Deputy Director — Division of Microbiology
Steven Foley, Ph.D.
Dr. Steven Foley is a Supervisory Research Microbiologist and Deputy Director of the Division of Microbiology at NCTR. Originally from Minnesota, Dr. Foley earned his Bachelor of Science in zoology and his Ph.D. in cellular and molecular biology/infectious diseases from North Dakota State University in Fargo. The focus of his research was on the expression and purification of the increased serum survival (Iss) protein, which was identified as an important virulence factor for Avian Pathogenic Escherichia coli, and the development and characterization of monoclonal antibodies towards Iss. He then completed a postdoctoral fellowship with the FDA Center for Veterinary Medicine, where the focus of his research was developing methods for source tracking of Salmonella from food-animal species. Following his postdoctoral fellowship, Dr. Foley served as an assistant professor at the University of Central Arkansas (UCA) where he taught courses in biology and microbiology and conducted research related to antimicrobial resistance in Salmonella and E. coli. During his time at UCA, Dr. Foley also served as a science advisor for the FDA Office of Regulatory Affairs, where he provided technical advice on research needs and methodologies. He continued as a science advisor after accepting a position as an associate research scientist with the National Farm Medicine Center at the Marshfield Clinic Research Foundation (MCRF). At MCRF, Dr. Foley led a research program focused on antimicrobial resistance and virulence of foodborne and zoonotic pathogens. In 2009, Dr. Foley joined NCTR and his research team has been focused in the fields of zoonotic diseases, food safety and tobacco-associated microbiology. In addition, Dr. Foley completed the Leadership Arkansas program and the Leadership in a Democratic Society program through the Federal Executive Institute and is serving as the co-chair of the NCTR Institutional Biosafety Committee and an adjunct professor in the Food Science Department at the University of Arkansas.
Dr. Foley’s research program has been multifaceted to address FDA research needs in the areas of antimicrobial resistance and virulence in foodborne pathogens and tobacco-associated microbiology. Plasmids that are present in Salmonella enterica and other enteric pathogens often contain multiple genes that can encode for antimicrobial resistance, increased colonization, and/or overall virulence. A long-term goal of Dr. Foley’s research is to better understand the role of plasmids in increased virulence among Salmonella enterica. In his previous studies, DNA sequencing of plasmids identified factors that are potentially important for increased virulence in Salmonella. For example, his team’s research has demonstrated the contribution of plasmid-encoded VirB/D4 Type 4 Secretion Systems to increased invasion and survival in model systems. Several other plasmid types also appear to encode potential virulence factors, often along with antimicrobial-resistance genes, thus our interests are to further elucidate their roles in virulence and whether there is a co-selection of increased virulence and resistance. Another related interest is to better understand the factors that impact plasmid-transfer efficiency; preliminary studies have shown that differential exposure to certain antimicrobial agents can impact the efficiency of plasmid transfer. The team’s ongoing research builds upon these earlier studies to evaluate a larger diversity of plasmids associated with Salmonella to identify their impact on pathogenicity (both looking at the pathogen and host sides of the equation), and refine the understanding of the role of antimicrobial exposure that may influence plasmid transfer among Salmonella and other enteric organisms. The second broad area of research in Dr. Foley’s laboratory is related to microbiology of smokeless tobacco products. He has been utilizing culture-based, molecular, and bioinformatics approaches to identify and characterize the bacterial and fungal populations in smokeless tobacco products and evaluate their potential to contribute to carcinogen formation.
Professional Societies/National and International Groups
American Society for Microbiology
1997 – Present
Arkansas Association for Food Protection
2009 – Present
2010 – 2012
International Association for Food Protection
2005 – Present
MidSouth Computational Biology & Bioinformatics Society (MCBIOS)
2016 – Present
Evaluation of the Genetics and Functionality of Plasmids in Incompatibility Group I1-Positive Salmonella Enterica.
Kaldhone P., Han J., Deck J., Khajanchi B., Nayak R., Foley S., and Ricke S.
Foodborne Path. Dis. 2018, 15: 168-176.
Impact of Co-Carriage of IncA/C Plasmids with Additional Plasmids on the Transfer of Antimicrobial Resistance in Salmonella Enterica Isolates.
Han J., Pendleton S., Deck J., Singh R., Gilbert J., Johnson T., Sanad Y., Nayak R., and Foley S.
Int. J. Food Microbiol. 2018, 271:77-84.
Association of the Gut Microbiota Mobilome with Hospital Location and Birth Weight in Preterm Infants.
Ravi A., Estensmo E., L’Abée-Lund T., Foley S., Allgaier B., Martin C., Claud E., and Rudi K.
Pediatr. Res. 2017, 82:829-838.
Comparative Genomic Analysis and Characterization of Incompatibility Group FIB Plasmid Encoded Virulence Factors of Salmonella Enterica Isolated from Food Sources.
Khajanchi B., Hassan N., Choi S., Han J., Zhao S., Colwell R., Cerniglia C., and Foley S.
BMC Genomics. 2017, 18:570.
Bacterial Populations Associated with Smokeless Tobacco Products.
Han J., Sanad Y., Deck J., Sutherland J., Li Z., Walters M., Duran N., Holman M., and Foley S.
Appl Enivron Microbiol. 2016, 82(20):6273-6283.
Transmissible Plasmid Containing Salmonella Enterica Heidelberg Isolates Modulate Cytokine Production in Intestinal Epithelial Cells.
Gokulan K., Khare S., Williams K., and Foley S.
DNA Cell Biol. 2016, 35(8):443-453.
Molecular Characterization of Salmonella Enterica Serovars Isolated from a Turkey Production Facility in the Absence of Selective Antimicrobial Pressure.
