In vitro Antimicrobial Activity of Some Plant Essential Oils against Organisms Associated with Urinary Tract Infection and Roasted Meat

Abstract

In search for alternative ways to control microbial infections, plant essential oils from clove, fenugreek, garlic, neem, eucalyptus and lemongrass were extracted using Soxhlet apparatus and petroleum ether as a solvent. Phytochemical screening of the oils/extracts revealead the presence of alkaloids, flavonoids, saponins, reducing sugars, steroids, tannins, glycosides and triterpenoids. The oils/extracts were then evaluated for their in vitro antimicrobial properties against Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Staphylococcus aureus and Candida albicans of Urinary Tract Infection and meat (suya) origins using disc diffusion and broth dilution techniques. Essential oil from clove was found to have the strongest inhibitory effect being able to inhibit growth of all assayed organisms followed by lemongrass extract, garlic oil, eucalyptus extract and neem oil while essential oil from fenugreek showed no inhibitory effect against all organisms tested. Highest and lowest susceptibility to these oils/extracts was demonstrated by S. aureus (mean zone= 11.7mm) and E. coli (mean zone= 5.8mm) respectively. Organisms isolated from urine showed more resistance than those isolated from meat. The LC50 analysis of the oils/extracts showed relatively high cytotoxic effects against brine shrimps, (<100 ppm). Maximum mortalities took place at a concentration of 1000 ppm whereas least mortalities were at 10 ppm concentration, which means that lethality of the oils/extracts was concentration-dependant.

Keywords

• Antimicrobial activity
• essential oils
• UTI
• Roasted meat