Intensive Care Unit Sluice Room Sinks as Reservoirs and Sources of Potential Transmission of Carbapenem-Resistant Bacteria in a South African Tertiary Care Hospital

Khelan R Dheda; Chad M Centner; Lindsay Wilson; Anil Pooran; Shireen Grimwood; Yonas T Ghebrekristos; Suzette Oelofse; Ivan A Joubert; Aliasgar Esmail; Michele Tomasicchio

doi:10.2147/IDR.S418620

Intensive Care Unit Sluice Room Sinks as Reservoirs and Sources of Potential Transmission of Carbapenem-Resistant Bacteria in a South African Tertiary Care Hospital

Infect Drug Resist. 2023 Aug 21:16:5427-5432. doi: 10.2147/IDR.S418620. eCollection 2023.

Authors

Khelan R Dheda¹, Chad M Centner², Lindsay Wilson^{3

4}, Anil Pooran^{3

4}, Shireen Grimwood², Yonas T Ghebrekristos², Suzette Oelofse^{3

4}, Ivan A Joubert⁵, Aliasgar Esmail^{3

4}, Michele Tomasicchio^{3

4}

Affiliations

¹ Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
² Division of Medical Microbiology, National Health Laboratory Services (NHLS)/Groote Schuur Hospital, Microbiology, University of Cape Town, Cape Town, South Africa.
³ Division of Pulmonology, Department of Medicine, Centre for Lung Infection and Immunity, University of Cape Town and UCT Lung Institute, Cape Town, South Africa.
⁴ South African MRC/UCT Centre for the Study of Antimicrobial Resistance, University of Cape Town, Cape Town, South Africa.
⁵ Division of Critical Care, Department of Anaesthesia and Perioperative Medicine, University of Cape Town, Cape Town, South Africa.

Abstract

Purpose: Carbapenem-resistant bacteria (CRB) pose a major health risk to patients in intensive care units (ICU) across African hospitals. There are hardly any data about the role of hospital sinks as reservoirs of CRB in resource-poor African settings. Furthermore, the specific within-sink location of the highest concentration of pathogens and the role of splash back as a transmission mechanism remains poorly clarified.

Methods: We swabbed ICU sluice room sinks in a tertiary hospital in Cape Town, South Africa. Swabs were taken from four different parts of the sluice room sinks (tap-opening, trap, below the trap, and u-bend). Dilutions were prepared and plated on carbapenem-infused agar. Colonies were identified and drug resistance profiles were determined using a biochemical analyser. To evaluate the potential transmission from the sink, similar plates were placed at fixed distances from the sink when the tap was turned on and off.

Results: CRB were isolated from the trap, water interface below the trap, and the u-bend (the latter harboured the highest density of CRB species). Five CRB, resistant to at least 7 antibiotic classes, were isolated including Pseudomonas, Klebsiella, Citrobacter, Serratia, and Providencia. CRB could be cultured from droplets that fell on agar-containing plates placed at a varying distance from the trap.

Conclusion: There is a higher density of CRB in the u-bend of ICU sluice room sinks which can act as a potential source of transmission. The data inform targeted CRB transmission-interruption strategies in resource-poor settings.

Keywords: antimicrobial resistance; carbapenem-resistant bacteria; intensive care units; multi drug resistant bacteria; sluice room sink.

Grants and funding

This work was supported by Antrum Biotech, a University of Cape Town spin off company, through an unrestricted student support grant. The research and development company does not work in the field of antibiotics, antimicrobial resistance, or decontamination products, and its employees played no role in the study design, collection, analysis and interpretation of data, writing of the report, or the decision to submit the article for publication. AE was supported by funding received from the European and developing Countries Clinical Trials Partnership (EDCTP TMA-2015CDF-1052). Some of work was supported by the South African MRC (RFA-EMU-02-2017). AP was supported by funding received from the European and developing Countries Clinical Trials Partnership (EDCTP TMA-2019CDF-2780).