Emergence and Resistance Patterns of Aerobactin-Positive Hypervirulent Klebsiella pneumoniae in Clinical Infections
DOI:
https://doi.org/10.64149/J.Carcinog.24.4s.86-91Keywords:
Hypervirulent Klebsiella pneumoniae (hvKp), Aerobactin, Antimicrobial resistance, Hypermucoviscosity, Multidrug resistance (MDR)Abstract
Background: Klebsiella pneumoniae is a prominent cause of hospital- and community-acquired infections. The hypervirulent pathotype (hvKp), characterized by enhanced invasiveness and metastatic potential, poses increasing clinical challenges. Aerobactin-mediated iron acquisition is a key virulence determinant of hvKp. This study aimed to detect aerobactin gene (iucA) in clinical isolates and assess its association with antimicrobial resistance patterns.
Methods: A cross-sectional study was conducted on 100 non-duplicate K. pneumoniae isolates from diverse clinical samples at a tertiary care hospital. Identification was done by biochemical methods and VITEK-2. Hypermucoviscosity was assessed by string test. Molecular detection of iucA gene was performed by PCR. Antimicrobial susceptibility was tested using Kirby–Bauer disk diffusion per CLSI 2023 guidelines. ESBL and carbapenemase production were identified by combined disk diffusion and phenotypic tests.
Results: Among 100 isolates, aerobactin gene was detected in 28% while hypermucoviscosity was seen in 22%. Not all hypermucoviscous isolates harbored iucA, highlighting the need for molecular confirmation. Resistance rates were high for third-generation cephalosporins (68%) and cotrimoxazole (60%), with carbapenem resistance in ~20%. ESBL producers accounted for 55%, carbapenemase producers for 14%. Multidrug resistance was significantly lower in aerobactin-positive hvKp (32.1%) than classical strains (65.3%). hvKp isolates showed greater association with invasive infections like bloodstream infections and abscesses.
Conclusion: Aerobactin gene detection is a reliable molecular marker for hvKp distinguishing it from classical strains. Despite lower multidrug resistance, hvKp isolates cause severe invasive infections, underscoring the need for vigilant surveillance and tailored therapeutic strategies to manage the dual threat of hypervirulence and emerging resistance in K. pneumoniae.
