RT Journal Article
T1 Genetic Determinants of Resistance to Extended-Spectrum Cephalosporin and Fluoroquinolone in Escherichia coli Isolated from Diseased Pigs in the United States
A1 Hayer, Shivdeep Singh
A1 Lim, Seunghyun
A1 Hong, Samuel
A1 Elnekave, Ehud
A1 Johnson, Timothy
A1 Rovira, Albert
A1 Vannucci, Fabio
A1 Clayton, Jonathan B.
A1 Perez, Andres
A1 Álvarez Sánchez, Julio
AB Fluoroquinolones and cephalosporins are critically important antimicrobial classes for both human and veterinary medicine. We previously found a drastic increase in enrofloxacin resistance in clinical Escherichia coli isolates collected from diseased pigs from the United States over 10 years (2006 to 2016). However, the genetic determinants responsible for this increase have yet to be determined. The aim of the present study was to identify and characterize the genetic basis of resistance against fluoroquinolones (enrofloxacin) and extended-spectrum cephalosporins (ceftiofur) in swine E. coli isolates using whole-genome sequencing (WGS). blaCMY-2 (carried by IncA/C2, IncI1, and IncI2 plasmids), blaCTX-M (carried by IncF, IncHI2, and IncN plasmids), and blaSHV-12 (carried by IncHI2 plasmids) genes were present in 87 (82.1%), 19 (17.9%), and 3 (2.83%) of the 106 ceftiofur-resistant isolates, respectively. Of the 110 enrofloxacin-resistant isolates, 90 (81.8%) had chromosomal mutations in gyrA, gyrB, parA, and parC genes. Plasmid-mediated quinolone resistance genes [qnrB77, qnrB2, qnrS1, qnrS2, and aac-(6)-lb′-cr] borne on ColE, IncQ2, IncN, IncF, and IncHI2 plasmids were present in 24 (21.8%) of the enrofloxacin-resistant isolates. Virulent IncF plasmids present in swine E. coli isolates were highly similar to epidemic plasmids identified globally. High-risk E. coli clones, such as ST744, ST457, ST131, ST69, ST10, ST73, ST410, ST12, ST127, ST167, ST58, ST88, ST617, ST23, etc., were also found in the U.S. swine population. Additionally, the colistin resistance gene (mcr-9) was present in several isolates. This study adds valuable information regarding resistance to critical antimicrobials with implications for both animal and human health.
PB American Society for Microbiology
YR 2020
FD 2020
LK https://hdl.handle.net/20.500.14352/129795
UL https://hdl.handle.net/20.500.14352/129795
LA eng
NO Hayer SSLim SHong SElnekave E, Johnson T, Rovira AVannucci FClayton JBPerez A, Alvarez J2020.Genetic Determinants of Resistance to Extended-Spectrum Cephalosporin and Fluoroquinolone in Escherichia coli Isolated from Diseased Pigs in the United States. mSphere5:10.1128/msphere.00990-20.https://doi.org/10.1128/msphere.00990-20
NO University of Minnesota
NO National Institute of Food and Agriculture
NO Swine Disease Eradication Center fund
DS Docta Complutense
RD 18 mar 2026