In my humble opinion, One may restrict his topic to the area that he/she is working in. As in "Characterization of halophilic bacteria in a cattle dung". Now if somebody else is working on it, one may change it as "Characterization of halophilic bacteria in a cattle dung from Assam or Northeast".
No problem. The train of science is moving and it is completely related to the nature of the science. You can compare your work with the similar work and find probable error in your work. It is an opportunity and not a challenge.