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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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Ph.D. Thesis Defense Announcement
QUANTITATIVE ESTIMATION OF ENTERIC PATHOGENS AND ANTIBIOTIC RESISTANCE GENES IN AEROSOLS NEAR URBAN WASTE FLOWS
by
Olivia Ginn
Advisor(s):
Dr. Joe Brown
Committee Members:
Dr. Kostas Konstantinidis (CEE-GT), Dr. David Berendes (CDC), Dr. Rodney Weber (EAS-GT), Dr. James Mulholland (CEE-GT)
Date & Time: April 12th 1pm EST
Location: https://bluejeans.com/539738661?src=join_info
Unsafe water and sanitation enable the transmission of enteric pathogens from infected individuals to new susceptible hosts through direct contact and/or through the environment via multiple pathways. While a rich and rapidly growing body of literature describes microbial risks associated with unsafe water, poor hygiene, and direct exposure to fecal contamination in the environment, few studies have examined indirect or direct exposure to enteric pathogens via the aeromicrobiological (AMB) pathway in cities of low- and-middle-income countries (LMICs), where wastewater is poorly managed and enteric pathogen transmission is prevalent. We deployed bioaerosol sampling strategies in three cities using coupled measurement of culturable fecal indicator bacteria (as an indirect proxy for viability) with multiplex quantitative PCR (qPCR) and droplet digital PCR (ddPCR) to estimate densities of enteric pathogens and antimicrobial resistance genes (ARGs). Two cities had poor sanitation infrastructure (La Paz, Bolivia and Kanpur, India), with reference sampling in Atlanta. We report the first absolute quantitative estimates of pathogens including ETEC, EIEC, Campylobacter jejuni, Salmonella spp., Cryptosporidium parvum, and Giardia duodenalis in extramural urban aerosols. We also report quantitative density estimates of enteric viruses including norovirus GI and GII and a range of ARGs. More frequent detections were observed near urban wastewater flows. We applied these data to an atmospheric diffusion equation derived for a line source representing an open sewer, demonstrating that aerosols containing culturable E. coli as well as gene targets specific to globally important enteric pathogens are present near fecal contaminated sources and may deposit downwind in densities that could be relevant to human exposure. The results of our study add to a growing body of evidence suggesting the potential importance of bioaerosols as a mechanism for transport of enteric microbes near concentrated fecal wastes in cities with poor sanitation.
