Journal of Chromatography & Separation Techniques
Open Access
ISSN: 2157-7064
+44 1300 500008
ISSN: 2157-7064
+44 1300 500008
Tariq M Aljarba,Paul Stapleton and Simon Gibbons
UCL School of Pharmacy, UK
Scientific Tracks Abstracts: J Chromatogr Sep Tech
Background: Multidrug-resistance among bacteria has become a global issue, bacteria
resistance occurs as a result of mutations in bacterial genes or the acquisition of resistance
determinants borne on plasmids, bacteriophages, transposons and/or by the action of
multidrug-efflux pumps. These pumps work to remove a variation of structurally irrelevant
antibiotics from the microorganism resulting in reduced susceptibility of the antibiotic;
Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa are an example
of these expel mechanism. This focus the urgency for new antibiotics or the potentiation
of existing antibiotics by inhibiting bacterial efflux pumps. This study inspects natural
products for their in vitro antibiotic potentiation against S. aureus strains reveal distinct
efflux-related multidrug-resistance pumps.
Methods: Quercus robur, Fraxinus excelsior, Fagus sylvatica, Ulmus minor, Robinia
pseudoacacia, Baptisia tinctoria and Frangula alnus. Hexane, chloroform, methanol
and aqueous extracts and fractions of each of the samples were investigated for their
antibiotic potentiation activity, were screened against effluxing strains of S. aureus using
a modulation assay. These strains included SA1199B (fluoroquinolone-resistant; NorA),
RN4220 (macrolide-resistant; MsrA) and XU212 (tetracycline-resistant; TetK). Extracts
and fractions were collected using Soxhlet, ultrasound-assisted and solid phase extraction.
Results: The results show that the chloroform extract of Baptisia tinctoria and Robinia
pseudoacacia 3 has the highest antibiotic potentiation activity against all S. aureus
effluxing strains tested. They also enhanced the activity of norfloxacin against SA1199B
by a 256-fold reduction in concentration. The chloroform extract of Baptisia tinctoria
enhanced the activity of erythromycin against RN4220 by 128-fold reduction. Where are
the chloroform extract of Robinia pseudoacacia 3 enhanced the activity of erythromycin
against RN4220 by an eight-fold reduction in the concentration of erythromycin needed
to inhibit the bacterial growth, also it enhanced the activity of tetracycline and norfloxacin
by an eight-fold.
Conclusions: Several of the extracts and fractions had observable potentiation
activity.