The presence of Gram-negative bacteria in cuticle and alimentary tract of cockroaches collected from four selected areas of Dhaka city was investigated. Using detection key, a total of 12 cockroaches were identified as Periplaneta americana (58.33%), Blattella germanica (33.33%) and Blatta orientalis (8.33%). From these three species 54 different bacterial isolates were obtained. Out of them, 3...