Antimicrobial agents particularly antibiotics have been critical in the fight against infectious diseases caused by pathogenic microorganisms including bacteria, fungi, viruses and protozoa [1]. There usage in clinical medicine for treating infectious diseases has drastically leads to increase in the life expectancy of the human race over the past six decades. This is because the discovery and usage of antibiotics in infectious disease management has helped to reduce the rate of morbidity and mortality caused by infectious disease pathogens in human population. However, in recent years there has been a marked rise in the number and type of antimicrobial resistant organisms [2].
Antibiotic resistance is one of the biggest challenges to the health sector worldwide, and this medical quagmire threatens our ability to effectively manage and treat some infectious diseases. Microbial resistance to antibiotics and/or antimicrobial agents has been documented not only against antibiotics of natural and semi-synthetic origin such as the penicillins, but also against some purely synthetic compounds (such as the fluoroquinolones) or those which do not even enter the cells (such as vancomycin). And unfortunately, the slow pace in the discovery and development of novel antibiotics have not actually kept pace with the emergence and rate at which bacteria develops and mount resistance to some available antibiotics [3].