Microbiologist — Division of Microbiology
Saeed Khan, Ph.D.
Dr. Saeed Khan received his Ph.D. from Banaras Hindu University, India in 1989, and postdoctoral training in the Department of Biochemistry at the University of Texas Health Science Center at San Antonio. He joined the Division of Microbiology at NCTR in 1997 as a visiting scientist, and is currently serving as a research microbiologist. Dr. Khan recently finished a study that was funded by the Collaborative Opportunities for Research Excellence in Science and developed in collaboration with FDA’s Center for Drug Evaluation and Research (CDER) and Center for Devices and Radiological Health (CDRH) that involved studying the susceptibility of mice to Listeria infection after a prolonged exposure of mice to silver, gold, and silica nanoparticles. Currently, he is studying the antimicrobial properties of TiO2 and ZnO nanoparticles and is a co-principal investigator on two other research projects that were developed in collaboration with CDER and CDRH. Dr. Khan’s work on Bacillus anthracis that was funded by the Department of Homeland Security and the USDA Food Safety and Inspection Service was lauded by FDA and included in the FDA’s Food Protection Plan in 2008. It also was chosen by the American Society for Microbiology and the American Chemical Society (ACS) for press releases.
Dr. Khan serves as an alternate member of the FDA’s Antimicrobial Resistance Steering Committee. He has also served as a panel member on FDA Science Genomics Symposium and was invited as a speaker by both the FDA Center for Veterinary Medicine-sponsored General Public Meeting and the National Antibiotic Resistance Monitoring System meeting. Dr. Khan was also invited by previous FDA Commissioners Dr. Henney and Dr. McClellan, and the Associate Commissioner for Food Protection, Dr. Jeff Farrar, to brief them on antimicrobial resistance and food safety issues. He was invited by the Animal Plant and Fisheries Quarantine and Inspection Agency, Government of Korea, to present several talks on the isolation of different foodborne pathogens. He has also fostered a cooperative relationship between NCTR and the Higher Education Commission of Pakistan (HECP). Dr. Khan reviews scientific papers for various journals, and is an editorial board member of the Journal of Bioterrorism and Biodefense.
Dr. Khan has received several awards from NCTR and the FDA in the past, including the recent NCTR Director’s “Award for Excellence in Laboratory Sciences” and an FDA “Award for Leveraging and Collaboration.” He has also received several requests from the organizers of international meetings to be an invited speaker. Additionally, Dr. Khan reviews scientific papers for various journals, and is an editorial board member of the Journal of Bioterrorism and Biodefense.
Dr. Khan’s research interests and expertise include:
- microbial physiology
- bacterial virology and molecular biology of host-pathogen interactions
- gene-expression studies
- antimicrobial resistance
- genome comparisons.
Dr. Khan uses state-of-the-art molecular tools to study host-pathogen interactions; gene-expression analysis; and antimicrobial-resistance genes in foodborne, animal, and human clinical isolates. He uses biochemical, molecular and pulsed-field gel electrophoresis techniques to characterize bacterial isolates from different ecological niches. He has developed a custom microarray chip for detection of 131 antimicrobial-resistance genes that confer resistance to 20 different antibiotics. Dr. Khan also uses real-time PCR analysis to study the expression of efflux pump and antimicrobial-resistance genes and developed quantitative multiplex PCR assays to detect multiple antimicrobial-resistance markers. He uses sequencing tools to study the mutations in genes responsible for fluoroquinolone resistance in bacteria from a variety of sources and uses NextGen sequencing to sequence several multidrug-resistant human clinical staphylococcal and enterococcal isolates. Currently, Dr. Khan is studying the gene-expression profiles of transformed and primary human cutaneous, gastrointestinal, and pulmonary cell lines after infection with B. anthracis spores to understand the differences in mortality rates of three forms of anthrax. Other projects that he is working on involve the mechanism of biofilm formation by S. aureus and uropathogenic E. coli. The research goals include understanding the mechanism of antimicrobial resistance, virulence, pathogenicity, and genetic evolution with a scope of developing countermeasure and mitigation strategies to control the spread of multidrug-resistant bacteria and help FDA in making science-based prudent decisions for regulatory needs.
