Airborne and Surface Cross-Contamination of Bacteria Resistant to Carbapenem in Critical Units of a Teaching Hospital

Hospital-acquired infections (HAIs) have been significantly exacerbated by the escalating environmental contamination of critical units in hospital settings. The surfaces equipment, as well as the surrounding air, may serve as a source for multidrug-resistant organisms (MDRO) to spread and causes HAIs. Among the MDROs, Carbapenem Resistant Enterobacterales (CREs) are the main cause of concern due to their potential to contribute to high morbidity and mortality rates, causing outbreaks, and spreading resistance to other bacteria. This study was conducted to investigate the presence of CRE cross-contamination in critical units at a teaching hospital located on the East Coast of Malaysia. The total colony forming unit (CFU) of microbial were compared in different critical units and between morning and evening sessions. A total of 304 environmental samples comprised of airborne and swab samples were collected, while the temperature, relative humidity and number of occupants in the units were recorded. Gram staining, oxidase tests, biochemical tests and disk diffusion tests using carbapenem antibiotics were carried out to screen and identify the presence of carbapenem-resistance bacteria, specifically CREs. The findings showed the total CFU, which indicates the extent of microbial contamination, varies across different critical units. The presence of carbapenem-resistance bacteria (17 isolates) were detected in the environment at Ward X (n=8, 47.1%), intensive critical units (n=4, 23.5%), Neuro-ICU (n=2, 11.8%), and surgical intensive care units (n=3, 17.6%). Most of the critical units exhibited no notable disparity in the total CFU of microbials collected between morning and evening sessions (p>0.05) except the Neuro-ICU. In conclusion, as there was a presence of CREs in the critical unit environments of the teaching hospital, therefore, strengthening surveillance policy on the hygienic condition of the critical units and routine sampling is highly suggested to reduce the risk of HAIs outbreaks related to CREs.