In vitro Antibacterial Activity of Ocimum suave Essential Oils against Uropathogens Isolated from Patients in Selected Hospitals in Bushenyi District, Uganda

Aims: To determine antibacterial activity of Ocimum suave essential oils against bacterial uropathogens.
Study Design: A cross sectional and experimental study.
Place and Duration of Study: Six selected hospitals in Bushenyi District, Uganda between June 2012 and July 2013.
Methodology: Clean catch midstream urine samples were collected and inoculated on Cystine Lysine Electrolyte Deficient (CLED) agar. The plates were incubated at 37°C for 24hrs to 48hrs. The O. suaveessential oils were extracted by hydrodistillation of leaves for 4hrs using a Clevenger apparatus. The oil was collected and dried over anhydrous sodium sulphate (Na2SO4) and kept at 4°C till further use. The antimicrobial activity of O. suave essential oils against isolates was determined by agar well method. The MIC of O. suave essential oil extract was carried out by micro-broth dilution method.
Results: Of the three hundred (300) midstream urine samples collected, 67(22.33%) had significant bacterial growth. Escherichia coli is the most common isolate (61.19%, n = 41). The essential oil from O. suave showed activity against isolates of E. coli, K. pneumoniae, S. aureus, E. feacalis, M. morganii, Citrobacter species, Enterobacter species and P. aeruginosa with mean zone of inhibition (ZI) ranging from 10-22 mm. The essential oils had no inhibitory activity on Acinetobacter species. The minimum inhibitory concentration (MIC) for O. suave essential oils ranged from 0.78 to 22 µg/ml. This study showed that O. suave essential oils had MIC value of 0.78 µg/ml against S. aureus and MIC values ranging from 3 to 22 µg/ml against the other tested isolates.
Conclusion: The most common uropathogen was E. coli (61.19% n = 41). O. suave essential oils exhibited antibacterial activity against majority of the uropathogens, except Acinetobacter species, mean ZI of 10-22 mm and MIC of 0.78 – 22 µg/ml.