Antimicrobial activity of Nigella sativa Linn. seed oil against multi-drug resistant bacteria from clinical isolates

Salman, Mohd Tariq; Khan, Rahat Ali and Shukla, Indu (2008) Antimicrobial activity of Nigella sativa Linn. seed oil against multi-drug resistant bacteria from clinical isolates. Natural Product Radiance, 7 (1). pp. 10-14. ISSN 0972-592X, IPC code; Int. cl.⁸— A61K 36/00, A61P 31/04.

Abstract

An alarming increase in bacterial strains resistant to existing antimicrobial agents demands a renewed effort to seek agents effective against pathogenic bacteria resistant to current antimicrobials. Nigella sativa Linn. essential oil was studied for antibacterial activity against various clinical isolates of bacteria resistant to a number of antibiotics, in varying concentrations by Disc Agar diffusion technique using impregnated filter paper discs on inoculated Muellar Hinton agar plates. The oil showed pronounced dose dependent antibacterial activity which was more against Gram positive than Gram negative bacteria. Among Gram positive bacteria tested, Staphylococcus aureus, S. epidermidis, other coagulase –ve Staphylococci and Streptococcus pyogenes were sensitive to the oil and Enterococcus faecalis, Streptococcus agalactiae were resistant. Among Gram –ve bacteria tested, only Pseudomonas aeruginosa was sensitive to oil and rest (Acinetobacter baumannii, Citrobacter freundii, Klebsiella pneumoniae, Proteus mirabilis, P. vulgaris and Vibrio cholerae) were insensitive. Out of 144 strains tested, most of which were resistant to a number of antibiotics, 97 were inhibited by the oil of black cumin. To the best of our knowledge, the activity of essential oil against coagulase negative Staphylococci (except S. epidermidis) and S. pyogenes is being reported for the first time.

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