Microbiologist — Division of Microbiology

Ashraf Khan, Ph.D.
(870) 543-7121
[email protected]  

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 About  |  Publications  |  Lab Member

Background

Dr. Ashraf Khan received his Master of Science and Ph.D. in biochemistry from the Central Drug Research Institute, Lucknow, India, then completed a postdoctoral fellowship at Oakland University. In 1992, Dr. Khan joined the Division of Microbiology at NCTR as a research microbiologist and since then he has been working on projects in food safety, antimicrobial-resistance mechanism, method development, environmental biotechnology, and microbial genetics of foodborne pathogens. Dr. Khan has authored more than 96 peer-reviewed papers and book chapters, and he is also a reviewer for several peer-reviewed journals.

Research Interests

Dr. Khan’s research interests are in the fields of antimicrobial resistance in foodborne pathogens from food and clinical sources, and the role of efflux pumps genetic characterization of enteric bacteria using molecular techniques. His research projects at NCTR include:

• Analyzing the function of efflux pump genes and their regulation in multidrug-resistant Salmonella enterica and E. coli. 
• Characterizing structural and regulatory genes responsible for antibiotic resistance, their role for low-level resistance [low minimum inhibitory concentration (MICs)], and their synergy with other resistance mechanisms (increased MICs) by analyzing efflux pump inhibition using efflux pump inhibitors.
• Whole-genome sequencing of multidrug-resistant Salmonella spp. isolated from food and clinical sources.
• Characterizing enterotoxigenic Bacillus cereus from dietary supplements. 
• Multi-lab validation of isolation and identification of non-tuberculous Mycobacteria associated with tattoo-related skin infections.
• Developing a cultural method for the detection. 

Professional Societies Membership

American Society for Microbiology
Member
1988 — Present
 

Selected Publications

Antimicrobial Resistance and Related Gene Analysis of Salmonella from Egg and Chicken Sources by Whole-Genome Sequencing. 
Hu L., Guojie C., Brown E., Allard M., Ma L., Khan A.A., and Zhang G. 
Poultry Science. 2020, 99:7076-83.

Identification of Novel Plasmid Replicons Harboring β-Lactamase Resistant Genes in Ampicillin-Resistant Uropathogenic Escherichia coli.  
Nawaz M., Khan A.A., Khan S., Marasa B., Nguyen K., Nawaz S., and Mobley H. 
Symbiosis. 2019, 2372-0956.

Analysis of Enterotoxigenic Bacillus cereus Strains from Dried Foods Using Whole Genome Sequencing, Ulti-Locus Sequence Analysis and Toxin Gene Prevalence and Distribution Using Endpoint PCR Analysis. 
Carter L., Chase H., Gieseker C., Hasbrouck N., Stine C., Khan A.A., Ewing L., Tall B., and Gopinath G.
Int J Food Microbiol. 2018, 284:31-39.

Draft Genome Sequences of Ciprofloxacin-Resistant Salmonella enterica Strains with Multiple-Antibiotic Resistance, Isolated from Imported Foods.
Khan A.A., Khajanchi B.K., Khan S.A., Elkins C.A., and Foley S.L.
Genome Announc. 2017, 5(45).

Isolation and Characterization of Antimicrobial-Resistant Nontyphoidal Salmonella enterica serovars from Imported Food Products.
Bae D., Kweon O., and Khan A.A.
J Food Prot. 2016, 79(8):1348-54.

Characterization of Extended-Spectrum Beta-Lactamase (ESBL) Producing Non-Typhoidal Salmonella (NTS) from Imported Food Products.
Bae D., Cheng C., and Khan A.
Int J Food Microbiol. 2015, 214:12-7.

Detection and Functionality of the CdtB, PltA, and PltB from Salmonella enterica serovar Javiana.
Mezal E., Bae D., and Khan A.
Pathog Dis. 2014, 72(2):95-103.

The Sub-Species Characterization and Antimicrobial Resistance of Listeria monocytogenes Isolated from Domestic and Imported Food Products from 2004 to 2011.
Bae D., Mezal E., Smiley R., Cheng C., and Khan A.
Food Res Int. 2014, 64;656-63.

Isolation and Molecular Characterization of Salmonella enterica serovar Enteritidis from Poultry House and Clinical Samples During 2010.
Mezal E., Sabol A., Khan M., Ali N., Stefanova R., and Khan A.
Food Microbiol. 2014, 38;67-74.

