Tracy H. Hazen, PhD

I received a Ph.D. in Applied Biology specializing in Microbiology from the Georgia Institute of Technology. During my Ph.D. I studied microbial ecology and the contribution of plasmids and phages to the genetic diversity of bacteria in coastal marine environments. I also used molecular methods to compare the genetic diversity of Vibrio parahaemolyticus from clinical and environmental specimens. I completed my postdoctoral training at the Institute for Genome Sciences and joined the faculty of the Department of Microbiology and Immunology and the Institute for Genome Sciences.

Since joining IGS I have used comparative genomics and transcriptomics to investigate the diversity of enteric and nosocomial pathogens. I have used genomics to study diverse microorganisms; however, much of my work has focused on E. coli associated with childhood diarrhea, or multidrug resistant nosocomial pathogens from patients in intensive care units. I have also carried forward my interest in plasmids from my graduate studies and have described the genetic diversity of virulence plasmids from E. coli as well as antibiotic resistance plasmids from E. coli and additional species including Klebsiella. My current research examines the genetic diversity and dissemination of antimicrobial resistance among enteric and nosocomial pathogens in health care settings. A goal of my research is to develop feasible molecular and sequencing-based approaches to enhance infection control. This includes the use of culture-independent sequencing for the real-time detection and tracking of pathogens and antimicrobial resistance in hospitals.

E. coli, Klebsiella, Vibrio, Enterobacterales, genomics, evolution, antibiotic resistance, microbial surveillance

1. Hazen, T.H., J.W. Sahl, M.S. Donnenberg, C.M. Fraser, F. Scheutz, and D.A. Rasko.  2013.  Refining the pathovar paradigm via phylogenomics of the attaching and effacing Escherichia coli.  Proc. Natl. Acad. Sci. USA, 110:12810-12815. (PMID: 23858472)
2. Hazen, T.H., L. Zhao, M.A. Boutin, G. Robinson, A.D. Harris, D.A. Rasko, and J.K. Johnson.  2014.  Comparative genomics of an IncA/C multidrug resistance plasmid from Escherichia coli and Klebsiella species isolated from ICU patients: the utility of whole genome sequencing in healthcare settings.  Antimicrob. Agents Chemother. 58: 4814-4825. (PMID: 24914121)
3. Hazen, T.H., J.B. Kaper, J.P. Nataro, and D.A. Rasko.  2015.  Comparative genomics provides insight into the diversity of the attaching and effacing Escherichia coli (AEEC) virulence plasmids. Infect. Immun. 83:4103-4117. (PMID: 26238712)
4. Hazen, T.H., M.S. Donnenberg,S. Panchalingam, M. Antonio, A. Hossain, I. Mandomando, J.B. Ochieng, T. Ramamurthy, B. Tamboura, S. Qureshi, F. Quadri, A. Zaidi, K.L. Kotloff, M.M. Levine, E.M. Barry, J.B. Kaper, D.A. Rasko, and J.P. Nataro.  2016.  Genomic diversity of EPEC associated with clinical presentations of differing severity.  Nat. Microbiol. (PMID: 27571975)
5. Hazen, T.H., S. Nagaraj, E.M. Barry, J. Bitoun, W.H. Chen, S.M. Tennant, and D.A. Rasko. 2019. Comparative genomics of CFA/I and CS6-producing ST-only enterotoxigenic Escherichia coli
   associated with human diarrhea. mSystems. (PMID: 30944874)
6. Hazen, T.H., Michalski, S. Tennant, D.A. Rasko. Genomic diversity of non-diarrheagenic fecal Escherichia colifrom children in sub-Saharan Africa and south Asia and their relatedness to pathotype E. coli. Nat Commun. 2023 Mar 14;14(1):1400. doi: 10.1038/s41467-023-36337-y. PubMed PMID: 36918537; PubMed Central PMCID: PMC10011798.