2014.ISDS.Abstracts.Final.pdf


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ISDS 2014 Conference Abstracts

Metagenomic Profiling and Identification of 
Antimicrobial Resistance Genes from Airborne Microbial 
Communities

Tamar Dickerson*1, Jonathan L. Jacobs1, Nicole Waybright1, Danielle Swales2, Peggy 
Lowary1, Jeanette Coffin1 and Joseph Bogan1

1Biosurveillance, MRIGlobal, Rockville, MD, USA; 2MRIGlobal, Charlottesville, VA, USA

Objective
To assess the temporal dynamics of airborne bacterial communities 

in four locations around the National Capital Region and the dispersion 
of antimicrobial resistant (AMR) genes present within them.

Introduction
Since the adoption of antibiotics in the early 20th century, a 

plethora of clinical pathogens have acquired resistance to one or more 
modern-day antibiotics. This has resulted in antimicrobial resistance 
(AMR) being recognized as a severe threat to human and animal 
health worldwide. Recent work has demonstrated that AMR bacteria 
are widely prevalent in the environment, perhaps exacerbated by the 
widespread use of antibiotics for clinical or agricultural purposes.

Methods
Dry air filter units were used to collect air samples daily for a 

period of three months at four locations inside and outside a transit 
center in the National Capital Region. Samples were concentrated 
with a Vivaspin 100,000 Dalton ultrafiltration concentrator for DNA 
extraction, then pooled by month and PCR amplified for 16S rRNA 
community profiling. Amplicon sequencing was carried out on 
Life Technologies (Thermo Fisher Scientific) Ion Torrent Personal 
Genome Machine (PGM). Additionally, pooled samples were 
subjected to shotgun metagenomic sequencing on the Ion Proton 
platform. Lastly, a functional metagenomics screen is being carried out 
for antibiotic resistance genes against seven antibiotics: gentamycin, 
chloramphenicol, ciprofloxin, trimethoprim, colistin, tetracyline and 
penicillin. Following confirmation of AMR, the functional gene from 
each positive clone will be sequenced and compared to the existing 
shotgun metagenomics results. This will enable the prevalence of 
AMR genes in each of the four airborne microbial communities to 
be assessed.

Results
Initial data from each of the four sites for both 16S rRNA 

community profiling and shotgun metagenomic sequencing have 
shown a diverse population of environmental, human, animal and 
plant bacteria, with the genus Pseudomonas representing the largest 
proportion of sequences in both data sets. Furthermore, analysis of 
the shotgun metagenomics data suggests the presence of antibiotic 
resistance genes, whose biological functionality remains to be 
confirmed by further laboratory testing.

Conclusions
Preliminary results suggest that airborne microbial communities 

are complex and serve as a dynamic reservoir for the dispersion 
of antimicrobial resistance factors in the environment, potentially 
complicating the existing world-wide public health crisis to combat 
AMR pathogens.

Keywords
Biosurveillance; Airborne; Bacteria

Acknowledgments

This work is supported by a MRIGlobal Internal Research & Development 
Award.

*Tamar Dickerson

E-mail: tdickerson@mriglobal.org    

Online Journal of Public Health Informatics * ISSN 1947-2579 * http://ojphi.org * 7(1):e18, 2015