Virulence factors and their associated genes in microbes

Abstract

Pathogenic microbes contain certain abilities to cause infections or diseases in hosts during interactions. Virulence factors aggravate the defense mechanisms of the host to establish infections. The nature and type of virulence factors determine the pathogenicity of microorganisms. This report addresses the several varieties of virulence mechanisms developed by the microorganisms (fungi, bacteria, and virus) which comprise virulence factors or genes. These virulence factors can be enzymes, toxins, lipids, flagella, exopolysaccharides, quorum sensing, etc. Signaling plays a very important role in pathogenicity which triggers the conformational change of receptors for ligands to reduce or activate the mechanisms. The pathogens such as bacteria and fungus express different sets of virulence genes and transcription factors during infections. The regulation of virulence factors followed the two prime regulatory mechanisms which includes sigma factors and two-component regulatory systems. Microbial-system-assisted virulence factors can be elucidated at cellular and molecular levels and are useful to develop strategies against microbe-mediated pathogenesis. © 2019 Elsevier B.V. All rights reserved.