<unk>  is a genus of Gram-negative bacteria. It is the only genus in the family<unk> ceae. Facultative intracellular parasites,<unk>  species can infect healthy people, but are considered especially important as opportunistic pathogens.<unk>  species are transmitted by vectors such as ticks, fleas, sand flies, and mosquitoes. At least eight<unk>  species or subspecies are known to infect humans.<unk>  henselae is the organism responsible for cat scratch disease.
Bartonella
Salmonella
Cryptosporidium
Listeria monocytogenes
Legionella
Mycoplasma
Edwardsiella 
Yersinia pestis