Genomic comparison of A. baumannii isolated from COVID-19 and non-COVID-19 patients admitted to an Intensive Care Unit: preliminary results
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Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
Department of Public Health and Infectious Diseases, Sapienza University of Rome, Sapienza, Italy
Publication date: 2023-04-27
Popul. Med. 2023;5(Supplement):A140
Background and Objective: A. baumannii is a major responsible of infections in patients admitted to the intensive care unit (ICU). In Policlinico Umberto I in Rome, A. baumannii was the main microorganism isolated in ICU SARS-COV-2 patients, and high clonal transmission profiles were documented. The purpose of this study was to compare the clonal profiles detected in COVID-19 patient’s samples with those obtained from non-COVID-19 patients admitted to the same unit. Methods: Bacterial isolates of A. baumannii were collected between January 2020 and January 2022. The isolates were typed by pulsed field electrophoresis to analyze their homology relationships. Results: A total of 587 COVID-19 patients and 304 non-COVID-19 patients were admitted to the ICU. They were predominantly male (N=398 and N=186, respectively) with a mean age of 63.5 years in the first group and 61.6 years in the second group. Genotypic analysis of 138 isolates in COVID-19 patients revealed two main patterns (A and B) and a few minor patterns. Patterns “A” (59.4%) were found throughout the study period, patterns “B” (35.5%) were isolated from October 2020 to March 2021. In non-COVID-19 patients, 67 isolates that showed more heterogeneous clonal profiles were typed. However, the pattern “A” (47.7%), was the most frequent pulsotype detected during the study period. The strains had high antibiotic resistance profiles and were isolated mostly from tracheobronchial aspirates and rectal swabs both in COVID-19 (42.8% and 29.6%) and in non-COVID-19 patients (34.3% and 42.8%). Conclusions: The identification of the pattern “A” in both cohorts of patients, may indicate the possible transfer of related isolates from one ICU to another in the same hospital among patients or through healthcare workers. Therefore, the use of strict infection control strategies to reduce cross-contamination of endemic clones of A. baumannii isolates is essential.