Antibacterial activity of lactic acid bacteria isolated from milk and traditional fermented dairy products of south Algeria against multidrug resistance pathogenic bacteria

Abstract

The alarming situation of the increasing problem of the antibiotics resistance in the whole world requires an immediate need of the exploration of better alternatives for combating resistance. The main aim of the present work was the isolation and the screening of large range of lactic acid bacteria with important potential of antibacterial activity against multidrug resistance pathogenic strains and the characterization of the molecules responsible for anti-bacterial activity. The primary screening indicated the isolation of total of 200 lactic acid bacteria (LAB) from harvested milk (camel and goat) and tradi-tional fermented dairy products (Jben and kamaria) of south Algeria and in-vestigated for their antibacterial activity against clinical pathogens bacteria. Furthermore, Nineteen representative isolates (19) were selected and char-acterized with regard to their functional properties. The obtained results indicated that produced bacteriocin by both bacterial strains L. raffinolactis LAB9 and Leuconostoc mesenteroides subsp. cremoris LAB13 has manifested an excellent antagonistic activity against P.aeruginosa (PA) and Staphylococcus aureus (MRSA), which was Methicillin resistant Staphylococcus aureus (MRSA). A Further investigation indicated that the produced bacteriocin by LAB9 and LAB 13 were heat stable, where their inactivation was observed when treated with pepsin and trypsin. Additionally, the purification of the produced bacteriocin by L.raffinolactis LAB9 and Leuconostoc mesenteroides subsp. cremoris LAB13 has been achieved by the using of the partial ammonium sulfate precipitation. The technological properties and the stability of bacteriocins of LAB may lead for bioprospection of antibacterial components in the current struggle against increasing pandrug resistance and slowing down the expansion of multi drug resistance.