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  1. Science & Research (NCTR)

Youngbeom Ahn Ph.D.

Research Biologist — Division of Microbiology

Dr. Youngbeom Ahn, Research Biologist, NCTR Division of Microbiology

Youngbeom Ahn, Ph.D.
(870) 543-7121
NCTRResearch@fda.hhs.gov  

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 About  |  Publications


Background

After earning a Ph.D. from Hanyang University, Seoul, Korea, Dr. Ahn’s career continued as a postdoctoral fellow in the Environmental Biology Department at the University of Guelph, Canada. He further advanced his career as a postdoctoral fellow and a research associate in the Biotechnology Center for Agriculture and the Environment at Rutgers University. Dr. Ahn joined the Division of Microbiology at FDA’s National Center for Toxicological Research (NCTR) as a staff fellow in 2009 and then became a research biologist. For his scientific contributions, Dr. Ahn was awarded the FDA/NCTR Outstanding Junior Investigator in 2013. He received the NCTR Special Act Award for outstanding research and regulatory impact on providing data to FDA/CVM on the effect of short- and long-term exposure to residual levels of tetracycline in food on the intestinal microbiome.

Research Interests

Dr. Ahn is collaborating with CDER on a project to explore strategies for resuscitation and enrichment of Burkholderia cepacia complex (BCC) strains in pharmaceutical products. The Centers for Disease Control has requested that FDA issue a rule or policy that establishes B. cepacia as an objectionable organism in pharmaceuticals, and the United States Pharmacopeia (USP) has revisited the concept of including B. cepacia in its chapters. For USP to include this species as an organism of interest, they must have a test that can be done by nearly any microbiology laboratory using conventional technology. However, existing USP methods use enrichment in Trypticase Soy Broth, which is inadequate for all strains. The objectives of Dr. Ahn’s research are to 1) develop a resuscitative step and enrichment technique for BCC recovery and 2) develop methodology to detect BCC and its 16 related genomovars. He also looks to evaluate the use of modern molecular technologies to identify BCC and "specified microorganisms" (i.e., E. coli, Pseudomonas aeruginosa, Salmonella spp., Staphylococcus aureus, Clostridia spp., Candida albicans and the Enterobacteriaceae family) in “real-world” water systems.

 

Professional Societies/National and International Groups

American Society for Microbiology
Member
2012 — Present

Selected Publications

A Comparative Metagenomic Analysis of Specified Microorganisms in Groundwater for Non-Sterilized Pharmaceutical Products
Daddy Gaoh S., Alusta P., Lee Y.J., Hussong D., Marasa B., and Ahn Y.
Curr Microbiol. 2024, 81, 273. doi: 10.1007/s00284-024-03791-w.

A Flow Cytometric Assay to Detect Viability and Persistence of Salmonella enterica subsp. enterica serotypes in Nuclease-Free Water at 4 and 25°C
Williams A., Daddy Gaoh S., Savenka A., Paredes A., Alusta P., Ahn Y., and Buzatu D.A. 
Front Microbiol. 2024, 15:1342478. doi: 10.3389/fmicb.2024.1342478. 

Propidium Monoazide (PMAxx)-Recombinase Polymerase Amplification Exo (RPA Exo) Assay for Rapid Detection of Burkholderia cepacia Complex in Chlorhexidine Gluconate (CHX) and Benzalkonium Chloride (BZK) Solutions
Daddy Gaoh S., Kweon O., and Ahn Y.
Microorganisms. 2023, 11(6):1401. doi: 10.3390/microorganisms11061401.

Desulfoluna spp. Form a Cosmopolitan Group of Anaerobic Dehalogenating Bacteria Widely Distributed in Marine Sponges. 
Horna-Gray I., Lopez N.A., Ahn Y., Saks B., Girer N., Hentschel U., McCarthy P.J., Kerkhof L.J., and Häggblom M.M. 
FEMS Microbiol Ecol. 2022, 98(7):fiac063. doi: 10.1093/femsec/fiac063.

Specific Detection and Enumeration of Burkholderia cepacia Complex by Flow Cytometry Using a Fluorescence-Labeled Oligonucleotide Probe
Daddy Gaoh S., Williams A., Le D., Kweon O., Alusta P., Buzatu D.A., and Ahn Y.
Microorganisms. 2022, 10(6):1170. doi: 10.3390/microorganisms10061170.

A Propidium Monoazide (PMAxx)-Droplet Digital PCR (ddPCR) for the Detection of Viable Burkholderia cepacia Complex in Nuclease-Free Water and Antiseptics
Daddy Gaoh S., Kweon O., Lee Y.J., Hussong D., Marasa B., and Ahn Y.
Microorganisms. 2022, 10(5):943. doi: 10.3390/microorganisms10050943.

