title: Extraintestinal Pathogenic and Antimicrobial-Resistant Escherichia coli, Including Sequence Type 131 (ST131), from Retail Chicken Breasts in the United States in 2013.
abstract: Chicken meat products are hypothesized to be vehicles for transmitting antimicrobial-resistant and extraintestinal pathogenicEscherichia coli(ExPEC) to consumers. To reassess this hypothesis in the current era of heightened concerns about antimicrobial use in food animals, we analyzed 175 chicken-sourceE. coliisolates from a 2013 Consumer Reports national survey. Isolates were screened by PCR for ExPEC-defining virulence genes. The 25 ExPEC isolates (12% of 175) and a 2:1 randomly selected set of 50 non-ExPEC isolates were assessed for their phylogenetic/clonal backgrounds and virulence genotypes for comparison with their resistance profiles and the claims on the retail packaging label ("organic," "no antibiotics," and "natural"). Compared with the findings for non-ExPEC isolates, the group of ExPEC isolates had a higher prevalence of phylogroup B2 isolates (44% versus 4%;P< 0.001) and a lower prevalence of phylogroup A isolates (4% versus 30%;P= 0.001), a higher prevalence of multiple individual virulence genes, higher virulence scores (median, 11 [range, 4 to 16] versus 8 [range, 1 to 14];P= 0.001), and higher resistance scores (median, 4 [range, 0 to 8] versus 3 [range, 0 to 10];P< 0.001). All five isolates of sequence type 131 (ST131) were ExPEC (P= 0.003), were as extensively resistant as the other isolates tested, and had higher virulence scores than the other isolates tested (median, 12 [range, 11 to 13] versus 8 [range, 1 to 16];P= 0.005). Organic labeling predicted lower resistance scores (median, 2 [range, 0 to 3] versus 4 [range, 0 to 10];P= 0.008) but no difference in ExPEC status or virulence scores. These findings document a persisting reservoir of extensively antimicrobial-resistant ExPEC isolates, including isolates from ST131, in retail chicken products in the United States, suggesting a potential public health threat.IMPORTANCEWe found that amongEscherichia coliisolates from retail chicken meat products purchased across the United States in 2013 (many of these isolates being extensively antibiotic resistant), a minority had genetic profiles suggesting an ability to cause extraintestinal infections in humans, such as urinary tract infection, implying a risk of foodborne disease. Although isolates from products labeled "organic" were less extensively antibiotic resistant than other isolates, they did not appear to be less virulent. These findings suggest that retail chicken products in the United States, even if they are labeled "organic," pose a potential health threat to consumers because they are contaminated with extensively antibiotic-resistant and, presumably, virulentE. coliisolates.
authors.affiliation: VA Medical Center and University of Minnesota, Minneapolis, Minnesota, USA johns007@umn.edu.
authors.forename: James R
authors.initials: JR
authors.lastname: Johnson
authors.affiliation: VA Medical Center and University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Porter
authors.affiliation: VA Medical Center and University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Johnston
authors.affiliation: VA Medical Center and University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Thuras
authors.affiliation: Food Safety and Sustainability Center, Consumer Reports, Yonkers, New York, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Clock
authors.affiliation: Food Safety and Sustainability Center, Consumer Reports, Yonkers, New York, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Crupain
authors.affiliation: Food Safety and Sustainability Center, Consumer Reports, Yonkers, New York, USA.
authors.forename: Urvashi
authors.initials: U
authors.lastname: Rangan
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002645:Chickens / Q000382:microbiology*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D005516:Food Microbiology; D059022:Food Safety / Q000379:methods; D058870:Food, Organic / Q000382:microbiology; D005517:Foodborne Diseases / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control; D008460:Meat / Q000382:microbiology*; D008461:Meat Products / Q000382:microbiology*; D014481:United States / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents
keywords: Escherichia coli infections; ExPEC; ST131; antimicrobial resistance; food safety; molecular epidemiology; phylogenetic groups; sequence types; virulence; virulence factors