Microbiologist — Division of Microbiology

Sangeeta Khare, M.S., Ph.D.
(870) 543-7121
[email protected]  

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 About  |  Publications  |  Lab Members

Background

Dr. Sangeeta Khare joined NCTR as a research microbiologist in the Division of Microbiology in 2010. She completed her Bachelor’s degree and Master’s degree from Kanpur University, India in life sciences with an emphasis on microbiology and immunology. She obtained her Ph.D. from the All India Institute of Medical Sciences in New Delhi, India in 1996, in immunomodulation as an alternative for the treatment of infectious disease.

Dr. Khare was awarded a College of Medicine postdoctoral fellowship in 1997 from the University of Saskatchewan in Saskatoon, Canada to work on the relationship between dose of antigen and bias for Th1 versus Th2 immune response. Thereafter, she moved to the College of Veterinary Medicine and Biomedical Sciences, at Texas A&M University where she worked as a research scientist and assistant professor. She conducted research on the host-pathogen interaction with emphasis on the receptor-ligand interaction, enteric pathogens and gut-associated mucosal immunity. Currently she has an adjunct faculty appointment at Texas A&M University. Dr. Khare has extensive experience working in BSL3- and A-BSL3-level laboratories. She established a special topic course at Texas A&M University to teach various compliance issues of “Laboratory Biosafety and Biosecurity” (BSL-2 and BSL-3) to undergraduate and graduate students.

Dr. Khare has received numerous awards and honors for her research. A few of them include:

• 2019 Indo-US Professorship by the American Society for Microbiology and the Indo-US Science and Technology Forum
• Research Fellowship from the Council of Scientific and Industrial Research (CSIR)
• Research Fellowship from the University of Saskatchewan, Saskatoon
• International Travel Award from CSIR
• Travel award from James W McLaughlin Fund
• Travel award from Burroughs Wellcome Fund
• “Best Paper Presentation” awards from various scientific organizations.
• Outstanding Service Award-Microbiome and Host Cell Interaction Study Team, FDA/NCTR
• FDA/NCTR Diversity Award
• FDA/NCTR Special Act Award

Dr. Khare is professional member of several scientific organizations. She represents NCTR and FDA in various scientific working groups including:

• Microbiome Working Group
• NIH-FDA Joint Agency Microbiome Group
• HESI Microbiome subcommittee
• High Impact Pathogen Working Committee/Technical Advisory Group
• Microbiome advisor for knowledge synthesis project, US-FDA
• Acute Radiation Syndrome committee
• Nano Research Coordination Group.

She is an expert reviewer for several journals and served as grant reviewer for FDA, U.S. Department of Agriculture, the National Institute of Environmental Health Sciences and several other international grant organizations. Dr. Khare has organized several workshops and conferences and supervised several undergraduate, graduate, and postdoctoral scientists. She served as an FDA Commissioner Fellow preceptor in 2013. She has been invited to share her research findings at other FDA Centers, several national and international conferences, as well as medical institutes and universities within the United States and abroad. These interactions have led to active collaborations with scientists from other federal agencies (NIEHS) and FDA Product Centers (Center for Veterinary Medicine, Center for Food Safety and Applied Nutrition, and Center for Drug Evaluation and Research) and FDA’s Office of Regulatory Affairs. She has also collaborated with scientists from academia including University of Connecticut, University of Arkansas for Medical Sciences, University of Arkansas at Little Rock, and Texas A&M University.

 
Research Interests

Dr. Khare has been working on the cutting-edge host-pathogen interaction, xenobiotic-microbiome-host communication, and nanoparticle research. She has successfully used in vivo, ex vivo, and in vitro models for microbiome assessment during the interaction of xenobiotics to disclose science-based evidences for regulatory sciences. She uses advanced new technologies (next generation sequencing, omics, and systems biology approaches) to establish in vitro permeability assays and ex vivo and in vivo models that could be used as endpoints to evaluate the safety of silver nanoparticles in the gastrointestinal tract. Furthermore, Dr. Khare’s laboratory has developed novel methods to evaluate carbon-based nanomaterial-induced toxicity on the population of intestinal microbiota and gut-associated immune response; a project under the Memorandum of Understanding between the Arkansas Research Consortium in Nanotechnology and NCTR. Dr. Khare’s laboratory has provided data that can be used as additional endpoints in the safety evaluation of nanotechnology-derived products which supplements the traditional metabolism, toxicity, and tissue-residue disposition information used in the toxicology risk assessments.

