Detection of Hypervirulence Genes and Drug Resistance in <i>Klebsiella pneumoniae</i> in Diagnostic Microbiology

<b>Objective:</b> Hypervirulent <i>Klebsiella pneumoniae</i> (hvKp) is emerging and gaining notoriety due to the acquisition of drug resistance. Differentiation of hvKp from classical <i>Klebsiella pneumoniae</i> (cKp) is essential for prompt initiation of therapy to prevent metastasis, detection of occult abscesses, and site-specific management for better patient outcomes. <b>Methods:</b> A total of 300 <i>K. pneumoniae</i> isolates from various clinical specimens were collected from 256 patients to determine their clinical profiles, antibiograms, risk factors, and patient outcomes. Hypermucoviscosity was demonstrated via a phenotypic string test. The hvKp pathotype was classified by molecular detection of the virulence genes <i>rmpA</i> and/or aerobactin-<i>iucA</i>. <b>Results:</b> <i>K. pneumoniae</i> infections affected the older age group (> 50 years) of both sexes, with a male preponderance (62.89%). Urinary tract infections were the most common clinical presentation (37.33%). Among the 300 isolates, 17 (5.66%) possessed hypervirulence genes, and 281 (93.66%) isolates were string test positive. Pyogenic liver abscess was more frequently observed in hvKp infections (5.88%) than in cKp infections (1.76%). Multiple sites were involved in 35.29% of the hvKp infections. (<i>p</i> < 0.05). Hypertension was the common comorbidity observed in the majority of the 256 patients (61.32%). The ICU stay (64.70%) predisposed patients to hvKp infections (<i>p</i> < 0.05). Compared with hvKp, cKp presented high rates of resistance to antibiotics. Although extended-spectrum beta-lactamase (ESBL) producers were significantly more common in cKp, 41.1% of hvKp strains were ESBLs. Carbapenem resistance and multidrug resistance were observed in 35.29% of the hvKp strains. The mortality rate in patients infected with hvKp was 23.52%. <b>Conclusion:</b> The potential for occult abscess and metastasis with life-threatening complications necessitates prompt, accurate identification of hvKp. Convergence of hvKp and cKp with shared traits poses a diagnostic and therapeutic dilemma for clinicians. The combination of genetic markers such as <i>rmpA</i> with <i>iucA</i> has high reported diagnostic accuracy. Further studies are needed to better characterize hvKp in the clinical laboratory.