Identification of Antimicrobial Resistance Patterns, Type VI Secretion System, and Virulence Factors in Clinical Isolates of : A Cross-Sectional Study.

is an opportunistic pathogen linked to a range of severe infections. It is classified into classic (cKp) and hypervirulent (hvKp) forms, with hvKp showing enhanced virulence. This study examines Type VI secretion system (T6SS) presence and virulence factors in cKp and hvKp strains while assessing antimicrobial resistance. Eighty-three isolates were collected from hospitalized patients in Ilam, Iran, between June and December 2023. Antimicrobial susceptibility testing was conducted using the disk diffusion method. Hypervirulent isolates were identified by string test, tellurite resistance, and presence of , , and using polymerase chain reaction (PCR). Furthermore, PCR detected virulence, -lactamases, and T6SS genes. Of 83 isolates, 16.87% and 83.13% were hvKp and cKp, respectively. All isolates were multidrug-resistant (MDR), with 18.07% exhibiting carbapenem resistance. The pattern of antibiotic resistance in hvKp and cKp is not significantly different, except for ciprofloxacin, tetracycline, and azithromycin. Also, there was no significant difference between T6SS-positive and T6SS-negative isolates except for ciprofloxacin. T6SS presence did not significantly correlate with virulence or resistance genes, except for ciprofloxacin resistance ( = 0.0219). Surveillance, infection control, and targeted therapies are essential to combat hypervirulent and drug-resistant .