Evaluation of Detection Methods for Wastewater Surveillance of Antimicrobial-Resistant Bacteria from Healthcare Facilities

Abstract Carbapenem resistance is an urgent public health threat. Wastewater surveillance could support antimicrobial resistance monitoring at long-term care facilities (LTCFs). Feasibility of wastewater sampling (via composite or passive sampler, and sewer biofilm swabs) for carbapenemase genes ( bla KPC , bla VIM , bla OXA-48-like , bla NDM , and bla IMP ) detected by qPCR or GeneXpert® Carba-R from a LTCF was assessed over 16 months and compared to clinical infections. bla KPC , bla OXA-48-like , and bla VIM were routinely detected in composite wastewater samples (6.4±0.8 log 10 gene copy (GC)/ml (100% of 61 samples), 5.5±0.8 (98%), and 5.9±1.3 (34%), respectively), passive samples (8.2±0.5 log 10 GC/g (31% of 55), 6.6±0.5 (96%), and 6.6±0.7 (31%)) and sewer biofilm (6.0±0.7 log 10 GC/cm 2 of pipe (100% of 17), 5.0±0.7 (100%), and 5.8±2.7 (24%)). Resistomes of wastewater and sewer biofilms differed, but both contained bla KPC, bla VIM, and bla IMP . Passive sampling may be a suitable alternative to composite sampling. Wastewater surveillance is a promising addition to carbapenemase monitoring.