title: Animal antibiotic use has an early but important impact on the emergence of antibiotic resistance in human commensal bacteria.
abstract: Antibiotic use is known to promote the development of antibiotic resistance, but substantial controversy exists about the impact of agricultural antibiotic use (AAU) on the subsequent emergence of antibiotic-resistant bacteria among humans. AAU for animal growth promotion or for treatment or control of animal diseases generates reservoirs of antibiotic-resistant (AR) bacteria that contaminate animal food products. Mathematical models are an important tool for understanding the potential medical consequences of this increased exposure. We have developed a mathematical model to evaluate factors affecting the prevalence of human commensal AR bacteria that cause opportunistic infections (e.g., enterococci). Our analysis suggests that AAU hastens the appearance of AR bacteria in humans. Our model indicates that the greatest impact occurs very early in the emergence of resistance, when AR bacteria are rare, possibly below the detection limits of current surveillance methods.
authors.affiliation: Department of Epidemiology and Preventive Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA. dave@needles.umaryland.edu
authors.forename: David L
authors.initials: DL
authors.lastname: Smith
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Harris
authors.forename: Judith A
authors.initials: JA
authors.lastname: Johnson
authors.forename: Ellen K
authors.initials: EK
authors.lastname: Silbergeld
authors.forename: J Glenn
authors.initials: JG
authors.lastname: Morris
mesh_terms: D000383:Agriculture; D000465:Algorithms; D000820:Animal Diseases / Q000188:drug therapy* / Q000382:microbiology; D000818:Animals; D000829:Animals, Domestic / Q000382:microbiology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000378:metabolism; D001424:Bacterial Infections / Q000382:microbiology; D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple; D006801:Humans; D008962:Models, Theoretical
chemical_list: D000900:Anti-Bacterial Agents