Whole-Genome Sequencing of Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae Isolated from Human Bloodstream Infections.

Klebsiella pneumoniae is a Gram-negative bacterium commonly associated with bloodstream infections (BSIs), which can lead to severe clinical outcomes, especially in immunocompromised individuals or patients with underlying health conditions. The increasing prevalence of K. pneumoniae that produces extended-spectrum β-lactamases (ESBL) poses a significant challenge for treatment and infection control, necessitating a swift diagnostic approach and tailored antimicrobial therapy to improve patient outcomes. A total of 32 K. pneumoniae isolates were recovered from BSIs from December 2021 to August 2022. Whole-genome sequencing (WGS) was performed on the 14 ESBL-producing isolates. All ESBL isolates carried the blaCTX-M-15 gene, together with other β-lactamase-encoding genes (blaTEM-1, blaSHV-28, blaSHV-26, or blaOXA-1). Three of the isolates also carried the blaKPC-3 gene. Resistance genes to quinolones, sulfonamides, tetracycline, aminoglycosides, and chloramphenicol were also detected. We can conclude that the presence of ESBL-producing isolates among K. pneumoniae of BSIs raises concerns, since these enzymes limit the available treatment options, and future research must include studies on alternative therapies for dealing with resistant bacterial infections and developing new approaches to disease treatment.