Mangrove Bacterial Isolate with Antibacterial Activity Against Selected Extended Spectrum Beta-Lactamase-Producing Clinical Enterobacteriaceae Strains

Abstract

Extended spectrum beta-lactamases, enzymes responsible for antibiotic resistance of most species of Enterobacteriaceae, continuously develop increased spectrum of hydrolytic activity against beta-lactam antibiotics. The diversity and natural abundance of antimicrobials produced by bacteria is remarkable since some substances are restricted to some bacterial groups, while others are widespread. This study aims to screen and identify mangrove bacteria with antibacterial activity against extended spectrum beta-lactamase producing clinical strains of Escherichia coli, Klebsiella ozanae and Klebsiella pneumoniae. The determination of antibacterial activity was performed through the agar-plug assay. One of the fifty-seven bacterial isolates (KNL1-3) showed inhibitory activity against ESBL strains of Escherichia coli (PGH 918) and Klebsiella ozanae (PGH 763). Isolate KNL1-3 was identified as Bacillus amyloliquefaciens through biochemical characterization, 16S rDNA sequencing and phylogenetic analysis.