Table 1.

Comparison between gram-negative and gram-positive extracellular vesicles

Features	Gram-negative EVs	Gram-positive EVs	References
Origin	Outer membrane	Cytoplasmic membrane	[39]
Size	10 nm-300 nm	20 nm-400 nm	[39]
Components	Outer membrane proteins, periplasmic proteins, virulence factors, cytoplasmic proteins, inner membrane proteins, lipopolysaccharides, phospholipids, and peptidoglycan (10%-20%)	Cytoplasmic proteins, membrane-associated proteins, lipoteichoic acid (LTA), peptidoglycan (> 50%)	[39]
Genetic components	sRNA, mRNA, miRNA, luminal and surface associated DNA	sRNA, extracellular and chromosomal DNA	[39, 201]
Proteins	Outer membrane: OmpA, OmpC, OmpF, lipoprotein (Lpp), periplasmic: Alkaline phosphatase and AcrA	Single lipid membrane proteins: penicillin-binding, immunoglobulin G-binding (protein A), staphopain A, α-haemolysins, heat-shock protein	[42, 202]
Lipids	Glycerophopholipids, phosphatidylethanolamine, phophotidylglycerol and cardiolipin	Phosphatidylglycerol, myristic and palmitic acids	[120, 202]
Coagulation	E-selectin, P-selectin, thrombomodulin	Fibronectin binding protein, staphylocoagulase precursor, Vonwillebrand factor binding protein	[202]
Antibiotic resistance	β-lactamase, enzyme L5, multidrug efflux protein (Mtr, Mex, TolC)	β-lactamase, Penicillin-binding proteins: PBP1, PBP2, PBP2a, PBP3 and PBP4	[202]
Virulence factor delivery	Enzymes: phospholipase C, esterase lipase, alkaline phosphatase, serine protease Toxins: adenylatecyclase, cholera, cytolethal distending, PagJ, PagK1, VacA	InIB, LLO, IgG binding protein SbI, protective antigen, lethal factor, edema toxin, anthrolysin	[202]
Bacterial survival	Hemin-binding protein, TonB-dependent receptors	β-lactamase protein	[202, 203]
Bacteria adhesion and invasion	Adhesin/invasin, OmpA	Plasma binding proteins, staphopain A	[202]
Immune evasion	Cytotoxic necrotizing factor 1, UspA1/A2	Coagulation factors, antibody degradation and sequestering factors, complement inhibition factors	[46, 202]
Host-cell modulation	Cytolysin A, VacA toxin, CNF1, heat-liable enterotoxin, shigatoxin, Cif, flagellin, α-haemolysin	Proteolysin, β2 toxin	[202]
Killing competing bacteria	Endopeptidase L5, murein hydrolase (Mtl, Slt), peptidoglycan hydrolase	N-aetylmuramoyl-L-alanine amindase	[202]
Biogenesis	a. Loss or relocation of covalent linkages between the OM and the underlying peptidoglycan layer b. Accumulation of peptidoglycan fragments in the outer leaflet of the OM c. Misfolded proteins in periplasmic space exerting turgor pressure on OM d. Enrichment of species-specific membrane curvature-inducing molecules	Action of cell wall-degrading enzymes; endolysin, autolysin	[36]
Lipids	Glycerophopholipids, phosphatidylethanolamine, phophotidylglycerol and cardiolipin	Phosphatidylglycerol, myristic and palmitic acids	[120, 202]
Coagulation	E-selectin, P-selectin, thrombomodulin	Fibronectin binding protein, staphylocoagulase precursor, Vonwillebrand factor binding protein	[202]