Abstract

Background:
Klebsiella pneumoniae, classified by the WHO as a critical priority pathogen, poses a major global health threat. K. pneumoniae causes a wide range of infections, including sepsis, urinary tract infections, meningitis, soft tissue infections, liver abscesses, and pneumonia. Its pathogenicity is driven by virulence and antimicrobial resistance (AMR) genes that complicate treatment and infection control.

Aim:
This study aimed to evaluate the virulence-linked traits of eleven K. pneumoniae isolates associated with neonatal infections and to compare them with two reference genomes (NTUH K2044 and MGH 78578) in order to assess virulence gene linkage and pathogenic potential.

Methods:
Eleven neonatal K. pneumoniae isolates (six from sepsis cases and five from feeding tubes) were evaluated. Isolates were characterised using standard microbiological methods, sequence typing, and whole genome sequencing (Illumina MiSeq). Efflux pump genes representing five families were compared between the neonatal isolates and the reference genomes that was based on the presence/ absence genes only.

Results:
Whole genome sequencing revealed eight sequence types (ST34, ST35, ST37, ST105, ST111, ST147, ST247 and ST526) and six O-antigen serogroups (O1, O2, O3, O4, O8 and O12). Phenotypically all represented isolates showed high amount of capsular production on powdered infant formula media than XLD media. Antibiotic resistance profiles of presented isolates were resistant to 10 from 11 antibiotics tested except ciprofloxacin, and were confirmed ESBL producers. Comparative analysis showed that the K. pneumoniae isolates carried a set of efflux pump associated genes which may be linked to multidrug resistance and virulence related potential, compared with the reference isolates NTUH K2044 and MGH 78578.

Conclusion:
The findings highlight the genomic diversity and multidrug resistant nature of neonatal K. pneumoniae isolates and support the use of comparative genomic analyses to improve understanding of resistance and virulence associated features in neonatal care settings.

Key words: Klebsiella pneumoniae; Efflux pump genes; Sepsis; Feeding tubes and neonates.