Antimicrobial Agents

Use of substances with antimicrobial properties is known to have been common practice for at least 2000 years. Ancient Egyptians and ancient Greeks used specific molds and plant extracts to treat infection. More recently, microbiologists such as Louis Pasteur and Jules Francois Joubert observed antagonism for some bacteria and discussed the merits of controlling these interactions in medicine. In 1928, Alexander Fleming became the first to discover a natural powerful antimicrobial fungus known as Penicillium Rubens. The substance extracted from the fungus he named Penicillin and in 1942 it was successfully used to treat a Streptococcus infections [1,2]. But nowadays, all over the world treatment of using antimicrobial agents is currently facing its own limitation, due to the development of resistance by the microbes over the period of time. Bacteria are involved in many aspects of ecology and health. It seems likely that all species both benefit and suffer from interactions with bacteria. For example we use bacteria for making yoghurt, curd, cheese and other fermented foods and also large number of bacteria lives on the skin and in the digestive tract. The human gut contains more than 1000 bacterial species which are beneficial [3]. Gut bacteria synthesize vitamins such as Folic Acid, Vitamin K and biotin and they ferment the complex, indigestible carbohydrates. Other useful bacteria in the gut flora include Lactobacillus species, which convert milk sugar into Lactic Acid. Also bacteria play very important role in the medicine such as vaccine component and in the production of antibiotics, drugs, hormones, and antibodies. On the other hand a pathogenic bacterium causes an enormous level of spoilage, suffering and death through the infection. The bacterial cells differs dramatically in structure and function compared to mammalian cells. The bacterial cytoplasm is separated from the external environment by a cytoplasmic membrane, as shown in Figure 1. The bacterial cell wall is chemically distinct from mammalian cell [4] walls and so is constructed by enzymes that often have no direct counterpart in mammalian cell construction. The following are the functions of the various parts of the bacterial cell. Cell Wall