Selectivity screening for antimicrobial compounds
Inventors
Lewis, Kim • D'Onofrio, Anthony • Curtis, Thomas • BERKES, Charlotte
Assignees
Northeastern University Boston
Publication Number
US-12247245-B2
Publication Date
2025-03-11
Expiration Date
2039-05-24
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
Assays for compounds having a desired biological activity against one but not both of a pair of microorganism species utilize separately detectable labels. The first and second microorganisms are different from each other, the first microorganisms exhibit a first detectable label, the second microorganisms exhibit a second detectable label different from the first detectable label, and neither of the labels interferes with detection of the other label. In various embodiments, the first and second microorganisms are incubated with a candidate compound or a producer thereof. The different labels permit isolation of microorganisms exhibiting one of the labels but not the other, indicating the desired activity, and the compound responsible for this differential response is isolated.
Core Innovation
The invention provides an assay method for identifying compounds with selective biological activity against one member of a pair of different microorganism species by using separately detectable, non-interfering labels. The first and second microorganisms each bear a distinct detectable label, which allows for the simultaneous assessment of compound activity on both types, without cross-interference of the detection methods. This approach enables the direct identification and isolation of compounds, or their producer microorganisms, that selectively inhibit one microorganism type but not the other.
The problem addressed is the limitation of conventional screening methods that can only reveal toxicity to a single test organism at a time and do not indicate toxicity to potential recipient organisms. Such limitations result in increased cost and time for drug discovery, requiring separate sets of assays to obtain necessary selectivity and toxicity data. The inability to simultaneously detect differential activities has hampered efficient detection of selective antimicrobials, leading to costly and time-consuming workflows.
Embodiments of the present invention utilize genetically modified microorganisms expressing different fluorescent proteins or labels, enabling their survival or inhibition to be independently detected upon exposure to candidate compounds or producer microorganisms. The invention encompasses both solid media (e.g., plate-based techniques) and microdroplet/microfluidic approaches, significantly increasing throughput for screening compounds from environmental samples such as soil. The methodology readily supports identification of compounds with activity against specific pathogens or mammalian cells, while sparing commensal or indicator species.
Claims Coverage
There is one independent claim that defines the main inventive features of the invention.
Method of identifying a producer microorganism making a compound with selective inhibitory activity using differentially labeled microorganisms
A method comprising: 1. Suspending first and second different microorganisms in a nutrient medium, where the first exhibits a first detectable label and the second a different, non-interfering detectable label, with the second being the target microorganism. 2. Contacting the first and second microorganisms with a producer microorganism making the compound, resulting in a mixed culture. 3. Incubating the mixed culture. 4. Isolating a portion of the nutrient medium where the first label is present but the second is not. 5. Identifying the producer microorganism responsible for the selective inhibitory activity against the target microorganism from that volume.
The inventive feature is a selective screening method using non-interfering detectable labels on distinct microorganisms, enabling direct identification and isolation of producer microorganisms that make compounds with selective inhibitory activity.
Stated Advantages
Permits detection of differential activity against one microorganism but not another, enabling identification of compounds with selective biological activity.
Eliminates large background of known and generally toxic compounds, increasing the probability of discovering non-toxic compounds.
Increases screening throughput for natural product or antimicrobial discovery by allowing simultaneous assessment of more than one microorganism type.
Reduces time and cost associated with traditional serial toxicity and selectivity assays.
Documented Applications
Screening environmental or soil-derived microorganisms for producers of selective antimicrobial compounds.
Discovery of antibiotics or bioactive compounds that selectively inhibit Gram-negative bacteria but not Gram-positive bacteria, or vice versa.
Identification of selective antifungal agents, such as compounds active against Candida albicans but not Gram-positive bacteria.
Screening for compounds with selective activity against mammalian cells, such as agents for cancer, inflammation, or apoptosis research.
High-throughput screening for compounds with differential activity against pathogen/commensal microorganism pairs relevant to various human microbiomes.
Interested in licensing this patent?