A high-throughput assay identifies molecules with antimicrobial activity against persister cells.

Persister cells are transiently non-growing antibiotic-tolerant bacteria that cause infection relapse, and there is no effective antibiotic therapy to tackle these infections. High-throughput assays in drug discovery are biased towards detecting drugs that inhibit bacterial growth rather than killing non-growing bacteria. A new and simple assay to discover such drugs is needed.

Deciphering the Antitoxin-Regulated Bacterial Stress Response via Single-Cell Analysis.

Bacterial toxin-antitoxin (TA) systems, which are diverse and widespread among prokaryotes, are responsible for tolerance to drugs and environmental stresses. However, the low abundance of toxin and antitoxin proteins renders their quantitative measurement in single bacteria challenging. Employing a laboratory-built nano-flow cytometer (nFCM) to monitor a tetracysteine (TC)-tagged TA system labeled with the biarsenical dye FlAsH, we here report the development of a sensitive method that enables the detection of basal-level expression of antitoxin.

Relationship Between Quorum Sensing and Secretion Systems.

Quorum sensing (QS) is a communication mechanism between bacteria that allows specific processes to be controlled, such as biofilm formation, virulence factor expression, production of secondary metabolites and stress adaptation mechanisms such as bacterial competition systems including secretion systems (SS). These SS have an important role in bacterial communication. SS are ubiquitous; they are present in both Gram-negative and Gram-positive bacteria and in sp.