Health guidelines updates

The opportunistic pathogen Pseudomonas aeruginosa is a major cause of antibiotic-tolerant infections in humans. P. aeruginosa evades antibiotics in bacterial biofilms by up-regulating expression of a symbiotic filamentous inoviral prophage, Pf4. We investigated the mechanism of phage-mediated antibiotic tolerance using biochemical reconstitution combined with structural biology and high-resolution cellular imaging. We resolved electron cryomicroscopy atomic structures of Pf4 with and without its linear single-stranded DNA genome, and studied Pf4 assembly into liquid crystalline droplets using optical microscopy and electron cryotomography. By biochemically replicating conditions necessary for antibiotic protection, we found that phage liquid crystalline droplets form phase-separated occlusive compartments around rod-shaped bacteria leading to increased bacterial survival. Encapsulation by these compartments was observed even when inanimate colloidal rods were used to mimic rod-shaped bacteria, suggesting that shape and size complementarity profoundly influences the process. Filamentous inoviruses are pervasive across prokaryotes, and in particular, several Gram-negative bacterial pathogens including Neisseria meningitidis, Vibrio cholerae, and Salmonella enterica harbor these prophages. We propose that biophysical occlusion mediated by secreted filamentous molecules such as Pf4 may be a general strategy of bacterial survival in harsh environments.

https://www.pnas.org/content/early/2020/02/14/1917726117

Secondary attack rate and superspreading events for SARS-CoV-2 A basic reproduction number, R0, of about 2 was estimated for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Wuhan, China, early in the outbreak.1,2 However, this value only captures the average dynamics of transmission; a crucial question for control is whether specific situations....

Coronavirus (COVID-19) NHS advice about coronavirus (COVID-19), including what the risk in the UK is, what the symptoms are and how to reduce your chances of getting it.

2019 Novel Coronavirus (SARS-CoV-2, COVID-19) - Life Extension Over the last few decades, several new viruses have emerged as threats to human health around the globe. The most recent example is the 2019 novel coronavirus.