From Amazon rain forest flora to the state-of-the-art technology devices, the incessant search for 'magic bullets' against Streptococcus mutans

Came 1910, and that was Paul Ehrlich's year. One day, that year, he walked into the scientific congress at Koenigsberg, and there was applause. It was frantic, it was long, you would think they were never going to let Paul Ehrlich say his say. He told of how the magic bullet had been found at last. (De Kruif¹ (1926) apud Sachs (2007)

Dear Readers,

After the keystone discovery of differences in the bacterial cells wall (i.e. the responsiveness to the crystal violet dye lead to the milestone gram-positive and gram-negative dichotomy), the Nobel Prize⁶ laureate Paul Ehrlich (Nobel Prize in Physiology or Medicine 1908 "in recognition of their work on immunity") reasoned that we could find a toxic dye only absorbed by bacteria (and not by host cells), it could be the 'magic bullet' of his dreams⁷.

After testing over nine hundred dyes and chemical compounds, the 606 compound (latter named Salvarsan) was found to be effective against the etiological agent of syphilis; but unfortunately such compound toxicity against the host was evidenced. While the '606' comprised a huge advance in the war on microbes, it became clear that search for the 'magic bullet' would be a long journey⁷.

From Ehrlich´s initial insight, passing by the first true antibiotic development (which resulted in the The Nobel Prize⁵ in Physiology or Medicine 1945 to Sir Alexander Fleming, Ernst B. Chain, Sir Howard Florey 'for the discovery of penicillin and its curative effect in various infectious diseases") to the modern days, researchers from numerous fields are still engaged in the search for a 'magic bullet'.

Considering the diversity and quantity of microbes present in the oral cavity even in healthy conditions, and the frequent pathogens that can trigger numerous oral conditions, Dentistry has been specially interested in 'magic bullets'. Tasks that sound quite simple, such as regular tooth brushing, can be quite effective in controlling Streptococcus mutans residing in the dental biofilm, and consequently, avoid its potential pathogenic effects in the development of dental caries. However, from the clinical viewpoint this 'simple task' was revealed to be quite more complex, where S. mutans virulence factors and host genetic susceptibility to S. mutans significantly add in complexity to this system^4,9. Beyond caries framework, the recent reports of the possible involvement of S. mutans in endocarditis and atheroscelerotic plaque development³ reinforces the necessity of efficient strategies to allow its control. While antibiotics can be very effective against S. mutans, the current standards for a rationale use of antibiotics reinforces the necessity of development of alternative anti-Streptococcal compounds.

In this scenario, the current issue of the Journal of Applied Oral Science presents two examples of the everlasting search for an anti-Streptococcal 'magic bullet' with clinical application potential.

In a traditional end, Silva, et al.⁸ (2014) screened over 2,000 rain forest (Brazilian Amazon) plant extracts regarding inhibitory activity against Streptococcus mutans in vitro. Indeed, the recognized knowledge of shamanic traditional medicine use of rain forest flora for treating native populations along the centuries has been a start point for several researchers in his search for new antimicrobial compounds. Indeed, Silva, et al.⁸ (2014) conclude that compounds from Casearia spruceana, Psychotria sp. (Rubiaceae) and Ipomoea alba show potential as antibacterial agents for use as chemical coadjuvants in prevention strategies to treat caries. Finally, in the technological end, Hakimiha, et al.²(2014) investigated the effectiveness of different photosensitizers and light sources in S. mutans targeted-photodynamic therapy (PDT). The authors concluded that both 662 nm laser and LED light associated with photosensitizers Radachlorin and TBO were effective against S. mutans in vitro.

Therefore, two promising Anti-Streptococcal strategies are described, and the time and futures studies may let us know if the a definitive 'magic bullet' against S. mutans will came from the Amazon rain forest flora or from the state-of-the-art technology devices.

REFERENCES

• ¹
  - De Kruif P. Microbe hunters by Paul De Kruif ... New York: Harcourt, Brace and company; [c1926] apud Sachs JS. Good germs, bad germs: health and survival in a bacterial world. New York: Hill and Wang; 2007.
• ²
  - Hakimiha N, Khoei F, Bahador A, Fekrazad R. The susceptibility of Streptococcus mutans to antibacterial photodynamic therapy: a comparison of two different photosensitizers and light sources. J Appl Oral Sci. 2014;22(2):80-5.
• ³
  - Kesavalu L, Lucas AR, Verma RK, Liu L, Dai E, Sampson E, et al. Increased atherogenesis during Streptococcus mutans infection in Apoe-null mice. J Dent Res. 2012;91(3):255-60.
• ⁴
  - Mattos-Graner RO, Klein MI, Smith DJ. Lessons Learned from clinical studies: roles of Mutans Streptococci in the pathogenesis of dental caries. Curr Oral Health Rep. Forthcoming 2013 [cited 2014 Feb 12]. Available from: http://link.springer.com/article/10.1007/s40496-013-0008-1/fulltext.html
  » http://link.springer.com/article/10.1007/s40496-013-0008-1/fulltext.html
• ⁵
  - Nobel Prize. Sir Alexander Fleming: biographical. Stockholm: The Nobel Foundation; 2014 [cited 2014 Feb 12]. Available from: http://www.nobelprize.org/nobel_prizes/medicine/laureates/1945/fleming-bio.html
  » http://www.nobelprize.org/nobel_prizes/medicine/laureates/1945/fleming-bio.html
• ⁶
  - Nobel Prize. The Nobel Prize in Physiology or Medicine 1908. Stockholm: The Nobel Foundation; 2014 [cited 2014 Feb 12]. Available from: http://www.nobelprize.org/nobel_prizes/medicine/laureates/1908/
  » http://www.nobelprize.org/nobel_prizes/medicine/laureates/1908/
• ⁷
  - Sachs JS. Good germs, bad germs: health and survival in a bacterial world. New York: Hill and Wang; 2007.
• ⁸
  - Silva JPC, Castilho AL, Saraceni CHC, Díaz IeC, Paciencia MLB, Suffredini IB. Anti-streptococcal activity of Brazilian Amazon Rain Forest plant extracts presents potential for preventive strategies against dental caries. J Appl Oral Sci. 2014;22(2):91-7.
• ⁹
  - Werneck RI, Mira MT, Trevilatto PC. A critical review: an overview of genetic influence on dental caries. Oral Dis. 2010;16(7):613-23.

Publication Dates

• Publication in this collection
  Mar-Apr 2014