Materials and Methods: A self-administered questionnaire constructed in local Malay language consisting of 13 questions on sociodemographic details and 10 questions on the knowledge domain was distributed to eligible respondents while they were waiting for their consultation in the periodontal clinic waiting hall. There were 330 study participants aged 16 years old and above, who participated in this study from all 12 dental clinics in the state of Perlis, Malaysia. Data were entered into Statistical Package for the Social Sciences version 20.0 for analysis. Descriptive statistics were used to describe the sociodemographic data, whereas association between potential factor and the knowledge of awareness was found using the Pearson Chi-square test of independence or a Fisher's exact test, depending on the eligibility criteria.
Results: Our study showed that 4.5% (n = 15) of the respondents were not aware that smoking did add risk for oral cancer, 14.5% (n = 48) were not aware that smoking could cause gum disease. Smoking status was significantly associated with the awareness of smoking effect on gum disease (P = 0.002). The proportion of the active smokers being aware that smoking could potentially cause gum disease was considerably less as compared to the nonsmokers (62.7% vs. 83.3%).
Conclusions: Continuous dental health campaigns and awareness program are crucial to instil awareness and health-seeking behavior as well as to enforce public's knowledge.
OBJECTIVE: The objective of this study was to evaluate whether SOS exerts fungicidal activities against common fungal species.
MATERIALS AND METHODS: The efficacy of SOS was tested against 6 fungal species (Candida albicans, Candida auris, Candida tropicalis, Candida parapsilosis, Sporothrix schenckii, Trichophyton mentagrophytes) using an in vitro time-kill assay.
RESULTS: SOS achieved 99.9999% reduction of all tested fungi within 1 minute of exposure.
CONCLUSIONS: This study shows that SOS may be an effective tool for the prevention and control of fungal infections.
METHODOLOGY/PRINCIPAL FINDINGS: Salivaricin 9 was found to be auto-regulated when an induction assay was applied and this finding was used to develop a successful salivaricin 9 production system in liquid medium. A combination of XAD-16 and cation exchange chromatography was used to purify the secondary metabolite which was shown to have a molecular weight of approximately 3000 Da by SDS-PAGE. MALDI-TOF MS analysis indicated the presence of salivaricin 9, a 2560 Da lantibiotic. Salivaricin 9 is a bactericidal molecule targeting the cytoplasmic membrane of sensitive cells. The membrane permeabilization assay showed that salivaricin 9 penetrated the cytoplasmic membrane and induced pore formation which resulted in cell death. The morphological changes of test bacterial strains incubated with salivaricin 9 were visualized using Scanning Electron Microscopy which confirmed a pore forming mechanism of inhibition. Salivaricin 9 retained biological stability when exposed to high temperature (90-100°C) and stayed bioactive at pH ranging 2 to 10. When treated with proteinase K or peptidase, salivaricin 9 lost all antimicrobial activity, while it remained active when treated with lyticase, catalase and certain detergents.
CONCLUSION: The mechanism of antimicrobial action of a newly discovered lantibiotic salivaricin 9 was elucidated in this study. Salivaricin 9 penetrated the cytoplasmic membrane of its targeted cells and induced pore formation. This project has given new insights on lantibiotic peptides produced by S. salivarius isolated from the oral cavities of Malaysian subjects.