Another aspect of Dr. Khare’s research is to delineate the impact of chronic and acute exposure of external stimulants on gastrointestinal microbes and gut-associated immune response. She has several ongoing studies that contribute extensively to the FDA mission and public health. For example, in collaboration with the National Toxicology Program her research group is investigating the effect of chronic exposure of xenobiotic compounds to which humans are exposed to in their daily lives. This study is a multi-investigator effort to use the animal models. Her laboratory is analyzing the effect on the intestinal microbiota and gut-associated immune response along with the other investigators who are looking for the pharmacokinetics, pharmacodynamics, and biodistribution of the xenobiotic compounds of its metabolic products.

The use of veterinary antimicrobial drugs in food-producing animals may result in antimicrobial-drug residues in or on the edible products (milk, egg, meat) derived from treated animals. There are ongoing concerns that the residual amount of antibiotic may cause emergence of antimicrobial-resistance in intestinal-microbial populations, as well as lead to the development of cross-resistance for other classes of antibiotics. In collaboration with FDA’s Center for Veterinary Medicine, studies are in progress to evaluate the effects of residual amounts of antibiotics on the development of antibiotic resistance and gastrointestinal permeability. Dr. Khare’s laboratory uses in vitro and ex vivo models to address this emerging FDA concern and highlights the importance of evaluating toxicity of residual concentrations of antimicrobial agents in food. Data from these studies may aid in establishing guidance for human food-safety assessments.

Scientists from academia and other government agencies have reached out to Dr. Khare for collaborations. For example, she is a collaborator on a study conducted at the University of Arkansas for Medical Sciences to address links between environment pollutant exposure, obesity, and the microbiome. She has also collaborated with investigators from the University of Arkansas at Little Rock to analyze the impact of tomatoes with accumulated carbon nanotubes on the human-intestinal microbiota. The outcomes of collaborative projects within NCTR and with FDA Product Centers, the National Toxicology Program, and academic institutions are in line with the FDA’s Strategic Plan on Regulatory Science to “Evaluate Innovative Emerging Technologies” and “Modernize Toxicology to Enhance Product Safety.” The long-term goal of Dr. Khare’s research is to advance regulatory science by understanding the complex relationship of the gastrointestinal tract with commensal bacteria, invading enteric pathogens and residues in consumed food products (antibiotics, drugs, pesticides, herbicides, and additives). The outcome of this research will have a direct impact on the discovery of biomarkers, improved food safety, and personalized treatment.

Professional Societies/National and International Groups

American Society of Microbiology
Member
2002 – Present

FDA and Arkansas Graphene Consortium
Member
2014 – 2016

Global Summit on Regulatory Science
Panel member
2016

Indian Immunology Society
Life Member

International Society of Infectious Diseases
Member
2010 – Present

Johne’s Disease Integrated Program
Member and grant reviewer
2005 – Present

Mid-South Computational Biology and Bioinformatics Society
Member
2015 – Present

Mycobacterial Diseases of Animals
Member
2016 – Present

Selected Publications

The Impact of Pristine Graphene on Intestinal Microbiota Assessed Using a Bioreactor-Rotary Cell Culture System.
Lahiani M.H., Gokulan K., Williams K.W., and Khare S.
ACS Applied Materials and Interface. 2019, 11(29):25708-25719.
 

A Single or Short Time Repeated Arsenic Oral Exposure in Mice Impacts mRNA Expression for Signaling and Immunity Related Genes in the Gut.
Arnold M.G., Gokulan K., Doerge D.R., Vanlandingham M., Cerniglia C.E., and Khare S.
Food and Chemical Toxicology. 2019, 132:110597.
 

Alteration in the mRNA Expression of Genes Associated with Gastrointestinal Permeability and Ileal TNF-α Secretion Due to the Exposure of Silver Nanoparticles in Sprague-Dawley Rats.
Orr S.E., Gokulan K., Boudreau M., Cerniglia C.E., and Khare S.
Journal of Nanobiotechnology. 2019, 17(1):63.
 

Effect of Aloin on Intestinal Bacterial Community Structure and the Production of Short Chain Fatty Acids.
Gokulan K., Kolluru P., Cerniglia C.E., and Khare S.
Frontiers in Microbiology. 2019, 10:474.
 

The Impact of Multi-walled Carbon Nanotubes Residues in Tomato Fruits on Human Intestinal Epithelial Cells Barrier Functions and Intestinal Microbiome Composition.
Lahiani M.H., Khare S., Cerniglia C.E., Boy R., Ivanov I., and Khodakovskaya M.
Nanoscale. 2019, 11:3639-3655.
 

Irreversible Effects of Trichloroethylene on Gut Microbial Community and Gut Associated Immune Responses.
Khare S., Gokulan K., Williams K.M., Bai S., Gilbert K.M., and Blossom S.J.
Journal of Applied Toxicology. 2019, 39(2):209-220.
 

