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

Carbapenem resistance in bacteria is an urgent public health threat. Wastewater surveillance could support antimicrobial resistance monitoring at long-term care facilities. We assessed feasibility of wastewater sampling at such facilities for carbapenemase genes (bla_KPC, bla_VIM, bla_OXA-48-like, bla_NDM, and bla_IMP) detected by quantitative PCR or GeneXpert Carba-R (Cepheid, https://www.cepheid.com over 16 months and compared those findings with those for clinical infections. The bla_KPC, bla_OXA-48-like, and bla_VIM genes were routinely detected in composite wastewater samples, passive samples, and sewer biofilm swab specimens. Wastewater and sewer biofilm resistomes differed, but both contained bla_KPC, bla_VIM, and bla_IMP. Wastewater surveillance for carbapenemases shows promise, but few clinical infections during the study period and contributions from sewer biofilms complicate correlations between wastewater measurements and clinical incidence, underscoring the need for further research.