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Bacillus cereus is a Gram-positive, aerobic, rod-shaped, spore-forming bacterium. The spores of Bacillus cereus are generally resistant to pasteurization and gamma radiation. It creates a menace for the food industry as they bind to all kinds of food, causing food borne diseases like food poisoning. Our laboratory isolates, Bacillus cereus strains MHS and MSM-S1 interestingly differ in their ability to swarm on semi-solid surface. One of these two strains have ability to swarm very fast compared to the second one, thus are termed as hyper-swarming bacteria and normal swarming bacteria, respectively. Preliminary studies in our laboratory revealed that under unfavorable condition like surface hardness, hyper-swarming Bacillus cereus expressed less number of flagella and failed to swarm fast as agar percentage was increased. There are contrasting reports regarding the relation between swarming and biofilm formation in bacterial world. In one hand, it is generally observed that swarming motility and biofilm formation are inversely correlated or two opposing phenomena but there are controversies regarding these two phenomena. Thus, existence of a common regulatory switch involved in decision making for swarming and/or biofilm formation is possible in bacterial system. It is therefore important to have a comparative study to explore the cellular and molecular networks involved in swarming and biofilm formation in these Bacillus cereus strains and also to find the molecular switch which regulates the decision making in favor of swarming or biofilm formation. Research findings from the proposed work will have implications in understanding the mechanism of bacterial survival and up-gradation of anti-bacterial therapy against Bacillus cereus. |