out of state processing trips took place between 4 and 30 times per year for an average of 391 miles round trip. For farmers’ future needs, similar numbers of farmers wanted only on-farm or only off-farm drop off processing (22% and 25% respectively), but 40% of the farmers surveyed were open to more than one processing option. The farmers were also asked to evaluate the importance of several attributes of processing facilities, and they chose quality of service to be the most important processing facility attribute, followed by cost of processing, distance from the farm, and USDA inspection

Consumers' interest in locally raised, small-scale poultry in Georgia

An online questionnaire was developed that targeted consumers with an interest in sustainable and local poultry production in Georgia. Approximately 97% of the respondents expressed an interest in supporting efforts to make sustainably raised poultry processed in Georgia available. Even for a high premium of $5.00/lb, some respondents would shift their current chicken purchases towards these locally raised chickens. Respondents reported some interest in attributes such as pasture raised, air chilled and Georgia grown for their poultry. Knowledge about the demand for local pastured poultry supports the need for infrastructure to support Mobile Processing Units for Georgia farmers interested in locally raised small-scale poultry production