Antimicrobial Screening of Silver Nanoparticles and Moringa Oleifera Leaf Extract on Salmonella Typhi

Salmonella typhi (S. typhi) is a gram-negative bacteria that affects the liver and intestine and also the causative agent of typhoid fever, a ravaging disease of underdeveloped and developing countries leading to over 110,000 deaths per year globally. S. typhi infection is characterized by watery stool, excessive sweating, prolonged fever and abdominal discomfort. Due to antimicrobial resistance (AMR), most of the conventional antibiotics are ineffective against the bacteria which make the discovery of alternate treatment imperative. Moring oleifera (M. oleifera) is a very common plant in Africa and Asia known as “the miracle tree” due its traditional use in the treatment of so many diseases. Silver nanoparticles were synthesized using M. oleifera leaves extracts and both the leaf extract and combination (nan0-moringa) were used in an invitro lab to screen against S. typhi. Ciprofloxacin, a conventional antibiotic was also screened and a zone of inhibition of 25mm was obtained at 0.01mg/ml while moringa extract and nano-moringa extract exhibited zones of inhibition of 11mm at 125mg/ml minimum inhibitoy concetration (MIC) and 8mm at 6.25mg/ml MIC respectively. The minimum bactericidal concentration (MBC) for was obtained as 250mg/ml and 12.5mg/ml for moringa and nano-moringa extracts respectively. Out of 10 antibiotics used, S. typhi was only susceptible to ciprofloxacin. M. oleifera leaves and synthesized silver nanoparticles showed extraordinary synergy and possess anti S. typhi properties. However, further studies are needed to outright conclude that they can substitute the conventional treatment been used.