<unk>  (formerly known as  Rochalimaea) is a genus of  Gram-negative bacteria. Facultative intracellular parasites,<unk>  species can infect healthy people but are considered especially important as opportunistic pathogens.<unk>  are transmitted by insect vectors such as ticks, fleas, sand flies and mosquitoes. At least eight<unk>  species or subspecies are known to infect humans. In June 2007, a new species under the genus, called<unk>  rochalimae, was discovered. This is the sixth species known to infect humans, and the ninth species and subspecies, overall, known to infect humans.
Members of the genus<unk>  are alpha 2 subgroup Proteobacteria. The genus comprises:
Bartonella
Salmonella
Brucella
Listeria
Salmonella enterica
Ehrlichia
Cryptosporidium
Francisella