ANTIBACTERIAL AND SYNERGISTIC ACTIVITY OF MANGROVE (Avicennia marina) EXTRACTS ON ESBL AND MBL PRODUCING UROPATHOGENS

Growing incidences of β-lactamase producing uropathogens have been observed worldwide. Extended Spectrum β-lactamase (ESBLs) and Metallo β-lactamase (MBLs) are two types of β-lactamases that have emerged as a major threat with limited treatment options. In the current study, the effect of Avicennia marina leaf and stem extracts was studied on 10 ESBL and 10 MBL producing uropathogens which were identified and characterized previously in our laboratory. The bioactive components from Avicennia marina were extracted at 60°C for 12h with the help of soxhlet apparatus using various solvents. This extract was concentrated at 40°C on water bath to obtain a semisolid mass which was used to carry out qualitative and quantitative analysis. The test isolates showed maximum inhibition (17-27mm) towards ethyl acetate extract of A. marina. The MBC of test isolates was found to be 20mg/ml. It also showed synergistic activity with ampicillin by lowering the MBC of ampicillin from over 10mg/ml to 200-300μg/ml. HR-LCMS analysis of ethyl acetate extract of A.marina showed the presence of 17 major bioactive components including terpenoids, flavones and anthraquinones which may be responsible for its antibacterial property. These results collectively indicate the possible use of A. marina extracts in combination therapy to treat infectious diseases caused by multiple drug resistant pathogens.