Related Experiment Video
Updated: Nov 20, 2025
Deciphering and Imaging Pathogenesis and Cording of Mycobacterium abscessus in Zebrafish Embryos
Published on: September 9, 2015
Developing Tadpole Xenopus laevis as a Comparative Animal Model to Study Mycobacterium abscessus Pathogenicity
Arianna Lopez1, Carolyn Shoen2, Michael Cynamon2,3
1Department of Immunology and Microbiology, Medical Center, University of Rochester, Rochester, NY 14642, USA.
Abstract:
Mycobacterium abscessus (Mab) is an emerging, nontuberculosis mycobacterium (NTM) that infects humans. Mab has two morphotypes, smooth (S) and rough (R), related to the production of glycopeptidolipid (GPL), that differ in pathogenesis. To further understand the pathogenicity of these morphotypes in vivo, the amphibian Xenopus laevis was used as an alternative animal model. Mab infections have been previously modeled in zebrafish embryos and mice, but Mab are cleared early from immunocompetent mice, preventing the study of chronic infection, and the zebrafish model cannot be used to model a pulmonary infection and T cell involvement. Here, we show that X. laevis tadpoles, which have lungs and T cells, can be used as a complementary model for persistent Mab infection and pathogenesis. Intraperitoneal (IP) inoculation of S and R Mab morphotypes disseminated to tadpole tissues including liver and lungs, persisting for up to 40 days without significant mortality. Furthermore, the R morphotype was more persistent, maintaining a higher bacterial load at 40 days postinoculation. In contrast, the intracardiac (IC) inoculation with S Mab induced significantly greater mortality than inoculation with the R Mab form. These data suggest that X. laevis tadpoles can serve as a useful comparative experimental organism to investigate pathogenesis and host resistance to M. abscessus.
Insights
Xenopus laevis tadpoles provide a new model for studying Mycobacterium abscessus infections. This amphibian model allows for the investigation of persistent infections and host resistance to smooth and rough morphotypes.
Area of Science:
- Microbiology
- Infectious Diseases
- Animal Models
Background:
- Mycobacterium abscessus (Mab) is a growing cause of human infections.
- Mab exhibits two morphotypes, smooth (S) and rough (R), with differing pathogenic potential.
- Existing models like mice and zebrafish have limitations for studying chronic Mab infections.
Purpose of the Study:
- To evaluate Xenopus laevis tadpoles as an alternative animal model for Mab pathogenesis.
- To compare the in vivo behavior of S and R Mab morphotypes in tadpoles.
- To investigate persistent Mab infection and host immune responses.
Main Methods:
- Intraperitoneal (IP) and intracardiac (IC) inoculation of S and R Mab morphotypes into Xenopus laevis tadpoles.
- Monitoring of bacterial dissemination, persistence, and mortality over 40 days.
- Comparative analysis of Mab morphotype behavior in the tadpole model.
Main Results:
- Mab disseminated to tadpole tissues, including liver and lungs, persisting for up to 40 days.
- The R morphotype showed greater persistence with higher bacterial loads compared to the S morphotype.
- IC inoculation with S Mab resulted in higher mortality than with R Mab.
Conclusions:
- Xenopus laevis tadpoles serve as a viable complementary model for studying persistent Mab infections.
- The tadpole model facilitates comparative studies of Mab morphotype pathogenesis and host resistance.
- This model offers insights into T cell involvement and pulmonary infections, overcoming limitations of previous models.
