In recent years, the subthreshold micropulse laser is a kind of laser mode which is characterized by long intermittence. It achieves effective therapeutic effect while minimizes the damage to tissues. At present, it has been used to treat diabetic macular edema. Early studies suggested that the laser selectively acts on retinal pigment epithelial cells to reduce macular edema by regulating the expression of inflammatory biomarkers, growth factors, heat shock proteins and other substances. In recent years, with the development of research, more and more emphasis has been placed on the role of retinal glial cells. Müller cells are also considered as one of the target cells affected by micropulse laser, but there is no evidence of direct or indirect effects of micropulse laser on Müller cells. In the near future, it is expected that we will have more clinical evidence to confirm the target cells of the micropulse laser, which may be further confirmed by in vitro experiments through Müller cells or Müller cells co-cultured with retina pigment epithelium cells, so as to make a more detailed statement on the mechanism of it.

OBJECTIVETo establish a systematic method for isolation and identification of aerobic and facultative anaerobic bacteria in the oral cavity.

METHODSSamples of the saliva, dental plaque and periapical granulation tissue were collected from 20 subjects with healthy oral condition and from 8 patients with different oral diseases. The bacteria in the samples were identified by morphological identification, VITEK automatic microorganism identification and 16s rRNA gene sequencing.

RESULTSVITEK automatic microorganism identification and 16s rRNA gene sequencing showed an agreement rate of 22.39% in identifying the bacteria in the samples. We identified altogether 63 bacterial genus (175 species), among which Streptococcus, Actinomyces and Staphylococcus were the most common bacterial genus, and Streptococcus anginosus, Actinomyces oris, Streptococcus mutans and Streptococcus mitis were the most common species. Streptococcus anginosus was commonly found in patients with chronic periapical periodontitis. Streptococcus intermedius and Staphylococcus aureus were common in patients with radiation caries, and in patients with rampant caries, Streptococcus mutans was found at considerably higher rate than other species.

CONCLUSIONAerobic and facultative anaerobic bacteria are commonly found in the oral cavity, and most of them are gram-positive. 16s rRNA gene sequencing is more accurate than VITEK automatic microorganism identification in identifying the bacteria.

Actinomyces ; isolation & purification ; Dental Caries ; Dental Plaque ; microbiology ; Humans ; Mouth ; microbiology ; RNA, Ribosomal, 16S ; genetics ; Saliva ; microbiology ; Staphylococcus aureus ; isolation & purification ; Streptococcus ; isolation & purification

Candida albicans is the most abundant fungal species in oral cavity. As a smart opportunistic pathogen, it increases the virulence by switching its forms from yeasts to hyphae and becomes the major pathogenic agent for oral candidiasis. However, the overuse of current clinical antifungals and lack of new types of drugs highlight the challenges in the antifungal treatments because of the drug resistance and side effects. Anti-virulence strategy is proved as a practical way to develop new types of anti-infective drugs. Here, seven artemisinins, including artemisinin, dihydroartemisinin, artemisinic acid, dihydroartemisinic acid, artesunate, artemether and arteether, were employed to target at the hyphal development, the most important virulence factor of C. albicans. Artemisinins failed to affect the growth, but significantly inhibited the hyphal development of C. albicans, including the clinical azole resistant isolates, and reduced their damage to oral epithelial cells, while arteether showed the strongest activities. The transcriptome suggested that arteether could affect the energy metabolism of C. albicans. Seven artemisinins were then proved to significantly inhibit the productions of ATP and cAMP, while reduced the hyphal inhibition on RAS1 overexpression strain indicating that artemisinins regulated the Ras1-cAMP-Efg1 pathway to inhibit the hyphal development. Importantly, arteether significantly inhibited the fungal burden and infections with no systemic toxicity in the murine oropharyngeal candidiasis models in vivo caused by both fluconazole sensitive and resistant strains. Our results for the first time indicated that artemisinins can be potential antifungal compounds against C. albicans infections by targeting at its hyphal development.
Animals ; Mice ; Candida albicans ; Candidiasis, Oral/drug therapy* ; Antifungal Agents/pharmacology* ; Hyphae ; Artemisinins/pharmacology*