Sanad Y., Johnson K., Park S., Han J., Deck J., Foley S., Kenney B., Ricke S., and Nayak R.
Foodborne Path Dis. 2016, 13(2):80-87.
Infection of Murine Macrophages by Salmonella Enterica Serovar Heidelberg Blocks Murine Norovirus Replication and Virus-Induced Apoptosis.
Agnihothram S., Basco M., Mullis L., Foley S., Hart M., Sung K., and Azevedo M.
PLoS One. 2015, 10(12):e0144911.
The Commensal Infant Gut Mobilome as a Reservoir for Persistent Multidrug Resistance Integrons.
Ravi A., Avershina E., Foley S., Ludvigsen J., Storrø O., Øien T., Johnsen R., McCartney A., L’Abée-Lund T., and Rudi K.
Sci Rep. 2015, 5:15317.
Characterization of Antibiotic and Disinfectant Susceptibility Profiles Among Pseudomanas Aeruginosa Veterinary Isolates Recovered During 1994-2003.
Beier R., Foley S., Davidson M., White D., McDermott P., Bodeis-Jones S., Zhao S., Andrews K., Crippen T., Sheffield C., Poole T., Anderson R., and Nisbet D.
J Appl Microbiol. 2014, 118(2):326–342.
Evaluation of Virulence and Antimicrobial Resistance in Salmonella Enterica Serovar Enteritidis Isolates from Humans and Chicken- and Egg-Associated Sources.
Han J., Gokulan K., Barnette D., Khare S., Rooney A., Deck J., Nayak R., Stefanova R., Hart M., and Foley S.
Foodborne Path Dis. 2013, 10(12):1008-1015.
Salmonella Pathogenicity and Host Adaptation in Chicken-Associated Serovars.
Foley S., Johnson T., Ricke S., Nayak R., and Danzeisen J.
Microbiol Mol Biol Rev. 2013, 77(4):582-607.
Impact of Plasmids, Including Those Encoding VirB4/D4 Type IV Secretion Systems on Salmonella Enterica Serovar Heidelberg Virulence in Macrophages and Epithelial Cells.
Gokulan K., Han J., Khare S., Rooney A., Lynne A., and Foley S.
PLoS One. 2013, 8(10):e77866.
Meta-Analysis of Salmonella Pulsed-Field Gel Electrophoresis Fingerprints Based on the Constructed Database.
Zou W., Chen H., Hise K., Tang H., Foley S., Meehan J., Lin W., Nayak R., Xu J., Fang H., and Chen J.
PLoS One. 2013, 8(3):e59224
DNA Sequence Analysis of Multidrug Resistance Encoding Plasmids from Salmonella Enterica Serotype Heidelberg Isolates.
Han J., Lynne A., David D., Tang H., Xu J., Nayak R., Kaldhone P., Logue C., and Foley S.
PLoS One. 2012, 7(12):e51160.
Recombinant Iss as a Potential Vaccine for Avian Colibacillosis.
Lynne A., Kariyawasam S., Wannemuehler Y., Johnson T., Johnson S., Spitler D., Moon H., Jordan D., Logue C., Foley S., and Nolan L.
Avian Dis. 2012, 56(1):192-199.
Genetic Characterization of Antimicrobial Resistance in Salmonella Enterica Serovars Isolated from Dairy Cattle in Wisconsin.
Marrero-Ortiz R., Han J., Lynne A., Stemper M., David D., Nayak R., and Foley S.
Food Res Int. 2012, 45(2):962-967.
Molecular Characterization of the Resistance to Extended-Spectrum Cephalosporins in Clinical Escherichia Coli Isolates from Companion Animals in the United States.
Shaheen B., Nayak R., Foley S., Kweon O., Deck J., Park M., Rafii F., and Boothe D.
Antimicrob Agents Chemother. 2011, 55(12):5666-5675.
Population Dynamics of Salmonella Enterica Serotypes in Commercial Egg and Poultry Production.
Foley S., Nayak R., Hanning I., Johnson T., Han J., and Ricke S.
Appl Environ Microbiol. 2011, 77(13):4273-4279.
Comparison of Salmonella Enterica Serovar Heidelberg Isolated from Human Patients with Those from Animal and Food Sources.
Han J., David D., Deck J., Lynne A., Kaldhone P., Nayak R., Stefanova R., and Foley S.
J Clin Micro. 2011, 49(3):1130-33.
Horizontal Gene Transfer has Resulted in a Dominant Avian Clonal Type of Salmonella Enterica Serovar Kentucky.
Johnson T., Thorsness J., Anderson C., Lynne A., Foley S., Han J., Fricke W., McDermott P., White D., Khatri M., Stell A., Flores C., and Singer R.
PLoS One. 2010, 5(12):e15524.
Evaluation of a Virulence Factor Profiling in the Characterization of Veterinary Escherichia Coli.
David D., Lynne A., Han J., and Foley S.
App. Environ Microbiol. 2010, 76(22):7509-7513.
Molecular Typing Methodologies for Microbial Source Tracking and Epidemiological Investigations of Gram-Negative Bacterial Foodborne Pathogens.
Foley S., Lynne A., and Nayak R.
Infect Genet Evol. 2009, 9(4):430-440.
Food Animal-Associated Salmonella Challenges: Pathogenicity and Antimicrobial Resistance.
Foley S. and Lynne A.
J Anim Sci. 2008, 86(14 Suppl):E173-187E.
Bijay Khajanchi, Ph.D.
- Contact Information
- Steven Foley
- (870) 543-7121
ExpertiseApproachDomainTechnology & DisciplineToxicology