Studies on the Use of Plant Extracts for the Prevention of Bacterial Biofilms on Urinary Catheters

Abstract

This study was undertaken to evaluate the potentials of six plant extracts to prevent bacterial biofilms on urinary catheters. Uniformly sized sections (9 mm&#1782) of sterile silicone catheters were impregnated with aqueous extracts of the various plants, dried and sterilized under a UV hood before immersing in fresh urine for 18 – 72 h. Untreated catheter and catheter treated with standard antibiotics (ciprofloxacin and gentamicin), which were similarly immersed in urine, served as controls. Biofilm formation on the catheter sections was evaluated by culture, microscopy and viable cell count procedures. The results showed that bacterial attachment occurred on the catheter sections within 24 h of immersion in urine. The various extracts and standard drugs reduced bacterial attachment on the catheters in the order: ciprofloxacin > Psidium guajava > Aloe vera > gentamicin > Gongronema latifolium > untreated sections. Carica papaya, Ocimum gratisimum and Vernonia amygdalina potentiated bacterial attachment. Furthermore, the effect of Psidium guajava extract was longer-lasting than that of the standard antibiotics. Direct sensitivity tests against the urinary isolates showed that only P. guajava, amongst all the plant extracts, was active. This preliminary study highlights the potentials of herbal extracts especially P. guajava and Aloe vera in preventing biofilm formation on urinary catheters.

Keywords: Biofilms, urinary catheters, plant extracts, Psidium guajava, Vernonia amygdalina, ciprofloxacin