Antimicrobial Resistance Hidden within Multiserovar Salmonella Populations

Amy T Siceloff; Naomi Ohta; Keri N Norman; Guy H Loneragan; Bo Norby; H Morgan Scott; Nikki W Shariat

doi:10.1128/AAC.00048-21

Antimicrobial Resistance Hidden within Multiserovar Salmonella Populations

Antimicrob Agents Chemother. 2021 May 18;65(6):e00048-21. doi: 10.1128/AAC.00048-21. Print 2021 May 18.

Authors

Amy T Siceloff¹, Naomi Ohta², Keri N Norman³, Guy H Loneragan⁴, Bo Norby⁵, H Morgan Scott², Nikki W Shariat⁶

Affiliations

¹ Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA.
² Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA.
³ Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA.
⁴ School of Veterinary Medicine, Texas Tech University, Amarillo, Texas, USA.
⁵ Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA.
⁶ Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA nikki.shariat@uga.edu.

Abstract

Salmonella enterica can exist in food animals as multiserovar populations, and different serovars can harbor diverse antimicrobial resistance (AMR) profiles. Conventional Salmonella isolation assesses AMR only in the most abundant members of a multiserovar population, which typically reflects their relative abundance in the initial sample. Therefore, AMR in underlying serovars is an undetected reservoir that can readily be expanded upon antimicrobial use. CRISPR-SeroSeq profiling demonstrated that 60% of cattle fecal samples harbored multiple serovars, including low levels of Salmonella serovar Reading in 11% of samples, which were not found by culture-based Salmonella isolation. An in vitro challenge revealed that Salmonella serovar Reading was tetracycline resistant, while more abundant serovars were susceptible. This study highlights the importance of AMR surveillance in multiserovar populations.

Keywords: CRISPR-SeroSeq; Salmonella; antimicrobial resistance; cattle; serovar Reading; tetracycline.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Animals
Anti-Bacterial Agents* / pharmacology
Cattle
Drug Resistance, Bacterial / genetics
Drug Resistance, Multiple, Bacterial / genetics
Microbial Sensitivity Tests
Salmonella / genetics
Salmonella enterica* / genetics
Serogroup

Substances

Anti-Bacterial Agents