Search for: All records

The size of fruit bat colonies ranges from dozens to hundreds of thousands of individuals, depending on the species. While a deterministic modelling approach is appropriate for large colonies, the role of population fluctuations can be all-important for small colonies. From this perspective, we analyse the infection dynamics in small zoonotic niches due to filoviruses, e.g. Ebola. To this end, we perform stochastic numerical simulations and analytical calculations. The inherent stochasticity in ecological processes may play a significant role in driving small populations towards extinction. Here, we reveal that fluctuations can either lead to virus eradication or to sustain infection compared with the deterministic dynamics, depending on the size of the zoonotic niche. Altogether, our findings reveal non-trivial stochastic effects, which can shed light on the infection dynamics in small- and medium-sized bat colonies and help design preventive measures for zoonotic diseases. 

Viral infection usually begins with adhesion between the viral particle and viral receptors displayed on the cell membrane. The exterior surface of the cell membrane is typically coated with a brush-like layer of molecules, the glycocalyx, that the viruses need to penetrate. Although there is extensive literature on the biomechanics of virus−cell adhesion, much of it is based on continuum-level models that do not address the question of how virus/cell-membrane adhesion occurs through the glycocalyx. In this work, we present a simulation study of the penetration mechanism. Using a coarse-grained molecular model, we study the force-driven and di"usive penetration of a brush-like glycocalyx by viral particles. For force-driven penetration, we find that viral particles smaller than the spacing of molecules in the brush reach the membrane surface readily. For a given maximum force, viral particles larger than the minimum spacing of brush molecules arrest at some distance from the membrane, governed by the balance of elastic and applied forces. For the di"usive case, we find that weak but multivalent attraction between the glycocalyx molecules and the virus e"ectively leads to its engulfment by the glycocalyx. Our finding provides potential guidance for developing glycocalyx-targeting drugs and therapies by understanding how virus−cell adhesion works.