# Tsukamurella pulmonis Isolated in Sputum Culture During Workup for Tuberculosis: Colonization or Infection?

**Authors:** Navin Bhatt, Shital Khanal, Maurice Policar

PMC · DOI: 10.7759/cureus.86438 · 2025-06-20

## TL;DR

A case study shows that finding Tsukamurella pulmonis in sputum may not always mean infection, especially in healthy individuals.

## Contribution

This case highlights that T. pulmonis in respiratory cultures may indicate colonization, not infection, in immunocompetent individuals.

## Key findings

- T. pulmonis was repeatedly isolated from sputum in an asymptomatic, immunocompetent patient.
- The patient had no signs of infection and did not require antimicrobial therapy.
- The case emphasizes the need to correlate microbiological findings with clinical and radiological data.

## Abstract

Tsukamurella pulmonis is a rare, opportunistic actinomycete most often associated with respiratory infections in immunocompromised patients. We report the case of a young immunocompetent man with a remote history of completely treated pulmonary tuberculosis, in whom T. pulmonis was repeatedly isolated from sputum during routine screening. Despite these findings, the patient remained asymptomatic, with normal inflammatory markers and stable chest imaging, and therefore did not receive antimicrobial therapy. This case underscores the importance of correlating microbiological results with clinical and radiological assessments. It highlights that, in immunocompetent individuals, the presence of T. pulmonis in respiratory cultures may represent colonization rather than true infection, and unnecessary antimicrobial treatment can be avoided with thorough evaluation.

## Linked entities

- **Diseases:** tuberculosis (MONDO:0018076)
- **Species:** Tsukamurella pulmonis (taxon 47312)

## Full-text entities

- **Diseases:** Tuberculosis (MESH:D014376), inflammatory (MESH:D007249), Infection (MESH:D007239), T. pulmonis (MESH:D001260), pulmonary tuberculosis (MESH:D014397), respiratory infections (MESH:D012141)
- **Species:** Tsukamurella pulmonis (species) [taxon 47312], Homo sapiens (human, species) [taxon 9606], uncultured actinomycete (species) [taxon 100235]

## Figures

2 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12276769/full.md

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Source: https://tomesphere.com/paper/PMC12276769