Burkholderia cepacia complex (BCC), or simply Burkholderia cepacia, is a group of catalase-producing, lactose-nonfermenting, Gram-negative bacteria composed of at least 20 different species, including B. cepacia, B. multivorans, B. cenocepacia, B. vietnamiensis, B. stabilis, B. ambifaria, B. dolosa, B. anthina, B. pyrrocinia and B. ubonensis. B. cepacia is an opportunistic human pathogen that most often causes pneumonia in immunocompromised individuals with underlying lung disease (such as cystic fibrosis or chronic granulomatous disease). Patients with sickle-cell haemoglobinopathies are also at risk. The species complex also attacks young onion and tobacco plants, and displays a remarkable ability to digest oil.