Understanding the movement of antimicrobial resistance genes (ARGs) in the environment is critical to managing their spread. To assess potential ARG transport through the air via urban bioaerosols in cities with poor sanitation, we quantified ARGs and a mobile integron (MI) in ambient air over periods spanning rainy and dry seasons in Kanpur, India (n = 53), where open wastewater canals (OCWs) are prevalent. Gene targets represented major antibiotic groups—tetracyclines (tetA), fluoroquinolines (qnrB), and beta-lactams (blaTEM)—and a class 1 mobile integron (intI1). Over half of air samples located near, and up to 1 km from OCWs with fecal contamination (n = 45) in Kanpur had detectable targets above the experimentally determined limits of detection (LOD): most commonly intI1 and tetA (56% and 51% of samples, respectively), followed by blaTEM (8.9%) and qnrB (0%). ARG and MI densities in these positive air samples ranged from 6.9 × 101 to 5.2 × 103 gene copies/m3 air. Most (7/8) control samples collected 1 km away from OCWs were negative for any targets. In comparing experimental samples with control samples, we found that intI1 and tetA densities in air are significantly higher (P = 0.04 and P = 0.01, respectively, alpha = 0.05) near laboratory-confirmed fecal contaminated waters than at the control site. These data suggest increased densities of ARGs and MIs in bioaerosols in urban environments with inadequate sanitation. In such settings, aerosols may play a role in the spread of AR.
Address correspondence to Joe Brown, Department of Environmental Sciences and Engineering, University of North Carolina, 135 Dauer Dr., Chapel Hill, NC, 27599. E-mail: email@example.com
Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the CDC.
Financial support: This material is based on work supported by the National Science Foundation under grant number 1653226.
Authors’ addresses: Olivia Ginn, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, E-mail: firstname.lastname@example.org. David Berendes, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Diseases, Centers for Disease Control and Prevention, Atlanta, GA, E-mail: email@example.com. Anna Wood, Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, E-mail: firstname.lastname@example.org. Aaron Bivins, Department of Civil and Environmental Engineering and Earth Science, University of Notre Dame, Notre Dame, IN, E-mail: email@example.com. Lucas Rocha-Melogno, Marc A. Deshusses, and Mike Bergin, Department of Civil and Environmental Engineering, and Duke Global Health Institute, Duke University, Durham, NC, E-mails: firstname.lastname@example.org, email@example.com, and firstname.lastname@example.org. Joe Brown, Deparment of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, E-mail: email@example.com.