Inhibition of Swarming Motility, Biofilm Formation and Virulence Factor Expression of Urinary Pathogens by Euphorbia Trigona Latex Extracts

Euphorbia trigona latex has been used most effectively in the traditional Indian medicinal system of Ayurveda for the treatment of urinary tract infection (UTI). However, various organic and aqueous extracts of its latex were found not to possess any antimicrobial activity against several gram positive and gram negative organisms including Proteus mirabilis and Pseudomonas aeruginosa (selected for the present study) which are important urinary pathogens especially in patients with catheters over which they can form biofilms. The observation, that bacterial cell-cell communication or quorum-sensing (QS) is closely linked to swarming differentiation and virulence factor production in bacteria suggests that several bacterial pathogens may be prevented from establishing symptomatic disease via inhibition of their QS system by using anti-QS compounds. This is a viable alternative to the antibiotic-mediated growth inhibition or killing of pathogens, which invariably selects for multiple drug resistant cells. In order to investigate the effects of Euphorbia latex extracts on the pathogenicity of Pr. mirabilis and Ps. aeruginosa, their growth rate and some QS-controlled phenomena such as the swarming behavior, ability to form biofilm and virulence factor production, were monitored in the presence/ absence of the extracts. While growth rate was not affected adversely, a remarkable reduction in the swarm zone, virulence factor production and biofilm formation was observed which suggests that Euphorbia latex contains compounds which can potentially be developed as anti pathogenic drugs.