1 Plant Archives Vol. 19, Supplement 2, 2019 pp. 583-589 e-ISSN:2581-6063 (online), ISSN:0972-5210 ANTIBACTERIAL ACTIVITY OF CONOCARPUS ERECTUS LEAVES EXTRACTS ON SOME MICROORGANISMS ISOLATED FROM PATIENTS WITH BURN INFECTION Shaimaa Abdulmajid Yasin and Ahmed H. AL-Azawi 1 * 1 Biotechnology Dept., Genetic Engineering and Biotechnology Institute for post graduate studies. University of Baghdad, Baghdad, Iraq. E-Mail: ahmedharbi_alazawi@yahoo.com* Abstract Medicinal plants are a source for a wide variety of natural active compounds and are used for the treatment of diseases throughout the world. Conocarpus erectus L. widely planted all over Iraq and has different secondary metabolites, which has been used in treatment of anemia, cancer, fever and diarrhea. The present study aims to estimate the antibacterial activity of Conocarpus erectus leaves extracts on some microorganisms collected from patients with burn infection. The study began with the collection of Conocarpus erectus leaves in June 2018 from the trees in university of Baghdad. Maceration method was used to prepare aqueous extract, while Soxhelt apparatus was used to prepare methanolic extract. The results of phytochemical test showed the presence of flavonoids, phenols, alkaloids, glycosides, tannins and saponine in the Conocarpus erectus leaves extracts, while alkaloids were not detected in aqueous extract. Agar well diffusion method was employed to determined the antibacterial activity, the best effect was seen on Staphylococcus aureus and Pseudomonas aeruginosa in concentration 100 mg/ml with inhibition zone (23 and 22 mm) respectively for methanolic extract, and 22 mm on Staph. aureus in the same concentration for aqueous extract, and their efficacy in terms of MIC and MBC were ranged from 50 to 75 mg/ml. Keywords: Conocarpus erectus, phytochemical, antibacterial activity, antibiotic sensitivity. Introduction Bacterial resistance to antimicrobial drug is one of the most serious threats to global health. Antimicrobial resistance threatens the effective treatment of an ever-increasing range of infections caused by bacteria, parasites, fungi, and virus. The causes of antibiotic resistance are complex and include human behavior at many levels of society; the consequences affect everybody in the world (Laxminarayan et al, 2013). In the past few decades, pharmacological companies have been developing new antimicrobial agents but microbial resistance has been increasing due to the ability of bacterial organisms acquiring resistant genes (Gislene et al., 2000). Herbal drugs have been used since ancient times to treat diseases and disorders with their antimicrobial properties making them a potent source of new drugs. The use of herbal medicine has been used to positively prevent and control diseases such as, heart disorders, diabetes and other forms of cancer (Srivastava et al., 2005). Several types of plant extracts or plant-derived molecules have been investigated for their potential as antibacterial sources against several diseases (Madaleno, 2015, AL-Azawi and Salih, 2019). In the folk medicine, the leaves of Conocarpus erectus are eaten and decoctions from bark, leaves and fruits are used against many diseases as catarrh, conjunctivitis, gonorrhea, diarrhea, fever, orchitis and syphilis (Nascimento et al., 2016). Phenolic compounds are the major secondary metabolites of this species, these molecules detected in different C. erectus extracts have been described to exhibit antioxidant, antifungal and antiviral activities, as well as act in the activation of the immune system (Chen et al., 2016). Few studies were published until now in relation to possible action mechanism promoted by C. erectus extracts in human lymphocytes or in microorganisms collected from human wounds (Santos et al., 2018). Thus, main purpose of this research is detection of active ingredients in Conocarpus erectus leaves extracts as well as evaluating the antibacterial activity against pathogenic bacteria isolated from patients with burn infection. Materials and Methods Plant Collection Plant leaves were collected from trees in university of Baghdad. Classified as Conocarpus erectus L. by the herbarium of the Biology Department, College of Science, University of Baghdad. The leaves were ground using a grinder and stored at -20°C for further analysis. Preparation of aqueous extract Water extract was prepared according to N’Guessan et al. (2007). Macerated 100 gram of Conocarpus erectus leaves in 700 ml of distilled water for 72 hours, after extraction, the mixture was vacuum filtered through Whitman No. 1 paper. The filtrate evaporated to dryness under vacuum at 50°C by a rotary evaporator to eliminate water. The resulting extract stored in amber glass vials at 4 °C until analyzed. Preparation of methanolic extract Methanolic extract was prepared according to AACC (1984) by using Soxhelt apparatus. Fifty gram of Conocarpus erectus leaves was put in a thimble and 350 ml of 70% methanol was added within 40-60 °C for 6 hours. The solution was filtered through a filter paper Whitman No.1 and evaporated to dryness under vacuum at 40°C by a rotary evaporator to get rid of methanol; the extract was stored in amber glass vials at 4 °C until analyzed. General chemical detection methods Methanolic and aqueous extracts were tested for the presence of the phytoconstituents according to the following standard tests (Harborne, 1984; Harborne, 1998; AACC, 1984; Smolensk et al., 1972 and Jaffer et al., 1988) to detected phenols, Flavonoids, Alkaloids, Tannins, glycosides and saponins.