Hospital plumbing an ideal environment for antibiotic-resistant plasmids, study finds

A study led by the National Institutes of Health (NIH) released the results of their investigation on plasmids that provide resistance to carbapenem – a last-line-of-defense antibiotic used against multidrug-resistant organisms. The study, which appeared in the American Society for Microbiology’s open access journal mBio, looked at where these organisms are found and how they spread in a hospital setting.

• The NIH’s Hospital Epidemiology Service regularly conducts an extensive sampling of high-touch surfaces, sink, and other areas in the hospital; however, for this study, the range was expanded to cover housekeeping closets, wastewater from internal hospital pipes, and external manholes over a two-year period.
• Moreover, the team collected five years’ worth of patient clinical and surveillance isolates, and this was compared with the samples collected.
• A total of 108 isolates underwent whole-genome sequencing and analysis to enable an in-depth genetic comparison of bla_KPC/bla_NDM-positive isolates.
• Tests revealed that wastewater from pipes that drain out of the intensive care unit and external manholes had carbapenemase-producing organisms (CPOs). These organisms were made up of different species and plasmids, which could have differing effects on the environment and people. Also, plasmid backbones common to both populations were also detected. This, according to the investigators, indicates a potentially large supply of factors that will be conducive to the spread of antibiotic-resistant genes.
• The results from the sequence analysis and epidemiology indicate that infection control and compliance measures were successful. However, researchers found a case of Leclercia sp. that was transmitted from the hospital in the surveillance.

The results of the investigation, according to researchers, will improve the understanding of how CPOs are transmitted in a hospital environment and could be useful in future infection control strategies.

Find the full text of the study at this link.

Journal Reference:

Weingarten RA, Johnson RC, Conlan S, Ramsburg AM, Dekker JP, Lau AF, Khil P, Odom RT, Deming C, Park M, et al. GENOMIC ANALYSIS OF HOSPITAL PLUMBING REVEALS DIVERSE RESERVOIR OF BACTERIAL PLASMIDS CONFERRING CARBAPENEM RESISTANCE. mBio. 2018;9(1). DOI: 10.1128/mBio.02011-17