Characterization of Antimicrobial and Metal Resistance in Contemporary and Historical clinical isolates of Histophilus somni from Feedlot cattle in Alberta
Abstract
This study was conducted to determine antimicrobial and metal resistance, associated resistant genes, and mobile genetic elements in contemporary (2012-2016, n=63) and historical (1980’s, n=31) clinical isolates of Histophilus somni from feedlot cattle in Alberta. A significant increase in antimicrobial resistance was observed in the contemporary isolates compared to the historical (P<0.001). Sixty-two percent of the contemporary isolates exhibited multidrug resistance (resistance to 3 drug classes). Sixty-eight percent and 52% of the contemporary isolates showed tolerance to copper and zinc concentrations above one millimolar, respectively. Multicopper oxidase and cation efflux pump genes associated with copper and zinc tolerance and tet(H) gene associated with oxytetracycline resistance were identified. We identified integrative conjugative element carrying antimicrobial, copper, and zinc resistance genes, which indicates the possibility of co-selection of antimicrobial resistance due to copper and zinc selection pressure, and the dissemination of resistance by horizontal gene transfer.
Description
Keywords
Microbiology, Biology--Molecular, Veterinary Science
Citation
Bhatt, K. (2016). Characterization of Antimicrobial and Metal Resistance in Contemporary and Historical clinical isolates of Histophilus somni from Feedlot cattle in Alberta (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25268