Multidrug-resistant pathogens and their plasmid curing by lactic acid bacteria

Antibiotics are used to treat and prevent infections, but the overuse of drugs makes the microorganisms drug resistant, and with the time they become resistant to more than one drug. These bacteria are known as multidrug-resistant bacteria. Resistivity of bacteria against the antibiotics makes them more hazardous for human beings and animals too and those bacterial infections become untreatable and lead to death of the person. The resistivity to bacteria is provided by the bacterial plasmids, which contains antibiotic resistant genes. This problem can be overcome by removing bacterial plasmids from the bacterial cells. This can be done by treatment with plasmid curing agents, but various plasmid curing agents such as acridine orange or SDS are toxic and mutagenic in nature. Various investigations have been undertaken to determine the antibacterial effect and plasmid curing ability of extracellular and intracellular extracts of lactic acid bacteria (LAB) to cure plasmids of antibiotic resistant bacterial isolates. The microtiter plate method was used to determine the minimum inhibitory concentration of LAB extracts. Plasmid curing mediated by LAB extracts resulted in the loss of antibiotics resistance encoded in plasmids, as well as the antibiotics resistance profile of cured strains. The extracellular extracts of LAB were considered a natural and harmless source to combat plasmid borne multidrug-resistant bacteria.