Related Experiment Video
Updated: Sep 20, 2025

Characterization of a Pathogenic Escherichia coli Strain Derived from Oreochromis spp. Farms Using Whole-Genome Sequencing
Published on: December 23, 2022
Functional Genomics of Antibiotic Susceptibility in Enterococcus faecalis From Infective Endocarditis
Yanhong Li1,2, Madison E Stellfox1, Kirsten M Evans1
1Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
None:
Enterococcus faecalis is an opportunistic pathogen that causes infective endocarditis. Despite in vitro synergy of the recommended combination ampicillin-ceftriaxone (AC), E faecalis infective endocarditis (EFIE) mortality remains high. We characterized 119 isolates from patients with EFIE in our health system from 2018 to 2023 genomically and phenotypically. Three genetic lineages (ST6, ST40, and ST179) accounted for 41% of all infections. ST6 isolates were less susceptible to ceftriaxone and AC in dual-antibiotic checkerboard assays, but also exhibited decreased survival in dual-antibiotic killing assays using humanized AC exposures. ST6 isolates encoded a known genetic disruption affecting pbp4 as well as mutation of a putative hydrolase called phnP. Functional studies confirmed that both alterations contributed to altered AC susceptibility. Finally, we found that ampicillin plus daptomycin showed robust growth inhibition and killing against EFIE isolates with decreased AC susceptibility. These findings enhance our understanding of EFIE and may guide better therapeutic strategies.
More Related Videos
08:58Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes
Published on: March 3, 2023
14:06Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays
Published on: November 12, 2012
Related Concept Videos
Development of Antibiotic Resistance
Endocarditis I: Introduction
Antibiotic Selection
Gene Regulation in Microbial Communities: Quorum Sensing
Genomic DNA in Prokaryotes
Genomic Diversity in Bacteria
Although bacterial genomes are much...
Endocarditis III: Medical Management