Molecular characteristics and analysis of drug resistance-virulence correlation of carbapenem-resistant Klebsiella pneumoniae in northern Henan region

Klebsiella pneumoniae , particularly carbapenem-resistant Klebsiella pneumoniae (CRKP), has emerged as a pressing threat to global public health. Its intrinsic multidrug resistance and hypervirulence collectively pose a dual burden to clinical management. This study used the modified carbapenem inactivation method (mCIM) and microbroth dilution method to analyze the 225 clinical isolates’ antimicrobial resistance phenotypes to characterize the clinical epidemiology, antimicrobial resistance spectrum, and virulence-associated phenotypes of CRKP isolates in the northern Henan region, which were primarily obtained from intensive care units (ICUs, 51.11%) and sputum specimens (71.56%), with the majority of affected patients aged 60 years or older (61.78%). They exhibited high resistance to β-lactam antibiotics, including imipenem (100%) and meropenem (99.55%), while remaining susceptible to tigecycline (resistance rate of 0.88%). Meanwhile, bla CTX-M and bla KPC were the predominant resistance-associated genes, whereas rmpA2 , iucA , peg , and rmpA served as key virulence-associated markers for hypervirulent CRKP (hv-CRKP). Notably, hv-CRKP showed a significant negative correlation with resistance gene carriage rates ( P < 0.05) and a significant positive correlation with the hypermucoviscous phenotype ( P < 0.01). CRKP strains in the northern Henan region exhibit concurrent high-level drug resistance and hypervirulence, with a prevalence of hypervirulent CRKP (hv-CRKP). IMPORTANCE Among the prevalent CRKP strains in Northern Henan, the detection rate of hv-CRKP is relatively high. Moreover, the high-mucus phenotype strains are positively correlated with the virulence gene cluster and negatively correlated with the drug resistance gene load. An analysis framework of “drug resistance gene profile–virulence phenotype–molecular association” is necessary to fill the gap in regional research and to provide key data support for building a three-level drug-resistant bacteria prevention and control system across the “national–regional–hospital” levels.