Table 2 Differences and similarities in EVs deriving from eukaryotic cells and bacteria

Spherical particles with a size range from 30 to 100 nm (exosomes), 100–1000 nm (MVs) or 500–2000 nm (apoptotic bodies)

Stable at 37 °C for 24 h. Sensitive to high temperature but stable in the frozen and freeze-dried states [204]

Spherical particles with a size range from 10 to 400 nm. The maximum size is smaller than eukaryotic EVs due to smaller sized bacterial cells

Stable at 37 °C for 24 h. Greater tolerance to hot temperatures [205]. Stable in the frozen and freeze-dried states

Exosomes are commonly enriched in endosome-associated proteins

Mainly composed of proteins and phospholipids of the outer membrane

Exosomes and MVs are released by healthy and damaged cells. Apoptotic bodies are released by dying cells on an apoptotic pathway

All Gram-negative bacteria produce outer membrane vesicles (OMVs) and possibly also all Gram-positive bacteria. Gram-negative bacteria can produce specific vesicles with a double layer using both the outer and inner membranes

Originates in the plasma membrane except exosomes, which are made by the endocytic pathway

Bacteria Gram-negative and Gram-positive have a different mechanism of vesicle formation due to their distinct membrane structure, which originates in the membrane

They are released from cells by a variety of mechanisms depending on their mode of biogenesis and they are not released homogeneously by the membrane

Production is not uniformly distributed along the bacteria surface but there are “hot spots”

High heterogeneity in the composition of the surface and the interior

High heterogeneity in the composition of the surface and the interior

There are universal markers such as CD40 for microvesicles or flotillin for exosomes

There are no universal markers for their identification due to their diversity

EVs can contain different RNAs such as miRNA or mRNA but it is unusual for them to carry DNA

EVs can contain genetic material and participate in horizontal gene transfer

Harmful cells such as tumor cells present EVs with specific and useful contents for their survival

In pathogenic bacteria, specific molecules have been found such as adhesins, toxins and/or immunomodulatory compounds as cargo of OMVs

The main function is intercellular communication, except for apoptotic bodies, which facilitates phagocytosis

They are more relevant as a mechanism to carry away toxic compounds for bacteria than in eukaryotic cells

Production depends on the cell type and its physiology state

Their production increases as a response to environmental stress

A non-spontaneous biological process

A non-spontaneous biological process