
The extensive use of antibiotics since they were discovered has lead many bacterial species of human and animal origin to develop innumerable mechanisms that provide them resistant to some antibiotics and in a few cases to nearly all of them. There are numerous significant pathogens that are resistant to many antibiotic classes, and these multidrug resistant (MDR) organisms cause infections that are restricting treatment options and as a result compromising effective therapy. Thus, the emergence of antibiotic resistant bacteria population is a pertinent field of study in medical practice as well as in evolutionary and molecular biology. In recent times, the greatest challenge to the effective treatment of infectious disease, in the field of medicine, is the ability of all pathogens, without exception, to develop mechanisms for resistance to the action of antimicrobial drugs. Due to advancement in automation, clinical epidemiological research, and molecular biology, our wisdom of resistance has expanded at a confusing rate in recent years. Anyhow, antimicrobial resistance remains a significant medical, financial, and social issue. In this review we showcase some recent data and literature on molecular mechanisms of antibiotic resistance.