Development of a PCR assay specific for Peptostreptococcus anaerobius

Abstract

Peptostreptococcus anaerobius is a gram-positive anaerobic coccus that is widely distributed in the normal human flora. The organism has also been implicated as a causative agent of several systemic infections, including endocarditis and infections of the genitourinary and gastrointestinal tracts. Its role in oral disease is less well defined, although it has been implicated in periodontal disease, gingivitis and root canal infections. Identification of P. anaerobius in clinical samples is currently reliant upon traditional culture and biochemical methods. The aim of this study was to develop a novel PCR assay for the detection of P. anaerobius and to attempt detection of this organism in oral samples. PCR primers specific for P. anaerobius DNA were developed by alignment of bacterial 16S ribosomal RNA gene sequences and selection of sequences specific at their 39 ends for P. anaerobius. When used in a PCR assay, positivity for P. anaerobius DNA was indicated by the amplification of a 943-bp product. The primers were shown to be specific for P. anaerobius DNA, as no PCR products were obtained when genomic DNA from a wide range of other Peptostreptococcus species and other oral bacteria were used as templates. The PCR assay was then applied to the detection of P. anaerobius DNA in subgingival plaque samples from adult periodontitis patients and pus aspirates from subjects with acute dento-alveolar abscesses. All of 60 subgingival plaque samples from 16 patients were negative for P. anaerobius DNA. None of the 43 pus samples analysed contained P. anaerobius DNA. These results suggest that P. anaerobius is not a major pathogen in adult periodontitis and dento-alveolar abscesses. The PCR assay is a more rapid, sensitive and specific alternative to culturebased methods for identification of P. anaerobius in clinical samples.

Antimicrobial Susceptibilities of Peptostreptococcus anaerobius and the Newly Described Peptostreptococcus stomatis Isolated from Various Human Sources

“…Downes and Wade (9) suggested that P. stomatis originates from the oral cavity, whereas P. anaerobius sensu stricto is involved in infections below the waistline. Their suggestion was consistent with a previous report of Riggio and Lennon (22), who failed to detect P. anaerobius in oral specimens by species-specific PCR. In line with these studies was our finding that most P. anaerobius isolates were from miscellaneous infectious specimens of the lower extremities and genitourinary tract.…”

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.…”

Peptostreptococcus stomatis sp. nov., isolated from the human oral cavity

“…2). Interestingly, the specific forward primer described by Riggio & Lennon (2002) was designed to anneal to this region, making it specific for P. anaerobius, but not Peptostreptococcus CK035. This further supports the hypothesis that P. anaerobius is not found in the human mouth.…”

“…However, a specific PCR assay for the species (Riggio & Lennon, 2002) failed to detect P. anaerobius in any of 60 subgingival plaque samples collected from subjects with periodontitis or 43 pus samples from dentoalveolar abscesses.…”