In Vitro antimicrobial activity of Allium cepa (dry bulbs) against Gram positive and Gram negative bacteria and fungi.

The present research was carried out at the Institute of Biotechnology and Genetic Engineering, the University of Agriculture Peshawar KPK Pakistan. Analysis of the data revealed that all the extracts from dry bulbs showed different ranges of antimicrobial activities. Ethyl acetate fractions showed inhibitory activities against all tested eight microbes including bacteria and a fungus while chloroform fractions inhibited all the microbes except Pseudomonas aeruginosa. Butanol fractions showed second highest activity at both lower and higher concentrations. Ethanol and water fractions were found least effective or ineffective. Among Gram positive microbes, Staphylococcus aureus was the most susceptible bacteria and the most resistant Gram negative bacteria were Pseudomonas aeurginosa and Salmonella typhi.