Engineered bacteria can function in the mammalian gut long-term as live diagnostics of inflammation

Abstract

Bacteria can be engineered to function as diagnostics or therapeutics in the mammalian gut but commercial translation of these technologies has been hindered by the susceptibility of synthetic genetic circuits to mutation and unpredictable function during extended gut colonization. Here we report stable, engineered bacterial strains that maintain their function for 6 months in the mouse gut. We engineered a commensal murine Escherichia coli strain to detect tetrathionate, which is produced during inflammation. Using our engineered diagnostic strain, which retains memory of exposure in the gut for analysis by fecal testing, we detected tetrathionate in both infection-induced and genetic mouse models of inflammation over 6 months. The synthetic genetic circuits in the engineered strain were genetically stable and functioned as intended over time. The robust, durable performance of these strains confirms the potential of engineered bacteria as living diagnostics.

Acoustic reporter genes for noninvasive imaging of microorganisms in mammalian hosts

“…The mammalian microbiome plays many important roles in health and disease 1,2 , and genetic engineering is enabling the development of microbial therapeutics and diagnostics 3–7 . A key determinant of the activity of both natural and engineered microbes in vivo is their location within the host organism 8,9 .…”

Harnessing synthetic biology for kelp forest conservation1

“…Complex synthetic circuitry (multi‐layered logic‐based circuits which are DNA encoded and behave in clearly defined ways similar to logic circuits in electronics) allowing for programming of cells, such as programmable gut microbiomes that persist and act as readable sensors for medical diagnostics (Riglar et al. , Lubkowicz et al. ), would not have been achievable in the 1990s when gene technology was in its infancy.…”

Escherichia coli NGF-1, a Genetically Tractable, Efficiently Colonizing Murine Gut Isolate

“…Escherichia coli NGF-1 is of particular interest because it was isolated from a healthy BALB/c mouse from Charles River Labs, colonizes mice efficiently, and can be engineered with complex genetic circuits (2–6) (Table 1). Kotula and colleagues placed a tetracycline-inducible trigger element and a memory element in E.…”

“…coli NGF-1 and found essentially identical responses to tetracycline treatment in vitro and in the mouse gut (2). Riglar et al showed that engineered NGF-1 was stable in C57BL/6 mice for over 6 months (3). In the work of Certain at al., E.…”