Skip to content
MicrobioHub
Back to database
Cocos Gram-positivos

Rothia mucilaginosa

Gram-positive cocci in pairs and clusters

Identification & Growth

Identification

  • Mucoid colonies adherent to the agar; variable catalase
  • Confirmation by MALDI-TOF

Growth Conditions

  • Blood agar, 35–37 °C, 5% CO₂, 24–48 h

Clinical Significance

  • Bacteremia in neutropenic patients with mucositis, endocarditis, shunt infection

Intrinsic Resistance

  • Aztreonam, colistin and nalidixic acid have no activity

Bench Alerts

  • Oral flora: only significant from sterile sites or in neutropenic patients

Clinical Notes

Clinical presentations

  • Causes infective endocarditis, especially in prosthetic valve carriers or congenital heart disease.
  • Associated with bacteremia in neutropenic patients and cerebrospinal shunt-related infections.
  • Can cause pneumonia and pleuropulmonary infection in immunosuppressed patients.

Specimens and collection

  • Serial blood cultures prior to antibiotic therapy are essential in suspected endocarditis.
  • Cerebrospinal fluid should be collected aseptically in suspected ventricular shunt infection.
  • Excised valve tissue is useful when blood cultures are negative with strong clinical suspicion.

Epidemiology and at-risk populations

  • Part of the normal oral microbiota, especially saliva and buccal mucosa.
  • Neutropenic patients with severe oral mucositis have increased bacteremia risk.
  • Carriers of intracardiac devices or ventricular shunts constitute an at-risk population for device infection.

Resistance and therapeutic implications

  • Generally penicillin and beta-lactam susceptible, but reduced susceptibility has been reported.
  • Individual susceptibility testing is recommended in invasive infections given the potential for emerging resistance.
  • Vancomycin is a therapeutic option in beta-lactam-allergic patients or resistant isolates.

Bench and reporting notes

  • Mucoid colonies adherent to agar are characteristic and aid presumptive recognition.
  • MALDI-TOF shows good accuracy for identification and is preferred over manual biochemical testing.
  • Isolation in blood culture from a patient with structural heart disease should prompt investigation for endocarditis.

Sources

Educational decision-support content. It does not replace laboratory validation, current guidelines or review by the responsible professional.

FAQ: Frequently Asked Questions

How to identify Rothia mucilaginosa in the lab?

Rothia mucilaginosa is identified through mucoid colonies adherent to the agar; variable catalase, confirmation by maldi-tof.

What are the intrinsic resistances of Rothia mucilaginosa?

This organism is naturally resistant to aztreonam, colistin and nalidixic acid have no activity. These drugs should not be reported as susceptible.

Where is Rothia mucilaginosa commonly found?

It is typically associated with bacteremia in neutropenic patients with mucositis, endocarditis, shunt infection.

Antibiogram InterpreterCheck BrCAST 2026 breakpointsRugai InterpreterBiochemical identification tools

Want the free Bench Kit?

Sign up to receive the PDF kit: agars, Gram, Rugai, dilutions and the antibiogram checklist.