Pantoea agglomerans is a Gram-negative

Gram-negative

Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...

 bacterium that belongs to the family Enterobacteriaceae

Enterobacteriaceae

The Enterobacteriaceae is a large family of bacteria that includes many of the more familiar pathogens, such as Salmonella, Escherichia coli, Yersinia pestis, Klebsiella and Shigella. This family is the only representative in the order Enterobacteriales of the class Gammaproteobacteria in the...

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Formerly called Enterobacter agglomerans, this bacterium is known to be an opportunistic pathogen in the immunocompromised, causing wound, blood, and urinary-tract infections. It is commonly isolated from plant surfaces, seeds, fruit (e.g. mandarin oranges), and animal or human feces.

It is difficult to differentiate Pantoea spp. from other members of this family, such as Enterobacter, Klebsiella, and Serratia species. However, Pantoea does not utilize the amino acids lysine, arginine, and orinthine, a characteristic that sets it apart from the other genera. (Winn, et al.; "Koneman's Color Atlas and Textbook of Diagnostic Microbiology", Sixth Edition, 2006: Lippincott, Williams, and Wilkins)

Pantoea agglomerans is found in the gut of locusts, which have adapted to use the guaiacol

Guaiacol

Guaiacol is a naturally occurring organic compound with the formula C6H4. Although it is biosynthesized by a variety of organisms, this colorless aromatic oil is usually derived from guaiacum or wood creosote. Samples darken upon exposure to air and light. Guaiacol is present in wood smoke,...

 that Pantoea agglomerans produces to initiate swarming of locusts.