# Establishment of an in vivo-based assay using a silkworm infection model for phenotypic evaluation of antimicrobial drug combinations against Mycobacterium abscessus

## TL;DR

A new silkworm model is developed to test antimicrobial drug combinations against Mycobacterium abscessus in a whole-organism setting.

## Contribution

The introduction of a silkworm-based in vivo assay for evaluating antimicrobial drug interactions against M. abscessus.

## Key findings

- The silkworm model produced interaction profiles consistent with in vitro results for tested drug combinations.
- The assay is rapid, reproducible, and suitable for assessing synergistic or antagonistic drug effects.

## Abstract

Mycobacterium abscessus exhibits high intrinsic drug resistance, requiring combination therapy. We developed a silkworm (Bombyx mori) infection model as a whole-organism, in vivo-based platform for quantitative, outcome-based evaluations of antimicrobial combinations. The system, examined using clarithromycin-amikacin and imipenem-cefoxitin combinations, showed interaction profiles that were qualitatively consistent with those observed in vitro. This rapid, reproducible, and ethical assay enables reliable phenotypic assessments of synergistic or antagonistic effects and may facilitate the evaluation and prioritization of antimicrobial combination regimens in preclinical studies.