Prospects application of polypyrrole-based immunosensor to Porphyromonas gingivalis quantification in subgingival plaque samples.
BACKGROUND
Periodontitis still poses a serious threat to oral and systemic health condition of humans. The proportion of the main pathogenic bacteria change in localized sites was associated with the initiation of the disease process. However, the limitations of microbiological diagnostic aids rendered the diagnosis of active periodontitis status point-of-care or chair-side based on microbiological data difficult.


METHODS
Porphyromonas gingivalis, a major putative etiological agent in the initiation and progression of chronic periodontitis, was used as the experimental subject. An immunosensor based on polypyrrole-coated interdigitated array microelectrodes was developed to quantify Porphyromonas gingivalis in pure culture, gingival crevicular fluid and saliva samples. The regression equation for the normalized impedance change (NIC) versus Porphyromonas gingivalis concentration (C) was measured. The correlation between results of the immunosensor and quantitative real-time PCR method in quantifying Porphyromonas gingivalis in subgingival plaque samples was evaluated.


RESULTS
Results of the study revealed that the lowest detection limits of the immunosensor was 1.9 x 10(4), 2.7 x 10(5), and 2.7 x 10(6) cells/mL in pure culture, gingival crevicular fluid, and saliva samples respectively. The values determined using the immunosensor strongly correlated with those obtained using quantitative real-time PCR method (R2 = 0.91, p < 0.05). The immunosensor did not require any labels and amplification steps, and the total detection time from sampling to measurement was less than one hour.


CONCLUSIONS
The immunosensor developed in the present study offered some insight into monitoring the change in the number of periodontal bacteria chair-side during routine clinical practice.
Zhenhua
Z
Pei
Baogang
B
Quan
Zhongying
Z
Niu
Shenggen
S
Shi
Liang
L
Shi
Chuhua
C
Tang
Yan
Y
Liu
D005240:Feasibility Studies; D006801:Humans; D007159:Immunologic Tests / Q000295:instrumentation* / Q000379:methods; D008839:Microelectrodes; D010510:Periodontal Diseases / Q000175:diagnosis / Q000382:microbiology*; D011108:Polymers; D016966:Porphyromonas gingivalis / Q000302:isolation & purification*; D011758:Pyrroles; D012463:Saliva / Q000382:microbiology
D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole