Abstract View
Exposure to Bacterial Aerosols with Antimicrobial Resistance Surrounding Septic Systems
GABRIELA RAMOS, Maria King, Texas A&M University
Abstract Number: 119
Working Group: Bioaerosols
Abstract
The aim of this study is to understand the role of aerosolization on the potential spread of antimicrobial resistant bacteria and genes (ARB/ARGs) from wastewater effluents. During the spraying process aerosolized ARB/ARGs can spread far from septic tank systems into houses, degrading indoor air quality and posing risks to residents. Bioaerosols from common wastewater treatment plants can be found 10 km downwind of the plant boundaries. However, a septic tank system is required to be only 1.5 m away from the house. It is critical to evaluate the aerosolization of ARB/ARGs from septic tank effluents to evaluate their potential contamination of the indoor air quality in nearby residences. Two different systems were tested in this study, consisting of an industrial and a residential septic system. From each system bioaerosols were collected in the winter and summer to observe the effect of different environmental conditions on bioaerosol emission and viability. Wastewater and sprinkler water from the industrial and residential septic systems, respectively, were also collected to compare the bacteria concentration and composition. Results from microbial and molecular analysis indicate lower concentrations of bacteria in the aerosols compared to the water samples. Antibiotic test results from the industrial system indicate that aerosolized bacteria from the winter are more resistant to the antibiotics used compared to aerosolized bacteria from the summer. Antimicrobial resistance (AMR) from the industrial septic system tests are comparable to residential testing, with both resulting in higher percentages of resistance in the bioaerosols during the winter seasons. The occurrence of aerosolized bacteria depends on operational conditions and discharge methods, and AMR development is related to seasonal changes, humidity, temperature, and air velocity. The results indicate that different mechanisms may be involved in the development of antibiotic resistance in the aerosolized bacteria compared to factors triggering resistance in the effluent microbiota.