Hospital sanitary facilities on wards with high antibiotic exposure play an important role in maintaining a reservoir of resistant pathogens, even over many years

Abstract

Background Hospitals with their high antimicrobial selection pressure represent the presumably most important reservoir of multidrug-resistant human pathogens. Antibiotics administered in the course of treatment are excreted and discharged into the wastewater system. Not only in patients, but also in the sewers, antimicrobial substances exert selection pressure on existing bacteria and promote the emergence and dissemination of multidrug-resistant clones. In previous studies, two main clusters were identified in all sections of the hospital wastewater network that was investigated, one K. pneumoniae ST147 cluster encoding NDM- and OXA-48 carbapenemases and one VIM-encoding P. aeruginosa ST823 cluster. In the current study, we investigated if NDM- and OXA-48-encoding K. pneumoniae and VIM-encoding P. aeruginosa isolates recovered between 2014 and 2021 from oncological patients belonged to those same clusters. Methods The 32 isolates were re-cultured, whole-genome sequenced, phenotypically tested for their antimicrobial susceptibility, and analyzed for clonality and resistance genes in silico. Results Among these strains, 25 belonged to the two clusters that had been predominant in the wastewater, while two others belonged to a sequence-type less prominently detected in the drains of the patient rooms. Conclusion Patients constantly exposed to antibiotics can, in interaction with their persistently antibiotic-exposed sanitary facilities, form a niche that might be supportive for the emergence, the development, the dissemination, and the maintenance of certain nosocomial pathogen populations in the hospital, due to antibiotic-induced selection pressure. Technical and infection control solutions might help preventing transmission of microorganisms from the wastewater system to the patient and vice versa, particularly concerning the shower and toilet drainage. However, a major driving force might also be antibiotic induced selection pressure and parallel antimicrobial stewardship efforts could be essential.

Exploring clonality and virulence gene associations in bloodstream infections using whole-genome sequencing and clinical data

“…The notable clustering of ST50 E. quasihormaechei isolates calls for focused investigations, given the escalating local and global issue of sewage-related clonal colonization in hospital sanitary facilities (Babouee Flury et al, 2016;Kehl et al, 2022;Stokes et al, 2022). Similarly, the recurring identification of ST147 K. pneumoniae and ST235 and ST823 P. aeruginosa isolates, even in wards geographically distant from those assumed to have a contamination source in our setting (Kehl et al, 2022;Neidhöfer et al, 2023a), urges us to implement transmission dynamics monitoring networks (Bohl et al, 2022;Ko et al, 2022;Neidhöfer et al, 2023b).…”

Sanitary installations and wastewater plumbing as reservoir for the long-term circulation and transmission of carbapenemase producing Citrobacter freundii clones in a hospital setting

“…1 toilet visit) may be sufficient for MDRO transmission since they found 4 unrelated patient isolates to be connected to toilet isolates in an outpatient clinic [ 28 ]. In a recent manuscript published during revision of our paper, Neidhöfer et al confirm that sanitary facilities play an important role in maintaining a reservoir for MDRO over many years, particularly in wards with high antibiotic exposure [ 22 ].…”

“…Since CPE colonisation usually occurs in the gastrointestinal tract, contamination of hospital sewage water is not unexpected [ 19 – 21 ]. Hospital sanitary installations (sink, toilet, shower) have been recognised as CPE reservoirs [ 7 , 22 ]. The watery environment creates ideal circumstances for microbial surface colonisation.…”

ESKAPEE Pathogen Biofilm Control on Surfaces with Probiotic Lactobacillaceae and Bacillus species

“…Despite the generally recognized safety of probiotics and the fact that most were derived from benign edible sources some of which are even consumed in large quantities, the use of these microorganisms in hospitals warrants further investigation to ensure their safety, particularly in dysbiotic, immunocompromised, leukopenic or even agranulocytic patients [172][173][174][175], as these are patient groups that could particularly benefit from such innovative solutions [176][177][178][179][180][181][182][183][184]. It is desirable for these microorganisms, which may be transferred from the environment to the patient, to retain their protective effects in the patient as well.…”