Rothia kristinae: Introduction, Pathogenicity, Lab Diagnosis, Treatment, Prevention, and Keynotes

Introduction & Taxonomy

Rothia kristinae is a Gram-positive bacterium increasingly recognized as an emerging opportunistic pathogen. While typically a harmless commensal of human skin and mucosal surfaces, it can cause severe systemic infections, particularly in individuals with compromised immune systems or indwelling medical devices.

• Classification: A member of the Micrococcaceae family, this organism was originally classified as Micrococcus kristinae (1974), moved to Kocuria (1995), and finally reclassified as Rothia in 2018 based on genomic data.
• Habitat: It colonizes human skin, the oropharynx, and the upper respiratory tract.

Pathogenicity & Clinical Manifestations

• Risk Factors: Primarily affects immunocompromised patients, such as those with cancer or indwelling devices.
• Clinical Picture: Causes infections, including catheter-related bacteremia (~36% of cases) and endocarditis (~13.7%).
• Virulence: Known to form biofilms on medical devices.

Laboratory Diagnosis of Rothia kristinae

• Identification: Appears as Gram-positive, non-motile cocci in pairs or clusters. Grows on blood agar within 48 hours, forming pale to orange colonies.
• Biochemical Profile: Catalase-positive, but oxidase and coagulase-negative.
• Distinction: Often distinguished from Staphylococcusby susceptibility to bacitracin and resistance to lysostaphin.
• Gold Standard: Identification is best achieved via 16S rRNA sequencing or MALDI-TOF MS.

Treatment & Prevention

• Treatment: Vancomycin is typically effective, along with linezolid or rifampicin, though resistance to certain drugs, such as clindamycin, can occur.
• Management: Successful treatment often requires removing infected catheters.
• Prevention: Adherence to infection control protocols (e.g., CLABSI bundles) is critical.

Keynotes on Rothia kristinae

• R. kristinaes should not be dismissed as a contaminant, particularly in recurring blood cultures.
• Commonly misidentified in labs as Coagulase-Negative Staphylococci (CoNS).

Further Readings

1. https://pmc.ncbi.nlm.nih.gov/articles/PMC11991707
2. https://medicallabnotes.com/rothia-kristinae-introduction-pathogenicity
3. https://www.idcmjournal.org/wp-content/uploads/2025/03/IDCM-2025-436.pdf
4. https://www.ovid.com/journals/idcpr/pdf/10.1097/ipc.0000000000001465~rothia-kristinae-nosocomial-sepsis-with-prolonged-bacteremia
5. https://pdfs.semanticscholar.org/a5ff/e64b14192cc8215ad5ed850881b5be48e2b5.pdf
6. https://en.wikipedia.org/wiki/Rothia_kristinae
7. https://en.wikipedia.org/wiki/Rothia_kristinae
8. https://revistascientificas.cuc.edu.co/JACN/article/download/6569/5870/57451
9. https://www.sciencedirect.com/science/article/abs/pii/S156713482100174X