Evolutionary consequences of bacterial resistance to a flagellotropic phage.

Bacteria often rapidly evolve resistance to bacteriophages (phages) by mutating or suppressing the phage-receptors, the factors that phages first target to initiate infection. Flagellotropic phages infect bacteria by initially binding to the flagellum. Since motility is an important fitness factor that allows bacteria to efficiently explore their environment, losing flagellar function to evade infection by flagellotropic phages represents a crucial trade-off.

Microscopic phage adsorption assay: High-throughput quantification of virus particle attachment to host bacterial cells.

Phages, viruses of bacteria, play a pivotal role in Earth's biosphere and hold great promise as therapeutic and diagnostic tools in combating infectious diseases. Attachment of phages to bacterial cells is a crucial initial step of the interaction. The classic assay to quantify the dynamics of phage attachment involves coculturing and enumeration of bacteria and phages, which is laborious, lengthy, hence low-throughput, and only provides ensemble estimates of model-based adsorption rate constants.

Microscopic Phage Adsorption Assay: High-throughput quantification of virus particle attachment to host bacterial cells.

Phages, viruses of bacteria, play a pivotal role in Earth's biosphere and hold great promise as therapeutic and diagnostic tools in combating infectious diseases. Attachment of phages to bacterial cells is a crucial initial step of the interaction. The classic assay to quantify the dynamics of phage attachment involves co-culturing and enumeration of bacteria and phages, which is laborious, lengthy, hence low-throughput, and only provides ensemble estimates of model-based adsorption rate constants.

Reassessing the Standard Chemotaxis Framework for Understanding Biased Migration in .

infections are a major cause of peptic ulcers and gastric cancers. The development of robust inflammation in response to these flagellated, motile bacteria is correlated with poor prognosis. Chemotaxis plays a crucial role in colonization, enabling the bacteria to swim toward favorable chemical environments.

Developing Phage Therapy That Overcomes the Evolution of Bacterial Resistance.

The global rise of antibiotic resistance in bacterial pathogens and the waning efficacy of antibiotics urge consideration of alternative antimicrobial strategies. Phage therapy is a classic approach where bacteriophages (bacteria-specific viruses) are used against bacterial infections, with many recent successes in personalized medicine treatment of intractable infections. However, a perpetual challenge for developing generalized phage therapy is the expectation that viruses will exert selection for target bacteria to deploy defenses against virus attack, causing evolution of phage resistance during patient treatment.

The Nucleus Bypasses Obstacles by Deforming Like a Drop with Surface Tension Mediated by Lamin A/C.

Migrating cells must deform their stiff cell nucleus to move through pores and fibers in tissue. Lamin A/C is known to hinder cell migration by limiting nuclear deformation and passage through confining channels, but its role in nuclear deformation and passage through fibrous environments is less clear. Cell and nuclear migration through discrete, closely spaced, slender obstacles which mimic the mechanical properties of collagen fibers are studied.

Mechanosensitive recruitment of stator units promotes binding of the response regulator CheY-P to the flagellar motor.

Reversible switching of the bacterial flagellar motor between clockwise (CW) and counterclockwise (CCW) rotation is necessary for chemotaxis, which enables cells to swim towards favorable chemical habitats. Increase in the viscous resistance to the rotation of the motor (mechanical load) inhibits switching. However, cells must maintain homeostasis in switching to navigate within environments of different viscosities.

Asymmetric random walks reveal that the chemotaxis network modulates flagellar rotational bias in .

The canonical chemotaxis network modulates the bias for a particular direction of rotation in the bacterial flagellar motor to help the cell migrate toward favorable chemical environments. How the chemotaxis network in modulates flagellar functions is unknown, which limits our understanding of chemotaxis in this species. Here, we determined that swim faster (slower) whenever their flagella rotate counterclockwise (clockwise) by analyzing their hydrodynamic interactions with bounding surfaces.

Roadmap on emerging concepts in the physical biology of bacterial biofilms: from surface sensing to community formation.

Bacterial biofilms are communities of bacteria that exist as aggregates that can adhere to surfaces or be free-standing. This complex, social mode of cellular organization is fundamental to the physiology of microbes and often exhibits surprising behavior. Bacterial biofilms are more than the sum of their parts: single-cell behavior has a complex relation to collective community behavior, in a manner perhaps cognate to the complex relation between atomic physics and condensed matter physics.

Switching and Torque Generation in Swarming .

swarm on semi-solid surfaces with the aid of flagella. It has been hypothesized that swarmer cells overcome the increased viscous drag near surfaces by developing higher flagellar thrust and by promoting surface wetness with the aid of a flagellar switch. The switch enables reversals between clockwise (CW) and counterclockwise (CCW) directions of rotation of the flagellar motor.