NILIMA LANKESHWAR AND U. S. BAGDE
Abstract
In traditional medicine, great emphasis is laid on the process of detoxification of metals and other inorganics. In the process of Shodhana, these purified metals are further processed in various herbal juices and increnated 100 times to get the final product (www.ayurvedas.com). Chinese material medica that was writtern 2735 B.C. contained many plant and metallic preparations and few animal products. Other studies by Chinese and Japanese investigators have shown a role between herbal preparations containing zinc and reduced symptoms of fatigue and related conditions. Increasing environmental concentrations of heavy metals pose a challenge to bacteria. In present investigation possible mechanism of zinc (Zn) resistance in Shigella dysenteriae, was studied. While the growth of sensitive Shigella dysenteriae was completely inhibited at 1mM/mL concentration of zinc, the resistant strain tolerated even 40mM/mL concentration of zinc. Mechanism of resistance was found to be presence of plasmid. Plasmid was analyzed by agarose gel electrophoresis. Plasmid curing was successful with 2-10% Sodium dodesyl sulfate (SDS) treatment. All colonies on plate after SDS treatment were tested for zinc resistance on nutrient agar containing different concentrations of zinc. It was observed that after SDS treatment zinc resistant Shigella dysenteriae cells got converted to zinc sensitive cells.