Professional Societies/National and International Groups
American Society for Microbiology
1997 – Present
Arkansas Biotechnology Association
1997 – Present
Escherichia coli Coalition Group
2010 – Present
International Association for Food Protection
2012 – Present
Journal of Bioterrorism and Biodefense
Editorial Board Member
2011 – Present
National Antimicrobial Resistance Steering Committee
2009 – Present
FDA Omics Technical Advisory Group
2017 – Present
Improvement of Bolton Broth by Supplementation with Tazobactam for the Isolation of Campylobacter from Chicken Rinses.
Chon J., Kim Y., Rashid F., Sung K., Khan S., Kim H. and Seo K.
Poult Sci. 2018 Jan 1, 97(1):289-293. doi: 10.3382/ps/pex169.
Prevalence, Toxin Gene Profile, Antibiotic Resistance, and Molecular Characterization of Clostridium perfringens from Diarrheic and Non-Diarrheic Dogs in Korea.
Chon J., Seo K., Bae D., Park J., Khan S. and Sung K.
J Vet Sci. 2018 May 31, 19(3):368-374. doi: 10.4142/jvs.2018.19.3.368
Investigating the Susceptibility of Mice to A Bacterial Challenge after Intravenous Exposure to Durable Nanoparticles.
Khan S., Zhang Q., Marasa B., Sung K., Cerniglia C., Ingle T., Jones M., Paredes A., Tobin G., Bancos S., Weaver J., Goering P., Howard P., Patri A. and Tyner K.
Nanomedicine (Lond). 2017 Sep, 12(17):2097-2111. doi: 10.2217/nnm-2017-0176.
Evaluating the Potential of Gold, Silver, and Silica Nanoparticles to Saturate Mononuclear Phagocytic System Tissues Under Repeat Dosing Conditions.
Weaver J., Tobin G., Ingle T., Bancos S., Stevens D., Rouse R., Howard K., Goodwin D., Knapton A., Li X., Shea K., Stewart S., Xu L., Goering P., Zhang Q., Howard P., Collins J., Khan S., Sung K. and Tyner K.
Part Fibre Toxicol. 2017 Jul 17, 14(1):25. doi: 10.1186/s12989-017-0206-4.
Diversity of Clostridium Perfringens Isolates from Various Sources and Prevalence of Conjugative Plasmids.
Rafii F., Park M., Steven M., Foley L., Nayak R., Glenn J., Songer J., Seibel M., Khan S., Alejandro P. and David W.
Anaerobe. 2016 Apr, 38:25-35.
Draft Genome Sequence of Multidrug-resistant Enterococcus faecium Clinical Isolate VRE3, ST16, with Novel Structural Arrangement of Tn1546.
Khan S., Sung K., Marasa B., Min S., Kweon O., Nawaz M. and Cerniglia C.
Genome Announc. 2015 Aug 13, 3(4): e00871-15.
Draft Genome Sequence of a Methicillin-Resistant Staphylococcus aureus ST1413 Strain for Studying Genetic Mechanisms of Antibiotic Resistance.
Bernard S., Revollo J., lram S., Sung K., Xu J. and Khan S.
Genome Announc. 2014 Mar 6, 2(2): e00162-14.
Molecular Characterization of Fluoroquinolone-Resistant Aeromonas spp. Isolated from Imported Shrimp.
Shakir Z., Khan S., Sung K., Khare S., Khan A., Steele R. and Nawaz M.
Appl Environ Microbiol. 2012 Nov, 78(22):8137-41.
A Transcriptomic Expression Array, PCR and Disk Diffusion Analysis of Antimicrobial Resistance Genes in Multidrug-Resistant Bacteria.
Khan S., Sung K. and Nawaz M.
Agriculture, Food and Anal Bacteriol. 2011 Nov, 1(2):123-39.
Lysozyme as a Barrier to Growth of Bacillus anthracis Strain Sterne in Liquid Egg White, Milk and Beef.
Sung K., Khan S., Nawaz M., Cerniglia C., Tamplin M., Phillips R. and Kelley L.
Food Microbiol. 2011 Sep, 28(6):1231-4.
