Antimicrobial Activity of Some Plant Extracts and Plant Nanoparticles Against Gram Negative Bacteria Isolated from Clinical Samples.

Document Type : Original Article


1 Prof. of organic chemistry, Faculty of science, Zagazig university

2 Prof. of Biochemistry, Faculty of Veterinary Medicine, Banha University, Qaliobia, Egypt

3 Department of Biochemistry, Faculty of science, Zagazig University, Sharkia, Egypt.

4 Prof. of Botany and Microbiology, Faculty of science, Zagazig University, Sharkia, Egypt


Sixty-two bacterial isolates were collected from clinical specimens of patients suffering from a bacterial infection. These bacterial isolates were obtained from 8 different specimens: urine, pus, sputum, Blood, Pleural fluid, Endotracheal aspirate, the central venous catheter, and a swab from the chest tube. Morphology and common laboratory biochemical tests carried out on the bacterial samples were grown on different isolation media namely: Blood agar, MacConkey agar, nutrient agar and CLED agar media and the biochemical tests are Coagulase, Catalase, Oxidase, Urease, Citrate utilization, Indole, Lysine Decarboxylase, Ornithine Decarboxylase, H2S production and TSI (Triple sugar iron agar test). The results showed that there are three different types of Gram-negative bacteria: Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii. The Antibiotics assay was performed by using 12 type of antibiotics using the disc diffusion methods and using the Well diffusion method to measure and record the inhibition zones produced by Nigella Sativa and Lawsonia inermis (Henna) extracts against the obtained Gram-negative bacterial isolates. The antimicrobial activity of Nigella Sativa extract against Klebsiella pneumonia, Acinetobacter baumannii, and Pseudomonas aeruginosa has inhibition zones respectively are 14,17 and 11mm with concentration 50mg% only however, Lawsonia inermis extract inhibition zones are [16 mm: 32 mm] with 10, 20, 25, and 50 mg% concentrations for all tested bacterium. The antimicrobial effect of Nigella Sativa nanoparticles was greater than Nigella Sativa extract in the case of Acinetobacter baumannii inhibition zone is 18± 1 mm followed by the effect against Klebsiella pneumoniae with 15± 1 mm diameter and no effect or no clear zone against Pseudomonas aeruginosa strain.
Keywords: Plant nanoparticles; Antimicrobial activity; plant extracts; Nigella Sativa; Lawsonia inermis(Henna)


Main Subjects