The tetA Gene Decreases Tigecycline Sensitivity of Salmonella enterica Isolates.
Akiyama T., Presedo J., and Khan A.
Int J Antimicrob Agents. 2013, 42(2):133-40.

Isolation and Molecular Characterization of Salmonella enterica serovar Javiana from Food, Environmental and Clinical Samples.
Mezal E., Stefanova R., and Khan A.
Int J Food Microbiol. 2013, 164(1):113-8.

Identification and Molecular Characterization of Class 1 Integrons in Multiresistant Escherichia coli Isolates from Poultry Litter.
Ponce-Rivas E., Munoz-Marquez M., and Khan A.
Appl Environ Microbiol. 2012, 78(15):5444-7.

Isolation and Characterization of Small qnrS1-Carrying Plasmids from Imported Seafood Isolates of Salmonella enterica that are Highly Similar to Plasmids of Clinical Isolates.
Akiyama T. and Khan A.
FEMS Immunol Med Microbiol. 2012 Apr, 64(3):429-32.

Molecular Characterization of Strains of Fluoroquinolone-Resistant Salmonella enterica serovar Schwarzengrund Carrying Multidrug Resistance Isolated from Imported Foods.
Akiyama T. and Khan A.
J Antimicrob Chemother. 2012, 67(1):101-10.

Molecular Characterization of Salmonella enterica serovar Saintpaul Isolated from Imported Seafood, Pepper, Environmental and Clinical Samples.
Akiyama T., Khan A., Cheng C., and Stefanova R.
Food Microbiol. 2011, 28(6):1124-8.

Identification and Characterization of Class 1 Integron Resistance Gene Cassettes Among Salmonella Strains Isolated from Imported Seafood.
Khan A., Ponce E., Nawaz M., Cheng C., Khan J., and West C.
Appl Environ Microbiol. 2009, 75(4):1192-6.

Prevalence and Characterization of Salmonella enterica serovar Weltevreden from Imported Seafood.
Ponce E., Khan A., Cheng C., Summage-West C., and Cerniglia C.
Food Microbiol. 2008, 25(1):29-35.

Identification and Molecular Characterization of Salmonella spp. from Unpasteurized Orange Juices and Identification of New Serotype Salmonella Strain S. enterica serovar Tempe.
Khan A., Melvin C., and Dagdag E.
Food Microbiol. 2007, 24(5):539-43.

Occurrence of Non-O157 Shiga Toxin-Producing Escherichia coli in Ready-To-Eat Food from Supermarkets in Argentina.
Balague C., Khan A., Fernandez L., Redolfi A., Aquili V., Voltattorni P., Hofer C., Ebner G., Duenas S., and Cerniglia C.
Food Microbiol. 2006, 23(3):307-13.

Novel Organization of Genes in a Phthalate Degradation Operon of Mycobacterium vanbaalenii PYR-1.
Stingley R., Brezna B., Khan A., and Cerniglia C.
Microbiology. 2004, 150(Pt 11):3749-61.

Classification of a Polycyclic Aromatic Hydrocarbon-Metabolizing Bacterium, Mycobacterium sp. Strain PYR-1, as Mycobacterium vanbaalenii sp. nov.
Khan A., Kim S., Paine D., and Cerniglia C.
Int J Syst Evol Microbiol. 2002, 52(Pt 6):1997-2002.

Characterization of United States Outbreak Isolates of Vibrio parahaemolyticus Using Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR and Development of a Rapid PCR Method for Detection of O3:K6 Isolates.
Khan A., McCarthy S., Wang R., and Cerniglia C.
FEMS Microbiol Lett. 2002, 206(2):209-14.

Identification of Predominant Human and Animal Anaerobic Intestinal Bacterial Species by Terminal Restriction Fragment Patterns (TRFPs): a Rapid, PCR-Based Method.
Khan A., Nawaz M., Robertson L., Khan S., and Cerniglia C.
Mol Cell Probes. 2001, 15(6):349-55.

Detection of Multidrug-Resistant Salmonella typhimurium DT104 by Multiplex Polymerase Chain Reaction.
Khan A., Nawaz M., Khan S., and Cerniglia C.
FEMS Microbiol Lett. 2000, 182(2):355-60.
 

Lab Member

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

Ms. Khulud Alotaibi
Graduate Student