Detection of aacA-aphD, qacEδ1, marA, floR, and tetA Genes from Multidrug-Resistant Bacteria: Comparative Analysis of Real-Time Multiplex PCR Assays Using EvaGreen® and SYBR® Green I Dyes.
Khan S., Sung K. and Nawaz M.
Mol Cell Probes. 2011 Apr-Jun, 25(2-3):78-86.
Detection and Characterization of Virulence Genes and Integrons in Aeromonas veronii Isolated from Catfish.
Nawaz M., Khan S., Khan A., Sung K., Quynhtien T., Kerdahi K. and Steele R.
Food Microbiol. 2010 May, 27(3):327-31.
The Survivability of Bacillus anthracis in Processed Liquid Eggs.
Khan S., Sung K., Nawaz M., Cerniglia C., Tamplin M., Phillips R. and Kelly L.
Food Microbiol. 2009 Apr, 26(2):123-7.
Genetic Diversity of Tn1546-Like Elements in Clinical Isolates of Vancomycin-Resistant Enterococci.
Sung K., Khan S. and Nawaz M.
Int J Antimicrob Agents. 2008 Jun, 31(6):549-54.
Heteroresistance to Vancomycin and Novel Point Mutations in Tn1546 of Enterococcus faecium ATCC 51559.
Khan S., Sung K. and Nawaz M.
Int J Antimicrob Agents. 2008 Jan, 31(1): 27-36.
Direct In-Gel Hybridization of DNA with Digoxigenin-Labeled Probes. In Protocols for Nucleic Acid Analysis by Nonradioactive Probes.
Khan S. and Nawaz M.
Methods Mol Biol. 2007, 353:93-103.
Characterization of Class 1 Integron Resistance Gene Cassettes in Salmonella enterica Serovars Oslo and Bareily from Imported Seafood.
Khan A., Cheng C., Van K., West C., Nawaz M. and Khan S.
J Antimicrob Chemother. 2006 Dec, 58(6):1308-10.
Molecular Characterization of Multidrug-Resistant Enterococcus spp. from Poultry and Dairy Farms: Detection of Virulence and Vancomycin Resistance Gene Markers by PCR.
Khan S., Nawaz M., Khan A., Hopper S., Jones R. and Cerniglia C.
Mol Cell Probes. 2005 Feb, 19(1):27-34.
A Simple and Efficient Triton-X-100 Boiling and Chloroform Extraction Method of RNA Isolation from Gram Positive and Gram Negative Bacteria.
Sung K., Khan S., Nawaz M. and Khan A.
FEMS Microbiol Lett. 2003 Dec 5, 229(1):97-101.
Influence of Growth Media on Vancomycin Resistance of Enterococcus Isolates and Correlation with Gene Determinants.
Nayak R., Khan S., Watson R. and Cerniglia C.
FEMS Microbiol Lett. 2002 Sep 10, 214(2):159-63.
DNA Packaging and Developmental Intermediates of a Broad Host Range Vibrio vulnificus Bacteriophage 71A-6.
Khan S., Khan A., Nawaz M., DePaola A., Andrews A. and Cerniglia C.
Mol Cell Probes. 2001 Apr, 15(2):61-9.
Human Health Impact and Regulatory Issues Involving Antimicrobial Resistance in the Food Animal Production Environment.
Nawaz M., Erickson B., Khan A., Khan S., Pothuluri J., Rafii F., Sutherland J., Wagner R. and Cerniglia C.
Regulatory Research Perspective. 2001 Jan, 1(1):1-10.
Characterization of Erythromycin-Resistant Methylase Genes from Multiple Drug-Resistant Staphylococcus spp. Isolated from the Milk of Lactating Cows.
Khan S., Nawaz M., Khan A., Steele R. and Cerniglia C.
Am J Vet Res. 2000 Sep, 61(9):1128-32.
Transfer of Erythromycin Resistance from Poultry to Clinical Staphylococcus aureus.
Khan S., Nawaz M., Khan A. and Cerniglia C.
J Clin Microbiol. 2000 May, 38(5):1832-8.
Contact information for all lab members:
Kidon Sung, Ph.D.
- Contact Information
- Saeed Khan
- (870) 543-7391