Method and device for rapid detection of bacterial antibiotic resistance/susceptibility
Inventors
Sauer-Budge, Alexis Fay • Sharon, Andre • Kalashnikov, Maxim • Wirz, Holger
Assignees
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Publication Number
US-9611501-B2
Publication Date
2017-04-04
Expiration Date
Abstract
Described herein is a method and a device for expediting delivery of an agent to a damaged bacterial cell. In one embodiment, the methods and devices are useful for screening candidate antibiotics. In another embodiment, the methods and devices described herein are used to determine susceptibility of bacteria to an antibiotic. The methods also provide a method for determining an appropriate antibiotic to treat an individual having a bacterial infection.
Core Innovation
The invention provides a method for determining sensitivity of bacteria to an antibiotic. Bacteria are immobilized from a bacterial suspension by covalent attachment to a solid support prior to exposing the bacterial suspension to a combination of a stressor and the antibiotic. The immobilized bacteria are then contacted with an agent comprising a reporter moiety that preferentially binds to damaged bacterial cells.
The immobilized bacteria are subjected to the stressor in the presence of the antibiotic without a bacterial growth phase subsequent to immobilization. A signal from the reporter moiety in the immobilized bacteria is detected after contacting the covalently immobilized bacteria with the stressor in the presence of the antibiotic, and comparison is made to a control comprising immobilized bacteria subjected to the stressor in the absence of the antibiotic.
The method determines susceptibility by indicating that an increase in the signal in the presence of an antibiotic compared to a control indicates that the bacteria are susceptible. In contrast, a signal comparable to the control in the presence of an antibiotic indicates that the bacteria are resistant to the antibiotic. The approach is described in a rapid format that applies immobilized, stressed bacteria to reporter-based signal detection without requiring post-immobilization growth.
Claims Coverage
The relevant independent claim identifies a single central inventive concept: an immobilized, covalently attached bacterial assay using a reporter moiety that preferentially binds to damaged cells, with stressor/antibiotic exposure performed without a post-immobilization growth phase, followed by signal comparison to a no-antibiotic control. The claim set further refines specific inventive aspects through dependent claims addressing reporter detection modality, stressor options, and assay implementation formats and constraints.
Covalent immobilization prior to antibiotic and stressor exposure with a reporter that binds damaged cells
A method for determining sensitivity of bacteria to an antibiotic, comprising immobilizing the bacteria from a bacterial suspension by covalent attachment to a solid support prior to exposing the bacterial suspension to a combination of a stressor and the antibiotic, and contacting said immobilized bacteria with an agent comprising a reporter moiety, which preferentially binds to damaged bacterial cells.
Stressor and antibiotic exposure without a bacterial growth phase subsequent to immobilization
Subjecting said immobilized bacteria to the stressor in the presence of the antibiotic without a bacterial growth phase subsequent to immobilization, wherein detection of an increase in said signal in the presence of an antibiotic compared to a control indicates that said bacteria are susceptible to said antibiotic.
Signal detection and control-based susceptibility versus resistance determination
Detecting a signal from said reporter moiety in said immobilized bacteria after contacting said covalently immobilized bacteria with the stressor in the presence of the antibiotic and without the need for bacterial growth phase subsequent to immobilization, and comparing the signal on the solid support from said immobilized bacteria in the presence of the antibiotic to a control comprising immobilized bacteria subjected to the stressor in the absence of the antibiotic, wherein a signal comparable to the control indicates that said bacteria are resistant to said antibiotic.
Overall, the claim coverage centers on a reporter-moiety-based assay performed on covalently immobilized bacteria, using a stressor/antibiotic combination applied without a post-immobilization growth phase, and interpreting susceptibility versus resistance by comparing reporter signal to a matched no-antibiotic control.
Stated Advantages
Not requiring bacterial growth phase subsequent to immobilization for detecting sensitivity of bacteria to an antibiotic.
Rapid differentiation of susceptibility versus resistance based on increased reporter signal compared to a control.
Documented Applications
Screening or determining sensitivity of bacteria to antibiotics, including distinguishing methicillin-resistant S. aureus (MRSA) from methicillin-sensitive S. aureus (MSSA).
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