Emergence of Severe Metastatic Hypervirulent Klebsiella pneumoniae infections in Texas

Background: Hypervirulent Klebsiella pneumoniae (hvKp) infections have mainly been described in Asia. Two patients in the age group of 30 to 50 years presented within a two month period to a tertiary referral hospital in Texas with septic shock, hepatic abscess and septic thrombophlebitis. Blood cultures were positive for Klebsiella pneumoniae (isolates 2020CK-00441 and 2021CK-00720 respectively). Methods: Whole genome sequencing was performed using paired-end Illumina MiSeq reads for both isolates. Nanopore sequencing to obtain a closed genome was performed for 2020CK-00441. Results: 2020CK-00441 belonged to ST23 type while 2021CK-00720 was a ST65 type isolate. Kleborate analyses predicted with high confidence that both the isolates were hvKp. Phylogenetic analyses showed that the two strains are not closely related to each other or to any other known hvKp isolates. Both the isolates had yersiniabactin, colibactin, aerobactin and salmochelin producing loci which likely confer these isolates hvKp phenotype. 2020CK-00441 had a unique pK2044 like plasmid. Conclusions HvKp strains capable of causing devastating metastatic septic infections have emerged in Texas. These isolates are unique when compared to other hvKp strains of the world. Country wide surveillance and whole genome sequencing of these strains is essential to prevent a major public health emergency in USA.