Zebrafish Treated for TB (image) University of Washington Caption The top zebrafish is heavily infected with TB bacteria, which are green fluorescent. The bottom fish has been treated with isoniazid for five days. While most of the infection is cleared, making the bottom fish barely visible, you still can see the residual, antibiotic-tolerant bacteria. Credit Lalitha Ramakrishnan Lab Usage Restrictions For use by news media, educational institutions, and museums only. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.