Use of randomly cloned DNA fragments for the identification of oral spirochetes.
DNA probes were produced for the detection and identification of 4 cultivable species of oral spirochetes, Treponema denticola, Treponema socranskii, Treponema vincentii and Treponema pectinovorum. To obtain probe sequences, chromosomal DNA, isolated from representative strains within each species, was cloned in Escherichia coli K-12. Cloned DNA fragments were screened for the ability to hybridize to DNA only from homologous strains. Several such fragments were identified and shown to be specific when tested against a series of DNAs from gram-negative and gram-positive oral bacteria. The selected probe sequences were semi-conserved within strains of T. denticola and T. socranskii such that restriction fragment length polymorphism (RFLP) was observed. In the case of T. socranskii, RFLP was useful in distinguishing between the 3 known subspecies. Chromosomal DNA fragments from 2 strains of T. vincentii failed to cross-hybridize, under stringent conditions, to genomic DNA from each of these strains. The hybridization probes were suitable for the identification of clinical isolates of T. denticola and could be used to detect the presence of individual Treponema species in mixed cultures. On this basis, the probes were used successfully to detect T. denticola in uncultured plaque samples.
Research Center, School of Dental Medicine, University of Pennsylvania, Philadelphia.
J M
JM
DiRienzo
S
S
Cornell
H
H
Boehringer
D015139:Blotting, Southern; D003001:Cloning, Molecular; D015342:DNA Probes; D004269:DNA, Bacterial / Q000032:analysis; D003773:Dental Plaque / Q000382:microbiology; D006089:Gram-Negative Anaerobic Bacteria; D006801:Humans; D009693:Nucleic Acid Hybridization; D010518:Periodontitis / Q000382:microbiology; D012150:Polymorphism, Restriction Fragment Length; D014208:Treponema / Q000302:isolation & purification*
D015342:DNA Probes; D004269:DNA, Bacterial