Spread of Multidrug-Resistant Enterobacterales Strains Isolated From the Hospital Environment and Clinical Specimens Within ICUs in Tunisia.

The hospital environment is a recognized reservoir for multidrug-resistant (MDR) bacteria, and inadequate hygiene practices by healthcare workers (HCWs) may contribute to the transmission and persistence of healthcare-associated infections (HAIs), particularly in ICUs. This study investigated the presence, genetic characteristics, and transmission pathways of MDR Enterobacterales in the environment and among HCWs in three ICUs, such as surgical (ICU-S), medical (ICU-M), and pediatric (ICU-P), at Sahloul Hospital, Sousse, Tunisia. From September to December 2020, 140 samples were collected from environmental surfaces (n = 114) and HCWs' hands (n = 26). Of these, nine samples (6.42%) tested positive for resistant Enterobacterales, yielding 15 resistant isolates, including one Klebsiella pneumoniae and eight Enterobacter cloacae. Notably, no resistant Enterobacterales were recovered from HCWs' hand samples. Whole-genome sequencing was performed on seven isolates (five clinical and two environmental) to assess genetic relatedness and resistance profiles. Three distinct sequence types (STs) of K. pneumoniae were identified: ST147 (clinical and environmental), ST307, and ST353. The ST147 isolate from an antiseptic bottle in ICU-M co-produced CTX-M-15 and NDM-1 enzymes and carried the biocide resistance gene qacE. Despite both being ST147, the environmental and clinical isolates were not clonal (140 single-nucleotide polymorphism (SNP) differences). The ST307 isolate from a blood sample co-produced CTX-M-15 and OXA-204. Among E. cloacae isolates, ST344 (n = 2) was identified from two different ICUs and differed by only 6 SNPs, suggesting inter-ICU transmission. These isolates harbored blaACT-16, blaCTX-M-15, and multiple other resistance genes. One environmental E. cloacae isolate belonged to the clone ST78 and was recovered from a soap dispenser in ICU-P, carrying blaACT-15 and fosA. These findings underscore the potential of contaminated surfaces to harbor and disseminate MDR Enterobacterales. Strengthened infection control measures, environmental monitoring, and genomic surveillance are essential to reduce HAIs in ICU settings.