Responses of Intestinal Virome to Silver Nanoparticles: Safety Assessment by Classical Virology, Whole-Genome Sequencing and Bioinformatics Approaches.
Gokulan K., Bekele A., Drake K., and Khare S.
Int J Nanomedicine. 2018, 13:2857-2867.
 

Opposing Actions of Developmental Trichloroethylene and High-Fat-Diet Co-Exposure on Markers of Lipogenesis and Inflammation in Autoimmune-Prone Mice.
Blossom S., Fernandes L., Bai S., Khare S., Gokulan K., Yuan Y., Dewall M., Simmen F., and Gilbert K.
Toxicol Sci. 2018, doi: 10.1093/toxsci/kfy091.
 

Structure and Inhibitor Specificity of L,D-Transpeptidase (LdtMt2) from Mycobacterium tuberculosis and Antibiotic Resistance: Calcium Binding Promotes Dimer Formation.
Gokulan K., Khare S., Cerniglia C., Foley S., and Varughese K.
AAPS J. 2018, 20(2):44. doi: 10.1208/s12248-018-0193-x.
 

An In Vitro Study to Assess the Impact of Tetracycline on the Human Intestinal Microbiome.
Jung J., Ahn Y., Khare S., Gokulan K., Piñeiro S., and Cerniglia C.
Anaerobe. 2018, 49:85-94.
 

Effects of Residual Levels of Tetracycline on the Barrier Functions of Human Intestinal Epithelial Cells.
Gokulan K., Cerniglia C., Thomas C., Pineiro S., and Khare S.
Food Chem Toxicol. 2017, 109(Pt 1):253-263.
 

Graphene and Carbon Nanotubes Activate Different Cell Surface Receptors on Macrophages Before and After Deactivation of Endotoxins.
Lahiani M., Gokulan K., Williams K., Khodakovskaya M., and Khare S.
J Appl Toxicol. 2017, 37(11):1305-1316.
 

Systems Biology Analysis of Temporal In Vivo Brucella melitensis and Bovine Transcriptomes Predicts host:Pathogen Protein-Protein Interactions.
Rossetti C., Drake K., Lawhon S., Nunes J., Gull T., Khare S., and Adams L.
Front Microbiol. 2017, 8:1275. doi: 10.3389/fmicb.2017.01275.
 

Silver Ion-Mediated Killing of a Food Pathogen: Melting Curve Analysis Data of Silver Resistance Genes and Growth Curve Data.
Gokulan K., Williams K., and Khare S.
Data Brief. 2017, 11:49-53.
 

Assessment of Antimicrobial Effects of Food Contact Materials Containing Silver on Growth of Salmonella Typhimurium.
Williams K., Valencia L., Gokulan K., Trbojevich R., and Khare S.
Food Chem Toxicol. 2017, 100:197-206.
 

Systems Analysis of Early Host Gene Expression Provides Clues for Transient Mycobacterium Avium ssp Avium vs. Persistent Mycobacterium Avium ssp Paratuberculosis Intestinal Infections.
Khare S., Drake K., Lawhon S., Nunes J., Figueiredo J., Rossetti C., Gull T., Everts R., Lewin H., and Adams L.
PLoS One. 2016, 11(9):e0161946.
 

Transmissible Plasmid Containing Salmonella Enterica Heidelberg Isolates Modulate Cytokine Production During Early Stage of Interaction with Intestinal Epithelial Cells.
Gokulan K., Khare S., Williams K., and Foley S.
DNA Cell Biol. 2016, 35(8):443-453.
 

Size and Dose Dependent Effects of Silver Nanoparticle Exposure on Intestinal Permeability in an In Vitro Model of the Human Gut Epithelium.
Williams K., Gokulan K., Cerniglia C., and Khare S.
J Nanobiotechnology. 2016, 14(1):62.
 

Dose and Size-Dependent Antiviral Effects of Silver Nanoparticles on Feline Calicivirus, a Human Norovirus Surrogate.
Bekele A., Gokulan K., Williams K., and Khare S.
Foodborne Pathog Dis. 2016, 13(5):239-244.
 

Guidelines for the Use and Interpretation of Assays for Monitoring Autophagy (3rd edition).
Klionsky D., Khare S., and Zughaier S.
Autophagy. 2016, 12(1):221-222.

Lab Members

Contact information for all lab members:
(870) 543-7121
[email protected]  

Amit Kumar, MS
ORISE Fellow

Mohamed Lahiani, Ph.D.
Postdoctoral Fellow