**1. Introduction**

Antimicrobial resistance is the capability of bacterial pathogens to neutralize the bactericidal effects of antibiotics. Antibiotic resistance arises due to the changes that take place in bacteria in a way that decreases the efficiency of antibiotics, chemicals, or other mediators that are used for infections control [1]. Globally, antimicrobial resistance is the main problem associated with humans' and animals' health. With the emergence of resistance clones, those antibiotics that were previously considered as broad-spectrum lost their efficacy, this increasing trend in resistant clone posture serious problem for the clinicians to deal with such pathogens. As we know that antibiotics are categorized according to the type of bactericidal activity, their mode of action, their chemical nature, and their origin. Further, these drugs can be characterized on the basis of their mode of action like their involvement in bringing complexity in the synthesis of the bacterial cell wall, depolarization of cell membrane, inhibiting microbial key protein synthesis, and altering nucleic acid synthesis. In early era, microbial secondary metabolites were considered the

main treatment option for microbial infection, but later due to increasing resistance issues, synthetic derivatives of these natural products were being searched. There is a different reason that has pushed microbes to adopt drug resistance strategies. The use and misuse of antimicrobial agents have led to the emergence of resistance [2] Similarly the usage of low-standard antibiotics in some parts of the world particularly in underdeveloped countries may be the source of the emergence of drug resistance [3]**.** *Escherichia coli* strains are resistant because they are part of the natural microbiota of animals, humans and are found in the ecosystem [4]. *E. coli* is the most prevalent facultative bacteria found in humans and animals some strains being responsible for initiating infections. The foremost concern is their probable transmission of resistant *E. coli* strains among humans and animals. It uses different routes for their transmission such as direct contact, through food chains, or contact with animal excretions. *E. coli* strains that are considered as multidrug or extreme drug-resistant responsible for enteropathogenic and uropathogenic clones are a specific concern for world health. World Health Organization (WHO) have shown serious concern over the freely spread of resistant clone in the community and environment as it will pose threat to human health and the economy [5]. Although, it is one of the main reservoirs of resistance genes that might be responsible for treatment failures in both human and animal medicine. An increasing trend of resistant genes has been observed in *E. coli* in the current decade. Due to its large genomic fragments, MGEs are involved in the transfer of resistance genes in the enterobacteriaceae family, particularly among *E. coli* strains. Plasmids are normally present in most of resistant strains, help in the transfer of genetic material among bacterial species. Transposons another MGEs, are being considered as one of the major sources of resistance transmission. In *E. coli* several antimicrobial resistance trends are associated with plasmid-mediated colistin resistance *Mcr-1* gene [6]**.** But horizontal gene transfer [HGT] are mainly involved in resistance dissemination [7]. It is estimated that almost 700,000 deaths are attributed yearly, and this could increase to 10 million deaths worldwide annually by 2050. Almost 2.8 million people are suffering, and approximately 35,000 peoples die each year in the USA alone due to antimicrobial resistance [8].
