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Primary osteomyelitis caused by hypervirulent Klebsiella pneumoniae
Bonnie C Prokesch1, Michael TeKippe2, Jiwoong Kim3
1Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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.
Insights
A hypervirulent Klebsiella pneumoniae strain caused osteomyelitis in the USA. This hypermucoviscous pathogen, expressing rmpA and rmpA2, can lead to severe invasive infections, requiring increased clinical awareness.
Area of Science:
- Microbiology
- Infectious Diseases
- Genomics
Background:
- Klebsiella pneumoniae is a significant cause of community and hospital-acquired infections globally.
- A hypervirulent strain of K. pneumoniae, characterized by hypermucoviscous phenotype, has emerged as a major cause of invasive infections.
- Osteomyelitis is a severe bone infection that can be caused by various bacterial pathogens.
Observation:
- A case of osteomyelitis in the USA was caused by a hypervirulent K. pneumoniae strain.
- The patient's K. pneumoniae isolate exhibited a hypermucoviscous phenotype, prompting genomic investigation.
- Genomic analysis identified the isolate as a K1 serotype, sequence type 23, expressing rmpA and rmpA2 virulence factors.
Findings:
- Whole-genome sequencing and PCR confirmed the presence of key virulence genes (rmpA, rmpA2) in the K. pneumoniae isolate.
- The identified strain (K1 serotype, ST23) is consistent with previously reported hypervirulent K. pneumoniae.
- The case highlights osteomyelitis as a potential manifestation of hypervirulent K. pneumoniae infection.
Implications:
- Clinicians must be aware of hypervirulent K. pneumoniae as a cause of severe, invasive infections, including osteomyelitis.
- Increased recognition and diagnostic capabilities for hypervirulent K. pneumoniae are crucial for effective patient management.
- Understanding the genomic basis of hypervirulence is essential for developing targeted therapeutic strategies.
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