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

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.