Growth Inhibitory Activity of Lactic Acid Bacteria against Clinical Isolates Enterobacter aerogenes and Proteus vulgaris

Abstract

Five microliters of cell-free supernatant of Lactobacillus plantarum, Lb. delbrueckii, Lb. paracasei, Lb. easel, and Pediococcus acidilactici growth media (MRS) was spotted on the surface of TSA plates streak-inoculated with clinical isolates Enterobacter aerogenes and Proteus vulgaris and development of clearing zones was observed. All lactic acid bacteria showed zones of clearing indicative of inhibitory activity against both clinical isolates. This may be explained by secreted metabolites such as lactic acid and hydrogen peroxide present in the supernatant. This data validates the information regarding the range of antimicrobial activity of lactic acid bacteria used in the study and implies their possible use against clinical isolates of E. aerogenes and P. vulgaris.