title: Prevalence of class 1 integrons and antimicrobial resistance gene cassettes among enteric bacteria found in multisite group-level cohorts of humans and swine.
abstract: The prevalence of antimicrobial resistance genotypic characteristics (class 1 integrons and antimicrobial resistance gene cassettes) among commensal Escherichia coli isolated from humans and swine in a semiclosed, integrated farrow-to-fork population was evaluated in a cross-sectional study. The objective of this study was to establish baseline antimicrobial resistance patterns of enteric bacteria from animals and humans within the study population; specifically, genotypic traits both unique and common to commensal E. coli derived from the different sources were evaluated. There were significant differences between host species; swine isolates were more likely to harbor integrons (odds ratio = 2.33, P = 0.0487). No significant differences were found for facility location, facility type, human housing cohort, or time of day (P > 0.05). There were significant differences (P = 0.006) among swine production groups (fecal samples from boars, dry sows, finishers, growers, intake boars, lactating sows, the lagoon, nursery piglets, influent, and piglets); the grower group was less likely than the nursery group to harbor a class 1 integron (nursery as referent: odds ratio = 0.22, P = 0.04). Among all isolates with an integron present, human isolates were more likely to harbor an antimicrobial resistance gene cassette (odds ratio = 6.36, P = 0.003). When isolates that possessed gene cassettes coding for resistance to specific antimicrobials were compared, no significant differences between host species (P > 0.05) were observed.
authors.affiliation: Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, Texas 77843-4458, USA.
authors.forename: L D
authors.initials: LD
authors.lastname: Campbell
authors.forename: H M
authors.initials: HM
authors.lastname: Scott
authors.forename: K M
authors.initials: KM
authors.lastname: Bischoff
authors.forename: R C
authors.initials: RC
authors.lastname: Anderson
authors.forename: R B
authors.initials: RB
authors.lastname: Harvey
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects*; D005838:Genotype; D006801:Humans; D032023:Integrons / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D013552:Swine / Q000382:microbiology*; D013781:Texas
chemical_list: D000900:Anti-Bacterial Agents