Class Betaproteobacteria

Bordetella

small, gram- coccobacillus, aerobic, very fastidious, causes pertussis (whooping cough)

Burkholderia

gram- bacillus, aerobic, aquatic, causes diseases in horses + humans, agents of nosocomial infections

Leptothrix

gram-, sheathed, filamentous bacillus, aquatic, oxidize iron and manganese, can live in wastewater treatment plants and clog pipes

Neisseria

gram-, coffee bean shaped coccus forming pairs, require moisture and high concentration of carbon dioxide, oxidase positive, grow on chocolate agar, pathogenic species causes gonorrhea and meningitis

Thiobacillus

gram- bacillus, thermophilic, acidophilic, strictly aerobic bacteria, oxidize iron and sulfur