On the red fluorescence emission of Aggregatibacter actinomycetemcomitans

A number of studies have indicated that bacteria able to emit red fluorescence can be detected by light in-duced fluorescence technique and killed by photodynamic therapy. The objective of this study was to investigate the red fluorescence properties of the single gram negative capnophilic bacterium Aggregatibacter actinomycetemcomitans, ATCC 33384, and to investigate if these properties were related to the growth, morphology and size of the bacterial colonies. Time trend assessment was made with red fluorescence by QLF (Quantitative Light-induced Fluorescence), as well as with white light digital imaging. It was demonstrated that A. actinomycetemcomitans, a single capnophilic bacterium, is able to produce red fluorescence on its own, i.e. in the absence of other bacteria strains, and that blood agar is necessary to obtain red fluorescence from this bacterium on culture plates. This bacterium formed smooth circular, bell/dome like colonies increasing in size with time exhibiting various red fluorescence behaviors. A large variation in the fluorescence behavior points out an inhomogeneous distribution of red fluorescence within and between the colonies, i.e. the size of the investigated colonies did not correlate with the red fluorescence area, suggesting a dependence on the colony morphology such as the colony growth in height. To our knowledge this is the first study that have shown that A. actinomycetemcomitans on its own is able to produce fluorescence in the red spectral region.

Periodontopathogen profile of healthy and oral lichen planus patients with gingivitis or periodontitis

Oral lichen planus （OLP） is a chronic inflammatory disease that is frequently detected in oral tissues. The aim of our study was to identify the prevalence of the detection of periodontopathogenic microorganisms （Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia and Treponema denticola in OLP patients and to compare with this prevalence of periodontopathogenic microorganisms in healthy non-OLP patients. Our study included 27 （18 chronic periodontitis （OLPP） and 9 gingivitis （OLPG）） patients diagnosed with OLP along with 26 （13 chronic periodontitis （HP） and 13 gingivitis （HG）） healthy non-OLP patients. The multiplex polymerase chain reaction （PCR）with subsequent reverse hybridization method （micro-IDent） was used for identifying periodontopathogenic microorganisms present in subgingival plaque samples. The percentages of detection for A. actinomycetemcomitans, P. gingivalis, P. intermedia, T. forsythia and T. denticola in subgingival plaque samples taken from OLP patients （OLPG and OLPP） were 18.5%, 85.1%, 81.4%, 88.8% and 74%, respectively. Meanwhile, in the non-OLP patients （HG and HP）, these values were 7.6%, 50%, 46.1%, 73% and 57.7%, respectively. Thus, comparing the non-OLP groups with the OLP groups, the periodontopathogens＇ percentages of detection in the OLP groups were higher than those in the non-OLP groups. According to our study results, OLP patients have higher levels of infection with A. actinomycetemcomitans, P. gingivalis, P. intermedia, T. forsythia and T. denticola than non-OLP patients. We argue that the high percentages in patients with OLP may help identify the importance of periodontopathoRenic microorganisms in the progress of periodontal diseases of OLP.