Graduation Year
2024
Document Type
Thesis
Degree
M.S.
Degree Name
Master of Science (M.S.)
Degree Granting Department
Integrative Biology
Major Professor
Valerie J. Harwood, Ph.D.
Committee Member
Kathleen Scott, Ph.D.
Committee Member
Mark Margres, Ph.D.
Keywords
Clonal complex 17, Genomic analysis, Multidrug resistance, Vancomycin-resistant Enterococcus, Wastewater treatment plant, Whole genome sequencing
Abstract
Vancomycin-resistant Enterococcus (VRE) are a serious health threat, causing 50,000 infections and 5,000 deaths each year in the United States (CDC, 2019). Multidrug-resistant VRE are becoming more prevalent, and treatment options for infections caused by these organisms are limited (Arias et al., 2010; CDC, 2019). Multidrug resistant VRE have been previously isolated from wastewater in Brazil, Canada, and Portugal (Araújo et al., 2010; de_Farias et al., 2022; Sanderson et al., 2019). Thirteen vancomycin-resistant Enterococcus faecium isolated from three stages of a Florida wastewater treatment plant were fully resistant to the following antibiotics: vancomycin, ampicillin, ciprofloxacin, erythromycin, tetracycline, and nitrofurantoin, and sensitive to linezolid, fosfomycin, and quinupristin-dalfopristin. The genomes of the thirteen VRE strains were sequenced via 50 paired-end sequencing on an Illumina NovaSeq and analyzed to determine relationships among the genomes and mobile genetic elements. All strains belonged to clonal complex 17, and three sequence types were identified (ST18, ST412, and ST584). Each strain contained a mean of 18 antimicrobial resistance genes and 22 virulence genes, and multiple putative plasmids and genomic islands (clusters of genes that are transferable between organisms) were identified. All strains shared Tn1546, which carries the vanA operon, as well as four putative genomic islands. The strains had 99.5% percent genomic identity and were more closely related to other wastewater and clinical VRE strains than to vancomycin-resistant E. faecium strains isolated from environmental habits, or vancomycin-susceptible E. faecium. The similarity among the strains as well as to clinical strains suggests an origin from hospital sewage.
Scholar Commons Citation
Brodrick, Eleanor, "Comparing the Genomes of Multidrug and Vancomycin-Resistant Enterococcus faecium from a Florida Wastewater Treatment Plant" (2024). USF Tampa Graduate Theses and Dissertations.
https://digitalcommons.usf.edu/etd/10478
