Detection of Peptostreptococcus micros DNA in clinical samples by PCR

Abstract

Peptostreptococcus micros is a gram-positive anaerobic coccus which, although considered to be a natural commensal of the human oral cavity, is associated with periodontal, endodontal and peritonsillar infections. Identi®cation of the organism has to date relied upon conventional culture methods and biochemical analyses. The purpose of this study was to develop a PCR method for rapid and speci®c identi®cation of this organism in clinical samples. A pair of primers was selected, each of which was speci®c at the 39 end for P. micros DNA; they were used in the PCR assay, resulting in a 1074-bp product. The primers were shown to be speci®c for P. micros DNA as no PCR products were obtained when genomic DNA extracts from a wide range of other Peptostreptococcus species and other oral bacteria were used as templates. The PCR assay was then applied to the identi®cation of P. micros DNA in subgingival plaque samples from adult periodontitis patients and pus samples from subjects with acute dento-alveolar abscesses. Con®rmation of speci®c ampli®cation of P. micros DNA was obtained by digestion of PCR products with the restriction endonuclease RsaI, which gives a unique restriction pro®le for P. micros, and DNA sequencing. Sixty-eight subgingival plaque samples from 18 patients were analysed, of which 19 (28%) were positive for P. micros DNA; the proportion of patients carrying P. micros DNA in at least one sampled site was 11 (61%) of 18. Twenty (71%) of 28 pus samples analysed by PCR contained P. micros DNA. These results con®rm that P. micros may be involved in the aetiology of acute dentoalveolar abscesses and adult periodontitis. The PCR assay provides a more rapid and reliable alternative to conventional methods for identi®cation of P. micros in clinical samples.

Rapid identification of Gram-positive anaerobic coccal species originally classified in the genus Peptostreptococcus by multiplex PCR assays using genus- and species-specific primers

“…blotting with probes is labour-intensive. More recently, Riggio et al (2001) and Riggio & Lennon (2002) have developed PCR assays that specifically detect P. anaerobius and M. micros in clinical samples. In the present study, based on a 16S rDNA sequence analysis, we developed a multiplex PCR protocol which allows the rapid identification of 14 GPAC species, including eight clinically relevant species.…”

Comparison of 16S rDNA-based PCR and checkerboard DNA–DNA hybridisation for detection of selected endodontic pathogens

“…In recent years, molecular methods have also been used to investigate the microbiota associated with infected root canals and with acute periapical abscesses [2,[9][10][11][12][13][14][15][16][17][18][19][20]. These methods have provided significant additional knowledge regarding the composition of the endodontic microbiota.…”

Identification of Oral Peptostreptococcus Isolates by PCR-Restriction Fragment Length Polymorphism Analysis of 16S rRNA Genes

“…We have developed PCR assays for the direct detection of P. micros (15) and P. anaerobius (14) in clinical samples. In this study, we report the development of a rapid, novel molecularbased method for accurately identifying clinical isolates of oral Peptostreptococcus species.…”