Single cell profiling of surface carbohydrates on Bacillus cereus

Abstract

Cell surface carbohydrates are important to various bacterial activities and functions. It is well known that different types of Bacillus display heterogeneity of surface carbohydrate compositions, but detection of their presence, quantitation and estimation of variation at the single cell level have not been previously solved. Here, using atomic force microscopy (AFM)-based recognition force mapping coupled with lectin probes, the specific carbohydrate distributions of N-acetylglucosamine and mannose/glucose were detected, mapped and quantified on single B. cereus surfaces at the nanoscale across the entire cell. Further, the changes of the surface carbohydrate compositions from the vegetative cell to spore were shown. These results demonstrate AFM-based 'recognition force mapping' as a versatile platform to quantitatively detect and spatially map key bacterial surface biomarkers (such as carbohydrate compositions), and monitor in situ changes in surface biochemical properties during intracellular activities at the single cell level.

The Exosporium Layer of Bacterial Spores: a Connection to the Environment and the Infected Host

“…The distribution of sugar residues on the spore surface glycoproteins and the roles that they may play are understudied aspects of spore biology. Atomic force microscopy was recently utilized to begin to define the distribution of sugars on the surfaces of B. cereus spores (205). Regulation of exosporium formation warrants further investigation.…”

Evaluation of whole cell fixation methods for the analysis of nanoscale surface features of Yersinia pestis KIM

“…These force curves allowed us to distinguish between specific and nonspecific interactions on the cell surface. For instance, curves classified as specific binding events show a cantilever deflection as a nonlinear delayed retraction curve with a different slope from that of the contact region (Wang et al, 2015). Figure 3(A) shows the spatial distribution of GlcNAc on a methanol inactivated cell.…”

“…For AFM imaging cells in liquid, cells need to be immobilized on substrates firmly. Here, we used chemical immobilization method developed by our group that enables to firmly immobilize the cells and leave its surface area (detected by AFM) untouched (Wang et al, 2015). Aminopropyl-functionalized mica (APmica) coupled with glutaraldehyde was used to immobilize cell samples.…”

“…For the first time, we present AFM images showing changes in the nanoscale morphology of Y. pestis following four different treatments (methanol, formaldehyde, heat, UV radiation). The biochemical nature of the cell surface is analysed using a functionalized AFM probe and a “force recognition mapping” strategy at the single cell level (Dufrene et al ., ; Wang et al ., ). We probe the surface lipopolysaccharides via the amino sugar N‐acetylglucosamine (GlcNAc).…”

Applications of Micro/Nano Automation Technology in Detecting Cancer Cells for Personalized Medicine

“…Thus, the specific unbinding peak in the retraction curve corresponds to the event of a drug-target pair and the magnitude of the peak is equal to the unbinding force of one drug-target pair. By obtaining arrays of force curves using the functionalized tip, the distributions of target molecules on the cell surface can then be quantitatively mapped [94]. By probing the individual target molecules on cancer cells, the relationship between the target's information (binding affinity and distribution) and the clinical therapeutic outcomes can be established, which may then potentially be used for predicting the efficacies of drugs for each patients.…”