**1. Introduction**

The awareness about pollution of the environment by antimicrobials/antibiotics is increasing globally. So is the literature, which is predominantly on antibiotic resistant bacteria, antibiotic resistance genes and antibiotic residues in the environment. The main concern about this, is the fear that resistance in the environment will get transferred to the clinical pathogens (for example, through horizontal gene transfer) leading to untreatable infectious diseases. It is estimated that antibiotic resistance may result in deaths of several million per year, if suitable measures are not taken up to mitigate the resistance problem [1]. The World Health Organization and the United Nations General Assembly have therefore called antimicrobial resistance a global threat that needs to be resolved with top priority [2,3].

The resistance generating sources in the environment are mainly human waste, animal waste and manufacturing waste. Both humans and animals (agriculture, poultry, aquaculture etc.), release large amounts of antimicrobials/antibiotics, which are consumed by them for therapeutic and prophylactic use, in the environment through excretions and improper disposal, and also the resistant bacteria in their systems, and make the environment prone to multiplication of resistant bacteria and abundance of resistance genes. An additional issue in this is the inappropriate use of antibiotics by humans for themselves and for their animals, because of lack of awareness regarding appropriate use of antibiotics. Interventions in the form of increasing public awareness and knowledge are the most commonly used strategies for effecting appropriate antimicrobial use and reducing antimicrobial resistance [4]. For example, in a survey in China it was found that the pig farmers' knowledge regarding antibiotic use for their pigs was very poor and it was accompanied with improper behaviour. The survey results further showed that the probability of improper antibiotic use decreased with the increase in farmers' knowledge about appropriate antibiotic use, and about the hazards of antibiotic residues in the environment [5]. The drug manufacturing units also, through their effluents, pollute the environment by antimicrobials. The available treatments/treatment plants for treating wastewater/effluents not being efficient to neutralize these pollutants, there is an abundance of antimicrobials/antibiotics, resistant microbes/bacteria and resistance genes in the environment. The share of literature is higher for antibiotic resistant bacteria compared to antibiotic residues and resistance genes as the detection of the latter two is relatively more expensive and also requires a little higher level of technology. In this article, we will mainly deal with antibiotic resistant bacteria, resistance genes and antibiotic residues in the environment.
