title: Primary osteomyelitis caused by hypervirulent Klebsiella pneumoniae.
abstract: Klebsiella pneumoniae is the most clinically relevant species of this genus, known to cause both community-acquired and nosocomial infections worldwide. In the past two decades, a distinct hypervirulent strain of K pneumoniae, characterised by its hypermucoviscous phenotype, has emerged as a clinically significant pathogen responsible for highly invasive infections. We present a case of osteomyelitis due to hypervirulent K pneumoniae reported in the USA. Genomic testing of the K pneumoniae isolate was performed due to the striking clinical presentation of the infection as well as the hypermucoid nature of the isolates, raising the suspicion for possible infection with the hypervirulent strain. Whole-genome sequencing and additional PCR testing demonstrated the isolate to be a K1 serotype, sequence type 23 strain expressing rmpA and rmpA2. Given the multiple reports of this pathogen causing invasive infections, clinicians should be aware of the possible presentation of metastatic and severe infection, including osteomyelitis, due to the hypervirulent strain of K pneumoniae not typical of classic K pneumoniae variants. In this Grand Round, we review the clinical features of hypervirulent K pneumoniae and its link to invasive infections, and discuss the need for improved awareness and identification of the pathogen.
authors.affiliation: Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA. Electronic address: bonnie.prokesch@gmail.com.
authors.forename: Bonnie C
authors.initials: BC
authors.lastname: Prokesch
authors.affiliation: Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: TeKippe
authors.affiliation: Quantitative Biomedical Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Jiwoong
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Prithvi
authors.initials: P
authors.lastname: Raj
authors.affiliation: Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Erin McElvania
authors.initials: EM
authors.lastname: TeKippe
authors.affiliation: Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: David E
authors.initials: DE
authors.lastname: Greenberg
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D044466:Asian People; D006801:Humans; D007710:Klebsiella Infections / Q000150:complications* / Q000188:drug therapy; D007711:Klebsiella pneumoniae / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D008297:Male; D008875:Middle Aged; D010019:Osteomyelitis / Q000209:etiology; D065288:Serogroup; D014774:Virulence / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents