In vitro Study of Moringa oleifera Lam. Leaf Extract Fractions against Multidrug-resistant Pseudomonas aeruginosa Strains from Surgical Wound Infections

Pseudomonas aeruginosa is an opportunistic pathogen that can cause serious surgical site infections and remains a major dilemma, especially in developing country like Nigeria. This issue has led to investigation of the antibacterial activity of Moringa oleifera leaf extract against multidrug-resistant (MDR) Pseudomonas aeruginosa strains. Pseudomonas aeruginosa strains were isolated from postoperative wounds at the two sites used in the study (Central Hospital, Benin and University of Benin Teaching Hospital) and antibiotic susceptibility testing was performed to identify MDR isolates. A qualitative phytochemical screening of leaves was performed using standard methods, followed by antibacterial testing of various M. oleifera leaf extracts against selected multidrug-resistant isolates. Results showed that 99 (35%) of the patients examined had wound infections, out of a total of 284 specimens collected. Thirty-four (54.8%) P. aeruginosa strains showed multidrug-resistance capacity from both learning sites. Qualitative analysis of phytochemicals revealed the presence of flavonoids, phenols, saponins, steroids, tannins and terpenoids. In vitro results of antibacterial tests showed that ethyl acetate extract from leaves of Moringa oleifera had the highest antibacterial activity against Pseudomonas aeruginosa strain Iraq.PA-9, followed by dichloromethane at a concentration of 100 mg/ml. The different effects may be attributed to secondary plant substances contained in different leaf extracts of Moringa oleifera. The results of this study demonstrated the potential of Moringa oleifera leaf extract as an antibacterial agent by inhibiting the growth of test organisms isolated from postoperative wound infections.