Virulence Factors of Environmental Microbes in Human Disease

Satish Gupte, Tanveer Kaur

Abstract

Environmental pathogens are organisms that survive in the outside environment but maintain the capacity to cause diseases in humans. They somehow adapt to the challenges of life in habitats that range from water and soil to the cytosol of the host cells. The key difference between environmental pathogens and other human pathogens is the ability of environmental pathogens to survive and thrive outside the host. Adaptation to wide ranges of temperature conditions, available nutrients and stresses encountered through physical conditions as well as those resulting from host immunological responses requires an ability to sense and rapidly adapt to new territories. Temperature is a critical and ubiquitous environmental signal that governs the development and virulence of diverse microbial species; microbial survival is contingent upon initiating appropriate responses to the cellular stress induced by severe environmental temperature change. In the case of microbial pathogens, development and virulence are often coupled to sensing host physiological temperatures. To escape various host defenses including temperature, these environmental pathogens express various factors as survival strategies in the new environment of the host body which prove to be virulent in the host ultimately making them environmental pathogens.