RESUMEN
Aims: Beta-lactamase production and subsequent resistance to β-lactam drugs has been a global concern in the treatment of Gram negative anaerobes. The aim of this study was to identify F. nucleatum strains producing Class D β-lactamase through the detection of FUS-1 (OXA-85) resistance gene. Place and Duration of Study: Department of Preventive Dentistry, Lagos University Teaching Hospital, Idi-Araba, between February 2010 and November 2010. Methodology: Twenty two oral clinical samples were obtained from patients with chronic periodontitis who admitted to previous use of amoxicillin. Antibacterial susceptibility of the bacterial isolates was determined by E-test on Brucella Blood agar. Amplification of the bacterial DNA was carried out by PCR using F. nucleatum species-specific primer, FUS-1 specific for blaFUS-1 and strain-specific primers for subspecies nucleatum,, fusiforme, polymorphum and vincentii. Results: From the 19 samples collected, F. nucleatum was isolated, and the identity of the isolates was confirmed by PCR. Four of the isolates produced similar bands with the control strain, 3 (15.7%) strains were able to produce amplication with FUS-1 primer specific for blaFUS-1 gene found in β-lactamase producing F. nucleatum subsp. polymorphum. Conclusion: This study shows the presence of class D β-lactamase producing F. nucleatum species in Nigeria.