SARS-CoV-2 pandemic and recurrent dengue epidemics in tropical countries are a global health threat. Both virus-caused infections may only reveal light symptoms, but also cause severe diseases. As known for Dengue infections, Antibody-Dependent Enhancement (ADE) can occur during a second infection with a different virus strain: Preexisting antibodies do not neutralize but enhance infection, possibly by triggering FcgR-mediated virus uptake. Thus, previous coronavirus infections or infections with different SARS-CoV-2 strains could promote ADE and aggravate COVID-19.

For the analysis of cell phenotype or for intracellular cytokine staining, blood is processed as in the Graphic Abstract. Blood is taken to a BLS2 room, where, wearing mask, coat, gloves and lens, blood is processed inside a biosafety cabinet; PBMCs are isolated, stained, and finally acquired by a flow cytometer. Then, analysis can be performed in other rooms, with no precautions. Some images are from http://www.onlinewebfonts.com/icon.

Example warning sign for a flow cytometry laboratory showing active sort and inactive sort indicators.

Schematic representation of (A) phylogenetic (cyanobacteria, cryptophytes, Chl c/fucoxanthin- and peridinin-containing species (chrysophytes, bacillariophytes and dinophytes) as well as chlorophytes/euglenophytes) and (B) morphologically based functional classification (MBFG I-VII) according to Kruk et al. (19) based on either red fluorescence signals by excitation with 488 and 561 nm or based on morphological image analysis, including longest axial dimension, aspect ratio (width/height) and perimeter of brightfield or red fluorescence object. (C) Shows exemplary images derived from imaging flow cytometric measurements, assigned to the respective phylogenetic group revealed by clustering via different fluorescence emission and sorted by longest axial dimension (small size class [solid border], medium-sized class [dashed border], and large size class [dotted-dashed border]).

Imaging in space and time: Light sheet fluorescence microscopy allows nondestructive, label-free in vivo imaging of microbial biofilms at intransparent surfaces. Biofilm growth and structural development can be monitored over time and thus linked to metabolic measurements, here electrochemical activity.

Bacterial communities change their structure rapidly due to short generation times of their members. How bacteria assemble to certain structures provides insight into ecological mechanisms that shape a bacterial community.