Occurrence of antimicrobial-resistant, extended-spectrum beta-lactamase and carbapenemase-producing bacterial isolates from intensive care unit environment in two hospitals of Ethiopia

BACKGROUND: Intensive care unit environments are a critical reservoir of antimicrobial-resistant bacterial species and facilitate the transmission of nosocomial infections. This unit harbors multidrug-resistant organisms, thereby complicating the management of infectious diseases within clinical settings, particularly in resource-limited countries. This study, therefore, aimed to determine the occurrence and antimicrobial resistance profiles of bacteria, including Extended-spectrum beta-lactamase- and Carbapenemase-producing isolates, in the intensive care units of two hospitals in Addis Ababa, Ethiopia. METHODS: A repeated cross-sectional study was conducted in Addis Ababa, Ethiopia, from July 2024 to April 2025. A total of 239 swab samples were collected from adult and neonatal intensive care unit environments during both the dry and rainy seasons. Samples were collected and processed aseptically. Bacterial identification and antimicrobial susceptibility testing were performed according to CLSI guidelines. RESULTS: From the total samples collected, 162/239 (67.8%) bacterial isolates were recovered from the Intensive Care Unit environment. Klebsiella pneumoniae 22/162 (13.6%) and Pseudomonas aeruginosa 21/162 (13%) were the most frequently isolated bacterial species. All P. aeruginosa were resistant to ceftazidime, while 19/22 (86.3%) and 18/22 (81.8%) of K. pneumoniae were resistant to cefuroxime and cefotaxime, respectively. All S.haemolyticus were also resistant to penicillin, and 8/12 (66.7%) of Enterococcus spp were resistant to erythromycin. Multidrug-resistant bacteria were seen in 89/150 (59.3%) of isolates. The highest multidrug resistance rate was obtained for Pseudomonas aeruginosa 18/21 (85.7%), followed by Klebsiella pneumoniae 16/22 (72.7%) and Acinetobacter spp 8/11 (72.7%). Extended-spectrum β-lactamase-producing isolates accounted for 23/105 (21.9%), and Carbapenemase-producers comprised 10/105 (9.5%). CONCLUSION: The environments within intensive care units are conducive to the proliferation of multidrug-resistant microorganisms, encompassing bacterial isolates that produce extended-spectrum beta-lactamases and carbapenemases, thereby complicating the management of infectious diseases. Consequently, it is crucial to address the issue of antimicrobial resistance in this critical setting to mitigate the incidence and dissemination of resistant bacteria, which may lead to the emergence of nosocomial infections.