Isolation of Enterococcus Species from Food Sources and Its Antibacterial Activity against Staphylococcus Aureus

Abstract

The microbial production of substances that have the ability to inhibit the growth of other microorganisms is possibly the most common defense strategy developed in nature. Microorganisms produce a variable collection of microbial defense systems, which include antibiotics, metabolic by-products, lytic agents, bacteriocins and others. The aim of the present study was to isolate and identify Enterococcus spp. and  its most prevalent species from food samples and determine its antibacterial activity against Staphylococcus aureus isolates. A total of 50 food samples from different sources (dairy products (20 samples) and vegetables and fish (15 samples each)) were collected from different local markets in Baghdad and cultured. Enterococcus spp were isolated from only 32 food samples. E. faecium was the most predominant species which was recovered from 20 samples (62.5 %), 10 dairies, 7 vegetables, and 2 fish. E. faecalis was found in 8 samples (25 %), 5 vegetables and 3 fish.  E. avium was recovered 6.25% as well as E. gallinarium (2 samples for each) Enterococcus avium were all isolated from dairy products but Enterococcus gallinarium one sample isolated from dairies and the other from fish. This study indicates the presence of Enterococcus spp. in the food samples and the ability of these bacteria to produce antibacterial substances which are active against closely related clinical isolates.