| Popis: |
Dental caries is the most common bacterial disease of humans and occurs when oral bacteria produce acids, following their fermentation of dietary carbohydrates. This acid can then cause a localised demineralisation of the tooth surface. A group of seven species of bacteria, collectively known as the mutans streptococci, have been predominantly implicated in the onset of dental caries. In particular, Streptococcus mutans and Streptococcus sobrinus have been shown to be the main aetiological agents of this disease in humans. Most attempts to control the microbial component of caries target these bacteria. The past 50 years has provided considerable information about the pathogenesis of dental caries, the likely route and time of transmission of cariogenic bacteria to susceptible hosts and possible ways of either treating or controlling the onset of this disease. In regards to the latter, many techniques (such as the use of tooth brushes, mouth washes, dental floss and tooth paste) for the control of plaque build-up exist and the examples listed are generally part of a daily routine. However, these techniques need to be applied regularly, and as such only highly-motivated individuals generally experience improved oral health. Therefore, the search for more effective less labour-intensive approaches continues. One area of research is into the potential application of small ribosomally-synthesised antimicrobial peptides, known as bacteriocins. Bacteriocins generally inhibit closely-related species that occupy the same ecological niche. Their relatively-specific targeting, plus the fact that many are remarkably heat and chemically-stable molecules, makes them excellent candidates for possible anti-caries applications. Numerous bacteriocins produced by the lactic acid bacteria have now been identified. Most can be broadly categorised into one of four main classes, of which Class I, the lantibiotics and Class II, the small |
