The molecular characteristics, clinical manifestations, and risk factors of hypervirulent Klebsiella pneumoniae infections in a large teaching hospital in southwest China

Hypervirulent Klebsiella pneumoniae (hvKp) has been globally disseminated recently, especially in Asia. The purpose of this study was to identify the molecular characteristics, clinical manifestations, and clinical risk factors of hvKp infections among patients in a large teaching hospital. A retrospective study was conducted in 123 patients infected with K. pneumoniae at the Affiliated Hospital of Southwest Medical University (Luzhou, China) from October 2016 to November 2018. An isolate that positive for both PCR amplification of aerobactin gene and Galleria mellonella infection model was defined as hvKp. Overall, 43.1% (53/123) of K. pneumoniae isolates were hvKp. String tests were performed on all isolates, and MLSTs of all hvKp were conducted. The K1 ST23 isolates were the dominant clone of hvKp (35.8%). Univariate analysis revealed the following risk factors for hvKp: hepatic abscess (OR = 41.818 [95% CI, 5.379-335.086]), bacteremia (OR = 19.94 [95% CI, 5.565-71.446]), metastatic spread (OR = 19.938 [95% CI, 6.344-62.654]), CRP (OR = 1.008 [95% CI, 1.001-1.015]), nitroimidazole treatment (OR = 7.907 [95% CI, 1.652-37.843]), diabetes (OR = 3.067 [95% CI, 1.38-6.817]), and admission to positive culture interval (OR = 3.636 [95% CI, 1.524-8.678]). Moreover, Multivariate analysis implicated hepatic abscess (OR = 74.332 [95% CI, 3.121-1769.588]), bacteremia (OR = 28.388 [95% CI, 3.039-264.200]), and metastatic spread (OR = 19.391 [95% CI, 3.633-103.498]) as independent risk factors for hvKp infections. Thirteen of twenty-one tested antibiotics were founded resistant to non-hvKp, which is significantly greater than hvKp. Importantly, the ESBL-hvKp and MDR-hvKp were responsible for 7.5% and 15.1% in the hvKp group, respectively.