In response to emergent antibiotic resistance, new strategies are needed to enhance the effectiveness of existing antibiotics. Here, we describe a phagemid-delivered, RNA-mediated system capable of directly knocking down antibiotic resistance phenotypes. Small regulatory RNAs (sRNAs) were designed to specifically inhibit translation of chloramphenicol acetyltransferase and kanamycin phosphotransferase. Nonlytic phagemids coding for sRNA expression were able to infect and restore chloramphenicol and kanamycin sensitivity to populations of otherwise resistant E. coli. This modular system could easily be extended to other bacteria with resistance profiles that depend on specific transcripts.

The emergence of extremely drug resistant Mycobacterium tuberculosis necessitates new strategies to combat the pathogen. Engineered bacteria may serve as vectors to deliver proteins to human cells, including mycobacteria-infected macrophages. In this work, we target Mycobacterium smegmatis, a nonpathogenic tuberculosis model, with E. coli modified to express trehalose dimycolate hydrolase (TDMH), a membrane-lysing serine esterase. We show that TDMH-expressing E. coli are capable of lysing mycobacteria in vitro and at low pH. Vectorized E. coli producing TDMH were found suppress the proliferation of mycobacteria in infected macrophages.

Human body odor is produced when sweat-secreted compounds are metabolized by bacteria present on the skin. The resulting volatile mixture is often negatively perceived, motivating the use of personal cosmetic deodorants. Yet body odor may also be positively perceived in some contexts, and is proposed to play a role in sexual attraction, kin identification and social bonding. Because only human smellers can report the hedonic qualities of body odor, their perceptions are a valuable complement to modern GC-MS-based quantitative chemical measurements. Here we present a crowdsourcing framework that engages volunteer smellers to characterize human sweat samples. Our approach seeks to reward both the sweat donor and the smeller with a web-based graphical interface that is informative, interesting, and fun. 300 samples from 87 individual donors were scored by 93 smellers for intensity, pleasantness, and a variety of odor descriptors. Body odor intensity and pleasantness were determined to vary with age, gender, and self-reported deodorant use. Counterintuitively, deodorant use showed no effect on the perceived intensity of body odor, and was associated with a decrease in the perceived pleasantness. From these data, we determine the precision and dynamic range of the volunteer nose as a body odor evaluation instrument. Given the high variability of smeller perceptions, a large-scale crowdsourcing effort may be needed to produce a comprehensive description of body odor perceptions. We discuss the role of learning, creativity and fun in motivating volunteer sweat donors and smellers for such an effort.

In recent years, the design community has started envisioning biology as a design medium and designers are entering laboratories to pursue designer-biologist collaborations. To ensure that these collaborations lead to rich outcomes, we need to better understand the roles performed by biologists and designers in these collaborations. In seven case studies of collaborations between designers and biologists, we found that strong role dynamics appeared during the collaboration and can be divided into four phases: discovering, defining, developing and delivering. We show how biologists successively act as guides, influencers, supervisors and librarians while designers act as visitors, apprentices, amateurs and lone makers. We found that, despite their interdisciplinarity, projects followed traditional design project structures. While biologists tended to take the lead on project content, designers framed the projects using their methods and processes.