Microbial adaptation and resistance to pesticides

Abstract

Dramatic escalations in fabrication and application of chemicals in the form of pesticides, explosives, dyes, drugs, antimicrobial agents, etc has had pervasive impacts on the microbial population, flora and fauna dwelling in the contaminating habitat, with creation of “mosaic pathways” or “mosaic organisms”, leading to evolution of species. It is well understood that gene transfer between microbes found in natural systems, assist them to tolerate and resist the effects of antimicrobials, e.g. in farms where cattle are sheltered and agricultural lands where various pesticides are used time and again. It has been suggested that at low concentrations some antibiotics serve as signaling molecules therefore few of the genes encoding antibiotic resistance were originally selected for metabolic functioning or for signal transductions in their host cells. Higher concentration of antibiotics discharged in specific habitats (e.g., clinics/hospitals) due to irresponsible human activity has the potential to shift these metabolic roles toward development of resistance to antibiotics/drugs. The chapter describes the occurrence of cross or co resistance to biocides and/antibiotics exhibited under persistent and selective pressure highlights the significance of mobile genes and lateral genetic transfers from one to another microbe. Such phenomenon is now common in particular areas where agricides occur in recalcitrant/lesser concentrated state in soil and water, and is transmitted directly to human or enter our bodies via food chain thereby facilitating the switch from cross to co-resistance.