Abstract
Agrobacterium is a plant pathogen, which is able to produce several kinds of diseases in various plant species such as crown gall disease and hairy root disease. The crown gall disease and hairy root diseases develop when a segment of the bacterial DNA is transferred into the plant cell and subsequently becomes integrated into the plant genome. Historically, this transfer has taken place only in plants. There is an assumption that Agrobacterium, a commonly used gene transfer vector for plants, cannot infect animal cells; however, this has been proved wrong and certain kinds of human diseases have been identified. Increasing evidence indicates that, under laboratory conditions, Agrobacterium is able to transfer its DNA into numerous and diverse nonplant eukaryotic species, such as fungi and yeast, as well as human cultured cells. Agrobacterium is responsible for opportunistic infections in humans with weakened immune systems. It is also found to be responsible for producing poisonous hydrogen sulfide (H2S) gas, sepsis, monoarticular arthritis, bacteraemia, cancer, Morgellons disease and so on, in humans.