◼︎ Effect of bismuth thiols (BTs) on slime (CPS)
◆ Effect of BTs on phagocytosis
● Effect of chlorhexidine (CHX) on slime (CPS)
▲ Effect of CHX on phagocytosis
The featured image on this post is from a key experiment we performed in the mid 1990s at Winthrop-University Hospital. It shows the uniqueness and potential of our antibacterial agents, the bismuth thiols (BTs). The bottom of the graph shows drug amounts in fractions of what it takes to inhibit bacterial growth (called the minimal inhibitory concentration or MIC). In other words, there is not enough drug present to inhibit the growth of these bacteria, and they are still growing. Nevertheless, something is happening to them, as the BT level increases. Slime (CPS) production gets reduced by 90% at less than half the BT concentration that actually inhibits bacterial growth (line in graph with black squares).
Slime functions to camouflage bacteria and protect them from host defenses. But BTs leave bacteria naked and susceptible. When human white blood cells are thrown into the mix, they readily eat BT-treated bacteria (a process called phagocytosis). The phagocytic index for BTs is represented by the line with diamonds. As the amount of slime drops, the amount of phagocytosis jumps precipitously. Each white blood cell contains several BT-treated bacteria, which are killed and degraded. However, without BT treatment, very few bacteria are taken up by the white blood cells. Simply put, immune cells have a much easier time engulfing slime-forming bacteria when small amounts of BTs are present.
The graph also shows the effects of a competitive compound, chlorhexidine (CHX), a popular dental antiseptic. The line with black circles shows the effects of CHX on slime production, which is minor. In turn, CHX effects on phagocytosis appear nil at these levels, as shown by the line with black triangles. Indeed, there are a lot of antimicrobials out there, but no other compound has the slime-inhibiting effects shown by the BTs, especially at such low concentrations. Some day this anti-slime effect may be used to boost our immune systems to fight harmful bacteria.
Granted, the BTs have many other antimicrobial properties, but this is what makes them so special. Most pathogens produce slime, which they use to evade immune defenses. Yet, tiny amounts of BTs stop them from making it. All of them.
BTs should prove useful for a variety of diseases and purposes. Our focus at present is on some of the most pressing needs in medicine, such as wound and lung infections (www.microbioncorp.com), but the BTs will eventually find their way into other areas of medicine, dentistry, agriculture and industry.