The DNA probes Pn17 and Pn34 were evaluated for their ability to specifically detect clinical strains of P. intermedia and P. nigrescens from a Korean population by dot blot hybridization. These probes were sequenced by extension termination and their specificity was determined by Southern blot analysis. The results revealed that the Pn17 sequence (2,517 bp) partially encodes an RNA polymerase beta subunit (rpoB) and that Pn34 (1,918 bp) partially encodes both rpoB (1-169 nts) and the RNA polymerase beta subunit (rpoB'; 695-1918 nts). These probes hybridized with both HindIII- and PstI-digested genomic DNAs from the strains of P. intermedia and P. nigrescens used in this study. Interestingly, each of the hybrid bands generated from the HindIII-digested genomic DNAs of the two bacterial species could be used to distinguish between them via restriction fragment length polymorphism. These results thus indicate that Pn17 and Pn34 can simultaneously detect P. intermedia and P. nigrescens.

• Joong-Ki Kook(Oral Biochemistry, School of Dentistry, Chosun University) Corresponding author
• Dong-Heon Baek(Department of Oral Microbiology & Immunology, College of Dentistry, Dankook University)
• Ki Woon Cho(Oral Biochemistry, School of Dentistry, Chosun University)
• Hyun-Sun Jang(Periodontology)
• Ho-Keel Hwang(Department of Conservative Dentistry)
• Jeong-Bum Min(Department of Conservative Dentistry)
• Hwa-Sook Kim(Department of Dental Hygiene, Chunnam Techno College)
• Pan Soon Kim(Periodontology) Contributed equally
• Chan-Ho Park(Department of Conservative Dentistry) Contributed equally