Includes bibliographical references.Plasmids are known to carry genes that allow bacteria to survive in different environments. Virulence genes that cause bacteria to be pathogenic are also found on plasmids. Bacillus megaterium is a non-pathogenic, spore-forming bacteria that is found in soil, but recently a strain of B. megaterium was reported to cause a mild case of diarrhea in an infant. This appears to be the first case of infection caused by B. megaterium (CHI). Bacillus cereus is a related species and a known gastroenteric pathogen. Research has shown that the pathogenicity in some strains of B. cereus is caused by either an operon containing four genes, hblA/B/C/D, or by a single gene, bceT. The pathogenic strain of B. megaterium, (CHI), was tested by PCR and hybridization, to see if it picked up either of these two factors that cause pathogenicity in B. cereus by plasmid exchange. PCR products were obtained in CHI for the genes hblA and bceT using specific primers suggesting that such genes are present in the B. megaterium (CHI) strain. However, a hybridization experiment using bceT product as a probe for CHI failed to show a signal.B.S. (Bachelor of Science