LABORATORY METHODOLOGY (POSTER PRESENTATION) Atmospheric Oxygen Sensitivity of Fusobacterium Strains Luizde Maceª do Farias 1 * , Maria Auxiliadora Roque de Carvalho 1 , Horace Houw 1 , Andre¨ a Aparecida Paiva de Oliveira 1 , Paulo Henrique Rodrigues 1 , Fla¨ vio Furtado de Farias 1 , Jacques Robert Nicoli 2 , andJose¨ Eusta¨ quioda Costa 3 1 Laborato Ârio de Microbiologia Oral e Anaero Âbios; 2 Laborato Ârio de Ecologia e Fisiologia Microbiana; Departamento de Microbiologia, Instituto de Cie Ãncias Biolo Âgicas; and 3 Faculdade de Odontologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil Key Words: anaerobes, Fusobacterium, oxygen sensitivity Introduction The Fusobacterium genus comprises anaerobic Gram- negative rods that are members of the indigenous microbiota of the upper respiratory tract, in particular, and also of the gastrointestinal and genitourinary tracts. They are prominent members of the bacterial microbiota of dental plaque, and they have been associated with severe oral and non-oral human infections, mainly in the lower respiratory tract, head and neck, periodontium, gingiva, and central nervous system [1±4]. The species more frequently isolated from patients with periodontal disease is Fusobacterium nucleatum. Others, such as Fusobacterium periodonticum, are also recovered, but at low frequencies [5,6]. The isolation and manipulation of anaerobic bacter- ia require specific conditions of oxygen tension, as this group comprises organisms with different degrees of oxygen tolerance [7,8]. The Fusobacterium genus tolerates oxygen tensions up to 8% [6,7]. The aim of this study was to evaluate the oxygen sensitivity of Fusobacterium strains exposed to atmo- spheric oxygen, in order to provide some knowledge about the oxygen tolerance of strains isolated in the `Laborato  rio de Microbiologia Oral e Anaero Âbios/ *Corresponding author. Tel.: +55 31 4992743; Fax: +55 31 4992730. E-mail: macedo@mono.icb.ufmg.br 1075±9964/99/030157 + 03 $30.00/0 # 1999 Academic Press Anaerobe (1999) 5, 157±159 Article No. anae.1999.0236