Acinetobacter baumannii and Klebsiella pneumoniae Isolates Obtained from Intensive Care Unit Patients in 2024: General Characterization, Prophages, Depolymerases and Esterases of Phage Origin

<i>Acinetobacter baumannii</i> and <i>Klebsiella pneumoniae</i> are significant nosocomial pathogens worldwide. In this study, the general characterization of <i>A. baumannii</i> and <i>K. pneumoniae</i> isolates obtained from the blood of intensive care unit patients of the multidisciplinary scientific and practical center of emergency medicine from January to September 2024 was performed. Prophage regions and prophage-derived tailspike polysaccharide-depolymerizing or -modifying enzymes within these isolates were identified and characterized in detail using a refined workflow. The protocol, encompassing a comprehensive survey of all predicted bacterial proteins, revealed an average of 6.0 prophage regions per <i>Acinetobacter baumannii</i> genome, including regions putatively derived from filamentous phages, and 4.8 prophage regions per <i>Klebsiella pneumoniae</i> isolate. Analysis of these putative prophage regions indicated that most were related to previously isolated, yet unclassified, temperate phages infecting <i>A. baumannii</i> and <i>K. pneumoniae</i>. However, certain identified sequences likely originated from phages representing novel groups comparatively distant from known phages.