Chloe Murrell’s research while affiliated with Cornell University and other places

What is this page?

This page lists works of an author who doesn't have a ResearchGate profile or hasn't added the works to their profile yet. It is automatically generated from public (personal) data to further our legitimate goal of comprehensive and accurate scientific recordkeeping. If you are this author and want this page removed, please let us know.

Publications (1)

Canine E. coli pangenome (N = 1,778). (A) Roary (50) matrix containing identified gene clusters. (B) Pangenome curve consisting of all genes in purple and core genes in green. (C) Distribution of the pangenome into cloud, shell, and core components.
Core genome phylogeny of E. coli sampled from dog hosts across US and Canadian regions participating in the surveillance program, with geographic regions, phylogroups, and antibiotic resistance phenotypes annotated on that phylogeny. The map was created using the ne_states function within the rnaturalearth R package, the geom_sf function within the sf R package, and ggplot2.
Number of candidate genes from Scoary analysis in four genomic categories with significant correlation to resistance (P < 0.01 with both empirical P and Bonferroni correction) by the antibiotic tested.
Group 1 CPS gene content from the 38 isolates carrying wza2 and wzi genes that were correlated with resistance to multiple antibiotics. The phylogeny is based on wza2 with the respective genome IDs as labels. ST of each genome is listed on the right. Color-coding of the isolate genome accessions denotes resistant (red) and susceptible (blue). Group 1 capsules that do not extend to gnd are because of truncated contigs.
Heatmap generated from computed pairwise TM scores between WzaCA, Wza1, Wza2, and GfcE protein structures. TM scores are between 0 and 1, the closer to 1 (red), the more similar the structures being compared; the further from 1 (blue), the less similar. All sequences used in this study (WzaCA, Wza2, and GfcE) are also annotated based on either their resistance (RES) or susceptibility (SUS) status for cefovecin.

+3

Evolutionary genomic analyses of canine E. coli infections identify a relic capsular locus associated with resistance to multiple classes of antimicrobials
  • Article
  • Full-text available

July 2024

·

75 Reads

Kristina Ceres

·

Jordan D. Zehr

·

Chloe Murrell

·

[...]

·

Infections caused by antimicrobial-resistant Escherichia coli are the leading cause of death attributed to antimicrobial resistance (AMR) worldwide, and the known AMR mechanisms involve a range of functional proteins. Here, we employed a pan-genome wide association study (GWAS) approach on over 1,000 E. coli isolates from sick dogs collected across the US and Canada and identified a strong statistical association (empirical P < 0.01) of AMR, involving a range of antibiotics to a group 1 capsular (CPS) gene cluster. This cluster included genes under relaxed selection pressure, had several loci missing, and had pseudogenes for other key loci. Furthermore, this cluster is widespread in E. coli and Klebsiella clinical isolates across multiple host species. Earlier studies demonstrated that the octameric CPS polysaccharide export protein Wza can transmit macrolide antibiotics into the E. coli periplasm. We suggest that the CPS in question, and its highly divergent Wza, functions as an antibiotic trap, preventing antimicrobial penetration. We also highlight the high diversity of lineages circulating in dogs across all regions studied, the overlap with human lineages, and regional prevalence of resistance to multiple antimicrobial classes. IMPORTANCE Much of the human genomic epidemiology data available for E. coli mechanism discovery studies has been heavily biased toward shiga-toxin producing strains from humans and livestock. E. coli occupies many niches and produces a wide variety of other significant pathotypes, including some implicated in chronic disease. We hypothesized that since dogs tend to share similar strains with their owners and are treated with similar antibiotics, their pathogenic isolates will harbor unexplored AMR mechanisms of importance to humans as well as animals. By comparing over 1,000 genomes with in vitro antimicrobial susceptibility data from sick dogs across the US and Canada, we identified a strong multidrug resistance association with an operon that appears to have once conferred a type 1 capsule production system.

Download