Loop-Mediated Isothermal Amplification (LAMP) Assay for Detecting Burkholderia cepacia Complex in Non-Sterile Pharmaceutical Products.
Daddy Gaoh S., Kweon O., Lee Y.J., LiPuma J.J., Hussong D., Marasa B., and Ahn Y.
Pathogens. 2021, 10(9):1071. doi: 10.3390/pathogens10091071.

Impact of Chronic Tetracycline Exposure on Human Intestinal Microbiota in a Continuous Flow Bioreactor Model.
Ahn Y., Jung J.Y., Kweon O., Veach B.T., Khare S., Gokulan K., Piñeiro S.A., and Cerniglia C.
Antibiotics (Basel). 2021, 10(8):886. doi: 10.3390/antibiotics10080886.

Detection of Campylobacter jejuni from Fresh Produce: Comparison of Culture- and PCR-Based Techniques, and Metagenomic Approach for Analyses of the Microbiome Before and After Enrichment.
Chon J.W., Jung J.Y., Ahn Y., Bae D., Khan S., Seo K.H., Kim H., and Sung K.
J Food Prot. 2021. doi: 10.4315/JFP-20-408. Online ahead of print.

A Comparison of Culture-Based, Real-Time PCR, Droplet Digital PCR and Flow Cytometric Methods for the Detection of Burkholderia cepacia Complex in Nuclease-Free Water and Antiseptics.
Ahn Y., Gibson B., Williams A., Alusta P., Buzatu D.A., Lee Y.J., LiPuma J.J., Hussong D., Marasa B., and Cerniglia C.
J Ind Microbiol Biotechnol. 2020, 47(6-7):475-484. doi: 10.1007/s10295-020-02287-3. Epub 2020 Jul 15.

Oligotrophic Media Compared with a Tryptic Soy Agar or Broth for the Recovery of Burkholderia cepacia Complex from Different Storage Temperatures and Culture Conditions.
Ahn Y., Lee U.J., Lee Y.J., LiPuma J.J., Hussong D., Marasa B., and Cerniglia C.
J Microbiol Biotechnol. 2019, 29(10):1495-1505. doi: 10.4014/jmb.1906.06024.

In vitro Test Systems to Determine Tetracycline Residue Binding to Human Feces.
Ahn Y., Jung J.Y., Veach B.T., Khare S., Gokulan K., Piñeiro S.A., and Cerniglia C.
Regul Toxicol Pharmacol. 2018, 99:105-115. doi: 10.1016/j.yrtph.2018.09.013. Epub 2018 Sep 15.

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. doi: 10.1016/j.anaerobe.2017.12.011. Epub 2017 Dec 30.

Effects of Extended Storage of Chlorhexidine Gluconate and Benzalkonium Chloride Solutions on the Viability of Burkholderia cenocepacia.
Ahn Y., Kim J., Lee Y., LiPuma J., Hussong D., Marasa B., and Cerniglia C.
J Microbiol Biotechnol. 2017, 27(12):2211-2220. doi: 10.4014/jmb.1706.06034.

Novel Reductive Dehalogenases from the Marine Sponge Associated Bacterium Desulfoluna spongiiphila.
Liu J., Lopez N., Ahn Y., Goldberg T., Bromberg Y., Kerkhof L., and Häggblom M.
Environ Microbiol Rep. 2017, 9(5):537-549. doi: 10.1111/1758-2229.12556. Epub 2017 Jul 21.

Intrinsic Resistance of Burkholderia cepacia Complex to Benzalkonium Chloride.
Ahn Y., Kim J., Kweon O., Kim S., Jones R., Woodling K., Gamboa da Costa G., LiPuma J., Hussong D., Marasa B., and Cerniglia CE.
MBio. 2016, 7(6). pii: e01716-16. doi: 10.1128/mBio.01716-16.

Survival and Susceptibility of Burkholderia cepacia Complex in Chlorhexidine Gluconate and Benzalkonium Chloride.
Kim J., Ahn Y., LiPuma J., Hussong D., and Cerniglia C.
J Ind Microbiol Biotechnol. 2015, 42(6):905-13. 

Evaluation of Liquid and Solid Culture Media for the Recovery and Enrichment of Burkholderia cenocepacia from Distilled Water.
Ahn Y., Kim J., Ahn H., Lee Y., LiPuma J., Hussong D., and Cerniglia C.
J Ind Microbiol Biotechnol. 2014, 41(7):1109-18.

Effect of Sterilized Human Fecal Extract on the Sensitivity of Escherichia coli ATCC 25922 to Enrofloxacin.
Ahn Y., Sung K., Rafii F., and Cerniglia C.
J Antibiot (Tokyo). 2012, 65(4):179-84.

In vitro Enrofloxacin Binding in Human Fecal Slurries.
Ahn Y., Linder S., Veach B., Steve Yan S., Haydée Fernández A., Pineiro S., and Cerniglia C.
Regul Toxicol Pharmacol. 2012, 62(1):74-84.


Contact Information
Youngbeom Ahn
(870) 543-7121
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