Antibacterial Activity of Aloe vera Gel against Multidrug Resistant Staphylococcus aureus and Pseudomonas aeruginosa

INTRODUCTION The development of resistance against convectional antibiotics has led to researchers looking for alternative medicine in many countries today (Ingrida et al., 2012). Approximately 20%of the world’s plants have been pharmacologically tested against majority of pathogenic microorganisms (Adnan et al., 2015). This has led to introduction of new antibiotics into the drug market (Radha and Laxmipriya, 2015). One of the plants that have gained a lot of popularity in medicine is Aloe barbadensis Miller (Aloe vera) belonging to the family Liliaceae (Seyyed et al., 2015). The plant is succulent with a whorl of elongated, pointed leaves with over 360 known species. Aloe vera has been shown to have anti-inflammatory activity, immune stimulatory, antioxidant, immune modulating and cell growth stimulating activity (Yebpella et al., 2011). In addition, extracts from Aloe vera have reported to possess antimicrobial, antiviral and antifungal properties (Jothi et al., 2014). Aloe vera has been used widely in the treatment of various skin conditions such as cuts, burns and eczema. It is reported that sap from Aloe vera eases pain and reduces inflammation. Hence, the current wide use of the plant in skin care, cosmetics and as nutraceuticals (Arunkumar and Muthuselvam, 2009). Staphylococcus aureus is one of the important hospital and community acquired pathogen. It is responsible for causing a broad spectrum of diseases ranging from mild superficial skin and soft tissue infections to life threatening infections such as infective endocarditis, septicaemia, deep-seated abscess, pneumonia and toxic-shock syndrome (Onemuand Ophori, 2013). S. aureus has been naturally susceptible to most of the antibiotics developed so far (Chambers and DeLeo, 2009). Abstract Staphylococcus aureus and Pseudomonas aeruginosa have been implicated as important nosocomial pathogens causing severe infections especially in hospitalized patients. The aim of the study was to assess the antibacterial activity of Aloe vera gel against multidrug resistant S. aureus and P. aeruginosa isolated from wound. Clinical isolates of S. aureus and P. aeruginosa from wound infection were collected from Microbiology laboratory of Barau Dikko Teaching Hospital (BDTH), Kaduna and re-confirmed using standard microbiological procedure. Antibiotic susceptibility pattern of the isolates was determined using Kirby Bauer disk diffusion method. Aloe vera gel was obtained fresh matured leaves of Aloe vera plant and was screened for the presence of phytochemical constituents. Antibacterial activity of the Aloe vera gel against Multidrug Resistant (MDR) Staphylococcus aureus and Pseudomonas aeruginosa isolates was determined by agar well diffusion technique. The result revealed that all the two isolates were resistant to more than three classes of antibiotics. The Staphylococcus aureus isolate was resistant to fluoroquinolone (ciprofloxacin), aminoglycoside (gentamicin), cephalosporin (cefaroline), folate pathway antagonist (trimethoprim-sulfamethoxazole), penicillin(cefoxitin) and macrolide (erythromycin) while the Pseudomonas aeruginosa isolate was resistant to βlactam (ticarcillin-clavulanate), fluoroquinolone (ciprofloxacin and norfloxacin), aminoglycoside (gentamicin) and cephalosporin (ceftazidime)hence regarded as MDR isolates. Phytochemical screening of the gel revealed the presence of saponins, flavonoids, terpenoids and alkaloids. The Aloe vera gel was found to have antibacterial activity against the test isolates with MIC and MBC values of 25μg/mL and 50μg/mL against MDR S. aureus 50μg/mL and 100μg/mL against MDR P. aeruginosa respectively. The study identified that Aloe vera gel possesses antibacterial activity against MDR S. aureus and P. aeruginosa isolated from wound infection.