Antimicrobial Effect of Phyllanthus amarus and Parquetina nigrescens on Salmonella typhi

Abstract

Phyllanthus amarus and Paraquetina nigrescens are economic plants grown 
in West Africa for antimicrobial properties. Crude aqueous (hot and cold 
water) and ethanolic extracts of the plants were investigated for antimicrobial 
activity against Salmonella typhi. The organism was collected from the 
University College Hospital, lbadan, Nigeria and was exposed to ten standard 
different antibiotics and also to crude extract of P. amarus and P. nigrescens. 
Agar cup diffusion method was employed fro the plants extracts while disk 
diffusion method for the standard antibiotics. Ethanolic extracts of P. amarus
had the strongest activity against Salmonella typhi with 8.0mm zone of 
growth inbibition followed by hot water (4.7mm) and cold water (3.8mm). 
This was statistically significant at P= 0.05 when compared with hot and cold 
water extracts. Amongst the commercial antibioticis examined, ciprofloxacin 
had the highest zone of growth inhibition of 9.0mm; Oflxation (6.0mm) 
Amoxycillin, (4.0mm) while other antibiotics had on effect on test organism. 
Screening carried out on P. amarus and P. nigrescens using standard methods 
revealed the presence of saponins, alkaloids, tannins and cardiac glycosides. 
P. amarus possesses significant antimicrobial activity and confirms the 
justification by herbalists as extract used for treatment of typhoid fever.