Biology subjects

Garstecki, P.

Publications and source records attributed to Garstecki, P..

3 recordsLinked to original sources

bioRxiv2022

You will know by its tail: a method for quantification of heterogeneity of bacterial populations using single cell MIC profiling

Severe non-healing infections are often caused by multiple pathogens or by genetic variants of the same pathogen exhibiting different levels of antibiotic resistance. For example, polymicrobial diabetic foot infections double the risk of amputation compared to monomicrobial infections. Although these infections lead to increased morbidity and mortality, standard antimicrobial susceptibility methods are designed for homogenous samples and are impaired in quantifying heteroresistance. Here, we propose a droplet-based label-free method for quantifying the antibiotic response of the entire population at the single-cell level. We used Pseudomonas aeruginosa and Staphylococcus aureus samples to confirm that the shape of the profile informs about the coexistence of diverse bacterial subpopulations, their sizes, and antibiotic heteroresistance. These profiles could therefore indicate the outcome of antibiotic treatment in terms of the size of remaining subpopulations. Moreover, we studied phenotypic variants of a S. aureus strain to confirm that the profile can be used to identify tolerant subpopulations, such as small colony variants, associated with increased risks for the development of persisting infections. Therefore, the profile is a versatile instrument for quantifying the size of each bacterial subpopulation within a specimen as well as their individual and joined heteroresistance.

microbiology↗

bioRxiv2020

Biofabricating murine and human myo-substitutes for rapid volumetric muscle loss restoration

The importance of skeletal muscle tissue is undoubted being the controller of several vital functions including respiration and all voluntary locomotion activities. However, its regenerative capability is limited and significant tissue loss often leads to a chronic pathologic condition known as volumetric muscle loss. Here, we propose a biofabrication approach to rapidly restore skeletal muscle mass, 3D histoarchitecture and functionality. By recapitulating muscle anisotropic organization at the microscale level, we demonstrate to efficiently guide cell differentiation and myobundle formation both in vitro and in vivo. Of note, upon implantation, the biofabricated myo-substitutes support the formation of new blood vessels and neuromuscular junctions - pivotal aspects for cell survival and muscle contractile functionalities - together with an advanced along with muscle mass and force recovery. Together, these data represent a solid base for further testing the myo-substitutes in large animal size and a promising platform to be eventually translated into clinical scenarios.

bioengineering↗

bioRxiv2018

Multiplex droplet assay reveals coinciding inoculum effect and phenotypic heterogeneity during beta-lactam treatment of bacteria

Heteroresistance is a phenomenon where isogenic bacteria population exhibits a diverse antibiotic resistance pattern at sub-population or single cell level. The sub-populations with higher resistance can remain undetected with conventional diagnostics which makes them subsequently harder to treat. Such surviving phenotypically heterogeneous sub-populations are also a potential hotbed for novel mutations, thus increasing the resistance permanently in bacteria. Droplet microfluidics gives tools for high-throughput analysis of bacteria and their response to antibiotics at single cell level, which is difficult to obtain with traditional agar plate technologies. In here we show for the first time the precise digital quantification of drug resistance profile in isogenic population at single cell level. We also see that the inhibiting amount of drug per bacteria remains quite stable regardless of bacteria density. Interestingly, the bacteria clump together preferably near these sub-inhibitory conditions. The technology and findings we describe here provide novel quantitative insight into the heteroresistance which is a key step in understanding the pathways leading to drug resistance. This knowledge is crucial in the context of global drug resistance threat as it can help us to find tools to prevent further escalation of drug resistance.

microbiology↗