Phenotypic and genotypic characteristics of carbapenemase- and extended spectrum β-lactamase-producing Klebsiella pneumoniae ozaenae clinical isolates within a hospital in Panama City

Klebsiella pneumoniae spp ozaenae is a versatile bacterial species able to acquire antimicrobial resistance; the species presents a higher antimicrobial resistance profile compared to Klebsiella pneumoniae spp pneumoniae. Carbapenemase and extended spectrum β-lactamase (ESBL)-producing bacteria commonly arise in clinical settings where antimicrobial stewardship is limited. Our study aims to report the phenotypical and genetic characteristics of nosocomial Klebsiella pneumoniae spp ozaenae isolates associated with mortality collected from a tertiary-level hospital in Panama City. In October 2020, 11 consecutive multidrug-resistant Gram-negative isolates were recovered from secretions and blood cultures from hospitalized patients. Nearly 90% (10/11) of these patients died, and bacteria was obtained from six patients for investigation. Biochemical evaluation of the six isolates revealed the presence of multidrug-resistant Klebsiella pneumoniae spp ozaenae. Phenotypic evaluation indicated resistance to carbapenemase and EBSL. In contrast, genetic evaluation by PCR showed that only 30% (2/6) were resistant to CTX-M-1 (CTX-M group 1), whereas 60.7% (4/6) presented carbapenemase resistance genes, and 33.3% (2/6) presented New Delhi metallo-β-lactamase (NDM) resistance genes. Klebsiella pneumoniae ST258 was identified in 83.3% (5/6) of the isolates. Phylogenetic analysis using 16S revealed low homology among the six isolates. These results suggest that antibiotic resistance genes may have been incorporated into these Klebsiella pneumoniae spp ozaenae isolates within the hospital environment. We recommend strengthening the antimicrobial stewardship program and antibiotic control policy, as well as heightened infection control and prevention measures, such as ward sanitation and increased hand washing frequency.