Detection of carbapenem-resistant bacteria in the public area of a hospital

Most studies of carbapenem resistance have been conducted on clinical isolates, but our understanding of the diversity and spread of carbapenem-resistant bacteria (CRB) in the hospital environment is still limited. Here we report the detection of CRB in the public area of a hospital to address this knowledge gap and to understand potential ways of how resistance can spread. A total of 65 swab samples were collected randomly from various surfaces that are frequently contacted by patients, hospital staff and visitors in an Australian hospital. Meropenem-resistant bacteria were cultivated from 25 (38.5%) of the 65 samples. Taxonomic classification and phylogenetic analysis showed that CRB were affiliated with three genera and six species, including Staphylococcus (S. haemolyticus, S. lugdunensis, S. hominis and S. pettenkoferi), Enterococcus (E. faecalis) and Pseudomonas (P. gessardii). This study revealed that CRB isolated from the public area of a hospital were mostly Gram-positive bacteria that appear to have evolved very high levels of resistance. This observation of high levels of meropenem-resistant bacteria in a public space of a hospital argue for stronger hygiene control, such as more thorough/frequent cleaning and disinfection, to prevent further spread of this resistance. The findings further raise concerns for public health, as carbapenem resistance might not only increase within pathogens targeted by carbapenems but also in other nosocomial bacteria.