Screening of natural extracts for their antibacterial activity against different enteric pathogens isolated from soil, water and rotten fruit samples

Abstract

Different bacterial strains were isolated from soil, water and rotten fruit samples, and biochemically characterized as Shigella, Pseudomonas, Escherichia coli, Klebsiella and Proteus. Unhygienic environment (for example, contaminated food, water and air) are the most common habitats of these pathogens. Mostly, all are involved in endemic breakouts causing urinary tract and gastro-intestinal infections. The antibacterial activity of four concentrations of natural crude extracts of medicinal plants namely Allium sativum (garlic), Nigella sativa (black cumin), Trigonella foenum-graecum (fenugreek), Ficus carica (fig), Azadirachta indica (Indian lilac) and honey was determined against a total of ten isolated organisms by well plate method. Test organisms were found to be more sensitive to aqueous extract of bulb of A. sativum, seeds of Nigella sativa and honey. The antibacterial activity of crude extract was comparable with ciprofloxacin and ceftriaxone, commonly used antibiotics for the treatment of infections in adults and children, respectively. It was observed from the studies that most of the test strains were resistant to the antibiotics used especially against ceftriaxone. Due to the emergence of drug resistant microorganisms, it is a need to search out more effective antimicrobial agents to cure the disease. Our studies suggest that aqueous crude extract of medicinally important plants and honey could be the alternative of the antibiotic to cure the diseases.

Keywords: Ceftriaxone, Ciprofloxacin, Nigella sativa, Shigella, Proteus