African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5210

Full Length Research Paper

Time kill-kinetics antibacterial study of Acacia nilotica

Oladosu, P.1, 2*, Isu, N.R.2, Ibrahim, K.1, Okolo, P.1 and Oladepo, D.K.1
1National Institute for Pharmaceutical Research and Development, Idu Industrial area, P.M.B 21, Garki, Abuja, Nigeria. 2BiologyDepartment, Faculty of Science, University of Abuja, Gwagwalada, Abuja, Nigeria.
Email: [email protected]

  •  Accepted: 08 October 2013
  •  Published: 21 November 2013


In vitro time-kill kinetics antibacterial study of Acacia nilotica was assessed against Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus determined by plate count technique and analyzed by percentage and log reduction. All test organisms were susceptible to the aqueous methanolic extract. The minimum inhibitory concentration ranged between 0.5 and 1 mg, while minimum bactericidal concentration ranged between ≥1 and ≥2 mg/ml. Average log reductions in viable cell counts for the extract ranged between 0.18log10 and 0.35log10 cfu/ml for P. aeruginosa, 0.27log10 and 1.95log10 cfu/ml for S. aureus and 0.27log10 and 0.45log10 cfu/ml for E. coli after 10 h interaction at 0.5x MIC and 1x MIC. Most of the extracts were rapidly bactericidal at 2x MIC achieving a complete elimination of most of the test organisms within 12 h exposure. A good correlation was found between the killing curves and the MIC of A. nilotica against the test organisms.


Key words: Time-kill kinetics, antibacteria, Acacia nilotica, percentage reduction.